Fitmath in Afterschool and Why It Is Effective Dissertation

Fitmath in Afterschool and Why It Is Effective - Dissertation Example School time and various resources are frequently diverted from various types of physical Education and openings for physical action for example recess. (HRDC, 2001). The program Fitmath the kids, under goes numerous stages in which they study how to turn out to be fit both bodily and mentally, the significance of having well eating habits with nourishing foodstuff, and to maintain body in correct shape, additionally to thorough mathematical abilities. And it helps to accomplishing and learning maths with fun and pleasure. (Wenger). According to Nancy Protheroe in his article called, what does Good Math Instruction look like? Says that, it entails good teachers, effectual math surroundings, and a curriculum that is more than a mile broad and an inch deep. This research article points out that it takes more than a good trainer to teach math. According to MUCHA in his article says that, Mathematics subject has always been an essential constituent of person thought and culture, and the d evelopment of technology in current times has further enlarged its significance. Nowadays mathematics is a crucial partner in areas where once it played no particular role. (Mucha). Fit math is one of the most significant programs in schools in the 21st century. It connects healthy academics and eating. This program assists students in increasing self-assurance in their physical capability, in addition to enhancing familiarity, by way of expressions in the fields of physiology, anatomy, and mathematics. Fundamental fact acquisition is a significant part of building up higher-order math abilities. (Springer). On the other hand, getting learners with a history of academic rebelliousness to engage in various activities associated to acquisition of various skills can be difficult. (Lynn Arthur Steen 2010). According to Michelle Kulas in her acrtcile called, Need for After-School Exercise Programs says that, program related to after-school fitness build exercise fun for children. Dependi ng on the style of program, it will help the child to study a new sport or have the alternative to join in in a large variety of exercise activities. She also says that, because of this exercise program it will helps to develop health of the kids by being physically active at the same time as also playing with and cooperating with other kids in a supervised setting. Also After-School Exercise Programs will be capable to create new friends and may enjoy superior self-assurance and self-esteem. (Kulas, 2011) According to Sam Piha in his article called AFTERSCHOOL PROGRAMS: WHAT SHOULD WE EXPECT AND HOW SHOULD WE MEASURE SUCCESS says that, after school programs offer young people with the various types of learning practices and opportunities that may not be obtainable to kids in their homes or classrooms. And also they recommend young people opportunities to study new things and build up significant skills that are essential to achievement in school and in life. The article Effective M athematics Instruction says that, Mathematics instruction is an extremely complex procedure that tries to create abstract ideas more tangible, difficult thoughts comprehensible and multifaceted evils solvable. Visual depictions bring

Climate Change and The Global Warming Debate Case Study

Climate Change and The Global Warming Debate - Case Study Example Perhaps the most illustrative and influential in getting the message across was Al Gore’s ‘An Inconvenient Truth.’ The title in itself denotes of the apprehension to identify global warming as an imperative issue that must be discussed in order to address what is necessarily happening in the world. The documentary showed among other things how the polar ice caps are swiftly melting to the effect that a huge amount of the sun’s heat is absorbed and trapped in our atmosphere causing an increase in the earth’s temperature. These glaciers play an important role and have a direct correlation to global warming. The film supports this with scientific data and research accompanied by actual pictures of places in between decades showing the discrepancy man have caused (Guggenheim & Gore, 2006). Faced with this global problem, scientists have also offered solutions to impede and slowdown the process. The most important tool in dealing with environmental woes i s the shift toward sustainability for purposes that human beings do not exhaust the Earth’s natural resources. ... Reliance on energy is a given fact and where our main sources of energy such as coal and fossil fuel are mainly consumable, they necessarily run out that those who are rich in them rake in the profit and play a major role in the determination of the world’s economy. Renewable energy comes in as an answer to this dilemma as a viable alternative source of energy. The Intergovernmental Panel on Climate Change on their 2007 Synthesis Report provides for the necessity and the benefits of renewable energy. The introduction of new policies that implement energy efficiency should entail the institution of renewable energy which also promotes economic benefits and sufficient energy accompanied by lesser pollution. Among the main thrust of the report is to identify how this should also be beneficial for developing countries who require more energy not only in the business establishments but also particularly in the household. These countries rely mostly on coal as a source of energy and often resort to deforestation. The IPCC provides that â€Å"Energy efficiency and utilisation of renewable energy offer synergies with sustainable development† (p. 59, 2007). This in consequence provides for economic benefits for countries requiring cost-efficient energy with security while reducing pollution. The main opposition to the proposition that there truly is global warming brought about mainly by the copious amount of greenhouse gasses are ubiquitously called greenhouse doubters. The advocates to bring global warming into the limelight on the other hand are most likely to call them as deniers. They have been more prominent in the 1980s through to early 2000 when there had been more scientists in consensus that global warming is a reality based on scientific data.

H.264 Video Streaming System on Embedded Platform

H.264 Video Streaming System on Embedded Platform ABSTRACT The adoption of technological products like digital television and video conferencing has made video streaming an active research area. This report presents the integration of a video streamer module into a baseline H.264/AVC encoder running a TMSDM6446EVM embedded platform. The main objective of this project is to achieve real-time streaming of the baseline H.264/AVC video over a local area network (LAN) which is a part of the surveillance video system. The encoding of baseline H.264/AVC and the hardware components of the platform are first discussed. Various streaming protocols are studied in order to implement the video streamer on the DM6446 board. The multi-threaded application encoder program is used to encode raw video frames into H.264/AVC format onto a file. For the video streaming, open source Live555 MediaServer was used to stream video data to a remote VLC client over LAN. Initially, file streaming was implemented from PC to PC. Upon successfully implementation on PC, the video streamer was ported to the board. The steps involved in porting the Live555 application were also described in the report. Both unicast and multicast file streaming were implemented in the video streamer. Due to the problems of file streaming, the live streaming approach was adopted. Several methodologies were discussed in integrating the video streamer and the encoder program. Modification was made both the encoder program and the Live555 application to achieve live streaming of H.264/AVC video. Results of both file and live streaming will be shown in this report. The implemented video streamer module will be used as a base module of the video surveillance system. Chapter 1: Introduction 1.1. Background Significant breakthroughs have been made over the last few years in the area of digital video compression technologies. As such applications making use of these technologies have also become prevalent and continue to be of active research topics today. For example, digital television and video conferencing are some of the applications that are now commonly encountered in our daily lives. One application of interest here is to make use of the technologies to implement a video camera surveillance system which can enhance the security of consumers business and home environment. In typical surveillance systems, the captured video is sent over a cable networks to be monitored and stored at remote stations. As the captured raw video contains large amount of data, it will be of advantage to first compress the data by using a compression technique before it is transferred over the network. One such compression technique that is suitable for this type of application is the H.264 coding standard. H.264 coding is better than the other coding technique for video streaming as it is more robust to data losses and coding efficiency, which are important factors when streaming is performed over a shared Local Area Network. As there is an increasing acceptance of H.264 coding and the availability of high computing power embedded systems, digital video surveillance system based on H.264 on embedded platform is hence a feasible and a potentially more cost-effective system. Implementing a H.264 video streaming system on an embedded platform is a logical extension of video surveillance systems which are still typical implemented using high computing power stations (e.g. PC). In a embedded version, a Digital Signal Processor (DSP) forms the core of the embedded system and executes the intensive signal processing algorithm. Current embedded systems typical also include network features which enable the implementation of data streaming applications. To facilitate data streaming, a number of network protocol standards have also being defined, and are currently used for digital video applications. 1.2. Objective and Scope The objective of this final year project is to implement a video surveillance system based on the H.264 coding standard running on an embedded platform. Such a system contains extensive scopes of functionalities and would require extensive amount of development time if implemented from scratch. Hence this project is to focus on the data streaming aspect of a video surveillance system. After some initial investigation and experimentation, it is decided to confine the main scope of the project to developing a live streaming H.264 based video system running on a DM6446 EVM development platform. The breakdown of the work to be progressive performed are then identified as follows: 1. Familiarization of open source live555 streaming media server Due to the complexity of implementing the various standard protocols needed for multimedia streaming, the live555 media server program is used as a base to implement the streaming of the H.264.based video data. 2. Streaming of stored H.264 file over the network The live555 is then modified to support streaming of raw encoded H.264 file from the DM6446 EVM board over the network. Knowledge of H.264 coding standard is necessary in order to parse the file stream before streaming over the network. 3. Modifying a demo version of an encoder program and integrating it together with live555 to achieve live streaming The demo encoder was modified to send encoded video data to the Live555 program which would do the necessary packetization to be streamed over the network. Since data is passed from one process to another, various inter-process communication techniques were studied and used in this project. 1.3. Resources The resources used for this project are as follows: 1. DM6446 (DaVinciâ„ ¢) Evaluation Module 2. SWANN C500 Professional CCTV Camera Solution 400 TV Lines CCD Color Camera 3. LCD Display 4. IR Remote Control 5. TI Davinci demo version of MontaVista Linux Pro v4.0 6. A Personal Workstation with Centos v5.0 7. VLC player v.0.9.8a as client 8. Open source live555 program (downloaded from www.live555.com) The system setup of this project is shown below: 1.4. Report Organization This report consists of 7 chapters. Chapter 1 introduces the motivation behind embedded video streaming system and defines the scope of the project. Chapter 2 illustrates the video literature review of the H.264/AVC video coding technique and the various streaming protocols which are to be implemented in the project. Chapter 3 explains the hardware literature review of the platform being used in the project. The architecture, memory management, inter-process communication and the software tools are also discussed in this chapter. Chapter 4 explains the execution of the encoder program of the DM6446EVM board. The interaction of the various threads in this multi-threaded application is also discussed to fully understand the encoder program. Chapter 5 gives an overview of the Live555 MediaServer which is used as a base to implement the video streamer module on the board. Adding support to unicast and multicast streaming, porting of live555 to the board and receiving video stream on remote VCL client are explained in this chapter. Chapter 6 explains the limitations of file streaming and moving towards live streaming system. Various integration methodologies and modification to both encoder program and live555 program are shown as well. Chapters 7 summarize the implementation results of file and live streaming, analysis the performance of these results. Chapter 8 gives the conclusion by stating the current limitation and problems, scope for future implementation. Chapter 2: Video Literature Review 2.1. H.264/AVC Video Codec Overview H.264 is the most advanced and latest video coding technique. Although there are many video coding schemes like H.26x and MPEG, H.264/AVC made many improvements and tools for coding efficiency and error resiliency. This chapter briefly will discuss the network aspect of the video coding technique. It will also cover error resiliency needed for transmission of video data over the network. For a more detailed explanation of the H.264/AVC, refer to appendix A. 2.1.1. Network Abstraction Layer (NAL) The aim of the NAL is to ensure that the data coming from the VCL layer is â€Å"network worthy† so that the data can be used for numerous systems. NAL facilitates the mapping of H.264/AVC VCL data for different transport layers such as: * RTP/IP real-time streaming over wired and wireless mediums * Different storage file formats such as MP4, MMS, AVI and etc. The concepts of NAL and error robustness techniques of the H.264/AVC will be discussed in the following parts of the report. NAL Units The encoded data from the VCL are packed into NAL units. A NAL unit represents a packet which makes up of a certain number of bytes. The first byte of the NAL unit is called the header byte which indicates the data type of the NAL unit. The remaining bytes make up the payload data of the NAL unit. The NAL unit structure allows provision for different transport systems namely packet-oriented and bit stream-oriented. To cater for bit stream-oriented transport systems like MPEG-2, the NAL units are organized into byte stream format. These units are prefixed by a specific start code prefix of three bytes which is namely 0x000001. The start code prefix indicates and the start of each NAL units and hence defining the boundaries of the units. For packet-oriented transport systems, the encoded video data are transported via packets defined by transport protocols. Hence, the boundaries of the NAL units are known without having to include start code prefix byte. The details of packetization of NAL units will be discussed in later sections of the report. NAL units are further categorized into two types: * VCL unit: comprises of encoded video data  · Non-VCL unit: comprises of additional information like parameter sets which is the important header information. Also contains supplementary enhancement information (SEI) which contains the timing information and other data which increases the usability of the decoded video signal. Access units A group of NAL units which adhere to a certain form is called a access unit. When one access unit is decoded, one decoded picture is formed. In the table 1 below, the functions of the NAL units derived from the access units are explained. Data/Error robustness techniques H.264/AVC has several techniques to mitigate error/data loss which is an essential quality when it comes to streaming applications. The techniques are as follows:  · Parameter sets: contains information that is being applied to large number of VCL NAL units. It comprises of two kinds of parameter sets: Sequence Parameter set (SPS) : Information pertaining to sequence of encoded picture Picture Parameter Set (PPS) : Information pertaining to one or more individual pictures The above mentioned parameters hardly changes and hence it need not be transmitted repeatedly and saves overhead. The parameter sets can be sent â€Å"in-band† which is carried in the same channel as the VCL NAL units. It can also be sent â€Å"out-of-band† using reliable transport protocol. Therefore, it enhances the resiliency towards data and error loss.  · Flexible Macroblock Ordering (FMO) FMO maps the macroblocks to different slice groups. In the event of any slice group loss, missing data is masked up by interpolating from the other slice groups.  · Redundancy Slices (RS) Redundant representation of the picture can be stored in the redundant slices. If the loss of the original slice occurs, the decoder can make use of the redundant slices to recover the original slice. These techniques introduced in the H.264/AVC makes the codec more robust and resilient towards data and error loss. 2.1.2. Profiles and Levels A profile of a codec is defined as the set of features identified to meet a certain specifications of intended applications For the H.264/AVC codec, it is defined as a set of features identified to generate a conforming bit stream. A level is imposes restrictions on some key parameters of the bit stream. In H.264/AVC, there are three profiles namely: Baseline, Main and Extended. 5 shows the relationship between these profiles. The Baseline profile is most likely to be used by network cameras and encoders as it requires limited computing resources. It is quite ideal to make use of this profile to support real-time streaming applications in a embedded platform. 2.2. Overview of Video Streaming In previous systems, accessing video data across network exploit the ‘download and play approach. In this approach, the client had to wait until the whole video data is downloaded to the media player before play out begins. To combat the long initial play out delay, the concept of streaming was introduced. Streaming allows the client to play out the earlier part of the video data whilst still transferring the remaining part of the video data. The major advantage of the streaming concept is that the video data need not be stored in the clients computer as compared to the traditional ‘download and play approach. This reduces the long initial play out delay experienced by the client. Streaming adopts the traditional client/server model. The client connects to the listening server and request for video data. The server sends video data over to the client for play out of video data. 2.2.1. Types of Streaming There are three different types of streaming video data. They are pre-recorded/ file streaming, live/real-time streaming and interactive streaming. * Pre-recorded/live streaming: The encoded video is stored into a file and the system streams the file over the network. A major overhead is that there is a long initial play out delay (10-15s) experienced by the client. * Live/real-time streaming: The encoded video is streamed over the network directly without being stored into a file. The initial play out delay reduces. Consideration must be taken to ensure that play out rate does not exceed sending rate which may result in jerky the picture. On the other hand, if the sending rate is too slow, the packets arriving at the client may be dropped, causing in a freezing the picture. The timing requirement for the end-to-end delay is more stringent in this scenario. * Interactive streaming: Like live streaming, the video is streamed directly over the network. It responds to users control input such as rewind, pause, stop, play and forward the particular video stream. The system should respond in accordance to those inputs by the user. In this project, both pre-recorded and live streaming are implemented. Some functionality of interactive streaming controls like stop and play are also part of the system. 2.2.2. Video Streaming System modules Video Source The intent of the video source is to capture the raw video sequence. The CCTV camera is used as the video source in this project. Most cameras are of analogue inputs and these inputs are connected to the encoding station via video connections. This project makes use of only one video source due to the limitation of the video connections on the encoding station. The raw video sequence is then passed onto the encoding station. Encoding Station The aim of the encoding station digitized and encodes the raw video sequence into the desired format. In the actual system, the encoding is done by the DM6446 board into the H.264/AVC format. Since the hardware encoding is CPU intensive, this forms the bottleneck of the whole streaming system. The H.264 video is passed onto the video streamer server module of the system. Video Streaming and WebServer The role of the video streaming server is to packetize the H.264/AVC to be streamed over the network. It serves the requests from individual clients. It needs to support the total bandwidth requirements of the particular video stream requested by clients. WebServer offers a URL link which connects to the video streaming server. For this project, the video streaming server module is embedded inside DM6446 board and it is serves every individual clients requests. Video Player The video player acts a client connecting to and requesting video data from the video streaming server. Once the video data is received, the video player buffers the data for a while and then begins play out of data. The video player used for this project is the VideoLAN (VLC) Player. It has the relevant H.264/AVC codec so that it can decode and play the H264/AVC video data. 2.2.3. Unicast VS Multicast There are two key delivery techniques employed by streaming media distribution. Unicast transmission is the sending of data to one particular network destination host over a packet switched network. It establishes two way point-to-point connection between client and server. The client communicates directly with the server via this connection. The drawback is that every connection receives a separate video stream which uses up network bandwidth rapidly. Multicast transmission is the sending of only one copy of data via the network so that many clients can receive simultaneously. In video streaming, it is more cost effective to send single copy of video data over the network so as to conserve the network bandwidth. Since multicast is not connection oriented, the clients cannot control the streams that they can receive. In this project, unicast transmission is used to stream encoded video over the network. The client connects directly to the DM6446 board where it gets the encoded video data. The project can easily be extended to multicast transmission. 2.3. Streaming Protocols When streaming video content over a network, a number of network protocols are used. These protocols are well defined by the Internet Engineering Task Force (IETF) and the Internet Society (IS) and documented in Request for Comments (RFC) documents. These standards are adopted by many developers today. In this project, the same standards are also employed in order to successfully stream H.264/AVC content over a simple Local Area Network (LAN). The following sections will discuss about the various protocols that are studied in the course of this project. 2.3.1. Real-Time Streaming Protocol (RTSP) The most commonly used application layer protocol is RTSP. RTSP acts a control protocol to media streaming servers. It establishes connection between two end points of the system and control media sessions. Clients issue VCR-like commands like play and pause to facilitate the control of real-time playback of media streams from the servers. However, this protocol is not involved in the transport of the media stream over the network. For this project, RTSP version 1.0 is used. RTSP States Like the Hyper Text Transfer Protocol (HTTP), it contains several methods. They are OPTIONS, DESCRIBE, SETUP, PLAY, PAUSE, RECORD and TEARDOWN. These commands are sent by using the RTSP URL. The default port number used in this protocol is 554. An example of such as URL is: rtsp://  · OPTIONS: An OPTIONS request returns the types of request that the server will accept. An example of the request is: OPTIONS rtsp://155.69.148.136:554/test.264 RTSP/1.0 CSeq: 1rn User-agent: VLC media Player The CSeq parameter keeps track of the number of request send to the server and it is incremented every time a new request is issued. The User-agent refers to the client making the request. * DESCRIBE: This method gets the presentation or the media object identified in the request URL from the server. An example of such a request: DESCRIBE rtsp://155.69.148.138:554/test.264 RTSP/1.0 CSeq: 2rn Accept: application/sdprn User agent: VLC media Player The Accept header is used to describe the formats understood by the client. All the initialization of the media resource must be present in the DESCRIBE method that it describes.  · SETUP: This method will specify the mode of transport mechanism to be used for the media stream. A typical example is: SETUP rtsp://155.69.148.138:554/test.264 RTSP/1.0 CSeq: 3rn Transport: RTP/AVP; unicast; client_port = 1200-1201 User agent: VLC media Player The Transport header specifies the transport mechanism to be used. In this case, real-time transport protocol is used in a unicast manner. The relevant client port number is also reflected and it is selected randomly by the server. Since RTSP is a stateful protocol, a session is created upon successful acknowledgement to this method.  · PLAY: This method request the server to start sending the data via the transport mechanism stated in the SETUP method. The URL is the same as the other methods except for: Session: 6 Range: npt= 0.000- rn The Session header specifies the unique session id. This is important as server may establish various sessions and this keep tracks of them. The Range header positions play time to the beginning and plays till the end of the range. * PAUSE: This method informs the server to pause sending of the media stream. Once the PAUSE request is sent, the range header will capture the position at which the media stream is paused. When a PLAY request is sent again, the client will resume playing from the current position of the media stream as specified in the range header. RSTP Status Codes Whenever the client sends a request message to the server, the server forms a equivalent response message to be sent to the client. The response codes are similar to HTTP as they are both in ASCII text. They are as follows: 200: OK 301: Redirection 405: Method Not Allowed 451: Parameter Not Understood 454: Session Not Found 457: Invalid Range 461: Unsupported Transport 462: Destination Unreachable These are some of the RTSP status codes. There are many others but the codes mentioned above are of importance in the context of this project. 2.3.2. Real-time Transport Protocol (RTP) RTP is a defined packet structure which is used for transporting media stream over the network. It is a transport layer protocol but developers view it as a application layer protocol stack. This protocol facilitates jitter compensation and detection of incorrect sequence arrival of data which is common for transmission over IP network. For the transmission of media data over the network, it is important that packets arrive in a timely manner as it is loss tolerant but not delay tolerant. Due to the high latency of Transmission Control Protocol in establishing connections, RTP is often built on top of the User Datagram Protocol (UDP). RTP also supports multicast transmission of data. RTP is also a stateful protocol as a session is established before data can be packed into the RTP packet and sent over the network. The session contains the IP address of the destination and port number of the RTP which is usually an even number. The following section will explain about the packet structure of RTP which is used for transmission. RTP Packet Structure The below shows a RTP packet header which is appended in front of the media data.s The minimum size of the RTP header is 12 bytes.. Optional extension information may be present after the header information. The fields of the header are:  · V: (2 bits) to indicate the version number of the protocol. Version used in this project is 2.  · P (Padding): (1 bit) to indicate if there padding which can be used for encryption algorithm  · X (Extension): (1 bit) to indicate if there is extension information between header and payload data.  · CC (CSRC Count) : (4 bits) indicates the number of CSRC identifiers  · M (Marker): (1 bit) used by application to indicate data has specific relevance in the perspective of the application. The setting for M bit marks the end of video data in this project  · PT (Payload Type): (7 bits) to indicate the type of payload data carried by the packet. H.264 is used for this project  · Sequence number: (16 bits) incremented by one for every RTP packet. It is used to detect packet loss and out of sequence packet arrival. Based on this information, application can take appropriate action to correct them.  · Time Stamp: (32 bits) receivers use this information to play samples at correct intervals of time. Each stream has independent time stamps.  · SSRC: (32 bits) it unique identifies source of the stream.  · CSRC: sources of a stream from different sources are enumerated according to its source IDs. This project does not involve the use of Extension field in the packet header and hence will not be explained in this report. Once this header information is appended to the payload data, the packet is sent over the network to the client to be played. The table below summarizes the payload types of RTP and highlighted region is of interest in this project. Table 2: Payload Types of RTP Packets 2.3.3. RTP Control Protocol (RTCP) RTCP is a sister protocol which is used in conjunction with the RTP. It provides out-of-band statistical and control information to the RTP session. This provides certain Quality of Service (QoS) for transmission of video data over the network. The primary functions of the RTCP are: * To gather statistical information about the quality aspect of the media stream during a RTP session. This data is sent to the session media source and its participants. The source can exploit this information for adaptive media encoding and detect transmission errors. * It provides canonical end point identifiers (CNAME) to all its session participants. It allows unique identification of end points across different application instances and serves as a third party monitoring tool. * It also sends RTCP reports to all its session participants. By doing so, the traffic bandwidth increases proportionally. In order to avoid congestion, RTCP has bandwidth management techniques to only use 5% of the total session bandwidth. RTCP statistical data is sent odd numbered ports. For instance, if RTP port number is 196, then RTCP will use the 197 as its port number. There is no default port number assigned to RTCP. RTCP Message Types RTCP sends several types of packets different from RTP packets. They are sender report, receiver report, source description and bye.  · Sender Report (SR): Sent periodically by senders to report the transmission and reception statistics of RTP packets sent in a period of time. It also includes the senders SSRC and senders packet count information. The timestamp of the RTP packet is also sent to allow the receiver to synchronize the RTP packets. The bandwidth required for SR is 25% of RTCP bandwidth.  · Receiver Report (RR): It reports the QoS to other receivers and senders. Information like highest sequence number received, inter arrival jitter of RTP packets and fraction of packets loss further explains the QoS of the transmitted media streams. The bandwidth required for RR is 75% of the RTCP bandwidth.  · Source Description (SDES): Sends the CNAME to its session participants. Additional information like name, address of the owner of the source can also be sent.  · End of Participation (BYE): The source sends a BYE message to indicate that it is shutting down the stream. It serves as an announcement that a particular end point is leaving the conference. Further RTCP Consideration This protocol is important to ensure that QoS standards are achieved. The acceptable frequencies of these reports are less than one minute. In major application, the frequency may increase as RTCP bandwidth control mechanism. Then, the statistical reporting on the quality of the media stream becomes inaccurate. Since there are no long delays introduced between the reports in this project, the RTCP is adopted to incorporate a certain level of QoS on streaming H.264/AVC video over embedded platform. 2.3.4. Session Description Protocol (SDP) The Session Description Protocol is a standard to describe streaming media initialization parameters. These initializations describe the sessions for session announcement, session invitation and parameter negotiation. This protocol can be used together with RTSP. In the previous sections of this chapter, SDP is used in the DESCRIBE state of RTSP to get sessions media initialization parameters. SDP is scalable to include different media types and formats. SDP Syntax The session is described by attribute/value pairs. The syntax of SDP are summarized in the below. In this project, the use of SDP is important in streaming as the client is VLC Media Player. If the streaming is done via RTSP, then VLC expects a sdp description from the server in order to setup the session and facilitate the playback of the streaming media. Chapter 3: Hardware Literature Review 3.1. Introduction to Texas Instrument DM6446EVM DavinciTM The development of this project based on the DM6446EVM board. It is necessary to understand the hardware and software aspects of this board. The DM6446 board has a ARM processor operating at a clock speed up to 300MHz and a C64x Digital Signal Processor operating at a clock speed of up to 600MHz. 3.1.1. Key Features of DM6446 The key features that are shown in the above are: * 1 video port which supports composite of S video * 4 video DAC outputs: component, RGB, composite * 256 MB of DDR2 DRAM * UART, Media Card interface (SD, xD, SM, MS ,MMC Cards) * 16 MB of non-volatile Flash Memory, 64 MB NAND Flash, 4 MB SRAM * USB2 interface * 10/100 MBS Ethernet interface * Configurable boot load options * IR Remote Interface, real time clock via MSP430 3.1.2. DM6446EVM Architecture The architecture of the DM6446 board is organized into several subsystems. By knowing the architecture of the DM6446, the developer can then design and built his application module on the boards underlining architecture. The shows that DM6446 has three subsystems which are connected to the underlying hardware peripherals. This provides a decoupled architecture which allows the developers to implement his applications on a particular subsystem without having to modify the other subsystems. Some of subsystems are discussed in the next sections. ARM Subsystem The ARM subsystem is responsible for the master control of the DM6446 board. It handles the system-level initializations, configurations, user interface, connectivity functions and control of DSP subsystems. The ARM has a larger program memory space and better context switching capabilities and hence it is more suited to handle complex and multi tasks of the system. DSP Subsystem The DSP subsystem is mainly the encoding the raw captured video frames into the desired format. It performs several number crunching operations in order to achieve the desired compression technique. It works together with the Video Imaging Coprocessor to compress the video frames. Video Imaging Coprocessor (VICP) The VICP is a signal processing library which contains various software algorithms that execute on VICP hardware accelerator. It helps the DSP by taking over computation of varied intensive tasks. Since hardware implementation of number cru H.264 Video Streaming System on Embedded Platform H.264 Video Streaming System on Embedded Platform ABSTRACT The adoption of technological products like digital television and video conferencing has made video streaming an active research area. This report presents the integration of a video streamer module into a baseline H.264/AVC encoder running a TMSDM6446EVM embedded platform. The main objective of this project is to achieve real-time streaming of the baseline H.264/AVC video over a local area network (LAN) which is a part of the surveillance video system. The encoding of baseline H.264/AVC and the hardware components of the platform are first discussed. Various streaming protocols are studied in order to implement the video streamer on the DM6446 board. The multi-threaded application encoder program is used to encode raw video frames into H.264/AVC format onto a file. For the video streaming, open source Live555 MediaServer was used to stream video data to a remote VLC client over LAN. Initially, file streaming was implemented from PC to PC. Upon successfully implementation on PC, the video streamer was ported to the board. The steps involved in porting the Live555 application were also described in the report. Both unicast and multicast file streaming were implemented in the video streamer. Due to the problems of file streaming, the live streaming approach was adopted. Several methodologies were discussed in integrating the video streamer and the encoder program. Modification was made both the encoder program and the Live555 application to achieve live streaming of H.264/AVC video. Results of both file and live streaming will be shown in this report. The implemented video streamer module will be used as a base module of the video surveillance system. Chapter 1: Introduction 1.1. Background Significant breakthroughs have been made over the last few years in the area of digital video compression technologies. As such applications making use of these technologies have also become prevalent and continue to be of active research topics today. For example, digital television and video conferencing are some of the applications that are now commonly encountered in our daily lives. One application of interest here is to make use of the technologies to implement a video camera surveillance system which can enhance the security of consumers business and home environment. In typical surveillance systems, the captured video is sent over a cable networks to be monitored and stored at remote stations. As the captured raw video contains large amount of data, it will be of advantage to first compress the data by using a compression technique before it is transferred over the network. One such compression technique that is suitable for this type of application is the H.264 coding standard. H.264 coding is better than the other coding technique for video streaming as it is more robust to data losses and coding efficiency, which are important factors when streaming is performed over a shared Local Area Network. As there is an increasing acceptance of H.264 coding and the availability of high computing power embedded systems, digital video surveillance system based on H.264 on embedded platform is hence a feasible and a potentially more cost-effective system. Implementing a H.264 video streaming system on an embedded platform is a logical extension of video surveillance systems which are still typical implemented using high computing power stations (e.g. PC). In a embedded version, a Digital Signal Processor (DSP) forms the core of the embedded system and executes the intensive signal processing algorithm. Current embedded systems typical also include network features which enable the implementation of data streaming applications. To facilitate data streaming, a number of network protocol standards have also being defined, and are currently used for digital video applications. 1.2. Objective and Scope The objective of this final year project is to implement a video surveillance system based on the H.264 coding standard running on an embedded platform. Such a system contains extensive scopes of functionalities and would require extensive amount of development time if implemented from scratch. Hence this project is to focus on the data streaming aspect of a video surveillance system. After some initial investigation and experimentation, it is decided to confine the main scope of the project to developing a live streaming H.264 based video system running on a DM6446 EVM development platform. The breakdown of the work to be progressive performed are then identified as follows: 1. Familiarization of open source live555 streaming media server Due to the complexity of implementing the various standard protocols needed for multimedia streaming, the live555 media server program is used as a base to implement the streaming of the H.264.based video data. 2. Streaming of stored H.264 file over the network The live555 is then modified to support streaming of raw encoded H.264 file from the DM6446 EVM board over the network. Knowledge of H.264 coding standard is necessary in order to parse the file stream before streaming over the network. 3. Modifying a demo version of an encoder program and integrating it together with live555 to achieve live streaming The demo encoder was modified to send encoded video data to the Live555 program which would do the necessary packetization to be streamed over the network. Since data is passed from one process to another, various inter-process communication techniques were studied and used in this project. 1.3. Resources The resources used for this project are as follows: 1. DM6446 (DaVinciâ„ ¢) Evaluation Module 2. SWANN C500 Professional CCTV Camera Solution 400 TV Lines CCD Color Camera 3. LCD Display 4. IR Remote Control 5. TI Davinci demo version of MontaVista Linux Pro v4.0 6. A Personal Workstation with Centos v5.0 7. VLC player v.0.9.8a as client 8. Open source live555 program (downloaded from www.live555.com) The system setup of this project is shown below: 1.4. Report Organization This report consists of 7 chapters. Chapter 1 introduces the motivation behind embedded video streaming system and defines the scope of the project. Chapter 2 illustrates the video literature review of the H.264/AVC video coding technique and the various streaming protocols which are to be implemented in the project. Chapter 3 explains the hardware literature review of the platform being used in the project. The architecture, memory management, inter-process communication and the software tools are also discussed in this chapter. Chapter 4 explains the execution of the encoder program of the DM6446EVM board. The interaction of the various threads in this multi-threaded application is also discussed to fully understand the encoder program. Chapter 5 gives an overview of the Live555 MediaServer which is used as a base to implement the video streamer module on the board. Adding support to unicast and multicast streaming, porting of live555 to the board and receiving video stream on remote VCL client are explained in this chapter. Chapter 6 explains the limitations of file streaming and moving towards live streaming system. Various integration methodologies and modification to both encoder program and live555 program are shown as well. Chapters 7 summarize the implementation results of file and live streaming, analysis the performance of these results. Chapter 8 gives the conclusion by stating the current limitation and problems, scope for future implementation. Chapter 2: Video Literature Review 2.1. H.264/AVC Video Codec Overview H.264 is the most advanced and latest video coding technique. Although there are many video coding schemes like H.26x and MPEG, H.264/AVC made many improvements and tools for coding efficiency and error resiliency. This chapter briefly will discuss the network aspect of the video coding technique. It will also cover error resiliency needed for transmission of video data over the network. For a more detailed explanation of the H.264/AVC, refer to appendix A. 2.1.1. Network Abstraction Layer (NAL) The aim of the NAL is to ensure that the data coming from the VCL layer is â€Å"network worthy† so that the data can be used for numerous systems. NAL facilitates the mapping of H.264/AVC VCL data for different transport layers such as: * RTP/IP real-time streaming over wired and wireless mediums * Different storage file formats such as MP4, MMS, AVI and etc. The concepts of NAL and error robustness techniques of the H.264/AVC will be discussed in the following parts of the report. NAL Units The encoded data from the VCL are packed into NAL units. A NAL unit represents a packet which makes up of a certain number of bytes. The first byte of the NAL unit is called the header byte which indicates the data type of the NAL unit. The remaining bytes make up the payload data of the NAL unit. The NAL unit structure allows provision for different transport systems namely packet-oriented and bit stream-oriented. To cater for bit stream-oriented transport systems like MPEG-2, the NAL units are organized into byte stream format. These units are prefixed by a specific start code prefix of three bytes which is namely 0x000001. The start code prefix indicates and the start of each NAL units and hence defining the boundaries of the units. For packet-oriented transport systems, the encoded video data are transported via packets defined by transport protocols. Hence, the boundaries of the NAL units are known without having to include start code prefix byte. The details of packetization of NAL units will be discussed in later sections of the report. NAL units are further categorized into two types: * VCL unit: comprises of encoded video data  · Non-VCL unit: comprises of additional information like parameter sets which is the important header information. Also contains supplementary enhancement information (SEI) which contains the timing information and other data which increases the usability of the decoded video signal. Access units A group of NAL units which adhere to a certain form is called a access unit. When one access unit is decoded, one decoded picture is formed. In the table 1 below, the functions of the NAL units derived from the access units are explained. Data/Error robustness techniques H.264/AVC has several techniques to mitigate error/data loss which is an essential quality when it comes to streaming applications. The techniques are as follows:  · Parameter sets: contains information that is being applied to large number of VCL NAL units. It comprises of two kinds of parameter sets: Sequence Parameter set (SPS) : Information pertaining to sequence of encoded picture Picture Parameter Set (PPS) : Information pertaining to one or more individual pictures The above mentioned parameters hardly changes and hence it need not be transmitted repeatedly and saves overhead. The parameter sets can be sent â€Å"in-band† which is carried in the same channel as the VCL NAL units. It can also be sent â€Å"out-of-band† using reliable transport protocol. Therefore, it enhances the resiliency towards data and error loss.  · Flexible Macroblock Ordering (FMO) FMO maps the macroblocks to different slice groups. In the event of any slice group loss, missing data is masked up by interpolating from the other slice groups.  · Redundancy Slices (RS) Redundant representation of the picture can be stored in the redundant slices. If the loss of the original slice occurs, the decoder can make use of the redundant slices to recover the original slice. These techniques introduced in the H.264/AVC makes the codec more robust and resilient towards data and error loss. 2.1.2. Profiles and Levels A profile of a codec is defined as the set of features identified to meet a certain specifications of intended applications For the H.264/AVC codec, it is defined as a set of features identified to generate a conforming bit stream. A level is imposes restrictions on some key parameters of the bit stream. In H.264/AVC, there are three profiles namely: Baseline, Main and Extended. 5 shows the relationship between these profiles. The Baseline profile is most likely to be used by network cameras and encoders as it requires limited computing resources. It is quite ideal to make use of this profile to support real-time streaming applications in a embedded platform. 2.2. Overview of Video Streaming In previous systems, accessing video data across network exploit the ‘download and play approach. In this approach, the client had to wait until the whole video data is downloaded to the media player before play out begins. To combat the long initial play out delay, the concept of streaming was introduced. Streaming allows the client to play out the earlier part of the video data whilst still transferring the remaining part of the video data. The major advantage of the streaming concept is that the video data need not be stored in the clients computer as compared to the traditional ‘download and play approach. This reduces the long initial play out delay experienced by the client. Streaming adopts the traditional client/server model. The client connects to the listening server and request for video data. The server sends video data over to the client for play out of video data. 2.2.1. Types of Streaming There are three different types of streaming video data. They are pre-recorded/ file streaming, live/real-time streaming and interactive streaming. * Pre-recorded/live streaming: The encoded video is stored into a file and the system streams the file over the network. A major overhead is that there is a long initial play out delay (10-15s) experienced by the client. * Live/real-time streaming: The encoded video is streamed over the network directly without being stored into a file. The initial play out delay reduces. Consideration must be taken to ensure that play out rate does not exceed sending rate which may result in jerky the picture. On the other hand, if the sending rate is too slow, the packets arriving at the client may be dropped, causing in a freezing the picture. The timing requirement for the end-to-end delay is more stringent in this scenario. * Interactive streaming: Like live streaming, the video is streamed directly over the network. It responds to users control input such as rewind, pause, stop, play and forward the particular video stream. The system should respond in accordance to those inputs by the user. In this project, both pre-recorded and live streaming are implemented. Some functionality of interactive streaming controls like stop and play are also part of the system. 2.2.2. Video Streaming System modules Video Source The intent of the video source is to capture the raw video sequence. The CCTV camera is used as the video source in this project. Most cameras are of analogue inputs and these inputs are connected to the encoding station via video connections. This project makes use of only one video source due to the limitation of the video connections on the encoding station. The raw video sequence is then passed onto the encoding station. Encoding Station The aim of the encoding station digitized and encodes the raw video sequence into the desired format. In the actual system, the encoding is done by the DM6446 board into the H.264/AVC format. Since the hardware encoding is CPU intensive, this forms the bottleneck of the whole streaming system. The H.264 video is passed onto the video streamer server module of the system. Video Streaming and WebServer The role of the video streaming server is to packetize the H.264/AVC to be streamed over the network. It serves the requests from individual clients. It needs to support the total bandwidth requirements of the particular video stream requested by clients. WebServer offers a URL link which connects to the video streaming server. For this project, the video streaming server module is embedded inside DM6446 board and it is serves every individual clients requests. Video Player The video player acts a client connecting to and requesting video data from the video streaming server. Once the video data is received, the video player buffers the data for a while and then begins play out of data. The video player used for this project is the VideoLAN (VLC) Player. It has the relevant H.264/AVC codec so that it can decode and play the H264/AVC video data. 2.2.3. Unicast VS Multicast There are two key delivery techniques employed by streaming media distribution. Unicast transmission is the sending of data to one particular network destination host over a packet switched network. It establishes two way point-to-point connection between client and server. The client communicates directly with the server via this connection. The drawback is that every connection receives a separate video stream which uses up network bandwidth rapidly. Multicast transmission is the sending of only one copy of data via the network so that many clients can receive simultaneously. In video streaming, it is more cost effective to send single copy of video data over the network so as to conserve the network bandwidth. Since multicast is not connection oriented, the clients cannot control the streams that they can receive. In this project, unicast transmission is used to stream encoded video over the network. The client connects directly to the DM6446 board where it gets the encoded video data. The project can easily be extended to multicast transmission. 2.3. Streaming Protocols When streaming video content over a network, a number of network protocols are used. These protocols are well defined by the Internet Engineering Task Force (IETF) and the Internet Society (IS) and documented in Request for Comments (RFC) documents. These standards are adopted by many developers today. In this project, the same standards are also employed in order to successfully stream H.264/AVC content over a simple Local Area Network (LAN). The following sections will discuss about the various protocols that are studied in the course of this project. 2.3.1. Real-Time Streaming Protocol (RTSP) The most commonly used application layer protocol is RTSP. RTSP acts a control protocol to media streaming servers. It establishes connection between two end points of the system and control media sessions. Clients issue VCR-like commands like play and pause to facilitate the control of real-time playback of media streams from the servers. However, this protocol is not involved in the transport of the media stream over the network. For this project, RTSP version 1.0 is used. RTSP States Like the Hyper Text Transfer Protocol (HTTP), it contains several methods. They are OPTIONS, DESCRIBE, SETUP, PLAY, PAUSE, RECORD and TEARDOWN. These commands are sent by using the RTSP URL. The default port number used in this protocol is 554. An example of such as URL is: rtsp://  · OPTIONS: An OPTIONS request returns the types of request that the server will accept. An example of the request is: OPTIONS rtsp://155.69.148.136:554/test.264 RTSP/1.0 CSeq: 1rn User-agent: VLC media Player The CSeq parameter keeps track of the number of request send to the server and it is incremented every time a new request is issued. The User-agent refers to the client making the request. * DESCRIBE: This method gets the presentation or the media object identified in the request URL from the server. An example of such a request: DESCRIBE rtsp://155.69.148.138:554/test.264 RTSP/1.0 CSeq: 2rn Accept: application/sdprn User agent: VLC media Player The Accept header is used to describe the formats understood by the client. All the initialization of the media resource must be present in the DESCRIBE method that it describes.  · SETUP: This method will specify the mode of transport mechanism to be used for the media stream. A typical example is: SETUP rtsp://155.69.148.138:554/test.264 RTSP/1.0 CSeq: 3rn Transport: RTP/AVP; unicast; client_port = 1200-1201 User agent: VLC media Player The Transport header specifies the transport mechanism to be used. In this case, real-time transport protocol is used in a unicast manner. The relevant client port number is also reflected and it is selected randomly by the server. Since RTSP is a stateful protocol, a session is created upon successful acknowledgement to this method.  · PLAY: This method request the server to start sending the data via the transport mechanism stated in the SETUP method. The URL is the same as the other methods except for: Session: 6 Range: npt= 0.000- rn The Session header specifies the unique session id. This is important as server may establish various sessions and this keep tracks of them. The Range header positions play time to the beginning and plays till the end of the range. * PAUSE: This method informs the server to pause sending of the media stream. Once the PAUSE request is sent, the range header will capture the position at which the media stream is paused. When a PLAY request is sent again, the client will resume playing from the current position of the media stream as specified in the range header. RSTP Status Codes Whenever the client sends a request message to the server, the server forms a equivalent response message to be sent to the client. The response codes are similar to HTTP as they are both in ASCII text. They are as follows: 200: OK 301: Redirection 405: Method Not Allowed 451: Parameter Not Understood 454: Session Not Found 457: Invalid Range 461: Unsupported Transport 462: Destination Unreachable These are some of the RTSP status codes. There are many others but the codes mentioned above are of importance in the context of this project. 2.3.2. Real-time Transport Protocol (RTP) RTP is a defined packet structure which is used for transporting media stream over the network. It is a transport layer protocol but developers view it as a application layer protocol stack. This protocol facilitates jitter compensation and detection of incorrect sequence arrival of data which is common for transmission over IP network. For the transmission of media data over the network, it is important that packets arrive in a timely manner as it is loss tolerant but not delay tolerant. Due to the high latency of Transmission Control Protocol in establishing connections, RTP is often built on top of the User Datagram Protocol (UDP). RTP also supports multicast transmission of data. RTP is also a stateful protocol as a session is established before data can be packed into the RTP packet and sent over the network. The session contains the IP address of the destination and port number of the RTP which is usually an even number. The following section will explain about the packet structure of RTP which is used for transmission. RTP Packet Structure The below shows a RTP packet header which is appended in front of the media data.s The minimum size of the RTP header is 12 bytes.. Optional extension information may be present after the header information. The fields of the header are:  · V: (2 bits) to indicate the version number of the protocol. Version used in this project is 2.  · P (Padding): (1 bit) to indicate if there padding which can be used for encryption algorithm  · X (Extension): (1 bit) to indicate if there is extension information between header and payload data.  · CC (CSRC Count) : (4 bits) indicates the number of CSRC identifiers  · M (Marker): (1 bit) used by application to indicate data has specific relevance in the perspective of the application. The setting for M bit marks the end of video data in this project  · PT (Payload Type): (7 bits) to indicate the type of payload data carried by the packet. H.264 is used for this project  · Sequence number: (16 bits) incremented by one for every RTP packet. It is used to detect packet loss and out of sequence packet arrival. Based on this information, application can take appropriate action to correct them.  · Time Stamp: (32 bits) receivers use this information to play samples at correct intervals of time. Each stream has independent time stamps.  · SSRC: (32 bits) it unique identifies source of the stream.  · CSRC: sources of a stream from different sources are enumerated according to its source IDs. This project does not involve the use of Extension field in the packet header and hence will not be explained in this report. Once this header information is appended to the payload data, the packet is sent over the network to the client to be played. The table below summarizes the payload types of RTP and highlighted region is of interest in this project. Table 2: Payload Types of RTP Packets 2.3.3. RTP Control Protocol (RTCP) RTCP is a sister protocol which is used in conjunction with the RTP. It provides out-of-band statistical and control information to the RTP session. This provides certain Quality of Service (QoS) for transmission of video data over the network. The primary functions of the RTCP are: * To gather statistical information about the quality aspect of the media stream during a RTP session. This data is sent to the session media source and its participants. The source can exploit this information for adaptive media encoding and detect transmission errors. * It provides canonical end point identifiers (CNAME) to all its session participants. It allows unique identification of end points across different application instances and serves as a third party monitoring tool. * It also sends RTCP reports to all its session participants. By doing so, the traffic bandwidth increases proportionally. In order to avoid congestion, RTCP has bandwidth management techniques to only use 5% of the total session bandwidth. RTCP statistical data is sent odd numbered ports. For instance, if RTP port number is 196, then RTCP will use the 197 as its port number. There is no default port number assigned to RTCP. RTCP Message Types RTCP sends several types of packets different from RTP packets. They are sender report, receiver report, source description and bye.  · Sender Report (SR): Sent periodically by senders to report the transmission and reception statistics of RTP packets sent in a period of time. It also includes the senders SSRC and senders packet count information. The timestamp of the RTP packet is also sent to allow the receiver to synchronize the RTP packets. The bandwidth required for SR is 25% of RTCP bandwidth.  · Receiver Report (RR): It reports the QoS to other receivers and senders. Information like highest sequence number received, inter arrival jitter of RTP packets and fraction of packets loss further explains the QoS of the transmitted media streams. The bandwidth required for RR is 75% of the RTCP bandwidth.  · Source Description (SDES): Sends the CNAME to its session participants. Additional information like name, address of the owner of the source can also be sent.  · End of Participation (BYE): The source sends a BYE message to indicate that it is shutting down the stream. It serves as an announcement that a particular end point is leaving the conference. Further RTCP Consideration This protocol is important to ensure that QoS standards are achieved. The acceptable frequencies of these reports are less than one minute. In major application, the frequency may increase as RTCP bandwidth control mechanism. Then, the statistical reporting on the quality of the media stream becomes inaccurate. Since there are no long delays introduced between the reports in this project, the RTCP is adopted to incorporate a certain level of QoS on streaming H.264/AVC video over embedded platform. 2.3.4. Session Description Protocol (SDP) The Session Description Protocol is a standard to describe streaming media initialization parameters. These initializations describe the sessions for session announcement, session invitation and parameter negotiation. This protocol can be used together with RTSP. In the previous sections of this chapter, SDP is used in the DESCRIBE state of RTSP to get sessions media initialization parameters. SDP is scalable to include different media types and formats. SDP Syntax The session is described by attribute/value pairs. The syntax of SDP are summarized in the below. In this project, the use of SDP is important in streaming as the client is VLC Media Player. If the streaming is done via RTSP, then VLC expects a sdp description from the server in order to setup the session and facilitate the playback of the streaming media. Chapter 3: Hardware Literature Review 3.1. Introduction to Texas Instrument DM6446EVM DavinciTM The development of this project based on the DM6446EVM board. It is necessary to understand the hardware and software aspects of this board. The DM6446 board has a ARM processor operating at a clock speed up to 300MHz and a C64x Digital Signal Processor operating at a clock speed of up to 600MHz. 3.1.1. Key Features of DM6446 The key features that are shown in the above are: * 1 video port which supports composite of S video * 4 video DAC outputs: component, RGB, composite * 256 MB of DDR2 DRAM * UART, Media Card interface (SD, xD, SM, MS ,MMC Cards) * 16 MB of non-volatile Flash Memory, 64 MB NAND Flash, 4 MB SRAM * USB2 interface * 10/100 MBS Ethernet interface * Configurable boot load options * IR Remote Interface, real time clock via MSP430 3.1.2. DM6446EVM Architecture The architecture of the DM6446 board is organized into several subsystems. By knowing the architecture of the DM6446, the developer can then design and built his application module on the boards underlining architecture. The shows that DM6446 has three subsystems which are connected to the underlying hardware peripherals. This provides a decoupled architecture which allows the developers to implement his applications on a particular subsystem without having to modify the other subsystems. Some of subsystems are discussed in the next sections. ARM Subsystem The ARM subsystem is responsible for the master control of the DM6446 board. It handles the system-level initializations, configurations, user interface, connectivity functions and control of DSP subsystems. The ARM has a larger program memory space and better context switching capabilities and hence it is more suited to handle complex and multi tasks of the system. DSP Subsystem The DSP subsystem is mainly the encoding the raw captured video frames into the desired format. It performs several number crunching operations in order to achieve the desired compression technique. It works together with the Video Imaging Coprocessor to compress the video frames. Video Imaging Coprocessor (VICP) The VICP is a signal processing library which contains various software algorithms that execute on VICP hardware accelerator. It helps the DSP by taking over computation of varied intensive tasks. Since hardware implementation of number cru

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I am majoring in the criminal justice because I am very interested in many aspects of the field. I have a few career aspirations, although I do not know which one or ones to pursue , I do know that no matter which I choose I will be using a lot of the information gained from my SOSC 102 course within my career choice. I also possess many personal strengths that make me best suited for my career choice. Some of My Future Career Aspirations My number one career aspiration is to become a forensic science technician. I’d like to become a forensic science technician because I love solving problems, and I think outside of the box in situations where most people would think the answer is obvious. The only reason I have other aspirations besides forensics is because forensic science is not one of the careers in high demand at this time; according to The Bureau of Labor Statistics â€Å"Employment of forensic science technicians is expected to grow by 19 percent from 2010 to 2020, about as fast as the average for all occupations. Competition for jobs will be strong because of substantial interest in forensic science. †( http://www. bls. gov/ooh/life-physical-and-social-science/forensic-science-technicians. htm). Another one of my career aspirations is to become a detective. I would love to become a detective because, just like forensic science technicians, they too have to find answers to problems by thinking outside of the box. In order to become a detective I would have to start as a police officer and work my up in the field, but the job outlook for police officers is more promising than that of a forensic science technician at this time. There is an expected 20,300 new jobs to be filled by the year 2018 for Police Identification and Records Officers. (http://www. recruiter. com/careers/police-identification-and-records-officers/outlook/) .

Poverty Satire Essay

With the advancement of poverty in the United States it is time to solve the homeless situation. Thousands of Americans are homeless and taking up space on the city’s streets. A simple solution to this problem would be to allow the homeless to reside in landfills. They would be able to sort through the waste to find appropriate cardboard boxes to live in. This could also be used as a form of employment allowing them to sort through recycling to improve the environment. It is also a statistical fact that many Americans throw away food that goes untouched. Not only would they have a permanent residence of their choosing but this also insures that they would have plenty of food to maintain their strength to sort trash. The act of throwing food away is often forgotten, but with this new profound idea other Americans can feel charitable each time they throw away their trash. Their leftover food will go straight to the landfill and become a nice snack or a whole meal for one of the landfill residents. Society will no longer have to worry about starvation because essentially anyone can provide for the poor. People will eventually feel better about the act of throwing away hundreds of thousands of dollars of wasted food knowing that it will go to a family in need. However, people will be questioning why it has to stop with food. Used tissues, old dental floss, and that rusted razor that everyone has lying about will ensure that the landfill residents have acceptable hygiene. The rainwater combined with the last few congealed drops of some liquid soap will keep the landfill inhabitants fresh and clean. There will be competition in the landfills for the best food and supplies or the best cardboard, but th at should be promoted because they need to understand that although everything will be essentially thrown out to them, it will still be â€Å"survival of the fittest†. The landfill inhabitants will be able to sleep in peace knowing that their shelter was handmade. Newspapers and junk mail will be of great use to the residents because it could provide as a floor or even a roof. Although there might be a rise in identity theft because of the information civilians have thrown out in the trash, it should come as a lesson because people should know to shred their important documents before throwing them out. The  landfill residents can also use their resources to better their education. The writings and nutrition facts on the backs of cereal boxes along with the short stories about fields of lavender and honeysuckles on lotion bottles can easily suffice as a quick English lesson. The shelters in the landfills will consist primarily of cardboard boxes but it will give the residents a chance to express their creativity. The residents could even form small village like shelters within the landfill to be better protected from the other scavengers. The fig ht for the best supplies will endanger quite a few residents, but in the long run they should be able to value the relationships they might form with one another. Many people would probably argue that this solution to homelessness is too dangerous or inhumane but it will prepare the homeless people for a life after the landfill. The landfill would offer a refuge for the poverty stricken victims to be provided for and it would also allow the homeless to provide a service for the public. The landfill already offers such valuable resources that are just going to waste. It would be unreasonable to think that the landfill residents couldn’t sort through the trash to figure out what could be recycled; this could be a form of employment in the landfills. Ensuring that the public will be rewarded for their generous donations, the homeless would essentially pay back the public with the use of reusable goods. The rising homeless count is rising and this is an adequate solution to a major problem. Not only would the landfill provide a new home for the homeless it would give city residents peace of mind knowing that the homeless people are safely a way out of sight.

bpa paper

bpa paper bpa paper Esther Faveur Psych 309-01 Professor Kaplan 9/26/13 Effects of BPA on Memory Bisphenol-A is a chemical that is found in food and beverage containers (Nienstedt, 2013). Many studies suggest that exposure to Bisphenol-A (BPA) during early development may cause memory inadequacy later in life. A study conducted by Luine, Eilam-Stock, Serrano & Frankfurt (2011), sought to investigate the effects of BPA on spatial and visual memory in adult rats. In their paper, they describe the influence of BPA on the brain areas that affect memory such as the hippocampus and prefrontal cortex. It is shown that estrogen and androgens play an important role in memory. But, BPA tends to inhibit estrogen increase in spine synapse formation as well as block androgens in spine synapses in the hippocampus and prefrontal cortex. This study was conducted to not only see the effects of spatial and visual memory, but also if the effects are linked to CA1 area of the hippocampus and the medial prefrontal cortex (mPFC, since those specific areas of the brain are responsible for the memory function. The hypothesis for this study is that acute BPA exposure would harm memory in adult rats, decrease spine density in the hippocampus and mPFC, as well as inhibit the activity of memory association related proteins in those areas. Method The species that were involved were Male Sprague- Dawley rats, aged 60 days upon their arrival. Animals were kept in a 12 hour light-dark cycle, with two rats in each cage with access to unlimited food and water. Their memory abilities were evaluated using object recognition (OR) and object placement (OP) tasks. Both trials began with a sample trail (T1) where rats were in an open box with two similar objects and were allowed to explore them for 3 minutes. After an intertrial interval, the rat is returned to the box for 3 minutes (T2). In the OR task, one of the objects is replaced by a different object in T2. In the OP task, one of the objects is placed in a different location in T2. In both tasks, if the rat remembers the old object/placement, it will spend more time with the new one. But if the rat does not remember it, it will spend the same amount of time on both objects. On the 1st day of the test, after the rat completes T1, it is immediately injected with 4ug//kg of BPA. Two hours after, they do the T2. Procedure: Two experiments were performed. The first consisted of giving the rats a week of getting used to the housing environment, followed by two weeks of habituation to the OR and OP tasks as well as BPA injections. Four days after the OR test, the rats did the OP test. Eleven days after the last task, the rats did the T1 test again followed by an injection of BPA. The rats were immediately killed 40 minutes after the BPA injection. The brains were removed and assessed. In the second experiment, it consisted of the examining the effects of BPA by itself on the dendritic spine density. There was no OR or OP test given. The rats were killed 4 hours after the injection and the brains were removed for assessment. I believed that sufficient controls were in place because for the 1st task, groups were switched in between so that the rats that did the OR test got BPA in the OP test and vice versa. Also the toys were replaced or switch in different positions to see if the rat would remember it.

Free Essays on Critical Review

Critical review of an article from The Guardian 18th December 2003 The article I’m reviewing comes from The Guardian 18th December 2003. Headed â€Å"Chirac calls on MP’s to ban headscarves†. A journalist called Paul Webster wrote this article. Briefly this piece is explaining the situation in France regarding President Chirac wanting to ban headscarves and other â€Å"conspicuous† religious signs from state schools. The tone of the article appears to be factual. It does, however seem to be a biased article in favour of the ban. There isn’t much criticism of the President and his decision for legislation regarding this. The French Council of the Muslim Faith is said to have called this a â€Å"disastrous† decision. Although the article says that the President is calling for legislation regarding headscarves and other â€Å"conspicuous† religious signs the focus of this piece is mainly the headscarves issue. There is an opinion poll mentioned, taken the previous day but it doesn’t actually state where this poll was taken or the cross section of people/religious backgrounds polled. The writer states this poll gave a result of 69% in favour of President Chirac’s decision regarding headscarves and religious signs in schools and public services and â€Å"opposed the introduction of public holidays to celebrate Muslim and Jewish feasts†. Paul then goes on to say that two thirds of the leftwing and National Front (rightwing) voters approved, as did 75% of the centre-right. This proposal is documented as â€Å"the most popular reform the President has sponsored since he was first elected in 1995†. â€Å"Discreet signs† of religious affiliation would be allowed, signs such as the hand of Fatima, the star of David, and the cross depending on the size – which would be determined by parliament. The writer then goes on to speak about President Chirac’s 35-minute address to an â€Å"invited audience† – presumably invited ... Free Essays on Critical Review Free Essays on Critical Review Critical review of an article from The Guardian 18th December 2003 The article I’m reviewing comes from The Guardian 18th December 2003. Headed â€Å"Chirac calls on MP’s to ban headscarves†. A journalist called Paul Webster wrote this article. Briefly this piece is explaining the situation in France regarding President Chirac wanting to ban headscarves and other â€Å"conspicuous† religious signs from state schools. The tone of the article appears to be factual. It does, however seem to be a biased article in favour of the ban. There isn’t much criticism of the President and his decision for legislation regarding this. The French Council of the Muslim Faith is said to have called this a â€Å"disastrous† decision. Although the article says that the President is calling for legislation regarding headscarves and other â€Å"conspicuous† religious signs the focus of this piece is mainly the headscarves issue. There is an opinion poll mentioned, taken the previous day but it doesn’t actually state where this poll was taken or the cross section of people/religious backgrounds polled. The writer states this poll gave a result of 69% in favour of President Chirac’s decision regarding headscarves and religious signs in schools and public services and â€Å"opposed the introduction of public holidays to celebrate Muslim and Jewish feasts†. Paul then goes on to say that two thirds of the leftwing and National Front (rightwing) voters approved, as did 75% of the centre-right. This proposal is documented as â€Å"the most popular reform the President has sponsored since he was first elected in 1995†. â€Å"Discreet signs† of religious affiliation would be allowed, signs such as the hand of Fatima, the star of David, and the cross depending on the size – which would be determined by parliament. The writer then goes on to speak about President Chirac’s 35-minute address to an â€Å"invited audience† – presumably invited ...

Analysis of Albania’s Tax System

Analysis of Albanias Tax System INTRODUCTION Every one can make the question: â€Å"why do we have taxes?†.Practically we can say , that one democratic state can not exist without taxes, even if he does not operate just with taxes.Taxes and taxability are a necessity. The standard of living of a modern society demands it; governments must collect the revenues in order to provide the goods and services that their citizens need, want and demand. The principal sources of Albanian tax legislation are the Constitution, various laws and decrees. The Parliament is the prime taxing authority in Albania, while the Ministry of Finance is the executive branch, responsible for administration of the laws. There is an important difference between tax and taxability in Albania.Taxability is an obligated and irreversible payment in state budget which include administrative charges and penalties for the delays provided by law. They are obligated payments of different contributors used for general public services, in that wa y state can accomplish his duty. While tax is an obligated contribute to pay from one person who profits directly from public services. They are a type of compensation for special public services accomplished from state in advantage of citizen. Taxes are mostly resource of locale organs entries of state, city halls, communes . Taxes for public services which we pay for has the element of volition, wich can not happen in no case with taxability. In financial point of view the taxes role is little than taxability ,so the role and the importance of taxes in confronting expenses for the public services is more sensible in the local budget than in the national budget. The following project aims to treat with no details the types of taxes and taxability in the Republic of Albania,their importance and influence in the economy.Often the country’s financial authorities have been propagating that tax levels in Albania are among the lowest in the region so in another section we will sti ck to the comparative analysis of tax burden. We will try to compare it with Macedonia and Greece. This article is structured as follows: First, we will briefly review the types of taxes and taxabilities in Albania. Second we will try to analyse and compare their importances in economy of our country with Macedonia and Greece. Finally, chapter four provides a summary and the conclusions on the issues treated.    OVERVIEW ON TAX SYSTEM IN ALBANIA In the following section we will briefly review the classification of taxability and taxes in Albania.1 1 This section is based mainly on a summary of tax system in Albania presented by Financat (2006). 2.1 Taxes 2.1.1 National Taxes National Taxes cover 23% of the income that the state recieves from the taxes system,that is why they are considered very important to the Government’s budget.Among the main national taxes,we can mention Road Traffic Tax,Higher Education Tax and Registration fee for Poker Games, Casinos, for sport compe titions taking place at the racetrack.Road Traffix Taxes include taxes imposed by the Government for the use of imported vehicles ,also the old ones,for the fuel consumption etc.The universities and other Academies are charged with the collection of Higher Education Tax.These taxes are cashed not later than 30 days from the official date of the beginning of the school year, in any academic year.While the tax on registration of gambling, casinos for sportive races held in hippodromes is payable only once at the beginning of such activities and their registration.

Product Design in Cyberspace Essay Example | Topics and Well Written Essays - 500 words

Product Design in Cyberspace - Essay Example This can facilitate them in their negative activities and can be a potential source of harm for the peace of the society as a whole. People who are in such professions that require use of GPS have little trouble accessing it even if it is not available through Ebay. However, others that are not in a position to purchase GPS from their local areas can easily purchase it on Ebay and use it for whatever purpose they want. There are many areas where people are supposed to get a license to keep a GPS with them because it is a potential source of help for criminals particularly when they want to perform their act in groups. Likewise, GPS software should also not be allowed to sell on Ebay because of the same reason as that for GPS device. Worst thing people have a problem with at Ebay: Worst thing people have a problem with on Ebay is that it does not allow sale of any kind of medication (Hubpages, 2011). Fake medicines are common in a lot of underdeveloped countries. In these countries, p eople produce false medicines in the name of real ones in order to make profits on the cost of customers’ life. People are highly skeptical about the quality of medicine they purchase. Medicines are already very costly.

The Role of Research Methods in Education Essay

The Role of Research Methods in Education - Essay Example Many different approaches have been developed for researchers internationally supporting their work in all its aspects especially regarding the gathering of data/ info that is necessary for the development of various scientific projects. It should be noticed that scientific projects are not necessarily practical, i.e. they do not refer only to mathematical figures (statistics etc.); they can also be theoretical, i.e. referring to the structure and the effectiveness of a specific theoretical model (e.g. Porter’s five forces - in the business sector). In the case of education both the above forms of research, i.e. the practical and the theoretical one are likely to be used by all participants in the educational environment (educators, school administrators, students) when having to conduct research on a specific issue which is included in the curriculum. The value of research in education cannot be doubted; various views have been stated regarding the role of research in various educational areas. We could refer indicatively to the study of Randall et al. (1999) who noticed that ‘research in education is a value-free, unbiased, neutral, social scientific pursuit of truth, using the best methods, and models available—or so we were told when we were learning the craft’ (Randall et al., 1999, 7). In other words, research in education cannot be stable; it should be rather active and dynamic being changed continuously in accordance with the needs of the students, the characteristics of the educational environment and the ability of a specific educational organization to respond to the needs and the demands of a particular research project. It should also be noticed that research in education does not have a specific form; it can have either qualitative or quantitative characteristics or even both of them (after appropr iate transformation of the relevant research framework).  

Environmental Values Essay Example | Topics and Well Written Essays - 1000 words

Environmental Values - Essay Example in 1974 drew inspiration from the feminist movements in which feminist activists rebelled against the traditional oppression of women by domineering men. In many countries, even developed countries, women are the weaker gender and without voice and are forced to accept the exploitation by men. Ecofeminism attempts to relate these events to the fact that nature and environment is exploited by men in the same way and nature attempts to meekly accept this racism, species segregation and exploitation. To a certain extent the main complaints and philosophy of the movement is indeed true and the arguments put forth by the movement is relevant. Man is the traditional defiler of all things and it is true that the major corporate positions in the world and in trade and industrial bodies are filled with men. Therefore, it would be men who constantly attempt to find new ways to exploit powerless nature, which cannot speak aloud. Later arguments of the Ecofeminism are at fault and their views on technology are not acceptable to me. It must be noted that when man does exploit forests and pollutes the waters, the beneficiaries are also women who make up the wives, daughters, sisters, mothers and other relatives of men. By tacitly accepting the cutting down of forests and gathering wood for firewood, women are also equally responsible for this defilement. Ecofeminism concepts also want to do away with technology and move towards primitivism where small communities would grow food in the natural way. This is not possible in the modern age as we need technology to produce food for the billions of people and both men and women have to find jobs and earn a living. So this philosophy is not acceptable. Schlosberg (1999) argues Pluralism or more specifically environmental pluralism places the right to exist for all things in nature, man, animals, plants and other inanimate entities such as water, air and earth that makes the environment. Then comes the concept of cost benefit

Managment and Cost Accounting Essay Example | Topics and Well Written Essays - 2000 words

Managment and Cost Accounting - Essay Example Since the costs of direct material and overheads are not determined accurately, there is a big risk that company might not produce competitive bids and unreasonably high prices are quoted to the insurance company. Therefore it is highly recommended that firstly the entity should classify accurately the costs associated with the product into fixed and variable. Secondly, actual charge is (should be) considered rather than standard costs, as it should be able to measure its actual cost of production. It is recommended that entity should consider using marginal costing method as it will allow the management to derive more relevant & important information for the purpose of decision-making. Information such as Contribution per unit, Break Even Sales (in units & value), Net Profit per unit and total can be of significant value to the management. In the era where companies are moving towards modern and world class business principles and reporting methodologies, there has been, since three decades, a significant debate on the validity of traditional absorption costing method in today’s decision making process. What are relevant costs when taking decisions relating to increasing the velocity of operating cycle and what are costs that are relevant solely when consideration is given to company objectives, goals and strategies? (Samford University, School of Business, Birmingham, Alabama, USA) We at William & Co. Consultants have made a feasibility study on the implications and benefits of implementing throughput accounting at BITE ME. "Throughput Accounting provides managers with a fresh set of eyes to identify and control bottlenecks. The drum, buffer, and rope will become part of the cost accounting lexicon in the future†, says Geoffrey Garland, Controller, StacoSwitch, Inc. (Steven Bragg). Throughput Accounting (TA) is a comprehensive management accounting approach which provides decision support information to managers

Reflection of the Vision Module Essay Example | Topics and Well Written Essays - 1000 words

Reflection of the Vision Module - Essay Example However, I soon realized that creativity is a funny thing. What sounds wildly creative and imaginative to one person sounds like a mess of silliness to another. Our first mistake as a group was not sorting out our differences from the beginning as to the very nature of the project itself. One idea that was pitched was a creative use of technology that involved newspaper headlines that were projected on a screen. This was my idea. Others in the group wanted a more traditional presentation of ideas through a featured lecturer set-up. Another faction of the group wanted to create a fully realized dramatic presentation complete with singing, poetry and props. We spent much energy and time trying to accommodate everyone’s ideas. There was a lot of conflict at this stage of the project, but that is to be expected. I kept thinking after each meeting that we would soon find something to do that everyone would be happy with, but after a while, I gave up hope. One of the biggest problem s was the fact that several group members refused to do anything that was not part of their original idea. Anything dramatic or any sort of performance was out of the question for these group members. We could not resolve this rift in the group, so we did something that in the end would prove to be unwise. We moved on with a hybrid of ideas that excluded these members. Basically, through frustration, the majority of the group sent a â€Å"like it or lump it† message to the minority that objected to the performance. This caused considerable problems. One is the fact that the few members that were marginalized failed to keep commitments and did not contribute much work towards the final product. This is understandable, but it really harmed our final product. We decided to write a dramatic performance that included technology I was in charge of utilizing. Just before the performance, some members wanted to make last minute changes to the script. There was a falling out among mem bers. Two members of the group sabotaged the performance by drawing the curtain and hiding behind it. Needless to say, the message of our presentation was somewhat lost among the chaos. Reflecting on this group learning activity really has been a thought provoking exercise. It has been a great opportunity to try something new, reflect on the possible mistakes and note how they could be avoided in the future. Themes that came up continually when I was thinking about this experience include group dynamics, group decision making, leadership styles and styles of communication. Reading about how groups form and share ideas has really helped me to better understand how this group learning activity could have been improved. Actually, the learning activity was great, it was the final product that needed to be improved. The idea that groups go through phases such as storming, norming and performing is interesting. Understanding that there will be differences of opinions in a group is powerfu l information that I do not think all of the members of our group understood. Looking back on the experience, too many people took criticism and critique personally, causing the group to stall in the storming phase. We never really established the norms of how the group should work. As a result, the person or people with the stormiest personalities got their way while the soft-spoken members were pushed to the side. Better resolution of the first phase of team formation would have led to a better end

Use Of Force Managemnt Essay Example | Topics and Well Written Essays - 500 words

Use Of Force Managemnt - Essay Example The U.S. Department of Justice, through its Community Oriented Policing Services, indicated that the use of force was a natural reaction in response to cases requiring apprehension of suspected criminals to protect one lives and that of others. Likewise, it was indicated in a published report by COPS that there was actually no clear and concise definition of the use of force but the accepted meaning was sourced from â€Å"the  International Association of Chiefs of Police  (IACP) in its study,  Police Use of Force in America 2001, defined use of force as "The amount of effort required by police to compel compliance by an unwilling subject.†" (U.S. DOJ: COPS, 2010). In this regard, the research aims to proffer issues on the use of force, specifically focusing on police brutality by identifying the problem, accountability, enhanced police accountability, accreditation and risk management, among others. A recommendation from the issues discussed would be presented prior to concluding remarks. Due to the critical position, tasks and responsibilities accorded to private security officers, there have been several documented instances of abuse of their authority. As such â€Å"most of these crimes fall into five broad areas: excessive force, sexual assaults, false arrest and fabrication of evidence, deprivation of property, and failure to keep from harm.† (FBI: Color of Law Abuses, 2010, par. 4). When the use of force becomes excessive and unreasonable, police brutality ensues, thereby posing dangers to the victims in terms of violations of human rights and even the possibility of grave injuries and death. According to David Mangan in his written article entitled Police Brutality: The Use of Excessive Force published as a Drury University paper, the use of excessive force tantamount to manifesting a form of police brutality is actually a criminal act constituting