Admission control and media delivery subsystems for video on demand proxy server /

Consultable des del TDXTítol obtingut de la portada digitalitzadaEl desarrollo y las avances recientes de la tecnología de los ordenadores y de la tecnología de alta velocidad de redes han hecho posible que las aplicaciones de video bajo demanda estén conectadas a «shared-computing» servidores reemplazando los sistemas tradicionales donde cada aplicación tenía su propia máquina dedicada para servirla. La aplicación de video bajo demanda permite a los usuarios seleccionar de una lista de videos su película favorita y ver su reproducción a su gusto. Sin embargo, la aplicación de video bajo demanda se considera como una de las aplicaciones que debería soportar largos «video streams», que consumen muchos recursos como el anch de banda de red y I/O, a gran número de clientes. Por eso, el servidor de video debería asegurar los recursos necesarios para cada «stream» durante un periodo de tiempo largo (e.g. 7200 segundos) para que los clientes reproduzcan el video sin «jitter» y «starvation» en sus búferes. Esta tesis presenta el diseño y la implementación de un Servidor Proxy de Video (VPS) que puede proveer video bajo demanda interactiva. El VPS consiste de tres componentes (partes) principales. La primera parte es el Modulo de Control de Admisión (ACM) que recibe las peticiones de los clientes, negocia los recursos requeridos, y decide si la petición puede ser aceptada o rechazada basado en la disponibilidad de los recursos. La segunda parte es el Modulo de Manejo de los Recursos (RMM) que maneja los recursos del sistema como el CPU, la Memoria, la Red, y el Disco. Este consta de cuatro «brokers» que reservan a los recursos necesarios basado en una política predefinida. La tercera parte es el algoritmo CB_MDA «Credit_Based Media Delivery Algorithm» que controla y regula el flujo de los «streams» del video. La CB_MDA utiliza una combinación de canales unicast y «multicast» para transmitir el video. Los «streams» de «multicast» se inician para empezar a emitir el video desde el principio, mientras los canales unicast se usan para juntar los llegados tardes a un «stream multicast» apropiado. En la implementación, el CB_MDA detecta los momentos cuando el servidor tiene disponibilidad de recursos y les asigna a los usuarios apropiados para crear un trabajo en adelanto.The recent advances and development of inexpensive computers and high speed networking technology have enabled the Video on Demand (VoD) application to connect to shared-computing servers, replacing the traditional computing environments where each application was having its own dedicated special purpose computing hardware. The VoD application enables the viewer to select, from a list of video files, his favourite video file and watch its reproduction at will. However, the VoD application is known as one of the applications that must provide long-lived video streams which consume high resources such as I/O and network bandwidth to a large number of clients. Therefore, a video server must secure the necessary resources for each stream during a long period of time (e.g. 7200 seconds) so that the clients can reproduce (play) the video data without witnessing jitter or starvation in their buffers. This thesis presents the design and implementation for a video proxy server (VPS) which can provide interactive video on demand. The VPS consists of three main parts. The first part is the Admission Control Module which receives the clients' requests, negotiates the required resources, and decides whether to accept or reject a client based on the available resources. The second part is the Resources Management Module which manages several shared resources such as the CPU, the Memory, the Network and the Disk It consists of four brokers that can reserve the necessary resources based on a predefined policy. The third part is the CB_MDA algorithm which is responsible for regulating the resources assignment and scheduling the video streams. The CB_MDA uses a combination of multicast and unicast channels for transmitting the video data. The multicast streams are initiated to start a video file from the beginning while the unicast channels are used to join the later arrivals to the appropriate multicast stream. In the implementation, the CB_MDA discovers the period of time when the server has plenty of resources an assigns them to appropriate clients in order to create work-ahead video data. The thesis further goes beyond the design of the VPS and presents a video client architecture that can synchronize with the server and work as a plug-in for producing the video data on different players such as MPEG-Berkely player, Xine…etc

Study of Some Features and Characteristics of Waves and Sea Surface Waters near the Higher Institute for Marine Research in Lattakia (Syria)

This research is concerned in studying the physical properties of water and surface waves of the Mediterranean Sea at the Syrian coast, along the High Institute for Marine Research (HIMR), (north of Lattakia). This field of study includes direct measurements of salinity, sea surface temperature (SST), the height of waves and its role in the surrounding of a study station built for this purpose in the position (N 35035\u2751, E 35044\u2749) located by GPS. Beside that we recorded the air temperature and the wind speed, above the mentioned station. These studies were done in the period of October 2000 till September 2003. From these we deduced the monthly rate for each parameter. These studies shows that the SST ranges between 15-30C30 while the salinity fluctuates between 36-39%. The wave heights which can be used to generate electric energy were re-corded in January and February. Also, we found that there is a proportional relation between the wind speed and the wave height in the study are

Short and Long-term Performance of a Skewed Integral Abutment Prestressed Concrete Bridge

This study presents the behavior of a precast skewed integral abutment bridge (IAB) using the recently developed NEXT-F Beam section in particular. In order to understand the bridge response, a 3-dimensional finite element model of a bridge (Brimfield Bridge) was developed to examine the thermal effect on the response of the bridge structural components. Eighteen months of field monitoring including abutments displacements, abutment rotations, deck strains, and beam strains was conducted utilizing 136 strain gauges, 6 crackmeters, and 2 tiltmeters. The behavior of the NEXT beams during construction was examined by conducting hand calculation considering all factors that could affect strain readings captured by strain gauges embedded in the 6 beams. Parametric analysis and model validation were conducted considering the effect of soil conditions, distribution of thermal loads, and the coefficient of thermal expansion used for the analyses. Using the validated model, the effect pile orientation was investigated. All the results and illustration plots are presented in detail in this study. As a result of this study, the behavior of the NEXT beams during construction was explained. Long term behavior of the bridge was also explained using field data and FE model. Furthermore, it was concluded that the coefficient of thermal expansion of concrete and temperature variation along the bridge depth and transverse direction can have a significant effect on the strain readings and calculated response, respectively. Lastly, it was found that orienting piles with their web perpendicular on the bridge centerline or with their web perpendicular to the abutment centerline will result in small ratio of moment demand to moment capacity

Short Communication A note on "The Ideal Generated by Codense Sets and the Banach Localization Property"

In this note we show by producing counter examples that some results which appeared in the articles by Jankovic and Hamlett [3] are incorrect

Using Remote Sensing and Geographic Information Systems to Study the Change Detection in Temperature and Surface Area of Hamrin Lake

اجريت هذه الدراسة على بحيرة حمرين الواقعة في محافظة ديالى وسط العراق بين خطي 44º 53ʹ 26.16 '- 45º 07 ʹ 28.03ʺ ودائرتي عرض  34º 04ʹ 24.75ʺ ــ 34º 19ʹ 12.74ʺ.اذ تمت في هذه الدراسة حساب المساحة السطحية لبحيرة حمرين من الصور الفضائية خلال الفترة الممتدة من شهر تشرين الاول 2019 الى ايلول 2020 وبمعدل صورة فضائية لكل شهر وباستخدام دليل اختلاف المياه الطبيعي NDWI فكانت اكبر مساحة سطحية 264.617كم2 لشهر اكتوبر واقل مساحة سطحية     140.202 كم2 لشهر ايلول . وتم ايضا حساب درجة الحرارة السطحية لمياه البحيرة من الصور الفضائية للقمر الصناعي لاندسات 8 بالاعتماد على الحزم 10(الأشعة تحت الحمراء الحرارية 1) و11(الأشعة تحت الحمراء الحرارية 2) التي تتحسس الاشعة الحرارية، حيث بلغت أعلى درجة حرارة سطح في حزيران 45.95 درجة مئوية. بسبب ارتفاع درجات الحرارة لهذا الشهر وأدنى مستوى لها في شياط 3.09 درجة مئوية، وهو أحد الأشهر التي تنخفض فيها درجات الحرارة إلى أدنى مستوى لها. ساعد استخدام الاستشعار عن بعد وابتكارات نظم المعلومات الجغرافية كثيرًا في التحقق من التغييرات، سواء في مساحة السطح أو درجة الحرارة، مما يوفر الجهد والوقت والتكلفة. وضعت نتائج هذه الدراسة متخذي القرار في اتخاذ الاحتياطات اللازمة لموسمي ندرة المياه والجفاف لتلبية احتياجات المجتمع المائية في مناطق الاستهلاك البشري المتعددة وفي نفس الوقت الاستفادة من مواسم الأمطار ووفرة المياه وتطوير خطط استراتيجية طويلة الامد لأجل الحفاظ على توازن مائي مستدام.This study was conducted on Lake Hamrin situated in Diyala governorate, focal Iraq, between latitudes 44º 53ʹ 26.16 '- 45º 07 ʹ 28.03ʺ and 34º 04ʹ 24.75ʺ ــ 34º 19ʹ 12.74ʺ . As in this study, the surface area of Hamrin Lake was calculated from satellite images during the period from October 2019 to September 2020, with an average satellite image for each month, furthermore,by utilizing the Normalized Differences Water Index (NDWI), the largest surface area was 264,617 km2 for October and the lowest surface area 140.202 km2 for September. The surface temperature of the lake water was also calculated from satellite images of the Landsat 8 satellite, based on bands 10 (Thermal Infrared 1) and 11 (Thermal Infrared 2) that are sensitive to thermal radiation, as the highest surface temperature reached in June 45.49°C degrees Celsius due to the high temperatures for this month and the lowest in February 3.09°C degrees Celsius, which is one of the months in which temperatures drop to the lowest level. The utilization of remote sensing and GIS innovations has helped a lot in checking changes, whether in surface area or temperature, which saves effort, time and cost. The results of this study put decision makers in taking the necessary precautions for the seasons of water scarcity and drought to meet the community’s water needs in the areas of multiple human consumptions and at the same time take advantage of rainy seasons and water abundance to develop long-term strategic plans to maintain a sustainable water balance

Descriptor Optimization for Multimedia Indexing and Retrieval

International audienceIn this paper, we propose and evaluate a method for optimizing descriptors used for content-based multimedia indexing and retrieval. A large variety of descriptors are commonly used for this purpose. However, the most efficient ones often have characteristics preventing them to be easily used in large scale systems. They may have very high dimensionality (up to tens of thousands dimensions) and/or be suited for a distance costly to compute (e.g. fflchi-square). The proposed method combines a PCA-based dimensionality reduction with pre- and post-PCA non-linear transformations. The resulting transformation is globally optimized. The produced descriptors have a much lower dimensionality while performing at least as well, and often significantly better, with the Euclidean distance than the original high dimensionality descriptors with their optimal distance. The method has been validated and evaluated for a variety of descriptors using TRECVid 2010 semantic indexing task data. It has then be applied at large scale for the TRECVid 2012 semantic indexing task on tens of descriptors of various types and with initial dimensionalities from 15 up to 32,768. The same transformation can be used also for multimedia retrieval in the context of query by example and/or relevance feedback