• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1938
  • 654
  • 307
  • 237
  • 142
  • 73
  • 55
  • 43
  • 29
  • 22
  • 19
  • 15
  • 15
  • 12
  • 11
  • Tagged with
  • 4084
  • 4084
  • 800
  • 793
  • 630
  • 618
  • 547
  • 540
  • 501
  • 430
  • 426
  • 424
  • 347
  • 332
  • 289
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Real-time cache design.

January 1996 (has links)
by Hon-Kai, Cheung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 102-105). / Abstract --- p.i / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview --- p.1 / Chapter 1.2 --- Scheduling In Real-time Systems --- p.4 / Chapter 1.3 --- Cache Memories --- p.5 / Chapter 1.4 --- Outline Of The Dissertation --- p.8 / Chapter 2 --- Related Work --- p.9 / Chapter 2.1 --- Introduction --- p.9 / Chapter 2.2 --- Predictable Cache Designs --- p.9 / Chapter 2.2.1 --- Locking Cache Lines Design --- p.9 / Chapter 2.2.2 --- Partially Dynamic And Static Cache Partition Allocation Design --- p.10 / Chapter 2.2.3 --- SMART (Strategic Memory Allocation for Real Time) Cache Design --- p.10 / Chapter 2.3 --- Prefetching --- p.11 / Chapter 2.3.1 --- Introduction --- p.11 / Chapter 2.3.2 --- Hardware Support Prefetching --- p.12 / Chapter 2.3.3 --- Software Assisted Prefetching --- p.12 / Chapter 2.3.4 --- Partial Cache Hit --- p.13 / Chapter 2.3.5 --- Cache Pollution Problems --- p.13 / Chapter 2.4 --- Cache Line Replacement Policies --- p.13 / Chapter 2.5 --- Main Memory Update Policies --- p.14 / Chapter 2.6 --- Summaries --- p.15 / Chapter 3 --- Problems And Motivations --- p.16 / Chapter 3.1 --- Introduction --- p.16 / Chapter 3.2 --- Problems --- p.16 / Chapter 3.2.1 --- Modern Cache Architecture Is Inappropriate For Real-time Systems --- p.16 / Chapter 3.2.2 --- Intertask Interference: The Effects Of Preemption --- p.17 / Chapter 3.2.3 --- Intratask Interference: Cache Line Collision --- p.20 / Chapter 3.3 --- Motivations --- p.21 / Chapter 3.3.1 --- Improvement Of The Cache Performance In Real-time Systems --- p.21 / Chapter 3.3.2 --- Hiding of Preemption Effects --- p.22 / Chapter 3.4 --- Conclusions --- p.25 / Chapter 4 --- Proposed Real-Time Cache Design --- p.26 / Chapter 4.1 --- Introduction --- p.26 / Chapter 4.2 --- Concepts Definition --- p.26 / Chapter 4.2.1 --- Tasks Definition --- p.26 / Chapter 4.2.2 --- Cache Performance Values --- p.27 / Chapter 4.3 --- Issues Related To Proposed Real-Time Cache Design --- p.28 / Chapter 4.3.1 --- A Task Serving Policy --- p.30 / Chapter 4.3.2 --- Number Of Private And Shared Cache Partitions --- p.31 / Chapter 4.3.3 --- Controlling The Cache Partitions: Cache Partition Table And Pro- cess Info Table --- p.32 / Chapter 4.3.4 --- Re-organization Of Task Owns Cache Partition(s) --- p.34 / Chapter 4.3.5 --- Handling The Bus Bandwidth: Memory Requests Queue ( MRQ ) --- p.35 / Chapter 4.3.6 --- How To Address The Cache Models --- p.37 / Chapter 4.3.7 --- Data Coherence Problems For Partitioned Cache Model And Non- partitioned Cache Model --- p.39 / Chapter 4.4 --- Mechanism For Proposed Real-Time Cache Design --- p.43 / Chapter 4.4.1 --- Basic Operation Of Proposed Real-Time Cache Design --- p.43 / Chapter 4.4.2 --- Assumptions And Rules --- p.43 / Chapter 4.4.3 --- First Round Dynamic Cache Partition Re-allocation --- p.44 / Chapter 4.4.4 --- Later Round Dynamic Cache Partition Re-allocation --- p.45 / Chapter 5 --- Simulation Environments --- p.56 / Chapter 5.1 --- Proposed Architectural Model --- p.56 / Chapter 5.2 --- Working Environment For Proposed Real-time Cache Models --- p.57 / Chapter 5.2.1 --- Cost Model --- p.57 / Chapter 5.2.2 --- System Model --- p.64 / Chapter 5.2.3 --- Fair Comparsion Between The Unified Cache And The Separate Caches --- p.64 / Chapter 5.2.4 --- Operations Within The Preemption --- p.65 / Chapter 5.3 --- Benchmark Programs --- p.65 / Chapter 5.3.1 --- The NASA7 Benchmark --- p.66 / Chapter 5.3.2 --- The SU2COR Benchmark --- p.66 / Chapter 5.3.3 --- The TOMCATV Benchmark --- p.66 / Chapter 5.3.4 --- The WAVE5 Benchmark --- p.67 / Chapter 5.3.5 --- The COMPRESS Benchmark --- p.67 / Chapter 5.3.6 --- The ESPRESSO Benchmark --- p.68 / Chapter 5.4 --- Simulations Parameters --- p.68 / Chapter 6 --- Analysis Of Simulations --- p.71 / Chapter 6.1 --- Introduction --- p.71 / Chapter 6.2 --- Trace Files Statistics --- p.71 / Chapter 6.3 --- Interpretation Of Partial Cache Hit --- p.72 / Chapter 6.4 --- The Effects Of Cache Size --- p.72 / Chapter 6.4.1 --- "Performances Of Model 1, Model 2, Model 3 And Model 4" --- p.72 / Chapter 6.5 --- The Effects Of Cache Partition Size --- p.76 / Chapter 6.5.1 --- Performance Of Model 3 --- p.79 / Chapter 6.5.2 --- Performance Of Model 1 --- p.79 / Chapter 6.6 --- The Effects Of Line Size --- p.80 / Chapter 6.6.1 --- "Performance Of Model 1, Model 2, Model 3 And Model 4" --- p.80 / Chapter 6.7 --- The Effects Of Set Associativity --- p.83 / Chapter 6.7.1 --- "Performance Of Model 1, Model 2, Model 3 And Model 4" --- p.83 / Chapter 6.8 --- The Effects Of The Best-expected Cache Performance --- p.84 / Chapter 6.8.1 --- Performance of Model 1 --- p.87 / Chapter 6.8.2 --- Performance of Model 3 --- p.88 / Chapter 6.9 --- The Effects Of The Standard-expected Cache Performance --- p.89 / Chapter 6.9.1 --- Performance Of Model 1 --- p.89 / Chapter 6.9.2 --- Performance Of Model 3 --- p.91 / Chapter 6.10 --- The Effects Of Cycle Execution Time/Cycle Deadline Period --- p.92 / Chapter 6.10.1 --- "Performances Of Model 1, Model 2, Model 3 And Model 4" --- p.92 / Chapter 7 --- Conclusions And Future Work --- p.95 / Chapter 7.1 --- Conclusions --- p.95 / Chapter 7.1.1 --- Unified Cache Model Is More Suitable In Real-time Systems --- p.99 / Chapter 7.1.2 --- Comments On Aperiodic Tasks --- p.100 / Chapter 7.2 --- Future Work --- p.100
122

MPS-based Domain-specific Language for Defining RTSJ Systems / MPS-based Domain-specific Language for Defining RTSJ Systems

Fechtner, Tomáš January 2012 (has links)
The Real-time Specification of Java (RTSJ) is an intention to introduce Java as a language for developing real-time system. However, the complexity of their development and a non-trivial programming model of RTSJ with its manual memory management often lead to programming errors. To mitigate the development of RTSJ systems it would be beneficial to provide an internal domain-specific language (DSL) extending the Java language which would allow to develop the systems in more intuitive and safer way. However, it is needed to find compromise between solution's power and level of usability, because this two attributes go often against each other. One possible way of DSLs creation concerns the Meta-Programming System (MPS). It allows to develop new domain-specific languages and corresponding projectional editors enabling different views on code. This thesis proposes a design and implementation of the DSL on the top of the MPS platform and corresponding code generator enabling development of RTSJ systems. Furthermore, the thesis provides a simple case-study to evaluate a proposed DSL. Additionally, the thesis assesses the suitability of MPS as a DSL-development platform.
123

A Real-Time Communication Framework for Wireless Sensor Networks

AAL SALEM, MOHAMMED January 2009 (has links)
Doctor of Philosophy(PhD) / Recent advances in miniaturization and low power design have led to a flurry of activity in wireless sensor networks. Sensor networks have different constraints than traditional wired networks. A wireless sensor network is a special network with large numbers of nodes equipped with embedded processors, sensors, and radios. These nodes collaborate to accomplish a common task such as environment monitoring or asset tracking. In many applications, sensor nodes will be deployed in an ad-hoc fashion without careful planning. They must organize themselves to form a multihop, wireless communication network. In sensor network environments, much research has been conducted in areas such as power consumption, self-organisation techniques, routing between the sensors, and the communication between the sensor and the sink. On the other hand, real-time communication with the Quality of Service (QoS) concept in wireless sensor networks is still an open research field. Most protocols either ignore real time or simply attempt to process as fast as possible and hope that this speed is sufficient to meet the deadline. However, the introduction of real-time communication has created additional challenges in this area. The sensor node spends most of its life routing packets from one node to another until the packet reaches the sink; therefore, the node functions as a small router most of the time. Since sensor networks deal with time-critical applications, it is often necessary for communication to meet real time constraints. However, research that deals with providing QoS guarantees for real-time traffic in sensor networks is still in its infancy.This thesis presents a real-time communication framework to provide quality of service in sensor networks environments. The proposed framework consists of four components: First, present an analytical model for implementing Priority Queuing (PQ) in a sensor node to calculate the queuing delay. The exact packet delay for corresponding classes is calculated. Further, the analytical results are validated through an extensive simulation study. Second, report on a novel analytical model based on a limited service polling discipline. The model is based on an M/D/1 queuing system (a special class of M/G/1 queuing systems), which takes into account two different classes of traffic in a sensor node. The proposed model implements two queues in a sensor node that are served in a round robin fashion. The exact queuing delay in a sensor node for corresponding classes is calculated. Then, the analytical results are validated through an extensive simulation study. Third, exhibit a novel packet delivery mechanism, namely the Multiple Level Stateless Protocol (MLSP), as a real-time protocol for sensor networks to guarantee the traffic in wireless sensor networks. MLSP improves the packet loss rate and the handling of holes in sensor network much better than its counterpart, MMSPEED. It also introduces the k-limited polling model for the first time. In addition, the whole sending packets dropped significantly compared to MMSPEED, which it leads to decrease the consumption power. Fourth, explain a new framework for moving data from the sink to the user, at a low cost and low power, using the Universal Mobile Telecommunication System (UMTS), which is standard for the Third Generation Mobile System (3G). The integration of sensor networks with the 3G mobile network infrastructure will reduce the cost of building new infrastructures and enable the large-scale deployment of sensor networks
124

Guidelines for implementing real-time process control using the PC

Stanford, Clayton R. 06 December 1996 (has links)
The application of the personal computer in the area of real-time process control is investigated. Background information is provided regarding factory automation and process control. The current use of the PC in the factory for data acquisition is presented along with an explanation of the advantages and disadvantages associated with extending the use of the PC to real-time process control. The use of interrupt-driven and polled I/O to obtain real-time response is investigated and contrasted with the use of a real-time operating system. A unique compilation of information provides guidelines for selecting an implementation method for real-time control. Experimental work is performed to evaluate the access time and latency periods for the hard drive, video monitor, and I/O devices operating in a DOS environment. The execution speeds of C and assembly language programs are investigated. A method to estimate the performance of a real-time control system using polled or interrupt-driven I/O is developed. / Graduation date: 1997
125

Real-time Mosaic for Multi-Camera Videoconferencing

Klechenov, Anton, Gupta, Aditya Kumar, Wong, Weng Fai, Ng, Teck Khim, Leow, Wee Kheng 01 1900 (has links)
This paper describes a system for high resolution video conferencing. A number of camcorders are used to capture the video, which are then mosaiced to generate a wide angle panoramic view. Furthermore this system is made “real-time” by detecting changes and updating them on the mosaic. This system can be deployed on a single machine or on a cluster for better performance. It is also scalable and shows a good real-time performance. The main application for this system is videoconferencing for distance learning but it can be used for any high resolution broadcasting. / Singapore-MIT Alliance (SMA)
126

Quantification and signaling of alternatively spliced GFRα2 isoforms

Too, Heng-Phon, Fung, Winnie Kar Yee 01 1900 (has links)
Neurturin (NTN) belongs to the glial cell-line derived neurotrophic factor (GDNF) family of growth factors. Both NTN and GDNF have been shown to potently prevent the degeneration of dopaminergic neuron in vitro and in vivo. The GDNF family receptor alpha 2 (GFRα-2) is the preferred receptor for NTN. In addition to the known full-length isoform (GFRα-2a), we have previously reported the isolation of two novel alternatively spliced isoforms (GFRα-2b and GFRα-2c). The expression levels of these isoforms have yet to be quantified and the functional properties determined. In this report, we have developed a real time polymerase chain reaction (PCR) using SYBR Green I to detect the expression levels of the three splice variants (GFRα-2a, GFRα-2b and GFRα-2c) in murine tissues. Both GFRα-2a and GFRα-2c were expressed at similar levels in all tissues examined. GFRα-2b was found to be 10 fold lower in expression. All three isoforms activated MAPK (ERK1/2) and Akt. Transcriptional profiling with DNA microarrays demonstrated that the spliced isoforms do not share similar profiles. In conclusion, we have now shown the expression levels of the spliced variants. All three isoforms are functional. However, each isoform appeared to have unique transcriptional profiles when activated. / Singapore-MIT Alliance (SMA)
127

Concurrent Multi-Path Real-Time Transmission Control Protocol

Jayaraman, Anand 01 January 2007 (has links)
In this thesis, a new transport protocol, the Concurrent Multi-Path Real-time Transmission Control Protocol (cmpRTCP) is proposed. The proposed protocol has been designed to handle real-time streams (video and audio) over IP-networks. One of the key strengths of this protocol lies in its ability to intelligently exploit the availability of multiple paths between multi-homed hosts for concurrent transmission of unicast real-time streams. This work describes the architecture and operation of cmpRTCP in detail. In addition, the limitations of currently used transport protocols in handling real-time streams are also discussed. These limitations of other protocols have played a vital role in the design process of the proposed protocol. Experiments to evaluate the performance of cmpRTCP against other protocols and the results obtained therein are also documented in this work. Results show that cmpRTCP is a best effort protocol that tries to maximize the amount of data that is successfully delivered to the destination in a timely manner under varying drop and delay conditions of the network.
128

Joint source-channel distortion modeling for image and video communication

Sabir, Muhammad Farooq, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
129

Evaluation of alterations in gene expression in MCF-7 cells induced by the agricultural chemicals Enable and Diazinon

Mankame, Tanmayi Pradeep 29 August 2005 (has links)
Steroid hormones, such as estrogen, are produced in one tissue and carried through the blood stream to target tissues in which they bind to highly specific nuclear receptors and trigger changes in gene expression and metabolism. Industrial chemicals, such as bisphenol A and many agricultural chemicals, including permethrin and fervalerate, are known to have estrogenic potential and therefore are estrogen mimics. Widely used agricultural chemicals, Enable (fungicide) and Diazinon (insecticide), were evaluated to examine their toxicity and estrogenicity. MCF-7 cells, an estrogen-dependent human breast cancer line, were utilized for this purpose. MCF-7 cells were treated with 0.033-3.3 ppb (ng/ml) of Enable and 0.3-67 ppm of Diazinon and gene expression was compared to that in untreated cells. Microarray analysis showed down-regulation of eight genes and up-regulation of thirty four genes in cells treated with 3.3 ppb of Enable, compared to untreated cells. Similarly, in cells treated with 67 ppm of Diazinon, there were three genes down-regulated and twenty seven genes up-regulated. For both chemicals, specific genes were selected for special consideration. RT-PCR confirmed results obtained from analysis of the microarray. These studies were designed to provide base-line data on gene expression-altering capacity of specific chemicals and will allow assessment of the deleterious effects caused by exposure to the aforementioned chemicals.
130

Combining structural and reduced-form models for macroeconomic analysis and policy forecasting

Monti, Francesca 08 February 2011 (has links)
Can we fruitfully use the same macroeconomic model to forecast and to perform policy analysis? There is a tension between a model’s ability to forecast accurately and its ability to tell a theoretically consistent story. The aim of this dissertation is to propose ways to soothe this tension, combining structural and reduced-form models in order to have models that can effectively do both.

Page generated in 0.0833 seconds