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  • 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.
11

TELEMETRY IN BUNDLES: DELAY-TOLERANT NETWORKING FOR DELAY-CHALLENGED APPLICATIONS

Burleigh, Scott 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Delay-tolerant networking (DTN) is a system for constructing automated data networks in which end-to-end communication is reliable despite low data rates, possible sustained interruptions in connectivity, and potentially high signal propagation latency. As such it promises to provide an inexpensive and robust medium for returning telemetry from research vehicles in environments that provide meager support for communications: deep space, the surface of Mars, the poles or the sub- Arctic steppes of Earth, and others. This paper presents an overview of DTN concepts, including “bundles” and the Bundling overlay protocol. One possible scenario for the application of DTN to a telemetry return problem is described, and there is a brief discussion of the current state of DTN technology development.
12

CURRENT STATUS OF DATA COMPRESSION IN TELEMETRY

Horan, Sheila B. 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / Reduction of bandwidth for signal transmission is of paramount concern to many in the telemetry and wireless industry. One way to reduce bandwidth is to reduce the amount data being sent. There are several techniques available to reduce the amount of data. This paper will review the various types of data compression currently in use for telemetry data and how much compression is achieved.
13

Control System Analysis of a Telemetry Network System (TmNS)

Araujo, Maria S., Moodie, Myron L., Abbott, Ben A., Grace, Thomas B. 10 1900 (has links)
ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / On the surface, network-based telemetry systems would appear to be simple, stateless, information collecting entities. Unfortunately, the reality of networking technologies brings a hierarchy of control loops into the system setup. At the top level, the command and status collection data loop that users manipulate the system with is a feedback loop. The commands themselves are transmitted across the network through competing streams of data, which are guided and controlled by Transmission Control Protocol (TCP) mechanisms. TCP mechanisms themselves have control loops in order to avoid congestion, provide reliability, and generally optimize flow. These TCP streams flowing across a network fabric compete at choke points, such as network switches, routers, and wireless telemetry links - all of which are also guided by control loops. This paper discusses the hierarchy of control loops present in a TmNS, provides an analysis of how these loops interact, and describes key points to be considered for telemetry systems.
14

The Role of pUL138 In HCMV Persistence

Petrucelli, Alexius January 2011 (has links)
Human cytomegalovirus (HCMV) coexists indefinitely in infected individuals through a poorly characterized latent infection in hematopoietic cells. We previously demonstrated a requirement for UL138 in promoting a latent infection in CD34+ hematopoietic progenitor cells (HPCs). UL138 is encoded on three co-terminal transcripts of, 1.7-, 2.7-, and 3.6-kilobases. Interestingly, the UL138 protein product (pUL138) is necessary but insufficient for HCMV latency. The mechanisms by which pUL138 contributes to the latent infection are unknown, however other viral determinants are required for the latent infection. We identified 3 novel proteins pUL133, pUL135, and pUL136 encoded on the UL138 transcripts. Similar to pUL138, pUL133, pUL135, and pUL136 are Golgi localized type I transmembrane proteins expressed with early kinetics during productive infection. We have named these UL138 related proteins, CLAMPs for HCMV Latency Associated Membrane Proteins. Through a systematic immunoprecipitation analysis, we identified interactions between the CLAMPs and characterized an interaction between pUL133 and pUL138. Further, we mapped the interacting region to a specific domain in the C-terminal, cytosolic tail of pUL138. Additionally, we show that each of the CLAMPs has the ability to self-associate. The localization of the CLAMPs to the Golgi suggests that these proteins likely promote HCMV latency through a novel mechanism involving Golgi functions. Additionally, through a Y2H screen of a human bone marrow cDNA library, we identified an interaction between pUL138 and the heat shock protein 40 (Hsp40) variant MRJ. We confirmed this interaction in mammalian cells and mapped the pUL138 region responsible for this interaction to a domain in the cytoplasmic tail of pUL138. We also demonstrated additional MRJ interactions with pUL133 and pUL136. Importantly, pUL138 specifically interacts with Hsp40 variants during productive infection. Preliminary data suggest that HCMV infection up regulates MRJ mRNA expression and recombinant viruses lacking pUL138 show a disproportionate up regulation of MRJ. pUL138 is the first HCMV protein demonstrated to promote a latent infection. While the mechanisms by which pUL138 contributes to latency remain unknown, the interaction with other CLAMPs and with MRJ, suggest that pUL138 may cooperate with other CLAMPs to modulate the cellular stress response at the Golgi to promote HCMV latency.
15

Transcriptional regulation of the Epstein-Barr virus immediate early genes

Jenkins, Peter John January 1999 (has links)
No description available.
16

Robust, High-Speed Network Design for Large-Scale Multiprocessing

DeHon, Andre 01 September 1993 (has links)
As multiprocessor system size scales upward, two important aspects of multiprocessor systems will generally get worse rather than better: (1) interprocessor communication latency will increase and (2) the probability that some component in the system will fail will increase. These problems can prevent us from realizing the potential benefits of large-scale multiprocessing. In this report we consider the problem of designing networks which simultaneously minimize communication latency while maximizing fault tolerance. Using a synergy of techniques including connection topologies, routing protocols, signalling techniques, and packaging technologies we assemble integrated, system-level solutions to this network design problem.
17

Exploiting level sensitive latches in wire pipelining

Seth, Vikram 17 February 2005 (has links)
The present research presents procedures for exploitation of level sensitive latches in wire pipelining. The user gives a Steiner tree, having a signal source and set of destination or sinks, and the location in rectangular plane, capacitive load and required arrival time at each of the destinations. The user also defines a library of non-clocked (buffer) elements and clocked elements (flip-flop and latch), also known as synchronous elements. The first procedure performs concurrent repeater and synchronous element insertion in a bottom-up manner to find the minimum latency that may be achieved between the source and the destinations. The second procedure takes additional input (required latency) for each destination, derived from previous procedure, and finds the repeater and synchronous element assignments for all internal nodes of the Steiner tree, which minimize overall area used. These procedures utilize the latency and area advantages of latch based pipelining over flip-flop based pipelining. The second procedure suggests two methods to tackle the challenges that exist in a latch based design. The deferred delay padding technique is introduced, which removes the short path violations for latches with minimal extra cost.
18

Multipath Router Architectures to Reduce Latency in Network-on-Chips

Deshpande, Hrishikesh 2012 May 1900 (has links)
The low latency is a prime concern for large Network-on-Chips (NoCs) typically used in chip-multiprocessors (CMPs) and multiprocessor system-on-chips (MPSoCs). A significant component of overall latency is the serialization delay for applications which have long packets such as typical video stream traffic. To address the serialization latency, we propose to exploit the inherent path diversity available in a typical 2-D Mesh with our two novel router architectures, Dual-path router and Dandelion router. We observe that, in a 2-D mesh, for any source-destination pair, there are two minimal paths along the edges of the bounding box. We call it XY Dimension Order Routing (DOR) and YX DOR. There are also two non-minimal paths which are non-coinciding and out of the bounding box created by XY and YX DOR paths. Dual-path Router implements two injection and two ejection ports for parallel packet injection through two minimal paths. Packets are split into two halves and injected simultaneously into the network. Dandelion router implements four injection and ejection ports for parallel packet injection. Packets are split into smaller sub-packets and are injected simultaneously in all possible directions which typically include two minimal paths and two non-minimal paths. When all the sub-packets reach the destination, they are eventually recombined. We find that our technique significantly increases the throughput and reduces the serialization latency and hence overall latency of long packets. We explore the impact of Dual-path and Dandelion on various packet lengths in order to prove the advantage of our routers over the baseline. We further implement different deadlock free disjoint path models for Dandelion and develop a switching mechanism between Dual-path and Dandelion based on the traffic congestion.
19

An Improved Algorithm for Tor Circuit Scheduling

Tang, Can January 2010 (has links)
Tor is a popular anonymity-preserving network, consisting of routers run by volunteers all around the world. It protects Internet users’ privacy by relaying their network traffic through a series of routers, thus concealing the linkage between the sender and the recipient. Despite the advantage of Tor’s anonymizing capabilities, it also brings extra latency, which discourages more users from joining the network. One of the factors that causes the latency lies in Tor’s circuit scheduling algorithm, which allows busy circuits to crowd out bursty circuits. In this work, we propose and implement a more advanced scheduling algorithm which treats circuits differently, based on their recent activity. In this way, bursty circuits such as those used for web browsing can gain higher priority over busy ones such as used for bulk transfer; the performance for most activities over Tor is improved, while minimal overhead is incurred. Our algorithm has been incorporated into the latest build of Tor.
20

Analysis of event-related potentials and telomere length in schizophrenic patients

W-Y. Yu, Younger 30 June 2001 (has links)
Telomere, the ends of chromosomes, consists of simple hexameric repeats. In human, TTAGGG repeat is found at the ends of all chromosomes. Telomeres progressively shorten with age in somatic cells, because the insufficient telomerase activity fails to compensate the progressive telomeric erosion. Thus, the reduction of telomeric length in senescent cells is believed to result from active cell division that erodes chromosomal termini. The telomere length supposed to have been an evaluation tool for aging in human. Schizophrenia is a thought, perception disorder, generally regarded as an illness with onset in late adolescence or early adult life with a prevalence rate of 1%. Although the long-term course of schizophrenia shows great heterogeneity among patients, a significant number of patients experience very poor outcomes, shows severe cognitive impairment that is suggestive of a progressive neurodegenerative disorder. The aim of this study is to explore the relationship between neurodegenerative process and telomere length in schizophrenic patients. The latency of P300 event-related potentials is prolonged in disorders associated with neural damage and degeneration and also becomes prolonged in the course of aging process. This study is separated as two parts: first part, using the event-related potentials P300 latency as a tool to evaluate the cognitive dysfunction and aging process in schizophrenics. One hundred and fifty three long-term hospitalization chronic schizophrenics were recruited as the experimental group of this research, including 44 male and 109 female patients with mean age of 38.4 years. These patients were divided into 2 groups according to the different responses to treatment, global assessment functional scale (GAF): 91 with good response to treatment; 62 with poor response to treatment. The normal control group included 101 normal people, male 37 and female 76, with mean age of 38.1 years. The event-related potentials was elicited by auditory oddball paradigm. The P300 latency prolonged in these two schizophrenic patients. The longest P300 latency was found in the poor response schizophrenic group. The shortest P300 latency was found in the normal group. Linear regression coefficients were computed to determine the slope of component P300 latency on age and other factors. The slope of P300 latency on age in normal control group is 1.2 ms/y. In schizophrenic groups, not only the age, but the GAF as the most contributing factors in the neurodegenerative process. Second part, the subjects were selected from part one, 48 chronic schizophrenia whose mean age was 37.9 years and 48 age-, handedness-, and gender-matched normal control subjects. The schizophrenic patients were divided into 2 groups according to the different responses to treatment: 34 with good response to treatment; 14 with poor response to treatment. The telomere length, measured by assay of terminal restriction fragments (TRFs), was determined in HinfI-digested DNA by Southern blot analysis using a (TTAGGG)4 probe. The shortest TRF length was found in the poor response schizophrenic group. There was no difference between the good response schizophrenic group and normal control group. TRF length in peripheral leukocytes obtained from normal control group decreased by approximately 89bP per year. In schizophrenic groups, the TRF length was found that not the age, but the age onset and GAF as the most contributing factors in linear regression model. This study shows that the poor response schizophrenic patients have the most rapid neurodegenerative process in P300 latency and TRF length evaluation. It implicates the homogeneous group, and can be considered as the kraepelinian schizophrenics, very poor outcome group.

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