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Articles 15361 - 15390 of 17312

Full-Text Articles in Engineering

A Sparse Program Dependence Graph For Object Oriented Programming Languages, Keith Garfield Jan 2006

A Sparse Program Dependence Graph For Object Oriented Programming Languages, Keith Garfield

Electronic Theses and Dissertations

The Program Dependence Graph (PDG) has achieved widespread acceptance as a useful tool for software engineering, program analysis, and automated compiler optimizations. This thesis presents the Sparse Object Oriented Program Dependence Graph (SOOPDG), a formalism that contains elements of traditional PDG's adapted to compactly represent programs written in object-oriented languages such as Java. This formalism is called sparse because, in contrast to other OO and Java-specific adaptations of PDG's, it introduces few node types and no new edge types beyond those used in traditional dependence-based representations. This results in correct program representations using smaller graph structures and simpler semantics when …

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Neural Network-Based Output Feedback Controller For Lean Operation Of Spark Ignition Engines, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier, Jonathan B. Vance, Pingan He Jan 2006

Neural Network-Based Output Feedback Controller For Lean Operation Of Spark Ignition Engines, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier, Jonathan B. Vance, Pingan He

Electrical and Computer Engineering Faculty Research & Creative Works

Spark ignition (SI) engines running at very lean conditions demonstrate significant nonlinear behavior by exhibiting cycle-to-cycle dispersion of heat release even though such operation can significantly reduce NOx emissions and improve fuel efficiency by as much as 5-10%. A suite of neural network (NN) controller without and with reinforcement learning employing output feedback has shown ability to reduce the nonlinear cyclic dispersion observed under lean operating conditions. The neural network controllers consists of three NN: a) A NN observer to estimate the states of the engine such as total fuel and air; b) a second NN for generating virtual input; …

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Experimental Analysis And Evaluation Of Tidy Tree Drawing Algorithms, Pankaj Mahajan Jan 2006

Experimental Analysis And Evaluation Of Tidy Tree Drawing Algorithms, Pankaj Mahajan

Electronic Theses and Dissertations

Tree Drawings have been used extensively in software engineering and many other business and computer applications. The basic structure of a tree allows for the organization and representation of complex information. Many commercial tools allow their users to draw or construct trees to represent a problem and/or its solution. Our focus is on dynamic trees - trees subject to frequent changes and redisplay in highly user-friendly interactive computer applications. Tree presentations in such interactive tools have to be precise and maintainable, which means, the tree presentations should maintain a particular structure so that user's mental perception of the tree is …

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Sensor-Based Computing Techniques For Real-Time Traffic Evacuation Management, Georgiana Hamza-Lup Jan 2006

Sensor-Based Computing Techniques For Real-Time Traffic Evacuation Management, Georgiana Hamza-Lup

Electronic Theses and Dissertations

The threat of terrorist incidents is higher than ever before and devastating acts, such as the terrorist attacks on the World Trade Center and the Pentagon, have left many concerns about the possibility of future incidents and their potential impact. Unlike some natural disasters that can be anticipated, terrorist attacks are sudden and unexpected. Even if sometimes we do have partial information about a possible attack, it is generally not known exactly where, when, or how an attack will occur. This lack of information posses great challenges on those responsible for security, specifically, on their ability to respond fast, whenever …

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Video Content Extraction: Scene Segmentation, Linking And Attention Detection, Yun Zhai Jan 2006

Video Content Extraction: Scene Segmentation, Linking And Attention Detection, Yun Zhai

Electronic Theses and Dissertations

In this fast paced digital age, a vast amount of videos are produced every day, such as movies, TV programs, personal home videos, surveillance video, etc. This places a high demand for effective video data analysis and management techniques. In this dissertation, we have developed new techniques for segmentation, linking and understanding of video scenes. Firstly, we have developed a video scene segmentation framework that segments the video content into story units. Then, a linking method is designed to find the semantic correlation between video scenes/stories. Finally, to better understand the video content, we have developed a spatiotemporal attention detection …

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Real-Time Monocular Vision-Based Tracking For Interactive Augmented Reality, Lisa Spencer Jan 2006

Real-Time Monocular Vision-Based Tracking For Interactive Augmented Reality, Lisa Spencer

Electronic Theses and Dissertations

The need for real-time video analysis is rapidly increasing in today's world. The decreasing cost of powerful processors and the proliferation of affordable cameras, combined with needs for security, methods for searching the growing collection of video data, and an appetite for high-tech entertainment, have produced an environment where video processing is utilized for a wide variety of applications. Tracking is an element in many of these applications, for purposes like detecting anomalous behavior, classifying video clips, and measuring athletic performance. In this dissertation we focus on augmented reality, but the methods and conclusions are applicable to a wide variety …

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Modeling Autonomous Agents In Military Simulations, Varol Kaptan Jan 2006

Modeling Autonomous Agents In Military Simulations, Varol Kaptan

Electronic Theses and Dissertations

Simulation is an important tool for prediction and assessment of the behavior of complex systems and situations. The importance of simulation has increased tremendously during the last few decades, mainly because the rapid pace of development in the field of electronics has turned the computer from a costly and obscure piece of equipment to a cheap ubiquitous tool which is now an integral part of our daily lives. While such technological improvements make it easier to analyze well-understood deterministic systems, increase in speed and storage capacity alone are not enough when simulating situations where human beings and their behavior are …

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Formalizing Ontology Alignment And Its Operations With Category Theory, Antoine Zimmermann, Markus Krotzsch, Jerome Euzenat, Pascal Hitzler Jan 2006

Formalizing Ontology Alignment And Its Operations With Category Theory, Antoine Zimmermann, Markus Krotzsch, Jerome Euzenat, Pascal Hitzler

Computer Science and Engineering Faculty Publications

An ontology alignment is the expression of relations between different ontologies. In order to view alignments independently from the language expressing ontologies and from the techniques used for finding the alignments, we use a category-theoretical model in which ontologies are the objects. We introduce a categorical structure, called V-alignment, made of a pair of morphisms with a common domain having the ontologies as codomain. This structure serves to design an algebra that describes formally what are ontology merging, alignment composition, union and intersection using categorical constructions. This enables combining alignments of various provenance. Although the desirable properties of this algebra …

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Development Of A Service-Oriented Communication Platform For Heterogeneous Voice Over Ip Networks., Aisling O'Driscoll Jan 2006

Development Of A Service-Oriented Communication Platform For Heterogeneous Voice Over Ip Networks., Aisling O'Driscoll

Theses

As broadband services have become more widespread in recent years due to a variety of government initiatives and the establishment of Wireless Internet Service Providers, user requirements have evolved and the market has become more competitive. Whilst this is beneficial for consumers it means that Internet Service Providers must offer a more diverse range of services coupled with standard broadband packages to distinguish themselves from their competitors, generate new revenue and strengthen their competitive advantage. Therefore many providers are looking to Service Oriented Architectures (SOAs) to provide communication platforms, enabling services such as Voice over IP (VoIP) along with other …

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Decentralized Power Control With Implementation For Rfid Networks, Kainan Cha, Anil Ramachandran, David Pommerenke, Jagannathan Sarangapani Jan 2006

Decentralized Power Control With Implementation For Rfid Networks, Kainan Cha, Anil Ramachandran, David Pommerenke, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

In radio frequency identification (RFID) systems, the detection range and read rates will suffer from interference among high power reading devices. This problem grows severely and degrades system performance in dense RFID networks. In this paper, we investigate a suite of feasible power control schemes to ensure overall coverage area of the system while maintaining a desired read rate. The power control scheme and MAC protocol dynamically adjusts the RFID reader power output in response to the interference level seen locally during tag reading for an acceptable signal-to-noise ratio (SNR). We present novel distributed adaptive power control (DAPC) and probabilistic …

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Distributed Power Control For Cellular Networks In The Presence Of Channel Uncertainties, Maciej Jan Zawodniok, Q. Shang, Jagannathan Sarangapani Jan 2006

Distributed Power Control For Cellular Networks In The Presence Of Channel Uncertainties, Maciej Jan Zawodniok, Q. Shang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel distributed power control (DPC) scheme for cellular network in the presence of radio channel uncertainties such as path loss, shadowing, and Rayleigh fading is presented. Since these uncertainties can attenuate the received signal strength and can cause variations in the received Signal-to-Interference ratio (SIR), a new DPC scheme, which can estimate the slowly varying channel uncertainty, is proposed so that a target SIR at the receiver can be maintained. Further, the standard assumption of a constant interference during a link's power update used in other works in the literature is relaxed. A CDMA-based cellular network …

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An Experience On Problem Based Learning In An Engineering Faculty, Cüneyt Güzeli̇ş Jan 2006

An Experience On Problem Based Learning In An Engineering Faculty, Cüneyt Güzeli̇ş

Turkish Journal of Electrical Engineering and Computer Sciences

In 2001, Engineering Faculty of Dokuz Eylül University has started to change its undergraduate education in a radical way. As being among the first examples in the world, the Departments of Electrical and Electronics, Geological and Geophysics Engineering in 2002 and Mining Engineering Department in 2003 have adopted the so-called "modular-staged problem based active learning system". The system is based on real engineering problems which values teamwork and the integration of information from different disciplines and it places the student at the center of the learning process. The faculty has learned many things and it needs to learn many other …

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An International Dialogue On Electrical Engineering Education, Thales Papazoglou Jan 2006

An International Dialogue On Electrical Engineering Education, Thales Papazoglou

Turkish Journal of Electrical Engineering and Computer Sciences

. PAPAZOGLOU Chairman -- ELCOMPEET'04 Technological Educational Institute of Crete, GREECE e-mail: [email protected]

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Online Learning Resource For Smooth Transition From High School To Engineering Education, Riadh W. Y. Habash, Christine Suurtaam, Mustapha C. E. Yagoub, Karima Kara, Ghanim Ibrahim Jan 2006

Online Learning Resource For Smooth Transition From High School To Engineering Education, Riadh W. Y. Habash, Christine Suurtaam, Mustapha C. E. Yagoub, Karima Kara, Ghanim Ibrahim

Turkish Journal of Electrical Engineering and Computer Sciences

Although high school mathematics curriculum documents in Ontario, Canada have, for the past two decades, made calls for classroom practices involving both modeling and applications, students still experience difficulties in moving into a university engineering program. This paper discusses a new initiative in online learning and the teaching of mathematical modeling and applications in engineering education at the University of Ottawa, Canada. In particular, we explore how modeling and Internet technologies can enhance progress in engineering education.

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Perceptually Meaningful Image Editing: Depth, Reynold J. Bailey, Cindy Grimm Jan 2006

Perceptually Meaningful Image Editing: Depth, Reynold J. Bailey, Cindy Grimm

All Computer Science and Engineering Research

We introduce the concept of perceptually meaningful image editing and present two techniques for manipulating the apparent depth of objects in an image. The user loads an image, selects an object and specifies whether the object should appear closer or further away. The system automatically determines target values for the object and/or background that achieve the desired depth change. These depth editing operations, based on techniques used by traditional artists, manipulate either the luminance or color temperature of different regions of the image. By performing blending in the gradient domain and reconstruction with a Poisson solver, the appearance of false …

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Design Of A Diversified Network Substrate, Jonathan Turner Jan 2006

Design Of A Diversified Network Substrate, Jonathan Turner

All Computer Science and Engineering Research

A diversified network substrate enables multiple end-to-end metanetworks to co-exist within a shared physical infrastructure. Metanetworks are implemented by metarouters, hosted by substrate routers, and metarouters are connected by metalinks. The substrate allocates resources (both link bandwidth and processing resources) to metarouters based on advance reservations received from metanetwork planning systems. It also enables dynamic creation of access metalinks, connecting end systems to metarouters, and supports mobility of end systems under the control of their metanetworks. This report defines a model for a diversified internet and presents a detailed design of the substrate that enables metanetworks to co-exist. The design …

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Mobiwork: Mobile Workflow For Manets, Gregory Hackmann, Rohan Sen, Mart Haitjema, Gruia-Catalin Roman, Gill Jan 2006

Mobiwork: Mobile Workflow For Manets, Gregory Hackmann, Rohan Sen, Mart Haitjema, Gruia-Catalin Roman, Gill

All Computer Science and Engineering Research

The workflow model is well suited for scenarios where many entities work collaboratively towards a common goal, and is used widely today to model complex business processes. However, the fundamental workflow model is very powerful and can be applied to a wider variety of application domains. This paper represents an initial investigation into the possibility of using workflows to model collaboration in an ad hoc mobile environment. Moving to a mobile setting introduces many challenges as the mobility of the participants in a workflow imposes constraints on allocation of workflow tasks, coordination among participants, and marshaling of results. We present …

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Discovering Weak Community Structures In Large Biological Networks , Jianhua Ruan, Weixiong Zhang Jan 2006

Discovering Weak Community Structures In Large Biological Networks , Jianhua Ruan, Weixiong Zhang

All Computer Science and Engineering Research

Identifying intrinsic structures in large networks is a fundamental problem in many fields, such as biology, engineering and social sciences. Motivated by biology applications, in this paper we are concerned with identifying community structures, which are densely connected sub-graphs, in large biological networks. We address several critical issues for finding community structures. First, biological networks directly constructed from experimental data often contain spurious edges and may also miss genuine connections. As a result, community structures in biological networks are often weak. We introduce simple operations to capture local neighborhood structures for identifying weak communities. Second, we consider the issue of …

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Design And Evaluation Of A Blast Ungapped Extension Accelerator, Master's Thesis, Joseph M. Lancaster Jan 2006

Design And Evaluation Of A Blast Ungapped Extension Accelerator, Master's Thesis, Joseph M. Lancaster

All Computer Science and Engineering Research

The amount of biosequence data being produced each year is growing exponentially. Extracting useful information from this massive amount of data is becoming an increasingly difficult task. This thesis focuses on accelerating the most widely-used software tool for analyzing genomic data, BLAST. This thesis presents Mercury BLAST, a novel method for accelerating searches through massive DNA databases. Mercury BLAST takes a streaming approach to the BLAST computation by offloading the performance-critical sections onto reconfigurable hardware. This hardware is then used in combination with the processor of the host system to deliver BLAST results in a fraction of the time of …

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Activepdf-Toolk, Washington University In St. Louis Computer Science Engineering Department Jan 2006

Activepdf-Toolk, Washington University In St. Louis Computer Science Engineering Department

All Computer Science and Engineering Research

This document provides information for deploying activePDF Toolkit Professional in a development environment. This document is organized into four sections: Getting Started, Tutorials, Technical Reference and the Toolkit Appendices. The Getting Started section covers setup and installation, includes a product overview and information related to operating Toolkit Professional. Tutorials includes examples of many Toolkit features, including PDF generation and form filling. All of the tutorials can be used with activePDF Toolkit. Technical Reference provides detailed information on Toolkit’s objects, subobjects, methods and properties.

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Fast Packet Classification Using Bloom Filters, Sarang Dharmapurikar, Haoyu Song, Jonathan Turner, John Lockwood Jan 2006

Fast Packet Classification Using Bloom Filters, Sarang Dharmapurikar, Haoyu Song, Jonathan Turner, John Lockwood

All Computer Science and Engineering Research

While the problem of general packet classification has received a great deal of attention from researchers over the last ten years, there is still no really satisfactory solution. Ternary Content Addressable Memory (TCAM), although widely used in practice, is both expensive and consumes a lot of power. Algorithmic solutions, which rely on commodity memory chips, are relatively inexpensive and power-efficient, but have not been able to match the generality and performance of TCAMs. In this paper we propose a new approach to packet classification, which combines architectural and algorithmic techniques. Our starting point is the well-known crossproducting algorithm, which is …

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Smooth Surface Reconstruction Using Charts For Medical Data, Cindy Grimm, Tao Ju Jan 2006

Smooth Surface Reconstruction Using Charts For Medical Data, Cindy Grimm, Tao Ju

All Computer Science and Engineering Research

We present a surface reconstruction technique that constructs a smooth analytic surface from scattered data. The technique is robust to noise and both poorly and non-uniformly sampled data, making it well-suited for use in medical applications. In addition, the surface can be parameterized in multiple ways, making it possible to represent additional data, such as electromagnetic potential, in a different (but related) coordinate system to the geometric one. The parameterization technique also supports consistent parameterizations of multiple data sets.

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An Improved Analysis For A Greedy Remote-Clique Algorithm Using Factor-Revealing Lps, Benjamin E. Birnbaum, Kenneth J. Goldman Jan 2006

An Improved Analysis For A Greedy Remote-Clique Algorithm Using Factor-Revealing Lps, Benjamin E. Birnbaum, Kenneth J. Goldman

All Computer Science and Engineering Research

Given a complete graph with nonnegative edge weights satisfying the triangle inequality and a positive integer p, the remote-clique problem is to find a subset of p vertices having a maximum-weight induced subgraph. A simple greedy algorithm for the problem has been shown to have an approximation ratio of 4, but a tight example has not been provided. In this paper, we use the technique of factor revealing linear programs to prove that this algorithm actually achieves an approximation ratio of 2, matching the best-known ratio for the problem. The greedy algorithm's running time of O(pn) makes it the fastest …

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The Design, Modeling, And Implementation Of Group Scheduling For Isolation Of Computations From Adversarial Interference, Terry Tidwell, Noah Watkins, Venkita Subramonian, Douglas Niehaus, Armando Gill, Migliaccio Jan 2006

The Design, Modeling, And Implementation Of Group Scheduling For Isolation Of Computations From Adversarial Interference, Terry Tidwell, Noah Watkins, Venkita Subramonian, Douglas Niehaus, Armando Gill, Migliaccio

All Computer Science and Engineering Research

To isolate computations from denial of service (DoS) attacks and other forms of adversarial interference, it is necessary to constrain the effects of interactions among computations. This paper makes four contributions to research on isolation of computations from adversarial interference: (1) it describes the design and implementation of a kernel level scheduling policy to control the effects of adversarial attacks on computations’ execution; (2) it presents formal models of the system components that are involved in a representative DoS attack scenario; (3) it shows how model checking can be used to analyze that example scenario, under default Linux scheduling semantics …

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Efficient Mapping Of Virtual Networks Onto A Shared Substrate, Jing Lu, Jonathan Turner Jan 2006

Efficient Mapping Of Virtual Networks Onto A Shared Substrate, Jing Lu, Jonathan Turner

All Computer Science and Engineering Research

Virtualization has been proposed as a vehicle for overcoming the growing problem of internet ossification [1]. This paper studies the problem of mapping diverse virtual networks onto a common physical substrate. In particular, we develop a method for mapping a virtual network onto a substrate network in a cost-efficient way, while allocating sufficient capacity to virtual network links to ensure that the virtual network can handle any traffic pattern allowed by a general set of traffic constraints. Our approach attempts to find the best topology in a family of backbone-star topologies, in which a subset of nodes constitute the backbone, …

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Adaptive Embedded Roadmaps For Sensor Networks, Gazihan Alankus, Nuzhet Atay, Chenyang Lu, Burchan Bayazit Jan 2006

Adaptive Embedded Roadmaps For Sensor Networks, Gazihan Alankus, Nuzhet Atay, Chenyang Lu, Burchan Bayazit

All Computer Science and Engineering Research

In this paper, we propose a new approach to wireless sensor network assisted navigation while avoiding moving dangers. Our approach relies on an embedded roadmap in the sensor network that always contains safe paths. The roadmap is adaptive, i.e., it adapts its topology to changing dangers. The mobile robots in the environment uses the roadmap to reach their destinations. We evaluated the performance of embedded roadmap both in simulations using realistic conditions and with real hardware. Our results show that the proposed navigation algorithm is better suited for sensor networks than traditional navigation field based algorithms. Our observations suggest that …

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A Theory Of Load Adjustments And Its Implications For Congestion Control, Sergey Gorinsky, Manfred Georg, Maxim Podlesny, Christoph Jechlitschek Jan 2006

A Theory Of Load Adjustments And Its Implications For Congestion Control, Sergey Gorinsky, Manfred Georg, Maxim Podlesny, Christoph Jechlitschek

All Computer Science and Engineering Research

Multiplicative Increase (MI), Additive Increase (AI), and Multiplicative Decrease (MD) are linear adjustments used extensively in networking. However, their properties are not fully understood. We analyze responsiveness (time for the total load to reach the target load), smoothness (maximal size of the total load oscillations after reaching the target load), fairing speed (speed of convergence to equal individual loads) and scalabilities of MAIMD algorithms, which generalize AIMD algorithms via optional inclusion of MI. We prove that an MAIMD can provide faster asymptotic fairing than a less smooth AIMD. Furthermore, we discover that loads under a specific MAIMD converge from any …

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Sliver: A Bpel Workflow Process Execution Engine For Mobile Devices, Gregory Hackmann, Mart Haitjema, Christopher Gill, Catalin-Gruia Roman Jan 2006

Sliver: A Bpel Workflow Process Execution Engine For Mobile Devices, Gregory Hackmann, Mart Haitjema, Christopher Gill, Catalin-Gruia Roman

All Computer Science and Engineering Research

The Business Process Execution Language (BPEL) has become the dominant means for expressing traditional business processes as workflows. The widespread deployment of mobile devices like PDAs and mobile phones has created a vast computational and communication resource for these workflows to exploit. However, BPEL so far has been deployed only on relatively heavyweight server platforms such as Apache Tomcat, leaving the potential created by these lower-end devices untapped. This paper presents Sliver, a BPEL workflow process execution engine that supports a wide variety of devices ranging from mobile phones to desktop PCs. We discuss the design decisions that allow Sliver …

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Multimodal Congestion Control For Low Stable-State Queuing, Maxim Podlesny, Sergey Gorinsky Jan 2006

Multimodal Congestion Control For Low Stable-State Queuing, Maxim Podlesny, Sergey Gorinsky

All Computer Science and Engineering Research

To discover an efficient fair sending rate for a flow, Transmission Control Protocol (TCP) saturates the bottleneck link and its buffer until the router discards a packet. Such TCP-caused queuing is detrimental for interactive and other delay-sensitive applications. In this paper, we present Multimodal Control Protocol (MCP) which strives to maintain low queues and avoid congestion losses at network links. The multimodal MCP engages routers and hosts in limited explicit communication. A distinguishing property of MCP is stable transmission after converging to efficient fair states. To ensure convergence to fairness, MCP incorporates an innovative mechanism that enables a flow to …

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A Comprehensive Analysis Of The Effect Of Microarray Data, Monika Ray, Johannes Freudenberg, Weixiong Zhang Jan 2006

A Comprehensive Analysis Of The Effect Of Microarray Data, Monika Ray, Johannes Freudenberg, Weixiong Zhang

All Computer Science and Engineering Research

Background: Microarray data preprocessing, such as differentially expressed (DE) genes selection, is performed prior to higher level statistical analysis in order to account for technical variability. Preprocessing for the Affymetrix GeneChip includes background correction, normalisation and summarisation. Numerous preprocessing methods have been proposed with little consensus as to which is the most suitable. Furthermore, due to poor concordance among results from cross-platform analyses, protocols are being developed to enable cross-platform reproducibility. However, the effect of data analysis on a single platform is still unknown. The objective of our study is two-fold: first to determine whether there is consistency in the …

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