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2001

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Articles 1501 - 1530 of 1795

Full-Text Articles in Engineering

An Integrated Design-Object Modeling Environment -- Pluggable Metamodel Mechanism --, Masaharu Yoshioka, Takayuki Sekiya, Tetsuo Tomiyama Jan 2001

An Integrated Design-Object Modeling Environment -- Pluggable Metamodel Mechanism --, Masaharu Yoshioka, Takayuki Sekiya, Tetsuo Tomiyama

Turkish Journal of Electrical Engineering and Computer Sciences

We propose a new integrated computational environment to support design object modeling, during engineering design process that requires a variety of design object models, such as a geometric model, a control model, and a finite element model. To integrate multiple design object models, we have developed a mechanism called a metamodel mechanism that maintains consistency among various models. The metamodel mechanism represents relationships among concepts used in these models and is useful, for example, to conduct concurrent engineering practices. In this framework, we formalize a design process as operations to the metamodel. This paper expands the concept of the metamodel …

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Combining Multiple Representations For Pen-Based Handwritten Digit Recognition, Fevzi̇ Ali̇moğlu, Ethem Alpaydin Jan 2001

Combining Multiple Representations For Pen-Based Handwritten Digit Recognition, Fevzi̇ Ali̇moğlu, Ethem Alpaydin

Turkish Journal of Electrical Engineering and Computer Sciences

We investigate techniques to combine multiple representations of a handwritten digit to increase classification accuracy without significantly increasing system complexity or recognition time. In pen-based recognition, the input is the dynamic movement of the pentip over the pressure sensitive tablet. There is also the image formed as a result of this movement. On a real-world database of handwritten digits containing more than 11,000 handwritten digits, we notice that the two multi-layer perceptron (MLP) based classifiers using these representations make errors on different patterns implying that a suitable combination of the two would lead to higher accuracy. We implement and compare …

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Placing Servers For Session-Oriented Services, Sumi Choi, Yuval Shavitt Jan 2001

Placing Servers For Session-Oriented Services, Sumi Choi, Yuval Shavitt

All Computer Science and Engineering Research

The provisioning of dynamic forms of services is becoming the main stream of today's network. In this paper, we focus on services assisted by network servers and different forms of associated sessions. We identify two types of services: transparent, where the session is unaware of the server location, and configurable, where the sessions need to be configured to use their closest server. For both types we formalize the problem of optimally placing network servers and introduce approximated solutions. We present simulation result of approximations and heuristics. We also solve the location problem optimally for a special topology. We show, through …

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The Fpx Kcpsm Module: An Embedded, Reconfigurable Active Processing Module For The Field Programmable Port Extender (Fpx), Henry Fu, John W. Lockwood Jan 2001

The Fpx Kcpsm Module: An Embedded, Reconfigurable Active Processing Module For The Field Programmable Port Extender (Fpx), Henry Fu, John W. Lockwood

All Computer Science and Engineering Research

While hardware plugins are well suited for processing data with high throughput, software plugins are well suited for implementing complex control functions. A plugin module has been implemented for the FPX that executes software on an embedded soft-core processor. By including this module in an FPX design, it is possible to implement active networking functions on the FPX using both hardware and software. The KCPSM, an 8-bit microcontroller developed by Xilinx Corp., has been embedded into an FPX module. The module includes circuits to be reprogrammed over the network and to execute new programs between the processing of data packerts. …

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Fuzzycast: Media Broadcasting For Multiple Asynchronous Receivers, Marcel Waldvogel, Wei Deng, Ramaprabhu Janakiraman Jan 2001

Fuzzycast: Media Broadcasting For Multiple Asynchronous Receivers, Marcel Waldvogel, Wei Deng, Ramaprabhu Janakiraman

All Computer Science and Engineering Research

When using an on-demand media streaming system on top of a network with Multicast support, it is sometimes more efficient to use broadcast to distribute popular content. There has been a lot of research in broadcasting on-demand content to multiple, asynchronous receivers. In this paper, we propose a family of novel, practical techniques for broadcasting on-demand media, which achieve lowest known server/network bandwidth usage and I/O efficient client buffer management, while retaining the simplicity of a frame-based single channel scheme.

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Fast Incremental Crc Updates For Ip Over Atm Networks, Florian Braun, Marcel Waldvogel Jan 2001

Fast Incremental Crc Updates For Ip Over Atm Networks, Florian Braun, Marcel Waldvogel

All Computer Science and Engineering Research

In response to the increasing network speeds, many operations in IP routers and similar devices are being made more efficient. With the advances in other areas of packet processing, the verification and regeneration of cyclic redundancy check (CRC) codes of the data link layer is likely to become a bottleneck in the near future. In this paper, we present a mechanism to defer CRC verification without compromising reliability. This opens the possibility of incremental updates of the CRC. We introduce a new high-speed technique and present efficient implementation, speeding up CRC processing by a factor of 15. Although the paper …

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The Smart Port Card: An Embedded Unix Processor Architecture For Network Management And Active Networking, John D. Dehart, William D. Richard, Edward W. Spitznagel, David E. Taylor Jan 2001

The Smart Port Card: An Embedded Unix Processor Architecture For Network Management And Active Networking, John D. Dehart, William D. Richard, Edward W. Spitznagel, David E. Taylor

All Computer Science and Engineering Research

This paper describes the architecture of the Smart Port Card (SPC) designed for use with the Washington University Gigabit Switch. The SPC uses an embedded Intel Pentium processor running open-source NetBSD to support network management and active networking applications. The SPC physically connects between a switch port and a normal link adapter, allowing cell streams to be processed as they enter or leave the switch. In addition to the hardware architecture, this paper describes current and future applications for the SPC.

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Evaluation Of Motion-Jpeg2000 For Video Processing, Wei Yu, Ruibiao Qiu, Jason Fritts Jan 2001

Evaluation Of Motion-Jpeg2000 For Video Processing, Wei Yu, Ruibiao Qiu, Jason Fritts

All Computer Science and Engineering Research

The new ISO/ITU-T standard for still image coding, JPEG2000, has been shown to provide superior coding efficiency to the previous standard, JPEG. Because of the superb performance of JPEG2000, it is reasonable to argue that Motion-JPEG2000, the corresponding moving picture coding standard of JPEG2000, has equally outstanding performance. However, there has not been a sufficient performance evaluation of Motion-JPEG2000. To this end, we have studied the potential of Motion-JPEG2000 for video processing. Our experiments show that Motion-JPEG2000 provides high compression performance, strong error resilience, and good perceptual image quality. Together with a rich set of features inherited from JPEG2000, Motion-JPEG2000 …

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Performance Of Deferred Reservations In Data Networks, Samphel Norden, Jonathan Turner Jan 2001

Performance Of Deferred Reservations In Data Networks, Samphel Norden, Jonathan Turner

All Computer Science and Engineering Research

This paper studies the performance of deferred resource reservation in data networks. Conventional resource reservation protocols, such as PNNI and RSVP adopt an all-or-nothing approach, where partially acquired resources must be released if resources are not available at all links on the chosen path. During periods of high network load, this leads users to retry requests repeatedly, adding control traffic at exactly the time when the network's capacity to process that control traffic is exhausted. Deferred REServation (DRES) can significantly improve performance by reducing the overall call rejection probability, allowing more traffic to be carried, using the same resources. Call …

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An Efficient Quality Scalable Motion-Jpeg2000 Transmission Scheme, Ruibiao Qiu, Wei Yu Jan 2001

An Efficient Quality Scalable Motion-Jpeg2000 Transmission Scheme, Ruibiao Qiu, Wei Yu

All Computer Science and Engineering Research

Video application over the Internet are getting increasingly popular because of the explosive growth of the Internet. However, video packets loss due to network congestions can degrade the video quality substantially. In this paper, we propose a transmission scheme for Motion-JPEG2000. It can be implemented in an active network environment efficiently. Our simulation shows that our scheme gracefully adapts to network congestion and improves the quality of video transmission in congested IP networks.

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Embedding Images In Non-Flat Spaces, Robert Pless Jan 2001

Embedding Images In Non-Flat Spaces, Robert Pless

All Computer Science and Engineering Research

Multi-dimensional scaling is an analysis tool which transforms pairwise distances between points to an embedding of points in space which are consistent with those distances. Two recent techniques in statistical patter recognition, locally linear embedding (LLE) and Isomap, give a mechanism for finding the structure underlying point sets for which comparisons or distances are only meaningful between nearby points. We give a direct method to extend the embedding algorithm to new topologies, finding the optimal embedding of points whose geodesic distance on a surface mathes the given pairwise distance measurements. Surfaces considered include spheres, cylinders, tori, and their higher dimensional …

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A Termination Detection Protocol For Use In Mobile Ad Hoc Networks, Gruia-Catalin Roman, Jamie Payton Jan 2001

A Termination Detection Protocol For Use In Mobile Ad Hoc Networks, Gruia-Catalin Roman, Jamie Payton

All Computer Science and Engineering Research

As computing devices become smaller and wireless networking technologies improve, the popularity of mobile computing continues to rise. In today's business world, many consider devices such as cell phones, PDAs, and laptops as essential tools. As these and other devices become increasingly independent of the wired infrastructure, new kinds of applications that assume an ad hoc network infrastructure will need to be deployed. Such a setting poses new challenges for the software developer, e.g., the lack of an established network topology, bandwidth limitations, and frequent disconnections. In this paper, we begin to explore design strategies for developing applications over ad …

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Parbit: A Tool To Transform Bitfiles To Implement Partial Reconfiguration Of Field Programmable Gate Arrays (Fpgas), Edson L. Horta, John W. Lockwood Jan 2001

Parbit: A Tool To Transform Bitfiles To Implement Partial Reconfiguration Of Field Programmable Gate Arrays (Fpgas), Edson L. Horta, John W. Lockwood

All Computer Science and Engineering Research

Field Programmable Gate Arrays (FPGAs) can be partially reconfigured to implement Dynamically loadable Hardware Plugin (DHP) modules. A tool called PARBIT has been developed that transforms FPGA configuration bitfiles to enable DHP modules. With this tool it is possible to define a partial reconfigurable area inside the FPGA and download it into a specified region of the FPGA device. One or more DHPs, with different sizes can be implemented using PARBIT.

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Relying On Safe Distance To Ensure Consistent Group Membership In Ad Hoc Networks, Qingfeng Huang, Christine Julien, Gruia-Catalin Roman, Ali Hazemi Jan 2001

Relying On Safe Distance To Ensure Consistent Group Membership In Ad Hoc Networks, Qingfeng Huang, Christine Julien, Gruia-Catalin Roman, Ali Hazemi

All Computer Science and Engineering Research

The design of ad hoc mobile applications often requires the availability of a consistent view of the application state among the participating hosts. Such views are important because they simplify both the programming and verification tasks. Essential to constructing a consitent view is the ability to know what hosts are within proximity of each other, i.e., form a group in support of the particular application. In this paper we propose a protocol that allows hosts within communication range to maintain a consistent view of the group membership despite movement and frequent disconnections. The novel features of this protocol are its …

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Scheduling Processing Resources In Programmable Routers, Prashanth Pappu, Tilman Wolf Jan 2001

Scheduling Processing Resources In Programmable Routers, Prashanth Pappu, Tilman Wolf

All Computer Science and Engineering Research

To provide flexibility in deploying new protocols and services, general-purpose processing engines are being placed in the datapath of routers. Such network processors are typically simple RISC multiprocessors that perform forwarding and custom application processing of packets. The inherent unpredictability of execution time of arbitrary instruction code poses a significant challenge in providing QoS guarantees for data flows that compete for such processing resources in the network. However, we show that network processing workloads are highly regular and predictable. Using estimates of execution times of various applications on packets of given lengths, we provide a method for admission control and …

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Design Of Wavelength Converting Switches For Optical Burst Switching, Jeyashankher Ramamirtham, Jonathan Turner Jan 2001

Design Of Wavelength Converting Switches For Optical Burst Switching, Jeyashankher Ramamirtham, Jonathan Turner

All Computer Science and Engineering Research

Optical Burst Switching (OBS) is an experimental network technology that enables the construction of very high capacity routers, using optical data paths and electronic control. In this paper, we study two designs for wavelength converting switches that are suitable for use in optical burst switching systems and evaluate their performance. Both designs use tunable lasers to implement wavelength conversion. One is strictly nonblocking design, that also requires optical crossbars. The second substitutes Wavelength Grating Routers (WGR) for the optical crossbars, reducing cost, but introducing some potential for blocking. We show how the routing problem for the WGR-based switches can be …

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Test 1789: John Deere 9200 24 & 12 Speed, Nebraska Tractor Test Lab Jan 2001

Test 1789: John Deere 9200 24 & 12 Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

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Solubilization Of Fe(Iii) Oxide-Bound Trace Metals By A Dissimilatory Fe(Iii) Reducing Bacterium, John M. Zachara, James K. Fredrickson, Steven Smith, Paul Gassman Jan 2001

Solubilization Of Fe(Iii) Oxide-Bound Trace Metals By A Dissimilatory Fe(Iii) Reducing Bacterium, John M. Zachara, James K. Fredrickson, Steven Smith, Paul Gassman

United States Department of Energy: Publications

Trace metals associate with Fe(III) oxides as adsorbed or coprecipitated species, and consequently, the biogeochemical cycles of iron and the trace metals are closely linked. This communication investigated the solubilization of coprecipitated Co(III) and Ni(II) from goethite (α-FeOOH) during dissimilatory bacterial iron reduction to provide insights on biogeochemical factors controlling trace-element fluxes in anoxic environments. Suspensions of homogeneously substituted Co-FeOOH (50 mmol/L as Co0.01Fe0.99OOH; 57Co-labeled) in eight different buffer/media solutions were inoculated with a facultative, metal-reducing bacteria isolated from groundwater (Shewanella putrefacians CN32), and incubated under strictly anaerobic conditions for periods up to 32 …

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Graduate Catalog 2001-2002 The Graduate School Of Computer And Information Sciences, Nova Southeastern University Jan 2001

Graduate Catalog 2001-2002 The Graduate School Of Computer And Information Sciences, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.

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Local Search And Encoding Schemes For Soft Constraint Minimization Problems, Michael P. Moran, Weixiong Zhang Jan 2001

Local Search And Encoding Schemes For Soft Constraint Minimization Problems, Michael P. Moran, Weixiong Zhang

All Computer Science and Engineering Research

Soft constraint minimization problems (SCMPs) contain hard constraints that cannot be violated and soft constraints that may be violated but carry penalties if not satisfied. In this paper, we first extend local search, WalkSAT in particular, to SCMPs and study the existing SAT encoding schemes for SCMPs. We propose a general encoding method called k-encoding. We then investigate the effects of local search neiborhood structures introduced by encoding schemes and analyze the anytime performance of extended WalkSAT using different encoding methods. Our experimental results on various graph coloring problems show that a direct extension of WalkSAT is most effective, and …

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Aggregated Hierarchical Multicast For Active Networks, Tilman Wolf, Sumi Y. Choi Jan 2001

Aggregated Hierarchical Multicast For Active Networks, Tilman Wolf, Sumi Y. Choi

All Computer Science and Engineering Research

Active Networking is the basis for a range of new and innovative applications that make use of computational resources inside network routers. One such application is Aggregated Hierarchical Multicast, which aims at implementing efficient many-to-many communication. In certain scenarios it is possible to transmit less accurate, aggregated data and thus achieve better scalability. Using Active Networks, this aggregation computation can be done transparently by network routers without end system support. We present how aggregated data streams can be structured in a hierarchical fashion to allow easy access of data at the desired aggregation level. We introduce two application examples to …

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A Distributed Annotation System, Robin Dowell Jan 2001

A Distributed Annotation System, Robin Dowell

All Computer Science and Engineering Research

One goal of any genome project is the elucidation of hte primary sequence of DNA contained within a given species. While the availability ot the primary sequence itself is valuable, it does not reach its full potential until i has been annotated. Generally defined, annotation is descriptive information or commentary added to text, in this case genomic sequence. Without a mechanism for collecting, recording, and disseminating community-based annotation, a valuable source of information is severely diminshed. In this report I outline the design and implementation of a Distributed Annotation System (DAS). DAS allowes sequence annotations to be decentralized among multiple …

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Phase Transitions And Backbones Of Constraint Minimization Problems, Weixiong Zhang Jan 2001

Phase Transitions And Backbones Of Constraint Minimization Problems, Weixiong Zhang

All Computer Science and Engineering Research

Many real-world problems involve constraints that cannot be all satisfied. The goal toward an overconstrained problem is to find solutions minimizing the total number of constraints violated. We call such a problem constraint minimization problem (CMP). We study the behavior of the phase transitions and backbones of CMP. We first investigate the relationship between the phase transitions of Boolean satisfiability, or precisely 3-SAT (a well-studied NP-complete decision problem), and the phase transitions of MAX 3-SAT (an NP-hard optimization problem). To bridge the gap between the easy-hard-easy phase transitions of 3-SAT, in which solutions of bounded quality, e.g., solutions with at …

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A Proposal For A Scalable Internet Multicast Architecture, Sherlia Shi Jan 2001

A Proposal For A Scalable Internet Multicast Architecture, Sherlia Shi

All Computer Science and Engineering Research

We propose a new network and system architecture for multicast in the Internet. Our main objectives are to find a cost-effective way to scale to a large number of multicast groups whose members are geographically dispersed, and to enable small and less capable devices to participate in group communications. In order to preserve the efficiency of data distribution gained by multicast, while avoiding the control complexity previously exhibited by IP multicast, we propose the use of an overlay network for multicast services. We construct "virtual" multicast trees, which consist of unicast connections joining multicast servers in the network. These servers …

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Indra: A Distributed Approach To Network Intrusion Detection And Prevention, Qi Zhang, Ramaprabhu Janakiraman Jan 2001

Indra: A Distributed Approach To Network Intrusion Detection And Prevention, Qi Zhang, Ramaprabhu Janakiraman

All Computer Science and Engineering Research

While advances in computer and communications technology have made the network ubiquitous, they ahve also rendered networked systems vulnerable to malicious attacks orchestrated from a distance. These attacks, usually called cracker attacks or intrusions, start with crackers infiltrating a network through a vulnerable host and then going on to launch further attacks. Crackers depend on increasingly sophisticated techniques like using distributed attack sources. On the other hand, software that guards against them remains rooted in traditional centralized techniques, presenting an easily-targetable single point of failure. Scalable, distributed network intrusion prevention software is sorely needed. We propose Indra - a distributed …

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Formal Specification And Design Of Mobile Systems, Gruia-Catalin Roman, Christine Julien, Qingfeng Huang Jan 2001

Formal Specification And Design Of Mobile Systems, Gruia-Catalin Roman, Christine Julien, Qingfeng Huang

All Computer Science and Engineering Research

Termination detection, a classical problem in distributed computing, is revisited in the new setting provided by the emerging mobile computing technology. A simple solution tailored for use in ad hoc networks is employed as a vehicle for demonstrating the applicability of formal requirements and design strategies to the new field of mobile computing. The approach is based on well understood techniquest in specification refinement, but the methodology is tailored to mobile applications and helps designers address novel concerns such as the mobility of hosts, transient interactions, and specific coordination constructs. The proof logic and programming notation of Mobile UNITY provide …

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Rad Module Infrastructure Of The Field-Programmable Port Extender (Fpx) Version 2.0, David E. Taylor, John W. Lockwood, Naji Naufel Jan 2001

Rad Module Infrastructure Of The Field-Programmable Port Extender (Fpx) Version 2.0, David E. Taylor, John W. Lockwood, Naji Naufel

All Computer Science and Engineering Research

The Field-programmable Port eXtender (FPX) provides dynamic, fast, and flexible mechanisms to process data streams at the ports of the Washington University Gigabit Switch (WUGS-20). In order to facilitate the design and implementation of portable hardware modules for the Reprogrammable Application Device (RAD) on the FPX board, infrastructure components have been developed. These components abstract application module designers from device-specific timing specifications of off-chip memory devices, as well as processing system-level control cells. This document describes the design and internal functionality of the infrastructure components and is intended as a reference for future component revisions and additions. Application module designers …

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Relationship Between Two Generalized Images For Discrete And Differential Camera Motions, Robert Pless Jan 2001

Relationship Between Two Generalized Images For Discrete And Differential Camera Motions, Robert Pless

All Computer Science and Engineering Research

The recent popularity of catadioptic and multi-camera imaging systems indicates a need to create formal models for general, non-perspective camera geometries. Development of algorithmic tools for interpreting images from a generalized camera model will lead to a better understanding of how to design camera systems for particular tasks. Here we define the corollary to epi-polar constraints for standard cameras - the relationship between two images of a scene taken by generalized cameras from viewpoints related by discrete or differential motions.

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Legends As A Device For Interacting With Visualizations, Mihail E. Tudoreanu, Eileen Kraemer Jan 2001

Legends As A Device For Interacting With Visualizations, Mihail E. Tudoreanu, Eileen Kraemer

All Computer Science and Engineering Research

Users and developers of visualization tools must deal with the problem of specifying what information to show and how to represent it. Typically, the user's focus of interest will change over time, and the specifications must change with the user's interests. Techniques for the simple, direct, and intuitive creation and refinement of these specifications can be useful. In this paper we show how legends, a natural element of graphical displays, may be used as a direct and unobstrusive interaction device through which users may interactively specify new visualizations and animations.

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Services Provision In Ad Hoc Networks, Radu Handorean, Gruia-Catalin Roman Jan 2001

Services Provision In Ad Hoc Networks, Radu Handorean, Gruia-Catalin Roman

All Computer Science and Engineering Research

The client-server model continues to dominate distributed computing with increasingly more flexible variants being deployed. Many are centered on the notion of discovering services at run time and on allowing any system component to act as a service provider. The result is a growing reliance on the service registration and discovery mechanisms. This paper addresses the issue of facilitating such service provision capabilities in the presence of (logical and physical) mobility exhibited by applications executing over ad hoc networks. The solution being discussed entailes a new kind of service model, which we were able to build as an adaption layer …

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