Computer Engineering Commons^™

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.

Network Abstractions For Context-Aware Mobile Computing, Gruia-Catalin Roman, Christine Julien, Qingfeng Huang

All Computer Science and Engineering Research

Context-Aware computing is characterized by the ability of a software system to continuously adapt its behavior to a changing environment over which it has little or no control. Previous work along these lines presumed a rather narrow definition of context, one that was centered on resources immediately available to the component in question, e.g., communication bandwidth, physical location, etc. This paper explores context-aware computing in the setting of ad hoc networks consisting of numerous mobile hosts that interact with each other opportunistically via transient wireless interconnections. We extend the context to encompass awareness of an entire neighborhood within the ad …

Synthesizable Design Of A Multi-Module Memory Controller, Sarang Dharmapurikar, John W. Lockwood

All Computer Science and Engineering Research

Random Access Memory (RAM) is a common resources needed by networking hardware modules. Synchronous Dynamic RAM (SDRAM) provides a cost effective solution for such data storage. As the packet processing speeds in the hardware increase memory throughput can be a bottleneck to achieve overall high performance. Typically there are multiple hardware modules which perform different operations on the packet payload and hence all try to access the common packet buffer simultaneously. This gives rise to a need for a memory controller which arbitrates between the memory requests made by different modules and maximizes the memory throughput. This paper discusses the …

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 …

Arc - An Oai Service Provider For Digital Library Federation, Xiaoming Liu, Kurt Maly, Mohammad Zubair, Michael L. Nelson

Computer Science Faculty Publications

The usefulness of the many on-line journals and scientific digital libraries that exist today is limited by the inability to federate these resources through a unified interface. The Open Archive Initiative (OAI) is one major effort to address technical interoperability among distributed archives. The objective of OAI is to develop a framework to facilitate the discovery of content in distributed archives. In this paper, we describe our experience and lessons learned in building Arc, the first federated searching service based on the OAI protocol. Arc harvests metadata from several OAI compliant archives, normalizes them, and stores them in a search …

Smart Objects And Open Archives, Michael L. Nelson, Kurt Maly

Computer Science Faculty Publications

Within the context of digital libraries (DLs), we are making information objects "first-class citizens". We decouple information objects from the systems used for their storage and retrieval, allowing the technology for both DLs and information content to progress independently. We believe dismantling the stovepipe of "DL-archive-content" is the first step in building richer DL experiences for users and insuring the long-term survivability of digital information. To demonstrate this partitioning between DLs, archives and information content, we introduce "buckets": aggregative, intelligent, object-oriented constructs for publishing in digital libraries. Buckets exist within the "Smart Object, Dumb Archive" (SODA) DL model, which promotes …

Buckets: Smart Objects For Digital Libraries, Michael L. Nelson

Computer Science Faculty Publications

Current discussion of digital libraries (DLs) is often dominated by the merits of the respective storage, search and retrieval functionality of archives, repositories, search engines, search interfaces and database systems. While these technologies are necessary for information management, the information content is more important than the systems used for its storage and retrieval. Digital information should have the same long-term survivability prospects as traditional hardcopy information and should be protected to the extent possible from evolving search engine technologies and vendor vagaries in database management systems. Information content and information retrieval systems should progress on independent paths and make limited …

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 …

Avalanche And Bit Independence Properties For The Ensembles Of Randomly Chosen N \Times N S-Boxes, Işil Vergi̇li̇, Melek D. Yücel

Turkish Journal of Electrical Engineering and Computer Sciences

Cryptographic test methods such as avalanche, strict avalanche and bit independence criteria, which measure the degree of security of the s-boxes of substitution-permutation networks, are applied to randomly generated ensembles of ( n \times n \) s-boxes. Statistical analysis of experimental data directs the work towards defining ``relative errors'' and examining the avalanche and strict avalanche criteria within ``relative error ranges''. Histograms of relative errors in each ensemble are evaluated, and combining the results of different ensembles corresponding to different values of the s-box size, variations of maximum relative errors versus the size of the s-box are depicted. Some predictions …

A More Efficient Design And Implementation Of Cal Programs In Natural Science Using Object-Oriented Technology, Jurgen Friedrich

Turkish Journal of Electrical Engineering and Computer Sciences

With the amount and complexity of science topics and applications increasing, the need for appropriate and effective science education is constantly growing. Computer-based education is very promising to help both teachers and learners in their difficult task, which involves complex psychological processes. This complexity is reflected in high demands on the design and implementation methods used to create computer-assisted learning (CAL) programs. Due to their concepts, flexibility, maintainability and extended library resources, object-oriented technology (OOT) is very suitable to producing this type of pedagogical tool. The introduced approach is demonstrated by a basketball simulation program for instruction in Newtonian mechanics …

Scalar Wave Diffraction By A Perfectly Soft Infinitely Thin Circular Ring, Fati̇h Di̇kmen, Ertuğrul Karaçuha, Yury Alexanderovich Tuchkin

Turkish Journal of Electrical Engineering and Computer Sciences

A new strong mathematically rigorous and numerically effective method for solving the boundary value problem of scalar (for example acoustic) wave diffraction by a perfectly soft (Dirichlet boundary condition) infinitely thin circular ring is proposed. The method is based on the combination of the Orthogonal Polynomials Approach, and on the ideas of the methods of analytical regularization. As a result of the suggested regularization procedure, the initial boundary value problem is equivalently reduced to the infinite system of the linear algebraic equations of the second kind, i.e., to an equation of the type ( (I + H) x = b …

Fuzzy Modeling Approach For Integrated Assessments Using Cultural Theory, Adnan Yazici, Fred E. Petry, Curt Pendergraft

Turkish Journal of Electrical Engineering and Computer Sciences

It has already been noted that the accurate prediction of societal responses requires the use of a formal model based on some social or cultural taxonomy. One such taxonomic candidate is Cultural Theory (CT). CT argues that all societies, irrespective of time or place, are informed by their underlying worldviews, which must be more or less Hierarchic, more or less Individualistic, more or less Egalitarian, and more or less Fatalistic. This approach appears to have a potential for cross-temporal and spatial comparisons that makes it a particularly attractive instrument for a study of the human dimensions of global climate change. …

Design And Implementation Of An Intranet-Solution Especially With Workflow Aspects, Robert Loew

Theses

An Intranet support a new or simply an easier information system for all the workers within a company using internet technology. On the one hand, employees can use Web technology and very simple tools to provide and navigate information. On the other hand, the costly and time-consuming business of installing and maintaining software on local PCs can be avoided by using Browser-based Intranet applications. Ideally, it would be possible to access all forms of information processing using one and the same Web browser. This is the aim of the Intranet Project upon which this thesis is based.

Various technologies for …

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 …

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 …

Dres: Internet Resource Management Using Deferred Reservations, Samphel Norden

All Computer Science and Engineering Research

In this proposal, we consider the problem of resource reservation for Integrated Services (IntServ) and Differentiated Services (DiffServ) networks. Current approaches for resource reservation in INtegrated Service Networks adopt an all-or-nothing approach, where partially acquired resources must be released if resources are not available at all routers on the chosen path. Furthermore, under high load, end-systems must retry requests repeatedly leading to inefficient allocation and increased traffic. We propose a new approach called Deferred REServation (DERS) that substantially improves performance (reduces the overall cell rejection probability and increases link utilization) over the all-or-nothing reservation approach. Call admissibility is increased by …

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 …

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 …

Layered Protocol Wrappers For Internet Packet Processing In Reconfigurable Hardware, Florian Braun, John Lockwood, Marcel Waldvogel

All Computer Science and Engineering Research

The ongoing increases of line speed in the Internet backbone combined with the need for increased functionality of network devices presents a major challenge. These demands call for the use of reprogrammable hardware to provide the required flexible, high-speed functionality, at all network layers. The Field Programmable Port Extender (FPX) provides such an environment for development of networking components in reprogrammable hardware. We present a framework to streamline and simplify networking applications that process ATM cells, AAL5 frames, Internet Protocol (IP) packets and UDP datagrams directly in hardware.

Implementation Of An Open Multi-Service Router, Fred Kuhns, John Dehart, Ralph Keller, John Lockwood, Prashanth Papu, Jyoti Parwatikar, Ed Spitznagel, David Richard, David Taylor, Jon Turner, Ken Wong

All Computer Science and Engineering Research

This paper describes the design, implementation, and performance of an open, high-performance, dynamically reconfigurable Multi-Service Router (MSR) being developed at Washington University in St. Louis. This router provides an experimentation platform for research on protocols, router software, and hardware design, network management, quality of service and advanced applications. The MSR has been designed to be flexible, without sacrificing performance. It support gigabit links and uses a scalable architecture suitable for supporting hundreds or even thousands of links. The MSR's flexibility makes it an ideal platform for experimental research on dynamically extensible networks that implement higher level functions in direct support …

Routing In Overlay Multicast Networks, Sherlia Y. Shi, Jonathan S. Turner

All Computer Science and Engineering Research

Multicast servises can be provided either as a basic network service or as an application-layer service. Higher level multicast implementations often provide more sophisticated features, and since they don't require network supoprt for multicast, they can provide multicast services, where no network layer support is available. Overlay multicast networks offer an intermediate option, potentially combining the flexibility and advanced features of application layer multicast with the greater efficiency of network layer multicast. Overlay multicast networks play an important role in the Internet. Indeed, since Internet Service Providers have been slow to enable IP multicast in their networks, Internet multicast is …

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 …

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 …

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 …

Scalable Ip Lookup For Programmable Routers, David E. Taylor, John W. Lockwood, Todd Sproull, David B. Parlour

All Computer Science and Engineering Research

Continuing growth in optical link speeds places increasing demands on the performance of Internet routers, while deployment of embedded and distributed network services imposes new demands for flexibility and programmability. IP adress lookup has become a significant performance bottleneck for the highest performance routers. New commercial products utilize dedicated Content Addressable Memory (CAM) devides to achieve high lookup speeds. This paper describes an efficient, scalable lookup engine design, able to achieve high-performance with the use of a small portion of a reconfigurable logic device and a commodity Random Access Memory (RAM) device. Based on Eatherton's Tree Bitmap algorithm [1] the …

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 …

Efficient Queue Management For Tcp Flows, Anshul Kantawala, Jonathan Turner

All Computer Science and Engineering Research

Packets in the Internet can experience large queueing delays during busy periods. Backbone routers are generally engineered to have large buffers, in which packets may wait as long as half a second (assuming FIFO service, longer otherwise). During congestion periods, these bufferfs may stay close to full, subjecting packets to long delays, even when the intrinsic latency of the path is relatively small. This paper studies the performance improvements that can be obtained by using more sophisticated packet schedulers, than are typical of Internet routers. The results show that the large buffers found in WAN routers ocntribute only marginally to …

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.

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 …

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 …