Open Access. Powered by Scholars. Published by Universities.®

Computer Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

University of Nebraska - Lincoln

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 1381 - 1410 of 1739

Full-Text Articles in Computer Sciences

Optimal Segment Size For Fixed-Sized Segment Protection In Wavelength-Routed Optical Networks, Raghunath Tewari, Byrav Ramamurthy Jan 2009

Optimal Segment Size For Fixed-Sized Segment Protection In Wavelength-Routed Optical Networks, Raghunath Tewari, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Protecting a network against link failures is a major challenge faced by network operators. The protection scheme has to address two important objectives - fast recovery and minimizing the amount of backup resources needed. Every protection algorithm is a tradeoff between these two objectives.

In this paper, we study the problem of segment protection. In particular, we investigate what is the optimal segment size that obtains the best tradeoff between the time taken for recovery and minimizing the bandwidth used by the backup segments. We focus on the uniform fixed-length segment protection method, where each primary path is divided into …

Go to article

A Flexible Divide-And-Conquer Protocol For Multi-View Peer-To-Peer Live Streaming, Miao Wang, Lisong Xu, Byrav Ramamurthy Jan 2009

A Flexible Divide-And-Conquer Protocol For Multi-View Peer-To-Peer Live Streaming, Miao Wang, Lisong Xu, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Multi-view peer-to-peer (P2P) live streaming systems have recently emerged, where a user can simultaneously watch multiple channels. Previous work on multi-view P2P streaming solves the fundamental inter-channel bandwidth competition problem at the individual peer level, and thus can be used with very limited types of streaming protocols. In this paper, we propose a new protocol for multi-view P2P streaming, called Divide-and-Conquer (DAC), which efficiently solves the inter-channel bandwidth competition problem using a divide-and-conquer strategy at the channel level, and thus is flexible to work with various streaming protocols. This makes DAC more suitable for upgrading current single-view P2P live streaming …

Go to article

Error Control In Wireless Sensor Networks: A Cross Layer Analysis, Mehmet C. Vuran, Ian F. Akyildiz Jan 2009

Error Control In Wireless Sensor Networks: A Cross Layer Analysis, Mehmet C. Vuran, Ian F. Akyildiz

School of Computing: Faculty Publications

Error control is of significant importance for Wireless Sensor Networks (WSNs) because of their severe energy constraints and the low power communication requirements. In this paper, a cross-layer methodology for the analysis of error control schemes in WSNs is presented such that the effects of multi-hop routing and the broadcast nature of the wireless channel are investigated. More specifically, the cross-layer effects of routing, medium access, and physical layers are considered. This analysis enables a comprehensive comparison of forward error correction (FEC) codes, automatic repeat request (ARQ), and hybrid ARQ schemes in WSNs. The validation results show that the developed …

Go to article

Smart Templates For Peak Pattern Matching With Comprehensive Two-Dimensional Liquid Chromatography, Stephen E. Reichenbach, Peter W. Carr, Dwight R. Stoll, Qingping Tao Jan 2009

Smart Templates For Peak Pattern Matching With Comprehensive Two-Dimensional Liquid Chromatography, Stephen E. Reichenbach, Peter W. Carr, Dwight R. Stoll, Qingping Tao

School of Computing: Faculty Publications

Comprehensive two-dimensional liquid chromatography (LC × LC) generates information-rich but complex peak patterns that require automated processing for rapid chemical identification and classification. This paper describes a powerful approach and specific methods for peak pattern matching to identify and classify constituent peaks in data from LC × LC and other multidimensional chemical separations. The approach records a prototypical pattern of peaks with retention times and associated metadata, such as chemical identities and classes, in a template. Then, the template pattern is matched to the detected peaks in subsequent data and the metadata are copied from the template to identify and …

Go to article

Directed Test Suite Augmentation, Zhihong Xu, Gregg Rothermel Jan 2009

Directed Test Suite Augmentation, Zhihong Xu, Gregg Rothermel

School of Computing: Conference and Workshop Papers

As software evolves, engineers use regression testing to evaluate its fitness for release. Such testing typically begins with existing test cases, and many techniques have been proposed for reusing these cost-effectively. After reusing test cases, however, it is also important to consider code or behavior that has not been exercised by existing test cases and generate new test cases to validate these. This process is known as test suite augmentation. In this paper we present a directed test suite augmentation technique, that utilizes results from reuse of existing test cases together with an incremental concolic testing algorithm to augment …

Go to article

Technical Reports (2004 - 2009) Jan 2009

Technical Reports (2004 - 2009)

School of Computing: Technical Reports

Authors of Technical Reports (2005-2009):
Choueiry, Berthe
Cohen, Myra
Deogun, Jitender
Dwyer, Matthew
Elbaum, Sebastian
Goddard, Steve
Henninger, Scott
Jiang, Hong
Lu, Ying
Ramamurthy, Byrav
Rothermel, Gregg
Scott, Stephen
Seth, Sharad
Soh, Leen-Kiat
Srisa-an, Witty
Swanson, David
Variyam, Vinodchandran
Wang, Jun
Xu, Lisong

Go to article

Cross-Layer Analysis Of The End-To-End Delay Distribution In Wireless Sensor Networks, Yunbo Wang, Mehmet C. Vuran, Steve Goddard Jan 2009

Cross-Layer Analysis Of The End-To-End Delay Distribution In Wireless Sensor Networks, Yunbo Wang, Mehmet C. Vuran, Steve Goddard

School of Computing: Conference and Workshop Papers

Emerging applications of wireless sensor networks (WSNs) require real-time quality of service (QoS) guarantees to be provided by the network. However, designing real-time scheduling and communication solutions for these networks is challenging since the characteristics of QoS metrics in WSNs are not well known yet. Due to the nature of wireless connectivity, it is infeasible to satisfy worst-case QoS requirements in WSNs. Instead, probabilistic QoS guarantees should be provided, which requires the definition of probabilistic QoS metrics. To provide an analytical tool for the development of real-time solutions, in this paper, the distribution of end-to-end delay in multi-hop WSNs is …

Go to article

Using Hadoop As A Grid Storage Element, Brian Bockelman Jan 2009

Using Hadoop As A Grid Storage Element, Brian Bockelman

School of Computing: Conference and Workshop Papers

Hadoop is an open-source data processing framework that includes a scalable, fault- tolerant distributed file system, HDFS. Although HDFS was designed to work in conjunction with Hadoop's job scheduler, we have re-purposed it to serve as a grid storage element by adding GridFTP and SRM servers. We have tested the system thoroughly in order to understand its scalability and fault tolerance. The turn-on of the Large Hadron Collider (LHC) in 2009 poses a significant data management and storage challenge; we have been working to introduce HDFS as a solution for data storage for one LHC experiment, the Compact Muon Solenoid …

Go to article

A Hybrid Test Architecture To Reduce Test Application Time In Full Scan Sequential Circuits, Priyankar Ghosh, Srobona Mitra, Indranil Sengupta, Bhargab B. Bhattacharya, Sharad C. Seth Jan 2009

A Hybrid Test Architecture To Reduce Test Application Time In Full Scan Sequential Circuits, Priyankar Ghosh, Srobona Mitra, Indranil Sengupta, Bhargab B. Bhattacharya, Sharad C. Seth

School of Computing: Conference and Workshop Papers

Abstract—Full scan based design technique is widely used to alleviate the complexity of test generation for sequential circuits. However, this approach leads to substantial increase in test application time, because of serial loading of vectors. Although BIST based approaches offer faster testing, they usually suffer from low fault coverage. In this paper, we propose a hybrid test architecture, which achieves significant reduction in test application time. The test suite consists of: (i) some external deterministic test vectors to be scanned in, and (ii) internally generated responses of the CUT to be re-applied as tests iteratively, in functional (non-scan) mode. The …

Go to article

Smartstore: A New Metadata Organization Paradigm With Metadata Semantic-Awareness For Next-Generation File Systems, Yu Hua, Hong Jiang, Yifeng Zhu, Dan Feng, Lei Tian Nov 2008

Smartstore: A New Metadata Organization Paradigm With Metadata Semantic-Awareness For Next-Generation File Systems, Yu Hua, Hong Jiang, Yifeng Zhu, Dan Feng, Lei Tian

School of Computing: Technical Reports

Existing data storage systems based on hierarchical directory tree do not meet scalability and functionality requirements for exponentially growing datasets and increasingly complex metadata queries in large-scale file systems with billions of files and Exabytes of data. This paper proposes a novel decentralized semantic-aware metadata organization, called SmartStore, which exploits metadata semantics of files to judiciously aggregate correlated files into semantic-aware groups by using information retrieval tools. The decentralized design of SmartStore can improve system scalability and reduce query latency for both complex queries (including range and top-k queries), which is helpful to construct semantic-aware caching, and conventional filename-based point …

Go to article

Ideas: An Identity-Based Security Architecture For Large-Scale And High-Performance Storage Systems, Zhongying Niu, Ke Zhou, Hong Jiang, Dan Feng, Tianming Yang Nov 2008

Ideas: An Identity-Based Security Architecture For Large-Scale And High-Performance Storage Systems, Zhongying Niu, Ke Zhou, Hong Jiang, Dan Feng, Tianming Yang

School of Computing: Technical Reports

We develop IDEAS, an identity-based security architecture for large-scale and high-performance storage systems, designed to improve security, convenience and total cost of access control by merging identity management with access control in these systems. IDEAS authenticates users at each I/O node by using a single-identity certificate without the service of a centralized security server and enforces access control mechanism by using an object-based access control (OBAC) model, which is designed to address the complexity and scalability issue of security administration in large-scale storage systems. We also discuss the issue of how to identify and authenticate a large number of users …

Go to article

An M-Sequence Based Steganography Model For Voice Over Ip, Lei Tian, Ke Zhou, Hong Jiang, Jin Liu, Yongfeng Huang, Dan Feng Sep 2008

An M-Sequence Based Steganography Model For Voice Over Ip, Lei Tian, Ke Zhou, Hong Jiang, Jin Liu, Yongfeng Huang, Dan Feng

School of Computing: Technical Reports

Differing from applying steganography on storage cover media, steganography on Voice over IP (VoIP) must often delicately balance between providing adequate security and maintaining low latency for real-time services. This paper presents a novel real-time steganography model for VoIP that aims at providing good security for secret messages without sacrificing real-time performance. We achieve this goal by employing the well-known least-significant-bits (LSB) substitution approach to provide a reasonable tradeoff between the adequate information hiding requirement (good security and sufficient capacity) and the low latency requirement for VoIP. Further, we incorporate the m-sequence technique to eliminate the correlation among secret messages …

Go to article

On Incorporating Learning Theories To Simulate A Computer-Supported Collaborative Learning Environment, Nobel Khandaker, Leen-Kiat Soh Sep 2008

On Incorporating Learning Theories To Simulate A Computer-Supported Collaborative Learning Environment, Nobel Khandaker, Leen-Kiat Soh

School of Computing: Technical Reports

The success of a computer-supported collaborative learning (CSCL) environment in improving student knowledge depends on factors like student attributes (e.g., ability and motivation) and elements of the CSCL environment (e.g., group size and group formation). Better understanding of the individual and combined effects of these factors on the learning outcome of students would help: (1) researchers design better CSCL systems and (2) teachers make better decisions while carrying out CSCL sessions. To aid the researchers and teachers, we have used the observations collected and derived from published theories on individual, peer-based, and collaborative learning to design SimCoL, a multiagent-based tool …

Go to article

Nmflux: Improving Degradation Behavior Of Server Applications Through Dynamic Nursery Resizing, Witawas Srisaan, Cheng Huan Jia Aug 2008

Nmflux: Improving Degradation Behavior Of Server Applications Through Dynamic Nursery Resizing, Witawas Srisaan, Cheng Huan Jia

School of Computing: Technical Reports

Currently, most generational collectors are tuned to either deliver peak performance when the heap is plentiful, but yield unacceptable performance when the heap is tight or maintain good degradation behavior when the heap is tight, but deliver sub-optimal performance when the heap is plentiful. In this paper, we present NMFLUX (continuously varying the Nursery/Mature ratio), a framework that switches between using a fixed-nursery generational collector and a variable-nursery collector to achieve the best of both worlds; i.e. our framework delivers optimal performance under normal workload, and graceful performance degradation under heavy workload. We use this framework to create two generational …

Go to article

Duts: Targeted Case Studies, Hui Nee Chin, Sebastian Elbaum, Matthew B. Dwyer, Matthew Jorde Aug 2008

Duts: Targeted Case Studies, Hui Nee Chin, Sebastian Elbaum, Matthew B. Dwyer, Matthew Jorde

School of Computing: Technical Reports

Our previous studies of DUTs addressed research questions of effectiveness, efficiency, and robustness with respect to one software artifact, Siena, and we believe the findings generalize to similar artifacts. Still, we realize that existing studies suffer from threats to validity. Specifically, the selected artifact provided limited exposure to CR in the presence of deeper heap structures, extensive software changes, and high number of methods invocations. We start to address those threats to the validity of our findings by investigating the performance of CR in the presence of such settings.
The findings in this report reveal that the performance of the …

Go to article

Multidomain Optical Networks: Issues And Challenges, Chava Vijaya Saradhi, Byrav Ramamurthy, Dominic A. Schupke, Eiji Oki Jun 2008

Multidomain Optical Networks: Issues And Challenges, Chava Vijaya Saradhi, Byrav Ramamurthy, Dominic A. Schupke, Eiji Oki

School of Computing: Faculty Publications

Today, many leading organizations are undertaking extensive research on a very broad range of new and evolving optical networking technologies. These efforts carry particular significance, especially in light of the “postbubble” dynamics of the optical networking market and have led to the investigation of various cost-efficient optical technologies. Today’s telecom carriers operate several independent optical domains based on diverse technologies, control solutions, standards, and protocols, making interdomain and intercarrier interworking extremely difficult. Standardized interworking across diverse multigranularity network interfaces, and interoperability across disparate vendor equipments and carrier domains are crucial to provisioning end-to-end services and achieving cost-efficient network operation. Needless …

Go to article

Hba: Distributed Metadata Management For Large Cluster-Based Storage Systems, Yifeng Zhu, Hong Jiang, Jun Wang, Feng Xian Jun 2008

Hba: Distributed Metadata Management For Large Cluster-Based Storage Systems, Yifeng Zhu, Hong Jiang, Jun Wang, Feng Xian

School of Computing: Faculty Publications

An efficient and distributed scheme for file mapping or file lookup is critical in decentralizing metadata management within a group of metadata servers. This paper presents a novel technique called Hierarchical Bloom Filter Arrays (HBA) to map filenames to the metadata servers holding their metadata. Two levels of probabilistic arrays, namely, the Bloom filter arrays with different levels of accuracies, are used on each metadata server. One array, with lower accuracy and representing the distribution of the entire metadata, trades accuracy for significantly reduced memory overhead, whereas the other array, with higher accuracy, caches partial distribution information and exploits the …

Go to article

Efficient Power Management Of Heterogeneous Soft Real-Time Clusters, Leping Wang, Ying Lu May 2008

Efficient Power Management Of Heterogeneous Soft Real-Time Clusters, Leping Wang, Ying Lu

School of Computing: Technical Reports

With growing cost of electricity, the power management of server clusters has become an important problem. However, most previous researchers only address the challenge in homogeneous environments. Considering the increasing popularity of heterogeneous systems, this paper proposes an efficient algorithm for power management of heterogeneous soft real-time clusters. It is built on simple but effective mathematical models. When deployed to a new platform, the software incurs low configuration cost because no extensive performance measurements and profiling are required. To strive for efficiency, a threshold-based approach is adopted. In this paper, we systematically study this approach and its design decisions.

Go to article

Proceedings Work-In-Progress Session Of The 14th Real-Time And Embedded Technology And Applications Symposium, 22-24 April, 2008 St. Louis, Usa, Ying Lu Apr 2008

Proceedings Work-In-Progress Session Of The 14th Real-Time And Embedded Technology And Applications Symposium, 22-24 April, 2008 St. Louis, Usa, Ying Lu

School of Computing: Technical Reports

The Work-In-Progress session of the 14th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS '08) presents papers describing contributions both to state of the art and state of the practice in the broad field of real-time and embedded systems. The 25 accepted papers were selected from 27 submissions. This proceedings is also available as University of Nebraska–Lincoln Technical Report TR-UNL-CSE-2008-0003, at
http://lakota.unl.edu/facdb/csefacdb/TechReportArchive/TR-UNL-CSE-2008-0003.pdf
Special thanks go to the General Chairs – Scott Brandt and Frank Mueller and Program Chairs – Chenyang Lu and Christopher Gill for their support and guidance. Special thanks also go to the Work-In-Progress Program Committee Members …

Go to article

Getting Started With Prpl, Qingfeng Guan Apr 2008

Getting Started With Prpl, Qingfeng Guan

School of Natural Resources: Faculty Publications

pRPL is an open-source1 general-purpose parallel Raster Processing programming Library developed by Qingfeng Guan, in the Department of Geography, University of California, Santa Barbara. pRPL encapsulates complex parallel computing utilities and routines specifically for raster processing (e.g., raster data decomposition, distribution and gathering among multiple processors, inter-processor communication and data exchange), and provides an easy-to-use interface for users to parallelize almost any raster processing algorithm with any arbitrary neighborhood (or moving window) configuration. pRPL enables the implementation of parallel raster-processing algorithms without requiring a deep understanding of parallel computing and programming, thus it greatly reduces the development complexity. Moreover, even …

Go to article

Loss-Rate Based Reliable Data Transport Mechanism For Dynamic Event Sensing In Wireless Sensor Networks, Yuyan Xue, Byrav Ramamurthy, Yong Wang Feb 2008

Loss-Rate Based Reliable Data Transport Mechanism For Dynamic Event Sensing In Wireless Sensor Networks, Yuyan Xue, Byrav Ramamurthy, Yong Wang

School of Computing: Technical Reports

Many wireless sensor network (WSN) transport protocols proposed in recent studies focus on providing end-to- end reliability as in TCP. However, traditional end-to-end reliability is energy and time consuming for common loss tolerant applications in WSNs. In this paper, we propose a Loss Tolerant Reliable (LTR) data transport mechanism for dynamic Event Sensing (LTRES) in WSNs. In LTRES, a reliable event sensing requirement at the transport layer is dynamically determined by the sink. A distributed source rate adaptation mechanism is designed, incorporating a loss rate based lightweight congestion control mechanism, to regulate the data traffic injected into the network so …

Go to article

Farmer: A Novel Approach To File Access Correlation Mining And Evaluation Reference Model For Optimizing Peta-Scale File System Performance, Peng Xia, Dan Feng, Hong Jiang, Lei Tian, Fang Wang Jan 2008

Farmer: A Novel Approach To File Access Correlation Mining And Evaluation Reference Model For Optimizing Peta-Scale File System Performance, Peng Xia, Dan Feng, Hong Jiang, Lei Tian, Fang Wang

School of Computing: Technical Reports

File correlations have become an increasingly important consideration for performance enhancement in peta-scale storage systems. Previous studies on file correlationsmainly concern with two aspects of files: file access sequence and semantic attribute. Based on mining with regard to these two aspects of file systems, various strategies have been proposed to optimize the overall system performance. Unfortunately, all of these studies consider either file access sequences or semantic attribute information separately and in isolation, thus unable to accurately and effectively mine file correlations, especially in large-scale distributed storage systems.
This paper introduces a novel File Access coRrelation Mining and Evaluation Referencemodel …

Go to article

Ldne: A Program For Estimating Effective Population Size From Data On Linkage Disequilibrium, Robin Waples, Chi Do Jan 2008

Ldne: A Program For Estimating Effective Population Size From Data On Linkage Disequilibrium, Robin Waples, Chi Do

United States Department of Commerce: Staff Publications

LDNE is a program with a Visual Basic interface that implements a recently developed bias correction for estimates of effective population size (Ne) based on linkage disequilibrium data. The program reads genotypic data in standard formats and can accommodate an arbitrary number of samples, individuals, loci, and alleles, as well as two mating systems: random and lifetime monogamy. LDNE calculates separate estimates using different criteria for excluding rare alleles, which facilitates evaluation of data for highly polymorphic markers such as microsatellites. The program also introduces a jackknife method for obtaining confidence intervals that appears to perform better …

Go to article

Investigating Adaptive, Confidence-Based Strategic Negotiations In Complex Multiagent Environments, Leen-Kiat Soh, Xin Li Jan 2008

Investigating Adaptive, Confidence-Based Strategic Negotiations In Complex Multiagent Environments, Leen-Kiat Soh, Xin Li

School of Computing: Faculty Publications

We propose an adaptive 1-to-many negotiation strategy for multiagent coalition formation in complex environments that are dynamic, uncertain, and real-time. Our strategy deals with how to assign multiple issues to a set of concurrent negotiations based on an initiating agent’s confidence in its profiling of its peer agents. When an agent is confident, it uses a packaged approach—conducting multiple multi-issue negotiations—with its peers. Otherwise, it uses a pipelined approach—conducting multiple single-issue negotiations—with its peers. The initiating agent is also capable of using both approaches in a hybrid, dealing with a mixed group of responding peers. An agent’s confidence in its …

Go to article

Efficient Selection Of Observation Points For Functional Tests, Jian Kang, Sharad C. Seth, Yi-Shing Chang, Vijay Gangaram Jan 2008

Efficient Selection Of Observation Points For Functional Tests, Jian Kang, Sharad C. Seth, Yi-Shing Chang, Vijay Gangaram

School of Computing: Faculty Publications

The fault coverage of existing functional tests can be enhanced by additional observation points. For a given set of functional tests, this paper proposes an efficient fault-dropping fault simulation method for selecting a subset of observation points at a small fraction of the cost of non-fault-dropping fault simulation. Experimental results on industrial circuits demonstrate the effectiveness of the method in achieving close to optimal results in the size of the selected subset with an order of magnitude less time, without losing achievable coverage. The technique is particularly applicable to industrial designs where fault-simulation times can be prohibitively expensive, even when …

Go to article

A Survey On Spectrum Management In Cognitive Radio Networks, Ian F. Akyildiz, Won-Yeol Lee, Mehmet C. Vuran, Shantidev Mohanty Jan 2008

A Survey On Spectrum Management In Cognitive Radio Networks, Ian F. Akyildiz, Won-Yeol Lee, Mehmet C. Vuran, Shantidev Mohanty

School of Computing: Faculty Publications

Cognitive radio networks will provide high bandwidth to mobile users via heterogeneous wireless architectures and dynamic spectrum access techniques. However, CR networks impose challenges due to the fluctuating nature of the available spectrum, as well as the diverse QoS requirements of various applications. Spectrum management functions can address these challenges for the realization of this new network paradigm. To provide a better understanding of CR networks, this article presents recent developments and open research issues in spectrum management in CR networks. More specifically, the discussion is focused on the development of CR networks that require no modification of existing networks. …

Go to article

Techniques For Computing Fitness Of Use (Fou) For Time Series Datasets With Applications In The Geospatial Domain, Lei Fu, Leen-Kiat Soh, Ashok Samal Jan 2008

Techniques For Computing Fitness Of Use (Fou) For Time Series Datasets With Applications In The Geospatial Domain, Lei Fu, Leen-Kiat Soh, Ashok Samal

School of Computing: Faculty Publications

Time series data are widely used in many applications including critical decision support systems. The goodness of the dataset, called the Fitness of Use (FoU), used in the analysis has direct bearing on the quality of the information and knowledge generated and hence on the quality of the decisions based on them. Unlike traditional quality of data which is independent of the application in which it is used, FoU is a function of the application. As the use of geospatial time series datasets increase in many critical applications, it is important to develop formal methodologies to compute their FoU and …

Go to article

Variable Neighbor Selection In Live Peer-To-Peer Multimedia Streaming Networks, Jagannath Ghoshal, Miao Wang, Lisong Xu, Byrav Ramamurthy Jan 2008

Variable Neighbor Selection In Live Peer-To-Peer Multimedia Streaming Networks, Jagannath Ghoshal, Miao Wang, Lisong Xu, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Data-driven (or swarming based) streaming is one of the popular ways to distribute live multimedia streaming traffic over Peer-to-Peer (P2P) networks. The efficiency and user satisfaction highly depend on the constructed overlays. The common neighbor selection algorithms in existing overlay construction schemes usually randomly select a fixed number of neighbors which satisfy the selection requirements, such as end-to-end delay or a peer's sojourn time. However, this fixed random neighbor-selection algorithm (FRNS) neglects the peers' upload bandwidth heterogeneity and therefore, the upload bandwidth cannot be efficiently used. In this paper, we propose a variable random neighbor-selection (VRNS) scheme to alleviate the …

Go to article

A Service-Differentiated Real-Time Communication Scheme For Wireless Sensor Networks, Yuyan Xue, Byrav Ramamurthy, Mehmet C. Vuran Jan 2008

A Service-Differentiated Real-Time Communication Scheme For Wireless Sensor Networks, Yuyan Xue, Byrav Ramamurthy, Mehmet C. Vuran

School of Computing: Conference and Workshop Papers

Supporting end-to-end real-time communication is important for wireless sensor networks (WSNs) to accomplish the collaborative sensing tasks with specific timing constraints. However, without considering the unique constraints for WSNs, many existing real-time communication protocols prove to be infeasible for low-cost WSNs. In this paper, we propose a novel real-time communication scheme (RCS) to provide service-differentiated soft real-time guarantees for end-to-end communication in WSNs. We use hop-based geographic grouping to enable location awareness for sensor nodes with extremely low control overhead.We use dynamic forwarding with load-balanced receiver contention to provide a light-weight, yet efficient, routing technique, which can be easily adapted …

Go to article

I-Minds: A Multiagent System For Intelligent Computer- Supported Collaborative Learning And Classroom Management, Leen-Kiat Soh, Nobel Khandaker, Hong Jiang Jan 2008

I-Minds: A Multiagent System For Intelligent Computer- Supported Collaborative Learning And Classroom Management, Leen-Kiat Soh, Nobel Khandaker, Hong Jiang

School of Computing: Faculty Publications

I-MINDS provides a computer-supported collaborative learning (CSCL) infrastructure and environment for learners in synchronous learning and classroom management applications for instructors, for large classroom or distance education situations. For supporting the instructor, I-MINDS includes a teacher agent. The teacher agent allows the instructor to interact with students, manage Q&A sessions, administer quizzes, post evaluations, form groups and monitor individual and group performances. For computer-supported collaborative learning, I-MINDS, which stands for Intelligent Multiagent Infrastructure for Distributed Systems in Education, provides a student agent for each student. Each student agent monitors and models its user and carries out group formation with other …

Go to article

First Prev Next Last