Computer Sciences Commons^™

Is Parallel Programming Hard, And If So, Why?, Paul E. Mckenney, Maged M. Michael, Manish Gupta, Philip William Howard, Josh Triplett, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Of the 200+ parallel-programming languages and environments created in the 1990s, almost all are now defunct. Given that parallel systems are now well within the budget of the typical hobbyist or graduate student, it is not unreasonable to expect a new cohort in excess of several thousand parallel languages and environments to appear in the 2010s. If this expected new cohort is to have more practical impact than did its 1990s counterpart, a robust and widely applicable framework will be required that encompasses exactly what, if anything, is hard about parallel programming. This paper revisits the fundamental precepts of concurrent …

Enumeration Of Optimal Pin-Jointed Bistable Compliant Mechanisms With Non-Crossing Members, M. Ohsaki, N. Katoh, T. Kinoshita, S. Tanigawa, D. Avis, I. Streinu

Computer Science: Faculty Publications

An optimization approach is presented for enumerating pin-jointed bistable compliant mechanisms. In the first stage, the statically determinate trusses with non-crossing members containing a given set of nodes and some pre-defined members are regarded as minimally rigid framework or a Laman framework, and are enumerated without repetitions by the graph enumeration algorithm. In the second stage, the nodal locations and the cross-sectional areas are optimized under mechanical constraints, where the snapthrough behavior is extensively utilized to produce a pin-jointed bistable compliant mechanism. In the numerical examples, many bistable compliant mechanisms are generated to show the effectiveness of the proposed method. …

Node Isolation Model And Age-Based Neighbor Selection In Unstructured P2p Networks, Zhongmei Yao, Derek Leonard, Dmitri Loguinov

Computer Science Faculty Publications

Previous analytical studies of unstructured P2P resilience have assumed exponential user lifetimes and only considered age-independent neighbor replacement. In this paper, we overcome these limitations by introducing a general node-isolation model for heavy-tailed user lifetimes and arbitrary neighbor-selection algorithms. Using this model, we analyze two age-biased neighbor-selection strategies and show that they significantly improve the residual lifetimes of chosen users, which dramatically reduces the probability of user isolation and graph partitioning compared with uniform selection of neighbors. In fact, the second strategy based on random walks on age-proportional graphs demonstrates that, for lifetimes with infinite variance, the system monotonically increases …

A Combined Routing Method For Ad Hoc Wireless Networks, Soumendra Nanda, Zhenhui Jiang, David Kotz

Computer Science Technical Reports

Several simulation and real world studies show that certain ad hoc routing protocols perform better than others under specific mobility and traffic patterns. In order to exploit this phenomena, we propose a novel approach to adapt a network to changing conditions; we introduce "a combined routing method" that allows the network to seamlessly swap from one routing protocol to another protocol dynamically, while routing continues uninterrupted. By creating a thin new virtual layer, we enable each node in the ad hoc wireless network notify each other about the protocol swap and we do not make any changes to existing routing …

Carving And Replaying Differential Unit Test Cases From System Test Cases, Sebastian Elbaum, Hui Nee Chin, Matthew B. Dwyer, Matthew Jorde

School of Computing: Faculty Publications

Unit test cases are focused and efficient. System tests are effective at exercising complex usage patterns. Differential unit tests (DUTs) are a hybrid of unit and system tests that exploits their strengths. They are generated by carving the system components, while executing a system test case, that influence the behavior of the target unit and then reassembling those components so that the unit can be exercised as it was by the system test. In this paper, we show that DUTs retain some of the advantages of unit tests, can be automatically generated, and have the potential for revealing faults related …

Team Collaboration In Virtual Worlds: The Role Of Task Complexity, Fiona Fui-Hoon Nah, B. Mennecke, S. Schiller

Research Collection School Of Computing and Information Systems

Virtual worlds are three-dimensional, computer-generated worlds where team collaboration is facilitated through the use of shared virtual space. In this research, we are interested in studying the effect of task complexity on team collaboration. We use a puzzle as the collaboration task and manipulate task complexity using the number of puzzle pieces. We hypothesize that task complexity will influence team cohesion as well as satisfaction with team process and outcome, increase the time taken to complete the task, and increase the relative unevenness in team members' contributions in terms of physical effort to accomplish the task due to the increased …

An Examination Of Perceptions Of Male And Female Avatars, D. Dewester, Fiona Fui-Hoon Nah, S. Gervais, Keng Siau

Research Collection School Of Computing and Information Systems

Virtual worlds are three-dimensional, computer-generated worlds in which users take the form of avatars. Through their avatars, users can interact with objects and other avatars in the virtual world. Virtual worlds are growing in importance in both educational institutions and businesses. Educational institutions have adopted virtual worlds as a medium for instructional delivery whereas businesses are using virtual worlds for recruitment, training, collaboration, and marketing. Given these emerging phenomena, a better understanding of behavioral and perceptual issues in virtual worlds is warranted. In this paper, we propose a research model to study gender stereotypicality of male and female avatars and …

Real-Time Near-Duplicate Elimination For Web Video Search With Content And Context, Xiao Wu, Chong-Wah Ngo, Alexander G. Hauptmann

Research Collection School Of Computing and Information Systems

With the exponential growth of social media, there exist huge numbers of near-duplicate web videos, ranging from simple formatting to complex mixture of different editing effects. In addition to the abundant video content, the social web provides rich sets of context information associated with web videos, such as thumbnail image, time duration and so on. At the same time, the popularity of Web 2.0 demands for timely response to user queries. To balance the speed and accuracy aspects, in this paper, we combine the contextual information from time duration, number of views, and thumbnail images with the content analysis derived …

Programmer Friendly Refactoring Tools, Emerson Murphy-Hill

Dissertations and Theses

Tools that perform semi-automated refactoring are currently under-utilized by programmers. If more programmers adopted refactoring tools, software projects could make enormous productivity gains. However, as more advanced refactoring tools are designed, a great chasm widens between how the tools must be used and how programmers want to use them. This dissertation begins to bridge this chasm by exposing usability guidelines to direct the design of the next generation of programmer-friendly refactoring tools, so that refactoring tools fit the way programmers behave, not vice-versa.

Right Whale Ais Project (Rap): Acoustic Detections In The Boston Approaches, Kurt Schwehr, Lee Alexander

Center for Coastal and Ocean Mapping

No abstract provided.

A Hybrid Scatter Search For The Discrete Time/Resource Trade-Off Problem In Project Scheduling, Mohammad Ranbar, Bert De Reyck, Fereydoon Kianfar

Research Collection Lee Kong Chian School Of Business

We develop a heuristic procedure for solving the discrete time/resource trade-off problem in the field of project scheduling. In this problem, a project contains activities interrelated by finish-start-type precedence constraints with a time lag of zero, which require one or more constrained renewable resources. Each activity has a specified work content and can be performed in different modes, i.e. with different durations and resource requirements, as long as the required work content is met. The objective is to schedule each activity in one of its modes in order to minimize the project makespan. We use a scatter search algorithm to …

Bmq-Processor: A High-Performance Border Crossing Event Detection Framework For Large-Scale Monitoring Applications, Jinwon Lee, Seungwoo Kang, Youngki Lee, Sangjeong Lee, Junehwa Song

Research Collection School Of Computing and Information Systems

In this paper, we present BMQ-Processor, a high-performance Border-Crossing Event (BCE) detection framework for large-scale monitoring applications. We first characterize a new query semantics, namely, Border Monitoring Query (BMQ), which is useful for BCE detection in many monitoring applications. It monitors the values of data streams and reports them only when data streams cross the borders of its range. We then propose BMQ-Processor to efficiently handle a large number of BMQs over a high volume of data streams. BMQ-Processor efficiently processes BMQs in a shared and incremental manner. It develops and operates over a novel stateful query index, achieving a …

Spamed: A Spam Email Detection Approach Based On Phrase Similarity, Yiu-Kai D. Ng, Maria Soledad Pera

Faculty Publications

Emails are unquestionably one of the most popular communication media these days. Not only they are fast and reliable, but also free in general. Unfortunately, a significant number of emails received by email users on a daily basis are spam. This fact is annoying, since spam emails translate into a waste of user’s time in reviewing and deleting them. In addition, spam emails consume resources, such as storage, bandwidth, and computer processing time. Many attempts have been made in the past to eradicate spam emails; however, none has been proved highly effective. In this paper, we propose a spam-email detection …

Learning Image‐Text Associations, Tao Jiang, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Web information fusion can be defined as the problem of collating and tracking information related to specific topics on the World Wide Web. Whereas most existing work on Web information fusion has focused on text-based multidocument summarization, this paper concerns the topic of image and text association, a cornerstone of cross-media Web information fusion. Specifically, we present two learning methods for discovering the underlying associations between images and texts based on small training data sets. The first method based on vague transformation measures the information similarity between the visual features and the textual features through a set of predefined domain-specific …

Stochastic Modeling Western Paintings For Effective Classification, Jialie Shen

Research Collection School Of Computing and Information Systems

As one of the most important cultural heritages, classical western paintings have always played a special role in human live and been applied for many different purposes. While image classification is the subject of a plethora of related publications, relatively little attention has been paid to automatic categorization of western classical paintings which could be a key technique of modern digital library, museums and art galleries. This paper studies automatic classification on large western painting image collection. We propose a novel framework to support automatic classification on large western painting image collections. With this framework, multiple visual features can be …

Scale-Rotation Invariant Pattern Entropy For Keypoint-Based Near-Duplicate Detection, Wan-Lei Zhao, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Near-duplicate (ND) detection appears as a timely issue recently, being regarded as a powerful tool for various emerging applications. In the Web 2.0 environment particularly, the identification of near-duplicates enables the tasks such as copyright enforcement, news topic tracking, image and video search. In this paper, we describe an algorithm, namely Scale-Rotation invariant Pattern Entropy (SR-PE), for the detection of near-duplicates in large-scale video corpus. SR-PE is a novel pattern evaluation technique capable of measuring the spatial regularity of matching patterns formed by local keypoints. More importantly, the coherency of patterns and the perception of visual similarity, under the scenario …

Collaborative Learning Utilizing A Domain-Based Shared Data Repository To Enhance Learning Outcomes, David J. Lubliner

Dissertations

A number of learning paradigms have postulated that knowledge formation is a dynamic process where learners actively construct a representation of concepts integrating information from multiple sources. Current teaching strategies utilize a compartmentalized approach where individual courses contain a small subset of the knowledge required for a discipline. The intent of this research is to provide a framework to integrate the components of a discipline into a cohesive whole and accelerate the integration of concepts enhancing the learning process. The components utilized to accomplish these goals include two new knowledge integration models; a Knowledge Weighting Model (KWM) and the Aggregate-Integrate-Master …

Voting In Group Support Systems : Theory, Implementation, And Results From An Exploratory Study, Kung-E Cheng

Dissertations

Group decision making is essential in organizations. Group Support Systems (GSS) can aide groups in making decisions by providing tools and process support. GSS is especially useful for geographically or temporally distributed groups. Researchers of GSS have pointed out that convergence processes are hard to accomplish in GSS. Voting tools in GSS can be a valuable asset in alleviating the difficulty of convergence processes because voting is a concise communication of individual preferences with a well defined procedure that is accepted by group members. In addition, voting results can serve as a group memory of the convergence processes. Field observations …

Road-Based Proactive Routing Protocols For Vehicular Networks, Neeraj Mahadevrao Rajgure

Theses

Vehicular networks are formed by vehicles communicating in an ad hoc manner or through cellular and IEEE 802.11 base stations. Routing in vehicular networks is challenging due to highly dynamic network topologies. Previous research done at the UbiNetS lab at NJIT has proposed the idea of Road-Based using Vehicular Traffic information (RBVT) routing. In RBVT, routes are sequences of road intersections, and geographical forwarding is used for sending packets between the intersections.

This thesis proposes two proactive RBVT protocols (RBVT-P and RBVT-PS) for city-based Vehicular Ad hoc NETworks (VANETs). RBVT-P is a completely distributed protocol that unicasts connectivity packets in …

Rna Secondary Structure Detection Programs With An Emphasis On Covariance Models, Justin Slotman

Theses

RNA secondary structure prediction requires a different approach from traditional alignment methods. Functional RNAs often have their secondary structure better conserved than their primary structure. Covariance models, probabilistic models that utilize stochastic-context-free grammars, are one approach. CMs allow for homology to be detected where purely sequence-based methods would fail. A background on CMs is given, as well as a background of the major classes of non-coding RNAs (ncRNAs). Comparisons are made between some CM-using tools (the Infernal suite and CMfinder) and some other RNA secondary structure tools (CARNAC, miRNAminer, Pfold, Mfold) as well as between Infernal and the primary alignment …

A Community Ice Sheet Model For Sea Level Prediction, William Lipscomb, Robert Bindschadler, Ed Bueler, David Holland, Jesse Johnson, Stephen Price

Computer Science Faculty Publications

Summary of a workshop that was held at Los Alamos National Laboratory, New Mexico, 18-20 August 2008, whose primary goal was to create a detailed plan for developing, testing, and implementing a Community Ice Sheet Model (CISM) to aid in predicting sea level rise.

Why Gujarat Needs Much Better Higher Education & Research To Succeed In Knowledge Economy & What We Can Do About It?, Amit P. Sheth, Kamlesh Lulla, Sanjay Chaudhary

Kno.e.sis Publications

This white paper distills the deliberations on the role of higher education and research as a key enabler of a Knowledge based Society. In particular it discusses (a) the importance of higher quality PhDs for building a knowledge society, (b) the initiatives and progress in competing economies in higher education and research, (c) where Gujarat stands in comparison, and (d) some recommendations on what Gujarat can do to enable timely progress towards building a knowledge based society and economy. These deliberations were conducted in conjunction with the International Conference on 'Reconnecting Gujarati Diaspora with its Homeland: Contribution to its Development …

Agent Sensing In Limited Resource Environments, Adam Eck, Leen-Kiat Soh

School of Computing: Technical Reports

One of the key challenges for multiagent systems (MAS) is optimizing performance in limited resource environments. Previous research in this area has focused on the problems of 1) resource allocation and arbitration, and 2) bounded rationality, which describe the relationship between resource constraints and both agent reasoning and actuation. However, less work exists ad-dressing the effect of consuming resources during agent sensing, particularly two important tradeoffs. First, sensing can reduce resource availability, resulting in a tradeoff between overall system performance and an agent’s sensing behavior (the Performance Tradeoff). Second, consuming resources during sensing can alter the outcome of the measurement …

Multiagent Simulation Of Collaboration And Scaffolding Of A Cscl Environment, Nobel Khandaker, Leen-Kiat Soh

School of Computing: Technical Reports

Multiagent techniques improves student learning in Computer-Supported Collaborative Learning (CSCL) environments through multiagent coalition formation and intelligent support to the instructors and students. Researchers designing the multiagent tools and techniques for CSCL environments are often faced with high cost, time, and effort required to investigate the effectiveness of their tools and techniques in large-scale and longitudinal studies in a real-world environment containing human users. Here, we propose SimCoL, a multiagent environment that simulates collaborative learning among students and agents providing support to the teacher and the students. Our goal with SimCoL is to provide a comprehensive testbed for multiagent researchers …

A Multiagent Framework For Human Coalition Formation, Nobel Khandaker, Leen-Kiat Soh

School of Computing: Technical Reports

Human users form coalitions to solve complex tasks and earn rewards. Examples of such coalition formation can be found in the military, education, and business domains. Multiagent coalition formation techniques cannot be readily used to form human coalitions due to the unique aspects of the human coalition formation problem, e.g., uncertainty in human user behavior and changes in human user behaviors due to human learning. Thus, a multiagent system designed to form human coalitions has to solve a learning problem, that is further made difficult by the limited learning opportunities and usability issues (i.e., actions or decisions being perceived as …

Debar: A Scalable High-Performance De-Duplication Storage System For Backup And Archiving, Tianming Yang, Hong Jiang, Dan Feng, Zhongying Niu

School of Computing: Technical Reports

We present DEBAR, a scalable and high-performance de-duplication storage system for backup and archiving, to overcome the throughput and scalability limitations of the state-of-the-art data de-duplication schemes, including the Data Domain De-duplication File System (DDFS). DEBAR uses a two-phase de-duplication scheme (TPDS) that exploits memory cache and disk index properties to judiciously turn the notoriously random and small disk I/Os of fingerprint lookups and updates into large sequential disk I/Os, hence achieving a very high de-duplication throughput. The salient feature of this approach is that both the system backup and archiving capacity and the de-duplication performance can be dynamically and …

Impact Of Tablet Pcs And Dyknow Software On Learning Gains In Inquiry-Learning Oriented Courses, Zdeslav Hrepic

Faculty Bibliography

Tablet PCs and DyKnow software were utilized at Fort Hays State University in the teaching of an inquiry-based physical science course for elementary education majors since the summer semester of 2006. This course was originally developed in 2004 and 2005 through an NSF sponsored research effort. In this paper we compare learning gains obtained in this course during three semesters when pen-based computing technology was not utilized (Fall 04 - Fall 05) with gains obtained during three later semesters (Fall 07 - Fall 08) in which we utilized Tablet PCs and DyKnow software in teaching the course. We also report …

Teaching In Ill-Defined Domains Using Its And Ai Appraoches, Rania Hodhod

Faculty Bibliography

Ill-defined domains offer many challenges to computer scientists. Developing intelligent tutoring systems (ITSs) in these domains is a very challenging task due to the difficulty in modeling these domains, answers to ill-defined problems are ambiguously identified as right or wrong, and no generally accepted architecture is currently existed. This paper presents general guidelines for the development of ITSs in ill-defined domains, such as Argumentation and Ethics. This is instantiated in the two example systems AEINS and ALES. These systems offer adaptive learning processes and personalized feedback aiming to transfer the required skills to the learners and develop their reasoning.

Modelling Groups Of Plausible Virtual Pedestrians, Christopher Peters, Cathy Ennis, Carol O'Sullivan

Articles

No abstract provided.

Talking Bodies: Sensitivity To Desynchronization Of Conversations, Rachel Mcdonnell, Cathy Ennis, Simon Dobbyn, Carol O'Sullivan

Articles

In this article, we investigate human sensitivity to the coordination and timing of conversational body language for virtual characters. First, we captured the full body motions (excluding faces and hands) of three actors conversing about a range of topics, in either a polite (i.e., one person talking at a time) or debate/argument style. Stimuli were then created by applying the motion-captured conversations from the actors to virtual characters. In a 2AFC experiment, participants viewed paired sequences of synchronized and desynchronized conversations and were asked to guess which was the real one. Detection performance was above chance for both conversation styles …