Computer Sciences Commons^™

The Min-Dist Location Selection Query, Jianzhong Qi, Rui Zhang, Lars Kulik, Dan Lin, Yuan Xue

Computer Science Faculty Research & Creative Works

We propose and study a new type of location optimization problem given a set of clients and a set of existing facilities, we select a location from a given set of potential locations for establishing a new facility so that the average distance between a client and her nearest facility is minimized. We call this problem the min-dist location selection problem, which has a wide range of applications in urban development simulation, massively multiplayer online games, and decision support systems. We explore two common approaches to location optimization problems and propose methods based on those approaches for solving this new …

Modular Reasoning About Region Composition, Thomas Cottenier, Aswin Van Den Berg, Thomas Weigert

Computer Science Faculty Research & Creative Works

Region composition is an operation where transitions of different automaton are woven together according to synchronization constraints. Reasoning about properties across regions is difficult, which is problematic in systems that are assembled by composing a large number of regions. We introduce two transactions constructs to enforce causality properties between transitions of a state machine. We show that transactions can be checked statically and that they support modular reasoning about region composition by preserving liveness properties within the scope of a transaction. © 2012 ACM.

Architecture Composition For Concurrent Systems, Thomas Cottenier, Aswin Van Den Berg, Thomas Weigert

Computer Science Faculty Research & Creative Works

We present a framework to assemble concurrent applications from modules that capture reusable architectural patterns. the framework focuses on concurrent systems where computational processes communicate through asynchronous messages. the language provides support to modularize architectural patterns at different levels of granularity, using agents, regions, aspects and morphing. We present sample implementations of the architectural patterns and show how they are composed using a real-world example. Finally discuss how the deployment and composition of patterns can be further automated. © 2012 ACM.

Management Of Feature Interactions With Transactional Regions, Thomas Cottenier, Aswin Van Den Berg, Thomas Weigert

Computer Science Faculty Research & Creative Works

This paper presents a modeling language to modularize the features of a system using orthogonal regions and to manage the interactions between these features. Orthogonal regions are a language construct to structure a state machine into a set of semi-independent behaviors. We introduce two concepts to manage the interactions between regions. First, we present a notion of interface between regions which captures the essence of their interactions. Second, we introduce a transactional composition operator to synchronize the regions and check the interaction for non-determinism and termination. the approach is evaluated by comparing a monolithic legacy implementation of a telecommunication component …

Experimental Evaluation Of The Effect Of Queue Management Schemes On The Performance Of High Speed Tcps In 10gbps Network Environment, Lin Xue, Cheng Cui, Suman Kumar, Seung Jong Park

Computer Science Faculty Research & Creative Works

Queue management schemes at the routers and congestion avoidance schemes at the end points cooperate to provide good congestion solutions in computer networks. While queue management schemes are still being developed, research on congestion avoidance has come a long way to serve the bandwidth requirement of the networks (e.g. high-speed networks, data centers, etc.) at the order of 10Gbps. Because of considerable lack on the evaluation research work, there is no consensus on the choice of the queue management algorithms over these networks. To the best of our knowledge, this is the first work that presents experimental evaluation of the …

Conflict Detection And Resolution For Product Line Design In A Collaborative Decision Making Environment, Xiaoqing Frank Liu, Eric Christopher Barnes, Juha Erik Savolainen

Computer Science Faculty Research & Creative Works

Ensuring that the non-functional requirements (NFRs), of a system are satisfied is an essential task in software development. However, this task is complicated by the fact that many NFRs conflict with each other from multiple perspectives. It is essential to resolve conflicts collectively in a collaborative decision-making process since stakeholders often disagree on how conflicts should be resolved. in this paper, we describe a method for dividing high-level NFR conflicts within a product line into more manageable sub-problems. Stakeholders make use of an argumentation based collaborative decision support system to determine which design alternatives provide the best trade-offs between NFRs. …

Ensuring Distributed Accountability For Data Sharing In The Cloud, Smitha Sundareswaran, Anna Squicciarini, Dan Lin

Computer Science Faculty Research & Creative Works

Cloud computing enables highly scalable services to be easily consumed over the Internet on an as-needed basis. a major feature of the cloud services is that users' data are usually processed remotely in unknown machines that users do not own or operate. While enjoying the convenience brought by this new emerging technology, users' fears of losing control of their own data (particularly, financial and health data) can become a significant barrier to the wide adoption of cloud services. to address this problem, in this paper, we propose a novel highly decentralized information accountability framework to keep track of the actual …

Transmission Scheduling Based On A New Conflict Graph Model For Multicast In Multihop Wireless Networks, Maggie Cheng, Quanmin Ye

Computer Science Faculty Research & Creative Works

In multicast applications, the end-to-end delay from the source to a group member is determined by the multicast tree topology and the waiting time at each relay node. This paper addresses when the multicast tree is given how to schedule wireless nodes for transmission so that network delay is minimized. We first model the conflict relation among wireless transmissions in a conflict graph, and then we compute a transmission schedule based on an Integer Linear Programming (ILP) model. Since solving ILP problem is NP-hard, a heuristic is designed to solve the ILP problem. the resulting schedule is conflict-free, which is …

Evolutionary Computing Driven Search Based Software Testing And Correction, Joshua Lee Wilkerson

Doctoral Dissertations

"For a given program, testing, locating the errors identified, and correcting those errors is a critical, yet expensive process. The field of Search Based Software Engineering (SBSE) addresses these phases by formulating them as search problems. This dissertation addresses these challenging problems through the use of two complimentary evolutionary computing based systems. The first one is the Fitness Guided Fault Localization (FGFL) system, which novelly uses a specification based fitness function to perform fault localization. The second is the Coevolutionary Automated Software Correction (CASC) system, which employs a variety of evolutionary computing techniques to perform testing, correction, and verification of …

Optimal Adaptive Control Of Nonlinear Continuous-Time Systems In Strict Feedback Form With Unknown Internal Dynamics, H. Zargarzadeh, T. Dierks, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel approach is proposed for multi-input multi-output (MIMO) optimal adaptive control of nonlinear continuous-time systems in strict feedback form with uncertain internal dynamics. First, it is shown that the optimal adaptive tracking problem of strict feedback systems can be reduced to an optimal regulation problem of affine nonlinear continuous-time systems expressed as a function of tracking error by designing a properly chosen adaptive feedforward control input. Then, an optimal adaptive feedback scheme is introduced for the affine system to estimate the solution of the Hamilton-Jacobi-Bellman (HJB) equation online which becomes the optimal feedback control input for the closed-loop system. …

A Self-Tuning Optimal Controller For Affine Nonlinear Continuous-Time Systems With Unknown Internal Dynamics, Travis Dierks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel neural network (NN) - based self-tuning controller for the optimal regulation of affine nonlinear continuous-time systems. Knowledge of the internal system dynamics is not required whereas the control coefficient matrix is considered to be available. the proposed nonlinear optimal regulator tunes itself in order to simultaneously learn the optimal control input, optimal cost function, and the system internal dynamics using a single NN. a novel NN weight tuning algorithm is derived which ensures the internal system dynamics are learned while simultaneously minimizing a predefined cost function. an initial stabilizing controller is not required. Lyapunov methods …

Optimal Adaptive Controller Scheme For Uncertain Quantized Linear Discrete-Time System, Qiming Zhao, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the Bellman equation is used to solve the optimal adaptive control of quantized linear discrete-time system with unknown dynamics. to mitigate the effect of the quantization errors, the dynamics of the quantization error bound and an update law for tuning the range of the dynamic quantizer are derived. Subsequently, by using adaptive dynamic programming technique, the infinite horizon optimal regulation problem of the uncertain quantized linear discrete-time system is solved in a forward-in-time manner without using value and/or policy iterations. the asymptotic stability of the closed-loop system is verified by standard Lyapunov stability approach in the presence …

State And Output Feedback-Based Adaptive Optimal Control Of Nonlinear Continuous-Time Systems In Strict Feedback Form, H. Zargarzadeh, T. Dierks, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper focuses on neural network (NN) based adaptive optimal control of nonlinear continuous-time systems in strict feedback form with known dynamics. a single NN is utilized to learn the infinite horizon cost function which is the solution to the Hamilton-Jacobi-Bellman (HJB) equation in continuous-time. the corresponding optimal control input that minimizes the HJB equation is calculated in a forward-in-time manner without using value and policy iterations. First, the optimal control problem is solved in a generic multi-input and multi output (MIMO) nonlinear system in strict feedback form with a state feedback approach. Then, the approach is extended to single …

Distributed And Collaborative Watermarking In Relational Data, Prakash Kumar

Masters Theses

"Watermarking relational data is an important topic in the field of copyright protection, given the increasing prevalence of piracy and illegal duplication of databases. While there exists solutions for watermarking relational data, the problems that arise due to multiple ownership (two or more) of databases have not been acknowledged. This research focuses on developing a novel watermarking scheme to counter the problems. The watermarking scheme proposed necessitates the owners of the database in consideration to come together to perform the watermarking process. The scheme can be applied to insert watermarks in both numerical and categorical data. The watermarking scheme is …

Vehicle Path Verification Using Wireless Sensor Networks, Gerry W. Howser

Masters Theses

"Path Verification is a problem where a verifier would like to determine how closely a vehicle actually traversed a path that it claims to have traversed. This problem has critical significances in terms of vehicle mobility. Mobile nodes can be patrols officers or cab drivers, while respective verifiers can be police dispatchers or cab operators. In this paper, we design a sensor network assisted technique for vehicle path verification. In our design, a number of static wireless sensors placed in road segments will serve as witnesses and certify vehicles as they move. Post movement, these witness certificates will be utilized …

How Should Plastic-Packaging Companies Apply Artificial Proofs And Topics Of Invention To Communicate Sustainability? : A Heuristic Developed On The Basis Of Rhetorical Analysis, Shristy Bashyal

Masters Theses

"This study examines how the ten plastic-packaging companies use artificial proofs and topics of invention to communicate sustainability-related information. The objective of this study was to answer the following research questions:

(i) Do plastic-packaging companies define sustainability on their website?

(ii) What are the strengths and weaknesses of the arguments in these companies' sustainability-related communications?

(iii) What invention strategies should technical marketing communicators use to communicate company's sustainable practices?

To answer these questions, I analyzed the sustainability-related documents available on the websites of the ten companies. On the basis of this analysis, I developed an invention heuristic that can be …

Semantic Preserving Text Tepresentation And Its Applications In Text Clustering, Michael Howard

Masters Theses

Text mining using the vector space representation has proven to be an valuable tool for classification, prediction, information retrieval and extraction. The nature of text data presents several issues to these tasks, including large dimension and the existence of special polysemous and synonymous words. A variety of techniques have been devised to overcome these shortcomings, including feature selection and word sense disambiguation. Privacy preserving data mining is also an area of emerging interest. Existing techniques for privacy preserving data mining require the use of secure computation protocols, which often incur a greatly increased computational cost. In this paper, a generalization-based …

Under Pressure: A Psychophysiological Analysis Of The Effect Of Temporal Constraints On Information Processing And Decision Making, Nagaratna Krishna Sneha Pochinapeddi

Masters Theses

"In recent times, decision making under time pressure has become more common than ever and hence, it has become a hot topic for behavioral researchers. This research studies the effects of temporal constraints on users' decision quality and decision strategy. The paper primarily addresses two research questions: (i) Does time pressure affect decision quality? (ii) Does time pressure affect decision strategy? The decision accuracy and decision strategy of the participants were measured for three time-pressure conditions namely, No time pressure, Reasonable time pressure and Extreme time pressure. Research results from the past revealed that, Cognitive style is also observed to …

Robust Evolutionary Algorithms, Brian Wesley Goldman

Masters Theses

"Evolutionary Algorithms (EAs) have shown great potential to solve complex real world problems, but their dependence on problem specific configuration in order to obtain high quality performance prevents EAs from achieving widespread use. While it is widely accepted that statically configuring an EA is already a complex problem, dynamic configuration of an EA is a combinatorially harder problem. Evidence provided here supports the claim that EAs achieve the best results when using dynamic configurations. By designing methods that automatically configure parts of an EA or by changing how EAs work to avoid configurable aspects, EAs can be made more robust, …

Roman: Routing And Opportunistic Management Of Airborne Networks, Hemanth Meka, Lekshmi Manian Chidambaram, Sanjay K. Madria, Mark Linderman, Mohan Kumar, Sharma Chakravarthy

Computer Science Faculty Research & Creative Works

Most of the routing and replication algorithms for Mobile Peer to Peer (M-P2P) networks assume the network to be large and therefore, the architecture and algorithms are designed to be scalable. These algorithms however may not perform well with limited number of nodes in a network such as of UAVs. Thus, it is better to design algorithms to increase the efficiency of a small network if scalability is no longer an issue. for such small networks, we design and simulate an effective two layered graph-based routing algorithm using store/forward concept. We also take into account UAVs orientation and configuration of …

Empirical Study Of An Intelligent Argumentation System In Mcdm, Xiaoqing Liu, Rubal Wanchoo, Ravi Santosh Arvapally

Computer Science Faculty Research & Creative Works

Intelligent argumentation based collaborative decision-making system assists stakeholders in a decision-making group to assess various alternatives under different criterion based on the argumentation. a performance score of each alternative under every criterion in Multi-Criteria Decision Making (MCDM) is represented in a decision matrix and it denotes satisfaction of the criteria by that alternative. the process of determining the performance scores of alternatives in a decision matrix for criterion could be controversial sometimes because of the subjective nature of criterion. We developed a framework for acquiring performance scores in a decision matrix for multi-criteria decision making using an intelligent argumentation and …

A Cooperative Game Theoretic Approach For Data Replication In Mobile Ad-Hoc Networks, Dan Hirsch, Sanjay Madria

Computer Science Faculty Research & Creative Works

The mobile computing environment provides many benefits such as ubiquitous access to computing but include constraints on resources such as: Available bandwidth and battery life. Replication is a widely recognized method for balancing the demands of storage space with bandwidth and battery life. We propose a novel scheme that seeks to strategically balance these constrained resources through a cooperative game-theoretic approach for replication in a mobile environment. Our replication strategy relies on the cooperation of the nodes within the network to make replica caching decisions which are spatiotemporally local-optimal for the network from an energy and bandwidth conservation standpoint. in …

A Secure And Distributed Framework To Identify And Share Needed Information, Wei Jiang, Bharath K. Samanthula

Computer Science Faculty Research & Creative Works

Information analysis and communication play significant roles in decision making, especially in battle grounds and situations where national security is under threat. in many situations when information in consideration is sensitive/confidential, it is in our best interests to analyze and share only needed information to minimize the potential of security breach regarding other irrelevant but sensitive information. Thus, the goal of this paper is to investigate the required methodologies and propose an advanced communication framework that enables different entities in distributed environments to identify, share and analyze only needed information, without disclosing other unwanted but sensitive information. Such a framework …

Scaling Laws Of Key Predistribution Protocols In Wireless Sensor Networks, Wenjun Gu, Sriram Chellappan, Xiaole Bai, Honggang Wang

Computer Science Faculty Research & Creative Works

Many key predistribution (KP) protocols have been proposed and are well accepted in randomly deployed wireless sensor networks (WSNs). Being distributed and localized, they are perceived to be scalable as node density and network dimension increase. While it is true in terms of communication/computation overhead, their scalability in terms of security performance is unclear. in this paper, we conduct a detailed study on this issue. in particular, we define a new metric called Resilient Connectivity (RC) to quantify security performance in WSNs. We then conduct a detailed analytical investigation on how KP protocols scale with respect to node density and …

Exploring Caching For Efficient Collection Operations, Swetha Surapaneni, Venkata Krishna Suhas Nerella, Sanjay K. Madria, Thomas Weigert

Computer Science Faculty Research & Creative Works

Many useful programs operate on collection types. Extensive libraries are available in many programming languages, such as the C++ Standard Template Library, which make programming with collections convenient. Extending programming languages to provide collection queries as first class constructs in the language would not only allow programmers to write queries explicitly in their programs but it would also allow compilers to leverage the wealth of experience available from the database domain to optimize such queries. This paper describes an approach to reducing the run time of programs involving explicit collection queries by leveraging a cache to store previously computed results. …

Personalized Searching For Web Service Using User Interests, Rong Hu, Wanchun Dou, Xiaoqing Frank Liu, Jianxun Liu

Computer Science Faculty Research & Creative Works

Users usually have different prospective even they input a same keyword to search Web services. It is a challenge to personalize web service search engine as more and more keyword-like Web services becoming available on Internet. User interest plays an important role in personalizing search result. Therefore, through interest extraction, Web service search engine is personalized. at last, an experiment is presented to demonstrate the feasibility of the method. © 2011 IEEE.

Wsrank: A Method For Web Service Ranking In Cloud Environment, Rong Hu, Wanchun Dou, Xiaoqing Frank Liu, Jianxun Liu

Computer Science Faculty Research & Creative Works

For services that have similar functionalities, if they are published by different cloud platforms, it is a challenge to evaluate them, for satisfying different end users' personal preferences. in view of this challenge, a method for web service ranking, named WSRank, is investigated in cloud environment in this paper. It aims at ranking different Web services published by different cloud platforms, taking advantage of Page Rank principle. at last, a case study and experiment are presented to demonstrate the feasibility of the method. © 2011 IEEE.

Middleware For Supporting Content Sharing In Dynamic Networks, Mohan Kumar, Sharma Chakravarthy, Sanjay Kumar Madria, Mark Linderman, Waseem Naqvi

Computer Science Faculty Research & Creative Works

This paper proposes a middleware architecture to enable seamless content sharing in highly dynamic networks, such as those involving a number of aerial unmanned autonomous vehicles (UAVs), which are characterized by constantly changing connectivity and network topology. the proposed middleware maintains up-to-date network status as well as metadata information about data objects in the network nodes, masking the content sharing applications from the network dynamics and faults. Mechanisms for node discovery, message passing, and network management are developed. a strategy is also proposed for efficient replication to ensure availability of data in highly mobile environments. the middleware includes a message …

Link Activity Scheduling For Minimum End-To-End Latency In Multihop Wireless Sensor Networks, Maggie X. Cheng, Xuan Gong, Yibo Xu, Lin Cai

Computer Science Faculty Research & Creative Works

End-to-end delay is an important QoS metric in sensor networks as well as any application that involves transferring of small-sized files. in this paper, we address how to minimize the end-to-end delay in a multihop wireless network. End-to-end delay is defined as the total time it takes for a single packet to reach the destination. It is a result of many factors including the length of the routing path and the interference level along the path. in this paper we present a transmission scheduling scheme that minimizes the end-to-end delay along a given route. the link scheduling scheme is based …

Information Flow Security In Cyber-Physical Systems, Thoshitha Gamage, Ravi Akella, Thomas Roth, Bruce Mcmillin

Computer Science Faculty Research & Creative Works

Preserving the confidentiality of sensitive internal actions is a unique challenge in Cyber-Physical Systems (CPSs) due to the inherent external observability of such systems and the tight coupling between their cyber and physical domains. the far-reaching objective of this work is to develop a science of self-obfuscating systems based on the composition of simple building blocks. a model of Nondeducibility composes the building blocks under information flow security properties. to this end, this paper proposes fundamental theories on external observability for basic regular networks and the concept of "event compensation". Copyright © 2011 ACM.