Digital Commons Network^™

Quantum Dot Enhanced Epitaxial Lift-Off Solar Cells, Mitchell F. Bennett

Theses

Embedded nanostructures such as quantum dots (QDs) have been studied for many applications in solar cells including enhanced mini-band absorption in intermediate-band solar cells and current matching in multi junction cells. The major drawbacks of using such techniques to decrease intrinsic solar cell loss mechanisms are twofold: first, it is difficult to maintain partially populated states using QDs due to a quick thermal extraction of carriers; second, QDs have a weak absorption which necessitates a near-perfect control of QD growth mechanisms to carefully ensure a balance between dot size and density. One avenue for improving absorption into QDs is to …

Group Selection And Key Management Strategies For Ciphertext-Policy Attribute-Based Encryption, Russell F. Martin

Theses

Ciphertext-Policy Attribute-Based Encryption (CPABE) was introduced by Bethencourt, Sahai, and Waters, as an improvement of Identity Based Encryption, allowing fine grained control of access to encrypted files by restricting access to only users whose attributes match that of the monotonic access tree of the encrypted file. Through these modifications, encrypted files can be placed securely on an unsecure server, without fear of malicious users being able to access the files, while allowing each user to have a unique key, reducing the vulnerabilites associated with sharing a key between multiple users.

However, due to the fact that CPABE was designed for …

An Analysis Of Teacher Perspectives On The Mississippi Alternative Assessment Of Extended Curriculum Framework, Greerlynn Myrtice Bezue-Tull

Dissertations

For more than a decade, federal legislation has been characterized by increasing standards of accountability for learning for all students. With the passage of No Child Left Behind Act of 2001, and the reauthorization of the Individuals With Disabilities Education Improvement Act (IDEIA) of 2004, schools are now accountable for special education students, even students with severe cognitive disabilities, in every aspect of education, including increased student achievement through access to the general education curriculum. Moreover, IDEIA (2004) mandated that students with severe cognitive disabilities participate in high-stakes accountability testing through individual state-developed alternate assessment measures.

This study investigated whether …

Manufacture And Investigation Of Organic Composite Polymer Based Films For Advanced Flexible Solar Cells, Raffie Arshak

Masters

Modern society has created big challenges in the area of sustainable supply of energy to satisfy the needs of growing population and to account for depleting fossil fuel resources. The Irish Government has set targets for the energy sector by 2020, with 33% of electricity to be generated from renewable sources. Organic photovoltaic devices offer several advantages over expensive silicon solar cells, including deposition of ultra-thin films by spin-coating, printing and spray-coating. This in turn provides for the exciting possibility to make lightweight, flexible solar cells for a broad range of existing and emerging applications for security, military and medicine. …

Openline Newsletter, December 2013, Civil Service Council

OpenLine Newsletter

A monthly newsletter for Civil Service employees, Volume XXXVIII, Number 6, December 2013.

A New Coulomb Gauge Based Electric Field Integral Equation Method, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Wei E.I. Sha, Yat Hei Lo

Electrical and Computer Engineering Faculty Research & Creative Works

The electric field integral equation (EFIE) method is one of the most commonly-adopted computational electromagnetic methods. Its popularity stems from the efficient surface triangulation, excellent numerical precision, and the powerful capability of handling open and complex geometries. However, when the frequency tends to zero, the method-of-moment (MoM) solution of EFIE using the Rao-Wilton-Glisson (RWG) basis functions suffers from the low-frequency breakdown, where the contribution from the vector potential is extremely imbalanced with that from the scalar potential. As a result, the matrix representation of EFIE operator is highly ill-conditioned and cannot be inverted reliably and efficiently. © 2013 IEEE.

Finite Horizon Stochastic Optimal Control Of Uncertain Linear Networked Control System, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, finite horizon stochastic optimal control issue has been studied for linear networked control system (LNCS) in the presence of network imperfections such as network-induced delays and packet losses by using adaptive dynamic programming (ADP) approach. Due to an uncertainty in system dynamics resulting from network imperfections, the stochastic optimal control design uses a novel adaptive estimator (AE) to solve the optimal regulation of uncertain LNCS in a forward-in-time manner in contrast with backward-in-time Riccati equation-based optimal control with known system dynamics. Tuning law for unknown parameters of AE has been derived. Lyapunov theory is used to show …

Solutions To Finite Horizon Cost Problems Using Actor-Critic Reinforcement Learning, Ivo Grondman, Hao Xu, Sarangapani Jagannathan, Robert Babuska

Electrical and Computer Engineering Faculty Research & Creative Works

Actor-critic reinforcement learning algorithms have shown to be a successful tool in learning the optimal control for a range of (repetitive) tasks on systems with (partially) unknown dynamics, which may or may not be nonlinear. Most of the reinforcement learning literature published up to this point only deals with modeling the task at hand as a Markov decision process with an infinite horizon cost function. In practice, however, it is sometimes desired to have a solution for the case where the cost function is defined over a finite horizon, which means that the optimal control problem will be time-varying and …

Eagle-Eye: A Near-Optimal Statistical Framework For Noise Sensor Placement, Tao Wang, Chun Zhang, Jinjun Xiong, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

The relentless technology scaling has led to significantly reduced noise margin and complicated functionalities. As such, design time techniques per se are less likely to ensure power integrity, resulting in runtime voltage emergencies. To alleviate the issue, recently several works have shed light on the possibilities of dynamic noise management systems. Most of these works rely on on-chip noise sensors to accurately capture voltage emergencies. However, they all assume, either implicitly or explicitly, that the placement of the sensors is given. It remains an open problem in the literature how to optimally place a given number of noise sensors for …

Two-Stage List Sphere Decoding For Under-Determined Multiple-Input Multiple-Output Systems, Chen Qian, Jingxian Wu, Yahong Rosa Zheng, Zhaocheng Wang

Electrical and Computer Engineering Faculty Research & Creative Works

A two-stage list sphere decoding (LSD) algorithm is proposed for under-determined multiple-input multiple-output (UD-MIMO) systems that employ N transmit antennas and Msystem; while Group 2 contains layers M+1 to N that contribute to the rank deficiency of the channel Gram matrix. Tree search algorithms are used for both groups, but with different search radii. A new method is proposed to adaptively adjust the tree search radius of Group 2 based on the statistical properties of the received signals. The employment of the adaptive tree search can significantly reduce the computation complexity. We also propose a modified channel Gram matrix to …

Zero-Sum Two-Player Game Theoretic Formulation Of Affine Nonlinear Discrete-Time Systems Using Neural Networks, Shahab Mehraeen, Travis Dierks, S. Jagannathan, Mariesa L. Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the nearly optimal solution for discrete-time (DT) affine nonlinear control systems in the presence of partially unknown internal system dynamics and disturbances is considered. The approach is based on successive approximate solution of the Hamilton-Jacobi-Isaacs (HJI) equation, which appears in optimal control. Successive approximation approach for updating control and disturbance inputs for DT nonlinear affine systems are proposed. Moreover, sufficient conditions for the convergence of the approximate HJI solution to the saddle point are derived, and an iterative approach to approximate the HJI equation using a neural network (NN) is presented. Then, the requirement of full knowledge …

Capacitance Calculation For Via Structures Using An Integral Equation Method Based On Partial Capacitance, Hanfeng Wang, Siming Pan, Jingook Kim, Albert E. Ruehli, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a new integral equation formulation for via structures is developed for the capacitance extraction between vias and planes. The formulation is initially developed for axially symmetric geometries and then extended to axially asymmetric geometries by changing the circular ring cells to arc cells. The extended method can be used to calculate the shared-antipad via structure, which is widely used in high-speed differential signal interconnects. In addition, the image theory is used to handle inhomogeneous media, and a new technique is given to reduce computational costs for via-to-plane structures based on properties of the capacitance-matrix elements. The proposed …

Distributed Generation And Storage Optimal Control With State Estimation, F. Meng, D. Haughton, B. Chowdhury, Mariesa Crow, G. T. Heydt

Electrical and Computer Engineering Faculty Research & Creative Works

The increasing demand coupled with expanding installation of distributed resources call for the development of smart technologies to control and optimize distribution system operations. In this paper, a distributed generation and storage optimization algorithm is proposed using pricing signals as distribution locational marginal pricing (DLMP). This signal is used to optimize the day-ahead operation planning of distributed generation and energy storage. A distribution level state estimation algorithm is also designed. The main conclusion is that the proposed optimal control and state estimation will improve the energy efficiency and economic benefits in a digitally controlled distribution power system. © 2013 IEEE.

A Research Agenda For The Uae Ipad Initiative, Christina Gitsaki, Matthew A. Robby, Troy Priest, Khaled Hamdan, Yazid Ben-Chabane

All Works

The 2012-2013 academic year has seen the beginning of a national initiative in the United Arab Emirates to equip all students in federal universities/colleges with iPads, and to make use of this mobile device in teaching and learning. Within the context of this national initiative, each federal institution (Zayed University, UAE University and the Higher Colleges of Technology) has begun to implement iPads in its curriculum, and to gather data about this implementation to inform further development. In this paper, representatives of the three federal institutions map out the research approach which they are taking to investigate the progress of …

Dense Image Correspondence Under Large Appearance Variations, Linlin Liu, Kok-Lim Low, Wen-Yan Lin

Research Collection School Of Computing and Information Systems

This paper addresses the difficult problem of finding dense correspondence across images with large appearance variations. Our method uses multiple feature samples at each pixel to deal with the appearance variations based on our observation that pre-defined single feature sample provides poor results in nearest neighbor matching. We apply the idea in a flow-based matching framework and utilize the best feature sample for each pixel to determine the flow field. We propose a novel energy function and use dual-layer loopy belief propagation to minimize it where the correspondence, the feature scale and rotation parameters are solved simultaneously. Our method is …

Determining The Feasibility Of Implementing An Effective Fungiculture Program With The Peace Garden At Illinois Wesleyan University, Mackenzie Rivkin '14

Outstanding Senior Seminar Papers

The Peace Garden at Illinois Wesleyan University (IWU), the organic garden at the small liberal-arts university in Bloomington, Illinois, is devoted to growing nutritious, pesticide-free food to be sold locally in an attempt to counterbalance the various food-related issues which stem from conventional food systems. Mushrooms, fungi with many nutritional benefits, are not currently produced by the Peace Garden. However, the unique nature of mushrooms may be attractive to certain consumers and could further contribute to the Peace Garden's mission if produced. This study, conducted September to December 2013 is guided by the following question: What is the feasibility of …

Apakah Kreativitas Dan Sikap Terhadap Ilmu Ekonomi Meramalkan Partisipasi Politik Mahasiswa? Peran Mediasi Efikasi Politik Pada Mahasiswa Di Malang, Jawa Timur, Juneman Abraham, Diantini Ida Viatre

Makara Human Behavior Studies in Asia

This research aims to find the psychological mechanism of students’ political participation. The research was designed with predictive correlational design and the data analysis technique was path analysis. The dependent variable was political participation intention. The predictor variables were creativity and students’ attitude toward economics. The mediator variables were the necessary political experience and political efficacy. One hundred and four students of Department of Psychology, FPPsi, Malang State University, participated (Mage = 19.50 years old; SDage = 2.397 years). The research found that creativity and attitude toward economics are significant predictors for students’ political participation intention and this prediction is …

Adjust Decision-Making Targets Based On Psychological Thresholds, Jian Liu, Shun Xiang Wu, Si Feng Liu, Qiao Wang

Electrical and Computer Engineering Faculty Research & Creative Works

This paper study the impact of psychological thresholds (PTs) on the decision maker's (DM's) decision target when making decision. A new approach of decision making is proposed in this paper. First, we construct criterion expected functions according to three different types of criteria: profit type, cost-type and intermediate-type, respectively. Then, we calculate the local degree of satisfaction (LDS) of each object when PTs exists, in order to adjust the initial decision target to make up new decision table. Later, by weighting the criteria reaching the DM's degree of satisfaction (DS) along with information aggregation algorithm, we obtain the overall satisfaction …

Decision Trees To Model The Impact Of Disruption And Recovery In Supply Chain Networks, Loganathan Ponnanbalam, L. Wenbin, Xiuju Fu, Xiaofeng Yin, Zhaoxia Wang, Rick S. M. Goh

Research Collection School Of Computing and Information Systems

Increase in the frequency of disruptions in the recent times and their impact have increased the attention in supply chain disruption management research. The objective of this paper is to understand as to how a disruption might affect the supply chain network - depending upon the network structure, the node that is disrupted, the disruption in production capacity of the disrupted node and the period of the disruption - via decision trees. To this end, we first developed a 5-tier agent-based supply chain model and then simulated it for various what-if disruptive scenarios for 3 different network structures (80 trials …

An Mpi-Enabled Mapreduce Framework For Molecular Dynamics Simulation Applications, Shuju Bai, Ebrahim Khosravi, Seung Jong Park

Computer Science Faculty Research & Creative Works

Computational technologies have been extensively investigated to be applied into many application domains. Since the presence of Hadoop, an implementation of MapReduce framework, scientists have applied it to biological sciences, chemistry, medical sciences, and other areas to efficiently process huge data sets. Although Hadoop is fault-tolerant and processes data in parallel, it does not support MPI in computing. The Map/Reduce tasks in Hadoop have to be serial, which results in inefficient scientific computations wrapped in Map/Reduce tasks. In the real world, many applications require MPI techniques due to their nature. Molecular dynamics simulation is one of them. In our research, …

A Hadoop Approach To Advanced Sampling Algorithms In Molecular Dynamics Simulation On Cloud Computing, Jin Niu, Shuju Bai, Ebrahim Khosravi, Seung Jong Park

Computer Science Faculty Research & Creative Works

Cloud computing has emerged as a prevalent computing paradigm with the advantages of virtualization, scalability, fault tolerance, and a usage-based pricing model. It has been widely used in various computational research fields. Replica exchange molecular dynamics (REMD) and replica exchange statistical temperature molecular dynamics (RESTMD) are two sampling algorithms in molecular dynamics. Due to the inherent parallel feature of REMD and RESTMD, it is practical to convert them into cloud computing applications. However, the performance of REMD and RESTMD on clouds has not been extensively investigated. In our work, we implemented REMD and RESTMD in cloud computing environment through Hadoop, …

Afcd: An Approximated-Fair And Controlled-Delay Queuing For High Speed Networks, Lin Xue, Suman Kumar, Cheng Cui, Praveenkumar Kondikoppa, Chui Hui Chiu, Seung Jong Park

Computer Science Faculty Research & Creative Works

High speed networks have characteristics of high bandwidth, long queuing delay, and high burstiness which make it difficult to address issues such as fairness, low queuing delay and high link utilization. Current high-speed networks carry heterogeneous TCP flows which makes it even more challenging to address these issues. Since sender centric approaches do not meet these challenges, there have been several proposals to address them at router level via queue management (QM) schemes. These QM schemes have been fairly successful in addressing either fairness issues or large queuing delay but not both at the same time. We propose a new …

Relative Value Iteration For Average Reward Semi-Markov Control Via Simulation, Abhijit Gosavi

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper studies the semi-Markov decision process (SMDP) under the long-run average reward criterion in the simulation-based context. Using dynamic programming, a straightforward approach for solving this problem involves policy iteration; a value iteration approach for this problem involves a transformation that induces an additional computational burden. In the simulation-based context, however, where one seeks to avoid the transition probabilities needed in dynamic programming, value iteration forms a more convenient route for solution purposes. In this paper, hence, we present (to the best of knowledge for the first time) a relative value iteration algorithm for solving average reward SMDPs via …

An Agent-Based Simulation Approach To Experience Management In Theme Parks, Shih-Fen Cheng, Larry Junjie Lin, Jiali Du, Hoong Chuin Lau, Pradeep Reddy Varakantham

Research Collection School Of Computing and Information Systems

In this paper, we illustrate how massive agent-based simulation can be used to investigate an exciting new application domain of experience management in theme parks, which covers topics like congestion control, incentive design, and revenue management. Since all visitors are heterogeneous and self-interested, we argue that a high-quality agent-based simulation is necessary for studying various problems related to experience management. As in most agent-base simulations, a sound understanding of micro-level behaviors is essential to construct high-quality models. To achieve this, we designed and conducted a first-of-its-kind real-world experiment that helps us understand how typical visitors behave in a theme-park environment. …

Depauw University Computer Science Department History, Gloria Childress Townsend

Computer Science Faculty publications

The Fiftieth Anniversary of Computer Science Classes (and) The Twentieth Anniversary of the Department of Computer Science

Forward:

It is a pleasure to record the History of the Department of Computer Science, as I taught computer science throughout the first twenty years of the department's existence and the first thirty‐one years that DePauw University granted computer science majors. During these years, many faculty members joined the department, and many departed, each leaving an imprint on the department. The natural evolution of a new department necessitates the slow process of acquiring tenure track positions, as the numbers of majors increase. Several …

Context Aware Identity Management Using Smart Phones, Vamsi Paruchuri, Sriram Chellappan

Computer Science Faculty Research & Creative Works

Cell phones are personal devices that are seldom used by more than one individual. Today's smartphone not only serves as the key computing and communication mobile device of choice, but it also comes with a rich set of embedded sensors. In other words, smartphones can be considered less of a "phone" in the traditional sense and more of an identity management device. Furthermore, the unique array of sensors on a smartphone can communicate its owner's identity to the world. Smartphones are pervasive computing devices that ubiquitously accompany humans and must adapt accordingly. In this paper, we propose architecture to fully …

Pip: Privacy And Integrity Preserving Data Aggregation In Wireless Sensor Networks, Vimal Kumar, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

With the exponential rise of pervasive computing applications, data privacy has become much more of an important issue than before. When data is aggregated at each hop in a sensor network, it becomes harder to protect its privacy. A number of privacies preserving data aggregation algorithms have recently appeared for wireless sensor networks (WSNs), very few of them however also address the issue of data integrity along with privacy. Data privacy and integrity are two contrasting objectives to achieve in general. In a privacy preserved data aggregation, it becomes easier for an attacker to inject false data hence, we suggest …

Implementation Of Freedm Smart Grid Distributed Load Balancing Using Iec 61499 Function Blocks, Sandeep Patil, Valeriy Vyatkin, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

This paper presents implementation of one of the Distributed Grid Intelligence (DGI) applications: Load Balancing, using the IEC61499 architecture. This enables system level design of distributed load balancing application with a direct pathway to deployment to hardware. The use of IEC 61499 improves scalability, re-configurability and maintainability of automation software. The application was deployed to commercial programmable automation devices and embedded controller (ARM based TS-7800). The application was verified using co-simulation approach: control and power system simulated using Matlab on PC networked with the number of distributed hardware running load balance algorithm. The use of IEC 61499 facilitates deployment of …

What You Like In Design Use To Correct Bad-Smells, Marouane Kessentini, Rim Mahaouachi, Khaled Ghedira

Computer Science Faculty Research & Creative Works

Over the past decades, many techniques and tools have been developed to support maintenance activities in order to improve software quality. One of the most efficient ones is software refactoring to eliminate bad smells. A majority of existing work propose "standard" refactoring solutions that can be applied by hand for each kind of defect. However, it is difficult to prove or ensure the generality of these solutions to any kind of bad-smells or software codes. In this paper, we propose an approach to correct bad smells using well-designed code. We use genetic algorithms to generate correction solutions defined as a …

A Qualitative Study Of School Staff Perceptions Of Lasting Effects After Implementation Of Gear Up In Five Rural East Tennessee Counties, Flora R. Craig Mrs

Electronic Theses and Dissertations

This study analyzed the perceptions of 13 school staff and their experiences with the implementation of GEAR UP TN. The primary purpose of this study was to examine how program activities and services are being sustained after funding for GEAR UP TN ceased.

Qualitative methodology guided this study. This approach allowed for the perspectives and lived experiences of the school staff to be voiced and heard. Data collected included their stories based on semistructured interviews and observations.

Findings are presented in 4 themes that pertain directly to the research questions regarding key elements that contributed to program continuation, procedures that …