Digital Commons Network^™

Bacteria Foraging: A New Tool For Simultaneous Robust Design Of Upfc Controllers, M. Tripathy, S. Mishra, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Robust tuning of lead-lag type controller used for regulating FACTS control signal to improve dynamic stability has been an area of interest in research. This paper presents a new approach based on the foraging behavior of E. coli Bacteria in the human intestine, to optimize simultaneously three constants each of four lead-lag type UPFC controller present in a Single Machine Infinite Bus (SMIB) power system. For the tuning purpose, a multi-objective cost function is formulated that accounts for damping factors and ratios of various system modes for a wide range of operating conditions. Robustness of the proposed tuning method is …

A Hierarchical Secure Routing Protocol Against Black Hole Attacks In Sensor Networks, Jian Yin, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

A black hole attack is a severe attack that can be easily employed against routing in sensor networks. In a black hole attack, a malicious node spuriously announces a short route to the sink node (the destination) to attract additional traffic to the malicious node and then drops them. In this paper, we propose a hierarchical secure routing protocol for detecting and defending against black hole attacks. The proposed protocol uses only symmetric key cryptography to discover a safe route against black hole attacks. The comparison of the proposed protocol with two other existing approaches proves that the proposed scheme …

An Internet Based Intelligent Argumentation System For Collaborative Engineering Design, Xiaoqing Frank Liu, Samir Raorane, Man Zheng, Ming-Chuan Leu

Computer Science Faculty Research & Creative Works

Modern product design is a very complicated process which involves groups of designers, manufacturers, suppliers, and customer representatives. Conflicts are unavoidable in collaboration among multiple stakeholders, who have different objectives, requirements, and priorities. Unfortunately, current web-based collaborative engineering design systems do not support collaborative conflict resolution. In this paper, we will develop an intelligent computational argumentation model to enable management of a large scale argumentation network, and resolution of conflicts based on argumentation from many participants. A web-based intelligent argumentation tool is developed as a part of a web-based collaborative engineering design system based on the above model to resolve …

A Methodology For Deriving System Requirements Using Agent Based System Modeling, Karthik Gopalakrishnan, Sreeram Ramakrishnan, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

In this paper, we duscuss a method to derive the requirements for developing an Industrial Automation and Constrol System (IACS). An IACS has software components and associated hardware, which together implement the required monitoring, supervision and control of operations an a production plant. The requirements of such a system are multi-dimensional and may require multiple layers of abstraction. For this domain, we propose an agent-based modeling adopting an agent-based modeling approach is the implicit flexibility afforded by agents and the negotiation techniques that can be implemented to streamline the change management process associated with requirements modeling and analysis. This paper …

Cadre: A Collaborative Replica Allocation And Deallocation Approach For Mobile-P2p Networks, Anirban Mondal, Sanjay Kumar Madria, Masaru Kitsuregawa

Computer Science Faculty Research & Creative Works

This paper proposes CADRE (Collaborative Allocation and Deallocation of Replicas with Efficiency), a dynamic replication scheme for improving the typically low data availability in mobile ad-hoc peer-to-peer (M-P2P) networks. The main contributions of CADRE are two-fold. First, it collaboratively performs both replica allocation and deallocation in tandem to facilitate optimal replication and to avoid 'thrashing' conditions. Second, it addresses fair replica allocation across the MHs. CADRE deploys a hybrid super-peer architecture in which some of the MHs act as the 'gateway nodes' (GNs) in a given region. GNs facilitate both search and replication. Our performance study indicates that CADRE indeed …

A Simulation Framework For Real-Time Management And Control Of Inventory Routing Decisions, Shrikant Jarugumilli, Sreeram Ramakrishnan, Scott Erwin Grasman

Engineering Management and Systems Engineering Faculty Research & Creative Works

We consider a logistics network where a single warehouse distributes a single item to multiple retailers. Retailers in the network participate in a Vendor Managed Inventory (VMI) program with the warehouse, where the warehouse is responsible for tracking and replenishing the inventory at various retailer locations. The information update occurs every time a vehicle reaches a location and the decision on the delivery quantity and the next location to visit is made. For a small increase of locations in the network, the state space for the solution increases exponentially, making this problem NP-hard. Thus, we propose a solution methodology where …

Energy And Communication Efficient Group Key Management Protocol For Hierarchical Sensor Networks, Biswajit Panja, Sanjay Kumar Madria, Bharat Bhargava

Computer Science Faculty Research & Creative Works

In this paper, we describe group key management protocosl for hierarchical sensor networks where instead of using pre-deployed keys, each sensor node generates a partial key dynamically using a function. The function takes partial keys of its children as input. The design of the protocol is motivated by the fact that traditional cryptographic techniques are impractical in sensor networks because of high energy and computational overheads. The group key management protocol supports the establishment of two types of group keys; one for the sensor nodes within a group, and the other in a group of cluster heads. The protocol handles …

Generalized Distance Metric As A Robust Similarity Measure For Mobile Object Trajectories, Garima Pathak, Sanjay Kumar Madria, Spandan Tiwari

Computer Science Faculty Research & Creative Works

In this paper, we propose a novel generalized distance metric based on a model that incorporates the time axis explicitly. The proposed metric is based fundamentally on the Mahalanobis distance metric, which eliminates the correlation and scaling errors in similarity searches on trajectory databases. We propose the incorporation of a weight matrix in the proposed distance metric, which allows for easy manipulation of the degree of significance of the different spatial and or temporal dimensions.

Modeling Net-Centric System Of Systems Using The Dystems Modeling Language Sysml, Rao Madwaraj, Sreeram Ramakrishnan, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Understanding the operations of a large 'net-centric system-of-systems requires in-depth knowledge of the interfaces among the various systems, sub-systems and components. Architectural modeling can help in reducing the complexity involved in designing such large networked systems. An example of such a complex system is the Global Earth Observation System of Systems (GEOSS) - a system for monitoring and collecting information related to Earth's resources. This paper demonstrates the use of Systems Modeling Language (SysML), which supports specification, analysis, design, verification and validation of a broad range of complex systems, to model some aspects of the GEOSS. The paper discusses issues …

Improving Channel Throughput Of Wlans And Ad Hoc Networks Using Explicit Denial Of Requests, Maggie Xiaoyan Cheng, Yadi Ma, Yi Wang

Computer Science Faculty Research & Creative Works

A new Multiple Access Control scheme for wireless ad hoc networks and WLANs is proposed. This scheme uses explicit denial of channel requests and a busy tone to improve channel throughput. Performance analysis shows significant improvement when the network is under heavy traffic load.

Secrout: A Secure Routing Protocol For Sensor Networks, Jian Yin, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

In this paper, we present a secure routing protocol for sensor networks (SecRout) to safeguard sensor networks under different types of attacks. The SecRout protocol uses the symmetric cryptography to secure messages, and uses a small cache in sensor nodes to record the partial routing path (previous and next nodes) to the destination. It guarantees that the destination will be able to identify and discard the tampered messages and ensure that the messages received are not tampered. Comparing the performance with non-secure routing protocol AODV (ad hoc on demand distance vector routing), the SecRout protocol only has a small byte …

Window Query Processing With Proxy Cache, Gao Xing, John Sustersic, A. R. Hurson

Computer Science Faculty Research & Creative Works

A location dependent query (LDQ) result set is valid only in a specific region called the validity region (VR). While limiting the validity of a particular result set to a given area, the VR may also be used in caching implementations to determine if cached results satisfy semantically equivalent queries. Existing LDQ caching schemes rely on the database servers to provide the VR at a cost of high computational overhead. Alternatively, a LDQ proxy cache, which approximates the VR can be employed, freeing the database servers from the high cost of calculating the VR. A LDQ proxy cache architecture is …

Modeling Of Dielectric Mixtures Containing Conducting Inclusions With Statistically Distributed Aspect Ratio, Marina Koledintseva, Sandeep K. R. Chandra, Richard E. Dubroff, Robert W. Schwartz

Electrical and Computer Engineering Faculty Research & Creative Works

An analytical model of composites made of a dielectric base and randomly oriented metal inclusions in the form of nanorods is presented. This model is based on the generalized Maxwell Garnett (MG) mixing rule. In this model, the nanorod particles are modeled as prolate spheroids with a statistically normal distribution of their aspect ratios. It is shown that parameters of the distribution laws affect the frequency characteristics of the composites both at microwave and optical frequencies. The results of computations are represented.

Surface Modification Of Su-8 By Photografting Of Functional Polymers For Lab-On-A-Chip Applications, Zhan Gao, David Henthorn, Chang-Soo Kim

Chemical and Biochemical Engineering Faculty Research & Creative Works

Due to the high flexibility and versatility in the process development of microfluidic devices, an epoxybased, high-aspect ratio photoresist SU-8 is now attracting attention as the main structuring material of the fluidic channels. Manipulation of the surface properties of SU-8 channel wall is critical to attach functional films such as enzyme-immobilized layers or biocompatible layers. We describe a new in situ patterning method to form a hydrogel film on SU-8 by a photografted polymerization procedure. The hydrophobic surface of SU-8 is modified using a surface bound initiator HCPK (1-hydroxycyclohexyl phenyl ketone). A p-HEMA (poly-2-hydroxyethylmethacrylate) hydrogel film is grafted by photopolymerization …

Predicting Load Harmonics In Three Phase Systems Using Neural Networks, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a artificial neural network (ANN) based method for the problem of measuring the actual harmonic current injected into a power system network by three phase nonlinear loads without disconnecting any loads from the network. The ANN directly estimates or identifies the nonlinear admittance (or impedance) of the load by using the measured values of voltage and current waveforms. The output of this ANN is a waveform of the current that the load would have injected into the network if the load had been supplied from a sinusoidal voltage source and is therefore a direct measure of load …

Recurrent Neural Network Based Predictions Of Elephant Migration In A South African Game Reserve, Parviz Palangpour, Ganesh K. Venayagamoorthy, Kevin Duffy

Electrical and Computer Engineering Faculty Research & Creative Works

A large portion of South Africa''s elephant population can be found on small wildlife reserves. When confined to enclosed reserves the elephant densities are much higher than observed in the wild. The large nutritional demands and destructive foraging behavior of elephants threaten rare species of vegetation. If conservation management is to protect threatened species of vegetation, knowing how long elephants will stay in one area of the reserve as well as which area they will move to next is essential. The goal of this study is to train a recurrent neural network (RNN) to continuously predict an elephant herd''s next …

Simulation Model For Assessing Transient Performance Of Capacitive Voltage Transformers, I. Sule, Ganesh K. Venayagamoorthy, U. O. Aliyu

Electrical and Computer Engineering Faculty Research & Creative Works

In determining the correct operation of relays of a protection scheme, proper representation of instrument transformers and their behavior in conditions where there can be transient is very critical. This paper presents a simulation model for assessing the transient performance of capacitive voltage transformers (CVTs). In order to test the validity of the developed model, four CVT operational conditions are considered using field data collected from one of the Nigerian electric utility 330/132/33 kV substations. The model simulation results revealed various configuration performance responses that could affect relay protection schemes to different degrees. As expected, the CVT responses showed that …

Synthesis And Characterization Of Nanocrystalline (Zr₀.₈₄Y₀.₁₆)O₁.₉₂-(Ce₀.₈₅Sm₀.₁₅)O₁.₉₂₅ Heterophase Thin Films, Aniruddha Kulkarni, Alexander Bourandas, Junhang Dong, Paul A. Fuierer, Hai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

A new type of nanocrystalline samarium-doped-ceria/yttrium-stabilized-zirconia (SDC/YSZ) heterophase thin film electrolytes was synthesized on MgO and Si substrates by spin coating and thermal treatment of SDC-nanoparticle-incorporated polymeric precursors. In the heterophase films, SDC nanoparticles were uniformly dispersed in a nanocrystalline YSZ matrix. The heterophase structure was stable when fired in air at temperatures up to 850 °C. The nanocrystalline heterophase thin films exhibited electrical conductivities significantly higher than that of the phase-pure YSZ and SDC nanocrystalline thin films at reduced temperatures. The effects of SDC grain size and volume fraction on the electrical conductivity of the heterophase films were also …

A Fault-Tolerant P-Q Decoupled Control Scheme For Static Synchronous Series Compensator, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Control of nonlinear devices in power systems relies on the availability and the quality of sensor measurements. Measurements can be corrupted or interrupted due to sensor failure, broken or bad connections, bad communication, or malfunction of some hardware or software (referred to as missing sensor measurements in this paper). This paper proposes a fault-tolerant control scheme (FTCS) for a static synchronous series compensator (SSSC). This FTCS consists of a sensor evaluation and (missing sensor) restoration scheme (SERS) cascaded with a P-Q decoupled control scheme (PQDC). It is able to provide effective control to the SSSC when single or multiple crucial …

Ac/Dc Power Systems With Applications In Future Human Habitat On Lunar And Mars Bases, Badrul H. Chowdhury, Sabbir A. Hossain, James T. Lawrence, Sushant Barave

Electrical and Computer Engineering Faculty Research & Creative Works

As NASA readies itself for new space exploration initiatives starting with a human return to the Moon by the year 2020 eventually leading to human exploration of Mars, the requirements for a safe, efficient and comprehensive power system to support the exploration missions as well human habitat will become important issues to consider. Certain issues dealing with electric power generation and distribution on board Mars-bound vehicles and those on Lunar and Martian surfaces are described. The requirements for lightweight power generation dictates the use of a high frequency ac machine. Preliminary results of investigating the design of a permanent magnet …

Adaptive Critic Designs Based Coupled Neurocontrollers For A Static Compensator, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

A novel nonlinear optimal neurocontroller for a static compensator (STATCOM) connected to a power system, using artificial neural networks, is presented in this paper. The heuristic dynamic programming (HDP) method, a member of the adaptive critic designs (ACD) family, is used for the design of the STATCOM neurocontroller. The proposed controller is a nonlinear optimal controller that provides coupled control for the line voltage and the dc link voltage regulation loops of the STATCOM. An action dependent approach is used, in which the controller is independent of a model of the network. Moreover, a proportional-integrator approach allows the neurocontroller to …

Adaptive Distributed Fair Scheduling And Its Implementation In Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda

Electrical and Computer Engineering Faculty Research & Creative Works

A novel adaptive and distributed fair scheduling (ADFS) scheme for wireless sensor networks is shown through hardware implementation. In contrast to simulation, hardware evaluation provides valuable feedback to protocol and hardware development process. The proposed protocol focuses on quality-of-service (QoS) issues to address flow prioritization. Thus, when nodes access a shared channel, the proposed ADFS allocates the channel bandwidth proportionally to the weight, or priority, of the packet flows. Moreover, ADFS allows for dynamic allocation of network resources with little added overhead. Weights are initially assigned using user specified QoS criteria. These weights are subsequently updated as a function of …

An Interval Type-Ii Robust Fuzzy Logic Controller For A Static Compensator In A Multimachine Power System, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel fuzzy logic based controller for a Static Compensator (STATCOM) connected to a power system. Type-II fuzzy systems are selected that enable the controller to deal with design uncertainties and the noise associated with the measurements in the power system. Interval type-II fuzzy is computationally more effective than the ordinary type-II fuzzy systems and is more suitable for the power network with fast changing dynamics. Using a proportional-integrator approach the proposed controller is capable of dealing with actual rather than deviation signals. The STATCOM is connected to a multimachine power system in order to provide extra …

A Comparison Of Diode-Clamped And Cascaded Multilevel Converters For A Statcom With Energy Storage, Ying Cheng, Chang Qian, Mariesa Crow, Steven Pekarek, Stan Atcitty

Electrical and Computer Engineering Faculty Research & Creative Works

The progression of distributed generation within a bulk power system will lead to the need for greater control of transmission-line power flows. Static synchronous compensators (STATCOMs) provide a power-electronics-based means of embedded control of transmission-line voltage and power flows. The integration of energy storage with a STATCOM can extend traditional STATCOM capabilities to four-quadrant power flow control and transient stability improvement. This paper discusses energy storage systems (ESSs) integrated with conventional and multilevel bidirectional power converters for a hybrid STATCOM/ESS. Conventional, diode-clamped, and cascaded multilevel converter-based STATCOM/ESSs are developed, and their performances for a variety of power system applications are …

A Non-Isotropic Model For Mobile-To-Mobile Fading Channel Simulations, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

Accurate modeling of the mobile-to-mobile fading channel is critical not only to physical layer transceiver design but also to the design and performance of link and network layers. A two-dimensional nonisotropic scattering model is developed in this paper, which adopts the von Mises probability density function for the angle of departure surrounding the transmitter and the angle of arrival surrounding the receiver. This model includes the isotropic scattering channel and the base-to-mobile channel as special cases. An efficient computer simulation model is also developed to generate the non-isotropic scattering channel impulse responses. Statistical properties of the non-isotropic mobile-to-mobile channels are …

Asia Pacific Perspectives Vol. 6 No. 1, May 2006, University Of San Francisco, University Of San Francisco

Asia Pacific Perspectives

Contents:

Philippine Studies and the Centennial of the Diaspora: An Introduction by Joaquin L. Gonzalez III, and Evelyn I. Rodriguez

Primerang Bituin: Philippines-Mexico Relations at the Dawn of the Pacific Rim Century by Evelyn I. Rodriguez

Since the end of WWII, the region of countries bordering, and various island nations within, the Pacific Ocean, has drawn much attention, and been subject to a variety of institutional arrangements intended to promote certain political, economic, and environmental interests. Because of this, the mid-twentieth century is widely held as the starting point for Pacific Rim relations, and studies of Pan-Pacific interactions almost strictly …

Efficient Mining Of Group Patterns From User Movement Data, Yida Wang, Ee Peng Lim, San-Yih Hwang

Research Collection School Of Computing and Information Systems

In this paper, we present a new approach to derive groupings of mobile users based on their movement data. We assume that the user movement data are collected by logging location data emitted from mobile devices tracking users. We formally define group pattern as a group of users that are within a distance threshold from one another for at least a minimum duration. To mine group patterns, we first propose two algorithms, namely AGP and VG-growth. In our first set of experiments, it is shown when both the number of users and logging duration are large, AGP and VG-growth are …

An Ethnoarchaeological Analysis Of Human Functional Dynamics In The Volta Basin Of Ghana: Before And After The Akosombo Dam, By E. Kofi Agorsah, Joanna Casey

Faculty Publications

No abstract provided.

Studies In Slang, Vii, Barry A. Popik, Gerald Leonard Cohen

Arts, Languages and Philosophy Faculty Research & Creative Works

No abstract provided.

Use Of A Classroom Response System To Enhance Classroom Interactivity, Keng Siau, Hong Sheng, Fiona Fui-Hoon Nah

Business and Information Technology Faculty Research & Creative Works

Classroom interactivity is a critical component of teaching and learning. This paper reports on the use of a classroom response system to enhance classroom interactivity in a systems analysis and design course. The success of the project was assessed using both quantitative and qualitative data. A pretest/posttest design was used to examine the effects of a classroom response system on interactivity. The results show that a classroom response system can significantly improve classroom interactivity. Qualitative data was also collected to identify the strengths and weaknesses of using a classroom response system to enhance classroom interaction. Based on the quantitative and …