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

Digital Commons Network

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

Articles 1 - 30 of 35

Full-Text Articles in Entire DC Network

Optimal Placement And Control Of Unified Power Flow Control Devices Using Evolutionary Computing And Sequential Quadratic Programming, Radha P. Kalyani, Mariesa Crow, Daniel R. Tauritz Nov 2006

Optimal Placement And Control Of Unified Power Flow Control Devices Using Evolutionary Computing And Sequential Quadratic Programming, Radha P. Kalyani, Mariesa Crow, Daniel R. Tauritz

Electrical and Computer Engineering Faculty Research & Creative Works

A crucial factor effecting modern power systems today is power flow control. An effective means for controlling and improving power flow is by installing fast reacting devices such as a unified power flow controller (UPFC). For maximum positive impact of this device on the power grid, it should be installed at an optimal location and employ an optimal realtime control algorithm. This paper proposes the combination of an evolutionary algorithm (EA) to find the optimal location and sequential quadratic programming (SQP) to optimize the UPFC control settings. Simulations are conducted using the classic IEEE 118 bus test system. For comparison …


Dynamic Programming-Based Energy-Efficient Rate Adaptation For Wireless Ad Hoc Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani Nov 2006

Dynamic Programming-Based Energy-Efficient Rate Adaptation For Wireless Ad Hoc Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Resource constraints require that ad hoc wireless networks are energy efficient during transmission and rate adaptation. In this paper we propose a novel cross-layer energy-efficient rate adaptation scheme that employs dynamic programming (DP) principle to analytically select the modulation scheme online. The scheme uses channel state information from the physical layer and congestion information from the scheduling layer to select a modulation rate. This online selection maximizes throughput while saving energy and preventing congestion. The simulation results indicate that an increase in throughput by 96% and energy-efficiency by 131% is observed when compared to the Receiver Based AutoRate (RBAR) protocol.


A P2p Integration Architecture For Protein Resources, K. T. Claypool, Sanjay Kumar Madria Oct 2006

A P2p Integration Architecture For Protein Resources, K. T. Claypool, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

The availability of a direct pathway from a primary sequence (denovo or DNA derived) to macromolecular structure to biological function using computer-based tools is the ultimate goal for a protein scientist. Today's state of the art protein resources and on-going research and experiments provide the raw data that can enable protein scientists to achieve at least some steps of this goal. Thus, protein scientists are looking towards taking their benchtop research from the specific to a much broader base of using the large resources of available electronic information. However, currently the burden falls on the scientist to manually interface with …


Adaptive Critic Neural Network Force Controller For Atomic Force Microscope-Based Nanomanipulation, Qinmin Yang, Jagannathan Sarangapani Oct 2006

Adaptive Critic Neural Network Force Controller For Atomic Force Microscope-Based Nanomanipulation, Qinmin Yang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Automating the task of nanomanipulation is extremely important since it is tedious for humans. This paper proposes an atomic force microscope (AFM) based force controller to push nano particles on the substrates. A block phase correlation-based algorithm is embedded into the controller for the compensation of the thermal drift which is considered as the main external uncertainty during nanomanipulation. Then, the interactive forces and dynamics between the tip and the particle, particle and the substrate are modeled and analyzed. Further, an adaptive critic NN controller based on adaptive dynamic programming algorithm is designed and the task of pushing nano particles …


An Automated Method For Rapid Identification Of Putative Gene Family Members In Plants, Ronald L. Frank, Ajay Mane, Fikret Erçal Sep 2006

An Automated Method For Rapid Identification Of Putative Gene Family Members In Plants, Ronald L. Frank, Ajay Mane, Fikret Erçal

Biological Sciences Faculty Research & Creative Works

Background: Gene duplication events have played a significant role in genome evolution, particularly in plants. Exhaustive searches for all members of a known gene family as well as the identification of new gene families has become increasingly important. Subfunctionalization via changes in regulatory sequences following duplication (adaptive selection) appears to be a common mechanism of evolution in plants and can be accompanied by purifying selection on the coding region. Such negative selection can be detected by a bias toward synonymous over nonsynonymous substitutions. However, the process of identifying this bias requires many steps usually employing several different software programs. We …


Pervasive Data Access In Wireless And Mobile Computing Environments, Ken C. K. Lee, Wang-Chien Lee, Sanjay Kumar Madria Sep 2006

Pervasive Data Access In Wireless And Mobile Computing Environments, Ken C. K. Lee, Wang-Chien Lee, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

The rapid advance of wireless and portable computing technology has brought a lot of research interests and momentum to the area of mobile computing. One of the research focus is on pervasive data access. with wireless connections, users can access information at any place at any time. However, various constraints such as limited client capability, limited bandwidth, weak connectivity, and client mobility impose many challenging technical issues. In the past years, tremendous research efforts have been put forth to address the issues related to pervasive data access. A number of interesting research results were reported in the literature. This survey …


A Methodology For Structured Object-Oriented Elicitation And Analysis Of Temporal Constraints In Hardware/Software Co-Analysis And Co-Design Of Real-Time Systems, Sun Yan, Xiaoqing Frank Liu, Bruce M. Mcmillin Sep 2006

A Methodology For Structured Object-Oriented Elicitation And Analysis Of Temporal Constraints In Hardware/Software Co-Analysis And Co-Design Of Real-Time Systems, Sun Yan, Xiaoqing Frank Liu, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

The hardware/software co-design of a high-quality real-time system relies heavily on the modeling of both the hardware and software components from three aspects: structures, functionalities, and constraints, especially the temporal constraints. However, there is not a systematic process for the elicitation and analysis of temporal constraints in hardware/software co-design. Furthermore, existing object-oriented methods provide no means for the explicit specification of system/component constraints in object models. This paper presents a systematic methodology for structured object-oriented analysis and specification of temporal constraints in hardware/software co-analysis and co-design using an extended High-Order Object-Oriented Modeling Technique (HOOMT). This methodology hierarchically elicits and analyzes …


An Instance-Based Structured Object Oriented Method For Co-Analysis/Co-Design Of Concurrent Embedded Systems, Matt Ryan, Xiaoqing Frank Liu, Bruce M. Mcmillin, Ying Cheng, Sule Simsek Sep 2006

An Instance-Based Structured Object Oriented Method For Co-Analysis/Co-Design Of Concurrent Embedded Systems, Matt Ryan, Xiaoqing Frank Liu, Bruce M. Mcmillin, Ying Cheng, Sule Simsek

Computer Science Faculty Research & Creative Works

The current object-oriented class-based approaches to hardware/software co-analysis/co-design of embedded systems are limited in their abilities to properly capture the structure of individual instances of hardware and software components and their interactions. This paper discusses a methodology to extend a structured objectoriented hardware/software co-design methodology based on the High Order Object-oriented Modeling Technique (HOOMT) to incorporate instance-based object and behavioral models. The instance-based structured object-oriented methodology will enable description of a system's structure based on individual instances of hardware and software components and specification of the interactions among them. In addition, lattices are introduced to specify the concurrent behavior of …


Two Energy Efficient Algorithms For Tracking Objects In A Sensor Network, Arvind Rapaka, Sanjay Kumar Madria Jul 2006

Two Energy Efficient Algorithms For Tracking Objects In A Sensor Network, Arvind Rapaka, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

We propose two energy efficient algorithms for locating a target object moving in an area covered by a wireless ad hoc network. The first algorithm developed conserve energy by efficiently identifying sensor nodes, as Home Nodes, and use only local messages between neighboring nodes to follow the trail of the object. Since we avoid the long-range transmission and maximize the localization, the algorithms reduce the communication cost. The dynamic nature of the second algorithm exploits the predefined parameters such as the object velocity. Our algorithm represents query shipping against the conventional data shipping as a means to reduce the amount …


Neural Network Based Decentralized Excitation Control Of Large Scale Power Systems, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch, David A. Cartes, Jagannathan Sarangapani Jul 2006

Neural Network Based Decentralized Excitation Control Of Large Scale Power Systems, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch, David A. Cartes, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a neural network (NN) based decentralized excitation controller design for large scale power systems. The proposed controller design considers not only the dynamics of generators but also the algebraic constraints of the power flow equations. The control signals are calculated using only local signals. The transient stability and the coordination of the subsystem controllers can be guaranteed. NNs are used to approximate the unknown/imprecise dynamics of the local power system and the interconnections. All signals in the closed loop system are guaranteed to be uniformly ultimately bounded (UUB). Simulation results with a 3-machine power system demonstrate the …


Genetic Code Based Coding And Mathematical Formulation For Dna Computation, Mingjun Zhang, Maggie Xiaoyan Cheng, Tzyh-Jong Tarn Jun 2006

Genetic Code Based Coding And Mathematical Formulation For Dna Computation, Mingjun Zhang, Maggie Xiaoyan Cheng, Tzyh-Jong Tarn

Computer Science Faculty Research & Creative Works

DNA computation is to use DNA molecules for information storing and processing. Challenges currently faced by DNA computation are (1) lack of theoretical computational models for applications, and (2) high error rate for implementation. This paper attempts to address these problems from genetic coding and mathematical modeling aspects. The proposed genetic coding approach provides a promising alternative to reduce high error rate. The mathematical formulation lays down groundwork for studying theoretical aspects of DNA computation.


Adaptive Neural Network Control And Wireless Sensor Network Based Localization For Uav Formation, H. Wu, Jagannathan Sarangapani Jun 2006

Adaptive Neural Network Control And Wireless Sensor Network Based Localization For Uav Formation, H. Wu, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

We consider a team of unmanned aerial vehicles (UAV's) equipped with sensors and motes for wireless communication for the task of navigating to a desired location in a formation. First a neural network (NN)-based control scheme is presented that allows the UAVs to track a desired position and orientation with reference to the neighboring UAVs or obstacles in the environment. Second, we discuss a graph theory-based scheme for discovery, localization and cooperative control. The purpose of the NN cooperative controller is to achieve and maintain the desired formation shape in the presence of unmodeled dynamics and bounded unknown disturbances. Numerical …


Nanomanipulation Using Atomic Force Microscope With Drift Compensation, Qinmin Yang, Jagannathan Sarangapani Jun 2006

Nanomanipulation Using Atomic Force Microscope With Drift Compensation, Qinmin Yang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes an atomic force microscope (AFM) based force controller to push nanoparticles on the substrates since it is tedious for human. A block phase correlation-based algorithm is embedded into the controller for compensating the thermal drift during nanomanipulation. Further, a neural network (NN) is employed to approximate the unknown nanoparticle and substrate contact dynamics including the roughness effects. Using the NN-based adaptive force controller the task of pushing nanoparticles is demonstrated. Finally, using the Lyapunov-based stability analysis, the uniform ultimately boundedness (UUB) of the closed-loop signals is demonstrated


The Antecedents Of M-Commerce Adoption, Morris Kalliny, Michael S. Minor Jan 2006

The Antecedents Of M-Commerce Adoption, Morris Kalliny, Michael S. Minor

Business and Information Technology Faculty Research & Creative Works

The growth of Internet shopping has been attributed to rapid advances in technology and other influences such as convenience. We empirically investigate the relationship between demographics, ease of use, convenience, usefulness and enjoyment and intention to use m-commerce and attitude toward m-commerce. Two studies were conducted where a student and a non student sample was used. Data analysis revealed age, gender and educational level of customers do not play a role in influencing intention to use m-commerce. However, convenience, ease of use, usefulness and enjoyment all play a role in the customer's intention to use m-commerce.


Use Of A Classroom Response System To Enhance Classroom Interactivity, Keng Siau, Hong Sheng, Fiona Fui-Hoon Nah Jan 2006

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 …


Adaptive And Probabilistic Power Control Algorithms For Dense Rfid Reader Network, Kainan Cha, Anil Ramachandran, Jagannathan Sarangapani Jan 2006

Adaptive And Probabilistic Power Control Algorithms For Dense Rfid Reader Network, Kainan Cha, Anil Ramachandran, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

In radio frequency identification (RFID) systems, the detection range and read rates may suffer from interferences between high power devices such as readers. In dense networks, this problem grows severely and degrades system performance. In this paper, we investigate feasible power control schemes to ensure overall coverage area of the system while maintaining a desired data rate. The power control should dynamically adjust the output power of a RFID reader by adapting to the noise level seen during tag reading and acceptable signal-to-noise ratio (SNR). We present a novel distributed adaptive power control (DAPC) and probabilistic power control (PPC) as …


Decentralized Power Control With Implementation For Rfid Networks, Kainan Cha, Anil Ramachandran, David Pommerenke, Jagannathan Sarangapani Jan 2006

Decentralized Power Control With Implementation For Rfid Networks, Kainan Cha, Anil Ramachandran, David Pommerenke, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

In radio frequency identification (RFID) systems, the detection range and read rates will suffer from interference among high power reading devices. This problem grows severely and degrades system performance in dense RFID networks. In this paper, we investigate a suite of feasible power control schemes to ensure overall coverage area of the system while maintaining a desired read rate. The power control scheme and MAC protocol dynamically adjusts the RFID reader power output in response to the interference level seen locally during tag reading for an acceptable signal-to-noise ratio (SNR). We present novel distributed adaptive power control (DAPC) and probabilistic …


Data Replication For Improving Data Accessibility In Ad Hoc Networks, Sanjay Kumar Madria, Takahiro Hara Jan 2006

Data Replication For Improving Data Accessibility In Ad Hoc Networks, Sanjay Kumar Madria, Takahiro Hara

Computer Science Faculty Research & Creative Works

In ad hoc networks, due to frequent network partition, data accessibility is lower than that in conventional fixed networks. In this paper, we solve this problem by replicating data items on mobile hosts. First, we propose three replica allocation methods assuming that each data item is not updated. In these three methods, we take into account the access frequency from mobile hosts to each data item and the status of the network connection. Then, we extend the proposed methods by considering aperiodic updates and integrating user profiles consisting of mobile users'' schedules, access behavior, and read/write patterns. We also show …


Model Checking Control Communication Of A Facts Device, Bruce M. Mcmillin, J. K. Townsend, David Cape Jan 2006

Model Checking Control Communication Of A Facts Device, Bruce M. Mcmillin, J. K. Townsend, David Cape

Computer Science Faculty Research & Creative Works

This paper concerns the design and verification of a realtime communication protocol for sensor data collection and processing between an embedded computer and a DSP. In such systems, a certain amount of data loss without recovery may be tolerated. The key issue is to define and verify the correctness in the presence of these lost data frames under real-time constraints. This paper describes a temporal verification that if the end processes do not detect that too many frames are lost, defined by comparison of error counters against given threshold values, then there will be a bounded delay between transmission of …


Improving Channel Throughput Of Wlans And Ad Hoc Networks Using Explicit Denial Of Requests, Maggie Xiaoyan Cheng, Yadi Ma, Yi Wang Jan 2006

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.


Distributed Power Control For Cellular Networks In The Presence Of Channel Uncertainties, Maciej Jan Zawodniok, Q. Shang, Jagannathan Sarangapani Jan 2006

Distributed Power Control For Cellular Networks In The Presence Of Channel Uncertainties, Maciej Jan Zawodniok, Q. Shang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel distributed power control (DPC) scheme for cellular network in the presence of radio channel uncertainties such as path loss, shadowing, and Rayleigh fading is presented. Since these uncertainties can attenuate the received signal strength and can cause variations in the received Signal-to-Interference ratio (SIR), a new DPC scheme, which can estimate the slowly varying channel uncertainty, is proposed so that a target SIR at the receiver can be maintained. Further, the standard assumption of a constant interference during a link's power update used in other works in the literature is relaxed. A CDMA-based cellular network …


A Mathematical Formulation Of Dna Computation, Mingjun Zhang, Maggie Xiaoyan Cheng, Tzyh-Jong Tarn Jan 2006

A Mathematical Formulation Of Dna Computation, Mingjun Zhang, Maggie Xiaoyan Cheng, Tzyh-Jong Tarn

Computer Science Faculty Research & Creative Works

DNA computation is to use DNA molecules for information storing and processing. The task is accomplished by encoding and interpreting DNA molecules in suspended solutions before and after the complementary binding reactions. DNA computation is attractive, due to its fast parallel information processing, remarkable energy efficiency, and high storing capacity. Challenges currently faced by DNA computation are (1) lack of theoretical computational models for applications, and (2) high error rate for implementation. This paper attempts to address these problems from mathematical modeling and genetic coding aspects. The first part of this paper presents a mathematical formulation of DNA computation. The …


Cadre: A Collaborative Replica Allocation And Deallocation Approach For Mobile-P2p Networks, Anirban Mondal, Sanjay Kumar Madria, Masaru Kitsuregawa Jan 2006

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 …


Adaptive Distributed Fair Scheduling And Its Implementation In Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda Jan 2006

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 …


Development And Implementation Of Optimized Energy-Delay Sub-Network Routing Protocol For Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda Jan 2006

Development And Implementation Of Optimized Energy-Delay Sub-Network Routing Protocol For Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda

Electrical and Computer Engineering Faculty Research & Creative Works

The development and implementation of the optimized energy-delay sub-network routing (OEDSR) protocol for wireless sensor networks (WSN) is presented. This ondemand routing protocol minimizes a novel link cost factor which is defined using available energy, end-to-end (E2E) delay and distance from a node to the base station (BS), along with clustering, to effectively route information to the BS. Initially, the nodes are either in idle or sleep mode, but once an event is detected, the nodes near the event become active and start forming sub-networks. Formation of the inactive network into a sub-network saves energy because only a portion of …


Neural Network-Based Output Feedback Controller For Lean Operation Of Spark Ignition Engines, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier, Jonathan B. Vance, Pingan He Jan 2006

Neural Network-Based Output Feedback Controller For Lean Operation Of Spark Ignition Engines, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier, Jonathan B. Vance, Pingan He

Electrical and Computer Engineering Faculty Research & Creative Works

Spark ignition (SI) engines running at very lean conditions demonstrate significant nonlinear behavior by exhibiting cycle-to-cycle dispersion of heat release even though such operation can significantly reduce NOx emissions and improve fuel efficiency by as much as 5-10%. A suite of neural network (NN) controller without and with reinforcement learning employing output feedback has shown ability to reduce the nonlinear cyclic dispersion observed under lean operating conditions. The neural network controllers consists of three NN: a) A NN observer to estimate the states of the engine such as total fuel and air; b) a second NN for generating virtual input; …


Neuro Control Of Nonlinear Discrete Time Systems With Deadzone And Input Constraints, Pingan He, Wenzhi Gao, Jagannathan Sarangapani Jan 2006

Neuro Control Of Nonlinear Discrete Time Systems With Deadzone And Input Constraints, Pingan He, Wenzhi Gao, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A neural network (NN) controller in discrete time is designed to deliver a desired tracking performance for a class of uncertain nonlinear systems with unknown deadzones and magnitude constraints on the input. The NN controller consists of two NNs: the first NN for compensating the unknown deadzones; and the second NN for compensating the uncertain nonlinear system dynamics. The magnitude constraints on the input are modeled as saturation nonlinearities and they are dealt with in the Lyapunov-based controller design. The uniformly ultimate boundedness (UUB) of the closed-loop tracking errors and the neural network weights estimation errors is demonstrated via Lyapunov …


Window Query Processing With Proxy Cache, Gao Xing, John Sustersic, A. R. Hurson Jan 2006

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 …


Multimedia Correlation Analysis In Unstructured Peer-To-Peer Network, Bo Yang, A. R. Hurson, Yu Jiao, Thomas E. Potok Jan 2006

Multimedia Correlation Analysis In Unstructured Peer-To-Peer Network, Bo Yang, A. R. Hurson, Yu Jiao, Thomas E. Potok

Computer Science Faculty Research & Creative Works

Recent years saw the rapid development of peer-topeer (P2P) networks in a great variety of applications. However, similarity-based k-nearest-neighbor retrieval (k-NN) is still a challenging task in P2P networks due to the multiple constraints such as the dynamic topologies and the unpredictable data updates. Caching is an attractive solution that reduces network traffic and hence could remedy the technological constraints of P2P networks. However, traditional caching techniques have some major shortcomings that make them unsuitable for similarity search, such as the lack of semantic locality representation and the rigidness of exact matching on data objects. To facilitate the efficient similarity …


Practical Experiences In Using Model-Driven Engineering To Develop Trustworthy Computing Systems, Thomas Weigert, Frank Weil Jan 2006

Practical Experiences In Using Model-Driven Engineering To Develop Trustworthy Computing Systems, Thomas Weigert, Frank Weil

Computer Science Faculty Research & Creative Works

In this paper, we describe how Motorola has deployed model-driven engineering in product development, in particular for the development of trustworthy and highly reliable telecommunications systems, and outline the benefits obtained. Model-driven engineering has dramatically increased both the quality and the reliability of software developed in our organization, as well as the productivity of our software engineers. Our experience demonstrates that model-driven engineering significantly improves the development process for trustworthy computing systems.