Engineering Commons^™

Delta-Sigma Subarray Beamforming For Ultrasound Imaging, Hasan Şaki̇r Bi̇lge

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, an ultrasonic digital beamformer based on subarray processing of 1-bit delta-sigma (\Delta \Sigma ) oversampled echo signals is presented. The single-bit oversampling \Delta \Sigma conversion simplifies the coherent processing in beamforming with improved timing accuracy. Subarray processing also aims to simplify the beamforming complexity, where the partial-beam sums (low-resolution beams) are acquired from small subarrays, and then these partial beams are coherently processed for producing high-resolution beams. In the \Delta \Sigma subarray beamforming, the \Delta \Sigma coded echo signals are summed over the subarray channels, and then these partial beam-sums are first \Delta \Sigma demodulated, then processed …

Design Of Optimal Sampling Times For Pharmacokinetic Trials Via Spline Approximation, Musa Hakan Asyali

Turkish Journal of Electrical Engineering and Computer Sciences

Understanding and comparison of different drug delivery formulations are based on pharmacokinetic parameters (PKP) such as area under curve, maximum concentration, and time to reach maximum concentration. Accurate estimation of PKP is of critical importance in capturing drug absorption and elimination characteristics and in reaching bioequivalence decisions. Since PKP are estimated from a limited number of samples, the timing of the samples directly influences the accuracy of estimation. Optimization of the sampling times may not only increase the accuracy of PKP estimation, but also reduce the number of samples to be drawn, which in turn lessens the inconvenience to the …

Optimal Feature Selection For 3d Facial Expression Recognition Using Coarse-To-Fine Classification, Hamit Soyel, Hasan Demirel

Turkish Journal of Electrical Engineering and Computer Sciences

Automatic facial expression recognition for novel individuals from 3D face data is a challenging task in pattern analysis. This paper describes a feature selection process for pose-invariant 3D facial expression recognition. The process provides a lower dimensional subspace representation, which is optimized to improve the classification accuracy, retrieved from geometrical localization of facial feature points to classify facial expressions. Fisher criterion-based approach is adopted to provide a basis for the optimal selection of features. Two-stage probabilistic neural network architecture is employed as a classifier to recognize the facial expressions. In the first stage, which can be regarded as the coarse …

Fast Computation Of Determination Of The Prime Implicants By A Novel Near Minimum Minimization Method, Fati̇h Başçi̇ftçi̇, Şi̇rzat Kahramanli

Turkish Journal of Electrical Engineering and Computer Sciences

In this study proposed is an off-set-based direct-cover near-minimum minimization method for single-output Boolean functions represented in a sum-of-products form. To obtain the complete set of prime implicants including given on-cube (on-minterm), the proposed method uses off-cubes (off-minterms) expanded by this On-cube. The amount of temporary results produced by this method does not exceed the size of the off-set. To make fast computation, we used logic operations instead of standard operations. Expansion off-cubes, commutative absorption operations and intersection operations are realized by logic operations for fast computation. The proposed minimization method is tested on several different kinds of problems and …

A Second Order Approximation To Reduce The Complexity Of Ldpc Decoders Based On Gallager's Approach, Aykut Kalaycioğlu, Oktay Üreten, H. Gökhan İlk

Turkish Journal of Electrical Engineering and Computer Sciences

A piece-wise second order approximation to the f (x) = -log [tanh (x/2)] function is proposed to reduce the computational complexity of LDPC decoder's utilizing Log-Likelihood Ratio Belief Propagation (LLR-BP) algorithm based on Gallager's approach. Simulation results show that the proposed low complexity approximation doesn't cause BER performance degradation.

Performance Analysis Of Swarm Optimization Approaches For The Generalized Assignment Problem In Multi-Target Tracking Applications, Ali̇ Önder Bozdoğan, Asim Egemen Yilmaz, Murat Efe

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this study is to investigate the suitability of selected swarm optimization algorithms to the generalized assignment problem as encountered in multi-target tracking applications. For this purpose, we have tested variants of particle swarm optimization and ant colony optimization algorithms to solve the 2D generalized assignment problem with simulated dense and sparse measurement/track matrices and compared their performance to that of the auction algorithm. We observed that, although with some modification swarm optimization algorithms provide improvement in terms of speed, they still fall behind the auction algorithm in finding the optimum solution to the problem. Among the investigated …

Stpso: Strengthened Particle Swarm Optimization, Ai̇şe Zülal Şevkli̇, Fati̇h Erdoğan Sevi̇lgen

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present a novel approach to strengthen Particle Swarm Optimization (PSO). PSO is a population-based metaheuristic that takes advantage of individual memory and social cooperation in a swarm. It has been applied to a variety of optimization problems because of its simplicity and fast convergence. However, straightforward application of PSO suffers from premature convergence and lack of intensification around the local best locations. To rectify these problems, we modify update procedure for the best particle in the swarm and propose a simple and random moving strategy. We perform a Reduced Variable Neighborhood Search (RVNS) based local search …

Split And Merge Functions For Supporting Multiple Processing Pipelines In Mercury Blastn, Jwalant Ahir, Jeremy Buhler, Roger D. Chamberlain

All Computer Science and Engineering Research

Biosequence similarity search is an important application in computational biology. Mercury BLASTN, an FPGA-based implementation of BLAST for DNA, is one of the alternatives for fast DNA sequence comparison. The re-design of BLAST into a streaming application combined with a high-throughput hardware pipeline have enabled Mercury BLAST to emerge as one of the fastest implementations of bio-sequence similarity search. This performance can be further enhanced by exploiting the data-level parallelism present within the application. Here we present a multiple FPGA-based Mercury BLASTN design in order to double the speed and throughput of DNA sequence computation. This paper describes a dual …

Optimal Time Utility Based Scheduling Policy Design For Cyber-Physical Systems , Terry Tidwell, Robert Glaubius, Christopher D. Gill, William D. Smart

All Computer Science and Engineering Research

Classical scheduling abstractions such as deadlines and priorities do not readily capture the complex timing semantics found in many real-time cyber-physical systems. Time utility functions provide a necessarily richer description of timing semantics, but designing utility-aware scheduling policies using them is an open research problem. In particular, optimal utility accrual scheduling design is needed for real-time cyber-physical domains. In this paper we design optimal utility accrual scheduling policies for cyber-physical systems with periodic, non-preemptable tasks that run with stochastic duration. These policies are derived by solving a Markov Decision Process formulation of the scheduling problem. We use this formulation to …

Global Constructive Optimization Of Vascular Systems, Manfred Georg, Tobias Preusser, Horst K. Hahn

All Computer Science and Engineering Research

We present a framework for the construction of vascular systems based on optimality principles of theoretical physiology. Given the position and flow distribution of end points of a vascular system, we construct the topology and positions of internal nodes to complete the vascular system in a realistic manner. Optimization is driven by intravascular volume minimization with constraints derived from physiological principles. Direct optimization of a vascular system, including topological changes, is used instead of simulating vessel growth. A good initial topology is found by extracting key information from a previously optimized model with less detail. This technique is used iteratively …

Arch: Practical Channel Hopping For Reliable Home-Area Sensor Networks, Mo Sha, Gregory Hackmann, Chenyang Lu

All Computer Science and Engineering Research

Home area networks (HANs) promise to enable sophisticated home automation applications such as smart energy usage and assisted living. However, recent empirical study of HAN reliability in real-world residential environments revealed significant challenges to achieving reliable performance in the face of significant and variable interference from a multitude of coexisting wireless devices. We propose the Adaptive and Robust Channel Hopping (ARCH) protocol: a lightweight receiveroriented protocol which handles the dynamics of residential environments by reactively channel hopping when channel conditions have degraded. ARCH has several key features. First, ARCH is an adaptive protocol that channel-hops based on changes in channel …

Sorting As A Streaming Application Executing On Chip Multiprocessors, Roger D. Chamberlain, Greg A. Galloway, Mark A. Franklin

All Computer Science and Engineering Research

Expressing concurrency in applications has always been a difficult and error-prone endeavor, yet effective utilization of multi-core processors requires that the concurrency in applications be understood. One approach to the expression of concurrency is streaming, which has shown real promise as a safe and effective method for many application classes. Here, we express a classic problem, sorting, in the streaming paradigm and explore the implications of various algorithm and architectural design parameters on the performance of the application.

Toward A Two-Tier Clinical Warning System For Hospitalized Patients, Gregory Hackmann, Minmin Chen, Octav Chipara, Chenyang Lu, Yixin Chen, Marin Kollef, Thomas C. Bailey

All Computer Science and Engineering Research

Clinical study has found early detection and intervention to be essential for preventing clinical deterioration in patients at general hospital units. In this paper, we envision a two-tiered early warning system designed to identify the signs of clinical deterioration and provide early warning of serious clinical events. The first tier of the system automatically identifies patients at risk of clinical deterioration from existing electronic medical record databases. The second tier performs real-time clinical event detection based on real-time vital sign data collected from on-body wireless sensors attached to those high-risk patients. We employ machine-learning techniques to analyze data from both …

An Inexpensive Robot Platform For Teleoperation And Experimentation, Daniel A. Lazewatsky, William D. Smart

All Computer Science and Engineering Research

Most commercially-available robots are either aimed at the research community, or are designed with a single purpose in mind. The extensive hobbyist community has tended to focus on the hardware and the low-level software aspects. We claim that there is a need for a low-cost, general-purpose robot, accessible to the hobbyist community, with sufficient computation and sensing to run ``research-grade'' software. In this paper, we describe the design and implementation of such a robot. We explicitly outline our design goals, and show how a capable robot can be assembled from off-the-shelf parts, for a modest cost, by a single person …

Gpu Based Processing For Airborne Detection, Dheeraj Singiresu

Masters Theses

"Onboard real-time processing is highly desirable in airborne detection applications. As the data processing involved here is computationally expensive, typically high power multi-rack system is required to achieve real-time detection. Use of such hardware is often not feasible in an airborne application due to space, power and weight constraints. In this thesis, different computing architectures suitable for real-time onboard processing are compared in terms of computation speed, watts/GFLOPS, and weight/GFLOPS. A brief description of the modem GPU architecture and the current GPGPU technology is provided. GPU implementations of some computationally expensive image processing applications such as band-to-band registration for Multi …

A Case Study In Quantitative Analysis Of Cyber-Physical Systems: Reliability Of The Smart Grid, Ayman Z. Faza

Doctoral Dissertations

"A cyber-physical system is the integration of a physical infrastructure with a cyber infrastructure, which provides control over its physical counterpart. The goal is to improve certain aspects of the physical infrastructure, such as its reliability. The Smart Grid, in which intelligent cyber control is added to improve the operation of the traditional power grid, is a prime example of a cyber-physical system. Quantitative models are needed in order to better understand the benefits and risks of adding intelligence to physical systems. To this end, we have developed an integrated cyber-physical reliability model, with a focus on the Smart Grid …

Adaptive Resource Allocation For Cognitive Wireless Ad Hoc Networks, Behdis Eslamnour

Doctoral Dissertations

"Widespread use of resource constrained wireless ad hoc networks requires careful management of the network resources in order to maximize the utilization. In cognitive wireless networks, resources such as spectrum, energy, communication links/paths, time, space, modulation scheme, have to be managed to maintain quality of service (QoS). Therefore in the first paper, a distributed dynamic channel allocation scheme is proposed for multi-channel wireless ad hoc networks with single-radio nodes. The proposed learning scheme adapts the probabilities of selecting each channel as a function of the error in the performance index at each step.

Due to frequent changes in topology and …

Efficient Modular Arithmetic Units For Low Power Cryptographic Applications, Rajashekhar Reddy Modugu

Masters Theses

"The demand for high security in energy constrained devices such as mobiles and PDAs is growing rapidly. This leads to the need for efficient design of cryptographic algorithms which offer data integrity, authentication, non-repudiation and confidentiality of the encrypted data and communication channels. The public key cryptography is an ideal choice for data integrity, authentication and non-repudiation whereas the private key cryptography ensures the confidentiality of the data transmitted. The latter has an extremely high encryption speed but it has certain limitations which make it unsuitable for use in certain applications. Numerous public key cryptographic algorithms are available in the …

Performance Tuning Of Streaming Applications Via Search-Space Decomposition, Shobana Padmanabhan, Roger D. Chamberlain, Yixin Chen

All Computer Science and Engineering Research

High-performance streaming applications are typically pipelined and deployed on architecturally diverse (hybrid)systems. Developers of such applications are interested in customizing components used, so as to benefit application performance. We present an efficient and automatic technique for design-space exploration of applications in this problem domain. We solve performance tuning as an optimization problem by formulating cost functions using results from queueing theory. This results in a mixed-integer nonlinear optimization problem which is NP-hard. We reduce the search complexity by decomposing the search space. We have developed a domain-specific decomposition technique using topological information of the application embodied in the queueing network …

Cloud Computing For Scalable Planning By Stochastic Search, Qiang Lu, You Xu, Ruoyun Huang, Yixin Chen

All Computer Science and Engineering Research

Graph search has been employed by many AI techniques and applications. A natural way to improve the efficiency of search is to utilize ad- vanced, more powerful computing platforms. However, expensive computing infrastructures, such as supercomputers and large-scale clusters, are traditionally available to only a limited number of projects and researchers. As a results, most AI applications, with access to only commodity com- puters and clusters, cannot benefit from the efficiency improvements of high-performance parallel search algorithms. Cloud computing provides an attractive, highly accessible alternative to other traditional high- performance computing platforms. In this paper, we first show that the …

Multi-Channel Reliability And Spectrum Usage In Real Homes: Empirical Studies For Home-Area Sensor Networks, Mo Sha, Gregory Hackmann, Chenyang Lu

All Computer Science and Engineering Research

Home area networks (HANs) consisting of wireless sensors have emerged as the enabling technology for important applications such as smart energy and assisted living. A key challenge faced by HANs is maintaining reliable operation in real-world residential environments. This paper presents two in-depth empirical studies on the wireless channels in real homes. The spectrum study analyzes the spectrum usage in the 2.4 GHz band where wireless sensor networks based on the IEEE 802.15.4 standard must coexist with existing wireless devices. We characterize the ambient wireless environment in six apartments through passive spectrum analysis across the entire 2.4 GHz band over …

End-To-End Delay Analysis For Fixed Priority Scheduling In Wirelesshart Networks, Abusayeed Saifullah, You Xu, Chenyang Lu, Yixin Chen

All Computer Science and Engineering Research

The WirelessHART standard has been specifically designed for real-time communication between sensor and actuator devices for industrial process monitoring and control. End-to-end communication delay analysis for WirelessHART networks is required for acceptance test of real-time data flows from sensors to actuators and for workload adjustment in response to network dynamics. In this paper, we map the scheduling of real-time periodic data flows in a WirelessHART network to real-time multiprocessor scheduling. We, then, exploit the response time analysis for multiprocessor scheduling and propose a novel method for the end-to-end delay analysis of the real-time flows that are scheduled using a fixed …

The Design And Implementation Of Mcflow: A Real-Time Multi-Core Aware Middleware For Dependent Task Graphs, Huang-Ming Huang, Christopher Gill, Chenyang Lu

All Computer Science and Engineering Research

Modern computer architectures have evolved from uni-processor platforms to multi-processor and multi-core plat- forms, but traditional real-time distributed middleware such as RT-CORBA has not kept pace with that evolution. To address those issues, this paper describes the design and implementation of MCFlow, a new real-time distributed middleware for dependent task graphs running on multi-core platforms. MCFlow provides the following contributions to the state of the art in real-time middleware: (1) it provides an efficient C++ based component model through which computations can be configured flexibly for execution within a single core, across cores of a common host, or spanning multiple …

Priority Assignment For Real-Time Flows In Wirelesshart Sensor-Actuator Networks, Abusayeed Saifullah, You Chenyang, Yixin Chen

All Computer Science and Engineering Research

Recent years have witnessed the adoption of wireless sensor-actuator networks as a communication infrastructure for process control applications. An important enabling technology for industrial process control is WirelessHART, an open wireless sensor-actuator network standard specifically developed for process industries. A key challenge faced byWirelessHART networks is to meet the stringent real-time communication requirements imposed by feedback control systems in process industries. Fixed priority scheduling, a popular scheduling policy in real-time networks, has recently been shown to be an effective real-time transmission scheduling policy in WirelessHART networks. Priority assignment has a major impact on the schedulability of real-time flows in these …

Multi-Tier Diversified Service Architecture For Internet 3.0: The Next Generation Internet, Subharthi Paul, Raj Jain, Jianli Pan, Chakchai So-In

All Computer Science and Engineering Research

The next generation Internet needs to support multiple diverse application contexts. In this paper, we present Internet 3.0, a diversified, multi-tier architecture for the next generation Internet. Unlike the current Internet, Internet 3.0 defines a new set of primitives that allows diverse applications to compose and optimize their specific contexts over resources belonging to multiple ownerships. The key design philosophy is to enable diversity through explicit representation, negotiation and enforcement of policies at the granularity of network infrastructure, compute resources, data and users. The basis of the Internet 3.0 architecture is a generalized three-tier object model. The bottom tier consists …

Cs 400-01: Data Structures And Software Design, Meilin Liu

Computer Science & Engineering Syllabi

This is a fundamental course for students majoring in Computer Science. Students will learn: basic algorithm analysis techniques; asymptotic complexity; big-0 and big-Omega notations; efficient algorithms for discrete structures including lists, trees, stacks, and graphs; fundamental computing algorithms including sorting, searching, and hashing techniques.

Cs 241-02: Computer Programming - Ii, Michael Ondrasek

Computer Science & Engineering Syllabi

The CS 241 course is a continuation of CS 240. The emphasis in CS 241 is on solving more complex problems using object oriented programming. Prerequisite: CS240. Students must register for both lecture and one laboratory section. 4 credit hours.

Cs 340-01: Programming Language Workshop In C#, Krishnaprasad Thirunarayan

Computer Science & Engineering Syllabi

This course is designed as a self-study in C#. You are expected to learn the language and solve a set of programming problems assigned to you using MS Visual Studio .NET. There are no exams. We officially meet only once in the quarter. However, I will be available in the posted office hours for clarifications and discussions about the programming problems.

Cs 790-01: Knowledge Representation For The Semantic Web, Pascal Hitzler

Computer Science & Engineering Syllabi

Semantic Web is a maturing field of technology that continues to be the emphasis of much focused research and industrial investigation. The central idea behind Semantic Web is to enhance data on the World Wide Web by so-called metadata, which describes the meaning (semantics) of the data and thus makes it available for processing in intelligent systems. In this course we cover in depth the standardized knowledge representation languages for expressing metadata, called ontology languages. We will in particular cover the Resource Description Framework RDF and the Web Ontology Language OWL, both of which are recommended standards by the World …

Cs 240: Computer Programming I, Vanessa Starkey

Computer Science & Engineering Syllabi

Basic concepts of programming and programming languages are introduced. Emphasis is on structured programming and stepwise refinement.