Fikret Ercal

• Missouri University of Science and Technology

Outlier detection is a well studied problem in various fields. The unique characteristics and constraints of wireless sensor networks (WSN) make this problem especially challenging. Sensors can detect outliers for a plethora of reasons and these reasons need to be inferred in real time. Here, we survey the current state of research in this area, co...

Outlier detection is a well studied problem in various fields. The unique challenges of wireless sensor networks such as limited bandwidth, memory, energy, and unreliable communi- cation make this problem especially difficult. Sensors can detect outliers for a plethora of reasons and these reasons need to be inferred in real time. Here, we present...

RNA transcripts from genomic sequences showing dyad symmetry typically adopt hairpin-like, cloverleaf, or similar structures that act as recognition sites for proteins. Such structures often are the precursors of non-coding RNA (ncRNA) sequences like microRNA (miRNA) and small-interfering RNA (siRNA) that have recently garnered more functional sign...

Outlier detection is a well studied problem in various fields. The unique challenges of wireless sensor networks make this problem especially challenging. Sensors can detect outliers for a plethora of reasons and these reasons need to be inferred in real time. Here, we present a new communication technique to find outliers in a wireless sensor netw...

Gene family identification from ESTs can be a valuable resource for analysis of genome evolution but presents unique challenges in organisms for which the entire genome is not yet sequenced. We have developed a novel gene family identification method based on negative selection patterns (NSP) between family members to screen EST-generated contigs....

Background/aims: Pigmented lesions are often difficult to evaluate clinically. Improvement of diagnostic accuracy by dermatoscopy has attracted much interet. With advanced digital imaging measurement of assymmetry, border irregularity and relative color as well as texture characteristics, lesional depth and changes in lesional area are now possible...

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) appea...

Clustering the ESTs from a large dataset representing a single species is a convenient starting point for a number of investigations into gene discovery, genome evolution, expression patterns, and alternatively spliced transcripts. Several methods have been developed to accomplish this, the most widely available being UniGene, a public domain colle...

A computer vision system to recognize license plates of vehicles in real-time environments is presented in this study. The images of moving vehicles are taken with a digital camera and analyzed in real-time. An artificial neural network (ANN) system is used to locate the area and position of the license plate. The system has the following stages: (...

Recent years have witnessed huge advances in computer technology and communication networks, entailing hard optimization problems in areas such as network design and routing. Metaheuristics are general high-level procedures that coordinate simple heuristics ...

EST clustering is a simple, yet effective method to discover all the genes present in a variety of species. Although using ESTs is a cost-effective approach in gene discovery, the amount of data, and hence the computational resources required, make it a very challenging problem. Time and storage requirements for EST clustering problems are prohibit...

The computing GRID infrastructure could benefit of techniques that can improve the over-all throughput of the system. It is possible that job submission will include different ontology in resource requests due to the generality of the GRID infrastructure. ...

the pixel value in the original image. In DPCM, the dierence between the predicted and actual values are computed. The image with these dierence values is called the Residual Image. This Residual Image is encoded using Human Coding and then transmitted or stored in the database. In this project, we rst compute the Residual Image and then nd the Ent...

In this study, we present an artificial neural network based computer vision system which can analyze the image of a car taken by a camera in real-time, locates its license plate and recognizes the registration number of the car. The model has four stages. In the first stage, vehicle license plate (VLP) is located. Second stage performs the segment...

Blue Gene/L (BG/L) is a 65, 536-node massively parallel computer being developed at the IBM Thomas J. Watson Research Center that promises to revolutionize large-scale scientific computing. However, its size alone will make programming BG/L a major challenge, ...

tion is: P (x; y) = a I(x 1; y) + b I(x 1; y 1) + c I(x; y 1) where P(x,y) is the predicted value for the pixel at coordinate (x,y); a, b and c are the predictor coecientsand I(x,y) is the pixel value in the original Image. In DPCM, the dierence between the predicted and actual values are computed. The image with these dierence values is called the...

First Page of the Article

Workstation clusters have become an increasingly popular alternative to traditional parallel supercomputers for many workloads requiring high performance computing. The use of parallel computing for scientific simulations has increased tremendously in the last ten years, and parallel implementations of scientific simulation codes are now in widespr...

r Function is: P (x; y) = a I(x Gamma 1; y) + b I(x Gamma 1; y Gamma 1) + c I(x; y Gamma 1) where P(x,y) is the predicted value for the pixel at coordinate (x,y); a, b and c are the predictor coefficientsand I(x,y) is the pixel value in the original Image. In DPCM, the difference between the predicted and actual values are computed. The image with...

A parallel ray tracing library is presented for rendering high detail images of three dimensional geometry and computational fields. The library has been developed for use on distributed memory and shared memory parallel computers and can also run on sequential computers. Parallelism is achieved through the use of message passing and threads. It is...

This paper deals with the implementation of a systolic array architecture in hardware using FPGAs for processing compressed binary images without decompressing them. Specifically, run-length encoding (RLE) is used for compression. Processing images in compressed form provides a significant speedup in the computation. Using a systolic architecture a...

Today, security cameras used in stores and buildings have a limited area of vision. Multiple cameras are needed if a larger area is to be covered. With the technique described in this paper, it is possible to get a 360-degree panoramic vision by using a spherical mirror placed vertically with respect to a camera. First, image reflected from a spher...

A new systolic algorithm which computes image differences in run-length encoded (RLE) format is described. The binary image difference operation is commonly used in many image processing applications including automated inspection systems, character recognition, fingerprint analysis, and motion detection. The efficiency of these operations can be i...

This paper consists of a review of current trends in web-based instruction and a review of a representative sample of web-based instruction efficacy research. The review of the current state of web-based instruction yields two principle themes: a) The prevalence of web-based instruction is growing exponentially, particularly in lifelong learning an...

We use a fully timing-driven experimental flow [4] [15] in which a set of benchmark circuits are synthesized into different cluster-based [2] [3] [15] logic block architectures, which contain groups of LUTs and flip-flops. We look across all architectures ...

A new systolic algorithm which computes image differences in run-length encoded (RLE) format is described. The binary image difference operation is commonly used in many image processing applications including automated inspection systems, character recognition, fingerprint analysis, and motion detection. The efficiency of these operations can be i...

On-line inspection of PCBs requires acquisition and processing of gigabytes of image data in a matter of few seconds, especially when multi-layer and very high-resolution boards are used. To meet the demands for speed and accuracy, our inspection system uses run-length encoding (RLE) for storage and operations and an inspection scheme which exploit...

In this work, we present an inspection method for power & ground (P&G) layers of printed circuit boards (PCB) also called utility layers. Design considerations for the P&G layers are different than those of signal layers. Current PCB inspection approaches cannot be applied to these layers. P&G layers act as internal ground, neutral or power sources...

The importance of the inspection process has been magnified by the requirements of the modern manufacturing environment. In electronics mass-production manufacturing facilities, an attempt is often made to achieve 100% quality assurance of all parts, subassemblies, and finished goods. A variety of approaches for automated visual inspection of print...

This paper presents a fast printed circuit board (PCB) inspection methodology based on the segmentation of the PCB image into basic patterns and context sensitive filtering of the difference image for functional defect detection. The system consists of three parts: (i) segmentation of the artwork and test board images into basic patterns using the...

A new systolic algorithm which computes image differences in run-length encoded (RLE) format is described. The binary image difference operation is commonly used in many image processing applications including automated inspection systems, character recognition, fingerprint analysis, and motion detection. The efficiency of these operations can be i...

We propose a new fingerprint image compression scheme based on the hybrid model of an image. Our scheme uses the essential steps of a typical automated fingerprint identification system (AFIS) such as enhancement, binarization and thinning to encode fingerprint images. The decoding process is based on reconstructing a hybrid surface by using the gr...

Without Abstract

Realizing the potential of massively parallel machines requires good solutions to the problem of mapping computations among processors so that execution is load-balanced with low inter-processor communication resulting in low execution time. This problem is typically treated as a graph partitioning problem. We develop a parallel heuristic algorithm...

An efficient recursive task allocation scheme, based on the Kernighan-Lin mincut bisection heuristic, is proposed for the effective mapping of tasks of a parallel program onto a hypercube parallel computer. It is evaluated by comparison with an adaptive, scaled simulated annealing method. The recursive allocation scheme is shown to be effective on...

Image difference operation is commonly used in on-line automated printed circuit board (PCB) inspection systems as well as many other image processing applications. In this paper, we describe a new systolic algorithm and its system architecture which computes image differences in run-length encoded (RLE) format. The efficiency of this operation gre...

The existing inspection systems are algorithmically slow and suffer from many drawbacks in meeting the inspection requirements of printed circuit board fabrication. The system presented in this paper can handle all of the defects simultaneously with the same approach and is significantly faster compared to the existing approaches. The system consis...

Segmentation is the first and foremost step in the inspection of the printed circuit boards, In this paper a new technique for the segmentation of printed circuit board (PCB) images is presented, The technique basically segments a given PCB into small windows containing primitive PCB subpatterns. The technique proposed exploits the simplicity and t...

The complete subcube recognition problem is defined as, given a collection of available processors on an n-dimensional hypercube, locate a subcube of dimension k that consists entirely of available processors, if one exists. Despite many algorithms proposed so far on this subject, improving the time complexity of this problem remains a challenge. E...

String matching problem received much attention over the years due to its importance in various applications such as text/file comparison, DNA sequencing, search engines, and spelling correction. Especially with the introduction of search engines dealing with tremendous amount of textual information presented on the world wide web and the research...

Skin cancers of all types comprise the largest group of cancers in the United States. This group accounts for 1% of all cancer deaths. Fortunately, even the deadliest form of skin cancer can be treated successfully if detected in its early stage. Therefore, automated detection and diagnosis of skin cancer has become an important issue in recent yea...

The routing problem is one of the most widely studied problems in VLSI design. Maze-routing algorithms are used in VLSI routing and robot path planning. Efficiency of the parallel maze routing algorithms which were mostly based on C. Y. Lee's algorithm8is poor. In this paper, we propose time-efficient algorithms to solve the maze-routing problem on...

An automated finite first-order model generator has been developed. The problem is viewed as a firstorder satisfiability problem. Most existing model generators reduce the problem to propositional satisfiability by converting the input first-order clauses into propositional clauses. This generator, unlike others, stores the input first-order clause...

This study is aimed at developing 2D parallel adaptive mesh refinement algorithms for engineering applications such as penetration mechanics, manufacturing and combustion which use the finite element method for simulation. A new algorithmic approach, called piecewise adaptive mesh refinement for parallelization, is developed and implemented to run...

Many vision problems are solved using knowledge-based approaches. The conventional knowledge-based systems use domain experts to generate the initial rules and their membership functions, and then by trial and error refine the rules a\nd membership functions to optimize the final system's performance. However, it would be difficult for human expert...

There are more than 50 process steps required to fabricate a printed circuit board (PCB). To ensure quality, human operators simply inspect the work visually against prescribed standards. The decisions made by this labor intensive, and therefore costly, procedure often also involve subjective judgements. Automatic inspection systems remove the subj...

This paper presents a parallel solution method of large sparse systems of linear equations arising in the context of a chemical process flowsheeting application on a message passing multicomputer. To maximize the performance, the algorithm uses a novel matrix decomposition and solution method, called parallel two-phased LU decomposition, which sche...

Malignant melanoma is the deadliest form of all skin cancers. Approximately 32,000 new cases of malignant melanoma were diagnosed in 1991 in the United States, with approximately 80% of patients expected to survive five years [1]. Fortunately, if detected early, even malignant melanoma may be treated successfully. Thus, in recent years, there has b...

Visual printed circuit board inspection in digital images is viewed as a pattern classification problem. The process involves a two level classification of the printed circuit board image sub-patterns into either standard non-defective class or a defective class. The patterns that are identified as being defective in the first level are thoroughly...

Skin cancers of all types comprise the largest group of cancers in the U.S. This group accounts for 1% of all cancer deaths. Fortunately, even the deadliest form of skin cancer can be treated successfully if detected in its early stage. In this study, we present a diagnostic-tree based hierarchical neural network system (HNN) which is integrated wi...

Boundary detection has been recognized as one of the difficult problems in image processing and pattern analysis, in particular in medical imaging applications. There is no unified approach to this problem which has been found to be application dependent. In this paper, we present a simple and yet effective method to find the borders of tumors as a...

A simple and yet effective method for finding the borders of tumors is presented as an initial step towards the diagnosis of skin tumors from their color images. The method makes use of an adaptive color metric from the red, green, and blue planes that contains information for discriminating the tumor from the background. Using this suitable coordi...

Directed Acyclic Graphs are often used to model circuits and networks. The path lengthin such Directed Acyclic Graphs represents circuit or network delays. In the vertex splittingproblem, the objective is to determine a minimum number of vertices from the graph to splitsuch that the resulting graph has no path of length greater than a given d. The...

This study involves the parallel solution of the linear equations, Ax = b, arising in the context of chemical process flowsheeting, on a hypercube multicomputer using an efficient LU-decomposition technique for the sparse matrices. The Newton-Raphson method is used as the iterative technique to solve the original nonlinear system of equations arisi...

Complex process controlling requires a crucial reduction in the number of robust discriminitating features. The use of wavelet transformations with other artificial neural network‐based methods will be given using real data.

Advances in microelectronic technology have made massively parallel computing a reality and triggered an outburst of research activity in parallel processing architectures and algorithms. Distributed memory multiprocessors - parallel computers that consist of microprocessors connected in a regular topology - are increasingly being used to solve lar...

An efficient distributed algorithm for evaluating an iterative function on all pairwise combinations of C objects on an SIMD hypercube is presented. The algorithm achieves uniform load distribution and minimal, completely local interprocessor communication.

Lee's maze routing algorithm is parallelized and implemented on an Intel iPSC/2 hypercube multicomputer. Our contribution to the previous work in [2] is that we propose a new parallel front wave expansion scheme which performs two front wave expansions concurrently, one starting from the source cell and the other one starting from the target cell....

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The task-to-processor mapping problem is addressed in the context of a local-memory multicomputer with a hypercube interconnection topology. Two heuristic cluster-based mapping strategies are compared: a nearest-neighbor approach and a recursive-clustering scheme. The nearest-neighbor strategy is shown to be more effective on hypercube systems with...

In this paper, the problem of assigning N parallel tasks onto a hypercube with N processors is considered. Three heuristics are developed to map arbitrary process graphs, in a one-to-one fashion, onto a hypercube architecture, in order to minimize the communication cost between processors:bit-toggling (BT), bit-swapping (BS), and node-swapping (NS)...

Finite-element discretization produces linear equations in the form Ax = b , where A is large, sparse, and banded with proper ordering of the variables x . The solution of such equations on distributed-memory message-passing multiprocessors implementing the hypercube topology is addressed. Iterative algorithms based on the conjugate gradient method...

The processor allocation problem is addressed in the context of the parallelization of a finite element modeling program on a processor mesh. A heuristic two-step, graph-based mapping scheme with polynomial-time complexity is developed: 1) initial generation of a graph partition for nearest-neighbor mapping of the finite element graph onto the proc...

Three distinct approaches to the task-allocation problem are pursued. In the first of three, a heuristic two-step, graph-based mapping scheme (nearest-neighbor mapping) with polynomial-time complexity is developed to map finite-element graphs onto hypercubes, and the effectiveness of the approach is measured both by estimation and experimental meas...

The task-to-processor mapping problem is addressed in the context of a local-memorymultiprocessor with a hypercube interconnection topology. Two heuristic cluster-basedmapping strategies are compared - 1) a nearest-neighbor approach and 2) a recursiveclusteringscheme. The nearest-neighbor strategy is shown to be more effective onhypercube systems w...

The finite element method is widely used as a computational method to model physical systems in various engineering disciplines. The tremendous amount of computation often required for accurate modeling has prompted a lot of interest in the use of parallel computers to speed up the computational task by distributing it amongst many processors. Howe...