bluuebunny/crossref_metadata_2025 huggingface dataset:
GENERATING n-ARY REFLECTED GRAY CODES ON A LINEAR ARRAY OF PROCESSORS
Authors: STOJMENOVIC IVAN
Published: October 2004

We present a cost-optimal parallel algorithm for generating n-ary reflected Gray codes, i.e. variations of m elements out of {0, 1,…, n–1} in a Gray code order. It uses a linear array of m processors, each having constant size memory and each being responsible for producing one part of a given variation. The algorithm is simple and uses a weaker model of computation than a recently published algorithm. In addition, it can be made adaptive (i.e. to run on a linear array with an arbitrary number of processors) and can be generalized to produce variations out of an arbitrary set of elements.
FUNCTIONAL ALGORITHM SIMULATION OF THE FAST MULTIPOLE METHOD: ARCHITECTURAL IMPLICATIONS
Authors: DIKAIAKOS MARIOS D. , ROGERS ANNE , STEIGLITZ KENNETH
Published: October 2004

Functional Algorithm Simulation is a methodology for predicting the computation and communication characteristics of parallel algorithms for a class of scientific problems, without actually performing the expensive numerical computations involved. In this paper, we use Functional Algorithm Simulation to study the parallel Fast Multipole Method (FMM), which solves the N-body problem. Functional Algorithm Simulation provides us with useful information regarding communication patterns in the algorithm, the variation of available parallelism during different algorithmic phases, and upper bounds on available speedups for different problem sizes. Furthermore, it allows us to predict the performance of the FMM on message-passing multiprocessors with topologies such as cliques, hypercubes, rings, and multirings, over a wider range of problem sizes and numbers of processors than would be feasible by direct simulation. Our simulations show that an implementation of the FMM on low-cost, scalable ring or multiring architectures can attain satisfactory performance.
FREE SUBMESH LIST STRATEGY: A BEST FIT SUBMESH ALLOCATION IN MESH CONNECTED MULTICOMPUTERS
Authors: KIM GEUNMO , YOON HYUNSOO
Published: October 2004

The submesh allocation problem is to recognize and locate a free submesh that can accommodate a request for a submesh of a specified size. In this paper, we propose a new best-fit submesh allocation strategy. The proposed strategy maintains and uses a free submesh list to get global information for free submeshes. For an allocation request, the proposed strategy tries to allocate a best-fit submesh which causes the least amount of potential processor fragmentation so as to reserve the large free submeshes as many as possible for later requests. For this purpose, we introduce a novel function for quantifying the degree of potential fragmentation of submeshes. The proposed strategy has the complete submesh recognition capability. Extensive simulation is carried out to compare the proposed strategy with the previous strategies and it is shown that the proposed strategy exhibits the best performance.
GOSSIPING IN d-DIMENSIONAL MESH-BUS NETWORKS
Authors: HILY ANDRÉ , SOTTEAU DOMINIQUE
Published: October 2004

Bounds are given for the minimum time to gossip in mesh-bus networks of arbitrary dimension in two models of store and forward communications.
GOSSIPING ON A RING WITH RADIOS
Authors: RAVISHANKAR KRISHNAMURTHI , SINGH SURESH
Published: October 2004

We study the problem of gossiping where n nodes equipped with radios are placed on a ring of circumference L. Each radio has a transmission range of 1 and we assume that simultaneous transmissions by neighboring nodes results in garbled messages. We present an algorithm for gossiping and show that it works in asymptotically optimal time.
A CHARACTERIZATION OF ONE-TO-ONE MODULAR MAPPINGS
Authors: DARTE ALAIN , DION MICHÈLE , ROBERT YVES
Published: October 2004

In this paper, we deal with modular mappings as introduced by Lee and Fortes [15,14,13], and we build upon their results. Our main contribution is a characterization of one-to-one modular mappings that is valid even when the source domain and the target domain of the transformation have the same size but not the same shape. This characterization is constructive, and a procedure to test the injectivity of a given transformation is presented.
USING A 0–1 INTEGER PROGRAMMING MODEL FOR AUTOMATIC STATIC DATA DISTRIBUTION
Authors: GARCIA JORDI , AYGUADÉ EDUARD , LABARTA JESÚS
Published: October 2004

This paper describes an automatic data distribution method which deal with both the alignment and the distribution problems in a single optimization phase, as opposed to sequentially solving these two inter-dependent approaches as done by previous work. The core of this work is called the Communication-Parallelism Graph, which describes the relationships among array dimensions of the same and different array references regarding communication and parallelism. The overall data distribution problem is then formulated as a linear 0–1 integer programming problem, where the objective function to be minimized is the total execution time. The solution is static in the sense that the layout of the arrays does not change during the execution of the program. We also show the feasibility of using this approach to solve the problem in terms of compilation time and quality of the solutions generated.
PROGRAM OPTIMIZATION BASED ON COMPILE-TIME CACHE PERFORMANCE PREDICTION
Authors: KAPLOW WESLEY K. , SZYMANSKI BOLESLAW K.
Published: October 2004

We present a novel, compile-time method for determining the cache performance of the loop nests in a program. The cache hit-rates are produced by applying the reference string, determined during compilation, to an architecturally parameterized cache simulator. We also describe a heuristic that uses this method for compile-time optimization of loop ranges in iteration-space blocking. The results of the loop program optimizations are presented for different parallel program benchmarks and various processor architectures, such as IBM SP1 RS/6000, the SuperSPARC, and the Intel 1860.
FAST PARALLEL COMPUTATION OF THE JORDAN NORMAL FORM OF MATRICES
Authors: ROCH JEAN-LOUIS , VILLARD GILLES
Published: October 2004

We establish that the problem of computing the Jordan normal form of a matrix over a field F is in [Formula: see text] for F being a field of characteristic zero or a finite field.
THREE TECHNIQUES FOR PARALLEL MAINTENANCE OF A MINIMUM SPANNING TREE UNDER BATCH OF UPDATES
Authors: FERRAGINA PAOLO , LUCCIO FABRIZIO
Published: October 2004

In this paper we provide three simple techniques to maintain in parallel the minimum spanning tree of an undirected graph under single or batch of edge updates (i.e., insertions and deletions). Our results extend the use of the sparsification data structure to the EREW PRAM model. For proper values of the batch size, our algorithms require less time and work than the best known dynamic parallel algorithms.
TIME-SIZE TRADEOFFS FOR RECONFIGURABLE MESHES
Authors: BEN-ASHER YOSI , SCHUSTER ASSAF
Published: October 2004

Many algorithms were devised for the reconfigurable mesh model (RN-mesh) for parallel computing which involve only a constant number of broadcasting steps. It was not known, however, how tight are the constants involved. Consider an n×n directed reconfigurable mesh (DRN-mesh) that computes a function f(n) in T steps, where T is a constant. In this paper we show that T can always be reduced to a single step, still using a polynomial size DRN-mesh. Furthermore, we show that this is in fact a general tradeoff: namely, the number of steps may be reduced to any value between 1 and T, paying by an exponential growth of the size of the DRN-mesh in the number of eliminated steps.
DETERMINISTIC LEADER ELECTION ON THE ASYNCHRONOUS QRQW PRAM
Authors: ARMEN CHRIS , JOHNSON DONALD B.
Published: October 2004

We describe a deterministic algorithm for the leader election problem on the asynchronous QRQW PRAM which runs in O( log n/ log log n) time and O(n) work using [Formula: see text] processors.
PROOF OF A REAL-TIME MUTUAL-EXCLUSION ALGORITHM
Authors: CARRUTH J. ALLEN , MISRA JAYADEV
Published: October 2004

Michael Fischer has proposed a mutual exclusion algorithm that ingeniously exploits real time. We prove this algorithm using the time-honored technique of establishing an appropriate invariant.
AN OPTIMISTIC PROTOCOL FOR A LINEARIZABLE DISTRIBUTED SHARED MEMORY SYSTEM
Authors: MIZUNO MASAAKI , NEILSEN MITCHELL L. , RAYNAL MICHEL
Published: October 2004

Recently, distributed shared memory systems have received much attention because such an abstraction simplifies programming. In this paper, we present a simple protocol which implements the linearizability consistency criterion in a distributed shared memory system. Unlike previously implemented protocols, our protocol is based on an optimistic approach. The protocol eliminates the necessity of potentially expensive synchronization among processors for each write operation, but may require processes to rollback.
BENCHMARKING LATTICE-BASED APPLICATIONS ON PARALLEL ARCHITECTURES
Authors: DESTRI GIULIO , MARENZONI PAOLO
Published: October 2004

The numerical analysis and solution of many physics and engineering problems is based on lattice-oriented algorithms. The Cellular Neural Network (CNN) computational paradigm embodies a wide set of grid problems characterized by locality of information exchanges among lattice points. Performance analysis tests using CNN-based algorithms may provide insights into the performance achievable by a given parallel architecture, with respect to a wide class of lattice problems. In this paper a message passing version of a general CNN-based algorithm is implemented and optimized for three general purpose parallel architectures: Connection Machine CM-5, Cray T3D, and IBM SP2. Separate measurements on computations and communications of the algorithm allow us to evaluate processing node and network communication performance of the machines. Moreover. the overall performance of the full application is analyzed, in order to understand the scalability and the range of applicability of this prototype of lattice problem.
A BETTER ANALYSIS OF BEN-ASHER’S ALGORITHM FOR THE CONDITIONAL CARTESIAN PRODUCT PROBLEM
Authors: WANG BIING-FENG
Published: October 2004

In [2], a new problem called conditional cartesian product problem was introduced. The problem has a trivial time lower bound [Formula: see text], where A and B are two groups of N elements and CA,B is a subset of the cartesian product A×B satisfying some unknown condition C. Ben-Asher proposed an efficient algorithm for the problem and showed that the proposed algorithm can be performed in [Formula: see text] time [2]. As compared with the trivial time lower bound, the algorithm is not optimal. In this paper, with a better analysis, we show that the worst-case time complexity of Ben-Asher’s algorithm is [Formula: see text], which is much better than [Formula: see text]. Consequently, it can be concluded that for case the rate of growth of |CA,B| is not smaller than [Formula: see text] is a tight lower bound and Ben-Asher’s algorithm is indeed optimal.
IMAGE TEMPLATE MATCHING ON RECONFIGURABLE MESHES
Authors: CHUNG KUO-LIANG
Published: October 2004

A mesh-connected computer enhanced by a reconfigurable bus system is referred to as a reconfigurable mesh (RM). Given an n×n grey-scale image and m×m template, in this paper, an O( log m) time parallel algorithm for template matching is presented on a RM with O(m2n2) processors. Suppose the image and template are binary, an O(1) time algorithm is presented on a RM with O(m3n2) processors. Both algorithms are superior to the best known algorithms on RMs.
SOLVING DISCRETE-TIME LYAPUNOV EQUATIONS FOR THE CHOLESKY FACTOR ON A SHARED MEMORY MULTIPROCESSOR
Authors: CLAVER JOSE M. , HERNANDEZ VICENTE , QUINTANA ENRIQUE S.
Published: October 2004

In this paper we study the parallel solution of the discrete-time Lyapunov equation. Two parallel fine and medium grain algorithms for solving dense and large order equations [Formula: see text] on a shared memory multiprocessor are presented. They are based on Hammarling’s method and directly obtain the Cholesky factor of the solution. The parallel algorithms work following an antidiagonal wavefront. In order to improve the performance, column-block-oriented and wrap-around algorithms are used. Finally, combined fine and medium grain parallel algorithms are presented.
ON BOTTLENECK PARTITIONING OF k-ARY n-CUBES
Authors: NICOL DAVID M. , MAO WEIZHEN
Published: October 2004

Graph partitioning is a topic of extensive interest, with applications to parallel processing. In this context graph nodes typically represent computation, and edges represent communication. One seeks to distribute the workload by partitioning the graph so that every processor has approximately the same workload, and the communication cost (measured as a function of edges exposed by the partition) is minimized. Measures of partition quality vary; in this paper we consider a processor’s cost to be the sum of its computation and communication costs, and consider the cost of a partition to be the bottleneck, or maximal processor cost induced by the partition. For a general graph the problem of finding an optimal partitioning is intractable. In this paper we restrict our attention to the class of k-ary n-cube graphs with uniformly weighted nodes. Given mild restrictions on the node weight and number of processors, we identify partitions yielding the smallest bottleneck. We also demonstrate by example that some restrictions are necessary for the partitions we identify to be optimal. In particular, there exist cases where partitions that evenly partition nodes need not be optimal.
GENERALISING THE UNIMODULAR APPROACH TO RESTRUCTURE IMPERFECTLY NESTED LOOPS
Authors: Xue Jingling
Published: October 2004

Although overcoming some limitations of the generate-and-test approach, unimodular transformations are limited to perfect loop nests only. Extending the unimodular approach, this paper describes a framework that enables the use of unimodular transformations to restructure imperfect loop nests. The concepts used previously for perfect loop nests, such as iteration vector, iteration space and lexicographic order, are generalised and some new concepts like preorder tree are introduced. Multiple unimodular transformations are allowed, one each statement in the loop nest. A code generation algorithm is provided that produces a possibly imperfect loop nest to scan an iteration space that is given as a union of sets of affine constraints.
FAST AND EFFICIENT OPERATIONS ON PARALLEL PRIORITY QUEUES
Authors: CHEN DANNY Z. , HU XIAOBO SHARON
Published: October 2004

The Parallel Priority Queue (PPQ) data structure supports parallel operations for manipulating data items with keys, such as inserting n new items, deleting n items with the first n smallest keys, creating a new PPQ that contains a set of items, and melding two PPQ’s into one. In this paper, we present fast and efficient parallel algorithms for performing operations on the PPQ’s that maintain data items with real-valued keys. The data structures that we use for implementing the PPQ’s are the unmeldable and meldable parallel heaps. Our algorithms have considerably less time and/or work bounds than the previously best known algorithms, and use a less powerful parallel computational model (EREW PRAM). The new ideas that make our improvement possible are two partition schemes dynamically maintained on the parallel heap structures: the minimal- path partition and the right-path partition. These partition schemes could be of interest in their own right. Our results also lead to optimal parallel algorithms for implementing sequential operations on several commonly-used heap structures.
A GENERALIZATION OF HYPERCUBIC NETWORKS BASED ON THEIR CHORDAL RING STRUCTURES
Authors: KWAI DING-MING , PARHAMI BEHROOZ
Published: October 2004

We prove that the hypercube and cube-connected cycles (CCC) networks can be viewed as chordal rings with periodic connection patterns and show how the period, chord length, and network size are related in each case. It is well-known that CCC is a subgraph of the hypercube; i.e., it can be derived by pruning the latter. We formulate a more general pruning strategy that leads to a spectrum of useful networks ranging from the hypercube at one end to CCC and CCC-like structures at the other. The resulting unified view of a large class of networks with varying cost and performance parameters leads to better understanding of the networks, facilitates comparisons, explicates the available cost/performance/reliability tradeoffs, and allows the construction of portable parametrized algorithms that can run on each instance of the general architecture at optimal speed.
APPLICATIONS OF EVOLUTIONARY STRATEGIES TO FINE-GRAINED TASK SCHEDULING
Authors: GUPTA AJAY K. , GREENWOOD GARRISON W.
Published: October 2004

Embedding task graphs onto hypercubes is a difficult problem. When the embedding is one-to-one, schedule length is strongly influenced by dilation. Therefore, it is desirable to find low dilation embeddings. This paper describes a heuristic embedding technique based upon evolutionary strategies. The technique has been extensively investigated using task graphs which are trees, forests, and butterflies. In all cases the technique has found low dilation embeddings.
TASK SCHEDULING FACILITY FOR PVM
Authors: LEE BU-SUNG , HENG ALFRED , CAI WENTONG , TAN TAI-ANN
Published: October 2004

Whilst the concept of a virtual metacomputer over a networked collection of heterogeneous computer systems has slowly emerged. there are still some shortcomings of these systems. For example. some systems are still incapable of balancing the load amongst the workstations; the problem is accentuated by the heterogeneity of the computers. In this paper. we first discuss the design issue of our centralized task scheduler. and then present our implementation details. To use the task scheduler. some new library routines are provided. The task scheduler is layered above PVM; this has the advantage of retaining its portability. Since load-balancing is considered in task scheduling. our approach has been also proven to be more effective than the existing PVM round-robin task allocation scheme.
ON NIL: THE SOFTWARE CONSTRUCTOR OF NEURAL NETWORKS
Authors: SIEGELMANN HAVA T.
Published: October 2004

Analog recurrent neural networks have attracted much attention lately as powerful tools of automatic learning. However, they are not as popular in industry as should be justified by their usefulness. The lack of any programming tool for networks. and their vague internal representation, leave the networks for the use of experts only. We propose a way to make the neural networks friendly to users by formally defining a high level language, called Neural Information Processing Programming Langage, which is rich enough to express any computer algorithm or rule-based system. We show how to compile a NIL program into a network which computes exactly as the original program and requires the same computation/convergence time and physical size. Allowing for a natural neural evolution after the construction, the neural networks are both capable of dynamical continuous learning and represent any given symbolic knowledge. Thus, the language along with its compiler may be thought of as the ultimate bridge from symbolic to analog computation.
A HEURISTIC REPLACEMENT SCHEDULING APPROACH FOR MULTI-UNIT SYSTEMS WITH ECONOMIC DEPENDENCY
Authors: HUANG JIANSHENG , OKOGBAA O. GEOFFREY
Published: October 2004

For a multi-unit system with economic dependency, it is difficult to develop an effective joint replacement schedule due to the stochastic complexity of the system failure-repair process. As a result, restrictions have often been introduced in the maintenance policy specification and decision problem formulation. In some cases, these restrictions have resulted in a reduction in the optimality or effectiveness of the proposed schedule.

In this paper, we propose a general opportunistic maintenance policy for multi-unit systems with economic dependency. Two cost boundary conditions are developed in order to evaluate the potential cost savings achieved by implementing the opportunistic maintenance policy. A heuristic approach based on the application of the single-unit model is presented for developing the opportunistic maintenance schedule via an example problem. The effectiveness of the resulting schedule is demonstrated through simulation experiments.
UNCERTAINTY IN BINOMIAL FAILURES AND DEMANDS WITH APPLICATIONS TO RELIABILITY
Authors: MARTZ HARRY F. , KVAM PAUL H. , ATWOOD CORWIN L.
Published: October 2004

In estimating a plant-specific binomial probability of failure on demand p in probabilistic risk assessment, the corresponding number of binomial demands n or the observed number of failures x (or both) may be uncertain. We present several methods which account for uncertainties in both x and n when using Bayesian methods to estimate p. A beta prior distribution on p is considered. While the methods formally require the use of numerical integration, approximations are provided to implement them in practice. Several numerical examples are used to illustrate the methods, including a real-data example involving commercial nuclear boiling water reactors.
BAYESIAN DYNAMIC MODELS FOR QUALITY AUDITS BASED ON COUNT DATA
Authors: IRONY TELBA Z. , TIWARI RAM C.
Published: October 2004

Three Bayesian models for quality audits based on count data are proposed. They allow the extraction of information from production experts and from observed data in order to provide more accurate inferences. The first model is based on a Poisson distribution. It fits those cases of production processes that improve with time, and enables the analyst in charge to estimate the improvement and to take advantage of it in order to reduce costs. The second model is based on a binomial distribution in which the quality index, expressed by the chance of producing a non-conforming item, may decrease or remain constant as time goes by. The third model, also based on a binomial distribution, is suitable to be used in an assembly line with several stages. Examples are given in order to illustrate the use of the models.
FUZZY RELIABILITY OF GRACEFULLY DEGRADING SYSTEMS WITH THE COMPOSITE SOFTWARE
Authors: GUROV SERGEY V. , UTKIN LEV V.
Published: October 2004

In this paper, we focus on the transient and steady-state reliability behavior of a computer system whose software component as a program executes an infinite loop to provide control function and consists of several subprograms sequentially executed during iterations of the loop. The performance degradation of the system is due to the hardware failure occurrence. For reducing a large number of the system performance levels, we assume that the system success and failure are characterized by the fuzzy success and failure states with the defined membership functions. The system failure behavior is fully characterized in the context of probability measures. All random variables, such as times to hardware failures and mission times of subprograms, are arbitrarily distributed. In fact, we solve two problems: (1) reliability analysing under condition of many states and (2) reducing the state reliability measures to fuzzy success and failure reliability characteristics. The systems of integral and linear equations are used to obtain the unsteady and steady-state reliability characteristics, respectively. A numerical example is provided to illustrate and analyze the results.
STATISTICAL METHODS FOR MANAGEMENT OF PROCESS QUALITY: A STATE-OF-THE-ART REVIEW
Authors: BARTON RUSSELL R. , CHANDRA M. JEYA
Published: October 2004

Companies use the Malcolm Baldridge Award criteria to provide a formal guide for self assessment. In most of the seven categories, statistical techniques play important roles. A basic tenet of Total Quality Management is that company business practices should evolve and improve over time. This philosophy of continuous improvement also applies to the development and refinement of appropriate statistical methods. This paper reviews recent developments in statistical methods for Total Quality Management, with a focus on applications to Category 5 of the Baldridge Award criteria: Management of Process Quality.
OVERVIEW OF MANUFACTURING STRATEGY IN JAPAN
Authors: LEE JAY
Published: October 2004

Japan has been a world leader in manufacturing in the past several decades. Undoubtedly, this leadership will persist well into the 21st century. It is, therefore, very important to understand the status of Japan's manufacturing technologies as well as its projected manufacturing strategies for the future, especially those technologies which would generate substantial impact on the manufacturing industries in the next five years.

This paper highlights current Japanese manufacturing strategies. Examples on several major industries including the industrial machinery industry, the semiconductor industry, and the automotive industry will be given. In addition, major initiatives on emerging technologies, including micromachine, environmentally conscious design and manufacturing, and manufacturing globalization support are described.
RELIABILITY DESIGN FOR TWO-COMPONENT SYSTEMS WITH GAMMA-DISTRIBUTED COMPONENTS
Authors: PHAM T. , TURKKAN N.
Published: October 2004

The design of a system, for reliability purposes, often requires the exact expression of its reliability function, which, however, is seldom available in closed form. Approximate methods are non-optimal and could even lead to errors. For two-component systems, with independent Gamma-distributed components, it is shown here that we can accurately determine the second component, within various configurations, when the first component is supposed known. Both classical and Bayesian approaches are considered.
PERFORMANCE OF PROCESS CAPABILITY INDICES FOR WEIBULL AND LOGNORMAL DISTRIBUTIONS OR AUTOREGRESSIVE PROCESSES
Authors: PADGETT W. J. , SENGUPTA A.
Published: October 2004

The usual definitions of process capability indices assume that observations are independent and identically normally distributed. The process mean may shift and from that point forward the process is out of control but the observations are still independent and normally distributed. When the observations are non-normal or correlated, the estimation of the standard capability indices can be greatly affected. In this paper comparison of estimators of capability indices is presented when the process measurements are from one of two families of skewed distributions, Weibull or lognormal. Also, an investigation of estimators of the standard index, Cpk, is presented for normally distributed process measurements which follow an autoregressive model of order one.
FEEDBACK CONTROL AND STATISTICAL PROCESS MONITORING
Authors: KEATS J. BERT , MONTGOMERY DOUGLAS C. , RUNGER GEORGE C. , MESSINA WILLIAM S.
Published: October 2004

In the industrial world, different methodologies have been applied to reduce variability. Engineers whose training is in the quality assurance sciences have frequently used statistical process control (SPC) whereas engineers whose background includes control theory have employed engineering process control (EPC), often in the form of feedback control. SPC is usually applied to processes that vary about a fixed mean, with successive observations viewed as statistically independent. EPC is usually applied to processes in which successive observations are related over time, and where the mean drifts dynamically. The objective of SPC is to reduce variability by the elimination of assignable causes that shift the mean off-target, while EPC continuously adjusts manipulatable variables in the process to keep the mean on target. This study demonstrates the effectiveness of integrating SPC with feedback control for three commonly encountered schemes: Integral Control, Proportional-Integral Control, and Proportional-Integral-Differential Control. A simulation study demonstrates that the combined EPC/SPC scheme significantly reduces overall variability in comparison to feedback control alone when assignable causes are present.
DEVELOPMENT OF THE OPTIMUM PRODUCT SPECIFICATION FOR AN EXPONENTIAL-TYPE QUALITY CHARACTERISTIC
Authors: CHO BYUNG-RAE , FERRELL WILLIAM G. , KIMBLER DELBERT L.
Published: October 2004

This paper investigates the problem of determining the most economical product specification (upper specification limit) for an exponential-type quality characteristic using the concept of a truncated quadratic loss function within the framework of a screening inspection scheme. Implementing a tight limit on products may provide a high outgoing quality, but it creates a high rejection cost on the rejected products. In contrast, implementing a loose limit may reduce the rejection cost, but it can result in a low outgoing quality. An immediate problem is then how to trade off these conflicting cost criteria to determine the most economical upper specification limit. This important issue has neither been satisfactorily addressed or received much attention in the literature. This paper presents the concept of the truncated quadratic loss function, applies the concept to screening inspection problems, derives the truncated statistics of interest, and presents the optimization model of the most economical upper specification limit for an exponential-type quality characteristic. A numerical example is presented.
APPLICATION OF FUZZY LOGIC IN PARAMETER DESIGN AND QUALITY CONTROL — A CASE STUDY ON A TURNING PROCESS
Authors: CHANG SHING I. , ALSTATT CRAIG A.
Published: October 2004

Parameter design has been an effective technique for quality improvement. One of the goals of parameter design for a manufacturing process is to manipulate process parameters to produce an acceptable quality level for the desired quality characteristic. This research explores the concept of implementing parameter design for a turning process using fuzzy logic as an alternative approach for parameter design and quality control. A fuzzy logic controller (FLC) is proposed to manipulate process parameters to find the proper setting for the desired part quality. In this research, we focus on a turning process with surface finish as the desired quality characteristic. The proposed FLC manipulates the most influential parameter, feed rate, while holding other parameters constant to find the proper setting of the parameters necessary for the level of surface finish required by the part. The proposed FLC is found to be an effective method for implementing parameter design for a turning process. In addition, the FLC is shown to be a robust tool through its ability to handle two types of material and two different tool geometries.
RELIABILITY OF ERROR CORRECTING CODES ON WIRELESS INFORMATION NETWORKS
Authors: SHOOMAN MARTIN L. , CASSARA FRANK A.
Published: October 2004

Error correcting codes are well known techniques for improving bit error rate (BER) performance in digital communication systems and are particularly important in wireless information networks to help establish reliable communication links. This paper examines the effect of coder/decoder circuitry failures on the overall communication system performance. A system analysis of the error correction coding scheme performance must include an evaluation of the reliability of the coder/decoder circuitry because their failures also serve as a source of undetected errors. The parity bit code, Hamming single error correcting and detecting code, and the Reed–Solomon code are included in the study. Results reveal that for applications as described in the text that require low bit error rate and operate at low data rates, the reliability of the coding circuitry can play a significant role in determining overall system performance. In fact, for such error and data rates, a simpler coding scheme with higher circuit reliability may actually be more beneficial than a more complex coding scheme with enhanced error correcting ability but with a higher chip failure rate.
A TWO-LEVEL HIERARCHICAL MOBILE NETWORK: STRUCTURE AND NETWORK CONTROL
Authors: FARAG EMAD N. , ELMASRY MOHAMED I. , SALEH MOHAMED N. , ELNADY NABIL M.
Published: October 2004

The increase in demand for mobile telecommunication systems, and the limited bandwidth allocated to these systems, have led to systems with smaller cell dimensions, which in turn led to the increase of control messages. In order to prevent controller bottle necks, it is desirable to distribute the network control functions throughout the network. To satisfy this requirement, a mobile network structure characterized by its hierarchical and decentralized network control is presented in this paper. The area served by the mobile system is divided into regions, and the regions are further divided into cells. Each cell is served by a base station, each base station is connected to a regional network through a base station interface unit (BIU). Each region has its own regional network. Connected to each regional network are the cellular controller, the home database, the visitor database, the trunk interface unit (TIU) and the gateway interface unit (GIU). The TIU connects the regional network to the public switched telephone network (PSTN). The GIU connects the regional network to other regional networks through the gateway network. This architecture distributes the network control functions among a large number of processing elements, thus preventing controller bottle necks — a problem faced by centralized controlled systems. The information and network control messages are transferred in the form of packets across this network. Processes inherent to the operation of this network structure are illustrated and discussed. These processes include the location update process, the setting up of a call, the handoff process (both the intra-region handoff process and the inter-region handoff process are considered), and the process of terminating a call.
RELIABILITY PERFORMANCE COMPARISON OF ADAPTIVE ROUTING ALGORITHMS IN A TACTICAL WIRELESS TELEPHONE NETWORK
Authors: SCHIRA CELT M.
Published: October 2004

This paper compares the reliability performance of five adaptive and two fixed routing algorithms in the context of a simplified military wireless network. The network is abstracted as a circuit switched network where the connectivity can change. The five algorithms are shown to differ widely in their sensitivity to the gain parameter, transient behavior and response to increasing load or lost trunk capacity. All the adaptive algorithms had a higher transient call blocking ratio under general overload conditions than an optimized fixed algorithm where the originating switch retains supervision of the call. This is consistent with the philosophy of network design that adaptive routing is most valuable when the network configuration is not fully known or when local overloads exist but additional capacity is available elsewhere. These results are applicable to commercial as well as military wireless systems. Interference on a wireless connection can lead to changes in network topology, or a local overload may exist at a congested node, creating the conditions where adaptive routing algorithms are useful.
DATA COMMUNICATION PERFORMANCE TESTING OF AN ADVANCED SATELLITE
Authors: WEIBEL MARJORIE L.
Published: October 2004

The results of a series of data communication tests that measured the digital end-to-end performance of the Advanced Communication Technology Satellite (ACTS) are presented. The experiment intended to determine the performance provided to a pair of users who use the satellite as the transmission medium. In order to accomplish this task, the performance parameters defined in the American National Standard X3.102 were measured. Some examples of the X3.102 parameters include Access Time, Access Denial Probability, Bit Error Probability, User Information Transfer Rate, Disengagement Time, and Disengagement Denial Probability.

The performance measured is dependent on the type of service offered (e.g., connection-oriented or connectionless, packet size, window size). The services analyzed included narrowband Integrated Services Digital Network (ISDN), X.25, and a dialed circuit-switched connection. For all services, test results showed that ACTS has a very clean data channel (only one lost byte was recorded during all the tests), the Access Time for most services needs to be shorter, and the parameter estimates did not vary substantially over time or destination location.
Arg333 and Arg334 in the COOH terminus of the human P2Y1 receptor are crucial for Gq coupling
Authors: Ding Zhongren , Tuluc Florin , Bandivadekar Kavita R. , Zhang Lili , Jin Jianguo , Kunapuli Satya P.
Published: October 2004

The P2Y1 ADP receptor activates Gq and causes increases in intracellular Ca2+ concentration through stimulation of PLC. In this study, we investigated the role of the amino acid residues in the COOH terminus of the human P2Y1 receptor in Gq activation. Stimulation of Chinese hamster ovary (CHO-K1) cells stably expressing the wild-type human P2Y1 receptor (P2Y1-WT cells), P2Y1-ΔR340-L373, or P2Y1-ΔD356-L373 with 2-methylthio-ADP (2-MeSADP) caused inositol phosphate production. In contrast, cells expressing P2Y1-ΔT330-L373, a mutant lacking the entire COOH terminus, completely lost their response to 2-MeSADP. Similar data were obtained by using these cell lines and measuring Ca2+ mobilization upon stimulation with 2-MeSADP, indicating that the 10 amino acids (330TFRRRLSRAT339) in the COOH terminus of the human P2Y1 receptor are essential for Gq coupling. Radioligand binding demonstrated that both the P2Y1-WT and P2Y1-ΔT330-L373-expressing cells have almost equal binding of [3H]MRS2279, a P2Y1 receptor antagonist, indicating that COOH-terminal truncation did not drastically affect the conformation of the receptor. CHO-K1 cells expressing a chimeric P2Y12 receptor with the P2Y1 COOH terminus failed to elicit Gq functional responses, indicating that the P2Y1 COOH terminus is essential but not sufficient for Gq activation. Finally, cells expressing a double-mutant P2Y1 receptor (R333A/R334A) in the conserved BBXXB region of the COOH terminus of the Gq-activating P2Y receptors completely lost their functional ability to activate Gq. We conclude that the two arginine residues (R333R334) in the COOH terminus of the human P2Y1 receptor are essential for Gq coupling.
Epinephrine induces tissue perfusion deficit in porcine endotoxin shock: evaluation by regional CO2 content gradients and lactate-to-pyruvate ratios
Authors: Martikainen Tero J. , Tenhunen Jyrki J. , Giovannini Ivo , Uusaro Ari , Ruokonen Esko
Published: October 2004

Epinephrine is widely used as a vasoconstrictor or inotrope in shock, although it may typically induce or augment lactic acidosis. Ongoing debate addresses the question of whether hyperlactatemia per se is a sign of tissue perfusion deficit or aerobic glycolysis. We wanted to test the hypothesis that epinephrine has selective detrimental effects on visceral perfusion and metabolism. We performed rigorous regional venous blood gas analyses as well as intraperitoneal microdialysis. We used a mathematical model to calculate regional arteriovenous CO2 content gradients and estimated the magnitude of the Haldane effect in a porcine model of prolonged hypotensive shock induced by endotoxin infusion (mean arterial blood pressure < 60 mmHg). Subsequently, vasopressors (epinephrine or norepinephrine) were administered and adjusted to maintain systemic mean arterial pressure > 70 mmHg for 4 h. Epinephrine caused systemic hyperlactatemia and acidosis. Importantly, both systemic and regional venous lactate-to-pyruvate ratios increased. Epinephrine was associated with decreasing portal blood flow despite apparently maintained total splanchnic blood flow. Epinephrine increased gastric venous-to-arterial Pco2 gradients and CO2 content gradients with decreasing magnitude of the Haldane effect, and the regional gastric respiratory quotient remained higher after epinephrine as opposed to norepinephrine infusion. In addition, epinephrine induced intraperitoneal lactate and glycerol release. We did not observe these adverse hemodynamic or metabolic changes related to norepinephrine with the same arterial pressure goal. We conclude that high CO2 content gradients with decreasing magnitude of the Haldane effect pinpoint the most pronounced perfusion deficiency to the gastric wall when epinephrine, as opposed to norepinephrine, is used in experimental endotoxin shock.
Heat-stable enterotoxin ofEscherichia colistimulates a non-CFTR-mediated duodenal bicarbonate secretory pathway
Authors: Sellers Zachary M. , Childs Debbie , Chow Jimmy Y. C. , Smith Anders J. , Hogan Daniel L. , Isenberg Jon I. , Dong Hui , Barrett Kim E. , Pratha Vijaya S.
Published: October 2004

The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is an important pathway for duodenal mucosal bicarbonate secretion. Duodenal biopsies from CF patients secrete bicarbonate in response to heat-stable enterotoxin from Escherichia coli (STa) but not cAMP. To explore the mechanism of STa-induced bicarbonate secretion in CF more fully, we examined the role of CFTR in STa-stimulated duodenal bicarbonate secretion in mice. In vivo, the duodenum of CFTR (−/−) or control mice was perfused with forskolin (10−4M), STa (10−7M), uroguanylin (10−7M), 8-bromoguanosine 3′,5′-cGMP (8-Br-cGMP) (10−3M), genistein (10−6M) plus STa, or herbimycin A (10−6M) plus STa. In vitro, duodenal mucosae were voltage-clamped in Ussing chambers, and bicarbonate secretion was measured by pH-stat. The effect of genistein, DIDS (10−4M), and chloride removal was also studied in vitro. Control, but not CF, mice produced a significant increase in duodenal bicarbonate secretion after perfusion with forskolin, uroguanylin, or 8-Br-cGMP. However, both control and CF animals responded to STa with significant increases in bicarbonate output. Genistein and herbimycin A abolished this response in CF mice but not in controls. In vitro, STa-stimulated bicarbonate secretion in CF tissues was inhibited by genistein, DIDS, and chloride-free conditions, whereas bicarbonate secretion persisted in control mice. In the CF duodenum, STa can stimulate bicarbonate secretion via tyrosine kinase activity resulting in apical Cl−/HCO3−exchange. Further studies elucidating the intracellular mechanisms responsible for such non-CFTR mediated bicarbonate secretion may lead to important therapies for CF.
Experimental analysis of critical oxygen delivery
Authors: Torres Filho Ivo P. , Spiess Bruce D. , Pittman Roland N. , Barbee R. Wayne , Ward Kevin R.
Published: October 2004

Systemic variables were evaluated with respect to O2 delivery to test the hypothesis that critical O2 delivery and critical Hb can be estimated by multiple variables collected simultaneously. Rats were subjected to transfusion with either fresh or stored blood and then subjected to stepwise isovolemic hemodilution. Critical levels were measured by the dual-regression method from plots of systemic variables against O2 delivery and Hb. Delivery was calculated from cardiac index and arterial O2 content. We found that 1) after hemodilution, O2 delivery changed in a nonlinear relationship with Hb; 2) critical delivery calculated using 30 different systemic variables was not statistically different from each other; 3) critical delivery and critical Hb were correlated but were not different between animals receiving fresh or stored blood; and 4) similar critical levels were found using a single variable from several animals and using several variables from the same subject. The best variables to estimate critical delivery were lactate, bicarbonate, base excess, O2 extraction ratio, expired CO2, pulse pressure, cardiac index, and systolic pressure. The data suggest that a multivariable analysis of critical delivery may help determine the physiological oxygenation boundary at the whole body level. This may assist in finding therapeutic triggers on an individual basis using systemic markers of the transition from aerobic to anaerobic metabolism.
Electroporation Loading of Calcium-Sensitive Dyes Into the CNS
Authors: Bonnot Agnès , Mentis George Z. , Skoch Jesse , O'Donovan Michael J.
Published: October 2004

Calcium imaging of neural network function has been limited by the extent of tissue labeled or the time taken for labeling. We now describe the use of electroporation—an established technique for transfecting cells with genes—to load neurons with calcium-sensitive dyes in the isolated spinal cord of the neonatal mouse in vitro. The dyes were injected subdurally, intravascularly, or into the central canal. This technique results in rapid and extensive labeling of neurons and their processes at all depths of the spinal cord, over a rostrocaudal extent determined by the position and size of the electrodes. Our results suggest that vascular distribution of the dye is involved in all three types of injections. Electroporation disrupts local reflex and network function only transiently (∼1 h), after which time they recover. We describe applications of the method to image activity of neuronal populations and individual neurons during antidromic, reflex, and locomotor-like behaviors. We show that these different motor behaviors are characterized by distinct patterns of activation among the labeled populations of cells.
Ideal extensions of ordered sets
Authors: Kehayopulu Niovi
Published: October 2004

The ideal extensions of semigroups—without order—have been first considered by Clifford (1950). In this paper, we give the main theorem of the ideal extensions for ordered sets. If P, Q are disjoint ordered sets, we construct (all) the ordered sets V which have an ideal P′ which is isomorphic to P, and the complement of P′ in V is isomorphic to Q. Conversely, we prove that every extension of an ordered set P by an ordered set Q can be so constructed. Illustrative examples of the main theorem in case of finite ordered sets are given.
Weak incidence algebra and maximal ring of quotients
Authors: Singh Surjeet , Al-Thukair Fawzi
Published: October 2004

Let X, X′ be two locally finite, preordered sets and let R be any indecomposable commutative ring. The incidence algebra I(X, R), in a sense, represents X, because of the well‐known result that if the rings I(X, R) and I(X′, R) are isomorphic, then X and X′ are isomorphic. In this paper, we consider a preordered set X that need not be locally finite but has the property that each of its equivalence classes of equivalent elements is finite. Define I*(X, R) to be the set of all those functions f : X × X → R such that f(x, y) = 0, whenever x ⩽ y and the set Sf of ordered pairs (x, y) with x < y and f(x, y) ≠ 0 is finite. For any f, g ∈ I*(X, R), r ∈ R, define f + g, fg, and rf in I*(X, R) such that (f + g)(x + y) = f(x, y) + g(x, y), fg(x, y) = ∑x≤z≤yf(x, z)g(z, y), rf(x, y) = r · f(x, y). This makes I*(X, R) an R‐algebra, called the weak incidence algebra of X over R. In the first part of the paper it is shown that indeed I*(X, R) represents X. After this all the essential one‐sided ideals of I*(X, R) are determined and the maximal right (left) ring of quotients of I*(X, R) is discussed. It is shown that the results proved can give a large class of rings whose maximal right ring of quotients need not be isomorphic to its maximal left ring of quotients.
On the Putnam‐Fuglede theorem
Authors: Chen Yin
Published: October 2004

We extend the Putnam‐Fuglede theorem and the second‐degree Putnam‐Fuglede theorem to the nonnormal operators and to an elementary operator under perturbation by quasinilpotents. Some asymptotic results are also given.
Common fixed point theorems of contractive‐type mappings
Authors: Park Hee Soo , Ume Jeong Sheok
Published: October 2004

Using the concept of D‐metric we prove some common fixed point theorems for generalized contractive mappings on a complete D‐metric space. Our results extend, improve, and unify results of Fisher and Ćirić.