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134

A model of periodic oscillation for genetic regulatory systems

In this paper, we focus on modeling and explaining periodic oscillations in gene-protein systems with a simple nonlinear model and on analyzing effects of time delay on the stability of oscillations. Our main model of genetic regulation comprises of a two-gene system with an autoregulatory feedback loop. We exploit multiple time scales and hysteretic properties of the model to construct periodic oscillations with jumping dynamics and analyze the possible mechanism according to the singular perturbation theory. As shown in this paper, periodic oscillations are mainly generated by nonlinearly negative and positive feedback loops in gene regulatory systems, whereas the jumping dynamics is generally caused by time scale differences among biochemical reactions. This simple model may actually act as a genetic oscillator or switch in gene-protein networks because the dynamics are robust for parameter perturbations or environment variations. We also explore effects of time delay on the stability of the dynamics, showing that the time delay generally increases the stability region of the oscillations, thereby making the oscillations robust to parameter changes. Two examples are also provided to numerically demonstrate our theoretical results

977

Behavior of Runge-Kutta discretizations near equilibria of index 2 differential algebraic systems

We analyze Runge-Kutta discretizations applied to index 2 differential algebraic equations (DAE's) near equilibria. We compare the geometric properties of the numerical and the exact solutions. It is shown that projected and half-explicit Runge-Kutta methods reproduce the qualitative features of the continuous system in the vicinity of an equilibrium correctly. The proof combines cut-off and scaling techniques for index 2 differential algebraic equations with some invariant manifold results of Schropp (Geometric properties of Runge-Kutta discretizations for index 2 differential algebraic equations, Konstanzer Schriften in Mathematik und Informatik 128) and classical results for discretized ordinary differential equations

932

Modeling of torsional vibration induced by extension-twisting coupling of anisotropic composite laminates with piezoelectric actuators

In this paper we present a dynamic analytical model for the torsional vibration of an anisotropic piezoelectric laminate induced by the extension-twisting coupling effect. In the present approach, we use the Hamilton principle and a reduced bending stiffness method for the derivation of equations of motion. As a result, the in-plane displacements are not involved and the out-of-plane displacement of the laminate is the only quantity to be calculated. Therefore, the proposed method turns the twisting of a laminate with structural coupling into a simplified problem without losing its features. We give analytical solutions of the present model with harmonic excitation. A parametric study is performed to demonstrate the present approach

1209

High-level language support for user-defined reductions

The optimized handling of reductions on parallel supercomputers or clusters of workstations is critical to high performance because reductions are common in scientific codes and a potential source of bottlenecks. Yet in many high-level languages, a mechanism for writing efficient reductions remains surprisingly absent. Further, when such mechanisms do exist, they often do not provide the flexibility a programmer needs to achieve a desirable level of performance. In this paper, we present a new language construct for arbitrary reductions that lets a programmer achieve a level of performance equal to that achievable with the highly flexible, but low-level combination of Fortran and MPI. We have implemented this construct in the ZPL language and evaluate it in the context of the initialization of the NAS MG benchmark. We show a 45 times speedup over the same code written in ZPL without this construct. In addition, performance on a large number of processors surpasses that achieved in the NAS implementation showing that our mechanism provides programmers with the needed flexibility

66

Regression testing of database applications

Database applications features such as Structured Query Language or SQL, exception programming, integrity constraints, and table triggers pose difficulties for maintenance activities; especially for regression testing that follows modifications to database applications. In this work, we address these difficulties and propose a two phase regression testing methodology. In phase 1, we explore control flow and data flow analysis issues of database applications. Then, we propose an impact analysis technique that is based on dependencies that exist among the components of database applications. This analysis leads to selecting test cases from the initial test suite for regression testing the modified application. In phase 2, further reduction in the regression test cases is performed by using reduction algorithms. We present two such algorithms. The Graph Walk algorithm walks through the control flow graph of database modules and selects a safe set of test cases to retest. The Call Graph Firewall algorithm uses a firewall for the inter procedural level. Finally, a maintenance environment for database applications is described. Our experience with this regression testing methodology shows that the impact analysis technique is adequate for selecting regression tests and that phase 2 techniques can be used for further reduction in the number of theses tests

619

Wavelet-based image segment representation

An efficient representation method for arbitrarily shaped image segments is proposed. This method includes a smart way to select a wavelet basis to approximate the given image segment, with improved image quality and reduced computational load

1439

On-line robust processing techniques for elimination of measurement drop-out

When processing measurement data, it is usually assumed that some amount of normally distributed measurement noise is present. In some situations, outliers are present in the measurements and consequently the noise is far from normally distributed. In this case classical least-squares procedures for estimating Fourier spectra (or derived quantities like the frequency response function) can give results which are inaccurate or even useless. In this paper, a novel technique for the on-line processing of measurement outliers will be proposed. Both the computation speed and the accuracy of the technique presented will be compared with different classical approaches for handling outliers in measurement data (i.e. filtering techniques, outlier rejection techniques and robust regression techniques). In particular, all processing techniques will be validated by applying them to the problem of speckle drop-out in optical vibration measurements (performed with a laser Doppler vibrometer), which typically causes outliers in the measurements

741

Mothball mania [3G licences]

Telefonica Moviles has frozen its 3G operations in Germany, Austria, Italy and Switzerland. With other 3G licence holders questioning the logic of entering already saturated markets with unproven technology, Emma McClune asks if the mothball effect is set to snowball any further

704

Multicell converters: active control and observation of flying-capacitor voltages

The multicell converters introduced more than ten years ago make it possible to distribute the voltage constraints among series-connected switches and to improve the output waveforms (increased number of levels and apparent frequency). The balance of the constraints requires an appropriate distribution of the flying voltages. This paper presents some solutions for the active control of the voltages across the flying capacitors in the presence of rapid variation of the input voltage. The latter part of this paper is dedicated to the observation of these voltages using an original modeling of the converter

1351

Analytic PCA construction for theoretical analysis of lighting variability in images of a Lambertian object

We analyze theoretically the subspace best approximating images of a convex Lambertian object taken from the same viewpoint, but under different distant illumination conditions. We analytically construct the principal component analysis for images of a convex Lambertian object, explicitly taking attached shadows into account, and find the principal eigenmodes and eigenvalues with respect to lighting variability. Our analysis makes use of an analytic formula for the irradiance in terms of spherical-harmonic coefficients of the illumination and shows, under appropriate assumptions, that the principal components or eigenvectors are identical to the spherical harmonic basis functions evaluated at the surface normal vectors. Our main contribution is in extending these results to the single-viewpoint case, showing how the principal eigenmodes and eigenvalues are affected when only a limited subset (the upper hemisphere) of normals is available and the spherical harmonics are no longer orthonormal over the restricted domain. Our results are very close, both qualitatively and quantitatively, to previous empirical observations and represent the first essentially complete theoretical explanation of these observations

1314

Multi-timescale Internet traffic engineering

The Internet is a collection of packet-based hop-by-hop routed networks. Internet traffic engineering is the process of allocating resources to meet the performance requirements of users and operators for their traffic. Current mechanisms for doing so, exemplified by TCP's congestion control or the variety of packet marking disciplines, concentrate on allocating resources on a per-packet basis or at data timescales. This article motivates the need for traffic engineering in the Internet at other timescales, namely control and management timescales, and presents three mechanisms for this. It also presents a scenario to show how these mechanisms increase the flexibility of operators' service offerings and potentially also ease problems of Internet management

897

Optimization of advertising expenses in the functioning of an insurance company

With the use of Pontryagin's maximum principle, a problem of optimal time distribution of advertising expenses in the functioning of an insurance company is solved

1050

Secrets of the Glasgow Haskell compiler inliner

Higher-order languages such as Haskell encourage the programmer to build abstractions by composing functions. A good compiler must inline many of these calls to recover an efficiently executable program. In principle, inlining is dead simple: just replace the call of a function by an instance of its body. But any compiler-writer will tell you that inlining is a black art, full of delicate compromises that work together to give good performance without unnecessary code bloat. The purpose of this paper is, therefore, to articulate the key lessons we learned from a full-scale "production" inliner, the one used in the Glasgow Haskell compiler. We focus mainly on the algorithmic aspects, but we also provide some indicative measurements to substantiate the importance of various aspects of the inliner

1015

Scalable techniques from nonparametric statistics for real time robot learning

Locally weighted learning (LWL) is a class of techniques from nonparametric statistics that provides useful representations and training algorithms for learning about complex phenomena during autonomous adaptive control of robotic systems. The paper introduces several LWL algorithms that have been tested successfully in real-time learning of complex robot tasks. We discuss two major classes of LWL, memory-based LWL and purely incremental LWL that does not need to remember any data explicitly. In contrast to the traditional belief that LWL methods cannot work well in high-dimensional spaces, we provide new algorithms that have been tested on up to 90 dimensional learning problems. The applicability of our LWL algorithms is demonstrated in various robot learning examples, including the learning of devil-sticking, pole-balancing by a humanoid robot arm, and inverse-dynamics learning for a seven and a 30 degree-of-freedom robot. In all these examples, the application of our statistical neural networks techniques allowed either faster or more accurate acquisition of motor control than classical control engineering

1268

Reachability in contextual nets

Contextual nets, or Petri nets with read arcs, are models of concurrent systems with context dependent actions. The problem of reachability in such nets consists in finding a sequence of transitions that leads from the initial marking of a given contextual net to a given goal marking. The solution to this problem that is presented in this paper consists in constructing a finite complete prefix of the unfolding of the given contextual net, that is a finite prefix in which all the markings that are reachable from the initial marking are present, and in searching in each branch of this prefix for the goal marking by solving an appropriate linear programming problem

678

Marketing in CSIR libraries and information centres: a study on promotional efforts

This paper examines the attitudes of librarians towards the promotional aspects in several CSIR libraries and information centres of India. The issues related to promotional activities of these libraries have been evaluated to determine the extent to which they are being practised. Librarians hold positive attitudes about promotional aspects of libraries and often practise them without knowing they are practising marketing concepts. Suggestions and strategies for improving the promotional activities in libraries and information services are put forth so as to meet the information needs and demands of clientele

110

A switching synchronization scheme for a class of chaotic systems

In this Letter, we propose an observer-based synchronization scheme for a class of chaotic systems. This class of systems are given by piecewise-linear dynamics. By using some properties of such systems, we give a procedure to construct the gain of the observer. We prove various stability results and comment on the robustness of the proposed scheme. We also present some simulation results

953

Take it to the next level [law firm innovation]

It's called innovating. Our clients do it. Our culture worships it. Our future hinges on it. Why is it so difficult in law firms? How can we make it easier? Viva la difference!

916

Attribute generation based on association rules

A decision tree is considered to be appropriate (1) if the tree can classify the unseen data accurately, and (2) if the size of the tree is small. One of the approaches to induce such a good decision tree is to add new attributes and their values to enhance the expressiveness of the training data at the data pre-processing stage. There are many existing methods for attribute extraction and construction, but constructing new attributes is still an art. These methods are very time consuming, and some of them need a priori knowledge of the data domain. They are not suitable for data mining dealing with large volumes of data. We propose a novel approach that the knowledge on attributes relevant to the class is extracted as association rules from the training data. The new attributes and the values are generated from the association rules among the originally given attributes. We elaborate on the method and investigate its feature. The effectiveness of our approach is demonstrated through some experiments

584

Hybrid fuzzy modeling of chemical processes

Fuzzy models have been proved to have the ability of modeling all plants without any priori information. However, the performance of conventional fuzzy models can be very poor in the case of insufficient training data due to their poor extrapolation capacity. In order to overcome this problem, a hybrid grey-box fuzzy modeling approach is proposed in this paper to combine expert experience, local linear models and historical data into a uniform framework. It consists of two layers. The expert fuzzy model constructed from linguistic information, the local linear model and the T-S type fuzzy model constructed from data are all put in the first layer. Layer 2 is a fuzzy decision module that is used to decide which model in the first layer should be employed to make the final prediction. The output of the second layer is the output of the hybrid fuzzy model. With the help of the linguistic information, the poor extrapolation capacity problem caused by sparse training data for conventional fuzzy models can be overcome. Simulation result for pH neutralization process demonstrates its modeling ability over the linear models, the expert fuzzy model and the conventional fuzzy model

1194

New methods for oscillatory problems based on classical codes

The numerical integration of differential equations with oscillatory solutions is a very common problem in many fields of the applied sciences. Some methods have been specially devised for this kind of problem. In most of them, the calculation of the coefficients needs more computational effort than the classical codes because such coefficients depend on the step-size in a not simple manner. On the contrary, in this work we present new algorithms specially designed for perturbed oscillators whose coefficients have a simple dependence on the step-size. The methods obtained are competitive when comparing with classical and special codes

1169

An efficient algorithm for sequential generation of failure states in a network with multi-mode components

In this work, a new algorithm for the sequential generation of failure states in a network with multi-mode components is proposed. The algorithm presented in the paper transforms the state enumeration problem into a K-shortest paths problem. Taking advantage of the inherent efficiency of an algorithm for shortest paths enumeration and also of the characteristics of the reliability problem in which it will be used, an algorithm with lower complexity than the best algorithm in the literature for solving this problem, was obtained. Computational results will be presented for comparing the efficiency of both algorithms in terms of CPU time and for problems of different size

579

Steinmetz system design under unbalanced conditions

This paper studies and develops general analytical expressions to obtain three-phase current symmetrization under unbalanced voltage conditions. It proposes two procedures for this symmetrization: the application of the traditional expressions assuming symmetry conditions and the use of optimization methods based on the general analytical equations. Specifically, the paper applies and evaluates these methods to analyze the Steinmetz system design. Several graphics evaluating the error introduced by assumption of balanced voltage in the design are plotted and an example is studied to compare both procedures. In the example the necessity to apply the optimization techniques in highly unbalanced conditions is demonstrated

685

Robotically enhanced placement of left ventricular epicardial electrodes during implantation of a biventricular implantable cardioverter defibrillator system

Biventricular pacing has gained increasing acceptance in advanced heart failure patients. One major limitation of this therapy is positioning the left ventricular stimulation lead via the coronary sinus. This report demonstrates the feasibility of totally endoscopic direct placement of an epicardial stimulation lead on the left ventricle using the daVinci surgical system

1295

Development of visual design steering as an aid in large-scale multidisciplinary design optimization. II. Method validation

For pt. I see ibid., pp. 412-24. Graph morphing, the first concept developed under the newly proposed paradigm of visual design steering (VDS), is applied to optimal design problems. Graph morphing, described in Part I of this paper, can be used to provide insights to a designer to improve efficiency, reliability, and accuracy of an optimal design in less cycle time. It is demonstrated in this part of the paper that graph morphing can be used to provide insights into design variable impact, constraint redundancy, reasonable values for constraint allowable limits, and function smoothness, that otherwise might not be attainable

1074

Inhibiting decoherence via ancilla processes

General conditions are derived for preventing the decoherence of a single two-state quantum system (qubit) in a thermal bath. The employed auxiliary systems required for this purpose are merely assumed to be weak for the general condition while various examples such as extra qubits and extra classical fields are studied for applications in quantum information processing. The general condition is confirmed by well known approaches toward inhibiting decoherence. An approach to decoherence-free quantum memories and quantum operations is presented by placing the qubit into the center of a sphere with extra qubits on its surface

1031

Noise-constrained hyperspectral data compression

Storage and transmission requirements for hyperspectral data sets are significant. To reduce hardware costs, well-designed compression techniques are needed to preserve information content while maximizing compression ratios. Lossless compression techniques maintain data integrity, but yield small compression ratios. We present a slightly lossy compression algorithm that uses the noise statistics of the data to preserve information content while maximizing compression ratios. The adaptive principal components analysis (APCA) algorithm uses noise statistics to determine the number of significant principal components and selects only those that are required to represent each pixel to within the noise level. We demonstrate the effectiveness of these methods with airborne visible/infrared spectrometer (AVIRIS), hyperspectral digital imagery collection experiment (HYDICE), hyperspectral mapper (HYMAP), and Hyperion datasets

798

ClioWeb, ClioRequest, and Clio database: enhancing patron and staff satisfaction

Faced with increased demand from students and faculty for a speedier and more user-friendly method of obtaining materials from other institutions, the interlibrary loan (ILL) department sought to implement a management system which would accomplish the task. Students wanted remote interconnectivity to the system and staff wanted increased workflow efficiency, reduced paper work, and better data management. This paper focuses on Washington College's experience in selecting and implementing an interlibrary loan system, which would enhance student satisfaction as well as that of the library staff

765

Simulating fermions on a quantum computer

The real-time probabilistic simulation of quantum systems in classical computers is known to be limited by the so-called dynamical sign problem, a problem leading to exponential complexity. In 1981 Richard Feynman raised some provocative questions in connection to the "exact imitation" of such systems using a special device named a "quantum computer". Feynman hesitated about the possibility of imitating fermion systems using such a device. Here we address some of his concerns and, in particular, investigate the simulation of fermionic systems. We show how quantum computers avoid the sign problem in some cases by reducing the complexity from exponential to polynomial. Our demonstration is based upon the use of isomorphisms of algebras. We present specific quantum algorithms that illustrate the main points of our algebraic approach

720

19in monitors [CRT survey]

Upgrade your monitor from as little as Pounds 135. With displays on test and ranging up to Pounds 400, whether you're after the last word in quality or simply looking for again, this Labs holds the answer. Looks at ADI MicroScan M900, CTX PR960F, Eizo FlexScan T766, Hansol 920D, Hansol920P, Hitachi CM715ET, Hitachi CM721FET, liyama Vision Master Pro 454, LG Flatron 915FT Plus, Mitsubishi Diamond Pro 920, NEC MultiSync FE950+, Philips 109S40, Samsung SyncMaster 959NF, Sony Multiscan CPD-G420, and ViewSonic G90f

1375

Evaluation of the usability of digital maintenance manuals developed without either user input or a task analysis

The primary objective was to investigate the value that can be added to a low-cost digital maintenance manual by the addition of a navigational aid. Two versions of a digital maintenance manual were developed, the difference between them being the number of design heuristics observed when designing navigational aids. Neither version was based on an analysis of the tasks carried out by users, nor were users involved in the design process. Instead, the manuals were developed directly from the digital information used to produce the existing paper manual. Usability trials were carried out to test both versions according to the time taken and errors committed by users during typical information retrieval tasks. Users were questioned to determine their ease of use (EOU) perceptions for each manual. The main outcomes were that the navigation aid used in the second version reduced the time taken to use the manual but increased the number of errors made by users. The navigational aid also seemed to reduce the perceived EOU compared with the first version. In both cases, the perceived EOU was lower than for a previous digital manual that had been developed using a task analysis and user input. The paper concludes by recommending the development of a generic task model of user interaction with digital maintenance manuals

1330

Strobbe Graphics' next frontier: CTP for commercial printers

Strobbe is one of the more successful makers of newspaper platesetters, which are sold by Agfa under the Polaris name. But the company also has a growing presence in commercial printing markets, where it sells under its own name

1458

Direct gear tooth contact analysis for hypoid bevel gears

A new methodology for tooth contact analysis based on a very general mathematical model of the generating process is proposed. Considering the line of action as a first order singularity of a certain operator equation we develop first and second order conditions for a pair of generated gear tooth flanks to be in contact. The constructive approach allows the direct computation of the paths of contact as the solution of a nonlinear equation system including the exact determination of the bounds of the paths of contact. The transmission error as well as curvature properties in the contact points are obtained in a convenient way. The resulting contact ellipses approximate the bearing area. Through the use of automatic differentiation all the geometric quantities are calculable within the machine accuracy of the computer

1089

Accuracy and stability of splitting with Stabilizing Corrections

This paper contains a convergence analysis for the method of stabilizing corrections, which is an internally consistent splitting scheme for initial-boundary value problems. To obtain more accuracy and a better treatment of explicit terms several extensions are regarded and analyzed. The relevance of the theoretical results is tested for convection-diffusion-reaction equations

758

Four-terminal quantum resistor network for electron-wave computing

Interconnected ultrathin conducting wires or, equivalently, interconnected quasi-one-dimensional electron waveguides, which form a quantum resistor network, are presented here in four-terminal configurations. The transmission behaviors through such four-terminal networks are evaluated and classified. In addition, we show that such networks can be used as the basic building blocks for a possible massive wave computing machine in the future. In a network, each interconnection, a node point, is an elastic scatterer that routes the electron wave. Routing and rerouting of electron waves in a network is described in the framework of quantum transport from Landauer-Buttiker theory in the presence of multiple elastic scatterers. Transmissions through various types of four-terminal generalized clean Aharonov-Bohm rings are investigated at zero temperature. Useful logic functions are gathered based on the transmission probability to each terminal with the use of the Buttiker symmetry rule. In the generalized rings, even and odd numbers of terminals can possess some distinctly different transmission characteristics as we have shown here and earlier. Just as an even or odd number of atoms in a ring is an important quantity for classifying the transmission behavior, we show here that whether the number of terminals is an even or an odd number is just as important in understanding the physics of transmission through such a ring. Furthermore, we show that there are three basic classes of four-terminal rings and the scaling relation for each class is provided. In particular, the existence of equitransmission among all four terminals is shown here. This particular physical phenomena cannot exist in any three-terminal ring. Comparisons and discussions of transmission characteristics between three-terminal and four-terminal rings are also presented. The node-equation approach by considering the Kirchhoff current conservation law at each node point is used for this analysis. Many useful logic functions for electron-wave computing are shown here. In particular, we show that a full adder can be constructed very simply using the equitransmission property of the four-terminal ring. This is in sharp contrast with circuits based on transistor logic

1348

Reconstructing surfaces by volumetric regularization using radial basis functions

We present a new method of surface reconstruction that generates smooth and seamless models from sparse, noisy, nonuniform, and low resolution range data. Data acquisition techniques from computer vision, such as stereo range images and space carving, produce 3D point sets that are imprecise and nonuniform when compared to laser or optical range scanners. Traditional reconstruction algorithms designed for dense and precise data do not produce smooth reconstructions when applied to vision-based data sets. Our method constructs a 3D implicit surface, formulated as a sum of weighted radial basis functions. We achieve three primary advantages over existing algorithms: (1) the implicit functions we construct estimate the surface well in regions where there is little data, (2) the reconstructed surface is insensitive to noise in data acquisition because we can allow the surface to approximate, rather than exactly interpolate, the data, and (3) the reconstructed surface is locally detailed, yet globally smooth, because we use radial basis functions that achieve multiple orders of smoothness

1420

PDF subscriptions bolster revenue

In 1999 SD Times offered prospective subscribers the option of receiving their issues as Adobe Acrobat PDF files. What set the proposal apart from what other publishers were doing electronically on the Web was that readers would get the entire version of the paper-including both advertising and editorial just as it looked when it was laid out and went to press. SD Times is only one of a small, but growing, number of publications that are taking on the electronic world and finding success. In the past six months alone, the New York Times, Popular Mechanics, trade magazine Electronic Buyers' News, and the Harvard Business Review have launched digital versions of their newspapers and magazines to augment their online and print versions. The reasons are as varied as the publishers themselves. Some companies are finding that readers don't like their Web-based versions either due to poor navigation or missing graphics and images. Others want to expand their publications nationally and internationally, but don't want the added cost of postage and printing. Still others are looking for ways to give advertisers additional visibility and boost advertising and subscription revenues. No matter what the reason, it's a trend worth watching

836

Recruitment and retention of women graduate students in computer science and engineering: results of a workshop organized by the Computing Research Association

This document is the report of a workshop that convened a group of experts to discuss the recruitment and retention of women in computer science and engineering (CSE) graduate programs. Participants included long-time members of the CSE academic and research communities, social scientists engaged in relevant research, and directors of successful retention efforts. The report is a compendium of the experience and expertise of workshop participants, rather than the result of a full-scale, scholarly study into the range of issues. Its goal is to provide departments with practical advice on recruitment and retention in the form of a set of specific recommendations

873

Programmatic efforts encouraging women to enter the information technology workforce

For over a decade the National Science Foundation (NSF) has been supporting projects designed to improve opportunities for women in computing. From an initial emphasis on increasing the number of women in graduate school studying computer science and engineering, NSF's current emphasis has broadened to include research studies examining the underlying reasons why women are underrepresented in the information technology (IT) workforce. This paper describes the recent history of NSF's activities in this area and the subsequent emergence of a research portfolio addressing the underrepresentation issue

1049

A typed representation for HTML and XML documents in Haskell

We define a family of embedded domain specific languages for generating HTML and XML documents. Each language is implemented as a combinator library in Haskell. The generated HTML/XML documents are guaranteed to be well-formed. In addition, each library can guarantee that the generated documents are valid XML documents to a certain extent (for HTML only a weaker guarantee is possible). On top of the libraries, Haskell serves as a meta language to define parameterized documents, to map structured documents to HTML/XML, to define conditional content, or to define entire Web sites. The combinator libraries support element-transforming style, a programming style that allows programs to have a visual appearance similar to HTML/XML documents, without modifying the syntax of Haskell

1111

The contiguity in R/M

An r.e. degree c is contiguous if deg/sub wtt/(A)=deg/sub wtt/(B) for any r.e. sets A,B in c. In this paper, we generalize the notation of contiguity to the structure R/M, the upper semilattice of the r.e. degree set R modulo the cappable r.e. degree set M. An element [c] in R/M is contiguous if [deg/sub wtt/(A)]=[deg/sub wtt/(B)] for any r.e. sets A, B such that deg/sub T/(A),deg/sub T/(B) in [c]. It is proved in this paper that every nonzero element in R/M is not contiguous, i.e., for every element [c] in R/M, if [c] not=[o] then there exist at least two r.e. sets A, B such that deg/sub T/(A), deg/sub T/(B) in [c] and [deg/sub wtt/(A)] not=[deg/sub wtt/(B)]

1154

The effect of voxel size on the accuracy of dose-volume histograms of prostate /sup 125/I seed implants

Cumulative dose-volume histograms (DVH) are crucial in evaluating the quality of radioactive seed prostate implants. When calculating DVHs, the choice of voxel size is a compromise between computational speed (larger voxels) and accuracy (smaller voxels). We quantified the effect of voxel size on the accuracy of DVHs using an in-house computer program. The program was validated by comparison with a hand-calculated DVH for a single 0.4-U iodine-125 model 6711 seed. We used the program to find the voxel size required to obtain accurate DVHs of five iodine-125 prostate implant patients at our institution. One-millimeter cubes were sufficient to obtain DVHs that are accurate within 5% up to 200% of the prescription dose. For the five patient plans, we obtained good agreement with the VariSeed (version 6.7, Varian, USA) treatment planning software's DVH algorithm by using voxels with a sup-inf dimension equal to the spacing between successive transverse seed implant planes (5 mm). The volume that receives at least 200% of the target dose, V/sub 200/, calculated by VariSeed was 30% to 43% larger than that calculated by our program with small voxels. The single-seed DVH calculated by VariSeed fell below the hand calculation by up to 50% at low doses (30 Gy), and above it by over 50% at high doses (>250 Gy)

993

A large deviations analysis of the transient of a queue with many Markov fluid inputs: approximations and fast simulation

This article analyzes the transient buffer content distribution of a queue fed by a large number of Markov fluid sources. We characterize the probability of overflow at time t, given the current buffer level and the number of sources in the on-state. After scaling buffer and bandwidth resources by the number of sources n, we can apply large deviations techniques. The transient overflow probability decays exponentially in n. In the case of exponential on/off sources, we derive an expression for the decay rate of the rare event probability under consideration. For general Markov fluid sources, we present a plausible conjecture. We also provide the "most likely path" from the initial state to overflow (at time t). Knowledge of the decay rate and the most likely path to overflow leads to (i) approximations of the transient overflow probability and (ii) efficient simulation methods of the rare event of buffer overflow. The simulation methods, based on importance sampling, give a huge speed-up compared to straightforward simulations. The approximations are of low computational complexity and are accurate, as verified by means of simulation experiments

544

Virtual reality treatment of flying phobia

Flying phobia (FP) might become a very incapacitating and disturbing problem in a person's social, working, and private areas. Psychological interventions based on exposure therapy have proved to be effective, but given the particular nature of this disorder they bear important limitations. Exposure therapy for FP might be excessively costly in terms of time, money, and efforts. Virtual reality (VR) overcomes these difficulties as different significant environments might be created, where the patient can interact with what he or she fears while in a totally safe and protected environment, the therapist's consulting room. This paper intends, on one hand, to show the different scenarios designed by our team for the VR treatment of FP, and on the other, to present the first results supporting the effectiveness of this new tool for the treatment of FP in a multiple baseline study

82

Bit-serial AB/sup 2/ multiplier using modified inner product

This paper presents a new multiplication algorithm and, based on this algorithm, proposes a hardware architecture, called modified inner-product multiplier (MIPM), which computes AB/sup 2/ multiplication based on a linear feedback shift register (LFSR). The algorithm is based on the property of the irreducible all one polynomial (AOP) over the finite field GF(2/sup m/). The proposed architecture reduces the time and space complexity for computing AB/sup 2/. The proposed architecture has a potential application to implementing exponentiation architecture for a public-key cryptosystem

1210

Adaptive optimizing compilers for the 21st century

Historically, compilers have operated by applying a fixed set of optimizations in a predetermined order. We call such an ordered list of optimizations a compilation sequence. This paper describes a prototype system that uses biased random search to discover a program-specific compilation sequence that minimizes an explicit, external objective function. The result is a compiler framework that adapts its behavior to the application being compiled, to the pool of available transformations, to the objective function, and to the target machine. This paper describes experiments that attempt to characterize the space that the adaptive compiler must search. The preliminary results suggest that optimal solutions are rare and that local minima are frequent. If this holds true, biased random searches, such as a,genetic algorithm, should find good solutions more quickly than simpler strategies, such as hill climbing

1255

Succession in standardization: grafting XML onto SGML

Succession in standardization is often a problem. The advantages of improvements must be weighed against those of compatibility. If compatibility considerations dominate, a grafting process takes place. According to our taxonomy of succession, there are three types of outcomes. A Type I succession, where grafting is successful, entails compatibility between successors, technical paradigm compliance and continuity in the standards trajectory. In this paper, we examine issues of succession and focus on the Extensible Markup Language (XML). It was to be grafted on the Standard Generalized Markup Language (SGML), a stable standard since 1988. However, XML was a profile, a subset and an extension of SGML (1988). Adaptation of SGML was needed (SGML 1999) to forge full (downward) compatibility with XML (1998). We describe the grafting efforts and analyze their outcomes. Our conclusion is that although SGML was a technical exemplar for XML developers, full compatibility was not achieved. The widespread use of HyperText Mark-up Language (HTML) exemplified the desirability of simplicity in XML, standardization. This and HTML's user market largely explain the discontinuity in SGML-XML succession

600

Development of railway VR safety simulation system

Abnormal conditions occur in railway transportation due to trouble or accidents and it affects a number of passengers. It is very important, therefore, to quickly recover and return to normal train operation. For this purpose we developed a system, "Computer VR Simulation System for the Safety of Railway Transportation." It is a new type simulation system to evaluate measures to be taken under abnormal conditions. Users of this simulation system cooperate with one another to correct the abnormal conditions that have occurred in virtual reality. This paper reports the newly developed simulation system

645

Oxygen-enhanced MRI of the brain

Blood oxygenation level-dependent (BOLD) contrast MRI is a potential method for a physiological characterization of tissue beyond mere morphological representation. The purpose of this study was to develop evaluation techniques for such examinations using a hyperoxia challenge. Administration of pure oxygen was applied to test these techniques, as pure oxygen can be expected to induce relatively small signal intensity (SI) changes compared to CO/sub 2/-containing gases and thus requires very sensitive evaluation methods. Fourteen volunteers were investigated by alternating between breathing 100% O/sub 2/ and normal air, using two different paradigms of administration. Changes ranged from >30% in large veins to 1.71%+or-0.14% in basal ganglia and 0.82%+or-0.08% in white matter. To account for a slow physiological response function, a reference for correlation analysis was derived from the venous reaction. An objective method is presented that allows the adaptation of the significance threshold to the complexity of the paradigm used. Reference signal characteristics in representative brain tissue regions were established. As the presented evaluation scheme proved its applicability to small SI changes induced by pure oxygen, it can readily be used for similar experiments with other gases

1396

Construction of double sampling s-control charts for agile manufacturing

Double sampling (DS) X-control charts are designed to allow quick detection of a small shift of process mean and provides a quick response in an agile manufacturing environment. However, the DS X-control charts assume that the process standard deviation remains unchanged throughout the entire course of the statistical process control. Therefore, a complementary DS chart that can be used to monitor the process variation caused by changes in process standard deviation should be developed. In this paper, the development of the DS s-charts for quickly detecting small shift in process standard deviation for agile manufacturing is presented. The construction of the DS s-charts is based on the same concepts in constructing the DS X-charts and is formulated as an optimization problem and solved with a genetic algorithm. The efficiency of the DS s-control chart is compared with that of the traditional s-control chart. The results show that the DS s-control charts can be a more economically preferable alternative in detecting small shifts than traditional s-control charts

7

Anti-spam suit attempts to hold carriers accountable

A lawsuit alleges that Sprint has violated Utah's new anti-spam act. The action could open the door to new regulations on telecom service providers

1403

IT: Utilities

A look at five utilities to make your PCs more, efficient, effective, and efficacious

1097

A study on an automatic seam tracking system by using an electromagnetic sensor for sheet metal arc welding of butt joints

Many sensors, such as the vision sensor and the laser displacement sensor, have been developed to automate the arc welding process. However, these sensors have some problems due to the effects of arc light, fumes and spatter. An electromagnetic sensor, which utilizes the generation of an eddy current, was developed for detecting the weld line of a butt joint in which the root gap size was zero. An automatic seam tracking system designed for sheet metal arc welding was constructed with a sensor. Through experiments, it was revealed that the system had an excellent seam tracking accuracy of the order of +or-0.2 mm

1446

The Tattletale technique

Practical experience has taught many Java developers one thing: critical resources (mutexes, database connections, transactions, file handles, etc.) require timely and systematic release. Unfortunately, Java's garbage collector is not up to that job. According to the Java Language Specification, there are no guarantees when a garbage collector will run, when it will collect an object, or when it will finalize an object - if ever. Even more unfortunately, Java's counterpart to the C++ destructor (the finally block) is both tedious and error-prone, requiring developers to constantly remember and duplicate resource-releasing code. Consequently, even good Java developers can forget to release critical resources. There is a light at the end of the tunnel. Java may make it easier to leak critical resources, but it also provides the necessary mechanisms to easily track them down. The Tattletale technique is a simple method for designing new classes and retrofitting existing classes to quickly and easily detect the offending code responsible for leaking resources

850

Encouraging women in computer science

At a cost to both their own opportunities and society's ability to produce people with much-needed technical skills, women continue to be underrepresented in computer science degree programs at both the undergraduate and graduate level. Although some of the barriers that women face have their foundations in cultural expectations established well before the college level, we believe that departments can take effective steps to increase recruitment and retention of women students. This paper describes several strategies we have adopted at Stanford over the past decade

815

The canonical dual frame of a wavelet frame

We show that there exist wavelet frames that have nice dual wavelet frames, but for which the canonical dual frame does not consist of wavelets, i.e., cannot be generated by the translates and dilates of a single function

1276

A comparative study of some generalized rough approximations

In this paper we focus upon a comparison of some generalized rough approximations of sets, where the classical indiscernibility relation is generalized to any binary reflexive relation. We aim at finding the best of several candidates for generalized rough approximation mappings, where both definability of sets by elementary granules of information as well as the issue of distinction among positive, negative, and border regions of a set are taken into account

1233

Advanced optimization strategies in the Rice dHPF compiler

High-Performance Fortran (HPF) was envisioned as a vehicle for modernizing legacy Fortran codes to achieve scalable parallel performance. To a large extent, today's commercially available HPF compilers have failed to deliver scalable parallel performance for a broad spectrum of applications because of insufficiently powerful compiler analysis and optimization. Substantial restructuring and hand-optimization can be required to achieve acceptable performance with an HPF port of an existing Fortran application, even for regular data-parallel applications. A key goal of the Rice dHPF compiler project has been to develop optimization techniques that enable a wide range of existing scientific applications to be ported easily to efficient HPF with minimal restructuring. This paper describes the challenges to effective parallelization presented by complex (but regular) data-parallel applications, and then describes how the novel analysis and optimization technologies in the dHPF compiler address these challenges effectively, without major rewriting of the applications. We illustrate the techniques by describing their use for parallelizing the NAS SP and BT benchmarks. The dHPF compiler generates multipartitioned parallelizations of these codes that are approaching the scalability and efficiency of sophisticated hand-coded parallelizations

623

Stochastic recurrences of Jackpot Keno

We describe a mathematical model and simulation study for Jackpot Keno, as implemented by Jupiters Network Gaming (JNG) in the Australian state of Queensland, and as controlled by the Queensland Office of Gaming Regulation (QOGR) (http://www.qogr.qld.gov.au/keno.shtml). The recurrences for the house net hold are derived and it is seen that these are piecewise linear with a ternary domain split, and further, the split points are stochastic in nature. Since this structure is intractable (Brockett and Levine, Statistics & Probability & their Applications, CBS College Publishing, 1984), estimation of house net hold obtained through an appropriately designed simulator using a random number generator with desirable properties is described. Since the model and simulation naturally derives hold given payscale, but JNG and QOGR require payscale given hold, an inverse problem was required to be solved. This required development of a special algorithm, which may be described as a stochastic binary search. Experimental results are presented, in which the simulator is used to determine jackpot pay-scales so as to satisfy legal requirements of approximately 75% of net revenue returned to the players, i.e., 25% net hold for the house (JNG). Details of the algorithm used to solve this problem are presented, and notwithstanding the stochastic nature of the simulation, convergence to a specified hold for the inverse problem has been achieved to within 0.1% in all cases of interest to date

908

Multivariable H/sub infinity // mu feedback control design for high-precision wafer stage motion

Conventional PID-like SISO controllers are still the most common in industry, but with performance requirements becoming tighter there is a growing need for advanced controllers. For the positioning devices in IC-manufacturing, plant interaction is a major performance-limiting factor. MIMO control can be invoked to tackle this problem. A practically feasible procedure is presented to design MIMO feedback controllers for electromechanical positioning devices, using H/sub infinity // mu techniques. Weighting filters are proposed to straightforwardly and effectively impose performance and uncertainty specifications. Experiments show that MIMO control can considerably improve upon the performance with multiloop SISO control. Some problems are highlighted that are important for industrial practice, but lacking a workable solution

1177

Comparative statistical analysis of hole taper and circularity in laser percussion drilling

Investigates the relationships and parameter interactions between six controllable variables on the hole taper and circularity in laser percussion drilling. Experiments have been conducted on stainless steel workpieces and a comparison was made between stainless steel and mild steel. The central composite design was employed to plan the experiments in order to achieve required information with reduced number of experiments. The process performance was evaluated. The ratio of minimum to maximum Feret's diameter was considered as circularity characteristic of the hole. The models of these three process characteristics were developed by linear multiple regression technique. The significant coefficients were obtained by performing analysis of variance (ANOVA) at 1, 5 and 7% levels of significance. The final models were checked by complete residual analysis and finally were experimentally verified. It was found that the pulse frequency had a significant effect on the hole entrance diameter and hole circularity in drilling stainless steel unlike the drilling of mild steel where the pulse frequency had no significant effect on the hole characteristics

1132

Semidefinite programming vs. LP relaxations for polynomial programming

We consider the global minimization of a multivariate polynomial on a semi-algebraic set Omega defined with polynomial inequalities. We then compare two hierarchies of relaxations, namely, LP relaxations based on products of the original constraints, in the spirit of the RLT procedure of Sherali and Adams (1990), and recent semidefinite programming (SDP) relaxations introduced by the author. The comparison is analyzed in light of recent results in real algebraic geometry on various representations of polynomials, positive on a compact semi-algebraic set

567

Hidden Markov model-based tool wear monitoring in turning

This paper presents a new modeling framework for tool wear monitoring in machining processes using hidden Markov models (HMMs). Feature vectors are extracted from vibration signals measured during turning. A codebook is designed and used for vector quantization to convert the feature vectors into a symbol sequence for the hidden Markov model. A series of experiments are conducted to evaluate the effectiveness of the approach for different lengths of training data and observation sequence. Experimental results show that successful tool state detection rates as high as 97% can be achieved by using this approach

61

Application of time-frequency principal component analysis to text-independent speaker identification

We propose a formalism, called vector filtering of spectral trajectories, that allows the integration of a number of speech parameterization approaches (cepstral analysis, Delta and Delta Delta parameterizations, auto-regressive vector modeling, ...) under a common formalism. We then propose a new filtering, called contextual principal components (CPC) or time-frequency principal components (TFPC). This filtering consists in extracting the principal components of the contextual covariance matrix, which is the covariance matrix of a sequence of vectors expanded by their context. We apply this new filtering in the framework of closed-set speaker identification, using a subset of the POLYCOST database. When using speaker-dependent TFPC filters, our results show a relative improvement of approximately 20% compared to the use of the classical cepstral coefficients augmented by their Delta -coefficients, which is significantly better with a 90% confidence level

935

Experimental feedforward and feedback control of a one-dimensional SMA composite

The control of embedded shape memory alloy (SMA) actuators has recently become a topic of interest in the field of smart structures. The inherent difficulties associated with SMA actuators has resulted in a variety of approaches. Homogenization provides a simplified, yet mathematically rigorous, method of determining average stress and strain fields in a composite. A modified constitutive model is presented based on experimental results demonstrating the inability of most simple phenomenological models to capture the effective behavior of SMAs during thermal activation. A feedforward controller is presented for a SMA composite based on the homogenization of a modified phenomenological model for SMAs in a linear matrix

970

Complex dynamics in nearly symmetric three-cell cellular neural networks

The paper introduces a class of third-order nonsymmetric Cellular Neural Networks (CNNs), and shows through computer simulations that they undergo a cascade of period doubling bifurcations which leads to the birth of a large-size complex attractor. A major point is that these bifurcations and complex dynamics happen in a small neighborhood of a particular CNN with a symmetric interconnection matrix

133

L/sub p/ stability and linearization

A theorem by Hadamard gives a two-part condition under which a map from one Banach space to another is a homeomorphism. The theorem, while often very useful, is incomplete in the sense that it does not explicitly specify the family of maps for which the condition is met. Recently, under a typically weak additional assumption on the map, it was shown that Hadamard's condition is met if and only if the map is a homeomorphism with a Lipschitz continuous inverse. Here, an application is given concerning the relation between the L/sub p/ stability (with 1 <or= p < infinity ) of a nonlinear system and the stability of related linear systems. We also give a result that directs attention to a fundamental limitation concerning what can be proved about linearization and stability for a related familiar family of feedback systems

703

Direct self control with minimum torque ripple and high dynamics for a double three-level GTO inverter drive

A highly dynamic control scheme with very low torque ripple-direct self control (DSC) with torque hysteresis control-for very high-power medium-voltage induction motor drives fed by a double three-level inverter (D3LI) is presented. In this arrangement, two three-level inverters that are connected in parallel at their DC sides are feeding the open motor windings. The DSC, well known from two- and three-level inverters, is adapted to the D3LI and optimized for a minimum torque ripple. An 18-corner trajectory is chosen for the stator flux of the induction machine since it is approaching the ideal circle much better than the hexagon known from DSC for two-level inverters, without any detriment to the torque ripple. The machine and inverter control are explained and the proposed torque quality and dynamics are verified by measurements on a 180-kW laboratory drive

746

Real-time transmission of pediatric echocardiograms using a single ISDN line

We tested the adequacy of a videoconferencing system using a single integrated systems digital network (ISDN) line (128 kilobits per second) for the remote diagnosis of children with suspected congenital heart disease (CHD). Real-time echocardiogram interpretation was compared to subsequent videotape review in 401 studies with concordance in 383 (95.5%) studies. A new diagnosis of CHD was made in 98 studies. Immediate patient transfer was arranged based upon a real-time diagnosis in five studies. In 300 studies, a normal diagnosis obviated further evaluation. A single ISDN line is adequate for transmission of pediatric echocardiograms and it allows for remote management of patients with CHD

1313

A collocation formulation of multistep methods for variable step-size extensions

Multistep methods are classically constructed by specially designed difference operators on an equidistant time grid. To make them practically useful, they have to be implemented by varying the step-size according to some error-control algorithm. It is well known how to extend Adams and BDF formulas to a variable step-size formulation. In this paper we present a collocation approach to construct variable step-size formulas. We make use of piecewise polynomials to show that every k-step method of order k+1 has a variable step-size polynomial collocation formulation

1356

Five-axis NC milling of ruled surfaces: optimal geometry of a conical tool

The side milling of ruled surfaces using a conical milling cutter was studied. This is a field that has largely been ignored by research scientists, but it is much used in industry, especially to machine turbine blades. We first suggest an improved positioning with respect to the directrices of the ruled surface. As compared with the methods already developed for the cylindrical cutter, this positioning enables the error between the cutter and the work-piece to be reduced. An algorithm is then introduced to calculate error so one can determine the cutter dimensions (cone radius and angle) in order to respect the tolerance interval imposed by the design office. This study provides an opportunity to determine cutters with greater dimensions, thus alleviating bending problems during milling

828

Verizon leapfrogs Sprint PCS with Q2 subscriber numbers

The wireless carrier industry's second-quarter results showed a surprising shift in market share as Sprint PCS fell from grace after a nearly four-year lead in subscriber additions and Verizon Wireless added considerably more customers than analysts expected

890

Multiple criteria decision making without optimization

We present a development intended to make interactive decision making schemes accessible for a wider spectrum of decision makers. To this aim we propose to eliminate the need to solve optimization problems at successive iterations of interactive decision processes. We show that the need for optimization can be eliminated by the ability of establishing sufficiently tight bounds on criteria values for efficient decisions prior to explicit identification of such decisions. We present a technique, fully operational and numerically simple, for establishing such bounds. Bounds are dynamic, i.e., they become stronger with the growing number of decisions explicitly identified. They are also parametric with respect to weighting coefficients. We also point out how this technique can enhance the existing interactive decision making methods

1012

Evolving receptive-field controllers for mobile robots

The use of evolutionary methods to generate controllers for real-world autonomous agents has attracted attention. Most of the pertinent research has employed genetic algorithms or variations thereof. Research has applied an alternative evolutionary method, evolution strategies, to the generation of simple Braitenberg vehicles. This application accelerates the development of such controllers by more than an order of magnitude (a few hours compared to more than two days). Motivated by this useful speedup, the paper investigates the evolution of more complex architectures, receptive-field controllers, that can employ nonlinear interactions and, therefore, can yield more complex behavior. It is interesting to note that the evolution strategy yields the same efficacy in terms of function evaluations, even though the second class of controllers requires up to 10 times more parameters than the simple Braitenberg architecture. In addition to the speedup, there is an important theoretical reason for preferring an evolution strategy over a genetic algorithm for this problem, namely the presence of epistasis

1057

Acceptance of a price discount: the role of the semantic relatedness between purchases and the comparative price format

Two studies are reported where people are asked to accept or not a price reduction on a target product. In the high (low) relative saving version, the regular price of the target product is low (high). In both versions, the absolute value of the price reduction is the same as well as the total of regular prices of planned purchases. As first reported by Tversky and Kahneman (1981), findings show that the majority of people accept the price discount in the high-relative saving version whereas the minority do it in the low one. In Study 1, findings show that the previous preference reversal disappears when planned purchases are strongly related. Also, a previously unreported preference reversal is found. The majority of people accept the price discount when the products are weakly related whereas the minority accept when the products are strongly related. In Study 2, findings show that the classic preference reversal disappears as a function of the comparative price format. Also, another previously unreported preference reversal is found. When the offered price reduction relates to a low-priced product, people are more inclined to accept it with a control than a minimal comparative price format. Findings reported in Studies 1 and 2 are interpreted in terms of mental accounting shifts

911

Scheduling schemes for an integrated flight and propulsion control system

We describe two schemes for scheduling an integrated flight and propulsion control system for an experimental vertical/short take-off and landing (V/STOL) aircraft concept in the acceleration from hover (0-120 kn) flight phase. Multivariable integrated flight and propulsion controllers are designed at several points over the V/STOL envelope and implemented as exact plant observers with state feedback. In the first scheduling scheme, the values of the state feedback and observer gain matrices are interpolated between the fixed-point designs as a function of aircraft speed. In the second approach, the control signals produced by the different fixed-point controllers are blended, allowing a significant reduction in the order of the scheduled controllers. Both scheduling schemes are shown in nonlinear simulation to provide excellent handling qualities as the aircraft accelerates from the hover

583

Neural networks in optimal filtration

The combined use and mutual influence of neural networks and optimal filtering is considered; the neural-network and filtering approaches are compared by solving two simple optimal-filtering problems: linear filtering and the filtering of a binary telegraph signal corresponding to observations in discrete white noise

954

Caring for your new lawyers

In any given year, a striking number of lawyers are in a state of flux, from newly minted law school graduates looking for their first job, to senior litigators migrating to new challenges with new firms. The one certainty is that lawyers new to any firm need care and feeding in myriad ways. All of them need to know and understand three things: (1) the firm's culture; (2) the resources available to help them develop their practices; and (3) where to get help and guidance for research and practice purposes. Obtaining a thorough understanding of a new firm's workings may be the greatest research project lawyers face. How can a firm help its new lawyers learn what they need to know? To offer an example, here are programs in place at my firm

117

Multiresolution Markov models for signal and image processing

Reviews a significant component of the rich field of statistical multiresolution (MR) modeling and processing. These MR methods have found application and permeated the literature of a widely scattered set of disciplines, and one of our principal objectives is to present a single, coherent picture of this framework. A second goal is to describe how this topic fits into the even larger field of MR methods and concepts-in particular, making ties to topics such as wavelets and multigrid methods. A third goal is to provide several alternate viewpoints for this body of work, as the methods and concepts we describe intersect with a number of other fields. The principle focus of our presentation is the class of MR Markov processes defined on pyramidally organized trees. The attractiveness of these models stems from both the very efficient algorithms they admit and their expressive power and broad applicability. We show how a variety of methods and models relate to this framework including models for self-similar and 1/f processes. We also illustrate how these methods have been used in practice

1193

Operator splitting and approximate factorization for taxis-diffusion-reaction models

In this paper we consider the numerical solution of 2D systems of certain types of taxis-diffusion-reaction equations from mathematical biology. By spatial discretization these PDE systems are approximated by systems of positive, nonlinear ODEs (Method of Lines). The aim of this paper is to examine the numerical integration of these ODE systems for low to moderate accuracy by means of splitting techniques. An important consideration is maintenance of positivity. We apply operator splitting and approximate matrix factorization using low order explicit Runge-Kutta methods and linearly implicit Runge-Kutta-Rosenbrock methods. As a reference method the general purpose solver VODPK is applied

682

Information and information technology

This paper reveals the concepts of information and information technology. It also describes the close relationship between information and information technology. It explains a basic mechanism of different devices of information technology and connotes how they are useful to store, process and retrieve the information. In addition of this, the paper shows the present status of information technology and Indian universities

1292

The heat is on [building automation systems]

Integrating building automation systems (BASs) can result in systems that have the ability to sense changes in the air temperature through a building's heating, ventilation, and air conditioning (HVAC) systems. Taking advantages of the Internet, using remote monitoring, and building interoperability through open protocol systems are some of the issues discussed throughout the BAS/HVAC community. By putting information over the Internet, facility managers get real-time data on energy usage and performance issues

1036

Nonlinear control of a shape memory alloy actuated manipulator

This paper presents a nonlinear, robust control algorithm for accurate positioning of a single degree of freedom rotary manipulator actuated by Shape Memory Alloy (SMA). A model for an SMA actuated manipulator is presented. The model includes nonlinear dynamics of the manipulator, a constitutive model of Shape Memory Alloy, and electrical and heat transfer behavior of SMA wire. This model is used for open and closed loop motion simulations of the manipulator. Experiments are presented that show results similar to both closed and open loop simulation results. Due to modeling uncertainty and nonlinear behavior of the system, classic control methods such as Proportional-Integral-Derivative control are not able to present fast and accurate performance. Hence a nonlinear, robust control algorithm is presented based on Variable Structure Control. This algorithm is a control gain switching technique based on the weighted average of position and velocity feedbacks. This method has been designed through simulation and tested experimentally. Results show fast, accurate, and robust performance of the control system. Computer simulation and experimental results for different stabilization and tracking situations are also presented

1073

Quantum retrodiction in open systems

Quantum retrodiction involves finding the probabilities for various preparation events given a measurement event. This theory has been studied for some time but mainly as an interesting concept associated with time asymmetry in quantum mechanics. Recent interest in quantum communications and cryptography, however, has provided retrodiction with a potential practical application. For this purpose quantum retrodiction in open systems should be more relevant than in closed systems isolated from the environment. In this paper we study retrodiction in open systems and develop a general master equation for the backward time evolution of the measured state, which can be used for calculating preparation probabilities. We solve the master equation, by way of example, for the driven two-level atom coupled to the electromagnetic field

849

Ten years of strategies to increase participation of women in computing programs. The Central Queensland University experience: 1999-2001

In the late eighties, the participation rate of women in information technology courses in most Australian Universities was around 25%. This low level of women's participation in computing courses occurs not only in Australia but also overseas. More studies indicate that the participation rates have not improved and in fact may be even further in decline. Participation rates in the workforce also appear to be in decline. Concerned at the imbalance within Australia, the Federal government directed all Australian Universities to increase the number of women in courses leading to a professional computing qualification (i.e., information technology courses) to 40% of students by 1995. This paper details one Australian university's approach, over a 10 year period (1991-2001), to redress this imbalance. We provide examples of intervention strategies developed and the outcomes for these strategies. We present the outcomes against a background frame of the Australian Higher Education scene of that decade which was influenced by funding levels to universities in general and to equity programs in particular. We present data related to the participation of women in computing programs along with snapshots of the overall changing student demographics over this period

727

Life after bankruptcy [telecom carriers]

How comeback telecom carriers are changing industry economics, and why others may have no choice but to follow their lead

762

Quantum computing with spin qubits in semiconductor structures

We survey recent work on designing and evaluating quantum computing implementations based on nuclear or bound-electron spins in semiconductor heterostructures at low temperatures and in high magnetic fields. General overview is followed by a summary of results of our theoretical calculations of decoherence time scales and spin-spin interactions. The latter were carried out for systems for which the two-dimensional electron gas provides the dominant carrier for spin dynamics via exchange of spin-excitons in the integer quantum Hall regime

1337

Some properties of Hadamard matrices coming from dihedral groups

H. Kimura (1996) introduced a method to construct Hadamard matrices of degree 8n + 4 from the dihedral group of order 2n. In this paper we study some properties of this construction

1372

Knowledge acquisition and ontology modelling for construction of a control and monitoring expert system

This paper presents the processes of knowledge acquisition and ontology development for structuring the knowledge base of an expert system. Ontological engineering is a process that facilitates construction of the knowledge base of an intelligent system. Ontology is the study of the organization and classification of knowledge. Ontological engineering in artificial intelligence has the practical goal of constructing frameworks for knowledge that allow computational systems to tackle knowledge-intensive problems and it supports knowledge sharing and reuse. To illustrate the process of conceptual modelling using the Inferential Modelling Technique as a basis for ontology construction, the tool and processes are applied to build an expert system in the domain of monitoring of a petroleum-production facility

1427

Training for trouble

In a security context, one example of digitized video's integration into a networked knowledge base is found in the Accident Response Group (ARG) at Sandia National Labs. A "national security laboratory" headquartered in Albuquerque, New Mexico, Sandia is operated by Lockheed Martin and primarily funded by the U.S. Department of Energy. The organization handles research, design and development of all non-nuclear components used in U.S. nuclear weapons programs, and is involved as well in programs related to energy, critical infrastructure, non-proliferation, materials control, and emerging threats. ARG's searchable video database has been implemented using the Screening Room package of applications from Convera in Vienna, Virginia. Formed in December 2000 from Excalibur Technologies and Intel's Interactive Media Services Division, Convera targets corporate and institutional markets with products for securely accessing, indexing, and searching rich media content-text, images, audio, and video-across interconnected computer networks. Among its public-sector clients are the FBI, NASA, the Nuclear Regulatory Commission, U.S. military services, the Departments of Justice and State, and various domestic and foreign intelligence agencies

874

The curious ways of professional cultures and the "two-body opportunity"

When two professionals are a couple, we sometimes refer to them as having a "two-body problem." However, when each partner of a couple exists in the same cultures, they also have an opportunity for deeply shared understanding and empathy, simply because each understands at a deep level the culture in which the other works. I explore this notion. A couple has what we call the "two-body problem" when both are professionals who are qualified for a kind of position that is relatively rare and who are very selective about the positions that they accept. For example, there are relatively scant numbers of jobs as a computer science professor-at any level. An individual considering an academic job may only be interested in research universities, or in teaching universities, restricting the choice of open positions substantially. The classic two-body "problem" arises when one partner wants to accept a new position that requires geographical relocation. Then, the other partner also needs to find a new position. Moreover, it can be very difficult to find a suitable position when they are naturally scarce

831

Software vendors' failure fuels consolidation theories [telecom interconnection and billing]

As independent software vendors like AP Engines fall by the wayside as independent entities, attrition could accelerate consolidation in the OSS space

889

Synthesis of the control systems via reflection onto auxiliary surfaces

An approach to robust control systems synthesis, both linear and nonlinear, and nonstationary is offered. The control is carried out, providing the given phase constraints varied in acceptable limits, in view of constraints on its value and incompleteness of the information about functioning disturbances. The approach is based on the introduction of auxiliary integral surfaces, on which the initial moving is projected. As a result the reduced equivalent moving is formed, being described by the scalar equation which in many important cases can be integrated directly. On the basis of the equation obtained solving a synthesis task is carried out and can be reduced to algebraic or integral inequalities. The final relations defined for linear equivalent moving are presented

85

Strategic implementation of IT/IS projects in construction: a case study

The need for improved implementation of Information Technology (IT) and Information Systems (IS) has been emphasised in both empirical and prescriptive research studies. This problem is magnified in the construction industry, which has been slow to embrace and utilise new technologies with negative consequences on productivity and innovation. This paper presents a strategic implementation framework for IT/IS projects in construction. The framework builds upon recent published works and encompasses well-documented predictors for effective IT/IS implementation. A case study with a large multi-national construction organisation is used to demonstrate the strategic implementation of a Project Management Information System (PMIS) used for the construction of a mobile phone telecommunications network in the South East of Queensland, Australia

1153

Direct aperture optimization: A turnkey solution for step-and-shoot IMRT

IMRT treatment plans for step-and-shoot delivery have traditionally been produced through the optimization of intensity distributions (or maps) for each beam angle. The optimization step is followed by the application of a leaf-sequencing algorithm that translates each intensity map into a set of deliverable aperture shapes. In this article, we introduce an automated planning system in which we bypass the traditional intensity optimization, and instead directly optimize the shapes and the weights of the apertures. We call this approach "direct aperture optimization." This technique allows the user to specify the maximum number of apertures per beam direction, and hence provides significant control over the complexity of the treatment delivery. This is possible because the machine dependent delivery constraints imposed by the MLC are enforced within the aperture optimization algorithm rather than in a separate leaf-sequencing step. The leaf settings and the aperture intensities are optimized simultaneously using a simulated annealing algorithm. We have tested direct aperture optimization on a variety of patient cases using the EGS4/BEAM Monte Carlo package for our dose calculation engine. The results demonstrate that direct aperture optimization can produce highly conformal step-and-shoot treatment plans using only three to five apertures per beam direction. As compared with traditional optimization strategies, our studies demonstrate that direct aperture optimization can result in a significant reduction in both the number of beam segments and the number of monitor units. Direct aperture optimization therefore produces highly efficient treatment deliveries that maintain the full dosimetric benefits of IMRT

1116

An interlingua-based Chinese-English MT system

Chinese-English machine translation is a significant and challenging problem in information processing. The paper presents an interlingua-based Chinese-English natural language translation system (ICENT). It introduces the realization mechanism of Chinese language analysis, which contains syntactic parsing and semantic analyzing and gives the design of interlingua in details. Experimental results and system evaluation are given. The result is satisfying

543

The development of virtual reality therapy (VRT) system for the treatment of acrophobia and therapeutic case

Virtual reality therapy (VRT), based on this sophisticated technology, has been used in the treatment of subjects diagnosed with acrophobia, a disorder that is characterized by marked anxiety upon exposure to heights and avoidance of heights. Conventional VR systems for the treatment of acrophobia have limitations, over-costly devices or somewhat unrealistic graphic scenes. The goal of this study was to develop an inexpensive and more realistic virtual environment (VE) in which to perform exposure therapy for acrophobia. It is based on a personal computer, and a virtual scene of a bunge-jump tower in the middle of a large city. The virtual scenario includes an open lift surrounded by props beside a tower, which allows the patient to feel a sense of heights. The effectiveness of the VE was evaluated through the clinical treatment of a subject who was suffering from the fear of heights. As a result, it was proved that this VR environment was effective and realistic at overcoming acrophobia according not only to the comparison results of a variety of questionnaires before and after treatment but also to the subject's comments that the VE seemed to evoke more fearful feelings than the real situation

994

Design and implementation of a flexible manufacturing control system using neural network

Design and implementation of a sequential controller based on the concept of artificial neural networks for a flexible manufacturing system are presented. The recurrent neural network (RNN) type is used for such a purpose. Contrary to the programmable controller, an RNN-based sequential controller is based on a definite mathematical model rather than depending on the experience and trial and error techniques. The proposed controller is also more flexible because it is not limited by the restrictions of the finite state automata theory. Adequate guidelines of how to construct an RNN-based sequential controller are presented. These guidelines are applied to different case studies. The proposed controller is tested by simulations and real-time experiments. These tests prove the successfulness of the proposed controller performances. Theoretical as well as experimental results are presented and discussed indicating that the proposed design procedure using Elman's RNN can be effective in designing a sequential controller for event-based type manufacturing systems. In addition, the simulation results assure the effectiveness of the proposed controller to overcome the effect of noisy inputs

969

Controlled projective synchronization in nonpartially-linear chaotic systems

Projective synchronization (PS), in which the state vectors synchronize up to a scaling factor, is usually observable only in partially linear systems. We show that PS could, by means of control, be extended to general classes of chaotic systems with nonpartial linearity. Performance of PS may also be manipulated by controlling the scaling factor to any desired value. In numerical experiments, we illustrate the applications to a Rossler system and a Chua's circuit. The feasibility of the control for high dimensional systems is demonstrated in a hyperchaotic system

1252

An agent-oriented and service-oriented environment for deploying dynamic distributed systems

This paper presents JASE, a Java-based Agent-oriented and Service-oriented Environment for deploying dynamic distributed systems. JASE utilizes two important concepts in the field of distributed computing: the concept of services and remote programming with mobile agents. In JASE, mobile agents are used to support applications, and service interface agents are used to wrap services. Service inter-face agents can dynamically register their services in Service Server. Mobile agent locates a specific service interface agent by submitting requests to the Service Server with descriptions of required services. JASE uses XML to describe both service descriptions and the mobile agent's queries. JASE supports two kinds of communication facility: tuple space and asynchronous messages. In this paper, the design and implementation of JASE are described. An application shows the suitability and the effectiveness of the JASE and performance evaluation is also made. Finally, related work and some conclusions are given