bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymptotic optimality of competitive associative nets and its application to incremental learning of nonlinear functions
Authors: Kurogi Shuichi 
Published: May 2007

AbstractThe competitive associative net CAN2 is a neural net that provides piecewise‐linear approximation through incremental learning of a nonlinear function by the associative net function. The effectiveness of this net has already been shown by applications to function approximation, control, precipitation estimation, and other problems. The learning algorithm essentially includes competitive learning based on the gradient method and suffers from the local solution problem. The purpose of this paper is to circumvent this problem. First, the asymptotic optimality condition, that is, the optimality condition for minimizing the mean‐square error of the approximation function, is derived for the case in which the net is composed of a very large number of units. This condition can be used to decide whether the weight assignment each time is close to the optimal solution, and also to suggest weight assignments closer to the optimal solution. The condition is incorporated into a learning algorithm based on the gradient method, resulting in the following learning algorithm: when it is decided that the weight assignment obtained by the gradient method is not close to the optimal solution, the weights of some units are reinitialized so that the weight assignment is closer to the optimal solution. Finally, numerical experiments are performed in which the proposed learning algorithm is applied to several benchmark functions. The effectiveness of the proposed algorithm is verified. The results are compared to the results of experiments by BPN (Back‐Propagation Net), RBFN (Radial Basis Function Net), and SVR (Support Vector Regression), and it is shown that CAN2 based on the proposed algorithm has excellent function approximation performance. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(9): 85–96, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10538
A competitive information recommendation system and its rational recommendation method
Authors: Sakamoto Toshiki , Kitamura Yasuhiko , Tatsumi Shoji 
Published: May 2007

AbstractRetrieval engines are widely used as a means for users to acquire information satisfying their requirements from the large amount of diversified Web information on the Internet. However, retrieval engines cannot be useful unless the requirements from the user are explicitly represented in terms of keywords. Consequently, information recommendation systems are attracting attention as a means of providing information which is likely to interest the user. This paper proposes a competitive information recommendation system, which recommends information to the user by competitive interaction of multiple agents, each having an individual character, with the user. In the competitive information recommendation system, if the agent simply recommends the information autonomously, information desired by the user may not be recommended, or many interactions may be needed before the user acquires the desired information. Therefore, this paper proposes a rational recommendation method in which the utility for the user that can be obtained from the recommended information is represented by a multi‐attribute utility function, and the agent recommends only information desirable to the user while learning the weight for each attribute. Then the best profit strategy, in which the profit of the agent has priority, and the best learning strategy, in which learning of the utility to the user has priority, are presented as information recommendation strategies for the agent. An evaluation experiment shows that the best profit strategy is better. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(9): 74–84, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10662
Generation of threshold functions of high‐order satisfying monotonicities
Authors: Kamada Yukihiro , Miyasaki Kiyonori 
Published: May 2007

AbstractThis paper presents a generation procedure for high‐order threshold functions, considering the high‐order neighbor vector and the monotonic property. Specifically, it is first shown that the high‐order neighbor vector can be derived from an input vector which is noncomparable by the high‐order threshold function. Then, it is shown that a monotonic function of a high‐order variable can easily be generated from the given monotonic function. Based on the generation process for the monotonic function, the generation procedure for high‐order threshold functions is derived. It is also shown that if a given high‐order threshold function preserves monotonicity, the generated high‐order threshold function also preserves monotonicity, and also the high‐order terms. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(9): 63–73, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20243
Bayesian classification of a human custom based on stochastic context‐free grammar
Authors: Mitomi Humikazu , Fujiwara Fuyuki , Yamamoto Masanobu , Sato Taisuke 
Published: May 2007

AbstractThis paper describes a new approach for gesture recognition based on stochastic context‐free grammar (SCFG). We focus on the actions in the Japanese tea ceremony, where structure of the action can be described by context‐free grammar. Our aim is to recognize the actions in the tea ceremony. Existing SCFG approach consists of generating symbol stream, parsing, and recognition. The symbol stream often includes uncertainty. Therefore, the parsing process needs to recover from errors in the entry process. This paper proposes an error‐free approach to segment an action into a set of events. This approach, based on acceleration of body motion, can produce events corresponding to a terminal symbol with little error. After translating the events into a set of symbol streams, parsing the set of the streams leaves a small number to be derived. The number of potential streams is not too large since each event is correctly segmented. Among the remaining streams, our SCFG can identify the action with a maximum posterior probability. Giving an SCFG rule the multiple probabilities, one SCFG can recognize multiple actions. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(9): 52–62, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20531
Spoken language understanding method using confidence measure and dialogue history
Authors: Fujiwara Noriki , Itoh Toshihiko , Araki Kenji , Kai Atsuhiko , Konishi Tatsuhiro , Itoh Yukihiro 
Published: May 2007

AbstractIn the real environment, it is hard for a speech recognizer to avoid misrecognitions completely. However, if misrecognitions occur, user's intentions are usually misunderstood by a conventional language understanding technique, which simply gives priority to the higher rank hypothesis of a speech recognition result (N‐best). The utterances in a dialogue are coherent and correct user's intentions might appear in the lower rank hypothesis of N‐best. To understand user's speech intentions in the real environment, we propose the language understanding technique that utilizes the dialogue context and confidence measure, which is the word posterior probability. The experimental results show that proposed technique is more efficient (about 15%) than the conventional technique. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(9): 21– 31, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20758
High‐speed processing and high‐reliability technology in an integrated fixed‐line and wireless, autonomous decentralized IC card system
Authors: Shiibashi Akio 
Published: May 2007

AbstractIncreasing the processing speed of automatic fare collection gates (AFCG) is a topic of great importance for supporting passengers who are getting on and off high‐density transportation at peak hours. On the other hand, reliability is indispensable for processing tickets, which are a type of noncurrency negotiable instrument. Therefore, a passenger ticket system that provides both high‐speed processing and high reliability is required. To increase passenger convenience and reduce maintenance costs, a wireless IC card ticket system is desirable. However, since this system uses wireless communication for processing that is carried out with the fare collection gates, the drop in data during ticket examination is a problem. In this paper, the author proposes an autonomous decentralized technology for satisfying the requirements of high‐speed processing and high reliability in a wireless IC card ticket system. IC cards, automatic fare collection gates, and a central server are designed as nodes of an autonomous decentralized system. In particular, to achieve high‐speed processing, the author proposes an autonomous decentralized algorithm for fare calculation by IC cards and automatic fare collection gates. To prove the effectiveness of this algorithm, the author creates models and performs comparison tests. Also, as a technology for ensuring high reliability, the author proposes an autonomous decentralized data consistency technology for each subsystem. These technologies were introduced in the Suica system (East Japan Railway Company) in Japan and their effectiveness was proven. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(9): 1–10, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20800
Cure rate model with interval censored data
Authors: Kim Yang‐Jin , Jhun Myoungshic 
Published: May 2007

AbstractIn cancer trials, a significant fraction of patients can be cured, that is, the disease is completely eliminated, so that it never recurs. In general, treatments are developed to both increase the patients' chances of being cured and prolong the survival time among non‐cured patients. A cure rate model represents a combination of cure fraction and survival model, and can be applied to many clinical studies over several types of cancer. In this article, the cure rate model is considered in the interval censored data composed of two time points, which include the event time of interest. Interval censored data commonly occur in the studies of diseases that often progress without symptoms, requiring clinical evaluation for detection (Encyclopedia of Biostatistics. Wiley: New York, 1998; 2090–2095). In our study, an approximate likelihood approach suggested by Goetghebeur and Ryan (Biometrics2000;56:1139–1144) is used to derive the likelihood in interval censored data. In addition, a frailty model is introduced to characterize the association between the cure fraction and survival model. In particular, the positive association between the cure fraction and the survival time is incorporated by imposing a common normal frailty effect. The EM algorithm is used to estimate parameters and a multiple imputation based on the profile likelihood is adopted for variance estimation. The approach is applied to the smoking cessation study in which the event of interest is a smoking relapse and several covariates including an intensive care treatment are evaluated to be effective for both the occurrence of relapse and the non‐smoking duration. Copyright © 2007 John Wiley & Sons, Ltd.
Cognitive radio realities
Authors: Le Bin , Rondeau Thomas W. , Bostian Charles W. 
Published: May 2007

AbstractA cognitive radio (CR) is a transceiver that is aware, adaptive, and capable of learning. It may be visualized and realized as an intelligent software package (cognitive engine) controlling a software defined radio platform. The cognitive engine executes a set of nested loops constituting a cognition cycle, drawing on experience and stored knowledge to optimize a set of user‐chosen quality of service measures. The process relies on the effectiveness of a set of tools that are individually well known but rarely found together: multi‐objective genetic algorithms, case‐based decision theory, and neural networks. Practical implementation problems include passing environmental information from the radio to the cognitive engine, acting on that information, and performing real‐time control of the radio platform by the cognitive engine. In this paper, we discuss our approach to developing and implementing a CR. Copyright © 2007 John Wiley & Sons, Ltd.
Spectrum sensing in cognitive radio networks: the cooperation‐processing tradeoff
Authors: Ghasemi Amir , Sousa Elvino S. 
Published: May 2007

AbstractOpportunistic unlicensed access to the (temporarily) unused frequency bands across the licensed radio spectrum is currently being investigated as a means to mitigate the spectrum scarcity. Such opportunistic access calls for the implementation of safeguards so that the ongoing licensed operations are not interfered with. Among different candidates, sensing‐based access, where thesecondary(unlicensed) users transmit if they sense theprimary(licensed) band to be free, is particularly appealing due to its low deployment cost and its compatibility with legacy primary systems. Incorporatingspectral awarenessfunctionality into the radio transceivers is a major step towards the realization of thecognitive radios. In this paper performance of spectrum‐sensing cognitive radios is studied under channel fading. In particular, it is shown that due to the uncertainty resulting from fading, local signal processing alone may be inadequate to meet the performance requirements. To remedy this issue, cooperation among secondary users is proposed and studied in this paper. Moreover, we characterize and study a tradeoff between local processing and cooperation, which should be balanced in order to maximize the spectrum utilization. Copyright © 2007 John Wiley & Sons, Ltd.
Spectrum sharing through distributed coordination in dynamic spectrum access networks
Authors: Zhao Jun , Zheng Haitao , Yang Guang‐Hua 
Published: May 2007

AbstractSpectrum sharing in Open Spectrum systems is a challenging problem, particularly since users experience dynamic spectrum availabilities that vary over time and location. In the absence of any centralized infrastructure, users coordinate their spectrum usage to support fair access of spectrum and avoid interference. One critical challenge is to construct an efficient signaling path in the presence of spectrum dynamics, where users exchange control and negotiation information reliably. In this paper, we propose a distributed coordination protocol (HD‐MAC) to construct an in‐band control path, without relying on the existence of a pre‐assigned out‐of‐band control channel. In particular, we propose a distributed group formation to construct coordination path using local common channels, and a heterogeneity‐aware ranking scheme to select channels for data transmissions. Extensive experimental results demonstrate the efficiency and reliability of the proposed approach. Copyright © 2007 John Wiley & Sons, Ltd.
Automatic antenna‐tuning unit for software‐defined and cognitive radio
Authors: Oh Sung‐Hoon , Song Hang , Aberle James T. , Bakkaloglu Bertan , Chakrabarti Chaitali 
Published: May 2007

AbstractThis paper discusses the implementation of an automatic antenna tuning unit system (ATU) for software‐defined and cognitive radio. The ATU simplifies radio frequency (RF) front‐end design for multi‐band, multi‐mode radios by allowing an electrically small reconfigurable antenna to become a frequency‐agile selective component (essentially a tunable filter). In implementing the ATU, impedance synthesizers (tunable matching networks) using RF MEMS switches as the control elements are used to match a more or less arbitrary load to a convenient impedance value. To generate feedback data that can be used to optimize the impedance synthesizer, the incident and reflected powers at the input to the impedance synthesizer are sampled using a power sensor block comprising directional coupler, logarithmic RF power detectors, analog‐to‐digital converters (ADCS), and return loss computation algorithms running on a field programmable gate array (FPGA). From a practical point of view, in order to be compatible with commercial wireless handset devices, we propose to design and ultimately implement a fully integrated ATU system. In this paper, a hard‐ ware implementation of the ATU prototype has been demonstrated to verify narrowband automatic tuning ability of the ATU under constantly changing environment conditions, and we present simulated results for a logarithmic power detector designed with 55 dB dynamic range over the 800 MHz–2 GHz frequency band using 0.25 µ CMOS technology. Copyright © 2007 John Wiley & Sons, Ltd.
DSP implementation of a bit loading algorithm for adaptive wireless multicarrier transceivers
Authors: Cudnoch Martin , Wyglinski Alexander M. , Labeau Fabrice 
Published: May 2007

AbstractIn this paper, we present a proof‐of‐concept, fixed‐point, DSP hardware implementation of an adaptive bit loading algorithm that is designed for wireless multicarrier transceivers. Adaptive bit loading is used to enhance the performance of multicarrier transceivers by tailoring the subcarrier signal constellations to the channel conditions, which can vary across the subcarriers. Since most bit loading algorithms possess a high computational cost and are unable to cope with rapid variations of wireless channels, they are seldom used in present wireless standards. To prove that adaptive bit loading is feasible for wireless transceivers, our work focuses on the implementation of a known bit loading algorithm that can quickly search for the final bit allocation in an iterative manner. The goal of this algorithm is to yield the largest‐possible throughput while satisfying a mean BER constraint. The performance of the hardware implementation operating in time‐varying channel conditions is studied in terms of the overall throughput. Furthermore, the robustness of the hardware implementation is evaluated, relative to sudden changes in the channel that interrupts the run of the algorithm. Real‐time operations and fixed‐point representation issues are included in the discussion. Additionally, we propose a modified algorithm implementation that is more robust to channel variations. Copyright © 2007 John Wiley & Sons, Ltd.
Cognitive engine implementation for wireless multicarrier transceivers
Authors: Newman Tim R. , Barker Brett A. , Wyglinski Alexander M. , Agah Arvin , Evans Joseph B. , Minden Gary J. 
Published: May 2007

AbstractThis paper presents a genetic‐algorithm driven, cognitive radio decision engine that determines the optimal radio transmission parameters for single and multicarrier systems. Determining the appropriate radio parameters, given a dynamic wireless channel environment is the primary feature of cognitive radios for wireless communication systems. Genetic algorithms (GAs) are designed to select the optimal transmission parameters by scoring a subset of parameters and evolving them until the optimal value is reached for a given goal. Although there have been implementations of GA‐based single carrier cognitive radio engines, the performance of these algorithms has not been thoroughly analyzed nor have the fitness functions employed by the algorithms been explored in detail. Multicarrier systems are common in today's communication environment, thus cognitive techniques that account for only single‐carrier systems neglect the practical issues of multiple carriers. A set of accurate single carrier and multicarrier fitness functions for our GA implementation that completely control the evolution of the algorithm have been derived. The performance analysis results illustrate the trade‐offs between the convergence time of the GA and the size of the GA search space. Copyright © 2007 John Wiley & Sons, Ltd.
Constitutive Equations, Stability and Bifurcation of Elastoplastic Structures
Authors: Germain P. 
Published: May 2007

AbstractThis review paper gives a uniform presentation of some recent results on the. stability of elastic plastic structures. It starts by recalling a general method to write constitutive equations in finite deformations with the introduction of an internat variable– generally a matrix – which describes the modification of material properties. First, this formulation is shown to be quite convenient to study cracks and their evolution under a varying load for brittle or ductile materials. Then, a quite general method for the treatment of the stability and bifurcations of equilibrium of an elastic plastic structure is presented and applied to some simple examples. The results already published in the literature are recovered.
Globales Verhalten erzwungener nichtlinearer Schwingungen und Einsetzen von Chaos
Authors: Schmidt G. 
Published: May 2007

AbstractDas globale, mit dem Einsetzen chaotischer Bewegungen verbundene Verhalten erzwungener nichtlinearer Schwingungen wird für verschiedene Formen der Duffing‐Gleichung, speziell für die von P. Holmes untersuchte Gleichung und die Pendelgleichung diskutiert. Der Vorteil der Erregungskurven, die die Resonanzamplituden in Abhängigkeit von den Erregungsamplituden bestimmen, und ihre Beziehung zu den Resonanzkurven werden gezeigt.
Internal Resonances in Weakly Nonlinearly Coupled Oscillators with Slowly Varying Parameters
Authors: Shivamoggi B. K. 
Published: May 2007

AbstractThe present paper considers the problem of internal resonances in a system of two linear oscillators which are weakly nonlinearly coupled. The system parameters such as the uncoupled frequencies of the oscillators vary slowly in time so that internal resonances prevail only temporarily. One issue of interest in such problems is how the presence of nonlinear coupling affects the adiabatic invariance of the individual actions of the two oscillators. The purpose of this paper is to give a method to investigate this issue quite generally, without assuming special forms of temporal variations of the uncoupled frequencies of the two oscillators and without considering the details of the transition region corresponding to an internal resonance.
Magnetohydrodynamic Stability of Boundary Layer Flow with Suction or Injection along a Flat Plate
Authors: Watanabe T. 
Published: May 2007

AbstractThe flow of an incompressible electrically conducting fluid past, a semi‐infinite flat plate in the presence of a transverse magnetic field is studied considering the effect of uniform suction or injection. The transformed boundary layer equations are obtained, and the numerical calculations of resulting equations are performed for various values of magnetic parameter and suction or injection parameter. The neutral stability curves for wavelike disturbances of Tollmien‐Schlichting type are then presented for the velocity profiles obtained above. The results are given for the velocity profiles, coefficient of skin friction, displacement thickness and the critical Reynolds numbers.
Bendixon‐Type Theorems with Applications
Authors: Tóth J. 
Published: May 2007

AbstractBendixson's theorem on the nonexistence of periodic solutions of differential equations is generalized to the N ‐dimensional case. An application of the theorem in formal reaction kinetics is shown. Then a theorem analogous to Schneider's generalization is given. Finally, a theorem on implicit systems is formulated and applied to get a sufficient condition for the absence of periodic solutions in a generalized Liénard‐equation.
Lösung linearer Fredholmscher Integralgleichungen mit Kernen vom Greenschen Typ
Authors: Micke A. 
Published: May 2007

AbstractEs wird eine Modifikation der Simpson‐ und der Simpsonschen‐3/8‐Formel vorgestellt, die es gestattet, Fredholmsche Integralgleichungen mit Kernen, die entlang der Diagonale s = t unstetig und entlang der Gerade s = a + b – t nicht differenzierbar sein können, mit einer Konvergenzordnung O(h4) aufzulösen. Zur Lösung der entstehenden linearen Gleichungssysteme wird eine iterative Variante des Nyström‐Verfahrens verwendet. Anhand von numerischen Beispielen erfolgt ein Vergleich mit anderen Quadraturverfahren.