bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linear, parameter‐varying control and its application to a turbofan engine
Authors: Balas Gary J. 
Published: September 2002

AbstractThis paper describes application of parameter‐dependent control design methods to a turbofan engine. Parameter‐dependent systems are linear systems, whose state‐space descriptions are known functions of time‐varying parameters. The time variation of each of the parameters is not known in advance, but is assumed to be measurable in real‐time. Three linear, parameter‐varying (LPV) approaches to control design are discussed. The first method is based on linear fractional transformations which relies on the small gain theorem for bounds on performance and robustness. The other methods make use of either a single (SQLF) or parameter‐dependent (PDQLF) quadratic Lyapunov function to bound the achievable level of performance. The latter two techniques are used to synthesize controllers for a high‐performance turbofan engine. A LPV model of the turbofan engine is constructed from Jacobian linearizations at fixed power codes for control design. The control problem is formulated as a model matching problem in the ℋ︁∞and LPV framework. The objective is decoupled command response of the closed‐loop system to pressure and rotor speed requests. The performance of linear, ℋ︁∞point designs are compared with the SQLF and PDQLF controllers. Nonlinear simulations indicate that the controller synthesized using the SQLF approach is slightly more conservative than the PDQLF controller. Nonlinear simulations with the SQLF and PDQLF controllers show very robust designs that achieve all desired performance objectives. Copyright © 2002 John Wiley & Sons, Ltd.
Identification of linear parameter varying models
Authors: Bamieh Bassam , Giarré Laura 
Published: September 2002

AbstractWe consider identification of a certain class of discrete‐time nonlinear systems known as linear parameter varying system. We assume that inputs, outputs and the scheduling parameters are directly measured, and a form of the functional dependence of the system coefficients on the parameters is known. We show how this identification problem can be reduced to a linear regression, and provide compact formulae for the corresponding least mean square and recursive least‐squares algorithms. We derive conditions on persistency of excitation in terms of the inputs and scheduling parameter trajectories when the functional dependence is of polynomial type. These conditions have a natural polynomial interpolation interpretation, and do not require the scheduling parameter trajectories to vary slowly. This method is illustrated with a simulation example using two different parameter trajectories. Copyright © 2002 John Wiley & Sons, Ltd.
Development and operation of a document database for university research and education activities
Authors: Nonaka Yusuke , Inoue Sozo , Hatano Katsuhiko , Harada Tsutomu , Nomura Yoshinari , Iwaihara Mizuho , Mine Tsunenori , Ushijima Kazuo 
Published: September 2002

AbstractThe academic staff research and education activity database of Kyushu University is a document database system which enables each academic staff member to input and update his or her activity report, administrators to maintain the database, and visitors to search and read reports via the Internet.Those databases and user interfaces can handle mixed report formats by storing metadata of formats and constraints. Through an analysis of the update history of the system and e‐mail records between users and developers, we confirmed that distributed administration style reduced human work load and that the majority of bugs are confined to small components. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(10): 41–53, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10043
An algorithm for an eye tracking system with self‐calibration
Authors: Takegami Takeshi , Gotoh Toshiyuki , Ohyama Ghen 
Published: September 2002

AbstractThis paper proposes a simple and highly accurate eye tracking system. The eye image is observed by a system, such as an infrared eye tracking system, where the relative position between the head and the camera is kept invariant. Calibration where the examinee is instructed to gaze at a particular marker is avoided, and the calibration is executed automatically using only the input time sequence images. In the eye image, when the relative position to the camera is kept invariant, two queues exist to estimate the eye direction, which are the center coordinate and the flatness of the pupil. There are problems in the accuracy and the stability of the detection in the flatness data, however, although the absolute direction can be estimated. In the study, the eye direction is estimated as follows. The flatness is estimated by using multiple images. The eye parameters, such as the radius and the center of the eye rotation, are corrected, and the eye direction is estimated with stability. An evaluation experiment used actual eye images, and it was found that a more accurate measurement is realized, compared to the estimation of the eye direction based on flatness. Thus, the usefulness of the proposed method is demonstrated. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(10): 10–20, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10125
Development of teaching material for cultivating logical thinking ability in a confrontational game system
Authors: Sasaki Hitoshi , Takeya Makoto 
Published: September 2002

AbstractThe importance of cultivating logical thinking ability has been strongly emphasized. In addition, logical aptitude tests are included in entrance and employment exams, and logical thinking ability is used as a criterion in admission and hiring decisions. Consequently, this study has developed material for cultivating logical thinking ability in the form of a confrontational (two‐player) game learning system. The programs constructed by students combat each other, and are then analyzed and improved as a means of supporting the cultivation of logical thinking ability. This paper proposes such a resource for cultivating logical thinking ability and reports the results of its experimental use in teaching high school students. © 2001 Scripta Technica, Syst Comp Jpn, 32(9): 1–10, 2001
Bitstream scaling by reference frame altering
Authors: Shimizu Atsushi , Sagata Atsushi , Watanabe Hiroshi , Kobayashi Naoki 
Published: September 2002

AbstractOn the Internet, the transmission rates and the quality of the transmission paths vary with the user's connection environment. Thus, to provide image transmission services on the Internet, bitstream scaling techniques are essential to convert to any transmission rate in real time. Already proposed scaling methods include methods that reduce the number of coding bits for the DCT coefficients and methods that discard coded frames not referenced by other frames. However, the degrees of freedom in scaling in previous methods are inadequate to provide image transmission services on the Internet. In this paper, we propose a bitstream scaling method that discards the reference frames to limit the computational costs. In the proposed method, instead of a search for motion vectors, new motion vectors are estimated from the original motion vectors and the reference relationship in motion‐compensated prediction is altered. The degrees of freedom in scaling can be expanded while limiting the computational costs. The estimated motion vectors are compared to the motion vectors detected from the decoded frame to verify the accuracy of the motion vector estimation method. © 2001 Scripta Technica, Syst Comp Jpn, 32(9): 11–21, 2001
A morphological filter with region expansion to extract minute convex regions and its applications to medical image processing
Authors: Hagihara Yoshihiro , Kobatake Hidefumi 
Published: September 2002

AbstractIn recent years morphological filters (M‐filters) have been used in a wide range of fields since they offer various capabilities through the use of the shape of structural elements in the image. In this paper the authors propose an M‐filter which can minimize the effect of the background for the purpose of extracting undefined minute convex regions such as lesions in medical X‐ray images. The proposed method is based on expanding the region by padding for each brightness level. In addition, the authors consider an approach to implement their proposed method effectively, then describe the resulting algorithm in detail. Experiments comparing the proposed method and a method using only conventional opening calculations are performed. In experiments using binary images and multibit simulation data and in experiments on the extraction of minute calcification images in a mammogram or kidney–lung shadows from real chest CTs, the proposed method was shown to be superior to the conventional method using opening calculations. © 2001 Scripta Technica, Syst Comp Jpn, 32(9): 22–31, 2001
A new fitness function for shape detection using genetic algorithm
Authors: Toyama Fubito , Shoji Kenji , Miyamichi Juichi 
Published: September 2002

AbstractWhen genetic algorithms (GA) are used for shape detection, the fitness function (evaluation function for chromosomes) must be designed in an appropriate way. Considering shape detection in terms of finding the parameters of model objects to provide the best matching with an input edge image, the chromosome is defined in terms of the object's parameters, and the fitness function is defined in terms of the rate of matching between the edge image of a model object generated using the chromosome's parameters and the input edge image. In this study, the model image and input image are divided into four images each by applying four directional filters, and the fitness function is defined as the sum of the matching rates for each edge direction. Experiments with flat objects were performed to compare the proposed fitness with the conventional technique. The results suggested that the proposed method required slightly more computation time (about 10%) than the conventional fitness function while improving the matching rate from 49% to 93%. © 2001 Scripta Technica, Syst Comp Jpn, 32(9): 54–60, 2001
High‐speed production system using dynamic two‐way switching of match algorithm
Authors: Nambo Hidetaka , Kimura Haruhiko , Hirose Sadaki 
Published: September 2002

AbstractExpert systems support reasoning based on experts' knowledge and data represented through a set of rules, thus substituting for human experts. Production systems are a popular tool for expert system building. However, production systems suffer from slow processing speed, and extensive research has been conducted to improve their performance. In particular, processing of high‐cost rules takes an extremely long time. This study offers dynamical switching between direct match algorithm, which was previously proposed for high‐cost rule processing, and conventional Rete algorithm; it is found that the two algorithms prove to make a complementary pair which ensures efficient processing. In addition, rules for which this dynamical switching is appropriate are defined, and efficiency of the proposed approach is confirmed through experiments with sample knowledge bases. © 2001 Scripta Technica, Syst Comp Jpn, 32(9): 61–70, 2001
Improvement of the method for monitoring autonomic nervous activity by pupillary flash response
Authors: Yamaji Kazutsuna , Hirata Yutaka , Usui Shiro 
Published: September 2002

AbstractIn our previous study, we proposed a noninvasive method for monitoring autonomic nervous activity from the changes in dynamic parameters of a pupillary flash response. The advantage of the method is that it allows independent evaluation of sympathetic and parasympathetic nervous activities. However, the sensitivity of the sympathetic parameter is lower than that of the parasympathetic one. This disadvantage should be eliminated for practical use. In this paper, an improved method that focuses on this issue is proposed. The improvement has been achieved by adopting a comblike flash response of which availability was examined based on the analysis using the pupillary muscle plant model. Validity of the improved method has been demonstrated by applying it to the subject whose autonomic nervous activity has been modified by sympathomimetic and sympatholytic drugs. © 2001 Scripta Technica, Syst Comp Jpn, 32(13): 23–30, 2001
Learning action sequences using recurrent neural network with multiresolutional channel
Authors: Morita Satoru 
Published: September 2002

AbstractThe author proposes a recurrent neural network structure that enables associations between resolution, field of view, and actions in order to connect actions with the surrounding view for executing multiresolutional vision control. In general, when a neural network is used, there are cases when some patterns cannot be learned. The current study describes obtaining surrounding views necessary for capturing actions by using a hereditary algorithm in order to control multiresolutional vision. The article demonstrates how in practice actions of a pan–tilt camera can be captured using multiresolutional vision control. © 2001 Scripta Technica, Syst Comp Jpn, 32(13): 31–40, 2001
Real‐time scheduling algorithms for maximum utilization of secondary battery in portable devices with discrete frequency control
Authors: Nakamoto Yukikazu , Tsujino Yoshihiro , Tokura Nobuki 
Published: September 2002

AbstractThe spread of portable devices has increased the importance of low‐power energy techniques. The authors have already proposed a real‐time scheduling algorithm which maximizes the utilization time of the secondary battery while preserving deadlines of real‐time tasks with arbitrary frequency control. This paper addresses a scheduling problem which maximizes the utilization time of the secondary battery with discrete frequency control. First, a decision problem corresponding to the scheduling problem is NP‐complete when the frequency can be changed on task switching. Second, when the frequency can be changed at an arbitrary time we propose an optimal scheduling algorithm which maximizes utilized time of the secondary battery under preserving a deadline of real‐time tasks, and demonstrate the correctness of the algorithm and its computation complexity. For each arrival task, the computation complexity of the algorithm is O(n) in general, where n is the number of tasks awaiting execution, and is O(1) in the amortized analysis when each task arrives in the order of its deadline. © 2002 Scripta Technica, Syst Comp Jpn, 33(3): 41–51, 2002
Struggling toward sustainability: considering grassroots development
Authors: Stevens Kris , Morris John 
Published: September 2002

AbstractGrassroots development (GRD) has long been seen as a way of involving the uninvolved stakeholders, a problem identified in other types of development. In examining traditional GRD this paper demonstrates that many of the neo‐liberal leanings that have been identified as problematic in macro‐scale development are also found in traditional GRD. These are shown to be detrimental to project outcomes. This paper's main contribution is to embed communitarian assumptions into GRD, an action that leads to the articulation of a communitarian grassroots development (CGRD). Extant case studies and conceptual graphic interpretations are used to illustrate the dimensions of CGRD. Central is the need for personal growth and its consequent contribution to community. It is argued that CGRD leads to sustainable development, a goal unattained under neo‐liberal assumptions. Copyright © 2001 John Wiley & Sons, Ltd. and ERP Environment
Urban regeneration and community development in Scotland: converging agendas for action
Authors: Lloyd M. Gregory 
Published: September 2002

AbstractDevolution is having a marked effect on policy design and delivery in Scotland. In particular, it is possible to identify a focus on a distinctive Scottish agenda, and in the priorities for action. Intervention is directed in particular at the community, in terms of its general well‐being, and in promoting positive discrimination for disadvantaged areas and groups. Community planning and Social Inclusion Partnerships are the vehicles for this approach. Significantly, the theme of leadership runs through these measures, and this may yet enable a more stable programme for community development to be sustained into the future. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment.
Dana Meadows: asking hard questions, speaking simple truths
Authors: Meadows Dennis 
Published: September 2002

AbstractThis paper was presented at the annual meeting of the System Dynamics Society, Atlanta, Georgia; 25 July 2001, in a special session in memory of Dana Meadows. In this talk, Dennis Meadows reviews Dana's career, the fundamental contributions she made to the field of system dynamics, and the continuing relevance of her work to the issues facing us today. Copyright © 2002 John Wiley & Sons, Ltd.
Using system dynamics to improve public participation in environmental decisions
Authors: Stave Krystyna A. 
Published: September 2002

AbstractDana Meadows believed that computer simulation models and systems thinking could be powerful tools for democracy, helping make social decisions and the assumptions on which they are based more transparent and open to public debate. She also believed that people should be more involved in making conscious and informed choices about their future. In the environmental arena, pressure to increase public participation in decision‐making is growing. Not only is public involvement seen as a cornerstone of democratic ideals, it is increasingly seen by decision‐makers as a practical means of putting decisions into effect. Involving the public in decision‐making helps avoid public obstruction of decisions and garners public resources for their implementation. However, traditional approaches to public involvement, which rely heavily on information campaigns, facilitated discussions, and public hearings for conveying information and capturing stakeholder input, frequently leave participants dissatisfied. They are often perceived as one‐way communication from agency experts to stakeholders or as a mechanism for powerful special interest groups to serve their own ends. System dynamics has the potential to improve public participation in environmental decisions by providing a framework for structured deliberation when stakeholders are involved in making decisions and a more transparent and participatory educational framework to persuade stakeholders to help implement decisions. This article describes a case study using group model building to support a stakeholder advisory group examining transportation and related air quality problems. One of the most valuable effects of the approach was the information feedback it added to the advisory process. Copyright © 2002 John Wiley & Sons, Ltd.
Assessment and monitoring in clinical trials when survival curves have distinct shapes: a Bayesian approach with Weibull modelling
Authors: Lecoutre Bruno , Mabika Bienvenu , Derzko Gérard 
Published: September 2002

AbstractThe comparison of Weibull distributions with unequal shape parameters, in the case of right censored survival data obtained from independent samples, is considered within the framework of Bayesian statistical methodology. The procedures are illustrated with the example of a mortality study where a new treatment is compared to a placebo. The posterior distributions about relevant parameters, which may provide support for a conclusion of clinical superiority of the treatment, and the predictive distributions, which may guide decision about early stopping at an interim analysis, are considered for a class of appropriate priors. Copyright © 2002 John Wiley & Sons, Ltd.
Time‐varying exposure and the impact of stressful life events on onset of affective disorder
Authors: Wainwright Nicholas W. J. , Surtees Paul G. 
Published: September 2002

AbstractStressful life events are now established as risk factors for the onset of affective disorder but few studies have investigated time‐varying exposure effects. Discrete (grouped) time survival methods provide a flexible framework for evaluating multiple time‐dependent covariates and time‐varying covariate effects. Here, we use these methods to investigate the time‐varying influence of life events on the onset of affective disorder. Various straightforward time‐varying exposure models are compared, involving one or more (stepped) time‐dependent covariates and time‐dependent covariates constructed or estimated according to exponential decay. These models are applied to data from two quite different studies. The first, a small scale interviewer‐based longitudinal study (n = 180) concerned with affective disorder onset following loss (or threat of loss) event experiences. The second, a questionnaire assessment as part of an ongoing population study (n = 3353), provides a history of marital loss events and of depressive disorder onset. From the first study the initial impact of loss events was found to decay with a half‐life of 5 weeks. Psychological coping strategy was found to modify vulnerability to the adverse effects of these events. The second study revealed that while men had a lower immediate risk of disorder onset following loss event experience their risk period was greater than for women. Time‐varying exposure effects were well described by the appropriate use of simple time‐dependent covariates. Copyright © 2002 John Wiley & Sons, Ltd.
Kappa coefficients in medical research
Authors: Chmura Kraemer Helena , Periyakoil Vyjeyanthi S. , Noda Art 
Published: September 2002

AbstractKappa coefficients are measures of correlation between categorical variables often used as reliability or validity coefficients. We recapitulate development and definitions of the K (categories) by M (ratings) kappas (K×M), discuss what they are well‐ or ill‐designed to do, and summarize where kappas now stand with regard to their application in medical research. The 2×M(M⩾2) intraclass kappa seems the ideal measure of binary reliability; a 2×2 weighted kappa is an excellent choice, though not a unique one, as a validity measure. For both the intraclass and weighted kappas, we address continuing problems with kappas. There are serious problems with using the K×M intraclass (K>2) or the various K×M weighted kappas for K>2 or M>2 in any context, either because they convey incomplete and possibly misleading information, or because other approaches are preferable to their use. We illustrate the use of the recommended kappas with applications in medical research. Copyright © 2002 John Wiley & Sons, Ltd.