bluuebunny/crossref_metadata_2025_split huggingface dataset:
TCP‐Peach for satellite networks: analytical model and performance evaluation
Authors: Akyildiz Ian F. , Morabito Giacomo , Palazzo Sergio 
Published: August 2002

AbstractCurrent TCP protocols have low throughput performance in satellite networks mainly due to the effects of long propagation delays and high link error rates. TCP‐Peach is a new congestion control scheme for satellite IP networks based on the use of low priority segments, called dummy segments. The sender transmits dummy segments to probe the availability of network resources. Dummy segments are treated as low priority segments thus, they do not effect the throughput of actual data segments. In this paper, TCP‐Peach is presented along with its analytical model which is used to evaluate the throughput performance. Experiments show that TCP‐Peach is robust to high link error rates as well as long propagation delays, and outperforms other TCP schemes for satellite networks. Copyright © 2001 John Wiley & Sons, Ltd.
Shadowing correlation assessment and modeling for satellite diversity in urban environments
Authors: Vazquez‐Castro M. , Perez‐Fontan F. , Saunders S. R. 
Published: August 2002

AbstractNon‐geostationary orbit satellite networks have dynamic, yet deterministic topologies. This paper deals with the consequences of relying on the use of multiple visible satellites to improve availability with time/locations through satellite diversity techniques. The assumption of independent blockage events in two different satellite‐to‐mobile links is generally not accurate and information on shadowing correlation should be taken into account in the assessment of availability.In this paper a shadowing correlation study for urban environments is presented and a model for the real environments, as well as for a generic urban environment is inferred. The model proposed here is simple and can be run on a computer. It also relates urban and constellation geometries thus allowing the identification of those cases for which satellite diversity gain should be expected. As a result of this analysis and modelling, we present empirical analytical expressions describing positive correlation coefficient as a function of satellite angular separation (azimuth and elevation). We also show that an angle exists above which correlation can be negative and satellite diversity can sensibly improve link availability. Copyright © 2002 John Wiley & Sons, Ltd.
DigitalEE: A support system for collaborative environmental education using distributed virtual space
Authors: Okada Masaya , Yoshimura Tetsuhiko , Tarumi Hiroyuki , Moriya Kazuyuki , Sakai Tetsuro 
Published: August 2002

AbstractWe have developed “DigitalEE,” a system that supports collaborative environmental education via distributed virtual space accessible from real and virtual worlds. With DigitalEE, learners in the real world and environmental specialists in virtual worlds can make interactive communication via “3D virtual nature,” which is a VRML world three‐dimensionally representing real forest, while mutually sharing learners' achievements and environmental specialists' knowledge that are accumulated in common knowledge databases on the server. Our system realizes various unique functions such as accumulation of environmental knowledge derived from real natural experiences, education supported by specialized knowledge of environmental specialists from all over the world, virtual tours to the natural environment that is not easily accessible, and global arguments on environmental issues with worldwide participants. The system aims at enlightening learners' consciousness of environmental preservation by realization of these functions that have been difficult to support with conventional methods in environmental education. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(8): 51–63, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10039
Development of a PC‐based real‐time surgical simulator
Authors: Mukai Nobuhiko , Harada Masayuki , Muroi Katsunobu , Miyamoto Yuji , Uratani Akihiro , Yano Toru 
Published: August 2002

AbstractPresently, in constructing a surgical simulator, a high‐performance graphics workstation (GWS) has generally been used because it is necessary that a highly faithful surgical image be generated in real time. There exist problems, however, in cost, operation, and working environment, which have prevented the widespread use of the simulator. In order to solve this problem, the authors constructed a real‐time PC‐based surgical simulator for the training of ophthalmologists in vitreoretinal surgery, based on the results of evaluation of a surgical simulator developed on GWS. From this study, the necessary conditions for the simulator have been identified, and a PC‐based surgical simulator satisfying these conditions has been successfully constructed. The constructed system can perform the following operations. The surgical image is displayed in stereo vision, through a binocular stereo vision display. The tactile sensation of surgical tool insertion is provided by using a simulated tool device. The surgery scene can be controlled by operating a foot switch. The constructed surgical simulator provides an environment which effectively simulates real surgery. If an increased number of ophthalmologists can use the proposed simulator more easily for repetitive surgery training, surgical techniques will be improved, and new surgical procedures may be developed. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(7): 11–20, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10076
Measurement of human vocal emotion using fuzzy control
Authors: Moriyama Tsuyoshi , Ozawa Shinji 
Published: August 2002

AbstractThis paper proposes a sentiment measurement system that is based on the relation between speech parameters and included emotion and that is implemented through a learning process using speech data which include known sentiments. In this study, “emotion” and “sentiment” are distinguished in a model of emotional communication by speech which for the first time includes the viewpoint of the observer in addition to those of the speaker and the listener. The sentiment measurement system is constructed by implementing a computational model of the observer. A fuzzy control method is applied in the learning process. The effectiveness of the system is verified by experiments in which the system outputs are compared with psychological evaluations by human subjects. © 2001 Scripta Technica, Syst Comp Jpn, 32(4): 59–68, 2001
The subspace method in Hilbert space
Authors: Tsuda Koji 
Published: August 2002

AbstractThe subspace method has usually been applied to a multidimensional space (i.e., feature space) which uses features as its basis. A subspace method can also be applied to a functional space, since the subspace can be defined by an arbitrary linear space. This paper proposes the mapping of a feature space onto the Hilbert subspace so that pattern recognition can be performed by the subspace method. The proposed method has been experimentally applied to the recognition of the Japanese hiragana syllabary and has achieved a higher recognition rate than the conventional method. This improvement is based on the fact that the dimension of the common part in all of the classes of the subspaces in the Hilbert function space becomes zero. © 2001 Scripta Technica, Syst Comp Jpn, 32(6): 55–61, 2001
Discriminating spinal deformity employing centroids difference on the moiré images
Authors: Kim Hyoung Seop , Ishida Kazufumi , Ishikawa Seiji , Ohtsuka Yoshinori , Shimizu Hisashi 
Published: August 2002

AbstractSpinal deformities, a condition in which the spine deviates to the left or right from the midline, are on the rise, particularly among elementary and middle‐school students. Group diagnoses are being performed at schools for the purpose of early detection, but the burden on physicians is high due to the need to process many images. Automated diagnosis using computers is highly desirable from the standpoint of treatment. In this paper the authors establish a left–right rectangular processing region in a moiré image of a human back, then propose a method to automatically detect spinal deformities with the differences in the centroid positions as a feature. Using an approximately symmetrical reference axis which closely follows the midline of a person, and the amount of the feature from the centroid position of the left–right rectangular region as centered on the reference axis, the authors' method discriminates between normal cases and abnormal cases using a linear discrimination function on a two‐dimensional surface. If this kind of primary diagnosis of spinal deformities can be automated, group diagnosis in schools would be more efficient and useful. The authors use their method, perform discrimination tests on 120 normal and abnormal cases, and find a recognition rate of 87.9%. © 2001 Scripta Technica, Syst Comp Jpn, 32(7): 20–28, 2001
A musical structure model and its visual mechanism for hypertext score systems
Authors: Ariyoshi Yusuke , Shimojo Shinji , Miyahara Hideo 
Published: August 2002

AbstractIn order to perform with consistency a musical score having multiple parts, as in an orchestra or a chorus, it is important that the conductor and performers share its musical semantic structures. However, past studies of the expression or visualization of musical semantic structure in the field of music information processing have dealt with scores having a single voice part. In this paper, we propose a new electronic musical score system, “HyperScore,” based on the hypertext data model. Expanding the hypertext data model and its visualization mechanism, HyperScore has a flexible semantic structure model and a strong visualization mechanism which help the conductor and performers understand the semantics of the score and communicate with each other. The musical semantic structure model consists of three components: phrase–motif–note tree structures of the musical score, musical structures such as particular musical forms, and links among these structures. The visualization mechanism generates various views of the semantic structure of the music from different perspectives. The view is generated by a visualization mechanism specifying four parameters: the XY axes, display rules, selection, and granularity. The view illustrates the musical semantics of series of notes clearly by their position in the view and their display attributes. © 2001 Scripta Technica, Syst Comp Jpn, 32(7): 39–51, 2001
Distributed shared memory with log based consistency for operations with commutative law or associative law
Authors: Hirayama Hideaki , Honda Hiroki , Yuba Toshitsugu 
Published: August 2002

AbstractWith progress in high‐performance networks, cluster systems with high‐performance and inexpensive work stations or personal computers are attracting much attention. For the cluster systems to become popular, it is necessary that it be easy to develop programs on them. Distributed Shared Memory is the key to achieving this objective. But Distributed Shared Memory cannot achieve high performance for all application programs. In particular, programs which frequently modify the same fields by multiple nodes cannot attain high performance with Distributed Shared Memory. In this paper, we propose Distributed Shared Memory with Log Based Consistency for such application programs, such as aggregation applications in the business application area. In this scheme, consistency is maintained by transferring logs among multiple nodes for operations with the commutative law or associative law. Distributed Shared Memory with Log Based Consistency can achieve much better performance than the traditional Distributed Shared Memory. Its performance is almost the same as that of SMP parallel computers. © 2001 Scripta Technica, Syst Comp Jpn, 32(8): 10–19, 2001
On‐line testing in fuzzy controllers
Authors: Kamiura Naotake , Hata Yutaka 
Published: August 2002

AbstractThis paper proposes an on‐line testing procedure for fuzzy controllers. A stuck‐at‐0 fault and a stuck‐at‐1 fault in the membership function are assumed as the fault models. In the proposed method, up to 7 extra functions are considered for each input variable in the antecedent part. The antecedent part and the consequent part can be tested in parallel. In the testing of the antecedent part, the sum of function values (degrees) derived based on the matching between the current measured input and the functions is observed. In the testing of the consequent part, the sum of the area of the output fuzzy sets, the sum of the degrees of applicability, and the sum of 7 degrees in the output fuzzy sets are observed. These procedures make it possible to handle simultaneously a fault in the antecedent part and a fault in the consequent part. Through comparisons with other methods, the proposed method is shown to be useful in terms of the number of faults that can be handled and the ease of application to multi‐input controllers. © 2001 Scripta Technica, Syst Comp Jpn, 32(8): 63–71, 2001
Building a design support tool for superscalar processors and its case studies
Authors: Kimura Yasunori , Shimura Kouya , Nishimoto Haruko , Kawaba Motoyuki , Eguchi Takeshi 
Published: August 2002

AbstractWe will describe Paratool, a support tool to efficiently design superscalar processors, and its case studies. Paratool is a software tool that predicts performance of superscalar processors being designed, using execution traces on a sequential processor, and it runs on a sequential processor. It can measure almost all microarchitectures for superscalar processors. It can measure an ideal microarchitecture, whose resources are limitless. Furthermore, we will describe the result of case studies and report findings designers tend to overlook. This support tool is useful not only for architecture design, but also for tuning of compilers/application software and education in universities. © 2001 Scripta Technica, Syst Comp Jpn, 32(12): 67–79, 2001
Efficient verification by exploiting symmetry and abstraction
Authors: Toshima Hiroshi , Yoneda Tomohiro 
Published: August 2002

AbstractIn general, systems are comprised of a large number of elements and might be very symmetric. In verification of such systems, they are reduced while upkeeping their global structure and verified with the intuitive expectation that the verification of such reduced systems will yield almost the same results as those of the original ones. However, such verifications do not guarantee the success of original system verifications. In this paper, the target is verification of arbitrary scale systems with star‐shape configuration which can be expressed by Petri nets. The proposed algorithm explores the reachable state space with no dependency on system scale. © 2001 Scripta Technica, Syst Comp Jpn, 32(14): 41–53, 2001
Scanning force microscopy of two‐dimensional structure formation in thin humic acid films
Authors: Mertig Michael , Klemm Denis , Zänker Harald , Pompe Wolfgang 
Published: August 2002

AbstractHumic acid films have been prepared by spin‐coating on mica substrates and imaged by scanning force microscopy (SFM). The deposited humic acid films exhibit typical dewetting patterns formed by rupture of the spin‐coated film. Two‐dimensional Fourier analysis of the SFM images shows that the observed film structures can be well described by a characteristic wavelength that depends on both the concentration of the humic acid solution and the evaporation rate of the solvent. The latter can be controlled by the relative humidity during film preparation. Thus, the investigations give clear evidence that structure formation in thin humic acid films is caused by dewetting during film deposition. Copyright © 2002 John Wiley & Sons, Ltd.
Summary of ISO/TC 201 Standard: III ISO 14707:2000—Surface chemical analysis—Glow discharge spectrometry—Glow discharge optical emission spectrometry—Introduction for use
Authors: Bengtson A. 
Published: August 2002

AbstractThis International Standard gives guidelines for the use of glow discharge optical emission spectrometry (GDOES) for bulk and depth profile analysis of rigid solids. The sample is sputter etched in a glow discharge device and the element‐characteristic optical emission recorded simultaneously. The standard specifies the type of equipment used and gives general guidelines for the operation of such equipment. Measuring techniques and procedures for verification of analytical results also are given. Copyright © 2002 John Wiley & Sons, Ltd.
Functional data analysis with application to periodically stimulated foetal heart rate data. II: Functional logistic regression
Authors: Ratcliffe Sarah J. , Heller Gillian Z. , Leader Leo R. 
Published: August 2002

AbstractWe present a basis solution for the modelling of a binary response with a functional covariate plus any number of scalar covariates. This can be thought of as singular longitudinal data analysis as there are more measurements on the functional covariate than subjects in the study. The maximum likelihood parameter estimates are found using a basis expansion and a modified Fisher scoring algorithm. This technique has been extended to model a functional covariate with a repeated stimulus. We used periodically stimulated foetal heart rate tracings to predict the probability of a high risk birth outcome. It was found that these tracings could predict 94.1 per cent of the high risk pregnancies and without the stimulus, the heart rates were no more predictive than chance. Copyright © 2002 John Wiley & Sons, Ltd.
Sensitivity analysis of longitudinal binary quality of life data with drop‐out: an example using the EORTC QLQ‐C30
Authors: Van Steen Kristel , Curran Desmond , Molenberghs Geert 
Published: August 2002

AbstractAnalysing quality of life data (QOL) may be complicated for several reasons. Quality of life data not only involves repeated measures but is also usually collected on ordered categorical responses. In addition, it is evident that not all patients provide the same number of assessments, due to attrition caused by death or other medical reasons. In the recent statistical literature, increasing attention is given to methods which can handle non‐continuous outcomes in the presence of missing data. The aim of this paper is to investigate the effect on statistical conclusions of applying different modelling techniques to QOL data generated from an EORTC phase III trial. Treatment effects and treatment differences are of major concern. First, a random‐effects model is fitted, relating a binary longitudinal response (derived from the physical functioning scale of the QLQ‐C30) to several covariates. In a second approach, marginal models are fitted, retaining the response variable and the mean structure used before. The fitted marginal models only differ with respect to the considered estimation procedure: generalized estimating equations (GEE); weighted generalized estimating equations (WGEE), and maximum likelihood (ML). Copyright © 2001 John Wiley & Sons, Ltd.
Properties of the summary receiver operating characteristic (SROC) curve for diagnostic test data
Authors: Walter S. D. 
Published: August 2002

AbstractThe summary receiver operating characteristic (SROC) curve has been recommended to represent the performance of a diagnostic test, based on data from a meta‐analysis. However, little is known about the basic properties of the SROC curve or its estimate. In this paper, the position of the SROC curve is characterized in terms of the overall diagnostic odds ratio and the magnitude of inter‐study heterogeneity in the odds ratio. The area under the curve (AUC) and an indexQ*are discussed as potentially useful summaries of the curve. It is shown that AUC is maximized when the study odds ratios are homogeneous, and that it is quite robust to heterogeneity. An upper bound is derived for AUC based on an exact analytic expression for the homogeneous situation, and a lower bound based on the limit caseQ*, defined by the point where sensitivity equals specificity:Q*is invariant to heterogeneity. The standard error of AUC is derived for homogeneous studies, and shown to be a reasonable approximation with heterogeneous studies. The expressions for AUC and its standard error are easily computed in the homogeneous case, and avoid the need for numerical integration in the more general case. SE(AUC) and SE(Q*) are found to be numerically close, with SE(Q*) being larger if the odds ratio is very large. The methods are illustrated using data for the Pap smear screening test for cervical cancer, and for three tests for the diagnosis of metastases in cervical cancer patients. Copyright © 2002 John Wiley & Sons, Ltd.
An empirical comparison of record linkage procedures
Authors: Gomatam Shanti , Carter Randy , Ariet Mario , Mitchell Glenn 
Published: August 2002

AbstractWe consider the problem of record linkage in the situation where we have only non‐unique identifiers, like names, sex, race etc., as common identifiers in databases to be linked. For such situations much work on probabilistic methods of record linkage can be found in the statistical literature. However, although many groups undoubtedly still use deterministic procedures, not much literature is available on deterministic strategies. Furthermore, there appears to exist almost no documentation on the comparison of results for the two strategies. In this work we compare a stepwise deterministic linkage strategy with a probabilistic strategy, as implemented in AUTOMATCH, for a situation in which the truth is known. The comparison was carried out on a linkage between medical records from the Regional Perinatal Intensive Care Centers database and educational records from the Florida Department of Education. Social security numbers, available in both databases, were used to decide the true status of each record pair after matching. Match rates and error rates for the two strategies are compared and a discussion of their similarities and differences, strengths and weaknesses is presented. Copyright © 2002 John Wiley & Sons, Ltd.
A comparison of statistical methods for meta‐analysis
Authors: Brockwell Sarah E. , Gordon Ian R. 
Published: August 2002

AbstractMeta‐analysis may be used to estimate an overall effect across a number of similar studies. A number of statistical techniques are currently used to combine individual study results. The simplest of these is based on a fixed effects model, which assumes the true effect is the same for all studies. A random effects model, however, allows the true effect to vary across studies, with the mean true effect the parameter of interest. We consider three methods currently used for estimation within the framework of a random effects model, and illustrate them by applying each method to a collection of six studies on the effect of aspirin after myocardial infarction. These methods are compared using estimated coverage probabilities of confidence intervals for the overall effect. The techniques considered all generally have coverages below the nominal level, and in particular it is shown that the commonly used DerSimonian and Laird method does not adequately reflect the error associated with parameter estimation, especially when the number of studies is small. Copyright © 2001 John Wiley & Sons, Ltd.