bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of communication traffic characteristics of a cellular system with ad hoc networking
Authors: Tanaka Akio , Nakano Keisuke , Sengoku Masakazu , Shinoda Shoji 
Published: May 2003

AbstractIn cellular communication systems, every call is carried through a base station, and when the communication path to the base station is obstructed by buildings or other obstacles, the communication may not be established. It is expected that ad hoc relaying of such an obstructed call will increase the performance of the network as a whole. This paper discusses how to theoretically analyze the communication traffic performance of a cellular system with ad hoc networking and shows that the network performance can be increased even with relatively small range of relaying capability of terminals. This paper also shows by simulation that multihop relaying does not give significantly greater performance improvement than that by two‐hop relaying. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(11): 1–10, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10135
Complex resonant converter with a power factor improvement by voltage feedback
Authors: Takahama Masanobu , Yasumura Masayuki 
Published: May 2003

AbstractAs a highly efficient, high‐power‐factor power supply system, the authors have proposed a voltage feedback power factor improved circuit that achieves a power factor improvement by using the primary switching voltage in a complex resonant converter in which voltage resonance is also provided on the secondary side in a primary voltage resonant converter. This technique, however, presented considerable difficulties in circuit design for achieving superior performance characteristics, due to the fact that the incorporation of multiple resonant systems resulted in complex operations, and performance was significantly influenced by the constants of the system components. In this paper, through simulation studies and experiments, we identify the impact on performance of the components of the power‐factor improvement circuit. By demonstrating performance changes due to four circuit parameters and the impact of the parameters on the switching operations, we have identified the conditions under which high efficiency can be maintained while achieving an improvement in the power factor. The effectiveness of the converter is also demonstrated by means of experiments. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(11): 93–101, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1181
A 100‐GHz‐band quadruple power combined monolithic HBT oscillator
Authors: Uchida Kenji , Matsuura Hiroyuki , Yakihara Tsuyoshi , Kobayashi Shinji , Oka Sadaharu , Fujita Tadashige , Miura Akira 
Published: May 2003

AbstractIn this paper we discuss a design methodology we used to fabricate a 100‐GHz‐band monolithic oscillator that power‐combines four heterojunction bipolar transistor (HBT) based suboscillators, and the experimental results we obtained. We analyzed the oscillation condition by considering the loop gain when feedback is present, and adjusted the design parameters so as to combine the output powers of four suboscillators by making them oscillate in phase. The active elements we used for the suboscillators were InGaP/InGaAs HBTs with emitter dimensions 1.0 µm × 5.0 µm, for which fT and fmax were 190 and 240 GHz, respectively. The signal frequency of the completed oscillator was 97. 4 GHz, its output power +3.0 dBm. The biases on the HBTs were IC = 10 mA and VCE = 2.0 V. In order to discuss the power combining efficiency, we fabricated test oscillators with only one and dual power combined oscillators, which were investigated under the same measurement conditions. These circuits oscillated at 100.5 and 100.4 GHz, respectively, with −3.2 and −0.4 dBm output powers. These results confirm that the output power increases with the number of suboscillators. As far as we know, our article is the first to report a monolithic oscillator that power‐combines four suboscillators. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(6): 13–22, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10003
Design of a robust PWM power amplifier using approximate two‐degree‐of‐freedom digital integral‐type control only with voltage feedback
Authors: Higuchi Kohji , Nakano Kazushi , Araki Kuniya , Chino Fumiho 
Published: May 2003

AbstractThere is a need for robust PWM power amplifiers whose transient response characteristics do not deteriorate in the presence of extensive load variation and/or direct‐current power‐supply voltage variation. In this paper, a methodology is proposed for designing a digital robust controller using only voltage feedback for PWM power amplifiers which can satisfy such demands. The controlled object (PWM power amplifier) is represented by a discrete‐time system with consideration of input dead‐time and the conversion of current feedback to voltage feedback. First, a model matching system using only voltage (output) feedback is created for this controlled object. Next, it is shown that an approximate two‐degree‐of‐freedom digital robust control system can be created by connecting the robust compensator obtained by approximating this model matching system. Furthermore, it is shown that a digital integral‐type controller using only voltage feedback is obtained by equivalent transformation. Methods for determining the parameters of the LC filter and the controller, and a sampling time which satisfies design specifications are shown. Finally, it is verified by simulation and experiment that all the given specifications are satisfied by the proposed digital controller and that the design method with consideration of input dead‐time is useful. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(6): 1–12, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10110
An automatic cloud region classification of satellite image by using clustering in local area
Authors: Ozawa Noriaki , Aoki Toshinori , Kato Nei , Nemoto Yoshiaki 
Published: May 2003

AbstractThis paper proposes a technique for automatically classifying cloud regions in satellite images. The proposed technique uses visible images and brightness temperature images to automatically classify cloud and noncloud regions. The authors assume that dividing the image into small regions (local regions) enables the feature vector distribution of each category within a local region to be approximated by using a Gaussian distribution, and they divide the distribution into two clusters. In addition, they introduce the “degree of coincidence” for judging whether or not it is appropriate to use each cluster for subsequent category classification and use the mean vectors of clusters that satisfy the degree of coincidence and the EM algorithm to perform classification. By using the degree of coincidence, the authors show that the vector distribution within the feature space becomes distinct and that clustering can be suitably performed. A feature of the proposed technique is that it aims to distribute feature vectors continuously so that they link each category. By considering the straight lines linking each category and using only those straight lines that are close to the mean vectors of each category, threshold values are determined dynamically for each image. Finally, the authors apply the proposed algorithm to NOAA and Himawari (GMS) images. Good classification results are obtained compared with results that were obtained manually by specialists. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(6): 33–43, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10153
Identification and localization of multiple robots using omnidirectional vision sensors
Authors: Kato Koji , Ishiguro Hiroshi , Barth Matthew 
Published: May 2003

AbstractThe development of multirobot systems for solving complex, dynamic problems in real‐world situations is one of the key issues in robotics research. Robust methods of identifying each robot are required to implement collaborative behavior in multirobot systems. In this paper, the authors propose a method of identifying each robot and obtaining its relative position in a robot system using omnidirectional vision sensors. In addition, they verified this system by performing experiments in simulations and a real‐world environment. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(6): 44–53, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10154
“Smartface”: A face recognition system robust to variations of facial pose and expression
Authors: Yamaguchi Osamu , Fukui Kazuhiro 
Published: May 2003

AbstractThere has been rapid progress in the development of techniques for identifying individuals from facial images, to be used in human interface and for security purposes. This paper proposes the Smartface recognition system, which can be used on a portable PC. To reduce restrictions on the user's movements, a face recognition should usually accept variations in the user's facial orientation and expression. The proposed system uses a motion image‐based algorithm with feature points that is robust to such variations. A method of reducing the cost of the additional computations is also proposed. Applications of the proposed system include: (1) individualized voice response and environment setting for different users; (2) use of face recognition to control a screen saver; and (3) real‐time disguise simulation. The proposed system consists only of software and can be operated on a portable PC equipped with a camera. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(6): 54–61, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10155
Resource leveling scheduling system: A two‐phase CLP relaxation method
Authors: Takada Masayoshi , Terano Takao 
Published: May 2003

AbstractWe have developed a production scheduling system called “K‐CHIP,” which handles operator resource leveling, using CLP (constraint logic programming). This system has the following features: (1) it approaches constraint satisfaction problems (CSP) as two‐phase problems, consisting of production line scheduling and operator assignment scheduling, (2) it uses an interactive method for relaxing constraints on operator skills and on the number of operators as the intra‐CSP adjustment method, and (3) it guarantees skill constraint satisfaction by creating a future training schedule. A simulation carried out based on this system produced the prospect of a 33% reduction in manpower. The simulation also demonstrated that the method can be effectively utilized to expand the system integration functions, centered on skills that are the main concern in plant management. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(6): 62–72, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10156
Deterioration detection system using local stationary binomial models for telecommunication services
Authors: Matsumoto Kazunori , Hashimoto Kazuo 
Published: May 2003

AbstractThis report concerns a system for monitoring the quality of connections in the gateway switches that interconnect telecommunication networks. Although the time series to be monitored is clearly nonstationary, movements that are almost periodic can be seen if a seven‐day interval is set as the period. Therefore, this system introduces a new technique, which is called “partition model optimization”, for using the Akaike information criterion (AIC) to determine appropriate groups of local stationary models from a quasi‐periodic time series. Also, to perform quality management in real time, a high‐speed decision technique called the sequential probability ratio test (SPRT) is introduced. The effectiveness of the partition model optimization technique was systematically investigated in advance by using actual traffic data. Not only was decision parameter maintenance unnecessary, but deterioration could also be detected more accurately than with the conventional system. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(6): 73–82, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10157
Very low bit rate video compression using MPEG‐4 sprite coding
Authors: Jinzenji Kumi , Watanabe Hiroshi , Okada Shigeki , Kobayashi Naoki 
Published: May 2003

AbstractThe new MPEG‐4 image coding standard that has recently been established offers higher image quality in low‐bit‐rate coding than conventional coding methods such as H.26X, MPEG‐1, and MPEG‐2, as well as coding for each object unit (a new function).This paper proposes an algorithm for the automatic extraction of video objects consisting of a foreground object and a background sprite. It is based on “sprite coding,” which can greatly reduce the number of code bits compared to conventional methods. The foreground and background video objects processed by the proposed method are subjected to MPEG‐4 object coding and sprite coding, respectively, and are compared with MPEG‐4 simple profile (normal) coding. In particular, the influence of the frame rate and the foreground object rate on the number of code bits was investigated. It was found that the proposed method can reproduce images with the same quality while using about one‐fourth to one‐half as many code bits as the normal coding method when the foreground rate is 10 to 15% of the whole image, regardless of the frame rate. In addition, the proposed method can attain more than double the frame rate of the normal coding method at a very low bit rate (e.g., 128 and 64 kbit/s) with a similar SNR. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(6): 83–93, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10158
Improving reliability of an ion flow head
Authors: Seino Taisaku , Mori Akira , Kamio Keiji 
Published: May 2003

AbstractThe charger of a solid state discharge type (solid state discharge device) used as an ion source in ion flow printers has a high ion generation capability but is degraded by electrical erosion. Therefore, its lifetime is short. In this investigation, by coating the ion generation electrode with a thick‐film glass, electrical erosion is reduced in an attempt to extend the life of the solid state discharge device. The relationship between the thickness of the passivation film for longer life and the ion generation capability is predicted from numerical calculations. This project is applied to estimation of the film thickness that will maintain the reduction of the ion supply capability due to formation of the passivation film within the allowable range. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(6): 23–32, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.1124
Geriatric depression in Nigerian primary care attendees
Authors: Sokoya Olukunle O. , Baiyewu Olusegun 
Published: May 2003

AbstractObjectiveTo determine the rate and correlates of geriatric depression in two primary care facilities within a teaching hospital in Nigeria.Method202 older people were screened using the Geriatric Depression Scale (GDS). The Geriatric Mental State schedule (GMS) was administered to participants who scored above the cut‐off on the GDS in order to assess psychopathology. Diagnosis of depression was based on ICD‐10 criteria as well as the GMS‐AGECAT program.ResultsThe rate of geriatric depression in primary care was found to be 7.4%. Severe depression was only 1.5%. Very low income and subjective report of poor health were significantly associated with depression in the cohort. AGECAT recognition of depression was comparable to that by the ICD‐10 (k = 0.7).ConclusionThe study is the first known study of geriatric depression in primary care in Nigeria. The rates are comparable with rates obtained in other countries. Specific correlates of depression in the older Nigerians identified included poor self‐assessed health and low income. Copyright © 2003 John Wiley & Sons, Ltd.
Bright light treatment improves sleep in institutionalised elderly—an open trial
Authors: Fetveit Arne , Skjerve Arvid , Bjorvatn Bjørn 
Published: May 2003

AbstractStudy ObjectivesThis study evaluates the effects of bright light therapy among demented nursing home patients with sleep disturbances.Design and setting11 nursing home patients with actigraphically measured sleep efficiency below 85% took part in an open, non‐randomised study where the subjects served as their own control.InterventionAfter two weeks of baseline measurements and two weeks of pretreatment measurements, patients received bright light exposure 2 h/day within the period 08:00–11:00 for two weeks.Measurements and ResultsSleep‐wake patterns during the 24‐h day were evaluated by nursing staff ratings and wrist‐worn motor activity devices (actigraphs). Sleep improved substantially with bright light exposure. Waking time within nocturnal sleep was reduced by nearly two h, and sleep efficiency improved from 73% to 86%. Corresponding improvements were found in nursing staff ratings. Effects were consistent across subjects.ConclusionsThe findings add further evidence of the effectiveness of morning bright light exposure in the treatment of disturbed sleep among demented nursing home patients. Copyright © 2003 John Wiley & Sons, Ltd.
Association of life events and psychosocial factors with early but not late onset depression in the elderly: implications for possible differences in aetiology
Authors: Grace Janet , O'Brien John T. 
Published: May 2003

AbstractBackgroundDepression occurring for the first time in later life (after age 60, late onset depression (LOD)) may have a different, more organic, aetiology from early onset depression (EOD). We investigated the possible role of life events, the presence of a confidante and personality factors in the aetiology of depression in the elderly, testing the hypothesis that these factors would be associated with EOD but not LOD.MethodsSubjects consisted of 66 elderly patients (aged over 60) with DSM‐IV Major depression (30 EOD, 33 LOD; groups matched for age) and 38 age and sex matched controls. Life events in the 12 months prior to onset of depression (or prior to interview for controls) were recorded using a previously validated 12‐item scale. Personality was assessed using the Eysenck Personality Questionnaire (EPQ).ResultsSubjects with EOD reported having a close confidente significantly less frequently (52%) than controls (82%, p < 0.05) or LOD (80%, p < 0.05). Bereavement life events occurred significantly more frequently in EOD (52%) than LOD (16%, p < 0.01) and were also more frequent in controls (42%) than LOD (p < 0.05). Higher EPQ ‘extraversion’ and ‘neuroticism’ were found in both EOD and LOD compared to controls, with no differences between EOD and LOD.ConclusionsLOD was associated with fewer bereavement life events and more frequent presence of a confidente than EOD. This supports a greater role for psychosocial factors in the aetiology of EOD and different, probably neurobiological, factors in LOD. Personality attributes may have a greater relevance for both EOD and LOD than previously recognized. Copyright © 2003 John Wiley & Sons, Ltd.
Delusions of Japanese patients with Alzheimer's disease
Authors: Ikeda Manabu , Shigenobu Kazue , Fukuhara Ryuji , Hokoishi Kazuhiko , Nebu Akihiko , Maki Naruhiko , Nomura Michie , Komori Kenjiro , Tanabe Hirotaka 
Published: May 2003

AbstractBackgroundDelusions constitute one of the most prominent psychiatric complications in Alzheimer's disease (AD). However, there is little consensus of the prevalence and associated factors for delusions in AD.AimsTo reveal the characteristics of delusions among Japanese patients with AD.Method112 consecutive patients with AD were recruited over a one year period and administered the Neuropsychiatric Inventory (NPI).ResultsDelusions were present in 53 patients (47.3%). Delusions of theft were the most common type of delusion (75.5% of patients with delusions), followed by misidentification delusions and delusions of suspicion. More hallucination, agitation, and female gender were found in the delusions group.ConclusionsThe authors found a high frequency of delusions, particularly of delusions of theft and suggested that gender was associated with the expression of delusions in Japanese patients with AD. Copyright © 2003 John Wiley & Sons, Ltd.
Recent trends in elderly suicide rates in a multi‐ethnic Asian city
Authors: Kua Ee‐Heok , Ko Soo‐Meng , Ng Tze‐Pin 
Published: May 2003

AbstractBackgroundThere are a few reports on the trends of elderly suicide rates in western countries but none from Asian countries.ObjectivesTo describe the trends of elderly suicide rates of Chinese, Malays and Indians in Singapore from 1991 to 2000.DesignData obtained from the National Department of Statistics were used in the analysis of sex‐ and age‐standardized suicide rates and relative risks.ResultsOverall, the suicide rates for the elderly showed a decline from 40.1 per 100,000 in 1990 to 17.8 per 100,000 in 2000, with the most pronounced decline occurring from 1995 to 2000. The suicide rate for elderly Chinese was at a peak of 52 per 100,000 in 1995 and declined to 20 per 100,000 in 2000. The rates for elderly Malays were consistently low at 2.2 per 100,000 for the 10 years; for elderly Indians the rates were between the other two ethnic groups.ConclusionIn the 10‐year period, the elderly suicide rates in Singapore declined markedly, especially for elderly Chinese. Copyright © 2003 John Wiley & Sons, Ltd.
Apathy and cognitive performance in older adults with depression
Authors: Feil Denise , Razani Jill , Boone Kyle , Lesser Ira 
Published: May 2003

AbstractObjectivesRecent studies have linked apathy to frontal lobe dysfunction in persons with dementia, but few studies have explored this relationship in older, depressed persons without dementia. We examined the association between apathy and cognitive function in a group of older persons with major depression using standardized neuropsychological tests. We hypothesized that presence of apathy in depression is associated with poorer frontal executive performance.MethodsWe analyzed data from 89 older adults with major depression. We defined apathy using four items from the Hamilton Psychiatric Rating Scale for Depression which reflect the clinical state of apathy, including ‘diminished work/interest,’ ‘psychomotor retardation,’ ‘anergy’ and ‘lack of insight.’ResultsApathy most strongly correlated with two verbal executive measures (Stroop C and FAS), a nonverbal executive measure (Wisconsin Card Sorting Test—Other Responses), and a measure of information processing speed (Stroop B). Apathy was not associated with age, sex, education, medical illness burden, Mini‐Mental State Examination score and Full Scale IQ score. Stepwise regression analyses of significant cognitive tests showed that apathy alone or apathy plus depression severity, age, or education accounted for a significant amount of the variance.ConclusionsThe results of this study provide support for an apathy syndrome associated with poorer executive function in older adults with major depression. Copyright © 2003 John Wiley & Sons, Ltd.