bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of VBR and CBR service classes for MPEG‐2 video multiplexing—Is statistical multiplexing really useful for bursty video transmission?
Authors: Wakamiya Naoki , Murata Masayuki , Miyahara Hideo
Published: August 2002

It has been believed that a statistical multiplexing technique can bring an effective bandwidth usage. When it is applied to MPEG‐2 video, it has been pointed out that two to several times multiplexing gain can be attained due to the highly bursty nature of video traffic. However, most of the past researches do not take into account the implementation aspects of this technique. In this paper, we thoroughly investigate the actual multiplexing gain by comparing ATM CBR and VBR service classes (deterministic and statistical service classes), and point out that the statistical multiplexing gain is far from what one might expect. Copyright © 2001 John Wiley & Sons, Ltd.
The effects of correlated arrivals at a server with credit‐based traffic policing
Authors: Mitchell K. , van de Liefvoort A. , Place J.
Published: August 2002

In this paper we observe the steady state and transient behaviour of correlated cell arrivals into a server with credit‐based traffic policing. We derive expressions for the lag‐kcorrelations of the departure process from the traffic policing mechanism, and observe how dependencies in the departure stream affect cell loss at the server. The results illustrate the impact of the second‐order statistics and the higher moments of the cell arrival processes on the traffic policing mechanism performance. Copyright © 2001 John Wiley & Sons, Ltd.
The distributed robust traffic controller for ATM networks
Authors: Zhang Hongyi , Yang Oliver W. , Mouftah H.
Published: August 2002

We propose an approach to design a distributed rate‐based traffic controller to flow‐regulate the best‐effort service (e.g. ABR) traffic and guaranteed service traffic through an ATM switch. The controller is distributed among the source nodes and has a very simple structure. Its local controller at each source node is open‐loop stable and only requires the knowledge of the buffer occupancy at the bottleneck switch. We show that this controller is fair and is not sensitive to the change of VCs over time. It does not have oscillation and can achieve a high utilization. Copyright © 2001 John Wiley & Sons, Ltd.
Measurement‐based admission control for bufferless multiplexers
Authors: Reisslein Martin
Published: August 2002

In this paper we study measurement‐based admission control for bufferless multiplexing, which is very attractive for real‐time traffic. We first discuss a novel large deviations (LD) approach to measurement‐based admission control. We then provide an extensive review of the existing literature on measurement‐based admission control. We conduct simulation studies with traces of MPEG 1 encoded movies to compare the performance of the admission rules in the literature with that of our large deviations approach. We demonstrate that our LD approach achieves higher link utilizations. Finally, we compare the performance of measurement‐based admission control with that of traditional admission control, which relies ona prioritraffic descriptors. Our numerical work indicates that measurement‐based admission control achieves significant gains in link utilizations over traditional admission control. Copyright © 2001 John Wiley & Sons, Ltd.
Virtual base stations for wireless mobilead hoccommunications: an infrastructure for the infrastructure‐less
Authors: Hassanein Hossam , Safwat Ahmed
Published: August 2002

In this paper, we propose a new protocol for wireless mobilead hocnetworks, which establishes a dynamic wireless mobile infrastructure. The proposed protocol, namely, the virtual base stations (VBS) protocol, mimics and maintains the operation of the conventional fixed infrastructure in cellular networks. In the VBS protocol, a mobile node is elected from a set of nominees to act as a temporary base station within its zone. We provide proofs for the correctness of the VBS protocol, and show lower and upper bounds for its global convergence time. Likewise, we study the characteristics and performance of VBS by means of simulation. It is shown that VBS scales well to large networks of mobile stations, and that it outperforms other infrastructure‐formation protocols in terms of stability. The VBS protocol would facilitate the development of a comprehensive and promising framework for quality of service (QoS) management in wireless mobilead hocnetworks once the proper integration of the MAC protocol with the routing and call admission control mechanisms is established. The VBS architecture lays the groundwork for assigning bandwidth, and/or implementing priorities, and hence for QoS‐based routing by conveying the quality of a path prior to call setup. Copyright © 2001 John Wiley & Sons, Ltd.
Extending critical bandwidth allocation techniques for stored video delivery across best‐effort networks
Authors: Feng Wu‐chi , Liu Ming
Published: August 2002

In this paper, we propose two new techniques for the delivery of compressed prerecorded video streams across best‐effort networks like the Internet. Current approaches for the delivery of stored video across best‐effort networks typically alter the quality of the video frames, the frame rate delivered to the user, or a combination of both. By using network feedback, these algorithms continually adjust the video quality to fit within the available network resources. These approaches, however, do not take advantage of thea prioriinformation available from stored video streams, namely the frame sizes that the movie consists of. We will show how monitoring thea prioriinformation and actively monitoring a client‐side buffer can helpsmooththe video frame rate delivered to the user, providing a more consistent quality of video. Copyright © 2001 John Wiley & Sons, Ltd.
Optical switch dimensioning and the classical occupancy problem
Authors: Eramo Vincenzo , Listanti Marco , Nuzman Carl , Whiting Phil
Published: August 2002

Results for optical switch dimensioning are obtained by analysing an urn occupancy problem in which a random number of balls is used. This analysis is applied to a high speed bufferless optical switch which uses tuneable wavelength converters to resolve contention between packets at the output fibres. Under symmetric packet routing the urn problem reduces to the classical occupancy problem. Since the problem is large scale and the loss probabilities are small, exact analysis by combinatorial methods is problematic. As an alternative, we outline a large deviations approximation which may be generalised in various ways. Copyright © 2002 John Wiley & Sons, Ltd.
Histologic and fine‐needle aspiration cytologic features of polycystic disease of the parotid glands: Case report and review of the literature
Authors: Layfield Lester J. , Gopez Evelyn V.
Published: August 2002

Polycystic disease of the parotid glands is a rare disorder, with only eight examples to our knowledge being reported in the literature. The disease presents as a painless enlargement of one or both parotid glands and does not appear to be associated with other disease processes within the head and neck, or with polycystic disease of the kidney, pancreas, or congenital fibrosis of the liver. The histology has been well described. The overall glandular architecture is preserved but the lobules are markedly distended by cysts whose lining appears to be intercalated duct in differentiation. Characteristic eosinophilic laminated spheroliths lie in many of the cystic spaces. Aspirate smears are characterized by a relatively clean background in which are distributed histiocytes, red blood cells, and small clusters of ductal epithelial cells. Polycystic disease of the parotid glands must be differentiated cytologically from mucous retention reaction, mucoceles, benign lymphoepithelial cysts, and cystic neoplasms, including Warthin's tumor, low‐grade mucoepidermoid carcinoma, cystadenoma, and papillary cystadenocarcinoma. Diagn. Cytopathol. 2002;26:324–328. © 2002 Wiley‐Liss, Inc.
Accuracy of the smear technique in the cytological diagnosis of 650 lesions of the central nervous system
Authors: Bleggi‐Torres Luiz Fernando , de Noronha Lúcia , Schneider Gugelmin Elizabeth , Martins Sebastião Ana Paula , Werner Betina , Marques Maggio Ewerton , Queiroz Telles José Ederaldo , Martins Collaço Luiz
Published: August 2002

The authors analyzed the results of 650 lesions of the central nervous system submitted to intraoperative cytological diagnosis by the smear technique. Cytological and paraffin section diagnoses were compared. The following statistical values were obtained: accuracy of 97.3%, sensitivity of 97.9%, specificity of 95%, positive predictive value of 99.1%, and negative predictive value of 89.6%. The authors comment on their main pitfalls using this cytological diagnostic procedure. Diagn. Cytopathol. 24:293–295, 2001. © 2001 Wiley‐Liss, Inc.
T‐cell subtypes in bronchoalveolar lavage fluid and in peripheral blood from patients with primary lung cancer
Authors: Domagała‐Kulawik Joanna , Hoser Grażyna , Droszcz Paweł , Kawiak Jerzy , Droszcz Wacław , Chazan Ryszarda
Published: August 2002

The changes in local immunology play an important role in lung cancer development. We used bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) for the analysis of cell profiles in patients with primary lung cancer. Twenty‐one patients with confirmed primary lung cancer and 13 healthy volunteers were investigated. All persons were smokers. The analysis of T‐cell subsets was performed with a flow cytometry method and with the following antibodies: anti CD3, CD4, CD8, CD16, CD25, CD45, CD56, and HLA‐DR. We found differences in the proportion of lymphocytes between BALF and PB, and a higher proportion of T cells and a lower proportion of B and natural‐killer (NK) cells in BALF. There was a significant difference in the proportion of T‐cytotoxic/suppressor lymphocytes, which was elevated in the BALF of patients and decreased in patients' PB. The T‐helper:T‐cytotoxic/suppressor (Th:Tc/s) ratio was significantly lower in the BALF of patients. These changes were visible in patients with a small cell type. The percentage of T cells with the α chain of receptor to IL‐2 (IL ‐R) was lower in the BALF of patients than in the control group. Our observations reflect local changes in lung environment in patients affected with lung cancer. Diagn. Cytopathol. 25:208–213, 2001. © 2001 Wiley‐Liss, Inc.
P2‐mediated responses in osteoclasts and osteoclast‐like cells
Authors: Steinberg Thomas H. , Jørgensen Niklas R. , Bong Jeffrey S. , Henriksen Zanne , Atal Namita , Lin George C. , Bennett Brian D. , Eriksen Erik F. , Sørensen Ole H. , Civitelli Roberto
Published: August 2002

Osteoclasts are multinucleated giant cells of the mononuclear phagocyte lineage that are responsible for bone resorption in vivo. Osteoprotegerin ligand (OPGL) has recently been identified as an important differentiation and activation factor for osteoclasts (Kong et al. [1999] Nature 397:315–323). We and others have demonstrated P2‐mediated responses in mononuclear phagocytes and ATP‐mediated effects on osteoclasts have also been described (Yu and Ferrier [1994] Cell Signal 6:905–914). The goal of these studies is to identify the role of P2 receptor activation in osteoclast formation and function. In particular, we assessed the role of P2 receptors in intercellular calcium signaling among macrophages and osteoclasts and between osteoblasts and osteoclasts, and studied the role of P2X7 in OPGL‐mediated osteoclast formation. We found that mechanically induced intercellular calcium signaling occurred between osteoblasts and osteoclasts, among J774 macrophage‐like cells, and among osteoclasts, but not among bone marrow‐derived macrophages. Interestingly, different P2 receptors seemed to be responsible for the propagation of intercellular calcium signals among different cells. In our studies of giant cell formation, we confirmed that expression of P2X7 enhances giant cell formation in J774 macrophages and in HEK cells. In contrast, RAW cell clones that were selected for resistance to ATP permeabilization were able to form giant cells in response to OPGL, suggesting that the pathways for giant cell and osteoclast may be different. Drug Dev. Res. 53:126–129, 2001. © 2001 Wiley‐Liss, Inc.
Different approaches to relating genotype to phenotype in developmental disorders
Authors: Karmiloff‐Smith Annette , Scerif Gaia , Thomas Michael
Published: August 2002

In this article, we discuss the complex problem of relating genotype to phenotype and challenge the simple mapping of genes to higher level cognitive modules. We examine various methods that have been used to investigate this relation including quantitative genetics, molecular genetics, animal models, and in‐depth psychological and computational studies of developmental disorders. Both single gene and multiple gene disorders indicate that the relationship between genotype and phenotype is very indirect and that, rather than identifying mere snapshots of developmental outcomes, the process of ontogenetic development itself must be taken into account. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 311–322, 2002. DOI 10.1002/dev.10035
Prospective study of diabetes mellitus and liver cancer in Japan
Authors: Fujino Yoshihisa , Mizoue Tetsuya , Tokui Noritaka , Yoshimura Takesumi
Published: August 2002

Background

Previous studies have identified the association between diabetes mellitus and liver cancer. However, the detail of this association is still unclear, in terms of confounding factors, the trend according to the duration of diabetes, and the interaction between diseases associated with the liver cancer and this association. The purpose of the present study was to examine the association between diabetes and liver cancer in view of the trend and the interaction.

Methods

The baseline survey was conducted during the period 1986–1989 among the general population of Fukuoka Prefecture, Japan (15 417 persons aged 30–79 years). The respondents were assessed for history of diabetes, age at which they had had diabetes, and other covariates by means of a baseline questionnaire. A total of 7308 persons aged 40–79 years were retrieved for the main analysis and 4902 persons for a subcohort from which the information on history of diseases associated with liver cancer were obtained. The relative risks (RRs) and their 95% confidence intervals (CIs) were estimated using the Cox proportional hazards model.

Results

After adjustment for smoking, alcohol and the diseases associated with liver cancer, the RR for liver cancer was 2.06 (95% CI=1.01–4.19). Diabetes increased the risk of liver cancer in persons with hepatitis and/or cirrhosis (RR=2.90, 95% CI=1.13–7.41). However, the RR of diabetes for liver cancer was 1.35 (95% CI=0.41–4.43) in persons without hepatitis and cirrhosis. The trend according to the duration of diabetes was not seen.

Conclusions

A significant association between diabetes and liver cancer was observed. Moreover, this association was modified by hepatitis and cirrhosis. Copyright © 2001 John Wiley & Sons, Ltd.
Hepatic glucose uptake, gluconeogenesis and the regulation of glycogen synthesis
Authors: Radziuk J. , Pye S.
Published: August 2002

Hepatic glycogen is replenished during the absorptive period postprandially. This repletion is prompted partly by an increased hepatic uptake of glucose by the liver, partly by metabolite and hormonal signals in the portal vein, and partly by an increased gluconeogenic flux to glycogen (glyconeogenesis). There is some evidence that the direct formation of glycogen from glucose and that formed by gluconeogenic pathways is linked. This includes: (i) the inhibition of all glycogen synthesis, in vivo, when gluconeogenic flux is blocked by inhibitors; (ii) a dual relationship between glucose concentrations, lactate uptake by the liver and glycogen synthesis (by both pathways) which indicates that glucose sets the maximal rates of glycogen synthesis while lactate uptake determines the actual flux rate to glycogen; (iii) the decrease of both gluconeogenesis and glycogen synthesis by the biguanide, metformin; and (iv) correlations between increased gluconeogenesis and liver glycogen in obese patients and animal models. The degree to which the liver extracts portal glucose is not entirely agreed upon although a preponderance of evidence points to about a 5% extraction rate, following meals, which is dependent on a stimulation of glucokinase. This enzyme may be linked to the expression of other enzymes in the gluconeogenic pathway. Perivenous cells in the liver may induce additional gluconeogenesis in the periportal cells by increasing glycolytically produced lactate. A number of potential mechanisms therefore exist which could link glycogen synthesis from glucose and gluconeogenic substrate. Copyright © 2001 John Wiley & Sons, Ltd.
A novel POZ/zinc finger protein, champignon, interferes with gastrulation movements in Xenopus
Authors: Goto Toshiyasu , Hasegawa Kouichi , Kinoshita Tsutomu , Kubota Hiroshi Y.
Published: August 2002

We have cloned a novel krüppel‐like transcription factor of Xenopus that encodes POZ/zinc finger protein by expression cloning. Overexpression of mRNA resulted in interference with gastrulation. Because the injected embryo looks like a mushroom in appearance at the neurula stage, we have named this gene champignon (cpg). In cpg‐injected embryos, the blastopore appeared normally, but regressed thereafter. The injected embryos then elongated along the primary dorsoventral axis during the tailbud stage. Histologic sections and reverse transcription‐polymerase chain reaction analysis showed that cpg had no effect on the cell differentiation. The animal pole region of cpg‐injected embryos was thick during the gastrula stage, and mesodermal cells remained in the marginal zone. Furthermore, neither Keller‐sandwich explants nor activin‐treated animal cap explants excised from cpg‐injected embryos elongated. These results suggest that cpg acts as a potent inhibitor of cell migration and cell intercalation during gastrulation. © 2001 Wiley‐Liss, Inc.
Coexpression of endothelial PAS protein 1 with essential angiogenic factors suggests its involvement in human vascular development
Authors: Favier Judith , Kempf Hervé , Corvol Pierre , Gasc Jean‐Marie
Published: August 2002

Endothelial PAS protein 1 (EPAS1) is a bHLH‐PAS transcription factor involved in cellular response to hypoxia. Its precise role in angiogenesis is unclear, but several genes essential to vascular development, including those encoding vascular endothelial growth factor (VEGF), its receptor VEGFR‐2 and Tie2, are thought to be targets of EPAS1. To investigate whether this transcription factor and its putative targets were expressed concomitantly, we performed in situ hybridization on serial adjacent sections of human embryos at gestational ages of 3 to 6 weeks. We studied expression of the genes encoding EPAS1, VEGF, VEGFR‐1, and ‐2, Tie2, and its ligands, angiopoietin (Ang) 1 and 2. We also compared these expression profiles with that of hypoxia‐inducible factor 1α (HIF1α). EPAS1 transcripts were detected in several types of endothelial cell: in blood vessels walls, the endocardium, the glomeruli of the mesonephros, and the sinusoids of the liver. In these endothelial cells, expression of EPAS1 systematically or partly coincided with Tie2 and the VEGF receptors expression. There was also some overlap between the sites of synthesis of EPAS1 and VEGF mRNAs, principally in hepatocytes and sympathetic ganglion cells. In addition, we found that EPAS1 and HIF1α transcripts were often colocalized, suggesting a functional redundancy of these two transcription factors during development. These observations are consistent with transactivation by EPAS1 of the expression of its putative target genes during embryogenesis, suggesting that this transcription factor is involved in human angiogenesis. They provide evidence that EPAS1 is involved in the regulation of vascular maturation, remodeling, or stabilization rather than in the early steps of embryonic angiogenesis. © 2001 Wiley‐Liss, Inc.
A design method to increase the signal‐to‐ambiguity ratio of scan SAR
Authors: Iwamoto Masafumi , Fujisaka Takahiko , Kirimoto Tetsuo , Mano Seiji
Published: August 2002

Scan synthetic aperture radar (SAR) is a synthetic aperture radar technique that observes a wide elevation width by conducting observations while successively switching the antenna orientation direction in the elevation direction. In this paper, we propose a method to increase the signal‐to‐ambiguity ratio (S/A ratio) in the azimuth direction of the image by adjusting the Scan SAR observation sequence. In addition, the procedure for planning the observation sequence by this method is presented and its effects are evaluated. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(12): 32–40, 2001
Shared concentration output queuing switch for multiple priority classes
Authors: Nishino Yoshiyuki , Sasase Iwao
Published: August 2002

In B‐ISDN, it is important to handle a variety of traffic having different loss probability requirements by using the same network. Since the shared concentration output queuing (SCOQ) switch has shared transmission networks, focus has been on its switch. In multimedia communications, the QoS (quality of service) is required and satisfied. Moreover, it is important to satisfy the requirement for cell loss probability. The switch has the advantage that the number of switching elements is small. However, it is not enough to correspond to priority classes. In this paper, we propose the SCOQ switch model for multiple priority classes, which is structured with a batcher network and independent banyan networks for each class and output buffers. We evaluate the cell loss probability and mean waiting time by computer simulations and analysis. The cell loss probability of the high‐priority class can be reduced since more high‐priority cells have priority to be transmitted to output buffers than low‐priority cells. As a result, we show that the proposed model is useful in satisfying different requirements of the cell loss probability for multiple priority classes. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(2): 41–50, 2002
100 km transmission of a 640 Gbit/s OTDM signal using femtosecond pulses
Authors: Yamamoto Takashi , Yoshida Eiji , Tamura Kohichi R. , Nakazawa Masataka
Published: August 2002

A 640 Gbit/s OTDM (Optical Time Division Multiplexed) signal using femtosecond optical pulses was successfully transmitted over a distance of 101 km. As a signal light source, a regenerative mode‐locked fiber laser that generates 10‐GHz pulses with a small jitter was used. The transmission path consists of a zero‐dispersion dispersion‐flattened transmission line 101 km long made of a combination of a 1.3‐µm zero‐dispersion single‐mode fiber, a dispersion‐shifted fiber, and a reverse dispersion fiber. The 640 Gbit/s OTDM signal after transmission was demultiplexed by means of an ultra‐high‐speed nonlinear optical loop mirror with a fiber length of 450 m in which walk‐off between the signal light and the control light was reduced. The reverse dispersion fiber in the transmission path had smaller polarization dispersion than both the dispersion slope compensation fiber previously used for compensation of the dispersion slope compensation and the 1.3‐µm zero‐dispersion single‐mode fiber. In addition, the wavelength dependence of its dispersion is small. © 2002 Scripta Technica, Electron Comm Jpn Pt 1, 85(5): 48–56, 2002
A peak power reduction scheme with parity carrier for multicarrier modulation
Authors: Muta Osamu , Takata Tatsuhiko , Akaiwa Yoshihiko
Published: August 2002

This paper proposes a method which reduces the peak‐to‐mean power ratio (PMPR) of the multicarrier modulation signal by providing a subcarrier for peak power reduction outside the information band. The proposed method includes the addition of a redundant signal, that is, parity carrier, in order to reduce the peak power of the multicarrier signal when its envelope exceeds a given threshold. The parity carrier for peak power reduction is placed outside the band of the multicarrier signal and can be easily removed in the receiver. It is shown by a computer simulation that when two carriers for peak power reduction are added to the multicarrier signal with eight carriers, the PMPR after the peak power reduction approaches 4.7 dB. It is also shown for the case in which the power amplifier has little nonlinearity that an outband spectrum density of −50 dB can be achieved by applying the proposed method for a back‐off of 4.7 dB. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(8): 34–46, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1116
Speaker verification based on speaker background model virtually synthesized using local acoustic information
Authors: Isobe Toshihiro , Takahashi Jun‐ichi , Nakamura Taichi
Published: August 2002

In this paper, a likelihood normalization method for verifying a speaker based on an HMM is proposed. In the proposed method, a speaker background model used in likelihood normalization is synthesized from the HMMs of neighboring speakers on the basis of local acoustic information expressed by the phonemes, states, and distributions of the HMMs. By this method, the statistical intermodel distance between the speaker and the background speaker in the acoustic space can be minimized and effective normalization capable of absorbing variations in the likelihood can be realized statistically. When likelihood normalization by a cohort speaker model generated on the basis of the distribution (the proposed method) was compared with the past method of using the cohort speaker model selected for speakers in speaker verifying tests using the telephone voices of 640 people (open tests without time differentials using 320 speakers and 320 impersonators), the equal error rate (EER) was reduced from 5.27% to 1.76% by the proposed method. In addition, when likelihood normalization combining a speaker‐independent model and a cohort speaker model generated on the basis of the distributions was compared with a method using only a speaker‐independent model in texts using the telephone voices of 100 people (open tests with a time differential of 3 months using 24 speakers and 75 impersonators), the EER was reduced from 3.41% to 2.51%, confirming the efficacy of the proposed method. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(4): 47–57, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10045
A quick search algorithm for acoustic signals using histogram features—time‐series active search
Authors: Kashino Kunio , Smith Gavin A. , Murase Hiroshi
Published: August 2002

Proposed here is an algorithm that offers quick detection and location of a target acoustic signal, such as a specific theme song or commercial in a long broadcast. With previous search techniques based on shifted matching of spectra or waveforms, searching through a long signal required enormous computation. On the other hand, with the proposed algorithm, considerable time saving is obtained by using a skipping technique in the histogram‐based search. For example, in experiments on a workstation, when spectral features were preliminarily extracted from acoustic signals, successful search for a target signal (15 s) in a 6‐h signal took only about 2.3 s. In addition, the proposed algorithm proved robust to white Gaussian noise even at a S/N ratio of 20 dB. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(12): 40–47, 2001
Fresnel transform of images for application to watermarking
Authors: Aoki Yoshinao
Published: August 2002

The Fresnel transform describes the diffraction phenomena of the waves and is used for simulation of diffraction phenomena. From the relationship to simulation of wave diffraction, it is found necessary to investigate various conditions when Fresnel transform is carried out numerically to apply to electronic watermarking. Difference in the numerical Fresnel transformation between the simulation of the wave diffraction phenomena and the application to electronic watermarking is studied by using the numerical simulation results of Fresnel transformation by the convolution method and the spectrum method. Further, an example is presented for an application of Fresnel transform to electronic watermarking by the convolution method. Characteristics of the electronic watermarking using Fresnel transform are discussed. It is discussed how the image compression of the wavelet transform can affect the electronic watermarking by Fresnel transform. Quantitative evaluation of the image quality of noted images extracted with PSNR is carried out. Further, it is studied when Fresnel transform method is effective for the cropping attack extracting a portion of the image. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(12): 48–58, 2001
Steady‐state analysis of complex adaptive IIR notch filters for the detection of single sinusoid
Authors: Jiang Haiyun , Nishimura Shotaro , Hinamoto Takao
Published: August 2002

In this paper, we present a new structure for a complex adaptive infinite impulse response (IIR) notch filter which is useful for the detection of complex sinusoids in communication and radar systems. The proposed structure is based on the gradient algorithm. The adaptive detection of a complex sinusoid with additive complex white noise has been investigated. A quantitative analysis for the steady‐state coefficient fluctuation has been developed. Analytical expressions for the steady‐state variance of complex variable coefficient fluctuation have been obtained. It has been shown that the variance of the complex coefficient fluctuation does not depend on the angular frequency of the input sinusoid. Finally, the results of computer simulations which confirm the theoretical predictions are presented. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(1): 32–40, 2002
Hierarchical BSG floorplan for hierarchical VLSI circuit design
Authors: Wu Zhonglin , Nakatake Shigetoshi , Takahashi Atsushi , Kajitani Yoji
Published: August 2002

As a hierarchical layout design method that can handle hierarchical designs of large‐scale integrated circuits, the BSG method, one of the general structural layout methods, is hierarchical and has evolved as a layout method including interconnections. It is the objective of this paper to construct a design system that will provide feedback as a guideline for circuit design modification in which the layers in the circuit design are faithfully represented and are evaluated from the point of view of layout, and the placement is reconstructed for optimization. Hierarchical BSG is realized by combining smaller BSGs (elemental BSGs) with root trees. The size, number, and hierarchical trees of BSGs can be specified by the designer. An experiment to demonstrate the hierarchical effect is carried out by artificially setting a hierarchical design environment with a combination of several thousands of cells. Performance competitive with that without a hierarchical approach is obtained in the resultant areas and interconnect lengths. As a layout algorithm, the number of rectangles to be treated is increased by one order of magnitude so that several tens of thousands of rectangles can be placed with high quality. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(3): 12–21, 2002
The influence of antioxidants on electrical tree generation in XLPE
Authors: Hirota Ken , Kanemitu Yasukuni , Kamada Norihisa , Sekii Yasuo
Published: August 2002

In conjunction with previous experiments studying the effect of decomposition products of dicumyl peroxide (DCP) and antioxidants (AOs) in cross‐linked polyethylene (XLPE) insulation on electrical tree generation, the authors conducted experiments investigating tree inhibition by phenolic AOs. The experiments were conducted using XLPE slabs containing four different phenolic AOs. Among the specimens containing these AOs, the specimen containing 4,4é‐thio‐bis(3‐methyl‐6‐tert‐butylphenol) was found to show the highest tree inception voltage. To examine the reasons for the significant increase in tree inception voltage in this specimen, further experiments were carried out on XLPE specimens containing both phenolic AO and a sulfur‐containing AO. The results demonstrated that the tree inception voltages of specimens containing both phenolic AO and sulfur‐containing AO were higher than those of the specimens containing only one of these two types of AOs. The roles of antioxidants in XLPE dielectrics are discussed with reference to the mechanisms of autoxidation of polymeric materials. The great increase in the tree inception voltage of XLPE specimens containing 4,4é‐thio‐bis(3‐methyl‐6‐tert‐butylphenol) appears to be due to a synergistic effect between the phenolic AO and the sulfur‐containing AO. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 1–7, 2001
High‐efficiency, low‐torque ripple control of a permanent magnet synchronous motor based on current tracking vector of electromotive force
Authors: Chen Shanzhong , Sekiguchi Takashi
Published: August 2002

Since ordinary magnetic field poles of a PM (permanent magnet) motor generate higher harmonic flux, sinusoidal current will cause torque ripple. This is usually removed by short pitch winding, skew slot method, and so on. These methods have a drawback in terms of lower efficiency.

Recently, new current control methods have been proposed to realize zero‐torque ripple and high‐efficiency drive at the same time. However, because the optimized reference current waveform obtained by these methods includes zero phase component, normal three‐phase full bridge inverter andd–qcoordinate control method cannot be used.

This paper proposes a new current control method that can achieve zero‐torque ripple and maximum efficiency by using a normal three‐phase inverter. The three‐phase optimum current can be derived by satisfying the following conditions: (1) the direction of the current resultant vector always agrees with that of the electromotive force resultant vector, and (2) the scalar product of the two vectors is held constant. By means of modifying the coordinate transformation angle, this method can also make it possible to compensate torque pulsation error with maximum efficiency using generald–qcoordinate control method.

The proposed method has been verified by experiments. © 2001 Scripta Technica, Electr Eng Jpn, 136(1): 57–64, 2001
Low‐voltage, low‐power, second‐generation current conveyors
Authors: Imazeki Isao , Takagi Shigetaka , Fujii Nobuo
Published: August 2002

This paper proposes second‐generation current conveyors (CCII's) for low supply voltage operation. The power consumption of the proposed circuits is much lower than that of a conventional circuit. A method for reducing the effect caused by channel‐length modulation is also proposed. Simulation confirms several advantages of the proposed circuits. © 2001 Scripta Technica, Electr Eng Jpn, 138(2): 41–48, 2002
Voluntary environmental policy instruments: two Irish success stories?
Authors: Flynn Brendan
Published: August 2002

Voluntary environmental policy instruments have attracted much interest in recent years, yet they remain firmly established only in the industrial setting of the typical environmental policy ‘leader’ states such as the Netherlands or Germany. This paper examines two Irish examples of innovative voluntary agreements, a farm plastic recycling scheme and a bird conservation project. These both suggest that the voluntary approach can be applied successfully outside the typical industrial sector. Noteworthy in explaining the emergence of the two case studies here was a policy transfer effect from the UK, involving organized Irish farming interests and Irish bird conservationists. A fear of impending state legislation, which is often cited as a vital precondition for successful voluntary approaches, was actually less important than the autonomous initiative of the interest groups themselves. It is suggested that a more important role for the state lies in ensuring good policy co‐ordination. A concluding discussion examines the general problems and potential of relying on interest groups to transfer and implement innovative voluntary environmental policy instruments. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment
The structure of prejudice: associative strength as a determinant of stereotype endorsement
Authors: Neumann Roland , Seibt Beate
Published: August 2002

Previous research obtained inconsistent findings as to whether implicit and explicit measures of prejudice are related. According to our view, some of these inconsistencies are due to whether implicit measures assess exclusively the strength of association between the social category and the evaluation or the activation of the social category in addition. Derived from recent theorizing we suggest that it is especially associative strength between the social category and its evaluation that determines the endorsement of prejudice assessed in explicit measures. To test this assumption we used the Implicit Association Test (IAT) to assess the associative strength of German students' prejudice towards Turkish people and the Blatant‐and‐Subtle‐Prejudice‐Scale (BS scale) as an explicit measure of prejudice. We obtained evidence for prejudice at a relative level in that the category of Turks was more closely associated with a negative evaluation and the category of Germans more closely associated with a positive evaluation. In line with our assumptions the implicit measure was correlated with the explicit measure in that the stronger the representation of Turks was associated with a negative evaluation the more prejudiced individuals responded in the explicit prejudice measure. Using a trait assignment technique, we found that neither associative strength nor the endorsement of the prejudice in the explicit measure were related to the contents of the stereotype. Copyright © 2001 John Wiley & Sons, Ltd.
Complexities of the DNA base excision repair pathway for repair of oxidative DNA damage
Authors: Mitra Sankar , Boldogh Istvan , Izumi Tadahide , Hazra Tapas K.
Published: August 2002

Oxidative damage represents the most significant insult to organisms because of continuous production of the reactive oxygen species (ROS) in vivo. Oxidative damage in DNA, a critical target of ROS, is repaired primarily via the base excision repair (BER) pathway which appears to be the simplest among the three excision repair pathways. However, it is now evident that although BER can be carried with four or five enzymes in vitro, a large number of proteins, including some required for nucleotide excision repair (NER), are needed for in vivo repair of oxidative damage. Furthermore, BER in transcribed vs. nontranscribed DNA regions requires distinct sets of proteins, as in the case of NER. We propose an additional complexity in repair of replicating vs. nonreplicating DNA. Unlike DNA bulky adducts, the oxidized base lesions could be incorporated in the nascent DNA strand, repair of which may share components of the mismatch repair process. Distinct enzyme specificities are thus warranted for repair of lesions in the parental vs. nascent DNA strand. Repair synthesis may be carried out by DNA polymerase β or replicative polymerases δ and ϵ. Thus, multiple subpathways are needed for repairing oxidative DNA damage, and the pathway decision may require coordination of the successive steps in repair. Such coordination includes transfer of the product of a DNA glycosylase to AP‐endonuclease, the next enzyme in the pathway. Interactions among proteins in the pathway may also reflect such coordination, characterization of which should help elucidate these subpathways and their in vivo regulation. Environ. Mol. Mutagen. 38:180–190, 2001. © 2001 Wiley‐Liss, Inc.
Semiparametric approaches to flow normalization and source apportionment of substance transport in rivers
Authors: Stålnacke Per , Grimvall Anders
Published: August 2002

Statistical analysis of relationships between time series of data exhibiting seasonal variation is often of great interest in environmental monitoring and assessment. The present study focused on regression models with time‐varying intercept and slope parameters. In particular, we derived and tested semiparametric models in which rapid interannual and interseasonal variation in the intercept were penalized in the search for a model that combined a good fit to data with smoothly varying parameters. Furthermore, we developed a software package for efficient estimation of the parameters of such models. Test runs on time series of runoff data and riverine loads of nutrients and chloride in the Rhine River showed that the proposed smoothing methods were particularly useful for analysis of time‐varying linear relationships between time series of data with both seasonal variation and temporal trends. The predictivity of the semiparametric models was superior to that of conventional parametric models. In addition, normalization of observed annual loads to mean or minimum runoff produced smooth curves that provided convincing evidence of human impact on water quality. Copyright © 2001 John Wiley & Sons, Ltd.
Modelling of a water treatment plant. A multi‐model representation
Authors: Ragot José , Grapin Gérard , Chatellier Patrice , Colin François
Published: August 2002

This paper examines the problem of modelling a non‐linear dynamic system by a Takagi–Sugeno model. Although this type of model is well adapted to the representation of a system with non‐linear behaviour, its use does however raise real problems in the identification of its structure and parameters, mainly because of the enormous combinatorial increase in model complexity as a function of the number of inputs, and the coupling between the premises and consequence parts. We propose a simplified model structure and an algorithm for the identification of this structure and its parameters. The method is illustrated with reference to data from a wastewater treatment plant of the Greater Nancy Urban Authority. Copyright © 2001 John Wiley & Sons, Ltd.
Compositional receptor modeling
Authors: Billheimer Dean
Published: August 2002

Receptor models apportion an ambient mixture of pollutants to the contributing pollution sources. Often, neither the number of sources nor their chemical profiles are known precisely. The dual goals of modeling are to estimate the chemical ‘signature’ of the sources, and to characterize the mixing process. The author develops a novel modeling approach for receptor data where all model components are compositions (i.e. vectors of proportions). This approach maintains positivity and summation constraints for source contributions and chemical profiles. Further, it incorporates available prior knowledge regarding the source chemical profiles. Including prior knowledge allows parameter estimation while avoiding restrictive assumptions regarding presence or absence of chemical tracers. This approach is illustrated by modeling air pollution data collected from a receptor near Juneau, Alaska. The compositional model produces point estimates of source profiles and mixing proportions similar to those obtained in a previous study. However, interval estimates for mixing proportions are roughly 30 per cent shorter than those found previously. Copyright © 2001 John Wiley & Sons, Ltd.
Design of change detection algorithms based on the generalized likelihood ratio test
Authors: Capizzi Giovanna
Published: August 2002

A design procedure for detecting additive changes in a state‐space model is proposed. Since the mean of the observations after the change is unknown, detection algorithms based on the generalized likelihood ratio test, GLR, and on window‐limited type GLR, are considered. As Lai (1995) pointed out, it is very difficult to find a satisfactory choice of both window size and threshold for these change detection algorithms. The basic idea of this article is to estimate, through the stochastic approximation of Robbins and Monro, the threshold value which satisfies a constraint on the mean between false alarms, for a specified window size. A convenient stopping rule, based on the first passage time of anF‐statistic below a fixed boundary, is used to terminate the iterative approximation. Then, the window size which produces the most desirable out‐of‐control ARL, for a fixed value of the in‐control ARL, can be selected. These change detection algorithms are applied to detect biases on the measurements of ozone, recorded from one monitoring site of Bologna (Italy). Comparisons of the ARL profiles reveal that the full‐GLR scheme provides much more protection than the window‐limited GLR schemes against small shifts in the process, but the modified window‐limited GLR provides more protection against large shifts. Copyright © 2001 John Wiley & Sons, Ltd.
Bayesian hot spot detection in the presence of a spatial trend: application to total nitrogen concentration in Chesapeake Bay
Authors: De Oliveira Victor , Ecker Mark D.
Published: August 2002

Extreme concentrations of water quality variables can cause serious adverse effects in an ecosystem, making their detection an important environmental issue. In Chesapeake Bay, a decreasing gradient oftotal nitrogen concentrationextends from the highest values in the north at the mouth of the Susquehanna river to the lowest values in the south near the Atlantic ocean. We propose a general definition of ‘hot spot’ that includes previous definitions and is appealing for processes with a spatial trend. We model these data using the Bayesian Transformed Gaussian (BTG) random field model proposed by De Oliveiraet al. (1997), which combines the Box–Cox family of power transformations and a spatial trend. The median function is used as the measure of spatial trend, which offers some advantages over the customarily used mean function. The BTG model is fitted by an enhanced Monte Carlo algorithm, and the methodology is applied to the nitrogen concentration data. Copyright © 2002 John Wiley & Sons, Ltd.
Generating multiple spectrum compatible accelerograms using stochastic neural networks
Authors: Lin Chu‐Chieh J. , Ghaboussi Jamshid
Published: August 2002

A new neural‐network‐based methodology for generating artificial earthquake spectrum compatible accelerograms from response spectra was proposed in 1997, in which, the learning capabilities of neural networks were used to develop the knowledge of the inverse mapping from the response spectra to earthquake accelerograms. Recently, this methodology has been further extended and enhanced. This paper presents a new stochastic neural network that is capable of generating multiple earthquake accelerograms from a single‐response spectrum. A new stochastic feature to the neural network has been combined with a new scheme for data compression using the replicator neural networks developed in the original method. A benefit of this extended methodology is gaining efficiency in compressing the earthquake accelerograms and extracting their characteristics. The proposed method produces a stochastic ensemble of earthquake accelerograms from any response spectra or design spectra. An example is presented that used 100 recorded accelerograms to train the neural network and several design spectra and response spectra to test this improved methodology. Copyright © 2001 John Wiley & Sons, Ltd.
Direct use of design criteria in genetic algorithm‐based controller optimization
Authors: Kim Yoon‐Jun , Ghaboussi Jamshid
Published: August 2002

In this study, genetic algorithms are applied to design controllers for the wind‐excited vibration reduction of a 76‐story tall building in the second‐generation benchmark problem. Design criteria and constraints including the comfort requirement for building occupants and the control robustness are directly incorporated in the formulation and evaluation of the fitness and penalty function of the genetic algorithm‐based control design. The method is efficient in obtaining optimal design with multiple constraint conditions. Two controllers are designed with realistic constraints and different robustness criteria. The corresponding results are investigated and compared with LQG optimal control results. Copyright © 2001 John Wiley & Sons, Ltd.