bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scanning fluorescent microscopy is an alternative for quantitative fluorescent cell analysis
Authors: Varga Viktor Sebestyén , Bocsi József , Sipos Ferenc , Csendes Gábor , Tulassay Zsolt , Molnár Béla 
Published: June 2004

AbstractBackgroundFluorescent measurements on cells are performed today with FCM and laser scanning cytometry. The scientific community dealing with quantitative cell analysis would benefit from the development of a new digital multichannel and virtual microscopy based scanning fluorescent microscopy technology and from its evaluation on routine standardized fluorescent beads and clinical specimens.MethodsWe applied a commercial motorized fluorescent microscope system. The scanning was done at 20× (0.5 NA) magnification, on three channels (Rhodamine, FITC, Hoechst). The SFM (scanning fluorescent microscopy) software included the following features: scanning area, exposure time, and channel definition, autofocused scanning, densitometric and morphometric cellular feature determination, gating on scatterplots and frequency histograms, and preparation of galleries of the gated cells. For the calibration and standardization Immuno‐Brite beads were used.ResultsWith application of shading compensation, the CV of fluorescence of the beads decreased from 24.3% to 3.9%. Standard JPEG image compression until 1:150 resulted in no significant change. The change of focus influenced the CV significantly only after ±5 μm error.ConclusionsSFM is a valuable method for the evaluation of fluorescently labeled cells. © 2004 Wiley‐Liss, Inc.
Scalable resource management for high‐performance Web servers
Authors: Hasegawa Go , Terai Tatsuhiko , Okamoto Takuya , Murata Masayuki 
Published: June 2004

AbstractAlthough many research efforts have been devoted to network congestion in the face of an increase in the Internet traffic, there is little recent discussion on performance improvements for endhosts. In this paper, we propose a new architecture, called scalable socket buffer tuning (SSBT), to provide high‐performance and fair service for many TCP connections at Internet endhosts. SSBT has two major features. One is to reduce the number of memory accesses at the sender host by using some new system calls, called Simple Memory‐copy Reduction (SMR) scheme. The other is equation‐based automatic TCP buffer tuning (E‐ATBT), where the sender host estimates ‘expected’ throughput of the TCP connections through a simple mathematical equation, and assigns a send socket buffer to them according to the estimated throughput. If the socket buffer is short, max–min fairness policy is used. We confirm the effectiveness of our proposed algorithm through both simulation technique and an experimental system. From the experimental results, we have found that our SSBT can achieve up to a 30% gain for Web server throughput, and a fair and effective usage of the sender socket buffer can be achieved. Copyright © 2004 John Wiley & Sons, Ltd.
The distribution of file transmission duration in the web
Authors: Nossenson R. , Attiya H. 
Published: June 2004

AbstractIt is well known that the distribution of files transmission duration in the Web isheavy‐tailed(A practical guide to Heavy Tails: Statistical Techniques and Application. Birkhauser: Boston, 1998; 3–26). This paper attempts to understand the reasons for this phenomenon by isolating the three major factors influencing the transmission duration: file size, network conditions and server load.We present evidence that the transmission‐duration distribution (TDD) of thesamefile from the same server to the same client in the Web is Pareto and therefore heavy tailed. Furthermore, text files transmission delay for a specific client/server pair is not significantly affected by the file sizes: all files transmitted from the same server to the same client have very similar transmission duration distributions, regardless of their size.We use simulations to estimate the impact of network conditions and server load on the TDD. When the server and the client are on the same local network, the TDD of each file is usually Pareto as well (for server files and client requests that are distributed in a realistic way).By examining a wide‐area network situation, we conclude that the network conditions do not have a major influence on the heavy‐tailed behaviour of TDD. In contrast, the server load is shown to have a significant impact on the high variability of this distribution. Copyright © 2004 John Wiley & Sons, Ltd.
Wireless video streaming with TCP and simultaneous MAC packet transmission (SMPT)
Authors: Fitzek Frank H. P. , Reisslein Martin 
Published: June 2004

AbstractVideo streaming is expected to account for a large portion of the traffic in future networks, including wireless networks. It is widely accepted that the user datagram protocol (UDP) is the preferred transport protocol for video streaming and that the transmission control protocol (TCP) is unsuitable for streaming. The widespread use of UDP, however, has a number of drawbacks, such as unfairness and possible congestion collapse, which are avoided by TCP. In this paper we investigate the use of TCP as the transport layer protocol for streaming video in a multi‐code CDMA cellular wireless system. Our approach is to stabilize the TCP throughput over the wireless links by employing a recently developed simultaneous MAC packet transmission (SMPT) approach at the link layer. We study the capacity, i.e. the number of customers per cell, and the quality of service for streaming video in the uplink direction. Our extensive simulations indicate that streaming over TCP in conjunction with SMPT gives good performance for video encoded in a closed loop, i.e. with rate control. We have also found that TCP is unsuitable (even in conjunction with SMPT) for streaming the more variable open‐loop encoded video. Copyright © 2004 John Wiley & Sons, Ltd.
A digital secure image communication scheme based on the chaotic Chebyshev map
Authors: Liao Xiaofeng , Li Xueming , Pen Jun , Chen Guanrong 
Published: June 2004

AbstractIn this paper, a simple image secure communication scheme based on the chaotic Chebyshev map and chaos synchronization is proposed. The scheme relies on the excellent correlation property of chaotic sequences, which is very desirable for secure image communication. The results obtained by computer simulation indicate that the transmitted source image can be correctly and reliably recovered using the proposed scheme, even through a noisy channel. Notably, the scheme possesses relatively high security and can be easily implemented. Moreover, the quality of the recovered image is satisfactory, quantified by such common criteria as the bit‐error rate performance. Copyright © 2004 John Wiley & Sons, Ltd.
An active scheduling paradigm for open adaptive network environments
Authors: Hussain S.A. 
Published: June 2004

AbstractActive and programmable networks change the functionality of routers and switches by using agents and active packets. This paper presents a new packet scheduling scheme calledActive Schedulingto control and maintain QoS parameters in virtual private networks (VPNs) within the confines of adaptive and programmable networks. InActive Schedulingan agent on the router monitors the accumulated queuing delay for each service. In order to control and to keep the end‐to‐end delay within the bounds, the weights for services are adjusted dynamically by agents on the routers spanning the VPN. If there is an increase or decrease in queuing delay of a service, an agent on a downstream router informs the upstream routers to adjust the weights of their queues. This keeps the end‐to‐end delay of services within the specified bounds and offers better QoS compared to VPNs using static WFQ. The paper describes the algorithm for Active Scheduling, and presents simulation results and these are compared with WFQ. Copyright © 2004 John Wiley & Sons, Ltd.
Presenilin 1 is essential for cardiac morphogenesis
Authors: Nakajima Mitsunari , Moriizumi Eiko , Koseki Haruhiko , Shirasawa Takuji 
Published: June 2004

AbstractPresenilin 1 (PS1) is the gene responsible for the development of early‐onset familial Alzheimer's disease. PS1‐deficient mice have been reported to show defects in neurogenesis, somitogenesis and angiogenesis. Here, we report cardiac anomaly in PS1‐deficient mice: the mutant hearts exhibited ventricular septal defect, double outlet right ventricle, and stenosis in the pulmonary artery. Immunohistochemistry using anti‐PS1 antibody revealed the prominent expression of PS1 in mesenchymal cells at the septal area of the wild‐type heart. These results suggest that PS1 may play an essential role in heart development. Developmental Dynamics 230:795–799, 2004. © 2004 Wiley‐Liss, Inc.
Critical role for retinol in the generation/differentiation of angioblasts required for embryonic blood vessel formation
Authors: LaRue Amanda C. , Argraves W. Scott , Zile Maija H. , Drake Christopher J. 
Published: June 2004

AbstractNumerous studies demonstrate that vitamin A (retinol) deficiency causes abnormal cardiovascular morphogenesis. We evaluated the impact of retinol deficiency on the regulation of the numbers of endothelial cells and angioblasts (endothelial progenitors) produced during embryonic quail development. At the one‐somite stage, there were no discernible differences in the mean number of endothelial cells or angioblasts in normal and retinol‐deficient embryos. However, retinol‐deficient embryos at the three‐somite stage had an increase in the mean number of endothelial cells but no difference in the mean number of angioblasts. By contrast, retinol‐deficient embryos at the five‐somite stage have 61% of the normal number of endothelial cells and 12% of the normal number of angioblasts. Similarly, retinol‐deficient embryos at the 10‐somite stage had 71% and 60% of normal numbers of endothelial cells in capillary‐like networks and the sinuses venosus, respectively. Furthermore, we show that retinol deficiency did not elicit a global reduction in mesodermal cell numbers but was specific to cells of the endothelial lineage. Taken together, our findings suggest that vascular abnormalities observed under conditions of retinol deficiency are due to reduction in the number of angioblasts and consequently an insufficiency in the number of endothelial cells required to build complex vascular networks. Developmental Dynamics 230:666–674, 2004. © 2004 Wiley‐Liss, Inc.
Performance improvement of PRML system using AR channel model in perpendicular magnetic recording
Authors: Okamoto Yoshihiro , Masunari Noriyuki , Yamamoto Hirofumi , Osawa Hisashi , Saito Hidetoshi , Muraoka Hiroaki , Nakamura Yoshihisa 
Published: June 2004

AbstractWe studied an improvement in the error rate performance of the PRML system in perpendicular magnetic recording. We improved the decoder performance by adopting an AR channel model in the estimation calculation of the input sequence in Viterbi decoding. We determined the required signal‐to‐noise ratio at the readout point and the line recording density needed to achieve a bit error rate of 10−4 from computer simulations and recording and playback tests using a spinstand, and compared them to a conventional PRML system. The results clearly showed improved performance in the PRML system by using a Viterbi decoder employing the AR channel model. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(7): 18–27, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10170
Acoustic models of the elderly for large‐vocabulary continuous speech recognition
Authors: Baba Akira , Yoshizawa Shinichi , Yamada Miichi , Lee Akinobu , Shikano Kiyohiro 
Published: June 2004

AbstractWidespread use of large‐vocabulary continuous speech recognition systems has recently occurred, encouraging the application of speech recognition techniques to various problems. One of the factors that adversely affect the performance of speech recognition systems is a mismatch between the acoustic properties of the speech of the system user and the acoustic model. The speech of young or middle‐aged adults is generally used in constructing the acoustic model. Thus, a mismatch occurs between the model and the acoustic properties of the speech of the elderly, which may degrade the recognition rate. In this study, a large‐scale elderly speech database (200 sentences ×301 subjects) is used to train the acoustic model, and the resulting elderly acoustic model is evaluated by using a large‐vocabulary continuous speech recognition system. In the experiments, the word recognition rate was improved by 3 to 5% compared to the recognition results of an acoustic model trained by young or middle‐aged adult speech, namely, by the JNAS speech database (150 sentences ×260 subjects, average 28.6 years). It is also verified experimentally that the recognition rate is further improved in speaker adaptation to elderly speech by making use of an acoustic model trained by elderly speech. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(7): 49–57, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20101
TelMeA: Effects of avatar‐like agents on asynchronous community systems and implementation in a web‐based system
Authors: Takahashi Toru , Takeda Hideaki 
Published: June 2004

AbstractThe effects of using an animation agent (avatar‐like agent) as an interface of an asynchronous community system, TelMeA, a system with such an agent implemented by the authors, and the results of test‐running this system are discussed in this paper. Psychological test results show that the agent not only has the effect of speaking simply for a speaker, but also differentiating between multiple speakers. Thus, use of this agent allows easy understanding of the state of human relations etc. within a community from conversation content and an increased awareness of the conversation context. In addition, the agent can represent nonlanguage expressions such as expressions, gestures, approaching, finger pointing, and the like by movements on a screen or animation. TelMeA is a system supporting asynchronous conversations by multiple persons through exchanges of scripts describing multimodal behavior of the above‐mentioned expressions via agents displayed on a web page. It was found from the results of test‐running TelMeA for 9 days that 17% of nonlanguage expressions were observed in total utterances and that the functioning of TelMeA was evaluated highly by its users. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(7): 58–69, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20102
Calculation of the correlation coefficient in the DCT domain
Authors: Inazumi Yasuhiro , Warashina Takuji , Yoshida Toshiyuki 
Published: June 2004

AbstractA method is studied for deriving the coefficient of correlation ρ between pixels from the DCT coefficient. The simplest way is to derive the pixel values by applying the fast inverse DCT to the DCT coefficients of interest and then to calculate ρ according to the definition in the image domain. When only the value of ρ is needed, the decoding operation by application of the inverse DCT is redundant. In this paper, a method of direct calculation of ρ in the DCT domain is proposed. First, the definition of ρ in the image domain is expressed in terms of the DCT coefficients. By using the orthogonality of DCT, the total amount of calculation is reduced so that ρ can be calculated with only 50% as much calculation as in the case with the fast inverse DCT. Next, for data such as picture images with high correlation, the energy of the DCT coefficients is concentrated in the lower frequencies. This property is used in reducing the amount of calculation to about 30% by neglecting the DCT coefficients at higher frequencies. The proposed method is applied to a number of picture images to verify its validity. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(12): 49–59, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10153
Accuracy of relative distance measurement with ultra wideband system
Authors: Shimizu Yuichiro , Sanada Yukitoshi 
Published: June 2004

AbstractDue to recent research and relaxed regulations, ultra wideband (UWB) wireless systems have come into practical use. UWB uses a wide bandwidth of several gigahertz and ultra‐short period pulses. Therefore, the position resolution is superior. If pulse locking exists between the transmitter and the receiver, the pulse locking point is shifted if the distance between the transmitter and the received is varied. This shift is corrected by DLL. By measuring this correction, relative position detection is possible. This paper studies the characteristics obtained when using a delay‐lock loop (DLL) for pulse locking, which is important for relative position detection. In particular, it focuses on an environment in which local timing jitter exists. The template waveform on the receiving side and the existence or nonexistence of the loop filter and data modulation are also studied in order to improve the characteristics of the entire system. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(12): 26–36, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ ecjc.20075
Impact of successive interference canceler on the performance of ubiquitous antenna‐based SDMA system
Authors: Okamura Shutai , Okada Minoru , Tsukamoto Katsutoshi , Komaki Shozo , Yamamoto Heiichi 
Published: June 2004

AbstractIn this paper, in order to improve the packet error rate of a ubiquitous antenna‐based SDMA (Space Division Multiple Access) system, the application of a successive interference canceler (SIC) is proposed. In a ubiquitous antenna‐based SDMA system, radio base stations (RBS) distributed throughout the service area are connected by radio‐on‐fiber links to the central control station (CCS). By performing all signal processing functions such as wireless modulation and demodulation at the CCS, simultaneous reception of several signals transmitted in the same frequency range is made possible and hence the frequency utilization efficiency can be enhanced. When an SIC is applied to the ubiquitous antenna system, the magnitude relationship of the power received by the user is different for each RBS as the RBSs are distributed at several locations. Hence, strength comparison of the received power is not easy. In the SIC proposed in this paper, the SINR (Signal to Interference plus Noise Ratio) after MMSE is estimated, and then the interference is eliminated according to size. A computer simulation is performed assuming a QPSK‐OFDM (Quadrature Phase Shift Keyed–Orthogonal Frequency Division Multiplex) signal with a coding rate of 1/2 in accordance with the IEEE 802.11a specification. It is made clear that by the use of the proposed scheme the required transmitted power satisfying the requirement of an average BER of 10−4can be reduced by about 7.2 dB, and that with a packet transmission success rate of 0.9 it can be reduced by 8 dB. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(12): 10–25, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20076
Low‐powered and accelerative synchronization in the coupled system of nonlinear hardware oscillators
Authors: Maeda Yoshinobu , Sakaguchi Shinya , Makino Hideo , Doi Shinji 
Published: June 2004

AbstractIn a diffusively coupled system using a mathematical model of heart muscle, an acceleration phenomenon has been reported in which the oscillation period after coupling becomes smaller than the intrinsic period prior to coupling. In the present research, an acceleration phenomenon is observed in a coupled system of an electronic circuit model. Also, by using an electronic circuit simulator, the conditions causing acceleration in a coupled system are studied. The power consumption of a coupled system is numerically derived. It is found that the power consumption can decrease when the acceleration phenomenon takes place. Heart muscle cells not only accelerate the oscillation (or increase the number of oscillations) by mutual coupling but also reduce the power (or energy) consumption at the same time. It is suggested that efficient information transmission may be carried out with less energy overall. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(12): 1–9, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20081
Development of instruction tracer for performance evaluation
Authors: Morimoto Hiroyuki , Komiyama Syoichiro , Mouri Koichi , Yoshizawa Yasufumi 
Published: June 2004

AbstractApplications such as network server programs and distributed multimedia applications, in which system calls and input/output processing are frequently used, are highly dependent on the operating system. In evaluating the performance of such applications, the execution data for the application and the operating system must be acquired consistently. Conventionally, the performance of a program has mostly been examined through the occurrences of particular events, by means of the performance monitoring function provided by the CPU. The most frequent is the measurement of time based on the cumulative number of clocks in the CPU. In the present computer environment, these values vary depending on the measurement timing. In addition, in these methods, the information concerning the time of occurrence is not preserved when multiple events occur, and there is no means of analyzing the dependency among the events. It is thus difficult for the user to locate the reason for the variation of the value. In order to solve these problems, this paper considers memory access as the measure for performance evaluation. The “SURU” kernel level instruction tracer, the set of “SURU tools” that analyze the output data from TSURU, and the “SURU library” used to construct TSURU tools, are proposed. TSURU can acquire dynamic information such as the execution instruction sequence, the refer address, and the interrupt. Using the TSURU tools to analyze the data acquired by TSURU, the operation of the program under consideration can be traced, and the execution time and the page fault generation rate can be determined. Based on this result, the factors responsible for performance degradation can be analyzed, and the performance improvement obtainable by solving the problem can be estimated. With the TSURU library, the user can easily construct TSURU tools. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(12): 73–83, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20131