bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Synthesis of Alkaline Earth Silicate Phosphor Sr3MgSi2O8:Eu2+,Dy3+.
Authors: Pan Wen , Ning Gui‐Ling , Wang Jing‐Hui , Lin Yuan
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Solvothermal Synthesis of Hexagonal CdS Nanostructures from a Single‐Source Molecular Precursor.
Authors: Zhang Yong Cai , Wang Gui Yun , Hu Xiao Ya
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Growth Modes of Fe(110) Revisited: A Contribution of Self‐Assembly to Magnetic Materials
Authors: Fruchart O. , Jubert P. O. , Eleoui M. , Cheynis F. , Borca B. , David P. , Santonacci V. , Lienard A. , Hasegawa M. , Meyer C.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Five‐Membered Metallacycles of Titanium and Zirconium — Attractive Compounds for Organometallic Chemistry and Catalysis
Authors: Rosenthal Uwe , Burlakov Vladimir V. , Bach Marc A. , Beweries Torsten
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Formation of Medium‐Ring Heterocycles by Diene and Enyne Metathesis
Authors: Chattopadhyay Shital K. , Karmakar Swastik , Biswas Titas , Majumdar K. C. , Rahaman H. , Roy B.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Design of Chiral Organocatalysts for Practical Asymmetric Synthesis of Amino Acid Derivatives
Authors: Maruoka Keiji , Ooi Takashi , Kano Taichi
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Organic Semiconducting Oligomers for Use in Thin Film Transistors
Authors: Murphy Amanda R. , Frechet Jean M. J.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemical Sensors Based on Amplifying Fluorescent Conjugated Polymers
Authors: Thomas Samuel W. III , Joly Guy D. , Swager Timothy M.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemistry in Organic Synthesis Utilizing MT‐Sulfone as a Reagent
Authors: Ogura Katsuyuki
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Optically Active Pyridines with a Chiral Center at the Next Position to the Ring
Authors: Uenishi Jun'ichi , Aburatani Sachiko
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Biological Activity of doxo‐Galactose and doxo‐Galactomannan: New Conjugates of Doxorubicin with D‐Galactose and 1,4‐β‐D‐Galactomannan
Authors: Klyosov Anatole A. , Tevyashova Anna N. , Olsufyeva Eugenia N. , Preobrazhenskaya Maria N. , Zomer Eliezer , Platt David
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Low‐Energy Electron Transmission Through Thin‐Film Molecular and Biomolecular Solids
Authors: Naaman R. , Sanche L.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Critical Properties of Binary Mixtures Containing Carbon Dioxide — Experimental Data
Authors: Abdulagatov A. I. , Stepanov G. V. , Abdulagatov I. M.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
RNA Bulges as Targets for Selective Cleavage by Metal Ions and Organic Compounds
Authors: Kuznetsova I. L. , Zenkova M. A. , Vlassov V. V.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
How Do Enzymes Activate Oxygen Without Inactivating Themselves?
Authors: Klinman Judith P.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Regulation of Globotriaosylceramide (Gb3)‐Mediated Signal Transduction by Rhamnose‐Binding Lectin
Authors: Nitta Kazuo , Kawano Tasuku , Sugawara Shigeki , Hosono Masahiro
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Regulation of Integrin Functions by N‐Glycans
Authors: Gu Jianguo
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Physicochemical Properties of Plasma — Solution Systems and Prospects for Their Use in Technology
Authors: Zakharov A. G. , Maksimov A. I. , Titova Yu. V.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
New Approaches to Improved Polymer Implant Toughness and Modulus
Authors: Deng Meng , Shalaby Shalaby W.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Molecular Interactions in Amphiphilic Assemblies: Theoretical Perspective
Authors: Nandi Nilashis , Vollhardt Dieter
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Understanding Odd—Even Effects in Organic Self‐Assembled Monolayers
Authors: Tao Feng , Bernasek Steven L.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Molecular Dynamics Simulation of Peptide Folding
Authors: Daura Xavier
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Molecular Recognition at the Gas—Solid Interface: A Powerful Tool for Chemical Sensing
Authors: Pirondini Laura , Dalcanale Enrico
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Microbiotests in Aquatic Toxicology: The Way Forward
Authors: Blaise C. , Ferard J.‐F.
Published: July 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis, Cruzain Docking, and in vitro Studies of Aryl‐4‐Oxothiazolylhydrazones Against Trypanosoma cruzi
Authors: Leite Ana Cristina Lima , de M. Moreira Diogo Rodrigo , de O. Cardoso Marcos V. , Hernandes Marcelo Zaldini , Alves Pereira Valéria R. , Silva Ricardo O. , Kiperstok Alice C. , da S. Lima Milena , Soares Milena B. P.
Published: July 2007

Research in recent years has demonstrated that the Trypanosoma cruzi cysteine protease cruzain (TCC) is a valid chemotherapeutic target. Herein we describe a small library of aryl‐4‐oxothiazolylhydrazones that have been tested in assays against T. cruzi cell cultures. The docking studies carried out suggest that these compounds are potential ligands for the TCC enzyme. The most promising compound of this series, N‐(4‐oxo‐5‐ethyl‐2′‐thiazolin‐2‐yl)‐N′‐phenylthio‐(Z)‐ethylidenehydrazone (6 f), was shown to be very active at non‐cytotoxic concentrations in in vitro assays with mammalian cells and has a potency comparable with reference drugs such as nifurtimox (Nfx) and benznidazole (Bdz).
Risks and benefits associated with novel phase 1 oncology trial designs
Authors: Koyfman Shlomo A. , Agrawal Manish , Garrett‐Mayer Elizabeth , Krohmal Benjamin , Wolf Elizabeth , Emanuel Ezekiel J. , Gross Cary P.
Published: July 2007

BACKGROUND.

Although aggressive dose escalation strategies were designed to improve the risk‐benefit profile of phase 1 oncology trials, they have not been adequately studied. The prevalence of several novel trial designs and their association with a variety of clinical endpoints was evaluated.

METHODS.

A review of the literature was performed to identify phase 1 oncology studies of cytotoxic agents published from 2002 through 2004.

RESULTS.

Of 955 phase 1 oncology articles initially identified, 149 studies, comprising 4532 patients, were analyzed. Only 34% of studies utilized aggressive dose escalation schemes, 22% permitted intrapatient dose escalation, and only 28% enrolled fewer than 3 patients to any dose level. Studies that allowed intrapatient dose escalation or used fewer than 3 patients per dose were not associated with different rates of response or toxicity, nor did they increase the number of patients who received the recommended phase 2 dose. However, aggressive dose escalations were associated with increased rates of both hematologic (17% vs 10%) and nonhematologic (17% vs 13%) toxicity with similar response rates. Only studies that used conservative dose escalation designs and those that studied U.S. Food and Drug Administration (FDA)‐approved agents required fewer patients to complete a trial. Trials of FDA‐approved agents were also associated with higher response rates than trials of non‐FDA‐approved agents (10% vs 2%), without an increased risk of toxicity.

CONCLUSIONS.

Several novel aggressive design strategies intended to improve the risk‐benefit profile of phase 1 oncology trials are not associated with improved clinical outcome, and may be harmful in certain instances. Cancer 2007. Published 2007 American Cancer Society.
A contention resolution algorithm for input‐buffered batcher‐banyan networks
Authors: Awdeh Ra'Ed Y. , Mouftah H. T.
Published: July 2007

A simple algorithm for resolving output contentions in an input‐buffered Batcher‐banyan network is described. The basic idea in this algorithm is to let the binary nodes of the Batcher network participate in the arbitration process. The proposed algorithm is completely distributed and parallel; thus it scales well to large size switches. Furthermore, our algorithm is fair and requires an overhead that is significantly less than that due to the well‐known three‐phase algorithm. Two variations of the algorithm are described.
An object‐oriented approach to dynamic service descriptions
Authors: Hellemans Patrick , Behnke Ulf , de Smedt Alex , Ronchetti Luigi
Published: July 2007

The former CCITT has defined a methodology, consisting of three stages, to evolve from a set of service descriptions to a protocol definition that supports these services. In the first stage, the service is described from a user's viewpoint. A part of this first stage consists of the descriptions of the dynamic behaviour of the service. The introduction of this paper elaborates on the interpretation of the ‘user's viewpoint’ of dynamic service descriptions. In the subsequent sections we introduce an object‐oriented approach to define a framework for the dynamic service descriptions. The flexible definition of services is facilitated by decomposing the service into a standard set of building blocks, referred to as service objects. A service object is the smallest service element that a user can independently reference and manipulate. By modelling in terms of service objects, we avoid the presumption that the total service consists of a specific number of parties or connections. The definition of a service mainly consists of imposing additional semantic rules on the way service objects can be manipulated within the context of that service. The complete system will thus consist of a servicespecific part and a generic part, i.e. a part which is common to all services. An overview of the system configuration and the behaviour of the generic part is illustrated by SDL Descriptions. Finally, we illustrate the method by describing a typical multiconnection multiparty service. The work presented within this paper is based on the results of the RACE MAGIC project.
Expanse software for distributed call and connection control
Authors: Bussey Howard , Minzer Steven , Mouchtaris Petros , Moyer Stanley L. , Porter Frederick
Published: July 2007

The experimental ATM network services environment (EXPANSE) prototype provides an experimental testbed for multimedia multiparty telecommunications services over heterogeneous communications networks. The EXPANSE software architecture supports the functional separation of call and connection control. At the call control layer an object‐oriented, transaction‐based call model provides for the co‐ordination of the negotiations among users for the establishment, modification and disconnection of telecommunications services. The connection control layer provides an object‐oriented protocol for the dynamic establishment, modification and release of network connections which include the control and allocation of network resources required for multimedia multiparty services.

The EXPANSE software includes an application programming interface (API) to the signalling protocol at the call control level. The API provides a uniform and powerful interface to the call model and allows different applications to co‐ordinate the control of local resources and session state.
VP dimensioning for high‐speed data communication in ATM networks
Authors: Saito Hiroshi
Published: July 2007

This paper describes a VP bandwidth dimensioning method for dynamic connection admission control (CAC) in ATM networks. Dynamic CAC judges the admission of a connection by using the measured number of cells arriving at each VP as well as the source traffic descriptor. The bandwidth assignment can therefore reflect the actual traffic characteristics so that the dynamic CAC can compensate for the difference between the negotiated and the actual values of the descriptor. This kind of CAC is especially appropriate for a service for which users have difficulties specifying accurate values for the source traffic descriptor.

The procedure for dimensioning the VP bandwidth is important for providing a service economically when the dynamic CAC is used. This paper develops the dimensioning method of the VP bandwidth for long‐term VP bandwidth management. The VP bandwidth management under dynamic CAC is difficult because this dimensioning method cannot use on‐line traffic measurement even though the CAC (the short‐term management) can. The dimensioning of the VP bandwidth is a key to making the service successful.
Performance analysis for the dynamic virtual path bandwidth control method in ATM networks
Authors: Baba Ken‐Ichi , Murata Masayuki , Miyahara Hideo
Published: July 2007

Broadband ISDN (integrated services digital network) should provide various kinds of communication services for multimedia traffic, including voice, computer data, still picture and motion video, and an ATM (asynchronous transfer mode) technology is expected to satisfy those demands. In ATM networks, a VP (virtual path) concept is introduced for simplifying the network resource management. However, if the bandwidth of each VP is fixed, it cannot absorb traffic load fluctuation. In this case, it is likely to happen that one VP has no remaining bandwidth while other VPs on the same physical link have free capacities. Another extremity is that a VP is not introduced, and that all VCs along the same physical link share the whole bandwidth of the link. This can achieve an efficient use of the link, but it apparently requires complicated call set‐up procedures.

In this paper, we propose a new dynamic VP bandwidth control method, in which the bandwidth allocated to each VP is dynamically changed according to traffic fluctuation. More specifically, in the case that multiple VPs are multiplexed on the same link between two nodes, when the utilization of some VP is increased, that VP requests an additional bandwidth. When the traffic load becomes low and the utilization of a VP is decreased, a part of the assigned bandwidth is released. We consider two methods for this purpose; one is the basic method in which the bandwidth increase request is issued after the VP bandwidth is exhausted. The other is the look‐ahead method where the bandwidth increase is requested in advance before the bandwidth starvation. An approximate analysis for the above methods is provided, and the validation of its accuracy is assessed by comparing with simulation results. Through numerical examples, we show that our methods can provide performance improvement in terms of call loss probabilities of each VP.
Virtual spacing for flexible traffic control
Authors: Roberts J. W.
Published: July 2007

Weighted fair queuing emerges as an elegant and effective solution to the problem of integrating real time services with strict delay constraints and high‐speed data services for which significant delays cannot always be avoided. Virtual spacing is a weighted fair queuing scheduling algorithm intended to be applied in the context of the ATM based BISDN. After discussing how virtual spacing allows flexible traffic control for a variety of service types, we discuss the issue of its implementation in switching nodes. The aim of the paper is to highlight the advantages of weighted fair queuing in enabling a truly integrated services network and to propose a technologically feasible implementation.
Methodologies for characterizing traffic in wide area networks: Analysis and benchmarking
Authors: Khalil K. , Hand J. C. , Mariswamy M. , Obaidat M. S.
Published: July 2007

Since computer networks play an important role in distributed computing environments, an application's performance depends heavily on the quality of service provided by the communication networks. To ensure a high performance, the characteristics of wide area networks, WANs, must be well understood. This paper presents methodologies to characterize WAN traffic based on real measurements from Bellcore's backbone network that connects remote sites using dedicated T1 links. This paper also suggests some workload models that can be used for wide area network sizing and performance evaluation studies. It is found that the inter‐site traffic pattern depends on the time of the day and the day of the week. Furthermore, the traffic between two sites is found to be reasonably symmetric, except for those sites designated as back‐up sites. The coefficient of variation is used as a measure for the traffic burstiness and it is found to be 1·5 degree during working hours. The methods presented here are easy to use and cost‐effective.
Network planning based on virtual path bandwidth management
Authors: Logothetis Michael , Kokkinakis George
Published: July 2007

Periodical performance evaluation and adaptive resource assignment, already proposed as performance‐oriented management, seems to be the most suitable strategy for network planning under demand uncertainty. In this paper, we exploit the inherent capability of ATM networks to rearrange dynamically the already installed resources, and propose performance‐oriented management combined with virtual path bandwidth (VPB) control for the planning of the extensions of bandwidth capacities of virtual paths (VPs) and transmission links of the network. We define a large network optimization problem and solve it by a rigorous, analytical procedure. The optimization model comprises specific requirements of the network‐planning problem and a bandwidth distribution scheme ensuring network reliability. We reveal the efficiency of the proposed scheme by applying it on a model network, considering two realistic case‐studies of network‐traffic evolution. We show that in the presence of VPB control: (a) the initial distribution of the total bandwidth to VPs is of no importance, since it can be adaptively rearranged according to the offered traffic, (b) the network is well used and bandwidth investment could be saved, and (c) whenever additional bandwidth must be installed in VPs which have an unanticipated bad grade‐of‐service, time savings result. We present the network performance in detail, in figures, and compare this with the performance of the network in the absence of VPB control.
Performance study of ATM multicast switching systems
Authors: Chen Xing , Lambadaris I. , Hayes Jeremiah F.
Published: July 2007

We evaluate the performance of anN × NATM discrete time multicast switch model with input queueing operating under two input access disciplines. First we present the analysis for the case of a purely random access discipline and subsequently we concentrate on a cyclic priority access based on a circulating token ring. In both cases, we focus on two HOL (head‐of‐line) packet service disciplines. Under the first (one‐shot transmission discipline), all the copies generated by each HOL packet seek simultaneous transmission during the same time slot. Under the second service discipline (call‐splitting), all HOL copies that can be transmitted in the same time slot are released while blocked copies compete for transmission in subsequent slots. In our analysis the performance measures introduced are the average packet delay in the input buffers as well as the maximum throughput of the switch. A significant part of the analysis is based on matrix geometric techniques. Finally, numerical results are presented and compared with computer simulations.
Analysis of leaky bucket mechanism based on burstiness characterization
Authors: Au Tat‐Ming , Mehrpour Hassan
Published: July 2007

In high‐speed networks, a congestion control strategy has to manage bandwidth allocation based on the characteristics of input traffic sources. Accordingly, the definition of traffic characterization becomes significant in all aspects concerning network performance. In this paper, the burstiness characterization of a traffic stream is based on a virtual queue principle. We study the leaky bucket mechanism as a regulator element that controls input traffic before access to a newwork, as well as inside a network. To protect an input traffic stream, we investigate the optimal parameter settings of a leaky bucket. In addition, we analyse the worst case performance, and obtain upper bounds on loss probability and packet delay. We also determine the characteristics of an output stream in the worst case. Such performance bounds reveal the effectiveness of a leaky bucket, and provide enough information for the QOS satisfaction of the network users.
Photonic transport networks based on optical paths
Authors: Sato Ken‐Ichi , Okamoto Satoru , Watanabe Atushi
Published: July 2007

This paper explores the technologies that will enable a further leap forward in transport network evolution. First, requirements of the future transport network are elucidated. Existing network cost is evaluated and the viable means to reduce transport network cost are identified. It is demonstrated that optical path technologies such as WP (wavelength path) and VWP (virtual wavelength path) will play a key role in this. They enhance not only transmission capacity but also cross‐connect node throughput cost‐effectively by capitalizing on the wavelength routeing scheme. Optical path realization technologies focusing on optical path cross‐connect systems are examined. Requirements for the optical path cross‐connect system are then elucidated, and a new cross‐connect system architecture is evaluated. The architecture exploits PLC (planar lightwave circuit) and other commercially available technologies suitable for large‐scale production. The evaluations include cross‐connect node upgradability, modular growth capability, total node cost, optical loss and switching power consumption. It is proved that the architecture has significant advantages over existing switch architectures. The optical path technologies provided in this paper will pave the way for a new transport network paradigm, a ubiquitous, bandwidth‐abundant and affordable broadband ISDN.
Some extension of modal‐decomposition theory and computational methods in multi‐conductor transmission lines
Authors: Sasaki Hiroshi
Published: July 2007

“Decomposition into independent line groups” is usually possible for multi‐conductor transmission lines in case the product of the per‐unit‐length impedance (z) and admittance (y) matrices, for uniform lines L can be diagonalized. Some reports have suggested that L could be “practically” decomposed into independent line groups just as the F‐matrix is decomposed by the “quasi‐real ideal transformer networks” (QRITN) P‐1 + tp. Here, P is a similarity transformation matrix that diagonalizes zy; + denotes the direct sum of the matrices, and tX is the transpose of X. This paper points out that some points in decomposition theory for transmission lines remain to be studied; these points are further examined by the author. First, the L decomposition theory is also applied to the ease when both Z and y are symmetric and non‐singular and the product z y is not necessarily diagonalizable. As a result, it is demonstrated that L can in general be decomposed by the QRITN into a set consisting of a few independent transmission lines. Second, a computer method for calculating a decomposition matrix for L is introduced, together with the L's F‐matrix. The method is a natural generalization of the conventional procedure for computing the L decomposition matrix and is only applicable in case no multiple eigenvalues exist. Finally, the author proposes a new method for computing the “reference zy matrix”, even for non‐uniform lines, as an application by the procedure.
Radiation characteristics of axial‐mode helical antenna
Authors: Shiokawa Takayasu , Karasawas Yoshio
Published: July 2007

The axial‐mode helical antennas with finitely large reflectors radiate sharp, circularly polarized beams along the antenna axis when the circumference of the helix is about one wavelength long and the pitch angle is 12° ∼ 14°. Although experimental results and approximate theories have been reported, no detailed theory has ever appeared. This paper discusses the radiation characteristics of the axial‐mode helical antenna with the reflector both theoretically and experimentally. First, assuming the reflector is infinite in size, we solve an integral equation satisfying the boundary conditions and obtain the current distributions on the antenna. Characteristics have been studied even for the case with a large number of turns. Next, using the current distribution thus obtained, we find the current distributions on the reflector. By means of the induced emf method, we analyze the radiation characteristics (directivity, power gain and axial ratio) of the axial‐mode helical antenna. Further, we confirmed the analysis experimentally.
Digital filters using round‐off noise control in frequency domain
Authors: Miyata Masachika
Published: July 2007

This paper proposes and discusses the noise feedback rounding using an integral‐coefficient digital filter in order to reduce round‐off noise caused by fixed point arithmetic. The following conventions are used; ΓX(z) and ΔX(z) denote the integer and fractional part of a sampled signal X(z), respectively; X(z) is abbreviated as X; N denotes a noise caused by rounding × to Γ (X + R) (R=z‐1GΔ (X + R)); and the round‐off noise HN under ΔG = 0 at an output is given byHN=K≥,K=‐H(1 ‐z‐1ΓG),N= Δ (1 ‐z‐1ΓG)‐1Xwhere H is the transfer function from a rounding point to the output point. Since N is ordinarily nearly at random, the power of HN can be controlled by determining G for the zeroes of (1 ‐z‐1ΓG) to be in the vicinity of the poles of H. In addition, the maximum value Poof the power HN is in the range of 2−2μ (K) ≤P0< μ (K) and therefore μ(K) can be used as an estimator for the worst design value where μ(K) is the maximum value of K(z) K(z‐1) on a unit circle. Both multipliers and combinatorial digital filters described in this paper are simpler in construction and more economical than the ordinary rounding using longer word length or the random rounding.
Design considerations on high sensitivity mos area image sensor
Authors: Ohba Shinya , Nakai Masaaki , Ando Haruhisa , Kubos Masaharu , Shimada Shigeru
Published: July 2007

By clarifying the design approach of the photoelectric conversion of the two‐dimensional MOS solid‐state image sensor, a 320 × 244 element high responsivity MOS sensor has been fabricated and characterized. In the design of the photodiode design formulas for sensing capacity, responsivity and spectral response are presented and are in good agreement with the measurement. In order to suppress blooming without lowering the responsivity, the threshold voltage of the vertical switch transistor is raised and the photodiode whose n+‐diffusion layer of the signal wire is surrounded by the p+‐layer is proposed. In the horizontal switch transistor design, the signal reading residue is obtained and a simple formula describing the vertical resolution affected by the residue is also obtained.

The main features of the MOS sensor developed by this design approach are: (1) high responsivity; (2) high resolution; and (3) strong blooming. The main characteristics are: for 1.4 μA saturation signal current, 71x saturation faceplate illumination (by Tungsten source) at 550 nm, the responsivity is 0.22 μA/μW, horizontal resolution is 240 TV lines, vertical resolution 190 TV lines and dissipation power is 30 mW.
A design of single‐tuned bandpass filters using charge transfer device
Authors: Iwanami Yasunori , Yoshida Bunya , Ikedas Tetsuo
Published: July 2007

In accordance with the recent tendency of miniaturizing failure with active elements, the non recursive transversal CTD (Charge Transfer Device) filters and the recursive CTD filters by means of the signal delay effect of CTD's have been analyzed and constructed. Comparing the latter with the former, a faster frequency response can be realized with less order although there exists a stability problem due to the poles produced by the recursive loop of the circuit. The recursive circuit is suitable in realizing a high‐Q single‐tuned bandpass filter. In this paper, a design method for the single‐tuned bandpass filter with CTD having higher stability against Q variation than that of the conventional second‐order CTD filters [6, 7] is presented. Assuming a pole and a zero which can move along the prescribed closed loci on the Z‐plane depending on the input frequency, the low coefficient sensitivity transfer function is obtained and an economical canonic form circuit is realized. A consideration on the proposed concept that poles and zeros can move corresponding to the input frequencies is presented in the Appendix and the experimental confirmation is shown.
Some methods of estimating the magnitude of total sensitivities for the transfer characteristics of a reactance filter
Authors: Kida Takuro , Kurogochis Katsumi
Published: July 2007

This paper proposed two methods (the decision theory method and the probability method) for estimating the approximate magnitude of the tolerances of the transfer characteristics which are caused by the deviation of elements of a reactance filter. The first method estimates the total element sensitivities of the filter by an estimation measure which gives an upper bound of the absolute sum of the second‐order element sensitivities for the attenuation characteristic of the reactance filter. The estimation measure is represented by the various quantities which can be derived from the characteristic function of the filter only. Therefore, the element sensitivities of the filter can be estimated by its characteristic function only before actually constructing the network. The second method is for determining the statistical mean value and variance of the tolerance of the transfer characteristics for a reactance ladder filter. A calculation algorithm for this method is proposed. The transfer characteristics include the attenutation characteristic and phase characteristic as well as the real and imaginary parts of the characteristic function expressed in nepers. The analytical technique is based on Taylor's series expansion. The first‐order to third‐order terms and the mean value of the fourth‐order term are used. The second method differs from the first in that the former utilizes the information about the internal structure of the network.
Two‐dimensional computer analysis of current‐phase relations in microbridge josephson junction
Authors: Sakura Shigeyuki , Kawamuras Mitsuo
Published: July 2007

In the microbridge Josephson junction, the current‐phase relation is obtained by solving simultaneously the Gintzburg‐Landau equation and Maxwell equation. The optimum geometry of the microbridge which produces a large Josephson effect is clarified. Unlike other Josephson junctions, the microbridge Josephson junction is of the strong‐weak‐strong superconducting structure which is generated by the current flow. A large Josephson effect is obtained when the bridge length is less than the coherence length and when the bridge width is less than the magnetic penetration depth, In and Sn are superior to Cd and Al as superconducting materials.
Estimation of time‐varying traffic parameters
Authors: Matsuda Jun , Takemori Eiji , Uedas Tohru
Published: July 2007

The rapid growth of telecommunication networks has brought about diversified applications. This trend will become clearer as these networks become integrated service networks. To control and operate the networks efficiently, necessary actions should be taken to measure traffic flows as precisely and as soon as possible.

In general, since actual communication traffic is time‐varying in its parameters, such as the call occurrence rate, requirements are needed for measuring these traffic variations in connection with analysis of traffic‐varying trends, detection of abnormal traffic, traffic prediction, and others. Therefore, this paper investigates an estimation method of time‐varying traffic parameters with the help of a filter. First, we construct a non‐stationary stochastic model of estimated objects and study the estimation accuracy with which the time series data obtained through the stochastic process measurements provide estimates of time‐varying parameters after filter processing. Second, we introduce the optimum filter which minimizes the estimation error, based upon the above analyses. Third, we show some examples of applications, i.e., estimation of varying call occurrence rates and detection of abnormal traffic, both of which are made using the filter.
Two‐dimensional multiple scattering for n slit array
Authors: Hongo Kohei , Furusawa Naoto , Horis Hidehiko
Published: July 2007

A new method has been proposed to analyze 2‐dimensional multiple scattering of a plane wave by N parallel cylindrical structures. Diffraction of a plane wave incident on N parallel slits is formulated exactly via Kobayashi‐Nomura's method in an asymptotic form in which the (i+1)‐fold scattering field is given in terms of the i‐fold scattering field. The solution consists of scattering pattern functions for a single slit and their derivatives. The pattern functions are modified when applied to multiple scattering by cylindrical structures of arbitrary cross sections. Numerical solutions are presented for multiple scattering by strips.
A simple numerical derivation of group delay and impulse response from the prescribed characteristic function of a reactance low‐pass filter
Authors: Kida Takuro , Kurogochis Katsumi
Published: July 2007

The numerical integration method is proposed to derive the group delay characteristics and impulse reponse of the reactance low‐pass filter for a given characteristic function of the filter. The approximate values of coefficients in the group delay characteristics τ(ω) are derived from given characteristic function by applying the numerical integration method to the integral formula using Hilbert transform. A simple method is proposed to evaluate the error due to the numerical integration. The coefficient of the transfer function is derived from the coefficient of (ω). Further, the impulse response is calculated from the transfer function by applying the numerical integration method to the integral formula of Laplace inverse transform in which the Bromwitch integral path is replaced by a special path. Finally, the transfer function of the low‐pass filter with sufficiently flat attenuation characteristics in the passband is derived by the minimization method for given group delay characteristics and step response.
Analysis of discrete wave system by optical ray operators
Authors: Aoki Yoshinao
Published: July 2007

The optical ray operators which are used for description and analysis of continuous‐variable wave systems are extended to the discrete‐variable wave systems, and several formulas for discrete wave systems and sampling operators are derived. The discrete wave system relates to diffraction by diffraction gratings. For the discrete wave systems with periodicity in case of a finite number of sampled values, the condition of completeness is derived in relation to the discrete Fourier transform. The result of the analysis is applied to the discussion of the recursive convolution and the derivation of the convolution theorem. The ray operators are applied further to two types of Fresnel transforms to describe wave propagation. The ray operators are also used for analysis of super‐resolution in the presence of both continuous and discrete wave systems.
QPSK modem system for tdma satellite communications
Authors: Fujino Tadashi , Umedas Yoshiaki
Published: July 2007

For the design of the QPSK‐TDMA satellite communication system, analyses and experiments of modem systems have been made. When the burst‐mode QPSK signals with white Gaussian noise are input into the demodulation system, the demodulation system including the carrier recovery circuit, is influenced by noise. In this paper, the symbol error rate in the CPSK transmission, the code error rate in the DCPSK transmission, the unique word error rate (UWER) [for PSK transmission for both C and DC] which is important for the frame timing synchronization signal extraction, and occurrence probability of cycle slip in CR as well as its effect on the UWER, have been analyzed. Furthermore, experiments have been made and their results have been compared with the results of the analyses. Also, it has been shown by examples that the modem system of the QPSK‐TDMA system can easily be designed by using the results of the analyses.
A design method for hairpin line circuits
Authors: Nakano Yoshihisa , Ikedas Tetsuo
Published: July 2007

The hairpin line circuit is one of the distributed coupling lines with special terminal conditions, and various design methods have been reported. However, because of the complexity in dealing with the terminal conditions, equivalent circuits for the hairpin line circuit are not easily derived unlike interdigital circuits. It is desired to establish a simple design method instead of using approximate theory from admittance matrices. In this paper, the equivalent circuit is derived from multiport admittance matrices with the terminal conditions taken into account and its properties are clarified. From these results, the design method is developed under given circuit specification. In this method, the circuit analysis and design are made by matrix calculation and are suitable for computer calculation.
Design theory and characteristics of solid‐state mutual coupling cable
Authors: Matsuda Shizuo
Published: July 2007

Previously, the author reported the theory of the solid‐state mutual coupling cable (hereafter, called SSMCC) which utilizes active coupling among three conductors to compensate the cable losses. In this paper, the optimum design theory of the SSMCC is presented with consideration of the realization condition. The design procedure is described for given transistor characteristics and cable conductor resistances. The design example of an experimental SSMCC and its transfer characteristics are presented. The SSMCC is lossless at the lossless frequency in the transmission band and has almost identical loss at frequencies above and below this lossless frequency. In the analysis, the conductor skin effect is ignored.
A design method of broadband polarizers using metal posts
Authors: Ishida Osami , Kaniya Shojiro , Takedas Fumio
Published: July 2007

A broadband polarizer with metal posts is designed on the basis of the fact that normalized capacitive susceptance of short posts decreases at high frequencies. To obtain the design data, the measurement is made for the optimum post diameter and its length which give negative normalized capacitive susceptance, and the magnitude of the post susceptance for the orthogonal two polarized waves. A method of determining the post size for a broadband polarizer is examined from the equivalent circuit. To obtain good VSWR characteristics, the post susceptance in the matching sections follows the raised cosine distribution. The relation between the number of posts and VSWR is clarified. An experimental polarizer has an ellipticity less than 0.25 dB in the specific broadband 12.6%.
Time domain analysis of networks containing lossless transmission lines via improved Gear's algorithm
Authors: Kishino Takumi , Hamada Nozomu
Published: July 2007

This paper considers time domain analysis of electrical networks consisting of lumped elements and lossless transmission lines. In this circuit analysis algorithm. Branin's equivalent circuit representation for lossless transmission line leads to an efficient algorithm for computer‐aided transient analysis.

In this paper, we point out some problems and propose the improvements for Gear's algorithm applied to the transient analysis of networks containing transmission lines. The improvements are made on the setting of time step size and the interpolation techniques. The proposed rules result in high accuracy and saving of time in the numerical transient analysis.
Fundamental consideration on heterogeneous packet switching involving message communications application
Authors: Yoshida Yutaka , Takenaka Toyofumi , Watanabe Naoya , Tsukadas Keiichi
Published: July 2007

Recently, the packet switching network which deals with relatively short data packets has been developed for the conversation‐type communication between the periphery and computer. However, in the message communication in which files and picture information are exchanged, the packet switching network must deal with long packets. The packet switching network which deals with long and short packets is called the heterogeneous packet switching network. In this paper, the optimum packet size for the message communication is discussed from the viewpoint of communication cost. Further, the segregated‐type and integrated‐type heterogeneous packet switching systems, the buffer memory and packet transfer delay time, are evaluated and compared.
Application of error‐correcting codes to the DCPSK system
Authors: Nakano Yukio , Kasahara Masao , Namekawa Toshihiko
Published: July 2007

The application of error‐correcting codes to the DCPSK system is discussed. Nakamura and Iijima have proposed a method in which the block code to be applied inside the differential coding is applied outside the differential coding. The method of Nakamura and Iijima is first investigated in detail from the viewpoint of coding theory. Based on the results it is shown that a paired error‐correcting code can be constructed in the block code from the random error‐correcting code by a linear transformation. Then, applying this to the convolution code, a method is devised for constructing the generating matrix for the paired error‐correcting code by carrying out a linear transformation of the generating matrix for the random error‐correcting code with differential coding. Search for a convolution code to be used in the DCPSK system is made on a computer. Finally, a code is constructed which can successfully correct the error caused by reference phase slip in synchronous detection as well as by random error in the channel. The usefulness of the code in the DCPSK system is demonstrated.
On code conversion by constant‐resistance distributed coupled‐line networks
Authors: Sakagami Iwata , Hatori Kozo
Published: July 2007

When a unit impulse is incident on a constant‐resistance distributed coupled‐line network consisting of equally long multisection two‐wire coupled lines and a π‐type resistive network, the output response is an infinite pulse train with diminishing amplitudes. With an appropriate choice of element values it is shown that the amplitude ratio of a first few pulses is (1, Om, 1), (1, Om, ‐1), (2, Om, 1, Om, ‐1) and (1, Om, 2, Om, 1) and the remaining pulses become negligibly small. These first few pulses are considered to be signal components with the remaining pulses constituting the characteristic wave distortion. It is possible to reduce this distortion by increasing the number of coupled line sections. In this paper, the distortion rate is defined as the ratio of the characteristic wave distortion power to the signal power. With the total reflected power of the circuit expressed in terms of a complex integral, calculation of the distortion rate is possible. We quantitatively characterize the operational circuit as a symbol converter. Calculations have been made for coupled lines with up to 4 sections. Since the formulation becomes complicated as the number of sections increases, the numerical calculations are made on a computer.
Approximate vector analysis of single‐mode optical fibers with arbitrary refractive index distribution
Authors: Matsuhara Masanori
Published: July 2007

The single‐mode optical fiber, which has stable polarization characteristics, is one of the most important components in the high‐density optical communication system, and R&D interest is focused intensively on this component. This paper presents a vector mode analysis of a fiber with arbitrary refractive index distribution and without axial symmetry, such as an elliptic fiber with arbitrary refractive index distribution, which has been mentioned as one possible optical fiber. An approximate vector solution is proposed. The approximate vector analysis is a practical method of analysis, in that the numerical computation required is that employed in the approximate scalar solution itself, which is simple and obvious, since most of the computation is analytic, and it is possible to determine directly the difference of propagation constants of the two vector modes in the single‐mode optical fiber. The paper discusses the theory, accuracy and application of the approximate vector analysis.