bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of downlink capacity and transmitter power using SIR‐based adaptive transmitter power control in DS‐CDMA systems—consideration of both common control channel and traffic channels
Authors: Fujii Teruya , Imai Tetsuro , Nakajima Nobuo 
Published: February 2003

AbstractThis paper analyzes the down‐link of a DS‐CDMA system and clarifies the relationship between the system capacity and base station transmitter power, while taking handover and transmission quality into account, when the base station transmitter power control is suitably controlled so that the instantaneous SIR of mobile stations will be uniform in relation to traffic channels in a model that simultaneously considers the traffic channels and common control channel. This paper also shows that system parameters can be easily optimized if the derived equations are used. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(6): 84–103, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1167
A study of a higher order FM mode‐locking laser with double phase modulators
Authors: Shikatani Motokazu , Izutsu Masayuki 
Published: February 2003

AbstractGenerating high‐repetition‐rate short pulses from higher order FM mode‐locked lasers requires many sidebands. However, in reality, the physical limit of modulators makes it impossible to increase the modulation index. This paper proposes a novel higher order FM mode‐locked laser that has two PM‐I‐FP sets (phase modulator, isolator, and Fabry‐Perot filter) and presents an analysis of its performance. The laser uses a new technique that makes the value of the synthesized transfer function of a PM‐I‐FP equal in both the 0 and π phase states. This technique improves the frequency characteristics of the modulator substantially. As a result, the maximum repetition rate is doubled, and the laser also generates a chirp‐free and narrower pulse train with uniform amplitude and pulse width. We also propose a system that has only one PM‐I‐FP. This eliminates problems that arise due to differences in the PM‐I‐FP characteristics when two PM‐I‐FP sets are used. The same effects as mentioned above are achieved. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(3): 1–10, 2003; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/ecjb.10083
Solving satisfiability problems by using reconfigurable hardware
Authors: Suyama Takayuki , Yokoo Makoto , Sawada Hiroshi , Nagoya Akira 
Published: February 2003

AbstractIn this paper, we will propose a new solution method for SAT (Satisfiability Problems) using FPGA (Field‐Programmable Gate Arrays) and logic synthesis system. This method is distinctive in that a logic circuit specialized to solve each problem instance is configured on FPGA. This approach has become possible due to the progress in reconfigurable computing technology in recent years and opens a new possibility in design principle of algorithms. SAT is a kind of constraint satisfaction problem and is a general framework which can represent many application problems. In this paper, we will propose various algorithms which are suitable for implementation on hardware. Among these algorithms, the one which has the highest performance has a performance equal to the Davis–Putman algorithm which introduced the heuristic with dynamic ordering of variables. From the evaluation results using simulation, we show that by the method proposed herein, the solution of a 3‐SAT problem instance with 400 variables generated in a very hard random can be obtained in 1.6 minutes when the circuit is operated at a machine cycle of 10 MHz. Moreover, a very hard problem instance with 128 variables and 256 clauses was packaged on FPGAs and its operation was confirmed. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(3): 35–46, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10134
Probing the neural mechanism of binocular information processing with VEPs
Authors: Hayashi Ryusuke , Miyawaki Yoichi , Maeda Taro , Tachi Susumu 
Published: February 2003

AbstractWe analyze the binocular stereo‐vision process, and the visual evoked potential (VEP) is examined for the case in which a random‐dot stereogram (RDS) is presented. In this study, three experimental parameters are considered, namely, stimulus presentation position, disparity, and correlation between binocular images. The analysis is based on the change of VEP latency, and the relation between the binocular stereo‐vision process and the binocular competition process is investigated. The VEP waveform for RDS presentation is divided into three main components. The first component is the initial vision response, observed to be localized in the occipital area, which is considered to reflect the local disparity detection process. The second and third components are responses with middle to long latency spreading from the occipital area to the frontal areas, and the latency greatly depends on the presentation position and the disparity. The latency is shorter when the presentation is at the center than at the periphery of the view field, and is shorter for crossed disparity than for uncrossed disparity. The difference of latency seems to reflect the processing mechanisms for the presentation position and the disparity. In an experiment using the RDS with the contrast reversed between two eyes (anti‐RDS), the latency is longer for crossed disparity than for uncrossed disparity, which is the reverse of the case of RDS. This phenomenon can be accounted for by the response of the disparity‐selective neuron in V1, which suggests that both binocular stereo vision and binocular competition are based on the local disparity detection mechanism as the neural basis. The response of the disparity‐selective neuron is simulated using the binocular energy model, and the difference between the two kinds of binocular vision processing. A mechanism that detects the unpairedness between the two eyes is proposed. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(3): 47–60, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10135
Estimation of motion parameters for a roaming robot using panoramic images
Authors: Hata Koichi , Aoki Toshimichi , Eto Minoru 
Published: February 2003

AbstractThis paper relates to studying a roaming robot rotating about a vertical axis while moving horizontally on a flat floor surface, and to a method for estimation of its motion parameters. For estimation of motion parameters this method uses correspondences of five or more direction angles in panoramic images captured from three viewpoints by a roaming robot. In this study, first, motion parameters of a roaming robot were limited to horizontal components of translational and rotational parameters, and then the authors concentrated on direction angles as horizontal components of features. Thus, the difference between the measured direction angles and the directional angles obtained by observation was formulated as the error evaluation function, and parameters were estimated by nonlinear minimization. In addition, numerical and computer graphics‐based simulation techniques were used for evaluating accuracy, and the effectiveness of this method was confirmed by tests using real images. This method enables capturing panoramic images by a roaming robot in multiple viewpoints with compensation of the capturing location errors. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(3): 61–72, 2003; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/ecjb.10136
Epipolar geometry estimation method based on maximizing image correlation
Authors: Hata Koichi , Eto Minoru 
Published: February 2003

AbstractThe authors proposed a method for estimation of epipolar geometry parameters based on correlation between two images. This method is characterized by the fact that, unlike conventional epipolar geometry estimation methods using correspondence of characteristic points between the images, it uses parametric block matching correlation with the results of block matching in the image approximated by a two‐dimensional function. This technique involves (1) performing block matching between the two images and obtaining the parametric block correlation function, and (2) minimizing the obtained parametric block correlation function by a robust estimation based on the epipolar geometry parameters, and estimating the epipolar geometry parameters. In the current study, the authors discussed a technique for estimating the epipolar geometry parameters by linear solution method, and then a technique for estimating the epipolar geometry parameters based on nonlinear solution method with those parameters set as initial values. Finally, it was shown by tests using real images that this method is suitable for estimating epipolar geometry parameters with highly correlated images. The tests confirmed that this technique is efficient for improving image quality in the course of image synthesis or improving encoding efficiency during image encoding. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(3): 73–81, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10137
Knowledge extraction from scenery images and recognition using fuzzy inference neural networks
Authors: Iyatomi Hitoshi , Hagiwara Masafumi 
Published: February 2003

AbstractA new method of extracting various types of human knowledge from scenery images in linguistic form and labeling the various regions of unknown images in an effective manner is proposed. In this system, partitioning of the input/output space can be performed in a self‐organizing manner. Rule extraction is performed in parallel and automatically by using a knowledge extraction network (KEN). Depending on the type of image to be learned, two‐phase processing including a self‐organization phase and an LMS learning phase is performed by several KENs. The overall network output is then unified and knowledge extraction and region recognition are performed linguistically. Software that performs a series of such operations has been implemented and it has been confirmed that knowledge extraction and better image recognition can be performed linguistically even if human knowledge is not provided. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(3): 82–90, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10138
Numerical analysis of ultra‐short pulse wavelength conversion characteristics of LiNbO3 waveguide nonlinear‐optic devices
Authors: Ishizuki Hideki , Suhara Toshiaki , Nishihara Hiroshi 
Published: February 2003

AbstractThe pulse wavelength conversion characteristics of various nonlinear optical processes in LiNbO3 waveguide nonlinear optic devices are analyzed by the beam propagation method. Detailed data for estimation of device characteristics and for optimal device design for a 1.5‐µm‐band signal are presented. The following results are obtained. (1) The conversion efficiency of second harmonic generation decreases as the pulse width of the input pump wave is decreased, and is improved as the device length is increased in the range where the walkoff between the optical waves is short. (2) In difference frequency generation, the optical pulse width of the difference frequency is close to that of the input signal wave. In continuous wave pumping, high efficiency is realized by increasing the device length. (3) In cascade second harmonic generation/difference frequency generation, high efficiency can be realized by increasing the device length in both continuous wave pumping and difference frequency pumping. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(3): 11–20, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.1118
Post‐breakdown conduction mechanism of thin oxide films and their aspects
Authors: Komiya Kenji , Oka Takashi , Okada Naoki , Omura Yasuhisa 
Published: February 2003

AbstractThis study investigates extremely thin silicon oxide with thicknesses of 3 to 5 nm produced by various fabrication processes, and the post‐breakdown characteristics are studied. This paper describes the results of comparison. By analysis of the conduction characteristics after intrinsic breakdown, it is shown that there exist two conduction mechanisms—resistive and barrier type—for oxide films with thicknesses of 3.3 and 5.2 nm. These properties of the conduction characteristics are very similar to those reported for the soft breakdown state, which indicates that the conduction mechanisms essentially do not differ much between soft and intrinsic breakdown. It is also shown that the intrinsic breakdown process progresses in two stages in an oxide film with a thickness of 3.3 nm, in contrast to film with a thickness of 5.2 nm. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(3): 21–27, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.1119
Investigation of oxygen source from vapor phase and target for growth of Pb(Zr,Ti)O3 thin film
Authors: Kim Je‐Deok , Sasaki Kimihiro , Hata Tomonobu 
Published: February 2003

AbstractThe authors are engaged in the study of fast low‐temperature fabrication of strongly dielectric Pb(Zr,Ti)O3 [PZT] thin film by reactive sputtering, using a metal (ZrTi)‐oxide (PbO) composite target. In this approach, there is an interaction between the metal target and the oxide target, affecting the fabricated film. When the area ratio of the oxide target is increased, there appears a sputtering mode (called the quasi‐metallic mode) in which metal and oxide are sputtered simultaneously. The deposition mechanism of PZT thin film in the quasi‐metallic mode is investigated, and it is revealed that oxygen is supplied not from the gas source, but from PbO. It is also determined that when a sufficient amount of oxygen is not supplied to the surface of the growing PZT film, reevaporation of Pb occurs, resulting in a deficit of Pb. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(3): 28–34, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.1120
Synthesis and Reactivity of Organoimido Complexes of Chromium
Authors: Leung Wa‐Hung 
Published: February 2003

AbstractOrganoimido groups are excellent spectator ligands for high‐valent organometallic compounds due to their strong π‐donating capability. Of interest are imidochromium complexes that are used as catalysts for olefin polymerization. This microreview provides an overview of the organometallic chemistry of high‐valent imidochromium complexes. Synthetic routes to alkyl‐ and arylimido complexes of chromium in oxidation states VI−IV will be presented. The reactivity of imidochromium complexes including imido group transfer and cycloaddition will be described. The use of imidochromium complexes as catalysts for regioselective ring opening of epoxides will be discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Unexpected Effect of Cyclodextrins on Water‐Soluble Rhodium Complexes
Authors: Caron Laurent , Canipelle Mickael , Tilloy Sébastien , Bricout Hervé , Monflier Eric 
Published: February 2003

AbstractAs shown by 31P NMR spectroscopy, addition of β‐cyclodextrin or randomly methylated β‐cyclodextrin to an aqueous solution of [HRh(CO){P(m‐C6H4SO3Na)3}3] has no effect on the organometallic complex. In contrast, [HRh(CO){(p‐tBuC6H4)P(m‐C6H4SO3Na)2}3] can be partially converted in the presence of the same β‐cyclodextrin derivatives into the hydroxy complex [HORh(CO){(p‐tBuC6H4)P(m‐C6H4SO3Na)2}2], under nitrogen, or to the hydrido complex [HRh(CO)2{(p‐tBuC6H4)P(m‐C6H4SO3Na)2}2] under carbon monoxide. This remarkable difference of behavior was attributed to the fact that the phosphane (p‐tBuC6H4)P(m‐C6H4SO3Na)2 forms more stable inclusion complexes with the β‐cyclodextrin derivatives than the phosphane P(m‐C6H4SO3Na)3. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Complexes of Rhodium(I) and Iridium(I) with the Chiral Tridentate Phosphane Pigiphos: Structure and Reactivity Studies
Authors: Hintermann Lukas , Perseghini Mauro , Barbaro Pierluigi , Togni Antonio 
Published: February 2003

AbstractThe chiral ferrocenyltriphosphane Pigiphos [bis{(S)‐1‐[(R)‐2‐(diphenylphosphanyl)ferrocenyl]ethyl}cyclohexylphosphane] forms four‐coordinate complexes with IrI and RhI. The tridentate ligand assumes different conformations in the derivatives [Rh(CO)(Pigiphos)]OTf (4) and [IrCl(Pigiphos)] (1b), the latter also showing a drastic deviation from the square‐planar geometry. Reactivity studies have focussed on the more reactive 1b. The HCl and O2 adducts have been characterized in solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Preparation of Rhodium Catalysts Supported on Carbon Nanotubes by a Surface Mediated Organometallic Reaction
Authors: Giordano Roberto , Serp Philippe , Kalck Philippe , Kihn Yolande , Schreiber Joachim , Marhic Christiane , Duvail Jean‐Luc 
Published: February 2003

AbstractThe dimeric complex [Rh2Cl2(CO)4] was grafted to multi‐walled carbon nanotubes (MWNTs) previously oxidised with nitric acid and then treated with sodium carbonate to produce carboxylate groups on their outer surface. The grafting mechanism involves bridge‐splitting and substitution of ‐COO for Cl, as evidenced by the presence of NaCl in the samples. A further reduction/decomposition step under dihydrogen at 573 K afforded highly dispersed rhodium nanoparticles (≈︁1.5−2.5 nm). This novel rhodium‐supported carbon material (Rh/MWNT‐COONa) was tested as a catalyst for the hydrogenation of trans‐cinnamaldehyde and the hydroformylation of hex‐1‐ene in the liquid phase: in both cases it was found to be very selective, toward C=C double‐bond hydrogenation and the production of linear and branched aldehydes, respectively. A comparison was made between its catalytic activity and that of rhodium supported on pristine MWNTs and on nitric acid‐oxidised MWNTs. We observed that these latter catalysts have larger particle sizes and lower activities, thus confirming the efficiency of our grafting procedure. Moreover, the better results obtained when using MWNT‐COONa as support with respect to carboxylate‐containing activated carbon also point to the important role played by the mesoporous nature of the carbon nanotube support, which can ameliorate transfer processes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Syntheses, Crystal Structures, and Properties of Four Two‐Dimensional Network Complexes with Multidentate Bis(Schiff Base) Ligands
Authors: Ouyang Xing‐Mei , Fei Bao‐Li , Okamura Taka‐aki , Bu Hong‐Wei , Sun Wei‐Yin , Tang Wen‐Xia , Ueyama Norikazu 
Published: February 2003

AbstractFour novel two‐dimensional coordination polymers [Ag2(L1)2](CF3SO3)2·H2O (1), [Ag3(L1)2](NO3)3·H2O (2), [Co(L1)2(SCN)2]·EtOH (3), and [Co(L2)2(SCN)2] (4) were obtained by reactions of the bis(Schiff base) ligand 1,2‐bis(4′‐pyridylmethyleneamino)ethane (L1) with silver(I) trifluoromethanesulfonate, silver(I) nitrate, and cobalt(II) thiocyanate, and 1,2‐bis(3′‐pyridylmethyleneamino)ethane (L2) with cobalt(II) thiocyanate, respectively. In complex 1, a 2D network structure was achieved by hydrogen bonding interactions between the two 1D chains, consisting of double‐stranded helicates, through solvate water molecules. The 2D network of complex 2 was formed by the coordination to a two‐coordinate silver(I) ion instead of hydrogen bonds as in complex 1. Complex 3 contains molecular square units, which are occupied by disordered ethanol molecules. Complex 4 exhibits a classic square‐grid network which is different from that of 3 due to the different terminal pyridyl groups in L1 (4‐pyridyl) and L2 (3‐pyridyl). These coordination polymers were characterized by X‐ray crystallography, electrospray mass spectrometry, cyclic voltammetry and magnetic measurements. The results show a 2D network superstructural diversity by the fine‐tuning of construction components. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Cover Picture
Authors: Hintermann Lukas , Perseghini Mauro , Barbaro Pierluigi , Togni Antonio 
Published: February 2003

AbstractThe cover picture shows the X‐ray crystal structure of the complex [IrCl(Pigiphos)], where Pigiphos is a unique chiral tridentate ligand containing two ferrocenyl units. Enantiomerically pure triphosphanes are still quite rare and Pigiphos is particularly attractive because of its simple synthesis − one step from commercially available precursors. The study of the coordination chemistry of Pigiphos has shown that it can accomodate metal ions in essentially perfect square‐planar geometries (NiII, PdII, PhI). In case of an ocatahedral coordination sphere it can adopt both a facial or an equatorial configuration (RuII). However, the present [IrCl(Pigiphos)] complex displays a severe deviation from the expected square‐planar geometry and shows a dynamic behavior in solution. Synthesis, characterization, and reactivity of this and other Pigiphos complexes of Ir and Rh are presented in the article by P. Barbaro, A. Togni et al. on p. 601 ff.
Reactivity of B(C6F5)3 with Oxovanadium(V) Complexes VOL3 (L = OCH2CF3, NEt2): Formation of the Organometallic Vanadium(V) Complex [VO(μ‐OCH2CF3)(OCH2CF3)(C6F5)]2 and the Lewis Acid Adduct [(Et2N)3VO·B(C6F5)3]
Authors: Wolff Fabien , Choukroun Robert , Lorber Christian , Donnadieu Bruno 
Published: February 2003

AbstractTreatment of the oxovanadium(V) complex [VO(OCH2CF3)3]2 (3) with the Lewis acid B(C6F5)3 leads to aryl/alkoxy group exchange and formation of the unexpected organometallic oxovanadium(V) [VO(μ‐OCH2CF3)(OCH2CF3)(C6F5)]2 (1), while reaction of B(C6F5)3 and [VO(NEt2)3] produces the Lewis acid adduct [(Et2N)3VO·B(C6F5)3] (2). The crystal structures of 1, 2 and 3 were determined. 51V NMR chemical shifts for complexes 1−3 and [VO(NEt2)3] are discussed. A concentration‐dependant monomer‐dimer equilibrium for 3 is observed in solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Formation and Reactivity of a Tantalocene Trihydride Containing an Aminoethyl‐Functionalised Ligand
Authors: Poulard Cyril , Perrey Danièle , Boni Gilles , Vigier Estelle , Blacque Olivier , Kubicki Marek M. , Moïse Claude 
Published: February 2003

AbstractThe complex [Cp*{C5H4(CH2CH2NMe2)}TaCl2] (1) was synthesised by reaction of the lithium salt LiC5H4(CH2CH2NMe2) with the tantalum compound [Cp*TaCl3(PMe3)]. Reduction of 1 with NaAl(H)2(OCH2CH2OMe)2 leads to the trihydride derivative [Cp*{C5H4(CH2CH2NMe2)}TaH3] (2). The oxidation of 2 in THF with ferrocenium ion leads to a cationic dihydride intermediate [Cp*{C5H4(CH2CH2NMe2)}TaH2]PF6 (3) with an intramolecular stabilization by the aminoethyl side‐chain of the cyclopentadienyl ligand. The hemilabile character of the functionalised cyclopentadienyl ligand was checked by treating 3 with electron‐donating ligands (e.g. phosphanes, sulfides, anions); in all cases, no displacement of the amino group was observed. When treated with HBF4, 2 undergoes a loss of the hydride and the resulting cation can be isolated as a solvento adduct by carrying out the reaction in dimethyl sulfide. Acidolysis of 2 in the presence of an excess of trifluoroacetic acid affords the compound [Cp*{C5H4(CH2CH2NHMe2)}TaH(OCOCF3)2](CF3COO) (5). Microanalytical and NMR spectroscopic data for these complexes are given. The X‐ray crystal structures are reported for [Cp*{C5H4(CH2CH2NMe2)}TaH2]PF6 (3) and [Cp*{C5H4(CH2CH2NHMe2)}TaH(OCOCF3)2](CF3COO) (5). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)