bluuebunny/crossref_metadata_2025_split huggingface dataset:
Van Atta Array Reflector
Authors: Chung Shyh-Jung , Ho Tan-Hsiung 
Published: April 2005

AbstractThe Van Atta array reflector has the simplest structure for retrodirective arrays, which has found many applications in wireless communications, RF identification (RFID), and intelligent transportation systems (ITSs). The antennas of the Van Atta array are paired and connected by transmission lines with equal length or length differences equal to multiples of a guided wavelength. No active device is required in the basic type; thus this array is much simpler than other kinds of retrodirective arrays. In this literature, the operation principle and a brief development history of the Van Atta array are first described. The theoretical analysis to predict the scattering field pattern in both monostatic and bistatic cases and experimental results of the Van Atta array reflectors is depicted in detail in Section 2. In Section 3, several design examples including one‐dimensional and two‐dimensional Van Atta reflector arrays are introduced. The design concept and operational performance of different kinds of Van Atta arrays are given. Besides passive ones, various active Van Atta reflector arrays are also depicted in this section. Section 4 briefly discusses the applications of the Van Atta arrays, especially in the field of vehicle‐mounting reflectors associated with the ITS. A detailed description of using the Van Atta reflector to enhance the radar cross section (RCS) in vehicle collision warning radar systems and to compose a transponder in the electronic toll collection (ETC) system is conducted. Two examples of transponders using the Van Atta array are introduced in this section. Finally, Section 5 gives a brief summary of the study.
HybridCADTechniques
Authors: Arndt F. 
Published: April 2005

AbstractMicrowave components/systems that meet the tight requirements of advanced applications—in particular concerning reduced mass and size, increased specs and performance, minimized design time, and cost—demandfastEM‐based CAD tools yielding accurate, optimized designs within adequately short response times. This goal makes flexible hybrid solutions desirable, which typically go beyond the efficiency possibilities of single methods. The article presents an overview of the state of the art of hybrid CAD mode‐matching (MM)/finite‐element (FE)/method‐of‐moments (MoM)/finite‐difference (FD) techniques applied for the rigorous, fast CAD and optimization of waveguide components and aperture antennas, and describes some more recent advances. The hybrid techniques presented combine advantageously the efficiency of the MM method with the flexibility of FE, MoM, and FD methods. Typical application examples illustrate the versatility of these techniques; the accuracy is demonstrated by comparisons with available measurements.
Piezoelectric Transducer Controlled Circuits
Authors: Yun Tae-Yeoul 
Published: April 2005

AbstractThis article introduces a new method for tuning microwave circuits of phase shifters, filters, resonators, and oscillators, controlled by a piezoelectric transducer (PET ), with computational and experimental results. An optimized PET ‐controlled phase shifter is demonstrated to operate up to 40 GHz with a maximum total loss of 4 dB and phase shift of 480°. PET controlled tunable bandpass filter, ring resonator, and one‐dimensional (1D) photonic bandgap (PBG ) resonator show a very wide tuning bandwidth of 17.5–28.5% near 10 GHz with little performance degradation. A new PET ‐controlled or voltage‐controlled dielectric resonator oscillator (VCDRO ) is demonstrated with a tuning bandwidth of 3.7% at the center frequency of 11.78 GHz. The tuning bandwidth is slightly less than that of a mechanical tuning using a micrometer‐head‐controlled tunable DRO with a tuning bandwidth of 4.7%. The new tuning method should have many applications in monolithic and hybrid microwave integrated circuits.
Ultra‐Wideband Wireless Systems
Authors: Donlan Brian M. , Buehrer R. Michael , Reed Jeffery H. 
Published: April 2005

AbstractThis article provides an overview of ultra‐wideband (UWB) wireless systems. System issues are discussed including modulation schemes, pulse shapes, interference issues, and channel characterization. Several communications‐ and radar‐specific implementation issues are also addressed. Much of the description is provided in the context of pulse‐based UWB or impulse radio. Furthermore, a section is dedicated to describing the role of the FCC and how current regulations are shaping UWB. The last section extends this discussion and presents several possible applications, providing examples of each.
Coulomb Gauge in Electromagnetics, The
Authors: Nevels Robert D. , Michalski Krzysztof A. 
Published: April 2005

Abstract
High‐frequency electromagnetic wave propagation and scattering problems where the fields are expressed in terms of potentials have been solved almost exclusively with the Lorentz gauge. However, in this article it is shown that any wave guidance or scattering problem that can be analyzed with the Lorentz gauge can as well be found subject to the Coulomb gauge. The Coulomb gauge displays some unique mathematical features that provide insight into the meaning and structure of potentials. The solution method presented here is sometimes referred to as the “hybrid method of moments (MM) Green's function method.” An important consequence of this method is that the Green functions are in their most general dyadic form. A dyadic Green's function formulation provides a compact procedure for handling general three‐dimensional boundary value problems that is uniquely suited to the Coulomb gauge. An interesting aspect of the Coulomb gauge is that is naturally divides the field into static and time‐harmonic components. Comparison between the Lorentz and Coulomb gauges is displayed through the surface current distribution obtained with each of these two gauges for cases where a plane wave illuminates a finite‐length straight wire and a cylinder tipped wedge. Depending on the problem configuration, the numerical solution to problems posed in the Coulomb gauge can have some computational advantage over a Lorentz gauge formulation.
Artificial Magnetic Conductor
Authors: Diaz Rodolfo E. , Clavijo Sergio A. 
Published: April 2005

AbstractThe artificial magnetic conductor (AMC) is a textured ground plane that presents a high impedance to incident waves and nearby horizontal antennas over a prescribed frequency range. In addition, it suppresses the propagation of both transverse electric (TE) and transverse magnetic (TM) surface waves, thus concentrating the radiation from a horizontal antenna into the upper half‐space. The resulting reduced backlobe and reduced mutual coupling to any other antennas on the same surface, combined with the high input impedance, make the AMC an ideal gain‐enhancing ground plane for ultrathin antennas. It is shown that these desirable features of are derived from the AMC's effective anisotropic magnetodielectric constitutive properties. Analysis and design approaches are given that enable the control of these properties according to the desired frequency and bandwidth of operation and the amount of surface‐wave suppression needed. Examples of the latest applications of AMC are given, as well as a brief history of its inception.
Multiresolution Techniques
Authors: Chen Yinchao , Cao Qunsheng , Mittra Raj 
Published: April 2005

AbstractWe begin by reviewing the foundation of the MRTD scheme—the multiresolution analysis (MRA ), and then exploring the properties of the scaling functions and wavelets. Also, we demonstrate the applications of the MRTD technique by analyzing a transverse electromagnetic (TEM ) wave propagation in a dielectric layered stratified space and an integrated microwave circuit, which can be extended to solve electromagnetic engineering problems of a general nature.
Parameter Estimation From Electromagnetic Simulations Using Signal Models
Authors: Naishadham Krishna 
Published: April 2005

AbstractThis article describes two algorithms for estimation of the optimal “system” parameters of time sequences (TSs) and frequency‐domain signatures generated in electromagnetic (EM) simulations. The time‐domain and frequency‐domain signal models are applied to data computed by the finite‐difference time‐domain (FDTD) method, and the method of moments, respectively. The FDTD method requires computation of very long TSs to accurately characterize the slowly decaying transient behavior of resonant structures. Therefore, it becomes critical to investigate methods of reducing the computational time for such objects. Existing methods in EM literature tend to use Prony‐based linear predictor‐type algorithms for modeling and extrapolating time‐domain data. These methods minimize a linearized “equation error” criterion that approximates the true nonlinear fitting‐error criterion posed by the estimation problem. In this article, we describe an efficient iterative method that minimizes the true nonlinear criterion and attains a significantly improved impulse response fitting over Prony's method, using fewer ARMA model parameters. The frequency‐domain state space method (SSM) presented in this article addresses the estimation of rational transfer function models from EM‐simulated data. The data are modeled in terms of complex sinusoids, whose amplitude and phase yield the decay/growth constants and the range, respectively, associated with discrete scattering centers. The model facilitates determination of key geometric and physical parameters of a circuit, antenna, or scatterer, which is an important first step in its design and optimization. Robust state space techniques, borrowed from linear systems theory, are applied to form the system matrix of the underlying microwave problem, whose complex eigenvalues, via signal compression and spectral decomposition, allow for the isolation of specific modal responses suited to calculation of the design parameters.
Submarine Antennas
Authors: Rivera David F. , Bansal Rajeev 
Published: April 2005

Abstract
The design of a submarine antenna differs from its commercial counterpart in two important respects. The antenna must be (1) physically smaller yet able be accommodate numerous electrical functions simultaneously and (2) rugged enough to survive the effects of an unforgiving ocean environment. The successful design of an antenna for such a demanding application is thus an outgrowth of cross‐disciplinary efforts from such diverse fields as materials science, electrochemistry, fluid mechanics, and other allied areas. This article briefly summarizes those aspects of submarine antenna design of importance to the engineer, with an emphasis on its implementation above, beneath or on the sea surface.
Personal Area Networking with Bluetooth
Authors: Zeadally S. , Kumar A. 
Published: April 2005

AbstractThe availability and adoption of a wide range of mobile computing devices (e.g., laptops, personal digital assistants (PDA s), wearable computers) of varying sizes and processing capabilities, along with the emergence of wireless local‐area networks (WLAN s) and wireless personal‐area networks (WPAN s), are enabling the ubiquitous access of information anywhere, anytime. These networks are frequently being used as extensions to the Internet, and end users are increasingly exploiting them to access wireless Internet services. One of the emerging short‐range wireless networking technologies that shows great promise as an enabling technology in the deployment of WPAN s is the recent industry‐standard Bluetooth. In this article, we explore by design, implementation, and experimental performance evaluation, mechanisms and approaches that enable Bluetooth devices to achieve (1) seamless IP connectivity to external IP ‐based networks, (2) high performance even in the presence of IEEE 802.11 interfering traffic, and (3) efficient support for high‐quality audio by exploiting the Audio/Video Distribution Transport Protocol (AVDTP ). We anticipate that our reported experiences and practical results will benefit network designers, developers, and users of Bluetooth technology in WPAN environments.
Adaptive Array Antennas
Authors: Sun Chen , Karmakar Nemai C. 
Published: April 2005

AbstractAdaptive array antennas play an important role in wireless communications systems. The article begins with a brief introduction to evolution of wireless communications systems. After that, the current and future applications of adaptive array antennas in wireless communications systems are described. The structures and implementations of the adaptive array antennas systems, including switched‐beam antennas, phased‐array antennas, digital beamforming (DBF ) array antennas, parasitic array antennas, and diversity antennas, are described in Section 4. The article concludes with a comparison of different adaptive array antenna architectures.
Molecular Recognition of Sialic Acid End Groups by Phenylboronates
Authors: Djanashvili Kristina , Frullano Luca , Peters Joop A. 
Published: April 2005

AbstractA multinuclear NMR study of the interaction between phenylboronic acid (PBA) and sialic acid (Neu5 Ac) has been performed. The latter compound is known to be overexpressed on the cell surface of tumor cells. The results of this investigation suggest that the binding of PBA to sialic acid is pH dependent. 17O NMR experiments with glycolic acid as the model compound prove that an interaction at the α‐hydroxycarboxylate occurs at pH < 9, while a study with threonic and erythronic acids shows that the PBA group interacts selectively with the vicinal diol functions at higher pH. Similarly, Neu5 Ac binds PBA through its α‐hydroxycarboxylate at low pH (< 9) and through its glycerol side chain at higher pH values. The conditional stability constant of the phenylboronate ester at pH 7.4 is 11.4. On cell surfaces, sialic acid is connected to the neighboring sugar unit through the 2‐hydroxy group. To mimic this the 2‐α‐O‐methyl derivative of Neu5 Ac was included in this study. The erythro configuration of the hydroxy substituents prevents stable‐complex formation at positions C7 and C8 and, consequently, the strongest interaction is observed at positions C8 and C9, leading to a five‐membered 2‐boron‐1,3‐dioxalate. In addition, a relatively small amount of the C7–C9 six‐membered complex was observed. Molecular modeling studies confirm that the C8–C9 boronate complex has the lowest energy.
New Layered Quaternary Tantalum Thiophosphates Containing Binuclear [Ta2S10] Units: Synthesis and Crystal Structures of the New Compounds K0.42TaPS5 and Rb0.42TaPS5.
Authors: Gutzmann Andreas , Naether Christian , Bensch Wolfgang 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Remarkable Substituent Effects on the Oxidizing Ability of Triarylbismuth Dichlorides in Alcohol Oxidation.
Authors: Matano Yoshihiro , Hisanaga Teppei , Yamada Hisatsugu , Kusakabe Shingo , Nomura Hazumi , Imahori Hiroshi 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Highly Efficient Chemoselective Deprotection of O,O‐Acetals and O,O‐Ketals Catalyzed by Molecular Iodine in Acetone.
Authors: Sun Jianwei , Dong Yanmei , Cao Liya , Wang Xinyan , Wang Shaozhong , Hu Yuefei 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Domino “[3 + 3]‐Cyclization‐Homo‐Michael” Reactions of 1,3‐Bissilyl Enol Ethers with 1,1‐Diacylcyclopropanes.
Authors: Bose Dopal , Nguyen Van Thi Hong Nguyen Van Thi Hong , Ullah Ehsan , Lahiri Sunanda , Goerls Helmar , Langer Peter 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
One‐Pot Synthesis of N‐Substituted (3‐Oxobutanyl)carbamates from Primary Amines Using Modified Zeolite Hβ at Room Temperature.
Authors: Raje Vivek P. , Bhat Ramakrishna P. , Samant Shriniwas D. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Three‐Component Reaction of Aryl Diazoacetates, Alcohols, and Aldehydes (or Imines): Evidence of Alcoholic Oxonium Ylide Intermediates.
Authors: Lu Chong‐Dao , Liu Hui , Chen Zhi‐Yong , Hu Wen‐Hao , Mi Ai‐Qiao 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Studies on the Chemistry of 2‐(2‐Oxo‐3‐phenylpropyl)‐benzaldehydes: Novel Total Synthesis of 3‐Phenylnaphthalen‐2‐ols and 2‐Hydroxy‐3‐phenyl‐1,4‐naphthoquinones.
Authors: Martinez Ana , Fernandez Marcos , Estevez Juan C. , Estevez Ramon J. , Castedo Luis 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
(S,E)‐N‐[1‐(3‐Heteroarylphenyl)ethyl]‐3‐(2‐fluorophenyl)acrylamides: Synthesis and KCNQ2 Potassium Channel Opener Activity.
Authors: Wu Yong‐Jin , et al. et al. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Condensation of Chromone‐3‐carboxaldehyde with Phenylacetic Acids: An Efficient Synthesis of (E)‐3‐Styrylchromones.
Authors: Silva Vera L. M. , Silva Artur M. S. , Pinto Diana C. G. A. , Cavaleiro Jose A. S. , Patonay Tamas 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient Synthesis of Functionalized 2‐Carbamoylpyran‐4‐ones by Ring Transformation of 5‐Alkylidene‐2,5‐dihydropyrrol‐2‐ones.
Authors: Anders Joachim T. , Nguyen Van Thi Hong , Langer Peter 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
IKCa‐Channel Blockers. Part 2. Discovery of Cyclohexadienes.
Authors: Urbahns Klaus , Goldmann Siegfried , Krueger Jochen , Horvath Ervin , Schuhmacher Joachim , Grosser Rolf , Hinz Volker , Mauler Frank 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Cocyclotrimerization of 6‐Alkynylpurines with α,ω‐Diynes as a Novel Approach to Biologically Active 6‐Arylpurines.
Authors: Turek Pavel , Kotora Martin , Tislerova Iva , Hocek Michal , Votruba Ivan , Cisarova Ivana 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis, Physico‐Chemical Properties and Biological Activity of 1‐(4‐Fluorophenyl)‐4‐[3‐(2‐, 3‐ and 4‐alkyloxyphenylcarbamoyloxy)‐2‐hydroxypropyl]piperazinium Chlorides.
Authors: Malik Ivan , Sedlarova Eva , Csoellei Jozef , Racanska Eva , Cizmarik Josef , Kurfuerst Pavel 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
An Efficient Synthesis of Novel Heterocycle‐Fused Derivatives of 1‐Oxo‐1,2,3,4‐tetrahydropyrazine Using Ugi Condensation.
Authors: Ilyn Alexey P. , Kuzovkova Julia A. , Potapov Victor V. , Shkirando Alexandre M. , Kovrigin Denis I. , Tkachenko Sergey E. , Ivachtchenko Alexandre V. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Pinacol Esters of 1‐Alkyl‐1H‐pyrazol‐5‐yl‐ and 1‐Alkyl‐1H‐pyrazol‐4‐ylboronic Acids.
Authors: Ivachtchenko Alexandre V. , Kravchenko Dmitry V. , Zheludeva Valentina I. , Pershin Dmitry G. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Silylcupration of Allene with the Lower Order Cuprate (t‐BuPh2Si)CuCNLi and Reaction with α,β‐Unsaturated Nitriles. An Unusual Diaddition Process Leading to Disilyl Functionalized Ketones.
Authors: Barbero Asuncion , Blanco Yolanda , Fernandez Hector , Pulido Francisco J. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Highly Enantioselective Reaction of α‐Selenoorganolithium Compounds with Chiral Bis(oxazoline)s and Preparation of Enantioenriched Benzylidencyclohexanes.
Authors: Nakamura Shuichi , Aoki Takayuki , Ogura Takahiro , Wang Libo , Toru Takeshi 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Benzo[1,2‐c:3,4‐c′]bis[1,2,5]selenadiazole, [1,2,5]Selenadiazolo[3,4‐e]‐2,1,3‐benzothiadiazole, Furazanobenzo‐2,1,3‐thiadiazole, Furazanobenzo‐2,1,3‐selenadiazole and Related Heterocyclic Systems.
Authors: Cillo Catherine M. , Lash Timothy D. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
First Enantiospecific Synthesis of Antileishmanial 12‐Deoxyroyleanone from Abietic Acid.
Authors: Alvarez‐Manzaneda Roldan E. J. , Chahboun R. , Bentaleb F. , Cabrera Torres E. , Alvarez E. , Haidour A. , Ramos Lopez J. M. , Alvarez‐Manzaneda Roldan R. , El Houssame S. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Transformations of 2β,3β‐Diacetoxy‐20‐(4,5‐dihydroisoxazol‐5‐yl)‐6‐oxo Steroids.
Authors: Litvinovskaya R. P. , Drach S. V. , Khripach V. A. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Enantiopure (S)‐(E)‐1‐Haloalk‐1‐ene‐3‐amines with Total or Very High Diastereoselectivity by Halomethylenation of α‐Amino Aldehydes Promoted by CrCl2.
Authors: Concellon Jose M. , Bernad Pablo L. , Mejica Carmen 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Thiosugars. Part 12. Synthesis of New 3′‐O‐Substituted 2′,5′‐Anhydro‐2′‐thio‐α‐D‐pentofuranosyl Nucleoside Analogues.
Authors: Voss Juergen , Wirsching Joern , Schulze Oliver , Adiwidjaja Gunadi , Giesler Anja , Balzarini Jan , De Clercq Erik 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Cyclobutane Hydrocarbons by Combination of [2 + 2] π‐Cycloaddition and Olefin Metathesis: Their Abilities as Effective Propellants
Authors: Finkelshtein E. Sh. , Anufriev V. S. , Strelchik B. S. , Chernykh S. P. , Gringolts M. L. , Portnykh E. B. , Americk A. B. , Chelkis F. Yu. 
Published: April 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Readily available sulfamide–amine alcohols for enantioselective phenylacetylene addition to aldehydes in the absence of Ti(OiPr)4
Authors: Mao Jincheng , Wan Boshun , Wu Fan , Lu Shiwei 
Published: April 2005

AbstractEphedrine‐derived sulfamide–amine alcohol 3 was found to be an effective catalyst for the asymmetric phenylacetylene addition to aldehydes at room temperature without using Ti(OiPr)4 and Zn(OTf)2. It afforded the propargylic alcohols in high yields (up to 99%) and good enantioselectivities (up to 84% ee), which were much higher than that based on N‐methylephedrine under the same reaction conditions. Its weakly coordinative sulfonamide moiety of the ligand plays an important role for further acceleration and stereocontrol in the alkynylation. Chirality 17:245–249, 2005. © 2005 Wiley‐Liss, Inc.
A Levenberg–Marquardt iterative solver for least‐squares problems
Authors: Ho H. W. , Wong S. C. 
Published: April 2005

AbstractThis paper presents a new iterative solver for least‐squares problems, which is developed based on the Levenberg–Marquardt and trust region methods. The proposed iterative solver substantially reduces computing time compared with the conventional Levenberg–Marquardt scheme, and can be efficiently applied to large‐scale problems. Three numerical examples are used to demonstrate the effectiveness of the proposed solver. Copyright © 2005 John Wiley & Sons, Ltd.
Rule‐based modeling of biochemical networks
Authors: Faeder James R. , Blinov Michael L. , Goldstein Byron , Hlavacek William S. 
Published: April 2005

AbstractWe present a method for generating a biochemical reaction network from a description of the interactions of components of biomolecules. The interactions are specified in the form of reaction rules, each of which defines a class of reaction associated with a type of interaction. Reactants within a class have shared properties, which are specified in the rule defining the class. A rule also provides a rate law, which governs each reaction in a class, and a template for transforming reactants into products. A set of reaction rules can be applied to a seed set of chemical species and, subsequently, any new species that are found as products of reactions to generate a list of reactions and a list of the chemical species that participate in these reactions, i.e., a reaction network, which can be translated into a mathematical model. © 2005 Wiley Periodicals, Inc. Complexity 10: 22–41, 2005