bluuebunny/crossref_metadata_2025_split huggingface dataset:
2D finite‐difference frequency‐domain method and its application for dispersion characteristic analysis of ferrite devices
Authors: Munir Achmad , Kubo Hiroshi , Sanada Atsushi , Awai Ikuo 
Published: April 2004

AbstractIn this paper, a two dimensional (2D) finite‐difference frequency‐domain (FDFD) method is applied to analyze the dispersion characteristics of ferrite devices. The FDFD formulation for ferrite devices is built from the integral form of Maxwell's equations. After implementing all the boundary conditions, the finite‐difference formulation is concluded as an eigen equation and then constructed by a highly sparse matrix. By solving the matrix‐eigen equation, the dispersion characteristics of ferrite devices for a given frequency can be obtained. In order to verify the validity of the proposed method, an infinite ferrite‐filled waveguide is examined and the numerical results are compared to both the theoretical result and the 3D finite‐difference time‐domain (FDTD) numerical result. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 437–439, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20163
Effects of weighting and damping coefficients on the accuracy of Higdon‐based absorbing boundary conditions
Authors: Wu Xin , Ramahi Omar M. 
Published: April 2004

AbstractIn this work, the effects of weighted difference schemes and damping factor on the spurious errors arising from the application of Higdon's absorbing boundary condition and the concurrent complementary operators method (C‐COM) are investigated. An optimized combination of the weighted difference scheme for boundary conditions and the damping term used to stabilize the boundary scheme are proposed to minimize the reflections. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 446–448, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20166
Design of dual‐band antenna for the ISM band using a backed microstrip line
Authors: Choi Seok H. , Park Jong K. , Kim Sun K. , Kim Hak S. 
Published: April 2004

AbstractIn this paper, we propose a new dual‐band antenna for applications of the ISM band. The proposed antenna is designed to operate at 2.4 and 5.8 GHz. The lower‐frequency band (2.4 GHz) can be obtained by using the meandering technique, and the upper‐frequency band (5.8 GHz) for dual‐band operation was achieved by embedding a backed microstrip line. Details of the proposed antenna design and experimental results are presented and discussed. The measured radiation patterns at 2.4 and 5.8 GHz and antenna gain across the respective frequency bands are also presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 457–460, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20170
An improved real‐frequency‐method technique for broadband matching of an HF antenna
Authors: Liu Yi‐Jun , Li Bin‐Hong , Chi Gao‐Ming 
Published: April 2004

AbstractAn improved real‐frequency method (RFM) technique which does not require any initial guess of the resistance excursions, is presented. According to the conjugate matching, the resistance excursions are obtained in least‐squares sense by a simpler process. A matching network is successfully synthesized to match an HF antenna well by using this improved technique. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 471–473, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20175
A dual‐band network of the feeding module utilized in diverse applications of a WLAN antenna
Authors: Wang Chien‐Jen , Tsai Wen‐Tsai 
Published: April 2004

AbstractIn this paper, a microstrip network of the feeding module used in diverse applications of an antenna for dual‐band wireless local‐area network (WLAN) operation is designed, fabricated, and measured. A wideband Wilkinson power divider with the defected‐ground structure (DGS) is integrated with a dual‐band SPDT switch module in order to provide two individual signal paths for the input of a two‐element antenna array. Two DGS slots are etched on the ground plane in order to reduce the loss of chip resistors, improve the impedance bandwidth, and enhance the efficiency of the output power. According to the simulated and measured results, the feeding module can be operated at the 2.4‐ and 5.2‐GHz bands. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 473–477, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20176
A dual‐mode uniplanar bandpass filter using an inset‐coupling structure
Authors: Görür Adnan , Çaliskan Şenol , Karpuz Ceyhun 
Published: April 2004

AbstractA novel dual‐mode uniplanar square slot‐loop resonator, using an inset‐coupling mechanism with capacitive gaps is proposed. The mode splitting of the uniplanar resonator is described with respect to the perturbation size. A dual‐mode uniplanar filter using such a resonator is designed and fabricated with 5% bandwidth at the center frequency of 2.97 GHz for demonstration. The measured filter performance is presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 481–483, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20178
Rigorous full‐wave analysis of rectangular microstrip patches over ground planes with rectangular apertures in multilayered substrates that contain isotropic and uniaxial anisotropic materials
Authors: Fortaki T. , Benghalia A. 
Published: April 2004

AbstractA rigorous full‐wave analysis of rectangular microstrip‐patch resonators over ground planes with rectangular apertures is presented. The rectangular patches, as well as the ground planes containing the rectangular apertures, are embedded in a multilayered substrate containing isotropic and/or uniaxial anisotropic materials. Using a matrix representation of each layer, the dyadic Green's functions of the problem are efficiently determined by the (TM, TE) representation. The validity of the solution is tested by comparing the computed results with the experimental data. Numerical results show that the rectangular apertures significantly affect the resonant frequencies of the rectangular microstrip patches. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 496–500, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20183
On the structure and packing of the moment matrix in problems supporting simultaneous electric and magnetic surface currents
Authors: Schoeman Marlize , Meyer Petrie 
Published: April 2004

AbstractAn efficient packing algorithm is presented for filling the method of moments (MoM) matrix in problems containing both electric and magnetic currents, and multiple coupled regions separated by infinite conducting ground planes. Provision is made for symmetric and unsymmetrical submatrices. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 500–505, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20184
A novel microstrip bandpass filter
Authors: Jianxin Chen , Mengxia Yu , Jun Xu , Quan Xue 
Published: April 2004

AbstractA novel compact microstrip bandpass filter which is realized by combining new slow‐wave effect with dual‐parallel coupling, is proposed. The filter is not only compact in size, but also has low insertion loss and sharp rejection. A demonstration filter is optimally designed and fabricated. Theoretical and experimental results are presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 505–506, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20185
Improvement in breast lesion characterization with dynamic contrast‐enhanced MRI using pharmacokinetic modeling and bookend T1 measurements
Authors: Cron Greg O. , Kelcz Frederick , Santyr Giles E. 
Published: April 2004

AbstractDynamic contrast‐enhanced breast MR imaging was performed on 14 patients (five cancerous lesions, nine benign) with slice‐selective spoiled gradient‐recalled echo (2D SPGR) imaging. Adiabatic saturation recovery T1 measurements were performed before (T1pre) and after (T1post) 2D SPGR imaging. These two “bookend” T1 measurements were used to calibrate the equations which were employed to convert the time course of the 2D SPGR signal strength to T1‐vs.‐time, which in turn was used to compute the gadolinium concentration‐vs.‐time ([C](t)) in the lesion. The extraction‐flow product (EF) was computed for each lesion by pharmacokinetic modeling of [C](t). For this study, EF provided a sensitivity and specificity for cancer of 100% and 78%, respectively. When only T1pre was used to estimate [C](t) (which assumes a priori knowledge of the shape and amplitude of the slice profile), the sensitivity and specificity fell to 80% and 56%, respectively. This is presumably due to unexpected variations in the shape and/or amplitude of the slice profile, which could be caused by factors such as patient‐to‐patient variations in breast geometry or inconsistently set transmit gains. Therefore, both T1pre and T1post measurements are necessary for optimum sensitivity and specificity using pharmacokinetic analysis. Magn Reson Med 51:1066–1070, 2004. © 2004 Wiley‐Liss, Inc.
Effects of, and corrections for, cross‐term interactions in q‐space MRI
Authors: Brihuega‐Moreno Oscar , Heese Frank P. , Tejos Cristián , Hall Laurance D. 
Published: April 2004

AbstractThe present study assesses the effects of cross‐term interactions between diffusion and imaging gradients in magnetic resonance imaging q‐space analysis, and corrects for those effects for both spin echo and stimulated echo diffusion‐weighted sequences. These corrections are demonstrated experimentally in unrestricted media for water and theoretically by simulating the case of restricted diffusion in a sphere. By correcting for the cross‐term interactions, large imaging gradients can be used without compromising the results. Ignoring cross‐term interactions could lead to a misunderstanding of the q‐space analysis; for instance, the microstructural size of the sample could be overestimated, or isotropic media could be misinterpreted as being anisotropic. Magn Reson Med 51:1048–1054, 2004. © 2004 Wiley‐Liss, Inc.
Analysis of multiple‐acquisition SSFP
Authors: Bangerter Neal K. , Hargreaves Brian A. , Vasanawala Shreyas S. , Pauly John M. , Gold Garry E. , Nishimura Dwight G. 
Published: April 2004

AbstractRefocused steady‐state free precession (SSFP) is limited by its high sensitivity to local field variation, particularly at high field strengths or the long repetition times (TRs) necessary for high resolution. Several methods have been proposed to reduce SSFP banding artifact by combining multiple phase‐cycled SSFP acquisitions, each differing in how individual signal magnitudes and phases are combined. These include maximum‐intensity SSFP (MI‐SSFP) and complex‐sum SSFP (CS‐SSFP). The reduction in SSFP banding is accompanied by a loss in signal‐to‐noise ratio (SNR) efficiency. In this work a general framework for analyzing banding artifact reduction, contrast, and SNR of any multiple‐acquisition SSFP combination method is presented. A new sum‐of‐squares method is proposed, and a comparison is performed between each of the combination schemes. The sum‐of‐squares SSFP technique (SOS‐SSFP) delivers both robust banding artifact reduction and higher SNR efficiency than other multiple‐acquisition techniques, while preserving SSFP contrast. Magn Reson Med 51:1038–1047, 2004. © 2004 Wiley‐Liss, Inc.
Estimation of the differential pressure at renal artery stenoses
Authors: Yim Peter J. , Cebral Juan R. , Weaver Ashley , Lutz Robert J. , Soto Orlando , Vasbinder G. Boudewijn C. , Ho Vincent B. , Choyke Peter L. 
Published: April 2004

AbstractAtherosclerotic disease of the renal artery can lead to reduction in arterial caliber and ultimately to conditions including renovascular hypertension. Renal artery stenosis is conventionally assessed, using angiography, according to the severity of the stenosis. However, the severity of a stenosis is not a reliable indicator of functional significance, or associated differential pressure, of a stenosis. A methodology is proposed for estimation of the renal artery differential pressure (RADP) from MR imaging. Realistic computational fluid dynamics (CFD) models are constructed from MR angiography (MRA) and phase‐contrast (PC) MR. The CFD model is constructed in a semiautomated manner from the MR images using the Isosurface Deformable Model (IDM) for surface reconstruction and a Marching Front algorithm for construction of the volumetric CFD mesh. Validation of RADP estimation was performed in a realistic physical flow‐through model. Under steady flow, the CFD estimate of the differential pressure across a stenosis in the physical flow‐through model differed by an average of 5.5 mmHg from transducer measurements of the pressure differential, for differential pressures less than 60 mmHg. These results demonstrate that accurate estimates of differential pressure at stenoses may be possible based only on structural and flow images. Magn Reson Med 51:969–977, 2004. Published 2004 Wiley‐Liss, Inc.
The effect of low‐temperature crystallization on the mechanical behavior of rubber
Authors: Fuller K.N.G. , Gough J. , Thomas A.G. 
Published: April 2004

AbstractIn cold climates the correct performance of rubber components such as seismic isolators depends on them maintaining their elastic properties when exposed to prolonged periods at low temperatures. The high damping compounds developed for seismic isolation are normally especially prone to crystallization when exposed to subzero temperatures for periods of a few weeks. The effect of low‐temperature crystallization on the mechanical stiffening of natural rubber is evaluated. The relationship between the shear modulus and amount of crystallization is measured using a technique in which the dimensional change and stiffness are monitored simultaneously. The relationship is found to be approximately independent of the crosslink density and the temperature of crystallization. It appears not to be realistically modeled by considering the crystals to behave as rigid filler particles but good qualitative agreement with experiment was obtained by modeling the crystals as a network of threads. Partially crystalline rubbers are found to yield under the application of a large stress like other partially crystalline polymers. Mechanisms for suppressing crystallization in rubber are discussed and the low‐temperature stiffening of specially formulated rubber compounds for seismic isolation is presented. These results show that carefully formulated high damping natural rubber compounds can give adequate performance at low temperatures. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2181–2190, 2004
Psychosocial problems among younger women with breast cancer
Authors: Avis Nancy E. , Crawford Sybil , Manuel Janeen 
Published: April 2004

AbstractWomen diagnosed with breast cancer at a younger age often have concerns less frequently faced by older women. A cross‐sectional survey of 204 women diagnosed with breast cancer at age 50 or younger within the past 3.5 years was conducted to examine issues particularly faced by younger women. The questionnaire included standardized measures of problems related to breast cancer (CARES) and open‐ended questions asking women about their experiences. Concerns about premature menopause and pregnancy related issues, among those women for whom these issues were applicable, had the highest ratings as problems experienced by women since their diagnosis. Among all women, sexual functioning was a greater problem than lack of sexual interest, and body image was of moderate concern. Overall, relationships with partners were not a problem. In multivariate analyses, having a mastectomy was associated with greater problems with body image and interest in sex. Chemotherapy was associated with greater sexual dysfunction. Responses to open‐ended questions were particularly informative and reflected the diversity of responses women have to breast cancer. Findings reinforce the need to develop interventions to help women deal with premature menopause and problems with sexual functioning following chemotherapy. Copyright © 2003 John Wiley & Sons, Ltd.
We are talking, but are they listening? Communication patterns in families with a history of breast/ovarian cancer (HBOC)
Authors: Kenen Regina , Arden‐Jones Audrey , Eeles Rosalind 
Published: April 2004

AbstractThis study explores how family communication patterns and family scripts influence the dissemination of genetic information and the sharing of feelings about genetic inheritance in families of healthy women who have attended a cancer genetics risk clinic because of their family history of breast and, or ovarian cancer. Family scripts are sets of expectations, beliefs, and norms that assign meaning to patterns of interaction, connect generations and provide guidance for action. We conducted an exploratory, qualitative study at a major clinical and research cancer center in the United Kingdom from January through June 2000 approved by the hospital clinical research and ethics committees. Twenty‐one semi‐structured, in‐depth interviews were conducted using a purposive sample of women coming to the cancer genetics risk clinic for the first time, supplemented by 5 months of participant observation. We identified several communication patterns: open and supportive; directly blocked, indirectly blocked, self‐censored and use of third parties. Some family members shared their feelings and discussed ways of trying to avoid developing breast or ovarian cancer; for others disseminating information or just talking about inherited susceptibility for breast and, or ovarian cancer fell into the script violation category; still others tried to renegotiate their family scripts. Copyright © 2003 John Wiley & Sons, Ltd.
Functional assessment of “in vivo” and “in silico” mutations in the guanine binding site of RNase T1: A DFT study
Authors: Mignon Pierre , Loverix Stefan , Steyaert Jan , Geerlings Paul 
Published: April 2004

AbstractExperimentally, the functional assessment of amino acid side chains in proteins is carried out by comparing parameters such as binding constants for the wild‐type protein and a mutant protein in which the considered side chain is deleted. In the present study, we apply a density functional theory (DFT) methodology to obtain changes in binding energy upon mutations in the enzyme ribonuclease T1. Mutant structures were either taken directly from crystallographic data (“in vivo”) allowing for conformational changes upon mutation, or derived from the wild‐type (“in silico”). Excluding entropic contributions, the computed interaction energy changes upon mutation in vivo correlate qualitatively well with experimental binding free energy changes. In contrast, the in silico approach does not perform as well, especially for residues that contribute largely to binding. Subsequently, we assessed the applicability of the in vivo approach by analyzing the functional cooperativity between pairs of side chains. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Test of treatment effect in pre‐drug and post‐drug count data with zero‐inflation
Authors: Paul Sudhir. R. , Jiang Xing , Rai Shesh Nath , Balasooriya Uditha 
Published: April 2004

AbstractA procedure for testing for treatment effect in data similar to the data on premature ventricular contractions (PVC) is presented. We consider a zero‐inflated beta‐binomial model. Based on this model, we develop score tests to test for treatment effect in the data in which observations in the form of counts are recorded before and after applying a therapy. Results of a small simulation experiment, to study small sample behaviour of a score test and a likelihood ratio test, are reported and the PVC data are analysed. Both the score and the likelihood ratio tests show good level properties. Either the score tests or the likelihood ratio tests can be used for testing the presence of treatment effect. The score tests, however, may be preferable because they use estimates of the parameters only under the null hypothesis and in the important range π<0.5 power of the score test statistic S1 is slightly better than the likelihood ratio statistic LR1. Copyright © 2004 John Wiley & Sons, Ltd.
Determination of gold, platinum and uranium in South African ores by high‐energy XRF spectrometry
Authors: Robertson M. E. A. , Feather C. E. 
Published: April 2004

AbstractAn automated energy‐dispersive x‐ray fluorescence spectrometer, called the AZTEC, was developed for the non‐destructive determination of gold, platinum and uranium in Witwatersrand ores, by utilizing the high‐energy spectral regions of the K x‐ray lines of these elements. It provides a viable alternative to fire assay, and measures gold concentrations down to <1 ppm. About 100 g of pulverized sample are presented for analysis in a 20 mm diameter tube, and the fluorescent x‐rays are detected by an array of up to 12 high‐purity germanium detectors. Count‐rates of up to 106 counts per second per detector can be processed by the signal processing electronics. The AZTEC technique is a variant of the scattered radiation technique. Concentration is related to peak intensities corrected for background, matrix variations, density and line overlaps. Provided that the samples are finely pulverised, the AZTEC analyses compare well with those obtained by fire assay. Production instruments are being used mainly in the gold mining industry, where they have analysed over 107 samples to date. Copyright © 2004 John Wiley & Sons, Ltd.
Asymptotic analysis of the Riemann problem for constant coefficient hyperbolic systems with relaxation
Authors: Hittinger J.A.F. , Roe P.L. 
Published: April 2004

AbstractThe discontinuous Riemann initial value problem is considered for dissipative, constant coefficient hyperbolic systems with relaxation source terms. A short‐time asymptotic expansion, a specialization of the results of Le Floch and Raviart [11], is constructed for the general linear system. Exact rates for the decay of the initial discontinuities are found to be in agreement with recent results from other approaches. A multiple scales analysis is used to identify the long‐time asymptotic behavior. Many of the results can be exemplified in a simple model problem for which the exact solution can be found.
Duration-constrained regular expressions
Authors: Xuandong Li , Jianhua Zhao , Tao Zheng , Yong Li , Guoliang Zheng 
Published: April 2004

Abstract.

This paper investigates the logic-automata-connection for Duration Calculus. It has been frequently observed that Duration Calculus with linear duration terms comes close to being a logic of linear hybrid automata. We attempt to make this relation precise by constructing Kleene-connection between
duration-constrained regular expressions
and a subclass of linear hybrid automata called
loop-reset automata
in which any variable tested in a loop is reset in the same loop. The formalism of duration-constrained regular expressions is an extension of regular expressions with duration constraints, which are essentially formulas of Duration Calculus without negation, yet extended by a Kleene-star operator. In this paper, we show that this formalism is equivalent in expressive power to loop-reset automata by providing a translation procedure from expressions to automata and vice verse.