bluuebunny/crossref_metadata_2025_split huggingface dataset:
Well‐posedness and approximation of solutions of linear divergence‐form elliptic problems on exterior regions
Authors: Auchmuty Giles , Han Qi 
Published: June 2014

AbstractThis paper describes well‐posedness, spectral representations, and approximations of solutions of uniformly elliptic, second‐order, divergence form elliptic boundary value problems on exterior regions U in when N ≥ 3. Inhomogeneous Dirichlet, Neumann, and Robin boundary conditions are treated. These problems are first shown to be well‐posed in the space E1(U) of finite‐energy functions on U using variational methods. Spectral representations of these solutions involving Steklov eigenfunctions and solutions subject to zero Dirichlet boundary conditions are described. Some approximation results for the A‐harmonic components are obtained. Positivity and comparison results for these solutions are given. Copyright © 2014 John Wiley & Sons, Ltd.
Optimal boundary control of hyperbolic equations with pointwise state and mixed control‐state constraints
Authors: Gao Peng 
Published: June 2014

AbstractThis paper is devoted to deal with optimal control problems of semilinear hyperbolic equations with pointwise state constraints and mixed control‐state constraints. We obtain necessary optimality conditions in the form of a Pontryagin's minimum principle. Our approach is based on modern methods of variational analysis. Copyright © 2014 John Wiley & Sons, Ltd.
Dual polarized microstrip patch antennas for ultra‐wideband applications
Authors: Kumar Pradeep , Masa‐Campos Jose Luis 
Published: June 2014

ABSTRACTThis article presents a novel design of dual polarized microstrip patch antennas for ultra‐wideband (UWB) applications. Two antennas are designed for different frequency band of UWB. Both antennas are loaded together and the combined antenna is designed for the entire UWB. The designed antenna is optimized using CST Microwave Studio simulator. The antennas are fed by a 50‐Ω coaxial probe. Both antennas are fabricated and measurement of return loss and radiation pattern is performed. The VSWR 2:1 bandwidth of individual designed Antenna I and Antenna II is 3.1–5.2 GHz and 4.9–11.5 GHz, respectively. The comparison between simulated results and measured results shows good agreement. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2174–2179, 2014
Comparative analysis of the electrical properties of a low noise oscillator embedded in a symmetrical square open‐loop with loaded stub resonator
Authors: Cho Sung‐Jin , Kim Nam‐Young 
Published: June 2014

ABSTRACTThe design of two types of miniaturized microstrip stub‐loaded square open‐loop resonators with asymmetrical feeder lines and their implementation into a microwave oscillator are presented in this article. The adopted resonator is based on a combination of electric and magnetic couplings in the central open gaps of the square loop resonators. The combined couplings generate an electromagnetic (EM) flux between the two square open‐loop resonators. The maximum coupling can be obtained by adjusting the open‐loop gap (the spacing between the two open‐loop resonators) and the orientation of the loaded‐stubs or T‐stubs inside the loop resonators. The asymmetrical port terminals also help couple EM energy by maintaining 50‐Ω impedance matching with the input/output devices. The improved high Q‐factor characteristics and the higher transmission zero result in high oscillator power and low phase noise characteristics. The square open‐loop with a loaded T‐stub resonator performance results are shown in a return loss of −24.8 dB, an insertion loss of −1.6 dB and a quality factor of 163 at 5.9 GHz C‐band application. In addition, careful design of the resonator resulted in an optimized oscillator. An oscillator with the proposed resonator shows good phase noise performance of −104.62 dBc/Hz at a 100 kHz offset from the carrier frequency of 6.2 GHz with an output power of 14.68 dBm. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2132–2136, 2014
A X/Ku dual‐band reflectarray design with cosecant squared shaped beam
Authors: Pan Yu , Zhang Yan (Rockee) , Yu Xining 
Published: June 2014

ABSTRACTA X/Ku dual‐band center‐fed microstrip reflectarray antenna with cosecant squared shaped beams has been developed. The circular reflectarray has a radius of 0.3 m and a flat aperture that emulates a cylindrical reflector antenna. The reflectarray is designed for two frequency bands: 10 GHz (X band) and 15 GHz (Ku band). Cross‐dipole elements and double‐ring elements are uniquely applied on a dual‐layer structure to achieve the desirable dual‐band operations. As the two operation frequency bands are close to each other, the coupling effects of the dual‐band reflectarray elements are investigated, and the unit cell design is optimized in simulations to suppress the interband interference. A phase‐only synthesis technique for cosecant squared patterns is also discussed and realized. For demonstration purpose, prototype antenna is fabricated and measured and the measured results are compared with the simulation results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2028–2034, 2014
An elliptically planar UWB monopole antenna with step slots defective ground structure
Authors: Hanapi Kausar M. , Abdul Rahim Sharul K. , Saad B.M. , Abdul Rani Mohd Subri , Abd Aziz Mohamad Zoinol 
Published: June 2014

ABSTRACTA novel ultrawideband (UWB) planar monopole antenna with step slots defective ground structure is presented in this article. The proposed microstrip‐based antenna is comprises of an elliptical shape radiating patch with 50‐Ω feed line. Eleven step slots have been used to implement defected ground plane which resulted to tremendous bandwidth increment. The proposed antenna is fabricated on an inexpensive FR4 substrate with overall dimension of 32.4 × 25.2 mm2. From the measured result, the proposed antenna covers 3.125–10.625 GHz, which is the UWB frequency range. Hence, the proposed antenna is suitable for UWB applications such as autonomous robot communication for disaster recovery, infostation systems communication, e‐ward round, and medical imaging communications. Moreover, the antenna is compact in size, low cost, easy to fabricate with nearly omnidirectional radiation pattern. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2084–2088, 2014
Suppression of cross‐polarization and mutual coupling between dual trace dual column coaxial microstrip array using dumbbell‐shaped resonator
Authors: Ghosh Chandan Kumar , Hazra R. , Biswas A. , Bhattachrjee A.K. , Parui S.K. 
Published: June 2014

ABSTRACTA compact two‐channel dual trace dual column (DTDC) printed microstrip antenna array integrated with dumbbell‐shaped resonator (DSR) is presented. The DSR has been integrated with DTDC array for the reduction of mutual coupling and suppression of cross‐polarization (XP) level at 5.2 GHz. In this work, an omnidirectional microstrip antenna array (OMAA) is designed with five elements and then two numbers of similar arrays have been used for multiple‐input multiple‐output (MIMO) application. A DSR placed in between two OMAA separated by 0.54λ suppressed 12 dB mutual coupling and 7.5 dB XP level. The mutual coupling has been studied by placing DSR on the upper trace first and then in the lower trace. The mutual coupling of 11 dB is reduced when DSR is placed on the upper trace and 12 dB when it is in the lower trace of the array structure. The DTDC antenna structure exhibits maximum XP suppression when DSR in the lower trace. The antenna with compact structure based on the design has a peak gain of 12.84 dBi and band width of 250 MHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2182–2186, 2014
Rectangular quasi‐self‐complementary antenna for wlan applications
Authors: Lin Chun‐Cheng , Huang Chih‐Yu , Chen Guan‐Han , Chiu Chung‐Hsiu 
Published: June 2014

ABSTRACTIn this study, a rectangular quasi‐self‐complementary antenna for wireless local area network (WLAN) applications is presented. The antenna is composed of a rectangular radiating patch fed by a 50‐Ω microstrip line, its complementary structure, and a rectangular parasitic element. With appropriately modifying the dimensions of the antenna, a conventional wideband self‐complementary antenna can be redesigned into a novel dual‐band antenna. This feature makes the proposed antenna exhibit two impedance bandwidths of 100 MHz (about 4.1% at 2.45 GHz) and 2690 MHz (about 48.9% at 5.5 GHz), respectively. The measured results also indicate a good dipole‐like radiating performance and respectable peak gain values of the proposed antenna. Details of the antenna design process and the experimental results are discussed. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2179–2182, 2014
A 26–47.9 GHz ultrawideband CMOS dual injection‐locked frequency divider
Authors: Liu Faen , Wang Zhigong , Li Zhiqun , Li Qin , Yang Geliang 
Published: June 2014

ABSTRACTA 26–47.9 GHz ultrawideband CMOS dual injection‐locked frequency divider (dual‐ILFD) with high input impedance is demonstrated. As the differential input signal is injected into the gate of the PMOS tail transistor and NMOS switch transistor, the proposed divider has high input impedance and can be driven easily by the preceding driving circuits. Meanwhile, the locking range of the proposed divider is extended significantly by fully utilizing the dual‐injection technique. The proposed dual‐ILFD is fabricated in a standard 90‐nm CMOS process and on‐wafer measurements are performed. The measurements show that the free‐running frequency of the divider is 19.11 GHz. At an incident power of 0 dBm, a total locking range from 26 to 47.9 GHz is achieved. The power consumption is 2.88 mW at a supply voltage of 1.2 V. The total chip size is 0.62 × 0.42 mm2. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2126–2129, 2014
A transistor array bank (TR bank) for a digitally controlled spin torque oscillator
Authors: Oh Inn‐Yeal , Park Seung‐Young , Park Chul‐Soon 
Published: June 2014

ABSTRACTA transistor array (TR) bank devised for operating a spin torque oscillator as the DCSO is first proposed. The TR bank supplies a minimum of 86% current per step of the targeted value at any condition and covers the 2.85‐GHz band fully with a 1 nA at the minimum code word step. Having driving capability up to 2.5 mA, the TR bank is operated from 0.6 to 1.4 mA at 1.7VDD. The spintronics oscillator size is as small as 0.014 µm2, excluding the TR bank of 0.23 mm2. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1991–1994, 2014
Generation of ultrawideband picosecond impulses with fast fall‐time
Authors: Nguyen Trang D. , Morimoto Akihiro 
Published: June 2014

ABSTRACTA method to generate ultrawideband picosecond impulses with fast fall‐time is presented. This impulse generator is based on a broadband bipolar transistor and a nonlinear transmission line comb generator. The transistor works in fast switch‐on mode and emits impulses with steep leading edges, which are further compressed by the comb generator. The experimental short impulses of 725 ps duration and 180 ps fall‐time were generated with output harmonic up to 10 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2165–2167, 2014
A compact transmission line with dual‐band filter characteristics using a CRLH metamaterial
Authors: Wang Yang , Yoon Ki‐Cheol , Lee Jong‐Chul 
Published: June 2014

ABSTRACTIn this article, a size‐reduced dual band‐pass transmission line (TL) with a composite right/left handed (CRLH) shunt‐stub is presented. It uses a T‐shaped quarter‐wavelength TL, which shows dual band‐pass characteristics, when the electrical length is +nλ/4 or −nλ/4, where n is odd integer. These wavelengths can be achieved at arbitrary frequencies by the CRLH‐TL with the property of a nonlinear β versus ω. The phase delay at the two operating frequencies can be adjusted by designing the series TL part, identical to the case of a conventional TL. The performance of this TL is demonstrated in both simulations and measurements, which show good agreement, exhibiting insertion losses of 0.32 and 0.98 dB at the two operating frequencies, respectively. Also, the phase response difference was determined to be 180° at these frequencies. The size of the proposed TL is 16 × 19 mm2. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2150–2153, 2014
In vivo proton T1 relaxation times of mouse myocardial metabolites at 9.4 T
Authors: Bakermans Adrianus J. , Abdurrachim Desiree , Geraedts Tom R. , Houten Sander M. , Nicolay Klaas , Prompers Jeanine J. 
Published: June 2014

PurposeProton magnetic resonance spectroscopy (1H‐MRS) for quantitative in vivo assessment of mouse myocardial metabolism requires accurate acquisition timing to minimize motion artifacts and corrections for T1‐dependent partial saturation effects. In this study, mouse myocardial water and metabolite T1 relaxation time constants were quantified.MethodsCardiac‐triggered and respiratory‐gated PRESS‐localized 1H‐MRS was employed at 9.4 T to acquire signal from a 4‐µL voxel in the septum of healthy mice (n = 10) while maintaining a steady state of magnetization using dummy scans during respiratory gates. Signal stability was assessed via standard deviations (SD) of zero‐order phases and amplitudes of water spectra. Saturation‐recovery experiments were performed to determine T1 values.ResultsPhase SD did not vary for different repetition times (TR), and was 13.1° ± 4.5°. Maximal amplitude SD was 14.2% ± 5.1% at TR = 500 ms. Myocardial T1 values (mean ± SD) were quantified for water (1.71 ± 0.25 s), taurine (2.18 ± 0.62 s), trimethylamine from choline‐containing compounds and carnitine (1.67 ± 0.25 s), creatine‐methyl (1.34 ± 0.19 s), triglyceride‐methylene (0.60 ± 0.15 s), and triglyceride‐methyl (0.90 ± 0.17 s) protons.ConclusionThis work provides in vivo quantifications of proton T1 values for mouse myocardial water and metabolites at 9.4 T. Magn Reson Med 73:2069–2074, 2015. © 2014 Wiley Periodicals, Inc.
A conformal decomposition finite element method for arbitrary discontinuities on moving interfaces
Authors: Kramer Richard M. J. , Noble David R. 
Published: June 2014

SUMMARYInterface capturing methods using enriched finite element formulations are well suited for solving multimaterial transport problems that contain weak or strong discontinuities. The conformal decomposition FEM decomposes multimaterial elements of a non‐conforming background mesh into sub‐elements that conform to material interfaces captured using a level set method. As the interface evolves, interfacial nodes move, and background nodes may change material. The present work describes approaches for handling moving interfaces in the context of the conformal decomposition FEM for both weakly and strongly discontinuous fields. Dynamic discretization methods using extrapolation and moving mesh approaches are considered and developed with first‐order and second‐order time integration methods. The moving mesh approach is demonstrated to be a stable method that preserves both weak and strong discontinuities on a variety of one‐dimensional and two‐dimensional test problems, while achieving the expected second‐order error convergence rate in space and time. Copyright © 2014 John Wiley & Sons, Ltd.
Mass scaling and stable time step estimates for isogeometric analysis
Authors: Hartmann Stefan , Benson David J. 
Published: June 2014

SummaryMetal stamping is one of the most cost effective manufacturing methods for producing precision parts. The precision of the parts is a function of the uniformity of the material used for the blank and the design of the dies. During the metal stamping process, the blank undergoes large, inelastic deformations, and once it is removed from the dies, springs back to a shape different from the die. This spring back must be accounted for in the design of the die, and its prediction is a major challenge in computational mechanics. Isogeometric analysis, which uses the same basis functions as the computer‐aided design programs used to design the shape of the part, is an attractive alternative to traditional finite element analysis for metal stamping. Mass scaling, and the underlying stable time step estimates, that are commonly used in metal stamping simulations are presented for isogeometric analysis. Example calculations are presented to demonstrate the effectiveness of isogeometric analysis in metal stamping. Copyright © 2014 John Wiley & Sons, Ltd.
White matter integrity in older females is altered by increased body fat
Authors: Ryan Lee , Walther Katrin 
Published: June 2014

ObjectiveTo assess whether the pattern of diffusion changes among a cohort of individuals showing BMI‐related increases in white matter volume reflects healthy expansion of myelin or damaged white matter.MethodsDiffusion MRI measures (axial, radial, and fractional anisotropy) were obtained from 94 females, aged 52‐92. Relationships between BMI and diffusion measures were assessed controlling for age, hypertension, and diabetes status using general linear modeling. Associations between diffusion measures and cognitive status (memory, executive functions, and visuomotor speed) were assessed using multiple regressions, controlling for age, education, hypertension, and diabetes status.ResultsHigher levels of BMI were associated with lower axial diffusion in frontal, temporal, parietal, internal capsule, and cerebellar white matter. Lower fractional anisotropy was observed in bilateral temporal white matter and the right corticospinal tract, with higher radial diffusion in temporal and temporoparietal white matter. Importantly, diffusion measures predicted reductions in executive functioning, memory, and visuomotor speed.ConclusionsThe pattern of diffusion changes in regions of white matter showing BMI‐related volume increases are not due to expansion of normal myelin, but instead suggests damage to white matter that has important consequences for cognitive functioning.
Meta‐ and cost‐effectiveness analysis of commercial weight loss strategies
Authors: Finkelstein Eric A. , Kruger Eliza 
Published: June 2014

ObjectiveTo estimate the incremental cost‐effectiveness of clinically proven nonsurgical commercial weight loss strategies for those with BMIs between 25 and 40.MethodsWe performed a systematic literature review to identify randomized controlled trials of commercially available weight loss studies of at least 1 year in duration. Using the results of these trials and publicly available cost data, we quantified the incremental cost per kilogram of weight loss and per quality adjusted life year (QALY) gained. We then use probabilistic sensitivity analyses to quantify uncertainty in our results.ResultsBased on the literature review, two lifestyle programs (Weight Watchers and Vtrim), one meal replacement program (Jenny Craig), and three pharmaceutical products (Qsymia, Lorcaserin, and Orlistat) were included in the analysis. Average cost per kilogram of weight lost ranged from $155 (95% CI: $110‐$218) for Weight Watchers to $546 (95% CI: $390‐$736) for Orlistat. The incremental cost per QALY gained for Weight Watchers and Qsymia was $34,630 and $54,130, respectively. All other interventions were prohibitively expensive or inferior in that weight loss could be achieved at a lower cost through one or a combination of the other strategies.ConclusionsResults suggest that, in the absence of other considerations and at current market prices, Weight Watchers and Qsymia represent the two most cost‐effective strategies for nonsurgical weight loss.
Pregnancy outcomes of prenatally diagnosed Turner syndrome: a French multicenter retrospective study including a series of 975 cases
Authors: Gruchy N. , Vialard F. , Blondeel E. , Le Meur N. , Joly‐Hélas G. , Chambon P. , Till M. , Herbaut‐Graux M. , Vigouroux‐Castera A. , Coussement A. , Lespinasse J. , Amblard F. , Jimenez M. , Lebel Roy Camille L. , Carré‐Pigeon F. , Flori E. , Mugneret F. , Jaillard S. , Yardin C. , Harbuz R. , Collonge Rame M. , Vago P. , Valduga M. , Leporrier N. 
Published: June 2014

ABSTRACTObjectivesThe objectives of this study were to report pregnancy outcomes after prenatal diagnosis of Turner syndrome (TS) and to compare and assess termination of pregnancy rates during two periods. The intervals selected were before and after 1997 when multidisciplinary centers for prenatal diagnosis (MCPDs) were established in France.MethodsA database of 975 cases of TS diagnosed between 1980 and 2012 was created from 21 French cytogenetics laboratories. For each case, the karyotype indication, maternal age, year of prenatal testing, sampling procedure, karyotype, associated ultrasound findings, and outcomes were recorded.ResultsKaryotypes were mainly performed because of abnormal sonographic findings (84%). Before 1997, there were no changes in the rate of termination (90%) of affected fetuses. After 1997, the rate fell to 80%. This decrease was mainly observed in cases of mosaicism, incidental diagnosis, and in later gestations. US abnormalities were more likely to be associated with a full 45,X karyotype.ConclusionThere was an evolution in the way genetic counseling was performed following prenatal diagnosis of Turner syndrome that coincided with the opening of MCPDs in France. This resulted in a decrease in the rate of termination of affected fetuses. © 2014 John Wiley & Sons, Ltd.
A data‐driven approach to modeling the tripartite structure of multidrug resistance efflux pumps
Authors: Phillips Joshua L. , Gnanakaran S. 
Published: June 2014

ABSTRACTMany bacterial pathogens are becoming increasingly resistant to antibiotic treatments, and a detailed understanding of the molecular basis of antibiotic resistance is critical for the development of next‐generation approaches for combating bacterial infections. Studies focusing on pathogens have revealed the profile of resistance in these organisms to be due primarily to the presence of multidrug resistance efflux pumps: tripartite protein complexes which span the periplasm bridging the inner and outer membranes of Gram‐negative bacteria. An atomic‐level resolution tripartite structure remains imperative to advancing our understanding of the molecular mechanisms of pump function using both theoretical and experimental approaches. We develop a fast and consistent method for constructing tripartite structures which leverages existing data‐driven models and provide molecular modeling approaches for constructing tripartite structures of multidrug resistance efflux pumps. Our modeling studies reveal that conformational changes in the inner membrane component responsible for drug translocation have limited impact on the conformations of the other pump components, and that two distinct models derived from conflicting experimental data are both consistent with all currently available measurements. Additionally, we investigate putative drug translocation pathways via geometric simulations based on the available crystal structures of the inner membrane pump component, AcrB, bound to two drugs which occupy distinct binding sites: doxorubicin and linezolid. These simulations suggest that smaller drugs may enter the pump through a channel from the cytoplasmic leaflet of the inner membrane, while both smaller and larger drug molecules may enter through a vestibule accessible from the periplasm. Proteins 2015; 83:46–65. © 2014 Wiley Periodicals, Inc.