bluuebunny/crossref_metadata_2025_split huggingface dataset:
Folded monopole LC‐loaded antenna and its polarization reconfigurability
Authors: Kim S. H. , Jang J. H. 
Published: March 2011

AbstractFolded monopole antenna loaded with the distributed inductors and capacitors is designed and characterized.The inductors and capacitor are realized by utilizing meanderline strips and the interdigitated structure, respectively. The resonance characteristics of the antenna are essentially determined by the uniquely arranged distributed elements, not by the length of the radiator, such that an electrically small structure can be realized. The designed antennas having a radiator length of 0.078 λ0 have good reflection characteristics and reasonable radiation gains of 0.29 dBi peak. The effect of the ground size on the resonant characteristics of the antennas is also investigated. Although the radiation characteristics are dependent upon the ground size, the variation of the resonance frequency was minimal. By utilizing the radiation characteristics depending upon the ground size of the folded monopole antenna with LC‐loadings, a polarization reconfigurable antenna can also be realized. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1197–1201, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25999
A dual‐resonant patch antenna for miniaturized active RFID tags
Authors: Wu Wei‐Jun , Yin Ying‐Zeng , Huang Yong , Wang Jie , Zhang Zhi‐Ya 
Published: March 2011

AbstractA dual‐resonant patch antenna applicable to active radio frequency identification (RFID) tags is designed. The designed antenna has been skillfully integrated with the active RFID tag circuit. The antenna consists of two parts. One part comprises stacked shorted patches and a ground plane. The other part is an active tag circuit mounted on the bottom of the antenna. The measurement results reveal that the antenna has the return loss less than –10 dB within the bandwidth of 42 MHz (from 911 to 953 MHz), which totally covers the 5 MHz bandwidth from 920 to 925 MHz (The band is also allowed for passive RFID) requirement for active RFID in China. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1280–1284, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26000
Eccentric core single‐mode fiber optical attenuator
Authors: Fan Linyong , Jiang Weiwei , Zhao Ruifeng , Pei Li , Jian Shuisheng 
Published: March 2011

AbstractAn all‐fiber optical attenuator is fabricated by splicing an eccentric core single‐mode fiber (ECSMF) between two single‐mode fibers (SMFs).The attenuation is mainly caused by the core offset between the ECSMF and the SMFs. Attenuators with different attenuations were fabricated. The device is simple, reliable, economical, and temperature independent. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1236–1238, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26003
Comparison of precorrected FFT/adaptive integral method matching schemes
Authors: Yang Kai , Yilmaz Ali E. 
Published: March 2011

AbstractThis article presents a detailed comparison of the moment, near‐field, and far‐field matching schemes that are used in precorrected FFT/adaptive integral method solvers to anterpolate currents (interpolate fields) on the nonuniform mesh of a structure of interest in terms of sources (observers) on an auxiliary regular grid. A general error measure is developed to evaluate the matching schemes in free space or layered media and for the high‐ or low‐frequency regime of operation. It is shown that moment matching is the most robust scheme, that far‐field matching is the most accurate scheme for high‐frequency regime but breaks down for low‐frequency regime, and that near‐field matching is more accurate than moment matching but requires the most preprocessing operations. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1368–1372, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26006
Modeling of compact microstrip resonator using neural network: Application to design of compact low‐pass filter with sharp cut‐off frequency
Authors: Hayati Mohsen , Lotfi Ali 
Published: March 2011

AbstractIn this article, S‐parameters of compact microstrip resonator cell are predicted using artificial neural network (ANN) to design class of elliptic function compact low‐pass filter with sharp cut‐off frequency. The ANN structure used in this work is multilayer perceptron (MLP) neural network. The data used for training the network is obtained using electromagnetic (EM) simulator. We compared measurement results and simulation results of filter by EM‐simulator and ANN. The results show accurate attenuation at cut off frequency. In comparison with EM‐simulator, simulation results by ANN have merits such as: mitigated consumption time, efficient performance and good accuracy. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1323–1328, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26008
High‐Q frequency shifting recirculating delay line bandpass photonic filter
Authors: Pulikkaseril C. , Chan E. H. W. , Minasian R.A. 
Published: March 2011

AbstractAn all‐optical photonic bandpass filter which achieves a very high‐Q performance while simultaneously exhibiting low noise operation, is presented. It can generate a large number of taps without the problem of lasing thus enabling the realisation of high‐resolution bandpass filtering. Experimental results for a photonic filter demonstrate a Q factor of 407, together with low noise and a stopband rejection of 50 dB. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1284–1286, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26011
Single probe‐fed circularly polarized patch antennas with U‐slots
Authors: Fong Lee Kai , Man Luk Kwai , Chi Mok Wing , Nayeri Payam 
Published: March 2011

AbstractDetailed studies were presented for two recent designs of single probe‐fed circularly polarized patch antennas with U‐slots. In one design, a square patch with truncated corners is used to generate circular polarization, while a symmetric U‐slot is etched on the patch to increase the usable bandwidth of the antenna. In the second design, both these functions are accomplished by means of an asymmetric U‐slot in a square patch. Previously published studies were on air substrate only. One of the purposes of this article is to extend the study of the two designs for material substrates. The second purpose is to compare the performances of the two designs. It was found that, for the same substrate thickness, both the bandwidth and the gain of the symmetric design are somewhat better than the asymmetric design. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1245–1253, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26012
Doubly miniaturized rat‐race hybrid coupler
Authors: Kurgan P. , Kitlinski M. 
Published: March 2011

AbstractTwo complementary miniaturization techniques have been applied to reduce the size of a rat‐race hybrid coupler: (i) conventional microstrip sections have been replaced with their diminished low‐impedance counterparts as the first step of size reduction and (ii) novel fractal‐shaped compact microstrip resonant cells dedicated to efficiently shorten low‐impedance transmission line segments have been implemented as the second step of circuit miniaturization.The experimental results are in excellent agreement with theoretical characteristics. Moreover, the application of the proposed complementary miniaturization methods enabled the achievement of ∼73% scale of size reduction, which illustrates the attractive possibilities of the approach. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1242–1244, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26013
Channel capacity study of polarization reconfigurable slot antenna for indoor MIMO system
Authors: Li Yue , Zhang Zhijun , Zheng Jianfeng , Feng Zhenghe 
Published: March 2011

AbstractThis article presents a polarization reconfigurable slot antenna with compact feed.Fed by dual modes of coplanar waveguide, a dual orthogonal linear polarization is excited in the slot and controlled by two PIN diodes. The proposed antenna has been built and its reflection coefficient, radiation pattern, gain were tested. The capacity performance in an indoor wireless local area network scenario was measured by using two proposed antennas as access point in a 2 × 2 multi‐input multi‐output system. The results show the advantage of polarization reconfigurable antennas in channel capacity, especially at the condition of non‐line‐of‐sight. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1209–1213, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26014
Electromagnetic modeling of massively coupled through silicon vias for 3D interconnects
Authors: Wu Boping , Gu Xiaoxiong , Tsang Leung , Ritter Mark B. 
Published: March 2011

AbstractThis article presents a full‐wave electromagnetic approach for analyzing the electrical performance of massively coupled through silicon vias (TSV). The TSVs are modeled with SiO2 insulation coating and are placed in the sandwiched SiO2‐Si‐SiO2 substrate. The planar guided wave is analyzed to determine the fundamental mode and high order modes in stratified media. Cylindrical wave expansions and Foldy–Lax equations for multiple scattering techniques are adapted to the TSV problems. The effect of SiO2 coating around the via is modeled by the general expression of T‐matrix coefficients. Both dispersive silicon loss and copper loss are included in this approach. Numerical simulation of a 4‐by‐4 TSV array is demonstrated to show the signal performance and crosstalk. It shows that the coupling issues among the TSVs will become significant beyond 15 GHz. The results are in excellent agreement with general purpose field solver. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1204–1206, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26021
Compact LTCC bandpass filter with vertically folded structure
Authors: Chin Kuo‐Sheng , Hung Jian‐Luen , Huang Chun‐Wei , Fu Jeffrey S. , Karmakar Nemai C. 
Published: March 2011

AbstractThis work designs miniaturized stub‐type microstrip bandpass filters and develops a novel vertical interconnection scheme in a multilayer structure to design vertically folded filters for size reduction. The current study exploits the fabrication process of low‐temperature cofired ceramic (LTCC) for filter realization and fabricates two LTCC Chebyshev stub‐type filters at 28 GHz and 5.8 GHz to verify effectiveness of the proposed structure with a maximum size reduction of 50%. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1389–1394, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26024
Experimental performance evaluation of multi‐echo ICNE pulse sequence in magnetic resonance electrical impedance tomography
Authors: Minhas Atul S. , Jeong Woo Chul , Kim Young Tae , Han Yeqing , Kim Hyung Joong , Woo Eung Je 
Published: March 2011

AbstractLatest experimental results in magnetic resonance electrical impedance tomography (MREIT) demonstrated high‐resolution in vivo conductivity imaging of animal and human subjects using imaging currents of 5 to 9 mA. Externally injected imaging currents induce magnetic flux density distributions, which are affected by a conductivity distribution. Since we extract the induced magnetic flux density images from MR phase images, it is essential to reduce noise in the phase images. In vivo human and disease model animal experiments require reduction of imaging current amplitudes and scan times. In this article, we investigate a multi‐echo based MREIT pulse sequence where we utilize a remaining time after the first echo within one TR to obtain more echo signals. It also allows us to prolong the total current injection time. From phantom and animal imaging experiments, we found that this method significantly reduces the noise level in measured magnetic flux density images. We describe experimental validation of the multi‐echo sequence by comparing its performance with a single‐echo method using 3 mA imaging currents. The proposed method will be advantageous for an imaging region with long T2 values such as the brain and knee. Depending on T2 values, we suggest using two or three echoes in future experimental studies. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Simulation and optimization of pulsed radio frequency irradiation scheme for chemical exchange saturation transfer (CEST) MRI—demonstration of pH‐weighted pulsed‐amide proton CEST MRI in an animal model of acute cerebral ischemia
Authors: Sun Phillip Zhe , Wang Enfeng , Cheung Jerry S. , Zhang Xiaoan , Benner Thomas , Sorensen A. Gregory 
Published: March 2011

AbstractChemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) is capable of measuring dilute labile protons and microenvironmental properties. However, the CEST contrast is dependent upon experimental conditions—particularly, the radiofrequency (RF) irradiation scheme. Although continuous‐wave RF irradiation has been used conventionally, the limited RF pulse duration or duty cycle of most clinical systems requires the use of pulsed RF irradiation. Here, the conventional numerical simulation is extended to describe pulsed‐CEST MRI contrast as a function of RF pulse parameters (i.e., RF pulse duration and flip angle) and labile proton properties (i.e., exchange rate and chemical shift). For diamagnetic CEST agents undergoing slow or intermediate chemical exchange, simulation shows a linear regression relationship between the optimal mean RF power of pulsed‐CEST MRI and continuous‐wave‐CEST MRI. The optimized pulsed‐CEST contrast is approximately equal to that of continuous‐wave‐CEST MRI for exchange rates less than 50 s−1, as confirmed experimentally using a multicompartment pH phantom. In the acute stroke animals, we showed that pulsed‐ and continuous‐wave‐amide proton CEST MRI demonstrated similar contrast. In summary, our study elucidated the RF irradiation dependence of pulsed‐CEST MRI contrast, providing useful insights to guide its experimental optimization and quantification. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
In vivo noninvasive 4D pressure difference mapping in the human aorta: Phantom comparison and application in healthy volunteers and patients
Authors: Bock Jelena , Frydrychowicz Alex , Lorenz Ramona , Hirtler Daniel , Barker Alex J. , Johnson Kevin M. , Arnold Raoul , Burkhardt Hans , Hennig Juergen , Markl Michael 
Published: March 2011

AbstractIn this work, we present a systematic phantom comparison and clinical application of noninvasive pressure difference mapping in the human aorta based on time‐resolved 3D phase contrast data. Relative pressure differences were calculated based on integration and iterative refinement of pressure gradients derived from MR‐based three‐directional velocity vector fields (flow‐sensitive 4D MRI with spatial/temporal resolution ∼ 2.1 mm3/40 ms) using the Navier‐Stokes equation. After in vitro study using a stenosis phantom, time‐resolved 3D pressure gradients were systematically evaluated in the thoracic aorta in a group of 12 healthy subjects and 6 patients after repair for aortic coarctation. Results from the phantom study showed good agreement with expected values and standard methods (Bernoulli). Data of healthy subjects showed good intersubject consistency and good agreement with the literature. In patients, pressure waveforms showed elevated peak values. Pressure gradients across the stenosis were compared with reference measurements from Doppler ultrasound. The MRI findings demonstrated a significant correlation (r = 0.96, P < 0.05) but moderate underestimation (14.7% ± 15.5%) compared with ultrasound when the maximum pressure difference for all possible paths connecting proximal and distal locations of the stenosis were used. This study demonstrates the potential of the applied approach to derive additional quantitative information such as pressure gradients from time‐resolved 3D phase contrast MRI. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Numerical modeling and neural networks to identify model parameters from piezocone tests: II. Multi‐parameter identification from piezocone data
Authors: Obrzud Rafał F. , Truty Andrzej , Vulliet Laurent 
Published: March 2011

SUMMARYThis paper completes the study presented in the accompanying paper, and demonstrates a numerical algorithm for parameter prediction from the piezocone test (CPTU) data. This part deals with a development of neural network (NN) models which are able to map multi‐variable input data onto typical geotechnical characteristics and constitutive parameters of the modified Cam clay model, which has been applied in this study. The identification procedure is designed for the coupled hydro‐mechanical boundary value problem in normally‐and lightly overconsolidated clayey soils including partially drained conditions that may appear during cone penetration. The NN models are trained with pseudo‐experimental measurements derived with the aid of the numerical model of the piezocone test, presented in the accompanying paper. Different input configurations containing CPTU measurements and some complementary data are studied with respect to the accuracy of predicted parameter values. Finally, the performance of the developed NN predictors is tested with field CPTU data which are derived from three well‐documented characterization sites, and the obtained predictions are compared with benchmark laboratory results. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of high performance, conductive PEDOT‐coated polyester yarns by OCVD technique
Authors: Bashir Tariq , Skrifvars Mikael , Persson Nils‐Krister 
Published: March 2011

AbstractProduction of high performance conductive textile yarn fibers for different electronic applications has become a prominent area of many research groups throughout the world. We have used oxidative chemical vapor deposition (OCVD) technique to coat flexible and high strength polyester yarns with conjugated polymer, poly(3,4‐ethylenedioxythiophene) (PEDOT) in presence of ferric (III) chloride (FeCl3) oxidant. OCVD is an efficient solvent free technique used to get uniform, thin, and highly conductive polymer layers on different substrates. In this paper, PEDOT‐coated polyester (PET) yarns were prepared under specific reaction conditions, and the electrical, mechanical and thermal properties were compared to previously studied PEDOT‐coated viscose yarns. Scanning electron microscopy (SEM) and FT‐IR analysis revealed that polymerization of PEDOT on the surface of the polyester yarns has been taken place successfully and structural analysis showed that PEDOT has strong interactions with viscose yarns as compared to PET yarns. The voltage–current (V–I) characteristics showed that PET yarns are more conductive than PEDOT‐coated viscose yarns. The variation in the conductivity of PEDOT‐coated yarns and the heat generation properties during the flow of current through coated yarns for longer period of time, was studied by time–current (t–I) characteristics. Thermogravimeteric analysis (TGA) was employed to investigate the thermal properties and the amount of PEDOT in PEDOT‐coated PET yarns compared to PEDOT‐coated viscose. The effect of PEDOT coating and ferric (III) chloride concentration on the mechanical properties of coated yarns was evaluated by tensile testing. The obtained PEDOT‐coated conductive polyester yarns could be used in smart clothing for medical and military applications. Copyright © 2011 John Wiley & Sons, Ltd.
Paradoxical effects of T‐cadherin on squamous cell carcinoma: up‐ and down‐regulation increase xenograft growth by distinct mechanisms
Authors: Pfaff Dennis , Philippova Maria , Kyriakakis Emmanouil , Maslova Kseniya , Rupp Katharina , Buechner Stanislaw A , Iezzi Giandomenica , Spagnoli Giulio C , Erne Paul , Resink Therese J 
Published: March 2011

AbstractMechanisms underlying cutaneous squamous cell carcinoma (SCC) tumour growth and invasion are incompletely understood. Our previous pathological and in vitro studies suggest that cell surface glycoprotein T‐cadherin (T‐cad) might be a controlling determinant of the behaviour of SCC. Here we used a murine xenograft model to determine whether T‐cad modulates SCC tumour progression in vivo. Silencing or up‐regulation of T‐cad in A431 (shTcad or Tcad+, respectively) both resulted in increased tumour expansion in vivo. To explain this unanticipated outcome, we focused on proliferation, apoptosis and angiogenesis/lymphangiogenesis, which are important determinants of the progression of solid tumours in vivo. shTcad exhibited enhanced proliferation potential in vitro and in vivo, and their signalling response to EGF was characterized by a higher Erk1/2:p38MAPK activity ratio, which has been correlated with more aggressive tumour growth. T‐cad over‐expression did not affect proliferation but staining for cleaved caspase 3 revealed a minimal occurrence of extensive apoptosis in Tcad+ tumours. Immunofluoresence staining of xenograft sections revealed increased intra‐tumoural total microvessel (CD31+) and lymphatic vessel (LYVE‐1+) densities in Tcad+ tumours. shTcad tumours exhibited decreased microvessel and lymphatic densities. Tcad+ expressed higher levels of transcripts for VEGF‐A, VEGF‐C and VEGF‐D in vitro and in vivo. Culture supernatants collected from Tcad+ enhanced sprout outgrowth from spheroids composed of either microvascular or lymphatic endothelial cells, and these in vitro angiogenic and lymphangiogenic responses were abrogated by inclusion of neutralizing VEGF antibodies. We conclude that T‐cad can exert pleiotropic effects on SCC progression; up‐ or down‐regulation of T‐cad can promote SCC tumour expansion in vivo but through distinct mechanisms, namely enhancement of angio/lymphangiogenic potential or enhancement of proliferation capacity. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.