bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of 15 dB directional coupler using substrate‐integrated waveguide technology
Authors: Mbaye Moustapha , Talbi Larbi , Hettak Khelifa , Kabiri Ali 
Published: February 2012

AbstractA 15‐dB directional coupler is designed and fabricated using the substrate‐integrated waveguide (SIW) technique and Bethe's holes method (BHM).The proposed design is a perfect candidate for design of highly integrated microwave and millimeter‐wave circuits. Three holes with optimized radius are positioned on the conducting wall to achieve the desired coupling operating at X‐band. A good agreement between experimental and simulation results is obtained. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:970–973, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26678
Two‐ and four‐channel‐incoherent multiple input multiple output system operating over multimode fiber
Authors: Siuzdak Jerzy , Kowalczyk Marcin 
Published: February 2012

AbstractThis article presents realization of two‐ and four‐channel‐incoherent multiple input multiple output systems operating over 4.4 km of 50‐μm core silica multimode fiber.The system featured 1/2QPSK modulation, 10 Mbit/s per channel, sampling of the received signals, and off‐line postprocessing. The quality of the received signals was acceptable only for 2 × 2 system, whereas for 4 × 4 system some channels experienced temporary fading. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:940–943, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26680
One‐piece, flat‐plate, coupled‐fed shorted monopole for 2.4‐GHz wireless local area network operation
Authors: Su Saou‐Wen 
Published: February 2012

AbstractA novel, one‐piece, coupled‐fed, short‐circuited monopole antenna for wireless local area network applications in the 2.4‐GHz (2400–2484 MHz) band is proposed. The monopole is in the shape of an inverted hook, short circuited to a small antenna ground of size 10 × 15 mm2 and capacitively excited by a driven coupling strip. The coupling strip is located in between the monopole and the ground by a tiny gap and grounded at one end. In this case, the antenna can be fabricated from a single metal plate at a low cost. The results showed that the antenna was very well matched with a return loss of 14 dB across the operating band and generated good dipole‐like, omnidirectional radiation patterns. Details of the design are discussed in this article. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:936–940, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26681
Experimental demonstration of nine double sideband OFDM‐UWB sub‐bands transmission along long‐reach PONs
Authors: Alves Tiago M. F. , Cartaxo Adolfo V.T. 
Published: February 2012

AbstractThe simultaneous distribution of nine double sideband orthogonal frequency division multiplexing ultra‐wideband signals along fiber lengths indicated for long‐reach passive optical networks is demonstrated experimentally. This is an efficient solution and an alternative to single sideband and chirped modulator approaches proposed to mitigate the dispersion‐induced power fading. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:995–999, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26686
A simple asymptotical model for analyzing wire antenna with different radius
Authors: Zhai Huiqing , Chen Qiang , Yuan Qiaowei , Sawaya Kunio , Li Long , Liang Changhong 
Published: February 2012

AbstractIn this research letter, a simple asymptotical model is present for analyzing wire antenna with different radius. Method of moments (MoM) based on sinusoidal basis function is used to give the analysis. In the process of using MoM for different radius, if we neglect the monopole along normal axis at the joint part, the different consideration of endpoint charges will make the final results different for conventional methods, and final results are also different with the results from HFSS and measurement results. In view of that, a simple asymptotical model is present to approximately deal with the joint part at the position of different radius. One advantage for the introduction of the present model is that the final results will be the same and independent of conventional methods. The other advantage is that the final results based on the present model have better agreement with HFSS and measurement results. Fabricated loop antennas with different radius are given as practical examples to show the advantages of the present model. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:960–964, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26689
Dipole model of rectangular patch antenna, application to self, and mutual impedance analysis
Authors: Kazemipour Alireza , Begaud Xavier , Jenu Mohd Zarar M. 
Published: February 2012

AbstractRectangular linear‐polarized patch antenna is modeled by two printed dipoles.This array of two parallel printed dipoles can be studied analytically to find the radiation characteristics of the patch antenna. Comparative results between measurement, numerical simulation, and analytical method are presented to show the performance of this new model. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1017–1019, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26706
Linearity improvement of 5.2‐GHz CMOS up‐conversion mixer for wireless applications
Authors: Murad S. A. Z. , Shahimin M. Mohamad , Pokharel R. K. , Kanaya H. , Yoshida K. 
Published: February 2012

AbstractThis letter presents linearity improvement up‐conversion mixer at 5.2 GHz for wireless applications. The design is based on Gilbert‐cell active double‐balanced mixer using derivative superposition method for linearity improvement. The design improvement is proposed in TSMC 0.18‐μm CMOS process. The linearity of the designed mixer is further improved using source degeneration inductors at transconductors stage. The measurement results indicate that the proposed method shows the third‐order intercept point (IIP3) of 13.5‐dBm, which is higher than previously published mixers. The mixer achieves the conversion gain of 2 dBm, and consumes 3.0 mA at 1.8 V power supply. The size of the whole chip is 0.56 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:923–925, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26711
Geometrically optimum ultra wide band 180° hybrids
Authors: Gurutzeaga Iñaki , Sedano Beatriz , Fabo Ane , Fernandez Sonia 
Published: February 2012

AbstractThis article presents two rat‐race 180° ring hybrid couplers that operate on ultra wide band at the frequency range of 3 to 10 GHz. All pass coplanar strip structure, based on one of the ten canonical coupled line circuits, is proposed for the λ/4 sections [1, 2], and two‐metal structure on suspended substrate [3] is used to improve the return‐losses of hybrid. Besides the two end‐shorted coupled lines for the 3λ/4 section, which is already known to broaden the narrowband behaviour of the traditional rat‐race ring [4], a three‐coupled lines structure [5] was studied as a design alternative. This hybrid could be used in a UWB low cost passive mixer with the advantage of maximizing the available space for the mixing devices and their associated circuitry, leaving free the internal area of the hybrid on the both sizes of the substrate. Consequently, the total size of the complete mixer is minimised and the compactness improved. The low coast approach is remarked by the use of standard FR‐4 laminate. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:909–915, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26718
Small size dual‐band rectangular dielectric resonator antenna based on calcium titanate (CaTiO3)
Authors: Oliveira E. E. C. , D'Assunção A. G. , Oliveira J.B. L. , Cabral A. M. 
Published: February 2012

AbstractA rectangular dielectric resonator antenna (DRA) based on CaTiO3 with low profile, dual‐band and high dielectric constant is proposed as a candidate for application in wireless communication systems at the microwave band. The proposed geometry is composed by a dielectric resonator mounted on a microstrip line section that is used as the feeding element. The antenna analysis is performed using Ansoft HFSS that implements the finite element method. Measured results are shown for several DRA prototypes. A good agreement between numerical and experimental results is observed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:976–979, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26729
Radiation efficiency enhancement using lumped inductors for dual‐mode mobile phone
Authors: Lee Seung‐Jun , Park Sung‐Won , Park Chul‐Woo , Kim Young‐Sik 
Published: February 2012

AbstractThis letter proposes a radiation efficiency enhancement technique using a lumped inductor for a dual‐mode mobile phone.Two planar inverted‐F antennas (PIFAs) with a collinear arrangement are used for dual‐mode operation at the CDMA band of 824–894 MHz and GSM band of 880–960 MHz. Each antenna is separately connected to a lumped inductor of 4.7 nH. The electric field is more confined on each inverted‐F section at its operating band in this configuration and the coupling between PIFAs is less than −10 dB. The simulated and measured results show that radiation efficiency of the proposed antenna is improved by up to 33%. The radiation patterns are similar to those of a dipole antenna with slightly tilted main beam directions due to the PIFA placement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1011–1013, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26735
Compact balanced bandpass filter using interdigital line resonator with high common‐mode noise suppression
Authors: Chen Jianzhong , Chen Jia 
Published: February 2012

AbstractA novel balanced microstrip bandpass filter (BPF) using compact interdigital line resonator (ILR) is proposed in this article. The presented balanced BPF has shown good common‐mode (CM) noise suppression, while the size is reduced. For design purposes, the differential‐mode (DM) and CM equivalent circuits of the ILR are given. The DM resonator has a smaller size compared to the conventional quarter‐ and half‐wave resonators. In addition, the CM resonant frequency is much higher than the DM resonator frequency in the ILR. Based on this property, the CM response can be strong suppressed over the DM operating frequency range. A fourth‐order balanced BPF with a size of 23 × 22.5 mm2 and 50 dB CM noise rejection within the passband is demonstrated and measured. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:918–920, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26737
Novel pressure sensor using a Hi‐Bi photonic crystal fiber FLM and ITS demodulation method
Authors: Zhaom Yong , Song Ting‐ting , Wang Qi 
Published: February 2012

AbstractTo eliminate the temperature influence on pressure sensor, high birefringence photonic crystal fiber is introduced to fiber loop mirror to sensing pressure.In the pressure 0∼1.5 Mpa range, pressure sensor with the sensitivity of 3.76 nm/Mpa is realized theoretically and experimental. Also, a novel demodulation method with the sensitivity of 6.67 dB/Mpa is proposed that changing the wavelength shift into power, which decreased the cost sharply. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:915–917, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26738
Identifying Patient‐Reported Outcomes in Rheumatoid Arthritis: The Impact of Foot Symptoms on Self‐Perceived Quality of Life
Authors: Otter S. J. , Lucas K. , Springett K. , Moore A. , Davies K. , Young A. , Walker‐Bone K. 
Published: February 2012

AbstractBackgroundThe importance of patient‐reported outcome measures in healthcare is increasingly recognized but these need to be patient generated. Given that foot symptoms are very common in rheumatoid arthritis (RA), we chose a patient‐centred model with which to investigate the patients' perspective on how their foot symptoms affected them as individuals and impacted on their self‐perceived quality of life, rather than using the traditional approaches of clinical examination (e.g. prevalence of deformities) or radiological assessments.MethodsA 33‐item self‐administered postal questionnaire was sent to all people with RA attending outpatient clinics in three hospitals over the course of one month (n = 390). The questionnaire used both quantitative and qualitative approaches to enquire about the nature and extent of foot complaints and how respondents believed this affected their quality of life.ResultsIn total, 190 usable replies were received (49%). Nearly all respondents (n = 177; 93.2%) reported that their quality of life was adversely affected by their foot complaint(s), with over half describing their quality of life as being badly or very badly affected. When asked to rate how severely foot complaints affected their quality of life using a 10 cm visual analogue scale, the mean score was 5.36 (range 0–10 ± SD 3), indicating that foot complaints have a moderate‐to‐severe effect on quality of life. Those aspects of daily living most significantly affected were: the ability to walk and the ability to wear a variety of shoes.ConclusionThis study demonstrated that people with RA focus on different aspects of the impact of their disease to doctors. Rather than foot deformity or ulceration, disease activity score or health assessment questionnaire score, patients were easily able to pinpoint the key negativities of living with RA in their feet and indicated choice of footwear and ability to walk as crucial. This study and similar ones are key to identifying appropriate patient‐reported outcome measures. Copyright © 2012 John Wiley & Sons, Ltd.
Multi‐pronged analysis of degradation rates of photovoltaic modules and arrays deployed in Florida
Authors: Davis K. O. , Kurtz S. R. , Jordan D. C. , Wohlgemuth J. H. , Sorloaica‐Hickman N. 
Published: February 2012

ABSTRACTThe long‐term performance and reliability of photovoltaic (PV) modules and systems are critical metrics for the economic viability of PV as a power source. In this study, the power degradation rates of two identical PV systems deployed in Florida are quantified using the Performance Ratio analytical technique and the translation of power output to an alternative reporting condition of 1000 W m−2 irradiance and cell temperature of 50 °C. We introduce a multi‐pronged strategy for quantifying the degradation rates of PV modules and arrays using archived data. This multi‐pronged approach utilizes nearby weather stations to validate and, if needed, correct suspect environmental data that can be a problem when sensor calibrations may have drifted. Recent field measurements, including I‐V curve measurements of the arrays, visual inspection, and infrared imaging, are then used to further investigate the performance of these systems. Finally, the degradation rates and calculated uncertainties are reported for both systems using the methods described previously. Copyright © 2012 John Wiley & Sons, Ltd.
Peer victimization and depression in children with and without motor coordination difficulties
Authors: Campbell Wenonah N. , Missiuna Cheryl , Vaillancourt Tracy 
Published: February 2012

AbstractDevelopmental coordination disorder (DCD) is a chronic disability that impacts children's performance of everyday motor‐based activities and is associated with the development of secondary social and mental health problems. The purpose of this study was to investigate peer victimization and depression in children who were and were not at risk for DCD. Selected from a population‐based sample, 159 at‐risk fifth graders were matched for age and gender to 159 controls. Children completed measures of depression and frequency of peer victimization. Results showed that children at risk for DCD reported more symptoms of depression and more frequent verbal and relational victimization than their peers. Being at risk for DCD and being bullied more frequently, especially relationally, significantly predicted increased depression symptoms. Findings highlight the importance of school psychologists remaining aware that children with DCD are at increased risk of experiencing bullying and depression. © 2012 Wiley Periodicals, Inc.
Field testing of visual odometry aided by a sun sensor and inclinometer
Authors: Lambert Andrew , Furgale Paul , Barfoot Timothy D. , Enright John 
Published: February 2012

AbstractIn this paper, we present a novel approach to planetary rover localization that incorporates sun sensor and inclinometer data directly into a stereo visual odometry pipeline. Utilizing the absolute orientation information provided by the sun sensor and inclinometer significantly reduces the error growth of the visual odometry path estimate. The measurements have very low computation, power, and mass requirements, providing localization improvement at nearly negligible cost. We describe the mathematical formulation of error terms for the stereo camera, sun sensor, and inclinometer measurements, as well as the bundle adjustment framework for determining the maximum likelihood vehicle transformation. Extensive results are presented from experimental trials utilizing data collected during a 10‐km traversal of a Mars analogue site on Devon Island in the Canadian high Arctic. We also illustrate how our approach can be used to reduce the computational burden of visual odometry for planetary exploration missions. © 2012 Wiley Periodicals, Inc.
Polymicrogyria in a fetus with human parvovirus B19 infection: a case with radiologic–pathologic correlation
Authors: Courtier J. , Schauer G. M. , Parer J. T. , Regenstein A. C. , Callen P. W. , Glenn O. A. 
Published: February 2012

AbstractWe report the prenatal magnetic resonance imaging (MRI) appearance of polymicrogyria with pathologic correlation in a fetus with congenital parvovirus B19 infection. Prenatal ultrasound revealed non‐immune hydrops, but detected no fetal brain abnormalities. A subsequent fetal MRI scan performed at 23 weeks' gestation demonstrated bilateral polymicrogyria, which was confirmed at autopsy. To our knowledge, prenatal diagnosis of polymicrogyria in association with congenital parvovirus B19 infection has not been previously described. This case provides further evidence for brain abnormalities resulting from congenital parvovirus B19 infection, and suggests that fetal neuroimaging with MRI would be of value in suspected cases of congenital parvovirus infection. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Aging and vision: changes in function and performance from optics to perception
Authors: Andersen George J. 
Published: February 2012

AbstractAge‐related declines in vision can have a major impact on the health and well‐being of an older population. A review of research on aging and vision indicates that these declines occur at multiple levels of the visual system including optics, sensory processing, and perceptual processing and are not likely due to a systemic change in brain function (e.g., generalized slowing; common cause hypothesis) as a result of normal aging. In addition, declines in sensory and perceptual processing are not due to low‐level explanations such as the amount of light that reaches the retina. Declines in visual performance are due to a variety of distinct factors that include spatial integration and difficulty in processing visual information in the presence of noise. Neurophysiological studies suggest that processing declines may be due in part to changes in cortical inhibition mediated by changes in the level of neurotransmitters associated with inhibition. Despite the widespread declines in function with normal aging, recent research suggests that perceptual learning can be used to dramatically improve visual function for older individuals. This research suggests a high degree of plasticity of the visual system among older populations and suggests that perceptual learning is an important tool for the recovery of age‐related declines in vision. WIREs Cogn Sci 2012, 3:403–410. doi: 10.1002/wcs.1167This article is categorized under:

Psychology > Perception and Psychophysics
Hemangioblast: an in vitro phantom
Authors: Nishikawa Shinichi 
Published: February 2012

AbstractThe hemangioblast, a bipotent progenitor that generates both endothelial cells (EC) and blood cells (BC) in the blood islands (BI) of the yolk sac (YS) has been a core notion of developmental hematology since the early 20th century. However, its actual presence has not been directly addressed for long. At the very end of the 20th century, the hemangioblast was revisited as a result of the development of new technologies that enable detection of such bipotent precursors in vitro. Such studies provided evidence for the presence of bipotent precursors for EC and BC. On the other hand, subsequent studies analyzing the processes occurring within BI strongly argued against the notion of hemanigioblasts and suggest that the hemangioblast is an in vitro artefact. In this article, I overview the history of the study of the hemangioblast and try to explain why hemangioblast that can be defined in vitro cannot be detected in BI. WIREs Dev Biol 2012, 1:603–608. doi: 10.1002/wdev.38This article is categorized under:

Gene Expression and Transcriptional Hierarchies > Cellular Differentiation
Nervous System Development > Vertebrates: Regional Development
Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches
Intraoperative Blood Transfusion Contributes to Decreased Long‐Term Survival of Patients With Esophageal Cancer
Authors: Komatsu Yoshihiro , Orita Hajime , Sakurada Mutsumi , Maekawa Hiroshi , Hoppo Toshitaka , Sato Koichi 
Published: February 2012

AbstractBackgroundSeveral prognostic factors for patients who have undergone esophagectomy owing to esophageal squamous cell carcinoma have been suggested, including intraoperative blood loss. There are few data, however, suggesting such an association with the prognosis following radical esophagectomy.MethodsPatients with esophageal squamous cell carcinoma who underwent radical esophagectomy were divided into two groups based on the median value of the intraoperative blood loss (510 g). A multivariate Cox proportional‐hazard regression analysis was performed to determine if intraoperative blood loss could be an independent prognostic factor for long‐term survival following radical esophagectomy. Kaplan–Meier survival analysis with a log‐rank test was performed between the groups.ResultsFrom April 2005 to May 2009, a total of 37 patients underwent radical esophagectomy for the treatment of esophageal squamous cell carcinoma at the Juntendo Shizuoka Hospital and were assigned either to one of two groups: those with ≥510 g blood loss [bleeding group (BG), n = 19] or of those with <510 g blood loss [less bleeding group (LBG), n = 18]. The distribution of the stage of disease, the number of positive lymph nodes, and the presence of lymphatic and vascular invasion was comparable between the groups, but the Kaplan–Meier survival analysis demonstrated that survival was significantly worse in the BG group than in the LBG group (p = 0.00295). This was supported by the multivariate analysis, which indicated that intraoperative blood loss was independently associated with long‐term survival after radical esophagectomy.ConclusionsIntraoperative blood loss could be a useful prognostic factor following radical esophagectomy in patients with esophageal squamous cell carcinoma.