bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calculation of self‐impedance and radiation efficiency of a dipole near a lossy cylinder with arbitrary cross section by using the moment method and a spectrum of two‐dimensional solutions
Authors: Yang Jian , Carlsson Jan , Kildal Per‐Simon , Carlsson Charlie 
Published: September 2002

AbstractWe present a computation method for the self‐impedance and radiation efficiency of a dipole near a lossy dielectric cylinder with arbitrary cross section by using a spectrum of two‐dimensional (2‐D) solutions. The 2‐D solutions for the spectral Green's functions of the cylinder as well as the 3‐D solution for the current on the dipole are found by the method of moments (MoM). The 2‐D MoM approach makes use of the algorithm G2DMULT (Green's function of 2‐D multiregion structures). The geometry of a dipole near a lossy circular dielectric cylinder is, in a parallel work, used to validate a reverberation chamber for measuring the radiation efficiency and self‐impedance of small antennas. Therefore, the results in the present paper could be verified against results from other numerical programs and from measurements in both an anechoic chamber and a reverberation chamber. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 108–112, 2002.
Measurement of free‐space impedances of small antennas in reverberation chambers
Authors: Kildal Per‐Simon , Carlsson Charlie , Yang Jian 
Published: September 2002

AbstractWe have recently shown that reverberation chambers can be used to measure the radiation efficiency of antennas for wireless and mobile terminals. In the present paper, we show that it is possible, in the same measurement setup, to measure the input impedance of the antenna as would be seen when the antenna radiates in free space. If the antenna is located close to, e.g., a head phantom inside the chamber, we will measure the impedance of the antenna as it would be seen if the dipole and the phantom were located in free space with the same location and orientation relative to each other. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 112–115, 2002.
A general computer simulation method for a 3‐D received signal level in wideband mobile communications
Authors: Zhao Xiongwen , Rekanos Ioannis T. , Vainikainen Pertti 
Published: September 2002

AbstractA wideband 3‐D received signal level has been simulated by assuming that the multipath number follows a Poisson distribution, the amplitudes follow either Rayleigh or Rice distributions, and the excess delay and the angle of arrival in the elevation plane follow exponential and Gaussian distributions, respectively. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 119–122, 2002.
Inside–outside lift power‐level statistics at universal mobile telecommunications system (UMTS) frequency
Authors: Vázquez Alejos Ana , Cuiñas Iñigo , García Sánchez Manuel 
Published: September 2002

AbstractThe use of mobile phones is being extended everywhere. Typical studies of indoor and outdoor propagation have to be improved with information related to specific places, like tunnels, basements, or lifts. In this paper, the variations in the power level within lift cabins, due to vertical movement and opening doors, are analyzed. Measurements have been made, and a statistic evaluation of these effects are presented. Results show that variations in power level are very strong during the movement of the cabin. Moreover, the effect of the mechanisms that open and close the doors is clearly highlighted in the measurements, where fast variations can be observed in the power level, even in static locations of the cabin. The presented results can be applied in network planning in places where mobile communications are often used in lifts, such as business buildings. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 122–124, 2002.
Analysis and design of a dual‐port compact microstrip antenna
Authors: Paulson Manju , Kundukulam Sona O. , Aanandan C. K. , Mohanan P. 
Published: September 2002

AbstractA dual‐port dual‐polarized compact microstrip antenna for avoiding cross coupling between the two frequency bands is proposed and analyzed. This antenna offers channel isolation better than 25 dB, and is more compact compared to a conventional rectangular patch. Analytical equations for calculating the resonant frequencies at both ports are also presented. The theoretical calculations are verified using experimental results. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 125–127, 2002.
An analytical study of the power distribution patterns of silica waveguides with high parabolic cylindrical deformation
Authors: Choudhury P. K. , Lessard Roger A. 
Published: September 2002

AbstractAn attempt is made to determine the relative power distribution in a step‐index parabolic cylindrical waveguide (PCW) with high deformation across the direction of propagation. The guide is assumed to be made of silica. The scalar field approximation is employed for the analysis under which a vanishing refractive‐index (RI) difference in the waveguide materials is considered. Further, no approximation for fields is used in the analytical treatment. Due to the geometry of such waveguides, PCWs lose the well‐defined modal discreteness, and a kind of mode bunching is observed instead, which becomes much more prominent in PCWs with high bends. However, with the increase in cross‐sectional size, the mode‐bunching tendency is slightly reduced. The general expressions for power in the guiding and nonguiding sections are obtained, and the fractional power patterns in all of the sections are presented for PCWs of various cross‐sectional dimensions. It is observed that the confinement of power in the core section is increased for PCWs of larger cross‐sectional size. Moreover, a fairly uniform distribution of power is seen over the modes having intermediate values of propagation constants. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 127–133, 2002.
Aluminum planar antennas circularly polarized on a glass substrate
Authors: Bourry M. , Drissi M. 
Published: September 2002

AbstractThe performances of an elliptical planar antenna that is circularly polarized are investigated. The proposed antenna is printed by CVD of aluminum on a glass substrate that is less used in microwave frequencies. A progressive design approach of the antenna is proposed, showing the influence of the geometrical design on the radio‐frequency performances. The measured characteristics in near and far fields of the optimized antenna are compared to the EM simulations, and the effect of a dielectric protection cover layer which is presented as a possible alternative to improve the polarization quality of the antenna. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 133–136, 2002.
A novel fractal microstrip PBG structure
Authors: Fu Yun‐Qi , Yuan Nai‐Chang , Zhang Guo‐Hua 
Published: September 2002

AbstractA novel fractal microstrip PBG structure is proposed. It is realized by replacing the etched rectangular holes in a ground plane with a Sierpinski carpet. A dual‐stopband characteristic not related to harmonics is observed. Different numbers of iterations of Sierpinski carpet are studied experimentally. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 136–138, 2002.
Model for optically biased short‐channel GaAs MESFET
Authors: Bose Srikanta , Adarsh  , Gupta Ritesh , Gupta Mridula , Gupta R. S. 
Published: September 2002

AbstractAn analytical model for an optically biased nonself‐aligned short‐channel GaAs MESFET is developed by solving the two‐dimensional Poisson's equation using a Green's function technique to obtain an optical radiation‐dependent threshold‐voltage expression incorporating the drain‐induced barrier lowering (DIBL), an important short‐channel effect. The developed model, being analytical, can be suitably used for simulation purposes in monolithic microwave integrated circuits using an optically biased MESFET for high‐frequency optical communication systems. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 138–142, 2002.
Design of chiral planar integrated antennas with cover via the method of lines
Authors: Alù Andrea , Bilotti Filiberto , Vegni Lucio 
Published: September 2002

AbstractThe analysis of patch antennas loaded by general inhomogeneous and lossy chiral media is presented in this paper, implementing a new method‐of‐lines (MoL) procedure, which considers inhomogeneous planar structures loaded by any bi‐isotropic material. Presented results refer to the effect of a chiral cover on the resonance frequency of a simple squared‐patch structure. Design charts are presented to simply analyze the separate effects of cover thickness and chirality. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 143–145, 2002.
Microwave technique for detection, location, and sizing of buried objects
Authors: Achrait‐Furlan L. , Lasri T. , Mamouni A. 
Published: September 2002

AbstractThe detection, location, and sizing of immersed objects in a host medium are tasks of interest in many fields. One of the most suitable tools for the noninvasive measurements of buried objects is the use of microwaves. We propose in this paper a microwave method based on the knowledge of the reflection coefficient. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 145–149, 2002.
Beamwidth enhancement of a circularly polarized microstrip antenna mounted on a three‐dimensional ground structure
Authors: Tang Chia‐Luan , Chiou Jyh‐Ying , Wong Kin‐Lu 
Published: September 2002

AbstractBy mounting a regular circularly polarized microstrip antenna on a three‐dimensional (3‐D) square ground structure, beamwidth enhancement of the circular polarization (CP) radiation can be obtained. Experimental results show that, owing to the 3‐D square ground structure, the 3 dB beamwidth of the CP radiation can reach more than 110°, which is about 30° greater than that of a corresponding regular microstrip antenna. Details of the proposed 3‐D square ground structure are described, and the effects of various dimensions of the proposed square ground structure on the beamwidth enhancement of CP radiation are experimentally studied. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 149–153, 2002.
Statistical description of the RCS of 2‐D ship models on rough sea surfaces
Authors: Pino M. R. , Rodríguez J. L. , Obelleiro F. 
Published: September 2002

AbstractThe statistical analysis of the data obtained from a Monte Carlo simulation of the radar cross section (RCS) of 2‐D targets on ocean rough surfaces is presented. The numerical results of the RCS have been obtained using an accelerated version of the generalized forward–backward method, computing the RCS as a function of the incidence angle and wind speed for a large number of sea‐surface realizations. It has been observed that two different regions appear, depending on the incidence angle and the wind speed. The RCS for each of those regions can be modeled using different statistical distributions, as will be shown in the Results section. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 153–159, 2002.
Complex circuit model for RF inductors
Authors: Zhang Daming , Li E. P. 
Published: September 2002

AbstractIn this paper, a complex circuit model is introduced for an RF choke by considering the magnetic, dielectric, and eddy current effect in ferrite. By calculating the active power and reactive power in an RF inductor, the resistive components and capacitive, inductive components in the circuit model are extracted. The circuit model is useful to determine the total loss and loss components with different magnetization levels at different frequencies. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 159–162, 2002.
Analysis of elliptical waveguides by a meshless collocation method with the Wendland radial basis functions
Authors: Jiang Pei‐Lin , Li Shu‐Qing , Chan Chi Hou 
Published: September 2002

AbstractThe cutoff wavelengths of elliptical waveguides are calculated by using a meshless collocation method with the radial basis functions, which only needs point sampling, and no mesh discretization is performed. The field value at any point inside the waveguide can be obtained by interpolation using the Wendland radial basis functions, which have been proven effective in scattered data interpolation. The Hermite interpolation is used to give a more accurate approximation of the first‐order derivatives. The accuracy and robustness of the proposed method are validated by numerical examples. Due to the advantage that no special consideration of the contour is needed, the method can also be applied to waveguides with arbitrary cross sections. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 162–165, 2002.
Magnetic field dependence of proton spin‐lattice relaxation times
Authors: Korb Jean‐Pierre , Bryant Robert G. 
Published: September 2002

AbstractThe magnetic field dependence of the water‐proton spin‐lattice relaxation rate (1/T1) in tissues results from magnetic coupling to the protons of the rotationally immobilized components of the tissue. As a consequence, the magnetic field dependence of the water‐proton (1/T1) is a scaled report of the field dependence of the (1/T1) rate of the solid components of the tissue. The proton spin‐lattice relaxation rate may be represented generally as a power law: 1/T1ω = Aω−b, where b is usually found to be in the range of 0.5–0.8. We have shown that this power law may arise naturally from localized structural fluctuations along the backbone in biopolymers that modulate the proton dipole‐dipole couplings. The protons in a protein form a spin communication network described by a fractal dimension that is less than the Euclidean dimension. The model proposed accounts quantitatively for the proton spin‐lattice relaxation rates measured in immobilized protein systems at different water contents, and provides a fundamental basis for understanding the parametric dependence of proton spin‐lattice relaxation rates in dynamically heterogeneous systems, such as tissues. Magn Reson Med 48:21–26, 2002. © 2002 Wiley‐Liss, Inc.
Phosphatidylinositol‐3‐OH kinase regulatory subunits are differentially expressed during development of the rat cerebellum
Authors: Trejo José L. , Pons Sebastián 
Published: September 2002

AbstractRecent evidence implicates a central role for PI3K signalling in mediating cell survival during the process of neuronal differentiation. Although PI3K activity is stimulated by a wide range of growth factors and cytokines in different cell lines and tissues, activation of this pathway by insulin‐like growth factor I (IGF‐I) most likely represents the main survival signal during neuronal differentiation. IGF‐I is highly expressed during development of the central nervous system, and thus is a critical factor for the development and maturation of the cerebellum. Upon ligand binding, the IGF‐I receptor phosphorylates tyrosine residues in SHC and insulin receptor substrates (IRSs) initiating two main signalling cascades, the MAP kinase and the phosphatidylinositol 3‐kinase (PI3K) pathways. Activated PI3K is composed of a catalytic subunit (p110α or β) associated with one of a large family of regulatory subunits (p85α, p85β, p55γ, p55α, and p50α). To evaluate the contributions of these various regulatory subunits to neuronal differentiation, we have used antibodies specific for each of the PI3K subunits. Using these antisera, we now demonstrate that PI3K subunits are differentially regulated in cerebellar development, and that the expression level of the p55γ regulatory subunit reaches a maximum during postnatal development, decreasing thereafter to low levels in the adult cerebellum. Furthermore, our studies reveal that the distribution of the various PI3K regulatory subunits varies during development of the cerebellum. Interestingly, p55γ is expressed in both glial and neuronal cells; moreover, in Purkinje neurones, this subunit colocalises with the IGF‐IR. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 39–50, 2001
Beyond risk seeking and risk aversion: personality and the dual nature of economic risk taking
Authors: Zaleskiewicz Tomasz 
Published: September 2002

In economic theories it is assumed that risk aversion is a typical human attitude toward risk, and differences are determined by the curvature of the utility function. The results of psychological studies have indicated, however, that people differ in how they make financial decisions under uncertainty and what motivates them to take economic risks. This paper introduces two kinds of risk taking, instrumental risk taking and stimulating risk taking, and reports their empirical examination in two studies. The purpose of these studies was to test the reliability and validity of the Stimulating–Instrumental Risk Inventory—a method used to measure the two risk taking tendencies. It was found that instrumental risk taking is related to risk preference in the investment domain and is determined by personality traits connected with orientation toward the future, the tendency to think rationally, impulsivity, and sensation seeking. Stimulating risk taking was found to be related to the preference for recreational, ethical, health, and gambling risks and was associated with personality features connected with paratelic orientation, arousal seeking, impulsivity, and strong sensation seeking. Copyright © 2001 John Wiley & Sons, Ltd.
Effects of inhaled gentamicin prophylaxis on acquisition of Pseudomonas aeruginosa in children with cystic fibrosis: A pilot study*
Authors: Heinzl Bernd , Eber Ernst , Oberwaldner Béatrice , Haas Gertrude , Zach Maximilian S. 
Published: September 2002

AbstractInhaled antibiotics are an established treatment for chronic Pseudomonas aeruginosa (PA) infection in patients with cystic fibrosis (CF). However, inhaled antibiotics might also have prophylactic potential to delay acquisition of PA in early stages of the disease. From 1986–1999, all CF patients at this center who experienced defined risk situations for acquisition of PA (28 patients) received inhaled gentamicin (80 mg BID for those < 12 months; 120 mg BID for those > 12 months) for a minimum of 3 years.Twelve patients had repeated risk situations and continued this prophylaxis without interruption during the entire study period (group 1). In the remaining 16 patients, inhaled antibiotics were discontinued at various times for a variety of reasons (group 2). None of the patients in group 1, but 7 in group 2, became chronically infected with PA (P = 0.01). Lung function and chest X‐ray scores were significantly worse in those 7 infected patients, when compared to the noninfected ones in both groups.This suggests that long‐term‐prophylaxis with inhaled gentamicin can effectively delay acquisition of PA and decrease disease progression in children with CF. Pediatr Pulmonol. 2002; 33:32–37. © 2002 Wiley‐Liss, Inc.
Effects of partial liquid ventilation with FC‐77 on acute lung injury in newborn piglets
Authors: Jeng Mei‐Jy , Kou Yu Ru , Sheu Ching‐Chung , Hwang Betau 
Published: September 2002

AbstractPartial liquid ventilation (PLV) with various types of perfluorochemicals (PFC) has been shown to be beneficial in treating acute lung injury. FC‐77 is a type of PFC with relatively high vapor pressure and evaporative losses during PLV. This study tested the hypothesis that using FC‐77 for PLV with hourly replacement is effective in treating acute lung injury. Fifteen neonatal piglets were randomly and evenly divided into 3 study groups: 1) lavage‐induced lung injury followed by conventional mechanical ventilation (Lavage‐CMV); 2) lavage‐induced lung injury followed by PLV using FC‐77 with hourly replacement (11.2 ± 1.5 mL/kg/hr) (Lavage‐PLV); and 3) sham lavage injury followed by conventional mechanical ventilation (Control).Immediately after induction, repeated saline lavages induced acute lung injury characterized by decreases in dynamic lung compliance, arterial oxygen tension, and arterial pH, and increases in arterial CO2 tension and oxygenation index, whereas the sham lavage procedure failed to do so. During the 3‐hr period of CMV, these pulmonary and cardiovascular parameters remained stable in the Control group, but deteriorated in the Lavage‐CMV group. In contrast, after acute lung injury, low lung compliance, abnormal gas exchange, acidosis, and inadequate oxygenation significantly improved in the Lavage‐PLV group. Histological analysis of these 3 study groups revealed that the Lavage‐CMV group had the highest lung injury score and the Control group had the lowest.These results suggest that, in comparison to CMV, PLV with FC‐77 and hourly replacement of FC‐77 promotes more favorable pulmonary mechanics, gas exchange, oxygenation, and lung histology in a piglet model of acute lung injury. Pediatr Pulmonol. 2002; 33:12–21. © 2002 Wiley‐Liss, Inc.
Aspiration: A factor in rapidly deteriorating bronchiolitis in previously healthy infants?
Authors: Hernandez Eduardo , Khoshoo Vikram , Thoppil Dipu , Edell Dean , Ross Gerald 
Published: September 2002

AbstractThe objective of this study was to evaluate the presence of indicators of aspiration in previously healthy infants with respiratory syncytial viral (RSV) bronchiolitis who experienced rapid deterioration in their respiratory status. Lipid‐laden macrophage index (LLMI) was assessed in 6 previously healthy infants with RSV bronchiolitis and no prior history of aspiration, who had a rapid deterioration of their respiratory status requiring mechanical ventilation. Five of 6 infants had a LLMI of more than 100, a level that is very suggestive of aspiration.We conclude that aspiration is likely to play a role when rapid deterioration occurs in infants with RSV bronchiolitis. Pediatr Pulmonol. 2002; 33:30–31. © 2002 Wiley‐Liss, Inc.
Evaluation of an asthma management program for Chinese children with mild‐to‐moderate asthma in Hong Kong
Authors: Hui Stephen H.L. , Leung Ting‐Fan , Ha Gladys , Wong Eric , Li Albert M. , Fok Tai‐Fai 
Published: September 2002

AbstractThere is inconclusive evidence on the efficacy of outpatient clinic‐based asthma management programs (AMP) in children. We hypothesized that an AMP based on key symptoms could improve outcome measures of asthma in Chinese children in Hong Kong. This study involved an outpatient clinic‐based prospective cohort of Chinese children with asthma. Each patient received one 2‐hr session of AMP which was conducted by a pediatric nurse specialist. Asthma outcomes were measured at baseline and at 6 and 12 months after completion of AMP. Demographic data, family history of allergic diseases, and changes in inhaled steroid therapy were also recorded.A total of 106 asthmatic children were enrolled, and they showed a significant decrease in nocturnal cough, wheezing attacks, and subjective assessment of severity at 6 and 12 months following participation in AMP, compared with their baseline status. Acute asthmatic attacks, unscheduled outpatient attendance, emergency room visits, school absenteeism, and number and duration of hospitalizations were also reduced during the follow‐up period. Significantly more (21%) children were reported to use inhaled beclomethasone at the end of the study. Nocturnal cough, wheeze, and symptoms due to rhinitis improved significantly after AMP.In conclusion, our cohort of Chinese children with mild‐to‐moderate asthma used significantly more inhaled corticosteroids and practiced more measures to control house dust mites at the end of the 1‐year treatment period. The main reason for better asthma control appeared to be related to the increased use of inhaled steroids, although some additional decrease in nocturnal cough, wheeze, and allergic rhinitis was found after adjusting for the use of inhaled corticosteroids. Pediatr Pulmonol. 2002; 33:22–29. © 2002 Wiley‐Liss, Inc.