bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of the work environment and safety activities on occupational accidents in eight wood‐processing companies
Authors: Varonen Unto , Mattila Markku
Published: September 2002

The study was conducted at 16 wood‐processing companies in southern Finland. The companies involved were selected according to the following criteria: (a) 8 companies were to have an accident rate that was clearly below the average rate for the wood‐processing industry in the period 1985–1989, and 8 companies a rate clearly higher than the average; and (b) the companies were to form pairs engaged in the same type of activity and exhibiting different rates.

Companies were divided into 2 groups. Two sawmills, 1 parquet, and 1 plywood factory with a low accident rate and 4 similar factories with a high rate were selected as “experiment companies” and received advice aimed at improving their work environment and safety activities. Eight similar companies were selected as a control group and received no advice. This study attempted to ascertain the effects of such advice on the work environment, safety activities, and occupational accidents. In addition, differences in the safety of the work environment, in safety activities, and in occupational accidents were studied in companies with a low accident rate as compared with the situation in companies with a high rate.

Work environment and safety activities showed a statistically significant correlation with accident rate. The better the situation, the lower the accident rate. In the companies with a low accident rate, the work environment and safety activities were also better than in the companies with a high rate.

In the period 1989–1994, the drop in the accident rate at the experiment companies was greater—to a statistically significant extent—than it was in the control group or in the wood‐processing industry as a whole. In cases where advice was given to the experiment companies with the aim of preventing particular occupational accidents, the rate of such accidents declined; there was no such trend in the control companies. By contrast, trends for other types of accidents were similar in the experiment and control companies. Changes in the accident rates of the experiment or control companies could not be explained by economic cycles or by changes either in the employees' work experience or in the duration of absences.

It is highly probable that the positive trend with regard to occupational accidents in the experiment companies was related to improvement in the work environment and safety activities and that this in turn was a result of the advice given to these companies in 1990. © 2002 John Wiley & Sons, Inc.
A comparative simulation study of work processes in autonomous production cells
Authors: Schlick Christopher , Reuth Ralph , Luczak Holger
Published: September 2002

An approach to human‐centered design and assessment of work processes in flexible manufacturing systems with the help of dynamic task networks is presented. To model and simulate the task networks, the method of timed colored Petri Nets is used. Two task networks are developed. The first task network is a model of work processes in Autonomous Production Cells (APCs). The second task network represents work processes in conventional Computer Numerically Controlled (CNC)‐based manufacturing systems. The material processing technology is associated with 5‐axis milling. The values of attributes of task elements were acquired empirically on a fine‐grained level with reference to a sample milling order. Comparative hypotheses regarding time‐on‐task, supervisory control functions, levels of cognitive control, human error (HE), and labor division were then formulated. To test these hypotheses, several simulation experiments were conducted. The results from inferential statistics show that single‐operator APCs have a 30% higher efficiency in relation to total time‐on‐task. Moreover, the level of cognitive control is significantly shifted toward rule‐ and knowledge‐based behavior. Surprisingly, the simulation of minor HE does not demonstrate a significantly worse performance from APCs. A simulated labor division among central process planner and production operator allows an additional efficiency improvement of approximately 15%. However, the labor division has two important drawbacks: first, a sequential incompleteness of operators' task spectrum occurs; second, the operator has to cope with hierarchical task incompleteness. Finally, a sensitivity analysis was carried out to investigate the effects of varying lot sizes and number of processed orders. © 2002 John Wiley & Sons, Inc.
The role of human factors in flexibility management: A survey
Authors: Kara Sami , Kayis Berman , O'Kane Shaun
Published: September 2002

Flexibility can be defined as the ability to respond effectively to the ever‐changing and increasing needs of the customer. For this demand to be satisfied, flexibility should be built into the total chain of acquisition, processing, and distribution stages. As a result, there is an increasing interest in flexibility and flexibility enabling mechanisms/parameters to achieve the best strategy for obtaining the right and desired output. Although quite a number of flexibility definitions and mechanisms can be found in the literature, flexibility remains poorly understood and utilized in practice. That is due to the lack of standardization in the terminology about the flexibility definitions and mechanisms.

This article presents the finding of an extensive literature survey to determine the Intra flexibility mechanisms/parameters. These mechanisms/parameters are then classified, according to their contribution to the supply chain stages and their interaction with Inter Flexibility mechanisms (e.g., Organizational structure flexibility, Technology flexibility, Information system flexibility, and Human resource flexibility). In addition, the crucial role of human factors and its relationship with flexibility mechanisms are investigated, and related flexibility mechanisms are identified. © 2002 John Wiley & Sons, Inc.
Work‐related learning as a core value: An Iowa perspective
Authors: Westbrook Thomas S. , Veale James R.
Published: September 2002

This research explored the amount of time that 1,031 full‐time workers in Iowa spent on work‐related learning, their attitudes about the amount of time spent, and the organizational and cultural aspects that enhanced or deterred their learning. Results showed that there is a disconnect between the emphasis on continuous learning in the human resource development literature and individual and organizational practices that advance learning as a core value.
Erodibility of cohesive streambeds in the loess area of the midwestern USA
Authors: Hanson G. J. , Simon A.
Published: September 2002

Excess stress parameters, critical shear stress (τc) and erodibility coefficient (kd), for degrading channels in the loess areas of the midwestern USA are presented based on in situ jet‐testing measurements. Critical shear stress and kd are used to define the erosion resistance of the streambed. The jet‐testing apparatus applies hydraulic stresses to the bed and the resulting scour due to the impinging jet is related to the excess stress parameters. Streams tested were primarily silt‐bedded in texture with low densities, which is typical of loess soils. Results indicate that there is a wide variation in the erosion resistance of streambeds, spanning six orders of magnitude for τc and four orders of magnitude for kd. Erosion resistance was observed to vary within a streambed, from streambed to streambed, and from region to region. An example of the diversity of materials within a river system is the Yalobusha River Basin in Mississippi. The median value of τc for the two primary bed materials, Naheola and Porters Creek Clay Formations, was 1·31 and 256 Pa, respectively. Streambeds composed of the Naheola Formation are readily eroded over the entire range of shear stresses, whereas only the deepest flows generate boundary stresses great enough to erode streambeds composed of the Porters Creek Clay Formation. Therefore, assessing material resistance and location is essential in classifying and modelling streambed erosion processes of these streams.
Expression and mutation analysis of the Wilms' tumor 1 gene in human neural tumors
Authors: Dennis Sally L. , Manji Shehnaaz S.M. , Carrington Darryl P. , Scarcella Deborah L. , Ashley David M. , Smith Peter J. , Algar Elizabeth M.
Published: September 2002

The Wilms' tumor 1 gene, WT1, encodes a zinc‐finger protein that is implicated in the development of Wilms' tumor. Mutant or aberrantly expressed WT1 isoforms have also been described in desmoplastic small round cell tumor, acute leukemias, mesothelioma, breast tumors and melanoma. During early development, WT1 is expressed in the brain and spinal cord, however its role in the malignancies that affect these tissues has not been previously investigated. In our study we have examined neural tumors including brain tumors and neuroblastomas for WT1 expression and for mutations affecting the zinc‐fingers. Although WT1 expression was detected in gliomas, medulloblastomas and neuroblastomas, neither zinc‐finger region mutations nor splicing anomalies affecting the KTS site were detected. We therefore conclude that WT1 does not play a significant role in the etiology of human neural tumors. © 2001 Wiley‐Liss, Inc.
P53 is the strongest predictor of survival in high‐risk primary breast cancer patients undergoing high‐dose chemotherapy with autologous blood stem cell support
Authors: Hensel Manfred , Schneeweiss Andreas , Sinn Hans‐Peter , Egerer Gerlinde , Solomayer Erich , Haas Rainer , Bastert Gunther , Ho Anthony D.
Published: September 2002

Our purpose was to determine the predictive value of tumor biologic parameters in patients with HRPBC who received HDCT with ASCT as first‐line treatment. From September 1992 to May 2000, 149 stage II or III HRPBC patients were enrolled in a single‐arm trial using a tandem HDCT regimen followed by ASCT. Her2/neu, p53, Ki67 and bcl‐2 protein expression was studied using immunohistochemic staining on formalin‐fixed, paraffin‐embedded primary tumor sections. DNA content of tumor cells (DNA index) and tumor cell proliferation (SPF) were measured by DNA flow cytometry. The relationship between these tumor biologic parameters, on the one hand, and DFS, DDFS and OS, on the other, was analyzed. With a median follow‐up of 43 months (range 7–106), p53 protein accumulation (p= 0.000004), negative combined hormone receptor status (p= 0.003) and Her2/neu overexpression (p= 0.02) were significant negative predictors of OS in univariate analysis. A poorer DFS was associated with p53 positivity (p= 0.04) and nodal ratio ≥0.8 (p= 0.008). Poorer DDFS was associated with p53 positivity (p= 0.03). In multivariate analysis, Her2/neu overexpression (RR = 3.86, 95% CI 1.48–10.1,p= 0.006) and p53 overexpression (RR = 6.06, 95% CI 2.22–16.52,p< 0.001) proved to be independent predictors of adverse OS. p53 overexpression was the only independent predictor of DFS (RR = 2.21, 95% CI 1.07–4.57,p= 0.03). p53 overexpression and Her2/neu overexpression are independent negative predictors of survival in HRPBC treated with HDCT. The adverse impact of these biologic features was probably not altered by HDCT. For HRPBC patients with tumors not overexpressing Her2/neu or p53, HDCT may be an appropriate approach to achieve long‐term survival and tumor control. © 2002 Wiley‐Liss, Inc.
Renal cell carcinoma–associated antigen G250 encodes a naturally processed epitope presented by human leukocyte antigen‐dr molecules to CD4+ T lymphocytes
Authors: Vissers Joost L.M. , de Vries I. Jolanda M. , Engelen Linda P.H. , Scharenborg Nicole M. , Molkenboer Janneke , Figdor Carl G. , Oosterwijk Egbert , Adema Gosse J.
Published: September 2002

We previously identified an HLA‐A2.1‐restricted epitope within the RCC‐associated antigen G250 that is recognized by CTLs. Using DCs of healthy individuals, which were loaded with overlapping 20 mer G250‐derived peptides, we here report the induction of CD4+ T cells that recognize the G250 peptide of amino acids 249–268. Moreover, naturally processed G250 protein is readily recognized by these G250‐specific CD4+ T cells in the context of HLA‐DR molecules. Interestingly, peptide G250:249–268 overlaps the previously identified HLA‐A2.1‐restricted G250 epitope recognized by CTLs. These data and the high prevalence of G250 in RCC patients make peptide G250:249–268 a potential target in peptide‐based vaccines to induce both CD4+ and CD8+ T‐cell responses in patients. © 2002 Wiley‐Liss, Inc.
Bounds testing approaches to the analysis of level relationships
Authors: Pesaran M. Hashem , Shin Yongcheol , Smith Richard J.
Published: September 2002

This paper develops a new approach to the problem of testing the existence of a level relationship between a dependent variable and a set of regressors, when it is not known with certainty whether the underlying regressors are trend‐ or first‐difference stationary. The proposed tests are based on standardF‐ andt‐statistics used to test the significance of the lagged levels of the variables in a univariate equilibrium correction mechanism. The asymptotic distributions of these statistics are non‐standard under the null hypothesis that there exists no level relationship, irrespective of whether the regressors areI(0) orI(1). Two sets of asymptotic critical values are provided: one when all regressors are purelyI(1) and the other if they are all purelyI(0). These two sets of critical values provide a band covering all possible classifications of the regressors into purelyI(0), purelyI(1) or mutually cointegrated. Accordingly, various bounds testing procedures are proposed. It is shown that the proposed tests are consistent, and their asymptotic distribution under the null and suitably defined local alternatives are derived. The empirical relevance of the bounds procedures is demonstrated by a re‐examination of the earnings equation included in the UK Treasury macroeconometric model. Copyright © 2001 John Wiley & Sons, Ltd.
Treatment of bleaching Kraft mill effluents and polychlorinated phenolic compounds with ozonation
Authors: Pérez Montserrat , Torrades Francesc , Domènech Xavier , Peral José
Published: September 2002

The effect of the simultaneous use of ozone, UVA or visible light, and small quantities of Fe(II)/Fe(III) ions in solution on the degradation rate of the organic content of a bleaching Kraft mill effluent was investigated. The same treatment was applied to synthetic samples of polychlorinated phenolic compounds, because these are one of the main groups of compounds found in real bleaching Kraft mill effluents. In order to improve the treatment efficiency and to lower the cost of the process several other strategies were investigated. It was found that a previous irradiation of the wastewater or the synthetic sample in the absence of ozone significantly improves the rate of removal of organic pollutants during the subsequent ozonation step.

© 2002 Society of Chemical Industry
Prenatal human ocular degeneration occurs in Leber's congenital amaurosis (LCA2)
Authors: Porto Fernanda B. O. , Perrault Isabelle , Hicks David , Rozet Jean‐Michel , Hanoteau Noëlle , Hanein Sylvain , Kaplan Josseline , Alain Sahel José
Published: September 2002

Background

Leber's congenital amaurosis (LCA) encompasses the most precocious and severe forms of inherited retinal dystrophy, displaying very significant visual handicap at or soon after birth1. Among the currently identified mutations, alterations in the gene coding for retinal pigment epithelium 65‐kDa protein (RPE65) lead to LCA22. Existing animal models for LCA2 (RPE65‐/‐ null mice3 and naturally occurring RPE65‐/‐ Briard dogs4) exhibit near normal retinal histology at birth, although no recordable photofunction can be detected. Structural degeneration in both cases occurs with delayed onset, cone death generally preceding that of rods.

Methods

We obtained retinal tissue from a voluntarily aborted embryo of an LCA2 carrier in order to compare histopathology and immunohistochemistry with age‐matched normal foetal retina.

Results

Compared to normal retinas, affected retina displayed cell loss and thinning of the outer nuclear (photoreceptor) layer, decreased immunoreactivity for key phototransduction proteins, and aberrant synaptic and inner retinal organisation. The gene mutation abolished detectable expression of RPE65 within the retinal pigment epithelium (RPE) of affected eyes, and ultrastructural examination revealed the presence of lipid and vesicular inclusions not seen in normal RPE. In addition, mutant eyes demonstrated thickening, detachment and collagen fibril disorganisation in the underlying Bruch's membrane, and the choroid was distended and abnormally vascularised, in comparison with controls.

Conclusions

Such data contrast with the late‐onset ocular changes observed in animal models, indicating caution should be exercised when inferring human retinal pathophysiology from information based on other species. Copyright © 2002 John Wiley & Sons, Ltd.
Evaluation of angiogenesis and side effects in ischemic rabbit hindlimbs after intramuscular injection of adenoviral vectors encoding VEGF and LacZ
Authors: Vajanto Ismo , Rissanen Tuomas T. , Rutanen Juha , Hiltunen Mikko O. , Tuomisto Tiina T. , Arve Katja , Närvänen Outi , Manninen Hannu , Räsänen Heikki , Hippeläinen Mikko , Alhava Esko , Ylä‐Herttuala Seppo
Published: September 2002

Background

Recent studies have suggested the therapeutic potential of vascular endothelial growth factor (VEGF) gene therapy in ischemic skeletal muscle. However, only limited information is available about the effects of VEGF gene therapy in different regions of ischemic limbs, effects of control adenoviruses, and biodistribution of the transgenes after intramuscular (i.m.) administration. Here we studied angiogenesis and side effects of adenovirus‐mediated VEGF and β‐galactosidase (LacZ) gene transfers in ischemic rabbit hindlimbs.

Methods and results

Ten days after induction of ischemia, rabbits were treated with i.m. injections of saline, LacZ adenovirus (AdLacZ; 2×1010 pfu) or adenovirus encoding mouse VEGF164 (AdVEGF; 2×1010 pfu). In rabbits treated with AdVEGF an increase in serum VEGF164 levels was detected by ELISA three and seven days after the gene transfer. 30 days after the gene transfer a positive effect on capillary density was observed in the thigh region both in rabbits treated with AdVEGF and AdLacZ compared with animals that received saline. On the other hand, AdVEGF and AdLacZ gene transfers had no effect on the capillary density in the calf region on day 30. A positive correlation between the capillary density and the number of collateral arteries was observed in the thigh. Hindlimb and testis edema and excess non‐physiological growth of capillaries were detected as adverse effects of the AdVEGF gene therapy. Biodistribution analysis showed that the transgene was present not only in the target muscle, but also in ectopic tissues seven days after i.m. gene transfer.

Conclusions

The results suggest that a high dose of adenoviral vector encoding either AdVEGF or AdLacZ induces angiogenesis in the rabbit hindlimb ischemia model; i.m. injection of adenovirus leads to the transfection of ectopic organs; and AdVEGF gene transfer induces edema in ischemic skeletal muscle. Copyright © 2002 John Wiley & Sons, Ltd.
Accuracy of the frequency‐domain TLM method and its application to microwave circuits
Authors: Hesselbarth J. , Vahldieck R.
Published: September 2002

This paper investigates the accuracy and convergence of frequency‐domain (FD) TLM solutions and describes a method to identify non‐physical solutions. The numerical dispersion characteristics of various discretization schemes (‘nodes’) are compared. The occurrence of non‐physical solutions when solving three‐dimensional problems is discussed and a method to identify the non‐physical solutions is described. The accuracy of the FDTLM method is shown to be of second order as long as singularities are absent, whereas it is between first and second order if the computational domain includes field singularities. Copyright © 2002 John Wiley & Sons, Ltd.
A longitudinal study of the relationship between career management and organizational commitment among graduates in the first ten years at work
Authors: Sturges Jane , Guest David , Conway Neil , Davey Kate Mackenzie
Published: September 2002

This paper reports the findings of a two‐wave longitudinal study investigating relationships between organizational and individual career management activities and organizational commitment in the early years of graduate careers. Several hypotheses are tested and receive mixed support. High organizational commitment predicts the practice of career management activities by graduates to further their career within the organization while low commitment is closely associated with behaviour aimed at furthering the career outside the organization. Graduates who manage their own careers also receive more career management help from their employer. This suggests that there may be the potential for employers to create a ‘virtuous circle’ of career management in which individual and organizational activities complement each other. Copyright © 2002 John Wiley & Sons, Ltd.
Raman microspectroscopic model of human breast tissue: implications for breast cancer diagnosis in vivo
Authors: Shafer‐Peltier Karen E. , Haka Abigail S. , Fitzmaurice Maryann , Crowe Joseph , Myles Jonathan , Dasari Ramachandra R. , Feld Michael S.
Published: September 2002

Raman spectroscopy has the potential to provide real‐time, in situ diagnosis of breast cancer during needle biopsy or surgery via an optical fiber probe. Understanding the chemical/morphological basis of the Raman spectrum of breast tissue is a necessary step in developing Raman spectroscopy as a tool for in situ breast cancer diagnosis. To understand the relationship between the Raman spectrum of a sample of breast tissue and its disease state, near‐infrared Raman spectroscopic images of human breast tissue were acquired using a confocal microscope. These images were then compared with phase contrast and hematoxylin‐ and eosin‐stained images to develop a chemical/morphological model of breast tissue Raman spectra. This model fits macroscopic tissue spectra with a linear combination of basis spectra derived from spectra of the cell cytoplasm, cell nucleus, fat, β‐carotene, collagen, calcium hydroxyapatite, calcium oxalate dihydrate, cholesterol‐like lipid deposits and water. Each basis spectrum represents data acquired from multiple patients and, when appropriate, from a variety of normal and diseased states. The model explains the spectral features of a range of normal and diseased breast tissue samples, including breast cancer. It can be used to relate the Raman spectrum of a breast tissue sample to diagnostic parameters used by pathologists. Copyright © 2002 John Wiley & Sons, Ltd.
Antioxidant activity of fresh and processed edible seaweeds
Authors: Jiménez‐Escrig Antonio , Jiménez‐Jiménez Isabel , Pulido Raquel , Saura‐Calixto Fulgencio
Published: September 2002

The antioxidant activity of aqueous/organic extracts of processed and raw edible seaweeds was determined using three methods, namely (a) free radical (DPPH·) scavenging, (b) ferric‐reducing antioxidant power (FRAP) and (c) inhibition of copper‐catalysed in vitro human low‐density lipoprotein (LDL) oxidation. Scavenging activity correlated well (r  = 0.73) with the corresponding total polyphenolic content measured by the Folin–Ciocalteu procedure and expressed as phloroglucinol equivalents (PGE). Of the seaweeds tested, Fucus showed the highest antioxidant activity in two of the test methods used (1 g (dry matter) had a DPPH· activity and a FRAP value equivalent to those 0.18 and 0.07 mmol of Trolox respectively) and the highest total polyphenolic content (41.4 gPGEkg−1 dry matter). The antioxidant activity and the content of phenolic compounds decreased with processing and storage in the seaweeds tested. In addition, Fucus showed good efficiency in the in vitro inhibition of LDL oxidation.

© 2001 Society of Chemical Industry
The effects of pleasure and arousal on recall of advertisements during the Super Bowl
Authors: Newell Stephen J. , Henderson Kenneth V. , Wu Bob T.
Published: September 2002

This study investigates whether pleasure and arousal levels of viewers watching a sports program affect advertisement recall. The results suggest that programs that evoke strong emotional reactions, such as the Super Bowl, may inhibit the recall of advertisements and brands. Specifically, these findings seem to support the Intensity (arousal) theory and may have important implications for advertisers who promote their products or services on sports‐related event programming. © 2001 John Wiley & Sons, Inc.
Upper and lower bounds of 180° unit element of a ridge waveguide: Calculations and measurements
Authors: Goussetis George , Budimir Djuradj , Helszajn Joe
Published: September 2002

The upper and lower bounds on the actual solution of any microwave structure is of general interest. The purpose of this letter is to compare some calculations using the mode‐matching and finite‐element methods, with some measurements on a 180° ridge waveguide insert between standard WR62 rectangular waveguides. The work suggests that the MMM produces an upper bound, while the FEM places a lower bound on the measurement. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 260–261, 2001.
L‐Band multiwavelength oscillation in erbium‐doped fiber ring laser
Authors: Mao Qinghe , Lit John W. Y.
Published: September 2002

In this letter, L‐band multiwavelength operation in an erbium‐doped fiber ring laser (EDFRL) is achieved by using a tunable Fabry–Perot etalon as the intracavity comb filter. It is found that, for a ring cavity, the gain spectrum can be controlled, and the flattened gain spectrum at the threshold can be obtained by optimizing the cavity Q‐factor. A maximum of six stable lines with a spacing of 1.3 nm in the wavelength range near 1590 nm has been produced at room temperature. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 88–91, 2002.
Optimal synthesis of a real‐valued template for synthetic aperture radar pattern recognition
Authors: Chen Chulung , Fang Jian‐Shuen
Published: September 2002

For distortion‐invariant radar image recognition with a hybrid electrical and optical signal processing technique, the design of the nonzero‐order joint transform correlator to achieve minimum average cross‐correlation energy has been studied. In this work, as we require the desired cross‐correlation peak to be real valued for all real‐valued training images, the optimized reference function will be real valued as well, although the reference function is optimized in the frequency domain with the method of Lagrange multipliers. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 91–95, 2002.
Chiral mode transformer for soft‐ and hard‐surface waveguides
Authors: Viitanen Ari J.
Published: September 2002

Electromagnetic fields inside circular, tuned corrugated waveguides, also called soft‐ and hard‐surface waveguides, are considered. The waveguides are filled with chiral material. The propagating eigenfields are presented. In this paper, a recently studied case with small chirality parameter values is generalized. Also, reflected and transmitted fields are considered. It is shown that the chiral soft‐ and hard‐surface waveguide section of a proper length can be used as a mode transformer between TE and TM modes. This kind of waveguide component may be used as a matching element between different kinds of circular waveguides and antenna elements. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 95–99, 2002.
Padé approximation for extended boundary condition method in electromagnetic scattering analysis
Authors: Abu‐Zaid Naser A. , Tosun Haluk
Published: September 2002

The Padé approximation technique in conjunction with the extended boundary condition method (EBC) is implemented to solve the scattering problem over a finite frequency interval. The algorithm is based on expanding the system equations in their power series, and then finding a recurrence relation for the series coefficients. Fairly good results are obtained. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 100–101, 2002.
A discrete phase‐unwrapping technique for interferograms
Authors: Ahmad Falih H. , Helms Gary L. , Castellane Ray M. , Durst Bartley P.
Published: September 2002

A discrete technique for phase unwrapping is presented. The technique is based on constructing the mth‐degree interpolating polynomials to approximate the involved functions using Legendre–Gauss–Lobatto collocation nodes. The relationship between the known wrapped phase and the unknown unwrapped phase and that between their derivatives are converted into a set of linear algebraic equations. This set of equations is solved for the unknown coefficients to produce the unwrapped phase. A numerical example is included to demonstrate the performance of the technique, where a comparison is made with exact results. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 101–104, 2002.
A finite‐element formulation for FDTD subgridding
Authors: Bonilla Matthieu , Wong Man‐Faï , Fouad Hanna Victor
Published: September 2002

In this paper, a finite‐element based 3‐D FDTD space/time subgridding scheme is presented. A classical Yee scheme is obtained strictly inside domains having different space and time discretizations. Considering one domain, the presence of the other domain is taken into account through an electric‐field excitation distributed throughout the mesh interface. The validity of the proposed technique is demonstrated through its application on two test cases: a Hertzian dipole and a mobile‐phone antenna. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 104–108, 2002.
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

We 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

We 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

A 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

The 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

A 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

An 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

The 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

A 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

An 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

The 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

The 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

By 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

The 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

In 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

The 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

The 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

Recent 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
Personality and judgements of abstract, pop art, and representational paintings
Authors: Furnham Adrian , Walker John
Published: September 2002

This study was concerned with the question of which personality variables are most predictive of judgements of particular types of painting. One hundred and twenty‐one participants rated 24 slides of abstract, pop art, and representational paintings. They then completed two questionnaires which measured sensation seeking (SS) and the ‘Big Five’ personality dimensions. Thrill and Adventure Seeking was positively correlated with a liking of representational art while Disinhibition was associated with positive ratings of abstract art and pop art. Neuroticism was positively correlated with positive ratings of abstract and pop art, while conscientiousness was linked to liking of representational art. Openness to Experience was linked to positive ratings of all three art types. Agreeableness was negatively linked to liking of pop art. It was also found that art education and frequency of visits to art galleries were linked to positive ratings of abstract paintings. Regressional analyses showed about a fifth of the variance could be accounted for by personality and demographic variables. Personality variables were most strongly linked to positive judgements of representational art and least related to ratings of pop art. Overall the sensation seeking variables accounted for more of the variance than the big five dimensions. Copyright © 2001 John Wiley & Sons, Ltd.