bluuebunny/crossref_metadata_2025_split huggingface dataset:
Meta‐material surface design using the hierarchical genetic algorithm
Authors: Yuan Yuan , Chan Chi Hou , Man Kim Fung , Luk Kwai Man 
Published: September 2003

AbstractIn this paper, we design a meta‐material surface emulating a perfect magnetic conducting plane (PMC) using the hierarchical genetic algorithm (HGA). This is achieved by manipulating the unit‐cell geometry of frequency‐selective surface screens and the electrical properties of the supporting dielectric medium in the optimization process. The properties of the structure are evaluated using a method of moments (MoM)‐based electromagnetic solver. By virtue of the HGA, prior information of the number of FSS screens and dielectric layers is not required. The designed PMC is employed as a dipole‐antenna reflector for gain enhancement. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 226–230, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11176
Influence of furniture on 60‐GHz radio propagation in a residential environment
Authors: Collonge S. , Zaharia G. , El Zein G. 
Published: September 2003

AbstractAt millimeter‐waves, home furniture's and objects' dimensions can be equal or superior to the wavelength. A comparison between propagation measurements conducted within a residential house for two configurations, furnished and empty, underscores the influence of the furniture on millimeter‐wave propagation. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 230–233, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11177
Analysis of coplanar LiNbO3 waveguide structures applicable to electrooptic modulator with FDTD method
Authors: Lee Byungje , Byun Joonho , Kim Bok‐Ki 
Published: September 2003

AbstractThe 3D finite‐difference time‐domain (FDTD) method and the 2D quasi‐static formulation have been used to calculate the characteristic impedance and the microwave effective index of coplanar waveguide structures on lithium niobate (LiNbO3) single‐crystal substrates with a yttria‐stabilized zirconia (YSZ) or SiO2 buffer layer. The results shown can be a good source to predict the modulator characteristics. The effects of the thin buffer layer and anisotropy of the LiNbO3 crystal (x‐cut and z‐cut) are discussed. The comparison between the FDTD and quasi‐static results shows good agreement. In this paper, the efficient modeling technique of the FDTD method for the coplanar waveguide (CPW) structures based on an anisotropic substrate with a thin buffer layer is developed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 234–237, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11178
Compact multi‐layer diplexer for dual mode portable telephones
Authors: Lee Byoung Hwa 
Published: September 2003

AbstractA new compact and effective lumped‐element diplexer structure targeted for low‐temperature co‐fired ceramic (LTCC) implementation that can exhibit high levels of isolation between low‐pass and high‐pass filters is proposed. Design equation formulations that take into account the isolation between the two filters are presented. As an example, a multilayer ceramic (MLC) chip diplexer in a dual‐mode portable telephone for 900‐MHz digital‐cellular and 1.9‐GHz personal communication systems is designed and fabricated. The simulated results are compared with the measured data and good agreement is reported. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 237–239, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11179
Fabry–Perot microcavity pressure sensor with a novel single deeply corrugated diaphragm
Authors: Wang W. J. , Lin R. M. , Ren Y. , Sun T. T. , Guo D. G. 
Published: September 2003

AbstractA new Fabry–Perot (FP) microcavity structure with a novel single deeply corrugated diaphragm (SDCD) is presented for use in pressure sensing. Both analytical expression and finite‐element model (FEM) are used to evaluate the device's performance. The FP microcavity is fabricated on a single chip using both surface and bulk micromachining techniques. The results show that the signal averaging effect can substantially be reduced for the FP microcavity pressure sensor by the flatness‐enhancing diaphragm structure. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 240–243, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11180
Two‐dimensional photonic‐crystal microwave waveguide
Authors: Coves A. , San Blas A. A. , Gimeno B. , Díez A. , Andrés M. V. , Boria V. E. 
Published: September 2003

AbstractThis paper reports on the use of 2D photonic crystals to design microwave waveguides. The waveguide consists of a periodic arrangement of holes, with a square or rectangular cross section, that extends along the waveguide with a central defect defined by the absence of a hole. The theoretical analysis of such a structure is based on a biorthogonal‐basis method and provides a full‐vector description of the modes guided by the defect. Our results show that such a waveguide can be designed to support only one mode at any operating frequency. This mode is a polarization doublet whose dispersion is controlled by the geometrical parameters, thus permitting the design of a novel polarization‐maintaining waveguide. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 243–246, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11181
5‐GHz compact two‐element metal‐plate antenna for WLAN operation
Authors: Su Chih‐Ming , Chen Wen‐Shyang , Wong Kin‐Lu 
Published: September 2003

AbstractA novel two‐element metal‐plate antenna arranged in a compact geometry and easily constructed from a single metal plate is presented. The antenna shows a high antenna‐gain level (> 4.0 dBi) and is suitable for WLAN operation in the 5.2/5.8‐GHz bands (5150–5350 MHz/5725–5875 MHz). The antenna‐gain level obtained can even be larger than 5.0 dBi for practical applications where the antenna is required to be placed in close proximity to a large metal plate, such as the metal plate or metal frame used to support the display of a laptop. Details of the proposed antenna design and obtained experimental results are presented. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 246–249, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11182
Modelling of two new kinds of optical filters for use in WDM networks
Authors: de Moraes Sam Lara , Alves Cordeiro Albino Adriano , Carvalho Lustosa da Costa João Paulo , Rocco Giraldi Maria Thereza Miranda 
Published: September 2003

AbstractIn the present work, we model and analyze two new kind of optical filters. We also compare their responses. Both of them are based on fiber Bragg gratings (FBGs). The first filter analyzed and modeled is a comb filter based on an acousto‐optic modulator in a sinc‐sampled fiber Bragg grating. The second one is based on the operation of an FBG and two all‐fiber Fabry–Perot filters, which are connected by an optical circulator. These filters showed to be very attractive for use in wavelength division multiplexing (WDM) networks. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 249–253, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11183
Complex resonance of the circular‐arc dipole antenna
Authors: Leung K. W. 
Published: September 2003

AbstractThe complex resonance of the circular‐arc dipole antenna is studied theoretically. The Green's function technique is employed to formulate an integral equation for the dipole current, and the method of moments (MoM) is used to convert the equation into a matrix equation. An equation for the complex frequency is then obtained by enforcing the determinant of the impedance matrix to zero. From the complex frequency, the resonant frequency and Q factor of the circular‐arc dipole antenna are found. The effects of the arc radius, dipole length, and dipole radius on the complex frequency are investigated and discussed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 253–256, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11184
Brain plasticity, learning, and developmental disabilities
Authors: Casey B.J. 
Published: September 2003

AbstractThis is a time of significant gains in methodological development for examining the developing human brain. New efforts are underway to unify the understanding of the development of brain anatomy with physiological, cellular and molecular processes that influence behavioral development. This special issue provides animal models of behavior and brain development, applications of noninvasive imaging and genetic methods to human brain development and behavior, and select reviews of how these models and methods have been applied to the examination of developmental disabilities. This issue reflects a sampling of current approaches to the study of brain plasticity, development and learning in typically and atypically developing humans and animals. MRDD Research Reviews 2003;9:133–134. © 2003 Wiley‐Liss, Inc.
Vocal learning in birds and humans
Authors: Wilbrecht Linda , Nottebohm Fernando 
Published: September 2003

AbstractVocal learning is the modification of vocal output by reference to auditory information. It allows for the imitation and improvisation of sounds that otherwise would not occur. The emergence of this skill may have been a primary step in the evolution of human language, but vocal learning is not unique to humans. It also occurs in songbirds, where its biology can be studied with greater ease. What follows is a review of some of the salient anatomical, developmental, and behavioral features of vocal learning, alongside parallels and differences between vocal learning in songbirds and humans. MRDD Research Reviews 2003;9:135–148. © 2003 Wiley‐Liss, Inc.
Early life influences on life‐long patterns of behavior and health
Authors: McEwen Bruce S. 
Published: September 2003

AbstractThe stability of a child's early life has profound effects on physical and mental health, and unstable parent‐child relationships, as well as abuse, can lead to behavioral disorders and increased mortality and morbidity from a wide variety of common diseases later in life. One common consequence, namely, depressive illness, is associated with chemical imbalances in the brain and hormonal dysregulation, constituting a form of allostatic load that alters interpretations of stimuli and influences, behavioral, and hormonal responses to potentially stressful situations. The brain not only encodes information and controls the behavioral responses but it is also changed structurally by those experiences. Structural changes in the hippocampus and amygdala, which are important brain structures for cognition and emotion, are representative of what may be occurring throughout the brain as a result of allostatic load resulting from the chronic stress of a disorder such as depression. Such structural changes include dendritic debranching and hypertrophy, cell proliferation, and synaptic remodeling; they are produced by the combined overactivity of stress hormones and endogenous neurotransmitters. These mediators are normally involved in adaptation, but can also promote damage when they are dysregulated and over‐active. They are very likely to be strongly biased by early life experiences. The findings from animal models thus provide a basis for understanding potential mechanisms of environmental and developmental determinants of individual differences in human stress reactivity, as well as anxiety, depression, and a host of related systemic disorders. There is an increasing amount of translational research that is beginning to tie the basic research to clinical outcomes of individuals exposed to abusive or inconsistent care‐giving in early life. A major goal of studies on this important topic is to define times in development and strategies for intervening to prevent or reverse the effects of adverse early life experiences. Although prevention is clearly the preferable route, some degree of reversal of psychopathology and pathophysiology caused by early life adversity appears to be an achievable goal. MRDD Research Reviews 2003;9:149–154. © 2003 Wiley‐Liss, Inc.
MRI‐based morphometric analysis of typical and atypical brain development
Authors: Kennedy David N. , Haselgrove Christian , McInerney Sean 
Published: September 2003

AbstractThe neuroinformatics landscape in which human brain morphometry occurs has advanced dramatically over the past few years. Rapid advancement in image acquisition methods, image analysis tools and interpretation of morphometric results make the study of in vivo anatomic analysis both challenging and rewarding. This has revolutionized our expectations for current and future diagnostic and investigative work with the developing brain. This paper will briefly cover the methods of morphometric analysis that available for neuroanatomic analysis, and tour some sample results from a prototype retrospective database of neuroanatomic volumetric information. From these observations, issues regarding the anatomic variability of developmental maturation of neuroanatomic structures in both typically and atypically developing populations can be discussed. MRDD Research Reviews 2003;9:155–160. © 2003 Wiley‐Liss, Inc.
Imaging the developing brain with fMRI
Authors: Davidson M.C. , Thomas K.M. , Casey B.J. 
Published: September 2003

AbstractAdvancements in magnetic imaging techniques have revolutionized our ability to study the developing human brain in vivo. The ability to noninvasively image both anatomy and function in healthy volunteers, including young children, has already enhanced our understanding of brain and behavior relations. The application of these techniques to developmental research offers the opportunity to further explore these relationships and allows us to ask questions about where, when and how cognitive abilities develop in relation to changes in underlying brain systems. It is also possible to explore the contributions of maturation versus learning in the development of these abilities through cross‐sectional and longitudinal research involving training and intervention procedures. Current imaging methodologies, in conjunction with new and rapidly evolving techniques, hold the promise of even greater insights into developmental issues in the near future. These methodologies and their application to development and learning are discussed in the current paper. MRDD Research Reviews 2003;9:161–167. © 2003 Wiley‐Liss, Inc.
Fiber tracking using magnetic resonance diffusion tensor imaging and its applications to human brain development
Authors: Watts Richard , Liston Conor , Niogi Sumit , Uluğ Aziz M. 
Published: September 2003

AbstractDiffusion tensor imaging is unique in its ability to noninvasively visualize white matter fiber tracts in the human brain in vivo. Diffusion is the incoherent motion of water molecules on a microscopic scale. This motion is itself dependent on the micro‐structural environment that restricts the movement of the water molecules. In white matter fibers there is a pronounced directional dependence on diffusion. With white matter fiber tracking or tractography, projections among brain regions can be detected in the three‐dimensional diffusion tensor dataset according to the directionality of the fibers. Examples of developmental changes in diffusion, tracking of major fiber tracts, and examples of how diffusion tensor tractography and functional magnetic resonance imaging can be combined are provided. These techniques are complimentary and allow both the identification of the eloquent areas of the brain involved in specific functional tasks, and the connections between them. The noninvasive nature of magnetic resonance imaging will allow these techniques to be used in both longitudinal developmental and diagnostic studies. An overview of the technique and preliminary applications are presented, along with its current limitations. MRDD Research Reviews 2003;9:168–177. © 2003 Wiley‐Liss, Inc.
Synaptogenesis and heritable aspects of executive attention
Authors: Fossella John A. , Sommer Tobias , Fan Jin , Pfaff Don , Posner Michael I. 
Published: September 2003

AbstractIn humans, changes in brain structure and function can be measured non‐invasively during postnatal development. In animals, advanced optical imaging measures can track the formation of synapses during learning and behavior. With the recent progress in these technologies, it is appropriate to begin to assess how the physiological processes of synapse, circuit, and neural network formation relate to the process of cognitive development. Of particular interest is the development of executive function, which develops more gradually in humans. One approach that has shown promise is molecular genetics. The completion of the human genome project and the human genome diversity project make it straightforward to ask whether variation in a particular gene correlates with variation in behavior, brain structure, brain activity, or all of the above. Strategies that unify the wealth of biochemical knowledge pertaining to synapse formation with the functional measures of brain structure and activity may lead to new insights in developmental cognitive psychology. MRDD Research Reviews 2003;9:178–183. © 2003 Wiley‐Liss, Inc.
A review of the biological bases of ADHD: What have we learned from imaging studies?
Authors: Durston Sarah 
Published: September 2003

AbstractAttention Deficit Hyperactivity Disorder (ADHD) is a common and impairing neuropsychiatric disorder with onset at preschool age. Although a significant amount of progress has been made investigating the neurobiology of this disorder, its precise etiology still remains unclear. Converging evidence from studies of the neuropharmacology, genetics, neuropsychology, and neuroimaging of ADHD imply the involvement of fronto‐striatal circuitry in ADHD. However, while it does appear that poor inhibitory control and the deficits in fronto‐striatal circuitry associated with it are central, there is evidence to suggest that more posterior cerebral areas are also implicated in this disorder. Anatomical studies suggest widespread reductions in volume throughout the cerebrum and cerebellum, while functional imaging studies suggest that affected individuals activate more diffuse areas than controls during the performance of cognitive tasks. The future impact of new MR imaging methodologies on the field is discussed. MRDD Research Reviews 2003;9:184–195. © 2003 Wiley‐Liss, Inc.
The development of reading impairment: A cognitive neuroscience model
Authors: McCandliss Bruce D. , Noble Kimberly G. 
Published: September 2003

AbstractThis review discusses recent cognitive neuroscience investigations into the biological bases of developmental dyslexia, a common disorder impacting approximately 5 to 17 percent of the population [Stanovich, 1986, Matthew effects in reading: Some consequences of individual differences in the acquisition of literacy. Reading Research Quarterly 21: 360–407]. Our aim is to summarize central findings from several lines of evidence that converge on pivotal aspects of the brain bases of developmental dyslexia. We highlight ways in which the approaches and methodologies of developmental cognitive neuroscience that are addressed in this special issue—including neuroimaging, human genetics, refinement of cognitive and biological phenotypes, neural plasticity and computational models—can be employed in uncovering the biological bases of this disorder. Taking a developmental perspective on the biological bases of dyslexia, we propose a simple cascading model for the developmental progression of this disorder, in which individual differences in brain areas associated with phonological processing influence the specialization of visual areas involved in the rapid processing of written words. We also discuss recent efforts to understand the impact of successful reading interventions in terms of changes within cortical circuits associated with reading ability. MRDD Research Reviews 2003;9:196–205. © 2003 Wiley‐Liss, Inc.
A systems neuroscience approach to autism: Biological, cognitive, and clinical perspectives
Authors: Eigsti Inge‐Marie , Shapiro Theodore 
Published: September 2003

AbstractAutism is a behaviorally defined disorder characterized by a broad constellation of symptoms. Numerous studies directed to the biological substrate demonstrate clear effects of neurodevelopmental differences that will likely point to the etiology, course, and long‐term outcomes of the disorder. Consistently replicated research on the neural underpinnings of autism is reviewed. In general, results suggest several main conclusions: First, autism is a heterogeneous disorder and is likely to have multiple possible etiologies; second, structural brain studies have indicated a variety of diffuse anatomical differences, reflective of an early developmental change in the growth or pruning of neural tissue, rather than localized lesions; similarly, neurochemical studies suggest early, neuromodulatory discrepancies rather than gross or localized abnormalities; and finally, there are a number of limitations on studies of brain activity that to date preclude definitive answers to questions of how the brain functions differently in autism. The large number of active research programs investigating the cognitive neuroscience of autism spectrum disorders, in combination with the exciting development of new methodologies and tools in this area, indicates the drama and excitement of work in this area. MRDD Research Reviews 2003;9:206–216. © 2003 Wiley‐Liss, Inc.
Response of saturated porous media to cyclic thermal loading
Authors: Blond E. , Schmitt N. , Hild F. 
Published: September 2003

AbstractThe response of a semi‐infinite saturated porous medium subjected to a harmonic thermal loading on its free face is studied herein. The pressure diffusion equation that governs the fluctuation of the interstitial pressure is established. It allows us to obtain prevalent parameters, i.e. the thermal and fluid mass diffusivities and the coefficient of relative bulk variation. Closed‐form solutions of the maximum fluid pressure Pmax and its location xcr are derived. It is shown that the location xcr of Pmax is localized and depends on the diffusivity ratio and the frequency of the thermal loading while the magnitude of Pmax depends on the diffusivity ratio and the thermal amplitude. Master curves for xcr and Pmax versus diffusivity ratio are built. It follows that three regimes can be distinguished: namely, thin spalling, thick spalling or in‐depth cracking and no cracking. Copyright © 2003 John Wiley & Sons, Ltd.
A local identification technique for geotechnical and geophysical systems
Authors: Zeghal Mourad , Oskay Caglar 
Published: September 2003

AbstractGeotechnical structures and natural soil deposits are massive multi‐phase particulate systems characterized by the development of localized response mechanisms under extreme loading conditions. Identification and analysis of such systems based on inverse boundary value problem formulations and sparse measurements are generally indeterminate. This paper presents an alternative local inverse problem technique. Point‐wise identification analyses of the constitutive behaviour of water‐saturated geotechnical and geophysical systems are performed using acceleration and pore pressure records provided by a cluster of closely spaced sensors. The developed novel technique does not require the availability of boundary condition measurements, or solution of an associated boundary value problem. The constitutive behaviour at a specific location of a soil‐system is analysed independently of adjacent response mechanisms or material properties. Numerical simulations and centrifuge tests of a soil‐retaining wall system are used to demonstrate the capabilities of the developed technique. Copyright © 2003 John Wiley & Sons, Ltd.