bluuebunny/crossref_metadata_2025_split huggingface dataset:
In whose interests? IT migration in an interconnected world economy
Authors: Millar Jane , Salt John 
Published: December 2006

AbstractThe paper focuses on the interaction between the national management of labour migration flows and the sourcing strategies used by transnational corporations in the IT sector which operate in an increasingly liberalised world economy. Through examination of employer‐sponsored immigration among IT professionals to the UK, it draws attention to the need for migration policy to balance the conflicting interests of employers and resident labour. It combines statistical evidence, largely derived from the UK work permit system, with in‐depth interviews among senior human resource executives. Its main conclusion is that the UK's broad‐brush approach to managed migration is out of touch with the international sourcing policies of firms in the IT sector and has been weak in defending the competitive position of the resident workforce. Copyright © 2007 John Wiley & Sons, Ltd.
A rather benign sexual culture: socio‐sexual lifestyles of youth in urban Central Java, Indonesia
Authors: Ford Nicholas J. , Shaluhiyah Zahroh , Suryoputro Antono 
Published: December 2006

AbstractSexuality is clearly a key, if often neglected, dimension for both population and medical geography. The challenge of HIV prevention has given rise to research efforts to understand the pattern and dynamics of sexual lifestyles. This paper reports upon findings from such a study undertaken upon the socio‐sexual lifestyles of youth (18–24 years of age) from factory (low‐income) and university (middle class) social environments in urban Central Java, Indonesia. The study involved a combination of quantitative (2000 person sample survey) and qualitative (8 focus group discussions and 15 in‐depth interviews) methods, with data collected from 2003–2004. Analysis of the basic sexual parameters reveals relatively low levels of pre‐marital sexual experience, but (of concern) very low levels of contraceptive precautions within such activity. The main part of the paper concerns a discussion of a range of young men and women's socio‐sexual lifestyles (identified by cluster analysis). The core Javanese concept of gaul is explored in discriminating different global/traditional orientations. The lifestyles are interpreted in terms of the reflexivity of leisure activities, taste and dress, within the broader contexts of Javanese culture and the social transition occurring in the Republic of Indonesia. Copyright © 2007 John Wiley & Sons, Ltd.
Tunneling anisotropic magnetoresistance effect in a p+‐(Ga,Mn)As/n+‐GaAs Esaki diode
Authors: Ciorga M. , Einwanger A. , Sadowski J. , Wegscheider W. , Weiss D. 
Published: December 2006

AbstractWe have performed magnetotransport experiments on p+‐(Ga,Mn)As/n+‐GaAs Esaki diode devices. The spin‐valve‐like signal was observed in these devices in an in‐plane magnetic field configuration due to Tunneling Anisotropic Magnetoresistance effect. The pattern of the observed magnetic reversal process strongly depends on the observed magnetic anisotropy of the (Ga,Mn)As layer – depending on its type the sign of the spin‐valve‐like signal can be changed by a simple rotation of the magnetic field by 90° or not. The type of the anisotropy is found to be strongly shaped, in a random way, during processing of the wafer. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Role of defects on the magnetic interactions in Mn‐doped ZnO
Authors: Iuşan Diana , Sanyal Biplab , Eriksson Olle 
Published: December 2006

AbstractOxide based diluted magnetic semiconductors are highly controversial from the point of view of intrinsic ferromagnetism brought in by doping with transition metal ions. By ab‐initio Korringa–Kohn–Rostoker‐Coherent‐Potential‐Approximation (KKR‐CPA) calculations in the framework of density functional theory, we have obtained the electronic structure and magnetic exchange interaction parameters of Mn‐doped ZnO in the presence and absence of several types of defects. A weak antiferromagnetic exchange interaction is observed in pure Mn‐doped ZnO in the dilute limit with an increase in the strength of interactions with increasing concentration of Mn. In the presence of donor defects, such as oxygen vacancies and interstitial Zn, the interactions remain antiferromagnetic whereas in case of acceptor defects like Zn vacancies and N substitution of O, ferromagnetic interactions are observed. We have used the ab‐initio exchange parameters in Monte‐Carlo simulations for calculating finite temperature properties. Due to the short ranged behavior of interactions and disorder effects, the Curie temperatures calculated from Monte Carlo simulations show moderate values, not exceeding 50 K when the Mn content is 5%. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparative study of Mn and Fe incorporation into GaN by metalorganic chemical vapor deposition
Authors: Kane M. H. , Gupta S. , Fenwick W. E. , Li N. , Park E.‐H. , Strassburg M. , Ferguson I. T. 
Published: December 2006

AbstractWide bandgap diluted magnetic semiconductors (DMS) have been of interest recently due to theoretical predictions of room temperature ferromagnetism in these materials. However, the mechanism of the observed ferromagnetism of the nitrde‐based DMS is still controversial, and may originate from a carrier‐mediated, defect‐related or nanoscale clustering mechanism. In this work, we present a comparative study of the incorporation of various transition metals and their effect on the optical, structural, and magnetic properties of GaN. Metal‐organic chemical vapor deposition (MOCVD) has been employed to produce epitaxial films of varying thickness and manganese and iron concentrations using bis‐cyclopentyldienyl (magnanese, iron) as the transition metal sources. High‐resolution X‐ray diffraction reveals no macroscopic secondary phases under optimized growth conditions. Magnetic hysteresis is observed at room temperature in both Ga1–x Mnx N and Ga1–x Fex N, though the strength of the magnetic ordering is roughly an order of magnitude weaker in the Fe‐alloyed samples. Increasing Mn concentrations significantly affects the long‐range lattice ordering, and the observation of local vibrational modes (LVMs) supports the formation of nitrogen vacancies, even under optimized MOCVD growth conditions. Such vacancies form shallow donor complexes and thus contribute to self‐compensation. Disorder‐induced modes at 300 cm–1 and 710 cm–1 and a LVM due to vacancies at 669 cm–1 were revealed by Raman spectroscopy. The iron‐doped samples also show the disorder‐induced modes, but the vacancy‐related mode is not observed which is attributed to Fermi level and defect formation energy considerations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical and magneto‐optical properties of ZnMnO and ZnMnFeO single crystals and thin films
Authors: Savchuk A. I. , Fediv V. I. , Kleto G. I. , Krychun S. V. , Savchuk S. A. 
Published: December 2006

AbstractSingle crystals of oxide diluted magnetic semiconductor Zn1–x Mnx O have been grown by chemical vapour transport and thin films of Zn1–x Mnx O, Zn1–x –y Mnx Fey O have been deposited by pulsed laser ablation and rf magnetron sputtering methods. Optical absorption spectra of the obtained crystals and films have features associated with band‐to‐band direct type transitions and d–d crystal‐field transitions due to presence of Mn2+ ions. The observed peculiarities of the Faraday rotation for Zn1–x Mnx O crystals and films suggest of paramagnetic behaviour. In contrast, Zn1–x –y Mnx Fey O film samples exhibit ferromagnetic‐like behaviour which is confirmed on typical magnetic field dependence of the Faraday rotation at room temperature. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Competing magnetic phases of Mn5Ge3 compound
Authors: Stroppa Alessandro , Peressi Maria 
Published: December 2006

AbstractGermanium‐based compounds have recently attracted considerable attention in Semiconductor Spintronics. The Mn5Ge3 compound have been grown on Ge(111) substrate so that epitaxial “spin valves” can be fabricated. Recent experiments suggest a spin structure that is likely non‐collinear. In order to gain deep insights into the magnetic structure of this compound, we have performed fully unconstrained ab‐initio pseudo‐potential calculations within spin density functional theory. We have considered several possible magnetic configurations: paramagnetic (PM), collinear (C) ferromagnetic (FM) and anti‐ferromagnetic (AFM), non‐collinear (NC) spin configurations. We first study the effect of the pressure. At equilibrium volume (V eq = 0.203 m3), the C‐FM and NC self‐consistent solutions (which have different magnetic states) are competing phases. For V ≃ 1.1V eq there is a crossover of the C‐FM and C‐AFM curves, with the C‐AFM becoming favourite with respect to C‐FM for larger volumes. Finally, we have studied the effect of strain field. Interestingly, the degeneracy of the NC phase with the C‐spin configurations (FM and AFM) is definitely removed under the effect of uniaxial structural distortions (NC spin configuration is favoured under tensile uniaxial strain). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The growth of Cr‐doped GaN by MOVPE towards spintronic applications
Authors: Cho Y. S. , Kaluza N. , Guzenko V. , Schäpers Th. , Hardtdegen H. , Bochem H.‐P. , Breuer U. , Ghadimi M. R. , Fecioru‐Morariu M. , Beschoten B. , Lüth H. 
Published: December 2006

AbstractThis paper reports on the growth of Cr‐doped GaN layers by metal organic vapor phase epitaxy (MOVPE) and their characterization for possible spintronic applications. We have used bis (cyclopentadienyl)chromium (Cp2Cr) to intentionally incorporate chromium (Cr) during GaN layer growth. The effects of the carrier gas, hardware setup, and growth temperature on the growth of Cr‐doped GaN were investigated. A linear dependence between mole fraction of Cp2Cr in the gas phase and incorporated Cr in the solid phase was found. The surface morphology was mostly influenced by carrier gas and growth temperature. A remanent magnetization was observed even above room temperature. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman studies of ZnO:Co thin films
Authors: Zhou Huijuan , Chen Limei , Malik Vivek , Knies Christoph , Hofmann Detlev M. , Bhatti Kanwal Preet , Chaudhary S. , Klar Peter J. , Heimbrodt Wolfram , Klingshirn Claus , Kalt Heinz 
Published: December 2006

AbstractIn this paper we investigate cobalt doped ZnO thin films prepared via different sol–gel methods. XRD shows only the diffraction peaks from wurtzite ZnO without secondary phase, as widely reported in literature, for the Co contents of our samples of 3 to 12%. Raman spectroscopy reveals the existence of antiferromagnetic cobalt oxides like CoO and Co3O4 already in intermediately doped samples. Furthermore, the Raman shifts of the doped samples exhibit a shift to higher energy with increasing Co doping content. Unfortunately, Raman spectroscopy is not sensitive to metallic Co and, therefore, cannot be employed to explore the presence of Co clusters. However, we demonstrate that XRD is not a suitable method to rule out the existence of magnetic secondary phases in ZnO doped with transition metals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magneto‐optical spectroscopy of spin injection and spin relaxation in ZnMnSe/ZnCdSe and GaMnN/InGaN spin light‐emitting structures
Authors: Buyanova I. A. , Chen W. M. , Oka Y. , Abernathy C. R. , Pearton S. J. 
Published: December 2006

AbstractIn this paper we review our recent results from in‐depth investigations of physical mechanisms which govern efficiency of several processes important for future spintronic devises, such as spin alignment within diluted magnetic semiconductors (DMS), spin injection from DMS to non‐magnetic spin detectors (SDs) and also spin depolarization within SD. Spin‐injection structures based on II–VIs (e.g. ZnMnSe/Zn(Cd)Se) and III–Vs (e.g. GaMnN/Ga(In)N) were studied as model cases. Exciton spin relaxation within ZnMnSe DMS, important for spin alignment, was found to critically depend on Zeeman splitting of the exciton states and is largely facilitated by involvement of longitudinal optical (LO) phonons. Optical spin injection in ZnMnSe/Zn(Cd)Se was shown to be governed by (i) commonly believed tunneling of individual carriers or excitons and (ii) energy transfer via localized excitons and spatially separated localized electron–hole pairs (LEHP) located within DMS. Unexpectedly, the latter mechanism is in fact found to dominate spin injections. We shall also show that spin depolarization in the studied structures is essentially determined by ef‐ ficient spin relaxation within non‐magnetic spin detectors, which is an important factor limiting efficiency of spin detection. Detailed physical mechanisms leading to efficient spin depolarization will be discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamics of spin interactions in diluted magnetic semiconductor heterostructures
Authors: Yakovlev D. R. 
Published: December 2006

AbstractThis paper gives an overview of the recent studies of spin dynamics in diluted magnetic semiconductor heterostructures based on (Zn,Mn)Se and (Cd,Mn)Te. The spin dynamics is controlled by energy and spin transfer between systems of magnetic ions, lattice (phonon system) and free carriers. Spin–lattice relaxation time of the Mn spin system is a very strong function of the Mn content, it decreases by five orders of magnitude when the Mn content changes from 0.4 to 11%. Additionally this time can be tuned by the varying free carrier concentration and by the growth of heteromagnetic structures with inhomogeneous profile of Mn ions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural and magnetic properties of GeMn layers; High Curie temperature ferromagnetism induced by self organized GeMn nano‐columns
Authors: Devillers T. , Jamet M. , Barski A. , Poydenot V. , Dujardin R. , Bayle Guillemaud P. , Rothman J. , Bellet Amalric E. , Cibert J. , Mattana R. , Tatarenko S. 
Published: December 2006

AbstractIn this paper we report on the structural and magnetic properties of GeMn layers grown on Ge(001). We show that for the optimized Mn concentration (6%) and for optimized growth temperature (close to 130 °C), GeMn samples exhibit a high Curie temperature (higher than 400 K) and Anomalous Hall Effect up to room temperature. Our GeMn layers grown at low temperature (70 °C to 130 °C) are composed of vertical Mn‐rich nano‐colums. Samples grown at temperatures higher than 130 °C contain GeMn nanoclusters. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Role of hyperfine interaction on electron spin optical orientation in charge‐controlled InAs–GaAs single quantum dots
Authors: Krebs O. , Eble B. , Lemaître A. , Urbaszek B. , Kowalik K. , Kudelski A. , Marie X. , Amand T. , Voisin P. 
Published: December 2006

AbstractWe report on electron spin physics in a single charge‐tunable self‐assembled InAs/GaAs quantum dot. The hyperfine interaction between the optically oriented electron and nuclear spins leads to the polarization of the quantum dot nuclei. The sign of the resulting Overhauser‐shift depends on the trion state X+ or X–, and remarkably its strength does not vanish in zero magnetic field. This explains the quenching of X+ spin relaxation under steady‐state excitation polarization. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hybrid image‐based collision detection in Java 3D
Authors: Xiao Gaoyu , Aziz Aamer , Nowinski Wieslaw L. 
Published: December 2006

AbstractCollision detection is highly important in computer graphics and virtual reality. Most collision detection methods are object‐based, relying on testing the geometrical interference of objects, and their performance therefore depends on the geometrical complexity of the objects. Recently, image‐based methods have gained increasing acceptance for their simplicity in implementation, robustness with respect to the object geometry, and the potential to distribute the computational burden onto graphics hardware. However, all existing image‐based methods require direct calls to OpenGL, but so far there is no direct way to access OpenGL through the Java 3D API. Although Java 3D provides its own built‐in collision detection classes, they are either incorrect or inefficient. In this paper, we present a hybrid image‐based collision detection method in Java 3D, which incorporates the Java 3D built‐in collision detection and the image‐based collision detection in our specially devised scene graph. In addition, we take advantage of the fact that the 3D position of successive offscreen views (i.e. virtual views perceived by the probing object) does not change significantly and thereby reduce the occurrences of offscreen rendering, so that the collision detection becomes even faster (up to 50% in our case). Experimental results prove the correctness and efficiency of our method. Copyright © 2006 John Wiley & Sons, Ltd.
High‐error approximate dictionary search using estimate hash comparisons
Authors: Rönnblom Johan 
Published: December 2006

AbstractA method for finding all matches in a pre‐processed dictionary for a query string q and with at most k differences is presented. A very fast constant‐time estimate using hashes is presented. A tree structure is used to minimize the number of estimates made. Practical tests are performed, showing that the estimate can filter out 99% of the full comparisons for 40% error rates and dictionaries of up to four million words. The tree is found to be efficient up to a 50% error rate. Copyright © 2006 John Wiley & Sons, Ltd.
Automated bug isolation via program chipping
Authors: Sterling Chad D. , Olsson Ronald A. 
Published: December 2006

AbstractThis paper introduces program chipping, a simple yet effective technique to isolate bugs. This technique automatically removes or chips away parts of a program so that the part that contributes to some symptomatic output becomes more apparent to the user. Program chipping is similar in spirit to traditional program slicing and debugging techniques, but chipping uses very simple techniques based on the syntactic structure of the program. We have developed a chipping tool for Java programs, called ChipperJ, and have run it on a variety of small to large programs, including a Java compiler, looking for various symptoms. The results are promising. The reduced program is generally about 20–35% of the size of the original. ChipperJ takes less than an hour on large programs to perform this reduction; even if it took overnight, that would be reasonable if it saves the developer time. Copyright © 2006 John Wiley & Sons, Ltd.
A simplified analysis and vibration control to super‐high‐rise buildings
Authors: Takabatake Hideo , Satoh Tetsuya 
Published: December 2006

AbstractThis paper clarifies the following four points on the dynamic behavior of super‐high‐rise buildings of 700m high consisting of doubly symmetric frame‐tubes with or without braces. A simple and accurate analytical method presented by Takabatake (1996) is shown to be very useful for the preliminary design of such a mega‐structure. The building is replaced by an equivalent rod which may allow the main deformation field composed of longitudinal deformation, bending, transverse shear deformation, and shear‐lag. It is pointed out originally that, after the horizontal component of earthquake ground motion fades away, noticeable swell breaks out for a long time and that phenomenon is undamping. The serious phenomenon of swell increases remarkably in addition to the action of the horizontal component of an earthquake wave having a long period. The effect of soil–structure interaction on such a structure is discussed using a general analytical method proposed here. An epochal method both to reduce the dynamic response and to leave out the undamping swell after earthquake action is proposed and its effectiveness as a device for vibration control is demonstrated through the numerical computation. Copyright © 2006 John Wiley & Sons, Ltd.
Influence of design procedures on the seismic response of bi‐eccentric plan‐asymmetric systems
Authors: Ghersi A. , Rossi P. P. 
Published: December 2006

AbstractThis paper investigates, by means of idealized one‐storey models, the seismic behaviour of bi‐eccentric plan‐asymmetric structures and the influence of different design practices on it. All the examined design procedures are based on the use of modal analysis, in order to grant, in any case, a reliable estimate of the elastic response. The first procedure requires the standard application of modal analysis (nominal positions of mass and stiffness centres), while the others employ a double application of the same analysis to reduce the ductility demand in occurrence of strong ground motions. Furthermore, within the aforementioned procedures, the importance and effectiveness of the combination of design internal forces induced by two orthogonal seismic components are discussed. In order to obtain statistically representative information on the structural response to seismic loads the models are subjected to a set of 30 bidirectional accelerograms. A wide parametric analysis allows observations and conclusions, which may be considered reliable for asymmetric models characterized by a wide range of values of the structural parameters. Copyright © 2006 John Wiley & Sons, Ltd.
Self‐concept and science achievement: Investigating a reciprocal relation model across the gender classification in a crosscultural context
Authors: Wang Jianjun , Oliver J. Steve , Staver John R. 
Published: December 2006

AbstractScience achievement and self‐concept are articulated in this study to examine a model of reciprocal relationship during a crosscultural transition. Trend data have been gathered to assess changes of the perceived English importance before and after Hong Kong's sovereignty handover from Britain to China. The data analyses were conducted four times across dimensions of gender and timing over which the political transition took place. Besides small gender differences in the statistical results, weak but significant reciprocal relationships have been found between science achievement and self‐concept. In line with a policy of switching the medium of instruction from English to Chinese in most secondary schools, interpretation of different path coefficients obliges incorporation of cross‐cultural understanding in science education. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 45: 711–725, 2008
An engineering process for the verification of real-time systems
Authors: Burns A. , Lin T. -M. 
Published: December 2006

Abstract

The complete verification of the timing properties of a large critical system cannot be undertaken in a single step or with a single method. In this paper we present a process that links together a number of techniques and approaches that cover all stages of development from requirements analysis to code testing. The key elements of the process are: a constrained form of timed automata that uses
delay
and
deadline
to define temporal behaviour, notions of
rely
and
guarantee
to cover temporal dependencies, model checking for design verification, SPARK and Ravenscar restrictions for programming, and scheduling and response time analysis for asserting implementation compliance. Extended examples of the use of the process are given.