bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of diffraction line broadening due to compositional fluctuations in L-alanine-doped triglycine sulfate
Authors: Choudhury Rajul Ranjan , Chitra R. , Ramanadham M.
Published: October 2003

Broadening of X-ray powder diffraction peaks as a result of compositional disorder in L-alanine-doped triglycine sulfate crystals is investigated using the Williamson–Hall method. The analysis indicates that L-alanine substitution in triglycine sulfate crystals leads to anisotropic strain in the crystal.
A neutron diffraction study of xylitol: derivation of mean square internal vibrations for H atoms from a rigid-body description
Authors: Madsen Anders Østergaard , Mason Sax , Larsen Sine
Published: October 2003

A neutron diffraction study of xylitol (C5O5H12) is presented. The nuclear anisotropic displacement parameters have been analysed showing that the carbon–oxygen skeleton conforms to a rigid-body (TLS) description. Applying this TLS model to the xylitol H atoms allows characterization of the internal molecular displacements of the H nuclei, assuming that the observed H nuclear mean-square displacements are a sum of the internal displacements and rigid-body displacements. These internal molecular displacements are very similar for chemically equivalent H atoms and in good agreement with the values obtained by other methods. In all cases the smallest eigenvector of the residual mean-square displacement tensor is almost parallel to the X—H bond. The use of ab initio calculations to obtain the internal vibrations in xylitol is discouraging. Another 12 structures extracted from the literature which have been investigated by neutron diffraction were subjected to a similar analysis. The results for the nine compounds investigated at low temperature conform to the results from xylitol and provide estimates of the internal vibrations of H atoms in a range of chemical environments.
Structural investigation of the Na–Fe–Mo–O system
Authors: Muessig E. , Bramnik K.G. , Ehrenberg H.
Published: October 2003

Four new crystalline structures within the Na–Fe–Mo–O system are reported: sodium tetrairon pentamolydate (1), NaFe4(MoO4)5, α-sodium diiron trimolybdate (2), α-NaFe2(MoO4)3, β-sodium diiron trimolybdate (3), β-NaFe2(MoO4)3, trisodium diiron trimolybdate (4), Na3Fe2(MoO4)3. All these structures belong to orthomolybdate class of compound and are described as networks of [FeO6] octahedra and [MoO4] tetrahedra. They are compared with each other and with other related structures.
Phase transitions in KTP isostructures: correlation between structure and T

c
in germanium-doped RbTiOPO4
Authors: Norberg Stefan T. , Gustafsson Joacim , Mellander Bengt-Erik
Published: October 2003

Crystals of germanium-doped rubidium titanyl phosphate, Rb2(Ti)(Ge0.121Ti0.879)O2(PO4)2 (GeRTP#1) and Rb2(Ge0.125Ti0.875)(Ge0.225Ti0.775)O2(PO4)2 (GeRTP#2), have been structurally characterized from X-ray diffraction data at room temperature. In addition, a third structure, Rb2(TiO)2(PO4)2 (RTP), has been reinvestigated. The exchange of titanium for germanium results in a less distorted octahedral coordination around the two crystallographically independent titanium sites. Additionally, rubidium split-cation positions have been found in these doped RTP crystals. Dielectric measurements show that the phase-transition temperature, T

c
, decreases with increasing germanium concentration, and a direct correlation between the room-temperature split of the rubidium cations and T

c
has been discovered. General trends regarding the relationship between the room-temperature structures of KTP-like compounds and their T

c
values are discussed.
The phases of [(CH3)4N](ClO4) at low temperature
Authors: Palacios Elías , Burriel Ramón , Ferloni Paolo
Published: October 2003

The low-temperature crystal structures of tetramethylammonium perchlorate, [(CH_{3})_{4}N](ClO_{4}), are analysed. At 210 K, a collection of 376 unique reflections on a single crystal gave R = 0.0567 for space group P4/nmm, with a_{1} ={}8.2376 (14), c_{1} = 5.8256 (12) Å and Z = 2, where the ClO_{4} groups are disordered over four orientations. Below T_{c} = 170 K, these groups order in four sublattices, each ion gradually choosing one unique orientation. At 150 K, the crystal is microtwinned. 1389 unique reflections were refined in the orthorhombic space group P2_{1}2_{1}2, with a_{3} = 11.714 (3), b_{3} = 11.784 (3), c_{3} = 5.8265 (9) Å, Z = 4 and R = 0.087. At 30 K, Rietveld refinement gave the same structure as is found at 150 K, with a clear difference between a_{3} and b_{3} [a_{3} = 11.566 (2), b_{3} = 11.806 (2) and c_{3} = 5.729 (1) Å]. The structural models and the phase transition are explained on the basis of electrostatic octopole–octopole interactions among the ClO_{4} groups within layers perpendicular to the c axis. The order parameters of the low-temperature phase are discussed in relation to the structural results.
Can we predict lattice energy from molecular structure?
Authors: Ouvrard Carole , Mitchell John B. O.
Published: October 2003

By using simply the numbers of occurrences of different atom types as descriptors, a conceptually transparent and remarkably accurate model for the prediction of the enthalpies of sublimation of organic compounds has been generated. The atom types are defined on the basis of atomic number, hybridization state and bonded environment. Models of this kind were applied firstly to aliphatic hydrocarbons, secondly to both aliphatic and aromatic hydrocarbons, thirdly to a wide range of non-hydrogen-bonding molecules, and finally to a set of 226 organic compounds including 70 containing hydrogen-bond donors and acceptors. The final model gives squared correlation coefficients of 0.925 for the 226 compounds in the training set and 0.937 for an independent test set of 35 compounds. The success of such a simple model implies that the enthalpy of sublimation can be predicted accurately without knowledge of the crystal packing. This hypothesis is in turn consistent with the idea that, rather than being determined by the particular features of the lowest-energy packing, the lattice energy is similar for a number of hypothetical alternative crystal structures of a molecule.
Competitor analysis practices of British charities
Authors: Bennett Roger
Published: October 2003

Competition among charities for donor income has increased dramatically in recent years. Moreover, charities have to compete against each other for cause related marketing contracts with commercial enterprises and sponsorship deals, and must bid competitively for government grants. This empirical study explored attitudes and behaviour in relation to competitor analysis (CA) within a sample of 134 British charities. It examined, inter alia, the main sources and uses of CA information, internal stakeholders’ views on whether non‐profit organisations should compete, CA management methods, satisfaction with CA, and possible linkages between CA and fundraising performance. An important aim of the investigation was to establish whether the presence of certain factors known to affect the extent of competition (and by implication the intensity of CA) in purely commercial markets similarly influenced organisations in the charity sector. Conversely, internal stakeholder resistance to the idea that charities should compete against each other did not appear to modify the sample organisations’ actual CA behaviours in any way.
The Internet revolution: some global marketing implications
Authors: Melewar T.C. , Smith Nichola
Published: October 2003

Advances in information technology have constantly impacted upon the global marketing strategies of firms. This paper assesses the implications that an Internet presence can bring to organisations’ global marketing strategies and evaluates the difficulties the Internet can pose to the global marketing strategies of firms, a topic often overlooked in published material. Providing real life examples of online corporate activism this article illustrates how the Internet facilitates an individual’s ability to hold corporations accountable for their actions and proposes strategies which marketers should consider when facing this other side of the Internet.
The marketing of 3G
Authors: Robins Fred
Published: October 2003

This paper is about the marketing of the next generation of mobile phones. It begins with comments on the state of the telecom industry and draws attention to elements of technological and product convergence, highlighting the point that while industry convergence on digital technology is a fact, today’s mobile telephony marketplace is nonetheless characterised by three generations of technology and the latest generation, 3G, embraces three related but competing standards. The paper examines 2G, 2 and a half G and 3G developments around the world and identifies factors relevant to the marketing of 3G, including recognition of geographical and user diversity and the consequent need for marketers to keep these various user perspectives in mind. There is recognition of the financial pressure on telephone operators and of the sometimes emotional and fickle preferences of telephone users. However, customer desire for personalisation, including personalised 3G services, are important features of the marketplace, as will be the availability of simple, secure payment systems.
Towards a value‐based view on operations and maintenance performance management
Authors: Liyanage Jayantha P. , Kumar Uday
Published: October 2003

Most of the North Sea oil companies have recognized the need to adjust their management processes, including those concerned with operations and maintenance, to the changed and changing business conditions in industry at large, particularly due to the volatile oil price. This has been a rationale to review organizational operations and maintenance policies by many. This paper describes findings from a research study on operations and maintenance performance conducted in the emerging operating environment with close cooperation of leading oil and gas organizations in the Norwegian continental shelf. An attempt has been made to develop an architecture for effective management of operations and maintenance performance linking results to performance drivers. This has further been extended to apply the balanced scorecard concept. The papers emphasize on the value rather than the cost of operations and maintenance in the emerging business environment, and stresses that there is a need to move from a plant‐based policy to a more or less long‐term business‐oriented approach.
Adaptive model for vibration monitoring of rotating machinery subject to random deterioration
Authors: Zhan Y. , Makis V. , Jardine A.K.S.
Published: October 2003

Due to the non‐stationarity of vibration signals resulting from either varying operating conditions or natural deterioration of machinery, both the frequency components and their magnitudes vary with time. However, little research has been done on the parameter estimation of time‐varying multivariate time series models based on adaptive filtering theory for condition‐based maintenance purposes. This paper proposes a state‐space model of non‐stationary multivariate vibration signals for the online estimation of the state of rotating machinery using a modified extended Kalman filtering algorithm and spectral analysis in the time‐frequency domain. Adaptability and spectral resolution capability of the model have been tested by using simulated vibration signal with abrupt changes and time‐varying spectral content. The implementation of this model to detect machinery deterioration under varying operating conditions for condition‐based maintenance purposes has been conducted by using real gearbox vibration monitoring signals. Experimental results demonstrate that the proposed model is able to quickly detect the actual state of the rotating machinery even under highly non‐stationary conditions with abrupt changes and yield accurate spectral information for an early warning of incipient fault in rotating machinery diagnosis. This is achieved through combination with a change detection statistic in bi‐spectral domain.
Application and implementation issues of a framework for costing planned maintenance
Authors: Mirghani Mohamed Ali
Published: October 2003

This paper develops a case study on the application and implementation issues of a framework for costing planned maintenance. It outlines the methodology for the development of the case study and presents the major findings of the existing maintenance‐costing system of the organization under study. It presents the results of a pilot study of the application of the proposed costing framework to a sample of planned maintenance jobs. It provides recommendations and identifies critical issues for a successful implementation.
Building digital libraries from simple building blocks
Authors: Suleman Hussein , Fox Edward A. , Kelapure Rohit , Krowne Aaron , Luo Ming
Published: October 2003

Metadata harvesting has been established by the Open Archives Initiative as a viable mechanism for connecting a provider of data to a purveyor of services. The Open Digital Library model is an emerging framework which attempts to break up the services into appropriate components based also on the basic philosophy of the OAI model. This framework has been applied to various projects and evaluated for its simplicity, extensibility and reusability to support the hypothesis that digital libraries should be built from simple Web service‐like components instead of as monolithic software applications.
Information literacy: an integrated concept for a safer Internet
Authors: Ramalho Correia Ana Maria , Carlos Teixeira José
Published: October 2003

This paper aims to provide an overview of some of the most recent developments in concepts and practices associated with information literacy worldwide, revealing the paradox that, while information literacy is a key discipline of the information society and knowledge economy and is well‐understood in its broader sense, it has made little progress educationally, save for a few exceptions in countries such as Australia, the USA, Canada and the UK. Deriving from the authors' background as university professors, the paper concentrates on approaches to promote information literacy in higher education. The paper concludes by pointing to the need to expand the debate on information literacy and how to raise ethical and moral concerns in the use of the Internet and the new technologies. It also explores the potential role that the European Commission eSafe (2003‐2004) programme can play to encourage research and practice on information literacy in its widest sense, as an intrinsic competency in the fight against the effects of disseminating illegal and harmful content through online and other new technologies.
Heuristics, tools, and systems for evaluating Internet information: helping users assess a tangled Web
Authors: Fritch John W.
Published: October 2003

This paper discusses facilitated Internet evaluation, explores heuristics, tools and systems that have been developed to help users evaluate Internet information. Delineates a taxonomy for these systems, and offers descriptive information and sample tools representative of each category.
Which academic subjects have most online impact? A pilot study and a new classification process
Authors: Thelwall Mike , Vaughan Liwen , Cothey Viv , Li Xuemei , Smith Alastair G.
Published: October 2003

The use of the Web by academic researchers is discipline‐dependent and highly variable. It is increasingly central for sharing information, disseminating results and publicising research projects. This pilot study seeks to identify the subjects that have the most impact on the Web, and look for national differences in online subject visibility. The highest impact sites were from computing, but there were major national differences in the impact of engineering and technology sites. Another difference was that Taiwan had more high impact non‐academic sites hosted by universities. As a pilot study, the classification process itself was also investigated and the problems of applying subject classification to academic Web sites discussed. The study draws out a number of issues in this regard, having no simple solutions and point to the need to interpret the results with caution.
Characteristics and choices of public access Internet users in Victorian public libraries
Authors: Hardy Gary , Johanson Graeme
Published: October 2003

Provision of public Internet access has been viewed by governments as a key step towards encouraging uptake among people who do not have access to information communication technologies, and as an important means of building an equitable information society. The Victorian Public Library network has led Australia in providing this access, at no small cost. However, little substantial data is available about the users of this public access, little is known of what they use the access for, nor how well it meets their needs. Through a wide‐scale survey, and through focus groups this study explores the demographic characteristics of public library public access Internet users, the extent to which public access Internet provision meets the needs of those users, and users' planned/future use of public access Internet. The role of public access and the policy implications of this data are discussed.
TIME-REVERSAL, LOOP-ANTILOOP SYMMETRY AND THE BESSEL EQUATION
Authors: ALFINITO ELEONORA , VITIELLO GIUSEPPE
Published: October 2003

The Bessel equation is shown to be equivalent, under suitable transformations, to a system of two damped/amplified parametric oscillator equations, which have been used in the study of inflationary models of the Universe, thermal field theories and Chern–Simons gauge theories. The breakdown of loop-antiloop symmetry due to group contraction manifests itself as breaking of time-reversal symmetry. The relation between some infinite dimensional loop-algebras, such as the Virasoro-like algebra, and the Euclidean algebras e(2) and e(3) is also analyzed.
THE SUPPRESSION OF QUANTUM PHENOMENA BY AN EXTERNAL STRONG WHITE-NOISE MAGNETIC FIELD: A PATH INTEGRAL ARGUMENT
Authors: BOTELHO LUIZ C. L.
Published: October 2003

We give a path-integral argument to obtain the classical regime of a quantum system by means of an external magnetic random field.
STUDY OF PROTEIN FOLDING USING THE LATTICE MODEL WITH UNRESTRICTED BOUNDARY
Authors: ZHANG WEI , SUN ZHI-BO , ZOU XIAN-WU
Published: October 2003

xProtein folding in a two-dimensional lattice with an unrestricted boundary is simulated by means of the simplified HP model. The proteins are regarded as peptide chains and fold into compact structures. These structures are classified by the number of core sites. It is found that the number of structures with the given designability and given number of core sites versus designability appears as the normal distribution. The simulation shows that the structures with a large number of core sites have a high designability.
OPTIMUM DISPERSION PROFILE AND PEDESTAL-FREE SOLITON PULSE COMPRESSION IN DISPERSION-DECREASING FIBER
Authors: VINOJ M. N. , SEEMA A. U. , KURIAKOSE V. C.
Published: October 2003

We propose soliton pulse compression mechanism in a dispersion decreasing fiber for the integrable case. We have studied the pulse propagation through various dispersion-decreasing profiles in the adiabatic approximation limit. Out of the different profiles studied, Gaussian profile is found to be the best choice for achieving maximum pulse compression and is found that compressed pulse is completely free from pedestals.
SOLITON PROPAGATION IN NONUNIFORM OPTICAL FIBERS
Authors: XIAO YAN , XU ZHIYONG , LI LU , LI ZHONGHAO , ZHOU GUOSHENG
Published: October 2003

In this paper, we construct the Lax pair for a soliton transmission system in nonuniform optical fibers and give N-soliton solution using the Darboux transformation. The explicit one-soliton and two-soliton solutions are presented. Further, we discuss the interaction scenario between two neighboring solitons and the effect of the inhomogeneities of the fiber (z0) on the interaction between two neighboring solitons.
STUDY OF SELF-PUMPED PHASE CONJUGATIONS AND THEIR SUPPRESSIONS AT THE COMMON INPUT OF TWO LASERS
Authors: JINYUN ZHOU , WEIJIANG WANG , YIHUA HU
Published: October 2003

Two He-Ne laser beams at some distance, with their included angle only a few tenths of a degree, are intersected on the surface of a photorefractive BaTiO 3: Ce crystal at the same incidence point to simultaneously conduct their self-pumped phase conjugations (SPPCs). Our experimental results and theoretical analysis show that, when a stronger laser and a weaker laser are applied to the crystal, the mutual competition of their build-up gratings can greatly interfere the weaker laser with the formation of its SPPC. The weaker SPPC response time is of the order of minutes, quite long compared with that of its normal circumstances.
AN ACCURATE METHOD FOR EXTRACTING NONLINEAR REFRACTION BY Z-SCAN TECHNIQUE IN THE PRESENCE OF NONLINEAR ABSORPTION
Authors: GUO SHENG-LI , XU LI , YAN JUN , WANG HUI-TIAN , YOU XIAO-ZENG , MING N. B.
Published: October 2003

We suggest an accurate method for extracting nonlinear refraction from the closed aperture Z-scan transmittance curve with the aid of the open aperture Z-scan transmittance curve; this method possesses very high accuracy, especially, in the presence of nonlinear absorption and/or for the larger linear transmittance of the aperture. The relative error of the results given by our method is only weakly dependent on the intensity of the incident light; which is a significant advantage over other methods. This method is also demonstrated experimentally on a solution of Ni(mpo) 2 complex.
OPTIMIZATION OF GdCOB:Nd AND YCOB:Nd CRYSTALS FOR SELF-FREQUENCY DOUBLING OUT OF THE PRINCIPAL PLANES
Authors: BRENIER ALAIN
Published: October 2003

From the linear, nonlinear optical and laser properties of GdCOB:Nd and YCOB:Nd self-frequency doubling crystals, we have found that the slow laser wave at 1060 nm has a higher emission cross-section than the fast one in the whole locus of SH phase matching, meaning that self-frequency doubling should be possible on this whole locus. We have pointed out that the phase matching direction for maximum nonlinear optical coefficient d eff is far from the one for maximum laser emission cross-section. The question of optimum direction for the self-frequency doubling laser was solved with a complete laser modelling. The maximum value of the SH yield occurs at a polar angle θ=68° for GdCOB:Nd , that is to say, close to the value of the optimum nonlinear optical coefficient d eff . For YCOB:Nd , the polar angle at maximum SH yield is shifted at 72°, that is to say, towards the direction of the largest laser emission cross-section. In both cases, we can notice a larger "angular acceptance" on the locus of phase matching for the self-frequency doubling laser than for extra-cavity single pass frequency doubling.
EFFECT OF SOLVENT ON NONLINEAR REFRACTIVE INDEX OF 2-(2′-HYDROXYPHENYL) BENZOXAZOLE
Authors: ZHANG GUILAN , XIONG FEIBING , ZHANG BAO , TANG GUOQING , CHEN WENJU , WANG LIANYING , BAI YUBAI
Published: October 2003

Nonlinear refractive indexes n2 of 2-(2′-hydroxyphenyl) benzoxazole (HBO) in three species of solvent (cyclohexane, ethanol and dimethyl sulfoxide) have been determined by using the Z-scan technique. The experimental results show that the n2 of HBO is strongly dependent on the polarity of the solvent. Through the study on the absorption and fluorescence spectra of HBO in different solvents, we regard that the principal origin of the nonlinear refractive index of HBO is not the thermal effect because of absorption of incident light but the excited state intramolecular proton transfer of HBO under the incident light.
NONLINEAR OPTICAL RESPONSE AND REVERSE SATURABLE ABSORPTION OF RARE EARTH PHTHALOCYANINE IN DMF SOLUTION
Authors: KUMAR G. A.
Published: October 2003

Nonlinear optical response and reverse saturable absorption behavior of various rare earth phthalocyanines such as Nd , Eu , Sm and La in dimethyl formamide (DMF) solution were studied under high power Nd:YAG laser excitation. Excited state absorption cross-sections and two-photon absorption cross-sections of these systems are measured from the limiting characteristics. The SmHPc 2 system yields maximum value for excited state absorption cross-section and its potential application in DMF as a suitable optical limiter is also discussed.
COMPARISON OF INTERCHANNEL FOUR-WAVE MIXING WITH CONTINUOUS WAVES, QUASI-CONTINUOUS WAVES AND ULTRASHORT PULSES
Authors: GAO SHIMING , YANG CHANGXI , JIN GUOFAN
Published: October 2003

We compare the interchannel four-wave mixing (FWM) in dense wavelength division multiplexing (DWDM) systems with continuous waves, quasi-continuous waves and ultrashort pulses. The differences are theoretically analyzed for the three inputs. We investigate the FWM conversion efficiency as a function of the channel spacing, the fiber length, the single bit energy and the pulse width. It is shown that the FWM effect in DWDM systems with quasi-continuous waves is the strongest and with ultrashort pulses is the lowest among the three cases. The FWM conversion efficiency changes periodically with the propagation length, and it is approximately an exponential function of the single bit energy. The performance of the pulse FWM effect versus the pulse width is different from that of the quasi-continuous wave FWM, which may be one possible way to suppress the interchannel FWM.
A STOCHASTIC GOLDEN RULE AND QUANTUM LANGEVIN EQUATION FOR THE LOW DENSITY LIMIT
Authors: ACCARDI L. , PECHEN A. N. , VOLOVICH I. V.
Published: October 2003

A rigorous derivation of quantum Langevin equation from microscopic dynamics in the low density limit is given. We consider a quantum model of a microscopic system (test particle) coupled with a reservoir (gas of light Bose particles) via interaction of scattering type. We formulate a mathematical procedure (the so-called stochastic golden rule) which allows us to determine the quantum Langevin equation in the limit of large time and small density of particles of the reservoir. The quantum Langevin equation describes not only dynamics of the system but also the reservoir. We show that the generator of the corresponding master equation has the Lindblad form of most general generators of completely positive semigroups.
CAPACITIES ON C*-ALGEBRAS
Authors: COMMAN HENRI
Published: October 2003

We distinguish three classes of capacities on a C*-algebra: subadditive, additive and maxitive. A tightness notion for capacities, the vague and narrow topologies on the set of capacities are introduced. The vague space of additive capacities which are finite on compact projections is a noncommutative version of the usual vague space of Radon measures on a locally compact Hausdorff space X. We give criterions of vague and narrow relative compactness in various classes of capacities. This allows us to extend most classical compactness theorems for Radon measures. The set of bounded (resp. tight) maxitive capacities is in bijection with the set of positive q-upper semicontinuous (resp. strongly q-upper semicontinuous) operators. This allows us to define a vague (resp. narrow) large deviation principle for a net of capacities as a vague (resp. narrow) convergence of this net towards a maxitive capacity, generalizing the classical notion for Radon probability measures on X. Next, we apply compactness theorems in order to extend some results in large deviations theory.
THE FIVE INDEPENDENCES AS NATURAL PRODUCTS
Authors: MURAKI NAOFUMI
Published: October 2003

Let [Formula: see text] be the class of all algebraic probability spaces. A "natural product" is, by definition, a map [Formula: see text] which is required to satisfy all the canonical axioms of Ben Ghorbal and Schürmann for "universal product" except for the commutativity axiom. We show that there exist only five natural products, namely tensor product, free product, Boolean product, monotone product and anti-monotone product. This means that, in a sense, there exist only five universal notions of stochastic independence in noncommutative probability theory.
MULTIPLE POSITIVE SOLUTIONS OF NONLINEAR EIGENVALUE PROBLEMS ASSOCIATED TO A CLASS OF p-LAPLACIAN LIKE OPERATORS
Authors: FUKAGAI NOBUYOSHI , NARUKAWA KIMIAKI
Published: October 2003

This paper deals with positive solutions of a class of nonlinear eigenvalue problems. For a quasilinear elliptic problem (#) - div (ϕ(|∇u|)∇u) = λf(x,u) in Ω, u = 0 on ∂Ω, we assume asymptotic conditions on ϕ and f such as ϕ(t) ~ tp0-2, f(x,t) ~ tq0-1as t → +0 and ϕ(t) ~ tp1-2, f(x,t) ~ tq1-1as t → ∞. The combined effects of sub-nonlinearity (p0> q0) and super-nonlinearity (p1< q1) with the subcritical term f(x,u) imply the existence of at least two positive solutions of (#) for 0 < λ < Λ.
EXISTENCE OF LATTICES IN KAC–MOODY GROUPS OVER FINITE FIELDS
Authors: CARBONE LISA , GARLAND HOWARD
Published: October 2003

Let [Formula: see text] be a Kac–Moody Lie algebra. We give an interpretation of Tits' associated group functor using representation theory of [Formula: see text] and we construct a locally compact "Kac–Moody group" G over a finite field k. Using (twin) BN-pairs (G,B,N) and (G,B-,N) for G we show that if k is "sufficiently large", then the subgroup B- is a non-uniform lattice in G. We have also constructed an uncountably infinite family of both uniform and non-uniform lattices in rank 2. We conjecture that these form uncountably many distinct conjugacy classes in G. The basic tool for the construction of non-uniform lattices in rank 2 is a spherical Tits system for G which we also construct.
CRITICAL GROUPS AT INFINITY, SADDLE POINT REDUCTION AND ELLIPTIC RESONANT PROBLEMS
Authors: LIU SHIBO , LI SHUJIE
Published: October 2003

We prove that if the Lyapunov–Schmidt method is applicable, then the critical groups at infinity of the reduced functional are isomorphic to those of the original functional. This observation, combining with our results on the critical groups of finite dimensional functional, enables us to compute the critical groups at infinity. New multiplicity results for resonant elliptic boundary value problems are obtained as applications.
STELLAR MODELS AND IRREGULAR SINGULARITIES
Authors: JAGER LISETTE , KICHENASSAMY SATYANAD
Published: October 2003

This paper proves two results on the determination of asymptotics of solutions of linear and nonlinear ODE. The first shows the stability of singular solutions of the point-source model of stellar structure. It hinges on the solution of a singular initial-value problem where data are prescribed at the singularity. As a further illustration of the use of such singular problems, a simple method to determine the eigenfunction asymptotics for problems with long-range potentials is included.
SOME UNIQUENESS RESULTS FOR ELLIPTIC EQUATIONS WITHOUT CONDITION AT INFINITY
Authors: PORRETTA A.
Published: October 2003

We prove in this work uniqueness results concerning a class of elliptic equations having gradient dependent absorption terms, whose simplest model is given in [Formula: see text] We deal with the question whether uniqueness for solutions in the whole space holds without any condition at infinity, giving a positive answer in the one dimensional case as well as in the radial case in ℝN.
A COMPARISON OF HOFER'S METRICS ON HAMILTONIAN DIFFEOMORPHISMS AND LAGRANGIAN SUBMANIFOLDS
Authors: OSTROVER YARON
Published: October 2003

We compare Hofer's geometries on two spaces associated with a closed symplectic manifold (M,ω). The first space is the group of Hamiltonian diffeomorphisms. The second space ℒ consists of all Lagrangian submanifolds of M × M which are exact Lagrangian isotopic to the diagonal. We show that in the case of a closed symplectic manifold with π2(M) = 0, the canonical embedding of Ham (M) into ℒ, f ↦ graph (f) is not an isometric embedding, although it preserves Hofer's length of smooth paths.
MIXED QUANTUM-CLASSICAL SEMI-RIGID VIBRATING ROTOR TARGET MODEL FOR ATOM-POLYATOM REACTION: O(3P) + CH4 → CH3 + OH
Authors: WANG MING-LIANG , ZHANG JOHN Z. H.
Published: October 2003

In this paper, a mixed quantum-classical semi-rigid vibrating rotor target (QC-SVRT) model has been applied to study the reaction O(3P) + CH4 → CH3 + OH based on H + CH4 potential surface of Jordan and Gilbert. In this approach, the relative translational motion between atom and polyatom molecules is treated classically while the others are treated quantum mechanically. The reaction probabilities and rate constants were carried out using the QC-SVRT approach. It was found that the QC-SVRT results are in good agreement with the quantum results and the reaction threshold is correctly produced in the present calculation. The application of this QC-SVRT approach makes it more practical to extend quantum reaction dynamics calculation to larger molecules and more complex systems without incurring significant loss of important quantum effects.
PREFACTOR-FREE FORWARD-BACKWARD SEMICLASSICAL DYNAMICS
Authors: YAN YUN-AN , SHAO JIUSHU
Published: October 2003

Within a differential expression of the Heisenberg operator, the forward and backward evolution can be joined together along a closed time contour. This manipulation leads to a dramatic cancellation of oscillations due to the two individual propagators in the Heisenberg operator and the resulting forward-backward propagator is more tractable to semiclassical approximations. This article gives a detailed description of the forward-backward semiclassical dynamics (FBSD) formalism. The semiclassical propagators, especially those of the initial value representations (IVRs), are briefly discussed. The derivation of the FBSD based on the Herman–Kluk propagator is reviewed. Different FBSD formulations with other semiclassical IVRs are worked out and numerical calculations show that they are also capable of describing quantum dynamics semiquantitatively and all display accuracy similar to the classical Wigner method.
EXCITON MIGRATION IN DENDRITIC AGGREGATE SYSTEMS USING THE QUANTUM MASTER EQUATION APPROACH INVOLVING WEAK EXCITON-PHONON COUPLING
Authors: TAKAHATA MASAHIRO , NAKANO MASAYOSHI , YAMAGUCHI KIZASHI
Published: October 2003

The quantum master equation approach involving a weak exciton-phonon coupling is applied to the exciton migration dynamics of dendritic molecular aggregates modeled after a phenylacetylene dendrimer, D25, which exhibits an efficient light-harvesting property. The mechanism of efficient exciton migration from the periphery to the core is studied by analyzing relaxation terms among the exciton states originating in weak exciton-phonon coupling. Partial overlaps of exciton distributions between neighboring exciton states are found to be important for realizing the unique migration behavior by step-by-step transfer from the periphery to the core via multi-step exciton states. The same calculation method is applied to the exciton dynamics of a larger dendritic aggregate model, D127, modeled after the largest synthesized phenylacetylene dendrimer D127 in order to examine the dependencies of the exciton migration on the strength of the intermolecular interaction and the temperature of phonon bath. In the case of the relatively weak dipole-dipole coupling, exciton is not observed to migrate efficiently from the periphery to the core, while the largest exciton population is found to remain in the intermediate generations. This is ascribed to the fact that the thermal excitation to the higher exciton states significantly contributes to the exciton distribution in the equilibrium state when the weak intermolecular interaction reduces the energy difference between exciton states. This indicates that the intermolecular interaction is important not only for the overlaps of the exciton distributions between the exciton states, but also the relation between the exciton energy differences and thermal excitations, which spoil the distinct concentration of exciton distribution in the core generation. In the case of a low temperature, even if the intermolecular interaction is weak, the exciton population in the core region is found to be the largest in all the generations. This suggests that exciton tends to efficiently migrate from the periphery to the core when the temperature is sufficiently low. Implications of these theoretical results are discussed in relation to design of magneto-optical materials and other technological applications.
QUANTUM TRANSPORT AND CURRENT-TRIGGERED DYNAMICS IN MOLECULAR TUNNEL JUNCTIONS
Authors: SEIDEMAN TAMAR , GUO HONG
Published: October 2003

The modelling of nanoelectronic systems has been the topic of ever increasing activity for nearly two decades. Yet, new questions, challenges and opportunities continue to emerge. In this article we review theoretical and numerical work on two new developments in the theory of molecular-scale electronics. First we review a density functional theory analysis within the Keldysh non-equilibrium Green function formalism to predict nonlinear charge transport properties of nanoelectronic devices. Next we review a recently developed quantum mechanical formalism of current-triggered nuclear dynamics. Finally we combine these theories to describe from first principles the inelastic current and the consequent molecular dynamics in molecular heterojunctions.
COMPARISON OF MULTIPLE LINEAR REGRESSION AND ARTIFICIAL NEURAL NETWORKS IN PREDICTING OCTANOL/WATER PARTITION COEFFICIENT OF A VARIETY OF ORGANIC MOLECULES
Authors: JALILI SEIFOLLAH , TAFAZZOLI MOHSEN , JALALI-HERAVI MEHDI
Published: October 2003

For estimating log P values of a group of organic compounds, a back-propagation neural network with a 9–6–1 architecture was developed with optimal learning rate (ε) and momentum (μ) of 0.24 and 0.82, respectively. A collection of 131 organic compounds was chosen as data set that consists of normal hydrocarbons, alcohols, ethers, amines, ketones, acids, benzene derivatives, phenols, and aldehydes. The data set was divided into a training set consisting of 118 molecules and a prediction set consisting of 18 molecules. The most important properties that affect the partition coefficients of organic compounds (surface/volume, dipole moment, and those which are related to electrostatic potentials such as the sum of charges on the carbon atoms) were used as descriptors. These descriptors were obtained using AM1 semiempirical MO method for the gas phase geometries. The descriptors were selected via developing a multiple linear regression analysis. The ANN calculated values of partition coefficients (log Ps) for molecules of the training and prediction sets are in good agreement with the experimental values.
CALCULATION OF THE DIFFUSION COEFFICIENTS FOR MIXTURES OF NO WITH He, Ne, Ar AND Kr AT LOW DENSITY USING SEMI-EMPIRICAL INVERSION METHOD
Authors: HAGHIGHI BEHZAD , DJAVANMARDI ALIREZA HASSANI , NAJAFI MOHSEN , PAPARI MOHAMMAD MEHDI
Published: October 2003

Diffusion coefficients for four equimolar binary gaseous mixtures of NO–noble gases are determined from the principle of corresponding states of viscosity by the inversion technique. The Lennard–Jones 12-6 (LJ 12-6) potential energy function is used as the initial model potential required by the technique. The interaction potential energies from the inversion procedure reproduce diffusion coefficients within 5%.
DESIGN OF AN INTERACTIVE VIRTUAL FACTORY USING CELL FORMATION METHODOLOGIES
Authors: KESAVADAS T. , ERNZER M.
Published: October 2003

This paper describes an interactive virtual environment for modeling and designing factories and shop floors. The factory building tool is developed as an open architecture in which various modules can be utilized to quickly implement factory design algorithms ranging from plant layout to factory flow analysis. Software modules and utilities have been implemented to allow easy set-up of the visual interface. In this paper, this virtual factory is used to implement cellular manufacturing (CM) system. CM has traditionally been a very complicated system to implement in practice. However successful implementation of the system has improved productivity immersely. Several issues involved in implementing CM within our virtual factory machine modeling and interface designs for defining the cells, are discussed. The mathematical clustering algorithm called Modified Boolean Method was implemented to automatically generate complex virtual environments. The virtual factory makes the process of CM-based factory design a very easy and intuitive process. Though the cell formation problem is NP-complete in 2D space, issues related to human factors and ergonomics can be better perceived in a 3D virtual environment. It also leads to further optimization with respect to maintainability and performance, and thus help get better solutions, which are not visible unless the factory is built. Our virtual factory interface also allows easy reassignment of machines and parts, subcontracting of bottleneck parts and rearranging of machines within the same design environment, making this a productive industrial tool. 3D virtual factory can also be automatically generated from the Part Machine interface called the Virtual Matrix Interface.
CHIP FORMATION ANALYSIS FOR HIGH SPEED CUTTING
Authors: LUO YAN
Published: October 2003

Enterprise has to reduce time and cost of product development to face global competition. New technologies and machining strategies have been widely adopted in manufacturing enterprise such as high-speed cutting (HSC). Tool wear prediction will be useful for tool management and thus, reducing the manufacturing cost of HSC. This related project is developed at the Institute of Production Management, Technology and Machine Tools (PTW), TU Darmstadt. The aim of the project is to find a solution to predict tool wear by calculation for HSC. This paper focuses on chip formation analysis. Chip geometry will be generated and calculated to estimate tool wear. The paper presents an algorithm to visualize chip geometry for ball end tool and discusses further the parameters features of chip section.
Postgenomics: Proteomics and Bioinformatics in Cancer Research
Authors: Bensmail Halima , Haoudi Abdelali
Published: October 2003

Now that the human genome is completed, the characterization of
the proteins encoded by the sequence remains a challenging task.
The study of the complete protein complement of the genome, the
“proteome,” referred to as proteomics, will be essential if new
therapeutic drugs and new disease biomarkers for early diagnosis
are to be developed. Research efforts are already underway to
develop the technology necessary to compare the specific protein
profiles of diseased versus nondiseased states. These
technologies provide a wealth of information and rapidly generate
large quantities of data. Processing the large amounts of data
will lead to useful predictive mathematical descriptions of
biological systems which will permit rapid identification of
novel therapeutic targets and identification of metabolic
disorders. Here, we present an overview of the current status and
future research approaches in defining the cancer cell′s proteome
in combination with different bioinformatics and computational
biology tools toward a better understanding of health and disease.
Challenges in Designing Human-Animal Interaction Research
Authors: Wilson Cindy C. , Barker Sandra B.
Published: October 2003

This article addresses challenges in designing Human-Animal Interaction (HAI) research. A summary of previous reviews of HAI research is presented, followed by a discussion of areas that present particular challenges to research in this field, specifically design issues, control of extraneous variables, sample selection, intervention development, and outcome measurement. Suggestions for addressing these areas also are presented.
Child Development and the Human-Companion Animal Bond
Authors: Melson Gail F.
Published: October 2003

Companion animals are more common in households with minor children than in any other household type. More than 70% of U.S. households with children also have pets, with most parents reporting acquisition of an animal "for the children." Yet, studies of children's development largely have been limited to children's relationships with other humans. This article argues for a biocentric approach to development, in which children's contacts with the non-human world—animals, plants, and natural ecologies—come under scientific scrutiny. To understand the developmental significance of this ubiquitous aspect of children's environments, theory and research on companion animals in relation to perceptual, cognitive, social, and emotional development are reviewed and evaluated. The significance of children's encounters with animals, especially in the context of a human-companion animal bond, is emphasized. Biocentric research directions are described.
A History of Prison Inmate-Animal Interaction Programs
Authors: Strimple Earl O.
Published: October 2003

Interest is growing in establishing animal-facilitated programs in prisons. Although food animals have been maintained by prisons for years, few have looked at the benefits inmates derive from working with animals. Recently, prisons have started dog and horse training programs. Preliminary evidence indicates that inmates benefit, learning life-enhancing skills and lowering the recidivism rates. Shelter dogs and wild horses trained by the prisoners help people with physical and emotional needs. State and federal funds are needed to further study the benefits derived for prisoners, animals, and society.
Human-Animal Interaction
Authors: Johnson Rebecca A. , Meadows Richard L. , Haubner Jennifer S. , Sevedge Kathy
Published: October 2003

There is growing and widespread use of complementary and alternative medical (CAM) techniques among cancer patients. The National Cancer Institute recognizes a myriad of CAM techniques that may be used. Research demonstrates that cancer patients use these techniques to try to regain control of their disease process and treatment and to facilitate quality of life. The purpose of this article is to discuss the uses of CAM among cancer patients and to present findings of a pilot study in which cancer patients being treated in an inpatient hospital unit were randomly assigned to receive either a brief visit from a trained visitor dog and its handler, a visit from a friendly human visitor, or a session of quiet reading. Findings revealed that those who received the dog visit were more likely to view the visit as part of their therapy and were more likely to tell another person about the visit.
Future Directions in Human-Animal Bond Research
Authors: Beck Alan M. , Katcher Aaron H.
Published: October 2003

Human-animal contact can influence psychological and physiological parameters important to health and welfare; nevertheless, there has been relatively little research on the variables that influence or mediate those health consequences. In addition, little attention has been paid on how to create or alter the animal interactions for the betterment of people and their animals. The investigation can be guided by two theoretical perspectives, which make powerful but different and testable predictions: the biophilia hypothesis and social support theory. Along with this theoretically driven research, there is a need for replication of salient research findings to resolve important discrepancies in the literature. Last, animal-assisted therapy (AAT) has to be placed in the context of alternative therapies now available to define its specificity, risks, and overall benefits.