bluuebunny/crossref_metadata_2025 huggingface dataset:
Pentacene organic field-effect transistor on metal substrate with spin-coated smoothing layer
Authors: Jin Yanbo , Rang Zhenlin , Nathan Marshall I. , Ruden P. Paul , Newman Christopher R. , Frisbie C. Daniel
Published: November 2004

In this letter we report the use of roughly polished aluminum substrates with spin-coated polymer-smoothing layers for the fabrication of pentacene field-effect transistors. Transistors with spin-coated poly(methylmethacrylate) gate insulator layers were fabricated and showed good performance. On the gate insulator surface, the root-mean-square roughness was found to be 0.18nm, significantly smaller than the aluminum surface roughness, which is on the scale of tens of nanometers. Field-effect carrier mobilities extracted from the device data reached 0.75cm2V−1s−1; the maximum on/off current ratio was near 5×106.
Short-period superlattices of AlN∕Al0.08Ga0.92N grown on AlN substrates
Authors: Nikishin S. A. , Borisov B. A. , Chandolu A. , Kuryatkov V. V. , Temkin H. , Holtz M. , Mokhov E. N. , Makarov Yu. , Helava H.
Published: November 2004

High-quality short-period superlattices of AlN∕Al0.08Ga0.92N have been grown by gas-source molecular-beam epitaxy with ammonia on Al face of AlN (0001) substrates. A significant reduction was achieved in the dislocation density, down to 3×108cm−2. Complete removal of residual Al2O3 surface oxide is needed in order to obtain low dislocation density in homoepitaxy on AlN. We show that the presence of Al2O3 islands with the surface coverage as low as 0.2% results in increased dislocation density.
Controlled intensity emission from patterned porous silicon using focused proton beam irradiation
Authors: Teo E. J. , Mangaiyarkarasi D. , Breese M. B. H. , Bettiol A. A. , Blackwood D. J.
Published: November 2004

We have fabricated light emitting porous silicon micropatterns with controlled emission intensity. This has been achieved by direct write irradiation in heavily doped p-type silicon (0.02Ωcm) using a 2MeV proton beam, focused to a spot size of 200nm. After electrochemical etching in hydrofluoric acid, enhanced photoluminescence is observed from the irradiated regions. The intensity of light emission is proportional to the dose of the proton beam, so the PL intensity of the micropattern can be tuned and varied between adjacent regions on a single substrate. This behavior is in contrast to previous ion beam patterning of p-type silicon, as light is preferentially created as opposed to quenched at the irradiated regions.
Pressure-tuned InGaAsSb∕AlGaAsSb diode laser with 700nm tuning range
Authors: Adamiec P. , Salhi A. , Bohdan R. , Bercha A. , Dybala F. , Trzeciakowski W. , Rouillard Y. , Joullié A.
Published: November 2004

In Ga As Sb ∕ Al Ga As Sb type-I midinfrared diode lasers emitting continuous wave at 2.4μm at room temperature have been studied under high hydrostatic pressure. When the pressure was increased up to 19kbar, the threshold current varied from 240to400A∕cm2, showing a minimum of 200A∕cm2 close to 8kbar, and the emission spectra shifted to shorter wavelengths by up to 700nm (i.e., from 2.4μmto1.7μm). This exceptional tuning range could be very useful in tunable diode laser absorption spectroscopy.
Improved characteristics for Au∕n-GaSb Schottky contacts through the use of a nonaqueous sulfide-based passivation
Authors: Liu Z. Y. , Saulys D. A. , Kuech T. F.
Published: November 2004

The influence of nonaqueous sulfide passivation (using Na2S in the inert solvent benzene) on Au∕n-GaSb Schottky junction behavior was studied. The junction parameters, Schottky barrier height and ideality factor, were derived and compared with those of as-received GaSb surfaces as well as surfaces treated with aqueous sulfide solutions. The Schottky junction made on as-received GaSb is highly nonideal, while S-based passivation treatment of the GaSb surface before contact formation improves the rectifying behavior, and markedly reduces the reverse current. A benzene-based nonaqueous sulfide treatment results in GaSb surfaces with lower oxide and elemental antimony content than does the aqueous sulfide treatment. The produced Schottky barrier height increases to 0.61eV and the Au∕n-GaSb contact is close to an ideal Schottky junction.
Correlation of molecular conformation with adhesion at AlOx∕poly (ethylene terephthalate) interface studied by sum-frequency generation spectroscopy
Authors: Miyamae Takayuki , Nozoye Hisakazu
Published: November 2004

The interface between AlOx and poly(ethylene terephthalate) has been investigated by sum-frequency generation (SFG). A considerable improvement in adhesion strength was achieved by short time Ar plasma modification. The increase of the adhesion strength shows good correlation with the increase of the SFG peak strength. By depositing AlOx, the increase of SFG intensities and appearance of a new peak are observed, indicating the formation of a CO⋯Al bond at the interface. Surface-modification and interfacial adhesion property are discussed.
Band-edge exciton states in AlN single crystals and epitaxial layers
Authors: Chen L. , Skromme B. J. , Dalmau R. F. , Schlesser R. , Sitar Z. , Chen C. , Sun W. , Yang J. , Khan M. A. , Nakarmi M. L. , Lin J. Y. , Jiang H.-X.
Published: November 2004

The band-edge excitonic properties of AlN are investigated using low-temperature (1.7K) optical reflectance and transmission measurements of samples with various crystal orientations. The A, B, and C excitons are found to have energies of 6.025, 6.243, and 6.257eV in unstrained material, which shift with strain. The results are compared to a calculation of exciton energies and oscillator strengths to yield a crystal-field splitting of −230meV in unstrained AlN, in good agreement with previous ab initio calculations.
Band-structure calculations of imperfect Co2MnGe Heusler compounds
Authors: Carey M. J. , Block T. , Gurney B. A.
Published: November 2004

The effect of imperfections on the bandstructure of Co2MnGe is explored. In particular, the effect of uniform and tetragonal distortions, and Cu, Al, O, Rh, and Sn impurities on the half-metallic behavior are examined. We find that a high spin polarization can be maintained even under significant strains and distortions. However, we find that impurities with as little as 3% concentration will generally have a significant detrimental effect on the half-metallic behavior of the Heusler alloy.
Colloid formation and laser-induced bleaching in fluorite
Authors: LeBret Joel B. , Cramer Loren P. , Norton M. Grant , Dickinson J. T.
Published: November 2004

Colloid formation and subsequent laser-induced bleaching in fluorite has been studied by transmission electron microscopy and electron diffraction. At high incident electron-beam (e-beam) energies, Ca colloids with diameter ∼10nm form a simple cubic superlattice with lattice parameter a∼18nm. The colloids themselves are topotactic with the fluorite matrix forming low-energy interfaces close to a Σ=21 special grain boundary in cubic materials. Laser irradiation using λ=532nm has been shown to effectively bleach the e-beam-irradiated samples returning the fluorite to its monocrystalline state. The bleached samples appear more resistant to further colloid formation.
Thermal stability of current gain in InGaP∕GaAsSb∕GaAs double-heterojunction bipolar transistors
Authors: Yan B. P. , Hsu C. C. , Wang X. Q. , Yang E. S.
Published: November 2004

The thermal stability of current gain in InGaP∕GaAsSb∕GaAs double-heterojunction bipolar transistors (DHBTs) is investigated. The experimental results show that the current gain in the InGaP∕GaAsSb∕GaAs DHBTs is nearly independent of the substrate temperature at collector current densities >10A∕cm2, indicating that the InGaP∕GaAsSb∕GaAs DHBTs have excellent thermal stability. This finding suggests that the InGaP∕GaAsSb∕GaAs DHBTs have larger emitter-base junction valence-band discontinuity than traditional GaAs-based HBTs.
Initial stages of oxide nanodot heteroepitaxial growth: Cu2O on SrTiO3(100)
Authors: Lyubinetsky I. , El-Azab A. , Lea A. S. , Thevuthasan S. , Baer D. R.
Published: November 2004

The growth mechanism in a heteroepitaxy of oxide nanodots is investigated by a combination of x-ray photoelectron spectroscopy (XPS), atomic force microscopy, and theoretical modeling. In contrast to the majority of semiconductor systems, in the studied metal oxide system of Cu2O–SrTiO3(100) the growth process starts without wetting layer formation with the appearance of small (∼10nm) square-based planar Cu2O nanodots. Continued deposition leads mainly to increase of the nanodot density, practically, without change of their size. Only after reaching some critical density (∼1013cm−2 for 760K growth temperature), growth of scattered, significantly larger islands starts through the coalescence of small nanodots. XPS analysis suggests that the interface between small nanodots and substrate is abrupt with only weak Cu–O(SrTiO3) interaction.
Polarization switching in (001)-oriented Pb(Mg1∕3Nb2∕3)O3−x%PbTiO3 crystals: Direct observation of heterogeneous nucleation by piezoreponse force microscopy
Authors: Bai Feiming , Li JieFang , Viehland D.
Published: November 2004

Polarization switching in (001)-oriented Pb(Mg1∕3Nb2∕3)O3−x%PbTiO3, PMN-x%PT, crystals for x=20 and 35 has been investigated in situ by scanning force microscopy in a piezoresponse mode, under a step-increased dc electrical voltage (Vdc). The results demonstrate that switching initiates by the nucleation of nanosized polar regions with a reversed polarization. For x=20, nucleation occurs heterogeneously throughout the volume of the crystal. However, with increasing PT content, nucleation tends to preferentially initiate near preexisting twin boundaries; with increasing Vdc, the domains becoming increasingly “diffuse” due to heterogeneous nucleation and growth throughout the crystal.
Ecological impacts on aquatic macroinvertebrates following upland stream invasion by a ponded pasture grass (Glyceria maxima) in southern Australia
Authors: Clarke Amber , Lake P. S. , O'Dowd Dennis J.
Published: November 2004

Glyceria maxima (Reed sweet-grass), an emergent aquatic grass native to Eurasia, has naturalised in North America, New Zealand and southern Australia. Introduced as a ponded pasture species, it threatens native biodiversity and ecosystem processes in freshwater wetlands and waterways. We compared paired sections, either invaded or not invaded by G. maxima, of three upland streams in Gippsland, Victoria, Australia to infer its impacts on macroinvertebrate abundance, morphospecies density, and morphospecies and functional feeding group (FFG) composition. Its potential effects in altering sedimentation were explored by comparing stream channel morphology in paired stream sections at one site. Invasion by G. maxima appears to drive changes in macroinvertebrate morphospecies composition and FFG composition, reducing a diverse array of macroinvertebrates to a more uniform fauna. The estimated volume of plant/sediment matrix in a 50 m invaded stream section was around 1100 m3, nearly 15-fold greater than in an adjacent uninvaded stream section. Glyceria maxima is an autogenic ecosystem engineer, with the ability to convert sections of fast-flowing aerobic streams into partially anaerobic swamps. By generating a root-mat swamp with a high capacity to process nutrients, G. maxima may facilitate its own growth and spread, as well as that of secondary invaders.
Tourists increase the contribution of autochthonous carbon to littoral zone food webs in oligotrophic dune lakes
Authors: Hadwen Wade L. , Bunn Stuart E.
Published: November 2004

Tourists can adversely influence the ecology of oligotrophic lakes by increasing algal production via direct nutrient inputs and/or re-suspension of sediments. To assess the influence of tourists on food web dynamics, we used the natural abundance of stable isotopes of carbon and nitrogen to calculate the relative importance of autochthonous and allochthonous carbon sources to littoral zone food webs across five variously visited perched dune lakes on Fraser Island, Australia. The relative importance of autochthonous (phytoplankton and periphyton) carbon to littoral zone consumers was highly variable across taxa and lakes. Despite the potential influence of algal biomass, ambient nutrient concentrations and tannin concentrations on the contribution of autochthonous carbon to littoral zone food webs, none of these variables correlated to the per cent contribution of autochthonous carbon to consumer diets. Instead, autochthonous sources of carbon contributed more to the diets of aquatic consumers in heavily visited lakes than in less visited lakes, suggesting that tourist activities might drive these systems towards an increased reliance on autochthonous carbon. The assessment of the contribution of autochthonous carbon to littoral zone food webs may represent a more robust indicator of the impact of tourists in oligotrophic lakes than standard measures of nutrient concentrations and/or algal biomass.
Infantile colic and the role of trait anxiety during pregnancy in relation to psychosocial and socioeconomic factors
Authors: Canivet Catarina A. , Östergren Per-Olof , Rosén Anne-Sofie , Jakobsson Iréne L. , Hagander Barbro M.
Published: November 2004

Aims: A study was undertaken to assess the impact of psychological, psychosocial and socioeconomic factors on the risk of having a child with infantile colic. Methods: Psychosocial and psychological factors were assessed by self-administered questionnaires in the 17th, and by telephone interviews in the 35th—37th pregnancy weeks; infantile colic occurrence was assessed by telephone interviews at infant age 5 weeks; subjects were 1,099 mother—infant dyads. Results: High trait anxiety increased the colic risk; OR 2.04 (95% CI: 1.16, 3.59), and so did affirming a perceived risk of spoiling young infants with too much physical contact; OR 1.77 (1.07, 2.91). In the final step of a multivariate model, not cohabiting with the child's father was the factor with the strongest association with colic; OR 3.48 (1.38, 8.77). Analyses of effect modification showed that high education seemed to protect from the influence of high trait anxiety. Young women were particularly high in trait anxiety, and being exposed to both these risk factors seemed to act synergistically on the risk of having a colicky infant; OR 2.41 (1.12, 5.18). Conclusions: Psychological and psychosocial factors were found to be significantly related to an increased risk for infantile colic, and these factors interacted with age, parity, social support, and educational level in a complex manner. Even though no single most important psychosocial risk factor was identified, the findings lend support to the strategy of offering special attention in terms of information and support in the maternal healthcare system to very young women, women who do not cohabit with the father, and women with high trait anxiety.
Protein kinase C spatially and temporally regulates gap junctional communication during human wound repair via phosphorylation of connexin43 on serine368
Authors: Richards Theresa S. , Dunn Clarence A. , Carter William G. , Usui Marcia L. , Olerud John E. , Lampe Paul D.
Published: November 2004

Phosphorylation of connexin43 (Cx43) on serine368 (S368) has been shown to decrease gap junctional communication via a reduction in unitary channel conductance. Examination of phosphoserine368 (pS368) in normal human skin tissue using a phosphorylation site–specific antibody showed relatively even distribution throughout the epidermal layers. However, 24 h after wounding, but not at 6 or 72 h, pS368 levels were dramatically increased in basal keratinocytes and essentially lost from suprabasal layers adjacent to the wound (i.e., within 200 μm of it). Scratch wounding of primary human keratinocytes caused a protein kinase C (PKC)-dependent increase in pS368 in cells adjacent to the scratch, with a time course similar to that found in the wounds. Keratinocytes at the edge of the scratch also transferred dye much less efficiently at 24 h, in a manner dependent on PKC. However, keratinocyte migration to fill the scratch required early (within <6 h) gap junctional communication. Our evidence indicates that PKC-dependent phosphorylation of Cx43 at S368 creates dynamic communication compartments that can temporally and spatially regulate wound healing.
Recycling endosomes can serve as intermediates during transport from the Golgi to the plasma membrane of MDCK cells
Authors: Ang Agnes Lee , Taguchi Tomohiko , Francis Stephen , Fölsch Heike , Murrells Lindsay J. , Pypaert Marc , Warren Graham , Mellman Ira
Published: November 2004

The AP-1B clathrin adaptor complex is responsible for the polarized transport of many basolateral membrane proteins in epithelial cells. Localization of AP-1B to recycling endosomes (REs) along with other components (exocyst subunits and Rab8) involved in AP-1B–dependent transport suggested that RE might be an intermediate between the Golgi and the plasma membrane. Although the involvement of endosomes in the secretory pathway has long been suspected, we now present direct evidence using four independent methods that REs play a role in basolateral transport in MDCK cells. Newly synthesized AP-1B–dependent cargo, vesicular stomatitis virus glycoprotein G (VSV-G), was found by video microscopy, immunoelectron microscopy, and cell fractionation to enter transferrin-positive REs within a few minutes after exit from the trans-Golgi network. Although transient, RE entry appears essential because enzymatic inactivation of REs blocked VSV-G delivery to the cell surface. Because an apically targeted VSV-G mutant behaved similarly, these results suggest that REs not only serve as an intermediate but also as a common site for polarized sorting on the endocytic and secretory pathways.
Second‐order cybernetics: an historical introduction
Authors: Scott Bernard
Published: November 2004

In 1974, Heinz von Foerster articulated the distinction between a first‐ and second‐order cybernetics, as, respectively, the cybernetics of observed systems and the cybernetics of observing systems. Von Foerster's distinction, together with his own work on the epistemology of the observer, has been enormously influential on the work of a later generation of cyberneticians. It has provided an architecture for the discipline of cybernetics, one that, in true cybernetic spirit, provides order where previously there was variety and disorder. It has provided a foundation for the research programme that is second‐order cybernetics. However, as von Foerster himself makes clear, the distinction he articulated was imminent right from the outset in the thinking of the early cyberneticians, before, even, the name of their discipline had been coined. In this paper, the author gives a brief account of the developments in cybernetics that lead to von Foerster's making his distinction. As is the way of such narratives, it is but one perspective on a complex series of events. Not only is this account a personal perspective, it also includes some recollections of events that were observed and participated in at first hand.
Questions about constructivism
Authors: Andrew Alex M.
Published: November 2004

A number of observations are made about the nature of constructivism, with the suggestion that it is a less revolutionary development that has been claimed, and that some accounts imply an unwarranted disregard of the environment. The presentation is meant to be provocative and to invite discussion that may clarify the issues.
Remarks on the foundations of cybernetics and cognitive science
Authors: Gelepithis Petros A.M.
Published: November 2004

The paper states that cybernetics has failed to live up to its dream as an interdisciplinary field unifying all the phenomena within the vast space of animals and machines. It reminds the reader of the cybernetic dream, the related aspirations in the fields of cognitive science and social theory and the overall aim of the unity of science movement. It briefly argues that ignoring communication and adopting continuous systems as its class of systems for theory construction (CSTC) was bound to lead cybernetics to the abandonment of its dream and points out that cognitive science may well be heading the same way. A proposed conception of communication that is both rich enough to be used as a unifying theoretical construct and general enough to cut across all disciplines studying “communication”. On that basis some major implications are outlined. The paper concludes with a brief note on the impact of our conception of communication on the structure of human society.
Essential structure in physical observation
Authors: Booth Anthony G.
Published: November 2004

At the heart of any process of observation there are certain basic things which must happen. These might be analysed in abstract terms, or then again in terms of the quantum physical irreducibles. The paper links between these concerns. It starts by exploring the macroscopic processes which are essential to observation and from there it develops the outline of a path heading towards a continuum based model of quantum mechanics, and in particular, electrodynamics. It exposes attributes which are fundamental to the existence of an observer process, and then explores how the seat of those attributes may be found in the way we set‐up our notion of the basic properties of physical reality. Such a model is offered as a contribution to what is called “second‐order cybernetics”, namely the study of how we go about observing the observer process.
Evidence into practice and health inequalities
Authors: Kelly Michael P. , Swann Catherine
Published: November 2004

This study focuses on the idea of an evidence‐based approach to medical problems, which has been in existence for more than 30 years. This idea of carrying systematic knowledge into practice in public health has recently become part of the present government's drive to modernisation and improved delivery. The study outlines the work of the Health Development Agency (HDA), which has the task of both assembling the public health evidence and obtaining evidence of effectiveness of public health interventions into practice. The underlying purpose is to get evidence together which would help to reduce inequalities in health. A number of lessons in this activity are described.
Knowledge management in non‐profit organizations
Authors: Lettieri Emanuele , Borga Francesca , Savoldelli Alberto
Published: November 2004

The non‐profit sector is at present involved in a deep renewal process. Non‐profit organizations are required to deliver tailored and high‐quality services in order to overcome environmental complexity and scarcity of resources. In this context, non‐profit organizations are being called to reengineer their core processes and organizational paradigms. To achieve excellence, all available resources should be managed with increased effectiveness and efficiency, the most important of these being knowledge. This paper contributes to the literature about the role which knowledge management plays in achieving excellence in the non‐profit sector. In particular, the main results from an explorative survey of Italian non‐profit organizations are formalized and discussed.
Strategic knowledge benchmarking system (SKBS): a knowledge‐based strategic management information system for firms
Authors: María Viedma Marti José
Published: November 2004

In accordance with the resource‐based view and the activity‐based view, sustainable competitive advantages are mainly due to core knowledge that, together with tangible and (especially) intangible resources, develops competitive products and services through the appropriate activities and processes of the value chain. Strategic knowledge benchmarking system (SKBS) is a knowledge‐based strategic management information system framework that has been built drawing direct inspiration from both the above‐mentioned perspectives and tries to refine the classic strategic SWOT analysis. This paper carefully describes OSKBS, one of the two versions of SKBS, and shows the main benefits to be obtained from the systematic use of OSKBS. The SKBS system has been successfully piloted in more than 40 small and medium size European enterprises.
Innovation in the knowing organization: a case study of an e‐commerce initiative
Authors: Wei Choo Chun , Johnston Ray
Published: November 2004

This paper explores the dynamics of information‐ and knowledge‐based activities in one of the world’s leading foreign exchange banks and its development of an innovative online trading system. These activities are analyzed using the framework of “the knowing organization,” which postulates that learning and innovation in organizations result from managing holistically the activities of sensemaking, knowledge creation, and decision‐making (Choo, 1998, 2002). In sensemaking, project members at the bank were driven by their shared beliefs about the competition, customers and technology to enact the challenge of building an online dealing system. Knowledge creation focused on filling perceived gaps, and involved both expanding non‐traditional capabilities within the group and acquiring expertise from outside the group. Decision making at the enterprise level to approve the project was formal and procedural, while decision making at the operational level was open and entrepreneurial. As predicted by the model, the interactions between these activities were vital. The outcome of sensemaking provided the context for knowledge creation and decision making, while the results of knowledge creation provided expanded resources for decision making. The three sets of activities were integrated through strong leadership, group norms of trust and openness, and a set of shared vision and values.
From “ancient” to “modern”: a cross‐cultural investigation of electronic commerce adoption in Greece and the United States
Authors: Chai Lin , Pavlou Paul A.
Published: November 2004

Globalization and the ubiquitous nature of the Internet facilitate e‐commerce activities across nations. An empirical study was conducted using data from Greek and US consumers in order to obtain a better understanding of cross‐cultural e‐commerce adoption. The results give support for the proposed hypotheses, emphasizing the moderating role of cultural differences on consumer e‐commerce adoption. The unique contributions of this paper are three fold. First, we introduce Hofstede's cultural dimension of uncertainty avoidance to the study of cross‐cultural e‐commerce adoption model. Second, we apply the theory of planned behavior perspective to capture behavioral intentions to transact online in two dissimilar countries – Greece and the US. Finally, the paper discusses several insights from this exploratory study that enrich the cross‐cultural e‐commerce literature.
SiteQual: an integrated measure of Web site quality
Authors: Webb Harold W. , Webb Linda A.
Published: November 2004

The development and testing of an instrument for obtaining user feedback on the overall quality of B2C electronic commerce Web sites, SITEQUAL, is discussed. Using previous research in information quality and service quality as a springboard, a conceptual model and an instrument to measure Web site quality were developed. A factor analysis was conducted which suggested that four minimum Web site quality factors and seven desired Web site quality factors are important to consumers in the retail music industry. The use of Web site quality factors for measurement of consumer expectations and perceptions, determining Web site requirements, and guiding the testing process is suggested.
PRUNING OF A LARGE NETWORK BY OPTIMAL BRAIN DAMAGE AND SURGEON: AN EXAMPLE FROM BIOLOGICAL SEQUENCE ANALYSIS
Authors: TOLSTRUP N.
Published: November 2004

Optimal Brain Damage (OBD) and Optimal Brain Surgeon (OBS) represent two popular pruning procedures; however, pruning large networks trained on voluminous data sets using these methods easily becomes intractable. We present a number of approximations and discuss practical issues in real-world pruning, and use as an example a network trained to predict protein coding regions in DNA sequences. The efficiency of OBS on large networks is compared to OBD, and it turns out that OBD is preferable to OBS, since more weights can be removed using less computational effort.
ANALYSIS OF TRAINING SET PARALLELISM FOR BACKPROPAGATION NEURAL NETWORKS
Authors: KING FOO SHOU , SARATCHANDRAN P. , SUNDARARAJAN N.
Published: November 2004

Training set parallelism and network based parallelism are two popular paradigms for parallelizing a feedforward (artificial) neural network. Training set parallelism is particularly suited to feedforward neural networks with backpropagation learning where the size of the training set is large in relation to the size of the network. This paper analyzes training set parallelism for feedforward neural networks when implemented on a transputer array configured in a pipelined ring topology. Theoretical expressions for the time per epoch (iteration) and optimal size of a processor network are derived when the training set is equally distributed among the processing nodes. These show that the speed up is a function of the number of patterns per processor, communication overhead per epoch and the total number of processors in the topology. Further analysis of how to optimally distribute the training set on a given processor network when the number of patterns in the training set is not an integer multiple of the number of processors, is also carried out. It is shown that optimal allocation of patterns in such cases is a mixed integer programming problem. Using this analysis it is found that equal distribution of training patterns among the processors is not the optimal way to allocate the patterns even when the training set is an integer multiple of the number of processors. Extension of the analysis to processor networks comprising processors of different speeds is also carried out.

Experimental results from a T805 transputer array are presented to verify all the theoretical results.
QUANTUM PHASE TRANSITIONS AND ENTANGLEMENT IN J1–J2 MODEL
Authors: ERYIĞIT RECEP , ERYIĞIT RESUL , GÜNDÜÇ YIĞIT
Published: November 2004

We study ground state pairwise entanglement within one-dimensional spin-1/2 antiferromagnetic J1–J2 model with competing interactions. Contrary to some claims we found that frustration does not increase entanglement. Concurrence of nearest and next nearest neighbors are found to show abrupt change at phase transition points. We also show that the concurrence can be used to classify the phase diagram of the model in anisotropy–frustration plane.
EXPONENTIAL AND POWER LAW DISTRIBUTION OF MASS CLUSTERS IN A (MAGNETIC-LIKE) DEPOSITION MODEL OF ELONGATED GRAINS IN 2D PILES
Authors: TROJAN K. , AUSLOOS M. , CLOOTS R.
Published: November 2004

A generalized magnetically controlled ballistic rain-like deposition (MBD) model of granular piles has been numerically investigated in 2D. The grains are taken to be elongated disks whence characterized by a two-state scalar degree of freedom, called "nip", their interaction being described through a Hamiltonian. The results are discussed in order to search for the effect of nip flip (or grain rotation from vertical to horizontal and conversely) probability in building a granular pile. The characteristics of creation of + (or -) nip's clusters and clusters of holes (missing nips) are analyzed. Two different cluster-mass regimes have been identified, through the cluster-mass distribution function which can be exponential or have a power law form depending on whether the nip flip (or grain rotation) probability is large or small. Analytical forms of the exponent are empirically found in terms of the Hamiltonian parameters.
ABOVE BARRIER POTENTIAL DIFFUSION
Authors: BERNARDINI ALEX E. , DE LEO STEFANO , ROTELLI PIETRO P.
Published: November 2004

The stationary phase method is applied to diffusion by a potential barrier for an incoming wave packet with energies greater than the height of the barrier. It is observed that a direct application leads to paradoxical results. The correct solution, confirmed by numerical calculations is the creation of multiple peaks as a consequence of multiple reflections. Lessons concerning the use of the stationary phase method are drawn.
ON A RELATIVISTIC DESCRIPTION OF THE DEEP INELASTIC SCATTERING ON THE DEUTERON
Authors: YU. UMNIKOV A. , KHANNA F. C.
Published: November 2004

The deep inelastic scattering on deuteron is considered in a fully covariant field theoretical approach. All calculations are performed within the Bethe–Salpeter formalism and the operator product expansion method. We obtain the explicit form of the nucleon contribution and mesonic exchange corrections to the deuteron structure function [Formula: see text]. The sum rules for the baryon number and energy-momentum of the deuteron are derived using the normalization condition of the Bethe–Salpeter amplitude and the virial theorem of field theory.
EMPIRICAL MANY-BODY POTENTIAL ENERGY FUNCTION CALCULATION FOR LITHIUM CLUSTERS IN BCC AND FCC SURFACE SYMMETRIES, AND CHEMISORPTION ENERGY OF ATOMIC OXYGEN ON LITHIUM BCC CLUSTERS
Authors: KOLSUZ NURI , ÇIVI MEHMET , ERKOÇ ŞAKIR
Published: November 2004

We have investigated the structure and energetics of lithium clusters containing 3 to 10 atoms in different bcc and fcc surface symmetries, and the interaction of an oxygen atom with lithium clusters in the bcc(100) and bcc(110) surface symmetries. Calculations have been performed by using an empirical many-body potential energy function, which comprises two- and three-body atomic interactions.
KP HIERARCHIES, POLYNOMIAL AND RATIONAL $\mathcal W$ ALGEBRAS ON RIEMANN SURFACES: A GLOBAL APPROACH
Authors: TOPPAN F.
Published: November 2004

A covariant pseudodifferential calculus on Riemann surfaces, based on the Krichever–Novikov global picture, is presented. It allows defining scalar and matrix KP operators, together with their reductions, in higher genus. Globally defined Miura maps are considered and the arising of polynomial or rational [Formula: see text] algebras on R.S. associated to each reduction are pointed out. The higher genus NLS hierarchy is analyzed in detail.
A PARITY INVARIANT SU(3)c ⊗ SU(3)L ⊗ U(1) MODEL
Authors: FOOT R.
Published: November 2004

We examine a SU (3)c ⊗ SU (3)L ⊗ U (1) gauge model which has a parity symmetric Lagrangian. The parity symmetry has the novel feature that it interchanges the gluons with the SU (3)L gauge bosons (which contain the ordinary SU (2)L weak gauge bosons). We show that the model reduces to the standard model at low energies and also predict new physics in the form of exotic fermions.
MSW PROCESS IN SUPERNOVAE
Authors: BUCCELLA F. , ESPOSITO S. , GUALDI C. , SANTORELLI P.
Published: November 2004

We show that with the muon neutrino mass which is necessary for explaining the solar neutrino problem through MSW mechanism, [Formula: see text] and [Formula: see text], we expect different spectra for νe and [Formula: see text] coming from supernovae.
A SIMPLE RELATION AMONG THE QUARK MASSES
Authors: TERAZAWA HIDEZUMI
Published: November 2004

Based on our recent suggestion that the first and second generations of quarks and leptons can be taken as almost and quasi Nambu–Goldstone fermions, respectively, we can derive a simple relation among the quark masses, [Formula: see text], from which the top quark mass is predicted to be mt ≅ (180±100) − (200±110) GeV .
QUARK MASS MATRIX WITH A STRUCTURE OF A RANK-ONE MATRIX PLUS A UNIT MATRIX
Authors: FUSAOKA HIDEO , KOIDE YOSHIO
Published: November 2004

A quark mass matrix model [Formula: see text] is proposed where [Formula: see text] and Oq is a unit matrix plus a rank-one matrix. Up- and down-quark mass matrices Mu and Md are described in terms of charged lepton masses and additional three parameters (one in Mu and two in Md). The model can predict reasonable quark mass ratios (not only mu/mc, mc/mt, md/ms and ms/mb, but also mu/md) and Kobayashi–Maskawa matrix elements.
q-PHASE OPERATOR IN A FINITE-DIMENSIONAL HILBERT SPACE
Authors: YANG YAPING , YU ZURONG
Published: November 2004

In this letter, the unitary and Hermitian phase operators for the single-mode electromagnetic field are given in the q-deformed case. A new kind of q-coherent states of a q-harmonic oscillator in a finite-dimensional Hilbert space are introduced. Some properties of these operators and q-coherent states are discussed.
CAN A GRAVITATIONAL GEON EXIST IN GENERAL RELATIVITY?
Authors: COOPERSTOCK F. I. , FARAONI V. , PERRY G. P.
Published: November 2004

It is shown that no spherically symmetric gravitational geon composed of small amplitude gravitational waves can be in consistent with general relativity. The necessity for high frequency gravitational waves in turn prevents their confinement. This suggests that no gravitational geon can exist.
DETERMINATION OF EFFECTIVE ACTIONS FOR SU(3) LATTICE GAUGE THEORY
Authors: TAKAISHI T.
Published: November 2004

The demon method is applied to determine the effective action on blocked SU(3) gauge configurations. First the method is tested on SU(3) gauge configurations with known couplings. It turns out that the method works well to determine couplings with good precision in rather short microcanonical updates. Next the method is implemented for a set of blocked SU(3) gauge configurations and we successfully determine an effective action in seven-dimensional coupling constant space.
THE GROSS–NEVEU MODEL ON THE LIGHT-CONE
Authors: PESANDO IGOR
Published: November 2004

We consider the (massive) Gross–Neveu model using the light-cone quantization where we solve the constraints explicitly. We show that the vacuum is trivial and that the quantization fails when m = 0. We show that the running coupling constant emerges as a pure normal ordering effect and we discuss the bound state equation.
ON CONDITIONALLY QUASI-EXACTLY SOLVABLE CLASS OF QUANTUM POTENTIALS
Authors: DUTT R. , VARSHNI Y. P. , ADHIKARI R.
Published: November 2004

A new class of potentials is generated for which exact solutions for one or few states are possible provided one of the potential parameters is assigned a fixed value and there is a constraint relation amongst the others. The method of construction of such conditionally quasi-exactly solvable potentials is illustrated by a few examples.
BLACK HOLE THERMODYNAMICS AND RENORMALIZATION
Authors: FURSAEV DMITRI V.
Published: November 2004

Ultraviolet regime in quantum theory with horizons, contrary to ordinary theory, depends on the temperature of the system which is due to additional surface divergences in the effective action. We evaluate their general one-loop structure paying attention to effects of the curvature of the space-time near the horizon. In particular, apart from the area term, the entropy of a black hole is shown to acquire a topological correction in the form of the integral curvature of the horizon. To get the entropy, heat capacity and other finite thermodynamical quantities, such as the kind of singularities should be removed by renormalization of a number of constants in a surface functional introduced in the effective action at arbitrary temperature. We also discuss a discrepancy in the different regularization techniques.
ON THE STATISTICS OF SU(1, 1)q and SU(2)q COHERENT STATES
Authors: JING SI-CONG , FAN HONG-YI
Published: November 2004

We find that the SU (2)q coherent state and SU (1, 1)q coherent state in the sense of statistics can be classified as q-binomial state and q-negative binomial state, respectively. Their relations with the q-Euler distribution and q-Heine distribution are discussed.
THE CASIMIR ENERGY FOR TWO-DIMENSIONAL DEFORMED SPHERE
Authors: SHTYKOV N. , VASSILEVICH D. V.
Published: November 2004

We compute the Casimir energy for a free scalar field on the spaces [Formula: see text] where [Formula: see text] is two-dimensional deformed two-sphere.
NONLINEAR NONLOCAL THEORY OF GRAVITY
Authors: NOVELLO M. , DE LORENCI V. A.
Published: November 2004

Deser and Laurent (1968) explored an alternative linear theory for spin-two field using a nonlocal divergence-free projection operator on the matter energy-momentum tensor. Here, we extend this theory by including nonlinearity of the gravitational field. We show that such extended model satisfy the four standard tests of weak gravity. The consequences for strong gravitational fields are under examination.
HAMILTONIAN BRST QUANTIZATION OF AN ABELIAN MASSIVE VECTOR FIELD WITH AN ANTISYMMETRIC TENSOR FIELD
Authors: SAWAYANAGI HIROHUMI
Published: November 2004

The Lagrangian of an Abelian massive vector field gives a system with second class constraints. We apply the Batalin–Fradkin formalism, which converts second class constraints to first class ones through the introduction of new variables. As a new variable, instead of the Stueckelberg field, we introduce an antisymmetric tensor field. A covariant gauge-fixed action is presented. The unitarity and the duality are also discussed.
LANDAU-GINZBURG ORBIFOLDS WITH DISCRETE TORSION
Authors: KREUZER MAXIMILIAN , SKARKE HARALD
Published: November 2004

We complete the classification of (2, 2) vacua that can be constructed from Landau-Ginzburg models by Abelian twists with arbitrary discrete torsions. Compared to the case without torsion, the number of new spectra is surprisingly small. In contrast to a popular expectation mirror symmetry does not seem to be related to discrete torsion (at least not in the present compactification framework). The Berglund-Hübsch construction naturally extends to orbifolds with torsion; for more general potentials, on the other hand, the new spectra neither have nor provide mirror partners in our class of models.
QCD CORRECTIONS TO THE $H^ + \to t\bar b$ DECAY WITHIN THE MINIMAL SUPERSYMMETRIC STANDARD MODEL
Authors: KÖNIG HEINZ
Published: November 2004

The results of the QCD corrections to the [Formula: see text] decay within the minimal super-symmetric standard model such that gluinos and scalar quarks are taken within the relevant loop diagram are presented. The mixing of the scalar partners of the left- and right-handed top quarks which is proportional to the top quark mass is included. The standard corrections via gluons and quarks are about +7% for a charged Higgs mass of 300 GeV and about −10% for a Higgs mass of 800 GeV. The standard corrections can be shown to diminish or enhance by a non-negligible amount of certain values of the supersymmetric parameter space. The sign changes can also be obtained.
NONCRITICAL BOSONIC STRING CORRECTIONS TO THE BLACK HOLE ENTROPY
Authors: ELIZALDE E. , ODINTSOV S.D.
Published: November 2004

We calculate the quantum corrections to the entropy of a very large black hole, coming from the theory of a D-dimensional, noncritical bosonic string. We show that for D>2, as a result of modular invariance the entropy is uv finite though it diverges in the ir (while for D=2 the entropy contains both uv and ir divergences). The issue of modular invariance in field theory, in connection with black hole entropy, is also investigated.
DIMENSIONAL CONTINUATION WITHOUT PERTURBATION THEORY
Authors: PERIWAL VIPUL
Published: November 2004

A formula is proposed for continuing physical correlation functions to noninteger numbers of dimensions, expressing them as infinite weighted sums over the same correlation functions in arbitrary integer dimensions. The formula is motivated by studying the strong coupling expansion, but the end result makes no reference to any perturbation theory. It is shown that the formula leads to the correct dimension dependence in weak coupling perturbation theory at one-loop.
NONEQUILIBRIUM THERMODYNAMIC FLUCTUATIONS OF (2+1)-DIMENSIONAL BLACK HOLES
Authors: BIN WANG , JIONG-MING ZHU
Published: November 2004

Applying the Landau-Lifshitz theory for thermodynamic fluctuations and the structure of (2 +1)-dimensional space-time, we calculate and estimate the second moments of some relevant quantities for (2+1)-dimensional Schwarzschild black hole, Kerr black hole and Reissner-Nordstrom black hole. The nonequilibrium second-order phase transition for extremal (2+1)-dimensional space-time is discussed.
EXCHANGE OPERATORS AND THE EXTENDED HEISENBERG ALGEBRA FOR THE THREE-BODY CALOGERO-MARCHIORO-WOLFES PROBLEM
Authors: QUESNE C.
Published: November 2004

The exchange operator formalism introduced recently for the Calogero problem is extended to that of the three-body Calogero-Marchioro-Wolfes. In the absence of oscillator potential, the Hamiltonian of the latter is interpreted as a free particle Hamiltonian, expressed in terms of the generalized momenta. In the presence of oscillator potential, it is regarded as a free modified boson Hamiltonian. The modified boson operators are shown to belong to a D6-extended Heisenberg algebra. A proof of the complete integrability is also provided.
BOSE-EINSTEIN CORRELATIONS AND THE FRAGMENTATION RADIUS
Authors: GAGO ALBERTO , HERRERA GERARDO
Published: November 2004

In nuclear reactions the radii of the fragmentation volume obtained with Bose-Einstein correlations reflect the effective radius of the projectile. However, according to the phenomenological parametrizations of the effect, the Compton wavelength scale of the meson is actually extracted. We propose a solution to this puzzle and conclude that in heavy-ion collisions Bose-Einstein interference does allow the spacetime description of the fragmentation region.
TYPE II ANYON SUPERCONDUCTIVITY
Authors: KIM JEWAN , KIM JUNGDAE , LEE TAEJIN
Published: November 2004

Assuming that the superconductivity which is described by the low energy effective action of the anyon system may be type II, we discuss its characteristics. We also study physical properties of the Chern-Simons vortices, which may be formed as the external magnetic field is applied to the system, such as their statistics, the free energy of single vortex and the interaction energy between two vortices.
CONSTRAINTS ON THE NUMBER OF HEAVY GENERATIONS FROM THE S AND T PARAMETERS
Authors: INAMI TAKEO , KAWAKAMI TADASHI , LIM C.S.
Published: November 2004

We show that precision measurements of the oblique correction parameters S and T can be used to derive an upper bound on the number of extra generations of heavy fermions Neg. The bound depends on the type of heavy neutrino masses. We have obtained Neg≤2 in the case of Dirac neutrinos and Neg≤5 in the case of neutrinos with Majorana masses, under some assumptions on the flavor and color contents of extra generations.
NEW LEP CONSTRAINTS ON SOME SUPERSYMMETRIC YUKAWA INTERACTIONS THAT VIOLATE R-PARITY
Authors: BHATTACHARYYA GAUTAM , ELLIS JOHN , SRIDHAR K.
Published: November 2004

We consider one-loop corrections to partial widths of the Z induced by supersymmetric Yukawa interactions that violate R-parity. The precise experimental values of the leptonic Z partial widths bound these Yukawa couplings, with the most interesting constraints being those on couplings involving τ, since previous constraints on them were very mild.
THE MSW EFFECT FOR MAJORANA NEUTRINO
Authors: LEE JAE SIK , KWON HAE MYOUNG , KIM JAE KWAN
Published: November 2004

We study the MSW effect when neutrinos are the Majorana particles with a nonvanishing CP-violating phase using the method based on the neutrino energy eigenstates in a medium with varying density. We calculate the transition probability P(νe→νe) as a function of the ratio of neutrino energy to neutrino mass difference E/Δ0 in the solar neutrino case for several values of the mixing angle θ and the CP-violating phase σ. We observe that the overall shape of the transition probability is not affected by the phase σ.
SUPERCRITICAL POMERON AND EIKONAL REPRESENTATION OF THE DIFFRACTION SCATTERING AMPLITUDE
Authors: GOLOSKOKOV S.V. , KULESHOV S.P. , SELYUGIN O.V.
Published: November 2004

The intercept of the supercritical pomeron is examined with the use of different forms of the scattering amplitudes of the bare pomeron. The one-to-one correspondence between the eikonal phase and the ratio of the elastic and total cross-section is shown. Based on new experimental data of the CDF collaboration, the intercept and power of the logarithmic growth of the bare and total pomeron amplitude are analyzed. It is shown that as a result of the eikonalization procedure, the bare QCD pomeron becomes compatible with experiment.