bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of imprinting pressure on residual layer thickness in ultraviolet nanoimprint lithography
Authors: Lee Heon
Published: July 2005

Since ultraviolet (UV) imprint lithography can be used to fabricate nanosized patterns with extremely high throughput, it is regarded as one of the most promising technologies for nanosized patterning. However, for it to become a mass production technology for the fabrication of nanosized patterns, UV imprint lithography must demonstrate the capability to perform imprinting with a uniform and minimized residual layer. In UV imprint lithography, the thickness of the imprint residual layer is determined by various process parameters, including the initial thickness of the applied resin layer dependent on the spin speed, the viscosity of the resin, the imprint pressure, and the structure of the imprint template and pattern area. Among these process parameters, the thickness of the applied resin layer and the imprint pressure are focused on in this study. In order to transfer patterns with a uniform and minimized residual layer, the imprint resin must be rearranged during imprinting. Thus, the ability to achieve uniform pressing with a high pressure (>15atm) is very important. In this study, a commercially available imprinting system was used. The imprint system is of the pressurized chamber type and uses isotropic pressure to deliver the pressing force uniformly. A commercially available UV curable imprint resin was used.
Thin-film transformations and volatile products in the formation of nanoporous low-k polymethylsilsesquioxane-based dielectric
Authors: Lazzeri P. , Vanzetti L. , Anderle M. , Bersani M. , Park J. J. , Lin Z. , Briber R. M. , Rubloff G. W. , Kim H. C. , Miller R. D.
Published: July 2005

The thermal transformation of spin-cast thin films to produce nanoporous low-k dielectric layers has been investigated using polymethysilsesquioxane (PMSSQ) for the low-k matrix and polymethylmethacrylate-co-dimethylaminoethylacrylate (PMMA-co-DMAEMA) as the porogen which is volatilized to leave nanopores in the matrix. Surface analysis methods, including time of flight-secondary ion mass spectrometry and x-ray photoelectron spectroscopy, and thin film analysis by small-angle neutron scattering revealed the kinetics of matrix crosslinking, while thermal desorption mass spectrometry showed the evolution of gaseous reaction products from porogen and matrix during the complex chemical transformations which occur with thermal cycling from 100°Cto450°C. Matrix crosslinking occurs primarily at lower temperatures (100–225°C), while porogen diffusion and decomposition begins somewhat above 200°C, leading to phase separation which creates the final nanoporous structure. Since matrix and porogen reaction kinetics have some overlap, relative kinetics can be important: e.g., matrix crosslinking proceeds more rapidly for PMSSQ precursors with high Si–OH content cf. low SiOH content, with implications for the morphology of porogen-derived nanostructure. As surface species transform (matrix crosslinking) and disappear (porogen volatilization), their complements are seen in the gas phase as reaction and decomposition products. Porogen decomposition is ligand selective, in that the N-containing ligand of DMAEMA is volatilized at considerably lower temperatures (∼200°C) than that (∼400°C) for the remaining species (the PMMA ligand and the common backbone for both PMMA and DMAEMA).
Effect of micro-twin defects on InSb quantum wells
Authors: Mishima T. D. , Keay J. C. , Goel N. , Ball M. A. , Chung S. J. , Johnson M. B. , Santos M. B.
Published: July 2005

We have investigated the effect of micro-twin defects on InSb quantum wells (QWs) grown on GaAs (001) substrates. Transmission electron microscopy analysis revealed that the QW layers are intersected by micro-twins that arise from lattice mismatch with the substrate. The intersected parts of the QWs lie near or in the {111} plane, which is tilted by 15.8° with respect to the (001) substrate. Hall effect measurements indicated that the degradation of electron mobility in the QWs is well correlated with the density of the micro-twins.
Site-controlled InAs quantum dots on GaAs patterned using self-organized nano-channel alumina template
Authors: Meneou K. , Tsai C. L. , Zhang Z. H. , Cheng K. Y.
Published: July 2005

Nano-pore arrays on GaAs by templated anodization of GaAs through a nano-channel alumina (NCA) membrane are reported for the first time. The NCA is formed by anodization of single-crystal aluminum grown epitaxially on a GaAs substrate. The anodization is continued into the GaAs underneath the NCA, which is anodized only at the pore bottoms of the NCA. After removal of the NCA, the nanostructured GaAs obtained is studied using scanning electron microscopy. The obtained nano-pores are 30–50 nm deep and spaced ∼100nm apart. Site-controlled InAs self-assembled quantum dots are demonstrated by regrowth on this nanostructured GaAs.
Imaging patterns of intensity in topographically directed photolithography
Authors: Paul Kateri E. , Breen Tricia L. , Hadzik Tanja , Whitesides George M. , Smith Stephen P. , Prentiss Mara
Published: July 2005

This article describes a process that consists of embossing a bas-relief pattern into the surface of a layer of photoresist and flood illuminating the embossed resist; this process uses the topography of the resist to generate a pattern of optical intensity inside the resist layer. Development of embossed, illuminated (λ=365–436nm) photoresist yields structures as small as 70nm. Numerical solutions of the Fresnel integral are used to calculate the pattern of intensity of light in the photoresist layer. Numeric simulation of a nondiffusion-limited development process results in theoretical structures that correlate well with the structures generated experimentally.
Characteristics of perylene-based organic thin-film transistor with octadecyltrichlorosilane monolayer
Authors: Park D. S. , Kang S. J. , Kim H. J. , Jang M. H. , Noh M. , Yoo K.-H. , Whang C. N. , Lee Y. S. , Lee M. H.
Published: July 2005

We fabricated perylene-based organic thin-film transistor (OTFT) with an octadecyltrichlorosilane (OTS) monolayer in an ultrahigh vacuum condition. By current–voltage characteristics, the saturation current and the field effect mobility of OTS–OTFT (gold∕perylene∕OTS∕SiO2∕p+-Si) increased over ∼100 times in comparison with normal-OTFT (gold∕perylene∕SiO2∕p+-Si), and on/off ratio increased over ∼100 times. The saturation current, field effect mobility, and on/off ratio were >1μA, 0.042cm2∕Vs, and >106, respectively. The uniformity of the OTS layer was confirmed by x-ray reflectivity. Perylene thin films on SiO2 and OTS∕SiO2 were compared by atomic force microscopy, scanning electron microscopy, x-ray diffraction, and x-ray photoscopy.
Self-terminated oxide polish technique for the waveguide ridge laser diode fabrication
Authors: Peng Te-Chin , Yang Chih-Chao , Huang Yun-Hsun , Wu Meng-Chyi , Ho Chong-Lung , Ho Wen-Jeng
Published: July 2005

Semiconductor lasers fabricated by the traditional process for communication application usually adopt a ridge-waveguide structure for its ease of manufacture. However, the rugged planes of these devices would cause metal coverage problems and interconnection difficulty. A planarization technique based on a self-aligned technique for fabricating the ridge-weaveguide semiconductor laser diode is introduced in this article. The technique is based on a process called “self-terminated oxide polish.” By using this technique, metal coverage problems usually encountered in the laser diode with a double trench structure will be reduced. Since the metal pad lies on a thick oxide layer, the device will also have a lower parasitic capacitance, which will be beneficial to high-speed operation. Device characteristics of several ridge-waveguide laser diodes fabricated using this self-aligned method will be presented.
Photoreflectance characterization of InP∕GaAsSb double-heterojunction bipolar transistor epitaxial wafers
Authors: Sugiyama Hiroki , Oda Yasuhiro , Kobayashi Takashi , Uchida Masahiro , Watanabe Noriyuki
Published: July 2005

We report photoreflectance (PR) measurements of InP∕GaAsSb double-heterojunction bipolar transistor epitaxial wafers grown by metalorganic vapor-phase epitaxy and discuss the correlation between the spectra and the electrical characteristics of the emitter–base (E∕B) heterojunctions. The origin of Franz–Keldysh oscillations (FKOs) in the PR spectra was identified by step etching of the samples. The current–voltage characteristics of the E∕B heterojunctions were examined by fabricating devices. FKOs from both the emitter and collector regions were observed in the wafers where the recombination forward current at the E∕B heterojunction was suppressed. In contrast, when the recombination current was significant, no emitter-related FKOs were observed. The absence of the FKOs from the emitter indicates the high concentration of recombination centers at the E∕B heterojunction.
Effect of carrier hopping and relaxing on photoluminescence line shape in self-organized InAs quantum dot heterostructures
Authors: Nee Tzer-En , Wu Ya-Fen , Lin Ray-Ming
Published: July 2005

A steady-state thermal model for carrier dynamics in self-organized InAs∕GaAs quantum dot heterostructure is presented. The effect of quantum-dot size distribution, density of states random population, thermal emission, retrapping, and relaxation are investigated. The temperature-dependent photoluminescence spectra obtained from two samples with different dot densities and size uniformities are simulated in this model and show a good agreement with experiment. The corresponding mechanisms of carrier dynamics related to the thermal redistribution and lateral transition of excited carriers as well as the observed phenomena resulting from these mechanisms, are discussed in detail.
Molecular beam epitaxial growth of Fe(Si1−xGex)2 epilayers
Authors: Cottier R. J. , Amir F. Z. , Hossain K. , House J. B. , Gorman B. P. , Perez J. M. , Holland O. W. , Golding T. D. , Stokes D. W.
Published: July 2005

The semiconducting silicides offer significant potential for use in optoelectronic devices. Full implementation of the materials, however, requires the ability to tailor the energy gap and band structure to permit the synthesis of heterojunctions. One promising approach is to alloy the silicides with Ge. As part of an investigation into the synthesis of semiconducting silicide heterostructures, a series of β-Fe(Si1−xGex)2 epilayer samples, with nominal alloy content in the range 0⩽x⩽0.15, have been prepared by molecular beam epitaxy on Si(100). We present results of the epitaxial and crystalline quality of the films, as determined by reflection high-energy electron diffraction, Rutherford backscattering spectroscopy, and double crystal x-ray diffraction, and of the band gap dependence on the alloy composition, as determined by Fourier transform infrared spectroscopy. We observe a reduction in band gap with increasing Ge content, in agreement with previous theoretical predictions [Tani et al., J. Solid State Chem. 169, 19 (2002)]. However we also observe Ge segregation in β-Fe(Si1−xGex)2 epilayers when x⩾0.04.
Ion beam sputter deposition of soft x-ray Mo∕Si multilayer mirrors
Authors: Schubert E. , Frost F. , Ziberi B. , Wagner G. , Neumann H. , Rauschenbach B.
Published: July 2005

Argon ion beam sputtering is used for production of high-quality Mo∕Si multilayer Bragg mirrors with 13.4nm center peak wavelength. The growth of the layer system was monitored in situ by real-time ellipsometry at multiple wavelengths within the visible to ultraviolet spectral region. The layer thicknesses of the individual multilayer constituents are obtained by model analysis of the ellipsometry data. Quality and performance of the soft x-ray mirrors is demonstrated by transmission electron microscopy, atomic force microscopy, glancing-angle of incidence CuKα reflectivity, and near-normal incidence soft x-ray reflectivity measurements. Thickness values obtained by transmission electron microscopy, reflectometry, and ellipsometry are critically compared.
Cross sections for the investigation of the electroluminescence excitation of InGaN∕GaN quantum wells in blue light-emitting diodes with multiquantum barriers
Authors: Nee Tzer-En , Wang Jen-Cheng , Lin Chung-Han , Lin Ray-Ming , Huang Ching-An , Fang Bor-Ren , Wang Ruey-Yu
Published: July 2005

Cross sections of the electroluminescence (EL) excitation of InGaN∕GaN multiquantum wells (MQWs) in blue light-emitting diodes (LEDs) with multiquantum barriers (MQBs) have been investigated. It was found that a device with an MQB structure exhibited a higher quantum efficiency, as well as higher temperature insensitivity, compared with the conventional MQW LEDs. A total cross section of 5.3×10−15cm2 was obtained for the MQB QWs, by fitting them to the measurement of the spectral intensity at room temperature; the value was 4.5×10−15cm2 for those devices with GaN barriers. Not only the EL excitation cross section for active region, but also the abnormal quantum efficiency evolutions were found to be a function of temperature. Moreover, they were in good agreement with the rate equation model.
Ta-rich atomic layer deposition TaN adhesion layer for Cu interconnects by means of plasma-enhanced atomic layer deposition
Authors: Furuya Akira , Tsuda Hiroshi , Ogawa Shinichi
Published: July 2005

Low via yield caused by low adhesion between Cu and a barrier metal is a cost issue when the atomic layer deposition (ALD) barrier metal process is integrated with Cu interconnection. To overcome this issue, an adhesion layer consisting of Ta-rich TaN obtained by plasma-enhanced ALD [i.e., ALD Ta(N)] is proposed. A 2nm thick ALD Ta(N) film, deposited by exposing a substrate to pentakisdimethylaminotantalum (Ta(N(CH3)2)5) and He∕H2 plasma in turn, demonstrated strong adhesion comparable to that of a conventional physical vapor deposition Ta∕TaN barrier. Both the via yield and the robustness against stress-induced voiding of single-damascene Cu/porous-low-k interconnects were improved by substituting an ALD Ta(N) adhesion layer for the conventional ALD TaN layer.
Fabrication and characterization of slanted nanopillars array
Authors: Fu Yongqi , Ann Bryan Ngoi Kok
Published: July 2005

A nanopillars array for the application of molecular controlling was fabricated by use of focused ion-beam (FIB) fine milling on a substrate of silicon. The nanopillars array can realize cell/molecular adhesion and movement control by the arrays high-density contact dots and tiled cone angle of the pillars. This can be obtained using FIB with two methods. One is direct fine milling with bitmap function, and the other is zero-overlap scanning in both directions of horizontal and vertical alternatively with a stage in a certain tilted angle. The milling process was investigated under different beam current and the stage-tilting angles, which determines an aspect ratio and the inclined angle of the pillars. In order to characterize the nanopillars array, we made a replica of the nanopillars array by aid of nanoimprinting with poly(dimethylsiloxane) (PDMS), and measured the replica by atomic force microscope (AFM). The pillars array can be used as a molecular manipulator to cause cell/molecular motion forward in only one direction. This motion cannot be backward. It will also be helpful for cell/molecular analysis, such as molecule separation and purification, molecular detection, DNA hybridization, etc.
Nanofabrication by scanning probe microscope lithography: A review
Authors: Tseng Ampere A. , Notargiacomo Andrea , Chen T. P.
Published: July 2005

In addition to its well-known capabilities in imaging and spectroscopy, scanning probe microscopy (SPM) has recently shown great potentials for patterning of material structures in nanoscales. It has drawn the attention of not only the scientific community, but also the industry. This article examines various applications of SPM in modification, deposition, removal, and manipulation of materials for nanoscale fabrication. The SPM-based nanofabrication involves two basic technologies: scanning tunneling microscopy and atomic force microscopy. Major techniques related to these two technologies are evaluated with emphasis on their abilities, efficiencies, and reliabilities to make nanostructures. The principle and specific approach underlying each technique are presented; the differences and uniqueness among these techniques are subsequently discussed. Finally, concluding remarks are provided where the strength and weakness of the techniques studied are summarized and the scopes for technology improvement and future research are recommended.
Growth related interference effects in band edge thermometry of semiconductors
Authors: Sacks R. N. , Barlett D. , Taylor C. A. , Williams J.
Published: July 2005

During epitaxial growth on GaAs and InP substrates two effects were observed that can interfere with correct substrate temperature measurements when using band edge thermometry. The first effect was due to specular reflection from a hot effusion cell opposite the optical detector. The worst case observed was a false temperature drop of ∼30°C upon starting growth. This effect was eliminated by moving the detector to a port that doesn’t allow specular reflection from any cell. The second effect is due to the development of constructive and destructive interference fringes while growing heterostructures. False temperature oscillations as large as ±5°C were seen when growing a thick AlGaAs∕GaAs heterostructure on GaAs. The solution to reducing the false TS oscillations is the use of a third derivative of the spectra, making the location of the band edge much less susceptible to interference effects. This technique reduced the false oscillations to ±1.5°C. However, the second interference effect also opens up new possibilities for adapting band edge thermometry to extracting real time growth rate and composition information by monitoring oscillations at several fixed wavelengths both above and below the band edge.
Ammonia molecular beam epitaxy growth of p-type GaN and application to bipolar junction transistors
Authors: Haffouz S. , Tang H. , Bardwell J. A. , Rolfe S. , Hsu E. M. , Sproule I. , Moisa S. , Beaulieu M. , Webb J. B.
Published: July 2005

We have investigated the effect of the growth temperature and magnesium flux on Mg incorporation in ammonia-MBE grown GaN epilayers. Secondary ion mass spectroscopy revealed that the incorporation of Mg is more sensitive to the growth temperature than to Mg flux. Simultaneously, the available amount of Mg at the substrate surface has to be accurately balanced in order to achieve the optimum electrical (p∼3×1017cm−3, μ∼12cm2∕Vs, ρ∼2ohmcm) and structural properties [ω-scan FWHM(0002)∼550arcsec]. The surface morphology of the Mg-doped GaN epilayers, using various growth temperatures and Mg fluxes, has been studied by atomic force microscopy showing a considerable change in the GaN average grain size. The optimum growth window for achieving high quality, p-type conductivity in GaN using ammonia-MBE will be discussed. As an application, n–p–n bipolar junction transistors were grown and fabricated. A current gain of 10 with VBC=0V was achieved using these devices.
THE HEIDER BALANCE: A CONTINUOUS APPROACH
Authors: KUŁAKOWSKI KRZYSZTOF , GAWROŃSKI PRZEMYSŁAW , GRONEK PIOTR
Published: July 2005

The Heider balance (HB) is investigated in a fully connected graph of N nodes. The links are described by a real symmetric array r (i, j), i, j =1, …, N. In a social group, nodes represent group members and links represent relations between them, positive (friendly) or negative (hostile). At the balanced state, r (i, j) r (j, k) r (k, i) > 0 for all the triads (i, j, k). As follows from the structure theorem of Cartwright and Harary, at this state the group is divided into two subgroups, with friendly internal relations and hostile relations between the subgroups. Here the system dynamics is proposed to be determined by a set of differential equations, [Formula: see text]. The form of equations guarantees that once HB is reached, it persists. Also, for N =3 the dynamics reproduces properly the tendency of the system to the balanced state. The equations are solved numerically. Initially, r (i, j) are random numbers distributed around zero with a symmetric uniform distribution of unit width. Calculations up to N =500 show that HB is always reached. Time τ(N) to get the balanced state varies with the system size N as N-1/2. The spectrum of relations, initially narrow, gets very wide near HB. This means that the relations are strongly polarized. In our calculations, the relations are limited to a given range around zero. With this limitation, our results can be helpful in an interpretation of some statistical data.
SATO–CRUTCHFIELD EQUATION FOR POPULATION GENETICS
Authors: ELETTREBY M. F.
Published: July 2005

In this paper, we applied the Sato–Crutchfield equation to population genetics. We studied it analytically and numerically. It is applied to some cases in population of one locus with two alleles. It is found that Sato–Crutchfield equation does not affect the stability of the evolutionary equations but the reinforcement of the choice of heterozygote state.
RECURRENCE PLOT AND RECURRENCE QUANTIFICATION ANALYSIS TECHNIQUES FOR DETECTING A CRITICAL REGIME.
Authors: FABRETTI A. , AUSLOOS M.
Published: July 2005

Recurrence Plot (RP) and Recurrence Quantification Analysis (RQA) are signal numerical analysis methodologies able to work with nonlinear dynamical systems and nonstationarity. Moreover, they well evidence changes in the states of a dynamical system. We recall their features and give practical recipes. It is shown that RP and RQA detect the critical regime in financial indices (in analogy with phase transition) before a bubble bursts, whence allowing to estimate the bubble initial time. The analysis is made on DAX and NASDAQ daily closing price between January 1998 and November 2003. DAX is studied in order to set-up overall considerations, and as a support for deducing technical rules. The NASDAQ bubble initial time has been estimated to be on 19 October 1999.
PCR-BASED SYNTHESIS OF REPETITIVE SINGLE-STRANDED DNA FOR APPLICATIONS TO NANOBIOTECHNOLOGY
Authors: ZEIN SIMA S. , VETCHER ALEXANDRE A. , LEVENE STEPHEN D.
Published: July 2005

Recent data show that assembly of repetitive-sequence, single-stranded DNA molecules (ssDNA) and carbon nanotubes (CNTs) depend on the specific sequence repeat. Therefore, it is of practical interest to assess various methods for generating single-stranded DNA molecules that contain repetitive sequences. Existing automated synthesis procedures for generating long (> 100 nt) ssDNA molecules generate ssDNA products of variable purity and yield. An alternative to automated synthesis is the polymerase chain reaction (PCR), which provides a powerful tool for the amplification of minute amounts of specific DNA sequences. Here we show that a modified asymmetric PCR method allows synthesis of long ssDNAs comprised of tandem repeats of the repetitive vertebrate telomeric sequence (TTAGGG)n, and is also applicable to arbitrary (repetitive or nonrepetitive) DNA. Long, repetitive deoxynucleotides produced by automated synthesis are surprisingly heterogeneous with respect to both length and sequence. Benefits of the method described here are that long, repetitive ssDNA sequences are generated with high sequence fidelity and yield.
ELECTRODEPOSITION OF NANOCOMPOSITE ORGANIC–INORGANIC COATINGS FOR BIOMEDICAL APPLICATIONS
Authors: PANG XIN , ZHITOMIRSKY IGOR
Published: July 2005

New method has been developed for the fabrication of nanocomposite hydroxyapatite (HA)-chitosan coatings. The method is based on the electrophoretic deposition (EPD) of HA nanoparticles prepared by a chemical precipitation technique, and electrochemical deposition of chitosan macromolecules. The deposit composition can be varied by the variation of HA concentration in chitosan solutions. X-ray studies revealed preferred orientation of HA nanoparticles in the nanocomposites with c-axis parallel to the coating surface. Nanocomposite coatings were obtained on Ti and Pt foils, Ti wires and gauzes. Deposition yield can be controlled by the variation of the deposition time. Coatings of various thicknesses in the range of up to 50 μm were obtained. The method enables the formation of dense, adherent and uniform deposits on substrates of complex shape. The obtained coatings provide corrosion protection of Ti and can be utilized for the fabrication of advanced biomedical implants.
AB-INITIO STUDY OF VARIOUS PROPERTIES OF SMALL DIAMETER ARMCHAIR CARBON NANOTUBES
Authors: AGRAWAL B. K. , AGRAWAL S. , SINGH S. , SRIVASTAVA R.
Published: July 2005

A comprehensive ab-initio investigation of the stability, structural, electronic, optical and Raman-active properties has been performed for the small diameter armchair carbon nanotubes. A number of new features not discussed earlier are observed in the present study. The binding energies (BEs) for the ultrathin nanotubes with respect to the graphine sheet are negative and the magnitude of the negative BE decreases with the diameter of the tube approaching zero for the graphine sheet. The separation between the two van Hove singularities (vHs) around the Fermi level increases with the diameter of the tube. The main absorption arises from the transitions between the states at nonzero values of kz lying in the range 0.38–0.50. There is a large variation in the magnitude of the optical matrix-element with the wave vector. The energy range of the strong optical absorption increases with the diameter of the tube. The presently predicted absorption and the RBM frequencies are in good agreement with the available experimental data. The variation of the radial breathing mode (RBM) frequency with diameter "d" of a tube obeys a relation which is very close to an experimentally determined relation obtained for a number of wide semiconducting nanotubes possessing a wide range of chiral angles.
INTEGRATED STATISTICAL ANALYSIS OF cDNA MICROARRAY AND NIR SPECTROSCOPIC DATA APPLIED TO A HEMP DATASET
Authors: REIJMERS T. H. , MALIEPAARD C. , VAN DEN BROECK H. C. , KESSLER R. W. , TOONEN M. A. J. , VAN DER VOET H.
Published: July 2005

Both cDNA microarray and spectroscopic data provide indirect information about the chemical compounds present in the biological tissue under consideration. In this paper simple univariate and bivariate measures are used to investigate correlations between both types of high dimensional analyses.

A large dataset of 42 hemp samples on which 3456 cDNA clones and 351 NIR wavelengths have been measured, was analyzed using graphical representations. For this purpose we propose clustered correlation and clustered discrimination images. Large, tissue-related differences are seen to dominate the cDNA-NIR correlation structure but smaller, more difficult to detect, variety-related differences can be found at specific cDNA clone/NIR wavelength combinations.
PREDICTION OF PROTEIN SUBCELLULAR LOCATIONS USING A NEW MEASURE OF INFORMATION DISCREPANCY
Authors: JIN LIXIA , TANG HUANWEN , FANG WEIWU
Published: July 2005

Given a raw protein sequence, knowing its subcellular location is an important step toward understanding its function and designing further experiments. A novel method is proposed for the prediction of protein subcellular locations from sequences. For four categories of eukaryotic proteins the overall predictive accuracy is 82.0%, 2.6% higher than that by using SVM approach. For three subcellular locations of prokaryotic proteins, an overall accuracy of 89.9% is obtained. In accordance with the architecture of cells, a hierarchical prediction approach is designed. Based on amino acid composition extracellular proteins and intracellular proteins can be identified with accuracy of 97%.
A PRIORICONTACT PREFERENCES IN MOLECULAR RECOGNITION
Authors: RANTANEN VILLE-VEIKKO , GYLLENBERG MATS , KOSKI TIMO , JOHNSON MARK S.
Published: July 2005

A molecular interaction library modeling favorable non-bonded interactions between atoms and molecular fragments is considered. In this paper, we represent the structure of the interaction library by a network diagram, which demonstrates that the underlying prediction model obtained for a molecular fragment is multi-layered. We clustered the molecular fragments into four groups by analyzing the pairwise distances between the molecular fragments. The distances are represented as an unrooted tree, in which the molecular fragments fall into four groups according to their function. For each fragment group, we modeled a group-specific a priori distribution with a Dirichlet distribution. The group-specific Dirichlet distributions enable us to derive a large population of similar molecular fragments that vary only in their contact preferences. Bayes' theorem then leads to a population distribution of the posterior probability vectors referred to as a "Dickey–Savage"-density. Two known methods for approximating multivariate integrals are applied to obtain marginal distributions of the Dickey–Savage density. The results of the numerical integration methods are compared with the simulated marginal distributions. By studying interactions between the protein structure of cyclohydrolase and its ligand guanosine-5′-triphosphate, we show that the marginal distributions of the posterior probabilities are more informative than the corresponding point estimates.
ON GENERALIZED MULTIPLE-INSTANCE LEARNING
Authors: SCOTT STEPHEN , ZHANG JUN , BROWN JOSHUA
Published: July 2005

We describe a generalisation of the multiple-instance learning model in which a bag's label is not based on a single instance's proximity to a single target point. Rather, a bag is positive if and only if it contains a collection of instances, each near one of a set of target points. We then adapt a learning-theoretic algorithm for learning in this model and present empirical results on data from robot vision, content-based image retrieval, and protein sequence identification.
A HYBRID OF GENETIC ALGORITHM AND SUPPORT VECTOR MACHINE FOR FEATURES SELECTION AND CLASSIFICATION OF GENE EXPRESSION MICROARRAY
Authors: MOHAMAD MOHD SABERI , DERIS SAFAAI , ILLIAS ROSLI MD
Published: July 2005

Constantly improving gene expression technology offer the ability to measure the expression levels of thousand of genes in parallel. Gene expression data is expected to significantly aid in the development of efficient cancer diagnosis and classification platforms. Key issue that needs to be addressed is the selection of small number of genes that contribute to a disease from the thousands of genes measured on microarrays that are inherently noisy. This work deals with finding a small subset of informative genes from gene expression microarray data which maximise the classification accuracy. This paper introduces a new algorithm of hybrid Genetic Algorithm and Support Vector Machine for genes selection and classification task. We show that the classification accuracy of the proposed algorithm is superior to a number of current state-of-the-art methods of two widely used benchmark datasets. The informative genes from the best subset are validated and verified by comparing them with the biological results produced from biologist and computer scientist researches in order to explore the biological plausibility.
FACE RECOGNITION IN COLOUR IMAGES USING NEURAL NETWORKS AND GENETIC ALGORITHMS
Authors: KARUNGARU STEPHEN , FUKUMI MINORU , AKAMATSU NORIO
Published: July 2005

In this paper, a system that can automatically detect and recognise frontal faces is proposed. Three methods are used for face recognition; neural network, template matching and distance measure. One of the main problems encountered when using neural networks for face recognition is insufficient training data. This problem arises because, in most cases, only one image per subject is available. Therefore, amongst the objectives is to solve this problem by "increasing" the data available from the original image using several preprocesses, for example, image mirroring, colour and edges information, etc. Moreover, template matching is not trivial because of differences in the template shapes and sizes. In this work, template matching is aided by a genetic algorithm to automatically test several positions around the target and automatically adjust the size of the template as the matching process progresses. Distance measure method depends heavily on good facial feature extraction results. The image segmentation method applied matches such demand. The face colour information is represented using YIQ and the XYZ colour spaces. The effectiveness of the proposed method is verified by performing computer simulations. Two sets of databases were used. Database1 consists of 267 faces from the Oulu university database and database2 (for comparision purposes) consists of 250 faces from the ORL database.
GENETIC-ALGORITHM MEMORY MINIMISATION FOR DESIGNING RECONFIGURABLE IP ADDRESS LOOKUP ENGINE
Authors: SHAMSHIRI SAEED , FAKHRAIE S. MEHDI
Published: July 2005

IP address lookup engine is the beating heart of a router. For meeting the requirements of a desirable high-speed router, speed, memory consumption, scalability, and reconfigurability of its IP lookup engine are critical. This paper uses a genetic-algorithm approach to optimise the structure of fixed-stride multibit-trie IP lookup methods. In this work, the genetic algorithm is used first in the design phase as an offline optimisation mechanism. This nature-inspired simulation finds the most memory-efficient configuration of IP address segmentation for a fixed number of address segments. Then, for adapting to network variations, the proposed method dynamically changes the number of address segments to compromise between speed and memory consumption. Each time the number of segments changes, an online genetic program is run to optimise the segmentation. Therefore, the lookup engine reconfigures itself to cover more prefixes during the time. The reconfigurability in response to the network variations, and scalability to the number of prefixes improves the life time of a router that uses this method.
ASSEMBLY OF VARIANT HISTONES INTO CHROMATIN
Authors: Henikoff Steven , Ahmad Kami
Published: July 2005

Chromatin can be differentiated by the deposition of variant histones at centromeres, active genes, and silent loci. Variant histones are assembled into nucleosomes in a replication-independent manner, in contrast to assembly of bulk chromatin that is coupled to replication. Recent in vitro studies have provided the first glimpses of protein machines dedicated to building and replacing alternative nucleosomes. They deposit variant H2A and H3 histones and are targeted to particular functional sites in the genome. Differences between variant and canonical histones can have profound consequences, either for delivery of the histones to sites of assembly or for their function after incorporation into chromatin. Recent studies have also revealed connections between assembly of variant nucleosomes, chromatin remodeling, and histone post-translational modification. Taken together, these findings indicate that chromosome architecture can be highly dynamic at the most fundamental level, with epigenetic consequences.
On modelling the drying of porous materials: analytical solutionsto coupled partial differential equations governing heat andmoisture transfer
Authors: Kulasiri Don , Woodhead Ian
Published: July 2005

Luikov′s theory of heat and mass transfer provides a framework to
model drying porous materials. Coupled partial differential equations governing the moisture and heat transfer can be solved using numerical techniques, and in this paper we solve them analytically in a setting suitable for industrial drying situations. We discuss the nature of the solutions using the physical properties of Pinus radiata. It is shown that the temperature gradients play a significant role in deciding the moisture profiles within the material when thickness is large and that models based only on moisture potential gradients may not be sufficient to explain the drying phenomena in moist porous materials.
A multilevel method of nonlinear Galerkin type for theNavier‐Stokes equations
Authors: El Hajji Said , Ilias Khalid
Published: July 2005

The basic idea of this new method resides in the fact that the major part of the relative information to the solution to calculate is contained in the small modes of a development of Fourier series; the raised modes of which the coefficients associated being small, being negligible to every instant, however, the effect of these modes on a long interval of time is not negligible. The nonlinear Galerkin method proposes economical
treatment of these modes that permits, in spite of a simplified calculation, taking into account their interaction correctly with the other modes. After the introduction of this method, we elaborate an efficient strategy for its implementation.
MEMD/ALCAM: A Potential Marker for Tumor Invasion and Nodal Metastasis in Esophageal Squamous Cell Carcinoma
Authors: Verma Amit , Shukla Nootan Kumar , Deo S.V.S. , Gupta Siddhartha Datta , Ralhan Ranju
Published: July 2005

Objective: TheMEMD gene was reported to be overexpressed in human esophageal squamous cell carcinoma (ESCC), using differential display. The aim of this study was to determine the clinical significance of MEMD/ALCAM in esophageal tumorigenesis. Methods: Analysis of MEMD/ALCAM expression in esophageal tissues was carried out at protein and RNA level using immunohistochemistry and semiquantitative RT-PCR, respectively. Results: Increased MEMD/ALCAM expression was observed in 42/65 (65%) ESCCs (p = 0.000, odds ratio, OR = 3.665) and in 17/25 (68%) dysplasias (p = 0.000, OR = 4.248) compared to paired distant histologically normal esophageal tissues. Increased MEMD mRNAlevels were observed in ESCCs and dysplasias showing overexpression of MEMD/ALCAM protein. Interestingly, increased membranous MEMD/ALCAM expression was observed in dysplasias in comparison with ESCCs (p = 0.002, OR = 3.177). MEMD/ALCAM overexpression in ESCCs was associated with late clinical stage (p = 0.002, OR = 3.619), enhanced tumor invasiveness (p = 0.002, OR = 3.619), and nodal metastasis (p = 0.000, OR = 4.206). Conclusion: To our knowledge, this is the first report showing MEMD expression at pre-malignant stage (dysplasia), suggesting that MEMD/ALCAM expression is an early event in the development of esophageal cancer. Furthermore, in ESCCs its correlation with late clinical stage, enhanced tumor invasiveness and nodal metastasis suggests an association with aggressive tumor behavior. Our data suggest that MEMD/ALCAM may serve as a potential marker for early diagnosis, tumor invasion and nodal metastasis in ESCCs.
A Phase I Multiple‐Dose Escalation Study Characterizing Pharmacokinetics and Safety of ABT‐578 in Healthy Subjects
Authors: Karyekar Chetan S. , Pradhan Rajendra S. , Freeney Tony , Ji Qin , Edeki Timi , Chiu Wenzi , Awni Walid M. , Locke Charles , Schwartz Lewis B. , Granneman Richard G. , O'Dea Robert
Published: July 2005

ABT‐578, a sirolimus analog, is being developed for administration from drug‐eluting stents to prevent postimplantation neointimal hyperplasia. The purpose of this study was to evaluate the safety, tolerability, and pharmacokinetics of multiple doses of ABT‐578. Healthy subjects randomly received placebo or ABT‐578 (200, 400, or 800 μg) as daily intravenous infusions for 14 days. ABT‐578 blood pharmacokinetics and urine excretion on days 1 and 14 were determined. The effect of ABT‐578 on mitogen‐stimulated lymphocyte proliferation was assessed. ABT‐578 pharmacokinetics was described by a 3‐compartment open model. The mean CL, Vss, and t1/2 ranges were 4.0 to 4.6 L/h, 92.5 to 118.0 L, and 24.7 to 31.0 hours, respectively. ABT‐578 pharmacokinetics was dose and time invariant. Approximately 0.1% of ABT‐578 was excreted in the urine. ABT‐578 was well tolerated, and no systemic changes were observed in the mitogen‐stimulated lymphocyte proliferation. ABT‐578 was shown to be safe over a wide range of systemic exposures.
Unpacking Regional Ethnicity and the Strength of Ties in Shaping Ethnic Entrepreneurship
Authors: Tsui-Auch Lai Si
Published: July 2005

This study is based on an interpretive content analysis of oral history data and documentary data on ethnic Indian and Chinese entrepreneurs in Singapore and their enterprises. This data is complemented by personal interviews with family members, informants and business community leaders, as well as historical analysis. The data reveals that most ethnic Indian entrepreneurs maintained their trade specializations and family management, whereas most ethnic Chinese entrepreneurs pursued unrelated diversification and incorporated outsiders into their operational management over time. What is particularly intriguing is the existence of an intra-ethnic division in business structure among the ethnic Indian enterprises. I argue that the opportunity structure in the country of residence and ethnic resources play only a limited role in shaping the differential management and business structures of the two ethnic groups. Rather, I attribute such differences primarily to the differential strength of ties of the entrepreneurs to their region/dialect-based networks. The strength of the ties reflects the degree of intra-community homogeneity and inter-community heterogeneity. These arguments are presented in the form of hypothesized relationships for future validation. The paper concludes with a critique of the structuralist, culturalist and interactionist perspectives on ethnic entrepreneurship, and suggests directions for future research into intra-ethnic entrepreneurship, comparative business systems and the paradox of embeddedness.
Peripheral Vision
Authors: Callon Michel , Muniesa Fabian
Published: July 2005

How to address empirically the calculative character of markets without dissolving it? In our paper, we propose a theoretical framework that helps to deal with markets without suspending their calculative properties. In the first section, we construct a broad definition of calculation, grounded on the anthropology of science and techniques. In the next sections, we apply this definition to three constitutive elements of markets: economic goods, economic agents and economic exchanges. First, we examine the question of the calculability of goods: in order to be calculated, goods must be calculable. In the following section, we introduce the notion of calculative distributed agencies to understand how these calculable goods are actually calculated. Thirdly, we consider the rules and material devices that organize the encounter between (and aggregation of) individual supplies and demands, i.e. the specific organizations that allow for a calculated exchange and a market output. Those three elements define concrete markets as collective organized devices that calculate compromises on the values of goods. In each, we encounter different versions of our broad definition of calculation, which we illustrate with examples, mainly taken from the fields of financial markets and mass retail.
The Rehabilitation of Indigenous Environmental Ethics in Africa
Authors: Kelbessa Workineh
Published: July 2005

This article examines the rehabilitation of an indigenous environmental ethic and indigenous environmental ethics in Africa. It seeks to provide an understanding of how the many culture-specific African societies view their relationship to the natural world. It aims to contribute to the articulation of environmental ethics grounded in indigenous traditions and inspired by broad ecological perspectives. The article begins with a survey of modern environmental ethics. It will then examine indigenous attitudes towards nature in Africa by focusing on the environmental ethics of the Oromo of Ethiopia. The Oromo constitute the largest ethnic group in Ethiopia. The last part provides a general conclusion.
Fengshui, or the Search for a Very Human Dragon
Authors: Obringer Frédéric
Published: July 2005

Like acupuncture, some signs of the Zodiac and three or four dishes, fengshui is now part of the collection of rare practices and skills that has emerged from China and been reworked in the local style. Everyone, or almost everyone, living in the West today has heard of it. In a word it has been, so to speak, ‘globalized’. This appearance in the daily life of hundreds of millions of people of a few fragments of Chinese material and intellectual culture touches some essential points, as we can see: the body and health, ‘fate’, food and, as far as fengshui is concerned, the influence landscapes and architecture have on the lives of human beings. This phenomenon can be received and understood in many ways, from scientistic and sectarian rejection to amused mockery or multiculturalistic enthusiasm. Nevertheless, people are now treated with needles in Paris, Berlin and New York, and at dinner parties you can hear anecdotes in which people's distress or success are discussed with reference to yin and yang. Here I would like to describe succinctly what is known about fengshui as it existed and still exists in China, and to examine how it saw and talked about nature.
The Spirit of Nature: A Conversation with Thierry Zarcone
Authors: Verdier Fabienne
Published: July 2005

TZ In China the art of gardens is often related to landscape painting (shanshui - mountains and water) and a particular genre of poetry (tianyuan - fields and garden) devoted to the life of withdrawal through detachment and the quest for serenity. Your autobiographical book Passagère du silence shows that these three arts, harmoniously combined, ran through your ‘ten years of initiation in China’. The balance that places your quest for the real at the centre of day-to-day life and in intimate connection with nature you have reconstructed at your home in France, when you evoke those three sites radiating energy in your life, the house, the studio and the garden, which you describe as ‘rich for the contemplation of the nature-universe, an essential source for my work as a painter’. Can you tell us about your garden … your studio … your house … and your osmosis with nature?
An Investigation of Square Delamination Effects on the Buckling Behavior of Laminated Composite Plates with a Square Hole by using Three-dimensional FEM Analysis
Authors: Zor Mehmet , Sen Faruk , Toygar M. Evren
Published: July 2005

In the present study, the effects of the square delamination, around a square hole, on the buckling loads of the simply supported and clamped woven steel-reinforced thermoplastic (LDPE, F.2.12) laminated composite plates have been investigated. Three-dimensional finite element models of laminated plates with four layers have been established. The square delaminations exist between second/third layers. The stacking sequences are chosen as [0]4, [15 / 15]s, [15 / 15]2, [30 / 30]s, [30 / 30]2, [45]4. Firstly the harmony between theoretical and finite element solution results of the plate without hole and delamination has been shown. Then, the buckling loads have been determined for each of the models having different square delamination dimensions. Significant decreases in the buckling loads occur after a certain value of delamination dimension. It is seen, for clamped plates that the changing ratios of the results of the symmetric or antisymmetric cases are approximately the same and there is a linear relationship between the values of the fiber angles and buckling loads.
Analysis of Multilayered Composite Cylinders under Thermal Loading
Authors: Akcay I. Hakki , Kaynak Idriis
Published: July 2005

In this investigation, a failure analysis is performed on analytical expressions of multilayered filament wound structures (FWS) in composite cylinders for the plane-strain and closed-end condition cases, under internal pressure and uniform thermal loading. The multilayer filament wound composite pressure closed-end cylinders are oriented symmetrically and antisymmetrically. The mechanical properties of composite cylinders are investigated considering a glass-epoxy multilayered composite cylinder. The failure analysis is carried out on different orientations of the multilayered composite cylinders. The failure pressure is found to be high at increased temperatures for the plane-strain cases. It is nearly the same for the closed-end case.