bluuebunny/crossref_metadata_2025 huggingface dataset:
Motion Comparison Between a Conventional Deep Draft Semi-Submersible and a Dry Tree Semi-Submersible
Authors: Hussain Anis , Nah Edwin , Fu Rain , Gupta Apurva
Published: February 2010

One of the major requirements for a floating vessel designed to support top tensioned risers is to have the heave response within a minimum specified range in extreme environments. The heave has a significant influence on the riser stroke. Usually floater designs aim to use conventional riser tensioners, available commercially, which typically have a maximum stroke range in the order of 30 to 35ft. One of the limitations of traditional Semi-submersible designs to support dry trees is that the heave ranges seen in central Gulf of Mexico (GoM) are outside the range that can apply a conventional tensioner. The Extendable Semi-submersible (E-Semi) utilizes a retractable Second Tier Pontoon (STP) to suppress heave motions and reduce its heave motion in order to support top tensioned risers in central GoM ultra deep waters. The design is based on an established deep draft Semi-submersible with the STP attached. This paper presents a comparison between motion characteristics of the deep draft Semi-submersible with and without the STP attached. The comparison is based on numerical computations to predict the responses together with model test results in the same environments. The analysis essentially shows the effectiveness of the STP is suppressing the heave motion.
Nonlinear Coupled Hydrostatics of Floating Conical Platforms
Authors: Dalane Oddgeir , Knutsen Finn Faye , Lo̸set Sveinung
Published: February 2010

The increased exploration of deeper Arctic waters motivates the designs of new floating structures to operate under harsh Arctic conditions. Based on several model tests and investigations, structures with conical sections at the waterline have been shown to be a good design for waters where drifting ice is present, because the approaching ice fails in bending which induces smaller loads than crushing failure. However, in most Arctic waters ice features are only present parts of the year and a large portion of the operation time of these structures will be in open water. Therefore, the floating structures must perform well in both these conditions. Conical sections at the waterline will induce nonlinear coupling in the hydrostatic restoring forces and moments. It is important to understand how this affects the behaviour in both ice and open water conditions. In order to investigate the nonlinear coupled hydrostatic restoring forces, an exact analytic expression for the metacentric height of a regular cone is presented. This is further derived to a frustum cone that can be used to develop an exact analytic expression for the hydrostatic restoring forces and moments for any conical body. A platform of the shallow draught-type is used as a basis for the discussion and the effect of the coupled nonlinear restoring forces is illustrated by two-degrees-of-freedom (2DOF) pitch-heave time domain simulations.
Risk Assessment and Management Using Accident Precursors Modeling in Offshore Process Operation
Authors: Kalantarnia Maryam , Khan Faisal I. , Hawboldt Kelly
Published: February 2010

Offshore oil and gas operations are located in remote and often harsh marine environments. An offshore development can never be completely safe; however the degree of safety can be increased by selecting the optimum design, and developing proactive risk management strategies. This requires the identification and assessment of major risk contributors, which can be accomplished using quantitative risk assessment techniques. Dynamic failure assessment is a new approach in process safety management, which enables the real time failure analysis of a process. This approach uses Bayesian and joint probability theories to develop a predictive failure model for a given process. As a process proceeds and generates incidents and accident precursors, the accident occurrence probability is predicted. This paper presents a methodology based on the concept of dynamic failure assessment and its use in revising the risk profile for a process system based on accident precursor data modeling. An event tree is formed for a given abnormal event. Subsequently, using accident precursor data from the facility prior and posterior failure probabilities of events are calculated. A predictive model is developed using joint probability theory. Accident likelihood is combined with consequence analysis results to estimate posterior risk profile. Application of the proposed methodology is demonstrated on a process in an offshore process facility.
Modelling of Flow Around a Square Cylinder of Different Roughness Using a Lattice Boltzmann Model
Authors: Alam M. S. , Cheng Liang
Published: February 2010

A Lattice Boltzmann model is developed to simulate flow around a square cylinder of different roughness heights. It is evident from this study that the influences of pipe roughness on the flow parameters are quite noteworthy. It is revealed that the circumferential pipe roughness has significant influences on the hydrodynamic forces, circumferential pressure distribution, vortex shedding frequency and the formation of vortices in the vicinity of cylinder. In addition, it is seen that the orientation of the roughness elements or the density of the roughness elements does not have significant influence on the flow parameters.
Hydrodynamic and Safety Aspects of Mooring Line Anchors in Accidental Free Fall
Authors: Lie Halvor , Fylling Ivar , Lehn Erik
Published: February 2010

The paper presents an initial study on anchor behavior in accidental free fall. The work is related to a deepwater field development located at around 1000 m depth offshore Norway, where one wants to be able to anchor floating units for drilling vessels. As input to the present study data from model tests performed more than a decade ago were used. Here two anchor models were tested in free fall at a moderate water depth of 300 m. Results from the test are presented and discussed. Statistical distributions of the horizontal excursion for two anchor types are established. Because of limited instrumentation only some initial estimates of the free falling speed could be established. In order to determine how the results can be used for deeper water, a statistical approach for estimation of the hit position at sea bed for various water depths is outlined. Some examples on how the excursion develops for various water depths are given, based on the model test results and the statistical approach. Also a statistical model of damage risk to seabed structures by falling anchors is discussed.
Prediction of Extreme Tether Tension for a TLP
Authors: Naess A. , Stansberg C. T. , Batsevych O.
Published: February 2010

The paper presents a study of the extreme value statistics related to measurements on a scale model of a large tension leg platform (TLP) subjected to random waves in a wave basin. Extensive model tests were carried out in three irregular sea states. Time series of the motion responses and tether tension were recorded for a total of 18 three hour tests (full scale). In this paper we discuss the statistics of the measured tether tension. The focus is on a comparison of two alternative methods for the prediction of extreme tether tension from finite time series records. One method is based on expressing the extreme value distribution in terms of the average upcrossing rate. The other is a novel method that can account for statistical dependence in the recorded time series by utilizing a cascade of conditioning approximations. Both methods rely on introducing a specific parametric form for the tail part of the extreme value distribution. This is combined with an optimization procedure to determine the parameters involved, which allows prediction of various extreme response levels.
Three-Column TLP Concept for Marginal Field Development
Authors: Williams Neil , Heidari Homayoun , Large Sean
Published: February 2010

This paper discusses the development of a new self-stable TLP concept for marginal field applications. This concept — called ThreeStar™ — is based on three rectangular columns arranged at the vertices of an equilateral triangle and battered towards its geometric center. The columns are joined by conventional rectangular pontoons. The reduced number of tendons/piles relative to a conventional four column TLP makes the ThreeStar a cost-effective solution in applications where the production riser count is relatively low or the topsides payload is small. This paper presents a description of the technical development of the ThreeStar TLP and outlines the unique features of the concept. The relative merits of the ThreeStar over comparable four-column TLPs for different environments and payload ranges are discussed. Finally, ThreeStar systems are presented for two example deepwater applications.
A DUAL-MODEL JUMPING FUZZY SYSTEM APPROACH TO NETWORKED CONTROL SYSTEMS DESIGN
Authors: WU FENGGE , SUN FUCHUN , LIU HUAPING
Published: February 2010

A discrete-time jump fuzzy system with two hidden Markov models (HMMs) is proposed to portray the asymmetric network characteristic of a class of nonlinear networked control systems (NCSs) with random but bounded communication delays and packets dropout. The less conservative state feedback controller and the dual-model-depend guaranteed cost controller are designed base on the model. A homotopy- based iterative algorithm solving for nonlinear matrix inequality (NMI) is developed to get the control gains. Simulation examples are carried out to show the effectiveness of the proposed approaches.
A REPAIR ALGORITHM FOR RADIAL BASIS FUNCTION NEURAL NETWORK AND ITS APPLICATION TO CHEMICAL OXYGEN DEMAND MODELING
Authors: QIAO JUN-FEI , HAN HONG-GUI
Published: February 2010

This paper presents a repair algorithm for the design of a Radial Basis Function (RBF) neural network. The proposed repair RBF (RRBF) algorithm starts from a single prototype randomly initialized in the feature space. The algorithm has two main phases: an architecture learning phase and a parameter adjustment phase. The architecture learning phase uses a repair strategy based on a sensitivity analysis (SA) of the network's output to judge when and where hidden nodes should be added to the network. New nodes are added to repair the architecture when the prototype does not meet the requirements. The parameter adjustment phase uses an adjustment strategy where the capabilities of the network are improved by modifying all the weights. The algorithm is applied to two application areas: approximating a non-linear function, and modeling the key parameter, chemical oxygen demand (COD) used in the waste water treatment process. The results of simulation show that the algorithm provides an efficient solution to both problems.
SOLITON RESONANCES FOR THE MODIFIED KADOMTSEV–PETVIASHVILI EQUATIONS IN UNIFORM AND NON-UNIFORM MEDIA
Authors: HAO HONG-HAI , ZHANG DA-JUN
Published: February 2010

The phenomena of soliton resonance can occur in (2+1)-dimensional modified Kadomtsev–Petviashvili equation (mKP). In this paper, we study the multisoliton solutions in Hirota's forms for isospectral and non-isospectral mKP. We take two-soliton solutions as examples to investigate soliton resonances occurring in uniform and non-uniform media according to different values of the phase shift parameter.
INVESTIGATIONS OF THE EPR PARAMETERS FORDy3+CENTER INZrSiO4CRYSTAL
Authors: DONG HUI-NING , LI DENG-FENG , LIU JUN , KEEBLE DAVID J.
Published: February 2010

The electronic paramagnetic resonance g factors g‖, g⊥of Dy3+centers and the hyperfine structure constants A‖and A⊥of161Dy3+and163Dy3+isotopes in ZrSiO4crystal are theoretically studied from the perturbation formulas of the spin Hamiltonian parameters for a 4f9ion in tetragonal symmetry. In these formulas, the contributions to g factors due to the J-mixing among the ground6H15/2, the first excited6H13/2and second excited6H11/2states via crystal-field interaction, the admixtures among the states with the same J value via spin-orbit coupling interaction and the interactions between the lowest Kramers doublet Γγ and other 20 Kramers doublets ΓXwithin the states6HJ(J=15/2, 13/2 and 11/2) via crystal-field and orbital angular momentum interactions are considered. The calculated EPR parameters show reasonable agreement with the observed values. The results are discussed.
POWER-LOSSLESS CHANNEL SWITCH BASED ON LATTICE SOLITONS
Authors: FANG YUN-TUAN , OUYANG ZHENG-BIAO
Published: February 2010

We propose an all-optical channel switch based on lattice solitons with weak light to control an intense light. Through adjusting the power, position and incident angle of the controlling light, the signal light can be switched to different channels. In the switching process, the signal light loses little energy.
NON-EQUILIBRIUM THERMODYNAMIC ANALYSIS ON THE PERFORMANCE OF AN IRREVERSIBLE THERMALLY DRIVEN BROWNIAN MOTOR
Authors: GAO TIANFU , CHEN JINCAN
Published: February 2010

Based on the general model of thermally-driven Brownian motors, an equivalent cycle system is established and the Onsager coefficients and efficiency at the maximum power output of the system are analytically calculated from non-equilibrium thermodynamics. It is found that the Onsager reciprocity relation holds and the Onsager coefficients are affected by the main irreversibilities existing in practical systems. Only when the heat leak and the kinetic energy change of the particle in the system are negligible, can the determinant of the Onsager matrix vanish. It is also found that in the frame of non-equilibrium thermodynamics, the power output and efficiency of an irreversible Brownian motor can be expressed to be the same form as those of an irreversible Carnot heat engine, so the results obtained here are of general significance. Moreover, these results are used to analyze the performance characteristics of a class of thermally-driven Brownian motors so that some important conclusions in literature may be directly derived from the present paper.
PUNCH-THROUGH CHARACTERISTICS OF AVALANCHE PHOTODIODES UNDER THE GEIGER MODE
Authors: GUO JIANPING , LIAO CHANGJUN , WEI ZHENGJUN , WANG JINDONG
Published: February 2010

A passive quench circuit is used to study the punch-through characters of avalanche photodiodes under the Geiger mode. The photocurrent–voltage curve indicated clearly the punch-through voltage while the dark current–voltage curve is insensitive to the punch-through. The experiments demonstrate different distributions of the carries. The dark carriers counts increase much faster than the photo-carriers counts due to the different collection efficiency. A proper selection of the bias can increase the signal-to-noise ratio (SNR) of the single photon detector.
ON OPTIMAL DESIGN AND EXPANSION OF ELECTRICAL POWER DISTRIBUTION SYSTEMS
Authors: RAVADANEGH SAJAD NAJAFI , VAHIDNIA ARASH , HATAMI HOJAT
Published: February 2010

Optimal planning of large-scale distribution networks is a multiobjective combinatorial optimization problem with many complexities. This paper proposes the application of improved genetic algorithm (GA) for the optimal design of large-scale distribution systems in order to provide optimal sizing and locating of the high voltage (HV) substations and medium voltage (MV) feeders routing, using their corresponding fixed and variable costs associated with operational and optimization constraints. The novel approach presented in the paper, solves hard satisfactory optimization problems with different constraints in large-scale distribution networks. This paper presents a new concept based on MST in graph theory and GA for optimal locating of the HV substations and MV feeders routing in a real-size distribution network. Minimum spanning tree solved with Prim's algorithm is employed to generate a set of feasible population. In the present article, to reduce computational burden and avoid huge search space leading to infeasible solutions, special coding method is generated for GA operators to solve optimal feeders routing. The proposed coding method guarantees the validity of the solution during the progress of the GA toward the global optimal solution. The developed GA-based software is tested in a real-size large-scale distribution system and the well-satisfactory results are presented.
LONG-TERM PREDICTION OF ETHERNET TRAFFIC USING MULTISCALE-BILINEAR RECURRENT NEURAL NETWORK WITH ADAPTIVE LEARNING
Authors: PARK DONG-CHUL
Published: February 2010

A prediction scheme for Ethernet traffic data using a Multiscale-Bilinear Recurrent Neural Network with Adaptive Learning (M-BRNN-AL) is proposed and presented in this paper. The proposed predictor integrates an M-BRNN and an AL algorithm. In M-BRNN, the wavelet transform is employed to decompose the original traffic signals into several simple traffic signals. A BRNN is then used to predict each decomposed traffic signal. An AL algorithm is also applied in order to improve the learning process at each resolution level in M-BRNN-AL. Experiments and results on a set of Ethernet network traffic predictions show that the proposed scheme converges faster and archives better prediction performance than the other conventional models such as the Multi-layer Perception Type Neural Network, BRNN, and the original M-BRNN in terms of the normalized mean square error.
IMPROVED FAST FUZZY C-MEAN AND ITS APPLICATION IN MEDICAL IMAGE SEGMENTATION
Authors: BALAFAR M. A. , RAHMAN RAMLI A. B. D. , IQBAL SARIPAN M. , MASHOHOR SYAMSIAH , MAHMUD ROZI
Published: February 2010

Image segmentation is a preliminary stage in diagnosis tools and the accurate segmentation of medical images is crucial for a correct diagnosis by these tools. Sometimes, due to inhomogeneity, low contrast, noise and inequality of content with semantic, automatic methods fail to segment image correctly. Therefore, for these images, it is necessary to use user help to correct method's error. We proposed to upgrade FAST FCM method to use training data to have more accurate results. In this paper, instead of using pixels as training data which is usual, we used different gray levels as training data and that is why we have used FAST FCM, because the input of FAST FCM is gray levels exist in image (histogram of the image). We named the new clustering method improved fast fuzzy C-mean (FCM). We use two facts to improve fast FCM. First, training data for each class are the member of the class. Second, the relevance distance of each input data from the training data of a class show the distance of the input data from the class. To cluster an image, first, the color image is converted to gray level image; then, from histogram of image, user selects training data for each target class, afterwards, the image is clustered using postulated clustering method. Experimental result is demonstrated to show effectiveness of the new method.
TEMPLATE MATCHING IN DIGITAL IMAGES USING A COMPACT GENETIC ALGORITHM WITH ELITISM AND MUTATION
Authors: DA SILVA RAFAEL R. , ERIG LIMA CARLOS R. , LOPES HEITOR S.
Published: February 2010

The emCGA is a new extension of the compact genetic algorithm (CGA) that includes elitism and a mutation operator. These improvements do not increase significantly the computational cost or the memory consumption and, on the other hand, increase the overall performance in comparison with other similar works. The emCGA is applied to the problem of object recognition in digital images. The objective is to find a reference image (template) in a landscape image, subject to distortions and degradation in quality. Two models for dealing with the images are proposed, both based on the intensity of light. Several experiments were done with reference and landscape images, under different situations. The emCGA was compared with an exhaustive search algorithm and another CGA proposed in the literature. The emCGA was found to be more efficient for this problem, when compared with the other algorithms. We also compared the two proposed models for the object. One of them is more suitable for images with rich details, and the other for images with low illumination level. Both models seem to perform equally in the presence of distortions. Overall, results suggested the efficiency of emCGA for template matching in images and encourages future developments.
WEAR RESISTANCE OF AZ91D MAGNESIUM ALLOY WITH AND WITHOUT MICROARC OXIDATION COATING AND Ti6Al4V ALLOY IN ARTIFICIAL SALIVA
Authors: ZHANG X. P. , ZOU Y. S. , WU F. M. , ZHAO Z. P. , YOU L. , GU C. F. , LIAO Y. Z.
Published: February 2010

The wear resistances of AZ91D magnesium alloy with and without microarc oxidation (MAO) coating and Ti 6 Al 4 V alloy in artificial saliva were investigated at room temperature. The wear resistance of AZ91D magnesium alloy in artificial saliva was significantly improved after microarc oxidation treatment. The volume loss of untreated AZ91D magnesium alloy sample was 20.95 times of that of AZ91D magnesium alloy with MAO coating, and that of Ti 6 Al 4 V was 5.42 times of that of MAO. Furthermore, the wear resistance of AZ91D magnesium alloy was lower than that of Ti 6 Al 4 V alloy in artificial saliva. The wear mechanisms of AZ91D magnesium and Ti 6 Al 4 V were discussed. It was found that the wear mechanism of the MAO was associated with abrasion and microfracture. There were two dominative wear mechanisms for AZ91D alloy and Ti 6 Al 4 V alloy under the loading conditions used in the experiment, namely, micro-machining wear and deformation-induced wear.
CORROSION INHIBITION OF ALUMINUM ALLOY 3SR INHClBY POLYVINYLPYRROLIDONE AND POLYACRYLAMIDE: EFFECT OF MOLECULAR STRUCTURE ON INHIBITION EFFICIENCY
Authors: UMOREN S. A.
Published: February 2010

The inhibitive performance of two water soluble polymers–polyacrylamide (PA) and polyvinylpyrrolidone (PVP) on the corrosion behavior of aluminum alloy 3SR in HCl solution was investigated using weight loss, hydrogen evolution, and thermometric methods at 30–60°C. Results obtained indicate that both polymers inhibited acid-induced corrosion of aluminum at the temperatures studied. PVP was found to be a better corrosion inhibitor than PA. All measurements from the three techniques show that inhibition efficiencies increase with increase in inhibitor concentration and decrease with increase in temperature. This indicates that the inhibitive actions of the polymers were mainly due to adsorption. Adsorption of these inhibitors follows Temkin and El-Awady adsorption isotherm models. Kinetic/thermodynamic parameters (Ea, Kads, [Formula: see text]) of adsorption of the studied inhibitors reveal that the adsorption was physical in nature and spontaneous. Differences in inhibition efficiency of the two polymers could be linked to their differences in molecular structure.
CALCULATIONS OF HYDROGEN DIFFUSION IN THE Ti(0001)–(1 × 1) SURFACE BY FIRST PRINCIPLES
Authors: GUO J. X. , GUAN L. , GENG B. , LI Q. , ZHAO Q. X. , WANG Y. L. , ZHU B. Y. , LIU B. T.
Published: February 2010

Diffusion of H atom in the Ti (0001) outer-layer and inter-layer surface is studied using density functional theory based on generalized gradient approximation (GGA). The energy barriers for the hydrogen atom diffusion in different interstitial sites at the same layers or between adjacent layers are calculated. It is found that the energy barriers of H atom diffusion in the adjacent interstitial layers are bigger than that in the same interstitial layers. For the diffusion of H atom between adjacent interstitial layers, the diffusion between tetrahedral sites is easier than that between octahedral sites. While for diffusion of H atom between the same interstitial layers, the diffusion between tetrahedral sites is easier than that between tetrahedral and octahedral sites. Moreover, it is found that the most possible inside diffusion from hcp site of a hydrogen atom in the Ti (0001) outer-layer goes through tetrahedral sites.
GROWTH OF AgInSe2 ON Si(100) SUBSTRATE BY PULSE LASER ABLATION
Authors: PATHAK DINESH , BEDI R. K. , KAUR DAVINDER
Published: February 2010

Laser ablation has attracted special interest for the growth of thin films. It allows the formation of high quality layers and maintain stoichiometry in the films of even very complex elemental materials. In this work, high quality AgInSe 2 (AIS) films were grown onto Si (100) substrates kept at different temperatures using ultra high vacuum pulsed laser deposition (PLD) technique from the AIS target synthesized from high-purity materials. It has been observed that compositional stoichiometry is largely maintained in the films. This suggests that PLD could be used as technique for fabrication of ternary semi-conducting films. The X-ray diffraction studies of the films show that films are textured in (112) direction. The structural and optical properties have been investigated as a function of substrate temperature. An increase in substrate temperature results in a more ordered structure. Roughness of the films is found to increase at higher deposition temperatures. The optical studies of the films show that the optical band gap lies in the range 1.20–1.27 eV.
TOPTMH: TOPOLOGY PREDICTOR FOR TRANSMEMBRANE α-HELICES
Authors: AHMED REZWAN , RANGWALA HUZEFA , KARYPIS GEORGE
Published: February 2010

Alpha-helical transmembrane proteins mediate many key biological processes and represent 20%–30% of all genes in many organisms. Due to the difficulties in experimentally determining their high-resolution 3D structure, computational methods to predict the location and orientation of transmembrane helix segments using sequence information are essential. We present TOPTMH, a new transmembrane helix topology prediction method that combines support vector machines, hidden Markov models, and a widely used rule-based scheme. The contribution of this work is the development of a prediction approach that first uses a binary SVM classifier to predict the helix residues and then it employs a pair of HMM models that incorporate the SVM predictions and hydropathy-based features to identify the entire transmembrane helix segments by capturing the structural characteristics of these proteins. TOPTMH outperforms state-of-the-art prediction methods and achieves the best performance on an independent static benchmark.
A QUANTUM-INSPIRED GENETIC ALGORITHM BASED ON PROBABILISTIC CODING FOR MULTIPLE SEQUENCE ALIGNMENT
Authors: HUO HONG-WEI , STOJKOVIC VOJISLAV , XIE QIAO-LUAN
Published: February 2010

Quantum parallelism arises from the ability of a quantum memory register to exist in a superposition of base states. Since the number of possible base states is 2n, where n is the number of qubits in the quantum memory register, one operation on a quantum computer performs what an exponential number of operations on a classical computer performs. The power of quantum algorithms comes from taking advantages of quantum parallelism. Quantum algorithms are exponentially faster than classical algorithms. Genetic optimization algorithms are stochastic search algorithms which are used to search large, nonlinear spaces where expert knowledge is lacking or difficult to encode. QGMALIGN — a probabilistic coding based quantum-inspired genetic algorithm for multiple sequence alignment is presented. A quantum rotation gate as a mutation operator is used to guide the quantum state evolution. Six genetic operators are designed on the coding basis to improve the solution during the evolutionary process. The experimental results show that QGMALIGN can compete with the popular methods, such as CLUSTALX and SAGA, and performs well on the presenting biological data. Moreover, the addition of genetic operators to the quantum-inspired algorithm lowers the cost of overall running time.
IS LGI2 THE CANDIDATE GENE FOR PARTIAL EPILEPSY WITH PERICENTRAL SPIKES?
Authors: LIMVIPHUVADH VACHIRANEE , CHUA LING LING , EISENHABER FRANK , ADHIKARI SHARMILA , MAURER-STROH SEBASTIAN
Published: February 2010

Partial epilepsy with pericentral spikes (PEPS) is a familial epilepsy with disease locus mapped to human chromosome region 4p15; yet, the causative gene is unknown. In this work, arguments based on protein sequence analysis and patient-specific chromosomal deletions are provided for LGI2 as the prime candidate gene for PEPS among the 52 genes known at the genome locus 4p15. Furthermore, we suggest that two reports of patients that were not classified as PEPS but show very similar phenotypes and deletions in the PEPS disease locus, could in fact describe the same disease. To test this hypothesis, patients with diagnosed PEPS or the described similar phenotypes could be screened for mutations in LGI2 and other shortlisted candidate genes. The linkage between PEPS and its disease causing gene(s) would allow diagnosis of the disease based on genetic screening as well as hereditary studies. Furthermore, previous knowledge on molecular disease mechanisms of related LGI proteins, for example LGI1 and autosomal dominant lateral temporal epilepsy, could be applied to deepen the understanding of the PEPS disease mechanism at the molecular level, which may facilitate therapeutic intervention in the future. Supplementary Table is available at .
CALBC SILVER STANDARD CORPUS
Authors: REBHOLZ-SCHUHMANN DIETRICH , YEPES ANTONIO JOSÉ JIMENO , VAN MULLIGEN ERIK M. , KANG NING , KORS JAN , MILWARD DAVID , CORBETT PETER , BUYKO EKATERINA , BEISSWANGER ELENA , HAHN UDO
Published: February 2010

The CALBC initiative aims to provide a large-scale biomedical text corpus that contains semantic annotations for named entities of different kinds. The generation of this corpus requires that the annotations from different automatic annotation systems be harmonized. In the first phase, the annotation systems from five participants (EMBL-EBI, EMC Rotterdam, NLM, JULIE Lab Jena, and Linguamatics) were gathered. All annotations were delivered in a common annotation format that included concept identifiers in the boundary assignments and that enabled comparison and alignment of the results. During the harmonization phase, the results produced from those different systems were integrated in a single harmonized corpus ("silver standard" corpus) by applying a voting scheme. We give an overview of the processed data and the principles of harmonization — formal boundary reconciliation and semantic matching of named entities. Finally, all submissions of the participants were evaluated against that silver standard corpus. We found that species and disease annotations are better standardized amongst the partners than the annotations of genes and proteins. The raw corpus is now available for additional named entity annotations. Parts of it will be made available later on for a public challenge. We expect that we can improve corpus building activities both in terms of the numbers of named entity classes being covered, as well as the size of the corpus in terms of annotated documents.
EVENT EXTRACTION WITH COMPLEX EVENT CLASSIFICATION USING RICH FEATURES
Authors: MIWA MAKOTO , SÆTRE RUNE , KIM JIN-DONG , TSUJII JUN'ICHI
Published: February 2010

Biomedical Natural Language Processing (BioNLP) attempts to capture biomedical phenomena from texts by extracting relations between biomedical entities (i.e. proteins and genes). Traditionally, only binary relations have been extracted from large numbers of published papers. Recently, more complex relations (biomolecular events) have also been extracted. Such events may include several entities or other relations. To evaluate the performance of the text mining systems, several shared task challenges have been arranged for the BioNLP community. With a common and consistent task setting, the BioNLP'09 shared task evaluated complex biomolecular events such as binding and regulation.Finding these events automatically is important in order to improve biomedical event extraction systems. In the present paper, we propose an automatic event extraction system, which contains a model for complex events, by solving a classification problem with rich features. The main contributions of the present paper are: (1) the proposal of an effective bio-event detection method using machine learning, (2) provision of a high-performance event extraction system, and (3) the execution of a quantitative error analysis. The proposed complex (binding and regulation) event detector outperforms the best system from the BioNLP'09 shared task challenge.
Influence of the Density of Crack-Initiating Defects on Crack Spacing for GaN Films on Si(111) Substrate
Authors: Kim Bumjoon , Jang Samseok , Jhin Junggeun , Lee Seungjae , Baek Jong Hyeob , Yu Youngmoon , Lee Jaesang , Byun Dongjin
Published: February 2010

This study examines the cracking of GaN films grown on Si(111) substrates, with particular focus on the effect of the density of crack-initiating defects (CIDs) on the crack spacing. The relationship between the CID density and crack spacing was examined by comparing specimens of the same thickness and under the same stress but with different CID density. The CID density in the GaN layer was changed by varying the ion-implanted area using patterning prior to metal–organic chemical vapor deposition (MOCVD) growth. The crack spacing decreased with increasing CID density, but this effect could not be explained by the previous model. Therefore, a CID-density related factor, n
d, was newly introduced to explain the crack spacing and film stress relationship.
Demonstration of AlGaN-Based Deep-Ultraviolet Light-Emitting Diodes on High-Quality AlN Templates
Authors: Sakai Yusuke , Zhu Youhua , Sumiya Shigeaki , Miyoshi Makoto , Tanaka Mitsuhiro , Egawa Takashi
Published: February 2010

The authors demonstrate AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs) on high-quality AlN/sapphire template (AlN template) by evaluating its characteristics. LED structures can be grown directly on 2-in.-diameter AlN template by metal–organic chemical vapor deposition. AlGaN epilayers are confirmed to have high crystal quality on AlN template through X-ray diffraction (XRD) and cross-sectional transmission electron microscopy (TEM). The fabricated LEDs exhibit a sharp single peak emission at DUV region around 260–270 nm from electroluminescence spectra measured at room temperature. The light intensity and current–voltage characteristics are improved by using higher quality AlN template as underlying substrate. This could facilitate the production of high-performance DUV-LEDs.
Real-time, In situ Measurement of Fuel and Crossover Methanol Vapor Concentration of a Vapor-Fed Passive Direct Methanol Fuel Cell Using Laser Absorption Spectroscopy
Authors: Chung Jinhwa , Heo Sungmoo , Song Soonho , Kim Jinho , Kang Sangkyun , Choi Kyounghwan
Published: February 2010

The concentration of methanol vapor in a vapor-fed direct methanol fuel cell (DMFC) is measured using absorption spectroscopy with a 3.39 µm He–Ne laser. A noise correction method is applied to compensate for the higher noise levels associated with the He–Ne laser. Based on this, real-time, in situ measurement of the methanol vapor concentration has been performed simultaneously in a methanol vapor transport layer and on the cathode surface (air transport layer) under various DMFC operating conditions. The change in methanol vapor concentration and cell performance is measured at various galvanostatic conditions and the impact of methanol concentration in the methanol transport layer on the methanol crossover amount is analyzed. Moreover, the changes of methanol vapor concentration are measured when the fuel supply is suspended during fuel cell operation. No previous method has been able to measure the concentration of the methanol vapor in the methanol transport layer and the air transport layer in real-time with noncontact. The results from this study can contribute to the development of stable and high-power vapor-fed DMFCs.
Do Sidewall Quantum Wells Exist in GaInN-Based Light-Emitting Diodes?
Authors: Ding Kai , Zeng Yiping
Published: February 2010

Sidewall quantum wells in the vicinity of hexagonal V-shaped pits with a reduced thickness and a higher band gap than the regular c-plane quantum wells were suggested as the origin of high luminescence efficiency in GaInN-based light-emitting diodes. In this Brief Note, by transmission electron microscopy combined with energy dispersive x-ray analysis, it was found that there must be no sidewall quantum wells around the V-shaped pits, which are just interference fringes arising from lattice strain.
Preparation of Superconducting Niobium Tips for Atomic-Resolution Scanning Tunneling Microscopy/Spectroscopy
Authors: Shimizu Ryota , Hitosugi Taro , Hashizume Tomihiro , Fukuo Noritaka , Hasegawa Tetsuya
Published: February 2010

We present a new reliable method to prepare superconducting niobium (Nb) tips for scanning tunneling microscopy/spectroscopy (STM/STS). Sharp Nb tips were fabricated by chemical etching using an electrolyte based on a hydrofluoric acid and hydrogen peroxide solution, followed by field evaporation utilizing field ion microscopy to remove Nb oxide layers from the tip apex. STM/STS measurements of Si(111) and Au(111) surfaces confirmed that the tips had atomic resolution capability together with bulk-like superconducting properties, indicating that the prepared Nb tips can be used as a unique probe for investigating local superconducting and magnetic properties on an atomic scale.
Growth of Single-Walled Carbon Nanotubes from Nonmagnetic Catalysts by Plasma Chemical Vapor Deposition
Authors: Ghorannevis Zohreh , Kato Toshiaki , Kaneko Toshiro , Hatakeyama Rikizo
Published: February 2010

Single-walled carbon nanotubes (SWNTs) are firstly grown from nonmagnetic catalysts such as Au, Pt, and Ag by plasma chemical vapor deposition (PCVD). Through the systematical investigation of the SWNT growth by thermal CVD (TCVD) and PCVD utilizing nonmagnetic and magnetic catalysts, it was revealed that an obviously opposite dependence of the SWNT yield on the H2 concentration exists between the growth experiments with the magnetic and nonmagnetic catalysts. This unique feature is explained by the difference of adsorption efficiency of hydrocarbon materials on the surface of catalysts. Optical emission spectra were also measured during the growth of SWNTs by PCVD. It was found that the intensity ratio of CH/Hα shows a tendency similar to the intensity ratio of G- and D-band (I
G/I
D) of SWNTs as a function of H2 concentration. This indicates the CH/Hα can be available to optimize the growth condition of SWNTs by PCVD, especially for nonmagnetic catalysts, whose catalytic activity is much more sensitive to the etching element than magnetic catalysts.
A Simple Combinatorial Method Aiding Research on Single-Walled Carbon Nanotube Growth on Substrates
Authors: Noda Suguru , Sugime Hisashi , Hasegawa Kei , Kakehi Kazunori , Shiratori Yosuke
Published: February 2010

Establishing fabrication methods of carbon nanotubes (CNTs) is essential to realize many applications expected for CNTs. Catalytic growth of CNTs on substrates by chemical vapor deposition (CVD) is promising for direct fabrication of CNT devices, and catalyst nanoparticles play a crucial role in such growth. We have developed a simple method called “combinatorial masked deposition (CMD)”, in which catalyst particles of a given series of sizes and compositions are formed on a single substrate by annealing gradient catalyst layers formed by sputtering through a mask. CMD enables preparation of hundreds of catalysts on a wafer, growth of single-walled CNTs (SWCNTs), and evaluation of SWCNT diameter distributions by automated Raman mapping in a single day. CMD helps determinations of the CVD and catalyst windows realizing millimeter-tall SWCNT forest growth in 10 min, and of growth curves for a series of catalysts in a single measurement when combined with real-time monitoring. A catalyst library prepared using CMD yields various CNTs, ranging from individuals, networks, spikes, and to forests of both SWCNTs and multi-walled CNTs, and thus can be used to efficiently evaluate self-organized CNT field emitters, for example. The CMD method is simple yet effective for research of CNT growth methods.
Adsorption Properties of BF4
- Anions on Graphene
Authors: Kunisada Yuji , Kishi Hirofumi , Dimas Fajarisandi , David Melanie Yadao , Nakanishi Hiroshi , Kasai Hideaki , Asari Takuma , Hayashi Shigeo
Published: February 2010

We theoretically have been investigating the basic adsorption properties of BF4
- anions on graphene as the first step in researching the properties of carbon nanotube (CNT) electrodes in an electric double layer capacitor. To clarify the basic adsorption properties, we used the first principles calculation based on the density functional theory with the generalized gradient approximation for the exchange–correlation energy. As for the results, we found that the adsorbed configuration of BF4
- anions on graphene changes as their nearest neighbor distance decreases. We show that the electric dipole moment per unit area of BF4
- adsorbed on graphene increases as the nearest neighbor anion distance decreases. On the other hand, the electric dipole moment per BF4
- anion decreases as the nearest anion neighbor distance decreases. We also found that BF4
- anions adsorbed on both sides of graphene are more stable than those on one side.
Magnetoresistance and Phase Breaking Behavior of a Nitrogen Doped Multi-Walled Carbon Nanotube
Authors: Togashi Yuko , Hatori Tetsuya , Nakamura Yoshihide , Aoki Nobuyuki , Bird Janathan P. , Terrones Mauricio , Kanako Katsumi , Ochiai Yuichi
Published: February 2010

The low temperature magnetoresistance (MR) has been studied in a nitrogen doped multi-walled carbon nanotube (CNxMWNT) with a four terminal resistance measurement. The phase coherent properties of electron transport in the CNxMWNT have been deduced from results of quantum-transport analysis. A zero-field peak of the weak localization can be observed in the low-temperature MR, however, there exhibits a clear boundary between the phase braking processes around 10 K. The phase coherence has been analyzed and the quasi-one-dimensional properties have been discussed in weakly localized metallic transport with a low temperature MR in terms of quantum interference.
Position Control and Electrical Characterization of Single-Walled Carbon Nanotubes Debundled by Density Gradient Ultracentrifugation
Authors: Kaneko Katsuhiro , Miyato Yuji , Kobayashi Kei , Matsushige Kazumi , Yamada Hirofumi
Published: February 2010

We fabricated field-effect transistors of isolated single-walled carbon nanotubes (SWNTs) that were debundled by density gradient ultracentrifugation (DGU). A solution of SWNTs in heavy water was mixed with iodixanol and then centrifuged. After DGU, the layer in which the SWNTs with a chirality of (6,5) were enriched was extracted and diluted with ultrapure water. The debundled SWNTs were bridged by dielectrophoresis between pairs of Pd electrodes. We also characterized the electrical properties of the SWNTs. Some SWNTs showed semiconductor characteristics, whereas others showed metallic behavior.
Electrical Transport Properties of Calcium-Encapsulated Single-Walled Carbon Nanotubes Realized Using Calcium Plasma
Authors: Shimizu Tetsuhiro , Kato Toshiaki , Oohara Wataru , Hatakeyama Rikizo
Published: February 2010

Calcium (Ca)-atom-encapsulated single-walled carbon nanotubes (Ca@SWNTs) are successfully formed by an ion irradiation method using Ca plasma. The electrical transport properties of Ca@SWNTs are experimentally investigated under a field-effect transistor configuration in vacuum and air. The conductance of Ca@SWNTs changes markedly compared with that of pristine SWNTs, and Ca@SWNTs exhibit air-stable unipolar n-type semiconductor behavior. This result indicates that Ca atoms are encapsulated in SWNTs and fulfill a crucial role as strong electron donors to SWNTs. A unique feature resembling a p–n junction is also observed in Ca@SWNTs.
Robust Noise Modulation of Nonlinearity in Carbon Nanotube Field-Effect Transistors
Authors: Kawahara Toshio , Yamaguchi Satarou , Maehashi Kenzo , Ohno Yasuhide , Matsumoto Kazuhiko , Kawai Tomoji
Published: February 2010

Carbon nanotubes (CNTs) are one of the candidates for nanosize devices such as field-effect transistors. CNT field-effect transistors (CNTFETs) have very special properties sometimes caused by surface states. For example, they are also well known as noisy devices caused by the molecule adhesion on the surface. Nonlinear systems, however, have some advantages such as weak signal detection or enhancement in working with noise. The small signal enhancement was conventionally studied as stochastic resonance. Therefore, we study the modification of nonlinearity of the systems under noise. For actual applications, the noise is also generated from the devices. Thus, we combined the noise CNTFET and another CNT transistor for the trial nonlinear system. Then, the sine wave amplification in the transistor with 1/ f noise of CNTFETs was measured. We used two different combinations of CNTFETs for noise and nonlinear CNTFETs, and observed the robustness of the noise modification on the nonlinearity.
On a New Reliable Algorithm
Authors: Alomari A. K. , Noorani M. S. M. , Nazar R.
Published: February 2010

An analytical expression for the solution of the prey‐predator problem by an adaptation of the homotopy analysis method (HAM) is presented. The HAM is treated as an algorithm for approximating the solution
of the problem in a sequence of time intervals; that is, HAM is converted into a
hybrid numeric‐analytic method called the multistage HAM (MSHAM). Comparisons between the MSHAM solutions and the fourth‐order Runge‐Kutta (RK4) numerical solutions reveal that the new technique is a promising tool
for the nonlinear systems of ordinary differential equations.
Characteristics of a Microcystin-Degrading Bacterium under Alkaline Environmental Conditions
Authors: Okano Kunihiro , Shimizu Kazuya , Kawauchi Yukio , Maseda Hideaki , Utsumi Motoo , Zhang Zhenya , Neilan Brett A. , Sugiura Norio
Published: February 2010

The pH of the water associated with toxic blooms of cyanobacteria is typically in the alkaline range; however, previously only microcystin-degrading bacteria growing in neutral pH conditions have been isolated. Therefore, we sought to isolate and characterize an alkali-tolerant microcystin-degrading bacterium from a water bloom using microcystin-LR. Analysis of the 16S rRNA gene sequence revealed that the isolated bacterium belonged to the genusSphingopyxis, and the strain was named C-1.Sphingopyxissp. C-1 can grow; at pH 11.0; however, the optimum pH for growth was pH 7.0. The microcystin degradation activity of the bacterium was the greatest between pH 6.52 and pH 8.45 but was also detected at pH 10.0. ThemlrAhomolog encoding the microcystin-degrading enzyme in the C-1 strain was conserved. We concluded that alkali-tolerant microcystin-degrading bacterium played a key role in triggering the rapid degradation of microcystin, leading to the disappearance of toxic water blooms in aquatic environments.