bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the deformed region on the (111) plane of MgO crystals by cathodoluminescence method
Authors: Boyarskaya Yu. S. , Schreiber J. , Grabko D. Z. , Dyntu M. P. , Pushkash B. M. 
Published: July 2007

AbstractThe (111) plane of MgO single crystals was deformed by a concentrated load. It was observed that the number of rows of a cathodoluminescence rosette is a factor of two lower than that for the etch pit one. The explanation of this phenomenon is given. The polarity of plastic deformation was revealed using both an etch pit technique and cathodoluminescence method. It is shown that deformation causes a change of the cathodoluminescence spectra. The spectra, obtained from crystal deformed by indentation and from compressed crystal, are similar.
Liquid phase epitaxial growth of AlGaAsGaAs heterostructures for solar energy conversion
Authors: Romero R. , Purón E. 
Published: July 2007

AbstractThe operation principles of four novel AlxGa1−xAsGaAs heterostructure concentrator cells are discussed together with the LPE growth of such structures. Typical temperature schedules, boat design and melt composition are presented, and a detailed description of the technological procedure involved is offered.
Low Temperature Studies on the Grain‐Size Effect on the Electro‐optical Properties of ZnO Luminophores
Authors: Kaza B. R. , Asare R. P. , Bhushan S. , Chandra B. P. 
Published: July 2007

AbstractThe electroluminescence and photoluminescence of the self‐activated ZnO luminophores exhibit three prominent bands in the green, yellow and Yellow‐orange regions. With the reduction in grain size, these bands shift towards lower energy side and their energies are enhanced. The bands shift towards lower energy side with decreasing temperature of the luminophores. Both the electroluminescence and photoluminescence have maximum overall brightness for 33 micron grain size. One additional peak at 120 °K is found during the brightness studies of electroluminescence and photoluminescence of the luminophores. The appearence of such an additional peak is also confirmed from the studies of the brightness waves. The effects of grain size on the electro‐optical properties of the self‐activated ZnO luminophores are discussed on the basis of the existing ideas about photo‐ and electroluminescence.
Eccentricity of symmetrical and asymmetrical etch pits on calcite cleavages
Authors: Mehta B. J. 
Published: July 2007

AbstractThere are two types of chemical eccentric etch pits.

Deepest points are always lying on the shorter diagonal. – Symmetrical etch pits the deepest points of which lying on the diagonals show dislocation lines in the plane (110). Eccentricity of symmetrical etch pits along the [110] direction is depending on the concentration of the etchant and on the inclination of the dislocation line in the plane (110).
Depth points do not lie on any diagonals. Eccentricity of asymmetrical etch pits along the [110] direction is depending on the concentration of the etchant and on the inclination of the dislocation line in the plane (110).
On the theory of steady state lamellar eutectic solidification at high solidification rates
Authors: Sellger R. , Löser W. 
Published: July 2007

AbstractThe famous theory of JACKSON and HUNT for the unidirectional eutectic solidification is extended considering the effect of the solidification rate on the interfacial solute concentration. Contributions attributed to nonsymmetric phase diagrams lead to corrections of the constant K in the λ2V = K relation between the lamellar half‐spacing λ and the solidification rate V. For high solidification rates deviations from this relation are derived.
On the shape of crystals grown by Kyropoulos technique
Authors: Singh Gurnam , Ghosh B. , Deshpande R. Y. 
Published: July 2007

AbstractThe shape of the crystal grown by Kyropoulos technique has been evaluated on the basis of simple mass transfer approach. For some specific cases we have computed the shapes which are resaonable and generally in conformity with physical requirements. To verify the results crystals of KCl were grown under two specific conditions. The shapes of the resulting crystals agreeing with the calculated shapes within limits of error lend support to the validity of mass transfer approach.
Synthesis and characterization of Ce2(SO4)3 · 5(H, D)2 O
Authors: de Saja A. , Pastor J. M. , Hernandez E. , Rull F. , de Saja J. A. 
Published: July 2007

AbstractThe synthesis of cerium sulphate pentahydrate and its structure investigated by X‐ray diffraction methods are reported. Analysis of the precession and Weissenberg photographs show that the crystals are twinned perfectly, in the sense that they are made of two single crystals with the true space group Cc. The dehydration of this compound has been studied using thermogravimetry and differential scanning calorimetric analysis in the temperature range 360 to 650 K. Powder Raman spectra of Ce2(SO4)3 · 5 H2O and Ce2(SO4)3 · 5 D2O have been measured at room temperature and the spectral assignments have been carried out by comparing these spectra with each other. Evidence of intermolecular hydrogen bonding has been found.
Linear constraints, robust‐weighting and efficient composite modeling
Authors: Guerard John B. 
Published: July 2007

AbstractRecent studies have shown that composite forecasting produces superior forecasts when compared to individual forecasts. This paper extends the existing literature by employing linear constraints and robust regression techniques in composite model building. Security analysts forecasts may be improved when combined with time series forecasts for a diversified sample of 261 firms with a 1980‐1982 post‐sample estimation period. The mean square error of analyst forecasts may be reduced by combining analyst and univariate time series model forecasts in constrained and unconstrained ordinary least squares regression models. These reductions are very interesting when one finds that the univariate time series model forecasts do not substantially deviate from those produced by ARIMA (0,1,1) processes. Moreover, security analysts' forecast errors may be significantly reduced when constrained and unconstrained robust regression analyses are employed.
Forecasting with growth curves: The effect of error structure
Authors: Meade Nigel 
Published: July 2007

AbstractThe logistic model is used for forecasting a number of different types of variable; adoption of durable goods, consumption, growth of human populations. This study investigates the effect of the error structure assumed, on the forecasting accuracy of the logistic. A local logistic model is developed with an additive error term, the variance of which can be made a function of the level of the variable being modelled and its distance from saturation. Evidence is found that suggests that the variance of the disturbance term, when using the logistic to forecast human populations, is proportional to at least the square of population size. Results for the adoption of durable goods are mixed. An error structure consistent with the intuitively reasonable binomial model performed well for some series but not for others. This suggests that some data sets may be inconsistent with the binomial model.
Forecasting with balanced state space representations of multivariate distributed lag models
Authors: Mittnik Stefan 
Published: July 2007

AbstractA procedure for estimating state space models for multivariate distributed lag processes is described. It involves singular value decomposition techniques and yields an internally balanced state space representation which has attractive properties. Following the specifications of a forecasting competition, the approach is applied to generate ex‐post forecasts for US real GNP growth rates. The forecasts of the estimated state space model are compared to those of twelve econometric models and an ARIMA model.
Prediction uncertainty in an ecological model of the oosterschelde estuary
Authors: Klepper O. , Scholten H. , Van Kamer J. P. G. De 
Published: July 2007

AbstractA storm surge barrier was constructed in 1987 in the Oosterschelde estuary in the south‐western delta of Holland to provide protection from flooding, while largely maintaining the tidal characteristics of the estuary. Despite efforts to minimize the hydraulic changes resulting from the barrage, it was expected that exchange with the North Sea, suspended sediment concentration and nutrient loads would decrease considerably. A model of the nutrients, algae and bottom organisms (mainly cockles and mussels) was developed to predict possible changes in the availability of food for these organisms. Although the model is based on standard constructs of ecology and hydraulics, many of its parameters are known with but low accuracy, being expressed as a range of possible values only. Running the model with all possible values of the parameters gives rise to a fairly wide range of model output responses. The calibration procedure used herein does not seek a single optimal value for the parameters but a decrease in the parameter range and thus a reduction in model prediction uncertainty. The field data available for calibration of the model are weighted according to their relationship with the model's objective, i.e. to predict food availability for shellfish. Despite the considerable physical changes resulting from the barrier food availability for shellfish is predicted to remain largely unchanged, due to the compensating effects of several other accompanying changes. There appears to be room for the extension of mussel culture, but at an increased risk of adverse conditions arising.
Forecasting the Italian industrial production index in real time
Authors: Bodo G. , Cividini A. , Signorini L. F. 
Published: July 2007

AbstractDaily electricity consumption data, available almost in real time, can be used in Italy to estimate the level of industrial production in any given month before the month is over. We present a number of procedures that do this using electricity consumption in the first 14 days of the month. (This is an extension of a previous model that used monthly electricity data.) We show that, with a number of adjustments, a model using half‐monthly electricity data generates acceptable estimates of the monthly production index. More precisely, these estimates are more accurate than univariate forecasts but less accurate than estimates based on monthly electricity data. A further improvement can be obtained by combining ‘half‐monthly’ electricity‐based estimates with univariate forecasts. We also present quarterly estimates and discuss confidence intervals for various types of forecasts.
A model to predict mid‐air and near‐mid‐air collisions
Authors: Datta K. , Oliver R. M. 
Published: July 2007

AbstractThe probability of mid‐air and near‐mid‐air collisions in terminal areas depends on a variety of factors such as visibility, number of air traffic controllers, communication channels, terrain, mix of aircraft and aircraft speeds, local densities of air traffic in specific subregions surrounding airports, as well as other measures of congestion. We develop, with the use of influence diagrams, a probabilistic model to analyze and predict mid‐air and near‐mid‐air collisions. The probability of near‐mid‐air and mid‐air collisions in the model is influenced by weather, traffic density, detection and collision avoidance maneuvres. Low‐hazard near‐mid‐air collisions (LNMACs) can escalate to critical near‐mid‐air collisions (CNMACs) and eventually to a mid‐air collision (MAC) with the probability of escalation reduced through the use of a collision‐avoidance system. The predictive probability of a collision in the model is the product of three factorsdensity, effectiveness of the collision‐avoidance system, and the conditional probability that independently of the collision‐avoidance system a CNMAC escalates, by chance alone, to a MAC. The paper obtains several conclusions based on sensitivity analysis of the model. Under the assumption that new designs of collision‐avoidance systems will result in much higher detection probabilities than presently available, it is important that both aircraft use the system if there is to be a significant improvement in collision avoidance. For maximum benefit, these collision‐avoidance systems should not reduce the probabilities of avoidance given that a near‐mid‐air collision has been detected.
On trend extraction models: Interpretation, empirical evidence and forecasting performance
Authors: Garcia‐Ferrer Antonio , Hoyo Juan Del 
Published: July 2007

AbstractThis paper deals with the economic interpretation of the unobserved components model in the light of the apparent problem posed by previous work in that several practiced methodologies seem to lead to very different models of certain economic variables. A detailed empirical analysis is carried out to show how the failure in obtaining quasi‐orthogonal components can seriously bias the interpretation of some decomposition procedures. Finally, the forecasting performance (in both the short and long run) of these decomposition models is analyzed in comparison with other alternatives.
Multiple time‐series modelling: Another look at the canadian money and income data
Authors: Abraham Bovas 
Published: July 2007

AbstractThe practice of modelling the components of a vector time series to arrive at a joint model for the vector is considered. It is shown that in some cases this is not unreasonable. A vector ARMA model is used to model the Canadian money and income data. We also use these data to discuss the issue of differencing a multiple time series. Finally, models based on first and second differences are compared using forecasts.
Autoregressive‐asymmetric moving average models for business cycle data
Authors: Brånnås Kurt , De Gooijer Jan G. 
Published: July 2007

AbstractMuch business cycle research is based on an assumption of symmetric cycles, though it is frequently argued that the downturns are steeper and more short‐lived than the upturns; implying cyclical asymmetries. A new class of nonlinear autoregressive‐asymmetric moving average models is introduced. These models are able to deal with symmetric as well as asymmetric phenomena. A likelihood estimation procedure and a Wald test statistic for symmetry are presented. Evidence of asymmetry is found in US real GNP growth rates.
An Integral Transform in de Sitter Space
Authors: Moylan P. 
Published: July 2007

AbstractAn integral transform on (4 + 1) de Sitter space, which is a generalization of the Fourier transform for a Dirac particle in Minkowski space, is considered, and proofs of its relevant properties are provided. With this integral transform we demonstrate explicitly that the momentum space eigenvalue equation for the second order Casimir operator of the de Sitter group is equivalent to a wave equation in Minkowski momentum space, which describes the mass‐spin relation of a mechanical system in Minkowski space, consisting of two equal mass, point‐like constituents rotating uniformly at a distance R from their geometric center, where R is the radius of the de Sitter space. Applications to the relativistic rotator are considered. Contrary to our previous results, we find that the relativistic rotator does not go into a structureless relativistic mass point in the elementary limit obtained by contracting the de Sitter group into the Poincaré group. Our analysis can be carried over, with relatively minor modifications, to anti‐de Sitter space, and similar results hold there. Additional physical consequences are also discussed.
Query processing that permits incompleteness of queries specifying a sequence of data in a motion picture database and the MeSOD model
Authors: Tabuchi Masahiro , Muraoka Yoichi 
Published: July 2007

AbstractThis paper proposes the database model for the motion picture database, together with the query processing. The existing motion picture database is not convenient in describing the change of the scene attribute in the query condition to specify the subsequence of the motion picture database. Another more serious problem of the existing data model is that the desired sequence can never be retrieved from the scene sequence where the scene which does not satisfy the query condition is mixed or a scene is missing.To cope with the former problem, the regular expression which enables users to represent the iteration of the condition is introduced into the MeSOD model. Thus, the change of the scene attribute can be described by the regular expression for the condition. To cope with the latter problem, a query processing is defined formally (incomplete query processing), where the condition containing the regular expression is tolerated according to the database.As an actual example of the proposed approach, the broadcast of a Sumo program is considered, where the broadcast pattern changes during the course of a Sumo match. An adequate scene sequence is required to be extracted according to the condition representing a typical match. It is verified that an adequate scene sequence can be extracted by the incomplete query processing as a Sumo match from an actual Sumo broadcast program. The validity of the result of experiment is verified theoretically, and the effectiveness of the proposed approach is demonstrated.
Fractal dependence of texture perception
Authors: Matsui Nobuyuki , Tsuruno Reiji , Bamba Eiichi 
Published: July 2007

AbstractHumans can easily discriminate not only simple figures but also similar complex textures. At present, a large information processing capability is required for a machine to process such texture image information in a short time on the CRT screen or medical images. It is important to analyze the visual information mechanism for those images.In recent studies of visual search, the texton is considered as a pop‐out discrimination element. There remain a number of problems in the recognition of the texture composed of complex patterns such that the texton in not clear. On the other hand, fractal can be a measure for the complexity, and is related closely to the visual system.This paper presents a recognition experiment and an attention allocation model by simultaneous presentation of multiple images, where a set of textures with known fractal dimensions are used as the image information. The relations are examined quantitatively. As a result, it is shown that a relation can be assumed between the fractal dimension (Dp, DH) of the texture and the allocation of attention fi to the texture. For the set (A) of textures, a multiple regression expression f(A) = 97.6 + 20.1 Dp − 55.3 DH can be applied with a high correlation coefficient. Thus, it is verified that the fractal information can be used as the pop‐out discrimination element in the recognition of the texture.
Continuous speech recognition based on A* search with word‐pair constraint as heuristics
Authors: Kawahara Tatsuya , Doshita Shuji , Matsumoto Shinji 
Published: July 2007

AbstractThis paper proposes an A* search algorithm for continuous speech recognition using phoneme HMM and Context‐Free (LR) parser. This best‐first search evaluates each sentence hypothesis with the matching score plus the heuristic score of the unsearched part. Heuristics computation is based on word‐pair constraint that is common to all the hypotheses. Word‐pair constraint, which is not computationally expensive, satisfies A*‐admissibility and provides powerful heuristics.The algorithm is guaranteed to obtain the optimal hypothesis and does not expand vain hypotheses very much. Compared with various kinds of beam search, therefore, it achieved better accuracy with less computation. This heuristics proved to be effective for beam search, too. Furthermore, it was implemented on stochastic grammar and some improved was obtained.
Development of document architecture extraction
Authors: Doi Miwako , Fukui Mika , Tamaguchi Kouji , Takebyashi Youichi , Iwai Isamu 
Published: July 2007

AbstractThe purpose of this study is the reduction of the burden in the document structurization process. A technique is presented for extracting the document architecture. As the technical document, 12,000 articles are extracted from the proceedings of a national convention. A summary of sample sentences as well as approximately 500 office documents within the organization also are examined as business documents. The rules for extracting the architecture are derived. The technique developed for document architecture extraction can extract such hierarchical structures as chapters and sections, as well as the reference structure to figures and tables from the technical document. The technique can also extract the hierarchical structure such as communications and reports from the business document. The technical and business documents can be discriminated by analyzing the character strings.As a result of evaluation using proceedings and in‐office documents other than those used for deriving the rules, the error rate is 10.0 percent for the technical document and 23.0 percent for the business document. The error in extracting the reference structure is 8 percent. A field test is executed after improving the method so that the equations, figures and tables embedded in the text can be handled. The error rate is 5.4 percent for the technical document and 15.4 percent for the business document. It is verified through examples that the structurization can be achieved in a considerably shorter time than by manual processing. The developed document architecture extraction technique is commercialized as an automatic system by combining the technique with the layout attribute. The developed extraction technique will be utilized effectively in the hypertext conversion of the existing document and other problems, in addition to the layout processing.
Speech segmentation and clustering problem based on an unknown‐multiple N signal source model—an application to segmented speech clustering based on speaker features
Authors: Sugiyama Masahide , Murakami Jinichi , Watanabe Hideyuki 
Published: July 2007

AbstractThis paper describes the speech segmentation and clustering problem based on unknown‐multiple signal source modeling, where a sequence of signals is generated by signal sources one by one without overlap. This problem and its subproblem with given segmentation information have wide applications in various fields.This paper formulates the problem, and the solution and its application of the subproblem are proposed. The solution is based on clustering symbol output probability functions. The other possible solution, which gives the segmentation and clustering simultaneously, is based on an ergodic HMM which can transit among all states.In this paper the subproblem is applied to speech clustering based on speaker features. Here, each speaker corresponds to a single signal source. The performance is evaluated using simulated dialog speech data.
Reconstruction of a decision tree with learning examples generated from an original tree and its characteristics
Authors: Asami Tohru , Unoki Hachisu , Hashimoto Kazuo , Yamamoto Seiichi 
Published: July 2007

AbstractThis paper describes the a posteriori method of decision tree learning after the tree is applied to a real domain, such as medical diagnoses. Without collecting a new set of diagnosis examples, the presented algorithm reconstructs a decision tree preserving the error rate of diagnosis from an original tree and a frequency of diagnoses, which is counted at reaching the corresponding terminal node of that tree when applied to a real domain. The new tree has a shorter path length to diagnose and a logically same meaning with the original tree because of generating a set of pseudoexamples whose unobserved attribute values uniformly distribute in the value range.To reduce the computational cost, a method to avoid a generation of a pseudoexample set also is presented. The context dependencies between attributes are considered by introducing an attribute concatenation. The experiments show that an average path length will be reduced by 6 to 10 percent after reconstruction of a randomly generated decision tree with nonoptimized diagnosis frequencies.