bluuebunny/crossref_metadata_2025 huggingface dataset:
Absorption and ionic conductivity of oxygen‐containing SrF2 crystals
Authors: Bollmann W.
Published: July 2007

An absorption band at 3644 cm−1 is caused by isolated OH− ions. O− ions cause an absorption band at 213 nm the oscillator strength of which is 0.020. Charge‐compensation of O− ions is effected by F− ion vacancies (F). As for CaF2 crystals there occur monomers and dimers of [O− – F] complexes. The mass action constants of association of F with oxygen centres are KAD = ⅓ exp (4.28 – 0.82 eV/kT) for [O− – F], KAT = 4 exp (17.4 – 1.25 eV/kT) for [2 O− – F] and KAQ = exp (4.2 – 0.89 eV/kT) for [2 O− – 2 F].
The Goldschmidt complication series, morphological extinction rules and phase relationships. A contribution to correspondence between crystal structure and habitus
Authors: Follner H. , Schwarz H.
Published: July 2007

For space group Pbn21 and organic structures with one acentric molecule in the asymmetric unit it has been demonstrated, that the morphological lattice is a Fourier transform of crystal morphology. The morphological lattice corresponds with the lattice of the centers of molecules.
An electrolytic method to grow copper dendrites and single crystals in gels
Authors: George M. T. , Vaidyan V. K.
Published: July 2007

A new electrolytic method for the growth of any metallic crystal in gel by using gel as a medium for controlled growth, is reported. Different types of large dendrites and single crystals of copper were grown by electrolytic method in the gel medium. It is found that pH of the gel medium, the concentration of the supernatant solution, the current density and the electrode material used, have considerable influence on the habits of the dendrites and the single crystals thus grown. The surface features and morphology of crystals and dendrites were studied by optical and scanning electron microscopy. Compared to other conventional electrolytic growth techniques, the present method has a number of additional parameters that can be varied, and hence a more effective controlled growth of crystals is possible.
Investigation of InAs—InSb solid solution heteroepitaxial layers and structures
Authors: Bert N. A. , Zhingarev M. Z. , Konnikov S. G. , Mursakulov N. M. , Tretyakov D. N.
Published: July 2007

The results of investigations concerning the peculiarities of obtaining InAs—InAs1−xSbx heterostructure and of its properties revealed that the quality of epitaxial layers as well as photoelectric and electroluminescent device structure characteristics are to a great extent determined by a disagreement magnitude of heterostructure materials. — To decrease the magnitude of disagreement at the layer‐substrate boundary and to achieve the composition with x > 0.1 at some distance the method of layer‐by‐layer growth (ANDREWS et al.) and the obtaining a graded heterojunction with optimization of component distribution along epilayer thickness seems to be promising.
Structure information from morphological data of organic crystals with the help of Patterson methods
Authors: Follner H.
Published: July 2007

The morphological points of a space group are special or general point configurations, respectively combinations of point configurations. There are mainly point configurations to be found, which in three‐dimensional space or at least in one projection, posses a higher translational symmetry than the crystallographic ones. The morphological lattice of organic structures with one molecule in the asymmetric unit e. g. corresponds to the lattice of the centers of gravity of molecules. Starting from the faces appearing on crystal, a possibility for deriving structure information with the help of Patterson methods will be demonstrated.
On the reproducibility of the orientation distribution function of texture samples from pole figures (IV). Reproduction methods
Authors: Matthies S.
Published: July 2007

The known reproduction methods for determination of the orientation distribution function from pole figures are discussed from the view of the structure of their solutions of the problem. The exact solution of the reproduction problem is derived.
Vickers hardness and microfracture of single and polycrystalline Al2O3
Authors: Krell A.
Published: July 2007

Various methods were tested with respect to their qualification for the hardness determination of sapphire and sintered alumina. From the load and time dependence of the hardness of different ceramic structures we get informations about the acting deformation mechanisms. Local plastic deformation and brittle microfracture are of importance for the room temperature behaviour of this basic oxide ceramic.
Growth and etching of anhydrous diglycine sulfate single crystals
Authors: Pandaya G. R. , Vyas D. D.
Published: July 2007

Single crystals of anhydrous diglycine sulfate are grown at constant temperature by evaporation method. The crystals are grown at various temperatures and their growth rate is determined. A chemical etchant for dislocation studies is reported. The perfection of the crystals grown at various temperatures has been studied using etching technique. It is found that the crystals contained inclusions of the mother liquid. The crystals grown below 28° are almost free of inclusions and the dislocation density is also low.
Mechanism of epitaxial ferrite‐spinel layer formation on magnesium oxide substrate
Authors: Aleksandrov L. N. , Mitlina L. A. , Molchanov V. V.
Published: July 2007

The initial stage of small gap heteroepitaxial growth of magnesium‐manganese ferrite films during chemical gas transportation reactions on orientation (100) magnesium oxide substrate was studied.

Film growth would begin with origination of parallely oriented three‐dimensional nuclei, their shapes at lower (1170 K) and at appear (1420 K) film synthesis temperature limits being different.

After little islands had grown together and continuous layer formed the secondary nuclei would appear, their shapes resembling cut‐up pyramids.

Continuous layer minimum thickness was 0.15 μm. The growing together of little islands results in film block structure. Block sizes could be as big as 300–400 μm if films grow at the speed of 2 μm/min, the density of islands being 106 cm−2.

Linear density of unconformity dislocations at film‐substrate boundary would be (3.7 ÷ 7.4) 103 cm−1. It would depend on magnesium content for a film.

Elastic stresses in films would come to 7 · 108 ÷ 3 · 109 dyne/cm2.

X‐ray topography pictures of block structures and of accumulations of admixtures at block boundaries are presented.
Structural changes of NaCl and Si single crystal surfaces under ion bombardment
Authors: Marinov M. , Stoyanchev R.
Published: July 2007

The surface structural changes under ion bombardment of NaCl and Si monocrystalline specimens are followed using electron microscopic technique. Formations and regions with circular symmetry are registered on the surface of NaCl and Si single crystals. Qualitative interpretation of the generation mechanism of the circular formations is made. The ion bombardment is used for the visualization of the surface structure of the specimens by the method of crystal selfdecoration.
Defect structure and the nature of the obstacles for dislocations in NaCl(Ca) crystals
Authors: Urusovskaya A. A. , Darinskaya E. V. , Voszka R. , Jansky J.
Published: July 2007

On the basis of the investigation of the influence of Ca concentration on yield point at different strain rates it is revealed the nature of the obstacles for dislocations overcomed with and without thermal activation.
Configuration entropy of ternary alloy superlattice
Authors: Šrobár F.
Published: July 2007

Difference in mixture‐related entropy between superlattice and the corresponding homogeneous crystal in which all composition gradients have been annihilated by equilibrating processes (the configuration entropy of superlattice, ΔSconf) is analytically formulated as a function of composition variables and geometry parameters. Numerical evaluations are performed for the important case of AlxGa1−xAs‐based superlattice. Qualitative trends confirm in general the intuitive expectations (− ΔSconf grows with increasing composition difference between the layers); the dependencies on geometry parameters exhibit a peculiar behaviour. The results are applicable to superlattices with periode lengths sufficiently in excess of the monoatomic layer thickness.
Calorimetric investigations of 2‐[4‐n‐alkylphenyl]‐5‐[4‐n‐alkyloxyphenyl]‐pyrimidines
Authors: Wiegeleben A. , Marzotko D. , Demus D.
Published: July 2007

We investigated temperatures and enthalpies of the phase transitions by means of the calorimeter DSC‐2. The kinetics of polymorphic transitions in the solid state, the pretransitional behaviour in the liquid crystalline phases and the transition enthalpies, ranging from 3 J/mol up to 50 kJ/mol, in relation to the occurrence of the liquid crystalline phase types SG, SF, SC, SA, and N are points of discussion.
Estimation of activation parameters for diffusion‐controlled crystallization of barium tungstate from sodium tungstate melts by differential thermal analysis
Authors: Roy B. N. , Roy M. R.
Published: July 2007

The proximity (d12) between a diffusing species and its host crystal necessary for a successful diffusion for diffusion‐controlled crystallization of barium tungstate from sodium tungstate melts in platinum crucibles was estimated. These distances increased with increased cooling rates (RT) and crystallization temperatures (T0). Energy (E), enthalpy (ΔHa), entropy (ΔSa) and free‐energy (ΔGa) of activation and the pre‐exponential factor (k0) were evaluated using an ordinary Arrhenius equation kD1 = k0e−E/RT, where kD1 was the diffusion rate‐constant. These parameters were virtually unaffected by the changes in T0 and RT.
Accuracy in forecasting: A survey
Authors: Mahmoud Essam
Published: July 2007

In this study, the author provides a brief and concise summary of empirical investigations pertaining to forecasting with special reference to the accuracy of different forecasting techniques. The study mainly focuses on comparisons of the accuracy of these techniques. The comparisons cover both quantitative and qualitative methods. In addition the summary includes studies seeking to test or improve accuracy by combining forecasting techniques.
Discount weighted estimation
Authors: Ameen J. R. M. , Harrison P. J.
Published: July 2007

The parsimonious method of exponentially weighted regression (EWR) is attractive but limited in application because it depends upon just one discount factor. This paper generalizes the EWR approach to a method called discount weighted estimation (DWE) which allowed distinct model components to have different associated discount factors. The method includes EWR as a special case. The general non‐limiting recurrence relationships will be useful in practice, especially when practitioners wish to specify prior information, to intervene with subjective judgement and to derive estimates and forecasts sequentially based upon limited data. Two theorems extend the important EWR limiting results of Dobbie and McKenzie to DWE. The latter permits the derivation of a large class of known processs for which DWE is optimal. The method is illustrated by two applications, one of which uses the famous international airline passenger data. This allows a comparision with the ICI MULDO system which uses a particular two discount factor forecasting method. A companion paper extends the discount methods to Bayesian forecasting, Kalman filtering and state space modelling.
The M‐competition with a fully automatic box–jenkins procedure
Authors: Libert G.
Published: July 2007

CAPRI is a fully automatic and quick procedure for forecasting. It is based on the Box–Jenkins methodology and needs no a priori knowledge about the time series. The 1001 series of the Makridakis competition have been analysed with this program and its accuracy measured in comparison with other methods. CAPRI is recommended for short term forecasting horizons in cases where the user does not want to interfere with the modelling process.
The chatfield‐prothero case study: Another look
Authors: Raveh Adi
Published: July 2007

The Chatfield‐Prothero case study in time series, ‘Sales of a company X’, is analysed from a perspective different to that of the authors. More accurate forecasting performance for these data is obtained by adopting the following two tactics: (1) shifting from a problem in transformation of the original series to one of seasonality adjustment; (2) assuming a mixed seasonality type model in contrast to employing a multiplicative assumption.
Forecasting system energy demand
Authors: Guinel Ipek
Published: July 2007

This paper presents the results of the Electric Power Research Institute Short Range Forecasting Project (EPRI‐SRF) performed by the Load Forecasts Department, Economics and Forecasts Division of Ontario Hydro, Ontario, Canada.

In this study a variety of short‐range forecasting techniques are applied to Ontario Hydro monthly data on total system energy demand. These techniques are available in a software package (FORECAST MASTER) developed for EPRI by two consultants—Scientific Systems, Inc. (SSI) and Quantitativ Economic Research, Inc. (QUERI).

The methods used for this study were the univariate Box‐Jenkins method, the multivariate state‐space method, Bayesian vector autoregression and autoregress ve econometric regression.

A comparison of the models developed show that the econometric models perform the best overall. The state‐space models are more suitable for very short‐term (one‐step ahead) forecasts. Although the Box‐Jenkins method has the advantage of simplicity in terms of estimation and data requirement, its performance was not as good as that of the others. Bayesian vector autoregresson results indicate that this program needs some modification for monthly data.
Do forecasts produced by organizations reflect anchoring and adjustment?
Authors: Bromiley Philip
Published: July 2007

In attempting to improve forecasting, many facets of the forecasting process may be addressed including techniques, psychological factors, and organizational factors. This research examines whether a robust psychological bias (anchoring and adjustment) can be observed in a set of organizationally‐produced forecasts. Rather than a simple consistent bias, biases were found to vary across organizations and items being forecast. Such bias patterns suggest that organizational factors may be important in determining the biases found in organizationally‐produced forecasts.
Forecasting from fallible data: Correcting prediction bias with stein‐rule least squares
Authors: Stanley T. D.
Published: July 2007

In the presence of fallible data, standard estimation and forecasting techniques are biased and inconsistent. Surprisingly, the magnitude of this bias tends to increase, and not diminish, in time series applications as more observations become available. A solution to this ever‐present problem, Stein‐rule least squares (SRLS), is offered. It corrects for the bias and inconsistency of traditional estimators and provides a means for significantly improving the predictive accuracy of regression‐based forecasting techniques. A Monte Carlo study of the forecasting accuracy of SRLS, compared to its alternatives reveals its practical significance and small sample behaviour.
The use of non‐time series information in sales forecasting: A case study
Authors: Edmundson Bob , Lawrence Michael , O'Connor Marcus
Published: July 2007

The contribution of product and industry knowledge to the accuracy of sales forecasting was investigated by examining the company forecasts of a leading manufacturer and marketer of consumable products. The company forecasts of 18 products produced by a meeting of marketing, sales, and production personnel were compared with those generated by the same company personnel when denied specific product knowledge and with the forecasts of selected judgemental and statistical time series methods. Results indicated that product knowledge contributed significantly to forecast accuracy and that the forecast accuracy of company personnel who possessed industry forecasting knowledge (but not product knowledge) was not significantly different from the time series based methods. Furthermore, the company forecasts were more accurate than averages of the judgemental and statistical time series forecasts. These results point to the importance of specific product information to forecast accuracy and accordingly call into question the continuing strong emphasis on improving extrapolation techniques without consideration of the inclusion of non‐time series knowledge.
A simple check of the time homogeneity of Markov chains
Authors: Mattsson Anders , Thorburn Daniel
Published: July 2007

In this paper we consider a population where the state of each individual follows a Markov chain. If the population is recorded for a very few periods only, it is still possible to estimate the transition matrix and to make projections into the far future. These forecasts are sensible if the chains are time homogeneous, but this is difficult to check if only a few periods are observed. We suggest a simple method to check this assumption, and obtain an upper bound on the time the process can have been time homogeneous. The method is also applied to a second‐order Markov chain and to the mover‐stayer model.

AMS subject classification (1980): Primary 62M05, Secondary 62M20.
Forecasting non‐seasonal time series with missing observations
Authors: Aldrin Magne , Damsleth Eivind
Published: July 2007

Most forecasting methods are based on equally spaced data. In the case of missing observations the methods have to be modified. We have considered three smoothing methods: namely, simple exponential smoothing; double exponential smoothing; and Holt's method. We present a new, unified approach to handle missing data within the smoothing methods. This approach is compared with previously suggested modifications. The comparison is done on 12 real, non‐seasonal time series, and shows that the smoothing methods, properly modified, usually perform well if the time series have a moderate number of missing observations.
Optimal conditional ARIMA forecasts
Authors: Guerrero Víctor M.
Published: July 2007

An optimal univariate forecast, based on historical and additional information about the future, is obtained in this paper. Its statistical properties, as well as some inferential procedures derived from it, are indicated. Two main situations are considered explicitly: (1) when the additional information imposes a constraint to be fulfilled exactly by the forecasts and (2) when the information is only a conjecture about the future values of the series or a forecast from an alternative model. Theoretical and empirical illustrations are provided, and a unification of the existing methods is also attempted.
Subjective versus objective combining of forecasts: An experiment
Authors: Flores Benito E. , White Edna M.
Published: July 2007

The paper reports results of an experiment conducted to evaluate subjective versus objective combination of forecasts. The subjects were undergraduate students at Texas A&M. The students forecasted two different types of time series. The results found show that the subjective combination of forecasts improves their accuracy as compared with individual efforts. Four ex‐ante weighting methods were also used to combine the forecasts. They all improve the accuracy of the forecasts. The best results, though, were from the subjective combination of forecasts.
Allocating the weights in the linear opinion pool
Authors: Genest Christian , McConway Kevin J.
Published: July 2007

A standard approach to the combination of probabilistic opinions involves taking a weighted linear average of the individuals distributions. This paper reviews some of the possible interpretations that have been proposed for these weights in the literature on expert use. Several paradigms for selecting weights are also considered. Special attention is devoted to the Bayesian mechanism used for updating expert weights in the face of new information. An asymptotic result is proved which highlights the importance of choosing the initial weights carefully.
A test of space‐time arma modelling and forecasting of hotel data
Authors: Pfeifer Phillip E. , Bodily Samuel E.
Published: July 2007

This paper describes the application of space‐time ARMA modelling to demand‐related data from eight hotels from a single hotel chain in a large US city. Important spatial characteristics of the space‐time process are incorporated into the model using a simple weighting matrix based on driving distances between the hotels. Using a hold‐out sample, the forecasting performance of this space‐time approach was found to be superior to eight separate univariate ARMA models.
Robust exponential smoothing
Authors: Cipra Tomáš
Published: July 2007

The paper is devoted to robust modifications of exponential smoothing for time series with outliers or long‐tailed distributions. Classical exponential smoothing applied to such time series is sensitive to the presence of outliers or long‐tailed distributions and may give inadequate smoothing and forecasting results. First, simple and double exponential smoothing in the L1 norm (i.e. based on the least absolute deviations) are discussed in detail. Then, general exponential smoothing is made robust, replacing the least squares approach by M‐estimation in such a way that the recursive character of the final formulas is preserved. The paper gives simple algorithmic procedures which preserve advantageous features of classical exponential smoothing and, in addition, which are less sensitive to outliers. Robust versions are compared numerically with classical ones.
Forecasting the federal budget with time‐series models
Authors: Baghestani Hamid , McNown Robert
Published: July 2007

The stochastic properties of conventionally denned federal expenditures and revenues are examined, and cointegration is found. Alternative time‐series models‐univariate ARIMA models, vector autoregressions in levels and differences, and an error correction model‐are specified and estimated using quarterly data from 1955:1 through 1979:4. Updated forecasts for up to three years beyond the sample period are evaluated against actual expenditures, revenues and the deficit. The vector autoregression in levels shows evidence of nonstationarity, which leads to strong biases in the forecasts. The remaining models produce forecasts that are satisfactory by the mean squared error criterion, and the magnitudes of biases at the longer horizons are significantly smaller than those of the official forecasts.
Prediction in the one‐way error component model with serial correlation
Authors: Baltagi Badi H. , Li Ql
Published: July 2007

This paper derives the best linear unbiased predictor for a one‐way error component model with serial correlation. A transformation derived by Baltagi and Li (1991) is used to show how the forecast can be easily computed from the GLS estimates and residuals. This result is useful for panel data applications which utilize the error component specification and exhibit serial correlation in the remainder disturbance term. Analytical expressions for this predictor are given when the remainder disturbances follow (1) an AR(1) process, (2) an AR(2) process, (3) a special AR(4) process for quarterly data, and (4) an MA(1) process.
A flexible model of technological diffusion incorporating economic factors with an application to the spread of colour television ownership in the UK
Authors: Karshenas Massou D. , Stoneman Paul
Published: July 2007

In this paper a new encompassing flexible diffusion model of the epidemic type is proposed and its properties explored. Economic factors are incorporated directly into the model. The new model allows freer interaction between exogenous and endogenous factors in the diffusion process than existing models of this type. The model is applied to the diffusion of colour television ownership in the UK and outperforms the existing models in the literature. The exogenous factors are shown to play a more dominant role in the diffusion of colour television in the UK than existing models allow.
On the use of dispersion measures from NAPM surveys in business cycle forecasting
Authors: Dasgupta Susmita , Lahiri Kajal
Published: July 2007

Qualitative survey data on changes in production, inventory, new order, and employment collected every month by the National Association of Purchasing Managers are analysed over 1948–90. The Probability method we use generates time‐series estimates of cross‐section variabilities across firms. It is shown that these diffusion measures have additional explanatory power in the prediction of business cycle turning points.
Forecasting stock returns an examination of stock market trading in the presence of transaction costs
Authors: Pesaran M. Hashem , Timmermann Allan
Published: July 2007

The paper presents new evidence on the predictability of excess returns on common stocks for the Standard and Poor's 500 and the Dow Jones Industrial portfolios at the monthly, quarterly, and annual frequencies. It shows that recursive predictions obtained on the basis of the excess returns regressions are capable of correctly predicting a statistically significant proportion of the signs of the actual returns. The paper also shows that the switching portfolios constructed on the basis of the signs of the recursive predictions mean‐variance dominate the respective market portfolios when trading takes place on a quarterly or annual basis. This result holds even under a high transaction cost scenario. However, due to the larger number of transactions at the monthly frequency the monthly switching portfolios only mean‐variance dominate the respective market portfolios when transaction costs are zero or low.
Combining var estimation and state space model reduction for simple good predictions
Authors: Gilbert Paul D.
Published: July 2007

A combination of VAR estimation and state space model reduction techniques are examined by Monte Carlo methods in order to find good, simple to use, procedures for determining models which have reasonable prediction properties. The presentation is largely graphical. This helps focus attention on the aspects of the model determination problem which are relatively important for forecasting. One surprising result is that, for prediction purposes, knowledge of the true structure of the model generating the data is not particularly useful unless parameter values are also known. This is because the difficulty in estimating parameters of the true model causes more prediction error than results from a more parsimonious approximate model.
A uniform network for VLSI massively parallel computers
Authors: Iwasaki Kazuhiko , Iseli Christian , Sato Yuji
Published: July 2007

Symmetrical Network Topologies (SNT's) for VLSI massively parallel computers are proposed. VLSI massively parallel computers can be expected to integrate more than dozens of processing elements. It is desired that the network in such a VLSI system is regular.

SNT consists of a two‐dimensional end‐around mesh with supplementary symmetrical branch connections, and therefore, it satisfies the condition of regularity. In this paper it is shown that the SNT's have desirable characteristics with regard to diameter and average distance. That is, the SNTs have smaller diameters and average distance compared to the hypercubes with the same number of nodes. For example, for 4096 nodes, the degree, diameter and average distance of a hypercube are 12, 12 and 6.001, respectively. The degree, diameter and average distance of the SNT can be 8, 8 and 5.324, respectively. It is shown also that SNTs are maximally connected graphs resulting in a fault‐tolerant network. Results show that SNT's are well suited for the VSLI implementation of massively parallel computers.
High speed display algorithm for 3D medical images using multilayer range image
Authors: Ban Hideyuki , Suzuki Ryuuichi
Published: July 2007

We propose a high‐speed, three‐dimensional display method for objects represented by voxels intended for three‐dimensional image diagnostic systems that can be operated interactively. The method extends the concept of the conventional range image and introduces the multilayer range image that stores the distance from the projection plane to the object regardless of whether the object is visible or not. A range image is generated on the surface of any projection plane from the multilayer range images of 6 projection planes perpendicular to the coordinate axes and displayed in three dimensions after shading. Fast speeds are achieved by selecting the multilayer range images that correspond to the projection direction for processing and by eliminating operations on voxels which are not needed in the processing. We were able to display a 2563—voxel object on a 22 MIPS workstation in about 0.5 seconds. Moreover, we anticipate a response of less than one second on the next generation of 100 MIPS workstations.
Extracting global structures using perceptual grouping
Authors: Hiratsuka Satoshi , Ohnishi Noboru , Sugie Noboru
Published: July 2007

One of the problems in the study of image recognition is to extract the global structure, e.g., the contour of the object, with a high reliability. There already exists a technique in which the model figure is pre‐determined. This gives a fairly satisfactory result. It is essentially desirable, however, that the system can handle the unknown figure.

This study considers a approach to such a problem, where the perceptual grouping as pointed out by Gestalt psychologists is applied. More precisely, the method is as follows. The connected component elements are extracted from the input image. Then, based on the factors for perceptual grouping (such as proximity, similarity, good continuity and closure), which are quantitatively given expressions by the psychological experiment conducted by the authors, elements which have high possibilities of forming a global structure are determined and connected, based on such information as relative position of elements.

Using the evaluation function, the optimal candidate for the figure is extracted from the result. When observing overlapped multiple figures, a human can separate the figures (figure segmentation). This aspect also is considered in this study. The foregoing idea is implemented on a computer. Simulation experiments are made for several patterns, and the operation of the proposed system is verified.
Bidirectional feature map for robotic arm control
Authors: Hirano Takashi , Sase Mikiya , Kosugi Yukio
Published: July 2007

When a neural network is used as an arm position controller, it is hoped that the network realizes at least two functions: (1) implementation of a desired input‐output relationship; (2) ensuring the ability of generalization. However, most well‐known networks, such as Back Propagation, and Feature Map clones do not satisfy these requirements simultaneously.

Based on a new architecture and the learning rules, this paper proposes a Bidirectional Feature Map model which has these functions. Then the network for an arm controller with newly proposed constraints is applied to avoid ill‐posed situations inherent to articulation mechanisms with excessive freedom.
A method of search space pruning based on search state dominance
Authors: Fujino Takayuki , Fujiwara Hideo
Published: July 2007

EST (Equivalent STate hashing) algorithm, which reduces the search space form a different point of view from the conventional methods, was proposed for test generation by Giraldi and Bushnell. In this method the processes and results of the test pattern searches are stored and used to avoid fruitless searches to reduce the search space. In this paper the concept of search state equivalence, which is introduced for EST, is extended to that of search state dominance. Based on that concept an algorithm DST (Dominant STate hashing) is proposed. The search state dominance can prune the search space more effectively than the search state equivalence.
Method for predicting utterances using a layered plan recognition model—disambiguation of speech recognition candidates by focusing on speaker intentions
Authors: Yamaoka Takayuki , Iida Hitoshi
Published: July 2007

A context‐sensitive method that predicts a subsequent utterance to reduce ambiguity in speech recognition candidates for use in a spoken‐language processing system is described. Current speech recognition technology cannot accomplish perfect speech recognition, and in many cases ambiguities remain in the results. On the other hand, linguistic processing techniques assume error‐free input. Therefore the effectiveness of this processing is reduced when there are multiple candidates in the input. In particular, in spite of the importance to dialogue translation of the degree of ambiguity in the sentence‐final expressions that indicate the speaker's intention and colloquial fragmentary expressions that are characteristic of spoken language, conventional techniques do not address this problem.

This paper describes first a method for dialogue understanding by means of a layered plan recognition method which uses knowledge on the conduct of a dialogue as well as knowledge concerning the topic, and the use of stacks to manage the states of understand‐ing that this method produces. Then a method is presented for obtaining abstract contextual information concerning the next utterance by referring to the stack contents.

Next, a method of applying that contextual information in the selection of speech recognition candidates is described. Finally, pragmatic knowledge concerning utterance intention is specified, and the effectiveness of these methods in reducing the ambiguity of expressions concerning utterance intention is demonstrated by experiment.
A fault‐tolerant parallel processor modeled by a two‐dimensional linear cellular automaton
Authors: Kawanaka Masataka , Tsunoyama Masahiro , Naito Sachio
Published: July 2007

A number of methods for constructing fault‐tolerant parallel processors using one dimensional linear cellular automaton model have already been proposed. When the methods are used, however, a large amount of hardware is required to realize the connections among processing elements for executing a given algorithm, and for reconfiguring the processor quickly when faults occur in the processor. Moreover, these processors require long communication distances between processing elements so that the method is difficult to be used for large scale processors. In this paper, a method for constructing parallel processors based on a two dimensional cellular automaton model is proposed to alleviate the problems. In the processor based on this model, processing elements are connected in two dimension and the average communication distance can be reduced and a higher fault‐tolerance due to the increase in the number of communication paths from 2 to 4.
Performance prediction of word recognition using the transition information between phonemes or between characters
Authors: Otsuki Takashi , Makino Shozo , Ito Akinori , Sone Toshio
Published: July 2007

This paper considers word recognition based on the existence of the transition between phonemes and characters with complete segmentation between phonemes and characters. A method is proposed which estimates theoretically the relation between the phoneme/character recognition score and the word recognition score. The word recognition score can be estimated by the evaluation formula based on the number of short‐distance words in the dictionary for the case where the word dictionary is used. The traditional evaluation formula for the word recognition score, however, has a problem in that the accuracy of estimation is deteriorated rapidly with the decrease of the phoneme/character recognition score and the increase of the short‐distance words.

From such a viewpoint, this paper proposes a new evaluation formula with a higher estimation accuracy. In this paper, the sequence that can be generated based on the transition information is used as the item in the word dictionary. Then the number of items increases exponentially with the length, making it difficult to estimate the number of short‐distance words. For this problem, this paper proposes an algorithm that calculates the number of short‐distance words in a polynomial time. For approximately 5000 important words in Japanese, the estimated word recognition score for the phoneme recognition score of 90 percent is given approximately 72 percent by the proposed method and approximately 66 percent by the traditional method. It is approximately 78 percent by simulation. Thus, it is shown that the proposed method gives a better approximation than the traditional method.
Enhancing the image quality of high‐resolution MR angiography
Authors: Sano Koichi , Koizumi Hideaki , Takane Atushi
Published: July 2007

In MR angiography, which is effective for screening of aneurysms, investigation for the quality of high‐resolution angiography method using the combination of asymmetric measurement with half scan reconstruction are presented. In addition to avoiding the flow void by the asymmetric measurement, it was found that there were improvements of: (1) blood contrast by isolation of small vessels and static regions; (2) blood continuation by interpolation in 3‐dimensional space; and (3) relative S/N of small vessels with the increasing resolution. Experimental results show that good contrast image is obtained by this method with no penalty of scanning time.
An efficient algorithm for solving optimization problems on Hopfield‐type neural networks
Authors: Tanaka Toshio , Higuchi Tetsuya , Furuya Tatsumi
Published: July 2007

When solving optimization problems on Hopfield neural networks, good solutions are not obtained due to convergence to local minima of the energy function. The Boltzmann machine can escape from local minima because of its stochastic behavior, but the computation time is very long to reach the (semi‐) global minimum.

To avoid these problems, this paper proposes an efficient algorithm for solving optimization problems by the use of binary Hopfield neural networks. This algorithm selects a neuron which reduces the energy function value the most to reduce the energy of the network efficiently. Those algorithms are applied to the traveling salesman problem (TSP) with 10 cities. Near‐optimal solutions were obtained more efficiently than an ordinary TSP algorithm because the energy level of the network can reach lower energy states. The computation time was reduced by one order of magnitude because the energy level of the network reached lower energy states much faster than an ordinary TSP algorithm.
Robust and fast text‐line extraction using local linearity of the text‐line
Authors: Goto Hideaki , Aso Hirotomo
Published: July 2007

Text region extraction is a necessary process before character recognition is done for document images. This paper describes a new algorithm, Linear Segment Linking (LSL), for text‐line extraction from document images. The algorithm groups together the piecewise linear elements in the document images, which may be assumed to be text lines, and then extracts them from the images. The algorithm requires less knowledge about document structure and is robust for distortion of the image. The primitive rectangles are introduced for the intermediate representation of image. It is easier and faster to create them than the usual circumscribing rectangles. A method of splitting the bridges between neighboring text lines is proposed. Combining the bridge splitting process with the text line extraction, the locally touching text lines will be extracted as individual ones.
The learning of linear neural nets with anti‐hebbian rules
Authors: Matsuoka Kiyotoshi , Kawamoto Mitsuru
Published: July 2007

Hebbian rule might be the most popular one as an unsupervised learning model of neural nets. Recently, the opposite of the Hebbian rule, i.e., the so‐called anti‐Hebbian rule, has drawn attention as a new learning paradigm. This paper first clarifies some fundamental properties of the anti‐Hebbian rule, and then shows that a variety of networks can be acquired by some anti‐Hebbian rules.
Control of associative dynamics by matching features in chaotic neural network
Authors: Deguchi Toshinori , Ishii Naohiro
Published: July 2007

When patterns are stored by using associative learning in a chaotic neural network consisting of chaotic neurons that easily produces chaos, whether dynamic (chaotic) or static (non‐chaotic) remembering occurs can be controlled by varying the parameters of the chaotic neurons. A pattern can be searched by using this dynamic remembering as a sampling procedure. If features of the output pattern of the network become similar to desired features during the search, the chaotic state is changed to a static remembering state so that the output pattern has desired features. In this paper, the state is controlled by using a model of presynaptic inhibition similar to that seen in real nerve cells (not using the parameters of the chaotic neurons). Extraction and comparison of the features are performed by back‐propagation networks. The extraction of features under this method is amenable to visual representation of its trajectory in feature space.
Improving the performance of global communication on a three‐dimensional torus network
Authors: Kawakura Yasushi , Tanabe Noboru , Oyanagi Shigeru
Published: July 2007

A high‐speed one‐to‐all broadcasting algorithm is proposed whose performance does not deteriorate much when the number of processors is increased in a massively parallel computer. For the network topology, 3D torus networks are considered. Two methods are discussed for a system which broadcasts by repeating one‐to‐one communications. One uses paths having a smaller maximum transfer number to reduce the number of transfers, and the other presets the hardware to reduce the overhead of individual one‐to‐one communications. These methods are evaluated using a double loop model which consists of an inner loop for local processing and an outer loop for global communications. When these methods are used, the scalability increases and for a 32K processor system a 4.2 times speedup in program execution can be achieved.
LSI module placement using the kohonen network
Authors: Inoue Takeshi , Abe Shigeo , Kayama Masahiro
Published: July 2007

This paper discusses a method for solving an LSI module placement problem using the Kohonen network. First, it is clarified how the neighborhood relations affect the solution called feature map. Specifically, each synapse weight vector is located at the gravitational center of the neighboring synapse weight vectors. Then, it is shown how to set the neighborhood relations to locate the synapse weight vectors at the lattice points, which is necessary in solving the placement problem. Finally, it is shown by computer simulations that performance of the modified Kohonen network is between those of the simulated annealing and the Min‐cut methods.
A description model of video content and its application for video structuring
Authors: Shibata Masahiro
Published: July 2007

A method has been investigated in which the video content description is handled by a computer and is applied to the video database, as a means of desktop video production. In the course of video production, it often happens that the description of the interpretation of the video content by the video producer is retained in the form of a document. Such a description is considered most important to describe the video, but there have been only a few efforts at handling the description by electronic means. This paper proposes a method to analyze the description style of the scenario or the raw memorandum by the on‐site producer, and the corresponding video component scene description model is constructed. The application to the video database is discussed, in order to demonstrate the usefulness of the model. An experiment to extract the layered structure is presented using the video in the actual broadcast program. The effectiveness of the structurization technique and the feasibility of the application of the descriptive model to the video database are demonstrated. An experimentally constructed video browser is also discussed.
Analysis of lengthy sentences using an english comparative structure model
Authors: Masui Fumito , Tsunashima Tadayuki , Sugio Toshiyuki , Tazoe Takehiro , Shiino Tsutomu
Published: July 2007

Today, technological expertise gained from studies on natural languages is applied to various practical systems, including machine translation systems. English‐Japanese machine translation, however, still remains difficult in the translation of lengthy sentences that contain multiple complicated expressions. Due to limited information volume installed in current machine translation systems, such systems cannot handle the complicated sentences actually used in English. This paper discusses comparative structures, which frequently appear in long English sentences, clarifies characteristics of such structures through grammatical studies and the statistical analysis of the sentences contained in Corpus, and explains the development of comparative structure models and a new analysis method using such models. Having more flexibility than the conventional machine translation method, the new method proposed in this paper has been proved suitable for long sentences for which the grammatical rules and vocabulary installed in conventional machine translation systems are insufficient. English newspaper articles were analyzed with a commercial machine translation system and the new method. The result showed that the new method provided translations that were 41.6 percent more accurate than the conventional system translations.
Timing verification of asynchronous sequential circuits with specifications—A method of reducing state transitions to be verified in detail
Authors: Ohnishi Atsuchi , Sugiyama Yuji , Okamoto Takuji
Published: July 2007

One of the important issues in the asynchronous sequential circuit is to verify that the state transitions as stated in the specification occur even if there is a delay variation in the element. When the exiting timing verification method is applied to this problem, however, the transient and other states must be examined, which requires an exponentially long time in the verification. This paper presents a formal procedure based on the circuit structure and the relation between the specification and the circuit, where the state transition to induce the transition in the specification is determined and the state transition to be verified in detail is restricted without generating the transient and other states.

First, the time‐invariant input values and state variable values are considered, and a sufficient condition is given for the above restriction. The sufficient condition ensures that the state transition occurs as is stated in the specification, independently of the element delay. A decision procedure for the sufficient condition is presented, and the time complexity is examined. It is shown that the proposed method is useful in reducing the verification time compared to the existing verification method. The sufficient condition is applied to sample circuits, and it is shown that the detailed verification can be omitted by the factor of 16/17 for the ring arbiter, and 20,24 for the D flip‐flop. Thus, it is expected that the time for the verification can be reduced greatly by the proposed method.