bluuebunny/crossref_metadata_2025 huggingface dataset:
Sales forecasting using multi‐equation transfer function models
Authors: Liu Lon‐Mu
Published: July 2007

The purpose of this study is first, to demonstrate how multivariate forecasting models can be effectively used to generate high performance forecasts for typical business applications. Second, this study compares the forecasts generated by a simultaneous transfer function model (STF) model and a white noise regression model with that of a univariate ARIMA model. The accuracy of these forecasting models is judged using their residual variances and forecasting errors in a post‐sample period. It is found that ignoring the residual serial correlation can greatly degrade the forecasting performance of a multi‐variable model, and in some situations, cause a multi‐variable model to perform inferior to a univariate ARIMA model. This paper also demonstrates how a forecaster can use an STF model to compute both the multi‐step ahead forecasts and their variances easily.
Forecast comparisons of four models of U.S. interest rates
Authors: Craine Roger , Havenner Arthur M.
Published: July 2007

In this paper we compare the out of sample forecasts from four alternative interest rate models based on expanding information sets. The random walk model is the most restrictive. The univariate time series model allows for a richer dynamic pattern and more conditioning information on own rates. The multivariate time series model permits a flexible dynamic pattern with own‐ and cross‐series information. Finally, the forecasts from the MPS econometric model depend on the full model structure and information set.

In theory, more information is preferred to less. In practice, complicated misspecified models can perform much worse than simple (also probably misspecified) models. For forecasts evaluated over the volatile 1970s the multivariate time series model forecasts are considerably better than those from simpler models which use less conditioning information, as well as forecasts from the MPS model which uses substantially more conditioning information but also imposes ‘structural’ economic restrictions.
Predicting nuclear incidents
Authors: Chow Tat Chi , Oliver Robert M.
Published: July 2007

In this paper we review earlier work in predicting incidents of like severity in nuclear power plants. Attention is focused on nuclear core‐melts which can lead to disastrous releases of radioactivity. By combining engineering knowledge with operational experience, we attempt to predict observable quantities such as the time to the next incident and the number of incidents in a fixed future period. The prior distribution of failure rates is obtained from Rasmussen et al (1975), the well‐known Wash‐1400 study. It is then compared with the Gamma prior, and conditions under which the latter is appropriate to use are discussed. The paper concludes with estimates of the expected time to the first core‐melt, the median and quantiles of time to the next partial core‐melt and the probability that at least one severe incident will occur in the next decade. Operating experience to data indicates that while the failure rate of complete core‐melt has been decreasing, that of partial core‐melt has increased dramatically.
Minimum variance pooling of forecasts at different levels of aggregation
Authors: Fuhrer Jeff , Haltmaier Jane
Published: July 2007

The most common approach to combining forecasts at different levels of aggregation has been to sum (or average) the more disaggregated forecast, and take a weighted average of the aggregate forecasts. This paper develops a simple method for obtaining minimum variance pooled forecasts at the disaggregated level. The major advantage that this method has over the common approach is that it provides pooled forecasts at both the aggregated and disaggregated level. As will be shown, the resulting aggregate pooled forecast is identical to the forecast which would be obtained by simply pooling two forecasts at the aggregate level, while the disaggregated forecast maintains the aggregation identity required by the problem.
Reducing uncertainty in short‐term projections: Linkage of monthly and quarterly models
Authors: Corrado Carol , Greene Mark
Published: July 2007

This paper shows how monthly data and forecasts can be used in a systematic way to improve the predictive accuracy of a quarterly macroeconometric model. The problem is formulated as a model pooling procedure (equivalent to non‐recursive Kalman filtering) where a baseline quarterly model forecast is modified through ‘add‐factors’ or ‘constant adjustments’. The procedure ‘automatically’ constructs these adjustments in a covariance‐minimizing fashion to reflect the revised expectation of the quarterly model's forecast errors, conditional on the monthly information set. Results obtained using Federal Reserve Board models indicate the potential for significant reduction in forecast error variance through application of these procedures.
Effects of difficulty on judgemental probability forecasting of control response efficacy
Authors: Harvey N.
Published: July 2007

A judgemental control task was framed as a problem of medical decision making. The control parameter of a recursive system (i.e. a patient) was initially set so that output (i.e. a diagnostic index) fell outside a designated criterion range (corresponding to health). Subjects were told to bring the system's output into the designated range by resetting this control parameter (by specifying the dose of a drug). After each of these control responses, they made a probabilistic forecast that it would have the desired effect. It was found that these forecasts were more overconfident when the control task was more difficult but that the reason for this varied. When difficulty was manipulated across subjects, there was little evidence that lower control performance was associated with any lowering of the probabilistic forecasts. When difficulty was manipulated within subjects, they did lower their forecasts for more difficult task variants but did so insufficiently. In fact, relations between probabilistic forecasts of control response efficacy and proportion of those responses that were actually effective was linear with a slope of 0.44.
Multiple prediction intervals for time series: Comparison of simultaneous and marginal intervals
Authors: Ravishanker N. , Wu L. Shiao‐yen , Glaz J.
Published: July 2007

Simultaneous prediction intervals for forecasts from time series models that contain L (L ≤ 1) unknown future observations with a specified probability are derived. Our simultaneous intervals are based on two types of probability inequalities, i.e. the Bonferroni‐ and product‐types. These differ from the marginal intervals in that they take into account the correlation structure between the forecast errors. For the forecasting methods commonly used with seasonal time series data, we show how to construct forecast error correlations and evaluate, using an example, the simultaneous and marginal prediction intervals. For all the methods, the simultaneous intervals are accurate with the accuracy increasing with the use of higher‐order probability inequalities, whereas the marginal intervals are far too short in every case. Also, when L is greater than the seasonal period, the simultaneous intervals based on improved probability inequalities will be most accurate.
Quasi‐rational expectations: Experimental evidence
Authors: Nelson Robert G. , Bessler David A.
Published: July 2007

The theory of quasi‐rational expectations was tested under the controlled conditions of the economics laboratory. Five experiments were conducted with a variety of stochastic processes. In each experiment, subjects produced one‐step‐ahead forecasts of the variable generated by a Monte Carlo process. Comparisons of the performance of an aggregate of subjects' forecasts versus an ARIMA model showed that for relatively simple series (such as those generated by autoregressive processes of first or second order) the aggregate forecast was indistinguishable from that of the model. These results lend support to the theory that forecasts from an ARIMA model can serve as substitutes for aggregate expectations in macroeconomic policy models under some conditions.
On the sign of the optimal combining weights under the error‐variance minimizing criterion
Authors: Liang Kuo‐Yuan
Published: July 2007

Building on the well‐known measure of the optimal combining weights under the error‐variance minimizing criterion, this note has extended the sign‐determination rule to the case of combining more than two competing forecasts. The algebraic rule derived provides a quick way to check the sign of each combining weight without directly comparing the correlation and variances of individual forecasting errors.
The predictive value of production expectations in manufacturing industry
Authors: Madsen Jakob Brøchner
Published: July 2007

Surveys of the production expectations in the manufacturing industry are collected monthly or quarterly in many OECD countries. The producers are asked about expected production over the next three or four months. This paper tests the predictive performance of production expectations in the manufacturing industry of eight OECD countries. Evidence indicates that: (1) survey expectations of production have a predictive value with respect to production; (2) in most cases the forecast horizon is more significant at 3 or 4 months compared to 2 or 5 months; (3) inflow of orders, order books, stocks of finished goods, etc. contain information to predict production for most countries which are not embodied in survey production expectations.
Economic forecasting at high‐frequency intervals
Authors: Klein L. R. , Park J. Y.
Published: July 2007

Forecasting on the basis of the daily flow of monthly or more frequent statistical reports on the economy can enhance the predictive accuracy of quarterly structural models. The high degree of serial correlation in economic data can be used advantageously in quarterly forecasting for a horizon as long as 6 months—perhaps somewhat longer. The model used for high‐frequency (weekly) forecasting of the US economy has a national accounting structure and tries to follow the choice of indicators that are used in preparing early estimates of national income and product accounts (NIPA). Estimates are separately generated for the income side and the product side of NIPA. At the level of GDP and closely related aggregates a third prediction is also generated from estimates of the principal components of major monthly indicators. A simple average of three estimates of GDP, together with detail on NIPA components and scores of monthly indicators has been produced every weekend, summarizing the business week's flow of information. This procedure is followed not only for producing a steady stream of high‐frequency forecasts but also for providing adjustment factors that can be used for model recalibration, without judgemental input. The tracking of the US economy is illustrated for the period starting before the invasion of Kuwait until the end of the Gulf War.
The forecasting attributes of trend‐ and difference‐stationary representations for macroeconomic time series
Authors: Dejong David N. , Whiteman Charles H.
Published: July 2007

We analyse the forecasting attributes of trenc and diffence‐stationary representations of the U.S. macroeconomic time series sudied by Nelson and Plosser (1982). Predictive densities based on models estimated for these series (which terminate in 1970) are compared with subsequent realizations compiled by Schotman and van Dijk (1991) which terminate in (1988). Predictive densities obtained using the, extended series are also derived to assess the impact of the subsequent realization on long‐range forecasts. Of particular interest are comparisons of the average intervals of predictive densities corresponding to the competing specifications In general, we find that coverage intervals based on diference‐stationary specifications are far wider than those based or. trend‐stationary specifications for the real series, and slightly wider for the nominal series. This additional width is often a virtue in forecasting nuninal series over the 1971‐1988 period, as the inflation experienced durnig this time was unprecedented in the 1900s. However, the evolution of the real series has been relatively stable in the 1900s, hence the uncertainty associated with difference‐stationary specifications generally seems excessive for these data.
International interdependence of business cycles in the manufacturing industry: The use of leading indicators for forecasting and analysis
Authors: Berk J. M. , Bikker J. A.
Published: July 2007

This article introduces new leading indicators for fifteen industrialized countries which enable the business cycle in manufacturing to be forecast fairly reliably between 4 and 6 months ahead. These indicators are based on an improved variant of the NBER method, yielding a composite leading indicator characterized by less erratic movements and clear turning points. The indicators are used to explore the international interdependence of business cycles and to examine the degree to which this interdependence is affected by growing economic integration, as in the EC. For each of the countries studied, the various foreign economies affecting the local business climate are identified. Since the business cycles of some countries clearly lead those of others, this international interdependence can be used to further improve the predictive power of the leading indicators in the lagging countries.
Prediction of final data with use of preliminary and/or revised data
Authors: Mariano Roberto S. , Tanizaki Hisashi
Published: July 2007

In the case of US national accounts the data are revised for the first few years and every decade, which implies that we do not really have the final data. In this paper we aim to predict the final data, using the preliminary data and/or the revised data. The following predictors are introduced and derived from a context of the non‐linear filtering or smoothing problem, which are: (1) prediction of the final data of time t given the preliminary data up to time t‐ 1, (2) prediction of the final data of time t given the preliminary data up to time t, (3) prediction of the final data of time t given the preliminary data up to time T, (4) prediction of the final data of time t given the revised data up to time t ‐1 and the preliminary data up to time t‐ 1, and (5) prediction of the final data of time t given the revised data up to time t‐1 and the preliminary data up to time t. It is shown that (5) is the best predictor but not too different from (3). The prediction problem is illustrated using US per capita consumption data.
Permanent time‐stamp ordering mechanism
Authors: Kobayashi Shinya , Nakanishi Hikaru , Tezuka Yoshikazu , Furukawa Makoto
Published: July 2007

This paper proposes a permanent time‐stamp ordering mechanism as a concurrency control mechanism in the distributed database, where transactions are served in the order of their arrivals. In the proposed mechanism, the read time stamp and the write time stamp are recorded on each data item; and when a conflict arises between transaction services, the transaction with a larger time stamp is aborted. This paper describes the algorithm for the permanent time‐stamp ordering mechanism and confirms the validity of the algorithm.
An object extraction method for image synthesis
Authors: Inoue Seiki
Published: July 2007

In image synthesis, extraction methods to extract meaningful regions (simple meanings) such as people or flowers from ordinary natural images are important. Although the chroma‐key method is widely used to extract these meaningful regions, it requires a blue background, a special photographic environment, and cannot be applied to natural images. Video‐matte, which extracts objects assisted by the user, has been developed and put to practical use as a method applicable to natural images. In this method, however, the region's boundary must be accurately specified in units of picture elements (pixels) and demands a great deal of effort and skill.

In this paper, we propose a new method that simplifies the task of specifying the region in video‐matte. The user only has to specify the object to be extracted, which is easily done; then the actual region extraction is performed automatically by image processing techniques. In addition, a new thinning method for obtaining precise boundaries is also proposed. This method has many practical features: applicability to any natural image, simple specification of the boundary, a one‐pixel wide boundary with no branches or breaks, and no parameters.
An optimal parallel algorithm for finding shortest paths inside simple polygons
Authors: Chen Wei , Nakano Koji , Masuzawa Toshimitsu , Tsujino Yoshihiro , Tokura Nobuki
Published: July 2007

Given a triangulation of a simple n‐gon P and two points a and b inside P, a parallel algorithm is presented for determining the path between a and b with the shortest Euclidean distance inside P. The algorithm has time complexity O(log n) on CREW PRAM with n/log n processors and thus is optimal in the sense that the time‐processor product agrees with Ω(n)—the lower bound of time complexity of the sequential algorithms.
Use of fourier transform and color image processing to extract design elements of yarn‐dyed fabric
Authors: Ohta Ken‐Ichi , Sakaue Katuhiko , Kosako Hideo , Takaoka Akira
Published: July 2007

In order to weave fabric based on a yarn‐dyed fabric sample, the information on the thread arrangement of the fabric must be obtained. In this paper, we will discuss a method for automatically extracting the design elements of yarn‐dyed fabric that correspond to thread placement information with the objective of automating a part of the fabric design process of yarn‐dyed fabrics. In yarn‐dyed fabrics, the pattern on the fabric's surface is formed by the placement of different colored warp and weft threads. Consequently, the features of the warp and weft threads are always continuous in the warp and weft directions. As a result, we show that the bandpass image obtained by filtering the fabric's surface in the spatial frequency domain with a rectangular filter restricted to the warp direction or weft direction extracts information related to the thread placement in that direction. In addition, a simple clustering preprocessing method that detects the brightness is proposed. Then it is verified that the design elements of yarn‐dyed fabric can be extracted based on clustering where the color difference in the bandpass image is the distance. When extracting yarn‐dyed fabric elements, these methods are not concerned with individual regions of the pattern on the fabric's surface or features of each thread but are only concerned with the placement of the colored threads that define the design elements of the yarn‐dyed fabric. They are also provided with an efficiency not available in earlier methods.
Dynamic control of utterance initiative in telephone operator dialogues
Authors: Toji Ryutaro , Yoshida Takashi
Published: July 2007

This paper proposes a new dialogue model that controls utterance initiatives dynamically according to the dialogue context. It classifies utterance intentions into two categories: active and passive. Based on this model, the authors have developed a telephone operator system that can understand utterance intentions by word‐spotting, respond suitably, induce utterances, and anticipate subsequent utterances. The system was developed through simulations using text data of real dialogues between a human telephone operator and callers. The system could understand the intentions of callers' utterances (97 percent) and generate the same reply as a human operator (96 percent).
Image degradation and stroboscopic images caused by rotary motion of the object in X‐ray computed tomography
Authors: Sakamoto Takashi , Sato Shunsuke
Published: July 2007

In an X‐ray computed tomography (CT), time to scan an object must be allowed to obtain its projection data. If the object is not steady during the scanning, its reconstructed image would contain errors called “motion artifacts.” Recently, two kinds of motion artifact, “blurred image” and “stroboscopic image,” have been found in clinical experience, and their theoretical analyses have been demanded. Assuming that an object is a rigid body, its motion can be divided into rotary and parallel motions.

This paper analyzes the degradation of reconstructed images and artifacts due to the rotary motion of a rigid object. The degradation of a CT image caused by rotation of an arbitrarily shaped rigid object is formulated by using a point‐spread function. The characteristics of blurred images of a rigid object due to its rotation in a CT and the shape of blurred images also are analyzed. The cause of stroboscopic images is explained by using line sources. The theories have been confirmed by computer simulation.
A perfect separation of discrete sample points by four‐layered perceptron with localized representation
Authors: Oohori Takahumi , Nagao Naoyuki , Watanabe Kazuhisa
Published: July 2007

The distributed representation‐type three‐layered perceptron with backpropagation has such problems as the local minimum, long learning time, and ambiguity in internal representation. As a method to cope with those problems, this paper proposes the four‐layered perceptron, together with the learning algorithm, where a hidden layer is added, so that each discrete sample point can perfectly be represented by the corresponding output of the upper hidden layer.

First, the learning algorithm of the perceptron is applied successively to the sample points, and the learning is executed so that the input sample points are separated perfectly by the piecewise sets of hyperplanes. In this mechanism, the output matrix of the lower bidder layer output is nonsingular. Consequently, the following four‐layered perceptron can be constructed, where the output matrix of the upper hidden layer is an identity matrix, and any discrete value can be produced as the output from the output layer by adjusting the network coefficients. Computational experiments are made for the realization of the three‐valued logic function, which is a learning problem on the two‐dimensional plane, as well as the pattern recognition problem by the representative sample points. As a result, it is shown that the learning converges in less than 1/100 computation time, compared to the three‐layered perceptron with the backpropagation.
A method of describing fingerprint structure and identification algorithm using geometric characteristics
Authors: Yamada Michio , Kodata Akihisa , Tominaga Hideyoshi
Published: July 2007

This paper proposes a method of describing the structure of fingerprint images. The proposed description method considers reconstruction of the topological feature of fingerprints, and describes a fingerprint image as locations of ridges in a connected component. The topological structure of a fingerprint image is described by three features: the local relation between connected components; the local relation of ridges in a connected component; and the feature of the ridge shape.

By using ridge‐shape characteristics which are independent of locational coordinates, numbers are given to ridges and minutiae, and graph features of the connected relation and adjacency relation are described by numbered ridges and minutiae. Therefore, even if fingerprints are rotated or parallel transferred, the same descriptive information of the structure can be obtained. Also, the proposed matching process is based on paired ridge lengths and therefore, unlike traditional methods, locational matching using the reference of registered/inputted fingerprints becomes unnecessary. The effectiveness of the two proposed algorithms is confirmed by simulation.
Formulation of the modified akaike information criterion (AIC) for a one‐dimensional multipulse model and its application to image coding
Authors: Koda Hiromu , Tanaka Hatsukazu
Published: July 2007

In recent years, attention has been given to coding based on the structurally extracted component and the three dimensional object model. However, it has a problem in that the content of the processing and the required model are fairly complex compared to the conventional waveform coding.

From such a viewpoint, the authors considered the one‐dimensionalmultipulse model, which was proposed as an analysis/synthesis technique for speech, and have been investigating the method using the model which can easily extract the structure of the image and provide the coding.

In this paper, the multipulse model is regarded as a stochastic model. A method is proposed, where the number of pulses required to represent the features of the image is determined automatically using Akaike's information criterion and a similar criterion (called modified AIC).

As the first step, the modified AIC for the multipulse model is derived, and the sequential computation procedure is shown. Then the relation between the penalty coefficient of the modified AIC and the optimal number of pulses is described, and a method is shown based on that result where the traditional information criterion is utilized selectively based on the constraint for the compression ratio of the number of pulses.

Finally, the modified AIC for the multipulse model is applied to the hierarchical coding from the two‐tone image to the gray‐level image, and the usefulness is demonstrated. It is expected that the proposed method will be applied to the image coding, image feature extraction and speech feature extraction.
Simultaneous recovering motion and shape of 3D moving objects
Authors: Kamada Hiroshi , Shiohara Morito , Hao Yingli
Published: July 2007

We propose a new algorithm to simultaneously recover the motion and 3D shape of moving objects from feature points of the moving objects in an orthographic projection. Given the assumption that the moving object is a rigid body, the newly proposed algorithm uses times series correspondence of feature point coordinates in the orthographic projections and is based on the correspondence of 4 feature points at 3 points in time where the existence of a solution has been demonstrated. The merit of this algorithm is that it is a linear algorithm for recovery that uses only observed data, has the condition of unique recovery solution in principle, and can be applied in a unified manner in the case of a unique solution. In this method, after the possibility of recovery is determined by calculating the rank of the matrix, the recovery solution can quickly be found in a unified manner through a linear computation including matrix inversion computations. This theory solves the usual problems in the linear recovery theory in the recovery of moving objects from the point correspondence in orthographic projections and is segmented in theory. We verified the validity of this algorithm using simulation data generated by a computer, and after obtaining corresponding points, verified that real‐time processing with an average recovery time of 4.6 ms is possible even for a personal computer CPU processing. In addition, the effectiveness of this algorithm was confirmed by using the real image of a moving object.
Adaptive exposure image input system for obtaining high‐quality color information
Authors: Moriwaki Kousuke
Published: July 2007

The color image processing based on the color information is not concerned with the accuracy of the color information in the original image. The color representation transformation and the processing algorithm assume that the accuracy of the input image is sufficiently high.

This paper considers the input of the RGB color image, and discusses the image input system, emphasizing the accuracy of the color information. Here, each pixel is inputted with sufficient intensity without saturation, independently of the brightness of the object, by the multistep exposure control. The obtained image is called the adaptive exposure color image since each pixel is inputted with an adequate exposure. This paper discusses also the exposure control using the variable electronic shutter function of the CCD camera, the pixel selection/storage algorithm for the time‐series images with different exposure times, and the reduction of the input time by reducing the number of exposures.

By an input experiment, it is verified that a stable input of the color image is realized for the scene with a high contrast, containing multiple colors and shadows. The region segmentation based on the chromatic component is considered, and it is shown that the adaptive exposure color image realizes satisfactory colors over the whole image compared to the ordinary color image. Thus the method is shown to be useful in improving the accuracy from the viewpoint of color discrimination and other applications.
Control of artificial respiration by adaptive pole‐placement method
Authors: Takahara Kenji , Wakamatsu Hidetoshi
Published: July 2007

Most organic functions are described by complex dynamics of unknown and/or ambiguous subsystems characterized by their nonlinearity, chronic change and individual difference. Nevertheless, a respiratory regulation system among these subsystems is described by a bilinear mathematical model whose state variables are alveolar and average mixed venous CO2‐concentrations, and whose inputs are the ventilation rate of alveolus and metabolic rate converted into CO2‐volume. However, its nonlinear dynamic characteristics depend on time‐varying parameters, in particular, on the blood flow rate which varies on a large scale incidental to metabolic rate change.

In this paper, an automatic control system of artificial respiration is discussed on the basis of the adaptive pole‐placement method using a linear mathematical model where the ventilation rate and alveolar CO2‐concentration are regarded as a controlling input and a controlled output, respectively. The feature of the proposed method is that desirable characteristics given beforehand by medical doctors can be realized automatically even with regard to individual difference and chronic change of characteristics seen distinctively in an organism.

Here, to confirm the robustness of the proposed control system, a simulation experiment is given with some metabolic rate change as an input change regarding its contribution to the output as an effect of disturbance from an environment. Then the proposed method is applied to clinical experiments using a respirator controlled by outside signals. This respirator has been developed to meet the aim of the present study, resulting in good performance of dynamic characteristics of alveolar CO2‐concentration on healthy subjects.
A method of handling virtual objects that incorporates the sense of touch
Authors: Ishii Ikuo , Karasawa Tatsuaki , Makino Hideo
Published: July 2007

This study aims at the application of the virtual reality technique to model construction and simulation in industrial design and the arts. This paper discusses several problems in the interactive direct manipulation of the virtual object from the viewpoint of real space.

The first point is to realize the representation system which can represent the motion parallax without experiencing the response delay. For this purpose, the reduction of the measurement time for the positions of both eyes is investigated, and the problem is solved by developing the both‐eye position measurement method using position‐sensitive devices (PSD).

The second point is to realize the accurate and direct specification method of manipulation from the real space. The direct specification using the hand or the stylus in the real space makes it difficult to realize an accurate manipulation since the error between the real space and the virtual space coordinates is sensed visually in a direct way. For this problem, a stylus for virtual object manipulation was developed. It has a special structure wherein the grip is in the real space and the pointer is in the virtual space.

By this elaboration, the visual error in the position relation between the pointer and the object to be handled can be eliminated. Then the real‐time processing is investigated for the decision of contact between the stylus pointer and the virtual object to be manipulated, as well as for the generation of the tactile sensation.

The real‐time processing is realized by utilizing the feature of the virtual pointer stylus and the drawing mechanism.
A support system for understanding list processing programs which generates explanations and input‐output examples
Authors: Hatori Kenji , Nagata Morio
Published: July 2007

We propose a system to support the human activity of understanding source code, which generates two descriptions: English‐language explanations and input‐output examples of programs. When the Prolog source code is given to our system, it extracts the basic relations are adjusted, they are converted into formal ones. Our system reconsiders these relations globally and reconstructs them. We have implemented a prototype system and have performed experiments that show the effectiveness of our approach. We discuss an extension of our approach which can be applied to procedural languages.
A scheme for constructing directional filters and its application to two‐channel coding of images
Authors: Tohne Toshio , Koda Hiromu , Tanaka Hatsukazu
Published: July 2007

In this paper, a directional filter is newly designed that extracts the edges in a particular direction using the discrete cosine transform (DCT). The filter is then applied to the two‐channel image coding. Especially, the cut‐off frequency response of the directional filter, which greatly affects the quality of the reconstructed image near the edge, is investigated and improved so that the ideal edge waveform can be extracted. In the proposed coding scheme, the original image is separated into the low‐frequency components and the high‐frequency components, according to the principle of the two‐channel image coding.

The low‐frequency component is the smooth component with smaller block distortions. The coding performance for the coding scheme of the low‐frequency component is discussed from the viewpoint of the coding rate and the image quality. The high‐frequency component is separated into the directional images containing edges in particular directions, and the results are encoded. By applying this scheme, little block distortion is produced even for the low bit rate, and the visually satisfactory image with clear edges can be reconstructed. The usefulness of the proposed scheme also is verified by a computer simulation compared to the conventional coding schemes.
Approximation of the size of the union
Authors: Jimbo Shuji , Maruoka Akira
Published: July 2007

Let k and n be integers with 1 ≤ k ≤ n; F(k, n) is the worst‐case relative error generated in approximating the size of a finite system of n sets when the sizes of the intersections of all subsystems of at most k subsets are given. Linial et al. proposed a strategy to estimate F(k, n) and suggested that the strategy is applicable for the problem of counting the number of truth assignments for a DNF formula and the problem of calculating the permanent of a 0/1 matrix, both of which belong to the class of #P‐complete problems. Although the time complexity increases as k increases, F(k, n) decreases their strategy.

This paper gives elementary formulas that describe upper and lower bounds on F(k, n) for any k and n. The upper bound is better than the previous one when 2 ≤ n ‐ k ≤ n/(8/loge n). Furthermore, F(k, n) = 1 + ⊖(nn‐k‐1/2n) is defined for any k and n such that n ‐ k is at most a constant.
Connected spoken word recognition using multistate Markov model for the feature vector
Authors: Takara Tomio , Higa Kazuya , Matayoshi Naoto
Published: July 2007

An automatic speech recognition method is proposed using the Markov model in which a large number of states is adopted to model the transitional characteristics of speech more accurately. Unlike the traditional HMM, the feature vector of this proposed model is considered to be the parameter of the state of the Markov model.

First, the transition‐probability of the state and the symbol output probability are estimated on the assumption that they are represented by multidimensional normal density functions of the feature vector. The optimal time sequence is determined by using DP‐matching.

Next, the multistate model is obtained by quantizing the feature vector space and calculating (or sampling) the value of the probability density function at each code vector (at multipoints). The probability distribution of the multistate Markov model is adapted by the retraining method to be more accurate in distribution. The resulting recognizer is evaluated on a vocabulary of English four‐digit numerals. The multistate model has attained a recognition score of 98.2 percent, i.e., 1.6 percent higher than that of a five‐state traditional HMM. The processing time for the reference pattern generation is one‐fiftieth that of the HMM.
Approximate analysis of access contention for multiprocessor systems with common bus arbiters
Authors: Hoshiai Takashige
Published: July 2007

In multiprocessor systems with a common bus arbiter, contention for access to the common bus and shared memory is a major cause of performance degradation. The first‐order moment match approximation is an effective technique of performance evaluation in such systems. Comparison with simulation results demonstrates that the first‐order moment match technique gives good accuracy. The performance of completely coupled multiprocessor systems is compared with that of bus‐arbitrated multiprocessor systems in order to determine the applications for which the latter is best suited.
The Figure Source Equation and Its Physical Consideration
Authors: Aoki Yasuhiro , Iijima Taizo
Published: July 2007

Theoretical studies on Iijima's “Theory of Pattern Recognition,” which is known as a method of multiple similarity, have shown clearly that there are situations when it is difficult to determine the viewpoint and visual field, important parameters to introduce topological aspects into the pattern space, observing a figure itself. To cope with this problem, this paper proposes transforming the observed image from a figure f(r) to a second‐order differential image p(r), called “figure source.” The aim is to reconstruct the theory in such a way as to enable the application of similarity evaluation methods as in the conventional case, without compromising the current theory, and all the necessary proofs are given. In this paper, the figure source equation as well as rules representing its properties are developed, and several related physical quantities are redefined.
Realization of multiwindow system with high‐speed operations of nonrectangular windows
Authors: Maeda Toshiyuki , Sato Yoichiro , Yokohira Tokumi , Okamoto Takuji
Published: July 2007

This paper describes the realization of the multi‐window system, where the framed nonrectangular windows can be operated with a high speed. The body image (the image to be displayed inside the frame) and the frame image (the image to be displayed as the frame), which are stored on the multiport memory, are read out in parallel, being synchronized to the CRT scanning. By selecting pixelwise one of those images, the window image displayed in the window is generated as a framed image. The selection signal for this purpose is generated based on the window shape information stored in the dedicated memory.

The multiwindow image is generated by selecting the image to be displayed for each pixel position on CRT using a hardware. A distributed priority encoder is used as the hardware for this purpose. According to the result of construction and experiment, it is expected that the multiwindow system can realize a sufficiently high‐speed operation from the practical viewpoint for the 1200 × 1000 CRT screen using the existing circuit technology.
Optimum threshold generation for automated visual inspection of large‐scale integration wafer patterns
Authors: Maeda Shunji , Kubota Hitoshi , Makihira Hiroshi
Published: July 2007

The authors have developed a submicron‐level defect detection method that avoids the unnecessary detection of grains produced by some layers. As part of an automated visual inspection system for Large‐Scale Integration wafer multilayer patterns, the developed method can detect defects reliably by automatically generating an optimum threshold for each pattern according to the occurrence of grains in each area of the pattern, and then binarizing the subtracted grayscale images with the threshold. This method is used in comparison inspections of periodic cell patterns in the same die. This can be realized without using design pattern and process information. This paper proposes an edge‐preserving grain‐noise smoothing algorithm that generates a uniform threshold for each region surrounded by the pattern edges according to the grains detected using the multiple cell patterns to be inspected. It is confirmed through experiments with actual LSI wafers that defects on the order of 0.5 μm and greater, which exist at pattern edges and in the regions having no grains, can be detected stably without the unnecessary detection of grains, even with grain sizes on the order of 1 ∼ 1.3 μm in some layers.
Evaluation of the optimal image reconstruction interval for coronary artery imaging using 64-slice computed tomography
Authors: Weininger M. , Ritter C. , Beer M. , Hahn D. , Beissert M.
Published: July 2007

Background: Cardiac computed tomography (CT) has become an established complement in cardiac imaging. Thus, optimized image quality is diagnostically crucial.

Purpose: To prospectively evaluate whether, by using 64-slice CT, a specific reconstruction interval can be identified providing best image quality for all coronary artery segments and each individual coronary artery.

Material and Methods: 311 coronary segments of 14 men and seven women were analyzed using 64-slice CT. Data reconstruction was performed in 5% increments from 5–100% of the R–R interval. Four experienced observers independently evaluated image quality of the coronary arteries according to the AHA classification. A three-point ranking scale was applied: 1, very poor, no evaluation possible; 2, diagnostically sufficient quality; 3, highest image quality, no artifacts.

Results: The best reconstruction point for all segments was found to be 65% of the R–R interval (mean value 2.4±0.5; P<0.05). On a per-artery basis, best image quality was again achieved at 65% of the R–R interval: RCA 2.2±0.4, LCA 2.4±0.5, LM 2.5±0.2, LAD 2.3±0.4, LCX 2.3±0.5.

Conclusion: By using 64-slice CT, the need for adjusting the reconstruction point to each coronary segment might be overcome. Best image quality was achieved with image reconstruction at 65% of the R–R interval for all coronary segments as well as each coronary artery.
Sowing the seeds of famine: the political economy of food deficits in Sudan
Authors: O'Brien Jay
Published: July 2007

After escaping the ravages of the Sahelian famine of 1968–73, Sudan has begun to experience famine in the current drought. This paper examines recent commercial and subsistence patterns of food production in Sudan In relation to shifting structures of accumulation in order to account for Sudan's rising vulnerability to famine. It argues that the combination of the cumulative effects of capitalist agricultural expansion with the ascendancy of policies of ‘trilateral co‐operation’ under Arab foreign capital during the 1970s set Sudan firmly on a course toward chronic and increasing food deficits. Peasant producers face a rapidly declining ability to meet their consumption needs, including food, through direct production at the same time that rain‐fed capitalist agriculture Is being reoriented toward increased export production. As we go to press severe famine threatens to spread throughout this country which is expected to provide both for its own population, and for a million refugees from the surrounding region.
Aid games
Authors: Thébaud Annie
Published: July 2007

The economic crisis has reduced the amount of medical aid from the first to the third world, but a profusion of private, voluntary, and non‐governmental organisations has stepped into the breach. What is the impact of NGO activities on the health of Africans, and what is the relation of NGO expansion to the economic crisis? A correspondent in Paris gives her analysis.
Ethnicity, society and conflict in Natal
Authors: Mare Gerhard , Wright John
Published: July 2007

In September 1992 a conference was held at the University of Natal in Pietermaritzburg. This Briefing is a slightly amended version which sets out the issues raised by that conference.
The decline of Eurafrica? Lomé's mid‐term review
Authors: Parfitt Trevor
Published: July 2007

The last day of June 1995 saw the completion of the review of the Lomé Convention, a comprehensive trade and aid relationship between the European Union and 70 African, Caribbean and Pacific (ACP) states. Given that the Lomé regime is one of the most long lived and comprehensive arrangements in North‐South relations it might have been expected that there would have been a considerable reaction by those interested in development issues. In fact, the general reaction has been muted. This is because there is a certain lack of enthusiasm for Lomé, not least on the part of powerful forces in the EU. It has been suggested that the Convention is in decline due to waning EU commitment to development in the ACP states. In this article we shall examine whether or not the Lomé relationship is actually being allowed to die on the vine by the EU. First, we shall examine developments over the history of the relationship in order to discern trends that have emerged over the longer term. We shall then turn to the recent history of the Convention since 1990. Finally, we will analyse the terms agreed at the recent Mid‐Term Review in order to assess what the future seems to hold for the Lomé regime.
Chemical Composition and Botanical Origin of Red Propolis, a New Type of Brazilian Propolis
Authors: Silva Bruno B. , Rosalen Pedro L. , Cury Jaime A. , Ikegaki Masaharu , Souza Vinícius C. , Esteves Alessandro , Alencar Severino M.
Published: July 2007

Red propolis is a new type of Brazilian propolis. This material, as well as the secretions of 20 plant species that are often mentioned as its probable botanical source, have been investigated by RP‐HPTLC. Phytochemical evidence based on UV‐VIS spectra, RP‐HPLC and GC‐MS, showed Dalbergia ecastophyllum (L.) Taub. to be the main source of red propolis in Alagoas state. The propolis and plant resin showed high relative percentages of the isoflavonoids 3‐Hydroxy‐8,9‐dimethoxypterocarpan and medicarpin. To our knowledge this is the first report of the secretion of a leguminous species being the source of propolis.
Globalization, Architecture, and Town Planning in a Colonial City: The Case of Jaffa and Tel Aviv
Authors: LeVine Mark
Published: July 2007

This article explores how modernity and globalization unfolded in the neighboring cities of Jaffa and Tel Aviv during the long twentieth century. Each city was the cultural and economic capital of its respective national community, because of which they were in continual contact and conflict in a manner that often muddied the nationalistically determined boundaries between them. I explore how, beginning with Tel Aviv's establishment in 1909, Zionist leaders deployed a narrative of progress and modernity versus tradition and stagnation to effect a discursive, and ultimately a physical, erasure of the Palestinian Arab population of the region surrounding both towns. I argue that such paradigms, and the ideologies that support them, are fundamental components of globalization, whether in the era of "high imperialism" when Jaffa and Tel Aviv's conflict began, or today. Next I move to the contemporary period and explore the intersection of globalization, tourism, and the liberalized market. I conclude by discussing how a "spatialization" of the contemporary Jaffa is crucial to understanding the continuing conflict between Israeli Jews and Palestinian Arabs, both within the borders of 1967 Israel and across the Green Line as well.