bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control charts to check yearly predictions by monthly observations
Authors: Van Knoop Han S. Der 
Published: July 2007

AbstractIn many cases an organization makes predictions of a variable on a yearly scale although the variable is actually observed at shorter time intervals. Given such a yearly prediction, the question will arise as to under which conditions one can say that the actual development of the variable at shorter time intervals deviates so much from the year estimate as to render the latter implausible. Policy makers confronted with such a problem tend to use rather primitive statistical methods of inference. In this paper the situation is judged from a statistical point of view and placed in the context of the ‘significance test’ approach to control chart theory. It is assumed that the variables are generated by a multivariate autoregressive moving average model. Thus we derive an approximate distribution of the future observations of the series given the values of some linear compounds of the variables. With this, three control charts can be constructed. The approach is illustrated by an example based on the monthly tax returns of the Dutch central government. The example suggests the usefulness of the approach in many practical situations of forecasting and planning.
Time‐series analysis supported by power transformations
Authors: Guerrero Victor M. 
Published: July 2007

AbstractThis paper presents some procedures aimed at helping an applied time‐series analyst in the use of power transformations. Two methods are proposed for selecting a variance‐stabilizing transformation and another for bias‐reduction of the forecast in the original scale. Since these methods are essentially model‐independent, they can be employed with practically any type of time‐series model. Some comparisons are made with other methods currently available and it is shown that those proposed here are either easier to apply or are more general, with a performance similar to or better than other competing procedures.
Linear regression forecasting in the presence of ar(1) disturbances
Authors: Latif Abdul , King Maxwell L. 
Published: July 2007

AbstractThis paper is concerned with time‐series forecasting based on the linear regression model in the presence of AR(1) disturbances. The standard approach is to estimate the AR(1) parameter, ρ, and then construct forecasts assuming the estimated value is the true value. We introduce a new approach which can be viewed as a weighted average of predictions assuming different values of ρ. The weights are proportional to the marginal likelihood of ρ. A Monte Carlo experiment was conducted to compare the new method with five more conventional predictors. Its results suggest that the new approach has a distinct edge over existing procedures.
A bayesian approach to modelling stochastic cycles
Authors: Brasil G. H. , Souza R. C. 
Published: July 2007

AbstractThis article deals with a fully Bayesian approach to describe the cyclical behaviour of a univariate time series. A damped sine wave where both the period and the damping factor are time varying is assumed as the underlying mathematical model for the cyclical component. The model is applied to two real data sets; the annual rainfall observations in Fortaleza, Brazil, and the annual Wolf sunspot numbers.
Periodically integrated subset autoregressions for dutch industrial production and money stock
Authors: Franses Philip Hans 
Published: July 2007

AbstractThe univariate quarterly Dutch series of industrial production and money stock are both modelled with a periodically integrated subset autoregression (PISA). This model for a non‐stationary series allows the lag orders, the values of the parameters and the cyclical patterns to vary over the seasons. The PISA models are found by applying a general‐to‐simple specification strategy, which deals with non‐stationarity and periodicity simultaneously. It is found that the two series show a common asymmetric cyclical behaviour. This paper further proposes a test for periodicity in the errors, with which it is argued that a non‐periodic model for the industrial production and money stock is misspecified and that seasonal adjustment does not remove periodicity in the autocorrelation function.
Forecasting from non‐linear models in practice
Authors: Lin Jin‐Lung , Granger C. W. J. 
Published: July 2007

AbstractIf a simple non‐linear autoregressive time‐series model is suggested for a series, it is not straightforward to produce multi‐step forecasts from it. Several alternative theoretical approaches are discussed and then compared with a simulation study only for the two‐step case. It is suggested that fitting a new model for each forecast horizon may be a satisfactory strategy.
Some advances in non‐linear and adaptive modelling in time‐series
Authors: Tiao George C. , Tsay Ruey S. 
Published: July 2007

AbstractThis paper considers some recent developments in non‐linear and linear time series analysis. It consists of two main components. The first emphasizes the advances in non‐linear modelling and in Bayesian inference via the Gibbs sampler. Advantages and the usefulness of these advances are illustrated by real examples. The second component is concerned with adaptive forecasting. This shows that linear models can provide accurate forecasts provided that the parameters involved are estimated adaptively. In particular, we focus on forecasting long‐memory time series. Again, a real example is used to illustrate the results.
Modelling non‐normal first‐order autoregressive time series
Authors: Sim C. H. 
Published: July 2007

AbstractWe shall first review some non‐normal stationary first‐order autoregressive models. The models are constructed with a given marginal distribution (logistic, hyperbolic secant, exponential, Laplace, or gamma) and the requirement that the bivariate joint distribution of the generated process must be sufficiently simple so that the parameter estimation and forecasting problems of the models can be addressed. A model‐building approach that consists of model identification, estimation, diagnostic checking, and forecasting is then discussed for this class of models.
Forecasting growth with time series models
Authors: Peña Daniel 
Published: July 2007

AbstractThis paper compares the structure of three models for estimating future growth in a time series. It is shown that a regression model gives minimum weight to the last observed growth and maximum weight to the observed growth in the middle of the sample period. A first‐order integrated ARIMA model, or 1(1) model, gives uniform weights to all observed growths. Finally, a second‐order integrated ARIMA model gives maximum weights to the last observed growth and minimum weights to the observed growths at the beginning of the sample period. The forecasting performance of these models is compared using annual output growth rates for seven countries.
Mutual relations among optimum image restoration filters
Authors: Yamashita Yukihiko , Ogawa Hidemitsu 
Published: July 2007

AbstractAn optimum image restoration filter is an image restoration filter satisfying some optimum criterion, and there are many different optimum restoration filters corresponding to different optimization criterion. Close relationships exist between these various filters, and through understanding these relationships we can, along with gaining a better understanding of the principles behind the filters, approximate or replace one filter by another and reduce the computing complexity required to compute it.The relationships between these filters have been explored on a one‐by‐one basis in the past, but in this paper a systematic assessment is made of the relationships between nine kinds of optimum restoration filters. In addition, it is confirmed experimentally that the parametric Wiener filter can approximate the averaged projection filter with arbitrary precision.
Test pattern generation for crosstalk faults considering the gate delay
Authors: Itazaki Noriyoshi , Kinoshita Kozo , Naitoh Hisao 
Published: July 2007

AbstractThis paper presents a new method of test pattern generation for detecting crosstalk faults. In general, to detect crosstalk faults, two successive test vectors are needed for exciting and propagating the crosstalk fault. A special signal corresponding to the two successive vectors is designed to simplify the test pattern generation algorithm and its implementation. By taking into consideration gate delay, more accurate test pattern generation can be expected. The algorithm was implemented in a C++ program, and applied to a few benchmark circuits. The experiments show that coverage for large‐scale integrated circuits is at least 70 percent, and for small‐scale integrated circuits up to 90 percent.
A large‐scale multiple‐access method for video‐on‐demand systems
Authors: Sakamoto Hideki , Nishimura Kazutoshi , Nakano Hirotaka 
Published: July 2007

AbstractA multiple‐access method is proposed for simultaneously providing video data to more than 100 terminals in a video‐on‐demand system. The proposed method divides up each video program into segments, stores the segments on multiple disk drives, and performs time‐division‐multiplex reading based on the time‐slot sequences for each disk drive that are periodically phase shifted with respect to each other. This method features: 1) theoretical limit on the maximum number of multiple accesses that can be implemented, and straightforward upscaling of the maximum number of multiple accesses because the amount of buffer memory needed for each terminal is fixed; 2) no request loss, even when many terminals request the same program because the load for reading each video program is always distributed across all the disk drives; and 3) system control that guarantees read‐request response times within a specified value by allowing the skipping of a very small amount of leading information in each video program. Numerical examples show that this access method makes it possible to design a system having no request losses and a guaranteed response time within one second, even for simultaneous accesses by 900 terminals.
Simplification of majority‐voting classifiers using binary decision diagrams
Authors: Ishii Megumi , Akiba Yasuhiro , Kaneda Shigeo , Almuallim Hussein 
Published: July 2007

AbstractVarious versions of the majority‐voting classification method have been proposed in recent years as a strategy for improving classification performance. This method generates multiple decision trees from training examples and performs majority voting of classification results from these decision trees in order to classify test examples. In this method, however, since the target concept is represented in multiple decision trees, its readability is poor. This property makes it ineffective in knowledge‐base construction.To enable the majority‐voting classification method to be applied to knowledge‐base construction, this paper proposes a simplification method that converts the entire majority‐voting classifier into compact disjunctive normal form (DNF) formulas. A significant feature of this method is the use of binary decision diagrams (BDDs) as internal expressions in the conversion process to achieve high‐speed simplification. A problem that must be addressed here is the BDD input variable ordering scheme. This paper proposes an ordering scheme based on the order of variables in the decision trees.The simplification method has been applied to several real‐world data sets of the Irvine Database and to data from medical diagnosis domain. It was found that the description size of the majority‐voting classifier after simplification was on the average from 1.2 to 2.7 times that of a single decision tree and was less than one‐third the size of a majority‐voting classifier before simplification. Therefore, the method is effective in reducing the description size and should be applicable to the knowledge acquisition process. Using the input variable ordering scheme proposed here, high‐speed simplification of several seconds to several tens of seconds is achieved on a Sun SPARC‐server 10 workstation.
Human face analysis based on distributed two‐dimensional appearance models
Authors: Sumi Yasushi , Ohta Yuichi 
Published: July 2007

AbstractThis paper proposes a method for building a system which automatically images the components of a human face. The method is useful in any number of different perspectives. It is assumed that facial appearance depends on the camera angle and perspective as well as individual facial characteristics. Appearances of a face are classified based on the applicable possibilities of the vision algorithms. Two‐dimensional models of different facial appearances are constructed and the algorithms based on these models are applied in parallel to each scene in a top‐down mode. An appearance model consists of agents, each of which has simple functions. The results of the analysis are re‐combined with their assumptions based on the Dempster‐Shafer probability model. Experiments using actual facial images confirm the usefulness of the proposed method.
Measuring the distance and orientation of a planar surface using nonstructured lighting
Authors: Tsukiyama Toshifumi 
Published: July 2007

AbstractThis paper proposes a method of 3‐dimensional measurement of a planar surface by using two fixed light sources and a TV camera. A set of two images is recorded by the camera switching on each light alternately. The peak of the luminance distribution in each image is detected, and the orientation and distance of the planar surface are calculated. The position of the peak of a luminance distribution can be estimated accurately by using an image processing. The light sources can be conventional apparatus with no particular structure. The method is simple and suitable for a vision system on an indoor mobile robot.
A simplification method for AND‐EXOR expressions for multiple‐output functions
Authors: Koda Norio , Sasao Tsutomu 
Published: July 2007

AbstractThis paper presents properties of Exclusive‐OR Sum‐of‐Products expressions (ESOPs) for multiple‐output functions and a simplification algorithm for ESOPs. First, lower bounds on the number of products in minimum ESOPs for multiple output functions are derived. Then, algorithms to simplify ESOPs and to prove their minimality are presented. Experimental results for arithmetic functions and randomly generated functions for up to ten variables are shown.
Thresholding methods considering the quantization error of an image
Authors: Sekita Iwao , Kurita Takio , Otsu Nobuyuki , Abdelmalek Nabih N. 
Published: July 2007

AbstractThresholding techniques are fundamental for region segmentation of a gray level image. It is often realistic to assume that gray pixel levels are subject to a mixture of normal distributions. This paper points out problems caused by the underestimation of variances from a frequency distribution and solves the problems by transforming a frequency distribution into a piecewise‐continuous distribution based on the maximum entropy criterion. This transformation improves conventional thresholding techniques. Experimental results showed the effectiveness of the transformation.
Speech recognition in nonstationary noise based on parallel HMMs and spectral subtraction
Authors: Mine Ryuji , Kobayashi Tetsunori , Shirai Katsuhiko 
Published: July 2007

AbstractThis paper proposes a method of speech recognition in a nonstationary noisy environment, combining the parallel HMMs and the spectral subtraction. In the proposed method, a set of hypothesis is generated with respect to the combination of the speech and the noise that can produce the observed data by a series of subtraction processes. Using HMMs prepared separately for the speech and the noise, the probabilities of occurrence are calculated.The 100‐word recognition in the noisy environment in an ordinary car running in an urban area, is defined as the task in the experiment. Comparative experiments, are made for the proposed method, the ordinary spectral subtraction method and other parallel HMM methods. Then, the effectiveness of the proposed method is verified.
Effects of the polarity of neural network units on back‐propagation learning
Authors: Gotanda Hiromu , Ueda Yoshihiro , Kawasaki Takeshi 
Published: July 2007

AbstractThis paper considers the neural network in which the initial values for the weights and the bias are given by random numbers as in usual cases. The results of BP learning in networks composed of unipolar units having an activity range from 0 to 1 and networks with bipolar units with a range from −0.5 to 0.5 are compared.When the input space is large, the separation hyperplane at the outset of learning passes near the center of the input space in the bipolar case, while that in the unipolar case passes near the vertex. Because of this property, the number of separation hyperplanes that effectively separate the input spaces of the layers during the updating or realization of the solution is larger in the bipolar case than in the unipolar case. The difference between the two becomes more remarkable with the increase of size. As a result of simulation, it is verified that the learning by the bipolar network gives better convergence for a wider range of initial values than the learning by the unipolar network when the network is large. It is shown also that the kinds of solution obtained by the unipolar network tend to be deviated.
Karamoja: colonial roots of famine in North‐East Uganda
Authors: Mamdani Mahmood 
Published: July 2007

Karamoja in Uganda's north‐east corner has always been regarded as a backward and troublesome area. The implication always is that it suffers from an inhospitable environment and its people follow a primitive way of life. The problem is either ‘natural’ and intractable, or due to conservatism.
A review of the historical evidence reveals, to the contrary, that before the colonial presence the Karamojong operated a viable system of land utilisation that left the country a ‘grass savanna’, where today it is burnt out bush. The deterioration of the environment in fact came about during and as a result of colonial rule and the particular forms of exploitation visited on the Karamojong. This included the alienation of grazing land; the conversion of hunting into ‘poaching'; and ‘de‐stocking’ of cattle was, to add insult to injury, urged as the solution to the resulting over‐grazing.
‘By‐day’ boys and dariga Men: casual labour versus Agrarian capital in Northern Ghana
Authors: Hear Nicholas 
                      Van 
Published: July 2007

The development of agrarian capitalism in Africa has accelerated in recent years and is taking several forms. In some areas, peasant labour is managed by state and international agencies and exploited on irrigation and settlement schemes; multinational agribusiness is frequently involved. Elsewhere private entrepreneurship by Africans, often subsidised by the state, is prominent, and the hire of wage labour by such entrepreneurs is widespread and expanding. It is with the latter form of capitalist agriculture that this paper is concerned.
In many parts of Africa the development of capitalist agriculture has led to immiseration among rural people and increased their exploitation. But this has not always been the case and it is not inevitable. In northern Ghana the rural population has not succumbed to the all‐powerful, rampant capitalism of the orthodox Marxist model. The real activity of rural labour has constrained the emergence of capitalist rice farming from the late 1960s. Through their struggles, labourers have done relatively well. This paper will examine how capitalist farmers attempted to mobilise labour, to induce workers’ commitment to capitalist production and how exploitation is carried on. All three processes involve struggles between capital and labour which have shaped agricultural development in the north.
Structural adjustment: why it wasn't necessary & why it did work
Authors: Bracking Sarah 
Published: July 2007

The ultimate measure of the awesome power, and the fundamental violence, of unfettered abstraction is to be found in the millions upon millions of nameless corpses which this most vicious of centuries has left as its memorial(Sayer, 1991:155).
Everyone is the most important person in democracy.
(IDASA at HYPERLINK http:// www.idasa.org.za on 10 February 1999).

This article provides a critical understanding of the broader historical context of structural adjustment. While a lot of contemporary analysis follows the given econometric boundaries of the policy debate many important political processes, which were part of the broader political economy of adjustment, remain unexplored. This exploration is important because the economic programmes have contained concepts that have taken root in a lot of African political debate like ‘freedom’, ‘efficiency’, ‘modernisation’, ‘markets’ and ‘liberalisation’ despite the apparent failure of programmes in socio‐economic terms. By reviewing the issue as one historical chapter in the relationship between poor countries and the managers of international finance, I indicate how oppositional political debate was constrained by pervasive, although ahistorical, ideas of economic necessity and the supposed economic benefits of ‘open’ markets.
Access to Justice: Foreign Persons and Russia's New Arbitration Procedure Code (Part I)
Authors:   Yarkov
Published: July 2007

AbstractThis article deals with the new rules—and court practice—for the hearing of disputes involving foreigners in state arbitration (commercial) courts of the Russian Federation. It is these courts that have been entrusted with the administration of justice in cases involving entrepreneurship as well as other business and commercial activity in Russia.The author examines, inter alia, questions of the legal status of foreign persons in Russian courts, as well as the enforcement of foreign arbitral awards and court judgments. He also analyzes the mutual relationship between Russian law and international treaties to which Russia is a party that deal with the participation of foreign persons in arbitration courts.
Direct observation of polyvinylchloride degradation in water at temperatures up to 500°C and at pressures up to 700 MPa
Authors: Nagai Yorihiko , Smith Richard L. , Inomata Hiroshi , Arai Kunio 
Published: July 2007

AbstractDegradation of polyvinylchloride (PVC) in high‐temperature and supercritical water was studied with a hydrothermal diamond anvil cell to determine phase change characteristics of the reacting polymer with respect to water density. During the reaction period of 500 s, at temperatures between 400 and 500°C and at water densities from 0 to 930 kg/m3, PVC particles exhibited clearly defined spreading on the anvil surface that was defined as spread time, St. The spread times decreased with increasing temperature and the values increased with increasing water density. Analysis of the residues with infrared spectroscopy showed the presence of both polyenes and polyols, whose formation was correlated with water density. From the analyses, nucleophilic substitution of PVC in water was found to be promoted at low temperatures (∼ 400°C) and high water densities (≫830 kg/m3), whereas the ionic chain dechlorination was promoted at high temperatures (≫ ∼ 450°C) and low water densities (∼ 750 kg/m3). A reaction pathway is proposed that shows OH nucleophilic substitution in competition with ionic chain reaction for dechlorination both of which vary with water density. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Precipitation and Dissolution in Dilute AlSi Alloys
Authors: Kovács‐Csetényi E. , Vassel C. R. , Kovács I. 
Published: July 2007

AbstractThe precipitation and dissolution processes in dilute Al‐Si alloys were investigated after cold work and quenching by resistivity measurements. The effect of the cooling rate after annealing also was studied. It is shown that after a suitable heat treatment the solubility curve and the heat of solution can be determined using a single sample.Experimental proof is given that there is no homogeneous nucleation in these alloys.