bluuebunny/crossref_metadata_2025 huggingface dataset:
Polytypism of kaolinite‐type minerals: An aid to visualize the stacking of layers
Authors: Ďurovič S. , Mikloš D. , Dornberger‐Schiff K.
Published: July 2007

A model consisting of 3 transparent sheets, moveable one relative to the other, is used to obtain pictorial representations of any of the 36 positions which one dioctahedral (mesooctahedral) kaolinite layer may occupy relative to its predecessor. In a similar manner such a model may be used to represent the corresponding 10 possible positions of any trioctahedral (homo‐octahedral) kaolinite layer relative to its predecessor. The model is based on the discussion of these possibilities in terms of OD theory which is given in outline.
The dissolution and crystallisation of amphoteric metal hydroxides from sodium hydroxide solutions: Ionic equilibria, crystalline phases and crystallisation mechanisms
Authors: Packter A. , Dhillon H. S.
Published: July 2007

The dissolution and recrystallisation of beryllium, zinc, cadmium and tin (II) hydroxides and chromium (III), iron(III), aluminium, scandium, yttrium, gallium and indium hydroxides, from sodium hydroxide solutions of concentrations C = 1 to 20 M at ambient temperatures, are surveyed. The different inic equilibria in metal hydroxide‐sodium hydroxide systems are examined: the phases crystallising from different sodium hydroxide solutions are tabulated and crystallisation mechanisms are analysed.
Estimation of the Debye temperature of diamond‐like semiconducting compounds by means of the Lindemann rule
Authors: Deus P. , Schneider H. A. , Voland U.
Published: July 2007

Application of the Lindemann rule to the estimation of the Debye temperature θ of diamond like semiconducting compounds is discussed. The classical formula of LINDEMANN was modified by a constant K2: θ = K1 \documentclass{article}\pagestyle{empty}\begin{document}$ \sqrt {T_{\rm m} /A \cdot v^{2/3} } + K_2 $\end{document} + K2. The constants K1 and K2 are given for AIIIBV, AIIBVI, AIIBIVC2V and AIBIIIC2VI compounds. These were calculated as well from X‐ray diffraction data as from θ evaluated from specific heat capacity and elastic constants.
Etch‐ and Transmission Electron Microscope Investigations of Microdefects in (001) LEC‐GaP Substrates
Authors: Gottschalch V. , Wagner G. , Pasemann M.
Published: July 2007

The etch pattern of (001) and (110) LEC‐GaP doped with sulphur (NDNA in the range from 3–7 × 1017 cm−3) do not only show dislocation etch pits but fine pits, so‐called “saucer pits” (S‐pits). The distribution of S‐pits, their etching behaviour and transmission electron microscope observations of etched samples indicated a clear correlation between S‐pits and microdefects (fauted‐, prismatic dislocation loops and precipitates).
Studies on twin boundaries in calcite crystals
Authors: Desai C. C.
Published: July 2007

Natural single crystals of calcite have been cleaved along (100) planes and cleavage faces have been etched in 2% and 3% citric acid solutions. Etching produces twin boundaries oriented in 〈010〉 directions. The etch pits on the two sides of the twin boundary are oppositely oriented. It has been conjectured that the rows of pits might have been formed due to etching of dislocations on twin boundaries. One to one correspondence of twin boundaries has been established on matched cleavage faces. This is further confirmed by studying the induced twin regions produced on a (100) cleavage plane by indenting that plane itself. The implications are discussed.
Auger electron spectroscopic studies of the water vapour adsorption on the (100) surface of austenitic chromium‐nickel steel
Authors: Uhilmann K. , Haupold G. , Müssig H.‐J. , Storbeck F.
Published: July 2007

The water vapour adsorption on the (100) surface of chromium‐nickel steel was studied by Auger electron spectroscopy (AES) in the temperature range of 300 K to 700 K at water vapour pressures of 13.3 μPa to 133 mPa. The water vapour adsorption goes on more slowly than the oxygen adsorption under the same conditions. The measured kinetic isotherms may be described by logarithmic time laws as they are typical of the adsorption on inhomogeneous surfaces. With rising temperature of the samples the rate of adsorption as well as the quantity of fragments of the water molecule adsorbed during saturation state increases, i.e. the adsorption is activated. By means of the measured adsorption isotherms it may be concluded that a dissociative adsorption takes place.
Fitting of growth curves over time when the data are obtained from a single realization
Authors: Wiorkowski John J.
Published: July 2007

This paper focuses on the general problem of forecasting the maximum value of a time series which by the nature of the data must approach an asymptotic value. Examples of such series include the growth of organisms, the concentration of a chemical reagent during a reaction occurring over time or the amount of a fossil fuel resource which has been discovered or produced as a function of time. The approach taken below differs from the usual models for this type of data in that it assumes that an unobserved time series is actually driving the process, and that the observed data series is a function of the unobserved process. In the case of fossil fuels the unobserved series might be a measure of the exploratory drilling, the number of production days in a given time period or even the amount of fiscal resources devoted to exploratory activities. A maximum likelihood method is developed for estimating the parameters of the process, especially the maximum S, and the covariance structure of the estimators is developed. The methodology is illustrated on an example of oil production. Finally, methods are developed for forecasting the data into the near future.
Combination of forecasts in electricity demand prediction
Authors: Smith D. G. C.
Published: July 2007

Accurate demand prediction is of great importance in the electricity supply industry. Electricity cannot be stored, and generating plant must be scheduled well in advance to meet future demand. Up to now, where online information about external conditions is unavailable, time series methods on the historical demand series have been used for short‐term demand prediction. These have drawbacks, both in their sensitivity to changing weather conditions and in their poor modelling of the daily/weekly business cycles. To overcome these problems a framework has been constructed whereby forecasts from different prediction methods and different forecasting origins can be selected and combined, solely on the basis of recent forecasting performance, with no a priori assumptions of demand behaviour. This added flexibility in univariate forecasting provides a significant improvement in prediction accuracy.
Forecasting the Antwerp maritime steel traffic flow: A case study
Authors: de Gooijer Jan G. , Klein Andre
Published: July 2007

This paper uses multivariate time series models to specify the maritime steel traffic flow in the port of Antwerp. The time series considered are the total outgoing and total incoming maritime steel traffic and the total steel production in the EEC. The obtained time series models provide useful insight into the general behaviour of the maritime steel traffic flow during the period 1971–82. In particular, they provide a quantitative interpretation of important changes which took place in the European steel industry during that period. The multivariate time series models produce forecasts which are a substantial improvement over those obtained by univariate time series models. This is especially the case for the series of total incoming maritime steel traffic in the port of Antwerp, when differencing and transformation of the original data are applied.
Quality/value relationships for imperfect weather forecasts in a prototype multistage decision‐making model
Authors: Katz Richard W. , Murphy Allan H.
Published: July 2007

Some theoretical results concerning the nature of the relationship between the scientific quality and economic value of imperfect weather forecasts are obtained. A prototype multistage decision‐making model is considered, involving only two possible actions and two possible states of weather. This particular form of model is motivated by a real‐world application known as the fruit‐frost problem. For an infinite‐horizon, discounted version of this model it is shown that economic value remains zero below a forecast quality threshold and then rises monotonically but nonlinearly above this threshold. In particular, the relative sensitivity of economic value to changes in the quality of forecasts increases as perfect information is approached. This curve is compared with quality/value relationships that have been obtained for other versions of the model; namely, a single‐stage model and a multistage, finite‐horizon model.
Robust estimation of level and trend
Authors: Ferelli Mario , Wilson G. Tunnicliffe
Published: July 2007

Numerical state space models are efficiently implemented for the estimation of the underlying level and trend of a time series. The model specification is chosen so that the estimation is insensitive to outliers yet adapts rapidly to step changes in level. An example illustrates, by means of projection plots, how at times of uncertainty in the evolution of the series the inferred distribution of level and trend may be multi‐modal.
Transformations and dynamic linear models
Authors: Lenk Peter J. , Tsai Chih‐Ling
Published: July 2007

The dynamic linear model (DLM) with additive Gaussian errors provides a useful statistical tool that is easily implemented because of the simplicity of updating a normal model that has a natural conjugate prior. If the model is not linear or if it does not have additive Gaussian errors, then numerical methods are usually required to update the distributions of the unknown parameters. If the dimension of the parameter space is small, numerical methods are feasible. However, as the number of unknown parameters increases, the numerial methods rapidly grow in complexity and cost. This article addresses the situation where a state dependent transformation of the observations follows the DLM, buta priorithe appropriate transformation is not known. The Box‐Cox family, which is indexed by a single parameter, illustrates the methodology. A prior distribution is constructed over a grid of points for the transformation parameter. For each value of the grid the relevant parameter esitmates and forecasts are obtained for the transformed series. These quantities are then integrated by the current distribution of the transformation parameter. When a new observation becomes available, parallel Kalman filters are used to update the distributions of the unknown parameters and to compute the likelihood of the transformation parameter at each grid point. The distribution of the transformation parameter is then updated.
Merging monthly and quarterly forecasts: Experience with mqem
Authors: Howrey E. Philip , Hymans Saul H. , Donihue Michael R.
Published: July 2007

Forecasts from quarterly econometric models are typically revised on a monthly basis to reflect the information in current economic data. The revision process usually involves setting targets for the quarterly values of endogenous variables for which monthly observations are available and then altering the intercept terms in the quarterly forecasting model to achieve the target values. A formal statistical approach to the use of monthly data to update quarterly forecasts is described and the procedure is applied to the Michigan Quarterly Econometric Model of the US Economy. The procedure is evaluated in terms of both ex post and ex ante forecasting performance. The ex ante results for 1986 and 1987 indicate that the method is quite promising. With a few notable exceptions, the formal procedure produces forecasts of GNP growth that are very close to the published ex ante forecasts.
Automatic arima modelling by the cartesian search algorithm
Authors: Höglund Rune , Östermark Ralf
Published: July 2007

In the present study we report on the development and test results of a Cartesian ARIMA Search Algorithm, designed for automatic generation of univariate models for time series data within specified parameter intervals of the identification and estimation stages. Model retention is determined within a preselected set of statistics. By interpreting these statistics as dimensions of the constructed criterion space, we obtain a subset of non‐dominated models according to the rule of maximum dispersion over the efficient set. The CARIMA algorithm allows free specification of the number of criteria used in the runs. The algorithm was tested with both simulated and real economic data. The results based on simulated data indicate that the precision of the CARIMA algorithm is lower for seasonal models and higher for non‐seasonal ones, thus suggesting an inverse relationship between algorithm performance and model complexity.
Dynamic relationship analysis of us gasoline and crude oil prices
Authors: Liu Lon‐Mu
Published: July 2007

This paper studies the dynamic relationships between US gasoline prices, crude oil prices, and the stock of gasoline. Using monthly data between January 1973 and December 1987, we find that the US gasoline price is mainly influenced by the price of crude oil. The stock of gasoline has little or no influence on the price of gasoline during the period before the second energy crisis, and seems to have some influence during the period after. We also find that the dynamic relationship between the prices of gasoline and crude oil changes over time, shifting from a longer lag response to a shorter lag response. Box‐Jenkins ARIMA and transfer function models are employed in this study. These models are estimated using estimation procedure with and without outlier adjustment. For model estimation with outlier adjustment, an iterative procedure for the joint estimation of model parameters and outlier effects is employed. The forecasting performance of these models is carefully examined. For the purpose of illustration, we also analyze these time series using classical white‐noise regression models. The results show the importance of using appropriate time‐series methods in modeling and forecasting when the data are serially correlated. This paper also demonstrates the problems of time‐series modeling when outliers are present.
A bayesian forecasting model for sequential bidding
Authors: Attwell D. N. , Smith J. Q.
Published: July 2007

In this paper we consider the problem facing a company in selecting the values of bids to submit on a sequence of contracts put out to tender. A simple‐to‐implement Bayesian forecasting model is presented, based on a steady Dirichlet process whose states are indexed by the possible bid decisions open to the company. The model gives an explicit algorithm for calculating the state probabilities, needing only data on the lowest bid made by the company's competitors. The flexibility of the basic model makes it a potentially powerful forecasting system for use by companies bidding for contracts.
Using the bootstrap for improved ARIMA model identification
Authors: Aczel Amir D. , Josephy Norman H.
Published: July 2007

This paper presents a new method of identifying ARIMA time‐series models. We use the bootstrap technique in estimating the distribution of sample autocorrelations both separately and in a simultaneous inference setting. The bootstrap has the advantage of being nonparametric and thus free of reliance on asymptotic normality, which may not hold for short or medium‐size series. The simultaneous procedure is unique, as it has no feasible parametric alternatives. An application to exchange rates illustrates our methodology. In the example chosen, we are able to produce better forecasts using the model identified via the bootstrap technique.
Control charts to check yearly predictions by monthly observations
Authors: Van Knoop Han S. Der
Published: July 2007

In 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

This 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

This 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

This 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

The 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

If 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

This 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

We 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

This 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

An 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

This 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

A 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

Various 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

This 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

This 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

This 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

Thresholding 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

This 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

This 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.
Zimbabwean workers, the MDC & the 2000 election
Authors: Alexander Peter
Published: July 2007

For the first time since Zimbabwe gained its independence in 1980, the country's president, Robert Mugabe, faces serious opposition. In the elections, held in June, the worker‐backed Movement for Democratic Change (MDC) won 57 out of 120 elected seats, with Mugabe's party, the Zimbabwe African National Union — Patriotic Front (ZANU‐PF) securing 62 (Endnote 1). The MDC's successes included all 27 contests in the three most populous urban areas (Harare, Bulawayo and Chitungwiza), and all the fully urbanised constituencies in the next six largest centres. There can be little doubt that, had the election been free and fair (which, clearly, it was not), the MDC would have won more constituencies than ZANU‐PF; though, since the president had the power to appoint an additional 30 MPs, one can be less certain that it would have obtained an overall parliamentary majority. Since the party had only existed for 16 months, this was a remarkable achievement, and in 2002, when Zimbabwe holds its presidential election, the MDC's leader, Morgan Tsvangirai, will be well placed to mount a victorious campaign.
Bank corruption becomes site of struggle in Mozambique
Authors: Hanlon Joseph
Published: July 2007

Three people have been murdered for investigating corruption in the Mozambican banking system and the loss of more than $400 million. All countries use banks politically, and in Mozambique, the banks were first used to build socialism, then to keep the country running during the war, and finally in the new capitalist era to promote local entrepreneurs and keep the economy out of foreign hands. But the nature of socialist banking and the process of transition combined to create the conditions under which powerful individuals could use the banking system for accumulation. But this has been contested, and there is an ongoing struggle within the elite between those groups which back what Peter Evans calls the ‘predatory’ and ‘developmental’ states. The recent murders suggest this contest is becoming more acute. Finally, we note that a key role has been played by the international financial institutions, which in their doctrinaire opposition to any serious role for the state chose to back the predatory state faction.
Peasants and bureaucrats
Authors: Coulson Andrew
Published: July 2007

This account of the sequence of Ujamaa policy implementation from 1968 to 1974 is the second half of an article prepared in Tanzania which asked: ‘Can a government bureaucracy bring about development?’ It traces chronologically the rise and decline of the strategy of Ujamaa and self‐reliance, and complements Raikes' analysis, and Tabari's review.
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.
The pastoral environment of northern Senegal
Authors: Toure Oussouby
Published: July 2007

In this article Toure catalogues a century of change in the nomadic way of life brought about by French colonialism and capitalism. He describes the transformation of the Peul who farmed and herded a variety of animals in a system of long‐distance transhumance into permanently settled cattle ranchers. The environmental consequences are disastrous, as the long drought made clear. The human consequences are more mixed. This article raises interesting questions about class differentiation and changes in women's responsibilities: do boreholes reduce the work of water carrying and do larger herds increase the work of milking and making butter?
Beyond the house of hunger: democratic struggle in Zimbabwe
Authors: Raftopoulos Brian
Published: July 2007

In 1980, after more than a decade of armed liberation struggle, ZANU‐PF took power in Zimbabwe. The new government under President Mugabe became increasingly repressive, seeking to force opposition either into alliance with ZANU, or into silence. This authoritarian process appeared to be culminating in a formal one‐party presidentialist state, de facto one‐party rule having being achieved in the late 1980s. This article describes the process and analyses growing opposition to it, both from within ZANU and from groupings within civil society — notably students, workers, peasant communities, and the petty bourgeoisie. In this section the role of the petty bourgeoisie is examined, especially its private sector component. Part two, to be published in ROAPE 55 describes and interprets peasant discontent and worker opposition.
Democracy in Mozambique: the significance of multi‐party elections
Authors: Harrison Graham
Published: July 2007

This article examines democracy as a process rather than an event, or some kind of transition from one regime to another via a period of exceptional change. In doing so, it reveals a set of often contradictory forces which seriously question the democratic content of social change in Mozambique since 1992. The key points which this article raises are: a particular model of democratisation has been, paradoxically, imposed on the masses by national and international elites, in the context of an extremely antidemocratic economic environment, dictated by the World Bank and IMF; people's views of democracy are inseparable from their economic condition and that consequently, ordinary peasants see democracy as meaningless in the face of the same old privations, or as something for others, in the context of differentiation; people have partially articulated the liberal‐democratic model around a challenge towards arbitrary state authority during an unstable and fluid conjuncture in Mozambique's history; the elections threw into relief local social dynamics, based on particular experiences of the war, Frelimo, and traditional authority. With the formal policy debate receiving little attention, beyond the ubiquitous promises for more schools and hospitals, local histories became active sites of contestation, used to legitimise and delegitimise the two main parties, and to re‐invent so‐called traditional power. While it may be true that the elections marked a reconciliation between Dhlakama and Chissano, at the local level conflict between the parties remains at a level which provokes daily concern for many villagers, especially as the material conditions of communal village life have generally remained very harsh since the end of the war.
‘From demons to democrats’: mali's student movement 1991–1996
Authors: Smith Zeric
                      Kay
Published: July 2007

Student's have been hard hit by IMF‐WB policies in Mali. They have also been portrayed as a violent group and a negative influence on Malian democracy. This article looks at the evolution of recent student protest and the internal politics of the Association des Eleves et Etudiants du Mali, The Association of Students and Pupils of Mali (AEEM), in order to provide a clearer picture of the students and their grievances and to demonstrate that the AEEM has pursued a tactical transformation. The author concludes that a strong AEEM is a potentially healthy part of Mali's civil society and a vital component of Malian democracy. This is because the student movement articulates the interest of its constituents effectively. If their political strength happens to contradict the adjustment policies of multi‐lateral lenders, this is no reason to conclude that they are ipso facto an anti‐democratic force.
Design for equity: linking policy with objectives in South Africa's land reform
Authors: Hall Ruth
Published: July 2007

The question posed in this article is why do land reform policies aiming at equity regularly result in inequitable outcomes?The question is examined in relation to the new land reform policy in South Africa (DLA, 1997), and with emphasis on the commitment to gender equity contained in this policy. Four points are made. First, planning for development needs to be realistic about the context of social relations within which the programme will take place. Second, policy objectives and criteria should not be contradictory. Third, equity considerations need to permeate all aspects of policy and not be limited to statements of vision and objectives. Fourth, the resource implications of policy should fit within existing resource constraints. These are some of the points of slippage which may result in the sacrifice of equity objectives in practice. The challenge at the level of policy is to anticipate and counteract the likely maldistribution of the benefits of land reform.
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.
The City Network Paradigm: Measuring Urban Network Externalities
Authors: Capello Roberta
Published: July 2007

In recent years, network behaviour has been analysed extensively as the emerging model for economic growth. By network behaviour, a metaphor for co-operative behaviour among individuals, corporate or territorial partners is intended. This is increasingly becoming the reference paradigm in an era of continuing innovation and fast technological change, in the presence of 'market failure' where dynamic and innovative behaviours are concerned and of the high costs of a growth strategy based solely on internal know-how. The theory of the city network paradigm claims that, through participation in the network, cities exploit scale economies in complementary relationships and synergies in co-operative activities. In this sense, network advantage is a real club good, achieved only by those economic actors who are partners in the economic and spatial network, and is distributed among partners despite the private marginal costs each partner bears to participate in the network. In this sense, the private marginal costs of network participation differ from private marginal benefits, and network advantages turn out to be network externalities. The aim of the present paper is to measure the impacts that city network behaviour has on city performance-i.e. to provide a quantitative measurement of network externalities stemming from network behaviour in territorial systems.
Access to Justice: Foreign Persons and Russia's New Arbitration Procedure Code (Part I)
Authors:   Yarkov
Published: July 2007

This 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.