bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelation of the state of inelastic deformation induced by a rigid indenter in a brittle material
Authors: Loges F.
Published: July 2007

In microhardness measurements an irreversible deformation field is produced within a sample in a region beneath the indenter. For macroscopically brittle material this can be modelled on the basis of the concept of a generalised linear‐elastic continuum theory. In discussing the results of structurally conditioned basic processes particulary the case of pressure‐induced densification is treated.
Orientation dependence of electrical and optical properties of ZnSiP2 crystals grown from melt
Authors: Siegel W. , Kühnel G. , Ziegler E. , Kirsten P. , Schneider H. A.
Published: July 2007

Undoped and Ga‐doped ZnSiP2 crystals grown by spontaneous crystallization from nonstoichiometric melt show a pronounced dependence of electrical properties (conductivity, carrier concentration) and cathodoluminescence on the orientation of various crystal faces. Breakdown voltage measurements and Hall measurements yielded that the (112)B face is always low‐resistivity n‐type and the (112)A face is always semi‐insulating. The spectral position of the broad luminescence band observed at 80 K differs in a characteristical manner for the various crystal faces. The luminescence behaviour correlates partly with the electrical properties. The results are explained by an orientation dependence of the impurity incorporation which is reflected also in the bulk properties of the crystals.
Influence of Bi1−xSbx and Sb overlayers on the annealing behaviour of Ag films
Authors: Gloede Ch. , Müller H. , Kaiser N. , Trapp M.
Published: July 2007

Annealing of thin Ag films covered by Bi1−xSbx (x = 0.09) and Sb overlayers, respectively, has been investigated by measuring the electrical resistance. Material exchange by diffusion leading to the formation of an intermetallic phase between Ag and Sb was found to be mainly responsible for the annealing effects. By X‐ray and electron diffraction the intermetallic compound has been identified as the ε‐phase Ag3Sb. The diffusion processes due to annealing were studied by SIMS. A correlation between the measured resistance and electron micrographs of the cross‐sectional film structure was found.
Structural and electrical properties of CdS thin films evaporated onto GaAs substrates
Authors: Schumann B. , Kühn G. , Tempel A. , Neumann H. , Müller A. , Leonhardt G.
Published: July 2007

CdS thin films on GaAs substrates are prepared by single source thermal evaporation under high vacuum conditions. Films on (111)A‐oriented substrates have the wurtzite structure, whereas in the case of (111)B‐oriented substrates the sphalerite structure predominates. Depositing films on pre‐annealed substrates a tetragonal phase with a composition near CdGa2S4 was found. The electron concentration in the CdS films is influenced by the substrate temperature, the growth rate of the films, and the substrate orientation.
Distinction between topography of prism faces of natural and cultured quartz crystals
Authors: Joshi M. S. , Kotru P. N. , Vagh A. S.
Published: July 2007

Results of detailed microtopographical studies on prism faces of a large number of natural and hydrothermally grown quartz crystals are described, illustrated and discussed. In the light of these results distinction between prism faces of the two varieties of quartz is assessed. Horizontal striations, parallelogram shaped and low angle tetrahedral growth pyramids are reported as characteristic features on prism faces of natural quartz crystals, whereas hexagonal and square shaped pyramids are shown to be characteristic features on prism faces of cultured quartz crystals. Evidence of independent growth on prism faces of both the varieties of quartz crystals are given. A wide variety of growth forms, like oriented snail shaped hillocks, pentagonal elevations, rectangular spiral patterns, screw ledges, missile‐like structures, influence of impurities on advancing growth fronts, microdiscs patterns and etch patterns due to chemical etching are explained.
Microtopographical studies of ‘a’‐faces of natural analcite crystals
Authors: Joshi M. S. , Rao P. Mohan , Antony A. V.
Published: July 2007

Vertical striation, isolated elliptical natural etch pits, natural etch grooves, flat‐bottomed natural etch pits on ‘a’‐(prism) faces of natural analcite crystals are illustrated and described. Freshly exposed surfaces due to general dissolution of these faces are reported. Isolated, well defined eccentric rhombus shaped natural etch pits are illustrated and, it is established that they are nucleated at sites of emergence of inclined dislocations on the face. Rows of tiny rhombus shaped etch pits along horizontal lines perpendicular to c‐axis are illustrated and explained.
Determination of the kinetic parameters of crystal growth rate with reference to the state of mixing of the solid phase
Authors: Winter B. , Gramlich K.
Published: July 2007

The crystal growth rate is investigated taking into account the state of mixing of the solid phase. Micro‐mixing of the solid phase in the crystallizer is described by means of the model of complete segregation in conjunction in with the vessel model. The experiments were carried out in a laboratory crystallizer and the residence time distribution and the increase in mass of the solid phase were measured. The data obtained show that the model of complete segregation is suitable for the description of the behaviour of the solid phase flow.
Temperature dependence of doping element incorporation with the chemical vapour deposition epitaxial silicon (VI) SiH4HClPH3H2 system
Authors: Kühne H. , Sperling R. , Morgenstern Th.
Published: July 2007

From comparing the incorporation behaviour of phosphorus in epitaxial silicon layers deposited from chlorosilane or silane‐hydrogen‐mixtures, it is theoretically concluded that silane hydrogen chloride‐mixtures should behave like chlorosilane mixtures and different hydrogen chloride partial pressures do not influence the dependence of the incorporation of phosphorus on temperature. The theoretical expectation had been confirmed by experiments. For very low layer growth rates, however, there is a partial pressure range of hydrogen chloride, where the temperature dependence of the incorporation of phosphorus increases with rising partial pressure of hydrogen chloride.
Mechanoluminescence and acoustical emission
Authors: Sodomka L. , Leistner M. , Tessmar H. , Karel F.
Published: July 2007

It is reported on the measuring of the synchronic mechanoluminescent (ML) and acoustical emission (AE). The source of both ML and AE was the mechanical deformation of organic glass, of steel and copper plates. The results confirmed the connection between MA and AE stimulated by the same deformation source.
Growth of different habits of lead bromide crystals in silica gel by the new gel technique
Authors: Abdulkhadar M. , Ittyachan M. A.
Published: July 2007

Lead bromide crystals of high optical perfection and of different habits have been grown in silica gel by new gel technique starting from colloidal lead tartrate and KBr solution. pH is found to be not a factor for habit modification. Certain habits of the grown crystals exhibit interesting surface features. The growth conditions have been optimized and the various aspects of the growth process have been widely investigated.
Growth of calcium iodate crystals by Gel method
Authors: Joshi M. S. , Trivedi S. G.
Published: July 2007

Synthesis of single crystals of calcium iodate by gel method is described. Fairly transparent crystals of reasonably large size with different habits obtained here are illustrated. Crystals grown are identified and characterized by electron microprobe, chemical, X‐ray, thermogravimetric and infra‐red analysis.
Proximity between reacting partners for diffusion‐controlled growth of barium tungstate crystals from sodium tungstate melts
Authors: Roy B. N. , Goh Kim Hong
Published: July 2007

The separation distance (d12) between a diffusing particle and its host necessary for a successful diffusion was estimated for diffusion‐controlled crystal growth of BaWO4 from Na2WO4 melts. Such distances slightly increased with increased cooling rates (RT) and crystallization temperatures (T0). The energy (E), enthalpy (ΔHa), entropy (ΔSa) and free‐energy (ΔGa) of activation, and the probability factor (P) were also estimated. These parameters did not change with the changes in RT and T0.
X‐ray investigations of friction stressed α‐Fe single crystals
Authors: Puff M. , Wuttke W.
Published: July 2007

A translation of a α‐Fe single crystal on a glass plate causes elastic and plastic deformations in regions near the surface. The dislocation density caused by the deformations and its dependence on the friction way were determined from Rocking curves. After having reached a certain friction way the monocrystalline surface layer changes into a polycrystalline layer. At the same time a friction texture develops within the polycrystalline layer.
Epitaxial AlGaAsSbGaSb (AlGaSb) heterostructures for injection lasers
Authors: Aarik J. A. , Dolginov L. M. , Druzhinina L. V. , Eliseev P. G. , Lǒuk P. A. , Milvidskij M. G. , Sverdlov B. N. , Friedenthal J. K.
Published: July 2007

A possibility is shown of obtaining nearly perfect heterojunctions in the GaAlAsSb—GaAlSb system which do not contain any remarkable density of lattice mismatch defects at the heteroboundaries. Application to low threshold DH injection lasers for 1.4–1.8 μm spectral region for optical communications, moist‐o‐graphs etc.
On the reproducibility of the orientation distribution function of texture samples from pole figures (V). Discussion of the reprojection relationship
Authors: Matthies S.
Published: July 2007

The exact solution of the problem \documentclass{article}\pagestyle{empty}\begin{document}$ \tilde P_{hi} (y) \to \tilde f(g) $\end{document} is discussed from the view of the structure of the reprojection relationship and its numerical realization.
X‐ray determination of mean square amplitudes of lattice oscillations in compounds with ZnS structure
Authors: Deus P. , Schneider H. A. , Voland U.
Published: July 2007

A general method of determination of the mean square amplitudes of lattice oscillations (MSA) for crystals with sphalerite structure is described and applied to InP. The linearity of suitable functions of the measured integral BRAGG intensities of sin2 θ/λ2 is used for the verification of the parameters selected for the correction of extinction and DTS. In this way the accuracy of the results is increased. The MSAs of the InP‐sublattices are evaluated. According to theoretical expectations the MSAs of the P‐sublattice are larger because of the greater contributions of optical phonons.
Contributions to the surface preparation of semiconductor materials of low hardness
Authors: Engel A.
Published: July 2007

Starting from the general demands made upon semiconductor surfaces (measuring samples, substrates) and the critical material properties, the boundary conditions for the surface preparation of substances of low hardness are stated and technological variants for Bi1−xSbx, Pb1−xSnxTe, and PbS1−xSex are presented. The results show that almost defectfree surfaces of a high quality can be produced in a repeatable way. The depths of significant and detectable damages are determined depending on the technique in question.
Energy levels diagram of rare earth ions in crystal fields (I) cubic crystals (Oh, O, Td)
Authors: Kustov E. F. , Maketov T. K. , Surogina V. A. , Petrov V. P.
Published: July 2007

The diagrams of the energy of RE ions in a crystal field with cubic symmetry are calculated by using the method of reduction symmetry. The main diagrams of the ions Ce3+, Pr3+, Nd3+, Sm3+, Eu3+ are listed graphically.
Energy levels diagram of rare earth ions in crystal fields (II) tetragonal crystals (D4th, D4, C4v, D2d)
Authors: Kustov E. F. , Maketov T. K. , Surogina V. A. , Steczko G.
Published: July 2007

Using the reduction symmetry method and a system of invariants parameters the matrices of the energy stark levels for the ion Nd3+ (Er3+) in crystal field with the tetragonal symmetry (groups D4th, D2, D2d, C4v) are calculated, and the new method for determining the parameters of the CF are developed by using the properties of the sum of diagonal elements and the sum of the square of all the matrix elements and without the fitting procedure.
The precipitation of barium chromate powders from aqueous solution at different pHs: Nucleation, final crystal numbers and sizes
Authors: Packter A. , Alleem A.
Published: July 2007

Barium chromate precipitations were studied from equivalent aqueous solutions of initial overall metal salt concentrations from 0.00013 to 0.010 M at ambient temperature and at pHs from 8 to 3. At pHs from 8 to 5, precipitation mainly occurred through homogeneous nucleation: the reciprocal induction periods (and nucleation rates) and the crystal numbers generally decreased with reduction of pH but the values at any effective mean metal salt concentration increased appreciably with increasing acidity. Presumably, both M++A and M++HA− species were taking part in the nucleation process. – At pHs below 5, heterogeneous nucleation predominated in most precipitations: the crystal numbers and nucleus numbers at any effective metal salt concentration increased with reduction of pH in these systems. Presumably, more active sites for heterogeneous nucleation were developed.
The dispersion of the dynamic scattering of colourless nematic liquid crystals
Authors: Wiegeleben A. , Demus D.
Published: July 2007

Using a photogoniometer the dispersion of the dynamic scattering process for visible light in colourless nematic liquid crystals was studied depending on sample voltage, observation angle and primary beam polarization. The results may be interpreted by means of a scattering model based on the dispersion effects of the birefringence and of the elliptical polarization.
On the theory of crystal growth from impure solution using monolayer adsorption mechanism
Authors: Dhanasekaran R. , Ramasamy P.
Published: July 2007

Assuming the lateral interaction energy of the adsorbed molecules of solvent, solute and impurity in an adlayer of crystal‐impure solution interface, the partition function and its partial derivatives are calculated using the Bragg‐William monolayer model with empty sites. The condition for ideality and deviations from ideality in the adlayer are discussed. The effects of impurity on the generalized form of the BCF differential equation for surface diffusion is established and the crystal growth rate as a function of supersaturation is calculated from numerical intergration. The applicability of this model for crystal growth from impure solution is discussed.
The precipitation of barium‐, strontium‐ and calcium molybdates from aqueous solution: Kinetics of the crystal growth
Authors: Packter A.
Published: July 2007

The kinetics of precipitation of barium, strontium and calcium molybdates, from supersaturated aqueous solutions of initial solute concentrations C0 = 0.0004 to 0.003 M, C0 = 0.002 to 0.015 M and C0 = 0.1 to 0.06 M, respectively, were studied at 25° by conductivity measurements and chemical analysis. Nucleation occurred during induction periods and continuous crystal growth then took place onto the crystallites formed during the induction periods. The growth rates at any time were expressed, in terms of degree of crystallisation, by the relation

equation image
.

The rate constants (kα) for the crystal growth of barium, strontium and calcium molybdates at 25° were 7700, 200, and 8.7 sec−1 M−2, respectively.
Thermal etch pits on calcite cleavages
Authors: Mehta B. J.
Published: July 2007

Thermal etch pits are observed on calcite cleavages when the latter are kept at 520°C to 560°C in atmosphere for some hours. Boundaries of the above etch pits are circular, hexagonal and rhombic and they are dependent upon the temperature of etching. Different etch pit morphology is observed in chemical etching on calcite cleavages. It is conjectured that origin of thermal etch pits are different from that of chemical etch pits.
The crystallisation of alkaline‐earth metal metasilicates from metal chloride melts: Preliminary experimental studies
Authors: Packter A. , Roy B. N.
Published: July 2007

The crystallisation of alcaline‐earth metal metalsilicates was studied by slow cooling of saturated solutions in the metal chloride melts at T0 = 830° to 1300°C, down to ambient temperature; cooling rates were varied from 20° to 200°C hr−1. Calcium metasilicate crystallised as β‐CaSiO3 prisms, strontium metasilicate as α‐SrSiO3 platelets and barium metasilicate as α‐BaSiO3 platelets. Final crystal lengths increased with reduction in cooling rate and with increase in initial crystallisation temperature.
The precipitation of sparingly‐soluble alkaline‐earth metal and transition metal oxalates and mixed metal oxalates from aqueous solution: Ionic equilibria, crystalline phases and precipitation mechanisms
Authors: Packter A.
Published: July 2007

The precipitations of alkaline‐earth metal and transition metal oxalates, from aqueous solution and from excess alkali metal oxalate solution, are surveyed: also the coprecipitations of transition metal oxalates together with alkaline‐earth metal oxalates. The ionic equilibria that influence these precipitations are examined, the crystalline precipitate phases are tabulated and precipitation mechanisms are analysed.
Growth Kinetics of GaP Layers in Liquid Phase Electroeptiaxy (LPEE) from Limited and Unlimited Source
Authors: Ivashchenko A. I. , Kopanskaya F. Ya. , Kuzmenko G. S. , Molodyan I. P.
Published: July 2007

Growth kinetics of GaP layers in two LPEE modifications has been experimentally studied. In the first modification the vapour phase is employed as a source of crystallization. In the second case the losses of the solute during crystallization are not compensated.

It has been found that growth kinetics can be treated in the frame work of the model where the growth rate is governed by mass‐transport in liquid phase. It's shown that electromigration gives the main contribution to mass‐transport at the considered experimental conditions.

The quantitative estimations of the effective mass‐transport parameters for phosphorus in gallium melt in the range 800 to 1050°C have been obtained.
Influence of defect‐matrix modulus effect on elastic interaction of point defects
Authors: Seifert W. , Michel B.
Published: July 2007

An attempt is made to take into account the surface influence upon the mechanical energy of point defects and volume defects in an isotropic elastic solid. In addition the defect‐matrix modulus effect is also considered which is usually neglected. A theorem is investigated refering to the sign of interaction energy between defect and surface. An axisymmetric finite element program (FEM) is applied to carry out numerical calculations. The application of this method to probelms in structural physics (microphysics of solids) seems to be very useful.
Quantitative analysis of the fibre texture of zirconium by time‐of‐flight neutron diffraction
Authors: Feldmann K. , Betzl M. , Walther K. , Matz W.
Published: July 2007

Quantitative analysis of the fibre texture of zirconium has been performed by the neutron time‐of‐flight method. On the pulsed reactor IBR‐30 16 diffraction spectra were measured for each of the three deformation states of the sample. Pole figures and inverse pole figures have been determined from the experimental spectra for all deformation states investigated. The development of preferred orientation of the (1010) lattice plane in the direction of the fibre axis in dependence on increasing deformation has been found.
Microstructures on {111} faces of stannic iodide single crystals
Authors: Desai C. C. , Rai J. L.
Published: July 2007

Single crystals of stannic iodide (SnI4) havebeen grown using the controlled reaction between SnCl2 and KI by diffusion process in silica gel medium. Orange to reddish octahedral stannic iodide crystals up to 3–4 mm in size have been grown at room temperature. Optical studies have been made on the various surface structures of {111} faces of the asgrown crystals. On octahedral faces of these crystals, triangular‐shaped hillocks with growth layers in the 〈110〉 directions have been observed. Occasionally, growth spirals on octahedral faces have also been reported. Close loops of growth fronts have been investigated and have been interpreted. It has been suggested that two‐diemensional nucleation, spreading and pilling up of triangular growth layers is mainly responsible for the growth and occasionally the growth is due to screw dislocations. The implications are discussed.
Characteristic temperature fields of crystal growth calculated with the aid of heat flow potentials
Authors: Tänzer D. , Geil W. , Fischbeck H. J.
Published: July 2007

In order to grow monocrystals of larger and larger diameters, more detailed knowledge about the steady state temperature field and its effects on the growing crystal is needed. It can be acquired from experimental data only by means of a subtilized numerical analysis. A mathematical model based on closed‐form solutions for the steady state cylindrical case is given. Using the so called “heat flow potential” defined in KIRCHHOFFS sense, any temperature dependence of the heat conductivity k can exactly be taken into account. It can be shown that the problem treated is linear and is generally of the Laplace type. So, the temperature field T(r, z) in cylindrical coordinates r, z can be calculated if the surface temperature function T(r0, z), the shape of the growth interface and the temperature‐dependent heat conductivity k(T) are known. Numerical examples of temperature fields of silicon crystal growth processes are presented.
Forecast evaluation and improvement using theil's decomposition
Authors: Ahlburg Dennis A.
Published: July 2007

Forecasters are concerned with the accuracy of a forecast and whether the forecast can be modified to yield an improved performance. Theil has proposed statistics to measure forecast performance and to identify components of forecast error. However, the most commonly used of Theil's statistics have been shown to have serious shortcomings. This paper discusses Theil's decomposition of forecast error into bias, regression and disturbance proportions. Examples using price expectations and new housing starts data are given to show how decomposition suggests a linear correction procedure that may improve forecast accuracy.
Integrating time‐series and end‐use methods to forecast electricity sales
Authors: Fischler Edward B. , Nelson Robert F.
Published: July 2007

Two types of forecasting methods have been receiving increasing attention by electric utility forecasters. The first type, called end‐use forecasting, is recognized as an approach which is well suited for forecasting during periods characterized by technological change. The method is straightforward. The stock levels of energy‐consuming equipment are forecast, as well as the energy consumption characteristics of the equipment. The final forecast is the product of the stock and usage characteristics.

This approach is well suited to forecasting long time periods when technological change, equipment depletion and replacement, and other structural changes are evident. For time periods of shorter duration, these factors are static and variations are more likely to result from shocks to the environment. The shocks influence the usage of the equipment. A second forecasting approach using time‐series analysis has been demonstrated to be superior for these applications.

This paper discusses the integration of the two methods into a unified system. The result is a time‐series model whose parameter effects become dynamic in character. An example of the models being used at the Georgia Power Company is presented. It is demonstrated that a time‐series model which incorporates end‐use stock and usage information is superior—even in short‐term forecasting situations—to a similar time‐series model which excludes the information.
Forecasting donors and donations
Authors: Britto Mark , Oliver Robert M.
Published: July 2007

The authors propose and evaluate a statistical model to make forecasts of donors, gifts and cumulative private donations to an educational fund. Within‐season forecasts and confidence intervals are based on binomial counts of donors and a compound Poisson distribution for cumulative donations. Forecasts for the 1984‐1985 fiscal year are based on data obtained in the previous two years. The effects of different promotional campaigns are studied.
The importance of non‐linearities in large forecasting models with stochastic error processes
Authors: Hall S. G.
Published: July 2007

This paper considers the consequences of the stochastic error process in large non‐linear forecasting models. As such models are non‐linear, the deterministic forecast is neither the mean nor the mode of the density function of the endogenous variables. Under a specific assumption as to the class of the non‐linearity it is shown that the deterministic forecast is actually the vector of marginal medians of the density function. Stochastic simulation techniques are then used to test whether one large forecasting model actually lies within this class.
Business cycle forecasting
Authors: Westlund Anders H.
Published: July 2007

Business cycle forecasting involves several different methodological problems. Some of these are discussed in the current issue of this journal and are introduced in this paper. The forecasting approach itself often focuses on turning points in the business cycle and a number of papers in this issue examine this particular aspect of business cycle forecasting. For example, a Bayesian technique for detecting changing random slopes in leading composite indexes is discussed. Business survey data are often used in the process of forecasting business cycles. A Kalman filtering procedure is suggested to make business survey information useful in predicting changes in industrial production. Other data issues of relevance to this topic that are discussed include the preliminary data and revision problem. Methodology for using high‐frequency data and for converting high‐frequency to low‐frequency data is also presented. A number of the papers discuss the analysis of dynamic structures, such as the existence of time‐varying dynamics, and the use of vector‐autoregressive (VAR) models. Finally, a few comments are made on general structural variability aspects, related to business cycle forecasting.
Jets in e+e−a‐Annihilation and QCD
Authors: Barreiro Fernando
Published: July 2007

The main features of the hadronic final states measured in e+e− annihilation at DORIS and PETRA energies are reviewed. Comparisons are made between data and QCD predictions. The importance of perturbative versus non‐perturbative contributions is critically examined.
A query‐based parallel logic simulation algorithm
Authors: Kudoh Tomohiro , Kimura Tetsuro , Amano Hideharu , Terasawa Takuya
Published: July 2007

LOGIQUE (LOGIc simulation with QUEry) is a parallel logic simulation algorithm for parallel machines with a shared memory. In order to make the best use of the parallelism, queries are issued aggressively. The large overhead in the traditional query‐based parallel discrete event simulation (PDES) algorithm is reduced by replacing the query message with a reference to the shared variables. LOGIQUE has been implemented on a multiprocessor and used to simulate logic circuits. The results, which demonstrate the efficiency of LOGIQUE, are presented.
A method of generating stone wall patterns
Authors: Miyata Kazunori
Published: July 2007

Recently, several kinds of mapping technology, e.g., texture mapping and bump mapping, have played a very important role in the achievement of more realistic image synthesis. The textures to be mapped often are obtained by using an optical scanner or a video camera. However, it is difficult to obtain a suitable image by taking a photograph. It is considered very important to be able to generate easily a variety of textures and patterns as required.

This paper proposes a new method of generating stone wall patterns as a specific case of a generalized texture generator. The advantage of the method is that it allows the user to generate a variety of stone wall pictures by specifying a few simple parameters. The method is applied to a visual simulation system to represent such stone textures as walls, pavements, and steps. Some illustrated examples of its applications also are given.
An improved √N algorithm for mutual exclusion in decentralized systems
Authors: Fuchi Takeshi
Published: July 2007

An algorithm is proposed which realizes mutual exclusion in a computer network system where communications are conducted by messages only without using a shared memory. With this method, and by transferring a token representing the exclusion the exclusion right, the mutual exclusion is realized.

A node wanting to execute a critical section first sends messages requesting exclusion to a set of nodes (members) assigned to it. The members keep this message, after receiving a finish exclusion message from some other node, transfer the exclusion request messages to the sender. The node receiving the token processes the critical section, and when finished, sends finish exclusion messages to the members. The members return information on nodes requesting exclusion known to them. According to this information, the next receiver of the token is determined. By contriving the selection of members and gathering information on nodes requesting exclusion, the mutual exclusion can be realized using √N + 1 or more but less than or equal to 3√N + 1 messages.
The γ–ω hough transform: Linearizing voting curves in an unbiased ϱ–θ parameter space
Authors: Wada Toshikazu , Fujii Takahiro , Matsuyama Takashi
Published: July 2007

The Hough transform is an effective method for detecting figure elements in images corrupted by noise. Voting on the feature points in the image space is performed in the parameter space, after which the points in the parameter space with many votes are focused on in order to detect the figure elements. In the Hough transform, the parameter space is partitioned into elements called cells where the votes are accumulated. However, when the subject is a digital image, if the parameter space is not sampled appropriately, a bias arises in the number of votes accumulated in the cells. In this paper, we present a sampling method for the parameter space that does not produce distortion in the ρ–θ parameter space used in line detection, and we construct a γ–ω space where no bias in the number of votes arises even when sampling is uniform. The γ–ω parameter space corresponds to the ρ–θ parameter space and has the features of no bias in the number of votes and voting loci, which are segmented lines. In addition, the characteristics of the γ–ω parameter space, where the feature points and voting loci are easily converted from one to the other, are used, and a verification method for the line segments is proposed that does not scan the image space again. By combining the line detection method that uses the γ–ω parameter space and this verification method, stable line detection becomes possible.
A knowledge‐based system for envisioning network flow
Authors: Kurokawa Hiroshi , Babaguchi Noboru , Tezuka Yoshikazu
Published: July 2007

This paper proposes a system called NEVIS (network envisioning system), which envisions a network flow by using a knowledge engineering technique based on qualitative reasoning. NEVIS models the network based on queueing theory. For the server that is the major component of the network, its state is defined for each domain knowledge, and the transition between states is defined based on a change of flow by generation of an event. The state transition is estimated by qualitative reasoning. To avoid ambiguity, quantitative information is added so that an accurate result of reasoning is obtained. The function of NEVIS are to estimate the propagation of the effect of the event by introducing a time concept, to generate a display and explanation for the change of state, and to improve the state of the network through an interaction with its user. Those functions help the user's understanding about the operation of the network. The effective use of the network as well as the means to cope with the event can be planned reflecting the request from the user.
Fast contour line extraction algorithm with selective thresholding according to line continuity
Authors: Nishimura Takashi , Fujimoto Tsuyoshi
Published: July 2007

This paper describes a new contour line extraction algorithm which makes better contour line continuation and accelerates processing speed.

When obtaining a contour line from an original gray‐scale image, the contour line extraction algorithm generally requires the following conditions:

extracted contour lines representing a good feature of the original image;

less invalid data such as noise;

contour line width is one pixel thickness; and

better contour connectedness.

Many contour line extraction algorithms have been proposed. However, usually the user has employed the contour line extraction algorithm selecting by experience and a sixth sense. In the conventional method, differential operators are carried out on an original image with thresholding at a given value. Afterward, a thinning operation is carried out to obtain a one‐pixel thickness contour line. However, this process takes considerable computing time because the thinning process needs recursive processing.

The new algorithm presented here carries out the process which performs the edge detection and thinning operation simultaneously eliminating the extra step. The process is effectively integrated in two ways: one is maximum point extraction in the differential image; and the other is the thresholding by introducing the selection of threshold values by using observance of the contour line connectedness in the differential image.

As a result, the proposed algorithm is 10 times faster than the conventional methods in processing speed, and provides almost the same quality in contour line image.
Analysis of MRI antenna loaded by an elliptical subject
Authors: Ochi Hisaaki , Yamamoto Etsuji , Sawaya Kunio , Adachi Saburo
Published: July 2007

Previously, the authors developed a computer code for obtaining the current distribution on the MRI antenna loaded by a man model with an arbitrary geometry and material properties by incorporating the impedance method into Richmond's method. By this method, the relation between the position of the feeding point and the sensitivity of the 1.5 T‐MRI antenna loaded by an elliptic cylindrical subject is discussed theoretically. It is found that the sensitivity of the antenna fed at the angle of 45 degrees measured from the minor axis of the ellipsoid of the subject is different from that of the antenna fed at the angle of ‐ 45 degrees because the elliptic polarization is produced inside the antenna.
Analysis of radio frequency magnetic field penetration in a body within magnetic resonance imaging antenna
Authors: Ochi Hisaaki , Yamamoto Etsuji , Sawaya Kunio , Adachi Saburo
Published: July 2007

The authors have previously developed a computer code for obtaining the current distribution on the magnetic resonance imaging (MRI) antenna loaded by a male model with an arbitrary geometry and material properties by incorporating the impedance method into the method of Richmond. Using this method, RF magnetic field penetration in a biological body within an MRI antenna is discussed theoretically. It is found that the RF magnetic field produced by the current in the body does not cancel the incident RF magnetic field produced by the current on the MRI antenna, since the phase difference between these magnetic fields deviates from 180°.
Zero‐one quadratic programming algorithm for resource leveling of manufacturing process schedules
Authors: Takamoto Masanori , Yamada Naoyuki , Kobayashi Yasuhiro , Nonaka Hisanori , Okoshi Shigeru
Published: July 2007

In industrial plant construction scheduling, it is necessary to minimize the fluctuation or the maximum peak of the fluctuation or the maximum peak value of the daily resources amount, which is calculated as the sum of daily resources for each process. Minimization of the fluctuation or the maximum peak value corresponds to leveling the pile of resources. To perform this resource leveling, we need to decide on an objective function which is a monotone function that simply increases with the degree of resources leveling and then solve the optimization problem by fixing the process start dates while minimizing the objective function. Industrial plant construction is, however, in many cases a large‐scale scheduling with an entire period of more than 1000 days and more than 100 processes, so it is very difficult to obtain a global optimization solution. In this study, we have developed an algorithm which solves a large‐scale optimization problem to level necessary resources. This algorithm can quickly search for a good suboptimal solution close to the global optimal solution of a 0–1 quadratic programming problem. The algorithm searches by repeating a pivot operation using variable selection rules for resources leveling. We applied this algorithm to largescale scheduling for an actual plant construction schedule, and successfully obtained a practical suboptimal solution within a few minutes (CPU power: 28MIPS). The results suggest that the algorithm is practical for resources leveling of large‐scale construction scheduling.
Evaluation of an environment for supporting development of a three‐dimensional image processing system VISUAL by development of virtual space manipulating system
Authors: Kitagawa Eiji , Toriwaki Jun‐Ichiro , Okada Minoru , Yokoi Shigeki
Published: July 2007

This paper improves and evaluates the performance of VISUAL, an environment supporting development of a 3‐D image processing system. A system of manipulating virtual space with VISUAL is developed and the easiness of system development is evaluated and its problems are shown. The concurrent interface with the 3‐D virtual space by two or more operators also is evaluated and it is found that users can develop a system efficiently with VISUAL.
Topic‐focusing mechanism for speech recognition based on probabilistic grammar and topic‐markov model
Authors: Kawabata Takeshi
Published: July 2007

Speech conversion can be considered as the most comfortable means of information transmission between the human and the machine. To realize such a mechanism, there must be a technique for efficient natural language processing.

This paper proposes a new topic‐control mechanism based on the statistical technique as a means to ameliorate the complexity of the natural language processing. The input speech is analyzed using the predictive CFG. The sequence of generated grammatical rules in used to drive HMM, and the topic is identified as the bias of the state distribution. Conversely, the bias of the distribution is reflected dynamically on the probabilities of the grammatical rules, thus, recognition search space is narrowed. Using the large‐scale dialogue database, the reduction effect for the perplexity to the text data input is evaluated, and it is verified that the proposed method has a high power to narrow the search space.
Magnetic resonance findings of clear-cell adenocarcinofibroma of the ovary
Authors: Sugiyama K. , Takehara Y.
Published: July 2007

We report the magnetic resonance (MR) findings of clear-cell adenocarcinofibroma of the ovary. A huge multilocular cystic tumor with solid components was seen in the lower abdominal and pelvic cavity. Thickened cyst wall had low intensity on T2-weighted images, which suggested abundant fibrous tissue. Its mural nodules were strongly enhanced on contrast enhancement, which reflected malignant epithelial growth. Adenocarcinofibroma of the ovary is a rare tumor, but MR findings may be helpful to reach the correct diagnosis.
Mauritius: class forces and political power
Authors: Seegobin Ram , Collen Lindsay
Published: July 2007

A long‐awaited General Election was held in Mauritius on 20 December 1976. The two major parties which contested the election were the governing Labour Party (in office since 1953) and the Mouvement Militant Mauricien (MMM). Since they first became constitutionally overdue in 1972, the Labour Party has had to postpone elections repeatedly. Village and municipal elections were cancelled to prevent embarrassing landslides to the MMM, a party founded in 1969, two years after the last General Election. Since 1970 when the MMM challenged the Labour Party in a ‘safe’ seat and won with a 68% majority, by‐elections also have been cancelled.

Despite allying with an opposition right‐wing party, the Parti Mauricien Social Democrate (PMSD), and enforcing a ‘State of Emergency’ since 1971, the Labour Party had, by the end of 1976, exhausted its constitutional manoeuvres. It neither had a sufficient internal consensus nor the authority to govern extra‐constitutionally — so the election was held. One month before the election it was anticipated that the right‐wing parties would use violence to provoke an extra‐constitutional intervention. Much credit must be given to workers who mobilised against violence in order to allow the legal challenge to take place.

In the event MMM won 34 seats in the 70‐seat House, just two short of an absolute majority. The Labour Party and its allies (28 seats) and the PMSD (8 seats), after a week of post‐electoral crisis in the power bloc, combined in a coalition to force out the MMM. The knife‐edge election and the insecure coalition government have raised once again the possibilities and limitations of ‘the parliamentary road’.

The final emergence of Mauritius as an African country was formally heralded by Prime Minister Ramgoolam heading the OAU. But more substantively Mauritius is linked intimately to the political economy of Southern Africa, particularly through South Africa's heavy involvement in the Mauritian tourist industry. In this Briefing two local correspondents examine the relationship between political power and class forces in Mauritius.
Underdevelopment in Northern Ghana: natural causes or colonial capitalism?
Authors: Plange Nii‐K
Published: July 2007

The ‘natural’ conditions of soil, climate and even population have been used by several anthropologists and historians to ‘explain’ the relatively underdeveloped condition of Northern Ghana during the colonial period and its aftermath. Such explanations take no account of the requirements of the colonial economy for the labour power for mines and cocoa plantations. It was the demand for labour which determined migration from the North, and not the North's mythical lack of resources. In fact, prior to colonial conquest, the North had been at the heart of 19th Century trade routes and food production. An analysis of the incorporation of the North into the circuit of the world economic system reveals the fallacy of the ‘naturalistic’ arguments.
The state of ambivalence: right and left options in Ghana
Authors: Marshall Judith
Published: July 2007

Judith Marshall examines the different interests of international capitalism and the politically powerful groups among the Ghanaian petty bourgeoisie in Ghana since 1960. She analyzes the conflicting and complementary relations among them, and compares the specific policies of successive regimes in Ghana, military and civilian. She shows that progressive plans for transformation of the neo‐colonial political economy could not succeed without an adequate class base and mass mobilization. While international capital has been able to profit from the changing policies of successive regimes it has been unable to establish stable conditions for its own domination, and the perpetuation of the privileges of its local partners. The continued failures of capitalist development strategies sustain the relevance of radical alternatives, as they did during the Nkrumah period.
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 part one (which appeared in ROAPE 54, July 1992), the role of the petty bourgeoisie is examined, especially its private sector component. Part two below describes and interprets peasant discontent and worker opposition.
People's education and ‘nation building’ for a New South Africa
Authors: Randall Stephen
Published: July 2007

My purpose in this article is to restate the continuing relevance of ‘people's education’ as a necessary mobilising dynamic in the project of social emancipation in South Africa today. The notion of ‘salvaging’ the concept of people's education implies that it is in process of being discarded, made over into something new having served its provisional utility. I want to suggest that this is indeed how people's education is now being viewed and that this perception is premature, even inappropriate.

My concerns are threefold: that the transformatory potential of education is being replaced with a ‘skills’ paradigm; that as a consequence of this and other factors, the mobilising element of people's education is in danger of being usurped by its converse — a demobilising or immobilising of the movement; and — related to this latter vis‐a‐vis the requirements of ‘nation‐building’ in a land despoiled by the ravages of apartheid — that this skills‐based notion of national development is misconstrued.
Farm workers and the ‘Agrarian question’
Authors: du Toit Andries
Published: July 2007

The poorest, most insecure and the least visible of South Africa's black workers are those who live and work on its white‐owned farms. They have been oddly peripheral to the current land debate, partly due to the technocratic nature of the discourse of ‘development’ which has foreclosed consideration of the irreducibly political nature of local power relations. Farms are not mere units of production: they are structured by paternalist discourses — practices that weave power relations into the very fabric of social identity and daily life. Legal reform creates a space for contesting these power relations. This article explores some of the issues they face and tries to link these to larger questions of transformation.
More than electronic toll booths: Singapore’s electronic road pricing innovation
Authors: PARAYIL GOVINDAN , YEO TIEN EE DOMINIC
Published: July 2007

This paper explores the dynamics of the Electronic Road Pricing (ERP) innovation in Singapore, tracing its implementation to subsequent diffusion to delineate the links between technology and society. The ERP system, introduced in 1998, is an elaborate and sophisticated toll collecting system using ICTs to regulate road usage. We use the actor–network theory (ANT) as a conceptual tool to analyse the dynamics of this innovation. Through a detailed examination of both human and non‐human actors, we are able to analyse how interests of heterogeneous members of a societal network can be aligned to introduce a technological innovation. In the process, we have observed issues arising from the differential power relationship that exists between road users and government planners as well as the integration of the social and technical aspects of this emerging socio‐technological system. As an emergent technology, the ERP innovation system reflects the social morphology of Singapore as it plays out its part in the making of this nascent nation.