bluuebunny/crossref_metadata_2025 huggingface dataset:
Automatic tracking of highway road edge based on vehicle dynamics
Authors: Negishi Shinji , Ozawa Shinji , Chiba Masataka
Published: July 2007

There are many efforts being made toward the visual navigation system for the autonomous vehicle. When the highway road is considered, where the constraint for the road structure can be utilized, it is effective to extract the white line (lane marker), which is enforced to be drawn as the borderline of the lane.

This paper considers the automatic extraction of the road edge from the white line in the road image taken by the vehicle camera. There is already proposed a technique which assumes that the road edge image is extracted from the white line, and estimates the horizontal curvature of the road and the vibration component of the vehicle (dynamic angle of the vehicle). It is adequate to use the break (end point) of the white dashed line as the feature point for estimation of the vehicle angle. To extract the road edge from the dashed line, however, it is required to trace the dashed line which moves between consecutive frames.

From such a viewpoint, this paper utilizes the result obtained by the already proposed estimation method for the vehicle angle, and predicts the motion of the end‐point of the dashed line on the image due to the motion of a vehicle. By restricting the range of search based on the result, the end‐point is tracked. An experiment was conducted for the sequence of the image taken for the actual road. It is verified that a sufficient accuracy is obtained for the position prediction, so that the restricted range of search contains the end‐point, which will help the automatic extraction of the road edge. Then, a system is constructed as a cooperative system, which estimates the vehicle angle the road shape from the real image, using the automatically extracted road edge.

It is verified by an on‐line experiment for the real image that the vehicle angle and the horizontal curvature of the road can effectively be estimated. Those results are reported in this paper.
Staging of awake and sleep based on feature map
Authors: Katayama Takafumi , Suzuki Eiji , Saito Masao
Published: July 2007

The staging of sleep EEG is executed by the decision by human observations, and is utilized in the diagnosis of insomnia or psychiatric diseases. On the other hand, the sleep EEG includes a large amount of data, and the automation of the sleep staging is considered to be desirable. However, there has not been established a method for staging the biological state based on the awake EEG.

This paper proposes an automatic method of staging the biological state based on the hypothesis that the biological state is the same if the same kind of waveforms occur with the same ratio. The proposed method is composed of two procedures: the first is to estimate the standard pattern for the waveform from the individual EEG and the cluster the waveforms; and the second is to examine the kind and ratio of the waveforms appearing in a specified interval of time so that the type of EEG can be identified. The results of staging the sleep EEG is compared to the result of the decision by a doctor, and an agreement of 79 percent is obtained. Generally, it is considered that there can be a difference of some 20 percent in the sleep staging by different doctors. Consequently, it is estimated that the proposed method has a performance comparable to that of the doctor. The staging of the awake EEG also is attempted, and the result is consistent with the skin potential response or the behavior of the subject. Thus it is concluded that the proposed method will be useful in the staging of the biological state.
Tree construction for compression of partially condensed one‐dimensional data in index space
Authors: Tanimizu Katsuyuki
Published: July 2007

Tree compression can be applied to the table of the index space that is used for the index method (image inspection method). The author presents a method of compressing a one‐dimensional string of quantized data that contains significant sequences of blocks. The data are equally divided into small areas and, if significant data exists, “1” is used to show its existence and division is performed for lower layers. Significant data are copied to the lowest layers. First, an equation to decide a two‐layer tree construction is obtained by considering the probability of the existence of significant data. Then by expanding the equation to a multilayer tree construction, equations are obtained that decide the optimal construction (number of layers and divisions) that minimizes memory. Examples for optimal tree construction are calculated for various data sizes. The relationship between the optimal tree and e is shown. Finally, variations of methods for applying the tree construction to the index space are shown using a sample image data and the validity of the method is confirmed.
Evaluation of multiple access scheduling for moving picture information
Authors: Fujii Hiroshi , Sakurai Norihiki , Ishikawa Atsushi
Published: July 2007

In the multiple access to moving picture data, there must be the simultaneous realization of the guarantee for the data transfer retaining the real‐time property, the fast response to the manipulation, and high multiplicity. For this purpose, there must be a multiple access scheduling method satisfying those requirements.

In the first prototype of the video‐on‐demand server constructed by the authors, the fixed time‐slot scheduling (FTSS) is used. This system attempts to satisfy those requirements by utilizing the feature of the moving picture data that the access is continuous for the time interval of approximately one scene. FTSS, however, has a problem in that the efficiency is low, since the scheduling is made based on the worst timing of the mechanical operation, such as the varying the seek time and the rotational latency depending on the position of the disk access.

This paper discusses the variable time‐slot scheduling (VTSS), which executes the scheduling based on the average time of the mechanical operation, and analyzes the efficiency. As a result of the analysis, it is seen that the multiplicity of VTSS is improved more remarkably with the improvement of the disk performance. In other words, the application can be expected to the video server in the future.
Cost coefficient control method for solving optimization problems on hopfield‐type neural networks
Authors: Tanaka Toshio , Higuchi Tetsuya , Furuya Tatsumi
Published: July 2007

In solving optimization problems on Hopfield‐type neural networks, a constraint coefficient and a cost coefficient of an energy function should be appropriately determined. Until recently, the values of these coefficients were decided on the basis of experience and trial and error. As a result, solutions that satisfy the constraints could not be obtained, and the quality of the solutions was not good. In order to avoid this problem, we propose a method to control cost coefficient values automatically while keeping the constraint coefficient constant. In this method, the constraint condition for a solution is changed gradually, when the last constraint condition is satisfied, the solution is obtained. Under each constraint condition, the maximum value of cost coefficient is calculated, leading the Traveling Salesman Problem (TSP) for 10 to 30 cities, and obtained near‐optimal solutions more efficiently than an ordinary TSP algorithm. The computation time was reduced 10‐fold, compared with an ordinary TSP algorithm.
A method for understanding intentions of indirect speech acts in natural language interfaces
Authors: Mima Hideki , Aoe Junichi , Fuketa Masao , Hayashi Yoshitaka
Published: July 2007

In an attempt to propose a robust method for understanding natural language (NL) interface commands, a scheme is proposed that infers intentions from an indirect speech‐act that does not express users' real intentions explicitly. This method classifies the real intentions of the indirect speech‐act into: 1) refusal; 2) reversal; 3) restriction; 4) benefit; and 5) disability. Further, concepts are abstracted for operations, e.g., displaying, moving, and deleting information systems; and constructing the operation knowledge base. This knowledge based comprises operational concepts and the relationships between them. These relationships are assigned the foregoing classifications for intentions. In addition, we construct the knowledge base of objects for the target of operations, e.g., files, figures, strings. This knowledge base contains the relationships: a) antonym; b) exclusive; c) part‐of, between the objects; and uses these relations to infer the transitions between the objects. An algorithm is the proposed to infer concepts for operations and concepts for target objects of operations that may represent the user's actual intentions.

This proposal scheme was tested with requests on UNIX and a commercially available Japanese Word Processor. The system successfully inferred the intentions for approximately 80 percent of the user's indirect speech‐act.
A general solution for combinatorial problems by neural networks
Authors: Chikamatsu Yoshitomo , Ae Tadashi , Yamashita Masafumi
Published: July 2007

Yao et al. have proposed the Dynamic‐Static Neural network (DS‐net) which includes the Tank and Hopfield model for linear programming problems as its special case. This paper proposes a modified DS‐net which is capable of solving optimization problems with quadratic constraints. Because the 3‐satisfiability problem of Boolean formula can be transformed to problems of this type, the model is applied to the problem. The simulation experiments using a digital computer show that this formulation bring the merit of greedy methods to the neural network solution and the initial state satisfying constraints is excellent for obtaining the optimal solution.
A topology for discrete spaces and its application in scratch detection for surface inspections
Authors: Imura Hiroshi , Eguchi Masayoshi , Fuwa Yasushi , Nakamura Yatsuka
Published: July 2007

In conventional digital image processing, topological properties have been studied only for selected types of neighborhoods such as a 4‐ or 8‐pixels connection. This paper analyzes properties of a finite topological space by defining it as a topological space with no restriction on the shape of a neighborhood. This leads to the identification of topological properties which are independent of the shape of a neighborhood and can be applied to image processing using neighborhoods other than a 4‐ or 8‐connection. Since a finite topological space can treat only a single neighborhood this cannot be applied to image processing which uses multiple neighborhoods simultaneously. A finite topological space has been extended to a formal topological space having multiple neighborhoods, and its properties are analyzed in this paper.

This theory is then applied to image processing. It has been difficult to detect scratches on a surface with patterns, such as a hard disk or a hairline‐finished metal, by using a conventional digital topology because the scratches often consist of many small blocks and their images are stained by noise. The properties obtained through the formal topology have successfully been applied to these problems, and its effectiveness has been confirmed.
Variable‐target‐time travel control algorithm of a robot vehicle by a neural network considering the centrifugal force
Authors: Kodaira Minoru , Ohtomo Teruhiko , Ohuchi Takao
Published: July 2007

The derivation of mathematical models for robot vehicles is extremely difficult due to the high non‐linearity of the motion characteristics, making it hard to apply the conventional control theory without using approximation methods which assume constant speed, etc. In this paper, the motion control method using a neural model proposed by Uno, Kawato et al. is extended in such a way to allow its application to the travel control problem of a robot vehicle, which is highly nonlinear with respect to the driving force and steering angle, and a method that generates motion commands and performs trajectory planning at the same time is proposed. In this case, the internal coordinates of the identification module which learns the motion characteristics of the robot vehicle are viewed as motion coordinates, and a method to convert the absolute coordinates for each discrete time into motion coordinates is proposed, making it possible to reduce greatly the number of learning patterns. Furthermore, a variable target time algorithm is proposed that counteracts the centrifugal force effects which act on the robot vehicle when the curvature of the generated trajectory is large. The proposed algorithm restrains the centrifugal force and generates optimal motion commands and trajectory, producing results close to those obtained by a human driver. The effectiveness of the proposed method is demonstrated by computer simulation.
A parsing method for context‐free languages using bottom‐up lookahead computation
Authors: Watanabe Yoshimichi , Tokuda Takehiro
Published: July 2007

A new parsing algorithm of context‐free languages using bottom‐up computation of lookahead information is presented. Earley's algorithm uses a great number of items during enumeration to recognize a context‐free language. If items with lookahead fields are used, the number of items can be reduced, but item spacing is considerably increased. The method presented here may reduce the number of items during enumeration without using lookahead fields of items. The computation of lookahead information takes place in a bottom‐up manner. It is not necessary to compute lookahead information until it is required during enumeration.
Between governance & under‐development: accumulation & Africa's ‘catastrophic corruption’
Authors: Szeftel Morris
Published: July 2007

Capital eschews no profit, or very small profit, just as nature was formerly said to abhor a vacuum.With adequate profit, capital is very bold. A certain 10 per cent will ensure its employment anywhere; 20 per cent will produce eagerness; 50 per cent positive audacity; 100 per cent will make it ready to trample on all human laws; 300 per cent and there is not acrime at which it will scruple, nor a risk it will not run, even to the chance of its owner being hanged. If turbulence and strife will bring a profit, it will freely encourage both. Smuggling and the slave trade have amply proved all that is here stated.

T J Dunning, quoted in Karl Marx, Capital I (1976:926, fn.).

This paper explores aspects of the tension between, on the one hand, international efforts by multilateral and bilateral creditors and aid donors to reduce corruption in developing countries and, on the other, the role played by political corruption in promoting local accumulation of wealth, property and capital in Africa. The process of globalisation includes a concerted effort to reduce the costs and increase the predictability of international business activities. The effort has been particularly directed at countries undergoing economic restructuring and democratic change. The weak bargaining position of African states, where debt and underdevelopment make dependence on international creditors and aid donors especially acute, has led to a variety of direct, unsubtle pressures to force these states to undertake ‘governance’ reforms. While many of these measures address important problems undermining African development, they also misunderstand the nature of corruption as an African problem in two important ways.

First, they seek to impose rules and norms of proper public behaviour, developed for and within liberal democracies, in environments where liberal democracy is not established. And, second, they threaten the dependence of the African petty bourgeoisie on access to the state and its resources. In the context of underdevelopment, local accumulation rests heavily on political power and the ability it provides to appropriate public resources. Corruption provides a means of transferring public resources to the new middle class and bourgeois strata which emerged in the post‐colonial order. And underdevelopment ensures that dependence on political power for accumulation is continuous. Africa's development crisis has intensified dependence on the political domain even more and increased conflict as claimants fight over a diminishing pool of resources. Far from arresting the upward spiral of corruption, liberalisation and governance measures imposed by the donors have encouraged the development of new forms of corruption.
The Lesotho highlands corruption trial: who has been airbrushed from the dock?
Authors: Bracking Sarah
Published: July 2007

The Lesotho government has taken four British business groups to court, charging them with paying bribes to the chief executive, Masupha Sole, of the Lesotho Highlands Water Authority. The companies, Balf our Beatty, Sir Alexander Gibb and Co, Stirling International Civil Engineering and Kier International are charged alongside the Swiss‐Swedish group, ABB, Impregilo of Italy, Acres International of Canada and Sogreah, Dumez and Cegelec of France. Balfour Beatty was a partner in the Lesotho Highlands Project consortium and is accused of paying more than £1 million to Sole over three years. Kier International and Stirling International, within the Highlands Water Venture consortium, are alleged to have paid him £250,000, while Sir Alexander Gibb and Co is accused of transferring £51,478.01.
Thriving on war: The Angolan conflict & private business
Authors: Billon Philippe
                      Le
Published: July 2007

With their huge demand for arms and substantial natural resource revenues, Angolan belligerents have made Angola a ‘dream country’ for savvy businessmen able to juggle political relations, arms dealing, and natural resources brokering. Recent investigations by the French judicial system, the UK‐based NGO Global Witness, and UN sanctions monitors have cast a new light on the arms deals and corruption that plagued Angola throughout the 1990s. This Briefing retraces the rise of two businessmen who benefited from and participated in the Angola tragedy. Their careers highlight the inadequacies and ambiguities of the international community and international law in terms of regulating businesses during armed conflicts. Recent initiatives bringing about more transparency and accountability in the use of resource revenues are important steps forward, but an international legal framework is required to take into account the commercialised nature of contemporary wars and war economies.
Don't touch, just listen! popular performance from Uganda
Authors: El‐Bushra Judy , Dolan Chris
Published: July 2007

The power of ‘indigenous performance forms’ to mobilise popular energy and enthusiasm has led politicians, political activists and non‐government agencies in Africa and elsewhere to see them both as a threat and an opportunity. This article examines some of the ways in which ‘external’ actors have sought to harness ‐ and in the process either reinforce, redirect, or indeed at times to neutralise ‐ the power of popular expression.

The first section examines the importance of indigenous performance in charting people's history and reflecting popular world views, and then identifies some of the ways in which governments, political activists and NGOs have appropriated it for their programmes. The second section presents examples from Uganda, which exemplify some of the issues around the use of popular forms of expression in the service of external agendas. In the discussion and conclusions we take issue with the concept of ‘indigenous performance’, and warn against assuming that ‘indigenous performances’ are automatically authentic in what they have to say. We also argue that the subversive elements of ‘indigenous performance’ are likely to be highly resilient to such manipulation. Just as external actors may abuse the form by imposing a foreign content, so local actors may play with an apparently innocuous form to transmit critical messages ‐ to a limited range of peers. In the light of these discussions, the pros and cons of politicians and NGOs using indigenous performance forms as a development communication strategy are assessed.
An intransitive transition
Authors: de Villers Gauthier , Tshonda Jean
                      Omasombo
Published: July 2007

Efforts to promote a ‘democratic transition’ in Congo go back to April 1990 when Mobutu declared the end of the Second Republic. Since then, and despite the changing regimes and conditions experienced under Mobutu and the Kabilas, father and son, the rhetoric of democratisation has had little relationship to the realities of power struggles. The authoritarianism of regimes in Kinshasa, the covetousness of the country's neighbours, the paralysis of opposition groups, the marginalisation of civil society's forces ‐ all have combined to ensure that transition remains stalled or intransitive.
The political economy of Mauritania: imperialism and class struggle
Authors: Bennoune Mahfoud
Published: July 2007

This article explores the way that colonial exploitation conditioned the political, social and economic life of the Mauritanian rural and urban communities. It shows how a neo‐colonial state was formed for the specific purpose not only of continuing colonial plunder under a new institutional arrangement but of intensifying the exploitation of Mauritanian workers for the benefit of multinational corporations, with far‐reaching and even tragic socio‐economic consequences for the majority of the Mauritanian people.
Class struggles in Ghana's mining industry
Authors: Silver Jim
Published: July 2007

The first 20 years of Ghanaian independence has seen industrial relations in the mining industry transformed from the relative stability of the early Nkrumah years when the mineworkers’ living standards constantly rose, to a fierce confrontation by the rank and file workers, not only with the military regime, but also with the trades union leadership. The alliance of mining capital, the State and the trades union bureaucracy which faces the mineworkers has resulted in their development of a militant class consciousness. As yet, it is a defensive consciousness, disruptive, but not linked to any socialist transition in Ghana.
Capitalism and hunger in Northern Nigeria
Authors: Shenton Bob , Watts Mike
Published: July 2007

The Hausa areas of the Sudanic belt of West Africa certainly experienced food shortages, due mainly to weather or pestilence, but had a variety of social mechanisms to reduce their impact on any one family. Many of these mechanisms were undermined in the various transitions that resulted from colonialism without other measures to replace them.

From this experience the meaning of ‘crisis’ in peripheral capitalist societies is explored as some combination of the ‘economic’ crisis of overproduction of commodities in advanced capitalism with the crisis of underproduction of use values characteristic of pre‐capitalist society.
The political economy of tourism in the Gambia
Authors: Dieke Peter U.C.
Published: July 2007

This article reviews the more general development problems confronting The Gambia and relates them to the tourism sector. The inherent benefits and disadvantages related to the development of tourism are examined concluding with policy recommendations utilising the economic opportunities created by tourism, thereby making the sector reasonably self‐sustaining.
The uruguay round: in whose interests?
Authors: Walker Lucy
Published: July 2007

The Briefing reviews the implications of the new World Trade Organisation (WTO), which replaces GATT (General Agreement on Tariffs and Trade), for Africa's place in international trade. In particular, it is suggested that the WTO, and the new disputes procedure, are unlikely to improve Africa's relative position in the world capitalist system and may, in some important respects, even undermine it.
What does the ‘militariat’ do when it rules? military regimes: the Gambia, Sierra Leone and Liberia
Authors: Kandeh Jimmy D.
Published: July 2007

A significant group of military interventions, especially in West Africa, has been carried out not by disaffected senior officers, but by junior officers and NCOs ‐ the militariat, occupying a class position within the army analogous to the working class within society as a whole. Such interventions are directed as much against the senior officers as against the political elite to which they are closely linked by clientelist ties. Despite this, and the populist rhetoric adopted by the militariat when first in power, the regimes they install have failed to adopt social transformative goals, or create new mobilisational political structures.

Comparison of Liberia under the PRC (1980–89), Sierra Leone under the NPRC (1992–96) and the Gambia under the AFPRC (1994) shows that instead the regimes are marked by violence and instability, and in two cases by the outbreak of civil war. Corruption and human rights abuses have been commonplace, and the regimes have failed to strengthen state capacities, to restore military discipline, or to create new social and political institutions. This underpins their reluctance to relinquish power voluntarily. These characteristics are attributed to the lumpen culture of the militariat, to its subversion of military discipline, and to the decay of political and social institutions under the precursor regimes. As the Gambia suffered to a lesser degree from all three of these, it shares the features of the militariat to a lesser degree than Liberia or Sierra Leone.
ROAPE & the radical Africanist: what next?
Authors: Saul John S. , Leys Colin
Published: July 2007

Giles Mohan has invited us to contribute to a debate in these pages ‘concerning the future of African studies and of ROAPE'spolitical‐intellectual role in this.’ He suggests that ‘some editors of ROAPEare concerned that the journal has lost the political focus with which it began and which marked it as a radical alternative to the “mainstream”.’ Note that in this latter formulation the question is less about the future of African studies per sethan it is about the future of ‘radical’ African studies. It is, in fact, the latter subject that our remarks will chiefly address (1). We do agree with Mohan that this seems a good moment to think aloud about what both ROAPEand radical Africanists are up to ‐ even though we will argue that neither need spend too much time apologising for what they/we have been/ are doing. The main challenge is to do ‘our thing’ even better, and to do it even more relevantly to the considerable complexities of the current moment. We will develop our thoughts by dealing, in turn, with each of the six specific questions Mohan raises in the ‘guidelines’ he proposes for the debate.
The reinvention of the market from below: the end of the women's money changing monopoly in Kinshasa
Authors: De Herdt Tom , Marysse Stefaan
Published: July 2007

Zaïre's transition to the Third Republic (1990–1997) was characterised by the decline of the national currency and the economy's partial dollarisation. This article describes the origins of the different types of cambistes(informal money exchange brokers). It argues that the evolution of the market of foreign currency is not only determined by changes in economic opportunities, but also by different kinds of social identity the cambisteshave adopted. More generally, insight is gained into the social re‐structuration of the market in an almost stateless society.
Parameters of economic reform in North Africa
Authors: Pfeifer Karen
Published: July 2007

The debates over the successes and limitations of structural adjustment in North Africa swirl around how to understand the institutional framework supporting economic activity in the non‐western world. To what extent are the investment roles for state leadership and for private enterprise, especially for export, a substitute for or complementary in the contemporary development process? How far should privatisation go? For example, should natural monopolies like telecommunications or strategic sectors like phosphate and oil production be sold off?
Entrepreneurship in Science: Case Studies from Liquid Crystal Application
Authors: Armstrong Peter , Tomes Anne
Published: July 2007

Current UK policy on the knowledge-driven economy places a heavy weight of expectation on the fostering of entrepreneurial attitudes amongst university scientists. Interviews with the owner-managers of innovative companies in liquid crystal technology suggest that scientist-entrepreneurs are not simply scientists who have become imbued with the entrepreneurial spirit. They are also characterised by particular approaches to science and market intelligence. As scientists, they are fascinated by science-based effects (rather than science as a body of knowledge), knowledge of which tends to be acquired through interpersonal networks. Their knowledge of markets, similarly, tends to be acquired by networking with users. The result is a dynamic mental landscape in which application possibilities constantly churn against user needs to yield a stream of new product concepts, and in which there exists the possibility of insuring against the risks of career moves and strategic changes of direction. Assuming these findings can be replicated in further research, the implication is that the formation of scientist-entrepreneurs may need to foster 'concrete' attitudes towards science and a networking style of operation.
Innovation and Industry Development: A Policy-relevant Analytical Framework
Authors: Marceau Jane
Published: July 2007

Public attention is increasingly focusing on the role played by product and process innovation in the economic development of modern nations. There have been many studies of national innovation systems, regional and local innovation systems, and technological and sectoral systems. There have been innovation surveys and efforts concentrating on measuring the effectiveness of different innovation systems. The 'system' debate has distracted attention from the search for policy mechanisms to encourage development in a more specific manner. The approach developed in this paper enables the analyst to both hone in on the general dynamics of industrial change as they relate to particular situations and to highlight the points that may need public or private action if a country, region or locality is to maximise the efficiency of the players in its national, regional or local innovation systems, or indeed its sectoral ones.
Analysis of glomerular filtration rate, serum cystatin C levels, and renal resistive index values in cirrhosis patients
Authors: Ustundag Yucel , Samsar Ufuk , Acikgoz Sereften , Cabuk Mehmet , Kiran Sibel , Kulah Eyup , Aydemir Selim
Published: July 2007

Clin Chem Lab Med 2007;45:890–4.
High-sensitivity C-reactive protein concentration in patients with myocardial infarction-environmental factors, and polymorphisms in interleukin-10 and CD14 genes
Authors: Lorenzová Alena , Staněk Vladimír , Gebauerová Marie , Bohuslavová Romana , Stávek Petr , Hubáček Jaroslav A. , Lánská Věra , Poledne Rudolf
Published: July 2007

Clin Chem Lab Med 2007;45:855–61.
Robust control of a class of non‐linear systems and applications to robotics
Authors: Samson Claude
Published: July 2007

This paper addresses the problems of designing and analysing a set of stable and robust controls for nonlinear systems whose equations are representative of mechanical systems such as robot manipulators. When applied to robotics, this theoretical analysis proves that most of the control schemes which are used in practice or proposed in the literature, ranging from the simplest PD control to more complex controls such as adaptive controls or controls based on the so‐called ‘computed torque method’, are liable to perform equally well if the manipulator is perfectly rigid and ideal sensors are used. Consequently, it appears that the main justification for using elaborate schemes is to avoid the need for including large constant control gains when high performance is demanded. At this stage, the analysis suggests the possibility of using more flexible non‐linear control gains as a way of improving all schemes.
Parallel architectures for RLS with directional forgetting
Authors: Chisci L. , Mosca E.
Published: July 2007

Efficient parallel architectures for recursive least squares with directional forgetting are presented. Two different arrays are proposed. The first employs O(n) processors and exhibits a 1/(2n + 3) throughput rate, n being the number of parameters to be estimated. The second can achieve a 1/(n + 2) throughput rate at the expense of an O(n2) processor complexity. Both architectures make use of the UD algorithm, here properly modified so as to embody the directional‐forgetting variant.
Über die Polymorphie unterschiedlich präparierter Cadmiumsulfide
Authors: Hartmann H.
Published: July 2007

Durch Fällungskristallisation wurde Cadmiumsulfid mit unterschiedlicher Struktur in Abhängigkeit von der Art des vorgelegten Cadmiumsalzes und als Folge des pH‐Wertes der Ausgangslösungen erhalten. Insbesondere gelang die Präparation fehlgeordneter Proben. Die thermische Nachbehandlung von kubischem CdS ergab eine Beeinflussung der polymorphen Strukturumwandlung durch die verwendete Gasatmosphäre. Dabei wurde im Vergleich zu Luftglühungen das zwischen etwa 300 und 500 °C liegende Transformationsgebiet in der Reihenfolge Stickstoff, Schwefelwasserstoff, Chlorwasserstoff nach niedrigeren Temperaturen verschoben. Mit längeren Versuchszeiten erhöhte sich allgemein der Umwandlungsgrad. Als Grund für das Wachstum der metastabilen kubischen CdS‐Phase bei Zimmertemperatur wurde eine Modifizierung der Keimbildungsarbeiten durch anionische Verunreinigungen angenommen.

Die hydrothermale Synthese von CdS‐Einkristallen und Epitaxieversuche werden beschrieben.
Über die Aufnahme von Natriumchromat in Natriumchloratkristalle bei der Kristallisation aus Schmelzen und aus übersättigten Lösungen
Authors: Kirkova E. K. , Janeva S. B.
Published: July 2007

In der vorliegenden Arbeit werden Versuchsergebnisse über die Verteilung von Chromationen in Natriumchloratkristallen beim Zonenschmelzen und bei der Kristallisation aus Lösungen dargelegt.

Bei der Kristallisation aus der Schmelze ist der Einfluß der Wanderungsgeschwindigkeit der geschmolzenen Zone und der Anzahl der Durchgänge verfolgt worden. Bei der Kristallisation aus Lösungen wurde der Einfluß der Kristallisationstemperatur und der Übersättigung ermittelt. In Gegenwart von Natriumchromat wurden Natriumchlorat‐Einkristalle erhalten.

Die beiden Reinigungsmethoden werden miteinander verglichen.
Über den Einfluß von Ultraschall auf das Segregationsverhalten von Gold in Tellur bei normaler Erstarrung
Authors: Hess S. , Kujawa R. V.
Published: July 2007

Es wird der Einfluß eines Ultraschallfeldes (15,8 kHz) auf den Segregationsvorgang untersucht und gefunden, daß der effektive Segregationskoeffizient von Gold in Tellur sich von 0,7 auf 0,1 senken läßt.
Zum Einfluß von Kristalldefekten auf das Sperrverhalten von n+pp+‐Anordnungen aus Silicium
Authors: Förstner G.
Published: July 2007

Elektrische und metallografische Untersuchungen von Silicium‐n+pp+‐Anordnungen ergaben Zusammenhänge zwischen den Sperrcharakteristiken dieser Dioden und groben Kristallstörungen. Diese Kristallstörungen haben die Form von Rissen. Die Risse bewirken eine Zunahme der Sperrströme und eine Abnahme der Sperrspannungen der n+pp+‐Anordnungen.

Mit großer Wahrscheinlichkeit werden die Kristallstörungen durch thermische Spannungen verursacht, die infolge des Anlötens von Kontakten entstehen.
Röntgentopographie von hochschmelzenden Metalleinkristallen mit dem Lang‐Verfahren
Authors: Becker C. , Schulze D.
Published: July 2007

Die Möglichkeiten der Anwendung des röntgentopographischen Verfahrens nach A. R. Lang auf kzr‐Metalle werden allgemein erörtert und im Falle des elektronen‐zonengeschmolzenen Molybdäns experimentell verifiziert.
Zur Geometrie der Ätzfiguren auf kubisch raumzentrierten Metallen
Authors: Schulze D.
Published: July 2007

Für die wichtigsten Flächen, Kanten und Ecken kubisch raumzentrierter Metalle werden die Bindungsenergien gemäß der Kossel‐Stranskischen Theorie zusammengestellt. Die kristallographisch bedingten geometrischen Formen von elektronenmikroskopisch am Wolfram aufgenommenen Ätzfiguren lassen sich in ihren wesentlichsten Zügen an Hand der Bindungsverhältnisse verstehen. Die tieferen Ursachen für die Entstehung der markanten erhabenen und offensichtlich mit Versetzungen im Zusammenhang stehenden Figuren auf Oktaederflächen bleiben weiterhin ein offenes Problem.
Texturerscheinungen in Oxidschichten aus reaktiver Kathodenzerstäubung
Authors: Salm J. , Schröder H.
Published: July 2007

Nickelferritschichten, die durch reaktive Kathodenzerstäubung auf amorphe Quarzglasunterlagen niedergeschlagen wurden, zeigten bei bestimmten Entladungsbedingungen eine [100]‐Fasertextur. Es wurden Morphologie und Struktur der Schichten und der Einfluß einiger Parameter auf diese Eigenschaften untersucht. Unter 45° aufgestäubte Schichten besitzen eine zweite bevorzugte Orientierung innerhalb der Schichtebene.
Synthese von Silikaten durch chemische Transportreaktionen
Authors: Novoselova A. V.
Published: July 2007

Die Ergebnisse der am Lehrstuhl für Anorganische Chemie der Chemischen Fakultät der Moskauer Lomonossov‐Universität durchgeführten Experimente zur Synthese von Silikaten, insbesondere Berylliumsilikat, durch chemische Transportreaktionen werden mitgeteilt.

Massenspektrometrische Aufnahmen der bei der Synthese von Berylliumsilikat durch Transportreaktionen in der Ampulle vorhandenen Gasphase erwiesen die Anwesenheit von SiOF2. Aus weiteren experimentellen Untersuchungen sowie Literaturdaten wurde die Reaktion 4 SiOF2 + 2 NaBeF3 ⇄ Be2SiO4 + 2 NaF + 3 SiF2 für die Bildung von Berylliumsilikat aus der Gasphase als wesentlich erkannt. Die Ergebnisse von Gleichgewichtsuntersuchungen im System BeOSiO2‐Na2BeF4 sowie der Berechnung der ΔG‐Werte verschiedener Reaktionen werden mitgeteilt.
Die initiierte Kristallisation eines Modellglases und die Morphologie der keimbildenden Metallkriställchen
Authors: Gutzow I. , Popov E. , Marinov M. , Toschev S.
Published: July 2007

Es wird die initiierte Kristallisation der Gläser an einem Modell untersucht. Zu diesem Zwecke werden in das NaPO3‐Glas Platinmetalle (Ir, Pt, Pd, Rh), wie auch Au, Ag, Cu eingeführt.

Es werden Größe, Verteilung, Anfangswachstumsformen, Konzentration und Habitus der initiierenden Metallkriställchen bestimmt und ihr Bildungsmechanismus diskutiert.

Die initiierende Wirkung der angewendeten Metalle wird als ein Fall der Keimbildung auf fremder Unterlage betrachtet, wobei sich um die Metallkriställchen Na3[P3O9]‐Sphärolithe bilden und weiterwachsen. Quantitativ wird dieser Entglasungsvorgang in einer folgenden Veröffentlichung behandelt.
Zu Betriebsweisen und Einsatzmöglichkeiten des Hochfrequenz‐Plasmabrenners
Authors: von Ardenne M. , Böhme J. , Knebel E. D.
Published: July 2007

Es wird eine Apparatur für die Kristallzüchtung nach dem Verneuil‐Verfahren beschrieben, die sich auf die Erzeugung eines stabilen Plasmas bei Atmosphärendruck stützt. Die Verfahren zum Zünden und Betrieb des induktiven Hochfrequenz‐Plasmabrenners mit Argon als Arbeitsgas werden besprochen.
Die Hydrothermalsynthese faseriger Amphibole und die Untersuchung einiger ihrer Eigenschaften
Authors: Fedoseev A. D. , Makarova T. A. , Nesterčuk N. I. , Sipovskij D. P.
Published: July 2007

In der vorliegenden Arbeit wird die Synthese faseriger Silikate nach dem hydrothermalen Verfahren dargestellt. Die optimalen Bedingungen für die Kristallisation faseriger Amphibole wurden ermittelt. Der Einfluß einiger Faktoren (Alkalikonzentration und Verdünnungsgrad der Ausgangsgemische) auf den Charakter der faserigen Kristallisationsprodukte wurde festgestellt. Die gezüchteten Amphibole wurden mit Hilfe chemischer, mikroskopischer, röntgenographischer und elektronenmikroskopischer Methoden identifiziert.
Zur Kristallperfektion von Halbleiterepitaxieschichten II. Über den Einfluß der Substratoberfläche auf die Kristallperfektion von Siliziumepitaxieschichten
Authors: Schulz M.
Published: July 2007

Es wird über den Einfluß der Substratoberfläche auf die Kristallperfektion von Siliziumepitaxieschichten berichtet. Die untersuchten Schichten waren aus der Gasphase epitaktisch auf korrespondierende Spaltflächenpaare aufgewachsen. Zur Untersuchung verschiedener Wachstumsparameter wurde jeweils eine Spiegelfläche als „Normal”︁ benutzt.

Die bei diesen Arbeiten erzielten Ergebnisse werden an einigen typischen licht‐ und emissionselektronenmikroskopischen Abbildungen diskutiert.
Die Anwendung des Zuverlässigkeitskriteriums für Polfiguren kubischer Metalle
Authors: Schläfer D.
Published: July 2007

Der Reihenentwicklungskoeffizient zweiten Grades ist ein brauchbares Maß für die Einschätzung des Fehlers experimentell bestimmter Polfiguren kubischer Materialien. Die Fehlerkoeffizienten höheren Grades ermöglichen außerdem die Trennung der systematischen von den statistischen Fehlern. Es wurden vierzig in der Literatur angegebene Polfiguren untersucht. Die aus röntgenographischen Durch‐ und Rückstrahlmessungen kombinierten Polfiguren weisen im allgemeinen wesentlich höhere Fehler auf als Messungen an Kugel‐ oder Zylinderproben, Proben mit Schräganschliff sowie Neutronenbeugungsmessungen.
Einkristallzüchtung von Paratellurit (TeO2)
Authors: Liebertz J.
Published: July 2007

Wegen seiner seltenen Punktgruppe D4 (422) ließ Paratellurit interessante physikalische Eigenschaften erwarten, deren Messung größere Einkristalle erforderte. Eine Untersuchung der Polymorphie des Tellurdioxids zeigte, daß von den beiden in der Natur vorkommenden Modifikationen Tellurit und Paratellurit nur letzteres synthetisch zugänglich ist. Züchtungsversuche nach dem Czochralski‐Verfahren führten zu großen, einwandfreien Paratellurit‐Einkristallen von maximal 60 mm Länge und 25 mm Durchmesser. Kleine Kristalle in Form quadratischer Nadeln (2 × 2 × 10 mm) konnten auch durch Hydrothermalsynthese erhalten werden. Einige optische Eigenschaften von Paratellurit wurden bestimmt.
Stresses in Silicon after Boron Diffusion (II). Stresses between the Glaze‐like Reaction Phase and Silicon and their Detection by Means of the Berg‐Barrett Method
Authors: Brümmer O. , Höche H. R.
Published: July 2007

If the specimens are specially prepared it is possible to detect the stresses between crystalline substrate and amorphous or crystalline thin covering layers by means of X‐ray topographic methods, espicially the Berg‐Barrett method. Investigations of the X‐ray contrast allow statements on whether the surface layers produce compressive or tensile stresses in the crystal. This method was used to obtain more detailed information on the glazelike surface layer formed during the boron‐diffusion process.
Über den Mechanismus von Festkörperreaktionen in Silicaten
Authors: Jost K.‐H.
Published: July 2007

Aus der Untersuchung topotaktischer Reaktionen abgeleitete Vorstellungen vom Mechanismus von Zersetzungsreaktionen und Phasentransformationen in Silicaten werden an Beispielen erläutert. Außerdem wird auf einige Fragen des Mechanismus von Pulverreaktionen mit Silicaten eingegangen.
Effect of crystallisation conditions on the shape and composition of ferroelectric crystals
Authors: Mareček V. , Novák J.
Published: July 2007

In the present paper the effect of crystallization conditions on the habit and chemical composition of some water‐soluble ferroelectric crystals as TGS, TGFB, TGSe, KDP, RbDP, mixed LiTl‐LiNH4‐tartrates and other tartrates is discussed. The influence of impurities or additives as well as different crystallisation conditions on growth and quality of crystals and additional treatment of samples for physical measurements are followed. Further, some established facts are mentioned concerning the chemical composition of perovskite type crystals of alkaline earth titanates prepared by crystallisation from molten potassium fluoride. The amount of impurities and additives is discussed. Many factors which affect the real crystallisation and which must be considered when evaluating the results of physical meausrements are reported.
Initiale Sulfidbildung an Versetzungen von Antimon (111)‐Spaltfolien
Authors: Herrmann F. P. , Mietz I.
Published: July 2007

Die initiale Sulfidkeimbildung an Versetzungen von Antimonspaltfolien kann durch Elektronenmikroskopie in Transmission untersucht werden. Die Größe solcher Partikel ist an Schrauben‐ und Stufenversetzungen unterschiedlich. Die Erklärung dafür wird durch die Annahme eines speziellen Diffusionsmechanismus gegeben.
Zur Bildung von Adsorptionsmischkristallen
Authors: Steinike U.
Published: July 2007

Durch Untersuchungen an den Systemen KCl‐H2O‐Fremdstoff und NH4Cl‐H2O‐Fremdstoff konnte die Vorstellung über die Bildung von Adsorptionsmischkristallen erweitert werden. Es wurden eine Reihe spezifischer Eigenschaften komplexer Mischsysteme festgestellt.
Über das Wachstumsverhalten Kleiner Impfkristalle von Ammoniumdihydrogenphosphat in einer modifizierten Zirkulationsapparatur
Authors: Weis J.
Published: July 2007

We have investigated the crystal growth of small seed crystals of NH4H2PO4. The crystal growth was measured by a modified circulation apparatus. The measured values are compared with those by other investigators and the reasons of differences in crystallization discussed. The influence of cobalt nitrate in solution on crystallization velocity and the impurity in crystals was investigated. A new crystal holder in the apparatus is described.
Bildung und Untersuchung von SixAl1−xAs‐Kristallen
Authors: Fischer P. , Kühn G. , Tempel A. , Beier W.
Published: July 2007

Bei der chemischen Transportreaktion von AlAs mit Jod als Transportmittel wird in geschlossenen Quarzampullen im Temperaturbereich von 900–1000°C SixAl1−xAs gebildet. Die gewonnenen Kristallplättchen und Whisker werden röntgenographisch, licht‐ und elektronenoptisch sowie mit der Elektronstrahlmikrosonde untersucht und der Bildungsmechanismus diskutiert.
Untersuchung der durch Metallspuren verursachten Störstellen in Si‐Epitaxieschichten
Authors: Kormány Teréz , Vecsernyés Lajos , Vértesy Miklós , Jutasim Erna
Published: July 2007

In den Silicium‐Epitaxie‐ und Bordiffusions‐Schichten wurde mit verschiedenen Methoden die Anreicherung einiger Verunreinigungen — vor allem des Aluminiums, Bariums, Calciums, Kaliums, Natriums, Magnesiums, Silbers, Sauerstoffes und Schwefels — nachgewiesen. Untersuchungen mit dem Elektronenstrahl‐Mikroanalysator zeigen, daß die Anreicherung dieser Verunreinigungen zur Ausbildung von Ausscheidungen verschiedener Zusammensetzung und Morphologie führen kann.
Die Herstellung und einige Eigenschaften von reinen und dotierten BaTiO3‐Einkristallen
Authors: Feltz A. , Langbein H.
Published: July 2007

Farblose BaTiO3‐Einkristalle werden erhalten durch langsame Kühlung eines BaTiO3/Ba2TiO4/BaCl2‐Gemisches im Platintiegel von 1300°C unter Anwendung einer Inertgastechnik. Die Kristalle haben eine Curietemperatur von 132°C.

Durch eine partielle Substitution des Titan durch Vanadin bzw. Niob wird die Curietemperatur des BaTiO3 erniedrigt. Die Abhängigkeit der Curietemperatur von der Konzentration an Fremdionen ist im untersuchten Bereich etwa linear.
Neutronographical investigations of the age hardening behaviour on Iron — Manganese — Nickel alloys
Authors: Tobisch J. , Bürger R. , Paul H. , Kleinstück K.
Published: July 2007

Age hardenable martensitic Iron—Manganese—Nickel alloys were neutronographically investigated in order to explain the age hardening effect occurring during the heat treatment. The formation of coherent precipitations of an ordering phase within the matrix proved to be the reason for the occurring hardness increase.
The growing of β‐copper phthalocyanine single crystals by evaporation
Authors: Hamann C.
Published: July 2007

Purification of copper phthalocyanine and purity tests are described. An apparatus for growing of β‐copper phthalocyanine single crystals and growing procedures are given.