Search

The paper studies a noncooperative repeated game describing the behavior of mobile agents with directional antennas or a wireless sensor network. Periodically, agents must direct antennas towards each other to exchange information. However, the actions required to turn the antenna are energy consuming, and a balance must be maintained between the information relevance and the energy consumed to maintain this relevance. Agents receive smaller payoff at the stage in which they decide to exchange information, but win in subsequent stage by increasing the relevance of information.

The rotator cuff is a complex anatomical and biomechanical structure which allows stabilization of the shoulder joint in the correct position and movements in it. The rotator cuff tears remain the most frequent injury as compared to those of other anatomical structures of the shoulder joint and reach the incidence of 21%, according to a number of authors. Such injuries are prone to inducing a fat replacement of muscle tissues in elderly patients against the background of degenerative changes in the structure of the rotator cuff. These injuries are hard-to-heal, and the incidence of relapses after the surgical treatment reaches 2090%, according to several authors. Based on the investigation of the postoperative treatment failures, alternative methods for the replacement, transfer or surgical repair of damaged tendons are adopted, but there is still no single approach and method in the treatment of this pathology. In this literature review, we have analyzed the data on the anatomical structure and biomechanics of the rotator cuff, the role of the rotator cuff damage in the dysfunction of the shoulder joint and possible methods for its recovery.

The paper considers the algorithm of the distributed organization of an agents’ formation specified by a graph of agents and a numerical simulation of such an algorithm. We describe a cellular automaton simulating the motion of agents, and study its features in connection with the type of landscape along which agents move. The specified cellular automaton has two representations—one-dimensional one and two-dimensional one.

The article is devoted to the study of the functions of the characters’ weapons in A.N. and B.N. Strugatsky’s novel “Hard to be a God”. It is important for writing a commentary on the prologue of the novel. The authors used the historical-typological and mythopoetic research methods. As the result of reviewing the history of words-concepts, as it made by A.N. Veselovsky, the authors managed to study the intertextual connections of “Hard to be a God” with V.T. Shalamov’s poem “Crossbow” and his story “May”, as well as N.S. Gumilev’s poem “Just looks through the cliffs...” and E. Hemingway’s play “The fifth column”. Through these connections, the image of weapons is formed in the work of science fiction writers. It is necessary to destruct the mythological enemy – the sea monster, which symbolizes the social evil within the novel framework. As we have found out, the reason for such an intricate symbolism lies in the peculiarities of the age: the image of the sea monster standing for public evil is due to historical reasons. And since the elimination of social problems by such radical methods, according to the authors, is impossible, the movement towards a bright future should be only gradual and peaceful. As in reality, weapons are fundamentally unable to perform their task. Moreover, the weapon is dangerous for its owner, which indicates the ambivalence of the image. In addition, the comparison, important for the novel “Hard to be God”, of the past and future appears the first in the comparison of crossbows and carbines, further developing by other means. Weapons are involved in creating a number of important motives: doom, the danger of using force, and interference in the course of history.

In the paper, we studied the continuous optimal control problem for multiagent pathfinding which is suitable for modelling various agents such as UAVs, swarms etc. Here, multiple agents try to find the best routes avoiding the obstacles and collisions. At first, we define path-traversing time cost functional. We show continuity of this functional and existence of the optimal path for a single agent. Then, we describe the multiagent pathfinding problem. Also, we consider game theory interpretation for the multiagent pathfinding with continuous routes and social behaviour. Various examples of optimal routes and agent behaviour strategies are provided.

The paper considers probabilistic properties of the trajectory of a moving agent. The agent finds a route close to the optimal one on a lattice consisting of cells with different impassabilities. We study the distribution of the agent’s exit time to the end point for random landscapes of different types using a special sort of simulation. After that, we compare the obtained empirical probability density function with the probability density function derived from theoretical considerations. We also obtain the probability density function for the ratio of Rician and uniform random variables. Finally, the probability distribution of the agent’s residence in a given cell at a given moment of time for random landscapes of different types is analyzed.

The purpose of the article is to analyze the characteristic features of the Enlightenment in Russian accounting in relation to the activity of its outstanding representative Alexander Galagan, who followed the motto, proclaimed in the essay “An Answer to the Question: What is Enlightenment?” by Immanuel Kant, “Sapere aude!” (Dare to know!). For the first time in the English language literature, Galagan is spoken about not only as a theorist but as an accounting historian and a teacher. A detailed description of his works and views is presented. The article’s attention is focused on Galagan’s main aim: improving the status of accounting as a science. Following the results of the research, the following hypothesis has been advanced: which period of time should be regarded in Russian accounting as the Enlightenment? It has also been explained why Alexander Galagan can be considered as a model of Enlightenment.

In neuroscience we know that there exist the following two basic effects in perceiving information: (i) the lateral inhibition, responsible for a cognitive blindness in seeing the whole picture; (ii) the lateral activation, responsible for a cognitive blindness in seeing the details. In this paper, we show that the same effects can be considered in the proof cognitions performed by mathematicians in proving sophisticated theorems, such as Fermat’s Last Theorem. Hence, we insist that there can be two different foundations of mathematics: (i) the discrete foundations, dealing with a logical way of automatic proving from some axioms (the lateral inhibition in math); (ii) the analogue foundations, combining proof trees on tree forests by using the analogies as inference metarules (the lateral activation in math). We propose a kind of analogue logic for analogue reasoning in mathematics.

The paper is devoted to finding the time optimal route of an agent travelling across a region from a given source point to a given target point. At each point of this region, a maximum allowed speed is specified. This speed limit may vary in time. The continuous statement of this problem and the case when the agent travels on a grid with square cells are considered. In the latter case, the time is also discrete, and the number of admissible directions of motion at each point in time is eight. The existence of an optimal solution of this problem is proved, and estimates of the approximate solution obtained on the grid are obtained. It is found that decreasing the size of cells below a certain limit does not further improve the approximation. These results can be used to estimate the quasi-optimal trajectory of the agent motion across the rugged terrain produced by an algorithm based on a cellular automaton that was earlier developed by the author.

The article is devoted to the construction of the motion model for agents with memory. Agents can be interpreted, for example, as mobile robots or soldiers. Agents move on the landscape consisting of squares with different passability. The model is based on the cellular automaton with one common to all agents layer corresponding to the landscape and many agent-specific layers corresponding to an agent’s memory. Methods for the random landscape generation are developed. The dependence between configuration entropy of the landscape, efficiency of the path-finding algorithm based on the cellular automaton was found. Also, the dependence of the average speed of the agents’ motion on the landscape configuration entropy was shown.

The work is devoted to constructing a cellular automaton based model of motion and combat activity of systems of hierarchically organized agents with allowance for terrain ruggedness, communication channels between the agents, and the necessity of choosing behavior adequate to the current situation.

The collective interaction of agents for jointly overcoming (negotiating) obstacles is simulated. The simulation uses a cellular automaton. The automaton’s cells are filled with agents and obstacles of various complexity. The agents' task is to negotiate the obstacles while moving to a prescribed target point. Each agent is assigned to one of three levels, which specifies a hierarchy of subordination between the agents. The complexity of an obstacle is determined by the amount of time needed to overcome it. The proposed model is based on the probabilities of going from one cell to another.

We describe one of the possible methods for organizing a control and communications system for agents such as unmanned aerial vehicles with directional antennae. A special kind of cellular automaton was proposed with an adjacency between cells changing every cycle to describe the group movement of agents forced to synchronize, as well as the corresponding game.

The optimal connecting network problem generalizes many models of structure optimization known from the literature, including communication and transport network topology design, graph cut and graph clustering, structure identification from data, etc. For the case of connecting trees with the given sequence of vertex degrees, the cost of the optimal tree is shown to be bounded from below by the solution of a semidefinite optimization program with bilinear matrix constraints, which is reduced to the solution of a series of convex programs with linear matrix inequality constraints. The proposed lower bound estimate is used to construct several heuristic algorithms and to evaluate their quality on a variety of generated and real-life data sets. Keywords: Optimal communication network, generalized Wiener index, origin-destination matrix, semidefinite programming, quadratic matrix inequality., 29 pages, 6 figures, 2 tables

The paper describes the construction of the motion and interaction model for agents with memory. Agents move on the landscape consisting of squares with different passability. We briefly characterize the cellular automata-based model with one common to all agents layer corresponding to the landscape and many agent-specific layers corresponding to an agent’s memory. Also, we develop methods for the random landscape generation and the simulation of a communication system. Finally, we study a connection between the discrete agent motion model and the continuous concentration law for the system of agents.

There has been little research into awareness of human papillomavirus (HPV) among dermatological out-patients, despite the fact that management of HPV infection causing genitoanal warts/cancer is part of the routine practice of dermato-venereologists. The aim of this study was to explore awareness of HPV among dermatological outpatients. A self-administered questionnaire was distributed to 360 consecutive attendees of a Munich dermatological outpatient clinic in November 2009. Of the total number of questionnaires, 77.2% were returned, and 69.7% (n=251, 51.8% females) were included in the analysis. 39.4% of the respondents had heard of HPV infection, and 23.9% of vaccination. Of those who had heard of HPV, 81.8% knew that HPV risk is associated with non-use condoms, number of sexual partners (77.8%), smoking (8.1%), and that HPV causes genital warts (65.7%), anal warts (39.4%) and cervical cancer (57.6%). HPV ignorance (never having heard of HPV) was predicted by being male (adjusted odds ratio=2.23, 95% confidence interval=1.32-3.80) and being a parent (adjusted odds ratio=2.11, 95% confidence interval=1.24-3.59). We conclude that dermatological outpatients have insufficient knowledge of HPV, its sequelae and prevention.

A thermodynamic assessment of the urea–biuret–water ternary system and its binary subsystems has been made. The Margules model has been applied for the description of excess Gibbs energies of binary solutions, and the properties of ternary solutions have been assessed by using the Muggiani method. Thermodynamic properties of (NH2CO)2NH·(NH2)2CO (I) and (NH2CO)2NH·0.7H2O (II) have been estimated from the condition of equilibrium between the solution and stochiometric phases. The liquidus surface and isothermal sections of the phase diagram of the urea–biuret–water system at the temperature interval T = (268 to 373) K have been calculated. The comparison of calculated and experimental data is discussed.

SUMMARY Purpose: A short HIV/AIDS risk behaviour knowledge index based on questions about HIV transmission and prevention of HIV infection during sexual intercourse and intravenous drug use is proposed and implemented for an HIV average risk population in Munich. Methods: Knowledge levels about HIV/AIDS risk behaviour was assessed in a group of people (n=210) in sexually active age range of 18-49 years which was at an average risk of contracting HIV. Four questions about HIV transmission by unprotected vaginal, anal, or oral sexual intercourse, and by needle sharing, and two questions about HIV prevention by condom use, and the single use of needles and syringes were chosen from ten others for making a four level risk behaviour knowledge index (HIV/AIDS Transmission through Sex and Intravenous Drug Use, HATSIDU) internally consistent according to Cronbach's alpha. Results: HATSIDU index (mean 3.0, SD±1.18) was not associated (p>0.05) with sex and marital status, but depended (p Conclusion: The HATSIDU is a simple and usable index for the assessment of HIV/AIDS risk behaviour knowledge in a population with an average risk of HIV infection. Key words: HIV/AIDS, risk behaviour knowledge INTRODUCTION Knowledge about HIV/AIDS is one usable indirect criterion for the assessment of behavioural risk and preventative behaviour regarding HIV infection. HIV/AIDS knowledge has been investigated in various populations, for example school students (1, 2), adolescents (3), migrant farm workers (4), pregnant women (5), the mentally ill (6), and also in a group of intravenous drug users (IDUs) who have a high risk of contracting HIV (7). The HIV/AIDS risk behaviour knowledge scale was first developed by Kelly et al. (1989) (8) using a group of students, and homosexual men (men who have sex with men, MSM). The assessment of HIV knowledge or HIV risk behaviour knowledge in population is usually performed by summing up correct answers to questions about HIV transmission and prevention according to age, gender, national, social, and educational status in a knowledge score (4, 6, 8). The summing up of correct answers to questions about the possibility of HIV transmission by sexual intercourse, intravenous drug sharing, from an infected mother to her child, by hand shaking, or by using public places assumes that all questions are of equal significance and the answers fall in the same rank of importance. Therefore, respondents who correctly answered questions about HIV transmission by sex and drug use but gave incorrect answers for questions about kissing and hand shaking, would receive the same summed knowledge score as the respondents who failed in questions about HIV transmission by sex and intravenous drug use but answered correctly on kissing and hand contact, for example. Because of the equality of all items in constructing a summed knowledge score, HIV/AIDS knowledge can be investigated, but it is not really useful for the assessment of risk behaviour knowledge regarding HIV/AIDS. Assessment of risk behaviour knowledge means that ignorance of some risks has more impact on risk behaviour than others. For example, ignorance about condom use cannot be equated with misconceptions about HIV transmission through hairdressing or by the use of public toilets. Since 2004, 26 European Union/European Economic Area countries with exception of Poland and Estonia have been reporting statistics regarding transmission routes of HIV infection (9). HIV incidence in EU/EEA decreased in 2009 (5.7/100,000 population) compared to 2004 (6.5/100,000) and was accompanied by a 40% decrease of intravenous transmission of HIV by intravenous drug users (IDUs), but by a 24% increase in homosexually (MSM) transmitted HIV. …

The paper considers two algorithms for searching quasi-optimal solutions of discrete optimization problems with regard to the tasks of avionics placing. The first one solves the problem of optimal placement of devices by installation locations, the second one is for the problem of finding the shortest route between devices. Solutions are constructed using a cellular automaton and the ant colony algorithm.

Aussiedler aus der ehemaligen Sowjetunion stellen in Deutschland eine der grosten Zuwanderergruppen dar. Manche kommen aus Gebieten mit relativ hoher HIV-Pravalenz wie Ukraine und Russland. Bis jetzt existieren keine Daten uber die Einstellungen und das Wissen zu HIV/AIDS in dieser Gruppe. Mittels einer anonymen postalischen multizentrischen Befragung in Bayern wurden 927 Aussiedler angeschrieben. An der Befragung nahmen 37,3% Aussiedler teil. Fur 81,7% Befragte war das Thema HIV/AIDS (sehr) wichtig, 62,3% fuhlten sich (sehr) gut informiert. Drogenabhangige (89,2%), Prostituierte (78%) und Homosexuelle (76%) wurden als Risikogruppen erwahnt. Spritzen/Nadeln (97%), Vaginal- (82,5%), Anal- (65,1%), Oralverkehr (50%) wurden als HIV-Ubertragungs-, Kondom (91,6%), Einwegspritzen/-nadeln (79,9%) als Schutzwege benannt. Aussiedler zeigten insgesamt ein akzeptables HIV/AIDS-Wissensniveau, obwohl das Wissen uber sexuelle Ubertragung ungenugend war; die Aussiedler werden kaum von der konventionellen HIV-Pravention in Deutschland erreicht.

The recently published German S3- guidelines for the treatment of psoriasis vulgaris offer an extensive evidence-based documentation and evaluation of currently available treatment modalities. In order to incorporate this detailed information into the actual treatment decisions in individual patients, we have transformed the recommendations regarding phototherapy and systemic therapies into an algorithm. This algorithm should allow a stepwise treatment approach in adult patients with moderate to severe psoriasis, in whom topical therapy is not sufficient. It can also facilitate documentation of treatment. In our hands the treatment algorithm proved to be feasible and reliable in a large number of patients.

We have three main goals in this paper. First, we will show the equivalences and relationships among some of the well-known classes of structured low density parity check (LDPC) codes. Second, we consider application of these codes to magnetic recording channel. We will make performance comparisons not only with bit-error-rate (BER) metric but also with sector failure rate (SFR) as the comparison dimension. Such a comparison is more meaningful from a system analysis perspective. Finally, we consider the case of these structured LDPC codes concatenated with conventional Reed-Solomon (RS) codes. We believe LDPC codes will not completely replace RS codes in the future storage devices. From this perspective, for LDPC codes to be contenders for future architectures, they will need to work in harmony with the outer RS codes. This implies that we have to take into account the redundancy introduced by the overall coding scheme, that is, RS code in concatenation with LDPC code, to reach meaningful comparisons from a system design perspective.

A novel class of a very high-rate low-density parity check codes is introduced, and investigated in the context of its application in a perpendicular magnetic recording system. New codes are well structured and, unlike random codes, can lead to a very low-complexity implementation. A systematic way of constructing codes is based on Kirkman systems. A hardware efficient encoding algorithm is proposed. The bit-error-rate characteristics are characterized by simulation of the soft iterative decoding in perpendicular magnetic read channel with different partial response targets and types of noise.

In 1985 and 1988, Gerard Guillet and Raymond Helenon, with colleagues, described a novel acquired hypopigmentation disorder in dark-skinned immigrants from the Caribbean which they named progressive macular hypomelanosis (PMH).1 2 Over the past 20 years, many other terms have been coined for this condition, including cutis trunci variata, nummular and confluent hypomelanosis, Creole dyschromia, or idiopathic multiple large-macule hypomelanosis.3 More than 600 PMH patients have been reported in the literature with skin phototypes II–VI, but the debate about the aetiology of this disorder is still open. We present an immunohistochemical and ultrastructural study on disseminated PMH extending beyond the trunk. No Propionibacterium colonisation of skin was found despite extensive examination. The evidence for a bacterial origin is discussed in consideration of the literature. A 29-year-old Romanian female patient (skin phototype III), who had relocated to Germany 8 years earlier, presented with a mottled hypopigmentation of her skin that had progressed over the past 12 years. At the age of 17, macules started to appear on the abdomen and then spread gradually to the flanks, axillae and back. Over the past 2 years, the patient had noticed a rapid progression to the neck, decollete and groin without any subjective symptoms. Physical examination revealed multiple partially coalescing oval or irregular hypopigmented …

HIV incidence in Germany is increasing even though the German Federal Centre for Health Education reported that the entire German population (99 %) has sufficient knowledge of sexual HIV transmission. We tried to find out the reason for this discrepancy. HIV transmission knowledge was investigated in a Munich population (n = 317) and the findings compared with a nationwide study. No differences in knowledge regarding needle sharing and HIV/AIDS curability were found but, in relation to sexual HIV transmission, only 55.5 % of Munich respondents had sufficient knowledge of vaginal, anal and oral transmission routes. The knowledge level reported in the nationwide study is overestimated as a result of the ambiguous character of the questions used.

Halide vapor phase epitaxy (HVPE) was performed for the growth of GaN films. The hexagonal phase α-GaN films were grown on (0001) and (112¯0) sapphire substrates, using the Ga/HCl/NH 3 /He system. Reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM) were used for the study of phase orientation and surface morphology of the resulting films. Luminescence was assessed by photoluminescence (PL) and local cathodoluminescence (CL) measurements at room temperature. It was observed that the oriented islands of cubic gallium nitride (β-GaN) were formed on the surface of as-grown α-GaN films. Their growth occurred during postgrowth, when the temperature in the deposition zone decreased. It was shown that the growth of the β-GaN islands was caused by the presence of trace moisture and oxygen remained in the gas phase. Apart from the partial pressures of H 2 O vapor and oxygen the growth conditions of α-GaN films showed a significant effect on the density of the resulting islands. Possible reasons for the formation of β-GaN followed by subsequent growth are discussed.

Growth of diamond particles on sharp silicon tips in a hot-filament CVD process was investigated. Highly preferential deposition of the particles on the ends of the tips has been found. An explanation is given for the phenomenon based on the idea that the ends have an increased temperature due to localized recombination of hydrogen, involved in the process, on the tips. HRTEM and electron diffraction investigations of the initial stages of the growth have demonstrated a direct localized epitaxial growth of diamond on silicon.

In Germany, immigrants from Former Soviet Union (FSU) countries represent one of the largest immigrant groups. Some FSU countries face the highest HIV prevalence in the region of Eastern Europe and Central Asia. However, the HIV knowledge, attitude and behavioral intent have not been investigated in FSU immigrants compared to the native population yet. A cross-sectional anonymous survey among 1,205 FSU immigrants and 435 native Germans (aged 18–65 years) in Bavaria. Data analysis from the participating 435 (36 %) immigrants and 334 (76.8 %) natives showed that the immigrants were less knowledgeable (p

The structure, surface morphology and photoluminescence properties for the undoped GaN films grown on the (0001), ( 1 012) and (10 1 0) α-Al2O3 substrates have been investigated using the halide vapor phase epitaxy (HVPE) method with the Ga/HCl/NH3/He system. X-ray diffratometer (XRD), reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM) are used for the study of the structure and surface morphology of the film. The luminescence property is assessed by photoluminescence (PL) measurement at room temperature. The following orientation relationships are observed; (0001) GaN/(0001) Al2O3, (11 2 0) GaN/( 1 012) Al2O3, and (10 1 3) and (1 2 12) GaN/(10 1 0) Al2O3. The (10 1 3) GaN films possess two types of surface morphology depending upon the growth conditions. A possible reason for this phenomenon is discussed. The optimum growth conditions of the GaN films for each orientation are established. The qualities of the films showing different orientations are compared. For the (10 1 3) GaN films, it is observed that the higher the growth temperature, the better the crystal structure and the smoother the surface morphology. The relative intensities of (1 2 12) and (10 1 3) films grown at higher temperature are much lower by several ten times than those of (0001), (11 2 0) and (10 1 3) GaN film grown at lower temperature.

We present a large family of low-density parity-check (LDPC) codes constructed from mutually orthogonal Latin rectangles. The construction is conceptually simple and gives high-rate LDPC codes with a structure of the parity check matrix that leads to a low complexity implementation of encoders and decoders. The bit-error rate characteristics are characterized by simulations of the soft iterative decoding in perpendicular magnetic read channels with different partial-response targets and types of noise.

Background Dermatologists are often the first-line specialists who recognize and diagnose human immunodeficiency virus (HIV) infection because of pathognomic skin signs. It is therefore important to investigate attitudes and knowledge regarding HIV/acquired immunodeficiency syndrome (AIDS) amongst dermatological patients in order to provide information for dermatologists and to draw their attention to the issues. Objectives Awareness of HIV/AIDS, its prevention, and hypothetical behaviour were surveyed in dermatological outpatients. Patients/method The anonymous cross-sectional survey was conducted with consecutive German-speaking outpatients aged 18–65 years, who registered at the dermatological outpatient's clinic (excluding venereology, genitourinary or HIV medicine) of the University of Munich (Germany). Results Three hundred forty-seven (77.5%) questionnaires were accepted for analysis. Most of the patients knew about HIV incurability (89.4%), HIV transmissibility during needle sharing (95.3%), or vaginal (87.4%) and anal intercourse (79.5%), as well as about HIV prevention by condom use (97.8%), and use of single needles (76.2%). However, knowledge gaps and misconceptions were detected regarding the risk of HIV transmission during oral sex, and the efficacy of sexual fidelity and avoidance of blood transfusions in HIV prevention. The lowest knowledge level (

Sir, German resettlers are German offspring, who immigrated in the 18–19th century to the Russian Empire following the invitation of Empress Catherine the Great.1 During 1991–2006, 2 092 865 resettlers and their relatives returned to Germany, and this process is still going on.2 Since 2001, an increasing of number of HIV infections has been reported in the resettlers' countries of origin, the former Soviet Union (FSU), which is comparable to an epidemic.3,4 There is no current data available on how many HIV-positive resettlers or immigrants from the FSU are registered in Germany, but an increasing number of HIV diagnoses in resettlers newly arrived from the FSU regions with a high prevalence of HIV is to be …

The recently published German S3- guidelines for the treatment of psoriasis vulgaris offer an extensive evidence-based documentation and evaluation of currently available treatment modalities. In order to incorporate this detailed information into the actual treatment decisions in individual patients, we have transformed the recommendations regarding phototherapy and systemic therapies into an algorithm. This algorithm should allow a stepwise treatment approach in adult patients with moderate to severe psoriasis, in whom topical therapy is not sufficient. It can also facilitate documentation of treatment. In our hands the treatment algorithm proved to be feasible and reliable in a large number of patients.