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OALib Journal期刊

ISSN: 2333-9721

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The Regionalisation of Natural Risks in the Some ul Mare Hills
ANDRAS-ISTVAN BARTA
Romanian Review of Regional Studies , 2006,
Abstract: The significance of studying natural risks derives from the human society’s necessity to live safely. This approach is at its best if the analysis is undertaken at a micro-scale, i.e. through regionalisation, which supposes the complex treatment of all its environmental components and the study of all the phenomena taking place in it. Most of the risk phenomena result from the interaction of many factors, each of them with different and specific laws, and evolution trends. The regionalisation of risks is necessary as it leads to highlighting the phenomena on certain risk-friendly areas. Because of the complexity of the natural and the anthropic factors, the Some ul Mare Hills are a favourable environment for the evolution of the geographic risk phenomena; hence the necessity of the regional analysis of those phenomena.
TIPOLOGIA A EZ RILOR RII AMLA ULUI
Ion-Hora?iu PAVEL,Andras-Istvan BARTA
Geographia Napocensis , 2011,
Abstract: The Settlements Typology of Amla Land. The settlements typology has an important role n regional geographic analysis of an area because, by using a large number of indicators, it can achieve a complete picture of the settlements system. Analyzing the population size of the localities, their structure, the functional typology, texture, spatial distribution, we can see the difficulties facing some localities and where the intervention is needed to remove the faults and ensuring higherstandards of living of the inhabitants.
Colibi a Climatic Resort (Bistri a-N s ud County) between Project and Purpose
Ion B?CA,Mircea MURE?IANU,Andras BARTA,Eduard SCHUSTER
Journal of Settlements and Spatial Planning , 2011,
Abstract: Colibi a Depression is located at the contact between the Barg u and C limani rock formations, overlapping the upper basin of the Bistri a Ardelean River. The area posses a significant tourist potential, exploited in the past by the existing climacteric resort. The hydroelectric development activities that took place between 1976 and 1996 deactivated the spa, but once they were finished, tourism experienced a powerful come-back. As a result, county institutions (namely the Bistri a-N s ud County Council) and local authorities (the mayoralty of Bistri a Barg ului commune) are interested in the revival of the Colibi a climatic resort. This is already happening, through several specific activities and projects. Under these circumstances, our study tries to realise an evaluation of the region’s attractive potential, as well as an analysis of the criteria needed to be fulfilled in order to reestablish Colibi a climatic resort.
Review of the Book “Optimization in Computer Engineering—Theory and Applications”: Chapter 8—Applying Graph Coloring to Frequency Assignment  [PDF]
Andras Orban
Wireless Engineering and Technology (WET) , 2012, DOI: 10.4236/wet.2012.32008
Abstract: This book focuses on the relationship between theory and applications of various optimization problems in computer engineering. In the first half of the book the theoretical foundations are presented, such as some selected graph algorithms, integer linear programming and complexity theory. The second half of the book brings the theory closer to the reader by applying them to real-world optimization problems. Its aim is to bridge the often significant gap between theory and applications bringing additional value to both: the theory becomes more interesting in light of a possible application and understanding the hardness and possible solutions of the real-world problem definitely benefits from a strong theoretical background. Chapter 8 is a good example of the above. Here the authors present several versions of the frequency assignment problem (FAP), which is an important practical optimization problem arising in wireless network design. It is shown how FAP can be reduced to the earlier presented graph coloring problem. It is interesting to note that often the practical problem needs significant simplification in order to fit into the model that the theory is able to handle, or the theoretical problem needs to be extended to be able to model the needs of the practical application. Various generalizations of the simple graph coloring problem such as list coloring and T-coloring are introduced to model the constraints of the FAP. With this reduction the specific engineering problem can be han-dled through well-understood mathematical models. Besides showing the reduction to the graph coloring problem, the authors apply a graph coloring solver on industry benchmark FAP instances to further understand the characteristics of the real-world FAP. They show that there are significant differences in the difficulty of the problem on random and real-world graphs and that the parameters of the particular instance play a crucial role in the hardness of the problem. They show that the FAPs show a phase transition property in every input parameter, ie. there is a critical parameter combination where the problem gets extremely hard, but otherwise the problem can be solved relatively easily even on large real-world networks. Readers will surely benefit from the unique nature of the book that brings theory and applications close together in a well-understandable yet theoretically solid way.
Forgetting the starting distribution in finite interacting tempering
Winfried Barta
Mathematics , 2014,
Abstract: Markov chain Monte Carlo (MCMC) methods are frequently used to approximately simulate high-dimensional, multimodal probability distributions. In adaptive MCMC methods, the transition kernel is changed "on the fly" in the hope to speed up convergence. We study interacting tempering, an adaptive MCMC algorithm based on interacting Markov chains, that can be seen as a simplified version of the equi-energy sampler. Using a coupling argument, we show that under easy to verify assumptions on the target distribution (on a finite space), the interacting tempering process rapidly forgets its starting distribution. The result applies, among others, to exponential random graph models, the Ising and Potts models (in mean field or on a bounded degree graph), as well as (Edwards-Anderson) Ising spin glasses. As a cautionary note, we also exhibit an example of a target distribution for which the interacting tempering process rapidly forgets its starting distribution, but takes an exponential number of steps (in the dimension of the state space) to converge to its limiting distribution. As a consequence, we argue that convergence diagnostics that are based on demonstrating that the process has forgotten its starting distribution might be of limited use for adaptive MCMC algorithms like interacting tempering.
A probabilistic proof of cutoff in the Metropolis algorithm for the Erd?s-Rényi random graph
Winfried Barta
Mathematics , 2011,
Abstract: We study mixing of the Metropolis algorithm for a distribution on the hypercube that corresponds to the Erd\H{o}s-R\'enyi random graph with edge probability p. This Markov chain has cutoff at max{p,1-p} n log n with window size n, a result proved by Diaconis and Ram (2000) using Fourier analysis. Here we give an alternative proof that relies on coupling and a projection to a two-dimensional Markov chain. This is done in the hope that probabilistic techniques will be easier to generalize to less symmetric distributions. We also describe a close relationship between the Metropolis and Gibbs samplers for this model. Our proof extends to the case where the edge probabilities vary with n. In that case, we also show that a natural coordinate wise coupling is sharp if and only if the edge probabilities are of order 1/n.
A Link-based Approach to Entity Resolution in Social Networks
Gergo Barta
Computer Science , 2014, DOI: 10.5121/csit.2014.4409
Abstract: Social networks initially had been places for people to contact each other, find friends or new acquaintances. As such they ever proved interesting for machine aided analysis. Recent developments, however, pivoted social networks to being among the main fields of information exchange, opinion expression and debate. As a result there is growing interest in both analyzing and integrating social network services. In this environment efficient information retrieval is hindered by the vast amount and varying quality of the user-generated content. Guiding users to relevant information is a valuable service and also a difficult task, where a crucial part of the process is accurately resolving duplicate entities to real-world ones. In this paper we propose a novel approach that utilizes the principles of link mining to successfully extend the methodology of entity resolution to multitype problems. The proposed method is presented using an illustrative social network-based real-world example and validated by comprehensive evaluation of the results.
Heating, Efficacy and Dose of Local Hyperthermia  [PDF]
Oliver Szasz, Andras Szasz
Open Journal of Biophysics (OJBIPHY) , 2016, DOI: 10.4236/ojbiphy.2016.61002
Abstract: Hyperthermia in oncology needs a definite dose which fixes well the clinical protocols. The temperature is far not a dose, it is mass independent. The half of the mass has the same temperature in equilibrium, so the basic criteria of the dose mass-dependence are lost. The energy could be a great option for dosing, (like it is in radiation therapies by Gy) but it has numerous drawbacks. These are discussed in this paper, trying to unify the dosing of ionizing and non-ionizing radiations.
LSFEM implementation of MHD numerical solver
Jan Skala,Miroslav Barta
Physics , 2012,
Abstract: Many problems in physics are inherently of multi-scale nature. The issues of MHD turbulence or magnetic reconnection, namely in the hot and sparse, almost collision-less astrophysical plasmas, can stand as clear examples. The Finite Element Method (FEM) with adaptive gridding appears to be the appropriate numerical implementation for handling the broad range of scales contained in such high Lundquist-number MHD problems. In spite the FEM is now routinely used in engineering practice in solid-state and fluid dynamics, its usage for MHD simulations has recently only begun and only few implementations exist so far. In this paper we present our MHD solver based on the Least-Square FEM (LSFEM) formulation. We describe the transformation of the MHD equations into form required for finding the LSFEM functional and some practical issues in implementation of the method. The algorithm was tested on selected problems of ideal (non-resistive) and resistive MHD. The tests show the usability of LSFEM for solving MHD equations.
Role of Cajal Bodies and Nucleolus in the Maturation of the U1 snRNP in Arabidopsis
Zdravko J. Lorkovi?, Andrea Barta
PLOS ONE , 2008, DOI: 10.1371/journal.pone.0003989
Abstract: Background The biogenesis of spliceosomal snRNPs takes place in both the cytoplasm where Sm core proteins are added and snRNAs are modified at the 5′ and 3′ termini and in the nucleus where snRNP-specific proteins associate. U1 snRNP consists of U1 snRNA, seven Sm proteins and three snRNP-specific proteins, U1-70K, U1A, and U1C. It has been shown previously that after import to the nucleus U2 and U4/U6 snRNP-specific proteins first appear in Cajal bodies (CB) and then in splicing speckles. In addition, in cells grown under normal conditions U2, U4, U5, and U6 snRNAs/snRNPs are abundant in CBs. Therefore, it has been proposed that the final assembly of these spliceosomal snRNPs takes place in this nuclear compartment. In contrast, U1 snRNA in both animal and plant cells has rarely been found in this nuclear compartment. Methodology/Principal Findings Here, we analysed the subnuclear distribution of Arabidopsis U1 snRNP-specific proteins fused to GFP or mRFP in transiently transformed Arabidopsis protoplasts. Irrespective of the tag used, U1-70K was exclusively found in the nucleus, whereas U1A and U1C were equally distributed between the nucleus and the cytoplasm. In the nucleus all three proteins localised to CBs and nucleoli although to different extent. Interestingly, we also found that the appearance of the three proteins in nuclear speckles differ significantly. U1-70K was mostly found in speckles whereas U1A and U1C in ~90% of cells showed diffuse nucleoplasmic in combination with CBs and nucleolar localisation. Conclusions/Significance Our data indicate that CBs and nucleolus are involved in the maturation of U1 snRNP. Differences in nuclear accumulation and distribution between U1-70K and U1A and U1C proteins may indicate that either U1-70K or U1A and U1C associate with, or is/are involved, in other nuclear processes apart from pre-mRNA splicing.
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