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[ 18 ]. In view of the results of the Hungarian Youth Study (A Magyar Ifjúság Kutatás) completed in 2016, 74–75% of young people doing sport regularly were driven by the goal of achieving and preserving fitness and health. Sixty-two percent
Maximal clique enumeration and maximum clique generation are well known NP-complete discrete optimization problems. Researchers experiment with parallel implementations of known algorithms in order to speed up the resolution process. Parallel implementations are equivalent to divisions of the feasible region that is an implicit decomposition of the original problem. The below study looks for the possible ways of explicit decomposition, which can subsequently serve as bases of parallel algorithms. The paper introduces formally the notion of decomposition, specifies explicit algorithms for different sorts of decomposition, provides and compares decomposition based algorithms for the maximum clique problem.
When the snake bites its own tail...
Messing up and solving meta-levels in informatics and in everyday problems
The crossing of meta-levels is a widely applied technology since the earliest roots of computer technology. It is unconsciously used, since it is unknown for most of people, that this has made today’s computers so powerful. Furthermore the same problem lies behind everyday paradoxes, and all the software technologies, that made the writing of loaders, compilers and also viruses possible.The article analyses the concept of UML-s four layer meta-level stack, and the bootstrapping technology of creating compilers. In the last section a new technology, called ‘semantic bootstrap’ is proposed that, analogously to compilers’ bootstrap, makes the migration of semantic data also possible.
The paper describes the SILK-Verifier component, a resolution-based verification tool for OCL constraints of UML static models. First, the projection of OCL constraints to first-order logic formulae is explained, then, the way of finding contradictions and inconsistencies in these formulae is shown. The concept of mixed strategy reasoning is introduced, i.e. the way to make the reasoning capabilities of several Constraint Logic Programming solvers to cooperate in an interacting manner. For the best understanding of the problem, a concrete example for the cooperation of solvers is presented. Finally, the experiences gained during the implementation are summarized.
A zero-one linear program is a global discrete optimization problem. Namely, it is a linear programming problem with zero-one variables. The real relaxation of a zero-one program is again a continuous linear programming problem. Simply, the zero-one variables are replaced by continuous variables varying between zero and one independently of each other. If the real relaxation, as a continuous problem, solved with the simplex method happens to have a zero-one optimal solution, then this particular solution is also an optimal solution of the original zero-one programming problem. Suppose that x 1,…,x n are all the variables of a given zero-one linear programming problem. For convenience we introduce further variables y 1,…,y n defined by y 1=1−x 1,…, y n=1−x n respectively. For a unified notation the variables x 1,…,x n and y 1,…, y n together will be denoted by z 1,…,z 2n . These variables will play the roles the nodes of the conflict graph Г associated with the given zero-one linear programming problem. Fixing the variables z i and z j both to be equal to one simultaneously reduces the number of variables in the problem. If the new smaller optimization problem does not have any feasible solution, then the nodes z i and z j will be connected by an edge in the graph Γ. The graph Γ simply records that there is a conflict between the assignments z i =1 and z j =1 which explains the name conflict graph. In other words the non-directed edge between the nodes z i and z j codes the fact that the inequality z i+z j≤1holds. The conflict graph was designed to generate additional constraints the so-called valid inequalities or cuts in order to expedite the solution of the zero-one linear program via its real relaxation. This particular solution strategy is aptly named the branch and cut method. It will be shown that the conflict graph besides its intended use can also be applied in another solution technique the method of implicit enumeration. We will illustrate by examples that the conflict graph provides us with rules to prune the search tree that are not offered by the commonly applied pruning rules. In addition the computations involved can easily be organized into a highly parallel computational scheme.
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First Hungarian Active House refurbishment won the Active House Award and the Energy Globe Hungary prize in 2017. This paper provides insight into the renewal design process of the typical home from the 70’s under disadvantageous site conditions. Dynamic thermal simulations helped to gain insight into space organization and building envelope concepts and their effects on comfort and energy performance. The Active House Standard was applied to evaluate the calculation results. The most advantageous concept was selected for final design elaboration and construction. The implemented building proved that in the refurbishment process it is possible to achieve highest level of efficiency in operation energy consumption with positive yearly balance by simultaneously being able to rearrange the complete interior space and as a consequence the building shape and envelope into a competitive design at international level.
Abstract
Natural and man-made disasters are vital issues that led to the increasing number of migrants, many of them stayed displaced for decades this requires more permanent dwellings. The main aim of the study is to investigate the impact of the bottom-up construction method on developing migrant’s shelters energy and thermal comfort performance. Dynamic simulation tool Indoor Climate and Energy (IDA ICE 4.8) has been used to assess nine different scenarios. The results quantified that the annually delivered energy and thermal comfort accepted hours of proposed scenario nine (S9) is better compared to base-case scenario one (S1) by 63% kWh and 4,215 h respectively. Methodologies and results of this paper can be adopted and applied for various places of the world affected by migration issue.
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This paper describes the adaptation of the formex configuration processing to the computer program Grasshopper 3D and focuses on the applied mathematical solutions. Formex algebra is a mathematical system, primarily used for planning structural systems like truss-grid domes and vaults, together with the programming language Formian. The goal of the research is to allow architects to plan truss-grid structures easily with parametric design tools based on the versatile formex algebra mathematical system. To produce regular structures, coordinate system transformations are used. Owing to the abilities of the parametric design software, it is possible to apply further modifications on the structures and gain special forms. The paper covers the basic dome types, and it introduces additional dome-based structures using special coordinate-system solutions based on a spherical coordinate system, vault structures and their modifications based on a cylindrical coordinate system and circular structures and their modifications based on polar coordinates. Moreover two rotational grid tools are introduced, which uses coordinate system transformations on a unique way to create surfaces of revolutions based on the given generating curve and create grid structures on these surfaces. It also describes the solution technique to implement the triangular grid version of every one of these tools based on diamatic domes. The adaptation of formex algebra and the parametric workflow of Grasshopper together give the possibility of quick and easy design and optimization of special truss-grid domes.
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During sketch design stage for the new block of the University of Pécs, Medical School comfort and lighting simulations were applied to quantify optimization strategies. Simulation cases about shading possibilities, façade glazing ratios and internal heat storage masses evaluate the impact of illumination, solar gains, loads and heat transmission on visual and thermal comfort. The goal was to select the most favorable comfort, coupled with maximum reduction of investment costs. Concepts represent 14% (shading), 10% (reduced wall-window ratio), 11% (slabs without suspended ceilings), and 17% (combined wall-window ratio and thermal mass) improvement in thermal comfort performance, and it was proposed for further design.
Abstract:
This paper proposes the application of energy efficient, low tech (passive) building design strategies and concepts in an industrial facility case study, in order to create a building with high efficiency and comfort within the boundaries of a tight investment cost. The planning process is supported by dynamic thermal and daylight simulations. Two versions were considered, a conventional industry building and a low tech one with climate zone based space organization. According to the evaluation of thermal and visual comfort as well as energy demand the selected version with the innovative passive concept delivered considerably better performance. According to the constructor’s concept, the reference building had to be placed by minimal adaptation on the new site. After considering and calling this concept into question, a new ‘energy design’ concept was elaborated at the sketch planning level. The new concept was compared with the reference building and a quantified, simulation assisted evaluation was provided about the cases. Since there was an essential improvement in comfort and energy level and, in addition, at architectural standard, the constructor could have been convinced to accept the new concept.
