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Moisture-related building envelope problems such as condensation, damp, delamination of coatings, unsatisfied user's comfort requirements usually arise from the unexamined/unforeseen interactions of materials with ambient environment, and with other system components during design. Today, it is possible to estimate the in-use performance of building envelopes by computer simulations except for test methods. While use of building simulation software intended to determine indoor climate systems providing appropriate environmental conditions and to assess building energy performance is increasing, the use of simulation software to assess hygrothermal performance of building envelopes has only been recently started to spread. This paper primarily deals with computer simulation software analysing hygrothermal performance of building envelopes, and important issues associated with their structure and use are considered. A typical wall design case performed by WUFI 2D is explained for contributing to extend the efficient use of simulation software in practice. Finally, when using simulation software to assess hygrothermal performance, 'selection of appropriate software' and 'planning of simulation work' processes are found matters of utmost importance in achieving goals set by the use of simulation. [ABSTRACT FROM AUTHOR]

In this paper, the goal is to primarily deal with the modeling of the railway traffic induced vibrations by using discrete computer models for analyzing related wave propagation problems with soil-structure interaction effects and mitigation of building responses by installation of wave barriers. Comprehensive parametric studies including the effects of localization and backfill material of trench barrier on the screening performance have been executed. [ABSTRACT FROM AUTHOR]

In this paper numerical technique through Computational Fluid Dynamics (CFD) codes was used in order to investigate thermo-fluid-dynamics field (velocity, pressure, temperature) in the combustion chamber of a Diesel engine. Another important objective was the possibility of modelling and prediction of pollutant formation during the combustion process in these engines. Mathematical model was based on the conservation equations of mass, momentum and energy (Favre-averaged Navier-Stokes equations). To close these equations system was add also: state relations equations, Renormalized Group Theory (RNG) k-epsilon turbulence model and spray mechanism model. Since processes in Diesel engine have not only thermo-fluid nature but also chemistry, a special attention was for chemistry models for both chemical reaction simulation and for the chemistry models of pollutants. Formation of NOx is predicted by Zeldovich mechanism. Soot formation relies on the nucleation, surface growth, coagulation and oxidation process. Result of simulation shown that thermal NOx is seen at stoichiometric mixture fraction at high temperatures, while soot formation is seen fuel-rich and relatively low- temperature regions. [ABSTRACT FROM AUTHOR]

In this paper, a systematic design process model is proposed to model Flexible Manufacturing Systems (FMS). Generally, FMS systems design is complicated and cost very high as installation phase. Therefore, technical analysis of system design should be exact and accurate even for the installation phase. At this stage, the proposed model is Integration Definition for Function Modeling (IDEF) diagram which is a structured design technique. Proposed model is exemplified with a practical example in TAI which is operating in the aerospace industry. The performance of the proposed model is analyzed using simulation and queueing network technique. In the performance analysis, test parameters are determined as service rates, number of servers, routing information and number of transporters and also performance parameters are determined cycle time and machine utilization. [ABSTRACT FROM AUTHOR]

This paper describes the optimal tuning for the parameters of the power system stabilizer (PSS), which can improve the system damping performance within a wide region of operation conditions to enhance power system stability using artificial bee colony algorithm (ABC) based PSS instead of a conventional PSS and particle swarm optimization (PSO) based PSS. The parameters of the optimized PSS are obtained by minimizing a performance index based on integral of the absolute error (IAE) that shows steady state stability of power system. Single machine infinite bus (SMIB) system and two types of excitation system were used for the present work. The simulation results demonstrate that the proposed ABC based PSS performs well in damping and quicker response when compared with the other two PSSs. [ABSTRACT FROM AUTHOR]

This paper studies the computerized tooth profile generation of involute helical gears cut by rack cutters with asymmetric teeth. The asymmetry means that different pressure angles are applied for driving and coast sides, respectively. Based on the theory of gearing and the geometry of straight-sided rack cutter, a complete mathematical model of asymmetric helical gears including working region, root fillet and bottomland is given. Undercutting analysis is also investigated by considering the relative velocity and equation of meshing. A computer program is developed to generate the tooth profile of helical gears with asymmetric involute teeth. [ABSTRACT FROM AUTHOR]

This paper examines how to automatically reconstruct 3D models from their orthographic two views and explains a new approach developed fort hat purpose. The approach is based on the identification of geometric features with the interpretation of 2B views, their volumetric intersections and reconstruction of solid models. A number of rules have been defined for this goal and they implemented on a prottype software with the approach of expert systems. The developed software allows determination of some features efficiently such as slot, holes, blind holes, closed prismatic holes, etc. Another contribution of this research is to reconstruct solid models from their sectional and half section views that is almost noneexistend in the related literature. [ABSTRACT FROM AUTHOR]