• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.9-18
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• 2009

This paper presents the state of the art of computational structures technology(CST) and comparison of two computational mechanics - CST and CFD, to the CFD engineers. Classical mechanics is based on the five classical axioms which describe the motion and behaviors of the continuum materials like solid structures and fluids. Computational structures technology uses the finite element method to solve the governing equation, whereas finite volume method is generally used in CFD. A few famous commercial structural analysis programs and DIAMOND/IPSAP will be introduced. DIAMOND/IPSAP is the efficient parallel structural analysis package developed by our research team. DIAMOND/IPSAP shows the better performance than the commercial structural analysis software not only in the parallel computing environments but also in a single computer.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.2
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• pp.41-50
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• 2003

In this paper, nonlinear parallel structural analyses are introduced by using the parallel multifrontal solver and damage localization for 2D and 3D crack models is presented as the application of nonlinear parallel computation. The parallel algorithms related with nonliear reduce the amount of memory used is carried out because many variables should be utilized for this highly nonlinear damage analysis. Also, Riks' continuation method is parallelized to search the solution when strain softening occurs due to damage evolution. For damage localization problem, several computational models having up to around 1-million degree of freedoms are used. The parallel performance in this nonlinear parallel algorithm is shown through these examples and the local variation of damage at crack tip is compared among the models with different degree of freedoms.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.389-395
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• 2004

We consider the interface between the parallel distributed memory multifrontal solver and the finite element method. We give in detail the requirement and the data structure of parallel FEM interface which includes the element data and the node array. The full procedures of solving a large scale structural problem are assumed to have pre-post processors, of which algorithm is not considered in this paper. The main advantage of implementing the parallel FEM interface is shown up in the case that we use a distributed memory system with a large number of processors to solve a very large scale problem. The memory efficiency and the performance effect are examined by analyzing some examples on the Pegasus cluster system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.405-406
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• 2006

Recently, the flat display modules such as plasma or TFT-LCD employ thin crystallized panels which are normally weak to high level transient mechanical energy inputs. As a result, anti-shock performance is one of the most important design specifications for TFT-LCD modules. However, most of large display module designs are generated based on engineers own experiences. Also, a large-scale analysis to evaluate complex material and structural behaviors is one of interesting topic in diverse engineering and scientific fields. The utilization of massively parallel processors has also been a recent trend of high performance computing. The objective of this paper is to introduce a parallel process system which consists of general purpose finite element analysis solver as well as parallelized PC cluster. The parallel processing system is constructed using thirty-two processing elements and the finite element program is developed by adopting hierarchical domain decomposition method. In order to verify the efficiency of the established system, an impact analysis on thin and complex sub-parts of flat display modules is performed. The evaluation results showed a good agreement with the corresponding reference solutions, and thus, the parallel process system seems to be a useful tool fur the complex structural analysis such as IT related products.

• Structural Engineering and Mechanics
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• v.9 no.4
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• pp.383-396
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• 2000

A new structure-vibration-control approach is proposed which uses a passive coupling element between two parallel structures to reduce the seismic response of a system due to earthquake excitation. Dynamic characteristics of the two coupled single-degree-freedom systems subject to stationary white-noise excitation are examined by means of statistical energy analysis (SEA) techniques. Optimal parameters of the passive coupling element such as damping and stiffness under different circumstances are determined with an emphasis on the influence of the structural parameters of the system on the optimal parameters and control effectiveness. Numerical results including the root mean square values of the response due to the filtered white-noise excitation and the time-histories of response to El Centro 1940 NS excitation are presented.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.4
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• pp.283-292
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• 2013

The objective of this research is to evaluate of global and local damage for steel-concrete composite structures under highway bridge exposed to fire loading. To enhance the accuracy and efficiency of the numerical analysis, the proposed transient nonlinear thermal structure interaction(TSI) parallel fire analysis method is implemented in ANSYS. To validate the TSI parallel fire analysis method, a comparison is made with the standard fire test results. The proposed TSI parallel fire analysis method is applied to fire damage analysis and performance evaluation for Buchen highway bridge. The result of analysis, temperature of low flange and web are exceed the critical temperature. The deflection and deformation state show good agreement with the fire accident of buchen highway bridge.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.411-420
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• 1999

The computational model and a new eigenvalue solution algorithm for large-scale structures is presented in the form of parallel computation. The computational loads and data storages required during the solution process are drastically reduced by evenly distributing computational loads to each processor. As the parallel computational model, multiple personal computers are connected by 10Mbits per second Ethernet card. In this study substructuring techniques and static condensation method are adopted for modeling a large-scale structure. To reduce the size of an eigenvalue problem the interface degrees of freedom and one lateral degree of freedom are selected as the master degrees of freedom in each substructure. The performance of the proposed parallel algorithm is demonstrated by applying the algorithm to dynamic analysis of two-dimensional structures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1702-1721
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• 2019

A workflow process (or business process) management system helps to define, execute, monitor and manage workflow models deployed on a workflow-supported enterprise, and the system is compartmentalized into a modeling subsystem and an enacting subsystem, in general. The modeling subsystem's functionality is to discover and analyze workflow models via a theoretical modeling methodology like ICN, to graphically define them via a graphical representation notation like BPMN, and to systematically deploy those graphically defined models onto the enacting subsystem by transforming into their textual models represented by a standardized workflow process definition language like XPDL. Before deploying those defined workflow models, it is very important to inspect its syntactical correctness as well as its structural properness to minimize the loss of effectiveness and the depreciation of efficiency in managing the corresponding workflow models. In this paper, we are particularly interested in verifying very large-scale and massively parallel workflow models, and so we need a sophisticated analyzer to automatically analyze those specialized and complex styles of workflow models. One of the sophisticated analyzers devised in this paper is able to analyze not only the structural complexity but also the data-sequence complexity, especially. The structural complexity is based upon combinational usages of those control-structure constructs such as subprocesses, exclusive-OR, parallel-AND and iterative-LOOP primitives with preserving matched pairing and proper nesting properties, whereas the data-sequence complexity is based upon combinational usages of those relevant data repositories such as data definition sequences and data use sequences. Through the devised and implemented analyzer in this paper, we are able eventually to achieve the systematic verifications of the syntactical correctness as well as the effective validation of the structural properness on those complicate and large-scale styles of workflow models. As an experimental study, we apply the implemented analyzer to an exemplary large-scale and massively parallel workflow process model, the Large Bank Transaction Workflow Process Model, and show the structural complexity analysis results via a series of operational screens captured from the implemented analyzer.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.8
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• pp.1043-1050
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• 2013

Parallel robots used in industry require high stiffness or high speed because of their structural characteristics. Nowadays, the importance of rapid transportation has increased in the distribution industry. In this light, an industrial parallel robot has been developed for high-speed transfer. The developed parallel robot can handle a maximum payload of 3 kg. For a payload of 0.1 kg, the trajectory cycle time is 0.3 s (come and go), and the maximum velocity is 4.5 m/s (pick amp, place work, adept cycle). In this motion, its maximum acceleration is very high and reaches approximately 13g. In this paper, the design, analysis, and performance test results of the developed parallel robot system are introduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3384-3390
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• 2011

This paper describes a domain decomposition method of parallel finite element analysis for elasto-plastic structural problems. As a parallel numeral algorithm for the finite element analysis, the authors have utilized the domain decomposition method combined with an iterative solver such as the conjugate gradient method. Here the domain decomposition method algorithm was applied directly to elasto-plastic problem. The present system was successfully applied to three-dimensional elasto-plastic structural problems.