• Journal of the Korean Society of Safety
• /
• v.26 no.1
• /
• pp.36-42
• /
• 2011

This paper presents a nonlinear soil-structure interaction analysis approach, which can consider precisely characteristics of structures, complicated soil profiles and nonlinear characteristics of soil. Although many methods have been developed to deal with the soil-structure interaction effects in past years, most of them are nearly unpractical since it is difficult to model complicated characteristics of structure and soil precisely. The presented approach overcomes the difficulties by adopting an maligned mesh generation approach and multi-linear model. The applicability of the proposed approach is validated and the effects of complicated characteristics of structure and soil on soil-structure interaction are investigated through the numerical example by the proposed nonlinear soil-structure interaction analysis approach.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.1049-1052
• /
• 1998

A new simplified circuit model for the switching noise analysis of the complicated multi-layer IC package is developed. The current flowing mechanism on the ground and power planes of the package is simplified by using the dependent current soures and partial plane circuit model. The methodology is very cost-efficient as well as accurate. It is demonstrated that the nosie based on the simplified circuit model has an excellent agreement with that of the complicated full circuit model. However, the simplified model takes only 5 minutes for the switching noise simulation, while the full circuit model takes more than 4 hours.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.8 no.11
• /
• pp.69-77
• /
• 1985

The queue theory is based on the assumption that most system are normally assigned to stay under steady state. Therefore, the initial problem can be represented by a symbolic model but such a representation does not permit analysis of all the interesting alternatives. When the solution to the problem is thus restricted to a particular subclass of available alternatives, the symbolic model can be solved by mathematics to deduce which alternative is optimal. However, when be consider slightly more complicated alternatives, the analytic procedures become interactable. The purpose of this study is to show how a simulation model enable us to handle the more complicated system after examining the characteristics of the complications that negate more complicated system. Then construct a simulation model and compare the solution of simulation models with analytic methods.

• Journal of KSNVE
• /
• v.10 no.3
• /
• pp.508-516
• /
• 2000

To study the possibility of F.E.M application to vibration and shock response of double stage elastic mounting system with complicated damped foundation structure like common-bed or raft in ships foundation structure model which has complicated damped sandwich cross-section is analyzed first. And then vibration responses experimental results and shock response of double stage elastic mounting system with complicated damped foundation structure like common-bed or raft in ships foundation structure model which adopts the above damped structure as intermediate foundation were compared. As a result it is found that F.E.M could be effectively used in analyzing the vibration and shock response of double and multi-stage elastic mounting system with complicated damped foundation structures.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.146.4-146
• /
• 2001

Various methods have been proposed for the time series prediction. Most of the conventional methods only optimize parameters of mathematical models, but to construct an appropriate functional form of the model is more difficult in the first place. We employ the Genetic Programming (GP) to construct the functional form of prediction models. Our method is distinguished because the model parameters are optimized by using Back-Propagation (BP)-like method and the prediction model includes discontinuous functions, such as if and max, as node functions for describing complicated phenomena. The above-mentioned functions are non-differentiable, but the BP method requires derivative. To solve this problem, we develop ...

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1994.03a
• /
• pp.159-166
• /
• 1994

A constitutive model was proposed to analyze creep densification and grain growth of alumina powder compacts during high temperature processing. Theoretical results from the constitutive model were compared with various experimental data of alumina powder compacts in the literature including pressureless sintering, sinter forging and hot pressing. The proposed constitutive equations were implemented into finite element analysis program (ABAQUS) to simulate densification for more complicated geometry and loading conditions. High temperature forming processing of alumina compact with complicated shape was simulated. Processing of Alumina Powder Compacts

• Journal of the Korea Society for Simulation
• /
• v.3 no.1
• /
• pp.151-165
• /
• 1994

Broadband network based on the Asynchronous Transfer Mode(ATM) concept are becoming the target technology for the emerging Broadband Integrated Services Digital Network(B-ISDN). Since B-ISDN is very complex and requites a great amount of investment, optimum design and performance analysis of such systems are very important. Simulation can be widely used to analyze and examine the broadband network behavior. However, for the complicated system like broadband networks it is extremely difficult and time-consuming to develop a complete model for simulation. In this paper, an object-oriented modeling approach for the broadband network simulation is presented for the effective and efficient modeling. Object-oriented approaches can provide a good structuring capability for complicated simulation models and facilitate the development of reusable and extensible simulation models. We have developed an object-oriented model which consists of object model and behavior model. In the object mode., the components of the broadband network and both constant bit rate(CBR) and variable bit rate(VBR) traffic types of call level, burst level, and cell level are modeled as object classes. In the behavior model, the dynamic features for each object class are represented using the state transition diagram. It has been shown by illustration that objectoriented modeling is an effective tool for modeling the complicated B-ISDN.

• Korean System Dynamics Review
• /
• v.6 no.1
• /
• pp.33-70
• /
• 2005

This study explores the process of corporate corruption via a percolation-based system dynamics model. The preliminary model is an agent-based model constructed in the terms of the corruption networking between ego and other. In the model, the agents behave depending on percolation rules, which represent (1) passing on the corruption opportunities and (2) accepting it. To describe the percolation process in the networks, we develop a further complicated model by combining the basic model with the Bethe lattice. Through the complicated model, we suggest (1) the dynamics of the systemic corporate corruption, (2) 4 patterns of the corruption, and (3) the institutionalization of the corruption. These simulation results provide theoretical and practical implications.

• Journal of the Korean Society of Safety
• /
• v.22 no.5
• /
• pp.50-56
• /
• 2007

In the past, a number of approaches, such as analytical, numerical or experimental methods, have been developed to deal with the soil-structure interaction effects. However, for many problems with complex geometry and material discontinuity most of approaches are nearly unpractical since it is difficult to model structures and complicated soil profiles precisely. This paper presents a soil-structure interaction analysis approach, which carl consider precisely characteristics of structures and complicated soil profiles. The presented approach overcomes the difficulties by adopting an unaligned mesh generation approach. From numerical examples, the applicability of the proposed approach is validated and dynamic responses of soil-structure systems subjected to earthquake loading are investigated considering characteristics of structures and complicated soil profiles.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.9
• /
• pp.1555-1561
• /
• 2003

Finite element analysis using modern constitutive equation is one of the most general tools to simulate the deformation behavior and to predict the life of the structure. Constitutive equation becomes complicated so as to predict the material behavior more accurately than the classical models. Because of the complexity of constitutive model, numerical treatment becomes so difficult that the calculation should be verified carefully. One-element tests, simple tension or simple shear, are usually used to verify the accuracy of finite element analysis using complicated constitutive model. Since this test is mainly focused on the time integration scheme, it is also necessary to verify the equilibrium iteration using material stiffness matrix and to compare FE results with solution of structures. In this investigation, viscoplastic solution of thick walled cylinder was derived considering axial constraints and was compared with the finite element analysis. All the numerical solutions showed a good coincidence with FE results. This numerical solution can be used as a verification tool for newly developed FE code with complicated constitutive model.