• Journal of the Korean Solar Energy Society
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• v.33 no.2
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• pp.101-107
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• 2013

It is evident that in the wind energy business as an economic activity there is a close relationship between the wind speed and the revenues. The wind turbine test facility for wind turbine accreditation is intended to be used by the industry for testing of both main components and systems. This paper suggest the wind test site for certification of prototype wind turbine with international regulations. The test site has an environmental permit for wind turbines with a maximum hub height of 120m and a rotor diameter up to 120m, and can accommodate prototypes with installed electrical powers up to 5MW each. A wind turbine manufacturer can lease the location for a period of type certification. And also researchers are the development of new methods for measuring the influence, performance and durability of the components, a mathematical and numerical modelling of component responses by using the site.

• Journal of Sasang Constitutional Medicine
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• v.27 no.4
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• pp.436-443
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• 2015

Objectives The aim of this study was to report an improvement on the symptoms of Eosinophilic Colitis (EC) by Yeoldahanso-tang.Methods The patient was diagnosed with Taeumin Ganyeol-paeJo Symptomatology and treated with Yeoldahanso-tang. The gastroendoscopy and eosinophilic infitration of mucosa of colitis are investigated. Also patient's subjective symptom of abdominal pain was scored using the Numerical Rating Scale(NRS) during the treatment period. And the number of defecation in a day is also used to decide the degree of colitis.Results and Conclusions The patient had been treated from December 13, 2014 to August 8, 2015. Eosinophilic infiltration of colon was disappeared after the treatment although chronic inflammation still existed. Subjective pain of abdominal pain was measured as NRS 6~8 at the beginning of the remedy, but diminished through the treatment sessions and became NRS 0 in the end. The number of defecation was in average 3, and at the endpoint it became 1. In conclusion, this study suggests that Sasang constitutional Medicine used for treating EC of Taeumin may be effective.

• Journal of Sasang Constitutional Medicine
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• v.27 no.4
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• pp.419-428
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• 2015

Objectives The aim of this study was to report an improvement on the symptoms of Restless Legs Syndrome (RLS) after using Hyeongbangsabaeksan.Methods The patient was diagnosed with Soyangin Soyang-sangpung Symptomatology and treated with Hyeongbangsabaeksan. The patient's subjective symptoms of pain on the lower limb and discomfort in sleeping were observed using the Numerical Rating Scale(NRS) and Visual Analogue Scale(VAS) respectively during the treatment period. And other specific symptoms of RLS were assessed once per week for a total of three times with Korean Versions of the International Restless Legs Scale.Results and Conclusions The pain on the patient's lower limb decreased from NRS 4 to NRS 0 after one week of treatment. And discomfort in sleeping decreased from VAS 5.5 to VAS 0 after one week of treatment. Furthermore, the score of Korean Versions of the International Restless Legs Scale decreased from 40 to 5 after two weeks of treatment. In conclusion, this study shows that Sasang Constitutional Medicine can be an effective treatment for Soyangin patient with Restless Legs Syndrome as Soyangin Soyang-sangpung Symptomatology.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.67-76
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• 2016

The asphalt-concrete trackbed system has many advantages in terms of maintenance and economics. However, methods to investigate practical use corresponding to the development of the trackbed system must be developed. The primary objective of this study was to evaluate the dynamic performance of the asphalt system in accordance with both the elastic and viscoelastic material characteristics and design thickness of the asphalt trackbed. More specifically, in order to reduce the uncertainty error of the Finite Element(FE) model, a three-dimensional full scale FE model was developed and then the infinite foundation model was considered. Finally, to compare the condition of viscoelastic materials, performance evaluation of the asphalt-concrete trackbed system was used to deal with the dynamic amplification factors; numerical results using isotropic-elastic materials in the FE analysis are presented.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2101-2108
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• 2008

Most of train fires which occur in usual cases do not grow up significantly on a large scale enough to bring about casualties and harmful damages. However, the consequence of some train fire accidents can be devastating disaster so that it would be even recorded in history in unusual cases. Accordingly, such a probability of fire disaster cannot be ignored in aspect of the railway safety assesment. A scale of injury and damage is very difficult to predict and analyze. Because it is depend on various factors, i.e. fire load, burning period, facilities, environment condition, and so on. Thus, a prediction of fire load could be understood as a one methodology to estimate railway safety assesment. The summation method which is one of them is used to evaluate the overall fire load by assuming that sum of heat release rate per unit area or mass of each composite material equals the total. However, since the train fire is classified into a compartment fire in under-ventilation condition. The summation method do not estimate a fire load completely. In this journal, Various methods to predict fire load are introduced and evaluated. Especially the fire simulation tool FDS(Fire Dynamics Simulator)which is based on the CFD(Computational Fluid Dynamics) is introduced, too. Through the FDS simulation, numerical analyses for the fire load and flame spread are performed. Then, these results of the simulation are validated through the comparison study with the experimental data. Then, limitations and approximations including in simulation process are discussed. The future direction of research is proposed.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.54-67
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• 2018

There have been recent efforts to establish methods for high-fidelity and multi-physics simulation with coupled thermal-hydraulic (T/H) and neutronics codes for the entire core of a light water reactor under accident conditions. Considering the computing power necessary for a pin-by-pin analysis of the entire core, subchannel-scale T/H analysis is considered appropriate to achieve acceptable accuracy in an optimal computational time. In the present study, the applicability of in-house code CUPID of the Korea Atomic Energy Research Institute was extended to the subchannel-scale T/H analysis. CUPID is a component-scale T/H analysis code, which uses three-dimensional two-fluid models with various closure models and incorporates a highly parallelized numerical solver. In this study, key models required for a subchannel-scale T/H analysis were implemented in CUPID. Afterward, the code was validated against four subchannel experiments under unheated and heated single-phase incompressible flow conditions. Thereafter, a subchannel-scale T/H analysis of the entire core for an Advanced Power Reactor 1400 reactor core was carried out. For the high-fidelity simulation, detailed geometrical features and individual rod power distributions were considered in this demonstration. In this study, CUPID shows its capability of reproducing key phenomena in a subchannel and dealing with the subchannel-scale whole core T/H analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.4
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• pp.619-628
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• 2002

This paper deals with the FE analysis for the free vibration of sloshing in horizontal cylindrical tank with baffles. We use Laplace equation based on potential theory as governing equation. This problem is solved by FEM using lineal isoparametric elements. We assume that the tank as well as baffles is rigid body and by separating nodes into two at the baffle location, baffle effect is obtained by separating nodes into two at the baffle location. For the calculation of natural frequencies and mode shapes, we introduce Lanczos transformation and Jacobi iteration methods. Numerical results of the first longitudinal and transverse modes, while comparing with literature cited, are very good. In order for the baffle effects on the free vibration of sloshing, various combinations of baffle parameters, which are location, inner diameter and number, are examined.

• Computational Structural Engineering
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• v.4 no.4
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• pp.125-133
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• 1991

For the purpose of efficiently calculating the design sensitivity and the reliability for the complicated structures in which the structural responses or limit state functions are given by implicit form, the probabilistic finite element method is introduced to formulate the deterministic design sensitivity analysis method and incorporated with the second moment reliability methods such as MVFOSM, AFOSM and SORM. Also, the probabilistic design sensitivity analysis method needed in the reliability-based design is proposed. As numerical examples, two thin plates are analyzed for the cases of plane stress and plate bending. The initial yielding is defined as failure criterion, and applied loads, yield stress, plate thickness, Young's modulus and Poisson's ratio are treated as random variables. It is found that the response variances and the failure probabilities calculated by the proposed PFEM-based reliability method show good agreement with those by Monte Carlo simulation. The probabilistic design sensitivity evaluates explicitly the contribution of each random variable to probability of failure. Further, the design change can be evaluated without any difficulty, and their effect on reliability can be estimated quickly with high accuracy.

• Computational Structural Engineering
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• v.4 no.4
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• pp.135-144
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• 1991

The finite element technique incorporatating infinite elements is applied to analyzing the general three dimensional wave-structure interaction problems within the limits of linear wave theory. The hydrodynamic forces are assumed to be inertially dominated, and viscous effects are neglected. In order to analyze the corresponding boundary value problems efficiently, two types of elements are developed. One is the infinite element for modeling the radiation condition at infinity, and the other is the fictitious bottom boundary element for the case of deep water. To validate those elements, numerical analyses are performed for several floating structures. Comparisons with the results by using other available solution methods show that the present method incorporating the infinite and the fictitious bottom boundary elements gives good results.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.4
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• pp.661-674
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• 2002

The objective of this study is to develop efficient numerical method to enable solution of optimal control problems of Navier-Stokes flows and to apply these technique to the problem of viscous drag minimization on a bluff body by controlling boundary velocities on the surface of the body. In addition to the industrial importance of the drag reduction problem, it serves as a model for other more complex flow optimization settings, and allows us to study, modify, and improve the behavior of the optimal control methods proposed here. The control is affected by the suction or injection of fluid on portions of the boundary, and the objective function represents the rate at which energy is dissipated in the fluid. This study shows how reduced Hessian successive quadratic programming method, which avoid converging the flow equations at each iteration, can be tailored to these problems.