Jin-Seon Park

The Rearch of Stress Route for Concrete Structure using Advanced Progressive Optimization

This research describe improved algorithm that is able to decide terminal criterion of Evolutionary Structural Optimization (ESO), reducing load of calculation to search load path of concrete beam, and apply to agricultural facilities. The ESO method is that make to discrete structure, structural analyze each element stress through FEM. And repeat generation with next material condition to become for most suitable composing. Individual element introduces concept of zero stiffness, but zero stiffness decisions are gone to direction of exclusion. In this stduy, improve algorithm to be convergence by `Rule of Alive or Die` in arrival because is most suitable. Also, existing terminal criterion lack consistency because that used depend on experience of researcher. This research procedure is fellowed. First, all modulus of elasticity assume a half of elasticity modulus of material, Second, structural analysis by FEM, Third, apply to the remove ratio and restoration ratio for the `rule of alive or die`. Forth, reconstruct the element and material conditions. And repeat the first to forth process. The terminal time of evolutional procedure is the all elastic modulus of element changed to blank value or elasticity modulus value of original. Therefore, in this study, consist the algorithm for programming, and apply to the agricultural facilities with concrete.

Reinforcing Effect of Thin-wall at Serviceability Condition

For the reasonable analysis of design problems for agricultural facilities, considered the reinforcing effect of thin-wall. The most of agricultural structure is constructed small scale and have many purposes. Thus it has been designed temporary rather than permanent structure, and has relatively large slenderness ratio, small section and semi-rigid condition. Therefore many agricultural facilities are consist of relatively strong frame with weak wall at the viewpoint of stiffness and have not been reflected in the design. But the tension field influences to collapse of structure have already known. Therefore, we need quantification the effect of tension field at structural analysis. In this study, present the method of quantification the effect of tension field that came out thin-plate surrounded by high stiffness frame. The numerical results show that the effect of tension field effect for thin-wall is about 5% of the sectional area of frame in study agricultural facilities.

Developing a Optimum Allocation system for Country of Renewable Energy Plant in Korea

To use renewable energy has been emphasized because being exhausted fossil fuel and fluctuation and increase petroleum price. The rural area needs to be collectivization and concentration of renewable energy plant for use renewable energy effectively due to the area of the rural village is small. So we needs to optimize the location of renewable energy plant. Growing economies of scale and becomes easier to manage because of change in the being regions. Thus, for economical and efficient use of energy is to optimize the location of the plant. The purpose of this study developing a system that decide most suitable location of the energy plant whether investigate the energy production latency amount and amount used of the village based on country unit.

Developing a Structural Design System base on load-path for Agricultural facilities using Alternative-ESO Technique

This research describe improved algorithm that is able to decide terminal criterion of Evolutionary Structural Optimization(ESO), reducing load of calculation to search load path of concrete beam, and apply to agricultural facilities.

Characteristics of Carbonation of Concrete using Infrared Image

The reinforced concrete structure has long life cycle but deteriorating for life time. The mainly reason of this phenomenon is accumulation of carbon dioxide. This study describes characteristics of carbonation among factors which shorten decline concrete of durability time. Generally, carbonation does not matter the concrete itself, but it makes of passivity films of reinforcing bar. The calcium carbonate is produced through carbonation of concrete. And this is bigger than calcium hydroxide volume, and molecular weight. So, the microstructure of concrete is hard and dense. The transition of void can be changed the temperature of concrete surface. Many experimental and theoretical studies of carbonation was conducted. This study introduce the infrared thermal technique to identify characteristics of carbonation and measure strength and deteriorating level by carbonation in concrete structures of agricultural improvement project using Infrared thermal technique and estimated the remaining life time.

Developing of the model to estimate concrete strength using Infrared thermography technique

The maintenance for concrete constructions has been emphasized and conducted using various equipments. The infrared methods are being used in many different places. Recently, infrared thermography technique is applied not only medical purpose but also non destruction testing for concrete structures. However Ir-NDT technique has been used only to evaluate internal defects for constructions. So, the method to estimate about concrete strength has to be developed.

Development and Assessment of Rural Ecological Backhouse

This research was focused on the new model and its utility value of environmental friendly backhouse that overcomes the weaknesses of traditional backhouse and modem backhouse. To develop the model, the characteristics, merits and demerits of backhouses and the effectives of additional materials were analyzed and the study result of Rhee etc.(2005) is based. The design drawing of an ecological backhouse was presented considering the sanitation, environment, economy, and utility among the merits of existing backhouses and it`s product showed. The new designed model is considered to conveniences in modern toilet and staff is used instead to water as it is suitable for additional material of night-soil. This product was established at farm house and it`s utility was proved. And a farmer easily are able to make this backhouse according it`s design drawing.

Design of Irrigation Facility using Evolutionary Structural Optimization

In order to determine the reinforcement location in the reinforced concrete irrigation facility, ESO method has been adopted. Reinforcing is located at tension part of load path. In this study, the load path of reinforced concrete member has been determined using ESO methods. Furthermore, using study methods, reinforcement problem has been considered. The ESO techniques is determined the reasonable load path which is traveling of load between in-flow and out-flow at a concrete structure using numerical analysis. And the results applied to the steel arrangement in reinforced concrete structures. The optimal algorithm, which determines the terminal criteria during ESO process, has been updated by using the obtained results. And the load path within the member has been determined automatically.

Estimation of Drought Rainfall by Regional Frequency Analysis Using L and LH-Moments (II) - On the method of LH-moments -

In the first part of this study, five homogeneous regions in view of topographical and geographically homogeneous aspects except Jeju and Ulreung islands in Korea were accomplished by K-means clustering method. A total of 57 rain gauges were used for the regional frequency analysis with minimum rainfall series for the consecutive durations. Generalized Extreme Value distribution was confirmed as an optimal one among applied distributions. Drought rainfalls following the return periods were estimated by at-site and regional frequency analysis using L-moments method. It was confirmed that the design drought rainfalls estimated by the regional frequency analysis were shown to be more appropriate than those by the at-site frequency analysis. In the second part of this study, LH-moment ratio diagram and the Kolmogorov-Smirnov test on the Gumbel (GUM), Generalized Extreme Value (GEV), Generalized Logistic (GLO) and Generalized Pareto (GPA) distributions were accomplished to get optimal probability distribution. Design drought rainfalls were estimated by both at-site and regional frequency analysis using LH-moments and GEV distribution, which was confirmed as an optimal one among applied distributions. Design rainfalls were estimated by at-site and regional frequency analysis using LH-moments, the observed and simulated data resulted from Monte Carlotechniques. Design drought rainfalls derived by regional frequency analysis using L1, L2, L3 and L4-moments (LH-moments) method have shown higher reliability than those of at-site frequency analysis in view of RRMSE (Relative Root-Mean-Square Error), RBIAS (Relative Bias) and RR (Relative Reduction) for the estimated design drought rainfalls. Relative efficiency were calculated for the judgment of relative merits and demerits for the design drought rainfalls derived by regional frequency analysis using L-moments and L1, L2, L3 and L4-moments applied in the first report and second report of this study, respectively. Consequently, design drought rainfalls derived by regional frequency analysis using L-moments were shown as more reliable than those using LH-moments. Finally, design drought rainfalls for the classified five homogeneous regions following the various consecutive durations were derived by regional frequency analysis using L-moments, which was confirmed as a more reliable method through this study. Maps for the design drought rainfalls for the classified five homogeneous regions following the various consecutive durations were accomplished by the method of inverse distance weight and Arc-View, which is one of GIS techniques.