• Tribology and Lubricants
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• v.13 no.1
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• pp.82-87
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• 1997

The modern orthopaedics frequently uses the total hip replacement in the artificial hip joint. The wear in this joint requires a re-replacement of hip joints because it is under the severe load and friction conditions. To solve these problems the previous studies have been mainly focussed on the development of new materials. The research of new materials, however, needs much time and effort since it should be experimented for its bio-compatibility, friction, and wear characteristics. To reduce the work, in this study, the finite element analysis is applied to find new combinations of bio-materials in the total hip replacement which has the excellent contact characteristics. A non-linear FEM program MARC with 5-node axisymmetric element was used for analyzing the contact stresses between the hip joints. The computed results show that in case of acetabulum UHMWP has good characteristics, in femoral head, $Al_2O_3$, and in stem, Ti6Al4V.

• Transactions of Materials Processing
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• v.19 no.3
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• pp.173-178
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• 2010

A die cast impeller blade has been developed in the effort on cost reduction in marine equipment industry. The purpose of this work is to optimize the die casting process using Taguchi's design of experiment for minimizing the internal defect of the die cast impeller blade. The experiments were preformed using the numerical simulation based on the L18 orthogonal array. As a results, the internal defect size of the die cast impeller blade for optimal design was controlled less than 1mm.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.2846-2859
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• 1994

This work deals with kinematic analysis of fault-tolerant 3 degree-of-freedom spherical modules which have force redundancies in its parallel structure. The performance of a redundantly actuated four-legged module with no actuator failure, a single actuator failure, partial and half failure of dual actuator are compared to that of a three-legged module, in terms of maximum force transmission ratio, isotropic characteristics, and fault-tolerant capability. Additionally, a system with an excess number of small floating actuators is considered, and the contribution of these small actuators to the force transmission and fault-tolerant capability is evaluated. This study illustrates that the redundant actuation mode allows significant saving of input actuation effort, and also delivers a fault tolerance.

• Journal of Photoscience
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• v.10 no.1
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• pp.1-7
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• 2003

The results of recent work on the dye-sensitized photooxygenation of sulfides is discussed. In the case of dialkyl sulfides, the weakly bonded adduct initially formed with singlet oxygen (the persulfoxide) decays unproductively unless protonation by an acid (an alcohol or a carboxylic acid) facilitates its conversion to the sulfoxide. The effect is proportional to the strength of the acid (eg., less than 0.1 % chloroacetic acid in benzene is sufficient for maximal efficiency) and corresponds to general acid catalysis, suggesting that protonation of the persulfoxide occurs. On the other hand, with sulfides possessing an activated hydrogen in ${\alpha}$ position (eg., benzyl and allyl sulfides), hydrogen transfer becomes an efficient process in aprotic media and yields a S-hydroperoxysulfoniumm ylide, possibly arising from a conformation of the persulfoxide that is different from the one protonated in the presence of acids. Calculations on some substituted sulfides support this hypothesis. This process, which leads to C-S bond fragmentation with formation of an aldehyde, may be viewed as a general method for the preparation of aryl and heteroaryl aldehydes. In this effort, mechanistic studies offered new hints on the structure of the intermediate persulfoxide.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.68-73
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• 2002

It is necessary first to understand dynamic characteristics of bus full BIW assembly for fatigue endurance analysis. FE model has been used usually for analyzing the dynamic behavior of structures. A lot of experience and effort, however, is necessary to make the credible FE model. Experimental modal analysis of structures has been performed to verify the credibility of initial FE model and to update the model. In this work, experimental modal analysis was performed to understand dynamic characteristics of bus full BIW assembly in free-free boundary condition and the result was used to verify the initial FE model. In addition, some practical techniques, which were used in this experiment, were mentioned.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.10a
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• pp.189-194
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• 1996

The modern orthopaedics frequently uses the total hip replacement in the artificial hip joint. The wear in this joint requires the re-replacement of the hip joint beacuse it is under the severe load and friction conditions. To solve these problems the previous studies have been mainly focused on the development of the new materials. The research of new material, however, needs much time and effort since it should be experimented for its bio-compatibility, friction, and wear characteristics. To reduce the work, in this study, the finite element analysis is applied to find the new combination of the materials in the total hip replacement which has the excellent contact characteristics. The finite element uses MARC and the 5-node aximetric element. The results show that in case of acetabulum UHMWP has good characteristics, in femoral head, the $Al_2O_3$, and in stem, Ti6Al4V.

• Journal of Korean Medical classics
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• v.31 no.1
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• pp.113-125
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• 2018

Objectives : The purpose of this paper is to investigate the educational meaning of Shanghanjiushilun in Shanghanlun education. Methods : The formal characteristics in medical records were compared between Shanghanjiushilun and the other 5 kinds of medical record books and the educational meaning was drawn by analysing medical records of Shanghanjiushilun a little more deeply. Resultss & Conclusions : 1. In a formal aspect, although Shanghanjiushilun is inferior to Liuduzhou's Clinical Medical Records Selection, it has merits in that it explains through quoting medical literature. 2. Xushuwei explained treatment based on syndrome differentiation in the new point of view in Shanghanjiushilun. 3. Through Shanghanjiushilun medical records Xushuwei's work to explain treatment based on syndrome differentiation in Shanghanlun in the new perspective is an effort to read medical classics to keep up with the times and has sufficient educational significance.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.460-465
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• 2001

Pollutant load using unit load method is calculated by simply equation, especially, very useful in the area that didn't exist about water quality data. However, it takes long time to calculate pollutant load with area in which there is various pollutants and if the boundary of a basin altered, the work of calculation about pollutant load must be begun from the first again. Therefore, a Total Daily Load Program(TDLP) was developed to calculate pollutant load automatically in rural area. The TDLP includes a geographic information system(GIS), relational database system(RDBS), User Interface. This Program can provide user with creating a boundary of the basin that user is concerned with to satisfy the water quality regulations and calculating daily load for various pollutants. The effort was conducted to apply the developed TDLP to calculating pollutant load in rural basin called Bok-ha river.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.4
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• pp.327-334
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• 2002

The work presents sensitivity and uncertainty analysis of 2-compartment model for the evaluation of indoor radon pollution in a house. Effort on the development of such model is directed towards the prediction of the generation and transfer of radon in indoor air released from groundwater. The model is used to estimate a quantitative daily human exposure through inhalation of such radon based on exposure scenarios. However, prediction from the model has uncertainty propagated from uncertainties in model parameters. In order to assess how model predictions are affected by the uncertainties of model inputs, the study performs a quantitative uncertainty analysis in conjunction with the developed model. An importance analysis is performed to rank input parameters with respect to their contribution to model prediction based on the uncertainty analysis. The results obtained from this study would be used to the evaluation of human risk by inhalation associated with the indoor pollution by radon released from groundwater.

• Journal of the Korean Society of Systems Engineering
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• v.5 no.2
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• pp.1-9
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• 2009

This paper proposes an effective method on the DFILS(Design for Integrated Logistics Support) in ammunition development applying QFD(Quality Function Deployment) method. The goal of this research is to define the Design for ILS approach at the start of the ammunition development and to yield a set of reusable requirements. Based on 000mm High-Explosive(Warship ammunition) development work, a QFD software tool, CUPID, was used to analyze and define the field force's requirements. Additionally, a set of reusable requirements are identified and defined for use during the Design for ILS development phase in the next-generation ammunition development process. These set of requirements that consider both the priority and importance of the VOC(Voice of Customer) will contribute to the early phase of the ammunition development to implement the Design for ILS specialty engineering effort.