• Korean Medical Education Review
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• v.16 no.3
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• pp.111-118
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• 2014

Over the last century, medical education in North America has evolved by identifying educational challenges within its own socio-cultural context and by appropriately responding to these challenges. A discipline-based curriculum, organ-system or integrated curriculum, problem-based curriculum, and competency-based curriculum are historical examples of the educational solutions that have been developed and refined to address specific educational challenges, such as students' lack of basic scientific knowledge, lack of integration between scientific knowledge and clinical practice, and lack of clinical practice. In contrast, Korean medical education has evolved with the influence of two forces: (1) the adoption of educational solutions developed in North America by pioneers who have identified urgent needs for medical education reform in Korea over the last three decades, and (2) the revitalization of Korean medical schools' curricula through medical education accreditation and national medical licensing examination. Despite this progressive evolution in Korean medical education, we contend that it faces two major challenges in order to advance to the next level. First, Korean medical education should identify its own problems in medical education and iteratively develop educational solutions within its own socio-cultural context. Secondly, to raise reflective doctors who have scientific knowledge and professional commitment to deal with different types of medical problems within a continuum from well-defined to ill-defined, medical education should develop innovative ways to provide students with a balanced spectrum of clinical problems, including uncertain, ill-defined problems.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.9
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• pp.1317-1324
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• 1998

In general, DI gasoline engine has the advantages of higher power output, higher thermal efficiency, higher EGR tolerance and lower emissions due to the operation characteristics of increased volumetric efficiency, compression ratio and ultra-lean combustion scheme. In order to apply the concept of stratified charge into direct injection gasoline engine, some kinds of methodologies have been adapted in various papers. In this study, a reflector was adapted around the injector nozzle to apply the concept of stratified charge combustion which leads the air-fuel mixture to be rich near spark plug. Therefore, the mixture near the spark plug is locally rich to ignite while the lean mixture is wholly introduced into the combustion chamber. The characteristics of combustion is analyzed with the variations of fuel injection pressure and load in a stratified -charge direct injection single cylinder gasoline engine. The obtained results are summarized as follows ; 1. The MBT spark timing approached to TDC with the increase of load on account of the increase of evaporation energy, but has little relation with fuel injection pressure. 2. The stratification effects are apparent with the increase of injection pressure. It is considered by the development of secondary diffusive combustion and the increase of heat release of same region, but proceed rapidly than diesel engine. Especially, in the case of high pressure injection (l70bar) and high load (3.0kgf m), the diffusive combustion parts are developed excessively and results in the decrease of peak pressure than in the case of middle load. 3. The index of engine stability, COVimep value, is drastically decreased with the increase of load. 4. To get better performance of DI gasoline engine development, staged optimizaion must be needed such as injection pressure, reflector, intake swirl, injection timing, chamber shape, ignition system and so on. In this study, the I50bar injection pressure is appeared as the optimum.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2181-2185
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• 2008

Fuel processing systems which convert HC fuel into $H_2$ rich gas (such as stream reforming, partial oxidation, auto-thermal reforming) need high temperature environment($600-1000^{\circ}C$). Generally, anode-off gas or mixture of anode-off gas and LNG is used as input gas of fuel reformer. In order to make efficient and low emission burner system for fuel reformer, it is necessary to elucidate the combustion and emission characteristic of fuel reformer burner. The purpose of this study is to develop a porous premixed flat ceramic burner that can be used for 1-5kW fuel cell reformer. Ceramic burner experiments using natural gas, hydrogen gas, anode off gas were carried out respectively to investigate the flame characteristics by heating capacity and equivalence ratio. Results show that the stable flat flames can be established for natural gas, hydrogen gas, anode off gas and mixture of natural & anode off gas as reformer fuel. For all of fuels, their burning velocities become smaller as the equivalence ratio goes to the lean mixture ratio, and a lift-off occurs at lean limit. Flame length in hydrogen and anode off gas became longer with increasing the heat capacity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.30-43
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• 2015

The purpose of this study is to figure out current situation of safety education to improve safety awareness and practice in Korean school students. In order to do this, it is necessary to identify the current level of safety awareness and practice with the actual status of accident occurrence. Furthermore it is try to figure out the most influencing factors on the safety education for Korean middle and high school students. The 412 students were taken from a random sample. The samples were one class of 2nd grade students in five different middle schools and four different high schools in Seoul, Korea. The survey was conducted from 29 September 2010 through 15 October 2010. An additional samples for the questionnaires posted in web were collected. The 305 respondents from school students and 80 respondents from web survey were used to analyze for this study out of 800 respondents. SPSS was used to analyze the questionnaires. The overall safety-awareness score was relatively high at 4.56/5 for fire safety and 4.32/5 for traffic safety. Safety awareness was higher for girls than boys and also for high school students than middle school students. Safety education by parents at home gives a good impact on high safety practices. Safety awareness was improved by feeling of necessity for safety training. The safety prevention training provided during the class by teacher and home training by parents improved safety practice. The correct direction of safety education for younger students can be easier in future.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.1
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• pp.121-131
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• 2010

Technological innovation depends on the quality of workers, whose ability is the key component to raise business competitiveness. Our study evaluates how satisfactory is the training of workers at small and medium sized firms, and suggest how to improve upon it. We show the theoretical framework for the relation between customer satisfaction and their behavioral intent on the one side, and factors of training service quality. Our result show: (1) Factors affecting customer satisfaction are, in descending order of importance, expertise, policy, follow-up service, attitude and behavior, and convenience. (2) Contrary to established views on the service quality, satisfaction for training would not be the prerequisite variable for intent to act, in case of training service quality. (3) Satisfaction level for training depends on the type of organization in charge of training (government, university, or private sector.) It also varied among different types of business (L-type, A-type, and J-type.) Small and medium sized firms find it difficult to commit to training education due to lack of money and manpower. The recent expansion of free training service would address part of this problem. On the other hand, the outfit in charge of training could boost service quality by customizing their training program to the type of business they cater to.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.251-267
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• 1991

Plastic strength analysis using plastic failure mode as a limit state is adopted instead of a conventional elastic structural analysis to predict the ultimate strength of Web frame idealized by a plane frame. Linear programming arid Compact procedure are developed for determining the collapse load factor. It is found that the final results are good agreement with the results of Elasto-plastic analysis. Besides, the redundant structures like Web frame is known to have multiple failure modes. Web frame may collapse under any of the possible failure modes. Thus, the identification of these possible failure modes is necessary and very important in the reliability analysis of Web frame. In order to deal with multiple failure modes, automatic generation method of all failure modes and basic failure modes is used for selecting the dominant failure modes. The probability of failure pastic collapse of Web frame is calculated using these dominant failure modes. The safety of Web frame is asscssed and compared by performing the deterministic and probabilistic analysis.

• Journal of the Korea Safety Management & Science
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• v.12 no.2
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• pp.183-192
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• 2010

Korean logistics industry have been focused on transportation business. However, with the expansion of the electronic commerce and on-line shopping, delivery service is now dramatically growing. Despite the expansion of logistics market, the domestic logistics industry have significant structural problems such as low productivity comparing with the advanced countries, relatively high cost and shortage of human resources and lack of professionalism of people in the industry. Logistics companies reallocate employees, use subcontractors, expand consignment and training the employees to overcome the labor shortages but it has some limits. In recognition of the importance of labor in the logistics industry, financial support and investment have increased. Logistics companies tend to hire consultants, set up logistics department or R&D center in order to establish highly productive logistics process and system so it is viewed that there will be considerable demands of human resources in the logistics industry. This study indicates implications and development direction of human resources in the logistics industry by looking into prospect and characteristic of the industry, employment status, training programs and qualification requirements.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.1-8
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• 1999

In order to study the implantation mechanism various methods for culture of endometrial cells in vitro have been attempted. However, a disadvantage is that primary cultures of stromal and epithelial cells do not have the ability to differentiate, and therefore cannot be reproduced in the same manner as in vivo endometrium. The object of this study is to establish a three dimensional culture of endometrial cells which are both morphologically and functionally identical to in vivo endometrium. Endometrial tissues obtained after hysterectomies were cut into thin slices and treated with collagenase and trypsin-EDTA. The stromal cells and the epithelial cells were separated by centrifugation and cultured for 24 hours in DMEM media containing 10% FCS, 100 nM progesterone, and 1 nM estradiol. The cultured stromal cells were mixed with collagen gel and solidified, after which it was covered with matrigel. Epithelial cells were inoculated on the top and then cultured for 3 days. The three dimensionally cultured endometrial cells were stained for integrin ${\alpha}1,\;{\alpha}4,\;{\beta}3$, and cyclooxygenase-l, -2 by immunohistochemistry, which all showed strong expression. The cultured epithelial cells showed the formation of microvilli, tight junctions and pinopodes by electron microscopy. Studies are currently under way utilizing this three dimensional culture model to ascertain the interaction between the embryo and human endometrial cells at the time of implantation, and it is thought that further studies into a new culture environment which would allow longer periods of culture will be necessary.

• YAKHAK HOEJI
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• v.55 no.4
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• pp.277-283
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• 2011

Simultaneous monitoring of catecholamines and serotonin with their appropriate extraction from the biological samples is required in order to understand thoroughly the regulation of the central and peripheral nervous system. In the present research the segmented gradient elution with the solid phase extraction using a C18 cartridge rather than the previous isocratic elution with alumina extraction is successfully employed to determine norepinephrine (NE), epinephrine (E), dopamine (DA), serotonin (5HT), 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5HIAA) simultaneously within 20 minutes using 3,4-dihydroxyhydrocinnamic aicd as the internal standard (IS). Linearities were obtained in the concentration range between $5{\times}10^{-6}M$ and $1{\times}10^{-4}M$ for all 7 compounds with detection limits of 0.6~1.9 ${\mu}M$. The present HPLC/ECD method yielded reasonable accuracy (relative error; -1.4~1.1%) and precision (relative standard deviation; 0.4~1.9%) for 9 measurements of the standard solution consisting of NE, E, DA, 5HT, DOPAC and 5HIAA compounds. Recoveries of catecholamines, serotonin and their metabolites from human serum were in the range of 57%~86%. While the concentrations of NE and 5HT in the serum of normal Sprague-Dawley rat were found as $1.4{\times}10^{-6}M$ and $2.6{\times}10^{-6}M$, respectively, the contents of NE and 5HT in the serum of the stressed rat were increased 5.6 times and 1.4 times more, respectively.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.2
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• pp.270-287
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• 2015

According to the increase of the operating cost and material cost of a ship due to the change of international oil price, a demand for the lightening of the ship weight is being made from various parties such as shipping companies, ship owners, and shipyards. To satisfy such demand, many studies for a light ship are being made. As one of them, an optimal design method of an existing hull structure, that is, a method for lightening the ship weight based on the optimization technique was proposed in this study. For this, we selected a hatch cover of a bulk carrier as an optimization target and formulated an optimization problem in order to determine optimal principal dimensions of the hatch cover for lightening the bulk carrier. Some dimensions representing the shape of the hatch cover were selected as design variables and some design considerations related to the maximum stress, maximum deflection, and geometry of the hatch cover were selected as constraints. In addition, the minimization of the weight of the hatch cover was selected as an objective function. To solve this optimization problem, we developed an optimization program based on the Sequential Quadratic Programming (SQP) using C++ programming language. To evaluate the applicability of the developed program, it was applied to a problem for finding optimal principal dimensions of the hatch cover of a deadweight 180,000 ton bulk carrier. The result shows that the developed program can decrease the hatch cover's weight by about 8.5%. Thus, this study will be able to contribute to make energy saving and environment-friendly ship in shipyard.