WWW상에서 VRML을 이용한 STEP 제품형상 정보 공유 시스템에 대한 연구 및 개발

김남국 서울대학교 대학원 1997 국내석사

朝鮮朝 內丹修鍊思想의 展開樣相에 대한 硏究

김남국 서울대학교 대학원 1999 국내석사

이차원전기영동법을 이용한 white muscle과 red muscle간의 단백질 발현양상에 대한 비교연구

김남국 건국대학교 대학원 2004 국내석사

A learning approach to asymptotic tracking in non-minimum phase nonlinear systems : 비최소위상 비선형 시스템의 점근적 추종을 위한 학습방식

김남국 서울大學校 大學院 2000 국내박사

에머지 분석을 이용한 국토의 환경용량 산정 및 지속가능성 평가

김남국 광운대학교 대학원 2016 국내박사

본 연구는 자연생태계에서 일어나는 에너지 및 물질의 흐름과 사회 및 경제와의 상호관계를 파악하는 에머지(Emergy) 분석을 이용하여 국토를 구성하는 자연환경과 경제시스템과의 상호작용을 규명하고, 국토환경용량과 지속성을 평가하는데 주안점을 두었다. 이를 통해 지속가능한 국토의 이용 및 관리 정책을 마련하는데 기여하고자 하였다. 국토의 환경용량 산정 및 지속성 평가를 위한 에머지 분석의 시간적 경계설정은 2003, 2008년 및 2013년을 기준으로 하였으며, 공간적 범위로는 대한민국 영토 전체를 설정하였다. 에머지 분석을 이용하여 국토의 환경용량과 지속가능성을 평가한 결과, 국토내에서 이루어지고 있는 경제활동이 자연환경에 부정적인 부담을 주고 있으며, 국토내부의 자연자원보다는 외부와의 교역에 기초한 외부 경제에 크게 의존하였다. 또한 현재 인구활동의 규모가 국토의 자연환경과 경제활동이 유지할 수 있는 인구수용력에 비해 과다하여 이를 해소하기 위하여 외부로부터 많은 양의 에머지가 유입되고 있는 것으로 파악되었다. 그러나 이와 같은 과다한 에머지 유입은 오히려 환경압박의 부담을 가중시켜 지속가능한 국토의 이용을 오히려 더 힘들게 하는 것으로 평가되었다. 따라서, 국토의 지속가능한 개발을 위해서는 환경용량에 기초한 국토계획정책과 국토의 수용능력의 한계를 파악하여 환경용량을 확대할 수 있는 정책개발이 요구된다. This study identified the interaction between natural environment that make up the national land and economic systems and assessed the sustainability and environmental capacity using the emergy analysis to identify the interrelationships between the flow of energy and substance occurring in natural ecosystems and the social and economic systems. This was to contribute to the provision of sustainable land use and management policies. Emergy analysis of temporal demarcation of land for environmental sustainability and capacity assessment was based on the years 2003, 2008 and 2013, the spatial range was set for the whole territory of the Republic of Korea. By using emergy analysis evaluating the sustainability and environmental capacity of the country shows that the economic activity that takes place in homeland gives a negative burden on the natural environment and relies greatly on the external economy based on trade with the outside world rather than natural resources of the country inside. It is also found that a large amount of emergy from the outside is introduced to solve the problem that the current size of the active population is excessive compared to the population carrying capacity of the land to sustain the natural environment and economic activities. But this is rather like entering a plethora emergy was evaluated by weighting the use of the land available to sustain the burden of environmental pressures rather more difficult. Thus, identifying the limits of the carrying capacity of the land development planning policy based on environmental capacity to expand the environmental capacity is required for the sustainable development of the country.

국가 대표 태권도 선수와 태권도 전공자들의 면역기능차이 비교

김남국 용인대학교 2007 국내석사

강도 높은 훈련을 실시하는 태권도 국가대표 선수와 규칙적인 운동을 실시하는 태권도 전공자를 대상으로 면역력에 어떠한 차이를 보이는가를 규명하기 위해 국가대표 태권도 선수 10명과 태권도 전공자 10명으로 총 20명을 대상으로 면역호르몬과 면역글로빈을 검사하여 다음과 같은 결론을 얻었다. 첫째, 면역호르몬의 GH와 IGF-1는 강도 높은 훈련을 실시하는 국가 대표선수가 높게 나타났으며, 통계적으로 유의한 차이는 없었고, Insulin은 국가대표 선수가 낮아, 규칙적인 태권도 훈련을 실시하는 것이 면역력이 높은 것으로 나타났으며, 통계적으로도 유의한 차이를 보였다. 둘째, 면역글로빈의 IgM, IgG는 규칙적인 훈련을 실시하는 태권도 전공자가 나타났으며, IgA는 국가대표선수가 높게 나타났다. 그러나 통계적으로는 유의한 차이를 발견할 수 없었다. This study examines differences in immunologic function targeting Taekwondo national athletes who undergo high-strength training and regular Taekwondo practitioners who majored Taekwondo. A total of 20 subjects are chosen from comparison groups: 10 Taekwondo national athletes and 10 regular Taekwondo practitioners. The results of the study are summarized as follows after testing immunologic hormone and immunoglobin. First, GH and IGF-1 of immunologic hormone show higher from national athletes who undergo high-strength training, which has no statistically significant difference. As for insulin, when practitioners practice regular Taekwondo trainings, immunity shows higher, which shows statistically significant difference. Second, IgM and IgG of immunoglobin show from regular Taekwondo practitioners who majored Taekwondo. IgA shows higher from national athletes. However, we found no statistically significant difference.

밀폐사이클을 적용한 LNG 연료탱크의 단열 특성연구

김남국 한국해양대학교 대학원 2017 국내석사

Recently the LNG(liquefied natural gas) public buses and LNG-fueled container trucks have been introduced to prevent the air pollution in metropolitan areas. As the LNG temperature in fuel tank is as low as -162℃, the thermal and structural effects of tank components need to be studied in order to keep liquid phase as long as possible by reducing heat leakage from outside ambient. The LNG for buses is stored in horizontal tank that is insulated with Mylar sheet and high vacuum between annular space of double-walled tanks. As the stored cryogenic liquid evaporates over 6.0% daily by the present insulation system, more efficient storage tank, that can reduce the evaporation rate, might be newly required. This research invented new triple tanks, that has middle tank having closed-cycle insulation filled with R134a refrigerant which evaporated by absorbing intake heat from ambient prior to LNG evaporation. The heat transfer rate and temperature distribution of tank body and support system were evaluated by FLUENT, and the thermal stress and strain were analysed using ANSYS. The results showed that the rate of heat transfer from outer vessel to inner one was reduced significantly compared with the common double tank having super insulation only. By the experimental evaluation, it showed that the evaporation rate of liquid nitrogen was 2.54% per day, whereas the national approval law for LNG fuel tank regulated the evaporation rate of 6.0% or below. New developed tank could be highly efficient LNG storage tank for vehicles and would help LNG fuel system safe.

청소년소비자의 스트레스와 인터넷 중독행동에 관한 연구

김남국 충남대학교 교육대학원 2002 국내석사

The purpose of this study is to identify seriously-discussed Internet addiction and to search its relations with stress, influential social factors. Besides, to examine Internet consumption behavior and life change through Internet addiction. The objectives of research are as follows: 1) to examine general tendency of Internet addiction and stress according to demographic variables. 2) to investigate the differences of Internet addiction according to stress, attitude toward Internet, demographic variables. 3) to investigate the correlations among variables influencing Internet addiction tendency. 4) to identify the correlation between Internet addiction and its consumption patterns and life changes. In this research, 420 male and female students of middle and high school in Busan were selected. The statistics methods used for data analysis were frequency, percentage, mean, standard deviation, factor analysis, one-way ANOVA, T-test, Chi-Squre, multipul regression analysis using SAS program. The research results are summarized as follows: first, 60.95% of respondents were normal users, and lightly addicted users of 34.76%, seriously addicted, 4.29%. So over 40% of respondents were lightly or seriously addicted. Second, total level of stress was 2.40 of 5, relatively low, but among stress sub-factors(appearance, heterosexual friend, parents attitude, family&economy, school grade, school life), school grade and school life factors were little high, each 3.43, 2.54. Considering socio-demographic variable, the level of stress was shown higher in female students than male by appearance and total stress factor, students of middle school graduate mothers by appearance and total stress, students of working class fathers by family and economy, low school grade students by school grade and school life, students of large allowance by heterosexual friends, students perceiving short of allowance by 6 factors and total stress. Third, In three group of stress factors(high, middle, low), group experienced high stress in appearance, school grade, school life factors showed high addiction score. Fourth, Relation between optimistic or negative attitude toward Internet and Internet addiction were studied in three group(high, middle, low) of optimistic or negative. Highly optimistic or negative attitude group toward Internet showed high addiction. Therefore, there was two-sides of Internet Attitude aspect impacting on Internet consumption behavior. Fifth, Considering Internet addiction tendency according to socio-demographic variable, students having large amount of allowance, perceiving short of allowance showed high Internet addiction. Sixth, Influential power according to Internet addiction was shown in order such as appearance(β=2.52), optimistic attitude toward internet(β=7.47), heterosexual friends(β=1.89). Seventh, There was drastic difference between normal Internet users and serious ones in view of Internet consumption addiction behavior. serious users spent more time in all week long and over 3 hours a day than normal users. Lastly, Lack of communication, bedtime, study time changed life style and other activities time like exercise, eating, playing with friends also have reduced in serious users. Based on these findings, some conclusions are as follows: First of all, stress of adolescent students are closely related with Internet addiction tendency. So it is necessary to make them open communication and part in various programs. some good activities as hobby in Internet joining all family members should be developed, including exact prognosis and protection from Internet addiction. The purpose of this study is to identify seriously-discussed Internet addiction and to search its relations with stress, influential social factors. Besides, to examine Internet consumption behavior and life change through Internet addiction. The objectives of research are as follows: 1) to examine general tendency of Internet addiction and stress according to demographic variables. 2) to investigate the differences of Internet addiction according to stress, attitude toward Internet, demographic variables. 3) to investigate the correlations among variables influencing Internet addiction tendency. 4) to identify the correlation between Internet addiction and its consumption patterns and life changes. In this research, 420 male and female students of middle and high school in Busan were selected. The statistics methods used for data analysis were frequency, percentage, mean, standard deviation, factor analysis, one-way ANOVA, T-test, Chi-Squre, multipul regression analysis using SAS program. The research results are summarized as follows: first, 60.95% of respondents were normal users, and lightly addicted users of 34.76%, seriously addicted, 4.29%. So over 40% of respondents were lightly or seriously addicted. Second, total level of stress was 2.40 of 5, relatively low, but among stress sub-factors(appearance, heterosexual friend, parents attitude, family&economy, school grade, school life), school grade and school life factors were little high, each 3.43, 2.54. Considering socio-demographic variable, the level of stress was shown higher in female students than male by appearance and total stress factor, students of middle school graduate mothers by appearance and total stress, students of working class fathers by family and economy, low school grade students by school grade and school life, students of large allowance by heterosexual friends, students perceiving short of allowance by 6 factors and total stress. Third, In three group of stress factors(high, middle, low), group experienced high stress in appearance, school grade, school life factors showed high addiction score. Fourth, Relation between optimistic or negative attitude toward Internet and Internet addiction were studied in three group(high, middle, low) of optimistic or negative. Highly optimistic or negative attitude group toward Internet showed high addiction. Therefore, there was two-sides of Internet Attitude aspect impacting on Internet consumption behavior. Fifth, Considering Internet addiction tendency according to socio-demographic variable, students having large amount of allowance, perceiving short of allowance showed high Internet addiction. Sixth, Influential power according to Internet addiction was shown in order such as appearance(β=2.52), optimistic attitude toward internet(β=7.47), heterosexual friends(β=1.89). Seventh, There was drastic difference between normal Internet users and serious ones in view of Internet consumption addiction behavior. serious users spent more time in all week long and over 3 hours a day than normal users. Lastly, Lack of communication, bedtime, study time changed life style and other activities time like exercise, eating, playing with friends also have reduced in serious users. Based on these findings, some conclusions are as follows: First of all, stress of adolescent students are closely related with Internet addiction tendency. So it is necessary to make them open communication and part in various programs. some good activities as hobby in Internet joining all family members should be developed, including exact prognosis and protection from Internet addiction.

광 직교코딩 시뮬레이션에 의한 지연선-광CDMA 시스템의 해석

김남국 慶熙大學校 2000 국내석사

In this paper, we would like to introduce the performance analysis of Delay Line-Optical CDMA system which is applied Optical Orthogonal Coding simulation, utilized the merits of optic fiber with low loss of transmission and wide frequence. In order to perform Delay Line-Optical CDMA system, we use Laser Diode to convert data signal to optical signal and encode optical signal to optical pulse sequences utilizing the structure of Optical Fiber Delay Line. At the receiver, we recover data with Autocorrelation property if they are equal to the structures of Optical Fiber Delay Line trasmission and Optical Fiber Delay Line receiver and can not recover data with Crosscorrelation property if they are different. Therefore, we simulate the Optical Orthogonal Code which is applied the algorithm with tree structure in order to decide the Optic Fiber Delay Line having the optimized Autocorrelation and Crosscorrelation property. After that, using the result of simulation, encoders and decoders of 2 stage and 4stage are composed. Increasing the number of users, we obtain the increased optimal condition value which is the ration of maximum peak of Autocorrelation porperty to maximum peak of Crosscorrelation property. so, If the critical value is set incorrectly, the data are not recovered. In order to overcome such results, if we are consist of the encoder and decoder utilizing optimized Optical Orthogonal Codes, although the maximum peak value of Crosscorrelation property is increased, the optimal condition value is decreased. So the critical value can be set diversely. Therefore, the probability of error decreases and it is efficient to recover data. Consequently, based on results of simulation, the technology of Delay-Line CDMA using Optical Orthogonal Coding can be applied to the Optical network fields of Optical LAN and Optical ATM.

애니메이션 技法을 活用한 2次元 流動의 數値模擬

김남국 濟州大學校 大學院 2001 국내석사

The SMAC(Simplified Marker And Cell) method is, one of the numerical simulation techniques for the fluid flows with free surfaces, modified from the original MAC(Marker And Cell) method for the time-dependent variation of fluid flows. Fundamentally, the SMAC method is a scheme that solves the continuity equation and the Navier-Stokes(N-S) equation of the fluid by the finite-difference method, with the forward differencing in time and centered differencing in space(FTCS) for the difference of the viscous term and the convective term. In this study, the difference of the convective term used Donor-Cell method. Although it is very important to evaluate exactly the convective term so as to calculate the accuracy of the turbulent fluid motions, this requires a very small grid interval and time step. In the SMAC method, the analytical region is divided into minute elements, and the fluid region is judged by marker particles according to how they were arranged beforehand. Several different cells can be distinguished: the cell without a marker(empty cell), the cell which touches empty cells(surface cell), the cell which is filled with a fluid(full cell), and the cell which is the obstacle(obstacle cell). In this study, numerical simulation of the two-dimensionaI fluid flows are carried out by modified SMAC method, and simulation results compared Martin-Moyce's experimental data and result of the MPS(Moving-Particle Semi-implicit) method. Simulation results are expressed the form of visual information with plots of marker particle configurations and velocity vectors. The particle configuration plot are made bye plotting the x and y coordinates of all the marker particles, and by drawing the boundaries. But particle plots don't convey complete information on all flow details. The velocity vector plots show the direction of flow and provide a feeling for the magnitude of the velocities in relation to each other. For every full cell or surface cell in system, a vector is drawn originating at the Cell center, with a length proportional to the velocity at the cell center. In addition to the marker particle and velocity vector plots, motion pictures are made by the animation technique. The motion pictures are created from still pictures of marker particle configurations. In this study, two types among several animation formats are used. One is the GIF(Graphic Interchange File) animation format, the other is the AVI(Audio Video interleave) format. The motion pictures provide a feeling for the nature of the flow that a still picture often cannot transmit. Animation techniques are considered one of the very useful demonstration techniques in the field of CFD(Computational Fluid Dynamics).