鐵筋콘크리트 土留構造物의 最適化에 關한 硏究

崔洪植,邊根周,李相旻 연세대학교 산업기술연구소 1984 논문집 Vol.16 No.2

A mathematical model is formulated for the minimum cost design of reinforced concrete earth structures. The design variables are selected to be the depth and steel ratio in the retaining wall, and the depth, steel ratio and footing sizes in the isolated column footings. An elastic analysis is performed and resulting designs are based on both the ultimate strength theory and the elastic theory of concrete design. Constraint requirements are imposed to insure structural strength and side constraints. The resulting mathematical model is a nonlinear constrained optimization problem. The modified Lagrange Multiplier method is suggested as a satisfactory algorithm for the optimum design of the R.C. earth structures.

大學卒業定員制의 實施에 따른 學生生活 指導方案에 關한 硏究

崔根爀,張忠根,李相祐,張鎭吉,張大熙 충남대학교 1982 學生生活硏究 Vol.10 No.1

Higher education in Korea is faced with a new situation since 1981 when the government implemented a college graduation quota system designed to broaden the opportunities for higher education, alleviate the problem of the students who fail the entrance examination, and improve the quality of college graduates. The change of the system has brought about several serious problems including how to supply enough faculty members, how to provide enough educational facilities, and how to cope with the huge increase in the number of students, 30% more than graduation quota. The greatest single problem resulting from the implementation of college graduation quota system is the psychological and emotional unease aroused among the students, because 30% of those students with unsatisfying results must be banished from college before their graduation. This study aims to find effective measures for student guidance that each of the colleges can implement to help students adjust to the changed circumstances. After objectively investigating the problems from the various educational environments, from the recent students' views of college, and from the psychological and emotional unease arising in them by the fear of failing to graduate from their college because of implementation of the graduation quota system, a survey was conducted by means of a questionnaire composed of 40 questions and by means of personal interviews, 5,903 students, who are influenced by the graduation quota system, attending 19 public and private universities and colleges selected throughout the country. The data obtained from this survey were statistically processed with the help of the C. N. U. Computer Center, and the ratios of the responses to each of the questions were analyzed and calculated according to the distinctions of the total, sex, region, and major. The conclusions that the interrelations among the variant factors from each of the questions which were surveyed, analyzed and arranged have suggested are as follows : 1. The original purpose of graduation quota system should continually be clarified and communicated to all students and a concrete, specialized guidance system should be established to guide the minority of the students (13%) who don't fully understand the basic properties of higher educational institutions. 2. The institutions should provide enough educational facilities and supply enough faculty memebers to solve the problem of accomodating the large numbers of students. At the same time, they should suggest how students should learn positively and effectively to gain an expert knowledge, and how professors should gain public confidence in grade evaluation. Accompanying those measures, the government should develop a good policy to expand and distribute job opportunities to college graduates. 3. The admission quota should be controlled depending on the rate of naturally failed students, and then the students' unease and suppression caused by excessive competition can be relieved. In addition, it is advisable that the banished students should be allowed to transfer to University of the Air without regard to their grades. 4. An education devised to let students have a sound sense and way of thinking should be accompanied by a guidance system which their seniors, parents and society take part in. 5. An atmosphere conducive to sweet and well-rounded friendship among classmates should be created, sound extra-curricular activities should be encouraged and the number of students and adviser professor is in charge of should be lessened to a reasonable number.

2-Methylisoborneol(2-MIB)제거를 위한 산화 및 흡착공정의 특성

최근주,김상구,류동춘,신판세,손인식,오광중 한국환경과학회 2002 한국환경과학회지 Vol.11 No.3

One of the Musty and earthy smell compounds in raw water is generally attributed to 2-methylisoborneol (2-MIB). It is well known that activated carbon and oxidants such as O_3, ClO_2 are effective ways to control 2-MIB. In isotherm equilibrium experiments, 2-MIB in distilled water was much more adsorbed to the activated carbon(A/C) than raw water containing dissolved organic carbon (DOC). The Freundlich constants(k) of distilled water and raw water were 3.36 and 0.049, and 1/n values were 0.80 and 0.42, respectively. The 2-MIB residual rate were Y = e^(0.55_x)~ e^(-0.54_x) with Ozone(O_3) dose by 5 minutes contact time at the 241 and 353 ng/L initial concentrations. The 2-MIB residual rate were Y = e^(-0.32_X)~ e^(-0.35_X) with Chlorine dioxide(ClO_2) dose by 15 minutes contact time at the 89 and 249 ng/L initial concentrations. 2-MIB was decreased from 1911 ng/L to 569ng/L by post-ozonation(70%removal efficiency) and removal efficiencies of 2-MIB by the following 4 kinds Granular Activated Carbon(GAC) process such as coal base, coconut base, wood base and zeolite+carbon base were 95.8, 89.5, 88.4, and 93.7% respectively.

모드해석에서의 경계조건 영향

최연선,박근영,배성준 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.1

Modal analysis is a fundamental procedure to analyze the dynamic characteristics of structures or machines. Modal analysis is composed of theoretical modal analysis using finite element method and experimental modal analysis. The discrepancy between these two makes modal analysis difficult and ususally comes from misunderstandings on boundary conditions of the structure. Boundary condition effect in modal analysis is investigated theorectically and experimentally in this study for a rod and a beam. The result shows that boundary condition affects on lower modes, but can be ignored for higher modes. Boundary condition can be modeled by a spring and a damper having finite values. Using this spring and damper model, the boundary conditions of a theoretical modal analysis model can be corrected by comparing the results of experimental modal analysis.

우리나라 대학교 관광관련 전공 재학생의 교육기대수준에 관한 연구 : 6개 대학교 재학생을 중심으로 : 강릉대학교, 경주대학교, 세종대학교, 숙명여자대학교, 순천향대학교, 한양대학교

최영민,이성근 한국문화관광학회 2001 문화관광연구 Vol.3 No.2

The main aim of this paper is to examine education expectation level of students majoring culture and tourism at universities in Korea. From the previous studies, Authors drew three general factors of educations of students (knowledge/humanity/ professional way). This study identifies the relation between three education factors mentioned and education environment of students(year/ sex/ major operation system). The data were collected from survey questionnaires on six universities for 3 month from late March to early July 2001. The empirical test is focused on discovering following points; - the efficiency of actual education operation system of universities - the differences of education expectation according to different academic year/ sex - the comparison of characteristics related to education expectation of university students

學校 學習風土와 槪念化 樣式

崔尙根 西江大學校 生活相談室 1981 人間理解 Vol.3 No.-

한국인 정신분열병 환자에서 Endothelial Nitric Oxide Synthase 유전자의 다형성

최명수,정상근,조광현,김달식,황익근 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.1

기제와 피부투과촉진제가 아포모르핀의 피부투과에 미치는 영향

최영근,최옥,김건남,박은석,지상철 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.2

In order to evaluate the effects of vehicles and penetration enhancers on skin permeation of apomorphine, the skin permeation rates of apomorphine from vehicles of different composition were determined using Franz diffusion cells fitted with excised rat skins. Solubility of apomorphine in various solvents was investigated to select a vehicle suitable for the percutaneous absorption of apomorphine. The solvents used were propylene glycol (PG), Transcutol^??, Labrasol^??, Labrafac hydro WL^??, Labrafil WL 2609 BS^?? and isopropyl alcohol. Even though permeation rates of apomorphine from each vehicle were low (0.08-0.36㎍/㎠/hr), the combination of PG and Labrafac^?? increased it significantly. The permeation rates of apomophine from PG/Labrafac^?? mixtures increased as the volume fraction of PG in the mixture increased. The maximum permeation rate of 18㎍/㎠/hr was achieved at 30% of PG, which decreased with further increase of PG fraction. A series of fatty acids, alcohols and monoterpenes were employed as penetration enhancers. Incorporation of each enhancer in the PG/Labrafac^?? (30:70) mixture at the level of 10% improved the skin permeation significantly. The highest permeation rate, 117㎍/㎠/hr, was attained with myristic acid.

돼지 신장세포(PK15)의 이종이식 거부반응에 대한 재조합 IL-18의 영향

최연실,김은미,김영관,박상연,심정현,윤도영,강형식,명평근 충남대학교 생물공학연구소 2004 생물공학연구지 Vol.10 No.1

Various cytokines including IL-1β, IL-2, IL-4, IL-10, IL-12p40, IFN-γ, and TNF-α have been recently reported to play important roles in both host and donor cell activations during xenotransplantation. Interleukin (IL)-18, a proinflammatory cytokine, can induce IL-4 and IL-13 production in T cells, NK cells, B cells, mast cells, and basophils. IL-18 has the capacity to stimulate innate immunity and both Th1-and Th2- mediated responses, but little is known to involve in the xenograft rejection. In order to investigate the role of IL-18 in xenograft rejection, we transplanted the pig kidney (PK15) cells to C57BL/6 mouse with or without intraperitoneal injection of mouse recombinatant IL-18. It was analyzed the population of T cell, B cell and NK cell in the mice transplanted with PK 15 cells and recombinant IL-18 by flow cytometry. We found that splenic CD3+ T cells were increased in mice injected PK15 cells with recombinant IL-18. These results suggest that recombinant IL-18 is critical in the xenograft rejection by increasing T cell population of the recipients.

흡착특성이 다른 내분비계 장애물질 3종, Amitrol, Nonylphenol, Bisphenol-A의 GACs에서의 흡착 특성

최근주,김상구,권기원,지용대,김승현,김창원 한국물환경학회 2004 한국물환경학회지 Vol.20 No.3

Adsorption characteristics of three endocrine disruptors, amitrol, nonylphenol, and bisphenol-A, were evaluated depending on the type and service duration of activated carbon (AC). Bituminous coal-, wood-, and coconut-based coals were tested. Bituminous coal-based AC (BCAC) had the greatest sorption capacity for the three chemicals tested, followed by wood-based AC (WAC) for nonylphenol and coconut palm-based AC (CAC) for bisphenol-A. During the column test, amitrol removal efficiency increased over time, indicating that hydrophilic endocrine disruptors are biodegraded in the AC column. Removal efficiencies of hydrophobic compounds such as nonylphenol and bisphenol-A decreased over time since the main removal mechanism was adsorption. The order of the amitrol removal was: BCAC-5.9 yr , CAC-3.1 yr > BCAC-2.2 yr > BCAC-virgin > CAC-virgin > WAC-virgin > WAC-3.1 yr. In general, used AC had greater removals than virgin AC. The order of the bisphenol-A removal was: CAC-virgin > BCAC-2.2 yr > CAC-3.1 yr > WAC-virgin > BCAC-5.9 yr > WAC-3.1 yr. The order of the nonylphenol removal was: BCAC-virgin > WAC-virgin > CAC-3.1 yr ,WAC-3.lyr> BCAC-2.2 yr > BCAC-5.9 yr > CAC-3.1 yr. Bituminous coal AC performed the best over time. Endocrine disruptors such as these three compounds appear to be removed effectively by activated carbon through biodegradation and adsorption. Wood and coal based among the virgin ACs and 3.1 years used wood base among the used ACs appeared the lowest carbon usage rate(CUR) for nonylphenol removal by prediction model. Virgin and used coconut base ACs except BCAC had the lowest CUR for removal Bisphenol-A. Biodegradation of nonylphenol and Bisphenol-A did not occurred during the 9,800 bed volume experiment period. BCAC had the highest biodegradation capacity of 46% for amitrol among virgin ACs and the used coal based ACs had 33-44% higher biodegradation capacity than virgin's for amitrol so biodegradation is the effective removal technology for hydrophilic material such as amitrol.