• Corrosion Science and Technology
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• 제21권6호
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• pp.476-486
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• 2022

Recently, aluminum 6061 instead of copper alloy is used for cooling heat exchangers used in the internal combustion of engines due to its economic feasibility, lightweight, and excellent thermal conductivity. In this study, aluminum 6061 alloy was anodized with oxalic acid, phosphoric acid, or chromic acid as an anodizing electrolyte at the same concentration of 0.3 M. After the third anodization, FDTS, a material with low surface energy, was coated to compare hydrophobic properties and anti-icing characteristics. Aluminum was converted into an anodization film after anodization on the surface, which was confirmed through Energy Dispersive X-ray Spectroscopy (EDS). Pore distance, interpore distance, anodization film thickness, and solid fraction were measured with a Field Emission Scanning Electron Microscope (FESEM). For anti-icing, hydrophobic surfaces were anodized with oxalic acid, phosphoric acid, or chromic acid solution. The sample anodized in oxalic acid had the lowest solid fraction. It had the highest contact angle for water droplets and the lowest contact hysteresis angle. The anti-icing contact angle showed a tendency to decrease for specimens in all solutions.

• Journal of Preventive Medicine and Public Health
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• 제9권1호
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• pp.11-24
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• 1976

This study was a part of large scale of a prospective study on attitudes of professional students in medicine, nursing and teaching toward population related issues in Korea. The study was first conducted in May 1974 and then in May 1975 for the 1974 class cohot using a questionaire consisted of attitude scales and other items developed by Lee. The purpose of stuay was twohold, namely, to determine the difference in students among specializations on one hand and between the first and second years in the 1974 class cohot regarding tile subject matter. A one-way analysis of variance was used for attitude scale, and absolute and relative frequency were computed for the analysis of non-attitude scale items by employing Fishers' Ratio and Duncan's multiple range test at 5% level and chi square test at 5% level as significance tests. The hypothesis 'students in health profession are more likely to have positive attitudes toward population related issues progressively as class year advances than students in teaching profession' was tested and the following results were obtained: 1) Nursing students were more likely to display favarable attitudes toward family planning than medical or teaching students although the class cohot showed slightly negative improvement in the second year. Medical and teaching students apperaed to have slightly improved attitudes in the second year. 2) Respondents in general perceived national family planning program as a means of population control and this tendency was more true among nursing students as the class year advances than two other professional groups of students. Students in teaching profession appeared to perceive it more as a means to improve individual family welfare while health students were likely to see as to improve maternal and child health. This tendency was progressively improved as the class year advanced. 3) The majority of students regardless of their respective specializations believed that family planning program should be directed toward the improvement of individual family welfare. No progressive changes in the class cohot were observed. 4) About the plan to use contraceptives in future, no singnificant differences were observes among different specializations nor in different class years. However, the majority was confirmed to have a plan to use contracepives in future. An increasing proportion of the undecided category was observed, as class year advanced among health students. 5) Students in health profession were found to be more favorable about 'more leisure opportunities' as motive for limiting number of children whereas education students indicated the reasons as 'facilitate ambitions' and 'economic base' The progressive changes toward positive direction in both groups were observed as the class years advanced. 6) Attitudes toward induced abortions of the health students were observed to be positively related to class years while an inverse relationship was found in teaching students who showed much less favor in the subject matter than health students. This phenomenon may be due to the different exposure to learning environments unique to respective specializations. 7) Health students were found to have more favorable attitudes toward population education in general than the teaching students. The teaching students appeared to have changed more to the negative direction when they became the second year while no such development was observed in health students. The teaching students seemed to hold a very conservative position with regard to sex education in schools. 8) About the equality of sexes, the nursing group was found to be most favorable while the reverse was true in the teaching group. A change in the negative direction as the class year advanced was found in the teaching group. 9) About questions related to fertility values-the 10 percent of respondents regardless of specialization indicated that they would maintain their single status in future, however no change was observed in the second year. The desired number of children was found to be two by the majority of students in nursing, medicine and teaching in order of high proportion. No changes in a different class year were observed. The childless marriage was seen by nursing students as a problem more than other students, but a slight change in positive direction was found when the nursing students became the second year. In summing, as data supported in the above, students in health profession demonstrated more favorable attitudes toward population related issues than the teaching students and this tendency became more apparent in the second year. It was noticed that health students were more conscious about the health aspect of population and family planning program while the teaching students gave more attention to the socioeconomic aspect. The sex variable seemed to have operated in the item related to the equality of sexes. In conclusion, as data presented in the above, the hypothesis of this study was accepted except in the few items. It should be noted that the limitation of this study is the short duration of the observation in measuring the possible attitude changes. It should include curriculum analysis for the respective specializations in order to indentify the area of curriculum impact on students in future study.

• 한국콘텐츠학회논문지
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• 제10권11호
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• pp.102-112
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• 2010

본 연구는 학문적 연구 대상에서 소외돼온 텔레비전 드라마 작가에 관한 후속 연구로, 한국 텔레비전 드라마에 홈드라마와 멜로드라마라는 장르 개념을 구축한 김수현 작가 홈드라마의 장르 차별성과 이데올로기 경향성을 논하고 있다. 김수현 작가의 멜로드라마에 관한 선행 연구에 이어 홈드라마 장르 연구를 시도한 첫 번째 목적은 기능주의적 사회규범 잣대의 편협한 단편적 평가를 재고하기 위해서이다. 또한 페미니즘 시각에 매몰된 평가에 의해서 김수현 홈드라마가 가부장 이데올로기를 옹호한다는 평가를 재고하기 위해서이다. 이 같은 평가야말로, 텔레비전 드라마 작가 연구의 부재라는 현실의 반증이기도 하다. 2008년 화제작 <엄마가 뿔났다>를 중심으로 한 연구 분석 결과, 김수현 작가의 홈드라마 장르문법은 안정적, 변동적 서사 전략을 적절히 융합, 구사함으로써 대중적 소구력을 획득하는 것으로 나타났다. 즉 대가족과 중층적 인물 구성, 일상성을 기초로 한 사실주의와 해피엔딩으로 끝나는 가족애의 주제 의식의 안정적 장르 관습에 시대상을 반영한 1대 가부장의 변화, 2대 전업주부의 역할 변화, 3대 결혼 풍속도의 변화라는 변동적 서사전략을 융합 구사함으로써 장르문법의 차별성을 보이고 있다. 또한 연구 대상 드라마의 갈등 유형과 갈등 관련 젠더 역할 분석 결과, 김수현 작가는 홈드라마 장르를 통해 그간의 남성 지배 가부장 젠더 이데올로기에 관한 진보적, 보수적 경향성 논의 보다는 그 저변에 자리한 작가의식, 즉 자본주의 이데올로기에 붕괴돼 가는 인간성의 회복과 사랑과 이해, 신뢰를 바탕으로 하는 가족애를 지향하는 인본주의적 경향성을 보인다.

• 한국자동차공학회논문집
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• 제14권4호
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• pp.12-19
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• 2006

It is positively necessary to study on the stiffness of a 13degree-type impact tester in order to improve the fracture prediction of impact testing in wheels using FE(finite-element) analysis. The 13degree-type impact tester consists of an impact striker, a wheel fixer, a steel plate, and four cylindrical rubbers. Important parts of the tester are the steel plate and four cylindrical rubbers which play a role of absorbing impact energy during impact testing. Because of these buffers, the RF(reaction force) variation of the lower part in the 13degree-type impact tester showed the tendency like a damped harmony oscillation during impact testing. In order to investigate the stiffness of a 13degree-type impact tester, this work measured each stiffness of a steel plate and cylindrical rubbers. The stiffness of a cylindrical rubber was measured using a compressive tester. On the other hand, the stiffness of a steel plate was predicted by simulating experimental method using FE analysis.

• 한국식품과학회지
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• 제19권3호
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• pp.273-278
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• 1987

건조 표고버섯에 대한 ethylene oxide 훈증처리와 감마선 조사가 사료의 품질에 관련된 몇가지 이화학적특성에 미치는 영향을 조사한 결과는 다음과 같다. 시료의 아미노산 함량은 감마선 조사구(1-5 kGy)에 비해 ethylene oxide처리구에서는 상당히 감소되었고, 환원당과 유리당(mannitol, arabitol, trehalose)의 함량은 조사선량에 따라 증가되었으나 훈증처리구에서는 감소되었다. 시료의 무기질의 함량은 처리구에 따라 다소 증감하였으나 유의적인 차이는 없었으며, 갈변색소와 산패도는 저장기간의 경과로 점차 증가되었는데 ethylene oxide처리구는 감마산 조사구보다 현저하게 나타났고 저장 상대습도에 따라서는 RH70%에 저장된 시료가 RH50%의 시료보다 이화학적 품질의 변화가 다소 심하였다.

• 환경위생공학
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• 제22권4호
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• pp.119-130
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• 2007

Sea food wastewater including high concentration of organics and nutrients is hard to treat stably by established traditional activated sludge process. This research is aimed to obey more and more of strengthened the law and to secure stable effluents by using advanced treatment process applied membrane filter in aeration tank for treatment of wastewater from marine products. It must maintain pH of influent over 6.0 to keep up stably biological sludge of advanced treatment process. At 38hr of HRT, removal rates of TBOD and TCOD were 99.9% and 99.4% respectively and TSS also removed with high efficiency. Most organics in the effluent was constituted with soluble type materials, it caused that membrane filter installed aeration tank should remove minute suspended particles. The reactor was operated well to get stable treatment results for operation period, in spite of high loading of organics like that $0.67{\sim}1.67\;kgTBOD/m^3/day$ of organics loading and $0.10{\sim}0.21\;kgBOD_5/kgMLSS/day$ of F/M ratio. At $36{\sim}48hr$ of HRT, removal rates of T-N and T-P were $89.7{\sim}90.7%\;and\;91.5{\sim}96.0%$ respectively. It means this treatment process also work to remove nutrients of high concentration. Upon investigation of advanced treatment's operation factors, optimum SRT was about 30days and average SNR that showed tendency to increase according to increase water temperature was calculated 0.014 gN/g MLVSS/d. SDNR was risen in conformity to increase F/M ratio of Non-aeration tank and investigated as $0.038{\sim}0.051\;gN/gMLVSS/d$.

• 한국재료학회지
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• 제22권9호
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• pp.482-488
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• 2012

To fabricate a precise micro metal mold, the electrochemical etching process has been researched. We investigated the electrochemical etching process numerically and experimentally to determine the etching tendency of the process, focusing on the current density, which is a major parameter of the process. The finite element method, a kind of numerical analysis, was used to determine the current density distribution on the workpiece. Stainless steel(SS304) substrate with various sized square and circular array patterns as an anode and copper(Cu) plate as a cathode were used for the electrochemical experiments. A mixture of $H_2SO_4$, $H_3PO_4$, and DIW was used as an electrolyte. In this paper, comparison of the results from the experiment and the numerical simulation is presented, including the current density distribution and line profile from the simulation, and the etching profile and surface morphology from the experiment. Etching profile and surface morphology were characterized using a 3D-profiler and FE-SEM measurement. From a comparison of the data, it was confirmed that the current density distribution and the line profile of the simulation were similar to the surface morphology and the etching profile of the experiment, respectively. The current density is more concentrated at the vertex of the square pattern and circumference of the circular pattern. And, the depth of the etched area is proportional to the current density.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.396-400
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• 2002

This study was conducted to evaluate the dry matter (DM) yield, quality and utilization of nutrients in Korean lespedeza (Lespedeza stipulacea Maxim.) swards as a roughage source. DM yield in various stages, chemical composition, and DM digestibility were observed, and DM intake, digestibility and utilization of nitrogen and energy by Korean native goat were determined. Experimental diets include three treatments: mixture hay (MH) 100%, MH (80%)+wild Korean lespedeza hay (LH) 20% and MH (60%)+LH (40%). As growth stage advanced, the DM yield of Korean lespedeza tended to increase significantly (p<0.05). The mean DM yield of all growing stages was observed as 7,336 kg/ha. Crude protein (CP) content of Korean lespedeza tended to decrease, but fibrous contents tended to increase when the growth stage advanced. The tannin content of Korean lespedeza was the highest at the bud stage (64.7 mg/g). However, it showed a tendency to decrease as the growth stage advanced, and thus it was the lowest at the ripe seed stage (26.8 mg/g) (p<0.05). With increasing level of LH, voluntary DM intake by Korean native goats slightly increased, but no differences were observed between diets. The digestibility of DM, cellular constituents and NDF was slightly higher in LH containing diets than that of MH 100% diet (p<0.05). There was no significant difference in apparently digested N% among all diets, but retained N% and retained N% of the absorbed were higher in MH (60%)+LH (40%) than those of other diets (p<0.05). A difference in the utilization of energy was not detected. In conclusion, Juvenile LH improved the digestibility of nutrients, presumably due to its high CP content and low fibrous compound. Especially, tannin in LH did not affect in DM intake, but increased the nitrogen utilization of Korean native goats. Accordingly, it could be suggested that Korean lespedeza has a potential to be provided as a roughage source for Korean native goats.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3083-3088
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• 2012

We investigated the prognostic value of pituitary tumor transforming gene 1 (PTTG1) expression according to clinicopathological features among localized or locally advanced prostate cancer cases receiving hormone therapy. A retrospective study involved 64 patients receiving combined androgen blockade treatment was performed. PTTG1 expression was determined by immunohistochemical staining using initial needle biopsy specimens for diagnosis. Associations of PTTG1 with various clinicopathological features and disease-free survival were examined via uni- and multivariate analyses. No association between PTTG1 expression and clinical T stage, Gleason score, pretreatment PSA levels, risk groups was found (p =0.682, 0.184, 0.487, 0.571, respectively). Univariate analysis revealed that increased PTTG1 expression, T3 stage and high risk group were associated with increased risk of disease progression (p =0.000, 0.042, and 0.001), and high PSA level had a tendency to predict disease progression (p =0.056). Cox hazard ratio analysis showed that PTTG1 low expression (p =0.002), PTTG1 high expression (p =0.000) and high risk group (p =0.0147) were significantly related to decreased disease-free survival. In conclusion, PTTG1 expression determined by immunohistochemical staining in needle biopsy specimens for diagnosis is a negative prognostic factor for progression in localized or locally advanced prostate cancer receiving hormone therapy.

• Nuclear Engineering and Technology
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• 제46권4호
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• pp.557-568
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• 2014

This paper presents the results of an analysis of wind characteristics and atmosphere dispersion modeling that are based on computational simulation and part of a preliminary study evaluating environmental radiation monitoring system (ERMS) positions within the Barakah nuclear power plant (BNPP). The return period of extreme wind speed was estimated using the Weibull distribution over the life time of the BNPP. In the annual meteorological modeling, the winds from the north and west accounted for more than 90 % of the wind directions. Seasonal effects were not represented. However, a discrepancy in the tendency between daytime and nighttime was observed. Six variations of cesium-137 ($^{137}Cs$) dispersion test were simulated under severe accident condition. The $^{137}Cs$ dispersion was strongly influenced by the direction and speed of the main wind. A virtual receptor was set and calculated for observation of the $^{137}Cs$ movement and accumulation. The results of the surface roughness effect demonstrated that the deposition of $^{137}Cs$ was affected by surface condition. The results of these studies offer useful information for developing environmental radiation monitoring systems (ERMSs) for the BNPP and can be used to assess the environmental effects of new nuclear power plant.