• 대한치과보철학회지
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• 제39권6호
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• pp.709-734
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• 2001

The aims of this experiment were to investigate the strain and temperature changes simultaneously within autopolymerzing acrylic resin specimens. A computerized data acquisition system with an electrical resistance strain gauge and a thermocouple was used over time periods up to 180 minutes. The overall strain kinetics, the effects of stress relaxation and additional heat supply during the polymerization were evaluated. Stone mold replicas with an inner butt-joint rectangular cavity ($40.0{\times}25.0mm$, 5.0mm in depth) were duplicated from a brass master mold. A strain gauge (AE-11-S50N-120-EC, CAS Inc., Korea) and a thermocouple were installed within the cavity, which had been connected to a personal computer and a precision signal conditioning amplifier (DA1600 Dynamic Strain Amplifier, CAS Inc., Korea) so that real-time recordings of both polymerization-induced strain and temperature changes were performed. After each of fresh resin mixture was poured into the mold replica, data recording was done up to 180 minutes with three-second interval. Each of two poly(methyl methacrylate) products (Duralay, Vertex) and a vinyl ethyl methacrylate product (Snap) was examined repeatedly ten times. Additionally, removal procedures were done after 15, 30 and 60 minutes from the start of mixing to evaluate the effect of stress relaxation after deflasking. Six specimens for each of nine conditions were examined. After removal from the mold, the specimen continued bench-curing up to 180 minutes. Using a waterbath (Hanau Junior Curing Unit, Model No.76-0, Teledyne Hanau, New York, U.S.A.) with its temperature control maintained at $50^{\circ}C$, heat-soaking procedures with two different durations (15 and 45 minutes) were done to evaluate the effect of additional heat supply on the strain and temperature changes within the specimen during the polymerization. Five specimens for each of six conditions were examined. Within the parameters of this study the following results were drawn: 1. The mean shrinkage strains reached $-3095{\mu}{\epsilon},\;-1796{\mu}{\epsilon}$ and $-2959{\mu}{\epsilon}$ for Duralay, Snap and Vertex, respectively. The mean maximum temperature rise reached $56.7^{\circ}C,\;41.3^{\circ}C$ and $56.1^{\circ}C$ for Duralay, Snap, and Vertex, respectively. A vinyl ethyl methacrylate product (Snap) showed significantly less polymerization shrinkage strain (p<0.01) and significantly lower maximum temperature rise (p<0.01) than the other two poly(methyl methacrylate) products (Duralay, Vertex). 2. Mean maximum shrinkage rate for each resin was calculated to $-31.8{\mu}{\epsilon}/sec,\;-15.9{\mu}{\epsilon}/sec$ and $-31.8{\mu}{\epsilon}/sec$ for Duralay, Snap and Vertex, respectively. Snap showed significantly lower maximum shrinkage rate than Duralay and Vertex (p<0.01). 3. From the second experiment, some expansion was observed immediately after removal of specimen from the mold, and the amount of expansion increased as the removal time was delayed. For each removal time, Snap showed significantly less strain changes than the other two poly(methyl methacrylate) products (p<0.05). 4. During the external heat supply for the resins, higher maximum temperature rises were found. Meanwhile, the maximum shrinkage rates were not different from those of room temperature polymerizations. 5. From the third experiment, the external heat supply for the resins during polymerization could temporarily decrease or even reverse shrinkage strains of each material. But, shrinkage re-occurred in the linear nature after completion of heat supply. 6. Linear thermal expansion coefficients obtained from the end of heat supply continuing for an additional 5 minutes, showed that Snap exhibited significantly lower values than the other two poly(methyl methacrylate) products (p<0.01). Moreover, little difference was found between the mean linear thermal expansion coefficients obtained from two different heating durations (p>0.05).

• Journal of Chest Surgery
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• 제36권7호
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• pp.527-530
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• 2003

재팽창성 페부종은 기흉이나 흉수 또는 무기폐로 인한 폐허탈을 치료할 때 생기는 매우 드문 합병증으로 때로는 중한 상태에 빠져 사망에 이르기도 한다. 재팽창성 폐부종은 오랜 기간동안 폐허탈이 있는 상태에서 빠른 속도로 많은 양의 공기나 흉수를 일시에 제거하여 발생한다 오랜 기간동안 허탈된 폐를 치료할 때에는 반드시 재팽창성 폐부종의 가능성과 합병증의 예방에 대하여 염두해 두어야 한다. 재팽창성 폐부종 환자에서 양측 폐의 기도저항과 탄성 차이가 심한 경우에, 관례적인 인공호흡기 치료법을 시행하면 정상인 한족 폐의 과폐창과 다른 한쪽 폐의 점차적인 허탈이 일어난다. 분리형 폐환기법은 이러한 문제점을 해결하는데 도움이 된다. 저자들은 두명의 남자 환자에서 심한 재팽창성 폐부종에 대하여 분리형 페환기법으로 치료하여 좋은 결과를 얻었기에, 분리형 폐환기법을 심한 재팽창성 폐부종의 치료법으로 제시한다.

• 대한기계학회논문집B
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• 제27권10호
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• pp.1464-1471
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• 2003

In order to investigate the flows with shock wave in branch, 108$^{\circ}$ elbow and T-junction of the IRWST system of standard Korean nuclear reactor, detail time dependent behaviors of unsteady flow with shock wave, vortex and so on are obtained by numerical method using compressible three-dimensional Navier-Stokes equations. At first, the complex flow including the incident and reflected shock waves, vortex and expansion waves which are generated at the corner of T-junction is calculated by the commercial code of FLUENT6 and is compared with the experimental result to obtain the validation of numerical method. Then the flow fields in above mentioned units are analyzed by numerical method of [mite volume method. In numerical analysis, the distributions of flow properties with the moving of shock wave and the forces acting on the wall of each unit which can be used to calculate the size of supporting structure in future are calculated specially. It is found that the initial shock wave of normal type is re-established its type from an oblique one having the same strength of the initial shock wave at the 4 times hydraulic diameters of downstream from the branch point of each unit. Finally, it is turned out that the maximum force acting on the pipe wall becomes in order of the T-junction, 108$^{\circ}$ elbow and branch in magnitude, respectively.

• 수산경영론집
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• 제14권2호
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• pp.110-138
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• 1983

After Liberation of Korea, Korean fisheries economy fell into an exhausted conditions because of the damage of Japanese colonization policy and the Korean War, and fisheries organizations of those days established for the improvement of fishermen's welfare could not carry out their primary purposes and functions. Under such circumstances, Fisheries Cooperatives starting on April 1st in 1961 played a great role in settling the socio-economic confusion of those days. Fisheries financing was also more systematic and substantial after establishment of Fisheries Cooperatives. In fact fisheries industry was faced with much more riskiness than any other industry on account of its speciality and such a riskiness induced general financial institutions to be reluctant to lend money to the fishermen. In order to overcome such a capital rationing, it was necessary to establish the reciprocal financing system based on the principle of mutual protection of economic weakers. Credit business in Fisheries Cooperatives beginning in 1963 was mainly dependent on governmental fund as fund sources. But the size of fund was too small to satisfy fishermen's fund demand, therefore Fisheries Cooperatives carried out the movement of raising its own fund. As a result of the movement the ratio of its own fund to total funds amounted to 47.7% in 1980, but external funds still take a greater part of all funds. To settle the weakness of the ratio of its own fund and chronic deficiency of fund, a conclusion can be drawn as follows : 1. The enlargement of Fisheries Cooperatives' raising ability of funds. .The expansion of urban branch to absorb idle funds in urban area. .The diversification of financing service to compete with genetral financial institutions. 2. The enlargement of governmental fund and preferential treatment of fishermen's savings. 3. Vitalization of mutual finance and fixation of Fisheries Cooperatives' two-phase organization. 4. The re-enforcement of supervisory financing and post management system.

• 한국공간정보시스템학회 논문지
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• 제6권2호
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• pp.3-13
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• 2004

TPR-tree의 각 노드는 이동체를 색인하기 위하여 시간 함수를 기반으로 한 경계사각형을 이용한다. 경계사각형의 각 축을 계산하기 위하여 시간함수를 사용하므로 시간이 흐름에 따라 노드의 경계사각형은 확장된다. 따라서 이웃하는 노드간의 중첩(overlap) 영역이 커지기 때문에 영역질의의 성능이 점차적으로 떨어지는 문제가 있다. 이 논문에서는 이동체 삽입과 삭제 시 노드의 경계사각형을 재구성하기 위한 기법들을 제시한다. 이동체를 삽입할 때 노드간의 중첩을 줄이기 위하여 중첩이 심한 두 개의 단말 노드를 강제 합병하고 재분할하는 강제 합병 기법을 사용한다. 그리고 이동체를 삭제할 때 다른 이동체도 재삽입하는 강제 재삽입 기법을 이용한다. 강제 재삽입 기법은 삭제 노드 강제 재삽입 기법과 중첩 노드 강제 재삽입 기법으로 분류된다. 실험 결과에서 중첩 노드 강제 재삽입 기법이 다른 두 기법에 비하여 우수함을 알 수 있다.

• 한국수자원학회논문집
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• 제42권6호
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• pp.433-443
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• 2009

토양수분에 관한 관심이 급증하면서 토양수분의 시공간적 특성을 이해하고자 하는 연구가 최근 꾸준히 일어나고 있다. 토양수분의 보다 나은 이해를 위해, 본 연구에서는 이에 대한 동역학을 추계학적 기법을 이용하여 기후변화에 따른 영향평가에 대한 적용을 염두에 둔 추계학적 토양수분모형을 제시하고자 하였다. 보다 현실적인 적용을 위하여 손실항을 세 가지로 구분하여 고려하였고 강우의 추계학적인 특성 역시 고려하였다. 모의 결과 본 연구에서 유도한 토양수분 모형으로 관측 자료를 적절하게 재현 할 수 있으며 토양수분이 계절별로 강수의 패턴에 따라 일정한 순환의 형태를 가짐을 재현하였다. 또한 CGCM3.1 자료를 이용한 미래 토양수분 상태 예측으로, 토양수분의 변동성이 현재보다 커질 것으로 예측되었다.

• 디지털콘텐츠학회 논문지
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• 제11권3호
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• pp.357-365
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• 2010

개인화 웹 검색 시스템은 사용자의 검색의도에 따라 질의어 확장, 검색 결과의 재순위화 등의 방법을 통하여 사용자에게 개인화된 검색 결과를 제공한다. 이를 위해 검색 시스템은 질의어와 사용자의 프로파일 정보를 활용하여 사용자의 검색 의도를 파악하고 분석하여, 검색 결과 페이지에 반영하여 보여주게 된다. 이때 검색 결과 페이지는 문서의 URL과 문서의 제목, 작은 텍스트 조각을 표시한다. 여기서 작은 텍스트 조각은 검색 질의어가 포함된 문서의 요약이며, 스니펫이라고 알려져 있다. 사용자는 이러한 문서의 요약을 통하여 웹 문서가 자신이 원하는 정보를 가진 문서인지를 판단하거나, 해당 URL에 직접 접속하지 않고도 원하는 정보를 얻을 수 있게 된다. 따라서 문서 요약은 사용자가 문서를 볼 것인지 아닌지에 대한 중요한 판단 기준이 되며, 만약 문서 요약 시스템이 개인화된 요약 결과를 제공한다면 사용자의 만족도는 더욱 증가할 것이다. 본 논문은 전체 웹 검색 시스템에서 검색 속도의 큰 하락없이 사용자의 만족도를 증가시킬 수 있는 개인화 문서 요약 시스템을 제안한다.

• Ocean and Polar Research
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• 제29권3호
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• pp.205-216
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• 2007

The purpose of this study was to investigate effects of large scale marine sand mining on the marine ecological community. For the study, four stations along the coast were selected and monitored in 1998 and 2001 at mining areas and non-mining areas about the Gyeonggi Bay. The result revealed that in 1998, 9 species of fishes, 16 species of crustaceans, and 6 species of mollusks were collected where as in 2001, 11 species of fishes, 5 species of crustaceans, and 2 species of mollusks were collected, uncovering the fact that fishes have diversified while crustaceans and mollusks have reduced on a grand scale. Also, there were two key characteristics regarding the changes of biological communities in mining and nonmining areas. The first was the dwindling of crustaceans inhabiting the sand area. This outcome may be accounted for by the facts that physical removal of seabed sediments and re-sediment due to expansion of floating particles cause direct influence on the ocean floor ecosystem and have continuous effect on the communities of crustaceans which feed on them. Secondly, the newly arrived species and their population during spring and summer seasons have increased in the non-mining areas and have decreased in the mining area. It can be concluded that highly nomadic fish species migrate toward areas with less disturbance or destruction of ecosystem from marine sand mining, and consequently, the communities of fishes change in the sea area. Setting aside the characteristics of the investigated sea areas where the arriving conditions of species vary by seasons, the clear differences of population of organisms in those areas are due to environmental alterations owing to the marine sand mining ; if those large-scale marine sand mining activities continue in the Gyeonggi Bay, their effects on biological communities in the areas will only grow.

• 복식
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• 제60권8호
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• pp.100-117
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• 2010

The cosmetics industry is executing the experiential marketing strategy, which focuses the brand experiential experience for the connection with consumers and differentiated strategy for the company's brand image, according to the expansion of quality service, which increasingly consume a diverse experience. Among these, the low-priced cosmetics market is trying a variety of experiential marketing to provide positive experience of their product and their brand through a unique service or event to stimulate the motions of young woman, who are changing rapidly, and is actively utilizing the means of marketing to form brand equity for these experiential marketing. Therefore, this study is to find out the effect of customer experiential on the brand equity through a variety of experiential marketing of low-priced cosmetics brand and based on the result, we were able to find out that the experiential marketing is also used as important means of marketing for low-priced cosmetics market to secure the brand equity and to maintain long-term relationship with the customer. This is expected to provide strategic and practical implications to the cosmetic marketing managers for customer management and this will recognize the importance of customer experiential in cosmetic marketing and suggest proper marketing strategy plan. In this study, the multiple regression analysis was mainly uses to find out the influence between the variables for low-cost cosmetic brand but we're hoping to execute a study, which directly and indirectly covers the complete path by using the various parameters, which can be effected on the brand equity.

• Clinical and Experimental Reproductive Medicine
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• 제39권4호
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• pp.153-160
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• 2012

Objective: The aim of this study was to compare vitrification optimization of mouse embryos using electron microscopy (EM) grid, cryotop, and thin plastic strip (TPS) containers by evaluating developmental competence and apoptosis rates. Methods: Mouse embryos were obtained from superovulated mice. Mouse cleavage-stage, expanded, hatching-stage, and hatched-stage embryos were cryopreserved in EM grid, cryotop, and TPS containers by vitrification in 15% ethylene glycol, 15% dimethylsulfoxide, 10 ${\mu}g/mL$ Ficoll, and 0.65 M sucrose, and 20% serum substitute supplement (SSS) with basal medium, respectively. For the three groups in which the embryos were thawed in the EM grid, cryotop, and TPS containers, the thawing solution consisted of 0.25 M sucrose, 0.125 M sucrose, and 20% SSS with basal medium, respectively. Rates of survival, re-expansion, reaching the hatched stage, and apoptosis after thawing were compared among the three groups. Results: Developmental competence after thawing of vitrified expanded and hatching-stage blastocysts using cryotop and TPS methods were significantly higher than survival using the EM grid (p<0.05). Also, apoptosis positive nuclei rates after thawing of vitrified expanded blastocysts using cryotop and TPS were significantly lower than when using the EM grid (p<0.05). Conclusion: The TPS vitrification method has the advantages of achieving a high developmental ability and effective preservation.