• 한국물환경학회지
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• 제22권2호
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• pp.288-293
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• 2006

Basic investigations have been carried out for the solvent extraction of silver contained in the waste photographic fixing solution using D2EHPA as an extractant. Extraction experiments were conducted using artificial waste solution which was made by dissolving $AgNO_3$ in distilled water along with actual waste fixing solution. For artificial waste solution, the extraction of silver was found to occur very rapidly at the initial stage of extraction. In addition, more silver was extracted as the volumetric ratio between aqueous phase and organic phase was decreased. The volumetric ratio of organic extractant to diluent was also taken as an influential variable and the extracted amount of silver was observed to decrease with temperature. The characteristics of silver extraction for actual fixing solution was generally similar to that for artificial waste solution. Regarding the kinetic analysis, the extraction of silver contained in the actual solution was observed to follow a first order reaction.

• 대한방사선기술학회지:방사선기술과학
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• 제30권2호
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• pp.167-175
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• 2007

2001년부터 본격적으로 보급되기 시작한 PACS 도입은 영상의학과에서는 필름비용 절감, 인건비 절감, 현상액 사용량 절감, 관리업무 축소, 재 촬영 건수의 감소 등의 효과를 볼 수 있었고, 임상 의사들에게는 의료영상동시 활용, 임상정보의 증대, 진료 환자수의 증가, 의료영상 및 판독결과 활용성 증대 효과를 기대할 수 있는 것으로 알려져 있다. 환자들에게는 방사선 피폭선량 감소, 진료비 절감, 임상정보를 신속하게 알 수 있는 효과가 있다. 이에 본 저자들은 Full PACS를 도입한 서울 및 경기도의 10개 종합병원을 대상으로 하여 PACS로 인한 긍정적인 여러가지 효과 중 현상, 정착 폐수의 감소 추이를 알아보기 위하여 도입 1년 전과 도입 3년 후를 비교 분석하여 다음과 같은 결론을 얻었다. 1. 1개월 당 검사 건수는 7357.7건이 증가하였으나 필름 사용량은 90%가 감소하였다. 2. 현상액 월 평균 소모량은 3년 후 92%가 감소하였고, 정착액은 86%가 감소하였다. 3. 필름 1장 당월 평균 현상액 소모량은 3년 후 149%가 증가하였고, 정착액은 300%가 증가하였다. 4. 현상 폐수 발생량은 3년 후 월 평균 88%가 감소하였고, 정착 폐수는 87%가 감소하였다. 5. 3년 후 필름 1장 당월 평균 현상폐수 발생량은 377%, 정착폐수 발생량은 385%가 증가하였다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 춘계 학술대회논문집
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• pp.128-134
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• 2005

In the CFD area, the numerical analysis of high Mach number flow over a blunt-body poses many issues. Various numerical schemes have been developed to cover the issues, but the traditional schemes are still used widely due to the complexities of new schemes and intricacy of modifying the established codes. In the present study, the well-known Roe's FDS based on TVD-MUSCL scheme is used for the solution of very high Mach number three-dimensional flows posing carbuncle and non-physical phenomena in numerical analysis. A parametric study was carried out to account for the effects of the entropy fixing, grid configurations and initial condition. The carbuncle phenomena could be easily overcome by the entropy fixing, and the non-physical solution could be eliminated by the use of the modified initial condition regardless of entropy fixing and grid configurations.

• 치과방사선
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• 제22권1호
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• pp.128-136
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• 1992

This study was undertakened to investigate the change of image characteristics on dental films according to the process of using time of processing solution in automatic processor. Base + fog density, film density and subject contrast were measured with the digital densitometer, the pH of developing and fixing solution were measured with Digital pH / ION Meter. The following results were obtained: 1. Base + fog density was increased with the process of using time of the processing solution and was over the maximum permissible base + fog density 0.25 from the 3rd day. 2. Film density was increased with the process of using time of the processing solution. 3. Subject contrast was decreased with the process of using time of the processing solution. 4. The pH of the developing solution was decreased with the process of using time, the pH of the fixing solution was increased.

• 한국수산과학회지
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• 제55권1호
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• pp.67-72
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• 2022

We investigated the changes in the egg diameter of chub mackerel Scomber japonicus with the stages of egg development (and distinguished between hydrated oocyte and non-hydrated oocyte) for 1, 2, 3, 5, 10, 15 and 30 days. The chub mackerel oocytes were preserved in seven fixing solutions (70% ethyl alcohol, 99.9% ethyl alcohol, 5% formalin, 10% formalin, 5% neutral buffered formalin, 10% neutral buffered formalin and Gilson's solution). At 30 days, the chub mackerel hydrated oocytes preserved in 70% ethyl alcohol and 99.9% ethyl alcohol had shrunk by 5.2% and 7.9%, respectively. Similarly, the non-hydrated oocytes in the same solutions shrunk by 10.3% and 14.0%, respectively. Oocytes preserved in Gilson's solution had an average egg diameter decrease in both the hydrated oocyte (by 16.9%) and non-hydrated oocytes (by 15.6%). The diameter of the preserved hydrated oocytes did not significantly differ between the 5% formalin, 10% formalin, 5% neutral buffered formalin and 10% neutral buffered formalin, with shrinkage percentages of 0.6%, 0.1%, 1.9% and 3.4%, respectively (P>0.05). Similarly, the shrinkage percentages of the non-hydrated oocytes were 4.3% (5% formalin), 5.5% (10% formalin), 4.3% (5% neutral buffered formalin), and 4.1% (10% neutral buffered formalin).

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.613-616
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• 2000

This paper considers the problem of subway crew scheduling. Crew scheduling is concerned with finding a minimum number of assignments of crews to a given timetable satisfying various restrictions. Traditionally, crew scheduling problem has been formulated as a set covering or set partitioning problem possessing exponentially many variables, but even the LP relaxation of the problem is hard to solve due to the exponential number of variables. In this paper, we propose two basic techniques that solve the problem in a reasonable time, though the optimality of the solution is not guaranteed. To reduce the number of variables, we adopt column-generation technique. We could develop an algorithm that solves column-generation problem in polynomial time. In addition, the integrality of the solution is accomplished by variable-fixing technique. Computational results show column-generation makes the problem of treatable size, and variable fixing enables us to solve LP relaxation in shorter time without a considerable increase in the optimal value. Finally, we were able to obtain an integer optimal solution of a real instance within a reasonable time.

• 대한방사선기술학회지:방사선기술과학
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• 제1권1호
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• pp.61-67
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• 1978

Recently, Demands of automatic X-ray film processors are increasing more and more at general hospitals and private clinics, but various troubles because of incorrect control were found out. Authors have researched to find out the function and activity of automatic X-ray film processor for 70 days with Kodak X-OMAT processor, and results obtained were as follows; 1. Automatic X-ray film processor have an advantage to conduct the rapid treatment of X-ray film processing, but incorrect handling of developing and fixing agents were brought about a great change in contrast and optical density of X-ray film pictures. 2. About 10,000 X-ray films could be finished by same developing and fixing solution without exchanging any other solutions in automatic X-ray film processor.

• Journal of Oral Medicine and Pain
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• 제3권1호
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• pp.23-27
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• 1977

The author thought that the results of cytologic tests could be changed according to the fixative methods. So the author has studied several methods of fixing exfolaiative cells collected from normal adult cheek mucosa with a solution of equal parts of ether and 95% ethylalcohol, 95 ethylalcohol and Isoprophyl alcohol, and compared the results with each other. The results were as follows : The effects of fixation, and staining efficiency of nucleus and protoplasm are similar in each method, but the staining efficiency of cytoplasm and the conversation of cytoplasmic membrane were best in 95% ethylalcohol.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.827-833
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• 2001

This study is an introduction of ADS in which we have written out programs which can design three-dimensional machine parts and reduce the required time for design them comparing with other CADs. Among the machine parts, screws are commonly used in joining one part to another because of easy handing but welding and rivet are used to join permanently them even thought hard operation. Consequently, we have developed the screw for permanent fixing using stairs type screw threads, which is considered as the main machine parts in joining. For that, we designed permanent fastened screws according to the different rotation angle using VisualLISP and transferred it to ANSYS, structural solution program, to find out allowance load, maximum equivalent stress and where it occur.

• 한국경영과학회지
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• 제27권4호
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• pp.67-86
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• 2002

This paper considers subway crew scheduling problem. Crew scheduling is concerned with finding a minimum number of assignments of crews to a given timetable satisfying various restrictions. Traditionally, crew scheduling problem has been formulated as a set covering or set partitioning problem possessing exponentially many variables, but even the LP relaxation of the problem is hard to solve due to the exponential number of variables. In this paper. we propose two basic techniques that solve the subway crew scheduling problem in a reasonable time, though the optimality of the solution is not guaranteed. We develop an algorithm that solves the column-generation problem in polynomial time. In addition, the integrality of the solution is accomplished by variable-fixing technique. Computational result for a real instance is reported.