• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 춘계학술대회 논문집
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• pp.35-39
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• 1998

Determination of effective EDM parameters is significant to increase productivity. However, With the complexity of EDM phenomena, a universal selection method of EDM parameters has not been established yet. Moreover, No attempt has been tried before to suggest a logical method in determining essential machining parameters for effective electrical discharge machining. Peak current, one of the most significant factors in EDM, is proportional to EDM area. This paper presents a method that can be Z-map modeling from CMM data, and calculate EDM area using Z-map.

• 약학회지
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• 제23권1호
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• pp.7-10
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• 1979

A gas chromatographic determination of dienestrol in dienestrol cream has been studied. Dienestrol cream was dissolved in pyridine and silylation was done by using N, O-bis (trimethylsilyl) trifluoroacetamide. The derivative was injected into 3% silicone OV-17 column for chromatographic estimation. The dienestrol peak was found to be well separated from the other components of the cream. The detection limit was obtained to be $5.6{\times}10^{11}$ mol of dienestrol for this method. As there is no need for prior separation procedure, this experiment is extremely simple and less time consuming as compared to the conventional methods for estimation of dienestrol in cream.

• Bulletin of the Korean Chemical Society
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• 제15권12호
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• pp.1045-1049
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• 1994

A simple and fast ion chromatographic method is developed for the determination of transition metals such as Fe, Cu, Ni, Zn and Co in atmospheric particulates. The method involves acid digestion, on-column preconcentration, and subsequent ion chromatogaphic detection. The precision of the method is less than 3${\%}$ RSD at parts per billion level for the metals studied. No significant interferences are observed. The results obtained with this method agree well with those by ICP-AES.

• 인간식물환경학회지
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• 제24권1호
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• pp.75-84
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• 2021

Background and objective: This study was conducted to examine the effects of the theme-based garden book (photo book) making integration program on social skills and self-determination of college students with developmental disabilities. Methods: We analyzed the changes in social skills and self-determination of college students with developmental disabilities. The first step was defining the theme-based garden book (photo book) making integration program, which was done by focus group interviews (FGI) comprised of specialists in the industry and academia. The second step was carrying out 8 sessions of the program. The third step was examining the effects of the program on social skills and self-determination of college students with developmental disabilities. The participants of this study were 36 college students with developmental disabilities attending N University, and 17 students were in the experiment group and the other 19 in the control group. Results: The control group showed no statistically significant changes in the three sub-domains of social skills, while the experimental group showed statistically significant differences across all three sub-domains, such as cooperation(P < .05), assertion(P < .05), and self-control(P < .05). The experimental group, that participated in the program showed statistically significant differences across all four sub-domains of self-determination skills, such as behavior (P < .05), cognition(P < .05), school support(P < .05) and home support(P < .05). This proved that the theme-based garden book (photo book) making program contributed to bringing positive effects to self-determination and social skills. Conclusion: These results suggest that the theme-based garden book (photo book) making integration program could improve self-determination and social skills of college students with developmental disabilities. These positive changes are related to the high level of interest in theme-based garden design programs among college students with developmental disabilities, and thus these programs can be used effectively to improve social adjustment.

• Earthquakes and Structures
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• 제25권4호
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• pp.249-267
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• 2023

Various methods for determining the damping ratio have been proposed by scholars both domestically and abroad. However, no comparative analysis of different determination methods has been seen yet. In this study, typical sand (Fujian standard sand) and cohesive soils were selected as experimental objects, and undrained strain-controlled dynamic triaxial tests were conducted. The differences between existing damping ratio determination methods were theoretically compared and analyzed. The results showed that the hysteresis curve of cohesive soils had better symmetry and more closely conformed to the definition of equivalent linear viscoelasticity. For non-cohesive soils, the differences in damping ratio determined by six methods were significant. The differences decreased with increasing confining pressure and relative density, but increased gradually with increasing shear strain, especially at high shear strains, where the maximum relative error reached 200%. For cohesive soils, the differences in damping ratio determined by six methods were relatively small, with a maximum relative error of about 50%. Moreover, they were less affected by effective confining pressure and had the same changing trend under different effective confining pressures. The damping ratio determination method has a large effect on the seismic response of soils distributed by non-cohesive soils, with a maximum relative error of about 15% for the PGA and up to about 30% for the Sa. However, for soil layers distributed by cohesive soils, the damping ratio determination method has less influence on the seismic response. Therefore, it is necessary to adopt a unified damping ratio determination method for non-cohesive soils, which can effectively avoid artificial errors caused by different determination methods.

• 의료법학
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• 제15권1호
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• pp.211-237
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• 2014

Because of unpredictability and high possibility of abnormal results by clinical trials compared to general medical behaviors, a procedure for ensuring with sufficient explanations by investigators must be secured. Therefore, in a sequence of clinical trials, what kinds of scope, stage, and method of explanations provided by investigators, including doctors or researchers, to trial subjects are closely related to the compensation for damages by violation of liability for explanation. In case of application of clinical trials to patients who have critical illness such as cancer, issues of "Quality of Life" regarding trial subjects, cancer patients, should be discussed. Especially, in case of clinical trials for terminal cancer patients, the right of subjects' self-determination, which is a fundamental principle in medical behaviors, should be discussed. The right of self-determination includes participation in clinical trials for the possibility of life-sustaining even a little bit, or no participation in clinical trials in order to have a time for completing the rest of his life. Like this, if the extent and scope of explanations related to the issues of "Quality of Life" are raised as main issues, the evaluation of "Quality of Life", should be a prerequisite. In many occasions, realistically, despite bad results such as deaths or serious adverse drug reactions after clinical trials, it may not be easy for compensating to trial subjects or their survivors, who requested civil compensation for damage. Futhermore, in abnormal results after concealment of clinical trials or performance of clinical trials without permission, and in the case of trial subjects' failures of proving proximate cause between the clinical trials and abnormal results, problematic results such as no protection to the trial subjects could be occurred. In performing clinical trials, investigators should provide sufficient explanations for trial subjects and secure voluntary informed consents from the trial subjects. Therefore, clinical trials without trial subjects' permissions and the informed consent process violate trial subjects' rights of self-determination, and the investigators shall be liable for compensation for damages. Then, issues might be addressed are what are essential contents of patients' "rights of self-determination" infringed by clinical trials without subjects' permissions. Two perspectives about patients' rights of self-determination might be considered. One perspective regards physical distress of patients (subjects) from therapies without sufficient explanations as the crux of the matter. The other perspective regards infringement of human dignity caused by being subjects without permission as the crux of the matter irrespective of risks' big and small influences. This research follows perspective of the latter. Forming constant fiduciary relation between investigators (doctors) and subjects (patients) pursuant medical contracts, and in accordance with this fiduciary relation, subjects, who are patients, have expectations of explanations and treatments by the best ways. If doctors and patients set this forth as a premise, doctors should assume civil liability when doctors infringe patients' expectations.

• 대한화학회지
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• 제7권2호
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• pp.186-188
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• 1963

An attempt to improve the method of volumetric determination of tungsten developed by Luke has been made successfully. Using amalgam coated lead instead of pure metallic lead in the reduction procedure. W(VI)-W(III) reduction has been found to be quantitative in rather concentrated hydrochloric acid. Since there was no excessive dissolution of lead via reduction of hydrogen ion, lead surface was totally accessible for the reduction of tungsten and no trouble was caused by dereposition of $PbCl_2$ crystals at the nozzle of Jones reductor. Furthermore, it has been confirmed that almost 100 mg. of $WO_3$ can be handled easily if the chloride concentration of the HCl is increased by adding solid $NH_4Cl$.

• Nuclear Engineering and Technology
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• 제5권3호
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• pp.234-239
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• 1973

페이퍼 크로마토그래피에 의한 o-iodohippuric acid-$^{131}$ I와 o-iodobenzoic acid-$^{131}$ I의 분리에 관한 기보된 방법은 착오인 것으로 밝혀졌다. 이들 두 유사 화합물들의 효과적 분리를 위하여 제시된 용매는 균일하게 섞여지지 않을뿐 아니라 그대로 사용하더라도 이들 두 화합물은 분리되지 않았다. o-iodohippuric acid-$^{131}$ I의 동위원소 교환법에 의한 제조과정에서 o-iodohippuric acid가 o-iodobenzoic acid로 변환되지 알음을 확인하였으며 Hippuran-$^{131}$ I의 방사화학적 순도 결정을 위한 간편한 방법을 제시하였다.

• 한국멀티미디어학회논문지
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• 제11권6호
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• pp.755-763
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• 2008

Silhouette is useful in computer graphics for a number of techniques such as non-photorealistic rendering, silhouette clipping, and blueprint generating. Methods for generating silhouette are classified into three categories: image-based, object-based, and hybrid-based. Hybrid-based method is effective in terms of time complexity but spatial coherence problem still remains. In this paper, we proposed a new hybrid-based method which produces 3D data for silhouette and also guarantees no spatial coherence problem. To verify the efficiency of the proposed algorithm, several experiments are conducted for various 3D models from simple to quite complex. Results show that our algorithm generates no gap between any two consecutive silhouette lines when the silhouette model is magnified significantly.

• 한국대기환경학회지
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• 제11권4호
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• pp.307-313
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• 1995

An automatic method is developed for the determination of SOx in atmosphere. The method involves SOx sampling in diffusion scrubber followed by ion chromatographic analysis. Filtered air is withdrawn at 1.8.ell./min through a diffusion scrubber of which inner tube is made of PTFE(Gore-tex) membrane tubing. 1mM $H_{2}$ $O_{2}$ is used as absorbing solution so that SOx is oxidized to S $O_{4}$$^{2-}$. The scrubbered solution is automatically injected into ion chromatograhpy eith conductivity detection for sulphate determination. Replacement of commonly used polyproplene membrane with PTFE gives several merits such as easy preparation of diffusion scrubber, better collection efficiency. No measurable memory effect is experienced, and this isin contrast to previous work for ammonia. Detection limit of this method defined by three times standard deviation is 0.56ppbv. The precision is 0.4% RSD at SOx concentration of 7.3ppbv Results for Seoulatmosphere ate presented.