齒科用 銀合金 製造에 關한 硏究

金哲偉,鮮牛良國,辛哲吉,金正雄,趙天植 大韓齒科器材學會 1967 대한치과재료학회지 Vol.2 No.1

The purpose of this study was to determint the dimensional change, flow, and crushing strength at various time intervals with amalgam alloys made by the mech. and met. division, the army research and testing laboratory, Seoul, Korea. the chemical composition of the alloy used in these tests are Ag:68.03%, Sn:26.53%, Cu:4.76%, Zn:0.68% and the size of the particles are 200-270 mesh, 270-325 mesh and 325 mesh. All specimens measured Ag:Hg, 5:8 by weight and triturated for 46 seconds in a mechanical amalgamator, and packed by Amalers Spring Tester with condensation pressure 300㎏/㎠ and 700㎏/㎠. From the experiments, we obtained the following results. 1. It was observed that the dimensional change reached at 13 microns per centimeter during the first 24-hour period. 2. the flow rate exhibits 2% during the succeeding 24 hours. 3. It was found that the compressive strength reached at 3,800㎏/㎠ at the first 8 hours.

참깨의 栽培環境이 收量構成要素, 脂肪酸組成 및 잎마름病 發生에 미치는 影響

李徹熙,朴然圭,朴栽成,崔仁植 충북대학교 농업과학기술연구소 1994 農業科學硏究 Vol.12 No.1

This experiment was carried out to investigate the effect of environments on yield components, fatty acid composition and leaf blight caused by Corynespora cassicola in sesame. Comparing yield components with different experimental locations, weight of 1,000 grains and maturation rate of grains were lower in Boeun area than that in other areas and there were no significantly different among soil textures. The repeated cultivation of sesame, 2-6 years, increased the occurrence rate of Corynespora leaf blight and fungi density of soil more than that with cultivation of first year and crop rotation. Yield and yield components were also decreased more with the repeated cultivation than that with first year cultivation. In fatty acids of sesame seeds, concentration of oleic acid was slightly high with sesame seeds harvested in Jungweon and Boeun areas, while linoleic acid was slightly high in Jecheon area located on the northern part of Chungbuk province. Concentration of palmitic and stearic acids which are saturated fatty acids were high in loam soil, while linoleic acid which is unsaturated fatty acids was no different among soil texture. Concentration of oleic acid was decreased more in the repeated cultivation of first year cultivation. Oil content was high in Jungweon area and with loam soil, and it was decreased through the repeated cultivation of sesame.

연속냉간압연의 두께제어 모델 개발에 관한 연구

손준식,김일수,권욱현,최승갑,박철재,이덕만 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.5

The quality requirements for thickness accuracy in cold rolling continue to become more stringent, particularly in response to exacting design specification from automotive customers. One of the major impacts from the tighter tolerance level is more unusable product on the head end and tail end of tandem mill coils when the mill is in transition to or from steady state rolling condition. A strip thickness control system for a tandem cold steel rolling mills is composed with blocked non-interacting controller and controllers for strip thickness and tension control of each rolling stands. An intelligent mathematical model included an elastic deformation of strip has been developed and applied to the field in order to predict the rolling force. The simulated results showed that the effect of elastic recovery should be included the model, even if the effect of elastic compression was not important.

KF114와 KB108 원료가공업의 연기증 Nicotine 및 Tar 함량의 변화

이철희,임흥빈,신주식,석영선 충북대학교 연초연구소 2004 煙草硏究 Vol.19 No.-

궐련담배 연기 중 Tar와 Nicotine 함량은 대부분의 국가에서 담배 포갑지에 표시하도록 규정하고 있으며 우리나라에서도 2003년부터 시행하고 있다. 그리하여 궐련담배 제품의 설정목표에 따라 엽배합의 방안을 강구하고자 우리나라에서 생산하고 있는 황색종과 버어리종의 주 품종인 KF114와 KB108의 원료 가공엽을 김천원료공장과 남원료공장에서 착엽위치 및 등급별로 채취하여 연기 중 Nicotine, Tar 및 CO 함량을 조사하였으며, 그 결과를 요약하면 다음과 같다. 1. 원료엽 중 니코틴 함량은 황색종 KF114에 비하여 버어리종 KB108이 높고, 본엽과 상엽에서는 등급이 낮을수록 함량이 높고, 중엽과 하엽에서는 등급이 낮을수록 함량이 낮았다. 2. 황색종 KF114는 궐련담배 1개비 당 중량이 본엽, 중엽, 상엽, 하엽 순으로 무거웠고, 엽위별 등급간에는 등급이 높을수록 무거웠다. 연소시간과 흡연회수는 본엽, 상엽, 중엽, 하엽 순으로 길고 많았다. 3. 버어리종 KB108은 궐련담배 1개비 당 중량이 상엽, 본엽, 중엽, 하엽 순으로 무거웠고, 엽위별 등급간에는 등급이 높을수록 무거웠다. 연소시간은 상엽, 본엽, 중엽, 하엽 순으로 길었으며, 중엽과 하엽에서는 등급이 높을수록 본엽과 상엽에서는 등급이 낮을수록 길었다.4. 황색종 KF114 원료 가공엽의 연기 중 니코틴과 타르 함량은 본엽에서는 등급이 낮을수록 높고, 중엽과 하엽에서는 등급이 높을수록 높은 값을 나타냈다. CO 함량은 본엽, 중엽, 상엽, 하엽순으로 많았고, 등급간 차이는 니코틴과 타르 함량에 대한 등급간 차이보다 적었다. 5. 버어리종 KB108 원료 가공엽의 연기 중 니코틴과 타르 함량은 상엽과 본엽에서는 등급이 낮을수록 높고, 중엽과 하엽에서는 등급이 높을수록 높은 값을 나타냈다. CO의 함량은 상엽, 본엽, 중엽, 하엽 순으로 높았고, 엽위 별 등급간에 차이가 없었다. 6. 잎담배 종류 및 가공엽의 등급에 따라 nicotine/tar 및 Co/tar 비율에 차이가 있는 것을 알 수 있으며, 엽위가 낮을수록 비율도 감소하였다. 7. 버어리종 KB108는 흡연회수, 니코틴, 타르및 CO가 각각 정의 상관관계가 인정되었으나, 황색종 KF114에서는 CO와 니코틴, CO와 타르 간에는 상관관계가 없었다. In most countries, nicotine and tar contents of cigarette smoke should be represented on the cigarette pack by law. It has been carrying out in Korea from 2003. In order to control those contents, It was tested the contents of tar, nicotine, carbon monoxide (CO) of smoke components and puff number for blending two major varieties produced in Korea, KF114, a flue-cured, and KB108, a burley. The processed leaf tobacco were taken from Kim-cheon and Ock-cheon leaf tobacco processing factory. The results were summarized as followed ; 1. Nicotine contents of processed leaf tobacco were higher in KB108, a burley, than in KF114, a flue-cured. Nicotine contents of leaf and tips were higher in low-grade leaves than in high-grade leaves, but those of cutters and lugs were lower in low-grade leaves than in high-grade leaves. 2. The weight per cigarette of KF114 was heavier in the order of leaf, cutters, tips and lugs, and was heavier in high-grade leaves than in low-grade leaves. Combustion time was longer and puff number was more in the order of leaf, tips, cutters and lugs. 3. The weight per cigarette of KB108 was heavier in the order of tips, leaf, cutters and lugs, and was heavier in high-grade leaves than in low-grade leaves. Combustion time was longer in the order of tips, leaf, cutters and lugs. The time of cutters and lugs was longer in high-grade leaves than in low-grade leaves, but those of leaf and tips was longer in low-grade leaves than in high-grade leaves. 4. Nicotine and tar contents of the smoke from the processed leaf tobacco of KF114 were higher in low-grade leaf than in high-grade leaf and cutters and lugs were higher in high-grade than in low-grade. CO contents were higher in the order of leaf, cutters, tips and lugs. The difference of CO contents between different grades was lower than that of nicotine and tar contents. 5. In nicotine and tar contents of the smoke from the processed leaf tobacco of KB108, leaf and tips were higher in low-grade than in high-grade and cutters and lugs were higher in high-grade than in low-grade. CO contents were higher in the order of tips, leaf, cutters and lugs. There was no significant difference of CO contents between different grades of the stalk position. 6. Nicotine/Tar and CO/Tar ratios showed significant difference according to tobacco variety and grade of processed leaf tobacco. The ratios were reduced in lower stalk position. 7. There were positive correlations between puff number, nicotine, tar and CO contents in KB108, but there were no correlations between CO and nicotine, or CO and tar in KF114.

Enterococcus faecalis 추출물이 임파구의 IL-2, IL-4, TGF-β1분비에 미치는 영향에 관한 연구

김현식,이우철,손원준,이상탁,김철호,임성삼 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.1

In order to examine the immunoresponse of host cells to Enterococcus faecalis, this in vitro study monitored the production of Interleukin-2 (IL-2), Interleukin-4 (IL-4) and Transforming growth factor-β1 (TGF-β1) in human lymphocytes. Lymphocytes were activated with PHA in the presence or abscence of sonicated extracts of E. Faecalis (SEF) and further incubated for 72 hours. The level of each cytokine was measured by ELISA. Data were analyzed with Kruskal-Wallis test and Mann-Whitney U test (P < 0.05). PHA-activated group did exhibit higher level of IL-2 and IL-4 than untreated control group. The levels of expression of both cytokines were significantly decreased following the treatment of high (25㎍/㎖) and medium concentration (12.5㎍/㎖) of SEF (P > 0.05) than those of PHA activated group. But low concentration (5㎍/㎖) of SEF showed th similar level of IL-2 and IL-4 production as those of PHA activated group. TGF-β1 was unaffected by SEF treatment. These results suggested that E. faecalis may suppress IL-2 and IL-4 production by lymphocytes and this could be one of possible factors why E. faecalis are found frequently in the teeth with failed endodontic treatment. 근관치료의 실패원인 중 중요한 세균으로 알려진 Enterococcus faecalis는 최근에 중요성이 더해지며 많은 연구들이 진행중이다. 여러가지 기전들이 보고되고 있으나 면역반응에 관한 연구는 거의 알려져 있지 않은 상태이다. 본 연구에서는 Enterococcus faecalis의 초음파 분쇄 추출물을 성인의 말초혈액으로부터 얻은 임파구에 적용시켜서 여기서 분비되는 interleukin-2, interleukin-4, transforming growth fater-β1의 농도를 Enzyme linked immunosorbent assay (ELISA)로 측정하여 비교, 평가하는 것을 목적으로 한다. E. faecalis를 적절한 조건에서 배양한 뒤 초음파 분쇄를 하여 추출물을 얻어냈다. 임파구는 건강한 성인의 말초혈액에서 추출하여 분리하였다. 임파구를 적절한 농도의 mitogen (Phytohemagglutinin: PHA)으로 자극시킨 뒤에 다양한 농도의 E. faecalis 초음파 추출물을 적용시키고 72시간 동안 배양하였다 ELISA를 이용하여 IL-2, IL-4,TGF-β1 의 농도를 측정하였다. 실험결과는 Kruskal-Wallis test, Man-Whitney rank sum test (p < 0.05)를 사용하여 통계처리 하였다. 실험결과 PHA로 처리한 군은 아무것도 처리하지 않은 군에 비해서 IL-2, IL-4의 수치가 유의성 있게 높았다 (p < 0.05). PHA로 처리한 군중에서 고농도와 중농도의 sonic extract of E. faecalis (SEF)로 처리한 군은 그렇지 않은 군에 비해서 IL-2 IL-4의 농도가 유의성 있게 낮았다 (p < 0.05). PHA로 처리한 군중에서 저농도의 SEF로 처리한 군은 그렇지 않은 군과 비교하여 유의할 만한 차이를 보이지 않았다.TGF-β1의 농도는 모든 군에서 유의할 만한 차이를 보이지 않았다 (p > 0.05). 따라서, E. faecalis의 추출물은 임파구의 IL-2, IL-4의 분비능력을 저하시킨다고 할 수 있다.

장기증분원가의 산출과 활용에 관한 비판적 검토 : 통신산업의 사례 A Case of Telecommunication Industry

홍철규,안태식 대한경영학회 2003 大韓經營學會誌 Vol.16 No.5

Traditionally, regulators have relied on accounting-based historical costs for price regulation in regulated industries including telecommunications, electricity and gas. With the introduction of competition, however, the economic cost called 'long run incremental cost (LRIC)' is increasingly being adopted in these fields. This study critically analyses and discusses from the accounting and economics perspectives the 'standard cost model' which was recently developed to compute LRIC in the Korean telecommunications industry. A special attention is paid to the issues: assumptions about the degree of efficiency, departure from economic capital costs, errors on the limited utilisation of cost drivers and cost estimation, capacity costing and sensitivity, unbalanced burden of risk(real option). This cost model produces costs conceptually different from accounting costs. However, accounting scholars need to pay attention to the economic cost model as it is an important case where the abstract concept of an economic cost was applied to a real world situation. In addition, LRIC has relevance to strategic management accounting since LRIC is conceptually similar to the costs which new efficient entrants would incur and thus allows firms to understand their competitive positions. This study has also important implications for management accounting practitioners who are expected to provide cost information of the firm itself as well as outside information including regulatory environment, competitors' strategies, and new production processes and technologies etc.

새로운 각도 다중화 방법을 이용한 홀로그래픽 광 메모리 시스템의 구현과 응용

김철수, 윤경식 김천대학교 1997 김천대학교 논문집 Vol.18 No.-

It is proposed that an holographic optical memory system for image storage in BaTiO3 crystal using new angular multiplexing method which controls the incident angle of reference beam electrically. In the new angular multiplexing method, the incident angle of the reference beam is controlled by using BPH(binary phase hologram), which is designed and optimized with SA(simulated annealing) algorithm and represented on LCTV(liquid crystal television) for real-time processing. The reference beam can be generated anywhere in two dimensional planes by Fourier transform of the BPH on the LCTV which is controlled by a computer. So, the vertical and horizontal incident angle of the reference beam on the BaTiO3 can be controlled simultaneously. Thus the proposedl holographic optical memory system is simple and stable because there is no mechanical movement in storage and reconstruction process of the images. By using the proposed system, we demonstrated storage and reconstruction experiments for four binary images. We also demonstrated an application experiment that can acquire large number of images than that of the stored images by controlling the number of reference beams. Through this experiment, the proposed holographic optical memory system is expected to be used in the realization of the weighted optical interconnections for optical computing and communications. 기준빔의 입사각도를 전기적으로 제어하는 새로운 각도 다중화 방법을 이용하여 BaTiO3에 영상을 저장히기 위한 홀로그래픽 광메모리 시스템을 제안하였다. 새로운 각도 다중화 방법에서, 기준빔의 입사각도는 SA 알고리듬으로 설계되고 최적화된 BPH를 이용하여 제어하며, 실시간 처리를 위해 LCTV에 표현한다. 기준빔은 컴퓨터에 의해 제어되는 LCTV위의 BPH를 푸리에 변화하므로써 이차원 평면 어느곳에서나 생성할 수 있어 BaTiO3에 입사되는 기준빔의 수직측 및 수평측 입사각도를 동시에 제어할 수 있다. 그러므로 제안된 홀로그래픽 광메모리시스템은 영상의 저장과 재생과정에서 기계적인 움직임이 없기 때문에 간단하고 안정한다. 제안된 시스템을 이용하여 네개의 이진 영상을저장하고 재생하는 광실험을 하였다. 또한 저장된 영상의 수보다 더 많은 수의 영상을 기준빔의 수를 제어하여 얻을 수 있는 응용실험도 하였다. 이 설험을 통하여 제안된 홀로그래픽 광메모리 시스템은 광컴퓨팅 및 통신에서 가중치 광연결을 실현하는데 이용될 것으로 기대된다.

심부전 백서의 대동맥과 폐동맥에서 보이는 C형 이뇨단백에 대한 이완반응의 이상

김철호,김광일,조영석,조주희,오병희,이명묵,박영배,최윤식,이영우 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.8

고압맥동 평류자극이 가토 상처치유에 미치는 영향

김식현,박래준,권혁철 한국전문물리치료학회 1996 한국전문물리치료학회지 Vol.3 No.3

한국인 태아의 악안면 성장 발육에 관한 연구

양원식,이석근,김철수 대한치과교정학회 1990 대한치과교정학회지 Vol.20 No.3

The objective of this study was to understand the major changes of craniofacial dimensions and spatial growth pattern during the late embryonic and fetal period of human fetures. This study was performed with the selective materials of normal fetuses received from the Registry of Congenital Malformation of Seoul National University Hospital. The specimens consisted of nineteen embryos and sixty-six fetuses. The photomicrographs from mid-segittal sections of embryos were used for angular measurement, and the lateral cephalograms taken with soft X-ray were also measured in liners and angular aspects. All of the anatomical landmarks for the tracing of the photomicrographs and cephalograms were referred to the previous reports on literature. The sequential changes of prenatal craniofacial dimensions and agles were analyzed statistically and discussed on the focus about the developmental growth directions of human oro-facial structure arised from heterogeneous origins. The results are as follows, 1) Cranial base angle was almost formed at about 6 weeks old embryos with the average angle of 127.4 ±6.33°(n=3) and it was almost constant onwards. 2) The linear increase rates of anterior cranial base length and anterior facial height exceeded those of the posterior cranial base length and posterior facial height, and the maxilla grows more rapidly on the horizontal dimension than the vertical dimension during the fetal period. 3) The angular relationship between the anterior cranial base and palatal plane decreased slightly during the fetal period, disclosing 11°at 12th week gestation and 5°at 41th weeks gestation. 4) Gonial angle was maintained almost constantly at about 130° during the fetal period from 12 weeks to 41 weeks of gestation.