• 한국분말재료학회지
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• 제3권1호
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• pp.13-24
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• 1996

Two grades of Permalloy strips, Fe-45Ni(PB) and Fe-78Ni-4Mo-5Cu(PC) were fabricated by powder rolling process from elemental powder mixtures. The roll compacted green strips were sintered, homogenized, cold rolled with or without an intermediate annealing and finally heat treated to measure magnetic properties. For a given thickness reduction, rolling with an intermediate annealing was found more effective to achieve a full densification with no visible micropores and also to obtain better magnetic properties. Increasing the final rolling reduction also produced a marked improvement of the magnetic properties whereas the cooling rate during the final heat treatment has little effect in both grades. Addition of a small amount, 0.4% Mn slightly degraded the properties. As an overall, The PM strips produced via powder rolling yielded the similar soft magnetic properties to the corresponding commercial grades produced via wrought processing.

• 한국공작기계학회논문집
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• 제16권6호
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• pp.125-132
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• 2007

Inherent dynamic interaction between flexible disk and workpiece creates partially non-flat surface profile. A flat zone was defined using minimum depth of engagement. Several key parameters were defined to explain the characteristics of the zone. Process conditions including disk rotation speed, initial depth of cut and feed speed were varied to produce product profile database. Correlation between key factors was examined to find the characteristic dependencies. Trends of key parameters were displayed and explained. Higher flat zone ratio was observed for lower depth of cut and higher disk rotation speed. Ratio of minimum depth of cut against target depth of cut increased for higher feed speed and disk rotation speed but was insensitive to the depth of cut variation. The process transition was visualized by continuously displaying instantaneous orientation of the deflected disk and the location of key parameters were clearly marked for comparison.

• 제어로봇시스템학회논문지
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• 제17권5호
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• pp.479-483
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• 2011

The automation of production process is actively expanding for the purpose of the cost reduction and quality assurance. Among these, automatic tracking of the product along the whole process of the production is also important topic. Typically this is done by adopting OCR technology. Conventional OCR technology operates well on the rather good quality of the image like as printed characters on the paper. In industrial application, IDs are marked on the metal surface, and this cause the height difference between background material and character. Illumination systems that guarantee an image with good quality may be a solution, but it is rather difficult to design such an illumination system. This paper proposes an algorithm for the recognition of vehicle's ID characters using edge projection and PCA (Principal Component Analysis). Proposed algorithm robustly operates under illumination change using the same parameters. Experimental results show the feasibility of the proposed algorithm.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.24-25
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• 2006

High-Speed Centrifugal Compaction Process is one of slip-using compacting method originally developed for processing of oxide ceramics. In this study, we apply the HCP to ultra-fine (0.1 micron) WC powder. Organic liquid of heptane was chosen as dispersing media to avoid possible oxidation of WC. The mixing apparatus was a key to obtain dense compacts. Only the slips mixed by high energy planetary ball mill were packed up to 55% by the HCP, and sintered to almost full density at 1673 K without any sintering aids. This sintered compact marked Vickers hardness of Hv 2750 at maximum.

• 약학회지
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• 제54권4호
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• pp.309-315
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• 2010

The Positive List System was newly introduced in South Korea as of January 2007. This study aims to survey and compare perception of and attitudes toward the Positive List System in the process of new drug listing that health professionals and pharmaceutical companies have. 50 professionals and 52 companies answered the questionnaire regarding health policy environments, policy decision/enforcement process, policy effects and satisfaction related to introducing the Positive List System. SAS 9.1 was used for statistical analyses. The results showed that participants had the general sympathy with health policy environments for the introduction of the Positive List System into South Korea. However, the response rates of policy decision/enforcement process and effects were negative and these tendencies were more striking in pharmaceutical companies. As for policy satisfaction, participants marked positive responses more than negative ones. It is necessary to remedy and supplement problems with policy decision/enforcement policy and effects revealed in this study and to improve the Positive List System through gathering opinions among groups and organization concerned.

• Bulletin of the Korean Chemical Society
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• 제25권9호
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• pp.1361-1365
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• 2004

Solvatokinetic and solvatochromic behavior of bis(indolinobenzospiropyranyl) sulfide derivatives 1a-1c have been studied in various solvents. The marked negative solvatochromism is exhibited for 1a and 1b in the whole region of solvent polarity examined. Whereas, it is found only in the polar solvent region ($E_T$ > 37) for 1c. The sensitivity order to the solvent media (slope values) is 1a > 1b > 1c. The branched linear plot with a zero slope was shown for the most sterically-hindered compound 1c in the less polar-solvent region (($E_T$ < 37). The biphasic plot is indicative of dual mechanistic process, i.e., a transition state with increased zwitter-ionic character in more polar solvents and electrocyclic process with an isopolar transition state in less polar solvents.

• 한국과학교육학회지
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• 제19권2호
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• pp.173-184
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• 1999

본 연구에서는 우리 나라 초 중 고등학교 학생들의 과학 탐구 능력에 대한 종단적 추이를 분석하였다. 1997년에는 우종옥 등(1998)이 개발한 검사지를 사용하였으며, 1999년에는 이를 일부만 수정하여 사용하였다. 조사 대상은 성별, 지역별 등을 고려하여 표집하였다. 조사된 자료는 각각 횡단적으로 분석하고, 이를 바탕으로 학생들의 과학 탐구능력이 어떻게 변해 가는지 종단적 추이를 분석하였다. 조사 결과 초등학생들의 과학 탐구 능력은 유의미한차이가 없었으나, 중 고등학생들의 과학 탐구 능력은 유의미하게 향상된 것으로 나타났다. 학교 과학 교육의 질을 과학적으로 관리하기 위해서는 교육과정이 추구하는 교육 목표의 달성이 성공적으로 이루어지고 있는지를 국가수준에서 주기적으로 측정하여 부진의 원인을 진단하고 개선 방안을 계속 연구하여야 할 것이다.

• 한국융합학회논문지
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• 제9권10호
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• pp.7-12
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• 2018

빠르게 성장하고 있는 현대 사회에서 생산 공정에 비전 시스템을 활용하여 자동화 하고자 하는 수요가 급증하고 있는 추세이다. 일반적으로 영상 인식은 주로 자동차 번호판과 같은 양각 문자에 대한 연구가 대부분으로, 음각 문자 인식에 대한 연구가 매우 미미한 상황이다. 특히 타이어 표면과 같은 고무 관련 제품에 마킹 되어 있는 음각 문자들은 주변과의 명도 차이가 크지 않기에 문자나 숫자를 영상을 통하여 인식하기에 매우 어려움을 가지고 있다. 이에 본 논문에서는 타이어 표면과 같은 고무 제품에 음각으로 마킹 되어 있는 문자의 인식률을 향상시키기 위한 시스템을 제안한 것으로, 조명의 환경에 따라 유연하게 적용할 수 있다. 제안 시스템을 통하여 타이어 및 고무 제품들의 생산 공정에 적용하면 생산 및 재고 관리와 불량 검출을 신속하게 처리할 수 있어 생산 효율성이 향상될 것으로 기대된다.

• 치과방사선
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• 제11권1호
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• pp.33-40
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• 1981

The author studied on the effects of x-irradiation to the development of digital malformation in gestation rats. The time-matings occured between 6 p.m. and 8 a.m. and females with copulation. plugs at 8 a.m. were isolated and properly marked for evidence of copulation. The lower abdomen of mothers were exposed to x-irradiation on the 11½th day of gestation, the critical period developing digital malformation, respectively 100, 150, 200, 250, 300 and 350 rads. At 18½th day of post-conception total 50 pregnant females were dissected and the incidence of digital malformations were obtained. Rat embryos on the 12, 13, 14, 15, 16th day of gestation irradiated by 250 rads were examined for morphogenesis of digital malformation. Digital radiating lines were examined in water and histologically by H-E stain. Supra vital stain samples by Nile-blue sulfate in 37℃ normal saline were prepared for the observation of cell necrosis regions and morphogenesis of digits. The results obtained were as follows; 1. By x-irradiation on 11th day of gestation, digital malformations of Ectrodactylia, Syndactylia Polydactylia and Hematodactylia were developed. Ectrodactylia showed the effective relationship to the amount of irradiation, however Syndactylia ans Polydactylia did not. 2. By x-irradiation, cell necrosis of digital germ was appeared markedly, but in 48 hours after irradiation was depressed to the periphery of digital germ and in 72hours after irradiation was disappeared. Digital radiating line showed marked stage of malformation in 48hours after irradiation and continued to show the same amount of physiological cell necrosis as the compared control group in 72hours. after irradiaion. But in the Syndactylia, physiological cell necrosis was not able to be recognized. 3. Ectrodactylia induced by x-irradiation was considered as the direct resoult of cell necrosis of digital origin, however, Polydactylia and Syndactylia were considered as the resoult of some effect in repair process of x-irradiation damages.

• Journal of Plant Biology
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• 제1권1호
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• pp.27-37
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• 1958

Durlng various experiments and investigations with antigrowth virus, I studied especially the infective and antiinfective process of it in small animals, and have got following results: 1. The rabbits are easily infected with this virus, having following five stages; incubation period of 2 to 3 days, stage of fever for 2 to 4 day, transient anemic stage, transient fcteric stage and stage of lasting iron-precipitation in the spleen. 2. According to the appearance of icteruis, I have divided the rabbits into following three groups, the first gorup, weighting less than 1000g, died after appearance of icterus, the second group, weighting 1000 to 1500 g. recoy ered after appearance of icterus, and the third group, weighting more than 1500 g. recovered without the appearance of jaundice. 3. In hematological study, marked decrease in R. B. C. and Hb were recognized but various leucocytes except lymphocytes slightly increased. 4. In pathological study, the spleen exhibited marked swelling with abundent blood and indistinct border between trabeculae and pulps at the initial stage of icterus and notable atrophy at the end stage of it. There are few iron-cells in the spleen histologically at the initial stage, but they increased in number with granuar appearance at the end stage. In the first group of rabbits above mentionel, the iron-cells increase suddenly with the death of animal and show diffuse precipitation of iron. The liver and indey have defferent aspects in proportion to icterus. If icterus appears, they show markel changes with turbidity and necrosis, but without icterus they present only slight changes. 5. The neutralining antibody is easily proved in the immunized rabbits for about one year. 6. The passive immunity has the defense immunability until 10\ulcorner 7. Gunia pigs are easily infected with this virus and get the immunity. On fowls this virus can be kept in the blood for about ten days by various inoculating methods, and the fowls obtain the defensive ability by reinoculation, but are unable to succeed this ability from generation to generation. 8. when young swine are infected with this virus, their growth are disturbed and result in atrophied swine. It is therofor presumed that the etiology of the antigrowth of these atrophied swine is similar morphological and functional changes observed in the above rabbits.