• 비파괴검사학회지
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• 제28권4호
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• pp.323-330
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• 2008

소구경 배관 소켓 용접부의 고주기 피로특성윽 평가하고 피로 균열의 발생을 음향방출법을 이용하여 실시간 모니터링 하였다. 스테인리스 316L강 시험편은 가스텅스텐아크용접 공정으로 루트부에 결함이 없는 시험편과 용입불량 결함이 있는 시험편으로 준비하였다. 피로파단은 고응력 일때는 토우부, 상대적으로 저응력일 때는 루트부에서 일어났다. 피로시험동안 음향방출 카운트가 급격히 증가하는 시점을 균열의 발생 싸이클 ($N_i$)로 정의하였고 방사선투과법과 전자현미경을 이용하여 피로균열 생성 싸이클 전과 후에서 균열을 확인하였다. 소켓용접배관의 굽힘피로 손상 진단 및 감시를 위해 균열의 존재와 파괴모드 그리고 균열의 발생 싸이클에 관한 연구를 수행하였다.

• 오토저널
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• 제7권2호
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• pp.18-26
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• 1985

최근에 들어 환경보전에 대한 시민의식이 고조되고 깨끗한 자연 및 생활환경을 유지하려는 노력 이 각계에서 일고 있다. 이와 관련된 문제점의 하나가 대기오염이며 이 오염원 중의 하나가 자 동차 배기물로서 특히 탄화수소(hydrocarbon:HC), 일산화탄소(CO), 질소산화물(NO$_{x}$)에 의 한 대기오염의 심각히 대두되어 왔으며 현재 환경청 등에 의해 국가적 차원에서 자동차 배기물에 대한 규젤ㄹ 강화하려는 움직임을 보이고 있다. 미국의 경우 연도별 배기규제기준을 살펴 보면 표.1 과 같으며, 국내에서도 88년까지 미국, 일본수준으로 신규제작차의 배출혀용기준을 강화할 계획으로 있다. 표1의 규제치르 보면 60년대의 비규제기간중의 배출량에 비해 탄화수소의 경우 96%, CO는 96%, NO$_{x}$는 76%의 감소를 보여주고 있으며 이 규제치는 5만mile을 규정된 방법으로 주행한 후 복잡한 사이클과정의 연방정부 시험절차 (Federal Test Procedure, FTP 또는 Constant Volume Sampling-Cold and Hot, CVS-CH)를 거쳐 만족하여야 한다. 상기의 규제치들을 만족시키기 위한 실용적 방법으로서 촉매전환기(catalytic converter)가 채택되고 있 으며 따라 본 해설에서는 자동차용 촉매전화기에 대한 자료들을 정리하여 특성, 문제점 등을 살펴 보고자 한다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.36-41
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• 2004

STX Shipbuilding Company is under construction design the marine training ship if Korea Maritime University. Processing q this training ship development, model test results and design if general arrangement results are introduced in this paper.

• Toxicological Research
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• 제13권1_2호
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• pp.149-152
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• 1997

This test was performed to evaluate the ocular and skin irritation of EPO (Erythropoietin). The results as follows: 1. Ocular irritation test There were no observed clinical signs, body weght changes by EPO during experimental period. The acute ocular irritation index(A.O.I.), mean ocular irritation index(M.O.I.) and Day-7 individual ocular irritation index(I.O.I.) of EPO at dose of 1000U and 10, 000U were 0, respectively. Therefore we evaluated that EPO was non-toxic to eyes. 2. Skin irritation test There were no observed clinical signs, body weght changes and gross pathologic findings by EPO during experimental period. There were no observed erythema, eschar formation and edema formation on intact and abraded skin treated by EPO. The primary irritation index(P.I.I.) of EPO at dose of 1000U and 10, 000U were 0, respectively and were evaluated none irritating product about skin irritation.

• Toxicological Research
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• 제13권1_2호
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• pp.139-147
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• 1997

Four-week toxicity of EPO(erythropoietin) was investigated using New Zealand White rabbits according to the established regulations of Korean National Institute of Safety Research. Rabbits were administered intravenously seven days per week for 28 days with dosage of 0, 80, 400 and 2000IU/kg B. W./day. Animals administered with EPO showed no significant changes of body weight, water consumption and feed consumption, and no clinical signs and death. They were not significantly different from the control group in hematological and serum biochemical analysis, urinalysis, prothrombin time, and partial thromboplastin time. In this study, we concluded that EPO had no toxic effect in the New Zealand White rabbits when they were administered intravenously below 2000IU/ kg B.W./ day for 28 days.

• Toxicological Research
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• 제13권1_2호
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• pp.127-130
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• 1997

Acute toxicity of EPO(Erythropoietin) was investigated using rats and beagle dogs according to Established Regulation of Korean National Institute of Safety Research (1994. 4. 14). Rats and beagle dogs were injected intravenously with dosages of 20000 IU/kg, 2000 IU/kg, 200 IU/kg, 20 IU/kg and 2 IU/kg. In animals injected with EPO, there were neither dead animals nor significant changes of body weights. In addition, no differences were found between control and treated groups in clinical signs and autopsy findings. Therefore $LD_50$ of EPO was considered to be higher than 20000 IU/ kg B. W. in rats and beagle dogs.

• Toxicological Research
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• 제13권1_2호
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• pp.131-138
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• 1997

Group of 40 male and 40 female Sprague-Dawley rats were given daily intravenous injections of different dosage of Erythropoietin (EPO), 80 IU/ kg/day (low dosage group), 400 IU/ kg/day (middle dosage group), or 2000 IU /kg/day (high dosage group)for 4 weeks by tail vein according to Established Regulation of Korean National Institute of Safety Research (1994. 4. 14). Appearance, behavior, mortality, and food consumption of rats of treated groups were not affected during the experimental periods. No significant EPO (erythropoietin)-related changes were found in urinalysts, eye examination, hematology, serum chemistry, and organ weight. No histopathological lesions were observed in both control and treatment groups. Our results strongly suggest that no toxic changes were found in rat treated intravenously with EPO (erythropoietin)for 4 weeks.

• Toxicological Research
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• 제14권2호
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• pp.217-226
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• 1998

SDK (skin decontamination kit) is new skin decontaminant which is developed by ADD (Agency for defence development). In this study, four-week toxicity of SDK was investigated using beagle dogs and Sprague-Dawley rats. The beagle dogs and Sprague-Dawley rats were dressed topically seven days per week for 28 days, with dosage of 0, 0.25, 0.8 and 1 g/kg/day. respectively. Animals treated with SDK did not cause any death and show any clinical signs. They did not show any significant changes of body weight, feed uptake and water consumption. They were not significantly different from the control group in urinalysis, ocular examination and histopathological examination. In hematological and serum biochemical assay, there were no-dose-defendent changes. Therefore, SDK was not indicated to have any toxic effect in the beagle dogs and Sprague-Dawley rats when it was dressed topically below the dosage 1 g/kg/day for four weeks.

• Toxicological Research
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• 제14권2호
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• pp.211-216
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• 1998

In order to evaluate the mutagenic potential of SDK(skin decontamination kit) produced by Agency for Defense Development(ADD), were performed Salmonella typhimurium reversion assay, chromosomal aberration test on chinese hamster ovarian cells and in vivo micronucleus assay using mouse bone marrow cells according to the established regulation of Korean Food and Drug Administration. In the reverse mutation test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 did not in-crease the number of revertant at any of the concentration tested in this study. SDK did not increase the number of cells having structural or numerical chromosome aberration in cytogenetic test. In mouse micronucleus test, no significant increase in the occurrence oj micro nucleated polychromatic erythrocytes were observed in ICR male mice intraperitoneally administered with SDK. These results indicate that SDK has no mutagenic effects under these experimental conditions.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2016년도 제54차 하계학술대회논문집 24권2호
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• pp.33-36
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• 2016

발사통제시스템의 주요 구성장치인 카운트다운 타임 생성 시스템은 카운트다운 신호를 생성하여 타 시스템에 제공하는 임무를 수행한다. 발사 관련 주요 장비들은 카운트다운 타임 생성 장치로부터 수신한 카운트다운 타임 정보에 따라 기능 수행을 하므로 안정적인 카운트다운 타임의 제공이 필수적이다. 따라서 카운트다운 타임 생성 시스템은 신뢰성과 고장 감내성을 보장하기 위한 설계가 요구된다. 이를 위해서는 시스템의 신뢰성을 보장하기 위한 방안으로 구성 장치들을 이중화하고 고장을 실시간 감시하여 고장 발생시 Active 장치에서 Standby 장치로의 절체 운용에 대한 설계가 필요하다. 본 논문에서는 카운트다운 타임 생성 장치의 이중화 설계에 따른 실시간 고장 감지 및 절체 운용 방법과 기능 시험 결과에 대하여 기술하였다.