• 한국농림기상학회지
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• 제19권3호
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• pp.130-139
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• 2017

기상청 동네예보 풍속으로부터 농작물의 강풍피해를 예측하기 위해, 방재기상관측지점 19곳의 2012년 풍속자료를 이용하여 기상청 동네예보의 3시간 간격과 동일한 0000, 0300 ${\cdots}$ 2100 시간대의 풍속과 직전 3시간 동안의 최대풍속 간의 관계를 직선회귀식으로 표현하였다. 매 3시간 마다 추정된 최대풍속 중 가장 큰 값을 일 최대풍속으로 간주하고, 이 때의 추정오차를 정규분포와 Weibull 분포 확률밀도함수로 표현하였다. 또한 일 최대풍속과 작물 피해 임계풍속 간의 편차를 추정오차 기반 확률 분포에 적용하여 확률누적값으로 풍해 '주의보'와 '경보' 단계를 설정하였다. 19지점별 최대풍속 추정 회귀계수(a, b)와 추정오차의 표준편차 및 Weibull 분포의 모수(${\alpha}$, ${\beta}$)는 공간내삽하여 분포도로 작성하고 종관기상관측지점 4곳(순천, 남원, 임실, 장수)의 격자값을 추출하였다. 이를 이용해 2012년의 일 최대풍속을 추정하고, 배 만삼길 품종의 낙과 발생 사례에서 제시된 풍속 10m/s를 낙과 임계풍속으로 간주, 풍해 주의보와 경보를 판정하였다. 그 결과, 최대풍속 추정오차를 Weibull 분포로 표현하여 풍해 위험 정도를 판정하는 것이 정규분포만을 이용하는 것보다 더 현장에 정확한 주의보를 발령할 수 있었다.

• Journal of Biosystems Engineering
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• 제5권2호
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• pp.58-66
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• 1980

A survey was conducted to investigate the power tiller accidents. Eight provinces were covered for this study, and 278 power tiller owners were selected randomly by computer random generator. The results are summarized as follows : A. Frequency of accident. (1) Each power tiller had an accident 0.98 times a year and once every 361 hours of use. Higher frequency of accident was found during the miscellaneous operations including the preparation for farming operation, and there was one accident for every 92 hours of use. (2) The power tiller, which are more than six years old, met an accident 1.19 times a year , or one every 311 hours of use. This value was the highest one compared with any other group. (3) Kerosene engine power tillers met an accident 0.97 times a year, or one every 389 hours of use. It was one tie a year, or once every 329 hours of use for diesel engine power tillers. (4) Among diesel-engine power tillers, 10 horse-power group showed a higher frequency tillers. B. Cause of accident (1) The accidents of power tiller were mainly of sefety , which occurred due to the lack of attention during the operation and 47.4% of the total accidents. The next was of accidental, which represented 26.3% of the total accidents. (2) High percentage of safety accidents occurred during the preparation for farming operation including adjustment. Most of the accidental accidents occurred during the transportation. (3) Lower frequency of accident was found in the power tiller group which were operated by the 21-40 years old operator in comparison with that of the power tiller which was operated by other age group. Power tillers which were operated by high school graduates experienced less accidents compared to other education levels. C. Damage by accident (1) Eighty seven pescents of the total accidents caused damage to the power tiller operator , and 13 % of the total accidents caused property damage only. (2) With regard to the damage to the power tiller operator, 73.8% of the total accidents caused light injury but 26.3% caused heavy injury. (3) Accidents which occurred during machine preparation , and farming operations caused minor injury to the operator, but the accidents during transportation caused heavy injury which cost more than 15 days for recovery. (4) Among the 39 accidents , which caused property damage 18 accidents were from the transportation . Among the total property damage accidents 53.8% were light one which cost only less than 1,000 won. (5) The property damage from each accident cost 1,017 won, on the average, with regard to the kinds of operation, the highest property damage occurred during transportation work, with the value of 2, 965won.

• 자원ㆍ환경경제연구
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• 제23권4호
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• pp.689-718
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• 2014

본 연구는 홍수피해가 관련 산업부문의 자본을 감소시킬 경우 국가경제에 미치는 파급효과를 완전예측형 동태CGE모형을 이용하여 2010년을 기준연도로 분석하였다. 여러 홍수피해 항목들 중에서 통계자료가 확보될 수 있는 농경지, 선박, 공공시설의 물적 피해 항목에 분석을 한정하였다. 홍수피해의 시나리오는 1991년~2010년 기간 홍수피해를 2010년 기준으로 불 변화하여 항목별 홍수피해의 평균과 최대로 각각 채택하였다. 분석 결과, 산업별 생산의 경우에는 자본스톡이 직접적으로 감소하는 수산업+운송업의 생산 감소율이 가장 크고 다음으로 농임 업의 생산감소율이 큰 것으로 나타났다. GDP는 충격 기준연도에 벤치마크 해 대비로는 0.001%~0.057% 그리고 초기 자본감소 대비로는 약 11% 감소하는 것으로 분석되었다. 동태적으로는 GDP는 말기로 가정된 2030년까지 서서히 감소하는 것으로 분석되어서 홍수피해가 자본을 감소시킬 경우 국가경제에 미치는 영향력은 오래 지속되는 것으로 나타났다.

• 산업경영시스템학회지
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• 제24권68호
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• pp.51-65
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• 2001

This study is to make LCIA(Life Cycle Impact Assessment) easier as a methodology of environmental scores(called E-score) that integrated environmental load of each emission substance based on environmental damage such as in human health, ecosystem and resources category. The concept is to analyzes the LCI(Life Cycle Inventory) and defines the level of environment damages for human health, ecosystem and resources to objective impact assessment standard, and makes the base of marginal damage to calculate the damage factor, which can present the indication that can establish the standard value of environmental impact. First, damages to human health are calculated by fate analysis, effect analysis and damage analysis to get the damage factor of health effect as a DALY(Disability Adjusted Life Years) unit. Second, damages to ecosystem are calculated by fate analysis, effect analysis and damage analysis to get the damage factor of the effect as a PDF(Potentially Disappeared Fraction) unit through linking potentially increased disappeared fraction. Third, damages to resources are carried out by resource analysis and damage analysis for linking the lower fate to surplus energy conception to get damage factor as a MJ(Mega Joule) unit. For the ranking of relative environment load level each other, LCIA can be carried out effectively by applying this E-score methodology to the particular emission substances. A case study has been introduced for the emission substances coming out of a tire manufacturer in Korea. It is to show how to work the methodology. Based on such study result, product-designers or producers now can apply the E-scores presented in this study to the substances of emission list, and then calculate the environment load of the product or process in advance at any time and can see the environment performance comparatively and expected to contribute to the environmental improvement in view of environmental pollution prevention.

• Smart Structures and Systems
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• 제18권3호
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• pp.501-523
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• 2016

Electromechanical impedance (EMI) based structural health monitoring is performed by measuring the variation in the impedance due to the structural local damage. The impedance signals are acquired from the piezoelectric patches that are bonded on the structural surface. The impedance variation, which is directly related to the mechanical properties of the structure, indicates the presence of local structural damage. Two traditional EMI-based damage detection methods are based on calculating the difference between the measured impedance signals in the frequency domain from the baseline and the current structures. In this paper, a new structural damage detection approach by analyzing the time domain impedance responses is proposed. The measured time domain responses from the piezoelectric transducers will be used for analysis. With the use of the Time Frequency Autoregressive Moving Average (TFARMA) model, a damage index based on Singular Value Decomposition (SVD) is defined to identify the existence of the structural local damage. Experimental studies on a space steel truss bridge model in the laboratory are conducted to verify the proposed approach. Four piezoelectric transducers are attached at different locations and excited by a sweep-frequency signal. The impedance responses at different locations are analyzed with TFARMA model to investigate the effectiveness and performance of the proposed approach. The results demonstrate that the proposed approach is very sensitive and robust in detecting the bolt damage in the gusset plates of steel truss bridges.

• 대한본초학회지
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• 제29권5호
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• pp.39-43
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• 2014

Objectives : The purpose of this sutdy was finding out the origin and daily dose of Allii Fistulosi Bulbus in Treatise on Cold Damage Diseases. Methods : In order to estimate the origin and daily dose of Allii Fistulosi Bulbus, I researched the Treatise on Cold Damage Diseases, Synopsis of Prescription of the Golden Chamber, Classified Emergency Materia Medica, Compendium of Materia Medica, and Huangdi's Internal Classic. Results : According to some important herbal textbooks, Allii Fistulosi Bulbus had no seed, was reproduced by rhizome, and its leaves were soft. Chongbaek in Treatise on Cold Damage Diseases did not include word 'raw'. The unit of the dose of it was the number of article. So Allii Fistulosi Bulbus in Treatise on Cold Damage Diseases was not Daepa but Jokpa, and was dried, and was round shaped bulb bigger than bean. The daily dose was 4, 9, 14 articles in Treatise on Cold Damage Diseases and Synopsis of Prescription of the Golden Chamber. These were estimated equal to 1, 2, 3 Ryang. 1 Ryang equals to 6.5 g in Treatise on Cold Damage Diseases, so the daily dose of Allii Fistulosi Bulbus was estimated 6.5 g, 13.0 g, and 19.5 g. I weighed the middle-sized Allii Fistulosi Bulbuses, the result was remarkably consistent with the estimated numerical value. Conclusions : In Treatise on Cold Damage Diseases, Allii Fistulosi Bulbus was dried bulb of Jokpa of Allium fistulosum Linn$\acute{e}$ and the daily dose was 4 or 9 articles, respectively equaled to 1 Ryang, 2 Ryang and 6.5 g, 13 g.

• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1577-1582
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• 2003

This study was conducted to determine the effects of prophylactic supplementation of vitamin E and Se on oxidative damage and antioxidant status. Fifteen healthy male buffalo (Bubalus bubalis) calves between the age of 6 to12 months were divided into three groups of five animals each: Group I-control, group II-endotoxic shock group infused with lyophilized E coli endotoxin @ 5 ${\mu}g$/kg body wt, and group III-supplemented with vitamin E @ 250 mg and Se @ 7.5 mg, one month prior to induction of endotoxic shock. All the animals in group II and group III exhibited signs of endotoxic shock. When the endotoxic shock was induced, there was significant (p<0.05) increase in the circulating levels of malonyl dialdehyde MDA (an indicator of lipid peroxidation). In the supplemented group III the magnitude of formation of MDA was also less as compared to group II at every stage of study. There was significant (p<0.05) decrease in circulating levels of SOD, GSH-Px, Catalase and G-6-PD activity from the normal (0 h) value with passage of time. As a result of endotoxic shock, these values reached a lowest value, and then showed a tendency towards the 0 h value. Prophylactic supplementation with vitamin E and Se was successful in reducing the quantum of oxidative damage due to formation of free radicals because of endotoxic shock.

• 한국인터넷방송통신학회논문지
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• 제10권6호
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• pp.113-118
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• 2010

주행 중인 자동차 타이어의 손상을 검출하기 위해 타이어에서 발생하는 초음파 신호에 대한 스플릿 스펙트럼 처리 알고리즘을 연구하였다. 스플릿 스펙트럼의 최대값을 추정하는 알고리즘을 사용하여 정상적인 타이어와 손상 물질에 의해 손상된 타이어에 대한 처리 결과를 비교하였다. 자기상관함수를 이용한 결과, 실험에 사용된 손상된 타이어에서는 주행속도 50km/h 일 때 162.9ms, 100km/h 일 때 84.81ms 주기로 손상 특이점을 검출 할 수 있었으며, 이에 의해 자동차 주행속도에 따른 손상 특징 점의 주기성을 이용하여 손상 물질에 의한 타이어의 손상 판단이 가능하였다.

• 한국안전학회지
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• 제30권3호
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• pp.7-12
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• 2015

CFRP composites are used as primary structural members in various industrial fields because their specific strength and specific stiffness are excellent in comparison to conventional metals. Their usage is expanding to high added-value industrial fields because they are more than 50% lighter than metals, and have excellent heat resistance and wear resistance. However, when CFRP composites suffer impact damage, destruction of fiber and interface delamination occur. This causes an unexpected deterioration of strength, and for this reason it is very difficult to ensure the reliability of the excellent mechanical properties. Therefore, for the destruction mechanism in bending with impact damage, this study investigated the reinforcement data regarding various external loads by identifying the consequential strength deterioration. Specimens were damaged by impact with a steel ball propelled by air pressure. Decrease in bending strength caused by the tension and compression of the impact side, and depending on the lamination direction of fiber and interface inside the specimen. From the bending test it was found that the bending strength reduced when the impact energy increased. Especially in the case of compression on the impact side, as tensile stress occurred at the damage starting point, causing rapid failure and a substantially reduced failure strength.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.123-128
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• 2001

The creep constants which are used to the reference stress equations of creep damage were obtained to type 316LN stainless steel, and their determining methods were described in detail. Typical Kachanov and Rabotnov(K-R) creep damage model was modified into the damage equations with reference stress concepts, and the modified equations were applied practically to type 316LN stainless steel. In order to determine the reference stress value, a series of high-temperature tensile tests and creep tests were accomplished at $550^{\circ}C$ and $600^{\circ}C$. By using the experimental creep data, the creep constants used in reference stress equations could be obtained to type 316LN stainless steel, and a creep curve on rupture strain was predicted. The reference stress concept on creep damage can be utilized easily as a design tool to predict creep life because the process, which is quantified by the measurement of voids or micro cracks during creep, is omitted.