• 한국항공우주학회지
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• 제50권7호
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• pp.471-478
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• 2022

본 논문은 한국항공대학교에서 연구 및 개발한 태양광 무인기 KAU-SPUAV에 관한 내용으로, 2020년 6월 32시간 19분 장기체공 비행에 성공한 주익 4.2m 태양광 무인기의 설계 과정에 관하여 기술하였다. 태양광 무인기의 장기체공 능력을 향상시키기 위해 항력을 줄이기 위한 원형 단면의 동체를 설계하였고, 유리섬유 복합재를 사용한 모노코크 구조를 적용하여 가볍고 튼튼한 동체를 제작하였다. 또한 4.2m 태양광 무인기의 날개 형상에 최적화된 태양광 모듈을 구성하여 배열하였고, 23[in] × 23[in] 프로펠러를 적용한 추진시스템을 구성하여 충전 및 비행 효율을 향상시켰다. 개발된 태양광 무인기는 순항할 때 평균 55W를 소비하고, 주간에 최대 165W 에너지를 공급받을 수 있으며 비행실험을 통해 장기체공 성능을 검증하였다.

• 한국작물학회지
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• 제50권2호
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• pp.147-150
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• 2005

ent-Kaurane- and ent-pimarane-type diterpenoids were isolated from the methanol extract of Siegesbeckia pubescens by column chromatography. Their structures were elucidated as ent-16$\alpha$H,17-hydroxy-kau­ran-19-oic acid (1), ent-4,17-dihydroxy-16$\alpha$-methyl-kau­ran-19-oic acid (2), ent-16$\beta$,17-dihydroxy-kauran-19-oic acid (3), kirenol (4) and ent-16$\beta$,17,18-trihydroxy-kauran­19-oic acid (5) by spectral analysis. The cytotoxicity of these compounds in Caki cells was assayed by a cell counting kit. Only one group treated with kirenol (4), an entpimarane-type diterpenoid, showed the inhibition of the cell growth in Caki cells.

• Structural Engineering and Mechanics
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• 제15권1호
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• pp.115-134
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• 2003

The Ting Kau Bridge in Hong Kong is a cable-stayed bridge comprising two main spans and two side spans. The bridge deck is supported by three towers, an end pier and an abutment. Each of the three towers consists of a single reinforced concrete mast which reduces its section in steps, and it is strengthened by transverse cables and struts in the transverse vertical plane. The bridge deck is supported by four inclined planes of cables emanating from anchorages at the tower tops. In view of the threat from typhoons, the dynamic behaviour of long-span cable-supported bridges in the region is always an important consideration in their design. This paper is devoted to the ambient vibration measurements of the bridge for evaluation of dynamic characteristics including the natural frequencies and mode shapes. It also describes the modelling of the bridge. A few finite element models are developed and calibrated to match with the field data and the results of subsequent structural health monitoring of the bridge.

• 한국항공운항학회지
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• 제27권1호
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• pp.57-68
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• 2019

The emission trading system implemented in Korea is a system in which the government allocates or sells emission rights by setting the emission allowable amount to economic players subject to the emission trading system, allowing companies to freely trade shortfall or extra money through the emission trading market. Korea also had implemented its first emission trading system scheme period of time from 2015 to 2017. As a result of the first planning period in which total of seven Korean airlines were targeted, the emission amount was about 5.51 million KAU, while the quota amount was only about 4.85 million KAU, about 116% of the actual quota was emitted and Domestic airlines have incurred additional costs of about 10.7 billion won. Due to ICAO's implementation of CORSIA, the airlines are expected to have to shoulder additional costs because purchasing exceed quota will be increased in order to offset excess emissions not only on domestic but also on international routes. Thus, this paper had analyzed the characteristics of the carbon trading system of air transport industry and suggested a mix of regulatory policies as an improvement method.

• International Journal of Computer Science & Network Security
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• 제21권7호
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• pp.284-296
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• 2021

Quality Models are important element of the software industry to develop and implement the best quality product in the market. This type of model provides aid in describing quality measures, which directly enhance the user satisfaction and software quality. In software development, the inheritance technique is an important mechanism used in object-oriented programming that allows the developers to define new classes having all the properties of super class. This technique supports the hierarchy design for classes and makes an "is-a" association among the super and subclasses. This paper describes a standard procedure for validating the inheritance metric in Quality Model for Object-Oriented Design (QMOOD) by using a set of nine properties established by Weyuker. These properties commonly using for investigating the effectiveness of the metric. The integration of two measuring methods (i.e. QMOOD and Weyuker) will provide new way for evaluating the software quality based on the inheritance context. The output of this research shows the extent of satisfaction of the inheritance metric in QMOOD against Weyuker nine properties. Further results proved that Weyker's property number nine could not fulfilled by any inheritance metrics. This research introduces a way for measuring software that developed using object-oriented approach. The theoretical validation of the inheritance metric presented in this paper is a small step taken towards producing quality software and in providing assistance to the software industry.

• 대한예방한의학회지
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• 제3권1호
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• pp.55-65
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• 1999

From January 1994 to April 1997, there was 15 survivals who was admitted to the department of internal medicine, Wonkwang Oriental Medicine Hospital in Cheun-ju, after ingestion of paraquat, and treated with Oriental and western medicine therapy. For the patients, I investigated clinical symptoms, gastroduodenoscopy, intake by oral and parenteral route, and output by urine and stool, serum ALP, AST. ALT, Bilirubin, BUN, Creatinine level and urine analysis. On admission day, the LFT level was as follows. The serum mean ALP, AST, ALT, Total Bilirubin and Direct Bilirubin was $10.05{\pm}2.75\;KAU$, $66.67{\pm}9.88\;IU／L$, $43.80{\pm}7.74\;IU／L$, $1.89{\pm}1.22\;mg／dl$ and $1.10{\pm}1.14\;mg／dl$ respectively. After that day, administered Gamdutang and checked the mean LFT level regullary. Until the 3rd day, the mean ALP, AST, ALT, Total Bilirubin and Direct Bilirubin level was $11.01{\pm}3.16\;KAU$, $56.47{\pm}7.19\;IU／L$, $59.00{\pm}7.57\;IU／L$, $2.54{\pm}1.78\;mg／dl$, $1.64{\pm}1.59\;mg／dl$ respectively. From 4th day to 7th day, the mean ALP; AST, ALT, Total Bilirubin and Direct Bilirubin level was $12.51{\pm}3.49\;KAU$, $77.85{\pm}7.17\;IU／L$, $58.00{\pm}9.09\;IU／L$, $2.54{\pm}1.97\;mg／dl$, and $1.80{\pm}1.81\;mg／dl$ respectively. From 8th day to 10th day, the mean ALP, AST, ALT, Total Bilirubin and Direct Bilirubin level was $12.43{\pm}3.14\;KAU$, $41.13{\pm}6.49\;IU／L$, $50.40{\pm}7.17\;IU／L$, $1.66{\pm}1.90\;mg／dl$ and $1.14{\pm}1.50\;mg／dl$ respectively. From 11th day to 14th day, the mean ALP, AST, ALT, Total Bilirubin and Direct Bilirubin level was $12.30{\pm}3.25\;KAU$, $31.07{\pm}3.85\;IU／L$, $43.33{\pm}5.49\;IU／L$, $1.62{\pm}1.95\;mg／dl$, $1.17{\pm}1.71\;mg／dl$ respectvely. On admission day, the mean RFT level as follows. Serum BUN and Creatinine level was $28.73{\pm}5.19\;mg／dl$ and $1.82{\pm}1.27\;mg／dl$ respectively. After that day, administered Gamdutang and checked the mean RFT level regullary. Until the 3rd day, the mean BUN and Creatinine level was $32.12{\pm}5.65\;mg／dl$ and $2.31{\pm}0.45\;mg／dl$ respectively. From 4th day to 7th day, the mean BUN and Creatinine level was $31.07{\pm}5.47\;mg／dl$ and $1.92{\pm}0.79\;mg／dl$ respectively. From 7th day to 10th day, the mean BUN and Creatinine level was $17.47{\pm}3.57\;mg／dl$ and $1.33{\pm}0.59\;mg／dl$ respectively. From 11th day to 14th day, the mean BUN and Creatinine level was $11.93{\pm}3.16\;mg／dl$, $1.27{\pm}0.38\;mg／dl$ respectively.

• 대한수학회보
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• 제57권1호
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• pp.195-206
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• 2020

The fundamental idea of this article is to present an effective way to obtain the large groups in terms of the split extension obtained by a finite cyclic group and a free abelian group rank 2. The proof of the main result on largeness property of this specific split extension groups will be given by using the connection of large groups with the groups having deficiency one presentations.

• 마이크로전자및패키징학회지
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• 제15권3호
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• pp.35-40
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• 2008

ENIG 층의 결함구조를 이해하고자 immersion gold 층의 결함을 TEM 분석을 이용하여 분석하였다. 세가지 다른 종류의 금도금액을 통하여 immersion gold 층을 얻은 후 습식적으로 TEM 시편을 만들어 이를 비교하였다 이를 통해 immersion gold 도금액의 종류에 의하여 도금막의 결함구조는 크게 영향을 받음을 확인할 수 있었다. 즉, 시안형 치환형 금도금 액을 이용하여 얻은 immersion 금도금 층인 경우에는 결정계면을 따라서 결함들이 집중적으로 존재함을 관찰할 수 있었다. 반면 유기환원제를 도금액에 첨가한 시안형 부분환원형 금도금 액을 이용하여 얻은 immersion금도금 층인 경우에는 grain boundary를 따라 존재하는 공극은 사라졌지만 $5\sim20nm$ 크기의 구형의 공극이 결정계면, 결정내를 상관하지 않고 존재하고 있음을 확인할수 있었다. 이에 비하여 아황산형 치환형 금도금 액을사용하여 얻어진 금도금 층에서는 이러한 결함들이 거의 사라지는 것을 관찰할 수 있었다.

• Structural Engineering and Mechanics
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• 제40권4호
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• pp.471-488
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• 2011

The Ting Kau Bridge in Hong Kong is a cable-stayed bridge comprising two main spans and two side spans. The bridge deck is supported by three towers, an end pier and an abutment. Each of the three towers consists of a single reinforced concrete mast strengthened by transverse cables and struts. The bridge deck is supported by four inclined planes of cables emanating from anchorages at the tower tops. In view of the heavy traffic on the bridge, and threats from typhoons and earthquakes originated in areas nearby, the dynamic behaviour of long-span cable-supported bridges in the region is always an important consideration in their design. Baseline finite element models of various levels of sophistication have been built not only to match the bridge geometry and cable forces specified on the as-constructed drawings but also to be calibrated using the vibration measurement data captured by the Wind and Structural Health Monitoring System. This paper further describes the analysis of axle loading data, as well as the generation of random axle loads and simulation of vibrations of the bridge using the finite element models. Various factors affecting the vehicular loading on the bridge will also be examined.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.757-762
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• 2014

Smoking is recognized as a health problem worldwide and there is an established tobacco epidemic in Saudi Arabia as in many other countries, with tobacco users at increased risk of developing many diseases. This cross sectional study was conducted to assess the prevalence of oral mucosal, potentially malignant or malignant, lesions associated with tobacco use among a stratified cluster sample of adults in Jeddah, Saudi Arabia. A sample size of 599 was collected and each participant underwent clinical conventional oral examination and filled a questionnaire providing information on demographics, tobacco use and other relevant habits. The most common form of tobacco used was cigarette smoking (65.6 %) followed by Shisha or Moasel (38.1%), while chewing tobacco, betel nuts and gat accounted for 21-2%, 7.7%, and 5% respectively. A high prevalence (88.8%) of soft tissue lesions was found among the tobacco users examined, and a wide range of lesions were detected, about 50% having hairy tongue, 36% smoker's melanosis, 28.9% stomatitis nicotina, 27% frictional keratosis, 26.7% fissured tongue, 26% gingival or periodontal inflammation and finally 20% leukodema. Suspicious potentially malignant lesions affected 10.5% of the subjects, most prevalent being keratosis (6.3%), leukoplakia (2.3%), erythroplakia (0.7%), oral submucous fibrosis (0.5%) and lichenoid lesions (0.4%), these being associated with male gender, lower level of education, presence of diabetes and a chewing tobacco habit. It is concluded that smoking was associated with a wide range of oral mucosal lesions, those suspicious for malignancy being linked with chewable forms, indicating serious effects.