• 수산해양기술연구
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• 제51권4호
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• pp.512-519
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• 2015

A historical tragic disaster happened by capsizing the passenger ship Sewol at South Western Sea of Korea in 16, April 2014. The ship which left Incheon harbour to bound for Jeju port passed Maengol strait and reached to approach of Byung Pung island, and then capsized and sank with a sudden inclination to the portside in the mean time of starboard the helm. In this time, the ship which has very poor stability without sufficient ballast waters and with over loading cargo listed port side caused by the centrifugal force acting to the outside of turning. A lot of cargoes not fastened moved to the port side consequently, and the ship came to beam end to capsize and sank in the end. No crews including especially captain would offer their own duties in a such extremely urgent time, as a result, enormous number of victims broke out including a lot of student. In this report, author carried out some calculation on the factors which influenced on the stability of the ship, i.e. the ship's speed, the rudder angle, the weight of cargoes and distance of movement, the surface effect of liquid in the tank. We found out that the most causes of capsize were the poor stability with heavy cargoes and insufficient amount of ballast water against the rule, and the cargoes unfastened moved one side to add the inclination as well. Above all, the owner be blamable because of the illegally operating the ship without keeping the rule.

• 대한장애인치과학회지
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• 제7권1호
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• pp.1-10
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• 2011

The purpose of this study was to examine the general attitude of dental hygiene students toward the disabled and their oral care in an effort to improve their awareness of the disabled and their accessibility to them and suggest some of the right directions for dental hygiene education related to dental treatment for the disabled. The subjects in this study were dental hygiene students at three different colleges located in South Jeolla Province. The general attitude of the selected students toward the disabled and their oral care were investigated from November 1 to December 20, 2007. The findings of the study were as follows: When their general attitude toward disabled people was checked, they agreed the most that there was nothing that the disabled lagged behind nondisabled people. Those who felt the need for that took a more positive attitude in eight items, and the differences between them and the others were significant. Whether they were cognizant of the necessity of dental treatment education for the disabled made the most significant differences to each variable of their attitude toward the oral care of disabled people, and those who were aware of the necessity showed a more positive attitude in five items. The differences between them and the others were significant. The findings of the study illustrated that the dental hygiene students took a relatively favorable attitude toward disabled people's oral health care, and that they hardly felt a sense of distance to them. So it can be predicted that they will get to take the right attitude to them in the future. Yet the dental hygiene curriculum should give more weight to dental treatment education for the disabled and offer more relevant information, since they didn't get high scores on positive attitude.

• 한국전자파학회논문지
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• 제19권1호
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• pp.61-70
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• 2008

본 논문에서는 멤스 기술의 하나인 연성 인쇄 회로 기판을 이용하여 임의의 형태로 변형이 가능한 초고주파 멤스 송신기를 제안하였다. 연성 인쇄 회로 기판은 그 무게가 가볍고 두께가 얇아 경량 소형화 모듈을 만드는데 유리한 장점이 있다. 또한, 연성 인쇄 회로 기판은 종이와 같이 유연한 특성을 가지고 있어 평면이 아닌 임의의 곡면 등에 실장할 수 있는 장정을 가지고 있다. 본 논문에서는 근거리 센서 네트워크 구성을 위한 직교 주파수 분할 다중 전송 방식을 위한 선형 무선 송신기를 설계 제작하였다. 송신 모듈의 능동 회로는 전력효율이 높고 선형성이 우수하여 전력 증폭기에 많이 사용되고 있는 InGaP/GaAs HBT 공정을 사용하여 설계 및 제작하였으며, 매칭 회로 및 필터 등의 수동 회로는 연성 인쇄 회로 기판에 직접 집적화 하여 제작하였다. 제작된 멤스 송신기는 EVM 특성을 통하여 시스템 성능을 분석하였다.

• 한국안전학회지
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• 제32권2호
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• pp.117-123
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• 2017

This study was intended to find methods of fire extinguishing system designs that can improve the equipment's usability. In this study, the fire suppression experiment through fire extinguishers and the data drawn through the experiment were analyzed, and then the guideline for the improvement of designs was presented. The procedure is as follows. A fire suppression experiment with the use of fire extinguishers was done by 43 average adults. The whole process of the fire suppression was videotaped, and then captured major scenes were analyzed with the use of RULA, a human engineering measurement tool. The analyzed data were divided into 4 steps, and then the guideline for design improvement was presented. The summary of the study is as follows. Step 1, Fire extinguisher distance step. To reduce overload occurring at the process of holding fire extinguishers suddenly, wheels are attached to the body of extinguishers, or pedestals are installed. Step 2, Fire extinguisher transportation step. The length of hose is extended, or fire fighting water is sprayed far, so that overload of legs occurring at the process of travel can be reduced. In addition, the weight of fire extinguisher shouldn't be over 2 kg. Step 3, Safety pin removal stage. Safety pins should be applied with button type, so that excessive posture of lower limbs and excessive twisting of wrists won't happen during safety pin removal process. Besides, safety pins should be designed for easy identification and operation. Step 4, Fire extinguishing agent spraying step. To reduce overload occurring at sudden spraying of fire fighting water, pressure should be increased gradually until high pressure. With the above study results applied to existing fire extinguisher design, it may contribute to reducing any fire damage.

• 한국산림과학회지
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• 제96권3호
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• pp.245-250
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• 2007

본 연구는 충북 진천의 활엽수림 지역에서 임도의 개설이 소형 설치류에 대한 영향을 파악하기 위해 실시되었다. 임도의 개설로 인해 하층식생의 피도량 증가, 상층 임관의 감소, 소경목의 증가와 같은 서식지의 변화가 발생하였다. 소형 설치류에 대한 포획 결과 두 지역에서 모두 흰넓적다리붉은쥐와 등줄쥐가 포획되었다. 흰넓적다리붉은쥐는 개설지에 비해 미개설지에서 행동권의 크기가 컸으며 포획된 개체수가 적었다. 등줄쥐는 포획 개체수와 평균 체중이 미개설지에 비해 개설지에서 모두 높은 것으로 나타났다. 또한 개설지의 임도 주변에서 많은 개체수의 소형 설치류가 포획된 반면, 미개설지에서는 전 지역에 걸쳐 비교적 고른 분포를 보였다. 임도의 개설은 그 지역에 서식하고 있는 소형 설치류의 개체수, 종 구성 및 서식지 이용 유형에 큰 영향을 미치는 것으로 판단된다.

• 한국전산유체공학회지
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• 제18권3호
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• pp.8-13
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• 2013

Drag reduction of a running vehicle is very important issue for the energy savings and emission reduction of its power train. Especially for a solar powered electric vehicle, the drag reduction and weight lightening are two serious problems to be solved to extend its driving distance under the given energy condition. In this study, the ground effect of an airfoil shaped road vehicle was studied for an optimum body design of an ultra-light solar powered electric vehicle. Clark-Y airfoil type was adopted to the body shape of the model vehicle to reduce aerodynamic drag. From the study, it was found that the drag of the model vehicle was reduced as the height(h) between ground and the lower surface of the model vehicle was decreased. It is due to the reduction of the down-wash decreasing the induced drag of the vehicle. The lift was also decreased as the height decreased. It is due to the turbulent boundary layer developed beneath the vehicle body. The drag is classified into two types; the form and friction drag. The fraction of form drag to friction one is 76 to 24 on the model vehicle. As the height(h) of the model vehicle from the ground surface increases the form drag also increases but the friction drag is in reverse.

• Asian-Australasian Journal of Animal Sciences
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• 제31권4호
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• pp.467-472
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• 2018

Objective: Molecular cloning and bioinformatics analysis of annexin A2 (ANXA2) gene in sika deer antler tip were conducted. The role of ANXA2 gene in the growth and development of the antler were analyzed initially. Methods: The reverse transcriptase polymerase chain reaction (RT-PCR) was used to clone the cDNA sequence of the ANXA2 gene from antler tip of sika deer (Cervus Nippon hortulorum) and the bioinformatics methods were applied to analyze the amino acid sequence of Anxa2 protein. The mRNA expression levels of the ANXA2 gene in different growth stages were examined by real time reverse transcriptase polymerase chain reaction (real time RT-PCR). Results: The nucleotide sequence analysis revealed an open reading frame of 1,020 bp encoding 339 amino acids long protein of calculated molecular weight 38.6 kDa and isoelectric point 6.09. Homologous sequence alignment and phylogenetic analysis indicated that the Anxa2 mature protein of sika deer had the closest genetic distance with Cervus elaphus and Bos mutus. Real time RT-PCR results showed that the gene had differential expression levels in different growth stages, and the expression level of the ANXA2 gene was the highest at metaphase (rapid growing period). Conclusion: ANXA2 gene may promote the cell proliferation, and the finding suggested Anxa2 as an important candidate for regulating the growth and development of deer antler.

• 한국항행학회논문지
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• 제24권1호
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• pp.1-8
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• 2020

본 연구에서는 항공기에 장착하여 S/C대역의 신호를 장거리 표적으로 방사하기 위한 장치를 개발하였다. 장치는 요구된 실효 등방성 복사전력을 충족시키기 위해 대역별 송신기와 광대역 안테나로 RF 인터페이스를 구성하였다. 장치의 외형은 항공기 연료탱크와 동일한 포드(pod) 형상으로 설계했고, 측정된 장치의 중량은 119.8 kg, 무게중심은 1391.35 mm 그리고 관성 모멘트는 46.07 ± 0.05(I_yy) kg·㎡과 45.36 ± 0.09(I_zz) kg·㎡로 모두 항공기 장착을 위한 요구도를 충족함을 확인하였다. 비행 안전을 확인하기 위해 전자기 간섭 시험(RE102, CE102), 환경시험(고온/저온 운용, 고도), 체계 내 전자기 적합성 시험 그리고 인체 전자기 복사 위해도 시험을 수행하였으며, 모든 항목의 시험 결과가 요구사항을 충족함을 확인하였다. 장치는 요구되는 전기적/기계적으로 요구되는 사항을 모두 충족함으로써 항공기 장착이 가능함을 확인하였다.

• 전기전자학회논문지
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• 제24권3호
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• pp.735-742
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• 2020

반도체 부품을 생산 및 검사하기 위한 다양한 공정 장비에서 상하직선운동과 회전운동을 동시에 수행하기 위한 Pick & Place 모듈이 핵심 모듈로 사용되고 있다. 기존의 Pick & Place 모듈은 회전운동을 직선운동으로 변환하는 변환장치를 사용하여 시스템의 정밀도 및 내구성이 저하되고 모듈의 크기와 무게가 증가되는 단점이 있다. 본 연구에서는 이와 같은 단점을 개선하여 변환장치 없이 상하직선운동을 구현하며, 평균 추력과 이동거리에 제한이 없는 선형모터를 적용한 Pick & Place 모듈을 제안하였다. 체적대비 추력비가 큰 코어 방식의 선형모터를 설계하기 위한 파라미터를 선정하고, 자기해석을 통해 설계 파라미터 변화에 따른 코깅힘의 영향을 분석하여 평균 추력을 유지하며 코깅힘을 저감할 수 있는 설계 파라미터 값을 선정하였다. 제작된 선형모터로 구성되는 Pick & Place 모듈에 대해 평균 추력 및 코기힘을 측정하여 설계값과 비교하였다.

• 대한족부족관절학회지
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• 제13권1호
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• pp.46-49
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• 2009

Purpose: The purpose of this study is to find out the normal angles of forefoot for diagnosis of bunionette deformity in Korea. This would be helpful as it would provide a basic angular measurement of bunionette deformity that indicates the need for operation. Materials and Methods: Within a period of four months from January 2007 to April 2007. We have established 300 males and 600 feet without trauma history of foot. The source to image distance is 40 inches and erect weight bearing radiographs are obtained in anteroposterior and lateral projections. The significant angular measurements that define a bunionette deformity are the fourth-fifth intermetatarsal angle, the fifth metatarsophalangeal angle Results: The mean age was 21 years(19-22 years) old. The mean $4^{th}-5^{th}$ intermetatarsal angle was $9.4{\pm}4.7^{\circ}$, the mean $5^{th}$ metatarsophalangeal angle was $7.9{\pm}9.2^{\circ}$. Conclusion: We can consider over the $14.1^{\circ}$ on the $4^{th}-5^{th}$ intermetatarsal angle and over $17.1^{\circ}$ on the $5^{th}$ metatarsophalangeal angle as an operational indication.