• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.473-481
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• 1997

Enhanced videomicroscopy was used to observe the dynamic behavior which occurred when water containing pure nonionic surfactant was carefully contacted with equal volumes of polar oils such as oleyl alcohol and oleic acid at various temperatures. A key component of the system is a vertical-stage microscope which provides for stable interfaces by locating the oil above the denser aqueous phase. This arrangement allowed intermediate phases formed at the surface of contact to be clearly observed, as well as any spontaneous emulsification which developed. Contacting experiments with $C_{12}E_5$ as the surfactant and with pure oleyl alcohol and oleic acid soils showed little activity below the cloud point but vigorous activity at higher temperatures including formation of an intermediate lamellar liquid crystalline phase. Diffusion path theory, which allows prediction of spontaneous emulsification resulting from diffusion and of intermediate phase formation during contacting processes, was used to understand the dynamic behavior seen during contacting experiments. Tentative diffusion paths for the contacting experiments with pure oleyl alcohol were presented with the aid of a partial phase diagram of the oleyl alcohol-water-$C_{12}E_5$ system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.4
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• pp.499-511
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• 2015

A room-and-pillar underground structure is characterized by its grid-type array of galleries. As a result, its construction and economical efficiency can be governed by excavation sequence of galleries. Therefore, this study aims to study the optimum excavation scheme of a room-and-pillar underground structure by considering its various design factors such as ground conditions and excavation sequences. Drill-and-blast method is assumed as a excavation method for a room-and-pillar underground structure. In addition, two kinds of excavation patterns corresponding to a concurrent and a sequential excavation patterns are considered in this study. For the assumed conditions, the structural stability and the construction efficiency based on the number of faces and the travel distance of a jumbo drilling machine are analyzed for the two excavation patterns. Even though the two kinds of excavation patterns show almost the same structural stability as each other, the concurrent excavation pattern is relatively preferable to the sequential excavation pattern in terms of the number of faces in operation and travel distance of a drilling jumbo.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.6
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• pp.98-116
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• 2006

For the next two decades the civil aviation industry is expected to grow. Both Airbus and Boeing predict a delivery of almost 20,000 new Large Civil Aircraft (LCA). LCA is defined as a large civil jet aircraft with 100 seats or more. Airbus offers the Superjumbo, A380 (>555 seats), while Boeing presents the Dreamliner, B787 (200 – 300 seats). Their philosophies are very different. In the wake of B787, Airbus intends to offer a new aircraft, A350, as the competitor against B787, with the same engines developed for B787. The U.S. government pushed by Boeing, on the day of October 6, 2004, filed a suit against Airbus for wrongful subsidy to the World Trade Organization (WTO). A brief overview is given on the LCA development status in the world commercial aircraft market. Since there have been little changes in engine and avionics manufacturers in the LCA industry, the airframe area only is the object of this study. An analysis is carried out to find out the differences in development and marketing strategies of two major LCA manufacturers, Airbus and Boeing. The authors predict that Boeing will recapture its No. 1 position soon, while the leading edge in technology may be slipped away from Boeing.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.32-39
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• 1998

This study was performed to develop jumbo granules floated and spreaded on the water surface after application, having low production and formulation cost, and safe to environment for paddy herbicides and to establish the formulation recipe. The jumbo granules of azimsulfuron with molinate(0.075+7.5%) was formulated by KCl as water soluble carrier and paraffin oil as solvent to impose the floating and spreading force to granules. That showed 100% of total granules to be floated on and spreaded upto the water surface within 25 minutes after application. Change in carriers, surfactants and pH did not affected to improve the time-course degradation of azimsulfuron in jumbo granules, but salt formation of azimsulfuron added by 1.15M solution of NaOH a little. Addition of N-methyl acrylate and modification of formulation process affected decrease in degradation of azimsulfuron upto 1.2, 2.1, and 7.2% after 2, 6 and 12 weeks under storage at $40{\pm}2^{\circ}C$, respectively, which showed the establishment of formulation recipe of the jumbo granules.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.243-253
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• 2013

The purpose of this study was to make a comparative analysis of the oral health practice between dental hygiene students and Non-Dental Hygiene students in an effort to shed light on the importance of oral health education and its implications for personnels responsible for oral health practice. Their oral health awareness was investigated, and what factors might affect their actual oral health practice was observed. An then a comparative analysis was conducted. Followings are the main results of this study. First, when the characteristics of the self-rated oral health of the college students were analyzed, the dental hygiene students were ahead of the other students who didn't major in dental hygiene in every factor including oral health concern(p<0.001), awareness of oral health importance(p<0.01) and self-perceived oral health status(p<0.01). Second, the dental hygiene students significantly excelled the other students in both the level of oral health awareness(p<0.001) and the level of oral health practice(p<0.001). The findings of the study showed that more oral health education experiences led to better oral health awareness and better oral health practice, and that better oral health awareness led to better oral health practice.

• 재활복지
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• v.20 no.3
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• pp.141-161
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• 2016

This research is to anticipate problems of Ray's disabled experiment welfare vehicles for 17 drivers with disability, improving them. In addition it is to provide the criteria for ergonomic design based on perspective of drivers with disability by investigating 18 items of usability test. The results are as follows. First, satisfaction degree of Ray, disabled experiment welfare vehicle, was shown to be 3.88 which is higher than normal vehicles whose degree is 3.20. This showed that the disabled experiment welfare vehicle is the one with much improvement. Second, so as to develop a welfare vehicle it needs to take into account some factors including rear slope, wheelchair locker, seat belt, safety grip, and high roof. Third, in case of rear slope, high roof and width of manual or automatic wheel chairs should be considered and motor-operated device should also be taken into account for safety lockers, which make a wheelchair firmly fixed. Moreover, motor-operated seat and rear slope can be chosen for either of the disabled and the elderly.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.589-591
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• 2004

인터넷 이용률이 급속하게 증가하면서 사회적 문제로 중독증이나 사이버 범죄와 같은 점보화의 역기능이 사회전반에 걸쳐 확산되었다. 특히 청소년들의 인터넷 중독이 심각한 사회적 문제로 대두됨에 따라 도시지역 청소년에 대한 인터넷 중독관련 연구는 다양하게 이루어지고 있으나, 농어촌 청소년에 대한 연구는 거의 없는 상태이다. 이에 본 연구에서는 영광지역의 고등학생 400명을 대상으로 인터넷 이용실태에 대한 설문조사와 김현수(2000)가 번안한 Young의 인터넷 중독 검사지를 이용하여 인터넷 중독 설문조사를 하였다. 연구결과 평균사용자는 44.2%, 초기 중독사용자 53.16%, 심각한 중독사용자 2.7%로 나타났으며, 학년별 초기 인터넷 중독 성향을 보면 1학년 52.9%, 2학년 66.3%, 3학년 50%의 비율을 보이고 있고, 인터넷을 이용한 모든 활동을 보면 온라인게임, 정보검색, mp3파일 다운로드, 동호회 활동등의 순으로 나타났다. 본 연구에서는 초기 중독자와 심각한 중독을 합하여 중독경향 군으로 통합하였다. 따라서 55.8%에 해당하는 학생이 인터넷 중독에 빠질 수 있는 가능성이 있다고 볼 수 있다. 이러한 상황임에도 학교현장에서는 전혀 인터넷 중독에 대한 교육이 이루어지지 않고 있어, 이들에 대한 지속적인 교육이 필요할 것으로 생각된다.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.551-554
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• 2004

현재 국악기의 음향특성에 대한 상세 정보가 매우 부족하며, 이러한 점보의 부재는 국악당의 설계에 있어서 최적의 음향을 전달하는 공간을 형성하지 못하게 하는 한 원인이 되고 있다. 따라서, 대표적인 각종 국악기의 음향특성을 측정하고 분류한 후 데이터베이스를 구축하면, (1) 향후의 국악 및 국악기 개발에 대한 기초연구로서 활용들 수 있으며, (2) 국악전용 연주장의 설계에 있어서 입력 데이터로 요긴하게 활용될 수 있으리라 판단된다. 본 연구는 국악기의 음향방사특성을 조사하기 위한 제 2 단계의 연구로서, 기존의 연구 [1] 에 새로운 국악기 8 종을 추가하였다. 선정된 국악기는 현악기중에서 거문고와 해금, 관악기 중에서 피리와 태평소, 타악기 중 북과 꽹가리, 징 및 남성창으로, 원거리 (far-field) 음향 방사 특성을 조사하였다.

• Journal of TMJ Balancing Medicine
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• v.5 no.sup
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• pp.6-10
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• 2015

A 8 year-old male patient with tic disorder was managed by appliance of Functional Cerebrospinal Therapy (FCST) for 7 months, combined with acupuncture. After being treated for 7 months, the patient's symptoms were improved. Assessment was made by Yale Global Tic Severity Scale (YGTSS) and clinical observation. A positive effect was observed and further clinical and biological research on FCST is expected.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.187-189
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• 2005

대학교 및 연구기관 등에서 수행되는 국가연구개발사업은 산업, 경제 및 학술적 측면에서 그 파급효과가 매우 크다. 이에 국가연구개발사업에 대한 수행 내용 및 결과가 담겨 있는 국가연구보고서의 이용이 매우 중요한 요소라 볼 수 있다. 한국과학기술정보연구원에서는 한해에 약 만 여개 이상의 연구보고서를 수집, 관리하고 그 내용을 원문과 함께 서비스 하고 있다. 한편, 일반적으로 데이터베이스를 구축하고 서비스하기 위한 대부분의 방식은 상용 DBMS를 이용하여 정보의 관리를 수행하고, 사용자 검색은 정보검색 시스템을 사용하는 DBMS와 정보검색 시스템의 연동방식을 채택하고 있다. 그러나 이러한 방법은 DBMS와 정보검색 시스템을 이중으로 운영해야하는 불편함이 있고, 데이터의 관리 및 처리를 위한 과정이 중복으로 이루어지는 단점이 있다. 따라서, 본 논문에서는 납본형태로 입수되는 연구보고서를 관리하고 원문과 함께 이용자에게 정보서비스를 위해 필요한 KRISTAL-2002 정보검색관리시스템 기반의 DB 구축, 점보검색 및 관리 모델을 제시하고, DBMS와 정보 검색 시스템의 연동방식과의 데이터 처리과정에 있어서 처리 속도를 비교 분석한다.