• 디지털산업정보학회논문지
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• 제14권3호
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• pp.103-113
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• 2018

The purpose of this study supports the establishment of national e-learning policy by analyzing e-learning status and current status of higher education. Enhance the competitiveness of higher education through sharing information between universities. And to improve e-learning quality management. We surveyed the current status of e-learning in 341 universities and questionnaires about e-learning content, e-learning application form, e-learning platform status was surveyed through each school's learning management system. As a result, the infrastructure of e-learning, the rate of platforms secured, and the contents are increasing gradually each year; however, still, not all students can receive the services equally. Dedicated servers and learning management systems were secured by more than 70% of general universities. In the current development status of e-learning content, multimedia, animation, and text forms are gradually decreasing, but video contents are increasing every year. Most of the online contents were used in the e-learning contents by application type, and blended learning, flipped learning, and mooc is not yet actively used since they are still in the beginning stage. Learning analysis techniques should be supported in order to easily use online learning contents such as flipped learning and mooc. We suggest that the effectiveness of e-learning should be measured and the current state of learning analysis for customized learning should be done. This study aims to contribute to the improvement of competitiveness of higher education by sharing information about e-learning among universities as a basis for improvement of e-learning policy. Future tasks are to improve the customized learning environment by adding whether the system environment for learning analysis is provided at the time of the survey.

• 한국해양공학회지
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• 제24권5호
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• pp.22-30
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• 2010

The fuel tank of a ship is filled with heavy fuel oil (HFO) that has a very high viscosity. In order to inject the HFO into the engine easily, heating coils are usually installed inside the fuel tank to heat the HFO and lower its viscosity. Currently, several different types of heating coils are used, e.g., fin-type, bare-type, drum-type, and shell-and-tube-type. It is well known that the shell-and-tube-type heating coil has good performance and high efficiency. In this study, experiments were conducted to determine the heat transfer efficiencies of three different shell-and-tube-type heating coils. Heat transfer efficiency was evaluated by using FLUENT 6.3.26 software. Also, structural safety was assessed by using ANSYS.simulation software.

• 산경연구논집
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• 제9권2호
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• pp.65-72
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• 2018

Purpose - One of the biggest problems in the e-learning distribution process is the lack of quality content and learners' discredit in e-learning content. In order to respond to the various demands of the corporate education field appropriately, it is necessary to search for directions of new e-learning models that are out of traditional e-learning contents. The purpose of this study is to identify recent trend issues related to corporate e-learning and to suggest directions for development. Research design, data, and methodology - Based on the literature review, trend issues that should be considered important in corporate e-learning were derived. Online survey was conducted to evaluate the importance-feasibility of each issue to 13 experts on e-learning and corporate education. The contents of the questionnaire are as follows: 1) recognition of importance and feasibility of trend issues to be considered important in the future corporate education field; 2) factors to be considered in developing future e-learning contents. Results - Six trends derived from a comprehensive literature review. The most important e-learning trends for corporate education field were 'mobile learning', 'micro learning', 'blended learning', 'social learning', 'adaptive learning', 'engaged learning'. As a result of evaluating the importance and feasibility of each issue, experts point out that 'mobile learning' and 'micro learning' should be actively considered for introduction and utilization at present. In addition, 'social learning' and 'blended learning' need to be actively considered in the near future. On the other hand, experts recognized that 'adaptive learning' and 'engaged learning' need to be prepared from a long-term perspective. Conclusions - There are two main reasons for this result. First, in corporate e-learning, it is important to 1) be able to update on time, 2) the connection with the workplace is important. Second, it requires realistic verification of the expected performance of the learning model. To be considered part of the future are as follows: First, the value and effectiveness of the new e-learning type should be studied. Seconds, e-learning contents should be developed through adopting SAM or Agile methodology. Through this process, we would be able to enhance the quality in e-learning content.

• 미생물학회지
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• 제40권1호
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• pp.7-11
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• 2004

eIF5B는 단백질합성의 개시 인자로서 Met-$tRNA^{Met}$을 AUG 개시코돈에 전달하고, 리보솜의 두 소단위체 결합을 유도한다. 이 인자의 기능을 연구할 목적으로 eIF5B를 코딩하는 FUN12 유전자의 5'말단 부위를 삭제하는 연구를 수행하였다. 프로모터의 대부분을 삭제한 FUN12를 함유한 pRS효모벡터를 FUN12가 삭제되어 천천히 자라는 돌연변이주 ($fun12{\Delta}g$)에 전달하였을 때 그 표현형을 부분적으로 상보하였다. 위와 같이 제조된 벡터에서 N-말단이 상실된 eIF5B 단백질이 발현되었고, 그 양이 정상 균주에서 발현되는 eIF5B 양의 약 5%에 불과하였다. 이와 같이 부분적으로 성장을 상보한 균주에서 발현된 적은 양의 단백질합성개시 인자 eIF5B는 직접적으로 그 성장을 제한하는 요소로 작용한다. 이러한 균주에서 성장의 제한인자인 eIF5B는 in vitro 에서도 역시 전체 단백질 합성의 활성을 조절하였다.

• 대한수의학회지
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• 제29권3호
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• pp.315-324
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• 1989

In order to establish the extent of Streptococcal arthritis piglets, isolation of Streptococci from arthritic lesions of 34 piglets were undertaken from November 1987 to October 1988 in Korea. Also determined were isolation frequency of Streptococci in nasal cavity of 250 healthy sows and antibiotic susceptibilities of the isolates. Streptococci were isolated from 52.9% of 34 arthritic piglets and 20 strains isolated belonged to 4 S suis type I, 8 S suis type II, 2 Lancefield group C and 6 group E. From 28.8% of 250 healthy sows, 72 strains of Streptococci were isolated and these consisted of 9 S suis type I, 51 S suis type II and 12 group C. Streptococcal arthritis seemed to occur prominently in piglets aged 2 to 4 weeks and in male than female. No significant difference were recognized in tarsal and carpal joints as affecting site. All of 92 isolates were sensitive to ampicillin and penicillin, and all strains of S suis type I and group E Streptococcus were also sensitive to chloramphenicol and cephalothin. To cephalothin all strains of group C Streptococcus were sensitive. The 1. 7 to 100% of 92 isolates were resistant with different prevalence to colistin, erythromycin, kanamycin, tetracycline, gentamicin, chloramphenicol and cephalothin. The 92.5% of these resistant Streptococci were multiply drug-resistant strains. The drug resistant patterns most frequently encountered were Tc Cl Em Km Gm(16.3%) in quintuple pattern, Tc Cl Em Km(16.3%) in quadruple pattern, Tc Cl Em(10.9%) in triple pattern and Cl Em(14.1%) in double pattern.

• Bulletin of the Korean Chemical Society
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• 제29권10호
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• pp.1911-1914
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• 2008

Second-order rate constants (kN) have been measured for Michael-type addition reactions of a series of alicyclic secondary amines to 1-phenyl-2-propyn-1-one (2) in MeCN at 25.0 ${\pm}$ 0.1 ${^{\circ}C}$. All the amines studied are less reactive in MeCN than in $H_2O$ although they are more basic in the aprotic solvent by 7-9 p$K_a$ units. The Bronsted-type plot is linear with $\beta_{nuc}$ = 0.40, which is slightly larger than that reported previously for the corresponding reactions in $H_2O$ ($\beta_{nuc}$ = 0.27). Product analysis has shown that only E-isomer is produced. Kinetic isotope effect is absent for the reactions of 2 with morpholine and deuterated morpholine (i.e., $k^H/k^D$ = 1.0). Thus, the reaction has been concluded to proceed through a stepwise mechanism, in which proton transfer occurs after the rate-determining step. The reaction has been suggested to proceed through a tighter transition state in MeCN than in H2O on the basis of the larger $\beta_{nuc}$ in the aprotic solvent. The nature of the transition state has been proposed to be responsible for the decreased reactivity in the aprotic solvent.

• Journal of Biosystems Engineering
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• 제41권3호
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• pp.201-207
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• 2016

Purpose: A water-spraying type automatic glochids removal system for cactus (Opuntia humifusa) stem was developed, and its performance was evaluated. The system was developed to reduce intensive human labor in removing glochids from cactus stem skin without inducing damage prior to further processing into value-added products. Methods: The developed system consists of conveyor and water-spraying systems. The conveyor system delivers cactus stems through water-spraying compartments and finally to a collecting box. In order to remove the glochids, rotating nozzles spray water over all areas (i.e., front and back faces and sides) of the cactus skin under controlled water pressure. Operating conditions such as conveyor speed, water pressure, angle of water-spraying nozzles, distance between conveyor belt and rotating nozzles, and angle of cactus flipping slide were adopted from our previous study and applied on the system design and manufacturing. The performance of glochids removal was evaluated by counting the number of glochids on the cactus stem before and after processing on the system. Results: The developed system performed efficiently and effectively under the pre-studied operating conditions except for the angle of cactus flipping slide. The new system had a glochids removal ratio of 94.1% without damaging the cactus skin. Considering the original number (approximately 30-60) of glochids, the remaining number was low (1-4), and most of them were found at the side edge of the cactus stem. This system can remove glochids from 360 cactus stems in 1 hr regardless of cactus size. Conclusions: The performance of the new system in glochids removal without damaging cactus skin is superior to any other existing device (i.e., brush type, rubber-friction type, and agitation type). The system is expected to be applied in cactus (O. humifusa) processing facilities.

• 한국산학기술학회논문지
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• 제13권3호
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• pp.1014-1020
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• 2012

본 논문은 3D 캐드모델을 기반으로 작업자의 수작업 및 설계오류를 최소화하는 금형설계 지원 툴 개발에 초점을 맞춘다. 금형설계 지원범위는 자동차 산업의 프레스 금형설계 공정에서 필수 요소인 선직 곡면 생성 및 옵셋, 패딩력 자동산출, 수정사항을 반영하는 재료표 자동출력, 홀 가공데이터 자동 산출, 원소재 크기 출력 및 검증 등 이다. 개발한 시스템을 주요 범용 3D 모델러 중 하나인 프로엔지니어의 확장 메뉴형태로 탑재하기 위하여 프로엔지니어 API와 Visual C++를 사용하여 개발하였다.

• 융합정보논문지
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• 제11권4호
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• pp.35-45
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• 2021

모바일 또는 웹을 활용한 e-커머스 산업은 빠른 성장세에 있으며, 다양한 플랫폼 서비스 출현으로 e-커머스 산업은 혁신적인 변화를 일으키고 있다. 본 연구는 e-커머스 이용자들의 애착유형요인들에 대해 파악하고 이들 요인이 지각된 사용용이성과 지각된 유용성에 기반한 기술수용모형(Technology Acceptance Model)에 얼마만큼의 영향을 미치는지와 수용의도 간의 인과관계를 실증 연구함으로써 e-커머스 서비스에서 효과적이고 효율적인 발전방안을 제시하고자 한다. 본 연구의 연구모형을 실증적으로 검증하기 위해 e-커머스를 이용한 경험이 있는 일반인들을 대상으로 설문조사를 실시하였으며 PLS(Partial Least Squares)를 활용한 내적 일관성, 확인적 요인분석, 판별 타당성, 적합도 검증을 통해 경로분석을 실시하였다. 그 결과, 지각된 안정과 지각된 유용성 및 지각된 사용용이성 간의 유의미한 인과관계를 확인해 볼 수 있었으며 TAM과 수용의도와의 연관성을 검증해 볼 수 있었다.

• 한국환경농학회지
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• 제17권4호
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• pp.301-305
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• 1998

본 연구는 농가에서 사용하는 저류조, 연속 폭기조, 혐기성 정치식, 혐기성 교반식의 4가지 형태의 부숙조를 이용하여 액상 가축분 퇴비 부숙효율을 평가하기 위하여 수행하였다. 호기성 폭기조는 BOD 및 악취 제거율에서 혐기성 부숙방법보다 우수하였다. 반면에 질소는 초기농도의 47%가 손실되어 혐기성 부숙방법보다 심한 편이었다. 혐기성 부숙방법중 교반식과 정치식간에는 큰 차이는 인정되지 않았다. 그러나 혐기성 교반식이 정치식보다 대장균 제거율, 악취제거율은 더 높았으며, 질소 손실율은 더 낮게 나타났다. 농가에서 사용하는 저류조 형태의 부숙조는 혐기 또는 호기성 처리 방법보다 BOD, 대장균, 악취제거율등이 낮았다. 각 개별요인들의 효율을 종합 평가한 결과 액비 부숙효율은 혐기성 교반조>호기성 폭기조>무교반 혐기성조>저류조 순으로 높았다.