• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.211-212
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• 2009

국내의 다이아몬드 마이크로 블레이드 산업의 경우 충분한 이론적 검증을 거치지 못하고 종전의 경험 및 외산품에 대한 분석을 토대로 제작된 제품에 간단한 물성만을 체크하여 업체에 공급한다 해도 과언이 아니다. 이러한 국내의 실정을 인지하여 본 연구에서는 Cu와 Sn을 주 결합재로 사용한 다이아몬드 마이크로 블레이드에 있어 고체윤활제인 흑연과 $MoS_2$의 첨가에 따른 마모 특성을 비교하였다. 마모시험의 분위기는 상온에서 건식 분위기로 진행 되었으며, 그 결과 흑연을 첨가할 경우 가장 높은 마찰감소를 보임을 확인할 수 있었다. 이번 연구는 상온 및 저 회전 속도에서의 사용을 목적으로 한 다이아몬드공구의 연구 자료로 활용될 것이다.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.129-133
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• 1987

To develop a microcomputer-based data acquisition system for measurement of variables such as temperature and weight in food process, a low-cost data acquisition system was developed using an Apple II microcomputer. The system consisted of a microcomputer, a temperature sensor made of pt-100, a strain gauge load cell for weighing, a preamplifier for signal conditionings and an interface device. Interface device was built with programmable interface chip MC 6821, tristate buffer 74244 and analog-to-digital converter ADC 0809. The analog signals of temperature and weight were serially acquisited upon the program. The BASIC language was used for operating the data acquisition and data handling programs. The system successfully measured the variables such as temperature and weight with various sampling intervals in food dehydration process.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.117-117
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• 2010

외뿔소자리 신성 1975는 발견 당시에는 백색왜성과 적색왜성의 근접쌍성계인 것으로 알려졌으나, 엑스선 관측과 그에 따른 표준 정류 상태 원반 모형에 근거한 해석으로 중성자별 또는 블랙홀의 가능성이 대두되었다. 곧이어, 광학관측에 의하여 블랙홀 이중성임이 간접적으로 동정되었다. 최근 들어 1975젼 당시의 많지 않은 전파 관측 자료들을 재해석하여 상대론적인 물질 분출 현상, 즉 마이크로퀘이사 현상이 있었을 가능성이 관측적으로 제시되었다. 우리는 시간 종속적 열적 불안정성 모형을 바탕으로 수치모형을 계산하여 관측적으로 제시된 물질분출의 가능성을 이론적으로도 제시할 수 있음을 보인다

• Photonics industry news
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• s.7
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• pp.54-59
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• 2001

본지에서는 한국과학기술정보연구원(KISTI)의 자료협조를 받아 광산업과 관련된 해외 신기술 동향을 소개한다.

• Korean Journal of Food Science and Technology
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• v.19 no.3
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• pp.200-205
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• 1987

A microcomputer-based on-line monitoring and controlling system was built and applied to the dehycration operation. Drying conditions-drying temperatures and air velocities-were successfully controlled by the control deveices incorporated on/off realy and thyristor, and with the high language program. Drying variables-temperature in drier and weight loss of radish slice were accurately measured and acquisited. The computer-based drying system effectively saved the man power required to measure and record data during the drying period and also made possible to conduct the process undisturbed for long period. The drying rate curves of radish at various drying conditions were obtained from automatic data analyzing program. And also the computer programmed control made possible to investigate the effect of air velocity change during the drying period. The dynamic change of air velocity of from one to another level could be performed and affected markedly the drying rate at first stages of drying, but no significant effect were found in falling rate period.

• Communications of Mathematical Education
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• v.29 no.4
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• pp.643-660
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• 2015

This study investigated how pre-service mathematics teaches' experience in microteaching influences their motivations toward teaching behaviors and changes by analyzing their teaching records and class reports. Although respondents planned to conduct various strategies pertaining to motivations, some of them were not used. Also, motivations toward their teaching behavioral changes leaded to positive aspects, but also leaded to negative ones. These findings imply that only two times microteaching experiences would not be sufficient to lead to positive teaching behavioral changes through their motivations. However, pre-service mathematics reported a high level of intention to change their teaching behavior through a comprehensive review process regarding their teaching. Therefore, teacher eduction institutions should develop well structured educational programs and apply them to pre-service mathematics teachers for a better understanding of their teaching and its review through motivations. In addition, providing opportunities for pre-service mathematics teachers to experience various educational programs including microteaching would be necessary for improving their teaching behavior through motivations.

• Atmosphere
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• v.30 no.4
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• pp.335-346
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• 2020

Three free parameters included in a cumulus parameterization are optimized by using micro-genetic algorithm for three precipitation cases occurred in the Korea Peninsula during the summer season in order to reduce biases in a regional model associated with the uncertainties of the parameters and thus to improve the predictability of precipitation. The first parameter is the one that determines the threshold in convective trigger condition. The second parameter is the one that determines boundary layer forcing in convective closure. Finally, the third parameter is the one used in calculating conversion parameter determining the fraction of condensate converted to convective precipitation. Optimized parameters reduce the occurrence of convections by suppressing the trigger of convection. The reduced convection occurrence decreases light precipitation but increases heavy precipitation. The sensitivity experiments are conducted to examine the effects of the optimized parameters on the predictability of precipitation. The predictability of precipitation is the best when the three optimized parameters are applied to the parameterization at the same time. The first parameter most dominantly affects the predictability of precipitation. Short-range forecasts for July 2018 are also conducted to statistically assess the precipitation predictability. It is found that the predictability of precipitation is consistently improved with the optimized parameters.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.157-160
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• 2008

이 논문은 허밍질의의 정확도 향상에 마이크와 같은 장비에 특성, 허밍을 하는 사용자의 숙련도가 어느 정도 반영되는지 알아본다. 연구의 결과 검색의 정확도는 마이크 성능에 독립적임을 보였고, 사용자가 노래를 아는 정도와 노래를 부른 만족도가 검색 순위를 상승시키는데 미치는 영향이 없거나 미미함을 실험결과를 통해 보다 이와 같은 실험 결과들은 허밍질의 검색의 정확도 향상을 위한 연구에서 참고자료로 사용될 것이다.

• Journal of Engineering Education Research
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• v.6 no.1
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• pp.22-31
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• 2003

The purpose of this study was to develop CD-ROM so that students can understand 8051 Microprocessor unit easily in electronics circuit practice subject of technical high school. The study gives students, who have difficulties in learning, a chance for self-directed and supplementary learning by suggesting interface process with 8051 Practice Kit. To achieve these purposes, literature survey, collecting textbooks and materials, development of CD-ROM were gradually carried out. Each steps were as follows: Firstly, in literature survey, concepts and characteristics of multimedia and application to class were reviewed. Secondly, text contents on 8051 Microprocessor unit were analyzed, main contents were extracted and graphic, sound, animation were made. It was consisted of eight basic learning subjects, and designed to flow systematically. In this study, we presented a kind of teaching-learning material by developing CD-ROM in 8051 microprocessor unit in electronics circuit practice subject as a central matter. This material will be able to help technical high school students in learning

• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.263-271
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• 2005

HPFRCC(High Performance Fiber Reinforced Cementitious Composite) is a class of FRCCs(Fiber Reinforced Cementitious Composites) that exhibit multiple cracking. Multiple cracking leads to improvement in properties such as ductility, toughness, fracture energy, strain hardening, strain capacity, and deformation capacity under tension, compression, and bending. These improved properties of HPFRCCs have triggered unique and versatile structural applications, including damage reduction, damage tolerance, energy absorption, crack distribution, deformation compatibility, and delamination resistance. These mechanical properties of HPFRCCs become different from the kinds and shapes of used fiber, and it is known that the effective size of fiber in macro crack is different from that in micro crack. This paper reports an experimental findings on the mechanical properties of HPFRCCs reinforced with the micro fiber(PP50, PVA100 and PVA200) and macro fiber(PVA660, SF500). Uniaxial compressive tests and three point bending tests are carried out in order to compare with the mechanical properties of HPFRCCs reinforced with micro fibers or hybrid fibers such as compressive strength, ultimate bending stress, toughness, deformation capacity and crack pattern under bending, etc.,