• 대한기계학회논문집 C: 기술과 교육
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• 제5권2호
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• pp.97-104
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• 2017

본 논문에서는 휠로더 냉각성능 평가를 위한 열유동해석의 효율성 향상과 비용 저감을 위해서 흡배기구 다공판형상을 Porous media 기법을 이용하여 단순화하고 해석 정도를 확인하였다. 여기서 Porous media에 적용된 다공판형상의 유동손실계수는 시험데이터를 바탕으로 정의하였다. 또한 다공판형상의 유동손실계수를 해석적으로 정의하기 위해 단위형상에 대한 압력손실을 계산하고 시험결과와 비교하였다. 마지막으로 휠로더 흡배기구를 단순화한 해석모델의 냉각해석 결과와 실차 방열시험 결과를 비교하였다. 이 연구를 통해 휠로더 흡배기구 단순화 해석기법의 적용 가능성을 확인하였으며 냉각성능 평가 및 개선 연구를 효과적으로 수행할 수 있는 기반을 마련하였다.

• 기술혁신학회지
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• 제20권4호
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• pp.989-1014
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• 2017

연구의 책임성을 추구하는 주요 선진국은 과학 연구와 기술 개발에 있어 성별특성분석의 중요성을 인식하여 젠더혁신을 진행하고 있다. 우리나라는 Fast Follower 단계에서 First Mover로 나아가기 위한 전략의 하나로 미개척 연구 분야를 선점하기 위한 젠더혁신을 적극 추진할 필요가 있다. 과학기술분야에서 젠더혁신을 확산하려면 우선 연구개발 사업 전 과정에서 성/젠더분석을 반영한 정책을 천명하고, 연구개발 지원 사업의 제안부터 평가에 이르기까지 젠더혁신 연구지원 방안을 도입하여야 한다. 특히 우리나라의 연구개발 추진체계에서 새로운 젠더혁신 연구를 정책적으로 지원하려면 법적 기반이 선행되어야 실효성을 거둘 수 있을 것이다. 본 연구에서는 해외사례를 분석하여 젠더혁신 관련 법 개정안을 제언하였다.

• 대한의생명과학회지
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• 제29권2호
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• pp.81-87
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• 2023

Pan-Enterovirus (Pan-EV) infects millions of children and infants worldwide every year. As severe infections have recently been reported, the need for monitoring has consequently intensified. Pan-EV is a categorical name for waterborne enteroviruses belonging to the Picornaviridae family, and includes a wide range of pathogens including Coxsackievirus (CoxV), Echovirus (EcoV) and Enterovirus (EV). In this study, we proposed an optimal RT-nested PCR method for diagnosis of various types of Pan-EV in an aquatic environment and developed a positive control. Considering detection sensitivity, specific reaction, and final identification, one condition capable of amplifying 478 bp among the four candidates in the 1^st round PCR (RT-PCR) and one condition in the 2^nd round PCR (nested PCR) were selected. Through the detection of nucleic acids extracted from 123 groundwater samples and the detection sensitivity test based on artificial spiking in the sample, the methods are optimal for non-disinfected water samples such as groundwater. We developed a positive control for Pan-EV detection that can be amplified to different sizes under the two conditions. Accuracy could be further improved by testing for contamination from the control group. The method proposed in this study and the positive control developed are expected to be used in monitoring Pan-EV in aquatic environments including groundwater through future research using more samples.

• Asian-Australasian Journal of Animal Sciences
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• 제16권1호
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• pp.116-123
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• 2003

Forages are the most important feed resource for ruminants worldwide, whether fed as pastures, forage crops or conserved hay, silage or haylage. There is large variability in the quality of forages so measurement and prediction of feeding value and nutritive value are essential for high levels of production. Within a commercial animal production system, methods of prediction must be inexpensive and rapid. At least 50% of the variation in feeding value of forages is due to variation in voluntary feed intake. Identification of the factors that constrain voluntary feed intake allows these differences to be managed and exploited in forage selection. Constraints to intake have been predicted using combinations of metabolic and physical factors within the animal while simple measurements such as the energy required to shear the plant material are related to constraints to intake with some plant material. Animals respond to both pre- and post-ingestive feedback signals from forages. Pre-ingestive signals may play a role in intake with signals including taste, odour and texture together with learned aversions to nutrients or toxins (post-ingestive feedback signals). The challenge to forage evaluation is identification of the factors which are most important contributors to these feedback signals. Empirical models incorporating chemical composition are also widely used. The models tend to be useful within the ranges of the datasets used in their development but none can claim to have universal application. Mechanistic models are becoming increasingly complex and sophisticated and incorporate both feed characteristics and use of biochemical pathways within the animal. Improvement in utilisation through the deliberate selection of pasture plants for high feeding value appears to have potential and has been poorly exploited. Use of Near Infrared Reflectance Spectroscopy is a simple method that offers significant potential for the preliminary screening of plants with genetic differences in feeding value. Near Infrared Reflectance Spectroscopy will only be as reliable as the calibration sets from which the equations are generated.

• 대한전자공학회논문지TE
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• 제37권2호
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• pp.54-61
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• 2000

본 논문은 레일레이 페이딩 채널 환경에서 IMT-2000 파일럿 심볼 구조의 W-CDMA 시스템 역방향 링크의 채널 추정에 관한 RLS 적응형 알고리즘 성능을 WMSA(K=1,3)와 Constant gain 방식의 성능과 비교 분석하였다. 본 논문의 모델은 IMT-2000 시스템 규격의 W-CDMA 채널 구조, 변조 및 파일럿 패턴을 이용하였다. 파일럿 심볼 위치의 채널추정은 RLS 적응형 알고리즘을 이용하고 데이터 심볼 위치의 채널 보상은 선형보간으로 수행하였다. RLS 적응형 알고리즘 성능은 저속 페이딩에서 WMSA(K=1,3) 성능과 유사하지만 Constant gain 알고리즘 성능보다는 약간 우수하다. 도플러 주파수 320㎐, BER=2.0×10/sup -2/에서 RLS 적응형 알고리즘 성능이 WMSA(K=1)과 Constant gain 성능에 비해 4㏈의 성능 우위를 보여주고 있으며, WMSA(K=3)의 성능과는 커다란 차이를 보여준다. 따라서 페이딩이 고속화 될수록 RLS 알고리즘 의 성능이 전반적으로 WMSA(K=1,3)와 Constant gain 알고리즘 성능보다 우수함을 확인하였다.

• 한국국방기술학회 논문지
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• 제5권2호
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• pp.23-30
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• 2023

TRA(Technology Readiness Assessment)는 현재의 국내 기술수준을 정량적으로 평가하여 국내 연구개발 가능성에 대한 판단과 위험관리를 위한 핵심도구로 활용되고 있다. 하지만 현재의 TRA는 하드웨어 중심의 TRL(Technology Readiness Level)을 활용하기 때문에 개별기술의 독립적 평가에는 적합하나 체계관점의 평가에는 한계가 있다. 또한 체크리스트 방식의 평가는 주관적 평가 개입 가능성이 크다. 본 연구는 체계공학의 시스템통합 관점에서 TRA 절차와 기준을 재정의하여 개선된 TRA 프레임워크를 제안한다. 현재의 TRL과 TRA가 가진 한계를 극복하고 좀더 쉽고 직관적인 평가가 가능한 프레임워크 개발에 중점을 두었다. 제안 프레임워크는 HW, SW 및 인터페이스 관점에서 TE(Technology Element)와 CTE(Critical Technology Element)를 구분하고 TRL을 재정의 한다. TRA는 위 3가지 관점에서 재정의된 TRL에 따라 수행되고 위험관리를 고려하여 가장 낮은 평가결과를 시스템 수준의 성숙도로 활용한다. 제안된 CTE 선정방법은 주요 ROC(Required Operational Capability)의 정량목표, 개발난이도 및 COTS(Common Off The Shelf) 기술의 적용여부를 활용하여 평가자 주관의 개입을 최소화 한다. 본 프레임워크는 TSS(Target Surveillance System) 체계의 Case Study를 통해 실효성을 확인하였다. 본 연구를 시작으로 프레임워크 차원의 연구가 활성화 되어 TRA 제도 개선에 기여하길 바란다.

• 한국기계가공학회지
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• 제15권1호
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• pp.1-7
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• 2016

In the dentistry field, an ultrasonic surgery unit is widely used in bone cutting and scaling to reduce operation time and minimize hemorrhage. The purpose of this study was to evaluate bone cutting and the effect of a specimen's temperature on the two-type ultrasonic surgery unit using a handpiece moving system(HMS). A HMS, which can cut the bone, was developed to perform the experimental procedure with precision of motion control. Bone specimens were prepared from a combination of epoxy-hardener and cortical bone of bovine leg. Through the bone-cutting experiment, the cutting depth was evaluated by not only scanning electron microscopy, but also Vernier calipers. Also, the temperature distribution was measured by a thermo-graphic camera. This study may be applied methodically in various experimental evaluations on a performance test by a HMS.

• 한국입자에어로졸학회지
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• 제8권2호
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• pp.55-68
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• 2012

Particulate matters (PM) which are collected into a diesel particulate filter (DPF) system have to be periodically removed by thermal oxidation. In this report, we fabricated an electrohydrodynamic-assisted pressure-swirl nozzle to spray diesel droplets finer. Atomization performance of the nozzle was evaluated using both experimental and numerical methods. Two types of nozzle designs, the charge induction type and the charge injection type, were tested. While the former generated diesel droplets of $400\;{\mu}m$ at an applied electric potential over 10 kV, the latter presented the droplets smaller than $23\;{\mu}m$ at an applied electric potential of 8 kV. The numerical simulation results showed that the reduced size of droplets caused higher evaporation of droplets and therefore the increased temperature, which would eventually increase the regeneration performance of the DPF system.

• 한국지열·수열에너지학회논문집
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• 제12권4호
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• pp.15-20
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• 2016

Even though the control device of the heating system works well, insufficient water flow rates can degrade control performance and thermal comfort. The water flow rate should be adjusted appropriately to cope with the heating load of each zone. In order to solve these problems, a new balancing concept 'dynamic balancing' was proposed where a balancing valve opening can be automatically modulated according to the heating condition of the room. This study analyzed the effects of dynamic balancing upon indoor thermal environment and energy consumption in a radiant floor heating system through field measurement. Under part-load conditions, the use of a dynamic balancing is a more effective method to reduce energy consumption and to prevent a cavitation. Dynamic balancing is able to help boost the temperature of a room in the start-up period.

• 농업과학연구
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• 제39권4호
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• pp.483-489
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• 2012

Preference of stink bugs to various leguminous seeds was evaluated by using VTS (Video Tracking System) in laboratory. Major soybean stink bugs such as bean bug, Riptortus pedestris (Fabricius), one-banded stink bug, Piezodorus hybneri (Gmelin), eastern green stink bug, Nezara antennata (Scott), and sole bug, Dolycoris baccarum (L.) were significantly most attracted to Cheongjakong, a soybean variety, baited fish-net trap, followed by soybean varieties Ilpumgeomjeongkong and Taekwangkong, a peanut variety Daekwangdangkong, a kidney bean variety Gangnangkong, and a adzuki bean variety Jungwonpat, respectively in a soybean field. VTS observation in laboratory showed that R. pedestris and D. baccarum had significantly higher frequency of visit on Cheongjakong, followed by Ilpumgeomjeongkong. However, P. hybneri, N. antennata and Halyomorpha halys (Stal) had significantly higher number of visits on Cheongjakong, Seonnogkong and Jinpumkong, followed by Ilpumgeomjeongkong. The sojourned time of stink bugs, however, was significantly longer on Cheongjakong regardless of species of the bugs. Accordingly, Cheongjakong was evaluated as the most preferred soybean seed by fish-net trap and VTS. Thus, VTS is found to be an effective means to evaluate the food preference of stink bugs.