• 한국추진공학회지
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• 제21권5호
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• pp.80-87
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• 2017

격벽으로 분리된 여폭약과 수폭약의 쌍으로 이루어진 파이로테크닉 장치의 성능은 격벽 내에서의 충격파 감쇠 및 폭약의 충격 감도에 의해 결정된다. 따라서 초소형 Kapton 비행편의 고속 충돌 실험을 통한 대상 HNS의 충격 점화 및 감도 분석을 목표로 EFI 기폭 장치를 고안하였다. 폭약에 전해지는 충격파의 강도 및 지속 시간의 측정을 위해 VISAR 속도 간섭계를 활용한 속도 측정 및 임피던스 정합 기법을 적용하였다. 본 연구는 비행편의 속도 및 충돌 시 발생되는 충격파의 강도와 지속 시간을 결정함으로써 소형 파이로테크닉 장치의 성능 및 기폭을 위한 비행편의 임계 속도의 예측 가능성을 확인하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.63-64
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• 2012

파이로 작동기구(PAD)는 고에너지 재료를 원격으로 폭발시켜 기구를 작동시키는 부품으로서 지금까지 이에 대한 설계는 주로 경험에 의해 이뤄졌다. 본 연구에서는 PAD의 작동 메커니즘을 해석적으로 모델링하는 효과적 방법을 개발하고 이를 설계에 활용하고자 한다. 해석모델은 서로 다른 해석특성을 가지는 세가지 순차적 스텝으로 구성되며 이들을 연계하여 통합 해석을 수행한다. 첫째 스텝은 작동기에서의 폭발 및 이로 인한 생성된 압력거동 해석, 둘째는 이러한 압력에 의해 피스톤을 작은 구멍 속으로 밀어넣는 압착거동 해석, 셋째는 피스톤 끝단에 있는 커터에 의해 박막을 관통하는 해석이며, 이로 인해 최종적으로 박막이 절개되면서 소기의 임무를 완성하게 된다. 본 발표에서는 이에 대한 개략적 소개와 일부 진행된 선행연구 결과를 소개한다.

• Biomedical Engineering Letters
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• 제8권4호
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• pp.383-392
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• 2018

For prompt gamma ray imaging for biomedical applications and environmental radiation monitoring, we propose herein a multiple-scattering Compton camera (MSCC). MSCC consists of three or more semiconductor layers with good energy resolution, and has potential for simultaneous detection and differentiation of multiple radio-isotopes based on the measured energies, as well as three-dimensional (3D) imaging of the radio-isotope distribution. In this study, we developed an analytic simulator and a 3D image generator for a MSCC, including the physical models of the radiation source emission and detection processes that can be utilized for geometry and performance prediction prior to the construction of a real system. The analytic simulator for a MSCC records coincidence detections of successive interactions in multiple detector layers. In the successive interaction processes, the emission direction of the incident gamma ray, the scattering angle, and the changed traveling path after the Compton scattering interaction in each detector, were determined by a conical surface uniform random number generator (RNG), and by a Klein-Nishina RNG. The 3D image generator has two functions: the recovery of the initial source energy spectrum and the 3D spatial distribution of the source. We evaluated the analytic simulator and image generator with two different energetic point radiation sources (Cs-137 and Co-60) and with an MSCC comprising three detector layers. The recovered initial energies of the incident radiations were well differentiated from the generated MSCC events. Correspondingly, we could obtain a multi-tracer image that combined the two differentiated images. The developed analytic simulator in this study emulated the randomness of the detection process of a multiple-scattering Compton camera, including the inherent degradation factors of the detectors, such as the limited spatial and energy resolutions. The Doppler-broadening effect owing to the momentum distribution of electrons in Compton scattering was not considered in the detection process because most interested isotopes for biomedical and environmental applications have high energies that are less sensitive to Doppler broadening. The analytic simulator and image generator for MSCC can be utilized to determine the optimal geometrical parameters, such as the distances between detectors and detector size, thus affecting the imaging performance of the Compton camera prior to the development of a real system.

• Asian-Australasian Journal of Animal Sciences
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• 제21권2호
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• pp.245-251
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• 2008

The effects of feeding diets containing 20% (L) or 30% (H) neutral detergent fiber (NDF) (DM basis) on performance and carcass traits were studied in three breeds of pig, including pure Mong Cai (MC), crossbred Landrace$\times$Yorkshire (LY) and crossbred MC$\times$Yorkshire (F1). The experiment had a factorial design with two factors, breed and diet. Eighteen piglets of each breed ($60{\pm}3days$) were randomly allocated to three treatments: L-L, low fiber diet in both growing and finishing periods; L-H, low and high fiber diet in the growing and finishing period, respectively; and H-H, high fiber diet in both periods. The diets were iso-energetic and iso-nitrogenous within feeding period. The main fibrous ingredients of the diets were rice bran and cassava residue. There were no effects of fiber level on daily dry matter feed intake (DMI), expressed as g/kg metabolic body weight (BW0.75), in both feeding periods (p>0.05). DMI was highest for MC, followed by F1 and LY (p<0.001). Average daily gain (ADG) in L-L and L-H was higher than in H-H in the growing period (p<0.001) and overall (p<0.05), while feed conversion ratio (FCR) was higher in H-H than in L-L and L-H in the growing period (p<0.05) and overall, but no significant differences between treatments were found in the finishing period. In both periods, Landrace$\times$Yorkshire had the highest ADG and the lowest FCR, followed by F1 and Mong Cai (p<0.001). There were no interactions between breed and diet for performance and carcass traits. Carcass and dressing percentage was lower for L-H and H-H than for L-L (p<0.05). There were no significant differences among treatments in back fat thickness and lean meat percentage, or in crude protein and ether extract contents of lean meat. Carcass, dressing and lean meat percentage was highest for LY, lowest for MC and intermediate for F1 (p<0.001). It can be concluded that feeding a high fiber diet in the growing period reduced pig performance, but there was no effect in the finishing period. Pure Mong Cai pigs are not particularly suitable for meat purposes, although the F1 cross with Large White had reasonably good growth performance and carcass quality.

• 한국컴퓨터정보학회논문지
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• 제25권12호
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• pp.305-313
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• 2020

본 논문은 외식프랜차이즈 가맹점의 배달 앱 이용속성이 만족도, 경영성과, 재이용의도에 어떠한 영향을 미치는가를 분석하고, 프랜차이즈 본사에서 가맹점에서 배달 앱의 가맹점 서비스가 어떠한 방식으로 이루어져야 하는지를 목적으로 배달 앱 지원방안을 제안하고자 한다. 본 연구에서는 외식 프랜차이즈 가맹점 중 배달 앱을 이용한 경험이 있는 가맹점 212명을 대상으로 설문하였다. 연구가설의 검증을 위해 단일 회귀분석, 다중회귀 분석하여 변수간의 관계를 검증했다. 연구결과 첫째, 외식 프랜차이즈 가맹점 배달 앱 이용속성이 만족도에 긍정적 관계가 있는 것으로 나타났다. 둘째, 외식 프랜차이즈 가맹점 배달 앱 이용속성이 경영성과에 긍정적 관계가 있는 것으로 나타났다. 셋째, 만족도는 경영성과에 영향을 미치는 것으로 나타났다. 넷째, 만족도는 재이용 의도에 영향을 미치지 않는 것으로 나타났으며, 경영성과는 재이용 의도에 긍정적 영향을 미치는 것으로 나타났다. 외식 프랜차이즈 가맹점의 원활한 배달 앱 이용을 위해, 지속적 관리와 합리적 가격정책을 통해 가맹점의 이용만족도를 높여야 하고, 프랜차이즈 본사에서는 배달 앱 기업과의 효과적인 협업을 통해 가맹점 매출 활성화에 기여할 수 있을 것이다.

• 품질경영학회지
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• 제44권3호
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• pp.639-648
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• 2016

Purpose: Existing precedent studies include success factors of individual management innovation activities constantly. However, those studies have limitations about the common key success factors of individual management innovation activities. Methods: For this study, we investigate the key success factors using literature research of the most typical management innovation activities adopted and implemented by many companies in Korea, such as 6sigma, TQM, Lean 6sigma, ERP, TPM, BPR, Project Management, System Engineering. Factors emerging repeatedly was combined into common factors and inherent factors that are necessary for the success of individual management innovation activities are designated to essential factors. Results: 'Essential factors for Six Sigma' consist of 5 items. Black belt operating system, personnel management system linkage, the correct management of the data, perform improvement projects associated with financial performance financial result, linked to financial performance improvement project, project progress management. 'Essential factors of TQM' are arranged 4 items. Quality team's independence and role, goal-setting, Quality Information System, corporate's philosophy of quality first. 'Essential factors of Lean Six Sigma' are the selection of value stream which is based on the customer needs and the value creation and identify the project based on the selected value in the company. 'Essential factors of ERP' are investigated 6 items. Ongoing system maintenance and upgrades, the measurement and support of user satisfaction, the operating systems and the policies for the maintenance, IT infrastructure, change adaption condition monitoring, focusing on improving business performance. 'Essential factors for TPM' are arranged 4 items. Motivated and energetic Bottom-Up, CEO's recognition of the importance facility management, long-term perspective of necessity and ongoing patience. 'Essential factors for BPR' are the pursuit of change process and the staff's sense of crisis management. 'Essential factors for Project Management' are the strategy that reduce the risk management skills through risk management and the understanding and organized management for the project participant's needs. 'Essential factors for System Engineering' consist of 2 items. The first is the design for the best balanced system with pre-analysis about the compromise the cost, schedule and the performance. The second is the analysis of large problem into small problems which can solved. We have found the solution considering components of the interface through the systematic perspective. Conclusion: Common factors and essential factors presented in this study will properly help to introduce the individual management innovation activities for the each business sector and implement management innovation. After this study, new literature research that reflect new studies should accomplish steadily.

• 한국엔터테인먼트산업학회논문지
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• 제15권4호
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• pp.45-54
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• 2021

배우 정선아는 데뷔 이후 20년간 선이 굵고 에너지가 넘치는 연기로 공연 이력을 쌓으며 한국의 대표적인 뮤지컬 배우라는 위상을 굳혔다. 이런 가치를 고려해 연기의 심리구조인 투사와 역투사 이론을 적용해 정선아를 심층 인터뷰하여 그녀의 고유한 연기 인입과 이탈 기법을 통한 정서적 패턴 및 특성을 도출했다. 정선아의 연기 메커니즘은 자아를 비우고 이전 공연, 동명 영화, 원작 소설, 대본 등을 집중 탐구해 창조한 배역을 투사해 페르소나를 구현한 뒤, 해외여행, 신체 훈련과 같은 역동적 활동으로 역투사해 자아를 환원하는 방식을 취했다. 리얼리티 표현의 극대화를 위해 인물이 처한 현장을 미리 찾아 체험하며 연기 방향을 탐구하였다. 작품마다 장르가 다른 보컬 트레이너와의 연습을 통해 색다름을 추구하고 파워풀한 가창 연기를 위해 보컬과 더불어 강도 높은 체력 단련을 뒷받침 했다. 대부분의 작품(75%)에서 공연 후 배역 이탈 장애로 인해 우울증, 자기애, 히스테리, 불면증 등의 정서들을 겪었지만 '셀프 처지'에 의존했기에 향후 전문가 상담 강화 등의 대안도 요구된다. 연평균 1.6편에 출연해 평균 1.7개월을 연습하고 평균 3.9개월간 공연하며 작품 사이 평균 100일 남짓 쉬며 강행군한 배우의 부단한 준비성과 열정, 그리고 에너지 비축과 안배의 노하우가 돋보인다. 도출된 정선아의 연기 인입 및 이탈 스킬은 뮤지컬 연기 교육과 배우의 자기관리에 큰 시사점을 제공한다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권10호
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• pp.1395-1403
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• 2012

The objective of the study was to quantify annual and seasonal differences in the chemical composition, in vitro gas production, in situ degradability and ruminal fermentation of grazing steers… diets. Diet samples were collected with four esophageal cannulated steers ($350{\pm}3$ kg BW); and four ruminally cannulated heifers ($342{\pm}1.5$ kg BW) were used to study the dry matter degradation and fermentation in rumen. Data were analyzed with repeated measurements split plot design. The crude protein, in vitro dry matter digestibility and metabolizable energy were higher during the first year of trial and in the summer (p<0.01). The values of calcium, phosphorus, magnesium, zinc and copper were higher in summer (p<0.05). The gas produced by the soluble and insoluble fractions, as well as the constant rate of gas production were greater in summer and fall (p<0.01). The ammonia nitrogen ($NH_3N$) and total volatile fatty acids concentrations in rumen, the soluble and degradable fractions, the constant rate of degradation and the effective degradability of DM and NDF were affected by year (p<0.05) and season (p<0.01). Our study provides new and useful knowledge for the formulation of protein, energetic and mineral supplements that grazing cattle need to improve their productive and reproductive performance.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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• pp.33.3-34
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• 2008

As an activity of building Korean Space Weather Prediction Center (KSWPC), we has studied of radiation effect on the spacecraft components. High energy charged particles trapped by geomagnetic field in the region named Van Allen Belt can move to low altitude along magnetic field and threaten even low altitude spacecraft. Space Radiation can cause equipment failures and on occasions can even destroy operations of satellites in orbit. Sun sensors aboard Science and Technology Satellite (STSAT-1) was designed to detect sun light with silicon solar cells which performance was degraded during satellite operation. In this study, we try to identify which particle contribute to the solar cell degradation with ground based radiation facilities. We measured the short circuit current after bombarding electrons and protons on the solar cells same as STSAT-1 sun sensors. Also we estimated particle flux on the STSAT-1 orbit with analyzing NOAA POES particle data. Our result clearly shows STSAT-1 solar cell degradation was caused by energetic protons which energy is about 700 keV to 1.5 MeV. Our result can be applied to estimate solar cell conditions of other satellites.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.837-844
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• 2015

Carob waste is a useful raw material for the second-generation ethanol because 50% of its dry weight is sucrose, glucose, and fructose. To optimize the process, we have studied the influence of the initial concentration of sugars on the fermentation performance of Saccharomyces cerevisiae. With initial sugar concentrations (S₀ ) of 20 g/l, the yeasts were derepressed and the ethanol produced during the exponential phase was consumed in a diauxic phase. The rate of ethanol consumption decreased with increasing S₀ and disappeared at 250 g/l when the Crabtree effect was complete and almost all the sugar consumed was transformed into ethanol with a yield factor of 0.42 g/g. Sucrose hydrolysis was delayed at high S₀ because of glucose repression of invertase synthesis, which was triggered at concentrations above 40 g/l. At S₀ higher than 250 g/l, even when glucose had been exhausted, sucrose was hydrolyzed very slowly, probably due to an inhibition at this low water activity. Although with lower metabolic rates and longer times of fermentation, 250 g/l is considered the optimal initial concentration because it avoids the diauxic consumption of ethanol and maintains enough invertase activity to consume all the sucrose, and also avoids the inhibitions due to lower water activities at higher S₀ .