• 한국추진공학회지
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• 제25권3호
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• pp.101-112
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• 2021

SpaceX는 Falcon 9과 Falcon Heavy의 재사용을 통해 다양한 탑재중량 포트폴리오를 구성하고, 한 종류의 엔진을 사용하여 발사체를 구성하며, 케로신 엔진에서 메탄 엔진으로의 전환, 3D 프린팅 사용 등 다양한 전략을 보여주고 있다. 본 연구에서는 아리랑 위성에서 천리안 위성까지 다양한 탑재중량 및 궤도를 감당할 수 있는 발사체 안을 구성하였으며, 케로신 가스발생기 사이클 엔진, 케로신다단연소 사이클 엔진, 메탄 다단연소 사이클 엔진을 사용한 10가지 발사체 안에 대해서 검토하였다. 10가지 안 중 35톤급 메탄 엔진을 사용한 재사용 발사체가 개발 가능성 측면에서 좋은 안으로 평가되었다.

• 한국임상수의학회:학술대회논문집
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• 한국임상수의학회 2006년도 추계학술대회 및 정기총회
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• pp.104-104
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• 2006

• 대한지구과학교육학회지
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• 제12권1호
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• pp.94-108
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• 2019

이 연구는 과학영재 학생의 탐구 사고력 향상을 위해 안내된 R & E 프로그램을 개발하여 그 효과를 확인하고자 하였다. 우선 교사중심에서 학생 중심으로 3단계의 과정을 거쳐 R & E를 수행할 수 있도록 하는 안내된 R & E 수업 모형을 개발하였고, 5단계 절차에 맞는 안내된 R & E 프로그램을 개발하여 중학교 과학 영재 학생 38명을 대상으로 수업을 진행하였다. 그 결과, '가설 설정 > 변인 추출 > 탐구문제 도출 > 결론 도출 > 실험 설계 > 일반화 > 평가 > 자료 해석 > 자료 변환' 순으로 높은 평균 점수를 나타냈다. 세부적으로는 9개 평가 요소 중 '탐구문제 도출, 변인 추출, 가설 설정, 결론 도출'은 높은 수준을, '실험 설계'는 평균 수준을, '자료 해석, 일반화, 평가'는 낮은 수준을, '자료 변환'은 매우 낮은 수준을 나타냈다. 이번 연구를 계기로 안내된 R & E 프로그램이 탐구 과정별 요소를 잘 반영하여 과학영재 학생의 종합적 사고력과 창의적 문제해결력 향상에 도움이 되길 기대한다.

• 기술혁신연구
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• 제5권1호
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• pp.181-205
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• 1997

There has been considerable controversy over the impacts of the tax credit on R&D expenditures in many countries. Korea has adopted various kinds of tax credit system to stimulate private firm' R&D expenditures. Korean government, Recently, is trying to reform tax system to reduce tax credit programmes according to Uruguay Round agreement and in line with OECD policy standards. The purpose of this paper is to analyze the effectiveness of current tax credit system on technology innovation in Korea and derive some policy implications over tax reform. In this paper, firstly, I investigate the size of tax reduction effects from each program in theoretical models and simulate the actual rate of individual tax incentive to a unit of R&D expenditure. I find that theoretically the reserve fund for technology development program has given the largest tax reduction effects to private firms irrespective of the R&D incentive system reform. Tax credit on R&D expenditure also has been very effective instrument to firm's tax reduction. Secondly, I try to measure the effectiveness of tax credit through the estimation of effective margianl tax rate between with the system and without the system of credit on R&D expenditure during the tax credit reform periods. I find that the tax credit on R&D has lowered firm's investment cost since the system introduced. I also have strong results that there has been a positive relation between the fluctuation of firm's R&D expenditure and the change of effective marginal tax rate. I suggest that it is better to sustain the system of tax credit on R&D for a while to increase firm's R&D expenditure.

• 산업경영시스템학회지
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• 제44권4호
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• pp.76-84
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• 2021

Military aircraft R&D projects require large-scale investment in cost and time, and involve a complex coordination process in decision-making. The R&D project manager should determine the development management priorities as accurately as possible and focus on R&D capabilities, thereby reducing the risks of the aircraft R&D project. To this end, this study aims to reduce R&D risk by prioritizing cost, schedule, and performance, which are basic management factors used in R&D project management in defense project management regulations. Analytic Hierarchy Process (AHP) is applied using a questionnaire for managers in charge of aviation R&D under the Defense Acquisition Program Administration. As a primary result, the importance of the factors that the aircraft R&D project manager should consider was derived in the order of performance, cost, and schedule, and the priorities of performance and cost in the lower layer were also identified. In addition, in order to provide practical risk management measures to aircraft R&D project managers, the results of analyzing 28 cases of US National Transportation Safety Board accidents were compared and analyzed with the AHP analysis results, and management measures suitable for the situation were specified.

• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1399-1402
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• 2007

The virulence of superoxide dismutase (SOD) mutants of Vibrio vulnificus, as tested by intraperitoneal injection into mice, decreases in the order of sodC mutant, sodA mutant, and sodB mutant lacking CuZnSOD, MnSOD, and FeSOD, respectively. The survival of SOD mutants under superoxide stress also decreases in the same order. The virulence of soxR mutant, which is unable to induce MnSOD in response to superoxide, is similar to that of the sodA mutant, as the survival of the soxR mutant under superoxide stress is similar to that of the sodA mutant. Consistently, the lowered survival of the soxR mutant is complemented not only with soxR but also with sodA. Thus, the virulence of V. vulnificus is significantly affected by the cellular level of SOD activity, and an increase in SOD level through MnSOD induction by SoxR under superoxide stress is essential for virulence.

• 지역사회간호학회지
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• 제8권1호
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• pp.45-60
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• 1997

Essential hypertension is a typical chronic disease requiring adequate and continuous management. Many studies supported that self-care was the essential factor to promote the wellbeing of hypertensives and self-efficacy increased healthy, behavior. The comprehensive self-regulation program was conducted as a nursing intervention on the promotion self-care performance for hypertensives in company. And this self-regulation program was recommended to apply for hypertensives in rural area. The purpose of this study is to identify the general characteristics affecting self-care and interrelationship among the factors including self-care, self-efficacy, HLOC, perceived benefits, barriers and family support. 40 subjects were interviewed from Dec. 1996 to Jan. 1997 and the data was analyzed by the SPSS PC+ program with t-test and multiple correlation to determine the variables affecting the self-care behavior. The results were as follows: 1) Level of self-care was significant difference according to sex(t= -2.27, p=.0l9). religion (t=1.57, p=.055) and smoking habit (t=4.42, P=.000). Perceived self-efficacy was more significantly high among the non-smoking group (t=3.25, P=.000) and female group (t=-2.534, p=.0l3). 2) There were significant positive correlation among the variables: self-care and self-efficacy (r=.5460, p=.000), external-LOC and self-care(r=.2548, p=.056), external-LOC and self-efficacy(r =. 2901, p=.035), self-efficacy and perceived benefits (r=3307, p=.019). And there were significant negative correlation between self-care and barriers (r=-.5438, p=. 000), self-efficacy and barriers (r= - .4153, p=.004). From the above results, it can be concluded that the self-care is more required in male hypertensives and self-efficacy is one of the important factors to increase healthy behavior in cluding self-care. Thus self-regulation program can be recommended in the management of the hypertensives in community settings.

• 농업생명과학연구
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• 제46권3호
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• pp.109-118
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• 2012

The gene encoding an esterase enzyme was cloned from a metagenomic library of cow rumen bacteria. The esterase gene (est2R) was 2,120 bp in length, encoding a protein of 516 amino acid residues with a calculated molecular weight of 57,286 Da. The molecular weight of the enzyme was estimated to be 57,000 Da by SDS-PAGE. Est2R shared 35.6% amino acid identity with esterase (CAH19079) of uncultured prokaryote. The Est2R was most active at $20-40^{\circ}C$, and showed optimum at $30^{\circ}C$ and pH 8.0. The most activity of Est2R for the different chain length of p-nitrophenyl ester group as substrate was p-nitrophenyl acetate. Moreover, the enzyme was found to be most active without organic solvent, followed by 98% active with ethanol, and the enzyme activity was highly affected by the acetonitrile. The enzyme was significantly inhibited by $Zn^{2+}$ but stimulated by $Ca^{2+}$. So, novel esterase gene est2R is likely to obtain from cow rumen metagenome and supposed to use for industrial purpose.

• Archives of Plastic Surgery
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• 제48권5호
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• pp.553-558
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• 2021

The diagnosis of the main complications resulting from lipoabdominoplasty has not yet been standardized. Infrared thermal imaging has been used to assess possible complications, such as necrosis and changes in micro- and macro-circulation, based on perforator mapping techniques, among others. The objective of this study was to present two clinical cases involving thermal imaging monitoring of the healing process of lipoabdominoplasty in the immediate postoperative evaluation and its preliminary results. Infrared thermography was performed 24 hours after the operation and on postoperative days 5, 25, and 27. In clinical case 1, it was found that the delta-R (∆T_R)-defined as the difference in minimum temperature between the highest and lowest points in the SA3 region (caution suction area) following the classification established by Matarasso-was 0.4℃ at 24 hours after surgery and decreased to 0.1℃ on a postoperative day 5. There were no complications in this case. In contrast, in clinical case 2, the ∆T_R was 1.7℃ at 24 hours after surgery (upon hospital discharge) and remained high, at 2.2℃, on postoperative day 5. A higher ∆T_R was found in the second patient, who developed necrosis of the surgical wound. The ∆T_R thermal index may be a new tool for predicting possible complications, complementing the clinical evaluation and therapeutic decision-making.

• 대한임상검사과학회지
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• 제48권4호
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• pp.378-387
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• 2016

심혈관계 위험인자를 비침습적으로 분석할 수 있는 PWV에 관한 다수의 선행연구에서 의견이 분분하고, 결과에 대한 일관성이 부족한 부분을 재현하고자 연구에 임하였으며, 더욱이 날로 증가하고 있는 노인을 대상으로 운동참여 여부와 성별에 따른 노인의 말초동맥파속도(baPWV), 신체구성과 심혈관계 변인의 상관성 및 재변인의 차이를 검증하는데 연구의 목적이 있다. 규칙적인 운동을 수행해온 노인남성 39명(이하, 운동군M) 과 운동을 수행해 오고 있지 않은 동일 연령대의 노인남성 38명(이하, 통제군M), 규칙적인 운동을 수행해온 노인여성 40명(이하, 운동군F) 과 운동을 수행해오고 있지 않은 동일 연령대의 노인여성 37명(이하, 통제군F)을 대상으로 변인에 대한 상관성과 집단별 재변인들 간의 차이를 알아본 결과 노인남성 운동군의 baPWV range와 근육량(r=0.357, p=0.026), 수축기혈압(r=0.468, p=0.003), rbaPWV (r=0.406, p=0.010), lbaPWV (r=0.333, p=0.038)가 통계적으로 유의한 상관관계를 보였고, 노인남성 통제군의 경우는 baPWV range와 심박수(r=0.395, p=0.014), rbaPWV (r=0.598, p=0.000), lbaPWV (r=0.602, p=0.000)가 유의한 상관성을 보였다. 노인여성 운동군은 baPWV range와 진단명(r=0.321, p=0.044), 수축기혈압 (r=0.399, p=0.011), 이완기혈압(r=0.545, p=0.000), rbaPWV (r=0.648, p=0.000), lbaPWV (r=0.676, p=0.000)가 유의한 상관성을 보였고, 노인여성 통제군 경우는 baPWV range와 나이 (r=0.471, p=0.003), rbaPWV (r=0.836, p=0.000), lbaPWV (r=0.801, p=0.000)가 통계적으로 유의한 상관성을 보였다. 반면 말초동맥파속도 변인 중 통계적으로 유의한 차이를 보인 그룹은 없는 것으로 나타났고, 요둔위($F_{3,150}=9.197$, p=0.000), 근육량($F_{3,150}=74.295$, p=0.000), 체지방율($F_{3,150}=35.045$, p=0.000), 수축기 혈압($F_{3,150}=3.525$, p=0.017)이 통계적으로 유의한 차이를 나타냈다. 본 연구에서는 집단별 특성에 따라 다양한 결과가 나타난다는 사실을 알 수 가 있었으며, 신체구성 변인과 심혈관계 변인 중 수축기 혈압은 운동 여부에 따라 민감한 변화와 차이를 보인 것으로 보아 노인의 경우 운동그룹은 신체구성과 심혈관계 일부 변인에 변화를 줄 수 있다고 단정지어 볼 수 있겠으나, 위팔-발목 맥박파전파속도에 대해서는 일관된 결과가 도출되지 않아서 이에 대한 지속적인 연구가 필요한 것으로 사료된다.