• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.42.3-43
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• 2009

Triplets of identical cubesats will be built to carry out the following scientific objectives: i) multi-observations of ionospheric ENA (Energetic Neutral Atom) imaging, ii) ionospheric signature of suprathermal electrons and ions associated with auroral acceleration as well as electron microbursts, and iii) complementary measurements of magnetic fields for particle data. Each satellite, a cubesat for ion, neutral, electron, and magnetic fields (CINEMA), is equipped with a suprathermal electron, ion, neutral (STEIN) instrument and a 3-axis magnetometer of magnetoresistive sensors. TRIO is developed by three institutes: i) two CINEMA by Kyung Hee University (KHU) under the WCU program, ii) one CINEMA by UC Berkeley under the NSF support, and iii) three magnetometers by Imperial College, respectively. Multi-spacecraft observations in the STEIN instruments will provide i) stereo ENA imaging with a wide angle in local times, which are sensitive to the evolution of ring current phase space distributions, ii) suprathermal electron measurements with narrow spacings, which reveal the differential signature of accelerated electrons driven by Alfven waves and/or double layer formation in the ionosphere between the acceleration region and the aurora, and iii) suprathermal ion precipitation when the storm-time ring current appears. In addition, multi-spacecraft magnetic field measurements in low earth orbits will allow the tracking of the phase fronts of ULF waves, FTEs, and quasi-periodic reconnection events between ground-based magnetometer data and upstream satellite data.

• 폴리머
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• 제28권5호
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• pp.404-411
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• 2004

인계 난연제인 트리페닐 포스페이트 (TPP)와 열적, 기계적 성질이 우수하고 네트워크 구조를 형성하는 노블락 형의 에폭시 수지를 이용하여 마이크로캡슐을 제조하였다. 유용성 인계 난연제인 TPP는 고분자압출 공정 가공 시 고분자 수지에서 기화 및 방출로 인하여 난연제의 손실과 고분자 복합재의 젖음성 문제들을 야기 시킨다. 이를 해결하기 위해 TPP를 마이크로캡슐화하였다. 즉, 본 공정은 캡슐의 심물질인 TPP와 벽막 물질인 노블락 형의 에폭시 레진을 혼합된 유화제와 함께 수중유형 (O/W) 상태로 역상유화시키고 제조된 유화액을 인시츄 중합법으로 가교반응을 진행하였다. 혼합된 유화제의 비율과 양 그리고 TPP 함량에 따른 실험을 진행하였으며 마이크로캡슐의 형성 및 열적 특성의 확인을 위해 DSC와 TGA에 의해 분석하였다. 또한 캡슐 입자의 형태학적 고찰을 위해 SEM과 TEM을 이용하여 캡슐의 크기 및 모폴로지 등을 분석하였다. 혼합된 유화제의 비율이 플로닉 Fl27과 소디움 도데실벤젠 설포네이트 (SDBS)가 1:1 일 때, 그리고 유화제의 도입량이 증가할수록 캡슐의 입자가 구형이며 좀 더 균일한 입자 형태를 보였다.

• Nuclear Engineering and Technology
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• 제39권1호
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• pp.31-42
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• 2007

Energy supply is increasingly showing up as a major issue for electricity supply, transportation, settlement, and process heat industrial supply including hydrogen production. Nuclear power is part of the solution. For electricity supply, as exemplified in Finland and France, the EPR brings an immediate answer; HTR could bring another solution in some specific cases. For other supply, mostly heat, the HTR brings a solution inaccessible to conventional nuclear power plants for very high or even high temperature. As fossil fuels costs increase and efforts to avoid generation of Greenhouse gases are implemented, a market for nuclear generated process heat will be developed. Following active developments in the 80's, HTR have been put on the back burner up to 5 years ago. Light water reactors are widely dominating the nuclear production field today. However, interest in the HTR technology was renewed in the past few years. Several commercial projects are actively promoted, most of them aiming at electricity production. ANTARES is today AREVA's response to the cogeneration market. It distinguishes itself from other concepts with its indirect cycle design powering a combined cycle power plant. Several reasons support this design choice, one of the most important of which is the design flexibility to adapt readily to combined heat and power applications. From the start, AREVA made the choice of such flexibility with the belief that the HTR market is not so much in competition with LWR in the sole electricity market but in the specific added value market of cogeneration and process heat. In view of the volatility of the costs of fossil fuels, AREVA's choice brings to the large industrial heat applications the fuel cost predictability of nuclear fuel with the efficiency of a high temperature heat source tree of Greenhouse gases emissions. The ANTARES module produces 600 MWth which can be split into the required process heat, the remaining power drives an adapted prorated electric plant. Depending on the process heat temperature and power needs, up to 80% of the nuclear heat is converted into useful power. An important feature of the design is the standardization of the heat source, as independent as possible of the process heat application. This should expedite licensing. The essential conditions for success include: ${\bullet}$ Timely adapted licensing process and regulations, codes and standards for such application and design ${\bullet}$ An industry oriented R&D program to meet the technological challenges making the best use of the international collaboration. Gen IV could be the vector ${\bullet}$ Identification of an end user(or a consortium of) willing to fund a FOAK

• 한국산학기술학회논문지
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• 제17권10호
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• pp.139-146
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• 2016

본 연구는 고등학생의 연구실 이용에 따른 안전 인식과 교육에 대한 필요성을 조사하였다. 이를 위하여 서울 소재 3개 고등학교 2학년 재학생 290명을 대상으로 설문 조사를 실시하였으며, 수집된 자료를 분석하였다. 분석 결과 정규 수업 전 안전교육은 64.8%가 경험한 것으로 나타났으며, 사고 경험 6.6%, 체험 교육 시 안전 교육 68.0%로 사전 안전교육이 부족한 것으로 나타났으며, 안전교육에 대한 인식도와 필요성은 높게 인식하고 있는 파악되었다. 특히, 연구실 사고 대처 방법에 관한 교육의 필요성을 안전 교육 경험 학생이 높게 나타나 연구실 안전 교육의 체계적인 관리 및 학생들의 안전 시 사고체계에 대한 다각적인 관리 방안 마련이 요구된다. 연구실 안전 인식과 교육 필요성 요인은 생활안전과 연구실 이용 안전교육 필요성과 상호 관련성이 높았고, 기기 및 실험 안전에 대한 필요성이 높을수록 연구실 이용 안전과 사고 대처 방법에 대한 인식도 높은 것으로 나타나 고등학생 대상의 연구실 안전 교육 프로그램 개발과 관리적 방안에 관한 연구를 제안한다.

• 여성건강간호학회지
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• 제9권1호
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• pp.5-17
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• 2003

Purpose : The purpose of this study was 1) to classify university student's attitudes toward sex, 2) to confirm the effects of sexuality course on sex-role stereotypes and sexual attitude in university student s. Method : The subjects in this study were 212 K university students in Kangwon Province between 3/7/2001 $\sim$ 6/13/2001. The instruments used for this study were the general characteristics, sexual attitude and sex-role stereotypes. The data was analyzed by frequency, percentage, mean, standard deviation, paired t-test, ANOVA, Pearson correlation coefficients, Factor analysis and Cronbach's $\alpha$ using the SPSS program. Result : 1. University students' attitude toward sex are divided into three types. Type I are called open mined : 16, 33, 28, 10, 18, 2, 30, 25, 26, 27, 22, 19, 29, 21, 9, 5 items. Type II are supporters of virginal purity : 8, 6, 31, 17, 14, 33 items. Type III express love through sexual intercourse : 20, 24, 7, 3, 15, 32 items. 2. There was a significant difference in the appearance and occupational characteristics of sex-role stereotypes before and after the sexuality course (t=2.562, p<.05). 3. In Type III, there was a significant difference in sexual attitude before and after the sexuality course (t=3.576, p<.0001). 4. The data showed the relationships between type III of sexual attitude and sex-role stereotypes (r=-.3 15, p<.0001). 5. Sex-role stereotypes according to the demographic characteristics before sexuality course were significantly different by age, gender, experience of military service, experience of sex edu cat ion an d experience of sexual intercourse. Sex-role stereotypes according to the demographic characteristics after sexuality course were significantly different by gender and experience of sexual intercourse. 6. Sexual attitude according to the demographic characteristics before sexuality course were significantly different by maj or (type I), age, grade, experience of military service and experience of sexual intercourse (type II), age, grade, gender, experience of military service, experience of sex education and experience of sexual intercourse. Sexual attitude according to the demographic characteristics after sexuality course were significantly different by religion and major(type I), age and grade(type II), age, grade, gender, religion and experience of sexual intercourse. Conclusion : This study showed that a sexuality course was effect ive in changing the sex-role stereotypes and sexual attitude of university students.

• Composites Research
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• 제34권5호
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• pp.283-289
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• 2021

본 연구에서는 압축력을 받는 얇은 복합재 원통 구조에 대하여 기하학적 혹은 하중에 대한 초기 결함 모델을 이용하여 수치해석적으로 좌굴 Knockdown factor를 새롭게 도출하였다. 전역 좌굴이 발생하기 이전에 타원형상의 변형 형상을 갖는 복합재 원통 구조를 사용하였다. 복합재 원통 구조의 기하학적 초기 결함만 고려하기 위하여 Single Perturbation Load Approach를 이용하였으며, 기하학적 초기 결함과 더불어 하중 불균일을 함께 구현하기 위하여 Single Boundary Perturbation Approach를 사용하였다. 기하학적 초기 결함 모델의 좌굴 Knockdown factor는 NASA의 기존의 좌굴 Knockdown factor보다 약 84% 높게 도출되었으며, 좌굴 시험에 비하여서는 약 9% 낮게 도출되었다. 기하학적 초기 결함과 하중 불균일을 함께 고려하는 모델의 좌굴 Knockdown factor는 NASA의 좌굴 Knockdown factor에 비하여서는 약 75% 높게, 그리고 좌굴 시험보다 약 14% 낮게 계산되었다. 따라서, 본 연구의 좌굴 설계 기준은 고려된 초기 결함 모델과 상관없이 기존의 좌굴 설계 기준에 비하여 경량 설계의 제공이 가능함과 동시에 좌굴 시험 대비 적절히 보수적인 설계 기준을 제공할 수 있음을 확인하였다.

• 중소기업연구
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• 제42권1호
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• pp.135-165
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• 2020

이 연구의 목적은 초기 스타트업 창업가의 기업가적 리더십, 팀 학습 행동, 팀 경계 확장 행동 및 지각된 성과의 관계를 구명하는 것이다. 연구 목적을 달성하기 위하여 초기 스타트업 창업가의 기업가적 리더십이 지각된 성과에 미치는 직접적인 정적 영향에서 팀 학습 행동이 갖는 매개효과와 팀 학습 행동이 지각된 성과에 미치는 직접적인 정적 영향에서 팀 경계 확장 행동이 갖는 조절효과를 분석하였다. 78개 초기 스타트업을 대상으로 진행한 이 연구의 결과는 다음과 같다. 첫째, 초기 스타트업 창업가의 기업가적 리더십이 지각된 성과에 미치는 정적 영향을 팀 학습 행동이 완전 매개하는 것으로 나타났다(β=.309, p<.05). 둘째, 초기 스타트업에서 팀 학습 행동이 지각된 성과에 미치는 정적 영향은 팀 경계 확장 행동에 의해 조절되었다(β=.259, p<.05). 팀 경계 확장 행동은 팀 학습 행동이 지각된 성과에 미치는 영향을 선형적으로 강화하는 것으로 나타났다. 이 연구의 결과를 통해 세 가지 시사점을 얻을 수 있다. 첫째, 초기 스타트업에서 팀 학습 행동은 성과를 창출하는데 기여하는 중요한 활동으로, 팀 학습 행동 활성화를 위한 노력이 필요하다. 둘째, 초기 스타트업의 학습 문화를 구축하는데 중요한 영향을 미치는 것은 창업가의 기업가적 리더십으로, 창업 생태계에서는 창업가의 기업가적 리더십을 진단, 개발할 수 프로그램을 기획해야 한다. 셋째, 팀 학습 행동이 성과에 미치는 영향을 더욱 강화하기 위해서는 외부와의 상호작용을 통한 정보의 탐색과 습득이 중요하다. 후속 연구를 위한 두 가지 제언은 다음과 같다. 첫째, 창업가의 기업가적 리더십과 팀 학습 행동을 시점 차이를 두고 측정하여 인과관계를 실증해야 한다. 둘째, 초기 스타트업들이 성장한 이후 재무성과와 이 연구에서 측정한 창업가의 기업가적 리더십, 팀 학습 행동, 팀 경계 확장 행동과의 관계를 구명해야 한다.

• Archives of Plastic Surgery
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• 제49권6호
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• pp.716-723
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• 2022

Background In March 2021, the United States Food and Drug Administration (FDA) safety communication cautioned against the use of acellular dermal matrix (ADM) products in breast reconstruction and reiterated that the FDA does not approve ADM use in breast surgery. This study aims to assess the safety of ADM use in breast reconstruction. Methods Women who underwent ADM and non-ADM assisted tissue expander (TE)-based breast reconstruction were identified using the National Surgical Quality Improvement Program database (2012-2019). Trends of ADM use over time, and 30-day outcomes of surgical site infection (SSI), dehiscence, and unplanned reoperation were assessed. Results Of the 49,049 TE-based breast reconstructive cases, 42.4% were ADM assisted and 57.6% non-ADM assisted. From 2012 to 2019, the use of ADM increased from 26.1 to 55.6% (relative risk [RR] =1.10; p < 0.01). Higher rates of SSI (3.9 vs. 3.4%; p = 0.003) and reoperation (7.4 vs. 6.0%; p < 0.001) were seen in the ADM cohort. There was no significant difference seen in dehiscence rates (0.7 vs. 0.7%; p = 0.73). The most common reoperation within 30 days for the ADM group (17.6%) was removal of TE without insertion of implant (current procedural terminology: 11,971). ADM-assisted breast reconstruction was associated with increased relative risk of SSI by 10% (RR = 1.10, confidence interval [CI]: 1.01-1.21; p = 0.03) and reoperation by 15% (RR = 1.15, CI: 1.08-1.23; p < 0.001). Conclusions ADM-assisted breast reconstruction more than doubled from 2012 to 2019. There are statistically higher complication rates of SSI (0.5%) and reoperation (1.4%) with ADM use in TE-based breast reconstruction, suggesting that reconstruction without ADM is safe when comparing immediate postoperative outcomes.

• Safety and Health at Work
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• 제14권2호
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• pp.141-152
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• 2023

Objective: We performed a meta-analysis of epidemiological results for the association between occupational exposure as a firefighter and cancer as part of the broader evidence synthesis work of the IARC Monographs program. Methods: A systematic literature search was conducted to identify cohort studies of firefighters followed for cancer incidence and mortality. Studies were evaluated for the influence of key biases on results. Random-effects meta-analysis models were used to estimate the association between ever-employment and duration of employment as a firefighter and risk of 12 selected cancers. The impact of bias was explored in sensitivity analyses. Results: Among the 16 included cancer incidence studies, the estimated meta-rate ratio, 95% confidence interval (CI), and heterogeneity statistic (I²) for ever-employment as a career firefighter compared mostly to general populations were 1.58 (1.14-2.20, 8%) for mesothelioma, 1.16 (1.08-1.26, 0%) for bladder cancer, 1.21 (1.12-1.32, 81%) for prostate cancer, 1.37 (1.03-1.82, 56%) for testicular cancer, 1.19 (1.07-1.32, 37%) for colon cancer, 1.36 (1.15-1.62, 83%) for melanoma, 1.12 (1.01-1.25, 0%) for non-Hodgkin lymphoma, 1.28 (1.02-1.61, 40%) for thyroid cancer, and 1.09 (0.92-1.29, 55%) for kidney cancer. Ever-employment as a firefighter was not positively associated with lung, nervous system, or stomach cancer. Results for mesothelioma and bladder cancer exhibited low heterogeneity and were largely robust across sensitivity analyses. Conclusions: There is epidemiological evidence to support a causal relationship between occupational exposure as a firefighter and certain cancers. Challenges persist in the body of evidence related to the quality of exposure assessment, confounding, and medical surveillance bias.

• Archives of Plastic Surgery
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• 제51권2호
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• pp.234-250
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• 2024

Background The impact of diabetes on complication rates following free flap (FF), pedicled flap (PF), and amputation (AMP) procedures on the lower extremity (LE) is examined. Methods Patients who underwent LE PF, FF, and AMP procedures were identified from the 2010 to 2020 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP®) database using Current Procedural Terminology and International Classification of Diseases-9/10 codes, excluding cases for non-LE pathologies. The cohort was divided into diabetics and nondiabetics. Univariate and adjusted multivariable logistic regression analyses were performed. Results Among 38,998 patients undergoing LE procedures, 58% were diabetic. Among diabetics, 95% underwent AMP, 5% underwent PF, and <1% underwent FF. Across all procedure types, noninsulin-dependent (NIDDM) and insulin-dependent diabetes mellitus (IDDM) were associated with significantly greater all-cause complication rates compared with absence of diabetes, and IDDM was generally higher risk than NIDDM. Among diabetics, complication rates were not significantly different across procedure types (IDDM: p = 0.5969; NIDDM: p = 0.1902). On adjusted subgroup analysis by diabetic status, flap procedures were not associated with higher odds of complications compared with amputation for IDDM and NIDDM patients. Length of stay > 30 days was statistically associated with IDDM, particularly those undergoing FF (AMP: 5%, PF: 7%, FF: 14%, p = 0.0004). Conclusion Our study highlights the importance of preoperative diabetic optimization prior to LE procedures. For diabetic patients, there were few significant differences in complication rates across procedure type, suggesting that diabetic patients are not at higher risk of complications when attempting limb salvage instead of amputation.