• Bulletin of the Korean Space Science Society
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• 2009.10a
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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.

• Polymer(Korea)
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• v.28 no.5
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• pp.404-411
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• 2004

The microcapsules containing triphenyl phosphate (TPP), a flame retardant, were prepared by phase-inversion emulsification technique using the epoxy resin (Novolac type) with excellent physical properties and network structure. This microencapsulation process was adopted for the protection of TPP evaporation and wetting of polymer composite during the polymer blend processing. The TPP, epoxy resin and mixed surfactants were emulsified to oil in water (O/W) by the phase inversion technology and then conducted on the crosslinking of epoxy resin by in-situ polymerization. The capsule size and size distribution of TPP capsules was controlled by mixed surfactant ratio, concentration and TPP contents, The formation and thermal property of TPP capsules were measured by differential scanning calorimetry and thermogravimetric analysis. The morphology and size of TPP capsules were also investigated by scanning and transmission electron microscopies. As the surfactant concentration increased, the TPP capsules were more spherical and mono-dispersed at the same weight ratio of mixed surfactants (F127: SDBS).

• Nuclear Engineering and Technology
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• v.39 no.1
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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

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.139-146
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• 2016

The purpose of this study is to investigate the necessity of safety awareness and education regarding the use of laboratories, and to foster safety awareness during intramural and extracurricular activities in high schools. The study conducted a questionnaire to 290 eleventh grade students of three high schools located in Seoul. The collected data were statistically analyzed. The result illustrates that 64.8% of students have experienced safety education during a regular class, 6.6% have experienced accidents, and 68.0% have experienced safety education during field activities. The result concludes that there is a lack of prior safety education as well as overall low awareness on the necessity of safety education. In particular, students who have experienced safety education recognizes the necessity of emergency education regarding laboratory accident more than those who did not receive such education. Thus, a systematic management of laboratory safety education and multilateral management measures for students' safety are required. There is a relatively high correlation between safety intention of R&D and Education factors and Community and Laboratory Safety Education. As much as there is a high safety demand regarding the laboratory instruments and experiment, it shows high intention of safety lab operation as well as count measurement of lab accident. This study recommends developing a laboratory safety education program and management methods appropriate for high school students.

• Women's Health Nursing
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• v.9 no.1
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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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• v.34 no.5
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• pp.283-289
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• 2021

This paper derives numerically the buckling Knockdown factors using two different initial imperfection models, such as geometric and loading imperfection models, to investigate the unstiffened composite cylinder with an ellipse pre-buckling deformation pattern. Single Perturbation Load Approach (SPLA) is applied to represent the geometric initial imperfection of a thin-walled composite cylinder; while Single Boundary Perturbation Approach (SBPA) is used to represent the geometric and loading imperfections simultaneously. The buckling Knockdown factor derived using SPLA is higher than NASA's buckling design criteria by approximately 84%, and lower than buckling test result by 9%. The buckling Knockdown factor using SBPA is higher than NASA's buckling design criteria by about 75%, and 14% lower than the buckling test result. Therefore, it is shown that the buckling Knockdown factors derived in this study can provide a lightweight design compared to the previous buckling design criteria while they give reasonably a conservative design compared to the buckling test for both the initial imperfection models.

• Korean small business review
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• v.42 no.1
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• pp.135-165
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• 2020

This study aimed to examine relationships between founders' entrepreneurial leadership, team learning behavior, team boundary spanning, and perceived performance in early-stage startups. The following results were recorded: (i) the indirect effects of entrepreneurial leadership on perceived performance via team learning behavior were statistically significant (β=.309, p<.05). (ii) relationships between team learning behavior and perceived performance were strengthened by team boundary spanning behavior (β=.259, p<.05). In this study, three practical implications are provided as follows: (i) startups need to seek team learning readiness and external learning stimulus to facilitate generative and transformative team learning; (ii) accelerators need to develop an entrepreneurial leadership program for founders; and (iii) startups need to explore external information by interacting with investors, R&D institutions, and other startups to strengthen the impact of team learning behavior on performance. Furthermore, two directions for future research are suggested as follows: (i) future researchers need to test causal relationships between entrepreneurial leadership and team learning behavior based on a newly designed time-series measurement plan; (ii) the actual effects of entrepreneurial leadership, team learning behavior and team boundary spanning on financial performance need to be tested two or three years later when the financial performance of early-stage startups usually becomes evident.

• Archives of Plastic Surgery
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• v.49 no.6
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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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• v.14 no.2
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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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• v.51 no.2
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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.