• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.4-10
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• 2012

75톤 추력급 터보펌프 터빈의 토크 특성을 성능시험 데이터를 바탕으로 분석하였다. 터빈의 비토크는 해석적으로 고정된 압력비에서 보정 선속도의 일차함수로 표현되며 이를 시험적으로 확인하였다. 일정 압력비 이상의 영역에서는 보정선속도-비토크 변화가 일정하게 나타나는 현상도 아울러 발견하였다. 분석된 토크 특성과 파이로 시동기의 시험 측정 데이터를 이용하여 터보펌프의 시동특성을 예측한 결과 터보펌프 설계회전수의 약 50%의 수준에 이르는 시간은 0.7초 이내인 것으로 나타났다. 파이로 시동기에서 터빈입구까지의 열손실은 최대회전수를 약 90 rpm 줄어들게 하는 것으로 예측되었다.

• 융합경영연구
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• 제12권2호
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• pp.19-26
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• 2024

In recent years, entrepreneurship has become a significant movement in Vietnam. Vietnamese youth has paid more attention on entrepreneurship. Local brand fashion is currently booming in Vietnam. Many young Vietnamese choose to start up in local brand fashion. Vietnamese government has show strong commitment to support entrepreneurial movement among young people. Purpose: The research focused on assessing the determinants of entrepreneurial intentions in local brands fashion in Vietnam. Research design, data and methodology: The sample size consist of 293 young Vietnamese who are passionate on starting up their business in fashion. The research method employ Exploratory Factor Analysis (EFA) and SPSS software is used to analysze the collected data. Data collection involved a mixed-methods approach, combining surveys and case studies. Results: The research findings confirm the determinants of entrepreneurial intentions in local brand fashions are Attitude towards behavior, Subjective norms, Cognitive behavioral control, Entrepreneurship education, and Capital. Conclusion: The study not only delved into the influencing elements for starting a business but also examined the current landscape of the youth-oriented local fashion brand market. Managerial implications are provided to promote entrepreneurial intention among young Vietnamese in fashion industry. Limitations and further research are also discussed to provide recommended research directions for future studies.

• 벤처창업연구
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• 제7권2호
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• pp.1-8
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• 2012

최근 청년층의 창업이 화두가 되고 있다. 창업에 있어서 사업계획 수립은 기본이 된다. 따라서 본 연구는 우리나라 대학생들의 사업계획 수립행태에 대해 살펴보았다. 특히 우리나라 대학생들이 교내, 외에서 사업계획을 접하고 있는지 살펴보고 그들이 사업계획과 기업성과를 관련이 있다고 생각하는지, 관련이 있다면 얼마나 밀접하게 생각하고 있는지를 알아보았다. 한편, 기존 연구들과 관련 서적들은 사업계획과 기업성과 간에는 높은 상관관계가 있다고 주장하고 있으나 이를 실증적으로 분석한 연구들은 국내외적으로 많지 않다. 본 연구는 이러한 문제에 대한 답을 찾기 위하여 실증적으로 접근하였다. 우선 사업계획의 구성요소들을 기존 연구들을 포함한 광범위한 문헌 연구를 통하여 선정하고 요인분석을 통하여 이들 구성요소들을 제품관리 요인, 제품개발 요인, 경영지원시스템 구축 요인, 조직관리 요인, 거시적(macro) 계획화 요인으로 분류하였다. 아울러, 본 연구에서는 기업성과를 계량적 성과와 비계량적 성과로 구분하여 각각에 미치는 사업계획 구성요소들의 영향을 살펴보았다. 연구결과, 우리나라 대학생들은 사업계획서 구성요소들이 기업의 계량적 및 비계량적 성과에 정(+)의 영향을 미친다고 인식하고 있었다. 아울러 우리나라의 내국인 대학생들은 창업에 대한 관심도가 높으며, 서비스업 창업을 희망하고 있으나 대부분 사업계획서를 작성해본 경험은 없는 것으로 나타난 반면, 외국인 학생은 상대적으로 높은 창업관심도와 사업계획서 작성경험을 가지고 있었으며, 창업희망 산업도 다양했다. 하지만 창업관심도나 창업희망 산업, 사업계획서 작성경험에서 성별에 따른 차이는 나타나지 않았다. 본 연구는 기업의 관점이 아닌 우리나라 대학생들의 시각에서 사업계획서의 구성요소와 기업 성과와의 관계를 살펴본 실증적 연구로서, 청년창업 성공률을 제고하기 위한 효과적인 창업교육의 방향을 제시하고 있다.

• 한국콘텐츠학회논문지
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• 제19권10호
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• pp.11-20
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• 2019

초임 특수교사들이 교직생활을 하는데 있어서 장애학생의 행동중재는 교직 적응 면에서 중요한 이슈가 된다. 본 연구는 초임 특수교사들의 행동중재 경험과 긍정적 행동지원에 대한 인식을 알아보는 것을 통해 초임특수교사들에 대한 지원에 도움이 되고자 하였다. 본 연구의 참여자는 경력이 2년 이하인 특수교사 5명을 대상으로 이루어졌으며 모든 면담은 일대일 심층면담으로 실시하였다. 모든 면담을 전사본으로 작성 후, 지속적 비교법을 통해 분석한 결과 '계기', '선택의 연속,' '중재에 대한 아쉬움', '긍정적 행동지원에 대한 인식'의 대주 제 4가지가 도출되었다. 또한, 9가지 하위주제로는 '교육적 필요', '생활적 필요', '중재의 시작', '중재의 과정', '중재의 결과', '자원의 부족', '소통의 부족', '새로운 분야', '새로운 시도'가 도출되었다. 논의에서는 연구결과에서 도출된 초임 특수교사의 행동중재에 대한 요구와 긍정적 행동지원에 대한 인식에 대하여 논의하고, 연구의 제한점을 제시하며 제언하였다.

• 한국세라믹학회지
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• 제55권6호
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• pp.590-596
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• 2018

To improve the injection behavior of brushite cement, dense ${\beta}-Ca_3(PO_4)_2$ (${\beta}-TCP$) granules were added to the starting material. The spherical ${\beta}-TCP$ granules prepared by spray-drying and subsequent sintering at $1000{\sim}1200^{\circ}C$ accounted for fractions of from 0.5 to 0.7 of the total ${\beta}-TCP$. The injection behavior was evaluated by measuring the injected mass divided by the loaded mass of paste in the syringe pump. The injected amount was increased with the increase in the fraction and sintering temperature of ${\beta}-TCP$ granules, except at $1200^{\circ}C$. The increase in the fraction of ${\beta}-TCP$ and its sintering temperature resulted in a decrease in the plastic limit, which is the volume of water required to liquefy the compact. The rest water could be utilized in the cement with the reduced plastic limit for improved injectability. The amounts of rest water assigned for powdery phase were estimated, and correlated with the injectability of paste.

• 한국세라믹학회지
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• 제34권11호
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• pp.1187-1197
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• 1997

Dry gel composed of primary particles more homogeneous than starting boehmite powder was prepared by dispersing and gelling the boehmite powder. The transformation temperatures of boehmite powder, dry gel seeded with 0, 1, 3, 5 wt% $\alpha$-Al2O3, and ball milled gel were 1192$^{\circ}C$, 1184$^{\circ}C$, 1141$^{\circ}C$, 1119$^{\circ}C$, 1117$^{\circ}C$, and 1106$^{\circ}C$, respectively. Sintering behavior of dry gel without seed was similar to that of boehmite powder, but the sintered density of dry gel was improved as much as 10%~15% than boehmite powder. In the case of dry gel seeded with 5 wt% $\alpha$-Al2O3, sintering behavior was much improved. The relative density of the gel seeded with 5 wt% $\alpha$-Al2O3 was 96% when sintered at 140$0^{\circ}C$ for 1h. On the other hand, ball milling of the non-seeded sol for 48h resulted in the relative density of 97% when sintered at 130$0^{\circ}C$ for 1h. The size and amount of $\alpha$-Al2O3 particles added by ball milling were 0.107 ${\mu}{\textrm}{m}$ and 0.5 wt%.

• 한국세라믹학회지
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• 제43권5호
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• pp.309-314
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• 2006

We synthesized lithium zirconate using solid-state reaction and analyzed thermal properties (TG/DTA) of starting materials and the synthesized one. When $Li_2ZrO_3$ powder was exposed to $CO_2$ environment at $500^{\circ}C$, 93% of the theoretical absorption weight was gained within 280 min with fairly high sorption rate. Almost all the absorbed $CO_2$ was generated by heating the sample to $800^{\circ}C$. We also investigated densification behavior of $Li_2ZrO_3$ under $CO_2$ environment. By sintering $Li_2ZrO_3$ at $760^{\circ}C$ using 2-step process, we obtained dense product, composed mainly of $Li_2ZrO_3\;and\;ZrO_2$, with relative density of 92%.

• 농업과학연구
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• 제43권3호
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• pp.459-467
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• 2016

In Korea, the market size for environment-friendly agricultural products has reached a plateau, even though many Korean consumers still show a high level of preference for environment-friendly agricultural products. In order to solve this problem, some Korean farmers and marketers are starting to try to export their products to many countries, including China. China, in particular, is becoming one of the fastest rising market for Korean environment-friendly agricultural products, after the signing of the Free Trade Agreement with China. However, little research has been done or reported about the purchase behaviors of Chinese consumers. The purpose of this paper is to analyze the environment-friendly agricultural product purchase behavior (especially, mandarin orange and muskmelon) of consumers in the Chinese market and to present some useful implications for Korean farmers and marketers. Through survey in China (especially, Beijing and Shanghai) and frequency analysis, this study made the following findings: first, Chinese consumers show a very strong concern for environment-friendly agricultural products. Second, many Chinese consumers usually buy environment-friendly agricultural products more than two times per month. Third, Chinese consumers give more value to freshness and food-safety than taste when they make decisions on buying environment-friendly mandarin orange and muskmelon. These can have some implications for the exportation of environment-friendly agricultural products.

• Geomechanics and Engineering
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• 제35권2호
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• pp.209-219
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• 2023

This paper presents numerical investigations into the particle crushing effect on the shear properties of gravel under direct shear condition. A novel particle crushing model was developed based on the octahedral shear stress criterion and fragment replacement method. A series of direct shear tests were carried out on unbreakable particles and breakable particles with different strengths. The evolutions of the particle crushing, shear strength, volumetric strain behavior, and contact force fabric during shearing were analyzed. It was observed that the number of crushed particles increased with the increase of the shear displacement and axial pressure and decreased with the particle strength increasing. Moreover, the shear strength and volume dilatancy were obviously decreased with particle crushing. The shear displacement of particles starting to crush was close to that corresponding to the peak shear stress got. Besides, the shear-hardening behavior was obviously affected by the number of crushed particles. A microanalysis showed that due to particle crushing, the contact forces and anisotropy decreased. The mechanism of the particle crushing effect on the shear strength was further clarified in terms of the particle friction and interlock.

• 한국농공학회논문집
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• 제66권1호
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• pp.15-24
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• 2024

Unlike artificially created homogeneous materials, the process of calculating the elastic modulus of natural soil involves the possibility of errors. Because the stress-strain behavior of soil is nonlinear, the secant modulus of elasticity is often used based on 1/2 of the stress at failure. Since soil has the property of changing its elastic modulus depending on the confining pressure, numerical analysis models that analyze its behavior inevitably include complex elements. The hyperbolic model, which relatively accurately simulates the behavior immediately after loading in soft ground, assumes that the stress-strain curve of the consolidated undrained triaxial test is hyperbolic and requires the slope of the tangent line at the starting point. However, the slope of the initial tangent in the stress-strain curve obtained from an actual triaxial test is difficult to have regularity according to changes in confining pressure. Additionally, due to the characteristics of a hyperbola, even small changes in related factors cause large changes in the hyperbola. Therefore, there is a lot of randomness in the process of calculating model parameters from the triaxial test results, which causes large differences in the results. Therefore, the method of calculating the initial elastic modulus by the consolidation test presented in this study is also used to verify the method by the triaxial test. It can be applied. However, since this study was applied to only one sample showing typical consolidation characteristics, it is necessary to check samples with various physical properties in the future.