• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.143-145
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• 2015

A mesoscale channel was designed to observe the flame stabilization at low strain rate conditions (< $10s^{-1}$). At this condition, the behavior of partially premixed flame was explored by changing a channel size and the oxygen ratio in the oxidant. In this work, experiment is conducted for propane case and it was compared with methane case of previous one. Conclusively, it can be observed that the strain rate of flame extinction and starting point of oscillation were varied with oxygen ratio. Moreover we can understand the effects of enhanced oxygen ratio of oxidant and flame behavior at low strain rate conditions.

• 한국표면공학회지
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• 제34권4호
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• pp.313-320
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• 2001

It is well known that the amount of hot-dip Zn coated sheet steels used for automotive is rapidly increasing. As hot-dip steel sheets show good corrosion resistance and excellent formability, the demand for outer panel of automotive has been increased in order to satisfy with the requirement of high surface qualify. There are many kinds of factors influencing on the surface quality and the dross control in the galvanising bath is regarded as one of the most important thing. In this study the characteristic and growing behavior of dross in the galvanizing bath were investigated and the effect of dross on the surface defect of GA was surveyed. The dross defects on the GA sheet steels result from bottom dross whose diameter are larger 50$\mu\textrm{m}$ in the Zn pot. Dross-free state exist for about 30 hours from starting time of GA production.

• 국제초고층학회논문집
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• 제12권4호
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• pp.351-362
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• 2023

In modern society, rapid environmental changes are occurring due to the complex interaction of various factors. Starting in 2020, the social environment is changing rapidly due to the impact of the pandemic, and the social and economic living environment is changing significantly not only in Korea but also internationally. In this trend, behavioral and spatial changes are occurring in response to changes in the architectural living environment. To analyze changes in behavior and space from an architectural perspective in response to changes in the social environment, first organize the concept and aspects of the pandemic that caused the change, examine the theory of the pandemic, and examine architectural responses to changes in the social environment. There is a need to analyze. Therefore, in order to architecturally review changes in the social environment due to the pandemic, the purpose of this study is to analyze the living behavior and space of major highrise residential complexes in the living environment and present new spatial alternatives in response.

• 한국분말재료학회지
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• 제16권6호
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• pp.431-437
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• 2009

Various inorganic fillers improve the thermal conductivity and physical properties of organic products. Alumina has been used a representative filler in the heat radiation sheet for the heat radiation of electric device. The high filling rate of alumina increases the thermal conductivity and properties of products. We successfully developed the spherical alumina by flame fusion process using the oxygen burner with LPG fuel. In the high temperature flame (2500$\sim$3000$^{\circ}C$) of oxygen burner, sprayed powders were melting and then rotated by carrier gas. This surface melting and rotation process made spherical alumina. Especially effects of chemical composition and particle size of stating materials on the melting behavior of starting materials in the flame and spheroidization ratio were investigated. As a result, spheroidization ratio of boehmite and aluminum hydroxide with endothermic reaction of dehydration process was lower than that of the sintered alumina without dehydration reaction.

• 응용통계연구
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• 제34권1호
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• pp.25-38
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• 2021

최근 동적 연결망의 비정상적 변화를 감시하기 위한 연결망 모니터링의 필요성이 높아지고 있다. 이 논문에서는 연결망의 구조적 변화를 감시하기 위한 동적 연결망의 모형으로 DCSBM(degree corrected stochastic block model)을 고려하였다. 관리도 절차를 사용하여 동적 연결망을 감시하려면 제1국면을 통해 초기 연결망을 확보한 후 모형의 모수를 추정하는 단계를 거쳐야 한다. 그러나 연결망의 감시에서는 충분한 수의 초기 연결망을 확보하기 어려운 경우가 대부분이다. 이 논문에서는 동적 DCSBM을 감시하기 위한 자기출발 관리도 절차를 제안한다. 이 절차는 모형의 모수 추정을 위해 확보한 연결망의 수가 아주 적은 경우에 유용하게 사용할 수 있는 절차이다. 모의실험을 통해 절차의 성능을 평가한 결과, 제안된 절차는 초기 연결망의 수가 아주 적은 경우에도 좋은 관리상태의 성능을 나타내는 것을 알 수 있었다.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.343-345
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• 2002

The influence of starting precursor powders on the phase formation and transport properties of Bi-2223/Ag tapes has been studied. The experimental results show that the average particle size of precursors as fine as 1.64 ${\mu}{\textrm}{m}$ and 1.51 ${\mu}{\textrm}{m}$ can still increase the transport properties. The J$_{c}$-B behavior is also enhanced in tapes fabricated with powders in finer particle sizes. However, at higher magnetic fields, J$_{c}$ of tape started from the powder with the finest particles drops rapidly at the direction of H//c, which is possibly attributed to the small grain sizes and weak flux pinning ability that due to the short induction period at the initial stage of phase formation as the result of fine particles in precursor powder.der.

• 한국분말재료학회지
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• 제13권4호
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• pp.243-249
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• 2006

Yttrium aluminum garnet (YAG) powders were synthesized via mechanochemical solid reaction using $Y_2O_3$ with three types of aluminum compounds. $Y_2O_3$ reacted mechanochemically with all A1 compounds and formed YAM (yttrium aluminum monoclinic), YAG and YAP (yttrium aluminum perovskite) phases depending on the starting materials. The ground samples containing ${\gamma}-A1_2O_3$ showed the best reactivity, whereas the ground sample containing A100H, which had the largest surface area, exhibited pure YAG after calcination at $1200^{\circ}C$. The sample containing Al had the least reactivity, producing YAP along with YAG at $1200^{\circ}C$. The types and grinding characteristics of the starting materials and grinding time are believed to be important factors in the mechanochemical synthesis of YAG.

• 한국콘텐츠학회논문지
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• 제7권10호
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• pp.221-228
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• 2007

창업보다 중요한 것은 어떻게 기업을 유지, 발전시키느냐의 문제이다. 그러므로 창업초기에 기업의 신뢰형성 문제는 이후 기업경영 성패를 좌우하는 요인이 되고 있다. 따라서 본 연구에서는 창업초기 인터넷 쇼핑몰에서의 신뢰형성에 영향을 주는 요인이 무엇인가를 분석하여 마케터들이 인터넷 쇼핑몰에 대한 성장전략 수립에 도움을 주고자 하였다. 선행연구를 통해 신뢰의 개념, 인터넷 환경 하에서의 소비자 구매행동과 신뢰형성 요인에 대한 요인들을 정리하였다 연구목적을 달성하기 위해 가설의 설정과 검증을 실시한 결과 정보품질, 웹디자인, 쇼핑 편의성이 초기신뢰에 영향요인으로 나타났다.

• 한국추진공학회지
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• 제17권1호
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• pp.35-41
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• 2013

75톤 추력급 터보펌프 터빈의 토크 특성을 성능시험 데이터를 바탕으로 분석하였다. 터빈의 토크는 해석적으로 고정된 압력비에서 보정 선속도의 일차함수로 표현되며 이를 시험적으로 확인하였다. 일정 압력비 이상의 영역에서는 보정선속도-무차원 토크 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 90 rpm 정도 줄어들게 하는 것으로 예측되었다.

• 대한한의학회지
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• 제24권3호
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• pp.23-34
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• 2003

Objective : In 2001, the rate of obesity in Korea reached 30.6%. There are many therapeutic ways to reduce body weight, such as low and very low calorie diet, exercise therapy, behavior modification therapy, etc. However, in many cases the patients feel stress under obesity treatment because of starvation. This study was aimed to evaluate the anti-starvation stress effect of Coicis Semen on mice. Methods : First, the mice were divided into 6 groups : Normal (group with no starvation), Control (administrated normal saline 6 times before starting 36 hours starvation), and Samples A, B, C, and D (administrated 0.25, 0.5, 1.0, 3.0 g/kg Coicis Semen respectively 6 times before starting 36 hours starvation). Then the plasma corticosterone level and rectal temperature were measured. The norepinephrine, dopamine, DOPAC (dihydroxy-phenylacetic acid), 5-HT (5-hydroxytryptamine) and 5- HIAA (5-hydroxy-indole-acetic acid) in the hypothalamus were measured by the HPLC method. Result : I. The rectal temperature in Sample group D showed a significant difference (P<0.05) compared with the Control group. 2. The DOPAC in Sample groups A, C and D showed the significant difference (P<0.05) compared with the Control group. Conclusion : It might be recognized that Coicis Semen has an anti-starvation stress effect.