• 한국식품영양학회지
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• 제17권1호
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• pp.32-40
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• 2004

간장으로 채워진 실린더 형태의 장조림 제품의 가열살균 시 온도변화를 유한요소분석법(finite element method)을 이용하여 예측하기 위하여 상업적 NISA (Numerical Integrated Elements for System Analysis, EMRC, USA)프로그램을 이용하여 실시하였다. 장조림 식품에서의 열전달은 냉점이 기하학적 중심에 위치하지 않고 y축으로 26.9 mm 뒤쪽에 위치하였다. 이는 간장소스의 비열이 장조림보다 20% 이상 큰 값이기 때문으로, 사용된 재료의 열전달계수에 의해서 냉점의 위치가 다르게 나타났다. 장조림 식품의 가열살균 시 열전달계수의 영향을 검토하기 위하여 온도와 치사율 오차를 종속변수로 하여 간장소스의 열전도계수, 장조림의 열전도계수, 열전달계수를 독립변수로 한 반응표면분석법을 행한 결과 장조림의 열전도계수가 p<0.01로 매우 높은 상관관계를 보이며, 치사율 오차를 최소로 하는 최적화값을 얻을 수 있었다.

• 한국재료학회지
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• 제30권9호
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• pp.465-473
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• 2020

For surface hardening of a continuous casting mold component, a fundamental metallurgical investigation on dissimilar laser clads (Cu-NiCrBSi) is performed. In particular, variation behavior of microstructures and mechanical properties (hardness and wear resistance) of dissimilar clads during long-term service is clarified by performing high-temperature post-clad heat treatment (temperature range: 500 ~ 1,000 ℃ and isothermal holding time: 20 ~ 500 min). The microstructures of clad metals (as-clads) consist of fine dendrite morphologies and severe microsegregations of the alloying elements (Cr and Si); substrate material (Cu) is clearly confirmed. During the post-clad heat treatment, the microsegregations are totally homogenized, and secondary phases (Cr-based borides and carbides) precipitated during the short-term heat treatment are also almost dissolved, especially at the heat treatment conditions of 950 ℃ for 500 min. Owing to these microstructural homogenization behaviors, an opposite tendency of the surface mechanical properties can be confirmed. In other words, the wear resistance (wear rate) improves from 4.1 × 10^-2 ㎣/Nm (as-clad condition) to 1.4 × 10^-2 ㎣/Nm (heat-treated at 950 ℃ for 500 min), whereas the hardness decreases from 453 HV (as-clad condition) to 142 HV (heat-treated at 950 ℃ for 500 min).

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2008년도 공동학술대회
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• pp.119-124
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• 2008

복소 전기비저항법은 지반내 미세 IP 효과를 측정할 수 있는 장비와 해석 기술의 발전으로 인해 그 응용분야를 넓혀가고 있는 방법이다. 이 연구에서는 복소전기비저항법을 시멘트 모르탈의 주입을 통해 지반보강을 수행하였던 전라남도 무안군 용월리에 위치한 시험조사 지역에 적용하여, 그라우팅으로 인한 지반변화를 확인해보기 위한 목적으로 수행되었다. 동일한 측선에 대하여 지반보강이 실시되는 동안 전기비저항 모니터링 및 토모그래피 탐사가 수행되었으며, 이 결과는 복소전기비저항 해석 결과와 비교하였다. 탐사결과 그라우팅 진행과 관련하여 수행한 전기비저항 모니터링자료의 4차원 역산해석 결과와 복소 전기비저항법의 위상단면의 이상대가 동일한 위치에서 확인되었다. 이는 시멘트 모르탈에 기인한 IP 효과가 위상 단면상에서 나타나는 것으로, 이는 그라우팅으로 인한 지반보강 조사의 목적으로 복소전기비저항 탐사가 효과적으로 적용될 수 있음을 보여준다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2101-2108
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• 2008

Most of train fires which occur in usual cases do not grow up significantly on a large scale enough to bring about casualties and harmful damages. However, the consequence of some train fire accidents can be devastating disaster so that it would be even recorded in history in unusual cases. Accordingly, such a probability of fire disaster cannot be ignored in aspect of the railway safety assesment. A scale of injury and damage is very difficult to predict and analyze. Because it is depend on various factors, i.e. fire load, burning period, facilities, environment condition, and so on. Thus, a prediction of fire load could be understood as a one methodology to estimate railway safety assesment. The summation method which is one of them is used to evaluate the overall fire load by assuming that sum of heat release rate per unit area or mass of each composite material equals the total. However, since the train fire is classified into a compartment fire in under-ventilation condition. The summation method do not estimate a fire load completely. In this journal, Various methods to predict fire load are introduced and evaluated. Especially the fire simulation tool FDS(Fire Dynamics Simulator)which is based on the CFD(Computational Fluid Dynamics) is introduced, too. Through the FDS simulation, numerical analyses for the fire load and flame spread are performed. Then, these results of the simulation are validated through the comparison study with the experimental data. Then, limitations and approximations including in simulation process are discussed. The future direction of research is proposed.

• 청정기술
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• 제18권3호
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• pp.295-300
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• 2012

입자의 크기, 모양, 및 기능기를 제어할 수 있는 제조 기술은 화학, 생물, 재료과학, 화학 공학, 의약 그리고 생명공학과 같은 다양한 적용분야에 적용될 수 있는 중요한 기술중의 하나이다. 본 연구는 볼록한 지붕을 지니는 이방성 고분자 입자의 곡률 제어를 위해 젖음성 유체를 도입한 새로운 미세몰딩(micromolding technique) 방법에 관한 것이다. 몰드의 종횡비 조절을 통하여 입자의 곡률 반경을 $20{\mu}m$에서 $70{\mu}m$까지 제어할 수 있었으며 서로 다른 습윤특성을 지닌 젖음성 용액을 이용하여 이방성 고분자 입자의 높이와 곡률반경을 조절할 수 있었다. 본 연구에서 제시한 미세몰딩 기술은 저렴하고, 간단하고, 쉽고 빠른 방법으로 이방성 입자를 제작할 수 있으며 3차원 입자 모양의 정밀제어가 가능한 새로운 방법으로 판단된다.

• 복식문화연구
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• 제16권3호
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• pp.588-594
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• 2008

Lookism is spread largely because many people think beautiful people are treated better and receive more favors. This trend has been influenced by mass media and impacted by commercial marketing strategy. The expectation for the beauty have risen higher than ever. People expect beautiful body and beautiful face which are more difficult to meet the standard of beauty. People desire tall and skinny body. The purpuse of this study was to find out body image from college females in the age which they are very sensitive to appearance. This research focused to find out how they perceived their own body shape and their perception of the most ideal body shape. Measuring tool for the research was 9 pictures of body silhouette from very skinny to very fat. To analyse the respondents' objective body image, Body Mass Index were employed. The result of this research indicated that there were distinct differences between their subjective body images and ideal body images. This result indicated that they were not satisfied with their own body shape and hence they were not confident towards their body images. Even though their objective bodies were normal or under weight, they still felt they were over weight. This meant their body images were misrepresented. They preferred thinner bodies even though their bodies were perfectly normal and healthy. But these misrepresented body images could be unhealthy physically, psychologically, or socially. These results showed that college females were overly obsessive with superficial appearance rather than improving ones capability to be more competitive in the society. From this research, I tried to find out perception of body image and it's distortion which was debated a lot in our society. I also want to provide basic reference material for establishing the body image study.

• 한국재료학회지
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• 제13권4호
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• pp.266-270
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• 2003

We studied BCl$_3$ dry etching of GaAs in a planar inductively coupled plasma system. The investigated process parameters were planar ICP source power, chamber pressure, RIE chuck power and gas flow rate. The ICP source power was varied from 0 to 500 W. Chamber pressure, RIE chuck power and gas flow rate were controlled from 5 to 15 mTorr, 0 to 150 W and 10 to 40 sccm, respectively. We found that a process condition at 20 sccm $BCl_3$ 300 W ICP, 100 W RIE and 7.5 mTorr chamber pressure gave an excellent etch result. The etched GaAs feature depicted extremely smooth surface (RMS roughness < 1 nm), vertical sidewall, relatively fast etch rate (> $3000\AA$/min) and good selectivity to a photoresist (> 3 : 1). XPS study indicated a very clean surface of the material after dry etching of GaAs. We also noticed that our planar ICP source was successfully ignited both with and without RIE chuck power, which was generally not the case with a typical cylindrical ICP source, where assistance of RIE chuck power was required for turning on a plasma and maintaining it. It demonstrated that the planar ICP source could be a very versatile tool for advanced dry etching of damage-sensitive compound semiconductors.

• 한국시뮬레이션학회논문지
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• 제20권2호
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• pp.49-57
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• 2011

치열한 경쟁과 원자재 가격 급등은 시행착오를 최소화 하면서 제철소를 최적으로 설계하여 운영할 것을 한층 더 강력하게 요구하고 있다. 컴퓨터 시뮬레이션은 이 요구에 부합되는 방법론을 제공할 수 있다. 본 논문의 목적은 제강 연주 공장의 설계와 운영을 지원하기 위한 시뮬레이터를 제안하는 것이다. 본 연구에서 제안하는 시뮬레이터는 유지보수와 확장에 용이하도록 널리 알려진 Arena로 개발되었으며 사용의 편의성을 위하여 엑셀 기반으로 입출력 인터페이스를 설계하였다. 또한 운반 대차와 천정 크레인으로 구성되는 복잡한 운반 모듈을 포함하여 모델의 정확도를 높였다. 시뮬레이터는 생산량 분석과 물류 분석을 통하여 제강 연주 공장 설계안의 적정성을 평가하는데 유용하게 사용될 수 있다. 그리고 다양한 상황별로 최적의 제품 조합을 도출하는데 적용될 수 있으며, 공정별 설비별로 작업을 배정하는 조업 운영 패턴을 평가하고 정확도를 향상시키는 도구로써 활용이 가능하다.

• 한국기계가공학회지
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• 제16권6호
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• pp.69-74
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• 2017

In the current machining industry, machining precision is necessary and machining is being carried out. In this ultra-precision machining industry, the fixation of the workpiece is very important and the degree of machining depends on the degree of fixation of the workpiece. In ultra-precision machining, various methods, such as using a vise chuck or the like and using bolt nut coupling, are used for fixing a workpiece to an existing machine tool. In particular, when the precision gripping force of the jig is insufficient during machining of the ultra-precision mold parts, the machining material shakes due to the vibration or friction, and the machining precision is lowered. In the ultra-precision machining of power transmission parts, such as gears, the accuracy of the product is then determined. In addition, the amount of heat generated during machining has a significant effect on the machining accuracy. This is because the vibration value changes according to the grasp force of the jig that fixes the workpiece, and the change in the calorific value due to the change in the main shaft rotation speed of the ultra-precision machining. The increase in the spindle rotation speed during machining decreased the heat generation during machining, and the machining accuracy was also good, and it was confirmed that the machining heat changed according to the fixed state of the workpiece and the machining accuracy also changed. In this study, we try to optimize the driving part of the power vise by using structural analysis, rather than the power vise, using the basic mechanical-type power unit.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.132-136
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• 1996

A Study is a experiment which is figure out to aptimum discharge cutting condition of the surfaceroughness, electric discharging speed and electro wear ratio with Ton Toff and V(voltage) as an input condition according to the current(Ip) in an electric spark machine ; 1)Electrode is utilized Cu(coper) and Graphite. 2)Work piece is used the material of carbon steel. The condition of experiment is; 1)Current is varied 0.7(A) to 50(A). 2)Pulse time(Ton) is varied 3($\mu$s) to 240($\mu$s) and also Toff is varied 7($\mu$s) to 20($\mu$s). 3)The time of electric discharging to work piece in each time is 30(min) to 60(min) 4)After the upper side of work piece was measured in radius (5${\mu}{\textrm}{m}$) of syulus analyzed the surface roughness to made the table and graph of Rmax by yielding data. 5)Electro wear ratio is; \circled1Coper was measured cx-machining and post machining but the electronic baiance. \circled2The ex-machining of graphite measured by it, the post-machining was found the data from volume specific gravity and analyzed to made its table and graph on ground the data 6)In order to keep the accuracy of voltage affected to the work piece was equipped with the A.V.R(Automatic Voltage Regulator). 7)The memory scope was sticked to the electric spark machine. 8)In order to preserve the precision of current, to get rid of the noise occured by internal resistance of electric spark machine and to force injecting for the discharge fluid, it made the fixed table for a work piece to minimize the work error by means of one's failure during the electric discharging According to above results, the surface roughness by the variation of electrodw and current was analyzed to compare KS(Korea Standards) It was decided the optimum condition of electric discharge cutting through analyzing the effect of electric discharge speed and electro wear ratio.