• The Korean Journal of Rheology
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• v.10 no.3
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• pp.143-151
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• 1998

실리콘 오일에 인산처리 셀룰로오스 분말을 분산시킨 비수계 전기유변성(ER) 유체 의 전기유변 거동을 상온에서 최대 2.5KV/mm의 전기장하에서 실험하였다. 넓은 온도 영역 에서 사용이 가증한 비수계 ER 유체를 개발하기 위해 셀룰로오스의 인산 에스테르 반응이 ER 유체의 전기유변효과에 미치는 영향을 조사하였다. 먼저 여러 가지의 인산처리 농도로 처리된 인산처리 셀룰로오스 미립자를 분산시킨 ER 유체를 제조한 후 ER 유체의 유전상수, 전류밀도 및 전기전도도 등과 같은 전기적 특성을 측정하였으며 ER 유체의 전기유변 특성 또한 측정하였다. 인산처리 셀룰로오스가 분산된 비수계 ER 유체의 전류밀도는 셀룰로오스 의 인산 에스테르 반응에서의 인산처리 농도에 의해 조절할수 있음을 알수있었으며 셀룰로 오스의 인산처리 농도가 2.5 M과 3.0 M 사이일 때 인산처리 셀룰로오스가 첨가된 비수계 ER 유체의 전기유변효과 ($\tau$/$\tau$0)가 가장 높게 측정되었다.

• Broadcasting and Media Magazine
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• v.28 no.2
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• pp.43-52
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• 2023

SBS에서는 다년간 지속적으로 핫클립 생성 딥러닝 기술을 방송 시스템에 적용하여 업무 효율을 높이려는 시도를 하였다. 본 기고문에서는 그동안 누적된 SBS의 핫클립 생성 딥러닝 기반 방송 시스템의 기획, 개발, 적용 및 운영 사례에 대한 전반적인 내용을 다루려 한다. 또한 구축 과정에서 발생하는 어려움과 그에 대한 해결책도 공유하려 하였다. 본 기고문에서 소개할 딥러닝 기반 방송 시스템은 하이라이트 구간 예측, UHD 방송 A-ESG 서비스 운영 시스템, 유튜브 채널 운영 시스템, 매쉬업 콘텐츠 제작 지원 시스템 등이다.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.53-58
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• 2013

In order to judge that non-esterified soybean oil could be used on diesel engine with electronic control of fuel injection system, The test of combustion performance using only gas oil, gas oil blended with esterified bio-diesel oil 5% and non-esterified soybean oil 5% were carried out. It is noticed that most performances of gas oil blended with esterified bio-diesel oil 5% and non-esterified 5% have similar characteristics but non-esterified bio-diesel oil 5% emitted smaller NOx, resulting from fuel NO.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.487-492
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• 2013

Transesterifications of waste oils mixed with animal tallows and vegetable oil by ultrasonic energy were examined over various catalysts for biodiesel production. Reaction activities of the transesterification were evaluated to the ultrasonic energy and thermal energy. The physicochemical properties of feedstock and products were also investigated to the biodiesels produced from the oils in the reaction using ultrasonic energy. The highest fatty acid methyl ester (FAME) yield was obtained on the potassium hydroxide catalyst in the transesterification by ultrasonic irradiation. The effective reaction conditions by ultrasonic energy were 0.5 wt% catalyst loading and 6:1 molar ratio of methanol to the mixed oils. The reaction rate of the transesterification by ultrasonic energy was faster than that by thermal energy. The highest yields of FAME were obtained as 80% in 5 min and the reaction equilibrium reached at that time.

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.174-177
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• 2010

In this study, non-catalytic transesterification from rapeseed oil using supercritical methanol was carried out by varying the operation parameters such as temperature ($320{\sim}365{^{\circ}C}$), time (0~20 min), pressure (10~35 MPa), molar ratio of oil to methanol (1 : 15~60) and agitation speed (0~500 rpm). In order to evaluate the effects of reaction parameters on the content of fatty acid methyl esters (FAMEs), we carried out the study using a batch reactor. The content of FAMEs increased when the temperature increased. However, the content of FAMEs decreased with temperature above $335^{\circ}C$ and time above 5 min. The content of FAMEs increased with increasing the molar ratio of methanol to oil but the content of FAMEs was slightly affected by molar ratio of oil to methanol above 1 : 45 and pressure above 20 MPa. It was found that the agitation speed above 100 rpm slightly affected the content of FAMEs. The highest content of FAMEs in biodiesel (95%) was obtained under the reaction conditions: temperature of 335 ${^{\circ}C}$, time of 10 min, pressure of 20 MPa, molar ratio of 1 : 45 (oil to methanol) and agitation speed of 250 rpm.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.390-394
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• 2009

In this study, partition coefficients(Kw) of phenoxyethanol in oil-water phase according to type of oils was investigated. Partition coefficients(Kw) were experimented by classified oils that hydrocarbones, fatty alcohols, fatty acids, esters, triglycerides and silicones. It was found that partition coefficients(Kw) of hydrocarbons and silicones were low, but partition coefficients(Kw) of fatty acids, fatty alcohols, esters and triglycerides were high. It was known that the emulsions which were made of oils having low partition coefficients value had a good antimicrobial effects. Thus, the cosmetics stability of microorganisms and skin safety of phenoxyethanol could be improved by using the oils which have low partition coefficients value.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.380-386
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• 1995

An attempt was made to determine the effects of drying methods including shady air drying, presteamed and shady air drying, microwave drying, and freeze drying on the volatile flavor components with Commelina communis L.. Essential oils from the samples were isolated by simultaneous steam distillation-extraction(SDE) method using diethyl ether as solvent. Concentrated samples were analyzed by gas chromatography(GC) and combined gas chromatography-mass spectrometry(GC-MS). Respective 29, 47, 36, and 24 volatile flavor components were identified in shady air dried samples, presteamed and shady air dried samples, microwave dried samples, and freeze dried samples. The kinds and amounts of volatile flavor components were evidently depended upon the drying methods. 6,10,14-trimethylpentadecanone was regarded as the most abundant component in shady air dried samples, 6,10,14-trimethyl-2-pentadecanone in presteamed and shady air dried samples, neophytadiene in microwave dried samples, and ethyl acetate in freeze dried samples.

• Journal of the Korea Convergence Society
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• v.3 no.4
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• pp.35-44
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• 2012

In this study, a simulation program is developed in order to investigate non steady-state cornering performance of 6WD/6WS special-purpose vehicles. 6WD vehicles are believed to have good performance on off-the-road maneuvering and to have fail-safe capabilities. But the cornering performances of 6WS vehicles are not well understood in the related literature. In this paper, 6WD/6WS vehicles are modeled as a 18 DOF system which includes non-linear vehicle dynamics, tire models, and kinematic effects. Then the vehicle model is constructed into a simulation program using the MATLAB/SIMULINK so that input/output and vehicle parameters can be changed easily with the modulated approach. Cornering performance of the 6WS vehicle is analyzed for brake steering and pivoting, respectively. Simulation results show that cornering performance depends on the middle-wheel steering as well as front/rear wheel steering. In addition, a new 6WS control law is proposed in order to minimize the sideslip angle. Lane change simulation results demonstrate the advantage of 6WS vehicles with the proposed control law.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.240-246
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• 1992

Preparation of soybean oil fatty acid methyl esters (soybean oil FAME) through the transesterification of soybean oil with alkaline catalyst was optimized in terms of contents of residual free fatty acids (FFA) in soybean oil FAME and yield of soybean oil FAME due to the inhibitory effect of FFA on sucrose polyesters synthesis. Soybean oil FAME and residual FFA were analyzed quantitatively by simultaneous gas chromatography on a fused silica capillary column after converting the FFA in soybean oil FAME to tert.-butyldimethylsilyl (TBDMS) derivatives. Transesterification of soybean oil was successfully performed with alkaline catalyst (NaOH, 95%), which resulted in 99.1% yield of soybean oil FAME and less than 0.1% residual FFA contents under the conditions such as $30^{\circ}C$, 20min. and 6:1 molar ratio of anhydrous methanol to soybean oil.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.45-46
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• 2017

본 논문은 사람에 의하여 발생하는 패턴과 기계적으로 발생하는 패턴과의 차이점을 인지함으로써 BAD USB 탐지하는 방안을 제안한다. BAD USB는 펌웨어를 조작하여 악의적인 행위를 수행하는 공격으로, BAD USB를 탐지하기 위한 많은 연구가 진행되었지만, 펌웨어 내부에 존재하는 악성코드를 효과적으로 탐지하기에는 어려움이 존재한다. 따라서 본 논문에서는 사람에 의하여 나타나는 행위에 대한 패턴과 기계적으로 발생하는 패턴을 구분하여 악의적인 행위를 인지함으로써 BAD USB를 탐지하는 방안을 제안한다.