• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.589-599
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• 2013

The concept of robust optimization is based on Taguchi's method. Especially, robustness indices of objective function pursue an insensitive and conservative design when there are variations on design variables and parameters. To accomplish the purpose, various robustness indices on the objective function have been developed. However, it can be caused limitations to develop the robustness index, because there is difference between the Taguchi's method and robust optimization. In this paper, an investigation is performed to identify the characteristics and the drawbacks of the previous studies. To achieve the purpose, evaluations are conducted by using the examples which have both a deterministic optimum and a robust optimum. Moreover, a new viewpoint as well as a robustness index using a supremum value of the objective function is proposed based on the investigation.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.1
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• pp.50-57
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• 2016

We studied the Lab-scale process for the development of DNAM in aspect of safety and overall efficiency. Melamine is used for starting material of process, DNAM was synthesized by oxidation and nitration reaction. In order to optimize the process parameters with the product in higher yield and purity, a systematic study with variation of different parameters like molar ratio of nitrating mixture, conditioning time and order of reactant was carried out. The optimized reaction conditions for the synthesis of DNAM were : conditioning time of $3{\pm}3.5$ hour and nitrating mixture in 1:1.4 molar ratio. In order to proceed a stable reaction, melamine was added with enough time to relieve reaction heat. From these reaction condition, DNAM could be obtained in a yield of more than 60%.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.4
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• pp.129-135
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• 2016

In this paper, we propose a novel tracking algorithm called slide window tracker (SWT) suitable for maneuvering target. To efficiently estimate trajectory of moving target, we adopt a sliding piecewise linear window which includes past trace information. By adjusting the window parameters, the proposed algorithm is to reduce measurement noise and to track fast maneuvering target with little computational increment as compared to ${\alpha}-{\beta}$ tracker. Throughout the computer simulations, we verify outstanding tracking performance of the SWT algorithm in noisy linear and nonlinear trajectories. Also, we show that the SWT algorithm is not sensitive to initial model parameter selection, which gives large degree of freedom in applying the SWT algorithm to unknown time-varying measurement environments.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2012.05a
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• pp.5-5
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• 2012

들깨는 아직 식물학적으로 분류는 되어 잇지 않으나 일반 식물분류학상 꿀풀과(진형과(唇形科); Labiatae)에 속하는 1년생 초본으로 동부 아시아지역이 원산지로 한국, 일본, 중국 동북부 등의 저위도 지역에서 광지역성 작물로 생육온도가 $10{\sim}15^{\circ}C$ 사이에서는 광합성 속도가 거의 변화가 없고 $20^{\circ}C$에서 최대에 이르며 $25^{\circ}C$ 이상의 온도에서는 급격히 떨어지는 것으로 보고되어 있다. 들깨의 생육 적온은 $20^{\circ}C$ 전후로 벼, 옥수수 등 다른 여름작물에 비해 낮으며, 온도에 대한 반응은 매우 둔감한 반면, 광량에는 아주 민감하게 반응하는 기름작물이다. 우리나라의 농서에는 이조시대인 1429년 정초(鄭招)의 농사직설(農事直說)에서 들깨를 유마(油麻), 수임자(水荏子)로 기록한 이래 여러 문헌에 임(荏), 임자(荏子), 수임(水荏), 수소마(水蘇麻), 유마(油麻), 지마(脂麻) 등으로 불리워져 왔다. 예로부터 들깨는 쓰임새도 다양하여 식용기름, 등화용 이외에도 잎에서 나는 독특한 냄새를 가축들이 싫어하여 농작물을 보호하기 위한 목적으로 밭 둘레에 심거나 기상재해로 소득 작물 재배가 어려울 때 대파작물(代播作物)로 이용되어 왔다. 세계적으로 한국인만 식용으로 즐겨 사용하는 들깨가 근래에는 경제성장으로 국민 소비형태가 다양화되는 추세로 들깨를 종실뿐 아니라 신선 잎채소로 이용하는 양이 크게 증가하고 있으며 들깨기름에 들어있는 ${\alpha}$-리놀렌산이 오메가-3 지방산으로서 고혈압 등의 성인병 예방과 학습능력향상에 효과적이라는 사실이 밝혀짐에 따라 들깨를 이용한 오메가3 계란, 오메가3 두유 등 다양하게 건강식품으로 응용되고 최근 동물성 어류에서 추출하던 오메가-3 해양 오염. 프랑크톤의 먹이사슬 등의 환경문제로 들깨기름의 식물성 오메가-3로 대체하는 영향이 세계적으로 인식되기 시작하여 우리 한국 들깨의 우수성을 세계인들에게 널리 알리는데 노력하여야 하고 국내에서 농촌에 들깨 심기을 보다 확대하여 소득작물로 육성하여야 한다고 본다. 들깨는 식물 유지류 작물중 오메가-3가 가장 많은 60%이상의 함유량으로 기능성 건강 보조식품의 원료 및 사료로 이용되는 등 새로운 소득 작물로 자리 잡아가고 있다.

• Korean Journal of Environmental Agriculture
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• v.11 no.3
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• pp.261-268
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• 1992

The membranes of mitochondria and chloroplasts contain a number of pigments that can act as endogenous sensitizers to produce activated oxygen species, most efficiently in blue light, which, in turn, attack functional targets in membranes. Therefore, intense blue light from the sun can exert various adverse effects on the functional and structural integrity of the membranes: one of the biochemical events of these negative effects could be the oxidative degradation of the unsaturated fatty acid constituents of membrane polar lipid. It may be assumed that as a strategy to avoid the light induced fatty acid degradation in membranes plant cells, responding to high intensity blue light, change the fatty acid compositions of membrane lipid in such that more-unsaturated fatty acid constituents are replaced by lessunsaturated fatty acid constituents. The results obtained in the present study, most importantly the measurements of double bond index of membrane polar lipid in concert with other measurements such as light quaility-dependent membrane peroxidation and the activities of membrane-bound proteins, seem to support this assumption.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.6
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• pp.37-44
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• 1999

In this paper, we present a new sliding surface with a time-varying repeated root for fast and robust tracking of higher-order uncertain systems. The repeated root is moved to target one with stabilizing the closed-loop time-varying system in sliding mode. This initial root is obtained so that shifting distance of the surface may be minimized with respect to an initial error, and the intercept is produced so that the surface may pass the initial error. Under the allowable input, fast shifting of the surface and movement of the repeated root enable the error convergence rate to be increased. The proposed sliding mode control makes the error always remain on the surface from the beginning, and therefore, the system is more insensitive to parameter uncertainties and external disturbances. In simulation, the effectiveness of the proposed method is proved by comparison with the conventional one.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.2
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• pp.1-11
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• 2001

In this paper, a chattering alleviation VSS controller for the sinusoidal type BLDC motor is designed. Dead Zone function is proposed to change the chattering occurring in the transient state from high frequency to low frequency and time varying gains arc applied for the control input to eliminate the steady state excessive chattering in the conventional ISM. The proposed Dead Zone function represents the sliding layer composed of two switching surfaces and if a state vector exists in this layer, the chattering don't occur. Simulation and experimental results confirm the useful effects of the above algorithm.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.402.2-402.2
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• 2014

과학과 기술이 발전할수록 나노크기를 넘어서 나노 크기미만의 관찰 분해능과 가공능력이 필수로 요구되어 측정장비와 가공장비의 연구 및 개발이 매우 중요하다. 현재는 주사전자현미경과 투과전자현미경의 발달로 나노크기 이하의 이미징 분해능에는 도달하였지만, 전자 입자의 가벼운 무게 때문에 가공측면에서는 한계를 가지고 있다. 또한 지난 수십 년간 정밀가공에 사용된 갈륨이온 LMIS(Liquid Metal Ion Source)기반의 집속이온빔 시스템은 수십 nm의 가공정밀도를 가지지만 10 nm 미만의 가공정밀도까지 구현하기에는 현재 기술적인 한계로 힘들다. 나노크기 이하의 이미징 분해능과 수 nm의 가공정밀도를 갖는 이온현미경이 최근에 상용화되어 판매되고 있는데, 이 이온 현미경에 사용되는 것이 가스장 이온원(GFIS:Gas Field Ionization Source)이다. 가스장 이온원은 작은 발산각, 작은 가상 이온원 크기 그리고 좁은 에너지 퍼짐의 특징을 가지며 이에 따라 구면수차 및 색수차에도 둔감한 특징을 가지고 있다. 또한 LMIS 는 갈륨이온이 시편속에 파고들어 시편의 물질 특성이 변화되는 문제가 있지만, GFIS에서는 주로 He, Ne 와 같은 불활성 기체를 주로 사용하므로 시편과 반응을 최소화 할 수 있는 장점도 있다. 위와 같은 특징을 갖는 이온빔을 GFIS 로 생성하고 이온현미경에 사용하기 위해서는 이온빔이 팁의 단원자 내지 수 개 정도의 원자에서 생성되도록 해야 한다. 본 연구에서는 GFIS 의 원리를 소개하고 장(전계)이온현미경(Field Ion Microscope)실험을 통하여 GFIS기반으로 생성된 이온빔의 형상을 보여준다. 또한 높은 각전류밀도 구현을 위하여 질소가스 에칭으로 텅스텐 팁 끝 단원자에서만 이온빔을 생성하고, 각전류 밀도 계산과 안정도 실험결과로 본 연구에서 개발한 이온원이 이온총으로서의 이온현미경 적용 가능성에 대해 보여준다.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.1-6
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• 2001

Eigenface method in face recognition is useful due to its insensitivity to large variations in facial expression and facial details. However its low recognition rate necessitates additional researches. In this paper, we present an efficient method for improving the recognition rate in face recognition using eigenface feature. For this, we performs a comparative study of three different classifiers which are i) a single prototype (SP) classifier, ii) a nearest neighbor (NN) classifier, and iii) a standard feedforward neural network (FNN) classifier. By evaluating and analyzing the performance of these three classifiers, we shows that the distribution of eigenface features of face image is not compact and that selections of classifier and sample training data are important for obtaining higher recognition rate. Our experiments with the ORL face database show that 1-NN classifier outperforms the SP and FNN classifiers. We have achieved a recognition rate of 91.0% by selecting sample trainging data properly and using 1-NN classifier.

• Cartoon and Animation Studies
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• s.35
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• pp.255-270
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• 2014

There is a dazzling display of colors used in contemporary visual media. The flood of color image in films leads to the application of partial colors onto the monotonous image, which is one of the reverse phenomena in this field of visual media. Nowadays, it became possible to revise the colors of moving images through computer graphics, and the excessive use of colors has a tendency to make visual impact uninteresting. The attempt is applied in a variety of ways from making video commercials and music videos as well as films. In particular, the application of partial color in the monotonous image in films such as Schindler's List(1993) and Sin City(2005) gave scores of audiences a fresh shock and added the depth of moving image. The purpose of this study is to examine how the principles and properties of the color affect us and how the application of monotone shows its effectiveness in moving images. By analyzing various case studies, this paper will propose and validate the progressive value toward the application of moving images in combination in the future.