• 전자공학회논문지
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• 제53권11호
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• pp.123-129
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• 2016

본 논문에서는 외바퀴 로봇의 균형 제어 성능을 향상할 목적으로 외란관측기를 사용한다. 외란관측기의 설계는 역 공칭 모델 설계와 Q필터 설계의 두 과정으로 구성된다. 외바퀴 로봇의 역 공칭 모델을 역 스틱 모델로 부터 유도하고 역 공칭 모델의 안정화를 위한 Q필터를 설계한다. 이 과정에서 Q31의 형태를 갖는 필터를 설계하고 Q필터 시정수의 영향에 관한 실험적인 검증 결과를 제시한다. 시정수는 외란 억제 대역폭을 결정하는 역할을 하지만 외란 억제와 센서 잡음 내성은 상보적인 특성을 갖고 있다. 그러므로 전체 시스템을 고려하여 적절한 시정수가 선택되어야만 한다. 이를 해결하기 위해 3개의 서로 다른 시정수가 외란관측기에 각각 사용되었을 때의 제어 성능을 비교하는 실험을 수행한다. 결과 분석을 바탕으로 한 바퀴 로봇의 균형 제어에 대한 외란관측기 설계에 적합한 시정수 변수의 설계 범위를 제안한다.

• 생약학회지
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• 제11권2호
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• pp.95-103
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• 1980

In our country there are five species of Morus genus including Morus alba L.. Also their varieties and hybrids are distributed so much. In sucession of previous report we collected control and marketing specimens of Mori Cortex Radicis, comparative experiments were pharmacognostically carried out to identify the control specimen by the differences of external and internal morphology. It was difficult to identify marketing specimens by external morphology, because they are similar in spite of conparating with control specimen which the origin is definite. In internal morphology, medullary ray is developed near the cambium to primary bark in control specimen A(Morus alba series) and C(M. Lhou series), but less developed in B(M. bombycis series). The difference of these three series was observed. The thickness of cork layer is almost the same($7{\sim}12$ layers) in A and C series, but B is thin layer and sample E(that on the market) is generally more thick and has a stick cork cell. The kinds of starch, Ca-oxalate and latex, cell centents were same, but it was easy to identify them by the differences of their distribution. The bast fibre of D(wild specimen) and E were light lignified, latex tube of A and C series was richer distributed than others. These results show that the origin of Mori Cortex Radicis on the market can be appreciated in four groups of Korean Morus genus which are M. alba, M. bambycis, M. Lhou series and the others.

• Journal of Biosystems Engineering
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• 제37권3호
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• pp.192-200
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• 2012

Purpose: Aerial application of chemicals with an agricultural helicopter allows for precise and timely spraying and reduces working labor and pollution. An attitude controller for an agricultural helicopter would be helpful to aerial application operator. The objectives of this paper are to determine the transfer function models and to estimate the handling qualities of a bare-airframe model helicopter. Methods: Transfer functions of a model unmanned helicopter were estimated by using NAVFIT and DERIVID modules of the $CIFER^{(R)}$ program to the time history data of frequency sweep flight tests. Control inputs of the transfer functions were elevator, aileron, rudder and collective pitch stick positions and the outputs were resulting on-axis movements of the fuselage. Results: Minimum realization of the transfer functions for pitch rate output to elevator control input and roll rate output to aileron control input produced second order transfer functions with undamped natural frequencies around 3.0 Hz and damping ratios of 0.139 and 0.530, respectively. The equivalent time delays of the transfer functions ranged from 0.16 to 0.44 second. Sensitivity analysis of the proposed parameters allowed derivation of minimal realization of the transfer functions. Conclusions: Handling quality of the model helicopter was addressed based on the eigenvalues of the transfer functions, corresponding undamped natural frequencies with damping ratios. The equivalent time delays of the lateral-directional motion ranged from 0.16 to 0.44 second, longer than the 0.1 to 0.15 second requirement for well-controlled typical manned aerial vehicles.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.469-479
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• 2003

A novel branched wax has been developed for the control of the hardness of oil-wax gels. Using this wax, glossier application and smoother texture but tough lipstick can be obtained. Oil-wax gels are oily solids composed of liquid and crystalline solid oils (waxes). They are widely used in various cosmetic products, especially lipsticks. The control of gel hardness is one of the most important techniques in improvement of the lipstick quality. Addition of small amounts of commercial branched paraffin wax (e.g. microcrystalline wax, b-PW) to n-paraffin wax (n-PW) has been commonly used to increase gel hardness. However, gel hardness is very sensitive to the quantity of b-PW and the gel obtained is not always hard enough for practical use. In this study we examined the relationship between the gel hardness and the properties of the wax crystal in the gel. We have found that, when b-PW is added to n-PW, the wax crystal size becomes smaller (hardening the gels) and its crystallinity is decreased (softening the gels) simultaneously. Considering this result, we have developed a novel branched wax, Bis(polyethylenyl)- tetramethyldisiloxane (named ESE). ESE molecules are composed of a central tetramethyldisiloxane unit (branch unit) with polyethylene units at both ends. The central unit may suppress crystal growth while the ends are expected to prevent a decrease in wax crystallinity during crystallization. When ESE is added to n-PW, the wax crystal obtained becomes smaller without decreasing in crystallinity; consequently, the gel hardness is dramatically increased. By using ESE, the total amount of wax in a lipstick can be decreased by 30％ without spoiling the stick toughness, thereby achieving glossy application and smooth texture.

• 전기학회논문지
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• 제64권7호
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• pp.1056-1063
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• 2015

In this paper, we develop an interface for aerial photograph platform which consists of a quadrotor and a gimbal using the human body and the head posture. As quadrotors have been widely adopted in many industries such as aerial photography, remote surveillance, and maintenance of infrastructures, the demand of aerial video and photograph has been increasing remarkably. Stick type remote controllers are widely used to control a quadrotor, but this method is not an intuitive way of controlling the aerial vehicle and the camera simultaneously. Therefore, a new interface which controls the serial photograph platform is presented. The presented interface uses the human head movement measured by head-mounted display as a reference for controlling the camera angle, and the human body posture measured from Kinect for controlling the attitude of the quadrotor. As the image captured by the camera is displayed on the head-mounted display simultaneously, the user can feel flying experience and intuitively control the quadrotor and the camera. Finally, the performance of the developed system shown to verify the effectiveness and superiority of the presented interface.

• 동의신경정신과학회지
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• 제28권3호
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• pp.231-248
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• 2017

Objectives: This study evaluates anti-stress and sleep-inductive effects of Dongshingihyeolyangsubang (DSGYSB) on rats induced by chronic mild stress (CMS). Methods: Twenty-five healthy rats were randomly divided into five groups: normal, CMS (Control), DSGYSB50, DSGYSB100, and DSGYSBS200. All rats except the normal group were exposed to unpredictable stress conditions such as water deprivation, empty bottles, and forced treadmill. A week after starting the experiment, rats in DSGYSB50, DSGYSB100, and DSGYSB200 groups were fed orally with water once a day for two weeks. Then blood samples were taken from the rats for analysis of complete blood count, AST, ALT, and glucose. Noradrenaline, corticosterone, serotonin, GABA and melatonin were measured by ELISA kit. BDNF, CREB, TrkB and $TNF-{\alpha}$ were measured by RT-PCT. Results: In Noradrenaline contents, the DSGYSB200 group revealed significant decrease compared to the control group. In corticosterone contents, the DSGYSB200 group revealed significant decrease compared to the control group. In serotonin contents, the DSGYSB200 group revealed significant increase compared to the control group. In GABA contents, the DSGYSB50, DSGYSB100, and DSGYSB200 groups revealed significant increase compared to the control group. In the activity of BDNF, the DSGYSB50, DSGYSB100 and DSGYSB200 groups revealed significant increase compared to the control group. In the activity of CREB, the DSGYSB100 and DSGYSB200 groups revealed a significant decrease compared to the control group. In the activity of TrkB, the DSGYSB100 and DSGYSB200 groups revealed significant decrease compared to the control group. In the activity of $TNF-{\alpha}$, DSGYSB100 and DSGYSB200 groups revealed significant decrease compared to the control group. In glucose contents, the DSGYSB100 and DSGYSB200 groups revealed significant decrease compared to the control group. In the leukocyte changes, white blood cells, neutrophil, lymphocytes, and monocyte significantly increased in the DSGYSB100 and DSGYSB200 groups than the control group. In the erythrocyte changes, hemoglobin significantly increased in the DSGYSB200 group than the control group. Conclusions: Results suggest that Dongshingihyeolyangsubang has anti-stress and sleep-inductive effects on rats induced by CMS.

• Asian-Australasian Journal of Animal Sciences
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• 제9권6호
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• pp.643-646
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• 1996

Experiments were conducted to determine potassium (K) requirement of mule ducklings. One-day-old ducklings with equal number of both sexes were fed diets containing graded levels of K for three weeks. In experiment 1, corn-soybean meal diet (CP 18.7%, ME 2,890 kcal/kg, K 0.80%) was used. The addition of K (0.00, 0.10, 0.20, 0.30, 0.40%) to the diet by potassium carbonate resulted in a decrease in weight gain and feed efficiency with the group fed on basal diet having the best performance. This means that the existing K in the basal diet is adequate for the growth of ducklings. In experiment 2, low K corn-isolated soy protein diet (K, 0.19%) was used. The supplementation of K (0.00, 0.16, 0.32, 0.48, 0.64%) resulted in an increase in weight gain and feed efficiency with the control group having the lowest performance. The minimum K requirement was found to be 0.49% for both maximum growth and best feed efficiency as determined by using bent-stick model.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3158-3163
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• 2013

본 연구에서는 회전속도, 브레이크 압력 제어가 가능한 브레이크 다이나모메타를 제작하여 스퀼 소음 실험을 실시하였다. 브레이크 패드는 각각 $34^{\circ}$, $30^{\circ}$, $26^{\circ}$로 가공하여 패드 각도에 따른 스퀼 발생 조건과 음의 기울기 발생에 따른 스퀼 연관성을 연구 하였다. 각도에 따라 특정한 회전속도와 브레이크 압력에서 스퀼이 발생하였으며, 각도에 상관없이 하모닉 성분을 가지는 특정 주파수 소음을 발견하였다. 햄머링 테스트 및 유한요소해석을 통해서 특정 주파수는 In-plane모드 성격을 갖고 있으며, 패드 각도에 둔감한 모드임을 밝혀냈다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.710-715
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• 2004

The design problem of manufacturing system is addressed, adopting the closed queueing network model with multiple loops and re-entrant flows. The entire design problem is divided into two hierarchical sub-problems of (1) determining the station configuration and (2) optimizing the lot constitution; then they are tackled by neighbor search algorithm (NSA) and greedy mean value analysis (GMVA), respectively. Unlike the conventional MVA concerning multi-class closed queueing networks, the GMVA doesn't stick to a fixed lot proportion; rather it tries to find the optimal balance. The NSA, on the other hand, improves the object function value by altering the station configuration successively with its superior neighbor. The moderate time complexity, presented in big-${o}$ notation, enables us to apply the method even to the large-size practical cases, and the CPU time of an enlarged problem can be approximated by the same equation. The validity of our analytic approach is backed up by simulation studies with a widespread simulation package.

• Journal of Welding and Joining
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• 제35권1호
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• pp.43-48
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• 2017

Pulse TIG (Tungsten Inert Gas) welding is often considered the most difficult of all the welding processes commonly used in industry. Because the welder must maintain a short arc length, great care and skill are required to prevent contact between the electrode and the workpiece. Pulse TIG welding is most commonly used to weld thin sections of stainless steel, non-ferrous metals such as aluminum, magnesium and copper alloys. It is significantly slower than most other welding techniques and comparatively more complex and difficult to master as it requires greater welder dexterity than MIG or stick welding. The problems associated with manual TIG welding includes undercutting, tungsten inclusions, porosity, Heat affected zone cracks and also the adverse effect on health of welding gun operator due to amount of tungsten fumes produced during the welding process. This brings the necessity of automation. Hence, In this paper an attempt has been made to build a customerized setup of Pulse TIG welding based on through review of Pulse TIG welding parameters. The cost associated for making automated TIG is found to be low as compared to SPM (Special Purpose machines) available in the market.