• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.507-514
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• 2022

This study is to compare and analyze the evaluation of cleaning cleanliness and usability according to the muscle activity and cleaning method in the wrist rotation motion when using a bottle washer for women with childbirth experience. To this end, when using an automatic bottle washer and a manual bottle washer, the muscle activity and cleaning cleanliness of the forearm muscles were quantitatively evaluated using equipment, and the effects of variables were analyzed and the following conclusions were obtained. First, it was found that the muscle activity was lower than that of the automatic baby bottle cleaner when using a manual bottle cleaner. Second, the cleanliness was judged to be the best in automatic washing (forward + reverse direction), followed by automatic washing (forward direction) and manual washing. Third, the usability evaluation of the use of the baby bottle washing machine showed higher satisfaction than that of the automatic baby bottle washing machine. Through these conclusions, this study can be used as basic data for product advancement in the future by proving the effectiveness of using an automatic bottle washer.

• Composites Research
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• v.13 no.5
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• pp.50-59
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• 2000

In this paper, two methods to suppress flutter of the composite panel are examined. First, in the active control method, a controller based on the linear optimal control theory is designed and control input voltage is applied on the actuators and a PZT is used as actuator. Second, a new technique, passive suppression scheme, is suggested for suppression of the nonlinear panel flutter. In the passive suppression scheme, a shunt circuit which consists of inductor-resistor is used to increase damping of the system and as a result the flutter can be attenuated. A passive damping technology, which is believed to be more robust suppression system in practical operation, requires very little or no electrical power and additional apparatuses such as sensor system and controller are not needed. To achieve the great actuating force/damping effect, the optimal shape and location of the actuators are determined by using genetic algorithms. The governing equations are derived by using extended Hamilton's principle. They are based on the nonlinear von Karman strain-displacement relationship for the panel structure and quasi-steady first-order piston theory for the supersonic airflow. The discretized finite element equations are obtained by using 4-node conforming plate element. A modal reduction is performed to the finite element equations in order to suppress the panel flutter effectively and nonlinear-coupled modal equations are obtained. Numerical suppression results, which are based on the reduced nonlinear modal equations, are presented in time domain by using Newmark nonlinear time integration method.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.1
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• pp.9-18
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• 2013

Two-phase vapor-liquid flows exist in many shell and tube heat exchangers such as condensers, evaporators, and nuclear steam generators. To understand the fluid dynamic forces acting on a structure subjected to a two-phase flow, it is essential to obtain detailed information about the characteristics of a two-phase flow. The characteristics of a two-phase flow and the flow parameters were introduced, and then, an experiment was performed to evaluate the pressure loss in the tube bundles and the fluid-dynamic force acting on the cylinder owing to the pressure distribution. A two-phase flow was pre-mixed at the entrance of the test section, and the experiments were undertaken using a normal triangular array of cylinders subjected to a two-phase cross-flow. The pressure loss along the flow direction in the tube bundles was measured to calculate the two-phase friction multiplier, and the multiplier was compared with the analytical value. Furthermore, the circular distributions of the pressure on the cylinders were measured. Based on the distribution and the fundamental theory of two-phase flow, the effects of the void fraction and mass flux per unit area on the pressure coefficient and the drag coefficient were evaluated. The drag coefficient was calculated by integrating the measured pressure on the tube by a numerical method. It was found that for low mass fluxes, the measured two-phase friction multipliers agree well with the analytical results, and good agreement for the effect of the void fraction on the drag coefficients, as calculated by the measured pressure distributions, is shown qualitatively, as compared to the existing experimental results.

• Proceedings of the Ginseng society Conference
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• 1984.09a
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• pp.97-105
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• 1984

Effect of water extract of red ginseng (Panax ginseng C.A. Meyer) from Nagano prefecture on (1) forced exercise in mice using rope climbing test, (2) extinction of memory in hanging stressed mice and rectal temperature during the exposure to hanging stress, (3) sex and learning behavior of chronic hanging stressed mice, (4) sex cycle in the adult female mice using chronic hanging stress, and (5) motor coordination and one trial passive avoidance response in $40\%$ alcohol administered mice using rotar-rod and step-through tests, were studied. Drugs tested were given orally. (1) When it was given before the forced exercise, it potentiated the performance of the forced exercise. When it was given just after the forced exercise once a day for 2 weeks, it protected the mice against the reduction of the performance on the forced exercise. (2) When it was given just after the stress once a day for 4 days, it delayed the extinction of passive avoidance response in both step through and stepdown tests, and protected the stressed mice against the decrease in rectal temperature slightly. (3) It protected the stressed mice against the decrease of sex behaviour and the increase in the failure of performance of passive avoidance response, and delayed the extinction of passive avoidanc

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.1
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• pp.17-29
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• 2003

This paper preliminarily investigates the effectiveness of various control systems, such as passive, active, semiactive and hybrid control, for seismic protection of cable-stayed bridges by examining the ASCE first generation benchmark problem for a cable-stayed bridge. This benchm.0.00000ark problem considers the cable-stayed bridge that is scheduled for completion in Missouri, USA In 2003. Seismic considerations were strongly considered in the design of this bridge due to location of the bridge and its critical role as a principal crossing of the Mississippi River. Based on detailed drawings of this cable-stayed bridge, a three-dimensional linearized evaluation model has been developed to represent the complex behavior of the bridge. A set of eighteen evaluation criteria has been developed to evaluate the capability of each control system. In this study, four passive control systems, one active control system, two semiactive control systems and three hybrid control systems are considered. Numerical simulation results show that all the control systems are effective in reducing the responses of the benchmark cable-stayed bridge under the historical earthquakes. To get good performance, however, the passive control systems need quite large control forces compared to other control systems. The simulation results also demonstrate that the passive, semiactive and hybrid control systems are robust to the stiffness uncertainty of the structure. Therefore, the semiactive and hybrid control systems are more appropriate in real applications for full-scale civil infrastructures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.30-30
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• 2007

현재 다양한 종류의 RF 통신 제품이 시장에 등장하면서 제품의 경쟁력 확보에 있어 소형화 정도가 중요한 이슈가 되고 있다. Passive Device는 RF Circuit을 제작할 때 많은 면적을 차지하고 있으며 이를 감소시키기 위해 여러 연구가 진행되고 있다. 가장 효과적인 방법으로 반도체 집적기술로 크기를 줄이는 방법이 있으나, 공정이 비싸고 제작 시간이 오래 걸려 제품개발 시간과 개발비용이 상승하게 된다. 반면에 SoP-L 공정은 PCB 제작에 이용되는 일반적인 재료와 공정을 사용하므로 개발 비용과 시간을 줄일 수 있다. SoP-L의 또 하나 장점은 다종 재료를 다층으로 구성할 수 있다는 점이다. 최근 chip-type의 Device를 PCB 기판 안에 내장하는 방법의 RF Circuit 소형화 연구가 많이 진행되고 있다. 본 연구에서는 SoP-L 공정으로 chip-type 수동소자를 PCB 기판 내에 함몰하여 수동소자회로를 구현, 분석하여 보았다. 수동소자회로는 880 MHz~960 MHz(GSM) 영역과 1.71 GHz~1.88 GHz(DCS) 영역을 나누는 Diplexer를 구성하였다. 1005 size의 chip 6개로 구현한 Diplexer를 표면실장과 함몰공정으로 제작하고 Network Analyzer로 측정하여 비교하였다. chip 표면실장으로 구현된 Diplexer는 GSM에서 최대 0.86 dB의 loss, DCS에서 최대 0.68 dB의 loss가 나타났다. 표면실장과 비교하였을 때 함몰공정의 Diplexer는 GSM 대역에서 약 0.5 dB의 추가 loss가 나타났으며 목표대역에서 0.6 GHz정도 내려갔다. 이 결과를 바탕으로 두 공정 간 차이점을 확인하고, 함몰공정으로 chip-type 수동소자를 사용하였을 때 고려해야 할 점을 분석하였다. 이를 바탕으로 SoP-L 함몰공정의 안정성을 높여서 이것을 이용한 회로의 소형화에 적용이 가능할 것으로 기대한다. 특히 능동소자의 DC Power Control에서 고용량의 수동소자를 이용할 때 집적도를 높일 수 있을 것이다.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.667-669
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• 2005

지중배전선로에 설치되어 있는 23kV 수동개폐기의 고장표시 상태를 단말장치와 소출력 RF 통신을 이용하여 배전자동화 주장치에서 FII(Fault Indicator)로 고장 판단할 수 있는 시스템 구성에 대해 논하고자 한다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.57-58
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• 2000

현재 우리 나라 대부분의 소형어선에서 사용중인 어로시스템은 주기관의 회전력을 이용하는 사이드 드럼이지만, 이 시스템은 조작이 불편하고, 어로 작업을 하면서 동시에 시스템을 조작하고자 할 때에는 어선 승조원이 조작 레버가 설치된 장소로 이동하여 수동으로 조작해야 하는 불편이 있다. 이 문제의 개선을 위해 과거부터 많은 노력이 행해져 왔지만 결국 조업시스템을 기계화 하지 않으면 효율적인 어로 작업이 어렵기 때문에 최근에는 인력 절감형 어업기계장치에 대한 관심이 높아지고 있다.(중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.45-46
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• 2001

제주도 연근해에서는 소형선박으로 수동식 채낚기 어구와 선상 집어등을 사용하여 갈치를 유집하여 어획하고 있으나, 많은 선원, 수입산 냉동미끼, 대출력의 선상 집어등으로 인한 조업경비의 지출이 크고 남획으로 인한 자원의 감소로 고소득을 기대하기 어려운 실정이어서 선상 조업인원을 줄일 수 있는 생력화된 자동식 채낮기 어구개발이 절실하게 요구되고 있다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.55-56
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• 2001

제주도 근해는 대마난류, 황해 난류, 황해 냉수, 한국 남ㆍ서해 연안수, 중국대륙 연안수 등이 출현하여 이질 수괴들이 시기와 계절별로 복잡한 해황을 형성하여 갈치, 고등어, 오징어, 삼치 등을 어획하는 좋은 어장을 이루고 있다. 제주도 연근해에서는 소형선박으로 수동식 채낚기 어구와 선상 집어등으로 갈치를 유집하여 어획하고 있으나, 많은 선원, 수입산 냉동미끼, 대출력의 선상 집어등 등 조업경비의 지출이 심하여 생력화 된 자동식 채낚기 어구 개발이 절실하게 요구되고 있다. (중략)