• 한국기계가공학회지
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• 제15권5호
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• pp.48-56
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• 2016

In this paper, we analyze the power flow of an eight-speed automatic transmission by using a lever analogy for the manufacturing of planetary gears. The results indicate that the engine power is passed down to the carrier and ring gear in the first double pinion planetary gear (DPPG1), and to the sun gear, carrier, and ring gear in DPPG3 for the first speed. Although the power flow is similar in the second speed, the power circulation occurs in the second single pinion planetary gear (SPPG2). For the third speed, the engine power is passed from the carrier to the ring gear in DPPG, at which point the power is split between the sun gears of SPPG2 and DPPG3.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.339-342
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• 2007

스마트무인기의 추진동력계통은 터보프롭 항공기와 유사한 피치 가버닝 개념으로 조종사가 엔진동력을 직접 입력하고 제어기는 프로펠러의 RPM을 일정하게 유지하는 방식을 사용한다. PW206C 엔진은 회전익 항공기에 맞게 개발된 전자식 엔진제어기(Electronic Engine Control)를 갖춘 터보축엔진으로 스마트무인기에서 요구되는 엔진제어개념과는 맞지 않는다. 따라서 기존 EEC의 엔진상태 모니터링 기능은 사용하되 엔진 출력은 수동방식으로서 전기식 작동기를 엔진의 Power Lever Arm(PLA)에 연결하여 조절한다. 본 논문에서는 엔진성능계산프로그램을 사용하여 비행고도 및 속도변화에 대한 엔진성능을 계산하여 각 비행조건에서의 PLA 작동범위를 예측하였다.

• 대한인간공학회지
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• 제29권1호
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• pp.33-37
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• 2010

This study was aimed at developing 1) iso-perception maps for various groups of drivers in terms of age, gender, and anthropometry and 2) the experiment framework required for obtaining subjective and objective measures. A total of 9 maps, which describe drivers' perceptions regarding their static behaviors inside a typical mid-size sedan, can be used to improve the utilization of the limited driver workspace, and to select better design alternatives for occupant packaging. An adjustable seating buck, $a^{***}$-camera motion capture system (Vicon), and $a^{**}$-channel EMG system were used for the experiment. Each iso-perception map was developed while H-PT, steering wheel center, or TGS knob center was moved to each of pre-defined positions relative to driver-selected positions. Adjustable ranges or positions of the seat, steering wheel, and TGS lever described in iso-perception maps can be used to determine better package layout alternatives.

• 한국소음진동공학회논문집
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• 제26권5호
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• pp.546-551
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• 2016

The objective of this study is to investigate the response delays between piezo-stack actuator and the displacement magnifier of jetting dispenser and to reduce its falling time in terms of displacement optimization. The dispenser is driven by the dual piezo-stack actuators with a hinge lever mechanism to precisely control flow rate of the working fluid (3000 cP). It is commonly found that piezo actuator-driven jetting dispensers involving viscous working fluids have displacement optimization problem for ideal performance. The response delay of the system is caused by the phenomenon that the displacement magnifier cannot exactly follow the motion of the piezo actuators. The response delay may lower the performance of the system due to the inaccurate discharge of working fluid or even damages to the system itself due to inharmonious motion of piezo actuators with lever system. To reduce its response delay, a new displacement profile obtained from displacement optimization is suggested; its performance is tested through finite element analysis; and experiments are carried out to verify the performance of the obtained displacement profile.

• The Korean Journal of Physiology and Pharmacology
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• 제18권2호
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• pp.103-108
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• 2014

Head restraining is an experimental technique that firmly secures the animal's head to a fixation apparatus for the precise control and sensing of behaviors. However, procedural and surgical difficulties and limitations have been obstructing the use of the technique in neurophysiological and behavioral experiments. Here, we propose a novel design of the head-restraining apparatus which is easy to develop and convenient for practical use. Head restraining procedure can be completed by sliding the head mounter, which is molded by dental cement during implantation surgery, into the port, which serves as matching guide rails for the mounter, of the fixation bar. So neither skull-attached plates nor screws for fixation are needed. We performed intracranial self stimulation experiment in rats using the newly designed device. Rats were habituated to acclimatize the head-restraint environment and trained to discriminate two spatially distinguished cues using a customized push-pull lever as an operandum. Direct electrical stimulation into the medial forebrain bundle served as reward. We confirmed that head restraining was stable throughout experiments and rats were able to learn to manipulate the lever after successful habituation. Our experimental framework might help precise control or sensing of behavior under head fixed rats using direct electrical brain stimulation as a reward.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제34회 추계학술대회 개최
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• pp.245-251
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• 2001

A fretting wear tester is developed for experimental study on the fuel fretting problem of light water reactor. The feature of the developed tester is it can simulate the existence of gap between spring and fuel rod as well as different contacting force including the just-contact condition (0 N on the contact). Used are a servo-motor, an eccentric cylinder and lever mechanism for driving system. A spacer grid cell is constituted with four strap segments (each segment has a spring). This fretting wear tester can also be used as a fatigue tester of a spacer grid spring with the frequency of more than 10 Hz. It is required to simulate the frequency of the vibrating fuel rod due to flow-induced vibration in a reactor. In fretting wear test, up to two span-length of a fuel cladding tube can be accommodated. A specimen of cladding tube of one span-length is specially designed, which can be extended for two-span test. For .fatigue test, a device for clamping the spring fixture is installed additionally, Presently, the tester is designed for the condition of air environment and room temperature. The variation of the reciprocal distance is measured to check the stability of input force, which will be exerted to the cladding (for fretting wear. test) and the spring (for fatigue test) specimen.

• 보건교육건강증진학회지
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• 제8권2호
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• pp.61-73
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• 1991

The purpose of this study was to awaken the necessity of death education and provide basic materials for healthy attitudes toward death and life. For this purpose, it observed the attitudes toward death by Juveniles and recognized life satisfaction & values related to it. The subjects for this study was based 504 students of high school in Seoul. The data was analyzed by the methods of frequency, percentage, reliability, t-test, ANOVA and Pearson's correlation coefficient. The results of this study were as follows: 1. The higher life satisfaction was the higher value on self one's ability and life. 2. There was a negative correlation that the higher life satisfaction is the higher lever death anxiety, negative to suicide and death. 3. There was no differences between values and death anxiety. However, there was negative correlation that the higher values was negative to suicide and reject death. 4. In the relationship between the individual background and attitudes toward death, there seem to be statistically significant differences: woman, general high school, the lower grade, the higher the lever of socioeconomic statues were the lower anxiety, positive to death and awaken the necessity of death education.

• 한국측량학회지
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• 제26권6호
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• pp.611-616
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• 2008

모바일 매핑시스템 (Mobile Mapping Systems)에 장착된 카메라로부터, 3차원 데이터를 취득시, 취득된 3차원 데이터의 정밀도를 결정하는 중요한 요소 중 하나는 IMU/GPS와 카메라 좌표계간의 상대적인 위치(lever-arm)와 자세(bore-sight) 얼라인먼트이다. 기존 연구는 지상기준점(GPS)을 통하여 카메라의 절대표정을 계산하기 때문에, 하나의 좌표계 (GPS 좌표계) 상에서 이 얼라인먼트가 이루어진다. 이 방법은 GCP을 기본적으로 필요로 하는 단점이 있다. 본 논문에서는 GCP가 필요하지 않고, 연관성이 없는 카메라 데이터와 IMU/GPS 데이터를 통하여 이 두좌표계 간의 얼라인먼트를 계산하는 수학적 모델링을 제시한다.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.568-572
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• 2003

The height of valve body is limited to 30mm in the cook-top style gas valves for the domestic gas ranges. But the all the safety specifications of KS should be fulfilled and the magnetic power unit(MPU) should be installed in the valve body for the safety reason. The length of MPU body is longer than the 30mm that it should be located in the square direction of the knob shaft and therefore the implementation of the lever mechanism to transmit the press motion of the knob to the MPU valve is very difficult. In this paper, the hinged lever with inclined plate is used to transmit the press motion of the knob to the MPU valve. The analysis of the gas flow with using the commercial software of FLOW-3D shows that the gas flow capacity is fit for the domestic gas range. The performance and responsibility of the valve is tested for the mass production and the test results shows that the valve can be installed in the commercial gas range.

• Earthquakes and Structures
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• 제13권1호
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• pp.1-8
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• 2017

This article is all about using the MR damper with an external lever system for mitigation torsional and transitional lateral displacements by using of PID control algorithm. The torsional modes are so destructive and can be varied during an earthquake therefore, using a semi-active control system mostly recommended for them. In this paper the corner lateral displacement of each floor obtains and then it equivalents in a solid member and it connects to an MR damper, which relies to a rigid structure to reduce the response. An MR damper is a semi-active control system, which can absorb a lot of energy by injecting current to it. This amount of current is very low and needs low power supply, but it increases the amount of damper force, rather than inactive systems like viscous dampers. This paper will show the appropriate algorithm for current injection into MR damper when the eccentricity of the load is changed by using of Bouc-Wen and Bingham's methods and illustrates the coincidence of them.