• 항공우주기술
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• 제6권2호
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• pp.245-249
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• 2007

무인 항공기의 주요 목적은 유인 정찰기의 최대 단점인 조종사의 인명 손실을 제거하구 원하는 지역 또는 물체를 정찰하는데 두고 있다. 업무를 수행하기 위해서는 조종사 눈 역할을 할 수 있는 카메라가 필요하며, 획득한 정보 또는 목표물이 무엇인지를 구분하여야 한다. 본 보고서는 임무수행을 위한 영상감지장치의 선정에 필요한 요구 사항을 기술하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.66-69
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• 2008

In this paper, The author present a load current feed-forward compensator by method that improve voltage controller of Step-down Chopper to get stable output voltage to sudden change of load current. To confirm the characteristicsof a presented load current feed -forward compensator compared each transfer function of whole system that load current feed-forward compensator is added with transfer function of whole system that existent voltage controller is included using Mason gains formula in Root locus and Bode diagram. As a result the pole of system is improved, extreme point of the wave and system improves, and size of peak value and phase margin of break frequency in resonance frequency confirmed that is good. Therefore, presented control technique could confirm that reduce influence by perturbation and improves stationary state and dynamic characteristics in output of Step-down Chopper.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1056-1061
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• 2003

CD-R disc drive is one of the basic options of personal computer today. In this trend, various CD-R discs can be purchased in every market. Even very low quality discs are in market too. Today's CD-R disc drive is being operated over 10,000 RPM. So the possibility of the disc fracture is growing faster. Sometimes, during the test of a new disc drive by various methods to confirm the quality of it, fracture of the disc happens. And it happens in end user's personal computer scarcely. In this reason, new methods to confirm the quality and the failure mechanism of the optical disc are studied in this paper.

• Journal of Power Electronics
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• 제17권5호
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• pp.1127-1136
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• 2017

This paper proposes a new soft switching dual input converter for renewable energy systems. Multi-input converters are produced by combining discrete converters. These converters reduce the number of circuit elements, cost, volume and weight of the converter and provide a constant output power in different weather conditions. Furthermore, soft switching techniques can be applied to increase efficiency. In this paper, a Zero Voltage Transition (ZVT) dual input boost converter is presented. Only one auxiliary circuit is used to provide the soft switching condition for all of the semiconductor elements. The proposed converter, which is simulated by ORCAD software, is theoretically analyzed. To confirm the validity of the theoretical analysis, a prototype of proposed converter was constructed. Simulation and experimental results confirm the theoretical analysis. An efficiency comparison shows a one percent improvement at nominal loads.

• 한국정밀공학회지
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• 제17권7호
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• pp.203-208
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• 2000

The vibration of a mask degrades the color purity in CRT Therefore, a damping wire is put into contact with the mask to reduce the vibration in perfectly flat CRT. In this study, we analyzed the vibration of the mask contacting with the damping wire using FEM. First we calculated the natural frequencies and mode shapes of the mask by modal analysis, and compared them with the measured results to confirm our finite element model. The modal analysis of the wire was also performed to investigate resonance with the mask. Finally, the transient dynamic analysis of the mask contacting with the wire was performed. The vibration of the mask was measured to confirm our analysis, and the results are in good agreement with the analysis.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제27권1호
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• pp.43-50
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• 2020

We investigate the domain of influence of the local volatility function on the solutions of the general Black-Scholes model. First, we generate the sample paths of underlying asset using the Monte Carlo simulation. Next, we define the inner and outer domains to find the effective volatility region. To confirm the effect of the inner domain, we use the root mean square error for the European call option prices, and then change the values of volatility in the proposed domain. The computational experiments confirm that there is an effective region which dominates the option pricing.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.980-984
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• 2002

This paper has studied thermal characteristics of machine tool to develope high speed spindle and optimum design condidering the thermal deformation. Comparing the test data of temperature measurement and structural analysis data using FEM, we verified the test validity and predicted thermal deformation, influence of spindle generation of heat, and established cooling system to prevent the thermal deformation. 1) The temperature rise of spindle system depends on increasing number of rotation and shows sudden doubling increment of number of rotation over 7,000rpm. 2) Oil jacket cooling can be effective cooling method below 8,000rpm but, over 8,000rpm, it shows the decrement of cooling effect. 3) Comparing FEM analysis results and revolution test results, we can confirm approximate temperature change consequently, it is possible to simulate temperature rise and thermal distribution on the inside of spindle system. 4) We can confirm that simulated approach by FEM analysis can be effective method in thermal-appropriate design.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권9호
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• pp.2341-2350
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• 2012

Face detection is the first step of vision-based driver fatigue detection method. Traditional face detection methods have problems of high false-detection rates and long detection times. A space-time restrained Adaboost method is presented in this paper that resolves these problems. Firstly, the possible position of a driver's face in a video frame is measured relative to the previous frame. Secondly, a space-time restriction strategy is designed to restrain the detection window and scale of the Adaboost method to reduce time consumption and false-detection of face detection. Finally, a face knowledge restriction strategy is designed to confirm that the faces detected by this Adaboost method. Experiments compare the methods and confirm that a driver's face can be detected rapidly and precisely.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.251-256
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• 2004

The image classification is one of the most important studies in the remote sensing. In general, the MLC(Maximum Likelihood Classification) classification that in consideration of distribution of training information is the most effective way but it produces a bad result when we apply it to actual hyperspectral image with the same classification technique. The purpose of this research is to reveal that which one is the most effective and suitable way of the classification algorithms iii the hyperspectral image classification. To confirm this matter, we apply the MLC classification algorithm which has distribution information and SAM(Spectral Angle Mapper), SFF(Spectral Feature Fitting) algorithm which use average information of the training class to both multispectral image and hyperspectral image. I conclude this result through quantitative and visual analysis using confusion matrix could confirm that SAM and SFF algorithm using of spectral pattern in vector domain is more effective way in the hyperspectral image classification than MLC which considered distribution.

• 한국항공운항학회지
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• 제22권3호
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• pp.33-49
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• 2014

The object of this study is to verify the effects of job stress on burnout and job satisfaction of flight attendants and to confirm the difference in the effect on the consciousness of full service carrier and low cost carriers' flight attendants. In order to confirm, the study examines the relationship between job stress, burnout, and job satisfaction of airline cabin attendant. A survey was done for 55days from January 5th 2014 on flight attendants and total 200 valid samples were analysed. The results of the study demonstrated significant relationship and difference in job stress, burnout and job satisfaction of flight attendants between full service carrier and low cost carrier. As a result, the study is significant as it satisfaction between divergent airline work environment.