• Journal of Aerospace System Engineering
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• v.11 no.1
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• pp.41-46
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• 2017

A new test bench for small multi-rotor type drones has been developed. Six degrees of freedom (DOF) motion is possible due to a ball bushing, wheels, and rotating plates. An FPGA (field programmable gate array) based controller, that supports realtime parallel processing, is used to measure attitude with an accelerometer and a gyro to adjust motor speed. Several tests were performed to check the operational properties of the test bench and the controller. The results show that this test bench is proper for verifying controllers and the control methods of small multi-rotor drones.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.227-230
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• 1999

잔향에 대한 인간의 주관적인 지각을 잔향기 설계에 객관적인 수치로써 반영하는 방법으로, 5 자유도 잔향 모델이 제안된 바 있다[1]. 5자유도 잔향 모델은 잔향에 대한 다섯 개의 객관적인 평가량들을 이용하여 시간에 따른 음 에너지 감쇠 곡선을 근사화한 것이다. 즉 5 자유도 잔향 모델을 이용하여 청취자가 원하는 특성을 갖는 잔향을 객관적으로 묘사할 수 있고, 이는 잔향을 합성할 때 잔향 필터의 설계 기준이 된다. 그러나 이 모델로부터 만들 수 있는 잔향 필터의 개수는 실로 무한하고, 그 중에는 인간이 듣기에 부자연스러운 합성음을 만들어 내는 경우도 있다. 즉 자연스러운 잔향을 만들기 위해서는 잔향 모델 외에도 부가적인 잔향 설계 기준이 필요하다. 시간, 주파수 영역에서 대표적인 특성을 갖는 몇 종류의 원음에 대한 청음실험을 통해, 필요한 잔향 설계 기준을 제시한다.

• Journal of the korean Society of Automotive Engineers
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• v.16 no.3
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• pp.19-29
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• 1994

본 연구에서는 상태방정식과 출력방정식에 외란항을 포함하게 된다. 최적조건을 이용하여 외란항을 포함한 리카티 방정식을 유도하고 그로부터 제어로직을 얻을 수 있다. 본 연구에서의 차량 모델링은 스프링 위 질량 3자유도와 스프링 아래 질량 4자유도 운전석의 연직방향 1자유도를 포함한 총 자유도의 선형모델로 하였다. 또 본 연구에서는 예견제어를 이용하였는데 차량앞에 미리 도로면의 정보를 인식할 수 있는 가상적인 측정장치가 있다고 가정하였다. 결과에서는 기존의 수동형 현가장치와 최적제어를 이용한 능동형 현가장치를 구분하고, 예견시간에 따른 차량의 성능을 비교 분석하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.1
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• pp.142-147
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• 2011

In this paper, we make a RT component as a configuration element of cooperation robot of 7 degree of freedom manipulator using RTM which was adapted international standardization among the robot middleware technology. We implemented the one system by connecting the RT component of elements of a robot organize to each other based on middleware network and tested an operation of implemented system using the 7 degree of freedom manipulator which was real made.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.52.1-52.1
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• 2010

본 연구에서는 자유수면 흐름을 해석할 수 있는 연직방향에 대해 좌표변환된 3차원 동수압 모형을 제시하였다. 제시한 모형은 자유수면파 동수압의 해석을 위하여, 2중 예측-수정(double predictor-corrector)방법을 적용하였다. 본 연구에서는 자유수면과 동수압을 고려하기 위하여 자유수면 보정단계와 동수압 보정단계로 나누어 정확한 동역학적 경계조건을 적용하는 방법을 제시하였고, 제시한 모형을 이용한 수치모의 결과를 검증하기 위하여 타원형 천퇴에 의한 파의 변형에 대한 수치모의를 실시하였다. 전반적으로 수치모의 결과는 실험자료와 일치하였다.

• Journal of Korean Philosophical Society
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• v.129
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• pp.247-265
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• 2014

In this paper I will undertake three tasks: first, to identify the difference between John Rawls's liberal conception of liberty and Will Kymlicka's; second, to briefly examine the problems with liberal conception of liberty; finally, to propose a certain alternative that will be able to make liberal conception of liberty more meaningful In Kymlicka's view, Rawls seems to fail to make the best defence of freedom of choice because he wants to explain of individual freedom on the basis of Kant's moral theory about liberty. Kymlicka thinks that it is not a desirable way of defending liberal conception of liberty. According to his liberal theory, Rawls's defence of freedom of choice might make us think that we should have our freedom of choice for its own sake because freedom is the most valuable in the world. So Kymlicka wants to provide stronger argument to defend freedom of choice in liberalism. He insists that it is our projects and tasks that are most important things in our lives. Furthermore, he argues that we should conceive our freedom of choice as a precondition for pursuing those projects and practices that are valued for our good lives. Now I want to look at two concepts of liberty in liberalism with Rawls's theory and Kymlicaka's. In this paper, I shall look at criticisms of the liberal account of freedom of choice. These would give us a certain chance for understanding true freedom.

• Journal of Korean Home Economics Education Association
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• v.29 no.1
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• pp.111-124
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• 2017

The purpose of this study was to determine the perception and understanding of Free Learning Semester (FLS) in home economics teachers and to provide basic informations for effective implement of FLS in future school curricula. Home economics teachers perceived that the objective of FLS was to help students explore their careers and make preliminary decisions. In addition, teachers thought that FLS should be run by active students' participation to find out their dreams and talents. However, teachers felt difficulties in obtaining information or documents related to implementing FLS. Moreover, there were lack of connected activities with local communities to operate FLS. Teachers recognized that it is necessary to receive FLS-related education. Regarding home economics teachers' role in FLS implement, they should provide career education with a perspective of lifelong career and nurture students' capability to lead their lives by themselves. In that sense, FLS should help students find out their dreams and talents, think about their career, set up lifelong career plan through home economics education, and nurture capability to lead their lives. In addition, home economics teachers should provide continuous career education in home economics education at academic semesters.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.1
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• pp.74-79
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• 2010

Many control techniques have been purposed in order to improve the control performances of the control system. The freedom on control in the control system is decided by the number of the closed-loop transfer function which can adjust independently. The design method of the controller with two degrees of freedom(TDOF) is used extensively for following the desired value and rejecting the disturbance. In this paper, the control system with the disturbance observer(DOB) for rejecting the disturbance is transformed by the control system with TDOF and the rejection of a transient response is easy at the starting time and load variation. The design method of the DOB is proposed in the frequency-domain and the control system with TDOF is constructed by using the DOB which is designed with this method. Through the simulation results, the usefulness of the proposed algorithm is proved.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.1
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• pp.56-61
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• 2011

Many control techniques have been proposed in order to improve the control performance of the control system. The degree of freedom on control in the control system is decided by the number of the closed-loop transfer function which can adjust independently. The controller design scheme with two degrees of freedom(TDOF) is extensively used for securing the good control performance to trace a desired value and reject disturbance. In this paper, PID controller is used by controller with TDOF and the design method for control system with TDOF is proposed by the normal method. Using the coefficients of the transfer function of the plant, the transfer function of the control system is normalized by the proposed design method and the parameters of the controller are determined. The control system with the TDOF is constructed by using this method. Through the simulation results, the usefulness of the proposed algorithm is proved.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.1
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• pp.10-20
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• 2017

This study presents the feasibility of CFD(computational fluid dynamic) analysis using the flow angularity wind tunnel test technique. The CFD analyzed data by the flow angularity technique has been constructed as the database to get store trajectories by 6-DOF simulation. The database has been checked out store aerodynamic coefficients by the analyses at each position under wing. After that process, the simulated trajectories by database have been compared with the store trajectories by CTS(Captive Trajectory Simulation) of CFD. The trajectories provided by the database of flow angularity have a good agreement with the store trajectories by CFD.