• Journal of Power Electronics
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• 제14권6호
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• pp.1178-1188
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• 2014

This study proposes a finite-state model predictive controller to regulate the load current and balance the DC-link capacitor voltages of a four-leg neutral-point-clamped converter. The discrete-time model of the converter, DC-link, inductive filter, and load is used to predict the future behavior of the load currents and the DC-link capacitor voltages for all possible switching states. The switching state that minimizes the cost function is selected and directly applied to the converter. The cost function is defined to minimize the error between the predicted load currents and their references, as well as to balance the DC-link capacitor voltages. Moreover, the current regulation performance is improved by using a two-step prediction horizon. The feasibility of the proposed predictive control scheme for different references and loads is verified through real-time implementation on the basis of dSPACEDS1103.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.765-768
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• 2000

Linearization of the biped dynamic equations and design of linear controller for the linearized equations are studied in this paper. The biped robot with inverted pendulum type trunk, used to stabilize the dynamic balancing of the biped robot during dynamic walking period, is modelled with 14 DOF and simulated. Despite of well defined linear control theories so far, the linear control methods was limited to the applications for a walking robot, because they have been inherently strong nonlinear properties, such as a modeling parameter uncertainties, external forces as noise, inertial and Coriolis terms by three dimensional modeling and so on. To linearize the nonlinear equations of motion of biped robot on MIMO and time varying linear equations of motion, 1st order Taylor series is used to formulate the linear equation. And a 2nd order numerical perturbation method Is used to approximate partial differential equations. Using the linearized equations of motion, a linear controller is designed by pole placement method with feed forward compensation. Using the obtained linearized equations and linear controller, the continuous walking simulation is performed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.139-141
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• 2006

Quantum-dot Cellular Automata (QCA) is one of the most promising next generation nano-electronic devices which will inherit the throne of CMOS which is the domineering implementation technology of large scale low power digital systems. In late 1990s, the basic operations of the QCA cell were already demonstrated on a hardware implementation. Also, design tools and simulators were developed. Nevertheless, its design technology is not quite ready for ultra large scale designs. This paper proposes a new approach which enables the QCA designs to inherit the verification methodologies and tools of CMOS designs, as well. First, a set of disciplinary rules strictly restrict the cell arrangement not to deviate from the predefined structures but to guarantee the deterministic digital behaviors. After the gate and interconnect structures of the QCA design are identified, the signal integrity requirements including the input path balancing of majority gates, and the prevention of the noise amplification are checked. And then the digital logic is extracted and stored in the OpenAccess common engineering database which provides a connection to a large pool of CMOS design verification tools. Towards validating the proposed approach, we designed a 2-bit QCA adder. The digital logic is extracted, translated into the Verilog net list, and then simulated using a commercial software.

• 한국CDE학회논문집
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• 제16권5호
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• pp.315-322
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• 2011

The goal of total knee replacement (TKR) surgery is to replace patient's knee joint with artificial implants in order to restore normal knee joint functions. Since mismatched knee implants often cause a critical balancing problem and short durability, designing a well-fitted implant to a patient's knee joint is essential to improve surgical outcomes. We developed a software system that three-dimensionally (3D) simulates TKR surgery based upon 3D knee models reconstructed from computed tomography (CT) imaging. The main task of the system was to extract precise 3D anatomical parameters of a patient's knee that were directly used to determine a custom fit implant and to virtually perform TKR surgery. The virtual surgery was simulated by amputating a 3D knee model and positioning the determined implant components on the amputated knee. The test result shows that it is applicable to derive surgical parameters, determine individualized implant components, rehearse the whole surgical procedure, and train medical staff or students for actual TKR surgery. The feasibility and verification of the proposed system is described with examples.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.135-138
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• 2006

가스발생기 사이클 엔진시스템 설계를 입력값과 기본 요구값으로 나누어 설계 요구값을 만족하기 위한 설계변수 11개를 정의하였다. 이 11가지의 설계변수를 통하여 설계 요구값을 만족하기 위한 압력 유량 파워 균형 관계식 11개를 제시하였으며, Newton 방법을 이용하여 해를 찾는 프로그램을 제작하였다. 고안된 프로그램을 이용하여 가스발생기 사이클 엔진의 시스템설계를 수행하여 그 유효성을 입증하였다.

• 한국게임학회 논문지
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• 제13권5호
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• pp.5-18
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• 2013

온라인 게임에서 게임통화의 순환과 관리는 단지 게임 내의 경제 밸런스 유지뿐만 아니라 상용화 게임으로서의 성공 여부를 판가름 짓는 중요한 요소로 인식되고 있다. 그리고 게임 머니의 발생과 흐름은 게임의 컨텐츠와 재미요소, 기획과 레벨 디자인이라는 요소들과도 밀접한 상관관계를 가지고 있다. 본 연구는 이러한 맥락에서 온라인 게임 경제, 특히 게임 통화관리라는 주제에 대해 이론적이고 실무적인 분석을 통해 다각적인 방향으로 접근을 시도했고 그것이 상용화 정책과 매출에 미치는 연관성에 대해서도 살펴보고 있다. 아울러 본 논문은 향후 '게임통화 관리모델'에 대한 다양한 연구와 접근방법의 유용한 토대로서 기여하고자 하며 게임제작과 관리운영에 실리적으로 활용가능한 연구결과를 이끌어 내고자 했다.

• The Journal of Advanced Prosthodontics
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• 제3권3호
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• pp.132-135
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• 2011

PURPOSE. To study the distribution of various occlusal schemes as well as associated static occlusal relationship among Thais. MATERIALS AND METHODS. The subjects'occlusal schemes on the left and right sides were classified as canine protected occlusion, group function, or unclassified according to the definition from Glossary of Prosthodontic Terms ($8^{th}$ edition). In addition, the presence of occlusal interferences during mandibular excursions were recorded. The measurement of the horizontal overlap and vertical overlap was also performed. Chi-square, One-way ANAVA and Mann-Whitney U statistical tests were used with level of significance set at P=.05. RESULTS. Total of 104 subjects were included in this study. The ratio for male to female was 1.8 to 1. Average age of the population was $25.01{\pm}6.87$ years old. The mean vertical overlap and horizontal overlap were $1.94{\pm}1.20$ and $2.41{\pm}1.32$ mm respectively. The majority of the populations (68.3%) possessed group function occlusal scheme. For the remaining, 17.3% possess canine protected occlusion and 12.5% possess combination of both occlusal schemes. We also found that occlusal interference was presented in 20.2% of the population. The most common was protrusive interference (57.14%), the second was balancing interference (38.1%) and the third was working interference (4.1%). CONCLUSION. Among Thais, the most common occlusal scheme was group function, however there were no significant occlusal factors related to any particular occlusal scheme.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.20-30
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• 2013

An intelligent grid computing architecture is proposed and developed for transient stability constrained total transfer capability evaluation of future smart grid. In the proposed intelligent grid computing architecture, a model of generalized compute nodes with 'able person should do more work' feature is presented and implemented to make full use of each node. A timeout handling strategy called conditional resource preemption is designed to improve the whole system computing performance further. The architecture can intelligently and effectively integrate heterogeneous distributed computing resources around Intranet/Internet and implement the dynamic load balancing. Furthermore, the robustness of the architecture is analyzed and developed as well. The case studies have been carried out on the IEEE New England 39-bus system and a real-sized Chinese power system, and results demonstrate the practicability and effectiveness of the intelligent grid computing architecture.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.244-247
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• 2008

The phenomena of oil whip in steam turbine takes place for the un-balancing force between rotor shaft and bearing oil film. The several parameters that affect onset of oil whip have been well known. However, the major parameter of oil whip is shaft mis-alinement. A oil whip causes the high vibration and the shutdown of rotor system. We mostly stop the steam turbine to adjust a shaft re-alinement concerning oil whip. In this case, It needs many costs for maintenance and long shutdown times. In this study, we study and observe the oil whip of the 300MW steam turbine in many years and we conduct the field test for another steam turbine for reducing vibration from oil whip. The results of this study are that a oil whip takes place with a particular rotating speed or a particular turbine output and the oil temperature change is a very effective method for on-line oil whip treatment.

• Asian Journal for Public Opinion Research
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• 제2권2호
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• pp.103-120
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• 2015

Since 1795, 106 districts in Japan have been selected as Important Historic Preservation Districts (Juuyo dentouteki kenzoubutsugun hozon chiku [Juudenken]). The system for protection of cultural properties enables the local government to name a "Preservation District" and allows for the development of a preservation plan based on local ordinances. Moreover, the well-organized, bottom-up networks, which are groups for community development activities on the basis of local participation, play an important role in raising awareness and conducting several preservation projects in their own towns. This study mainly focused on cultural resources management in the local community. The system, which possibly bridged the gap between the local authorities and the community, was revealed. Fifty non-profit groups and active citizens, who were engaged in an advanced stage of community participation in Juudenken, were selected to be interviewed. The results then were analyzed using STAT program. The significant associations were shown by mapping the associations related to the public process of community involvement. Each variable had its own significant meaning and contributed credible indirect association to community involvement. The network mapping indicated that balancing the local economy and technical conservation was important in generating community involvement, which provided a model on how local authorities and communities could articulate and maintain their own cultural resources.