• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권6호
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• pp.1926-1945
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• 2014

In this paper, we propose a distributed signal subspace interference alignment algorithm for single beam K-user ($3K{\geq}$) MIMO interference channel based on sum rate maximization and game theory. A framework of game theory is provided to study relationship between interference signal subspace and altruistic-egoistic bayesian game cost function. We demonstrate that the asymptotic interference alignment under proposed scheme can be realized through a numerical algorithm using local channel state information at transmitters and receivers. Simulation results show that the proposed scheme can achieve the total degrees of freedom that is equivalent to the Cadambe-Jafar interference alignment algorithms with perfect channel state information. Furthermore, proposed scheme can effectively minimize leakage interference in desired signal subspace at each receiver and obtain a moderate average sum rate performance compared with several existing interference alignment schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권12호
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• pp.4305-4323
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• 2014

In this paper, we investigate the degrees of freedom (DOF) of the Y channel consisting of three single-antenna users and a two-antenna common access relay, where each user intends to exchange independent messages with the other two users with the assistance of the relay. We show that the DOF of this particular scenario is 1.5. In order to prove this result, we firstly derive a DOF upper bound based on cut-set bound by allowing cooperation among users, which shows that the total DOF is upper bounded by 1.5. Then we propose a novel transmission scheme based on asymmetric signal space alignment (ASSA) to demonstrate the achievability of the upper bound. Theoretical evaluation and numerical results confirm that the upper bound can be achieved by utilizing ASSA, which also proves the optimality of the ASSA-based scheme in terms of DOF. Combining the upper bound and achievability, we conclude that the exact DOF is 1.5. Moreover, we present a novel iterative joint beamforming optimization (I-JBO) algorithm to further improve the sum rate. Numerical simulations have been provided to demonstrate the convergence speed and performance advantage of the I-JBO algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.334-339
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• 1994

In this work, we propose a planar three degree-of-freedom parallel mechanism as another type of assembly device which utilized joint compliances. These joint compliances can be adjusted either by properly replacing the joint compliances or by actively controlling stiffness at joints, in order to generate the desired operational compliance characteristics at RCC point, The operational compliance matrix for this mechanism is explicitly obtained by symbolic manipulation and its operational compliance characteristics are examined, it is found that the RCC point exists at the center of the workspace when the mechanism maintains symmetric configurations. Compliance characteristic and its sensitivity of this mechanism is analyzed with respect to the magnitude of the diagonal compliance components and two different matrix norms measuring compliance sensitivity. It is expected that the analysis results provide the designer with a helpful information to determine a set of optimal parameters of this RCC mechanism.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1545-1548
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• 1997

A Force-refecting hand controller can provide the kinesthetic information obtained from a slave manipulator to the operator of a teleoperation system. This thesis presents the desgn and the analysis of a 6-degree-of-freedom force-reflecting hand controller using fivebar parallel mechanism. The goal of this thesis is to construct a superior hand controller that can provide large workspace and good force-reflecting ability. The forward kinematics of the fivebar paprallel mechanism has been calculated in real-time using three pin-joint sensors in addition to six actuator position sensors. A force decomposition approach is used to comput the Jacobin. To analyze the characteristics of the fivebar parallel mechanism, it has been compared with the other three parallel mechanisms in terms with workspace and manipulability measure. The force-reflecting hand controller using the fivebar parallel mechanism has been constructed and tested to verify the feasibility of the design concept.

• Bulletin of the Korean Chemical Society
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• 제24권6호
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• pp.744-750
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• 2003

In quantum dynamics of many-body systems, to identify the Hamiltonian becomes more difficult very rapidly as the number of degrees of freedom increases. In order to simplify the dynamics and to deduce dynamically relevant Hamiltonian information, it is desirable to control the dynamics to lie within a reduced space. With a judicious choice for the cost functional, the closed loop optimal control experiments can be manipulated efficiently to steer the dynamics to lie within a subspace of the system eigenstates without requiring any prior detailed knowledge about the system Hamiltonian. The procedure is simulated for optimally controlled population transfer experiments in the system of two degrees of freedom. To show the feasibility of steering the dynamics to lie in a specified subspace, the learning algorithms guiding the dynamics are presented along with frequency filtering. The results demonstrate that the optimal control fields derive the system to the desired target state through the desired subspace.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권4호
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• pp.692-710
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• 2013

Conventional interference alignment (IA) for a MIMO interference channel (IFC) requires global and perfect channel state information at transmitter (CSIT) to achieve the optimal degrees of freedom (DoF), which prohibits practical implementation. In order to alleviate the global CSIT requirement caused by the coupled relation among all of IA equations, we propose an IA scheme with a single feedback link of each receiver in a limited feedback environment for a three-user MIMO IFC. The main feature of the proposed scheme is that one of users takes out a fraction of its maximum number of data streams to decouple IA equations for three-user MIMO IFC, which results in a single link feedback structure at each receiver. While for the conventional IA each receiver has to feed back to all transmitters for transmitting the maximum number of data streams. With the assumption of a random codebook, we analyze the upper bound of the average throughput loss caused by quantized channel knowledge as a function of feedback bits. Analytic results show that the proposed scheme outperforms the conventional IA scheme in term of the feedback overhead and the sum rate as well.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1095-1098
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• 2005

Most electronic chassis control systems until today have been designed with optimization on its own performance. However, According to the increase of the interest regarding a vehicle safety and development of information technique, the integration technique of current chassis systems is being emphasized. Each enterprise proposed it with name of GCC(Global Chassis Control) or UCC(Unified Chassis Control). This study realizes control algorithm of suspension and brake by using the vehicle model of low degree of freedom as the primary stage of realization of integrated chassis control system. The proposed algorithm build the simulation environment connected to the CarSim having full vehicle model of 27 degree of freedom for raising the thrust of results

• 기록학연구
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• 제56호
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• pp.113-145
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• 2018

일본은 행정기관의 기록관리 부실을 방지하고 국민에 대한 설명책임을 다하기 위하여 2011년부터 공문서관리법을 시행하였다. 그러나 공문서관리법이 행정기관에 변화를 가져오기도 전에 2013년 특정비밀보호법이 제정되었다. 특정비밀보호법은 국민의 알 권리와 행정의 투명성을 후퇴시킨다는 우려를 불러일으켰으며, 특히 기록관리 및 정보공개 체제 발전에 걸림돌이 되었다. 본 논문에서는 특정비밀보호법의 제정 배경과 법률 구성 내용을 분석하였다. 그리고 특정비밀보호법이 내포한 적성평가 제도의 인권침해 가능성, 독립적인 감시기관의 역할 미비, 내부고발이 불가능한 구조, 광범위한 비밀지정 가능성의 문제점을 확인하고, 그 문제점이 일본의 기록관리 및 정보공개 체제에 어떤 영향을 주는지도 분석하였다. 이를 통하여 우리나라의 비밀기록관리 체제 개선 시 법률 수준의 제도 정비, 비밀기록관리의 명확한 목적 설정, 트와니 원칙의 준용, 독립적이고 전문적인 감시기관 설치를 고려할 필요가 있다고 제안하였다.

• 경영과정보연구
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• 제16권
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• pp.95-115
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• 2005

Although advertising plays an important role of information source for consumer, also advertising affect negative influence to the consumer and social system. Under the such a concept, this study reviewed the social responsibility of advertising and the freedom of expression including the foreign country's advertising regulation system as the theoretical background of advertising regulation. In addition, this study analyzed the case of the advertisement reviews by Korea Advertising Review Board(august 1, 2000, the business concerning prior deliberation of broadcast advertisements was entrusted to the Korea Advertising Review Board, a civilian self-regulatory body, by the Korean Broadcasting Commission) and Fare Trade Commission. As the result of data analysis, some problems of regulation system and codes are suggested and discussed as follows: (1) the high ratio of rejection (2) using the unnecessary foreign language (3) inconsistency application of deliberation standard.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 2004년도 추계학술대회
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• pp.444-453
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• 2004

This research investigates the rising new role of mileage system as private e-money in a exploratory study. The key research questions are 'How does mileage system evolve with expansion of e-business and what are the cases for real experiences in 'money-like' mileage and their implications?' This research focuses on the proposition that mileage points created in commercial transactions as a royalty program are observed to serve a new role as payment tool. In an attempt to identify factors that determine mileage system as private money, we employ three factors: confidence, transaction cost, and monetary freedom. Also, this research proposes a direction for further research and follow-up studies to establish legal and institutional issues and the relevant architecture, all of which are essential elements to make the mileage points global money with a certain trade ratio in the near future.