• 한국정보시스템학회지:정보시스템연구
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• 제9권1호
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• pp.217-234
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• 2000

This paper is to develop an information infrastructure to support managing process in design, planning, production, and quality control. Multi-media data set of design, product, and management information flow between organizational units of a virtual enterprise. The process is the logical organization of people, technology and practices incorporated into work activities to make an end product. The core of the infrastructure is the enterprise framework which coordinates activities and controls the process. The proposed framework manages collaborative activities across space and time, and between users and computers who share information in virtual community. It utilizes knowledge distributed through virtual community and fosters cooperation between organizations. The framework provides the following facilities； coordinating activities, sharing data and processes, visualizing multi-media data, customizing and updating processes, reusing data and processes. This paper covers design and manufacturing activities but our focus is initially targeted at design area.

• International Journal of Internet, Broadcasting and Communication
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• 제14권3호
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• pp.161-170
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• 2022

Recently, NAND-type flash memory has been regarded to be new promising storage media for large-scale database systems. For flash memory to be employed for that purpose, we need to reduce its expensive update cost caused by the inablity of in-place updates. To remedy such a drawback in flash memory, we propose a new flash-aware buffering scheme that enables virtual flushing of dirty pages. To this end, we slightly alter the tradional algorithms used for the logging scheme and buffer management scheme. By using the mechanism of virtual flushing, our proposed buffering scheme can efficiently prevent the frequenct occureces of page updates in flash storage. Besides the advantage of reduced page updates, the proposed viurtual flushing mechanism works favorably for shorneing a recocery time in the presense of failure. This is because it can reduce the time for redo actions during a recovry process. Owing to those two benefits, we can say that our scheme couble be very profitable when it is incorporated into cutting-edge flash-based database systems.

• 제어로봇시스템학회논문지
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• 제8권8호
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• pp.682-690
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• 2002

This paper presents an output feedback controller design method for uncertain linear systems with sinusoidal disturbance of uncertain frequencies. The controller needs to compensate for the performance deterioration due to the uncertain frequencies of sinusoidal disturbance. To this end, we introduce a virtual system including the dynamics corresponding to the uncertain frequencies and design a controller which minimizes the output difference between the virtual system and the closed-loop system. In other words, the controller is designed so that the closed-loop system approximates the virtual system. The feedback controller is achieved by solving an LMI optimization problem involving a robust $H_{\infty}$ constraint. The advantages of the proposed design method are examined by comparing it with a design method that only minimizes the $H_{\infty}$ norm of the transfer function between the sinusoidal disturbance and the output. The proposed design method is applied to the track-following system of rewritable optical disk drives and is evaluated through an experiment.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.213-218
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• 2001

VR (Virtual reality) technologies have given engineers the ability to design, test, and evaluate engineering systems in a virtual environment. The virtual plant is the highlight of the application of the VR technology to plant engineering. Plant design, maintenance, control, management, operation are integrated in the virtual plant. The VR monitoring system including the concept of the virtual plant is developed to replace a current control room that has number of gages and warning lamps in two-dimensional panels which shows the operating status of a plant. The operating status of the plant is displayed in the VR monitoring system through the realistic computer graphics. Sophisticated, realistic and prompt control becomes possible. The VR monitoring system consists of advanced visualization, walk-through simulation and navigation. In the virtual environment, a user can navigate and interact with each component of a plant. In addition, the user can access the information by just clicking interesting component. The VR monitoring system is operated with various modules, such as (1) virtual plant constructed with Graphic Management System (GMS), (2) Touch & Tell System, and (3) Equipment DB System of Part. In order to confirm the usefulness of the VR monitoring system, a pilot gas plant which is currently being used for plant operator training is taken as application. The end of the paper gives an outlook on the future work and a brief conclusion.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.254-259
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• 1992

In this paper, we propose an optimal method for the tracking a trajectory of the end-effector of flexible robot arms with multiple joints. The proposed method finds joint trajectories and joint torques necessary to produce the desired end-effector motion of flexible manipulator. In inverse kinematics, optimized joint trajectories are computed from elastic equations. In inverse dynamics, joint torques are obtained from the joint equations by using the optimized joint trajectories. The equations of motion using finite element method and virtual work principle are employed. Optimal control is applied to optimize joint trajectories which are computed in inverse kinematics. The simulation of flexible planner manipulator is presented.

• 한국CDE학회논문집
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• 제19권2호
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• pp.138-147
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• 2014

In manufacturing companies, different types of production have been developed based on diverse production strategies and differentiated technologies. The production systems have become smart, factories are filled with unmanned manufacturing lines, and sustainable manufacturing technologies are under development. Nowadays, the digital manufacturing technology is being adopted and used in manufacturing industries. When this technology is applied, a lot of efforts, time and cost are required and training professionals in-house is limited. In this paper, we introduce e-FEED system (electronic based Front End Engineering and Design) that is the integrated design and analysis system for optimized manufacturing line development on virtual environment. This system provides the functions that can be designed easily using library and template based on standardized modules and analyzed automatically the logistic and capacity simulation by one-click and verified the result using visual reports. Also, we can review the factory layout using automatically created 3D virtual factory and increase the knowledge reuse by e-FEED system.

• Journal of Communications and Networks
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• 제13권6호
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• pp.591-601
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• 2011

Today's Internet which provides communication channels with best-effort end-to-end performance is rapidly evolving into an autonomic global computing platform. Achieving autonomicity in the Future Internet will require a performance architecture that (a) allows users to request and own 'slices' of geographically-distributed host and network resources, (b) measures and monitors end-to-end host and network status, (c) enables analysis of the measurements within expert systems, and (d) provides performance intelligence in a timely manner for application adaptations to improve performance and scalability. We describe the requirements and design of one such "Future Internet performance architecture" (FIPA), and present our reference implementation of FIPA called 'OnTimeMeasure.' OnTimeMeasure comprises of several measurement-related services that can interact with each other and with existing measurement frameworks to enable performance intelligence. We also explain our OnTimeMeasure deployment in the global environment for network innovations (GENI) infrastructure collaborative research initiative to build a sliceable Future Internet. Further, we present an applicationad-aptation case study in GENI that uses OnTimeMeasure-enabled performance intelligence in the context of dynamic resource allocation within thin-client based virtual desktop clouds. We show how a virtual desktop cloud provider in the Future Internet can use the performance intelligence to increase cloud scalability, while simultaneously delivering satisfactory user quality-of-experience.

• 대한교통학회:학술대회논문집
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• 대한교통학회 2003년도 제43회 학술발표회논문집
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• pp.119-126
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• 2003

The aim of this research was to compare driver's workload among AHS (Automate Highway Systems) road sections in a virtual AHS environment that is based on a re Korean expressway in order to predict and compare the workloads imposed by the change (driver-vehicle interface and vehicle control authority. Road sections included the M (Manual Lane), TL1 (Transition Lane to enter the automated lane), AL (Automated Lane TL2 (Transition Lane to enter the manual lane after the end of automated driving), an post-AHS manual lane.

• 제어로봇시스템학회논문지
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• 제5권1호
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• pp.105-114
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• 1999

By using the conceptual impedance and the elasticity of a serial chain of spring-damper system, a real-time collision-free trajectory generation algorithm is proposed. The reference points on a trajectory connected by the spring-damper system have a mechanism for self-Position adjustment to avoid a collision by the impedance, and the local adjustment of each reference point is propagated through the elasticity to a real robot at the end of the spring-damper system. As a result, the overall trajectory consisting of the reference points becomes free of collision with environmental obstacles and efficient having the shortest distance as possible. In this process, the reference points connected by the spring-damper system take role of virtual robot as global guidance for a real robot, and a cooperative optimization is carried out by the system of virtual robots. A control algorithm is proposed to implement the impedance for a car-like mobile robot.

• 정보처리학회논문지B
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• 제12B권1호
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• pp.101-108
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• 2005

식물을 모델링 한 기존의 시스템들은 시각적인 사실성에 초점을 맞추어 연구되어졌다. 그러나 환경적인 요소를 고려하지 않은 식물 모델링은 가상세계에서의 식물에 대한 논리적 사실성을 감소시켜 사용자들의 몰입감을 떨어뜨린다. 본 논문에서는 환경과 상호작용하는 식물 성장에 초점을 맞추어 다양한 환경에서 식물의 성장을 시뮬레이션 하는 것을 목적으로 한다. 이를 위해 온톨로지에 기반한 식물 객체의 구조를 살펴보고 젊음 에너지를 이용한 식물의 성장률을 계산하는 방법을 제시한다.