• Journal of Power Electronics
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• v.6 no.2
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• pp.104-113
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• 2006

Satellites have provided the impetus for the orderly development of reliability engineering research and analysis because they tend to have complex systems and hence acute problems. They were instrumental in developing mathematical models for reliability, as well as design techniques to permit quantitative specification, prediction and measurement of reliability. Reliability engineering is based on implementing measures which insure an item will perform its mission successfully. The discipline of reliability engineering consists of two fundamental aspects; $(1^{st})$ paying attention to details, and $(2^{nd})$ handling uncertainties. This paper uses some of the basic concepts, formulas and examples of reliability theory in application. This paper emphasizes the practical reliability analysis of a Low Earth Orbit (LEO) Micro-satellite power subsystem. Approaches for specifying and allocating the reliability of each element of the power system so as to meet the overall power system reliability requirements, as well as to give detailed modeling and predicting of equipment/system reliability are introduced. The results are handled and analyzed to form the final reliability results for the satellite power system. The results show that the Electric Power Subsystem (EPS) reliability meets the requirements with quad microcontrollers (MC), two boards working as main and cold redundant while each board contains two MCs in a hot redundant.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1612-1620
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• 2016

This paper presents the dynamic excitation control of a siphon-turbine coupled pico-hydro powered cage rotor induction generator and load matching for off-grid electricity generation. Through the proposed dual-role of the current-controlled voltage source converter (VSC), acting as static synchronous compensator and load controller, real and reactive power are dynamically controlled in a decoupled manner with a self supported DC-bus. The proposed scheme entails minimal computation for ensuring the rated (set) capacity of real power. The scheme also exhibits fault immunity for protection, thus enabling the effective handling of constant power electrical loads presented by base telecom station towers in remote locations. The performance of the system is evaluated under MATLAB/Simulink and is experimented through a developed hardware prototype. Simulation and experimental results show close conformity and validate the effectiveness of the proposed scheme.

• Korean Journal of Remote Sensing
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• v.24 no.5
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• pp.389-396
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• 2008

In these days, various kinds of web applications based on web 2.0 paradigm have been developed. In web 2.0 paradigm pursuing participation, sharing, and openness on the web-as-platform, web mapping or web GIS application are regarded as top most applications, so that web applications, handling geo-spatial contents, with user-interaction interface and search engine of high performance have been provided for both public users and expert users in the special domains. Public and industrial needs for web mapping mashup application by open API, linked with the practical web computing technologies, are gradually increasing. In this study, a user interface in mashup for geo-spatial feature generation was implemented by using mainly Google maps API. Spatial database resources in this implementation are those of Google mapping server. As the results, public users on web client can create their own geo-spatial data sets in web vector formats, without the help of any GIS tools or access to proprietary databases. It is concluded that web-based mashup application in client-side using open API can be used as an alternative for geo-browsing system or portable feature generation system.

• Proceedings of the Korea Association of Information Systems Conference
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• 1997.10a
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• pp.113-125
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• 1997

The objective of this research is to construct and build a software platform to enable collaboration among enterprise headquarters, product designers, software engineers, manufacturing plants, and suppliers which are located at different remote locations via internet. In specific, agent technology is adopted as a software vehicle to automate demand as a software vehicle to automate demand and supply process in the internet environment. Agents are programs that act an behalf of their human users to perform laborious tasks such as information locating, accessing, filtering, integrating, adapting and resolving inconsistencies. Global competition is forcing the present day industry to produce high quality product more fast and inexpensively. In Korea, most labor-intensive industries have moved to China and other Asian countries for cost reduction. The need for fast information exchange has increased among the remote locations for the cooperation and coordination. In this research, a virtual global manufacturing system will be constructed that distributes production schedule among remote places, acts as a bridge between the headquarters and manufacturing plants, distributes tasks and collates different solutions between demand and supply using agent. The external communication protocol takes HTML format, internal message handling requires SGML for document exchange, and KQML for agent implementation. The expected benefits will be : reduced cost of real-time information exchange, realization of global manufacturing environment, the maximum utilization of internet for the enterprise data exchange.

• The Journal of Information Systems
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• v.6 no.2
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• pp.85-105
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• 1997

The objective of this research is to construct and build a software platform to enable collaboration among enterprise headquarters, product designers, software engineers, manufacturing plants, and suppliers which are locate at different remote locations via internet. In specific, agent technology is adopted as a software vehicle to automate demand and supply process in the internet environment. Agents are programs that act on behalf of their human users to perform laborious tasks such as information locating, accessing, filtering, integrating, adapting and resolving inconsistencies. Global competion is forcing the present day industry to produce high quality product more fast and inexpensively. In Korea, most labor-intensive industries have moved to China and other Asian countries for cost reduction. The need for fast information exchange has increased among the remote locations for the cooperation and coordination. In this research, a virtual global purchasing and ordering system will be constructured that distributes production schedule among remote places, acts as a bridge between the headquarters and manufacturing plants, distributes tasks and collates different solutions between demand and supply using agent. The external communication protocol takes HTML format, internal message handling requires SGML for document exchange, and KQML for agent implementation. The expected benefits will be : reduced cost of real-time information exchange, realization of global manufacturing environment, the maximum utilization of internet for the enterprise data exchange.

• Journal of Astronomy and Space Sciences
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• v.20 no.4
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• pp.403-416
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• 2003

There are common features, in both imaging surveys and image processing, between astronomical observations and remote sensing. Handling large amounts of data, in an easy and fast way, has become a common issue. Implementing pipeline software can be a solution to the problem, one which allows the processing of various kinds of data automatically. As a case study, the development of pipeline software for the EIS (European Southern Observatory Imaging Survey) is introduced. The EIS team has been conducting a sky survey to provide candidate targets to the 250 VLTs (Very Large Telescopes) observations. The survey data have been processed in a sequence of five major data corrections and reductions, i.e. preprocessing, flat fielding, photometric and astrometric corrections, source extraction, and coaddition. The processed data are eventually distributed to the users. In order to provide automatic processing of the vast volume of observed data, pipeline software has been developed. Because of the complexity of objects and different characteristic of each process, it was necessary to analyze the whole works of the EIS survey program. The overall tasks of the EIS are identified, and the scheme of the EIS pipeline software is defined. The system structure and the processes are presented, and in-depth flow charts are analyzed. During the analyses, it was revealed that handling the data flow and managing the database are important for the data processing. These analyses may also be applied to many other fields which require image processing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.631-634
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• 2001

In this study, the graphic simulation system of multi joint manipulator is developed to analyze and optimize the remote handling processes for the spent fuel assembly. This system consists of a 3-D graphical modeling system, a device assembling system, and a motion simulation system. To analyze and optimize the processes involved in multi-joint manipulator operation such as NFBC transportation process and bottom nozzle removal process, the virtual work place is implemented using a computer graphic technology. This virtual workcell is exactly same as that of the real environment. This graphic simulation system of the multi-joint manipulator can be effectively used for designing the main processes and maintenance processes of the spent fuel management.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.247-250
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• 2018

The remote diagnostic system has been developed for enhancing operability of Data Service Platform(DSP) of Korean e-Navigation Project performed by Ministry of Oceans and Fisheries(MOF) since 2016. It plays a critical role to find and handling logical, physical error in early time in order to maximize operability of DSP, which makes DSP to provide seamless service to various ships voyaging in the sea. Therefore, as developing a system to diagnose resource and operation status of DSP immediately in a remote place, and a system to feed it back to operator or to recover it on its own, DSP can have short period of MTTR as well as high chance of providing proper service to ships in voyage.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.445-450
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• 1998

In this paper, a robust nonlinear prediction-type controller (RNPC) is developed for the continuous time nonlinear system whose control objective is composed of system output and its desired value. The basic control law of RNPC is derived such that the future response of the system is first predicted by appropriate functional expansions and the control law minimizing the difference between the predicted and desired responses is then calculated. RNPC which involves two controls, i.e., the auxiliary and robust controls into the basic control, shows the stable closed loop dynamics of nonlinear system of any relative degree and provides the robustness to the nonlinear system with parameter/modeling uncertainty. Simulation tests for the position control of a two-link rigid body manipulator confirm the performance improvement and the robustness of RNPC.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.155.2-155
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• 2001

A heavy duty power manipulator consisting of high reduction ratio joints is usually used in heavy duty tasks. When the heavy duty power manipulator is used as the slave manipulator in the teleoperated bilateral control system, the position control performance of the slave manipulator and the system stability tend to deteriorate due to the windup phenomenon caused by actuator saturation. KAERI has developed a teleoperated bilateral control system for the study of the remote handling of a spent fuel mockup bundle, which has an enhanced bilateral control algorithm improving the position tracking performance of the slave manipulator while compensating for the windup phenomenon. In this paper, the developed bilateral control system ...