• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.9
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• pp.18-23
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• 2006

This paper presents an operator training simulator for power system restoration against massive blackout. The system is designed especially focused on the generality and convenient setting up for initial condition of simulation. The former is accomplished by using power flow calculation methodology, and PSS/E data is used to set up the initial state for easy setting. The proposed simulator consists of three major components-a power flow(PF), a data conversion(CONV), and, a GUI module. The PF module calculates power flow, and then checks over-voltages of buses and overloads of lines. The CONV module composes a Y-Bus array and a database at each restoration action. The initial Y-Bus array is composed from PSS/E data. A user friendly GUI module is developed including a graphic editor and a built-in operation manual. The maximum processing time for one step operation is 15 seconds, which is adequate for training purpose.

• Korean Management Science Review
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• v.9 no.1
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• pp.41-52
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• 1992

The QOS(Quality of Service) recognized by the customer will become the most important thing under the competitive telecommunications market. Korea Telecom is going to develop many system to manage the telecommunication network, to improve the level of QOS, and to increase the revenue. Operation and Maintenance Adiministration System is one of the systems developed to meet those purposes efficiently. This system gathers qualities data from telephone offices or operation centers and analyze the results of QOS improvement activities and evaluate overall QOS. And also system makes it possible to improve the cost/effectiveness of operation and maintenance of telecommunication network. Operation and Maintenance Administration System has four functional modules, i.e., the user interface module, the database management module, the QOS management module, and the database conversion module. The purpose of this study is to develop the QOS management program, one of the four functional modules of the system,using FOCUS 4GL/DBMS. Since Operation and Maintenance Administration System is developed using FOCUS 4GL, every user can handle and maintain the system very easily and reduce system backlogs.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.110-113
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• 2003

In this paper, the multi-channel high speed data acquisition system is implemented. This high speed signal processing system for 3-D image display is applicable to the manipulation of a medical image processing, multimedia data and various fields of digital image processing. In order to convert the analog signal into digital one, A/D conversion circuit is designed. PCI interface method is designed and implemented, which is capable of transmission a large amount of data to computer. In order to, especially, channel extendibility of images acquisition, bus communication method is selected. By using this bus method, we can interface each module effectively. In this paper, 32-channel A/D conversion and PCI interface system for 3-dimensional and real-time display of the retina image is developed. The 32-channel image acquisition system and high speed data transmission system developed in this paper is applicable to not only medical image processing as 3-D representation of retina image but also various fields of industrial image processing in which the multi-point realtime image acquisition system is needed.

• Journal of IKEEE
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• v.23 no.3
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• pp.1096-1099
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• 2019

In this paper, we propose the protocol for construction of smart factory. The proposed protocol for construction of smart factory consists of an OPC UA Server/Client, a technology of TSN realtime communication, a NTP & PTP time synchronization protocol, a FieldBus protocol and conversion module, a technology of saving data for data transmit latency and synchronization protocol. OPC UA server/client is a system integration protocol which makes interface industrial hardware device and supports standardization which allows in all around area and also in not independent from any platform. A technology of TSN realtime communication provides an high sensitive time management and control technology in a way of sharing specific time between devices in the field of high speed network. NTP & PTP time synchronization protocol supports IEEE1588 standardization. A fieldbus protocol and conversion module provide an extendable connectivity by converting industrial protocol to OPC. A technology of saving data for data transmit latency and synchronization protocol provide a resolution function for a loss and latency of data. Results from testing agencies to assess the performance of proposed protocol for construction of smart factory, response time was 0.1367ms, synchronization time was 0.404ms, quantity of concurrent access was 100ea, quantity of interacting protocol was 5ea, data saving and synchronization was 1,000 nodes. It produced the same result as the world's highest level.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.6
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• pp.1-10
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• 2005

This paper describes the implementation of HTML converter for wireless internet access in wireless application protocol environment. The implemented HTML converter consists of the contents conversion module, the conversion rule set, the WML file generation module, and the frame contents reformatting module. Plain text contents are converted to WML contents through one by one mapping, referring to the converting rule set in the contents converting module. For frame contents, the first frameset sources are parsed and the request messages are reconstructed with all the file names, reconnecting to web server as much as the number of files to receive each documents and append to the first document. Finally, after the process of reformatting in the frame contents reformatting module, frame contents are converted to WML's table contents. For image map contents, the image map related tags are parsed and the names of html documents which are linked to any sites are extracted to be replaced with WML contents data and linked to those contents. The proposed conversion method for frame contents provides a better interface for the users convenience and interactions compared to the existing converters. Conversion of image maps in our converter is one of the features not currently supported by other converters.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.192-194
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• 2006

To elucidate possible challenges for outdoor practical use of dye-sensitized solar cells(DSC), compared with conventional Si solar cells. DSC modules still need the larger area than conventional Si solar modules to attain the same rated output because of lower photoelectron-chemical conversion efficiency. However, using batteries backup systems, the measured data shows that DSCs gathered over 12% more electricity than Si solar cells of the same rated output power in same outdoor condition. Moreover, battery charging time of DSC is about 1 hour faster than same rate of Si solar module. In this paper, 12 single DSC cells prepared for 4 serialized DSC cells was connected in 3 row parallel which have same output power rate of Si solar module. This DSC module was practiced generating characteristic experiment over outdoor daylight condition and applied with PV battery charger by using DC-DC converter. The main advantages of DSC module battery charger as compared with conventional Si solar module one are shorter charge time and lower cost.

• Journal of IKEEE
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• v.19 no.3
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• pp.319-326
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• 2015

This paper proposes method about development of conversion software for controller without OPC stack to communicate with OPC DA client. The proposed method is composed of development of OPC server based on OPC DA standard protocol, development of GUI application can be checked the OPC tag and point informations, development of conversion module to convert from OPC protocol to open standard protocol. In the stage of development of OPC server based on OPC DA standard protocol, we develope server in the pc to transmit and receive datum through OPC DA protocol with OPC DA client. In the stage of evelopment of GUI application can be checked the OPC tag and point informations, run the OPC DA server and register to window system registry and check OPC tags, points, transmitting and receiving of data from serial communication. In the stage of development of conversion module to convert from OPC protocol to open standard protocol, convert from OPC tag data which has received from OPC DA client to protocol can be communicated with industrial controller using open standard protocol so that support to transmit and receive data. To evaluate the efficiency of the proposed software, we connected OPC DA server software and OPC client, and 5 sample industrial controller which use open standard protocol, as a result we got 96.98% average communication succeeding rate among entire transmitting and receiving packets. We also confirmed that successfully communicated between industrial building controller which uses modbus protocol and industrial OPC DA client using OPC DA conversion software proposed by this dissertation.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.2067-2070
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• 2002

In this paper, a VLSI architecture for transform and quantization module, which consists of 2D-DCT, quantization, AC/DC prediction block, scan conversion, inverse quantization and 2D-IDCT, is presented. The architecture of the module is designed to handle a macroblock data within 1064 cycles and suitable for MPEG-4 video codec handling CIF image formats. Only single 1-D DCT/IDCT cores are used for the design instead of 2-D DCT/IDCT, respectively. 1-bit serial distributed arithmetic architecture is adopted for 1-D DCT/IDCT to reduce the hardware area in this architecture. As the result, the maximum utilization of hardware can be achieved, and power consumption can be minimized. The proposed design is operated on 27MHz clock. The experimental results show that the accuracy of DCT and IDCT meet the IEEE specification.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.35-42
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• 2003

We have studied DC energy conversion of RF card by wireless communication. In order to attain an objective, it used the system which is a Rectenna. The main purpose of energy conversion system is the operation of the circuits at RF-ID system. The proposed RF-ID system is a lot classified with the reader and tag. Reader is a kind of the base station role supporting RF energy. And priority tag convert RF energy from the reader it was delivered with a wireless to DC energy. The energy which is converted like Tag. It transmits to the reader characteristic ID of each card. The tag is mainly divided into rectifier, power module, memory and controller. The FRAM maintains the data like a ROM in no-power situation. And the advantage is a low power element compared with other EEPROM. There are two considerations, when RF energy is converted into DC source by wireless. One is energy amount supported from the reader, the other is high power efficiency. This paper presents a study of simulation and experiments on the RF-DC conversion circuit in tag by the power efficiency concentrated.

• Journal of the Korean Solar Energy Society
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• v.32 no.2
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• pp.1-10
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• 2012

A photovoltaic/thermal (PVT)solar system is the solar technology that allows for simultaneous conversion of solar energy into both electricity and heat. This paper compared the performance of PVT system with a conventional PV module and solar collector and analyzed electrical and thermal efficiency of PVT system in terms of solar irradiance and inlet temperature of the working fluid. Based on the experimental data, thermal and electrical efficiencies of he glazed PVT system were57.9% and14.27% under zero reduced temperature condition which were lower by 13.6% than the solar thermal absorber plate and by 0.08% than the PV module respectively. For the unglazed PVT system it had lower thermal efficiency than the solar thermal absorber plate but higher electrical performance than the PV module due to the cooling effect by the working fluid. However, total efficiency of the glazed PVT system was72.2% which was higher than combined efficiencies of the solar collector and PV module. Besides, total efficiency of the PVT system would be much higher if calculated based on unit area.