• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.3
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• pp.65-78
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• 2013

To analyze influences under open fault conditions in switching devices, an integrated simulation and condition monitoring scheme for a permanent magnet synchronous generator (PMSG) based variable speed grid-connected wind turbine system are presented. Among various faults in power electronics components, the open fault in switching devices may arise when the switches are destructed by an accidental over current, or a fuse for short protection is blown out. Under such a faulty condition, the grid-side inverter as well as the generator-side converter does not operate normally, producing an increase of current harmonics, and a reduction in output and efficiency. As an effective way for a condition monitoring of generation system by online basis without requiring any diagnostic apparatus, the estimation schemes for generated voltage, flux linkage, and stator resistance are proposed and the validity of the proposed scheme is proved through comparative simulations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1606-1611
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• 2008

Recently, The diagnosis techniques of electric facilities are developed on live line. This paper describes the discharge characteristics of polymer insulator(EPDM A type). Keeping the facilities in good working order, the goal of this paper will provide the information to enable user to easily judge conditions of facilities on the spot. The performance of polymer insulator is assessed from the KS C IEC 60270 and CEA LWIWG-01(96)(Tracking Wheel Test). As the results, UV generation patterns of polymer insulator grow like a jellyfish shape follow the ramping voltage. Discharging UVs are detected at about 31.25% of breakdown voltage. Just then, dimension of UV image is about $0.84cm^{2}$. The dimension of max. UV image is about $297.4cm^{2}$ at $160kV(V_{bd})$. The position of UV generation due to surface discharge of polymer insulator is the center of insulator in the early, then moved the ground side and the last, UV image moved through the junction part of source side. Surface of aged polymer insulator is cracked and faded due to arc. UV absorption spectrum of polymer insulator are appeared the C-H bond of scissoring vib. at $1014cm^{-1}$ and C=O bond of recombination structure. Also, recombined UV absorption peak such as C-H, N-H, and O-H is detected at the $3321cm^{-1}$. Through the paper, there are inspection data which are the relations between surface discharge of polymer insulator and UV detecting image.

• Journal of the Korean Institute of Educational Facilities
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• v.6 no.1
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• pp.5-20
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• 1999

With the advent of internet, the modern society is enjoying the benefits of the information age. As one of undesirable side effects of utilization of internet, however, it is often mentioned that young students are helplessly exposed to inappropriate and unqualified information. Therefore, in this paper, we will clarify the nature of inappropriate information to the younger generation and will argue for the needs of protecting the youth from inappropriate information. Especially the merits and limits of often motioned five different protective and regulatory measures are presented and analyzed, those are, establishment of acceptable use policy, active utilization of supervisory organization, promotion of Internet rating system, installation of filtering software, and legal and regulatory protection. As a fundamental means of resolving the problems, however, enforcement of systematic information literacy education, promotion of active utilization of sound information, development of search engines for the youth, design of diverse filtering softwares which can be selected by users, and increased attention by parents and teachers are suggested.

• Journal of Ocean Engineering and Technology
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• v.13 no.1 s.31
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• pp.11-17
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• 1999

A three dimensional finite element generation code has been developed attaching simple blocks. Block can be either a quadrature or a cube depending on the dimension of a subject considered. Finite element serendipity basis functions are employed to map elements between the computational domain and the physical domain. Elements can be generated with wser defined progressive ratio for each block. For blocks to be connected properly, a block should have a consistent numbering scheme for vertices, side nodes, edges and surfaces. In addition the edge information such as the number of elements and the progressive ratio for each direction should also be checked for interfaces to have unique node numbers. Having done so, user can add blocks with little worry about the orientation of blocks, Since the present the present code has been written by a Visual Basic language, it can be developed easily for a user interactive manner under a Windows environment.

• Journal of Multimedia Information System
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• v.6 no.1
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• pp.15-22
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• 2019

There are many ways to perform face recognition. The first step of face recognition is the face detection step. If the face is not found in the first step, the face recognition fails. Face detection research has many difficulties because it can be varied according to face size change, left and right rotation and up and down rotation, side face and front face, facial expression, and light condition. In this study, facial features are extracted and the extracted features are geometrically reconstructed in order to improve face recognition rate in extracted face region. Also, it is aimed to adjust face angle using reconstructed facial feature vector, and to improve recognition rate for each face angle. In the recognition attempt using the result after the geometric reconstruction, both the up and down and the left and right facial angles have improved recognition performance.

• Convergence Security Journal
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• v.6 no.4
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• pp.59-66
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• 2006

There is a tendency that next-generation tactical information network for the military has been developed from tactical environment based on commercial Internet technology to Tactical Internet(TI) of which purpose is providing various informations such as data, voice and image. On the other side, with an introduction of commercial information communication technology onto Tactical Internet had progressed rapidly on the basis of U.S. Army, threats and attack patterns against Tactical Internet have changed into various types gradually. In this paper, we will examine security factors and technologies to be considered in case of accepting Tactical Internet as a next-generation tactical information network, and discuss its countermeasures with those technologies for a basis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.836-838
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• 2013

In recent years, the future direction of information technology social computing, mobile computing, cloud computing. Web technology industries beyond IT convergence technology for the service side of the parameters has been developed. In particular, the rapid increase of data in a web-based open Web and the importance of the next generation Web technology is increasing. In this paper, the next generation Web technology, an open Web and the importance of increasing domestic and international standardization trends were studied.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.55-64
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• 2012

Until now, Side Channel Attack has been known to be effective to crack decrypt key such as smart cards, electronic passports and e-ID card based on Chip. Combination of Masking and shuffling methods have been proposed practical countermeasure. Newly, S.Tillich suggests biased-mask using template attack(TA) to attack AES with masking and shuffling. However, an additional assumption that is acquired template information previously for masking value is necessary in order to apply this method. Moreover, this method needs to know exact time position of the target masking value for higher probability of success. In this paper, we suggest new practical method called Biasing Power Analysis(BPA) to find a secret key of AES based on masking-shuffling method. In BPA, we don't use time position and template information from masking value. Actually, we do experimental works of BPA attack to 128bit secret key of AES based on masking-shuffling method performed MSP430 Chip and we succeed in finding whole secret key. The results of this study will be utilized for next-generation ID cards to verify physical safety.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3795-3802
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• 2022

NaI(Tl) scintillation materials are considered to be one of many materials that are used exclusively for γ-ray detection and spectroscopy. The gamma-ray spectrometer is not an easy-to-use device, and the accuracy of the numerical values must be carefully checked based on the rules of the calibration technique. Therefore, accurate information about the detection system and its effectiveness is of greater importance. The purpose of this study is to estimate, using an analytical-numerical formula (ANF), the purely geometric solid angle, geometric efficiency, and total efficiency of a cylindrical NaI(Tl) γ-ray detector with a side-through hole. This type of detector is ideal for scanning fuel rods and pipelines, as well as for performing radio-immunoassays. The study included the calculation of the complex solid angle, in combination with the use of various points like gamma sources, located axially and non-axially inside the through detector side hole, which can be applied in a hypothetical method for calibrating the facility. An extended γ-ray energy range, the detector, source dimensions, "source-to-detector" geometry inside the side-through hole, path lengths of γ-quanta photons crossing the facility, besides the photon average path length inside the detector medium itself, were studied and considered. This study is very important for an expanded future article where the radioactive point source can be replaced by a volume source located inside the side-trough hole of the detector, or by a radioactive pipeline passing through the well. The results provide a good and useful approach to a new generation of detectors that can be used for low-level radiation that needs to be measured efficiently.

• Korean Institute of Interior Design Journal
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• no.28
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• pp.44-50
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• 2001

This study propose the new concept of residence by analyzing the change of residence through the characteristic of popularity and degree of development of technology on home network information appliance for intelligent home. Accordingly, Cyber village represented as home automation and extend to information of society. it encourage need of information and multimedia of home. It expect home information infrastructure for accepting informations, which make smart home to linked home-working home-learning home-treatment. home-shopping and home-banking. The system of intelligent home is the intelligence of human-biology in the side of environmental friendly and multi-function. it distinguish the system of security, controlling system of inside environment, supporting system of house-working, automatic controlling, house working. Future house require to meet demand of young generation, such as small residental space, the multi-functional space, the flexible space, making mood for dual income couple and of single as intelligent home. Accordingly, basic purpose which are pleasantness, the safe and the convenience the mobile multi-function as well as networking with controlling of temperature, security, health-test, home-entertainment, home-office and consider environment together.