• Smart Media Journal
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• v.12 no.5
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• pp.81-87
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• 2023

In this paper, accidents in high-voltage overhead distribution lines, which provide stable power supply in the power system, cause inconvenience in life and disruption of production of companies. 22.9 [kV] high-voltage overhead power distribution lines aim to improve reliability and stability, such as damage caused by rain, snow, wind, etc., or electric shock prevention. Therefore, in order to prevent wire disconnection accidents due to deterioration of electrical conductivity or tensile strength due to corrosion of overhead distribution lines, it is necessary to prevent unexpected accidents in the future through regular inspection and repair. In order to diagnose deterioration due to corrosion of distribution lines, a diagnostic system (measuring instrument) is installed on the wires to monitor the condition of the wires. The manager on the ground receives the measured data through ZigBee wireless communication, controls the diagnosis system through the diagnosis system program, and grasps the condition of the overhead distribution line through the measured data and photographed photos, and predicts the life of the wire along with the visual inspection method. developed a program.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.9
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• pp.117-123
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• 2009

Recently, the failures of electrical equipment have been reduced due to the improvement of its quality and the advance of operation techniques but the failure rates caused by natural disasters such as wind and lightning have been increased. To reduce the failures due to lightning, it is necessary for insulation design of transmission lines to be done, effectively. Also the analysis on the lightning characteristics is essential to the effective insulation design. In this paper, we describe lightning distribution, multiplicity, IKL(Iso-Keraunic Level) and amplitude distribution of lightning current base on the lightning data by KLDNet.

• Journal of the Korea Society of Computer and Information
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• v.7 no.4
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• pp.211-219
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• 2002

The introduction of CRM alter production materials oriented into customer oriented, reengineering all process into customer's view and it means introduction of information system. This means introduction of information system which can support CRM strongly. This paper examines developmental transition of CRM marketing. proposes CRM approach and practical strategy. and CRM can embody Customer, Relationship. Management and System in many respects. It is desirable to build on CRM more serving than sell products in the Marketer's view point.

• Journal of the Korean Data and Information Science Society
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• v.20 no.1
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• pp.57-64
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• 2009

In this paper, 30 main cities are clustered based on precipitation, temperature, wind speed, photo period, and humidity. We found that the resulting clusters has strong relationships with geographical locations. These results make sense because, although Korea is a small country, Korean weather is known to have strong locality. The largest number of clusters is found when wind speed is used as an interested variable for clustering and the smallest number of clusters is found when photo period is used. The large number of clusters based on wind speed indicates that wind speed is affected easily by local geography.

• Journal of the Korean Data and Information Science Society
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• v.20 no.1
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• pp.109-115
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• 2009

Many internet companies are holding marketing activity through customer relationship management to satisfy complicated and diversified consumer demands. Use of customer lifetime value as a marketing metric tends to place greater emphasis on customer service and long-term customer satisfaction, rather than on maximizing short term sales. And so many internet companies have been interested in customer lifetime value, which is a primary key for discovery customer values to promote the competitive power in their business fields. In this paper, we apply a life table technique to lifetime analysis of internet site customers by membership pattern and provide the opportunity using revised life tables in several kinds of internet companies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.1027-1030
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• 2015

In the airborne SAR, the motion errors induced by atmospheric turbulence decrease the resolution and increase the sidelobes. If the sidelobes are not properly compensated, the image quality is degraded. Thus, in this paper, we have introduced the sidelobe reduction method to increase the image quality. After we calculate the scene center based on the estimated squint angle for the flight path partitioned by the subaperture technique, we perform the motion compensation for the scene center. Then, after we perform the recursive sidelobe reduction for the region of interest in the reconstructed SAR image, we extend it for the full image.

• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.257-266
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• 2016

Random Coefficient Autoregressive models (RCA) have attracted increased interest due to the wide range of applications in biology, economics, meteorology and finance. We consider an RCA as an appropriate model for non-linear properties and better than an AR model for linear properties. We study the methods of RCA parameter estimation. Especially we proposed the special case that an random coefficient ${\phi}(t)$ has the initial value ${\phi}(0)$ in the RCA model. In practical study, we estimated the parameters and compared Prediction Error Sum of Squares (PRESS) criterion between AR and RCA using Korean Mumps data.

• Environmental and Resource Economics Review
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• v.20 no.2
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• pp.357-379
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• 2011

The problem of invasive species has been recently emerged as one of complicated issues due to increasing globalisation and its consequence of species immigrations. Since in most cases of invasive species it is less likely to fully eradicate them through human efforts, it is often interested in reducing the possibility of ecological disaster caused by the invasive species. This paper provides an optimal control model to minimize such possibility while allowing the stochastic nature of biological growth of the invasive species. Conditions under which the partial eradication effort is optimal are derived. Simple numerical illustration is provided using H1N1 data which is categorized as an invasive disease in microorganism level.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.124-130
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• 2005

This paper presents the simulation modeling and analysis of variable wind speed turbine system(VWTS) using Psim program In the simulation, using the Vestas V47 VWTS located in Hangwon wind farm in Jeju-Do as a model, wind model, blade model, pitch control model and grided connected generator are modeled. The VWTS is controlled by the optimal pitch angle for maximum output power under the rated wind speed and for the rated output power over the rated wind speed. To verify the effectiveness of proposed method, simulation results are compared with the actual data from the model system According to the comparison of these results, this method shows excellent performance. So it is very useful for understanding and applications of wind power control system.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.394-397
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• 2018

휴대폰을 개인마다 보유할 정도로 보편화하고 무선 네트워크 기술이 발전하면서 대학가에서 출결관리를 자동화하려는 바람이 불고 있다. 이는 이전의 출결시스템의 결점인 출결 확인 시간을 줄이기 위한 것이다. 그러나 자동화된 스마트 출결시스템에 허점이 많아 출결 정보에 대한 신빙성과 공정성에 문제가 발생하고 있고, 그에 대한 대책이 없는 것이 현재 상황이다. 이번 연구는 얼굴인식을 이용한 스마트 출석 체크 프로그램이다. 수업에서 사진을 찍으면 AWS Recognition 기술을 활용해 얼굴을 인식하여 Django web sever로 보내고 그 얼굴과 학사 시스템에 등록되어있는 학생의 사진을 비교하여 어떤 인물인지 파악한다. 비교한 인물이 일정 유사율을 넘었을 경우 그 학생의 얼굴 사진을 학습, 계속해서 서버 안에 있는 같은 인물 파일에 넣어서 유사율을 높이는 식으로 진행된다. 그렇게 하여 스마트 출결시스템의 목적에 맞게 출결 확인 시간을 대폭 줄일 것이고, 부정적인 방법으로 출석할 수 있는 방법을 없애 기존의 시스템에 없던 신빙성과 공정성을 확립할 것이다. 또한, 어플리케이션을 통해 학생의 경우 언제 어디서든지 자신의 출결 상황을 확인할 수 있고, 교수님 또한 손쉽게 학생들의 출결을 관리할 수 있도록 하였다. 최종적으로 무결성이 확보된 정확한 출결 정보를 자동으로 데이터화하여 이용자와 관리자의 편의를 보장할 것이다.