• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.3997-4003
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• 2014

Background: Infection with certain human papillomavirus (HPV) genotypes is the most important risk factor related with cervical cancer. The objective of the present study was to investigate the prevalence of HPV infection, the distribution of HPV genotypes and HPV E6/E7 oncogene mRNA expression in Turkish women with different cervical cytological findings in Mersin province, Southern Turkey. Materials and Methods: A total of 476 cytological samples belonging to women with normal and abnormal cervical Pap smears were enrolled in the study. For the detection and genotyping assay, a PCR/direct cycle sequencing approach was used. E6/E7 mRNA expression of HPV-16, 18, 31, 33, and 45 was determined by type-specific real-time NASBA assay (NucliSENS EasyQ$^{(R)}$HPV v1.1). Results: Of the 476 samples, 106 (22.3%) were found to be positive for HPV DNA by PCR. The presence of HPV was significantly more common (p<0.001) in HSIL (6/8, 75%) when compared with LSIL (6/14, 42.9%), ASC-US (22/74, 29.7%) and normal cytology (72/380, 18.9%). The most prevalent genotypes were, in descending order of frequency, HPV genotype 66 (22.6%), 16 (20.8%), 6 (14.2%), 31 (11.3%), 53 (5.7%), and 83 (4.7%). HPV E6/E7 oncogene mRNA positivity (12/476, 2.5%) was lower than DNA positivity (38/476, 7.9%). Conclusions: Our data present a wide distribution of HPV genotypes in the analyzed population. HPV genotypes 66, 16, 6, 31, 53 and 83 were the predominant types and most of them were potential carcinogenic types. Because of the differences between HPV E6/E7 mRNA and DNA positivity, further studies are required to test the role of mRNA testing in the triage of women with abnormal cervical cytology or follow up of HPV DNA positive and cytology negative. These epidemiological data will be important to determine the future impact of vaccination on HPV infected women in our region.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.5
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• pp.60-67
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• 2007

In this paper, a simulation method of the internal winding fault is proposed to calculate winding current and electromagnetic force in a distribution power transformer by suing FEM program. The model of the transformer is a single phase, 60[Hz], 1[MVA], 22.9[kV]/220[V], cable-type winding. The short-circuit current and electromagnetic force are calculated by FEM(Finite Element Method) program(Flux2D) and the results we verified with theoretical formula and PSPICE program. The simulation results are fairly good agreement with the other verified methods within 5[%] error rate. The turn-to-turn short-circuit current is 500 times of the rated current and the electromagnetic force is about $20{\sim}200times$. The method presented in this study may serve as one of the useful tools in the electromagnetic force analysis of the transformer winding behavior under the short circuit condition for design of the structure.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.479-485
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• 2011

In 22.9kV underground distribution system, power cables are provided with multiple-point ground in which each neutral line of the distribution cable(A, B, C phases) and three-wire common grounded at every connecting section. But in such grounding methods, circulating current flows between the neutral wire and grounding wire. And power loss due to circulating current also occurs in all conductors. Therefore it is getting necessary reducing circulating current in underground distribution system. This paper presents improved grounding method to overcome such problems. The proposed grounding method eliminates circulating current in the neutral line effectively and is verified that there is no electrical problem or any ineffectiveness of operating protection systems. These analyses are carried out by EMTP/ATPDraw to compare each grounding methods in steady and transient state. This grounding method suggested in this paper can be applied on real distribution system after field tests considering elimination of circulating current was implemented.

• Proceedings of the KIEE Conference
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• summer
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• pp.375-377
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• 2004

22.9kV급 가공배전선에서의 뇌격현상은 직접측정이 어렵기 때문에 지금까지 절연협조수준의 도출은 수치적인 모의해석과정에서 얻어진 과전압강도를 근거로 하고 있다. 대표적인 모델에 대해서 만이라도 실측자료를 확보할 수 있다면 해석과정의 정확도를 높이는 중요한 전기가 될 수 있다. 이러한 가공배전선로의 뇌격현상을 측정하기 위한 상용설비를 이용한 경제적 측정시스템을 구성하였다. 접지회로에서 발생하는 과전압으로 인한 인명뿐 아니라 계측설비의 안전성도 확보하고 과 경제성확보를 위하여 전주 중간에 장시간용 UPS 및 파형측정설비를 2중 차폐함 안에 넣어 1점 접지상태가 되도록 고정하고 측정point에 HV divider 및 로고스키코일을 설치하여 한 지점에서의 측정회로를 구성하였다. 전체적으로 뇌격전류 주입 위치에서부터 3지점을 선정하여 측정설비를 설치하고 경제적인 Rs485 multi-drop 회로를 구성하여 통신망을 확보하였다. 직렬통신망에는 뇌격시험 시 발생하는 과전압에 대한 보호회로로서 간단한 수동식 개폐회로를 구성하였다. 측정파형을 전체적으로 전송받는 속도가 약간 늦기는 하나 간단한 data acquisition program을 사용하여 전체 측정회로를 가동시킬 수 있었다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.171-176
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• 2010

This paper presents the electric field for 22.9[kV]/380[V], 2[MVA] mold transformer are analysed using FEM(finite element method). The electric field was calculated for the voltage applied to the transformer. Then, it is analysed that the maximum electric field occurred between high voltage turns. Capacitance is calculated with energy method. Surge impulse test simulation is studied by modeling circuit with capacitance and inductance. This paper obtain the result that is about influence of electric field in distribution mold transformer adopted.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1340-1347
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• 2017

Utilization of Electric Vehicles (EVs) have been growing popularity in recent years due to increment in fuel price and lack of natural resources. Random unexpected charging by home EV charger in distribution is predicted in the future. The power quality problems such as fluctuation of power factor in a residential distribution network was explored with random EV chargers. This paper proposes a high-performance nonlinear sliding mode controller (SMC) for an EV charging system to compensate voltage distortions and to enhance the power factor against the unbalanced EV chargers. For the verification of the proposed scheme, MATLAB-Simulink simulations are performed on 22.9-kV grid. The results show that the proposed scheme can improve the power factor of a smart grid due to the EV chargers on the grid.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.966-968
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• 1997

Our country is still suffering from much work outage, nearly 80% of total outage time, in 22.9kV-Y multi-grounded distribution lines. Therefore, KEPCO which is the sole utility owned by the Korean government has developed outage-free work techniques to improve the reliability of power supply in Our country. This paper is to introduce the developing process and good effects of outage-free work techniques, and the equipment developed and applied in Our country. This paper will aid many utilities to try to reduce the work outage.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.1
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• pp.1-7
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• 2005

This paper proposes a novel UPQC(unified power quality conditioner) based on H-bridge modules, isolated through single-phase multi-winding transformers. The dynamic performance of proposed system was analyzed by simulation with PSCAD/EMTDC, assuming that the UPQC is connected with the 22.9kV distribution line. The proposed system can be directly connected to the transmission line without series injection transformers. It has flexibility in expanding the operation voltage by increasing the number of H-bridge modules and can compensate reactive power, harmonics, voltage sag and swell, voltage unbalance. The proposing UPQC has the ultimate capability of improving power quality at the point of installation on power distribution systems.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.5
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• pp.502-507
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• 1999

An improved, accurate and reliable high-voltage measuring system utilizing a bushing-type capacitor is proposed in this study. This system measures voltages and phase angles of three-phase 22.9 kV power distribution lines and provides enough current to charge a battery for a motor-driven load switch and to operate the measuring and communication circuits for the distribution automation. For reliability, epoxy resin was used as the dielectric material of the bushing-type capacitor since the dielectric strength of epoxy resin is very stable over the wide range of temperature. Capacitances were investigated and found to be stable over the wide range of temperature and applied voltage, and the results indicate that the proposed measurement system is very reliable.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.3
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• pp.105-111
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• 2001

The research presented in this paper focuses on a method for the detection of High Impedance Fault(HIF). The method will use the wavelet transform and neural network system. HIF on the multi-grounded three-phase four-wires primary distribution power system cannot be detected effectively by existing over current sensing devices. These paper describes the application of discrete wavelet transform to the various HIF data. These data were measured in actual 22-9kV distribution system. Wavelet transform analysis gives the frequency and time-scale information. The neural network system as a fault detector was trained to discriminate HIF from the normal status by a gradient descent method. The proposed method performed very well by proving the right state when it was applied staged fault data and normal load mimics HIF, such as arc-welder.