• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.185-186
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• 2015

TSC는 전력계통의 무효전력 보상을 위한 SVC 시스템의 주요 장치이다. 본 논문에서는 TSC의 커패시터 뱅크의 열화 및 고장진단에 활용할 수 있는 커패시터 용량 측정 기법을 제안한다. 제안한 커패시터 용량 측정 기법은 시간영역 해석 기법으로서 커패시터의 전압 및 전류 신호에 포함된 고조파 및 잡음, 주파수 변동, 과도 상태 전이 등의 왜란에 강인하다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.183-184
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• 2015

디지털 AVR은 동기발전기의 출력전압을 부하변동에 관계 없이 일정하게 제어하며 발전기 및 시스템 보호를 위한 각종 제어 알고리즘을 포함하고 있다. 종래의 아날로그 타입 AVR은 제어 설정이 불편하고 제어 신뢰성이 떨어지기 때문에 점차 디지털 타입으로 교체되고 있는 실정이다. 본 논문에서는 디지털 타입의 AVR에 익숙하지 않거나 심화 학습이 필요한 정비 기술자의 교육에 활용할 수 있도록 디지털 AVR 시뮬레이터를 개발하였으며 제어기와 HMI 간의 UDP 통신을 위해 프로토콜 하드웨어 컨버터, HMI, 및 EWS를 개발하였다. 추가로 스마트 단말기에서도 운전 상황을 확인할 수 있는 OIS 앱을 개발하였다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.2
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• pp.243-253
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• 2021

In the dismantling process of a reactor coolant system (RCS) piping, a radiation protection plan should be established to minimize the radiation exposure doses of dismantling workers. Hence, it is necessary to estimate the individual effective dose in the RCS piping dismantling process when decommissioning a nuclear power plant. In this study, the radiation exposure doses of the dismantling workers at different positions was estimated using the MicroShield dose assessment program based on the NUREG/CR-1595 report. The individual effective dose, which is the sum of the effective dose to each tissue considering the working time, was used to estimate the radiation exposure dose. The estimations of the simulation results for all RCS piping dismantling tasks satisfied the dose limits prescribed by the ICRP-60 report. In dismantling the RCS piping of the Kori-1 or Wolsong-1 units in South Korea, the estimation and reduction method for the radiation exposure dose, and the simulated results of this study can be used to implement the radiation safety for optimal dismantling by providing information on the radiation exposure doses of the dismantling workers.

• Korean Journal of Pharmacognosy
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• v.36 no.4 s.143
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• pp.318-323
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• 2005

The leaves (KPL) of Kalopanax pictus (KP) are used as a vegetable or a functional food in Korean society. The stem bark (Kalopanacis Cortex, KPS) has been traditionally used to treat neurotic pain, rheumatoid arthritis and diabetic disease. This research was undertaken to demonstrate that the leaf extract of KP (KPL) has also the antinociceptive and antiinflammatory effects like the extract (KPS) of Kalopanacis Cortex and to compare the activity levels of several extracts obtained from KP. Antinociceptive and antiinflammatory effects were measured against the extracts described as followings; KPL-1 (the MeOH extract obtained from the leaf shoot of KP collected on May), KPL-2 (the MeOH extract from KP collected on June), KPL-3 (the MeOH ectract from KP with no thorns), KPS-1 (MeOH extract from KPS of a Korean habitat), KPS-2 (MeOH extract from KPS of a Chinese habitat). The antimociceptive test undertaken by acetic acid-induced writhing, hot plate-, and tail-flick methods using mice. The anti-inflammatory test was also undertaken by measuring the edema in the carrageenan-induced test. The order of activity potency in the antinociceptive and antiinflammatory assays was commonly shown as followings: KPL-3>KPS>1>KPS-2>KPL-1>KPL-2. This order was also observed in acetic acid-induced vascular permeability test. The antiinflammatory activity in carrageenan-induced assay was also observed as the following order: KPL-3>KPS- 1>PS-2>KPL-1>KPL-2. In addition, adjuvant-induced rats were used for a model to assess the oxidative stress. Treatment of the rat with the extracts reduced serum thiobarbituric acid-reactive substances (TBARS), hydroxy radical(OH) and superoxide dismutase(SOD) activity caused by FCA together together with the inhibition of hepatic TBARS level and lipofuscin content. The above finding suggests that the leaf extract has the antinociceptive and antinflammatory activity. It is also suggested that KPL-3 with more potent activity than other tested extracts could be developed for a new available biomaterial.

• Development and Reproduction
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• v.12 no.2
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• pp.151-158
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• 2008

The variability within and between Korean pond-smelt (Hypomesus nipponensis; KPS) and Canadian capelin (Mallotus villosus; CCP) were studied in order to clarify the genetic distances and differences. The dendrogram obtained by the seven primers indicates cluster 1 (KOREAN 01$\sim$KOREAN 11) and cluster 2 (CANADIAN 12$\sim$CANADIAN 22). The longest genetic distance displaying significant molecular differences was found to exist between individuals in the two geographic species of Osmeridae, between individuals' no. 10 of Korean and no. 18 of Canadian (0.686). 121 unique shared loci to each species, with an average of 17.3 per primer, were observed in the KPS species, and 264 loci, with an average of 37.7 per primer, were observed in the CCP species. 77 shared loci by the two species, with an average of 11.0 per primer, were observed in the two fish species. RAPD analysis showed that the KPS species was more genetically diverse than the CCP species. KPS species may have high levels of genomic DNA variability owing to the introduction of the wild individuals from the other sites to sampling sites although it may be the geographically diverse distribution of this species. As stated above, the existence of species discrimination and genetic variability between the KPS and the CCP species was identified by RAPD analysis.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.187-188
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• 2015

본 논문은 시간영역에서 대칭좌표법을 사용한 전력품질 이벤트 검출에 관한 연구이다. sag, swell. interruption, harmonic, flicker, transients, notches, spike 등과 같은 전력품질 이벤트들이 이 방법으로 쉽게 검출된다. 본 방법은 웨이블릿, s-변환, 힐버트 변환 등의 방법이 가지고 있는 계산 부담이 없기 때문에 온라인 응용프로그램에 쉽게 사용될 수 있다. 단상 전력품질 이벤트 신호는 시간 영역에서 대칭요소를 계산하기 위하여 120도, 240도 위상차를 가지고 생성되는 다른 두 신호와 함께 이동되어 간다. 전력품질 이벤트 신호의 시작점(triggering point)은 역상분으로부터 쉽게 검출될 수 있고 이벤트는 정상분과 역상분의 합을 사용한 파형의 특징 분석으로 쉽게 분류될 수 있다. 시뮬레이션된 결과는 전력품질 이벤트의 검출과 분류를 위한 본 방법의 효과를 보여주기 위하여 다수의 전력품질 이벤트를 보여주고 있고 전력계통망 지락사고 시뮬레이션을 수행하여 유용성을 확인하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.527-532
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• 2014

Generator is the main equipment of a power plant that generates electric power. The line frequency is 60Hz, since that is operated at 3600rpm in fossil power plant. Therefore, the specific frequency 120Hz by the electromagnetic excitation force is generated inherently. If the looseness of stator at generator happens, abnormal sound that has 120Hz and the harmonic frequency is emitted from generator frame. In that case, binding of end-winding or re-wedging is needed for the reduction of sound level. In case of severe level of sound, belly band can be additionally installed at core. In this paper, the characteristics of generator sound is described and modal data is analyzed after installation of belly band.

• Archives of Pharmacal Research
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• v.24 no.2
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• pp.119-125
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• 2001

We have reported that kalopanaxsaponin A (KPS-A) Isolated from Kalopanax pictus have anti-rheumatoidal activity in the rat treated with Freunds complete adjuvant (FCA) reagent. In addition, it has been also reported that KPS-A is a potent antioxidant in the rheumatoidal rat. This research was undertaken to examine whether the saponins of KPS-A and -1 could adjust the abnormal lipid metabolisms and hematological changes in immunological diseases. KPS-A significantly inhibited the increases in both triglycerides and total proteins in addition to the decrease in total cholesterol induced by FCA reagent treatment. KPS-A treatment decreased the number of leucocytes elevated by FCA reagent treatment. Excess dose of the methanol extract produced no severe toxicity on the body weight, wet organ weights and hepatic functions. Since $LD_50$ value of K. pictus methanol extract was shown to be 4,033 ${mg/kg}$, it could be estimated to be a safe agent for anti-rheumatoidal herbal medicines.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.4
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• pp.305-317
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• 2020

The navigation message is composed of the information contained in the message and the structure for transmitting this information. In order to design a navigation message, considerations in terms of message content and message structure must be elicited. For designing a Korea Positioning System (KPS) navigation message, this paper explains performance indicators in terms of message structure and message content. Most of the performance analysis of GNSS navigation messages already in operation was performed only for Time-to-first-fix-Data (TTFFD). However, in the navigation message, the message content is composed of Clock-Ephemeris Data (CED) and additional information. So, this paper proposes a new performance indicator R_(Non-CED) that can be analyzed from the viewpoint of receiving additional information along with an explanation of TTFFD focusing on the CED reception time. This paper analyze the performance in terms of message structure using these two performance indicators. The message structures used for analysis are the packetized message protocol like GPS CNAV and the packetized and fixed pattern message protocol like GPS CNAV-2. From the results, it is possible to proffer how KPS navigation messages can have better performance than GPS navigation messages. And, these two performance indicators, TTFFD and R_Non-CED, can help to design the minimum TTFF required performance of KPS navigation messages.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.177-184
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• 2023

In order to reserve frequency bands for stable operation of the Korean Positioning System (KPS), it must be demonstrated that the impact of interference caused by KPS on other services operating in the same bands is tolerable. The International Telecommunication Union (ITU) provides the radio regulations and a compatibility assessment methodology for the coexistence of different services in limited frequency resources. The purpose of this paper is to investigate the radio regulations regarding the compatibility issues between the KPS and other services sharing the same frequency bands. The results of the investigation show that the RNSS system can be operated in the L5-band under the condition that the Power Flux Density (PFD) and Aggregated Equivalent PFD (AEPFD) thresholds specified in the radio regulations are met. In addition, the ITU recommends that the interference-to-noise ratio (INR) protection criteria be met to prevent degradation of the performance of radar systems operating in the L2/L6-band. In the case of the S-band, coordination of allocations for RDSS space stations with respect to terrestrial services is not required if the PFD does not exceed regulated thresholds regulated by ITU.