• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.793-796
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• 2003

The electronics of a mobile robot ill nuclear facilities is required to satisfied the reliability to sustain survival in its radiation environment. To know how much radiation the robot has been encountered to replace sensitive electronic parts, a dosimeter to measure total accumulated dose is necessary. Among many radiation dosimeters or detectors, semiconductor radiation sensors have advantages in terms of power requirements and their sires over conventional detectors. This paper describes the use of the radiation-induced threshold voltage change of a commercial power pMOSFET as an accumulated radiation dose monitoring mean and that of the photo-current of a commercial PIN Diode as a dose-rate measurement mean. Commercial p-type power MOSFETs and PIN Diodes were tested in a Co-60 gamma irradiation facility to see their capabilities as radiation sensors. We found an inexpensive commercial power pMOSFET that shows good linearity in their threshold voltage shift with radiation dose and a PIN diode that shows good linearity in its photo-current change with dose-rate. According to these findings, a radiation hardened hybrid electronic radiation dosimeter for nuclear robots has been developed for the first time. This small hybrid dosimeter has also an advantage in the point of view of reliability improvement by using a diversity concept.

• 한국항행학회논문지
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• 제15권5호
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• pp.789-794
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• 2011

본 논문에서는 7.9 GHz~8.4 GHz 에서 동작하는 위성통신용 X-밴드 TWT의 AM-AM과 AM-PM 변환특성을 분석하고 선형화기를 이용하여 선형성과 IMD 특성을 개선하였다. 선형화기를 포함하는 TWT는 개선된 AM-AM과 AM-PM 변환특성을 나타내며, 1 dB 압축점은 12.3 dB, $2.0^{\circ}/dB$ 위상왜곡점은 10 dB 개선되었다. 또한 동작출력에서 3차 상호변조 특성인 IMD3는 16.2 dB 개선되어 37.0 dBc로 측정되었다. 또한, 고출력 증폭기의 IMD 측정 방안을 제시하고, TWT의 AM-PM 왜곡 특성을 보상하여 출력전력과 선형 특성을 개선할 수 있음을 나타내었다.

• 전자공학회논문지SC
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• 제44권2호
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• pp.32-38
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• 2007

본 논문은 Doherty 증폭기의 높은 효율을 유지하면서 선형성을 개선하기 위해 아날로그 전치왜곡기를 가진 Doherty 증폭기를 보여준다. 3차 전치왜곡기는 전치왜곡기와 Doherty 증폭기에서 3차와 5차 혼변조 성분이 이루는 위상차를 같게 만들어 3차뿐만 아니라 5차 혼변조 왜곡신호를 동시에 상쇄시킨다. 이것은 전치왜곡기에서 위상조절 왜곡발생기를 이용하여 3차와 5차의 위상차를 독립적으로 조절함으로서 이루어진다. 또한, 간단하고 정확한 위상 측정 장치를 이용하여 왜곡발생기의 위상조절 능력을 실험적으로 확인한다. 실험적인 검증을 위해, 3차 전치왜곡기는 2.11-2.17 GHz의 WCDMA 대역에서 180-W Doherty 증폭기와 구현된다. 투톤 실험결과는 3차와 5차 혼변조 왜곡성분이 크게 상쇄될 수 있음을 보여준다. 또한, 4-carrier WCDMA 응용에서도 넓은 출력 범위에서 상당한 ACLR이 개선된다. 이 기법은 간단한 구조, 작은 크기, 세 가지의 조절 파라미터 때문에 가격 효율적이며 편리하다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1509-1510
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• 2006

ERA PD measuring system has been using for partial discharge evaluation of power appratus in test laboratories. So, the measurement uncertainty of PD measuring system (ERA), such as PD pulse calibrator rise and fall time, sacle factor(k) and linearity, transfer impedance etc, is very important factor of test result in test laboratory. In this paper, we describe tracebility and uncertainty improvement of PD measuring system in test laboratory based on IEC 60270.

• 한국한의학연구원논문집
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• 제15권1호
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• pp.85-89
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• 2009

The aim of this study was to study the quantitative analysis of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with Paecilomyces japonica, Ganoderma lucidum, honey or Nuruk. The amounts of dry on loss were measured and the quantitative analysis of glycyrrhizic acid was performed by high performance liquid chromatographic (HPLC). HPLC method was performed on C18 column ($250\;mm\;{\times}\;4.6\;mm$, $5\;{\mu}m$, RS tech) using gradient solvent mixtures of water-acetonitrile with photodiode array detector (254 nm). The flow rate was $1.0\;m{\ell}/min$. Retention time of glycyrrhizic acid was about 23.96 min and linearity of calibration was $R^2$=0.9998. Contents of glycyrrhizic acid in Glycyrrhizae Radix extract (control) was $5.048\;{\pm}\;0.14$; Contents of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with Paecilomyces japonica (SDT) was $1.975\;{\pm}\;0.07$; Contents of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with Ganoderma lucidum (SYT) was $2.676 \;{\pm}\;0.07$; Contents of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with honey (SST) was $5.191\;{\pm}\;0.06$; Contents of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with Nuruk (SNT) was $5.305\;{\pm}\;0.34$, respectively. Contents of glycyrrhizic acid in SDT and SYT were decreased but that in SST and SNT was increased when compared to control.

• 한국한의학연구원논문집
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• 제15권2호
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• pp.119-124
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• 2009

The purpose of this study was investigation of quantitative analysis of marker substances in Paeonia lactiflora extracts by solid fermentation. High performance liquid chromatography (HPLC) for the determination of albiflorin and paeoniflorin in P. lactiflora extracts by solid fermentation, the separation method was performed on C18 column ($250\;mm\;{\times}\;4.6\;mm$, $5\;{\mu}m$, RS tech) using gradient solvent mixtures of water-acetonitrile with photodiode array detector (230nm). The flow rate was 1.0 ml/min. Retention time of albiflorin and paeoniflorin was about 28.88, 31.92 min and linearity of calibration was showed good result(r2 = 0.9998, 0.9996), respectively. Content of albiflorin was $0.090\;{\pm}\;0.03%$ in P. lactiflora extract(control), $0.102\;{\pm}\;0.00%$ in P. lactiflora extract fermented with Paecilomyces japonica, $0.056\;{\pm}\;0.01%$ in P. lactiflora extract fermented with Ganoderma lucidum, $0.093\;{\pm}\;0.00%$ in P. lactiflora extract fermented with honey and $0.046\;{\pm}\;0.00%$ in P. lactiflora extract fermented with Nuruk. Content of paeoniflorin was $4.506\;{\pm}\;0.13%$ in control, $2.599\;{\pm}\;0.04%$ in P. lactiflora extract fermented with Paecilomyces japonica, $1.222\;{\pm}\;0.03%$ in P. lactiflora extract fermented with Ganoderma lucidum, $2.750\;{\pm}\;0.05%$ in P. lactiflora extract fermented with honey and $0.847\;{\pm}\;0.00%$ in P. lactiflora extract fermented with Nuruk, respectively. Content of the marker substances did not increase in all fermentation experiment group.

• 한국통신학회논문지
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• 제29권1C호
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• pp.9-17
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• 2004

본 논문에서는 일종의 멀티코드 시스템인 Binary CDMA의 성능을 향상시키기 위해 상관도 값을 평활화하는 방법을 제안한다. DS-CDMA 방식과는 달리, Binary CDMA 에서는 멀티레벨 신호를 이진 클리핑하여 전송하므로 선형성이 떨어지는 전력증폭기를 사용해도 무방하다. 그러나, 전송신호가 이진 클리핑되는 과정에서 각 채널사이의 직교성이 감소하여 수신부에서의 채널별 상관도 값은 랜덤해지며, 가장 작은 상관도 값을 갖는 채널에 의해 시스템의 평균 BER이 결정된다. 본 연구에서는 수신부 상관도 값이 불균형한 분포를 갖지 않고, 전 채널에 대해 고르게 분포하게 하는 상관도 평활화 방법을 적용하여 시스템의 평균 BER을 개선하였다. 여러 종류의 확산코드를 이용하여 실험한 결과, BER은 낮아지고 가용 채널의 수는 증가하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.978-980
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• 1999

In this paper, DC degradation of ZnO varistor sintered in the atmospheres of nitrogen and oxygen was investigated. The content of $SiO_2$ containing 0.0, 0.2, 0.5 mol% respectively was addicted for the improvement of degradation property. ZnO varistor was fabricated in the special electrical furnace which had the vacuum system. The temperature and the voltage for the DC degradation test were $115{\pm}2^{\circ}C$, $0.85V_{1mA/cm^2}$. The time conditions for this test were 0, 2, 4, 8 hours and Current-voltage analysis is used to determine nonlinear coefficients($\alpha$). Frequency analysis are accomplished for the understanding of electrical properties as DC degradation test. In this experiment, We concluded that nonlinear coefficient decreased as the amount of $SiO_2$ addition increased, but degradation rate coefficient increased as the amount of $SiO_2$ addition increased. Also, degradation test with the analysis of equivalent circuit showed that the degradation phenomenon of ZnO varistor wasn't linearity.

• 한국약용작물학회지
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• 제19권6호
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• pp.446-455
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• 2011

Galgeun-tang (GGT) is a traditional medicinal formula that is widely prescribed to treat cold, asthma, and hives in Korea. Fermented herbal medicines can be made more effective than normal herbal medicines by increasing the absorption and bioavailability of the active compounds. In this study, we fermented Galgeun-tang to produce bioconversion constituents using Lactobacillus plantarum (GGT144), and found that four peaks were decreased, three peaks were increased and two new peaks appeared in the HPLC-DAD chromatogram. After HPLC-DAD-guided fractionation of the newly-appearing compounds (1 and 5) and the increased (6, 7, and 9) compounds, the structure of the compounds was determined using NMR and MS. Using this approach the compounds were identified to be pyrogallol (1), daidzein (5), liquiritigenin (6), cinnamyl alcohol (7), and formononetin (9), respectively. In addition, the decreased compounds were identified to be daidzin (2), liquiritin (3), ononin (4), and cinnam aldehyde (8) using HPLC-DAD analysis with standard compounds. The high performance liquid chromatography method was used to quantify the nine constituents in GGT and GGT144. All calibration curves of the standard compounds displayed excellent linearity with a $R^2$ > 0.9968.

• Current Research on Agriculture and Life Sciences
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• 제25권
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• pp.13-18
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• 2007

The aim of this research is to set improvement guidance a character analysis of woodland edge to cope with the ecological dysfunction of woodland which was caused by massive development project and thoughtless development in country areas. The summary of research result are as follows. 1) From the result of landscape ecology characteristic analysis of woodland in all seven research sites, to begin with, in proportion of appearance by vegetation layer and condition of composition, site 5 showed to be most satisfactory. 2) A width of woodland edge was revealed 7.5m as a minimum, 17.0m as a maximum, and 11.4m as a average and minimum edge was set as 10m according to integrated analysis on each example place. 3) As a result of flexibility analysis, site 1, 2 and 5 was shown high value 3, and it is thought that curve rather than linearity should be maintained in order to increase the ecological function. Also, a phenomenon of straight was prominent, and as a woodland edge, green network and buffering system showed to be somewhat unsatisfactory. 4) Based on the result of character analysis of landscape ecology, main guidelines for improvement of woodland edge were categorized into five in parallel structure and three in vertical structure respectively. The guidelines for improvement of woodland edge suggested by the research has a deep meaning in that it is used as a basic material to induce for controling more systematically or landscape-friendly the defamed forest problems caused by road construction, various development projects, and enlargement of agricultural lands.