선박에서 배출되는 환경오염물질 저감 및 연료 소비를 줄이기 위한 다양한 연구가 진행되고 있다. 이에 따라 기존의 전력망과 신재생에너지를 연계 시킬 수 있는 직류배전시스템의 한 부분인 전력변환시스템에 대한 연구가 활발히 이루어지고 있다. 현재 전력변환 장치로 주로 사용되고 있는 다이오드 정류기는 부하의 입력전류에 많은 저차고조파가 포함되어 공급전압의 왜곡을 초래하고 전체시스템 의 전력품질을 저하시킨다. 일정하지 않은 출력 전압파형은 발전기, 부하기기 등에 오작동 유발 및 인버터 단의 스위칭 소자에 영향을 미 치며 스위칭 손실을 증가 시킨다. 본 논문에서는 AFE(Active Front End) 방식 PWM(Pulse Width Modulation) 정류기의 직류출력, 입력 전원의 역률 및 총고조파왜형률(Total Harmonic Distortion)을 개선하기 위해서 PLL회로를 사용한 제어기를 설계하였고, 시뮬레이션 결과 직류 출력 전압 파형과 입력전원의 역률이 기존 보다 개선되었으며 총고조파왜형률 또한 IEEE Std514-2014 규정에 적합한 결과를 얻을 수 있었다.

본 연구는 식물공장에서 미나리 재배시 명/암주기와 암기시간 동안의 상대습도 조절이 미나리의 생육과 품질에 미치는 영향을 알아보고자 수행하였다. 정식 후 30일째에 수확하여 생육 및 품질을 비교하였을 때 상대습도 60/ 90%(명/암기) 처리가 60/60% 처리보다 지상부 생체중이 뚜렷이 증가하였다. 상대습도60/60% 처리에서 명기가 연장될수록 지상부 생체중이 증가하였지만 60/90% 처리에서는 16/8h 처리에서 지상부 생체중이 가장 높았으며, 20/ 4h, 22/2h 순이었다. 팁번의 발생은 상대습도 60/90%에서 는 명/암주기 16/8h로 처리했을 때 1.4%로 매우 낮았으나, 명기 시간이 연장된20/4h, 22/2h 처리에서 각각 15.5% 30.3%로 급격히 증가하였다. 상대습도 60/60%에서는 명/ 암주기 16/8h에서도 팁번의 발생이 15.5%로 높았으며 20/ 4h, 22/2h 처리에서는 25% 이상 높게 나왔다. 줄기의 경도는 상대습도 60/90%, 명/암주기 16/8h 처리에서 가장 낮았다. 잎의 무기성분은 명기시간이 연장될수록 감소하였지만Ca의 함량은 상대습도 60/60%, 명/암주기 22/2h 처리를 제외하고는 유의한 차이가 없었다.

To establish low-temperature process conditions, process-property correlation has been investigated for Ga-doped ZnO (GZO) thin films deposited by pulsed DC magnetron sputtering. Thickness of GZO films and deposition temperature were varied from 50 to 500 nm and from room temperature to 250 oC, respectively. Electrical properties of the GZO films initially improved with increase of temperature to 150 oC, but deteriorated subsequently with further increase of the temperature. At lower temperatures, the electrical properties improved with increasing thickness; however, at higher temperatures, increasing thickness resulted in deteriorated electrical properties. Such changes in electrical properties were correlated to the microstructural evolution, which is dependent on the deposition temperature and the film thickness. While the GZO films had c-axis preferred orientation due to preferred nucleation, structural disordering with increasing deposition temperature and film thickness promoted grain growth with a-axis orientation. Consequently, it was possible to obtain a good electrical property at relatively low deposition temperature with small thickness.

지황은 현삼과(Scrophulariaceae)에 속하는 다년생 초본식물 Rehmannia glutinosa(Gaertn.) DC.로 서 한의학에서는 뿌리를 지황(地黃)이라는 한약재로 이용하고 있다. 지황은 선지황(鮮地黃), 생지황(生 地黃), 숙지황(熟地黃) 등으로 널리 사용되고 있지만 종자파종에 의한 재배보다 종근을 이용한 영양번식 으로 재배하고 있다. 종근을 이용한 재배법은 뿌리 썩음병으로 인해 종근의 관리와 생산성이 높은 고품 질의 지황 생산이 어려운 실정이다. 본 연구에서는 형태적 특징과 유전자 분석을 통해 기원이 검증된 지황 기원식물을 이용하여 정확한 기원의 무균 배양묘와 종근 생산을 위한 최적 조건을 확립하고자 하 였다. 기내배양묘 생산에 필요한 최적의 생장율과 다개체 형성율, 그리고 뿌리 형성율 및 비대조건을 탐색한 결과, WPM 배지와 1.0mg/L의 IAA와 0.5mg/L의 IBA 옥신계 생장조절제가 첨가된 배지(WPM + IAA 1.0mg/L + IBA 0.5mg/L)에서 최적 생장율과 뿌리다개체 형성율을 나타내었으며, 0.1mg/L의 NAA가 첨가된 WPM 배지(WPM + NAA 0.1mg/L)에서 가장 많은 수의 뿌리가 형성되었고 비대율도 높 게 나타났다. 이러한 최적조건에서 생산한 기내식물체는 토양 순화 후 정식하였을 경우에도 높은 뿌리 형성율과 지속적인 비대 효과를 보였다. 이상의 결과는 지황의 무균 배양묘 생산과 배양묘기반 종근 생 산을 통해 지황 대량 생산에 필요한 배양묘와 종근 생산에 유용하게 활용될 수 있을 것으로 판단되며, 고품질 지황 생산량에기여할 것으로 사료된다.

Ti films were deposited on glass substrates under various preparation conditions in a chamber of two-facing-target type dc sputtering; after deposition, the electric resistivity values were measured using a conventional four-probe method. Crystallographic orientations and microstructures, including the texture and columnar structure, were also investigated for the Ti films. The morphological features, including the columnar structures and surface roughness, are well explained on the basis of Thornton’s zone model. The electric resistivity and the thermal coefficient of the resistivity vary with the sputtering gas pressure. The minimum value of resistivity was around 0.4 Pa for both the 0.5 μm and 3.0 μm thick films; the apparent tendencies are almost the same for the two films, with a small difference in resistivity because of the different film thicknesses. The films deposited at high gas pressures show higher resistivities. The maximum of TCR is also around 0.4 Pa, which is the same as that obtained from the relationship between the resistivity and the gas pressure. The lattice spacing also decreases with increasing sputtering gas pressure for both the 0.5 μm and 3.0 μm thick films. Because they are strongly related to the sputtering gas pressures for Ti films that have a crystallographic anisotropy that is different from cubic symmetry, these changes are well explained on the basis of the film microstructures. It is shown that resistivity measurement can serve as a promising monitor for microstructures in sputtered Ti films.

This study was to investigate whether the bioactivity of L. plantarum L67 can be enhanced by treatment with Zanthoxylum piperitum DC (ZPDC) glycoprotein or compounds of similar molecular weights (24 kDa). When L. plantarum L67 was treated with ZPDC glycoprotein of various concentrations, the intensities of a few SDS-PAGE bands were slightly changed. The amount of a 23-kDa protein was increased upon treatment with increasing concentrations of ZPDC glycoprotein. The activities of antioxidant enzymes (SOD, GPx, and CAT), growth rate, and β-galactosidase activity were more increased at treatment with ZPDC glycoprotein than at treatment of L. plantarum L67 only, whereas the ATPase activity was decreased. Interestingly, it did not affect scavenging activity for the DPPH. The founding result suggest that, one of beneficial strategies for increase the bioactivity of L. plantarum L67 might be to take ZPDC.

In this study, the lower power consumption FET-DC contactor for golf cart and low speed electric vehicle has been designed and developed. Also, the author carrying out many measurements and tests such as an electric power consumption, current consumption, calorific value, size, volume and weight of the DC contactor for the various cases. As a result, the author found that a prototype of the lower power consumption FET-DC contactor can not only reduce calorific value, size, volume and weight but also improve an electric power and current consumption.

The microstructures and cyclic voltammograms of Al-Si/C nano-composites were investigated as the anode of lithium ion batteries. Al-Si nanoparticles were prepared by the arc-discharge method. Al-Si/C nanoparticles were obtained by coated Al-Si nanoparticles with the precursor of glucose (C6H12O6) as carbon source. It was indicated that the post carbon coating treatment can reduce Al2O3 film on Al-Si particles, and new phase Al4C3 formed in the process can activate the inactivated materials of electrode in a certain extent.

Antioxidant activity of dropwort fermented extract (DFE) was measured according to fermentation period, and liverprotective effects were examined using Sprague-Dawley rats. Total polyphenol and flavonoid contents as well as DPPH andABTS radical scavenging activities increased up to 60~80 days and then decreased slightly. Proper fermentation time forDFE was more than 60 days and less than 80 days. Administration of alcohol to rats for 10 days at 10mL/kg/day raisedserum AST, ALT, total cholesterol, and triglyceride (TG) levels, which were then lowered by DFE and sugar liquid with thesame soluble solids. While sugar liquid increased the blood lipid profile, especially TG levels, DFE had no effect due to itsantioxidant activity. When TBARS content of the DFE group in liver tissue significantly decreased in a concentration-dependent manner compared to that of the ALH group (p<0.05). Liver damage was recovered by DFE treatment and wasconfirmed by hamatoxylin-eosin staining. These results suggest that DFE has a protective effect against alcohol-inducedhepatotoxicity in SD rats.

기존의 기술 진화 경로 연구는 주로 거시적 동향 분석 수준에서 이루어져 왔으 며 포괄적인 기술정책 방향 수립에는 시사점이 있었으나, 기업 기술 및 특허전략에는 활용 가치가 낮았다. 2000년대부터 논문 및 특허 등의 데이터를 활용해 미시적인 기술의 진화 경 로를 분석하고, 기업 기술전략에 적용하려는 연구가 증가하고 있다. 그러나 대부분 과거 진 화 경로의 서술에 그치고 있으며 기술의 진화 또는 파생-융합 등의 변화에 대한 분석은 전문 가의 정성적 판단에 상당부분 의존하고 있다. 본 연구에서는 특허 인용 네트워크를 구축해 미시적 기술의 진화 경로를 도출하고, 기술의 진화와 파생을 동적 기술트리를 통해 분석하는 방법론을 제시한다. 동적 기술트리 분석은 기술의 핵심요소를 체계화하고, 신기술 요소의 신 규성과 확장성을 평가해 차세대 기술진화와 파생에 대한 정량적 판단을 가능하게 한다. 이를 통해 차세대 신기술과 파생기술에 대하여 파악, 평가, 비교하고 나아가 예측의 토대를 구축 한 것이 본 연구의 의의이다. 본 연구의 결과는 기술 및 특허전략과 포트폴리오 구축의 신뢰성을 높일 수 있는 좋은 도구가 될 것이다. 본 연구에서 제안한 방법론을 이용하여 최근 전력 산업에서 기존 교류 송전의 대안으로 주목을 받고 있는 초고압 직류송전 시스템 기술을 대상 으로 실증분석을 수행하였다.

The aim of this work was to investigate the effects of electrodeposition conditions on the microstructural characteristics of copper thin films. The microstructure of electroplated Cu films was found to be highly dependent on electrodeposition conditions such as system current and current density, as well as the bath solution itself. The current density significantly changed the preferred orientation of electroplated Cu films in a DC system, while the solution itself had very significant effects on microstructural characteristics in a pulse-reverse pulse current system. In the DC system, polarization at high current above 30 mA, changed the preferred orientation of Cu films from (220) to (111). However, Cu films showed (220) preferred orientation for all ranges of current density in the pulse-reverse pulse current system. The grain size decreased with increasing current density in the DC system while it remained relatively constant in the pulse-reverse pulse current system. The sheet resistance increased with increasing current density in the DC system due to the decreased grain size.

콘크리트 도로 하부의 이상대를 찾기 위해 전기비저항 탐사를 수행하였다. 콘크리트의 접지저항효과를 줄이기 위해 전기전도성이 좋은 매질과 평판 전극을 이용하였다. 전기비저항 탐사 결과를 분석하고 같은 장소에서 수행한 지하투과레이더 탐사, 충격응답기법, 다중채널 표면파 탐사 결과와 비교하였다. 전기비저항 탐사 결과는 함몰과 포장 구간에서 높은 비저항 분포를 보였으며, 지하투과레이더 탐사 결과는 보강으로 인한 형태를 보였다. 또한 충격응답기법과 전기비저항 탐사 결과의 비교를 통하여 보강 구간에서의 높은 동적강성도가 높은 비저항 분포의 원인임을 확인하였다. 동일한 장소에서 수행한 전기비저항 탐사와 다중채널 표면파 탐사 결과를 공동 크리깅한 결과, 지구통계학적 복합 해석이 각 지구물리 탐사결과에 대한 개별적인 분석보다 더 명확하게 이상대를 확인 할 수 있었다. 이 연구는 지구물리 탐사에 기초한 의사결정 과정에서 지구통계학을 이용한 복합 해석 결과의 활용 가능성을 제시한다.

The paper describes variable circuits technique the enable of differential circuit of charge pump. It is able to pump an input voltage of 2V to measure several output voltage through several clock signal with each pumping capacitor of 1 pF and smoothing capacitor of 1 pF at the output. From the simulation result, it is evident that charge pump circuits offer verity high voltage pumping gain. The circuits which are implemented in this paper is simulated with LT SPICE tool of computer.

The paper describes variable circuits technique the enable of differential circuit of charge pump. It is able to pump an input voltage of 2V to measure several output voltage through several clock signal with each pumping capacitor of 1 pF and smoothing capacitor of 1 pF at the output. From the simulation result, it is evident that charge pump circuits offer verity high voltage pumping gain. The circuits which are implemented in this paper is simulated with LT SPICE tool of computer.

Three rice planthoppers, the brown planthopper (Nilaparvata lugens), the white back planthopper (Sogatella furcifera), and the small brown planthopper (Laodelphax striatellus) and the green rice leafhopper (Nephotettix cincticeps) are major homopteran sap-sucking rice pests in Korea. These insect pests commonly have highly modified mouthparts, the stylet bundle, for piercing and sucking. Two pairs of mandibular and maxillary stylets consist of the stylet bundle by interlocking each stylet, which forms the two canals, larger one for food canal and smaller one for salivary canal. Destructive damages result from direct feeding effects (hopperburing) with heavy infestation and/or transmitting virus diseases (Rice stripe virus and Rice black-streaked dwarf virus by L. striatellus and Rice dwarf virus by N. cincticeps). Damage level is closely related to the feeding behavior of sap-sucking insects, so generally honeydew excretion amount on the resistant rice variety is smaller than that on the susceptible. Therefore, the method to measure the honeydew excretion amount has been primarily used as an indirect way to compare the feeding amount between the susceptible and the resistant. On the other hand, the electrical penetration graph (EPG) technique was firstly developed by McLean and Kinsey (1964) to measure voltage changes during piercing and sucking of insect on the plant. Since specific voltage waveforms were identified and it was known that each waveform is commonly related to salivary and feeding behavior of insect stylets in the plant tissue, EPG technique has been used to real-timely and quantitatively measure feeding behavior of piercing and sucking insects on susceptible and resistant rice variety. However, identifying each different waveform distinctly and understanding biological function of each waveform are certainly necessary to analyze feeding behavior in the plant tissue such as phloem sap ingestion. In this study, the stylet penetration behavior of N. lugens, S. furcifera, L. striatellus, and N. cincticeps on rice plants (Oryza sativa) was evaluated through the use of a direct current based electrical penetration graph (DC-EPG). To accomplish this, we classified the EPG waveforms of planthopper group into seven different patterns, np, N1, N2, N3, N4-a, N4-b, and N5, according to their shapes, voltage amplitudes, voltage levels, and frequencies. The N4-b pattern was always preceded by N3 and N4-a, in that order. Continuous honeydew excretion only occurred during the N4-b period, and the honeydew deposited on a filter paper containing ninhydrin reagent during the N4-b period were stained into violet. Based on the location of the stylets in the cross-section of rice tissue and honeydew excretion, the EPG waveforms for the stylet penetration behaviors of the three rice planthoppers were assigned to the following groups; np: non-penetration of stylets, N1: penetration initiation, N2: salivation and stylet movement, N3: an extracellular activity near the phloem region, N4-a: an intracellular activity in phloem region, N4-b: phloem sap ingestion, and N5: activity in the xylem region. Futhermore, we classified the EPG waveforms of the green rice leafhopper, N. cincticeps into seven different patterns, Nc1, Nc2, Nc3, Nc4, Nc5, Nc6, and Nc7 according to their shapes, voltage amplitudes, voltage levels, and frequencies. The Nc6 pattern was always preceded by Nc5 pattern. The Nc6 pattern of the leafhopper was carefully considered as a phloem sap feeding behavior based on regular honeydew excretion. On the other hand, the planthopper group and the leafhopper hardly showed the phloem sap feeding pattern on resistant rice varieties during an EPG-recording. In addition, the duration of the phloem sap feeding patterns was highly decreased on resistant rice varieties relative to susceptible ones. From these results, it is suggested that the phloem sap feeding related patterns are an important parameter to determine resistance of rice plant.

This study analyzes the resistance spot weldability of DP60 steels. To analyze the resistance spot weldability of DP60 steels, tensile strength test and macro-section test were conducted for the resistance spot welds. Acceptable welding conditions were determined as a function of the resistance spot welding process parameters such as electrode force, welding time, and welding current. The lower limit of the welding lobe was the minimum shear tension strength for 590MPa-grade steel while the upper limit was determined whether or not expulsion was detected.