• 한국표면공학회지
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• 제55권6호
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• pp.353-362
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• 2022

Recently, transmittance of photomasks for ultra-violet (UV) region is getting more important, as the light source wavelength of an exposure process is shortened due to the demand for technologies about high integration and miniaturization of devices. Meanwhile, such problems can occur as damages or the reduction of yield of photomask as electrostatic damage (ESD) occurs in the weak parts due to the accumulation of static electricity and the electric charge on chromium metal layers which are light shielding layers, caused by the repeated contacts and the peeling off between the photomask and the substrate during the exposure process. Accordingly, there have been studies to improve transmittance and antistatic performance through various functional coatings on the photomask surface. In the present study, we manufactured antireflection films of Nb₂O₅, | SiO₂ structure and antistatic films of ITO designed on 100 × 100 × 3 mmt sodalime glass by DC magnetron sputtering system so that photomask can maintain high transmittance at I-line (365 nm). ITO thin film deposited using In/Sn (10 wt.%) on sodalime glass was optimized to be 10 nm-thick, 3.0 × 103 𝛺/☐ sheet resistance, and about 80% transmittance, which was relatively low transmittance because of the absorption properties of ITO thin film. High average transmittance of 91.45% was obtained from a double side antireflection and antistatic thin films structure of Nb₂O₅ 64 nm | SiO₂ 41 nm | sodalime glass | ITO 10 nm | Nb₂O₅ 64 nm | SiO₂ 41 nm.

• The Plant Pathology Journal
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• 제39권1호
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• pp.39-51
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• 2023

Common bean (Phaseolus vulgaris L.) is one of the most important crops in human food production. The occurrence of diseases, such as white mold, caused by Sclerotinia sclerotiorum can limit the production of this legume. The use of Trichoderma has become an important strategy in the suppression of this disease. The aim of the present study was to evaluate the effect of volatile organic compounds (VOCs) emitted by Trichoderma azevedoi CEN1241 in five different growth periods on the severity of white mold in common bean. The in vitro assays were carried out in double-plate and split-plate, and the in vivo assays, through the exposure of the mycelia of S. sclerotiorum to the VOCs of T. azevedoi CEN1241 and subsequent inoculation in bean plants. Chemical analysis by gas chromatography coupled to mass spectrometry detected 37 VOCs produced by T. azevedoi CEN1241, covering six major chemical classes. The profile of VOCs produced by T. azevedoi CEN1241 varied according to colony age and was shown to be related to the ability of the biocontrol agent to suppress S. sclerotiorum. T. azevedoi CEN1241 VOCs reduced the size of S. sclerotiorum lesions on bean fragments in vitro and reduced disease severity in a greenhouse. This study demonstrated in a more applied way that the mechanism of antibiosis through the production of volatile compounds exerted by Trichoderma can complement other mechanisms, such as parasitism and competition, thus contributing to a better efficiency in the control of white mold in bean plants.

• Steel and Composite Structures
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• 제52권3호
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• pp.343-356
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• 2024

This paper presents an analytical solution for correctly predicting the Lateral-Torsional Buckling critical moment of simply supported castellated beams, the solution covers uniformly distributed loads combined with compressive loads. For this purpose, the castellated beam section with hexagonal-type perforation is treated as an arrangement of double "T" sections, composed of an upper T section and a lower T section. The castellated beam with regular openings is considered as a periodic repeating structure of unit cells. According to the kinematic model, the energy principle is applied in the context of geometric nonlinearity and the linear elastic behavior of materials. The differential equilibrium equations are established using Galerkin's method and the tangential stiffness matrix is calculated to determine the critical lateral torsional buckling loads. A Finite Element simulation using ABAQUS software is performed to verify the accuracy of the suggested analytical solution, each castellated beam is modelled with appropriate sizes meshes by thin shell elements S8R, the chosen element has 8 nodes and six degrees of freedom per node, including five integration points through the thickness, the Lanczos eigen-solver of ABAQUS was used to conduct elastic buckling analysis. It has been demonstrated that the proposed analytical solution results are in good agreement with those of the finite element method. A parametric study involving geometric and mechanical parameters is carried out, the intensity of the compressive load is also included. In comparison with the linear solution, it has been found that the linear stability underestimates the lateral buckling resistance. It has been confirmed that when high axial loads are applied, an impressive reduction in critical loads has been observed. It can be concluded that the obtained analytical solution is efficient and simple, and offers a rapid and direct method for estimating the lateral torsional buckling critical moment of simply supported castellated beams.

• 마이크로전자및패키징학회지
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• 제28권1호
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• pp.39-46
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• 2021

Cu 배선(interconnect) 적용을 위한 다층박막의 적층 구조에 따른 최적 계면접착에너지(interfacial adhesion energy, Gc) 평가방법을 도출하기 위해, Ta, Cu 및 tetraethyl orthosilicate(TEOS-SiO2) 박막 계면의 정량적 계면접착에너지를 double cantilever beam(DCB) 및 4-점 굽힘(4-point bending, 4-PB) 시험법을 통해 비교 평가하였다. 평가결과, Ta확산방지층이 적용된 시편(Cu/Ta, Cu/Ta/TEOS-SiO2)에서는 두 가지 평가방법 모두 반도체 전/후 공정에서 박리가 발생하지 않는 산업체 통용 기준인 5 J/㎡ 보다 높게 측정되었다. Ta/Cu 시편의 경우 DCB 시험에서만 5 J/㎡ 보다 낮게 측정되었다. 또한, DCB시험 보다 4-PB시험으로 측정된 Gc가 더 높았다. 이는 계면파괴역학 이론에 따라 이종재료의 계면균열 선단에서 위상각의 증가로 인한 계면 거칠기 및 소성변형에 의한 에너지 손실이 증가 하는것에 기인한다. 4-PB시험결과, Ta/Cu 및 Cu/Ta계면은 5 J/㎡ 이상의 높은 계면접착에너지를 보이므로, 계면접착에너지 관점에서는 Ta는 Cu배선의 확산방지층(diffusion barrier layer) 및 피복층(capping layer)으로 적용 가능할 것으로 생각된다. 또한, 배선 집적공정 및 소자의 사용환경에서 열팽창 계수 차이에 의한 열응력 및 화학적-기계적 연마 (chemical mechanical polishing)에 의한 박리는 전단응력이 포함된 혼합모드의 영향이 크므로 4-PB 시험으로 측정된 Gc와 연관성이 더 클 것으로 판단된다.

• 대한지리학회지
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• 제30권2호
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• pp.132-145
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• 1995

지금 우리나라가 지향하고 있는 '지방화를 통한 $\ulcorner$세계화$\lrcorner$ 발전전략'은 하향식 개 발패러다임과 상향식 개발패러다임의 통합이 전제되어야 한다. 본 연구는 기든스(A. Giddens)의 $\ulcorner$구조화이론(structuration theory)$\lrcorner$을 토대로 이들 상반된 양대 개발패러다임 을 통합하고 이에 입각해서 지방발전 개발전략을 논구하고자 한다. 통합적개발 패러다임이 란 세계자본주의체계의 확대, 심화 과정인 하향식 개발패러다임을 $\ulcorner$발전$\lrcorner$ 혹은 $\ulcorner$종속$\lrcorner$ 둘 중 하나인 것으로만 규정짓는 이원론적 인식에서 부터 그것을 $\ulcorner$구조화이론$\lrcorner$에 입각된 그대로 인식하는 것, 즉 그것을 세계자본주의 중심국가로서는 발전으로 보지만 주변국으로 서는 사안에 따라 종속으로 볼 수 있다는 일원론적 인식에로의 구조적 전환이다. 따라서 주 변국이 발전을 성취하기 위한 핵심적 과제는 먼저, 발전이란 단독.고립적 현상이 아니라 세계의 '체계 현상'이고 또 종속은 실제적 현실임이 $\ulcorner$구조의 이중성$\lrcorner$ 매카니즘의 학적 내 면화를 토대로 인식되어야 한다. 그리고 이러한 인식 위에서 휴머니즘에 입각된 생동감 넘 치는 정치가 이루어지는 정의로운 지역사회를 만들어 경제를 그러한 국가 혹은 지역사회의 정치적 권위 '밑에' 두고 한편으로 지역민의 $\ulcorner$자력(empowerment)$\lrcorner$과 $\ulcorner$능력 (capacitation)$\lrcorner$을 증강시켜야 한다. 지방화시대의 개발전략에는 이러한 통합적 패러다임의 실천적 과제가 효율적으로 달성될 수 있는 구체적인 지리공간정책이 포함되어야 한다.

• Smart Structures and Systems
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• 제3권3호
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• pp.281-298
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• 2007

The load carrying capacity of a bridge needs to be properly assessed to operate the bridge safely and maintain it efficiently. For the evaluation of load carrying capacity considering the current state of a bridge, static and quasi-static loading tests with weight-controlled heavy trucks have been conventionally utilized. In these tests, the deflection (or strain) of the structural members loaded by the controlled vehicles are measured and analyzed. Using the measured data, deflection (or strain) correction factor and impact correction factor are calculated. These correction factors are used in the enhancement of the load carrying capacity of a bridge, reflecting the real state of a bridge. However, full or partial control of the traffic during the tests and difficulties during the installment of displacement transducers or strain gauges may cause not only inconvenience to the traffic but also the increase of the logistics cost and time. To overcome these difficulties, an alternative method is proposed using an excited response part of full measured ambient acceleration data by ordinary traffic on a bridge without traffic control. Based on the modal properties extracted from the ambient vibration data, the initial finite element (FE) model of a bridge can be updated to represent the current real state of a bridge. Using the updated FE model, the deflection of a bridge akin to the real value can be easily obtained without measuring the real deflection. Impact factors are obtained from pseudo-deflection, which is obtained by double-integration of the acceleration data with removal of the linear components on the acceleration data. For validation, a series of tests were carried out on a steel plategirder bridge of an expressway in Korea in four different seasons, and the evaluated load carrying capacities of the bridge by the proposed method are compared with the result obtained by the conventional load test method.

• 한국응용곤충학회지
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• 제31권3호
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• pp.205-240
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• 1992

In reality, it is a green revolution of the entire agricultural matrix in Korea that integrated pest control plays an important role in the possible breakthrough in rice self-sufficiency. In paddy agroecosystem as man-modified environment, rice is newly established every year by transplantation under diverse water regimes which affect a microclimate. Standing water benefits rice by regulating the microclimate, but it favors the multiplication of certain pets through the amelioration of the microclimate. Further, the introduction of high yielding varieties with the changing of cultural practices results in changing occurrence pattern of certain pests. In general, japonica type varieties lack genes resistant to most of the important pests and insect-borne virus diseases, whereas indica type possesses more genes conferring varietal resistance. Thus, this differences among indica type, form the background of different approaches to pest management. The changes in rice cultivation such as double cropping, growing high-yielding varieties requiring heavy fertilization, earlier transplanting, intensvie-spacing transplanting, and intensive pesticide use as a consequence of the adoption of improves rice production technology, have intensified the pest problems rather than reduced them. The cultivation of resistant varieties are highly effective to the pest, their long term stability is threathened because of the development of new biotypes which can detroy these varieties. So far, three biotypes of N. lugens are reported in Korea. Since each resistant variety is expected to maintain several years the sequential release of another new variety with a different gene at intervals is practised as a gene rotation program. Another approach, breeding multilines that have more than two genes for resistance in a variety are successfully demonstrated. The average annual rice losses during the last 15 years of 1977-’91 are 9.3% due to insect pests without chemical control undertaken, wehreas there is a average 2.4% despite farmers’insecticide application at the same period. In other words, the average annual losses are prvented by 6.9% when chemical control is properly employed. However, the continuous use of a same group of insecticides is followed by the development of pest resistance. Resistant development of C. suppressalis, L. striatellus and N. cincticeps is observed to organophosphorous insecticides by the mid-1960s, and to carbamates by the early 1970s in various parts of the country. Thus, it is apparent that a scheduled chemical control for rice production systems becomes uneconomical and that a reduction in energy input without impairing the rice yield, is necessarily improved through the implementation of integrated pest management systems. Nationwide pest forecasting system conducted by the government organization is a unique network of investigation for purpose of making pest control timely in terms of economic thresholds. A wise plant protection is expected to establish pest management systems in appropriate integration of resistant varieties, biological agents, cultural practices and other measures in harmony with minimizing use of chemical applications as a last weapon relying on economic thresholds.

• 한국전자파학회논문지
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• 제21권9호
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• pp.979-986
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• 2010

본 논문에서는 합성 개구 레이더(SAR: Synthetic Aperture Radar) 영상에서 SAR 보정용으로 설치된 삼각 전파 반사기(TCR: Trihedral Corner Reflector)의 레이더 단면적(RCS: Radar Cross Section)을 정확하게 추출하는 방법을 연구하고, SAR 보정 정확도를 분석한다. TCR의 이론적 RCS를 geometrical optics(GO)와 physical optics(PO) 방법을 이용하여 이론적으로 계산하고, 측정값과 비교하여 정확성을 검증한다. 이때에 단일 반사는 PO로, 이중 반사는 GO-PO로, 삼중 반사는 GO-GO-PO로 계산하고, 모서리 영향은 PTD(Physical Theory of Diffraction) 방법을 이용하여 이론적 RCS를 정확하게 계산한다. 크기가 다른 5개의 TCR를 설치하고, TerraSAR-X로 그 지역에 대한 위성 영상을 취득하여 그 TCR들에 대한 RCS를 추출한다. 레이더 IRF(Impulse Response Function) 특성에 의해 분산된 전력(power spill)을 모두 구하기 위해 정사각형 모양의 면적(window)을 설정하여 정확하게 RCS를 추출하고, 이 RCS를 이론적 RCS와 비교한다. 면적의 크기와 배경의 레이더 후방 산란 계수 크기에 따른 TCR의 RCS 오차를 계산하며, 최소 적분 면적과 최대 배경 산란계수 크기를 제안한다.

• 한국균학회지
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• 제26권4호통권87호
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• pp.450-457
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• 1998

Cryparin은 Cryphonectria parasitica의 세포벽에 풍부한 소수성 단백질에 속한다. cryparin은 비록 하나의 유전자에 의해 발현되지만 액체배양 후 48시간이 지나면 발현된 전체 유전자중에서 22%를 차지할 정도의 높은 발현 양상을 나타낸다. 또한 cryparin은 RNA mycovirus인 Cryphonectria hypovirus 1의 감염에 의해 발현이 현저히 억제되는 유전자로 알려졌다. 이미 지난 실험(Kim et al., 1999)에서 상동염색체간의 재조합을 이용하여 cryparin 유전자를 항생제 hygromycin B 저항성 유전자로 치환한 치환체를 제조하였다. 발현율이 매우 높으면서도 virus에 의해 밀접하게 영향받는 cryparin 유전자의 promoter 분석을 위하여서는 대상이 되는 유전자 치환을 위한 vector만을 포함하며, 분석에 이용될 여러 유전자 운반체들이 어느 한곳에만 삽입되도록 하는 성질을 가진 균주의 개발이 필요하다. 그러나 지난번 실험의 결과 얻어진 cryparin 치환체는 치환용 vector외에도 무작위로 삽입된 vector가 존재하고 나아가 새로운 vector들이 어느 한곳에만 삽입되도록 하는 성질을 갖지 못하였다. 따라서 본 실험에서는 cryparin 유전자 치환체와 영양요구성 돌연변이체인 균주간의 교잡을 이용하여 분석 대상이 되는 유전자의 치환에 이용된 vector만을 포함하며, 분석에 이용될 여러 유전자 운반체들이 genome내의 어느 한곳에만 삽입되도록 하는 성질을 가진 균주를 제조하였다.

• KSBB Journal
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• 제11권1호
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• pp.8-14
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• 1996

Bacillus subtilis를 재조합이종 단백질 생산에 응 용하고 그 발현효율의 향상을 위하여, aprE 프로모 터를 모델계로서 이에 작용하는 전이상태 조절유전 자 변이와 포자형성변이의 영향을 살펴보았다. 사용 된 균주는 두 개의 프로테아제가 제거된 DB104이며, 조절인자 변이주는 $degU^h$와 hpr을 각각 활성인자와 억제인자로 선택하였고, 이중변이주는 DB104 ($\DeltaspoIIG(Pm) degU^h his^+$) 및 DB104($\DeltaspoIIG(Pm) \Deltahpr(Em)$) 를 제조하였다. 이에 목적유전 자연 aprE유전자를 재조합하여 변이에 의한 과발현 양상을 확인하였다. degUh 및 hpr 조절변이주는 야 생주와 비교하여 각각 약 7배 빛 약 2배의 발현효율 향상을 보여주었다. 이들 전이상태 조절유전자 변이 는 모두 목적유전자 복제 수의 증가에 따라 발현효 율의 감소를 나타내어 증폭된 목적유전자에 대한 조 절유전자의 희석효과(gene dosage effect)를 확인할 수 있었다. 이중변이주 DB104($\DeltaspoIIG(Pm) degU^h his^+$)::pMK101 및 DB104($\DeltaspoIIG(Pm) \Deltahpr(Em)$)::pMK101에서의 aprE 발현은 각각 약 10배 빛 3배의 발현증가를 가져와 aprE 발현에 대한 포자변이주 및 전이상태 조절유전자의 독립적인 부가효과를 확인하였다.