• Membrane and Water Treatment
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• 제10권1호
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• pp.45-55
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• 2019

Climate change has significantly affected the rainfall characteristics which can influence the pollutant build-up and wash-off patterns from the catchment. Therefore, this study explored the influence of varying rainfall characteristics on urban and agricultural runoff pollutant export using statistical approaches. For this purpose, Mann-Kendall and Pettitt's test were applied to detect the trend and breakpoint in rainfall characteristics time series. In addition, double mass curve and correlation analysis were used to drive the relationship between rainfall-runoff and pollutant exports from both catchments. The results indicate a significant decreased in total rainfall and average rainfall intensity, while a significant increased trend for antecedents dry days and total storm duration over the study periods. The breakpoint was determined to be 2013 which shows remarkable trend shifts for total rainfall, average rainfall intensity and antecedents dry days except total duration. Double mass curve exhibited a straight line with significant rainfall-runoff relationship indicates a climate change effect on both sites. Overall, higher pollutant exports were observed at both sites during the baseline period as compared to change periods. In agricultural site, most of the pollutants exhibited significant (p< 0.05) association with total rainfall, average rainfall intensity and total storm duration. In contrast, pollutants from urban site significantly correlated with antecedent dry days and average rainfall intensity. Thus, total rainfall, average rainfall intensity and total duration were the significant factors for the agricultural catchment while, antecedents dry days and average rainfall intensity were key factors in build-up and wash-off from the urban catchment.

• 융합경영연구
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• 제8권4호
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• pp.1-12
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• 2020

Purpose- The purpose of this study is to increase the effect of public technology transfer through government R&D support to secure the competitiveness of public technology startups. The government's R&D budget in 2019 is over 20 trillion won, and there is a legitimate need to increase the performance of technology startups through such R&D results. Research design, data, and methodology- In this paper, we comprehensively analyzed the current status of public research institutes and R&D support projects suitable for founders and analyzed and presented cases of follow-up research conducted by the Institute of Science and Technology Jobs to analyze actual performance cases of R&D support institutes. Results- In this conclusion, a developmental model of public technology entrepreneurship was proposed to increase the performance of public technology commercialization with the scalability of research institutions. In order to create a public technology information system between consumers and suppliers, a Steinweiss-type technology commercialization model for public technology commercialization, and a job-creating enterprise-type linkage R&D support business model were presented to create the results of R&D support organizations. Conclusions- Through the results of this study, it is meaningful to analyze the performance cases of technology commercialization of R&D support institutions, which have not been studied so far, to build competitiveness of research institutions and to present a growth model for the spread of technology startups. This study has implications in terms of suggesting a way to build competitiveness in technology commercialization between market demanders and suppliers by linking existing public technology startups, which deviated from the simple commercialization support system, with job creation by expanding the R&D support system.

• 한국정밀공학회지
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• 제17권9호
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• pp.189-195
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• 2000

RP techniques have their unique characteristics according to the working principles : star-stepped surface of parts due to layer-by-layer stacking low build speed caused by line-by-line solidification to fish one layer and post processing to improve surface finish etc The objective of this study is to propose a new RP technique Variable Deposition Mnanufacturing (VDM) which can make up for the disadvantages of the existing RP techniques and to develop an apparatus to implement the technique. The proposed process can greatly reduce the build time and improve the surface finish of parts generated. Experiments are carried out to obtain the range of temperature of molten material to maintain its fluidity and to investigate the effect of gas cooling on the preservation of the slopes. Some simple shapes such as a line-shape an S-shape and a circle-shape are fabricated from Ethylene Vinyl Acetatecopolymer(EVA) In order to examine the applicability of VDM to more general shapes a tensile specimen and a yo-yo shape were manufactured by the proposed RP method using EVA material as a trial approach. The current basic study shows a high potential of practical use of the proposed VDM process to prototyping of a general three-dimensional shape.

• 한국건설관리학회논문집
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• 제13권3호
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• pp.14-24
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• 2012

최근 세계 건설시장에서의 발주방식은 빠른 속도로 변화하고 있으며, 이에 대한 건설 사업도 대형화 및 고난이도 공사가 증가하고 있다. 이러한 사업의 많은 부분이 설계시공일괄방식 사업으로 발주 되고 있으며, 공사금액기준으로 2009년 국내 조달청 발주공사의 약 40%를 일괄입찰방식(Design-Build)으로 발주를 하고 있다. 반면 설계시공일괄방식 사업의 증가로 그 중요성은 강조되지만, 사업수행자의 사업비용 관리차원에서 기대이상의 성과를 얻지 못하고 있는 실정이다. 그 이유는 사업방식의 특성상, 기본설계 이후 사업 수행계약이 체결되며, 관련 신기술 및 공법 적용에 대한 발주 검토 미흡과 설계과정에서의 불충분한 협의 등으로 사업비용(Cost) 증가에 대한 리스크가 상존하기 때문이다. 이를 해결하기 위해 사업수행 과정에서 사업비용의 증가 원인에 대한 요인을 찾고, 전체 사업 업무단계(Business Process)에서 리스크요인(Risk Factor)에 대한 우선순위 선정과 긴밀한 관리가 필요하다. 따라서 본 연구는 설계시공일괄방식 사업의 특성과 관련한 문제점을 근거로 사업비용에 대한 업무단계별 중요도를 분석하고, 사업수행자 측면의 업무단계별 사업비용 증가에 대한 리스크요인을 도출하여, 그에 대한 영향도(Impact assessment)를 FMEA(Failure Mode and Effect Analysis)기법을 통해 평가하였다.

• 한국조경학회지
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• 제31권2호
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• pp.48-57
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• 2003

The objective of this study is to review and verify whether the functions and effect of roadside trees generally hewn in theory are actually realized in urban roads and how well they are performed if the function and effect are realized. The study was conducted with a focus on 3 functions and effects including roadside tree's urban landscape improvement function (green area visibility ratio), effect of introducing green area within a city, and urban green network building function. The major study results are as follows: First, the average green area visibility ratio of 41 study areas is currently about 25.90%. The green area visibility ratio of commercial area within downtown was lowest among 5 road types. It showed that it is possible to raise the average green area visibility ratio up to 32.49% through roadside tree management and additional plantation. Second, in a section between Paldal Mountain and Suwon City Hall where there is no forest fragments and parks at all, a green area of 4,826 roadside trees represented 2.4% of total area and served as the only linear green area. Third, an analysis of 15 cities in Kyonggi province showed that urban forests are concentrated in outskirts. The suey showed that because forest fragments and parks exist in a form of points in urban areas, roadside trees are the only green areas that link each other and build a network.

• 대한방사선기술학회지:방사선기술과학
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• 제19권1호
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• pp.81-87
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• 1996

When high energy photon beam is incident upon an air cavity interface the effect of ionization build-up observed. This phenomenon is resulting from the surface layers of the lesions are significant deficiency of electrons reaching the layers because of the replacement of solid scattering material by the air cavity, that is lack of electronic equilibrium. Measurement have been made in an acrylic phantom with a parallel plate chamber and high energy Photon beams, CO-60, 4MV, 6MV and 10MV X-rays have been investigated. The result of our study show that a significant effect was measured and was determined to be very dependent on field size, air cavity dimension and photon energy. The reductions were much larger for 10MV beam, underdosage at the interface was 12, 12.2, 16.9 and 20.6% for the CO-60, 4 MV, 6MV and 10MV, respectively. It was found that this non-equilibrium effect at the interface is more severe for the higher energy beams than that of lower energy beams and the larger cavity dimensions it is, the larger beam reductions we have. This problem is of clinical concern when lesions such as carcinoma beyond air cavities are irradiated, such as larynx, glottic and the patients with maxillectomy and ethmoidectomy and so forth.

• 한국콘텐츠학회논문지
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• 제11권4호
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• pp.347-360
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• 2011

본 연구에서는 서비스품질과 종업원신뢰, 점포신뢰 및 점포충성도 간의 경로관계를 확인하고, 서비스품질과 종업원신뢰 및 점포신뢰 간의 관계에서 서비스기업과 고객 간의 관계기간의 조절효과를 확인하였다. 본 연구는 국내 주요은행에서 서비스경험을 가진 소비자를 대상으로 자료를 수집하였으며, Amos 18.0 통계패키지를 이용한 구조방정식 모형분석으로 연구가설을 검증하였다. 연구결과는 다음과 같다. 첫째, 공감성 서비스품질 요인과 종업원신뢰 간의 관계 그리고 확신성 서비스품질요인과 점포신뢰 간의 관계에서 관계기간의 조절효과를 확인하였다. 둘째, 서비스품질은 구성차원에 따라 종업원신뢰와 점포신뢰에 영향력의 차이를 보였지만, 종업원신뢰는 점포신뢰에 영향을 미침으로써 점포충성도가 형성되었다. 결론적으로 관계가 형성된 소비자에게 서비스종업원에 대한 신뢰를 높이기 위해서는 공감성을 형성하여야 하고, 점포에 대한 신뢰를 높이기 위해서는 확신성을 제공하여야 하며, 종업원에 대한 신뢰를 형성함으로써 점포에 대한 신뢰와 충성도를 구축할 수 있음을 확인하였다.

• Restorative Dentistry and Endodontics
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• 제37권3호
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• pp.155-159
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• 2012

Objectives: To investigate the effect of dentin moisture degree and air-drying time on dentin-bond strength of two different one-step self-etching adhesive systems. Materials and Methods: Twenty-four human third molars were used for microtensile bond strength testing of G-Bond and Clearfil $S^3$ Bond. The dentin surface was either blot-dried or air-dried before applying these adhesive agents. After application of the adhesive agent, three different air drying times were evaluated: 1, 5, and 10 sec. Composite resin was build up to 4 mm thickness and light cured for 40 sec with 2 separate layers. Then the tooth was sectioned and trimmed to measure the microtensile bond strength using a universal testing machine. The measured bond strengths were analyzed with three-way ANOVA and regression analysis was done (p = 0.05). Results: All three factors, materials, dentin wetness and air drying time, showed significant effect on the microtensile bond strength. Clearfil $S^3$ Bond, dry dentin surface and 10 sec air drying time showed higher bond strength. Conclusions: Within the limitation of this experiment, air drying time after the application of the one-step self-etching adhesive agent was the most significant factor affecting the bond strength, followed by the material difference and dentin moisture before applying the adhesive agent.

• 한국재료학회지
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• 제19권11호
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• pp.625-630
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• 2009

Embedding of active devices in a printed circuit board has increasingly been adopted as a future electronic technology due to its promotion of high density, high speed and high performance. One responsible technology is to embedded active device into a dielectric substrate with a build-up process, for example a chipin-substrate (CiS) structure. In this study, desmear treatment was performed before Cu metallization on an FR-4 surface in order to improve interfacial adhesion between electroless-plated Cu and FR-4 substrate in Cu via structures in CiS systems. Surface analyses using atomic force microscopy and x-ray photoemission spectroscopy were systematically performed to understand the fundamental adhesion mechanism; results were correlated with peel strength measured by a 90o peel test. Interfacial bonding mechanism between electrolessplated Cu and FR-4 substrate seems to be dominated by a chemical bonding effect resulting from the selective activation of chemical bonding between carbon and oxygen through a rearrangement of C-C bonding rather than from a mechanical interlocking effect. In fact, desmear wet treatment could result in extensive degradation of FR-4 cohesive strength when compared to dry surface-treated Cu/FR-4 structures.

• 환경생물
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• 제22권4호
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• pp.494-500
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• 2004

In order to investigate the effect on morphology of Rhizopus oryzae and production of lactic acid, various interface materials were used. Morphology of fungal showed sheet and flock when resin was added. The production of lactic acid was increased dramatically when interface materials were added. Furthermore, the effect of resin was more significant than that of others. It was assumed that interface materials could absorb substrate and microorganism together, so microorganism was not inhibited by substrate. The effect of static electric field on the interface culture was studied. When the exerting potential was 6.78 voltage, the biomass y was obviously higher than that of zero voltage. A simulated gas-solid interface system was developed to study the growth and two phases model for the growth of Rhizopus oryzae was build up that depended on the symmetric branching theory. An important parameter F was researched. The results indicated that the value of F had obvious difference at exponential and deceleration period, respectively.