• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.5-8
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• 2006

In this study, various fundamental experiments including durability and time-dependent deformation are performed to compile a database for a utilization of high-strength concrete for PSC bridges. In the mix design, concrete strength at early age when prestressing forces are introduced to the PSC member and slumpflow suitable for pumping of concrete are considered to make a concrete fit for PSC bridges. The main parameters investigated are the kinds and replacement ratios of mineral admixtures and low-heat cement. Experimental tests on durability include penetration of chloride ions, freezing-thawing, combined deterioration, and simple adiabatic temperature rise test. In addition, time-dependent deformation such as creep, drying and autogenous shrinkage, which is particularly important factor in the design and construction of PSC bridges, is tested and analyzed.

• 한국건축시공학회지
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• 제13권1호
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• pp.48-57
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• 2013

To consider the practicality and economic feasibility of developing reactive powder concrete (RPC), the strength and microstructure properties of RPC using ternary pozzolanic materials (silica fume, blast furnace slag, fly ash) were investigated in this study. Through the investigation, it was found that the compressive strength of RPC using ternary pozzolanic materials was increased significantly compared to that of the original RPC containing silica fume only. A considerable improvement in the flexural strength of RPC using ternary pozzolanic materials was found, and then the utilization of a structural member subjected to bending was expected. The X-ray diffractometer (XRD) analysis and Scanning Electronic Microscope (SEM) revealed that the microstructure of RPC was denser using the ternary pozzolanic materials than the original RPC.

• Asia pacific journal of information systems
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• 제10권2호
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• pp.97-123
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• 2000

This paper proposes a model for assessing enterprise network maturity. We define maturity in terms of the institutional and member support for the network(organizational maturity) and its technical sophistication(technological maturity), and examine their relationships. We build several hypotheses about the relationships between the maturity types and between the maturity of the network and various organizational factors including industry, size, and performance of the enterprise. We test the hypotheses using data collected from a questionnaire survey with Korean firms. The results show that there is a positive correlation between organizational and technological maturity. It is also found that investment in the network infrastructure has a positive influence on the organizational efficiency. However, it is found that industry type does not affect network utilization, but size does, suggesting that large firms utilize network infrastructure more than small ones do. We also identify various relationships among performance, satisfaction level and the maturity of the enterprise networks. Finally, we provide an overview on the current technological state of the Korean enterprise networks.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.281-284
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• 2004

The most important reason of using of ultra high strength concrete in super tall building is that ultra high strength concrete can reduce the section of members and control side sway effectively. However, the practical utilization of ultra high strength concrete is dependent not only on the production techniques, but also the overall preparation including proper code provisions, construction technique. The purpose of this study is to evaluate of mechanical properties of UHSC, such as modulus of elasticity, stress-strain behavior, modulus of rupture and tensile splitting strength. It is similar to normal or high strength concrete but necessary to discern the difference between normal or high strength concrete and ultra high strength concrete and modify existed equations. And in this study another important factor is to discern the difference according to member size, curing method in ultra high strength concrete experimentally.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.531-534
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• 2006

The first RDF production plant in Korea is going to start commercial operation at Won-Ju city in October this year, where municipal solid waste is treated and converted to RBF. Korean government is preparing the quality standard of RDF and starting a new waste policy of RDF promotion instead of general waste treatment technologies such as incineration or landfill. In Europe the EU member states have decided the united quality standard of RDF to increase the amount of new & renewable energy through the promotion of RDF utilization. New quality standard of RDF and trade market of RDF in Europe is introduced in this paper.

• 한국항공운항학회지
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• 제31권4호
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• pp.1-6
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• 2023

EBT has designed and implemented a training program that relies on evidence from events such as Flight Operation Quality Assurance (FOQA), accidents, and incidents specific to each airline. The goal is to enhance the overall skills of the flight crew. This involves assessing the capabilities of individual crew members and, based on the findings, providing additional training to address any shortcomings. To create a training program aligned with the objectives of EBT, this study focused on analyzing data from hard landing incidents in domestic airlines obtained through FOQA events. A practical EBT training program was then developed, specifically targeting adverse weather conditions. The program evaluates landing capabilities, and the results guide the supplementation of any deficiencies in the landing skills of each flight crew member, ultimately aiming to enhance their confidence.

• 한국콘텐츠학회논문지
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• 제18권9호
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• pp.178-198
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• 2018

본 연구는 비서직 노동자를 대상으로 변혁적 리더십이 도움행동에 미치는 영향과 변혁적 리더십과 도움행동의 관계에서 직무자원(LMX)과 직무요구(퇴근 후 모바일기기 업무사용)에 대한 조절효과를 종합적으로 실증 분석하였다. 비서직 노동자 140명을 대상으로 한 연구결과는 다음과 같다. 첫째, 변혁적 리더십은 구성원들의 도움행동에 유의미한 긍정적인 영향을 주었다. 둘째, 변혁적 리더십과 도움행동의 긍정적 관계에서 LMX의 조절효과(강화효과, synergistic effect)가 검증되었다. 마지막으로 변혁적 리더십과 도움행동의 관계에서 퇴근 후 모바일기기 업무사용의 상호작용효과(완화효과, buffering effect)가 확인되었다. 이러한 연구결과는 노동자들의 도움행동을 강화하기 위해 중간관리자들의 변혁적 리더십도 중요하지만, 리더십의 수용에 있어서 구성원들의 의지와 자발성에 영향을 주는 맥락적 요인인 사회적 지원(LMX)과 업무환경(퇴근 후 모바일기기 업무사용)에 대한 이해가 필요하다. 마지막으로 본 연구의 학문적 및 실무적 시사점을 제안하고, 한계 및 향후 연구 방향을 제시하였다.

• 전자공학회논문지
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• 제49권9호
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• pp.18-26
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• 2012

차세대 광대역 무선 네트워크의 성능이 급격히 증가함에 따라 스마트 모바일 플랫폼 기반으로 다양한 서비스 (교육, 비디오 컨퍼런싱, 온라인 게임 등)가 사용자에게 제공되고 있다. 하지만, 대부분의 이러한 서비스들은 중앙 집중식 구조로 서비스가 제공되고 있기 때문에, 트래픽 관리에 대한 확장성 있는 통신 서비스를 제공하는데 어려움이 있다. 기존의 이러한 문제점을 해결하기 위해, 본 논문에서는 스마트 이동 단말을 이용한 P2P 기반 그룹 통신 관리 서비스 구조를 제시한다. 좀 더 구체적으로, P2P 기반의 그룹 사용자 관리와 트래픽 관리를 위한 그룹 통신 관리 프로토콜과 알고리즘을 설계하였다. 제안된 방법을 통해 확장성 있는 멀티미디어 스트리밍 서비스를 사용자에게 제공할 수 있다. 이를 증명하기 위해 평균 전송 지연시간 (Average Transmission Delay) 및 대역폭 이용률 (Bandwidth Utilization) 에 대한 수학적인 분석을 수행하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제25권6호
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• pp.1-11
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• 2021

국내 대형 SOC 시설물의 노후화가 가속화됨에 따라 시설물 유지관리도 현재 상태 기준의 안전성 평가에서 미래 노후도 수준 예측을 기반으로 한 성능 중심의 예방적·선제적 유지 관리로 전환되고 있다. 특히, 교량의 경우 1·2종 교량은 많은 연구와 함께체계적으로 관리되고 있으나, 중소형 3종 교량은 사용 연한 동안 성능저하를 대변하는 이력 데이터 수집과 활용은 전무한 실정이다. 따라서 본 연구에서는 부재별 외관 손상에 대해 생애주기별 유지관리 이력을 3차원 교량 객체에 등록함으로써 손상 위치의 손상변화율 등을 직관적으로 확인 할 수 있고, API 기반 종합성능평가가 가능하도록 3D 교량모델 기반의 실증 DB시스템을 설계하여 개발하였다.

• 한국유기농업학회지
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• 제5권1호
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• pp.67-77
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• 1996

The Organic agricultural techinques were investigated through the observations made for 3 years of the actual conditions of a farmer who has been practicing organic agriculture over 21 years. The farmer was a member of the Ichijima-cho Organic Agriculture Association. The Farmer had not performed much of the organic agricultural techinques at the beginning of his farming history. However, he has gradually developed techniques upon the experiences with trial and error. The notable characteristic of his basic organic agriculture was the utilization of a suitable organic fertilizer to make the soil fertile. Crop damages by diseases and insect pests were prevented through a fertile soil, raising of good seedlings, adoption of tolerant varieties and planting at a wide spacing and consequently considering not to use chemical pesticides. Introduction of power weeder for weed control and paddy-upland crop rotation reduced the cost of production for farming. The crop pattern and method of land us such as mix cropping, crop rotation and conversion of paddy field-upland fieldd were appeared to be very important in organic agriculture. The organic agricultural techniques get systematized upon the adaptation the regional ecology and the development of skills of the farmer. The most important point to achieve the success in organic agriculture system is not only by the development of the technical matters but also by the building of healthy relation and understandings between producers and consumers.