• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 2부
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• pp.91-96
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• 2008

우리나라 초등학교 교육현장에서는 학생들의 탐구능력을 길러주기 위해 현장체험학습을 빈번히 활용하고 있다. 하지만 기존 현장학습은 학생들에게 구체적 탐구활동 및 효과적인 피드백 환경을 제공하지 못해 충분한 교육효과를 거두지 못하고 있다. 우리는 이를 해결하기 위해 현장학습에서 이용 가능한 교사/학생 간 휴대폰을 활용한 지령기반 탐구활동을 제안한다. 본 연구에서는 교사와 학생이 참여하는 동물원 현장학습 사례연구를 중심으로 제안한 교육매체의 활용 및 개선방향에 대해 논의해 본다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1267-1274
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• 2005

The system which can manage and analyse the tunnel information in design and construction stage was developed through several years' research named ITIS(Intelligent Tunnel Information System). Now, the system is being modified and improved for the use of international tunnel construction information sharing. Some countries have their own management system for tunnel construction, and one of them, called DEST(Data Evaluation System for Tunneling), is adopted for the international cooperation for this research of development. The aimed system is operated under world wide web environment.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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• pp.11-16
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• 1999

Discharge characteristics research for high voltage and large current electric machinery design, the development of ozonizer with high yield and efficiency for environment improvement, generation of plasma & laser and EMI EMC are research fields of Enersy & Environment Electromagnetic Laboratory(EEEL) in the school of electrical & electronic engineering of Yeungnam University. On this paper, we would like to introduce the discharge and ozone generation characteristics of ozonizers designed and manufactured by EEEL. After starting research for fluid gas discharge characteristics early in the 1980's, high voltage nozzle(HVN) type ozonizer, neon lamp(Nelamp) type ozonizer, ozone lamp(Olamp) type ozonizer and multi-discharge type ozonizer(MDO) have been investigated since 1990.

• International Journal of Aeronautical and Space Sciences
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• 제4권1호
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• pp.19-25
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• 2003

A low speed wind tunnel test for the canard airplane model was conducted in KARI LSWT. To measure the required level of accuracy, the image system was applied for all elevator deflection and different canard incidence conditions. By doing so, the difference in aerodynamic characteristics between the forward swept and straight canards can be precisely evaluated, and the pros and cons of both canards arrangements can be discussed. Compared with both canard configurations at the same incidence angle setting, the straight canard has benefits in lift and drag, and the slope of pitching moment increases more moderately than the forward swept canard. The listed data and discussion would be useful to whom wants to design a canard airplane.

• 한국터널지하공간학회 논문집
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• 제8권3호
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• pp.219-225
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• 2006

터널시공에 있어서 굴진장은 기술적인 면뿐만이 아니라 경제적인 면에서도 큰 영향을 끼치지만 현재까지 굴진장 결정을 위한 일관된 절차는 연구되지 않았다. 본 연구에서는 수치해석을 통해 굴진장이 연암터널의 거동형태에 끼치는 영향을 알아보았다. 터널 막장과 무지보구간의 거동형태를 막장안전률과 설계차트를 이용해 정량적으로 판단할 수 있도록 하였으며, 설계단계에서의 최적 굴진장을 사이클타임과 공사비 등의 시공자료를 이용해 분석하였다. 비록 본 연구결과가 몇몇 적용한계를 가지고 있지만 설계단계에서 터널 굴착을 최적화하기 위한 정보를 제공할 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.140-143
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• 1993

Station Blackout(SBO) event means the complete loss of alternating current(AC) electrical power to the essential & nonessential switchgear buses in a nuclear power plants. Since many safety systems in nuclear power plants depend upon alternative current power, the SBO event could be an important contributor to damage of reactor core. Therefore, the SBO events have been considered as a very important safety issues in a nuclear power plants. In this paper, as evaluating the design characteristics of offsite & emergency power systems, an acceptable minimum SBO duration is calculated. And it is presented that the design method for alternative AC(AAC) sources to cope with the SBO events.

• 디지털융복합연구
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• 제15권11호
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• pp.463-470
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• 2017

VR 영상을 활용한 가상현실 콘텐츠는 제작의 용이성과 사용자 편의성으로 인해 주목받고 있으나 상호작용이 결여된 상태이기 때문에 응용 분야와 활용성에 있어서 한계가 있다. 본 연구에서는 이러한 문제점을 극복하고자 360도 파노라마 영상과 게임엔진을 활용하여 상호작용이 가능한 고해상도 VR 서비스를 구축하는 방안을 제시한다. 특히 복잡한 연산이 소요되는 배경 영상은 파노라마 영상으로 미리 렌더링하여 생성한 것이므로 낮은 사양의 단말기에서도 높은 프레임 수를 유지하면서 서비스를 제공할 수 있는 특징이 있으며, 사용자의 시점과 움직임에 반응하여 고해상도의 배경영상을 발췌하여 보여주기 때문에 상당한 몰입감을 구현할 수 있다. 본 제안 방법의 효과성을 보이기 위해 가상 동물원 환경을 VR로 구성하여 보았으며 사용자의 상호작용과 몰입감을 증대시킬 수 있음을 보이기 위해 상호작용 게임을 사례로 보인다.

• Architectural research
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• 제11권1호
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• pp.25-33
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• 2009

This study presents the testing of 15 hwangtoh-based cementless concrete mixes to explore the significance and limitations of the development of eco-friendly concrete without carbon dioxide emissions while maintaining various beneficial effects. Hwangtoh, which is a kind of kaolin, was incorporated with inorganic materials, such as calcium hydroxide, to produce a cement-less binder. The main variables investigated were the water-to-binder ratio and fine aggregate-to-total aggregate ratio to ascertain the reliable mixing design of hwangtoh-based cementless concrete. The variation of slump with elapsed time was recorded in fresh concrete specimens. Mechanical properties of hardened concrete were also measured: including compressive strength gain, splitting tensile strength, moduli of rupture and elasticity, stress-strain relationship, and bond resistance. In addition, mechanical properties of hwangtoh-based cement-less concrete were compared with those of ordinary portland cement (OPC) concrete and predictions obtained from the design equations specified in ACI 318-05 and CEB-FIP for OPC concrete, wherever possible. Test results show that the mechanical properties of hwangtoh-based concrete were significantly influenced by the water-to-binder ratio and to less extend by fine aggregate-to-total aggregate ratio. The moduli of rupture and elasticity of hwangtoh-based concrete were generally lower than those of OPC concrete. In addition, the stress-strain and bond stress-slip relationships measured from hwangtoh-based concrete showed little agreement with the design model specified in CEB-FIP. However, the measured moduli of rupture and elasticity, and bond strength were higher than those given in ACI 318-05 and CEB-FIP. Overall, the test results suggest that the hwangtoh-based concrete shows highly effective performance and great potential as an environmental-friendly building material.

• 조명전기설비학회논문지
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• 제30권2호
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• pp.93-101
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• 2016

This paper presents the surface discharge characteristics in Dry-Air on laminated epoxy solid dielectrics and conductive particles in order to provide the valuable information for the insulation design of eco- friendly gas insulated switchgear. To improve insulation performance, the three types of the laminated epoxy solid dielectrics were proposed, and it was revealed that their surface discharge characteristics were similar to the bakelite dielectrics of same-laminated types. From the surface discharge characteristics of dry air, it was demonstrated that the effect of conductive particles on surface discharge voltage was dominant when there are this particles at the shortest electrode gap and that the degradation of insulation performance on the conductive particles was evident in epoxy than teflon. These phenomena were interpreted in terms of particle-triggered discharge mechanism and electric field of triple junction, respectively.

• Tribology and Lubricants
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• 제31권1호
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• pp.28-34
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• 2015

This paper addresses the problems of using anti-freeze lubricants for different machines that must function at extremely low temperatures during winter operation in the Republic of Sakha (Yakutia). We discuss the possibility of obtaining anti-freeze base oils from Talakan crude oil, an area with major oil and gas deposits of the Republic of Sakha, and also provide the trade and technological classification of Talakan crude oil. We propose two different schemes for processing Talakan crude oil: the fuel scheme (obtaining light and heavy fractions as a fuel oil) and the base oil scheme (obtaining light fractions and base oils). We investigate the influence of pour point depressants on alkyl-methacrylate base on the low-temperature properties of the fractions obtained from Talakan crude oil and Korean base oils, and establish the optimal concentration of pour point depressants. We compare the properties of these fractions with the low-temperature properties of Korean base oils and find that the commercial oil "Ravenol 0W-40" provides optimistic results. We obtain oil with a pour point of minus $50^{\circ}C$ and a viscosity index greater than 100. The Design of Experiment was used to establish the optimum composition of the pour point depressants and the base oil S-8 to obtain lubricant oil with a kinematic viscosity of 17 cSt, viscosity index of 208, and a pour point of minus $64^{\circ}C$.