• 월간 기계설비
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• s.242
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• pp.14-15
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• 2010

우리나라는 건물 냉난방에 연간 250조원에 이르는 에너지를 수입하고 있다. 비용도 엄청나지만 에너지 자원의 확보도 갈수록 어려워지고 있다. 미국과 유럽에서는 2030년까지의 지열 보급계획을 수립, 국가별로 건물 냉난방에너지의 20~60%까지를 지열로 대체한다는 계획을 추진하고 있다. 우리나라도 에너지절약 의무화제도, 그린홈 100만호제도, 시설원예사업 등 다양한 정부정책을 추진하고 있다. 그러나 민간부문의 참여가 없으면 에너지절감 효과는 극히 제한적일 수 밖에 없다. 제2 롯데월드에서 지열시스템 도입한 것은 우리나라 지열시장의 수준을 한 단계 레벨업 시킬 것으로 예상된다. 본지는 코텍엔지니어링(주)가 수주한 제2 롯데월드 지열냉난방시스템 공사에 대해 알아보고, 앞으로 시공과정을 자세히 보도할 예정이다.

• Annual Conference of KIPS
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• 2010.11a
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• pp.845-847
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• 2010

미래전은 센서체계에서 지휘통제체계간 실시간 전장정보를 수집, 분석 및 공유할 수 있는 네트워크 중심전으로 변화하고 있다. 지휘통제체계의 정보융합기술은 센서가 보내온 정보를 다른 기종의 센서 정보 또는 현재까지 종합된 정보와 융합하여 최신의 정확한 정보로 생산하는 기술이다. 본 논문은 지휘통제체계 정보융합기술의 동향분석에 관한 것으로 국내외 기술현황, 기술수준분석, 기술발전목표, 핵심기술 및 확보방안 등을 제시하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.80-81
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• 2023

세계적으로 전기차 보급이 빨라지면서 한국 배터리 업계는 공격적인 생산시설 투자와 지속적인 기술개발을 통한 제품 신뢰성을 확보로 가파른 성장세 시현 중 ... 국제 전기차 판매량은 2019년 212만대에서 2020년 299만대로 늘어났으며, 2021년 상반기에도 전년 동기대비 168% 늘어난 263만대를 기록하는 등 성장세 지속... 성장을 주도하는 곳은 독일, 프랑스, 영국 등 유럽 지역으로 전기차 판매 침투율이 2019년 2~3%대에서 2021년 상반기에는 10% 중후반 수준으로 상승...

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.276-286
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• 2021

General high fluidity concrete is the area of high strength concrete with a high amount of cement to secure the required fluidity and workability. Since most of the concrete structures currently used have normal strength, there is a limit to the practical expansion and practicality of use. Thus it is necessary to develop normal strength-high fluidity concrete with low binders that can be used not only in general buildings but also in special buildings, and can greatly reduce construction time and save labor costs. This requires to develop and apply the polycarboxylate-based superplasticizer. In this study, PCE was prepared for each combination of starting materials(WR, HB, RT) and the rheological properties of cement paste were analyzed using ringflow cone and a rotary viscometer. As a result, when PCE with a combination of WR 80%, HB 6.5%, and RT 13.5% was applied, the yield stress can be minimized while securing the plastic viscosity at level of the normal strength. In addition, high fluidity due to the high dispersion effect was confirmed.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.42-51
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• 2022

An eVTOL aircraft, which is required to operate with low pollution/low noise in urban environments, mostly use battery-powered electric propulsion systems as power sources, not traditional propulsion systems such as reciprocating or turbine engines. Accordingly, certification preparation for the electric propulsion system and securing the safety of the electric propulsion system, are important issues. In the U.S., special technical standards equivalent to FAR Part 33 were issued to certify electric engines, and in Europe, various special conditions were established to certify electric propulsion systems. Thus, in Korea, the technical standards for the electric propulsion system for eVTOL aircraft must also be prepared in line with the U.S. and Europe. In this paper, SC E-19, the technical standard of the electric/hybrid propulsion system (EHPS) in special conditions, was analyzed. Additionally, securing the safety of the electric propulsion system of the aircraft are proposed, through the collaboration of SC E-19 technical standards with the existing aircraft safety evaluation procedure ARP 4761. Finally, through a case study of the Ehang 184 electric propulsion system, it has been confirmed that the proposed safety assurance method is applicable at the aircraft level.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.1
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• pp.237-251
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• 2023

This study tried to understand the effect of internal resources, capabilities, and business model innovation of venture enterprises on industrial property performance, as based on previous studies that securing industrial property rights has a positive effect on the technology commercialization of venture companies. Venture company capabilities were classified into intrinsic elements of a company (company's research resources) and creative elements (commercialization capabilities) that implement them, and they were intended to show that they could lead to a company's potential competitiveness through innovation in business models. In order to verify this research purpose, an empirical analysis was conducted on 1,733 corporate companies among venture confirmation companies subject to the 2019 venture company precision survey. It was confirmed that the systematic research organization and commercialization capabilities of venture companies were significant (+) in industrial property performance. However, in the final research model that applied both the rules of the business model's innovation variable, commercialization capability and business model innovation were significant (-), and research organization × business model innovation showed significant results (+). This means that venture companies' excellent resources and capabilities can have a positive impact on industrial property performance individually, but when applying the level of innovation in the actual business model, they must interact with the business model. The results of this study are meaningful in that it is necessary to pursue business model innovation that secures clear differentiators compared to competitors as well as strengthening the company's internal resources and capabilities to secure industrial assets and innovation growth.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.9
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• pp.861-868
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• 2016

Dummy messages are usually generated for faking in preserving the location privacy of a sink or source against the global eavesdropping in wireless networks. In this paper, we propose a new method in which a certain number of nodes determined by considering the required privacy level are made to transit to the dormant state doing nothing so that the total number of dummy messages is reduced, while the paths from the sink to the sources are ensured. Through simulation we verify the success ratio of path establishments between the sink and a set of sources and the location privacy level of them.

• Journal of Korean Society of Steel Construction
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• v.9 no.2 s.31
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• pp.159-169
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• 1997

Recently, due to the increasing overloaded heavy vehicles and traffic volumes fatigue failures of steel highway bridges frequently occur. Therefore, it is important to decide rational fatigue design procedure which can reflect lifetime cumulative fatigue damage reasonably. In this study, cumulative fatigue damages are simulated for various bridge systems and traffic conditions. The AASHTO LRFD fatigue design procedure is reviewed and the current fatigue design loading format, in which a single representative truck is loaded regardless of bridge width, is found to yield inconsistent safety level. Improved loading format with rational design load level for fatigue design is suggested.

• The Journal of the Korea Contents Association
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• v.5 no.2
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• pp.107-114
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• 2005

This paper proposes to analyze a security level about information property systems. This method uses objective and quantitative risk level assessment. The method analyzes administrative, physical and technical aspects of information property system commonly. This method also uses administrative, physical and technical weights. Individually according to requirements security assessment purpose. And it shows risks weighting mean and importance of information property by graph. The most right and up systems in maps is prior to other systems. Also, Quantitative analysis presents more objective and efficient results for security level assessment of information system.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.63-63
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• 2009

최근 연비 향상 및 배기가스 저감을 위한 친환경 경량 굴삭기에 대한 연구가 활발히 진행되고 있다. 이러한 시도는 굴삭기의 소재의 강도를 490MPa급에서 700MPa급으로 고강도화를 통하여 작업장치의 경량화를 도모하고 있다. 본 연구에서는 중장비용 고강도 열연강재로 재발중인 ATOS70강재의 기본 용접성 및 GMAW 용접부 특성을 검토하였다. 사용한 시험재는 현장시험재인 14~16mmt두께의 ATOS70강재를 사용하였고, 용접경화성 및 저온균열감수성을 평가하였다. 또한 GMAW 용접을 실시하여 용접부의 이음부 특성을 검토하였다. 14mmt 두께의 ATOS70강재의 탄소당량은 약 0.44수준이고, 모재 인장강도는 약 760MPa급 수준을 보였다. 한편 최고경도시험에 의한 용접부 최도경도는 약 300Hv 수준을 보였으며, 경사 y-groove구속시험에 의한 14mmt두께의 한계예열온도는 상온이었다. 한편 GMAW 용접부 인장시험결과 740MPa급 이상의 인장강도를 확보하였고, $-5^{\circ}C$ 용접부 Charpy 충격시험결과 48J 이상의 충격인성을 나타내었다.