• 항공우주산업기술동향
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• 제9권1호
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• pp.15-26
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• 2011

금융위기에 따른 경기침체로 위축되었던 항공운항시장은 빠르게 회복되고 있으며, 국제유가 급등에 따른 영향으로 구형항공기의 퇴역 및 신형항공기로의 교체가 활발히 이루어지고 있다. 2010년의 항공기 순 주문대수는 2009년과 비교하여 감소하였으나 수주잔량은 역대 최고수준을 기록하고 있어, 민간항공기 시장의 호황은 앞으로도 한동안 이어질 것으로 예상되고 있다. 이러한 시장 성장은 100~200인승 급의 단일 통로기가 선도하고 있으며, Airbus, Boeing의 기존 제작업체의 신규 항공기 개발과 Bombardier 및 중국, 러시아 등의 신규 업체에서도 시장에 새로이 진입하기 위해 노력하고 있다. 이러한 신형기체 수요의 증가와 기존 기체의 퇴역은 기존 기체에 대한 MRO 및 임대 시장을 위축을 가져오고 있으며, 국제 유가 불안과 경쟁심화에 따른 고효율 신형항공기에 대한 선호는 더욱 강조되고 있는 상황이다. 향후 20여 년간의 시장 전망을 살펴보면, 신흥시장의 성장과 기존 시장의 회복에 따라 견고한 성장세를 이어갈 것으로 예상된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권3호
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• pp.551-569
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• 2024

With the rapid development of electric vehicles (EVs) industry, EV charging service becomes more and more important. Especially, in the case of suddenly drop of air temperature or open holidays that large-scale EVs seeking for charging devices (CDs) in a short time. In such scenario, inefficient EV charging scheduling algorithm might lead to a bad service quality, for example, long queueing times for EVs and unreasonable idling time for charging devices. To deal with this issue, this paper propose a Deep-Q-Network (DQN) based two-stage scheduling method for the large-scale EVs charging service. Fine-grained states with two delicate neural networks are proposed to optimize the sequencing of EVs and charging station (CS) arrangement. Two efficient algorithms are presented to obtain the optimal EVs charging scheduling scheme for large-scale EVs charging demand. Three case studies show the superiority of our proposal, in terms of a high service quality (minimized average queuing time of EVs and maximized charging performance at both EV and CS sides) and achieve greater scheduling efficiency. The code and data are available at THE CODE AND DATA.

• 한국수산과학회지
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• 제5권3호
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• pp.88-96
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• 1972

1. 주문진, 포항, 부산, 충무, 여수, 완도를 중심으로 한 식용해조류 17종에 대한 수은, 카드뮴, 납 구리 등등 신독성 중금속의 함양분포를 조사하였다. 2. 수은은 전국적으로 풍건물에 대해 <$0.02\~0.52ppm$의 범위에 있다. 파래가 <$0.09\~0.5ppm$에, 평균이 0.36ppm로 가장 높고, 미역이 $0.14\~0.31$에 0.25, 김이 <$0.02\~0.52$에 0.19, 다시마가 <$0.02\~0.24$에 0.10으로서 가장 낮다. 그러나, 이 값을 생체에 대한 값으로 환산한다면 이것의 $1/4\~1/5$ 값밖에 되지 않는다. 각종류마다 대분로 동해안산보다 남해안산이 함양이 많으나, 전반적으로는 안전기준값보다 낮다. 3. 카드뮴은 전체적으로 <$0.02\~1.48ppm$이고, 톳이 $0.41\~1.18$에 평균이 0.97로 가장 높고, 미역이 $0.03\~0.68$에 0.33, 김이 $0.04\~0.67$에 0.32ppm로 가장 낮다. 역시 생체시료에 대한 값은 이들의 $1/4\~1/5$이 된다. 동해안의 돌김보다 서해안의 양식김이 더욱 높은 값이고, 남해안의 양식김이 가장 높으나, 역시 안전기준값보다 낮다고 볼 수 있다. 4. 납도 전체적으로 $0.20\~1.31ppm$이며, 허용기준치이하이다. 생체의 함량은 $0.05\~0.3ppm$ 정도로 생각된다. 5. 구리 역시 전체적으로 $0.90\~17.0ppm$이므로, 문제되지 않으며, 생체로는 약 $0.2\~4.0ppm$로 생각된다. 부산근해산이 비교적 높은 값이다. 6. 한국산 식용해조류에 있어서는 중독성중금속함량의 수준은 아직 안전한 상태이다. (이 연구는 문교부 연구조성비로 이루어졌으며, 본학교수 원종훈박사, 그리고, 천병호, 서윤희, 윤태수 제군의 조력에 감사합니다)

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2731-2736
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• 2013

We report a new tetrameric supramolecular Cu(II) complex ($Cu_4L_4$ = tetrakis(N,N'-bis(salicylidene)-2,2'-ethylenedianiline)Copper(II)) with a Schiff-base ligand ($H_2L$ = N,N'-bis (salicylaldimine)-1,2-ethylenediamine) containing two N,O-bidentate chelate groups. Though the copper sites of $Cu_4L_4$ are non-coupled, the complex exhibits a unsually high catecholase-like activity ($k_{cat}=935h^{-1}$) when the $Cu_4L_4$ solution is treated with 3,5-di-tert-butylcatechol (3,5-DTBC) at basic condition in the presence of air. Combined information obtained from UV-VIS and EPR measurements could lead the suggestion of the reaction pathway in which the substrate may bind to Cu(II) ions by anti-anti didentate bridging mode.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.347.2-347.2
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• 2016

Recently, in order to improve the performance of the colloidal quantum dot solar cells (CQDSCs), various efforts such as the modification of the cell architecture and surface treatment for quantum dot (QD) passivation have been made. Especially, the incorporation of halides into the QD matrix was reported to improve the performances significantly via passivating QD trap states that lower the life-time of the minority-carrier. In this work, we fabricated a lead sulfide (PbS) QD bilayer treated with different ligands and utilized it as a photoactive layer of the CQDSCs. The bottom and top PbS layer was treated using metal iodide ($MI_x$ and butanedithiol (BuDT), respectively. All the depositions and ligand treatments were carried out in air using layer-by-layer spin-coating process. The fabrication of the active layers as well as the n-type zinc oxide (ZnO) layer was successfully carried out on the bendable indium-tin-oxide (ITO)-coated polyethylene terephthalate (PET) substrate, which implies that this technique can be applied to the fabrication of flexible and/or wearable solar cells. The power conversion efficiency (PCE) of the CQDSCs with the architecture of $PET/ITO/ZnO/PbS-MI_x/PbS-BuDT/MoO_x/Ag$ reached 4.2 %, which is significantly larger than that of the cells with single QD (PbS-BuDT) layer.

• Advances in aircraft and spacecraft science
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• 제5권2호
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• pp.205-223
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• 2018

During launch a spacecraft is subjected to a variety of dynamical loads transmitted through the launcher to spacecraft interface or air-born transmission excitations in the acoustic pressure field inside the fairing. As a result, spacecraft are tested on ground to ensure and demonstrate the global integrity of the structure against these loads, to screen the flight hardware for quality of workmanship and to validate mathematical models. This paper addresses the numerical modelling and simulation of the low frequency sine and random vibration tests performed on electrodynamic shaker facilities to comprise the mechanical-borne transmission loads through the launcher to spacecraft interface. Consequently, the paper reviews techniques and methodologies to derive a reliable and representative coupled virtual vibration testing simulation environment based on experimental data. These technologies are explored with the main objectives to ensure a stable, reliable and accurate control while testing. As a result, the use of the derived simulation models in combination with the added value of improved control and signal processing algorithms can lead to a safer and smoother vibration test control of the entire environmental test campaign.

• Design & Manufacturing
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• 제8권2호
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• pp.18-22
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• 2014

Two shot molding is one of the injection method which uses two materials or two color materials simultaneously in one mold. Two shot molding is good rate of productivity and economical because of no extra-progress necessary. The cowl grille is located in the bottom of wind shield glass and rolls as a passage of air inlet to inside of vehicle. It consists of body and seal. Firstly, the body is injected with PP. Next seal is extruded with EPDM and engineered and then assembled with body. These procedures lead high cost of production and the quality of part has problems. Therefore, it has effects on saving production cost and being a solution of the quality problems with the development of two shot molding cowl grille. It is guaranteed that two shot molding will be widely used in the vehicle parts industry afterwards.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.603-607
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• 2009

About a Structure is performance external insulation is fundamantal performance for enrgy-saving. these day, most of residential structures have constructed by internal insulation method structure. The method structure internal insulation have construction and economical efficiency, but on the other hand, be generated heat loss by heat bridge especially, be generated loss heat-energy logical consequence in structure ondol. The external insulation structure method has a mert able to minimum to loss heat about heat-bridge. But the external insulation technique is unsatisfactory statues within the know-how and method of construction and materials compared with developed countries. The recently, the requirement of market related to the external insulation technique is resulted by the energy efficiency system, but it can lead to the lack of alternative technique In study on the korea type passive house building design for insulation block method of wall system has to experimental characteristic heat-energy of practice building. In result field-experimental, the heat-bridge appeared to characteristic spent heat-energy of blow 2L class and have a suffience performance it.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.54-59
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• 2008

The poor maintenance and management of HVAC systems finally lead to the shortening of the life expectancy and result in the increase of operating costs and energy consumptions due to low efficiencies. Also, it is essential to try to develop ways to adequately maintain and to use the building facilities efficiently in order to preserve earth environment and the limited resource. In this study, an analysis on the maintenance and management cost for HVAC systems was carried out with the capacity of equipment. Besides, the LCC(Life Cycle Cost) based analysis was carried out to verify the effect of the doing maintenance and management. As the results, the case of the good maintenance and management is able to save LCC to 11 % than the case of the poor method.

• 상하수도학회지
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• 제18권2호
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• pp.222-227
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• 2004

Flotation processes involve the use of very small bubbles (micro-bubbles) to separate particles from water. The process has become a good alternative to sedimentation, especially where the particles are small or of low density. Although the flotation process commences with a collision between particles and bubbles, most research has been focused only on the characteristics of the particles. In this paper, recent theoretical and experimental research on the characteristics of bubbles is summarized. The effect on the collision efficiency of the size and charge of bubbles is calculated through trajectory analysis. The size and charge of bubbles are measured under different conditions and the ramifications of the results are discussed. The results may lead to a better understanding and optimization of the existing process. In particular, we discuss an idea that a new advanced flotation process might be possible by the modification of the characteristics of the bubble alone or of both bubble and particle.