• 한국환경보건학회지
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• 제36권3호
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• pp.247-253
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• 2010

Recycling is a main issue in protection of the environment and waste collection and sorting have much higher value in current recycling policies than they did previously. Waste collectors, like firefighters and policemen, are working for the public benefit, however, waste collection is more dangerous than either police or firefighting work. In the USA, waste collectors are 10 times more likely than the average worker to die on the job. Waste collectors also suffer from musculoskeletal disorders, infectious diseases and various injuries. If we truly appreciate the worth of waste collectors, we need to improve their working environment and personal hygiene. Furthermore, abolishing discrimination will be a very important step towards greater protection for waste collectors.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.163.2-163.2
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• 2010

In this work, nano-flake shaped nickel oxide (NiO) films were synthesized by chemical bath deposition technique for electrochemical capacitors. The deposition was carried out for 1 and 2 h at room temperature using nickel foam as the substrate and the current collector. The structure and morphology of prepared NiO film were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). And, electrochemical properties were characterized by cyclic voltammetry, galvanostatic charge-discharge, and AC impedence measurement. It was found that the NiO film was constructed by many interconnected NiO nano-flakes which arranged vertically to the substrate, forming a net-like structure with large pores. The open macropores may facilitate the electrolyte penetration and ion migration, resulted in the utilization of nickel oxide due to the increased surface area for electrochemical reactions. Furthermore, it was found that the deposition onto nickel foam as substrate and curent collector led to decrease of the ion transfer resistance so that its specific capacitance of a NiO film had high value than NiO nano flake powder.

• 한국수소및신에너지학회논문집
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• 제20권2호
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• pp.125-132
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• 2009

Cylinder shaped air-breathing PEMFC has been developed to have small volume, low contact resistance and better air accessibility to the open cathode. This cylinder shaped design consists of an anode cylinder with helical flow channel and a cathode current collector with slits. The pressure distribution measurement according to the shapes was performed. The test result indicated that cylinder shaped fuel cell has better pressure distribution compared with the planar shaped fuel cell. The better pressure distribution was connected to the higher performance. The maximum power density of cylinder shaped fuel cell was about 20% higher than the planar shaped fuel cell. The maximum power density of the developed cylinder shaped air-breathing PEMFC with dry hydrogen was $220\;mW/cm^2$ and with humidified hydrogen was $293\;mW/cm^2$.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.970-977
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• 2014

In this paper, the artificial neural network is used to predict the junction temperature of the IGBT power module, by measuring the temperature sensitive electrical parameters (TSEP) of the module. An experiment circuit is built to measure saturation voltage drop and collector current under different temperature. In order to solve the nonlinear problem of TSEP approach as a junction temperature evaluation method, a Back Propagation (BP) neural network prediction model is established by using the Matlab. With the advantages of non-contact, high sensitivity, and without package open, the proposed method is also potentially promising for on-line junction temperature measurement. The Matlab simulation results show that BP neural network gives a more accuracy results, compared with the method of polynomial fitting.

• 동양고전연구
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• 제34호
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• pp.167-206
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• 2009

본고는 금영작(金永爵)이 중국 문인들로부터 받은 편지를 모아놓은 척독집 "중조학사서한록(中朝學士書翰錄)"을 새로 발굴하고 소개한 글로, 정공수(程恭壽), 옹학함(翁學涵), 장병염(張丙炎), 소언한(少言翰)과 자렴함(子廉銜), 이문원(李文源) 등이 김영작에게 보낸 편지 10통, 조정황(趙廷璜)이 김영작의 아들 김홍집(金弘集)에게 보낸 편지 1통 및 시(詩) 5수가 수록되어 있다. 김영작은 많은 중국 문인들과 직접 또는 간접적인 교유를 진행하였다. 그는 연행을 갔다 온 친구 홍양후(洪良厚)의 소개로 중국 문인 이백형(李伯衡), 수방울(帥方蔚)과 편지를 주고받으며 30여 년간 간접적인 교유를 진행하였다. 1858년에는 동지사(冬至使)의 부사(副使)로 직접 북경에 가서 현지 중국 문사 섭명례(葉名澧), 장병염(張丙炎), 오곤전(吳昆田), 정공수(程恭壽), 조광(趙光) 등과 만나서 교유하고 귀국 후에도 지속적으로 척독교류를 진행하였다. 김영작은 학계에 별로 알려지지 않은 인물이나 한중 문화교류에서 빼놓을 수 없는 중요한 인물이다. 김영작이 생면부지의 중국 문사 이백형(李伯衡)과 수방울(帥方蔚)에게 먼저 편지를 보내어 교유를 청하였고 상대방 역시 흔쾌히 답장을 보내면서 평생 편지로만 문학적, 개인적 교류를 진행하였으며, 또한 김영작이 조선의 명문가의 사대부로서 연행사(燕行使)의 부사(副使)라는 높은 신분으로 중국 현지의 문사들과 친밀하게 교유할 수 있었던 것은 그만큼 한중 인사들의 마음이 열려있고 신뢰성과 친숙감이 전제되어 있다는 사실을 알 수 있다. 이는 홍대용을 비롯한 많은 선배 문인들의 교유의 전통이 있어 기초를 닦아놓았기에 가능했다. 이런 의미에서 19세기 후반 김영작과 중국 문사들의 교유는 중요한 의미를 지니며 그 사실을 보여주는 척독집 "중조학사서한록(中朝學士書翰錄)"도 중요한 자료적 가치를 갖고 있다. 다만 아쉬운 점은 "중조학사서한록(中朝學士書翰錄)"만으로는 김영작과 중국 문사들이 주고받은(교류의) 내용을 완전하게 파악할 수 없다는 자료적 한계를 갖고 있는 점이다. 앞으로 중국 측에 교유 기록이 남아있는 자료들을 더욱 많이 발굴해낼 것을 기대할 뿐이다.

• The Korean Journal of Ecology
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• 제19권6호
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• pp.529-541
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• 1996

During the period of December 1992 (winter-spring) and from February 1995 (winter-spring), the leaf processing rates of oak (Quercus serrata) and tulip (Liriodendron tulipifera) tree was investigated in the headwater streams in southeastern part of Korea in conjunction with the distribution pattern of macroinvertebrate fauna. Using two types of bags ($10\times30cm$ with 5 g of dry leaves; open bag with holes, closed bag without holes), decomposition rates of oak and tulip tree by shredder and/or microbiota at a reatively undisturbed 2nd-order stream were compared, Regardless of leaf type, leaves in the open bage decomposed slightly faster than those in the closed bags. In the 1992 experiment, osk leaves decomposed much slower than tulip leaves (after 138 degree days, osk : closed, 0.006% loss/day ; open, 0.008 ; tulip: closed, 0.021 ; open, 0.023; n=2). The of the first experiment using oak leaves in 1995 were similar to those of the first experiment (after 151 degree days, oak: closed, 0.005% loss / day; open, 0.006; n=6). Over 50% of invertebrates from 122 leaf pack samples collected from 12 streams during the winter period of 1994 were identified as shredders (shredder, 56.2; collector, 32.7; scraper, 8.65; predator, 2.45%). Among shredders, Gammarus sp. and Tipula sp. were dominant species in terms of number and biomass (8.2 ind./g, 1.0 ind./g AFDW of leaves). Among many physico-chemical parameters, the width of stream channel was found to be the most influential factor in the distribution of Gammarus and Tipula (Gammarus: r=-0.34, P<0.001;Tipula:r=0.40, P<0.001). Considering the fact that oak is one the dominant riparian vegetation in the southeastern part of korea, the patterns of oak processing and shredder distribution shown in theis study may well represent some of the important characteristics of headwater steams in southeastern Korea.

• 전기전자학회논문지
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• 제20권2호
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• pp.184-187
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• 2016

본 논문에서는 빌딩 자동제어용 센서 및 신호의 듀플리케이터(Duplicator)를 개발한다. 개발된 듀플리케이터는 빌딩 자동제어에 사용되는 여러 개의 센서를 원거리에 있는 빌딩자동화기기에 직접 연결하지 않고 데이터 수집장치와 데이터 송신장치간의 논리적 통신방식을 사용하여 센서 데이터를 그대로 복원한다. 이때 센서의 신호가 원거리로 전송될 때 발생될 수 있는 전기적인 오차를 줄일 수 있고 자동제어의 시공원가를 절감시킬 수 있다. 또한 논리적 통신방식으로 개방형 프로토콜을 사용하기 때문에 상용 HMI와 호환이 되어 확장성을 보장한다. 개발된 듀플리케이터의 성능을 평가하기 위하여 실제 환경에서 시운전을 수행하여 정상 동작함을 보였다. 또한 측정 오차율, 동작 온도, 동작 습도 등에 대하여 공인 시험기관의 장비를 사용하여 실험한 결과 우수한 성능을 나타내었다.

• 설비공학논문집
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• 제22권4호
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• pp.197-204
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• 2010

Schools are one of the most suitable buildings for renewable energy systems because they have favourable demand profiles for renewable energy system (e.g. solar thermal collector, photovoltaic panels), modular-based building plan and large open spaces (e.g. play ground, gardens, roof) for the installation. This paper presents a methodology of the feasibility test for renewable energy systems to be installed at schools. The methodology is based on the analysis of the demand/supply profiles dynamic matching. a case study is also presented to test the applicability of the proposed assessment methodology.

• 한국재료학회지
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• 제16권5호
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• pp.297-301
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• 2006

Si/Mo multilayer anode consisting of active/inactive material was prepared using rf/dc magnetron sputtering. Molybdenum acts as a buffer against the volume change of the Silicon. Multilayer deposited on RT (reversible treatment) copper foil current collector to enhance adhesion between Silicon and copper foil. Deposited Silicon was identified as an amorphous. Amorphous has a relatively open structure than crystal structure, thus prevents the lattice expansion and has many diffusion paths of Li ion. When deposited time of Silicon and Molybdenum is 30 second and 2 second respectably, electrode has more capacity and good cycle stability. A 3000 nm thick multilayer was maintained 99% of the initial capacity (1624 $mAhg^{-1}$) after 100 cycles. As the increase of the multilayer thickness (4500 nm, 6000 nm), Si/Mo mutilayer anodes show aggravation cycle stability.

• 전기학회논문지
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• 제67권3호
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• pp.454-459
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• 2018

The BIPV system must be designed to reflect the architectural and electrical characteristics simultaneously because it replaces the role of the exterior material of the building, which makes it difficult to design the BIPV. The thin film type BIPV module has an electrical characteristic that the open voltage is higher and the short circuit current is lower than that of the crystalline type BIPV module. However, there are many differences in the design of the array, the collector distribution board, and the inverter in the system configuration since the crystal type BIPV module has the opposite feature. In this study, a crystalline BIPV module and a thinfilm BIPV module were applied to actual buildings. As a result, the elements to be considered in designing BIPV system were derived, and the architectural and electrical characteristics were mutually analyzed.