• 한국재료학회지
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• 제20권4호
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• pp.210-216
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• 2010

This paper investigates the dependence of a-Si:H/c-Si passivation and heterojunction solar cell performances on various cleaning processes of silicon wafers. It is observed that the passivation quality of a-Si:H thin-films on c-Si wafers depends highly on the initial H-termination properties of the wafer surface. The effective minority carrier lifetime (MCLT) of highly H-terminated wafer is beneficial for obtaining high quality passivation of a-Si:H/c-Si. The wafers passivated by p(n)-doped a-Si:H layers have low MCLT regardless of the initial H-termination quality. On the other hand, the MCLT of wafers incorporating intrinsic (i) a-Si:H as a passivation layer shows sensitive variation with initial cleaning and H-termination schemes. By applying the improved cleaning processes, we can obtain an MCLT of $100{\mu}sec$ after H-termination and above $600{\mu}sec$ after i a-Si:H thin film deposition. By adapting improved cleaning processes and by improving passivation and doped layers, we can fabricate a-Si:H/c-Si heterojunction solar cells with an active area conversion efficiency of 18.42%, which cells have an open circuit voltage of 0.670V, short circuit current of $37.31\;mA/cm^2$ and fill factor of 0.7374. These cells show more than 20% pseudo efficiency measured by Suns-$V_{oc}$ with an elimination of series resistance.

• 한국측량학회지
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• 제29권3호
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• pp.293-301
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• 2011

전리층에 의한 신호지연 오차는 2000년 5월 SA해제 후 GPS 측위의 가장 큰 오차 요인이다. 이 연구에서는 전리층 오차를 산출하기 위한 방법으로 국토지리정보원 44개소의 상시관측소로부터 제공된 위상평활코드 의사거리 관측값을 이용하여 전리층 총전자수를 추정하였다. 총전자수를 정확하게 추정하기 위해 위성과 수신기의 하드웨어 바이어스인 DCB(Differential Code Bias)를 산출하여 적용하였으며, 적용 효과를 확인하기 위해 GlM을 기준으로 DCB 적용 전 후의 전리층 총전자수를 비교하였다. 그 결과, DCB를 적용했을 때 약 3~4 TECU, 적용하지 않았을 때 약 35~45 TECU의 RMS 오차를 나타냈다. DCB를 적용하여 $1^{\circ}{\times}1^{\circ}$ 공간해상도의격자형 전리층 총전자수 지도를 생성하였으며, 이때 총전자수 추정에 이용되는 상시관측소의 개소 수 증가에 따른 효과를 분석하기 위해 상시관측소의 개소 수를 10개소, 20개소, 30개소, 44개소 순으로 증가시키며 총전자수를 추정하였다. 각 총전자수 지도를 GIM과 비교하여 RMS 오차를 산출한 결과, 10개소의 상시관측소를 이용한 경우 5.3 TECU에서 44개소의 상시관측소를 이용한 경우 3.9 TECU로 감소하는 것을 확인하였다.

• 한국대기환경학회지
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• 제34권3호
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• pp.393-405
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• 2018

Volatile organic compounds (VOCs) are representative air pollutants due to their detrimental effects on human health and their role in formation of secondary organic aerosols. Assessments and monitoring programs of VOCs using periodic grab sampling like Tedlar bags, canisters, and sorbent traps provide limited information, often with delay times of days or weeks. Selected ion flow tube mass spectrometry (SIFT-MS) is an emerging analytical technique for the real-time quantification of VOCs in air. It relies on chemical ionization of the VOCs molecules in air introduced into helium carrier gas using $H_3O^+$, $NO^+$, and $O_2{^+}$ precursor ions. Real-time monitoring method of 60 VOCs in the ambient air was developed using TO-15 standard gas mixture. Calibration curves, method detection limit, and quantitation reproducibility of the target compounds were tested. Dynamic dilution system was used to dilute standard gas from 0.174 ppbv to 100 ppbv, where calibration curves showed good linearity with $r^2$> 0.95 in all target analytes. Limit of detection (LOD) all compounds were sub ppbv, and some halogenated compounds showed pptv levels. Seven consecutive analyses of target compounds showed good repeatability with relative standard deviation of less than 10%. One day monitoring of VOCs in ambient air was conducted in Geoje. Average concentration of target VOCs in Geoje were relatively lower than other regions, among which formaldehyde showed the highest concentration ($15.4{\pm}5.78ppbv$). SIFT-MS provided good temporal resolution data (1 data per 3.2 minute), which can be used for identifying ephemeral short-term event. It is expected that SIFT-MS will be a versatile monitoring platform for VOCs in ambient air.

• 한국측량학회지
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• 제33권5호
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• pp.343-351
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• 2015

차량 항법장치에서 활용하고 있는 GNSS는 차분기법을 이용하더라도 수 미터 수준의 측위 정밀도를 확보할 수 있으므로, 길안내 수준의 위치기반서비스만 가능하다. 반면 정밀 측지/측량분야에서는 민간용 코드 대신 반송파 위상정보를 이용하여 센티미터에서 밀리미터까지의 위치 정확도를 확보할 수 있다. 본 연구에서는 국토교통부 국토지리정보원의 NRTK(Network-RTK) 서비스를 차량항법에 적용하기 위한 기반연구를 수행하였다. 이를 위해, 차량에 GNSS 장비를 탑재하고 전국범위에서 NRTK를 수행하였으며, 그 결과를 바탕으로 NRTK의 차량항법 적용가능 여부를 판단하고자 하였다. 본 연구의 분석결과, NRTK는 대체적으로 높은 모호정수 결정율을 보이며, 지상 차량항법에 충분히 적용할 수 있을 것으로 판단된다. 다만, 도심지에서는 모호정수 결정율이 급격히 낮아지며, 실수해일 경우에는 측위 오차가 10m 이상의 수준에 달할 정도로 불안정할 수 있다. 따라서 안정적인 위치정확도를 확보하기 위해서는 실수해의 오차영향을 최소화할 수 있는 방안 등이 모색되어야 할 것으로 사료된다. 그러나 수신환경이 양호한 일부 도심지에서는 NRTK를 활용하여 센티미터 수준의 측위 정확도를 확보할 수 있을 것으로 판단된다. FKP는 고속 주행 시 모호정수 결정율이 약 55%까지 낮아지는 경우가 발생하였으므로 여러 수신환경을 고려하여 측위 정확도를 결정하여야 한다. 마지막으로 대기교란(2단계 이상)에 의해 NRTK(FKP) 접속오류로 의심되는 사례가 발생하였으며, 이에 대한 정확한 원인규명이 필요하다.

• 대한환경공학회지
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• 제22권3호
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• pp.511-521
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• 2000

디젤자동차와 같이 희박연소 상태에서 많이 배출되는 질소산화물을 선택적 촉매환원(SCR)으로 제거하기 위하여 제올라이트와 금속산화물을 조합한 촉매를 석영 반응로에서 설험하였다. 환원제는 자동차 배출가스에 포함되어 있어 실용 가능성이 크다고 판단되는 탄화수소 중 안전성 및 환원효율이 좋은 올레핀계 탄화수소인 프로필렌을 사용하였다. 본 연구에서는 제올라이트 및 금속산화물계의 단일촉매 상태에서의 NOx 전환율을 파악하고, 저옹 및 고온에서 활성이 다른 촉매를 기계적으로 조합하여 NOx 전환 활성 온도창(Temperature Window)을 확대하고 내구성이 좋은 촉매를 찾고자 하였다 0.55wt%Pt-$TiO_2$/5wt%Cu-ZSM-5 촉매와 0.28wt%Pt-$TiO_2$/$Al_2O_3$ 촉매 및 1.1 wt%Pt-$TiO_2$/$Mn_2O_3$ 촉매 모두 $400^{\circ}C$를 변곡점으로 저온과 고온에서 NOx 제거활성이 있었는데, 저온에서 활성이 가장 큰 것은 0.28wt%Pt-$TiO_2$/$Al_2O_3$ 촉매이었고, 고온에서는 1.1wt%Pt-$TiO_2$/$Mn_2O_3$(21) 촉매가 제일 높은 활성을 보였다. 그러나 수분 및 아황산가스 공존시와 열적 내구성 면에서는 0.55wt%Pt-$TiO_2$/5wt% Cu-ZSM-5 촉매가 가장 우수하게 나타났다.

• 무역상무연구
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• 제51권
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• pp.317-358
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• 2011

The purpose of this study aims to analyse the key differences of the sea waybill and electronic B/L in the international transport documents. Sea waybills look remarkably like ordinary bills of lading. Indeed, in two important ways, they are just like bills of lading: the front of the document will near a description of the quantity and apparent condition of the goods; and the back of the document provides evidence of the terms of the contract of carriage. They differ from bills of lading in that, far from indicating that the goods described are deliverable to the order of the shipper or of the consignee, they will make it explicit that the goods are deliverable only to the consignee. Again, different carries will do thai in a variety of ways. For example, the document may call itself non-negotiable, omitting the word order from the consignee box on the front of the document, and stating explicitly that the goods will be deliverable to the consignee or his authorised representative on proper proof of identity and authorisation. The Hague-Visby Rules and Hamburg Rules give no guidance as to any right to instruct the carrier in respect of goods while they are in transit. However, in applying Article 50 of the Rotterdam Rules, in particular when applying it in the context of seawaybills, straight bills of lading or ship's delivery orders, regard would need to be had to preserve the shipper's rights under any of those three documents even after the buyer of goods covered by them has acquired rights of its own. And, the right of control is defined at Article 1.12 of the Rotterdam Rules. The right to give instruction is further limited by the terms of Article 50.1 to three particular types of instruction in respect of the goods, relating broadly to the goods, their delivery en route, and the identity of the consignee. And, the CMI formulated the CMI Uniform Rules for Sea Waybills for voluntary incorporation into any contract of carriage covered by such a document. Recognising that neither the Hague nor the Hague-Visby Rules are applicable to sea waybills, the CMI Rules provide that a contract of carriage covered by a waybill shall be governed by whichever international or national law, if any, would have been compulsorily applicable if the contract had in fact been covered by a bill of lading or similar document of title.

• 유통과학연구
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• 제12권2호
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• pp.27-37
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• 2014

Purpose - As economic activities between different countries have rapidly spread in a world of free trade, it is inevitable that a large volume of cargo will be carried between countries. It is natural, then, that CO2 emissions and other environmental pollutions have followed, which exposes people and society to serious environmental problems and social costs, and so on. Therefore, the need to understand logistics is not only a matter of transportation but also an environmentally oriented matter. The purpose of this study is to look at some lessons and implications from the European case in terms of green logistics matters. Research design, data, and methodology - In order to look into this matter, first, it has to be established that some cargo transport volumes using different transportation modes have clearly declined because of previous economic recessions. Some transport policies produced by the European Union (EU) are based in a long history of struggling to cope with transport matters in European countries. In its recent transport policies, the EU has provided greener transportation alternatives, realizing that pollution matters affect the European transport market. This study tries to determine what policies the EU has implemented to deal with green logistics matters. This study concentrates in particular on the Marco Polo program in the EU. Results - This study found that the EU seems to consider these kinds of matters, that is, transport and the environment in the context of green logistics. The EU launched some policy instruments to solve this matter relatively earlier than other countries and reviewed them as necessary. In order to make these policy tools work, the EU provided PACT for combined transport, and then the Marco Polo I and II European transport white paper packages. These European policies deal with green logistics matters in two ways. First, some restrictions have been imposed, especially taxation, and so on. Transport subsidies are also powerful means of handling green logistics matters in Europe. Along with these two means of dealing with transport and the environment, the EU eventually targeted integration of different transport modes. Instead of employing only a single transport instrument mode to deliver the cargo to be carried, such as trucking, rail, ocean-going carrier, flight, or inland waterway transport, the EU has proposed that combining transport modes is the best alternative for transport and the environment. That is, the EU is pursuing the adoption of multimodalism as an answer to the green logistics challenge as it provides a more cost efficient and more productive means of transport. Conclusions - In conclusion, multimodal transport should be considered when applying green logistics, as it can provide an alternative way to achieve transport and environmental solutions together at the present time. Two methods can be used to encourage multimodal transport: restrictions and subsidies. These are the lessons and implications from European green logistics policies.

• 유통과학연구
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• 제12권10호
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• pp.123-128
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• 2014

Purpose - The purpose of the study is to reexamine the price fairness as practiced by low cost airlines, as a consumer has to experience such inconveniences as inferior airport transportation, extra fees on in-flight meals, and non-negotiable seats, and consumers evaluate such experiences keeping in mind their total costs. This evaluation includes price fairness and allows a reasonable and overall consideration of factors of low cost airlines. It tries to set up a measurement of the indicators consumers' perceptions of price fairness academically as it adapts price fairness to airline services which are renowned for price volatility. Research design, data, and methodology - The research proposes an alternative pricing strategy for the long term profit of low cost airlines after going over conflicts between the traditional theory of consumers' price perception mechanism and flexible fair policy of low cost airlines. It was meaningful when it relates to the early stage of the business, while it enhances the risks relating to the long term survival of low cost airlines. In addition, it is significant as it highlights the negative influences on consumers' perceptions of price fairness, as low cost airlines run on extremely low cost perspectives. Results - The results of the research provide insight into four perspectives, as consumers' perceptions of price fairness are influenced by the frequency and range of price changes and services. The first perspective is that it would lead to positive price evaluation when a low cost airline cuts prices frequently with little changes than one big change. It also would lead to the same result when it comes to necessary services. The second perspective is that one big increase of price would rather undermine the negative aspects of price changes than those of several smaller ones. The third perspective is that additional services would be good to consumers' perceptions of price fairness as compared to discount benefits with respect to the cost. Finally, a low cost airline should consider that consumers will change airlines or defer their flight schedule if the flight fares increase beyond their limits. Conclusions - Low cost airlines should reconsider their pricing policies for services that were provided free earlier. A consumer would not like discount benefits when made to pay for services that were, for long, free of charge. If a low cost airline can provide services with no charge, it should improve volumes if the costs are standardized and, moreover, should consider the charging fees. Alternatively, a consumer can choose between services and fair discount. Low cost airlines are implementing sales promotion strategies, as the competition is more intense than it used to be. In these days, they should regard services over sales promotion, as consumers may prefer to spend money on good premium services. Some differentiation in services could create a good market position for the airlines and, hence, good financial performance.

• 한국미생물·생명공학회지
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• 제7권1호
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• pp.1-8
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• 1979

혈액 및 생체반응물질등에 함유된 미량의 glucose를 효소적으로 간편하게 측량하기 위하여 먼저 고가의 glucose oxidase를 고정화 시켰다. 전리 방사선조사에 의하여 이 효소를 쉽게 고정화 시킬수 있는 방법과 그 알맞는 조건 및 높은 잔여 활성에 관한 결과는 다음과 같다. 1) 여러가지 monomer 및 polymer의 combination 중에서 AA-Bis, NK ester 23G, 물 (1:1:2)에 가용성 효소 1ml를 고정화 시켰을 경우를 비롯하여 GOD의 잔여활성이 50%이상인 여러 monomer Combination 찾았다 2) Carrier의 방사선중합에 필요한 선량은 100 krad 이상 이였으나, 400~500krad가 적당하였고, solvent는 toluene, n-haxane, petoleum ether chloroform 등을 이용할 때 고정화된 GOD의 잔여 활성 및 이화학적 성장이 좋았다. 3) GOD 고정화에 이용될 수 있는 완충 용액은 tris-glycerol buffer (pH 7.0)가 phosphate (pH 7.0) 보다 높은 활성을 보여 주었다. 4) 고정화된 GOD의 최적 pH는 6.0~6.5 또 온도는 30~4$0^{\circ}C$로서 가용성 효소보다 작용범위가 넓었고, pH 및 온도의 변화도 완만하였다. The author acknowledges with gratitude financial assistance from International Atomic Energy Agency, Vienna, Austria and also sincerely thanks Dr. K. Kawashima and his colleagues, National Food Research Institute, Tokyo, Iapan for encouragement and assistance.

• 한국도서관정보학회지
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• 제41권2호
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• pp.251-272
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• 2010

IFLA의 국제목록규칙에 관한 목록전문가회의(IME ICC)에서 결정한 국제목록원칙(International Cataloguing Principles)을 반영하고, 서지레코드의 기능상의 요건(FRBR)에 제시된 목록의 개념 모형과 전거데이터의 기능상의 요건(FRAD)에 제시된 전거데이터의 개념 모형을 구현할 수 있는 새로운 목록규칙인 RDA(Resource Description and Access) 초안이 2008년 제시되었다. 이에 따라 RDA 규칙에 기반하여 MARC21 포맷에 신규 태그 및 필드를 추가시키고, RDA 및 FRBR을 실질적으로 구현하기 위한 프로토타입에 관한 연구가 진행되고 있다. 이러한 국제적인 목록 환경의 변화에 따라 국내에서 RDA 규칙의 수용을 위해 목록규칙과 엔코딩 포맷인 KORMARC의 개정이 요구된다. 이를 위해 한성대학교 MARC 데이터에서 RDA 및 FRBR의 저작 및 표현형 요소의 입력 정도를 분석하여, RDA를 위한 현행 MARC 데이터의 한계를 파악하였다. 이러한 데이터 입력의 한계를 바탕으로, 국내 목록 환경에서 RDA 규칙을 접목하기 위한 목록규칙과 KORMARC 추가 태그 및 필드를 제시하였다. 고려할 목록 규칙 및 기술 원칙으로는 표현원칙, 기본표목 및 "rule of three", 채택서명, 내용/매체/수록매체 유형 적용 등이었다. 본 연구는 국내에서 RDA를 위한 목록규칙 및 KORMARC 개정의 방향을 제안하였다는 데 그 의의가 있다.