• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.176-181
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• 2009

In this work, a new type of DSCs based on nanoporous FTO structure is being developed for research aimed at low-cost high-efficiency solar cell application. The nanoporous FTO materials have been prepared through the sol-gel combustion method followed by thermal treatment at $450{\sim}850[^{\circ}C]$. The properties of the nanoporous FTO materials were investigated by IR spectra, BET and TEM analyses, and the photovoltaic performance of the prepared DSCs were examined. It can be seen from the result that the nanoporous FTO exhibited good transparent conductive properties, well suited for DSCs application.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.119-119
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• 2012

섬유염색산업 중 면섬유의 염색과정에서 발생되는 머서라이징 폐액은 폐수처리장의 pH(수소이온농도)를 올리는 주원인이 되고 있어, 높은 pH에 따른 폐수처리 부과금이나 황산을 이용한 폐수 중화에 사용되는 약품비용이 과다하게 소요되고 있으며, 머서라이징공정에 사용되는 약품인 가성소다 비용이 계속 증가하고 있어, 기업의 환경처리비용 및 약품소모비용에 대한 부담이 매우 큰 실정이다. 본 기술은 머서라이징 폐액에 멤브레인 공정에 적용하여 폐가성소다로부터 가성소다를 회수할 뿐만 아니라, 회수된 가성소다를 다시 머서라이징 공정에 재이용할 수 있도록 하여 약품 절감효과 뿐만 아니라 폐수의 발생량과 오염물질의 농도의 획기적인 저감이 가능한 것이다. 본 연구에서는 서로 다른 기공크기를 갖는 막을 적용하여 투과플럭스, 부피회수율, 부유물질 및 유기물 제거율, 가성소다회수율, 파울링지수 등을 고려하여 폐수 특성에 맞는 가장 적합한 막을 선정하고, 각각의 막에 대하여 온도조건, 압력조건, 화학세정 등의 운전변수를 최적화, 고효율 폐알카리 회수 장치의 경제성 및 기술적 타당성 평가를 통한 가성소다 회수공정을 구성하였다.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.43-53
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• 2008

Hyper text transfer protocol (HTTP) over transmission control protocol (TCP) is currently used to transfer objects in the Internet. Stream control transmission protocol (SCTP), an alternative to TCP, which allows for independent delivery among streams, and can thus reduce the mean response delay of web object. We present an analytical model to find the mean response delay for HTTP over SCTP, therefore, estimate the effectiveness of SCTP over TCP. Typical TCP delay models assume the wired environment. On the contrary, the proposed model in this paper assumes the multiple packet losses and wireless environment where fast retransmission is not possible due to small window. The estimated mean response time can be used the benchmark to meet quality of service (QoS) at end-user. We validate the accuracy of our model using experiments. It is shown that the differences between the results from model and those from experimental are very small below 6 % on average. We also find that the mean response delay for HTTP over SCTP is less than that for HTTP over TCP.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.195-203
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• 2003

With the spread of interment, the digitalization and knowledge-based information are in progress. Specially, numerous users make the various works and use the services on the web. For the most part, these works make use of the XML. The XML shines the reusing of the Documents because it is separated from contents and styles. Also, it can re-define the logic structure of the Document for requirement of the developer. However, the XML document's size is much larger than common text document because it basically handles the document type and adds numerous tags for representing structure of the document. To utilize the limited storage of Palmtop, PDA and so on, it is necessary to compress and handle the documents efficiently. Recently, the compression techniques for efficiently handling and compressing the XML documents are in progress to solve this problem. But the existing research doesn't support the query processing for that. In this paper, we design and implement the XML compression algorithm that compresses the XML document and processes the quay of compressed XML document faster and mote effciently than the previous techniques.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.107-114
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• 2014

The satellite 2.1 GHz frequency bands, 1980-2010 MHz and 2170-2200MHz are allocated for mobile satellite service including satellite IMT, while it does not preclude the use of these bands for mobile services. The concept of an integrated satellite/terrestrial network has been introduced in worldwide because the terrestrial use in these bands adjacent to existing terrestrial IMT bands is attractive to provide mobile broadband services. The integrated satellite/terrestrial infrastructure with a high degree of spectrum utilization efficiency has the ability to provide both multimedia broadband services and public protection and disaster relief solutions. In addition, it is required to consider interference issues between the terrestrial and satellite components in order to reuse the same frequency band to both satellite and terrestrial component. This paper analyzes the interference for satellite uplink in the satellite/terrestrial integrated system and the interference reduction scheme for satellite uplink interfered by terrestrial user equipment.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.81-88
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• 2013

The satellite 2.1 GHz frequency bands, 1980-2010 MHz and 2170-2200MHz are allocated for mobile satellite service including satellite IMT, while it does not preclude the use of these bands for mobile services. The concept of an integrated satellite/terrestrial network has been introduced in worldwide because the terrestrial use in these bands adjacent to existing terrestrial IMT bands is attractive to provide mobile broadband services. The integrated satellite/terrestrial infrastructure with a high degree of spectrum utilization efficiency has the ability to provide both multimedia broadband services and public protection and disaster relief solutions. In addition, it is required to consider interference issues between the terrestrial and satellite components in order to reuse the same frequency band to both satellite and terrestrial component. This paper analyzes the interference for satellite downlink in the satellite/terrestrial integrated system and presents the interference mitigation techniques for satellite mobile earth station interfered by terrestrial base stations.

• The Journal of the Korea Contents Association
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• v.4 no.1
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• pp.90-99
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• 2004

With the spread of internet, the digitalization and the knowledge informatization are in progress rapidly. Specially, numerous users make the various works and use the services on the web. For the most part, these works make use of the XML The XML shines the reusing of the documents because it is separated from contents and sues. Also, it can re-define the logic structure of the document for requirement of the developer. However, the XML document’s size is much larger than common text document because it handles the document type and adds numerous tags for representing structure of the document. To utilize the limited storage devices of Palmtop, PDA and so u, it is necessary to compress and handle the documents efficiently. Recently, the compression techniques for efficiently handling and compressing the XML documents are under way to solve this problem. But most of the existing researches don't support the query processing for the compressed XML documents. In this paper, we design and implement the XML compression algorithm that compresses the XML document and Processes the query of compressed XML document faster and more efficiently than previous techniques.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.114-119
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• 2008

With the improvement of industrial society, the high quality electrical energy, simplification of operation and maintenance, ensuring reliability are being required. We request urgently change a $SF_6$ for an environment friendly gas insulation material. In this paper the experiments of breakdown characteristics by pressure and gap change of Imitation-Air in model GIS(Gas Insulated Switchgear) were described. Also assess of breakdown characteristics about Imitation-Air and $SF_6$. It is considered in this paper that the results are fundamental data for electric insulation design of Distribution Power Facilities which will be studied and developed in the future. The pressure to be confronted to $SF_6$ gas 1[atm] for Distribution Power Facilities is Imitation-Air 3[atm]. And we could make an environment friendly gas insulation material with maintaining dielectric strength by Imitation-Air which generates a lower level of the global warming effect.

• 보존과학연구
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• s.34
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• pp.84-99
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• 2013

There are more than 2,900 different species of termites in the world, and just there are 23 species in Japan. They caused more severe infestation compared with Korea. When a structure has become infested with termites, it is important that appropriate action must be taken: the chemical pest control (fumigation, soil termiticide treatment, bait system etc.) or the non-chemical pest control (low oxygen treatment, carbon dioxide treatment, high/low temperature treatment etc.). Especially, there were attempts to make practical protocol of various alternatives since the fumigant(methyl bromide) had been phased out in 2005 in Japan, and practically non-chemical methods would be effective alternatives for some cases, where the scale of infestation is small and limited and when long treatment is possible. But most of all, it is important that the process of pest control is made according to each species of termites with consideration for different characteristics of termites.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.560-564
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• 2008

환경부에서는 2000년 3월에 수립 시행된 물 절약 종합대책의 실효성 확보를 위해 시도별로 "물 수요관리 종합계획"을 수립하여 환경부의 승인을 받도록 하였다. 수요관리를 위한 주요 정책 수단은 유수율제고, 절수기기 보급, 수도요금현실화, 중수도 설치, 하폐수처리수 재이용 등이며 2006년까지 서울, 제주도를 제외한 14개 시도에서 물 수요관리 종합계획을 수립하여 승인 받았다. 본 연구에서는 두 가지 측면에서 수요관리 절감량을 평가하고자 하였다. 첫 번째로는 환경부에서 시범평가에 사용하였던 수요관리 수단별 사업추진실적 평가 이외에 지자체에서 절수량을 고려하여 계획하였던 1인 1일급수량 및 유수율과 상수도통계에서 발표된 실제 1인1일급수량 및 유수율 자료를 이용하여 목표달성율을 산정하고 이를 이용해 평가하였다. 두 번째로는 통합수자원평가계획모형인 K-WEAP(Korea-Water Evaluation And Planning System) 모형을 통해 금강권역을 대상으로 사업추진실적 자료 및 절수량 산정식을 사용하여 K-WEAP 모형에서 수요관리 절수량을 산정하고 물수지분석을 수행하여 가용수량을 평가하였다. 수요관리 평가 기반이 구축된 K-WEAP 모형을 통해 여러 시나리오에 따른 수자원 절감가능량 산정 및 정부, 지자체의 수요관리 정책을 평가할 수 있으며 수요관리, 중수도 이용 등 다양한 수자원 보전환경의 변화를 용수수요 추정에 반영할 수 있다. 또한 수요관리 효과 증대방안 향상으로 국가 및 지자체 오염총량관리 계획 및 수자원장기종합계획 수립에 기술적 발전을 도모할 수 있을 것으로 기대된다.