• 한국재료학회지
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• 제25권12호
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• pp.678-682
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• 2015

The electrical property of polymer matrix composites with added carbon powder is studied based on the temperature dependency of the conduction mechanism. The temperature coefficient of the resistance of the polymer matrix composites below the percolation threshold (x) changed from negative to positive at 0.20 < x < 0.21; this trend decreased with increasing of the percolation threshold. The temperature dependence of the electrical property(resistivity) of the polymer matrix composites below the percolation threshold can be explained by using a tunneling conduction model that incorporates the effect of the thermal expansion of the polymer matrix composites into the tunneling gap. The temperature coefficient of the resistance of the polymer matrix composites above the percolation threshold has a positive value; its absolute value increased with increasing volume fraction of carbon powder. By assuming that the electrical conduction through the percolating paths is a thermally activated process and by incorporating the effect of thermal expansion into the volume fraction of the carbon power, the temperature dependency of the resistivity above the percolation threshold can be well explained without violating the universal law of conductivity.

• 정보관리학회지
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• 제14권2호
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• pp.85-103
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• 1997

정보통신기술의 발달로 각종 정보의 전자화에 따라 정보의 생산과 수집, 저장, 관리 및 이용과정이 지금까지의 평면적 인쇄정보에서 입체적이며 다감각적인 네트워크형 멀티미디어 정보형태로 변환되고 있다. 본 연구에서는 정보사회에서 필연적으로 요구되는 효율적인 전자정보 관리를 위하여 미국을 중심으로 선진국들의 전자정보 관리 현황을 비교, 분석하여 우리나라 현실에 적용 가능한 전자정보 관리시스템 모형을 제시하고자 한다.

• 한국해안해양공학회지
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• 제2권2호
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• pp.96-103
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• 1990

A local Iribarren number is suggested for the universal use of breaker type classification, which relates the bed slope to the wave steepness, both being given from the breaking point. The existing Iribarren number uses the wave length at an offshore point, while the local Iribarren number uses the wave length at the breaking point so that it can imply any influences due to current interaction and diffraction. The modified form of Miche's breaking criterion includes 고 breaking parameter which may be related to the local Iribarren number. Using the modifiedform of Miche's criterion with the local Iribarren number, the inclusion of Doppler effect seems to describe well the wave breaking mechanism in a current-interacted flow on a sloping beach without any additional effects implemented.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2006년도 춘계학술대회
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• pp.129-134
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• 2006

Environmental pollution was begun to rise suffering increase in population with fast economic growth after industrial revolution teeth. Be, air pollution out of them, pollution most seriously happen, and began to cope in greenhouse gas danger from this time. Presents greenhouse gas problem is becoming universal interest ago, and our country is becoming problem. Wish to reduce greenhouse gas in world climatic change convention through Gyoto mekanijeum to reduce greenhouse gas. Wish to present standard for consideration in among CDM business, base line formation out of them.

• Bulletin of the Korean Chemical Society
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• 제5권4호
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• pp.140-145
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• 1984

A theory is given for determining the molecular weights of block copolymers from the experimental elution volume in GPC. Interaction effect between a sample of block copolymer and a column packing material as well as the size effect are separately considered for the first time applying the partial exclusion mechanism proposed by Dawkins. The molecular weight determination shows 6${\%}$ standard-deviation from the molecular weights measured by an osmometric method for eight block copolymers, which is much more improved result than other methods, e.g., the universal plot method (13 ${\%}$) and the Runyon's method (12 ${\%}$). The reason which explains the better result is that our theory takes into account the interaction effect correctly.

• Applied Microscopy
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• 제49권
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• pp.2.1-2.11
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• 2019

Nanomaterials (NMs) find widespread use in different industries that range from agriculture, food, medicine, pharmaceuticals, and electronics to cosmetics. It is the exceptional properties of these materials at the nanoscale, which make them successful as growth promoters, drug carriers, catalysts, filters and fillers, but a price must be paid via the potential toxity of these materials. The harmful effects of nanoparticles (NPs) to environment, human and animal health needs to be investigated and critically examined, to find appropriate solutions and lower the risks involved in the manufacture and use of these exotic materials. The vast number and complex interaction of NM/NPs with different biological systems implies that there is no universal toxicity mechanism or assessment method. The various challenges need to be overcome and a number of research studies have been conducted during the past decade on different NMs to explore the possible mechanisms of uptake, concentrations/dosage and toxicity levels. This review article examines critically the recent reports in this field to summarize and present opportunities for safer design using case studies from published literature.

• 수완나부미
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• 제11권2호
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• pp.159-186
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• 2019

Southeast Asia accounts for nearly a tenth of total worldwide cross-border movements of migrant workers. Cambodia, Indonesia, Laos, Myanmar, and Philippines make up the sending countries while Malaysia, Singapore, and Thailand are the major destinations. Migrant worker movements are predominantly in production process and low- to medium-skilled sectors. It is not unusual for irregular or undocumented movements to take place. In not a few instances, migrants work under harsh and exploitative conditions. In recent years, however, ASEAN has taken steps to manage labor migration at the regional level. The paper argues that ASEAN has not managed these cross-border labor flows as well as it should particularly in terms of protecting and promoting the human rights of migrants. It will be difficult to establish the genuine building blocks for a regional human rights mechanism unless there is a diffusion of alternative universal norms and standards to what ASEAN already embodies. As long as states resist any attempt to weaken or question or deligitimize their capacity to determine who gets to enter, stay, and leave their jurisdictions, it will be difficult to establish an effective migrant rights framework for the region.

• 대한기계학회논문집A
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• 제35권6호
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• pp.661-667
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• 2011

접촉식 측정 프로브는 3 차원 좌표 측정기 및 CNC 공작기계 등에서 제품 검사에 많이 활용되고 있고, 최근 품질 향상을 위한 가공 및 검사장비의 고정도화에 따라 측정의 정확도도 또한 매우 중요시 되고 있다. 이에 따라 스트레인 게이지 등을 이용한 고정도의 측정 프로브가 사용되고 있기는 하지만, 본 연구에서는 경제적인 측면을 고려하여 산업현장에서 공작기계에 많이 활용되는 일반 접촉식 측정 프로브의 메커니즘을 이해하고, 측정 시 발생할 수 있는 프로빙 오차에 대한 분석 및 보정을 통하여 그 활용성을 높이고자 하였다. 이를 위하여 스타일러스 반경 및 중심 정렬오차가 규명되었고, 3 차원 공간상의 측정 좌표에서 프로빙 오차에 대한 해석이 이루어졌다. 이러한 오차들을 보정하기 위한 알고리즘이 개발되었으며, 실제 CNC 공작기계 상에서 기준구 측정을 통한 검증이 이루어졌다.

• 방송공학회논문지
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• 제14권3호
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• pp.288-298
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• 2009

본 논문에서는 방송콘텐츠 저작권 식별관리를 위한 방송콘텐츠의 Video Signature와 국가표준콘텐츠식별체계인 UCI(Universal Content Identifier)의 연계 방안을 제시한다. Video Signature는 UCI와 같은 식별자의 인위적인 부여 과정이 없더라도 동영상 콘텐츠 자체에서 직접 특징정보를 추출할 수 있기 때문에, 이미 배포 유통된 콘텐츠에 대해서도 식별 확인이 가능하다. 따라서, 본 연구에서는 최근 국가표준콘텐츠식별체계로 통합, 단일화된 UCI 식별체계와 내용기반 식별정보인 Video Signature의 지속적인 연계를 위하여, 바이너리로 표현된 Video Signature를 포함하는 UCI 응용메타데이터를 정의한다. 그리고 UCI 표준식별체계 기반 Video Signature 전송 및 관리 메카니즘에 기반한 방송콘텐츠의 저작권 식별관리 및 부가서비스 시나리오를 제시한다.

• Journal of Astronomy and Space Sciences
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• 제31권3호
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• pp.235-240
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• 2014

The communications link in a space program is a crucial point for upgrading its performance by handling data between spacecraft bus and payloads, because spacecraft's missions are related to the data handling mechanism using communications ports such as a controlled area network bus (CAN Bus) and a universal asynchronous receiver and transmitter (UART). The NEXTSat-1 has a lot of communications ports for performing science and technology missions. However, the top level system requirements for the NEXTSat-1 are mass and volume limitations. Normally, the communications for units shall be conducted by using point to point link which require more mass and volume to interconnect. Thus, our approach for the novel communications link in the NEXTSat-1 program is to use CAN and serializer and deserializer low voltage differential signal (SerDesLVDS) to meet the system requirements of mass and volume. The CAN Bus and SerDesLVDS were confirmed by using already defined communications link for our missions in the NEXTSat-1 program and the analysis results were reported in this study in view of data flow and size analysis.