• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.304-304
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• 2011

최근 도시화에 따른 인구증가와 더불어 도로포장 등 불투수면적의 증가로 인하여 우기시 빗물 침투가 차단되어 도심의 지하수위가 저하되며 토양의 건토화, 열섬현상 등의 문제가 발생하게 되었다. 이러한 문제점에 착안하여 본 연구에서는 투수효과를 최대한 고려할 수 있는 고강도의 친환경 콘크리트 블록(에크스톤 바이오 블록; ECOSTONE-BIO BLOCK)을 개발하였으며 기존 콘크리트 블록의 자연적 빗물침투 억제의 문제점을 일부 개선하였다. 본 블록은 캡슐공법을 사용하여, 공극률은 높이면서(투수성 향상), 강도와 내구성이 유지됨은 물론 캡슐안에 황토성분을 첨가하여, 바이오적인 기능 및 재생골재를 이용한 친환경적 제품으로 투수성, 내구성, 기능성을 극대화 시켰다. 또한 제품표면은 천연 백색돌맹이, 흑색돌맹이의 배합으로 자연석재 느낌을 구현하였으며, 쇼트블라스트 및 커링 표면공정으로 미끄럼저항지수를 조절할 수 있어, 기존 콘크리트 보도블록에 비해 투수율, 내구성, 기능성, 안전성이 우수하여, 안전한 보행환경이 가능한 것으로 분석되었다. 마지막으로, 주변 환경과 잘 어울리도록 디자인된 바이오기능성 친환경 블록으로 도심지역 시공시 투수효과에 따른 지하수고갈방지 및 침수피해에 도움을 주리라 사료된다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.62.2-62.2
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• 2011

산업화 이후, 석탄 석유를 중심으로 한 화석연료가 이산화탄소를 대량으로 배출하며 지구 온난화를 야기함에 따라, 기존의 화석연료를 대체할 청정하고 무한 재생 가능한 대체에너지로 가장 큰 기대를 받고 있는 것은 태양에너지이며, 이에 보조를 맞춰 태양광발전에 대한 연구개발이 국내외적으로 활발히 진행되고 있는 실정이다. 태양 전지는 빛 에너지를 직접 전기 에너지로 바꿔주는 소자로, 셀의 효율을 높이기 위해서는 최대한 많은 빛을 흡수시킬 수 있는 것이 중요하다. 빛의 반사를 줄이는 방법에는 texturing과 antireflecting coating이 있다. Antireflecting coating은 반도체와 공기의 중간 굴절율을 갖는 박막을 증착하여 측면 반사를 감소시킴으로서 빛의 손실을 감소시키는 역할을 한다. 과거에 반사방지막으로 가장 많이 사용되었던 물질은 SiO로써 굴절률은 1.8~1.9로서 최소의 반사율은 1% 미만이지만, 가시광선영역에서의 흡수에 의한 손실이 생기므로, SiNx가 대체 물질로 제안되었다. SiNx의 경우 굴절률이 약 1.5로서 Si에 쉽게 형성시킬 수 있고, texturing된 Si 표면에 적합하며 반사율을 10%에서 2%로 줄일 수 있는 장점을 가지고 있다. 따라서 본 연구에서는 high power, high frequency PECVD 방법으로 $SiH_4$와 $NH_3$ gas의 비율, $N_2$ carrier gas 등 공정 변수를 변화시켜 증착한 SiNx 박막의 결정학적 특성을 X-ray diffraction 분석과 XPS (X-ray photoelectron spectroscopy)를 통해 화학적 결합을 확인하였고, 이를 FT-IR (Fourier Transform-Infrared spectroscopy)를 통해 관찰한 결과와 연관시켜 분석하였다. 굴절율의 경우 ellipsometer를 이용하여 측정하였으며 위의 측정을 통하여 SiNx박막의 반사 방지막으로써의 가능성을 확인 하였다.

• Journal of the Korean Solar Energy Society
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• v.39 no.6
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• pp.137-151
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• 2019

This study estimated the available renewable market potential based on Levelized Cost Of Electricity and then assessed the renewable derived energy self-sufficiency for the unit of local government in South Korea. To calculate energy self-sufficiency, 1 km gridded market renewable generation and local government scale of final energy consumption data were used based on the market costs and statistics for the recent three years. The results showed that the estimated renewable market potentials were 689 TWh (Install capacity 829 GW, 128 Mtoe), which can cover 120% of power consumption. 55% of municipalities can fully replace the existing energy consumption with renewable energy generation and the surplus generation can compensate for the rest area through electricity trade. However, it was confirmed that, currently, 47% of the local governments do not fully consider all renewable energy sources such as wind, hydro and geothermal in establishing 100% renewable energy. The results of this study suggest that energy planning is decentralized, and this will greatly contribute to the establishment of power planning of local governments and close the information gap between the central government, the local governments, and the public.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.22-28
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• 2019

Cement is a basic material for the construction industry and it requires high temperature sintering when manufacturing cement. $CO_2$ emissions from raw materials and fuels are recognized as new environmental problems and efforts are underway to reduce them. Techniques for reducing $CO_2$ in concrete are also recommended to use blended cement such as blast furnace slag or fly ash. In addition, the construction waste generated in the dismantling of concrete structures is recognized as another environmental problem. Thus, various methods are being implemented to increase the recycling rate. The purpose of this study is to utilize the inorganic raw materials generated during the dismantling of the structure as a raw material for the low carbon type cement binder. Such as, waste concrete powder, waste cement block, waste clay brick and waste textile as raw materials for low carbon type cement binder. From the research results, low carbon type cement binder was manufactured from the raw material composition of waste concrete powder, waste cement block, waste clay brick and waste textile.

• Journal of Environmental Policy
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• v.8 no.3
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• pp.27-51
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• 2009

This study looked for ways to carry out development projects in a sustainable manner by generating improvement plans, and focused on reviewing the status and problems associated with the environmental and ecological planning that is currently applied to new town and large-scale development projects. Improved methods were suggested based on differences between urban development and housing development projects. Based on principles set for the introduction of environmental and ecological planning, the size of the projects subject to environmental and ecological planning was set. With regard to the procedural improvements for environmental and ecological planning, nine problems were singled out from the development planning phases. Solutions were suggested by separating the problems into the site and district designation phase, development planning phase, implementation planning phase, and post-management phase based on a literature review and the opinion of experts. In consideration of improvements to the planning system, the scope of environmental and ecological planning was set after looking at information related to environmental and ecological planning, literature review, expert interviews, and the relevance of related plans. The scope of the environmental and ecological planning was divided into the overview of planning, environmental and ecological conception, conception of spatial structure and framework, and urban environment regeneration and impact reduction plans. By synthesizing the above-described results, the functions of environmental and ecological planning, development planning, and environmental assessment and their inter-relations were defined. The defined inter-relations seem likely to be developed into a form that would enable sustainable land development.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.1
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• pp.39-46
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• 2011

This study was carried out to determine the forage yield, quality, and regrowth of Italian ryegrass (IRG) and barley sown on 2 March 2009 in Suwon. The five treatments were two IRG cultivars (Kowinearly with early maturity and Kowinmaster with medium maturity), one barley cultivar (Yuyeon), and two mixtures (Kowinearly + Yuyeon and Kowinmaster + Yuyeon). The first harvest date was 26 May, which was at late heading, heading and early dough stage of Kowinearly, Kowinmaster and barley, respectively. Regrowth yield was investigated on 29 June. The heading dates of Kowinearly and Kowinmaster were 16 May and 22 May, respectively, and that of barley was 13 May. The dry matter (DM) percentage were 13.0~18.4% at first harvest, and 22.5~24.8% at regrowth in all treatments. The forage yield of barley and Kowinmaster + Yuyeon mixture at first harvest was higher than that of IRG (p<0.05), but higher regrowth yield was observed in IRG, and then IRG + barley mixtures (p<0.05). The crude protein (CP) content and in vitro DM digestibility (IVDMD) of IRG at first harvest were 16.7~17.1% and 78.3~80.4%, respectively, which were higher than those of barley (CP 12.2% and IVDMD 72.6%) and IRG + barley mixtures. The total yields of DM, CP and digestible DM were high in Kowinmaster + Yuyeon mixture as 11,628 kg, 1,669 kg and 8,457 kg per ha, respectively. In conclusion, spring seeding of IRG + barley mixtures and/or barley were recommended when early harvest. Regrowth of IRG sown in early spring was vigorous. Mixture cultivation of IRG and barley was effective, because of forage yield and stable production, and harvest at June instead of May was desirable for forage productivity of spring sown IRG and barley.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.453-460
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• 2018

Owing to rising oil prices and anthropogenic global warming, focused attempts are being made toward production of industrially important compounds by using renewable biomass. In this context, algal biomass as third-generation biomass is important because it doesn't compatible with food resource, has high yield, and helps abate greenhouse gases. Here, we investigate whether Undaria has the highest sugar content, which would make it the most suitable biomass for lactic acid production among the four algal biomasses tested. For effective pretreatment of Undaria, the response surface methodology was used. The amount of solid loaded and catalyst concentration were related to the extraction rate of total sugar. Lactic acid was produced by pretreatment of Undaria by using four Lactobacilli, and L. alimentarius and L. brevis were found to be suitable for lactic acid production.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.49.1-49.1
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• 2009

산업화 이후, 석탄 석유를 중심으로 한 화석연료가 이산화탄소를대량으로 배출하며 지구 온난화를 야기함에 따라, 석유를 대체할 새로운 에너지원에 대한 관심이 높아지고 있다. 많은 대체에너지 가운데, 청정하고 무한 재생 가능한대체에너지를 이야기할 때, 가장 큰 기대를 받고 있는 것은 태양에너지이며, 이에 보조를 맞춰 태양광 발전에 대한 연구개발이 국내외적으로 활발히 진행되고 있는 실정이다. 태양 전지는 빛 에너지를 직접 전기 에너지로 바꿔주는 소자로, 셀의효율을 높이기 위해서는 최대한 많은 빛을 흡수시킬 수 있는 것이 중요하다. 빛의 반사를 줄이는 방법에는 Texturing 과 Antireflecting coating 이있다. Antireflecting coating은 반도체와 공기의 중간 굴절율을 갖는 박막을 증착하여 측면 반사를 감소시킴으로서 빛의 손실을 감소시키는 역활을 한다. 반사 방지막으로 쓰이는 SiNx는 SiOx의 대체 물질로 굴절률이 약 1.5로서 Si에 쉽게 형성시킬 수 있고, texturing된 Si 표면에 적합하며 반사율을 10 %에서 2 %로 줄일 수 있다. 나아가 고성능의 반사방지막은 박막의 균일도확보 및 passivation 공정이 필수적이라 판단된다. 따라서 본 연구에서는 PECVD 방법으로 SiH4와 NH3 gas 의 비율을 변화시켜 증착한 SiNx 박막의 결정학적 특성을 X-ray Diffraction 분석과 TEM (TransmissionElectron Microsopy) 을 통해 관찰하였으며, XPS (X-rayphotoelectron spectroscopy) 를 통해 화학적결합을 확인하였고, 이를 FT-IR (Fourier Transform-Infrared spectroscopy)를 통해 관찰한 결과와 연관시켜분석하였다. 굴절율의 경우 Ellipsometry를 이용하여측정하였으며 위의 측정을 통하여 SiNx박막의 반사 방지막으로써의 가능성을 확인하였다.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.439-449
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• 2014

RPS (Renewable Portfolio Standard) has increased wood pellet demand dramatically in recent years in Korea where self-supply rate of wood pellet is not more than 10%. However global production capacity of wood pellet is prospected to be unable to meet the global demand after 2020. Therefore it is urgently needed to develop new sustainable biomass energy resources which can replace wood pellet at lower cost. As a result of this study EFB (empty fruit bunch) and MF (mesocarp fiber), the representative solid palm biomass, are estimated to be generated at the rate of 20 and 28 million tons per year (based on 10% moisture content) in Malaysia and Indonesia, respectively in 2012. Total annual generation rate of EFB and MF is estimated as 48 million tons per year only in Malaysia and Indonesia in 2012. With calorific value of over 90% of wood pellet EFB is expected to be a excellent biomass energy resource which can replace wood pellet. EFB can be utilized as fuel for power generation or industrial purpose. However EFB may not be a proper fuel for domestic and greenhouse heating because of its high ash content.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.553-556
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• 2013

Currently green growth and energy saving are major issues and solution using low-power LED lighting devices are gaining popularity. There are a few standards to control these LED lighting equipment and DMX512 protocol is a typical communication control standard used. DMX512 lighting control protocol is one of standard protocols widely used in various fields which include mainly stage lighting and landscape lighting. But in DMX512 protocol, line is to be connected to a wired connection. Advantage of wired connection is stable data transfer operation but it adds complexity and certain constraints as well in wired connection. To solve this problem, wired connection can be replaced efficiently with a wireless connection but for wireless, problem of data loss and two way communications arises. In this paper, these problems of wireless communication for DMX512 have been addressed and solutions for two way communications and data loss problem have been proposed.