• Resources Recycling
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• v.2 no.2
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• pp.16-21
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• 1993

This study was carried out to investigate the settling characteristics of Fe(II) and Fe(III) hydroxide precipitates formed by pH adjustment of aqueous solution to remove ferrous and ferric ion in waste water. The results obstained in this study are as fellows : The settling rate was effectively increased with increasing the pH values of aqueous solution regulated by CaO and with increasing the amount of flocculant, on the other hand, application of excess flocculants decreased the settling rate. It is desirable that the concentration of iron ion is kept under $10^{-2}$ mol/ㅣ because the settling rate was decreased with increasing the concentration of iron hydroxide precipitates.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.833-844
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• 2008

Bio-energy offers the opportunity to lessen fossil fuel consumption. Energy derived from solar, wind, hydroelectric, geothermal, and biomass sources are considered renewable. Because most forms of bio-energy are derive deither directly or indirectly from the sun, there is an abundant supply of renewable energy available, unlike fossil fuels. The use of bio-energy also provides environmental, economic and political benefits. Bio-energy can be produced from a marine source such as biomass provides a $CO_2$ neutral, non-polluting form of energy. In this paper, the potential of marine biomass is increasingly discussed, given the size of the resource in that more than three quarters of the surface of planet earth is covered by water.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.4
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• pp.472-487
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• 1999

본 논문에서는 효율적인 이동성 관리를 위한 이동성 예측 기법을 소개한다. 이동 컴퓨팅 환경에서는 사용자가 지리적 위치의 제약없이 언제, 어디서나 다른 네트워크 시스템과 메시지를 주고 받을수 있다. 그러나, 통신자원의 부족, 잦은 접속단절 , 사용자의 움직임 등과같은 이동 컴퓨팅 시스템의 특징 때문에, 지능적이고 효율적인 이동성관리가 요구된다. 이동 컴퓨팅 시스템이 지능적이고 효율적인 이동성관리를 통하여 높은 질의 서비스를 제공하기 위해서는 이동 사용자의 움직임 패턴들을 능동적으로 고려하는 것이 바람직하다. 본 논문에서는 이동 사용자의 과거수일, 수개월동안의 움직임 패턴 즉, 이동사용자의 위치연혁으로부터 미래 위치를 예측하는 지능적 이동성 예측기법(intelligent mobility prediction scheme)을 제안한다. 모델링 방법으로서 뉴로-퍼지 추론시스템(neuro-fuzzy inference system)을 이용한다. 뉴로-퍼지 추론 시스템이 이동 사용자가 움직이게 되는 미래 위치를 예측하기 때문에 , 본 논문에서의 이동성 예측 기법은 통신채널의 사전 배당, 부족한 자원의 사전 할당등을 위해서 사용될 수 있다. 게다가, 본 논문의 시뮬레이션 결과는 제안하는 기법이 다양한 이동 환경에 대해서 높은 예측 정확도를 갖음을 보여준다.

• Resources Recycling
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• v.32 no.1
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• pp.3-12
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• 2023

Bauxite residues represent industrial wastes that have been accumulating over the past 120 years since the beginning of the alumina industry. They are typically classified as harmful substances owing to their strong alkalinity and salinity characteristics. These residues, with quantities steadily increasing by more than 150 million tons annually worldwide, are recycled into various industrial materials using dealkalization processing. This study investigates the generation process of alkaline substances in bauxite smelting and the recent techniques adopted for controlling their alkalinity. The properties of bauxite residues are known to vary depending on the raw mining and digestion methods. Thus, the dealkalization process must be selected considering the type of alkaline material, local environment, and infrastructure.

• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.403-412
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• 2011

This study aims at proposing clear direction of tourism policy through analyzing the correlation between tourism resource, tourism system and activation of regional economic. A total of 283 samples were ultimately collected in survey of 300 researchers from the national and public institutes in provinces Chungchong-do and Kyungsang-do in July 2010 alone. SPSS 15.0 and AMOS 6.0 were used to test the model. Analysis showed that the more regional tourism resources have more significant effect on tourism system and tourist-attracting strategy, and that tourism system exerts influence on tourist-attracting strategy. So it was proved that the tourism policy effects meaningfully on vitalization of regional economic, and it was confirmed that the tourism system is more effective on the energization of regional economic than the tourist-attracting strategy. But the hypothesis has been rejected unexpectedly that tourist attractions have consequences for the activation of regional economic. It establishes the fact that it is useless for regional economy regardless of abundant regional tourism resources, if the tourism policy is not concretely in force. Therefore, Korean government must intercept overissue and overlapping investments on tourism development by the local government and induce qualitative growth of tourism sector through upgrading of development guidelines and the criteria for selecting tourism special zone, regional festival and cultural assets, and its continuous assessment and management. And it is desirable to enforce the connected cooperation projects between local governments and the 5+2 great-sphere economic blocs on government-level.

• Journal of the Korean association of regional geographers
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• v.19 no.3
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• pp.476-493
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• 2013

Geoturism has been discussed from multiple perspectives in geomorphology and geology as well as tourism domain since 2000. As of May 2013, 172 academic papers and reports on Geoturism have been published in domestic journals. Themes of these researches can be categorized into 6 topics: resource development (i.e. natural resource development, cultural resource development, development of geopark), conservation and management, geoturist, local resident participation and public relations marketing, political approaches. Resource development among those topics has been treated the most: development and utilization of important geomorphological and geological landscape resources, storytelling development about cultual resources, contents development for geopark. On the whole, it is significant that geotourism is actively discussed in geography domain such as geomorphology rather than in geology domain. Up to date, those topics have also been treated only in certain academic areas. In the future researches, efforts for the balance among those topics and creating new themes from various research areas is necessary. Moreover, community networking among locals-municipalities-academia is also necessary to increase local participants.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.29-36
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• 2012

In order to create a wind resource map, we need wind data, contour map and roughness map. Moving Filter technique was applied to Udo of Jeju Island to improve the accuracy and efficiency of creating roughness map based on the Land Cover Map of the Ministry of Environment. The Land Cover Map was simplified using moving filtering, and the roughness map was created with this Land Cover Map. The wind resource map was created using this roughness map. Finally, we verified the validity and application of moving filter technique for wind resource map. As a result, the wind map which was created using the roughness map with moving filtering showed bias values which were all negative. It means the wind map is underestimated to values of wind energy and RMSE values were also from 0.0237m/s to 0.0253m/s at 50m height. In other words, estimation of wind resource using image filtering provides reliable results at 80m height typically when the wind turbine is installed. Finally, we found that image filtering technique is very useful tool to make wind resource map.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.76-78
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• 2006

Jakarta-Slide는 인터넷을 통하여 다양한 컨텐츠의 비동기적인 협업 저작을 지원하는 WebDAV 서버로 널리 사용되고 있다. Jakarta-Slide를 사용하여 개별 사용자가 원격지 자원에 접근하기 위해서는 등록된 개별 사용자에게 적절한 접근 권한이 부여되어야 한다. 하지만 현재의 Jakarta-slide에서는 이러한 사용자 관리를 시스템 관리자가 직접 수작업으로 처리하여야 하므로 관리 작업이 복잡하고 비효과적이다. 따라서 Tomcat 서버에서 사용자를 관리하는 Tomcat Admin 관리도구처럼 Jakarta-Slide의 사용자를 효과적으로 관리할 수 있는 사용자 관리도구가 지원되는 것이 바람직하다. 본 논문에서는 Jakarta-Slide의 사용자 관리도구 개발에 대하여 기술한다. Jakarta-Slide Admin 관리도구는 Tomcat Admin 관리도구를 확장하여 구현되었으며, 효과적인 사용자 관리 기능을 제공한다. 시스템 관리자는 개발된 관리도구를 이용하여 사용자를 생성, 삭제할 수 있으며 역할을 추가하여 사용자에게 적용함으로써 사용자에게 접근 권한을 부여할 수 있다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.181.1-181.1
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• 2010

풍력터빈에서 전력생산량은 속도의 세제곱에 따라 바람의 속도에 크게 영향 받는다. 본 연구에서는 기상청에서 제공하는 새만금 인근 해안의 2005부터 2007년까지의 AWS(지역별 관측자료)와 해양에서 떨어진 새만금 서해의 2000년부터 2009년까지 QuikSCAT위성 데이터를 이용하여 속도에 따른 확률 밀도 분포를 획득하였다. 측정된 관측 데이터는 80m 높이에서의 보정 자료를 근거로 하였으며, IEC 61400-12와 13을 근거로 실증단지 적합성에 대한 분석을 하였다.

• Journal of the Korean Geographical Society
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• v.35 no.1
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• pp.77-93
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• 2000

본 연구는 북한의 지역격차를 분석하고, 상대적으로 낙후된 지역에 대한 개발전략으로서, 북한의 경제발전을 위해 확대.설치가 불가피한 경제특구와 연계하여 지역균형개발전략을 모색해 보았다. 북한의 지역간 인구성장 분석에 의하면, 북한은 지역균형개발정책에도 불구하고, 종주도시 평양과 여타 지역간에 극심한 지역격차를 보이고 있다. 따라서 앞으로 경제특구는 낙후된 지역 즉, 평양을 제외한 여타 지역에 고르게 입지하는 전략이 요구된다는 점을 가조하였다. 그리고 경제특구는 북한의 보유자원 관점에서 노동집약적인 가공공업형 경제특구와 관광형 경제특구로 나누어 추진되는 것이 바람직하며, 입지 후보지로는 신의주.남포.해주.청진.김책.함흥.원산 등의 지구는 가공공업형 경제특구로, 금강산.백두산.묘향산 등의 지구는 관광형 경제특구로 적합하다고 제안하였다.