• 제목/요약/키워드: 기반구조

Search Result 16,545, Processing Time 0.055 seconds

Experimental Study on Helical Turbine Efficiency for Tidal Current Power Plant (조류 발전용 헬리컬 수차의 효율에 대한 실험적 연구)

  • Han, Sang-Hun;Lee, Kwang-Soo;Yum, Ki-Dai;Park, Woo-Sun;Park, Jin-Soon;Yi, Jin-Hak
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2006.05a
    • /
    • pp.530-534
    • /
    • 2006
  • 조류발전은 조류 유속이 빠른 곳에 수차발전기를 설치하여 해수의 운동에너지로부터 전기를 생산하는 발전방식이다. 2001년부터 해양연구원에서는 울돌목의 우수한 조류발전 개발 여건을 바탕으로 조류에너지 실용화 기술을 개발하고 있다. 본 연구에서는 조류발전 시스템에 사용되는 헬리컬 수차의 효율을 현장실험을 바탕으로 판단하고자 하였다. 현장실험을 위하여 지름 2.2 m, 높이 2.5 m의 수차를 제작하고, 울돌목 협수로의 한 쪽 면에 쟈켓구조물을 설치하여 수차를 거치한다. 수차가 회전함에 따라 회전봉에 일정 마찰을 주어 토크와 RPM을 측정하고, 함께 측정된 유속자료를 이용하여 수차를 효율을 산정한다. 유속-수차효율, TSR(수차의 날개속도와 유속의 비)-수차효율의 상관관계로 실험결과를 고찰하였다. 1중 날개 수차인 경우에 유속 1.4에서 2.6 m/s 사이에서 최대효율이 30 - 35 % 정도였고, 2중 날개 수차에 대한 실험에서는 유속 1.4에서 2.6 m/s 사이에서 최대수차효율이 25 - 35 % 사이임을 알 수 있었다. TSR과 최대수차효율의 상관관계는 실험 case별로 조금씩 다르다. 전체적으로 1중 날개의 경우가 최대수차효율에서 2중 날개보다 TSR 값이 조금 큰 경향을 나타냄을 알 수 있다. 이것은 1중 날개가 2중 날개보다 가벼워 좀 더 큰 RPM을 발생시켜서 나타난 현상으로 생각된다. 현재의 실험결과들을 이용하여 TSR과 최대수차효율을 상관관계를 나타내는 모델식을 도출하였다. 현장시험결과를 종합하면, 현장조류발전 시설이 최소 600 kW의 전력이 생산되기 위해서는 지름 3 m, 높이 3.6 m 인 수차 3개가 하나의 축에 설치되어야하는 것으로 계산되었다. 정격유속이 4.8 m/s이고 수차의 지름이 3m 라면, 최적 전력발생시의 RPM은 1중 날개의 경우 79이고 2중 날개의 경우는 63정도임을 추정할 수 있었다.촬영하여 실시간으로 전송하기 때문에 홍수시 하천 상황에 대한 모니터링 목적으로 사용될 수 있다. 영상수위계는 우물통 등을 이용하는 기존 방법과 비교하여 구조물이 필요 없어 설치 비용이 저렴하고, 영상에 의한 하천 모니터링 기능을 자체적으로 가지고 있기 때문에 효율적이라고 할 수 있다.따른 4개의 평가기준과 26개의 평가속성으로 이루어진 2단계 기술가치평가 모형을 구축하였으며 2개의 개별기술에 대한 시범적용을 실행하였다.하는 것으로 추정되었다.면으로의 월류량을 산정하고 유입된 지표유량에 대해서 배수시스템에서의 흐름해석을 수행하였다. 그리고, 침수해석을 위해서는 2차원 침수해석을 위한 DEM기반 침수해석모형을 개발하였고, 건물의 영향을 고려할 수 있도록 구성하였다. 본 연구결과 지표류 유출 해석의 물리적 특성을 잘 반영하며, 도시지역의 복잡한 배수시스템 해석모형과 지표범람 모형을 통합한 모형 개발로 인해 더욱 정교한 도시지역에서의 홍수 범람 해석을 실시할 수 있을 것으로 판단된다. 본 모형의 개발로 침수상황의 시간별 진행과정을 분석함으로써 도시홍수에 대한 침수위험 지점 파악 및 주민대피지도 구축 등에 활용될 수 있을 것으로 판단된다. 있을 것으로 판단되었다.4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주식시장에 적합한 거래전략은 반전거래전

  • PDF

Development of Landscape Urbanism in Practice (랜드스케이프 어바니즘의 실천적 전개 양상)

  • Kim, Youngmin;Jeong, Wookju
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.42 no.1
    • /
    • pp.1-17
    • /
    • 2014
  • The Practice of Landscape Urbanism has been criticized on two aspects; Landscape Urbanism does not yet provide differentiated forms of planning and design neither able to fill the gap between theory and practice. In response to these criticisms, Landscape Urbanists have tried to provide additional cases that can exemplify achievements of Landscape Urbanism in practice. There has been another type of effort to suggest distinct planning and design strategies of Landscape Urbanism from theoretical texts. However, these approaches overlooked the fact that professional practice actually gave huge influence on the theoretical framework of Landscape Urbanism. Based on this observation, the study examined the development process of Landscape Urbanism by verifying the correlation between its practice and theory. Through an extensive literature review, the study suggested horizontality, infrastructure, process, ecology, media, hybrid, site, and scale as eight major concepts of Landscape Urbanism. Afterwards, the study classified 51 projects cited in major essays and articles of Landscape Urbanism into four categories: Archetypal projects, precedent projects, exemplary projects, and progressive projects. The correlation between strategies of the selected projects and main theoretical concepts was analyzed. The study found out that the early stage of the theory was focused on defining and explaining the new design and planning approaches of contemporary design projects related with landscape. However, these days, Landscape Urbanism became a more productive in providing diverse types of practice sharing the direction and vision proposed by the theory. Various projects influenced in constructing theoretical structure of Landscape Urbanism as well as proved that the suggestions of Landscape Urbanism could be effective to reorganize contemporary cites in the form of design and planning strategies. The observation of this study can contribute to provide proper answers to the criticism on practice of Landscape Urbanism and be helpful in understanding the limits and unrealized potentials of Landscape Urbanism as a practical theory.

A Study on Storytelling of Yeongweal-palkyung Applied by Halo Effect of King Danjong' Sorrowful Story (단종애사(端宗哀史)의 후광효과를 적용한 영월팔경의 스토리탤링 전략)

  • Rho, Jae-Hyun
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.36 no.3
    • /
    • pp.63-74
    • /
    • 2008
  • With the awareness that Sinyeongwol Sipgyeong(ten scenic spots in Yeongwol) were designed too hastily and only for PR purposes after the change in the tourism environment, this paper indicates that most tourism and culture sources in Yeongwol are related to King Danjong, the sixth king of the Joseon Dynasty. This study proposes a 'Storytelling Plan' for the landscape content called 'Cultural Landscapes - Yeongwol Palgyeong(eight scenic spots in Yeongwol)' after reviewing types and content of Yeongwol Palgyeong through the halo effect of the well-known sad history of King Danjong and the cultural value of Yeongwol. The significance of the unity of the historic site and neighboring landscape is focused on by investigating the anaphoric relations between cultural landscape texts('Yeongwol Palgyeong') and historic content(the sad history of King Danjong). For this, the cultural lnddscape of Yeongwol has been framed and layered to make spatial texts. To emphasize the 'Telling' as well as the 'Story,' interesting episodes have been reviewed to discover a motive. To diversify the 'Telling' methods, absorptive landscape factors have been classified as 'Place,' 'Object' and 'Visual Point.' In addition the storytelling of Yeongwol Palgyeong was examined in consideration of the story and background of 'Yeongwol Palgyeong - Sad Story of King Danjong' and the interaction of a variety of cultural content by suggesting micro-content such as infotainment and edutainment as absorptive landscape factors. In order to make the storytelling plan available in practice as an alternative plan for Yeongwol Tourism, a visual point should be properly set to make the landscape look sufficiently dynamic. In addition, real landscape routes and narration scenarios should be prepared as well. Professional landscape interpreters who are well informed of the natural features of Yeongwol and the history of King Danjong should be brought into the project, and Internet and digital technology-based strategies should be developed.

Feasibility Test on Automatic Control of Soil Water Potential Using a Portable Irrigation Controller with an Electrical Resistance-based Watermark Sensor (전기저항식 워터마크센서기반 소형 관수장치의 토양 수분퍼텐셜 자동제어 효용성 평가)

  • Kim, Hak-Jin;Roh, Mi-Young;Lee, Dong-Hoon;Jeon, Sang-Ho;Hur, Seung-Oh;Choi, Jin-Yong;Chung, Sun-Ok;Rhee, Joong-Yong
    • Journal of Bio-Environment Control
    • /
    • v.20 no.2
    • /
    • pp.93-100
    • /
    • 2011
  • Maintenance of adequate soil water potential during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement within and below the rooting zone can facilitate optimal irrigation scheduling aimed at minimizing the adverse effects of water stress on crop growth and development and the leaching of water below the root zone which can have adverse environmental effects. The objective of this study was to evaluate the feasibility of using a portable irrigation controller with an Watermark sensor for the cultivation of drip-irrigated vegetable crops in a greenhouse. The control capability of the irrigation controller for a soil water potential of -20 kPa was evaluated under summer conditions by cultivating 45-day-old tomato plants grown in three differently textured soils (sandy loam, loam, and loamy sands). Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30 cm depths. Even though a repeatable cycling of soil water potential occurred for the potential treatment, the lower limit of the Watermark (about 0 kPa) obtained in this study presented a limitation of using the Watermark sensor for optimal irrigation of tomato plants where -20 kPa was used as a point for triggering irrigations. This problem might be related to the slow response time and inadequate soil-sensor interface of the Watermark sensor as compared to a porous and ceramic cup-based tensiometer with a sensitive pressure transducer. In addition, the irrigation time of 50 to 60 min at each of the irrigation operation gave a rapid drop of the potential to zero, resulting in over irrigation of tomatoes. There were differences in water content among the three different soil types under the variable rate irrigation, showing a range of water contents of 16 to 24%, 17 to 28%, and 24 to 32% for loamy sand, sandy loam, and loam soils, respectively. The greatest rate increase in water content was observed in the top of 10 cm depth of sandy loam soil within almost 60 min from the start of irrigation.

Type A behavior pattern and social control of parents (A형행동양상과 부모의 사회적인 통제)

  • Lee, Choong-Won;Yoon, Nung-Ki;Suh, Suk-Kwon;Shin, Dong-Hoon
    • Journal of Preventive Medicine and Public Health
    • /
    • v.23 no.1 s.29
    • /
    • pp.22-32
    • /
    • 1990
  • Associations between type A behavior Pattern (TABP) and parental social control were examined by a questionnaire survey in a sample of 803 undergraduates of the three universities in Daegu city in 1988. TABP was assessed by the Student Jenkins Activity Survey (SJAS, short form) and social control of parents by Bernstein and Brandis' Index of control and communication which were both dichotomized by median. The mean age of the sample was 20.7 (standard deviation, 2.2) and mean of total score of SJAS was 5.6 with its standard deviation and median, 2.7 and 5, respectively. In stratified analysis for TABP-social control association by the native place, sex and socioeconomic status (SES), males of rural origin with low SES showed odds ratio (OR), 2.49 but those with high SES 0.40. For females of rural origin, those with low SES showed OR, 1.02, whereas those with high SES did 0.35. For those who was of urban origin, males with low SES had OR 1.27, and those with high SES did 1.29. Females with high SES showed 0.85 and those with low SES 0.67. None of the TABP-social control associations among the strata showed confidence intervals not including unity. In multiple logistic regression by native place, for those with rural origin the only term showed a statistically significance was the social control-SES of parents interaction, OR 3.99 (95% confidence interval, $1.03{\sim}15.46$). For those of urban origin, none of the terms are statistically significant. These results suggest a social upward mobility by education of the rural disadvantaged group and a Confucian idea that regards academic achievement as one of social virtues, both of which may reflect the different sociocultural structures from the West.

  • PDF

Characterization and Feasibility Study of the Soil Washing Process Applying to the Soil Having High Uranium Concentration in Korea (우라늄 함량이 높은 국내 토양에 대한 토양학적 특성 규명 및 토양세척법의 적용성 평가)

  • Chang, See-Un;Lee, Min-Hee
    • Journal of Soil and Groundwater Environment
    • /
    • v.13 no.5
    • /
    • pp.8-19
    • /
    • 2008
  • The physicochemical properties of soils having high uranium content, located around Duckpyungri in Korea, were investigated and the lab scale soil washing experiments to remove uranium from the soil were preformed with several washing solutions and on various washing conditions. SPLP (Synthetic Precipitation Leaching Procedure), TCLP (Toxicity Characteristic Leaching Procedure), and SEP (Sequential Extraction Procedure) for the soil were conducted and the uranium concentration of the extracted solution in SPLP was higher than Drinking Water Limit of USEPA (30 ${\mu}g$/L), suggesting that the continuous dissolution of uranium from soil by the weak acid rain may generate the environmental pollution around the research area. For the soil washing experiments, the uranium removal efficiency of pH 1 solution for S2 soil was about 80 %, but dramatically decreased as pH of solution was > 2, suggesting that strong acidic solutions are available to remove uranium from the soil. For solutions with 0.1M of HCl and 0.05 M of ${H_2}{SO_4}$, their removal efficiencies at 1 : 1 of soil vs. washing solution ratio were higher than 70%, but the removal efficiencies of acetic acid, and EDTA were below 30%. At 1 : 3 of soil vs. solution, the uranium removal efficiencies of 0.1M HCl, 0.05 M ${H_2}{SO_4}$, and 0.5M citric acid solution increased to 88%, 100%, and 61% respectively. On appropriate washing conditions for S2 soil such as 1 : 3 ratio for the soil vs. solution ratio, 30 minute for washing time, and 2 times continuous washing, TOC (Total Organic Contents) and CEC (Cation Exchange Capacity) for S2 soil were measured before/after soil washing and their XRD (X-Ray Diffraction) and XRF (X-Ray Fluorescence) results were also compared to investigate the change of soil properties after soil washing. TOC and CEC decreased by 55% and 66%, compared to those initial values of S2 soil, suggesting that the soil reclaimant may need to improve the washed soils for the cultivated plants. Results of XRF and XRD showed that the structural change of soil after soil washing was insignificant and the washed soil will be partially used for the further purpose.

Development of Biocompatible Vascular Graft -Endothelialization of Small Vascular Graft- (생체적합성 인조혈관의 개발 -혈관내피화 인조혈관-)

  • 김형묵;이윤신
    • Journal of Chest Surgery
    • /
    • v.29 no.4
    • /
    • pp.373-380
    • /
    • 1996
  • Prevention of thromboembolism is the most important task in the development of bioconpatible small caliber artificial vascular graft. In normal vessels, vascular endothelial cells maintain homeosatsis by secreting numerous factors. The aim of this study is to develope a method which Improves biocompatibility of small caliver polyurethane graft using endothelial cell culture technique, and ev luate the efTectiveness of extracelluar matrix for endothelization which was produced by cultured fibroblast. Methods ; Multiporous polyurethane tube of 3 mm diameter, 0.3 mm thickness was manufactured for vascular graft. Three mongrel dogs were intubated and internal jugular veins removed. Extracelluar matrix produced by cultured flbrobast which was obtained from dog's internal jugular vein were coated to the polyurethane graft. Then, endothelial cells extracted from Jugular vein were cultured and fixed on the extracelluar matrix layer of vascular graft. Endothelial cell coated vascular grafts were implanted to the carotid arteries of experimental dogs as interposed autograft. Implanted grafts were removed after 3 and 6 weeks. As a control, PTFE graft was interposed on carotid artery. These experiments demonstrated that extracelluar matrix produced by fibroblast can afford a base for endothelial cell linings of polyurethane graft. Although thrombosis were developed on autografted en othelial cell coated graft, 33% opening was noticed, and showed less adhesion to adjacent tissue layer. These findings suggest that fiboblast produced extracelluar matrix which can be used for edothelial cell lining vascular graft, and by improving the cultured endothelial cell function, there will be a new modality for reducing thrombosis on small vascular graft.

  • PDF

A Study on the Differentiation of a City image with City Identity (CI(City Identity)에 의한 도시이미지 차별화를 위한 연구)

  • 이충훈
    • Archives of design research
    • /
    • v.15 no.4
    • /
    • pp.57-66
    • /
    • 2002
  • With the advanced localization followed by the settlement of the local autonomous systems, every city has faced new realities that it is inevitable to change its environment and image designs which have been uniformly made without consideration of its characteristics. Accordingly, they have failed to effectively achieve the development goal which make them distinctive.. The identity of a city means an image rather than its attribute. It can be drawn only when the city has its own municipality as well as the superiority to others. For Corporate Identity(CI) to function effectively as a comprehensive medium of communication, We should take into consideration all the situations which surround the city. It should be emphasized on the culture and environment oriented image. To do so we first of all have to analyze in detail the current situations and characteristics of the city. Hence, this paper tried to propose the strategies of making the CI which expresses the unique identity and communication of the city applying the CI program which have been used as the way of business management. The creation of the CI of the city takes the following steps. First, find the potentials for the image of the city through the survey of its resources. Second, provide the motive for citizens to actively participate in making plans with a dear vision for the improvement of the city image, physical development and so on. Third, provide with the events and the projects for specialized goods of the city to strengthen the ability of delivering the information, to design the city image and the street environment of the city. Fourth, apply the communication design system to use actively the administration organization, to enhance the citizenship, and to differentiate the city image. To do so, a variety of efforts should be followed to integrate and promote the regional culture, develope the structure and the facility functions of the city connecting those factors effectively. The establishment of the city identity is required a variety of activities to make the environment of the city, and the agreeable residential environment for a better life by differentiating the characteristics the city has.

  • PDF

Preliminary Environmental Impact Assessments on Fish Compositions and the Ecological Health of Jeokbyeok River on the Road Construction of Muju-Geumsan Region (무주-금산간 도로건설에 따른 적벽강의 어류 종 조성 분석 및 생태건강도 사전환경성평가)

  • Lee, Sang-Jae;Park, Hee-Sung;An, Kwang-Guk
    • Journal of Environmental Impact Assessment
    • /
    • v.26 no.1
    • /
    • pp.27-43
    • /
    • 2017
  • The objectives of the study were to evaluate fish compositions, endangered species, community structure, physical habitat, and general water quality for a preliminary environmental impact assessment of Jeokbyeok River on the road construction between two regions. Total number of species and total number of individuals, based on CPUE, were 23 and 1186, respectively. The endangered species (I, II) as the legal protection species were Pseudopungtungia nigra (79 samples) Gobiobotia brevibarba) (5) Gobiobotia macrocephala (2), indicating a requiring of endangered species conservation. In the meantime, exotic species and ecological disturbing species such as Micropterus salmoides and Lepomis macrochirus, were not present, indicating a well conserved area. According to fish community analysis, values of species diversity index were high (range: 0.788 - 1.030), and the dominance index were low (range: 0.097 - 0.183), indicating that the fish community in this area was maintained well without high dominacne by specific species. Also, fish analysis on tolerance guilds and trophic guilds showed that the proportions of sensitive species were largely exceeded the proportions of the tolerant species, while the proportions of insectivore species were largely exceeded the proportions of the omnivore species. This outcome suggests that the ecosystem was well maintained in terms of tolerance and trophic compositions (food chain). Ecological health, based on the multi-metric fish model of Fish Assessment Integrity (FAI), reflected those fish conditions. In other words, values of FAI model averaged 82.4, which means a "good condition" in the criteria of ecological health by the Minstry of Environment, Korea. In addition, general water quality and physical habitat analyses showed that the system was in good condition. Under these conditions, if the road constructions between the two regions happen in the future, inorganic suspended solids may increase in the waterbody, and this may result in indirect or direct influences on the physical habitats and food chain as well as fish compositions, so the ecological protections and prevention strategy from the soil erosion are required in the system.

The Brassica rapa Tissue-specific EST Database (배추의 조직 특이적 발현유전자 데이터베이스)

  • Yu, Hee-Ju;Park, Sin-Gi;Oh, Mi-Jin;Hwang, Hyun-Ju;Kim, Nam-Shin;Chung, Hee;Sohn, Seong-Han;Park, Beom-Seok;Mun, Jeong-Hwan
    • Horticultural Science & Technology
    • /
    • v.29 no.6
    • /
    • pp.633-640
    • /
    • 2011
  • Brassica rapa is an A genome model species for Brassica crop genetics, genomics, and breeding. With the completion of sequencing the B. rapa genome, functional analysis of the genome is forthcoming issue. The expressed sequence tags are fundamental resources supporting annotation and functional analysis of the genome including identification of tissue-specific genes and promoters. As of July 2011, 147,217 ESTs from 39 cDNA libraries of B. rapa are reported in the public database. However, little information can be retrieved from the sequences due to lack of organized databases. To leverage the sequence information and to maximize the use of publicly-available EST collections, the Brassica rapa tissue-specific EST database (BrTED) is developed. BrTED includes sequence information of 23,962 unigenes assembled by StackPack program. The unigene set is used as a query unit for various analyses such as BLAST against TAIR gene model, functional annotation using MIPS and UniProt, gene ontology analysis, and prediction of tissue-specific unigene sets based on statistics test. The database is composed of two main units, EST sequence processing and information retrieving unit and tissue-specific expression profile analysis unit. Information and data in both units are tightly inter-connected to each other using a web based browsing system. RT-PCR evaluation of 29 selected unigene sets successfully amplified amplicons from the target tissues of B. rapa. BrTED provided here allows the user to identify and analyze the expression of genes of interest and aid efforts to interpret the B. rapa genome through functional genomics. In addition, it can be used as a public resource in providing reference information to study the genus Brassica and other closely related crop crucifer plants.