• 제목/요약/키워드: Site period

검색결과 2,636건 처리시간 0.028초

Site suitability for conifer plantation and a new challenge to utilize deciduous trees

  • NAGASHIMA, Keiko
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 추계학술대회
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    • pp.24-24
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    • 2018
  • Degraded plantation forests are increasing because of unfavorable forestry conditions prevailing in Japan, including falling timber prices, increasing operational costs, and aging and declining forestry workforce. To remedy this situation, appropriate management strategy is required. This study introduces the challenges of Odai Town, Mie Prefecture that employed a new management strategy by evaluating site suitability for conifer forests and that proposes a new forest management regime of planting deciduous trees in unsuitable sites. The site suitability for conifer forests was evaluated from two aspects: the natural site conditions and the relationship among site conditions, growth, and damage by Anaglyptus subfasciatus Pic. in Cryptomeria japonica D. Don and Chamaecyparis obtusa Sieb. Et Zucc. forests. By analyzing the relationship among site conditions, growth, and insect damage based on field data obtained in plantation forests, growth evaluation and insect damage evaluation maps were developed. Based on the natural forest investigation, natural site condition maps for C. japonica and C. obtusa were established. Furthermore, by integrating these evaluation maps with the forest road maps showing the accessibility to the forest, the forest management regime for the whole plantation area of Odai Town was established. The forest management regime map indicates the sites suitable for forestry: suitable for long-rotation, short-rotation, and potential sites for short-rotation. The sites unsuitable for forestry were considered to be more suitable for broadleaved forests. Clear-cutting was conducted in a small area and different seral stage saplings (approximately 20 deciduous tree species) suitable to the site conditions were planted in an area of $80-120m^2$ protected by deer-fences. This might establish a forest composed of many species with a multilayer vertical forest structure in a short period. The planted saplings were distributed neither randomly nor uniformly to reflect the natural distribution of trees in the forest. A challenge to develop new products using the deciduous trees has started, such as wood chips for preparing smoked food, essential oil, and deodorizer. As these challenges have just begun, their effects on enhancing sustainable resource management are still being monitored. Even with the challenges, this regime can be of high value as a management strategy to remedy the situation of expansion of degraded forests in Japan.

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경주 지역의 지반공학적 지진 민감도 분석 (Analysis of geotechnical Seismic Sensitivity in Kyeongju)

  • 선창국
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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    • pp.130-140
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    • 2000
  • The earthquake hazard has been evaluated for 10km by 10km area around Kyeongju which is located near Yangsan fault and has abundant historical earthquake records. The ground motion potentials were determined based on equivalent linear analysis by using the data obtained from in situ and laboratory tests and the El centro eartqhuake record scaled to CLE and OLE of the region. The in situ tests include 9 boring investigations 2 crosshole 7 downhole 13 SASW tests and in the laboratory X-ray diffraction analyses and resonant column tests were performed. The peak ground accelerations range between 0.140g and 0.286g on CLE and between 0.051g and 0.116g on OLE respectively showing the good potential of amplification in the deep alluvial layer which is common in Kyeongju area. the response spectrum based on the Korea design guide was sometimes underestimate the motion. particularly near the natural period of the site and the importance of site-specific analysis and need for the improved site categorization method were introduced.

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쓰레기 매립지 침출수 거동 예측평가 연구 (A Study on the Transfer Prediction of Landfill Leachate)

  • 정종관;장원
    • 환경영향평가
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    • 제4권1호
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    • pp.9-15
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    • 1995
  • For the purpose of saving the waste disposal cost a self-governing community on the whole reclamates the wetland and uses it as a landfill site. During the operation period of site, the environmental impact by the leachate is usually neglected. Therefore, to predict the environmental impact and dispersion of leachate, the wetland adjacent to the South Han River in Chungju is selected as a site of case study. The main content of this article is to apply the simulation model CONMIG to leachate transfer in the ground water and to derive the impact by the leachate. A kind of non-reacting conservative material, chloride ion is used as a tracer to quantify impacts by the leachate.

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굴착공사 중 계측결과 활용을 통한 효과적인 현장관리 사례 분석 (The Case Study of the Effective Management of the Site Using Measurement Result During the Excavation Construction)

  • 남궁한;정경식;고형선
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.428-444
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    • 2010
  • After underground excavation being introduced in dometic, many technologies have been storing up. One of them, measurement, has been recognized as an important item under excavation construction. But, unlike a large-scale construction, it was not been treated importantly at the general small-scale structures with poor ordering and original design was unchanged under construction was normal if the problem didn't occur on monitoring. In this paper, the site which safe and economical management as well as shortening construction period was made effectively using measurement result was introduced. Also, the site which was completed safely with analyzing measurement and reinforcement when unusual symptom happened was introduced. Using measurement result effectively will be able to obtain the safety and prevent unnecessary economical loss.

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Evaluation of wind power potential for selecting suitable wind turbine

  • Sukkiramathi, K.;Rajkumar, R.;Seshaiah, C.V.
    • Wind and Structures
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    • 제31권4호
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    • pp.311-319
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    • 2020
  • India is a developing nation and heavily spends on the development of wind power plants to meet the national energy demand. The objective of this paper is to investigate wind power potential of Ennore site using wind data collected over a period of two years by three parameter Weibull distribution. The Weibull parameters are estimated using maximum likelihood, least square method and moment method and the accuracy is determined using R2 and root mean square error values. The site specific capacity factor is calculated by the mathematical model developed by three parameter Weibull distribution at different hub heights above the ground level. At last, the wind energy economic analysis is carried out using capacity factor at 30 m, 40 m and 50 m height for different wind turbine models. The analysis showed that the site has potential to install utility wind turbines to generate energy at the lowest cost per kilowatt-hour at height of 50 m. This research provides information of wind characteristics of potential sites and helps in selecting suitable wind turbine.

Chytrid Distribution in Diverse Boreal Manitoba Sites

  • Lee, Eun-Ju
    • Animal cells and systems
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    • 제4권1호
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    • pp.57-62
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    • 2000
  • Soil samples were collected in thirteen Manitoba boreal forest sites. Spatial distribution of chytrids from diverse boreal forest microhabitats was investigated by baiting with jack pine pollen. After baiting, the pollen was surveyed for chytrids for 8 ten day period and individual species were counted. Total infestations of pollen by chytrids ranged from 5.8% to 90.2% from various soils. Each site with high infestation was characterized by litter with high needle content while mineral soil or soil with limited organic matter yielded low levels of pollen infestation. Species diversity tended to be higher in soils with higher pollen infestation and lower in soils with lower pollen infestation. Lower diversity was generally observed in mineral soils or soils with a limited organic horizon comprised, in part, of broad leaf litter. Based on coefficients of association and species in common among species across the collection sites, it was possible to relate dominant species assemblages in site groups. These species assemblages in the site groups suggest that the chytrids are distributed by litter and soil types. It can be concluded that the substratum characteristics of litter types and availability of litter may be important in describing chytrid distribution in boreal forest sites.

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감은사지(感恩寺址) 동탑(東塔) 사리용기(舍利容器) 양식(樣式)에 반영된 복두형(覆斗形) 천장(天障)에 대하여 (About the Ceiling with Bokdu(覆斗) Design Reflected on the Sarira Casket Discovered from a East Pagoda in Gameunsa Temple Site)

  • 이난영
    • 헤리티지:역사와 과학
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    • 제33권
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    • pp.136-161
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    • 2000
  • This paper is a study on the design of the gilt-bronze sarira caskets discovered in 1959 and 1996, from a east and a west three-story stone pagodas in Gameunsa Temple site which was built in 682. One of the most interesting discoveries is the ceiling with Bokdu(覆斗) design which can be seen in Dun-Huang grotto of China, reflected upon the ceiling structure of the cover (outer casket) and the square box (inner casket). The structure of these sarira caskets, as art crafts, directly represents architectural structure of Dun-Huang grotto that was made during the early T'ang period of China. Moreover, the sarira caskets are decorated with ornate designs and these designs also can be seen on the murals of Dun-Huang grotto. Accordingly, those sarira caskets tell us creative ability and international taste of Silla's craftsmen. By tracing the origin of structure and design pattern of the sarira caskets to Central Asian and Chinese architectures, it is able to understand international style of the sarira caskets of Gameunsa Temple site.

고종조 중창된 경복궁 후원 영역 및 건축 규모 분석 연구 - 국립문화재연구소 소장본 북궐후원도형 및 북궐도형을 중심으로 - (A Study on the Area of Rear Garden and its Architectural Dimension at Gyeongbok Palace Constructed during King Gojong's Reign)

  • 김성도
    • 대한건축학회논문집:계획계
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    • 제34권8호
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    • pp.95-104
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    • 2018
  • This thesis aims to determine the size of the rear garden and its architectural dimension at Gyeongbok Palace constructed during King Gojong's reign by analyzing Bukgyeol dohyeong(Site plan of Gyeongbok Palace) and Bukgyeol huwon dohyeong(Site plan of Rear Garden of Gyeongbok Palace) applied of scale unit and made from 1905 untill 1909. The results of this study were as follows; With respect to its site, the maximum horizontal length is estimated to be around 448m, the maximum vertical length is around 544m, and the entire area is around $203,905m^2$. Concerning the architecture, the total number of the buildings made up of one or more gan(間) is 32 and the total number of its gan is 292.5, etc.

PC 부재의 현장 생산효과 분석 (In-situ Production Effect Analysis of Precast Concrete Elements)

  • 이동주;오진혁;김선국
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 가을 학술논문 발표대회
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    • pp.52-53
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    • 2021
  • PC (Precast Concrete) method was preferred for reasons such as shortening of construction period, cost reduction, and quality. However, in the case of factory production, precast concrete has a problem in that transportation conditions in the transportation process, damage during transportation, overhead and profit of the factory are required. If work and PC members are produced on site, transportation and installation costs can be reduced. However, research on field production has not been conducted. Therefore, based on the on-site production plan without PC, the cost and quality of factory production and on-site production are compared and analyzed.

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국내 지반특성에 적합한 지반분류 방법 및 설계응답스펙트럼 개선에 대한 연구 (II) - 지반분류 개선방법 (Development of Site Classification System and Modification of Design Response Spectra considering Geotechnical Site Characteristics in Korea (II) - Development of Site Classification System)

  • 윤종구;김동수;방은석
    • 한국지진공학회논문집
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    • 제10권2호
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    • pp.51-62
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    • 2006
  • 동반논문 (I)에서는 국내 지반특성에 적합하도록 국내 내진설계기준이 개선되어야 한다는 결론을 얻었다. 본 논문에서는 우수한 지반분류 방법을 찾기 위하여 상부 토층 30m의 평균 전단파속도$(V_{S30})$, 지반의 고유주기$(T_G)$ 및 기반암 깊이를 이용한 지반분류 방법에 대하여 심도있게 검토하였다. 증폭계수$(F_a,\;F_v)$의 표준편차, 해석결과의 평균 스펙트럼 가속도와 재산정된 응답스펙트럼을 비교한 결과 각각의 방법에서 큰 차이가 발생하지 않아 특정한 방법이 우수하다고 판단하기 힘들었다. 그러나, $T_G$를 이용한 방법에서 RRS 값의 증폭구간이 좁은 구간에 집중되는 경향을 보여 지진시 유사한 거동특성을 나타내는 지반을 같은 지반그룹으로 분류할 수 있는 장점이 있었다. 또한, 증폭계수와 $T_G$의 상관관계를 나타내는 추세선의 경우, $V_{S30}$ 방법 보다 입력 가속도의 증가에 따른 지반의 비선형성 효과를 더욱 명확하게 나타낼 수 있었다. 마지막으로, $V_{S30}$을 이용하여 지반을 분류할 경우 기반암이 30m 보다 얕은 곳에 존재하는 경우에도 무조건 심도 30m까지 기반암의 전단파속도를 가정하여 계산해야 하나, $T_G$를 이용할 경우 이러한 불확실성을 제거할 수 있어 우수한 방법으로 판단된다. 본 논문에서는 지반의 고유주기를 이용한 방법을 기반암 깊이가 얕은 국내지반특성에 적합한 지반분류 방법으로 제안하였다.