• Title/Summary/Keyword: habitat evaluation

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Seismic Performance of High-Rise Intermediate Steel Moment Frames according to Rotation Capacities of Moment Connections

  • Han, Sang Whan;Moon, Ki-Hoon;Ha, Sung Jin
    • International Journal of High-Rise Buildings
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    • v.4 no.1
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    • pp.45-55
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    • 2015
  • The rotation capacity of the moment connections could significantly influence on the seismic performance of steel moment resisting frames. Current seismic provisions require that beam-to-column connections in Intermediate Moment Frames (IMF) should have a drift capacity as large as 0.02 radian. The objective of this study was to evaluate the effect of the rotation capacity of moment connections on the seismic performance of high-rise IMFs. For this purpose, thirty- and forty-story high-rise IMFs were designed according to the current seismic design provisions. The seismic performance of designed model frames was evaluated according to FEMA P695. This study showed that the forty-story IMF satisfied the seismic performance objective specified in FEMA P695 when the rotation capacity of the connections was larger than 0.02. However, thirty-story IMFs satisfied the performance objective when the connection rotation capacity is larger than 0.03.

Structural Health Monitoring of Shanghai Tower Considering Time-dependent Effects

  • Zhang, Qilin;Yang, Bin;Liu, Tao;Li, Han;Lv, Jia
    • International Journal of High-Rise Buildings
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    • v.4 no.1
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    • pp.39-44
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    • 2015
  • This paper presents the structural health monitoring (SHM) of Shanghai Tower. In order to provide useful information for safety evaluation and regular maintenance under construction and in-service condition, a comprehensive structural health monitoring (SHM) system is installed in Shanghai Tower, which is composed of a main monitoring station and eleven substations. Structural responses at different construction stages are measured using this SHM system and presented in this study. Meanwhile, a detailed finite element model (FEM) is created and comparison of results between SHM and FEM is carried out. Results indicate that the time-dependent property of concrete creep is of great importance to structural response and the measured data can be used in FEM updating to obtain more accurate FEM models at different construction stages. Therefore, installation of structural health monitoring system in super-tall buildings could be considered as an effective way to assure structural safety during the construction process.

Evaluation of Potential Distribution Area of the Red Swamp Crayfish (Procambarus clarkia) in South Korea (미국가재(Procambarus clarkia)의 국내 출현 및 잠재 분포 지역 평가)

  • Lee, Dae-Seong;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • v.52 no.4
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    • pp.340-347
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    • 2019
  • The red swamp crayfish (Procambarus clarkia) originated from the North America distribute widely as invasive species throughout the world including Europe, Asia, Africa, North America and South America. The red swamp crayfish is also an invasive species in South Korea. We aimed to characterize the occurrence and distribution pattern of the red swamp crayfish, and evaluate the potential distribution of this species in South Korea. In South Korea, the red swamp crayfish was firstly reported in Seoul in 1996, and recently its occurrence is frequently reported at streams or reservoirs at different regions, showing the expansion of its distribution area. The red swamp crayfish has high potential to occur in the nationwide scale in South Korea because of their biological adaptation, effects of climate change, changes of their habitat condition, and various types of human activities. Finally, our results revealed the necessary to conduct an extensive field survey, to keep up a monitoring program for the occurrence of alien species, and to implement a strategy to prevent the dispersal of alien species in the natural ecosystems.

Evaluation of the Nutrient Uptakes of Floating and Submerged Plants under Experimental Conditions (실험실 조건에서 부유식물과 침수식물의 영양염류 흡수능 및 특성 평가)

  • Lee, Geun-Joo;Sung, Kijune
    • Journal of Korean Society on Water Environment
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    • v.28 no.1
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    • pp.71-77
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    • 2012
  • The performance and characteristics of nutrient removal in wetlands influenced by plant type. We tested a floating plant, Eichhornia crassipes, and a submerged plant, Ceratophyllum demersum, under the same environmental conditions to understand the differences in nutrient uptake by these different plant forms. The total nitrogen and phosphorus in the water decreased in the following order: Water Only < Water + Soil < Floating Plants ${\approx}$ Submerged Plants and Water Only < Water+Soil < Floating Plants < Submerged Plants. Nitrogen and phosphorous concentrations increased in both plants; however, the phosphorous concentration was greater in C. demersum than E. crassipes. The submerged plant exhibited higher phosphorus uptake per unit biomass than the floating plant, but nitrogen uptake did not differ significantly. These results suggest that the presence of soil influences nitrogen and phosphorus removal from water, and that wetland plants play an important role in the assimilation and precipitation of phosphorus. Understanding the differences in contaminant removal performance and characteristics of various plant forms can help in the selection of diverse plants for constructed wetlands to improve water quality and provide ecosystem services such as wildlife habitat and landscape enhancement.

Evaluation of conservation of endangered species through somatic cell nuclear technology (체세포복제를 통한 멸종위기동물의 종 보전 평가)

  • Hyun, Sang Hwan;Jeong, Yeon Woo;Hwang, Kyu Chan;Lee, Guk Jin;Yang, Il Suk
    • Korean Journal of Veterinary Research
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    • v.55 no.3
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    • pp.155-161
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    • 2015
  • The number of wild animal species is gradually decreasing due to poaching, hunting and habitat loss. While several endangered animal species have been successfully preserved at the zoo, assisted reproductive technology (ART) must be applied to restore wild animals. In the case of critically endangered animals, somatic cell cloning is considered the most appropriate method of ART. Somatic cell cloning can be beneficial for the reproduction of endangered species with limited female populations. However, gene and cell banks, and understanding of reproductive physiology and optimization of ART for wild animals are urgently required for further activation of artificial reproduction of endangered species, which enlarges its application and maintains biodiversity. Care should also be taken to consider ethical and legal issues associated with somatic cell cloning for conservation of endangered animals.

Plastic Deformation Capacity of Steel Beam-to-Column Connection under Long-duration Earthquake

  • Yamada, Satoshi;Jiao, Yu;Narihara, Hiroyuki;Yasuda, Satoshi;Hasegawa, Takashi
    • International Journal of High-Rise Buildings
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    • v.3 no.3
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    • pp.231-241
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    • 2014
  • Ductile fracture is one of the most common failure modes of steel beam-to-column connections in moment resisting frames. Most proposed evaluation methods of the plastic deformation capacity of a beam until ductile fracture are based on steel beam tests, where the material's yield strength/ratio, the beam's moment gradient, and loading history are the most important parameters. It is impossible and unpractical to cover all these parameters in real tests. Therefore, a new attempt to evaluate a beam's plastic deformation capacity through analysis is introduced in this paper. Another important issue is about the loading histories. Recent years, the effect on the structural component under long-duration ground motion has drawn great attentions. Steel beams tends to experience a large number of loading cycles with small amplitudes during long-duration earthquakes. However, current research often focuses on the beam's behavior under standard incremental loading protocols recommended by respective countries. In this paper, the plastic deformation capacity of steel beams subjected to long duration ground motions was evaluated through analytical methodology.

Species richness related to landscape characteristics of uninhabited islands in Korea

  • Rho, Paikho
    • Journal of Ecology and Environment
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    • v.33 no.2
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    • pp.105-114
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    • 2010
  • The principal objective of this study was to characterize the relationships between geographical conditions (e.g., island area, distance to mainland) and landscape structures of uninhabited islands, and to evaluate the effects of islands and their landscape structures on species richness. One hundred randomly selected islands and 5,000 m buffered areas derived from the boundaries of each island were used to summarize the number of observed bird species, and landscape pattern indices, particularly patch density, edge density, shape index, and mean nearest neighboring distance. Spatial arrangements of individual patch type at the class level, which are markedly affected by the distance from an island to the mainland, have a superior ability to explain the variances in species richness, as compared to the geographical conditions and landscape pattern indices at the landscape level. The results demonstrate that the patch type landscape structure is the primary factor affecting species richness, as well as the distance to the mainland. In particular, landscape pattern indices of cropland/pasture and woody cover are statistically significant in terms of explaining species richness, which suggests that food resources and appropriate conditions in landscape structures of habitat types are assumed as important elements in attracting bird species. This study also proposes the importance of evaluation on the landscape structure of each island, in order to designate protected areas and to establish a management plan for species conservation in uninhabited islands.

State of Practice of Performance-Based Seismic Design in Indonesia

  • Sukamta, Davy;Alexander, Nick
    • International Journal of High-Rise Buildings
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    • v.1 no.3
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    • pp.211-220
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    • 2012
  • The current 2002 Indonesian Seismic Code consists of prescriptive criteria that are intended to result in buildings capable of providing certain levels of performance. However, the actual performance capability of buildings is not assessed as part of the code procedures. Several analysis procedures are allowed, and the state of practice is to use the RSA with six-zone seismic map developed for 475-year earthquake. This code is being revised and will adopt many of the ASCE7-10 provisions and 2475-year earthquake for MCE. The growth of tall buildings compels engineers to look for more optimal lateral system. The use of RC core wall as single system has been adopted by very few engineering firms, which is allowed in the current code but will no longer be the case if the new one is in effect. Other innovative structural system such as core wall and outrigger is not addressed in the proposed new code. Engineers must then resort to NLRHA. Currently, one 50-story building under construction using RC core wall and outrigger has been designed with RSA and employing capacity design principles, then evaluated using NLRHA per TBI Guidelines. Based on the evaluation, the performance of the 50-story building generally still meets the criteria of the TBI Guidelines. The result of the case study is presented in this paper.

Evaluation of Progressive Collapse Resisting Capacity of Tall Buildings

  • Kwon, Kwangho;Park, Seromi;Kim, Jinkoo
    • International Journal of High-Rise Buildings
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    • v.1 no.3
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    • pp.229-235
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    • 2012
  • In this paper the progressive collapse potential of building structures designed for real construction projects were evaluated based on arbitrary column removal scenario using various alternate path methods specified in the GSA guidelines. The analysis model structures are a 22-story reinforced concrete moment frames with core wall building and a 44-story interior concrete core and exterior steel diagrid structure. The progressive collapse resisting capacities of the model structures were evaluated using the linear static, nonlinear static, and nonlinear dynamic analyses. The linear static analysis results showed that progressive collapse occurred in the 22-story model structure when an interior column was removed. However the structure turned out to be safe according to the nonlinear static and dynamic analyses. Similar results were observed in the 44-story diagrid structure. Based on the analysis results, it was concluded that, compared with nonlinear analysis procedures, the linear static method is conservative in the prediction of progressive collapse resisting capacity of building structure based on arbitrary column removal scenario.

Using GIS Spatial Analysis to Protect Critical Habitats in the Big Cyprus Watershed, South Florida (GIS 공간분석을 통한 남부 플로리다 Big Cyprus 분수계 보존서식지 보호)

  • Kim, Jin-Ho;Kim, Chang-Ho;Kim, Hyun-Woo
    • Journal of KIBIM
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    • v.7 no.4
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    • pp.31-38
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    • 2017
  • Big Cyprus watershed, which is located in the Southwestern Florida and covers Everglades National Park that has high proportions of endangered species' habitats, plays an important role for the entire Florida ecosystem. Due to the rapid urbanization and high population growth, however, the watershed has been continuously polluted and the current regional watershed plan is not created to accommodate the speed of growth. The purpose of this study is to suggest proper protection policies and strategies for the Big Cyprus watershed by employing the Inverse Distance Weighted interpolation tool in Geographic Information System. The findings show that conservation priorities should be given in the North and South portion of the watershed area, which are proven to be the most important aisle for the habitats in the Big Cyprus. The study concludes with policy suggestions that local environmental planners should concentrate for adopting their new watershed plan in the near future.