• Title/Summary/Keyword: terrain factors

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Evaluation of mode-shape linearization for HFBB analysis of real tall buildings

  • Tse, K.T.;Yu, X.J.;Hitchcock, P.A.
    • Wind and Structures
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    • v.18 no.4
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    • pp.423-441
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    • 2014
  • The high frequency base balance (HFBB) technique is a convenient and relatively fast wind tunnel testing technique for predicting wind-induced forces for tall building design. While modern tall building design has seen a number architecturally remarkable buildings constructed recently, the characteristics of those buildings are significantly different to those that were common when the HFBB technique was originally developed. In particular, the prediction of generalized forces for buildings with 3-dimensional mode shapes has a number of inherent uncertainties and challenges that need to be overcome to accurately predict building loads and responses. As an alternative to the more conventional application of general mode shape correction factors, an analysis methodology, referred to as the linear-mode-shape (LMS) method, has been recently developed to allow better estimates of the generalized forces by establishing a new set of centers at which the translational mode shapes are linear. The LMS method was initially evaluated and compared with the methods using mode shape correction factors for a rectangular building, which was wind tunnel tested in isolation in an open terrain for five incident wind angles at $22.5^{\circ}$ increments from $0^{\circ}$ to $90^{\circ}$. The results demonstrated that the LMS method provides more accurate predictions of the wind-induced loads and building responses than the application of mode shape correction factors. The LMS method was subsequently applied to a tall building project in Hong Kong. The building considered in the current study is located in a heavily developed business district and surrounded by tall buildings and mixed terrain. The HFBB results validated the versatility of the LMS method for the structural design of an actual tall building subjected to the varied wind characteristics caused by the surroundings. In comparison, the application of mode shape correction factors in the HFBB analysis did not directly take into account the influence of the site specific characteristics on the actual wind loads, hence their estimates of the building responses have a higher variability.

A Study on the Improvement of River Management System Based on Riverbed Change Data Management Program for Utilization of Advanced Bathymetry Data (선진화된 하천측량자료 활용 및 관리를 위한 하상변동 자료관리 프로그램 기반의 하도유지관리체계 개선에 관한 연구)

  • Jo, Myung-Hee;Kim, Kyung-Jun;Kim, Hyun-Jung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.3
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    • pp.115-125
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    • 2013
  • The systematic management of river is difficult due to various environmental factors such as season and terrain deformation. Especially, river terrain are rapidly changing by natural and anthropogenic factors such as torrential rain during the summer and river development projects. Thus in this conditions, building the advanced river management system is an essential condition to support the ongoing management of survey data and to acquire data regularly through river terrain survey in order to maintain an active river. The need to build an efficient system have been increased through the enhancement and advancement of River Management Geographic Information Systems(RIMGIS). In this study, database design system and Riverbed Change Data Management Program was developed for systematic management of new river terrain survey data and the efficient use of river data dynamic changes. The key features are construction of river survey data, cross and longitudinal section monitoring and analysis of riverbed change data. Maintenance tasks which can be utilized in river-based architecture was constructed. The expected results are to be able to manage river systematically, and utilization of river topographic survey data efficiently for river maintenance work.

A Study on the Category of Factors for the Landslide Risk Assessment: Focused on Feature Classification of the Digital Map(Ver 2.0) (산사태 위험도 항목 분류에 관한 연구 -수치지도(Ver 2.0) 지형지물 분류체계를 중심으로-)

  • Kim, Jung-Ok;Lee, Jeong-Ho;Kim, Yong-Il
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.371-374
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    • 2007
  • For development of landslide risk assessment techniques using GIS(Geographic Information System), this study classifies the category of socioeconomic factors. The landslide quantitative risk assessment performs first prediction of flow trajectory and runout distance of debris flow over natural terrain. Based on those results, it can be analyzed the factors of socioeconomic which are directly related to the magnitude of risk due to landslide hazards. Those risk assessment results can deliver factual damage situation prediction to policy making for the landslide damage mitigation. Therefore, this study is based on feature classification of the digital map ver. 2.0 provided by the National Geographic Information Institute. The category of factors can be used as useful data in preventing landslide.

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A Case Study for Construction Hazard Zonation Maps and its Application (석회암 지역 재해 등급도 작성 및 응용에 관한 사례 연구)

  • 정의진;윤운상;김중휘;마상준;김정환;이근병
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.165-172
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    • 2002
  • We presents an hazard zonation mapping technique in karst terrain and its assessment. From the detailed engineering geological mapping. Controlling factors of sink hole and limestone cave formation were discussed and 4 main hazard factors affecting hazard potential are identified as follows: prerequisite hazard factor(distributions of pre-existing sink holes and cavities), geomorphological hazard factors(slope gradient, vegetation, and drainage pattern etc.) geological hazard factors(lithology, fracture patterns and geological structures etc.) and hydraulic conditions(hydraulic head, annual fluctuation of ground water table and composition of g/w water). From the construction of hazard zonation map along the Jecheon-Maepo area, and vertical cross-sectional hazard zonations specific tunnel site we suggest hazard zonation rating systems.

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Analyzing the Disaster Vulnerability of Mt. Baekdusan Area Using Terrain Factors (지형 요소를 고려한 백두산 지역의 위험도 분석)

  • Choi, Eun-Kyeong;Kim, Sung-Wook;Lee, Young-Cheol;Lee, Kyu-Hwan;Kim, In-Soo
    • Journal of the Korean earth science society
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    • v.34 no.7
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    • pp.605-614
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    • 2013
  • Most steep slope failures tend to take place in geographically unstable areas. Mt. Baekdusan is known as a potentially active volcano in a typical mountainous terrain. This study prepared a digital elevation model of Mt. Baekdusan area and created a hazard map based on topographical factors and structural lineament analysis. Factors used in vulnerability analysis included geographical data involving aspect and slope distribution, as well as contributory area of upslope, tangential gradient curvature, profile gradient curvature, and the distribution of wetness index among the elements that comprise topography. In addition, the stability analysis was conducted based on the lineament intensity map. Concerning the disaster vulnerability of Mt. Baekdusan region, the south and south west area of Mt. Baekdusan has a highest risk of disaster (grade 4-5) while the risk level decreases in the north eastern region.

Development of the Surface Forest Fire Behavior Prediction Model Using GIS (GIS를 이용한 지표화 확산예측모델의 개발)

  • Lee, Byungdoo;Chung, Joosang;Lee, Myung-Bo
    • Journal of Korean Society of Forest Science
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    • v.94 no.6
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    • pp.481-487
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    • 2005
  • In this study, a GIS model to simulate the behavior of surface forest fires was developed on the basis of forest fire growth prediction algorithm. This model consists of three modules for data-handling, simulation and report writing. The data-handling module was designed to interpret such forest fire environment factors as terrain, fuel and weather and provide sets of data required in analyzing fire behavior. The simulation module simulates the fire and determines spread velocity, fire intensity and burnt area over time associated with terrain slope, wind, effective humidity and such fuel condition factors as fuel depth, fuel loading and moisture content for fire extinction. The module is equipped with the functions to infer the fuel condition factors from the information extracted from digital vegetation map sand the fuel moisture from the weather conditions including effective humidity, maximum temperature, precipitation and hourly irradiation. The report writer has the function to provide results of a series of analyses for fire prediction. A performance test of the model with the 2002 Chungyang forest fire showed the predictive accuracy of 61% in spread rate.

A study of thematic map for military terrain analysis cartography (군 지형분석지도 제작을 위한 국내 주제도 활용방안연구)

  • Lee, Eun-seok;Park, Jong-kook;Kim, Jong-hee;Kim, Jeong-su;Kim, Jong-bae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.384-386
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    • 2014
  • As the type of property data of military terrain analysis map is using FACC of DIGEST, there is a limitation in utilizing a domestic thematic map which is in use of other type of property data. However, even though the attempts to utilize the domestic thematic map are made at military sites, the study has not been conducted enough. Therefore, we defined it by matching the property data necessary for the military terrain analysis cartography and property of the domestic thematic map, and analyzed in accordance with the method to analyze the cross-country movement roads specified in FM 5-33. But, there was no data for the diameter of trees in the vegetation map among a terrain analysis map, whereas there being data for the sort of trees. As the diameter of trees can be broken through to the extent of certain diameters by tracked vehicles, they are the factors necessary in analyzing. In this study, the research was conducted focusing on calculating the diameters for some trees described in a stand yield table by using the age-class for trees in a forest floor map with a scale of 1:5000 and calculating the diameters of trees by using the diameter-class for the diameters of other trees.

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Spatial Analysis of Precipitation with PRISM in Gangwondo (강원도 지역의 PRISM를 이용한 강우의 공간분포 해석)

  • Um, Myoung-Jin;Jeong, Chang-Sam
    • Journal of Korea Water Resources Association
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    • v.44 no.3
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    • pp.179-188
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    • 2011
  • In this study, the regional factors in Gangwondo were used to analysis the relationship between point precipitation and areal precipitation. The most province area in Gangwondo is consist of mountainous terrain. At the east part of the Taebaek Mountains, the slope is very steep and the coastal plains don't exist. At the west part of the Taebaek Mountains, the slope is mild, there are many rivers, such as South Han-river and North Han-river, and the regions are very complex terrain. The data of 66 stations in Gangwondo and the PRISM (Parameter-elevation Regression on Indepedent Slope Model) were used to estimate the spatial distribution of precipitation. According to the topographic conditions, such as elevation and slope, and the regional conditions, such as Youngdong and Youngseo, the spatial distribution of precipitation is well shown. At the results of cross-validation, the RRBIAS and the RRMSE are under 0.1 and therefore the analysis of the PRISM are well conducted. Consequently the PRISM in this study is a appropriate method to estimate the spatial distribution of precipitation in Gangwondo.

A Study of Damage District Forecast by Combine Topograph Modeling of Insular Areas Using GIS

  • Choi, Byoung Gil;Na, Young Woo;Ahn, Soon Myoung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.2
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    • pp.113-122
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    • 2017
  • Natural disasters caused by climate change are increasing globally. There are few studies on the quantitative analysis methods for predicting damages in the island area due to sea level rise. Therefore, it is necessary to study the damage prediction analysis method using the GIS which can quantitatively analyze. In this paper, we analyze the cause and status of sea level rise, quantify the vulnerability index, establish an integrated terrestrial modeling method of the ocean and land, and establish a method of analyzing the damage area and damage scale due to sea level rise using GIS and the method of making the damage prediction figure was studied. In order to extract the other affected areas to sea level rise are apart of the terrain model is generated by one requires a terrain modeling of target areas are offshore and vertical reference system differences in land, found the need for correction by a tidal observations and geoid model there was. Grading of terrain, coastline erosion rate, coastal slope, sea level rise rate, and even average by vulnerable factors due to sea level rise indicates that quantitative damage prediction is possible due to sea level rise in the island area. In the case of vulnerable areas extracted by GIS, residential areas and living areas are concentrated on the coastal area due to the nature of the book area, and field survey shows that coastal changes and erosion are caused by sea level rise or tsunami.

A Study on Level-of-Service Changes of Expressway in Accordance with the Revision of Traffic Capacity at Work-Zone (교통용량 개정에 따른 고속도로 공사구간의 서비스 수준에 대한 연구)

  • Ryu, SungWoo;Park, Kwon-Jea;Han, SeungHwan;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.16 no.3
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    • pp.109-117
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    • 2014
  • PURPOSES : This study analyzes the available working time at work-zone on the Expressway in accordance to the new capacity manual. METHODS : Sensitivity analysis on variables were conducted to calculate the adjusted capacity at work-zone based on previous researches. RESULTS : The main factors which affect available working time at the work-zone were its capacity, number of lanes, terrain and lane width. Other factors have minimal effect on the available working time. Based on the analysis, a calendar of lane closures was suggested. CONCLUSIONS : A series of studies concluded that the capacity at work-zone in the new capacity manual reduced to 76-82% of the existing manual. As such, the available working time decreased. Furthermore, the factors affecting the available working time needs to be considered when making a plan to rehabilitate the distressed pavement.