• Spatial Information Research
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• v.16 no.3
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• pp.373-383
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• 2008

LiDAR, unlike satellite imagery and aerial photographs, which provides irregularly distributed three-dimensional coordinates of ground surface, enables three-dimensional modeling. In this study, urban area was classified based on 3D information collected by LiDAR. Morphological and spatial properties are determined by the ratio of ground and non-ground point that are estimated with the number of ground reflected point data of LiDAR raw data. With this information, the residential and forest area could be classified in terms of height and density of trees. The intensity of the signal is distinguished by a statistical method, Jenk's Natural Break. Vegetative area (high or low density) and non-vegetative area (high or low density) are classified with reflective ratio of ground surface.

• Structural Engineering and Mechanics
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• v.76 no.1
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• pp.83-99
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• 2020

Shear walls are structural members in buildings that are used extensively in reinforced concrete frame buildings, and almost exclusively in the UK, regardless of whether or not they are actually required. In recent years, the UK construction industry, led by the Concrete Centre, has questioned the need for such structural elements in low to mid-rise reinforced concrete frame buildings. In this context, a typical modern, 5-storey residential building is studied, and its existing shear walls are replaced with columns as used elsewhere in the building. The aim is to investigate the impact of several design variables, including concrete grade, column size, column shape and slab thickness, on the building's structural performance, considering two punching shear limits (V_Ed/V_Rd,c), lateral drift and accelerations, to evaluate its maximum possible height under wind actions without the inclusion of shear walls. To facilitate this study, a numerical model has been developed using the ETABS software. The results demonstrate that the building examined does not require shear walls in the design and has no lateral displacement or acceleration issues. In fact, with further analysis, it is shown that a similar building could be constructed up to 13 and 16 storeys high for 2 and 2.5 punching shear ratios (V_Ed/V_Rd,c), respectively, with adequate serviceability and strength, without the need for shear walls, albeit with thicker columns.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_1
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• pp.507-516
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• 2007

Segmentation and organization of the LiDAR (Light Detection and Ranging) data of the Earth's surface are difficult tasks because the captured LiDAR data are composed of irregularly distributed point clouds with lack of semantic information. The reason for this difficulty in processing LiDAR data is that the data provide huge amount of the spatial coordinates without topological and/or relational information among the points. This study introduces LiDAR data segmentation technique by utilizing histograms of the LiDAR height image data and analyzing roof shape for 3D reconstruction and visualization of the buildings. One of the advantages in utilizing LiDAR height image data is no registration required because the LiDAR data are geo-referenced and ortho-projected data. In consequence, measurements on the image provide absolute reference coordinates. The LiDAR image allows measurement of the initial building boundaries to estimate locations of the side walls and to form the planar surfaces which represent approximate building footprints. LiDAR points close to each side wall were grouped together then the least-square planar surface fitting with the segmented point clouds was performed to determine precise location of each wall of an building. Finally, roof shape analysis was performed by accumulated slopes along the profiles of the roof top. However, simulated LiDAR data were used for analyzing roof shape because buildings with various shapes of the roof do not exist in the test area. The proposed approach has been tested on the heavily built-up urban residential area. 3D digital vector map produced by digitizing complied aerial photographs was used to evaluate accuracy of the results. Experimental results show efficiency of the proposed methodology for 3D building reconstruction and large scale digital mapping especially for the urban area.

• Structural Engineering and Mechanics
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• v.75 no.5
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• pp.529-540
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• 2020

The mechanical properties of timber construction have drawn more attention after the 2013 Lushan earthquake. A strong desire to preserve this ancient architectural styles has sprung up in recent years, especially for residential buildings of the mountainous areas. In the column-and-tie timber construction, continuous-tenon joints are the most common structural form to connect the chuanfang (similar to the beam in conventional structures) and the column. To study the cyclic performance of the continuous-tenon joints in column-and-tie timber construction, the reversed lateral cyclic loading tests were carried out on three 3/4 scale specimens with different section heights of the chuanfang. The mechanical behavior was assessed by studying the ultimate bending capacity, deformation ductility and energy dissipation capacity. Test results showed that the slippage of chuanfang occurred when the specimens entered the plastic stage, and the slippage degree increased with the increase of the section height of chuanfang. An obvious plastic deformation of the chuanfang occurred due to the mutual squeezing between the column and chuanfang. A significant pinching was observed on the bending moment-rotation curves, and it was more pronounced as the section height of chuanfang increased. The further numerical investigations showed that the flexural capacity and initial stiffness of the continuous-tenon joints increased with the increase of friction coefficient between the chuanfang and the column, and a more obvious increasing of bending moment occurred after the material yielding. The compressive strength perpendicular to grain of the material played a more significant role in the ultimate bending capacity of continuous-tenon joints than the compressive strength parallel to grain.

• Wind and Structures
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• v.23 no.5
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• pp.449-464
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• 2016

Catastrophe models appraise the natural risk of the built-infrastructure simulating the interaction of its exposure and vulnerability with a hazard. Because of unique configurations and reduced number, mid/high-rise buildings present singular challenges to the assessment of their damage vulnerability. This paper presents a novel approach to estimate the vulnerability of mid/high-rise buildings (MHB) which is used in the Florida Public Hurricane Loss Model, a catastrophe model developed for the state of Florida. The MHB vulnerability approach considers the wind pressure hazard exerted over the building's height as well as accompanying rain. The approach assesses separately the damages caused by wind, debris impact, and water intrusion on building models discretized into typical apartment units. Hurricane-induced water intrusion is predicted combining the estimates of impinging rain with breach and pre-existing building defect size estimates. Damage is aggregated apartment-by-apartment and story-by-story, and accounts for vertical water propagation. The approach enables the vulnerability modeling of regular and complex building geometries in the Florida exposure and elsewhere.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.209-212
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• 2005

Recently, since structures have become extremely airtight with the development of high-rise apartments, mixed use residential and commercial buildings and offices, large capacity range hoods have become commonly implemented. However, the high noise level caused by this range hood system made of thin plate is the cause of increased complaints among users. In this study, the level of noise emitted from this type of range hood was measured by height at the user's location in the kitchen. It was confirmed that a great deal of noise was emitted in the downward direction of the hood. In order to minimize the noise emitted from this type of range hood, a new type of fan was manufactured. This was done by changing only the material and shape of the fan, since it was determined to be the primary source of noise emission. Then a comparison and evaluation were carried out regarding the noise characteristics between the new type of fan and the existing type of fan. As a result, it was confirmed that the noise from the new fan was reduced by more than 2 dB compared to the existing fan without noise interference at the discharge end.

• Journal of the Korean Wood Science and Technology
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• v.19 no.3
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• pp.45-52
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• 1991

To investigate opportunities for wood frame housing and to activate wood frame house construction, trends of construction activities. preference about housing, and building codes related to wood frame housing were discussed. And two models of wood frame house were developed and construction cost was analyzed to compare with comparative masonry houses. The results obtained were as follows: 1. While 77.8% of people prefer single-family houses, majority of people(74.9%), ironically, possess multi-family houses such as apartments Wood work cost was ratio of 4% of total building cost. while wood material cost accounted merely for 11 % out of total building material cost. 2. Building code was not major barrier to residential house at height under 13m. The building code regulated major structural member and family boder wall of multi-family house to be built with fire retardant material. 3. The proper wood frame house was analyzed of town house or villa type locating in suburban of big city with hot ondol system for the upper middle class. 4 There was no difference in construction cost between western style wood frame house and comparable masonry house, but construction cost for Korean style wood frame house is 27% higher than that of comparable masonry house. It was necessary to reduce materials and cost down by prefabrication technique for both style of wood frame house.

• Korean Institute of Interior Design Journal
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• no.12
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• pp.25-32
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• 1997

The fast growth of the elderly population and nuclear families have been creating substantial needs for residential facilities of aged people in Korea. In this study, reviews on housing preference and physical constraints have been performed based on previous researches. In this study, the results of the analyses propose developmental strategies for the elderly housing in Korea as follows: 1)Housing preference and other psychological trends of Korean elderly are rooted in changeable condition of the emotion and lack of knowledge. Therefore, the housing preference of the Korean elderly should not be considered a fixed reflection ; rather, it should be regarded as a continuously adjusted trends according to later experience and emotional status after residing in the elderly care facilities. 2)Design of elderly housing should be guided within two principles of easy access and high usability. The principles also require maximazation of social interactions among frail elderly residents on age-segregated structure. 3) The experiment among 201 frail elderly shows that each shower stall should accommodate 5-by-5 feet square for wheelchair u-turn, and 48 inch height for kitchen topsink. Finally, the experiment shows that ramp slope of the ederly housing should be within 1/16 and 1/20.

• Journal of Korean Society of Rural Planning
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• v.11 no.4 s.29
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• pp.99-108
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• 2005

In this study, thirteen villages in Chonnam province were selected as case study sites and the spatial distribution of the facilities in the villages was examined to provide basic information fur the establishment of rural plans. According to the questionnaire survey, various problem such as environmental pollution, position, scene, management etc. was brought owing to cattle shed, and dissension was more or less seen by scale of facilities, management of facilities and waste, regional factor(stock farming management condition, life style and attitude of inhabitants) and topographical factor (height, position physical aspect of a mountain, distance with water resources etc.) etc.. The facilities could be classified into 6 types based on the their spatial locations: 1) Type 1, facilities located at the waterside; 2) Type 2, facilities located at the entrance of village; 3) Type 3 facilities, scattered in the residential area: 4) Type 4 facilities, collectivized in village; 5) Type 5 facilities, adjoining village; and 6) Type 6 facilities, scattered irregularly inside and outside of village. Based on the classification, possible implementations for the reduction of environmental impacts were suggested. The results of this study could be used as an example of study on the distribution, classification, and rearrangement of environment-impacting facilities in rural areas for improvement of their roles in providing amenity resources.

• Computers and Concrete
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• v.16 no.1
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• pp.141-161
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• 2015

A significant portion of residential areas of Turkey is located in active earthquake zones. In Turkey occurred major earthquakes in last twenty years, such as Erzincan (1992), Kocaeli and $D{\ddot{u}}zce$ (1999), $Bing{\ddot{o}}l$ (2003), Van (2011). These earthquakes have demonstrated that reinforced concrete (RC) buildings having horizontal and vertical irregularities are significantly damaged, which in turn most of them are collapsed. Architectural design and arrangement of load-bearing system have important effect on RC building since architectural design criteria in design process provide opportunity to make this type of buildings safer and economical under earthquake loads. This study aims to investigate comparatively the effects of weak story irregularity on earthquake behavior and rough construction costs of RC buildings by considering different soil-conditions given in the Turkish Earthquake Code. With this aim, Sta4-CAD program based on matrix displacement method is utilized. Considering that different story height and compressive strength of concrete, and infill walls or their locations are the variables, a set of structural models are developed to determine the effect of them on earthquake behavior and rough construction costs of RC buildings. In conclusion, some recommendations and results related to making RC buildings safer and more economical are presented by comparing results obtained from structural analyses.