• Smart Structures and Systems
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• v.21 no.2
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• pp.139-149
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• 2018

Understanding the current status of a construction project is necessary to achieve successful on-site management. Real-time information delivery is a major concern for construction industry practitioners in order to expedite decisions and discussions. We propose the use of a first personal view (FPV) system of a quadcopter drone as a tool for monitoring on-site status and communicating between construction participants. The most important function of the drone FPV system is its ability to visually monitor construction site situations in real time. An on-site management system process is developed, verified, and applied to several construction work tasks after determining factors that affect efficient construction management. The proposed system is expected to assist the construction manager in achieving high efficiency.

• Journal of Environmental Impact Assessment
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• v.15 no.4
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• pp.271-277
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• 2006

In this study, we investigated the applicable plan of GIS on the environmental impact assessment of 60 Hz Powerline. So we assessed distance data based on calculations by use of 2D and 3D Geographical information systems(GIS) and distance data based on measurements on 1: 5000 maps accord with on site distance measurements to use input data for calculating magnetic field. One hundred eight of the on site measured addresses were selected from residences. The data were achieved by measuring the distance between residence and power line on maps with scales of 1: 5000. The digital map was obtained from National Geographic Information Institute with scales of 1: 5000, and we made 2D and 3D map. Correlation analyses were performed for statistical analyses. For the 3D GIS versus on site comparison of different exposure categories, 70 of 108 measurements were assigned to the correct category. Similarly for 2D GIS versus on site comparison, 71 of 108 were correctly categorized. When comparing map measurement with on site measurement, 62 of 108 were correctly categorized. When the correlation analysis was performed, best correlation was found between 3D GIS and on site measurements with r = 0.84947 (p<0.0001). The correlation between map and on site measurement yielded an r of 0.76517 (p<0.0001). Since the GIS measurements and map measurement were made from the center point in the building and the on site measurements had to be made from the closest wall on the building, this might introduce and additional error in urban areas. The difference between 2D and 3D calculations were resulted from the height of buildings.

• Earthquakes and Structures
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• v.21 no.6
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• pp.627-639
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• 2021

Fragility curves are being more significant as a useful tool for evaluating the relationship between the earthquake intensity measure and the effects of the engineering demand parameter on the buildings. In this paper, the effect of different site conditions on the vulnerability of the structures was examined through the fragility curves taking into account different strength capacities of the precast columns. Thus, typical existing single-story precast RC industrial buildings which were built in Turkey after the year 2000 were examined. The fragility curves for the three typical existing industrial structures were derived from an analytical approach by performing non-linear dynamic analyses considering three different soil conditions. The Park and Ang damage index was used in order to determine the damage level of the members. The spectral acceleration (Sa) was used as the ground motion parameter in the fragility curves. The results indicate that the fragility curves were derived for the structures vary depending on the site conditions. The damage probability of exceedance values increased from stiff site to soft site for any Sa value. This difference increases in long period in examined buildings. In addition, earthquake demand values were calculated by considering the buildings and site conditions, and the effect of the site class on the building damage was evaluated by considering the Mean Damage Ratio parameter (MDR). Achieving fragility curves and MDR curves as a function of spectral acceleration enables a quick and practical risk assessment in existing buildings.

• Water Engineering Research
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• v.1 no.1
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• pp.11-23
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• 2000

Regional flood frequency analysis has been developed by employing the nearby site's information to improve a precision in estimating flood quantiles at the site of interest. In this paper, single site and regional flood frequency analyses were compared based of the 2-parameter Weibull model. For regional analysis, two approaches were employed. The First one is to use the asymptotic variances of the quantile estimators derived based of the assumption that all sites including the site of interest are independent each other. This approach may give the maximum regional gain due to the spatial independence assumption among sites. The second one in Hosking's regional L-moment algorithm. These methods were applied to annual flood data. As the results, both methods generally showed the regional gain at the site of interest depending on grouping the sites as homogeneous. And asymptotic formula generally shows smaller variance than those from Hosking's algorithm. If the shape parameter of the site of interest from single site analysis is quite different from that from regional analysis then Hosking's results might be better than the asymptotic ones because the formula was derived based on the assumption that all sites have the same regional shape parameter. Furthermore, in such a case, regional analysis might be worse than single site analysis in the sense of precision of flood quantile estimation. Even though the selected sites may satisfy Hosking's criteria, regional analysis may not give a regional gain for specific and nonexceedance probabilities.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.4
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• pp.11-20
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• 2004

This paper suggests the site-dependent ductility factor which is a key component of response modification factor(R). To compute the ductility factor, a group of 1,860 ground motions recorded from 47 earthquake was considered. Based on the local site conditions at the recording station, ground motions were classified into four groups according to average shear wave velocity. This site classification was consistent with site categories of the UBC(1997), NEHRP(1997) and IBC 2000(1997). Based on the results of regression analysis, a simplified equations were proposed to compute site-dependent ductility factors. The proposed equations were relatively simple and provide a good estimation of mean ductility factors. Based on the proposed equation, ductility factors considering the site conditions can be evaluated in accordance with the present building codes.

• Journal of Soil and Groundwater Environment
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• v.21 no.6
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• pp.1-13
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• 2016

The programmable logic array to match the treatment technology to the soil contaminated site based on the site properties in Korea was developed. Based on the previous technology screening system of FRTR (Federal Remediation Technology Roundtable) in USA, total 9 evaluation factors indicating the site characteristics were used for the technology matching process and 8 factors among them were quantitatively weighed in the order of importance. The class interval for each evaluation factor was linearly distributed to give the weighed score and 8 scores were summed up to prioritize the treatment technology. The optimal treatment technology for a specific site was determined according to the total score acquired from 8 evaluation factors used in this technology matching process. The reliability test for the developed technology matching system was done by using information of two real cleanup sites in Korea, suggesting that this guideline will be available to determine the most effective treatment technology to cleanup the soil contaminated site and also to assist the government or the company to design a successful and cost-effective site cleanup plan in Korea.

• Journal of Ecology and Environment
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• v.40 no.2
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• pp.84-88
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• 2016

To understand the effects of habitat characteristics on the genetic diversity of Persicaria thunbergii, three sites of different environmental conditions in a water system were surveyed. Site A was the closest to the source of the water system, and there was a dam between sites A and B. Site C is located on the lowest downstream in the water system. Vegetation survey of four quadrats at each site was performed, and soil samples were collected for physicochemical analysis. Random amplification of polymorphic DNA (RAPD) analysis of ten P. thunbergii individuals at each site was conducted to calculate population genetic diversity and genetic distance among populations. Soil was sterile sand at site A, whereas loamy soil at sites B and C. A pure stand of P. thunbergii appeared at site A, while other species occurred together (such as Humulus japonicus and Phragmites australis) at sites B (Shannon-Wiener index; $H_B=0.309$) and C ($H_C=0.299$). Similar to the species diversity, genetic diversity (Nei's gene diversity; h) within population of site A ($h_A=0.2381$) was relatively lower than sites B ($h_B=0.2761$) and C ($h_C=0.2618$). However, site C was separated from sites A and B in genetic distance rather than the geographical distance (Nei's genetic distance; A~B, 0.0338; B~C, 0.0685; A~C, 0.0833).

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.512-519
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• 2016

In this paper, we compared the user experience according to utilize parallax scrolling technique in web site. For this purpose, we divided subjects into two groups. The subjects of Group1 were given to use web site interface with Parallax scrolling and the Group2 were given to use web site interface with non Parallax scrolling. Then, All Subjects answered the questionnaire of user experience. User experience were evaluated by four entries as Novelty, Esthetics, Usage of Satisfaction, Cheerfulness. Consequently. As a result, the web site interface with Parallax scrolling showed significantly higher score of Novelty, Esthetics, Cheerfulness than the web site interface with non-Parallax scrolling. In this study. we proved that using the parallax scrolling technique in web site interface improves the overall user experience, and suggested to apply as a way to advance the attention and persistency on creating a web site.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.1
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• pp.58-64
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• 2015

There are a lot of different types of noise from construction site and it depends on construction stage, equipment type and number of operating equipments. The problem is that the almost noise from construction site is high level and some kinds of noise levels are over 100 dB. In addition, if construction site is located in downtown, there are a few options to reduce noise level. Therefore several site mitigation plans were developed to reduce different types of construction noises such as breaker work, gang form and asphalt saw. They were applied in site and evaluated noise reduction performance. The test result of site insertion loss was between 4~8 dB depends on the equipment and type of work.

• Journal of the Korean Institute of Educational Facilities
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• v.11 no.6
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• pp.13-21
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• 2004

The purpose of this study is to make planning factors for outdoor space in elementary school site, with analyzation focusing on a Japanese elementary school examples. We evaluated the planning factors which encourage the development of children’s behaviors from quality of space. And we can get the important points as planning factor for school site as follows: 1) The base point of zoning is school building, building entrance, entrance of site and track 2) The importance of linked space plan with inside of site and surrounding environment 3) Preservation linked system of space in school site for linked pattern of child’s behavior.