• Korean Journal of Construction Engineering and Management
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• v.1 no.3 s.3
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• pp.108-115
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• 2000

The average height of buildings in most cities is increasing in an effort to more effectively use land. In addition, as construction technology develops, rapid construction methods have been pursued. However, while there have been great strides in construction technology, the development of a temporary structure that can support the high-rise building under construction and the rapid construction methods has been relatively limited. If the temporary structure is not built on an outer wall of a building being constructed, a worker may be injured or killed in a fall and building materials such as blocks and other objects may fall to the ground, causing the build-up of trash around the building and possible injuries to persons in proximity to the building. This paper proposes a Self Climbing Safety Fence for construction building(SCfence). SCfence was developed to solve the above problems, a tent has been setup to cover the outer wall of the building, or a falling preventing net has been pitched in a direction perpendicular to the outer wall of the building. A case study was performed to verify the validity of SCfence through comparing the safety and cost experience between SCfence and the existing method.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.66-77
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• 2005

We have investigated microclimatic controls on the spatiotemporal variations of net primary production (NPP) of a rugged forested watershed using the process-based biogeochemical model (BIOME-BGC). To validate the model simulation of water and carbon cycles at the plot scale, we have conducted field survey over deciduous broadleaf forest (DBF) and evergreen needleleaf forest (ENF) since 2000. The modeled values of soil temperature, soil moisture and soil respiration showed high correlation with those from the field measurements. The modeled seasonal changes of NPP showed high correlation with air temperature but no significant correlation with water related parameters. The precipitation frequency turned out to be the best climatic factor to explain the annual variation of NPP. Furthermore, NPP of ENF was more sensitive to precipitation frequency than that of DBF. With changes in vegetation cover and topography, the spatial distribution of NPP was of great heterogeneity, which was negatively correlated with the magnitude of NPP. Despite the annual precipitation of 1,400mm, NPP at the study site was constrained by the amount of water available for the vegetation. Such a modeling result should be verified by the field measurements.

• Journal of Korea Spatial Information System Society
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• v.12 no.1
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• pp.57-65
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• 2010

In this study, disaster damage investigation system was developed using high resolution satellite images and GIS technique to afford effective damage investigation system for widely disaster damaged area. Study area was selected in Bonghwa, Gyungsangbukdo where high magnitude of damages from torrential rain has occurred at July in 2008. GIS DB was built using 1:5,000 topographic map, cadastral map, satellite image and aerial photo to apply for investigation algorithm. Disaster damage investigation system was developed using VB NET languages, ArcObject component and MS-SQL DBMS for effective management of damage informations. The system can finding damaged area comparing pre- and post-disaster images and drawing damaged area according to the damage item unit. Extracted object was saved in Shape file format and overlayed with background GIS DB for obtaining detail information of damaged area. Disaster damage investigation system using high resolution spatial images can extract damage information rapidly and highly reliably for widely disaster areas. This system can be expected to highly contributing to enhance the disaster prevention capabilities in national level field investigation supporting and establishing recovery plan etc. This system can be utilized at the plan of disaster prevention through digital damage information and linked in national disaster information management system. Further studies are needed to better improvement in system and cover for the linkage of damage information with digital disaster registry.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.3
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• pp.172-181
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• 1994

The mesh selectivity of diamond and suare mesh cod-ends at the Southern Korean Sea and the East China Sea were compared for Pampus argenteus, Trachurus japonicus, Trichiurus lepturus. Selection trials were carried out using diamond and square mesh cod-end by trouser type cod-end with cover net. of which the mesh cod-end has four types : A(51.2mm), B(70.2mm), C(77.6mm), D(88.0mm). Selection curves and selection parameters were calculated using a logistic model. The results obained are summarized as follows : 1. Harvest fish : In B. C and D type selection range and fifty percent selection length of the square mesh were about 21mm, 11mm : 12mm, 18mm and 34mm, 5mm higher than those of the diamond mesh, respectively. Selection factor of master curve for the diamond mesh was 1.54 and for the square mesh was 1.68. The optimum mesh size for the diamond mesh was 97.4mm and for the square mesh was 89.3mm, the difference was 8.1mm. 2. Horse mackerel : In A type, selection range was nearly the same for the diamond and the square mesh, but fifty percent selection length of the square mesh was 43mm higher than the diamond mesh. In B. C and D type, selection range and fifty percent selection length of the square mesh were about 6mm, 3mm : 24mm, 21mm and 11mm, 42mm higher than those of the diamond mesh, respectively. Selection factor of master curve for the diamond mesh was 2.37, for the square mesh was 2.77. The optimum mesh size for the diamond mesh was 78.1mm and for the square mesh was 66.8mm, the difference was 11.3mm. 3. Hair tail : In A, B and C type, selection range of the square mesh was about 34mm, 8mm, 60mm higher than those of the diamond mesh. Fifty percent selection length for the diamond mesh was about 5mm, 7mm, 8mm higher than that of the square mesh. Selection factor of master curve for the diamond mesh was 3.11, for the square mesh was 3.48. The optimum mesh size for the diamond mesh was 64.3mm and for the square mesh was 57.5mm, the difference was 6.8mm.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1413-1425
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• 2023

The increasing frequency of wildfires due to climate change is causing extreme loss of life and property. They cause loss of vegetation and affect ecosystem changes depending on their intensity and occurrence. Ecosystem changes, in turn, affect wildfire occurrence, causing secondary damage. Thus, accurate estimation of the areas affected by wildfires is fundamental. Satellite remote sensing is used for forest fire detection because it can rapidly acquire topographic and meteorological information about the affected area after forest fires. In addition, deep learning algorithms such as convolutional neural networks (CNN) and transformer models show high performance for more accurate monitoring of fire-burnt regions. To date, the application of deep learning models has been limited, and there is a scarcity of reports providing quantitative performance evaluations for practical field utilization. Hence, this study emphasizes a comparative analysis, exploring performance enhancements achieved through both model selection and data design. This study examined deep learning models for detecting wildfire-damaged areas using Landsat 8 satellite images in California. Also, we conducted a comprehensive comparison and analysis of the detection performance of multiple models, such as U-Net and High-Resolution Network-Object Contextual Representation (HRNet-OCR). Wildfire-related spectral indices such as normalized difference vegetation index (NDVI) and normalized burn ratio (NBR) were used as input channels for the deep learning models to reflect the degree of vegetation cover and surface moisture content. As a result, the mean intersection over union (mIoU) was 0.831 for U-Net and 0.848 for HRNet-OCR, showing high segmentation performance. The inclusion of spectral indices alongside the base wavelength bands resulted in increased metric values for all combinations, affirming that the augmentation of input data with spectral indices contributes to the refinement of pixels. This study can be applied to other satellite images to build a recovery strategy for fire-burnt areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6128-6134
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• 2012

In so many real estate development projects, there were strong needs to have a powerful tool to check feasibility of those projects. But there were not enough tool and measure to cover risk of real estate development and construction. Therefore I tried to find a real tool to measure investment value of development properly and efficiently, by means of case studies of many real estate development projects. Finally I found a fact that no tools of investment value analysis are perfect and efficient to hedge all kinds of risks in projects. Especially NPV(Net Present Value) and IRR(Internal Rate of Return) were not sufficient by themselves to measure investment value. So I found out that MIRR(Modified IRR), XIRR(X-IRR), ARR(Average Rate of Return), PP(Payback Period) and so on, would be supplementaries of proper and efficient investment value analysis.

• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.139-149
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• 2011

A cable structures have the advantage that cover a large space without column but it is very sensitive to deal with shape control because of its flexibility. Especially, location of control member and needed elongation of member are important things. Therefore, the purpose of this paper is studied on displacement control technique for pre-stressed cable structures by force method considering order of control. The layout of this paper is as follows. Firstly, in section 2, the control technique by force method for cable structures is given. Secondly, section 3 briefly introduces simple cable net in order to apply control technique considering ordering of actuator. Finally, more complex example for effective member and the conclusion are in section 4 and 5, respectively.

• Nuclear Engineering and Technology
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• v.44 no.7
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• pp.825-830
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• 2012

Radiation and its various industrial applications have been growing at approximately 10 percent per year for the past decade in Korea. As a result, the importance of the Education and Training (E&T) in radiation protection is of upmost importance. This paper is intended to investigate the present status of the E&T on radiation protection and safety in Korea and to draw up the improvements of the E&T courses required for building the national radiation safety infrastructure. For these purposes, the E&T data from the six major domestic organizations providing radiation protection training courses were investigated and analyzed. Each of the organizations is offering several kinds of E&T courses based on their own specific functions. These organizations have administrative facilities equipped with the latest technology for E&T in radiation protection. The E&T courses mainly cover the training courses for radiation workers, radiological emergency staff, license applicants, license holders, and regulatory staff. In 2010, a total of 58 E&T courses were carried out across six organizations. The conclusions make a number of observations highlighting challenges such as: establishing a formal feedback mechanism, introducing more practical training sessions, developing training courses tailored to the job categories and target audiences, and designing education and training courses in radiation protection that comply with current obligations as well as future requirements.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.141-149
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• 2009

The objective of this study was to propose a development length equation for bottom and top GFRP bars. Including the bottom and top GRPP bars, a total of 104 modified pullout tests were completed. The test variables were embedment length (15, 30, 45db), net cover thickness (0.5~2.0db), different GFRP bar types, and bar diameters (10, 13, 16mm). The average bond stresses were determined based on the modified pullout test results. Two variable linear regression analyses were performed on the results of the average bond stresses. Utilizing the 5% fractile concept, a conservative development length design equation was derived. The design equation of the development length for bottom and top GFRP bars was proposed and the design equation derived in this study was compared to the ACI 440.1R-06 committee equation.

• Journal of the Korea Institute of Building Construction
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• v.16 no.5
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• pp.463-470
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• 2016

Construction companies calculate their revenues and costs from constructing activities using the 'Percentage of Completion Method', which is based on ratio of actual construction cost to total costs estimated. The reliability of the net profit of construction companies is being evaluated lower than other industries due to incorrect application of 'Percentage of Completion Method' to cover losses actually occurred. Therefore, the purpose of this study is to verify the quality of earnings calculated based on 'Percentage of Completion Method' in terms of information usefulness. Results from empirical analysis show that investors in stock market underestimate the value of the construction companies' earning information by applying 'Percentage of Completion Method' and not actively use in investment decision making. Accordingly, it has been confirmed that the association between income information and stock prices falling. These results suggest the need for strict supervision of the supervisory authorities and the practical application of 'Percentage of Completion Method' in reliability.