• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.219-224
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• 2007

As use of construction equipment has been increasing continuingly, the proportion of equipment expense to the total construction cost has become higher. However, there is a difference between the equipment expenses section in 'Poom-Sam' and practical data, because 'Poom-sam' does not consider non-working days due to weather conditions, legal holidays and management conditions. Therefore, 'Poom-Sam' does not present a reasonable standard for estimating construction equipment expenses. In this study, to estimate realistic construction equipment operating hours, firstly, construction equipment was classified according to work, and weather conditions, in which each work could not be executed, were established. Then, weather data on Seoul and Busan(2004${\sim}$2006) and legal holidays were analyzed to suggest annual standard operating hours. The annual standard operating hours of earthmoving & excavating, compaction, and drilling equipment was estimated to be 1,430 hours, and lifting equipment, concrete paving equipment, asphalt paving equipment, concrete equipment, and crushing & conveying equipment were estimated to be 2,124 hours, l,156hours, 1,188hours, 1,688hours, and 2,152hours respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.1
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• pp.131-138
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• 2009

This research was carried out to keep a sharp look-out on changes of estimated unit power and material in landscape architectural construction in Korea from 1962 to 2007 and to suggest basic information for its desirable direction in the near future. The research results are as follows. At first, work classification of estimated unit power and material landscape architectural construction was included under the earth work and in 1974 it had the name which was called landscape architectural process with earth works, and in 1984 the estimated unit power and material of landscape architectural construction was separated from the earth work but it was still under name of estimated unit manpower and material of the engineering construction. In 1972 the estimated unit power and material began with a 'planting' and a 'pruning' and still consists of 7 work classification total: 'sodding and herbaceous sowing', 'digging out', 'planting', 'digging round the root', 'keeping and management', 'rubble masonry' and 'planting for protection of rocks split section'. The processes consist of 29 sub-processes in total. The lawn construction was mainly established in the 1960s, the planting construction in the 1970s, the keeping and management in the 1980s, split section protection in the 1990s along with new technology with keeping management in the 2000s. On the basis of these research results, the process to be added in the near future could be related to new material and new technology and the process might be much more subdivided.

• Journal of the Korean Geotechnical Society
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• v.37 no.3
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• pp.31-41
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• 2021

A dozer is a construction machinery used to move soil mass along large open tracts of land. Soil thrust generated on the soil-track interface determines the performance of the dozer; to improve the tractive performance of the dozer, the outer surface of the continuous-track is designed to protrude with grousers. In this study, we calculated soil thrust of the dozer equipped with grousers with various shape ratios, and evaluated the optimal grouser shape ratio considering ground conditions. Grouser generated additional soil thrust on the side of the continuous-track (e.g., side soil thrust) and converted the shearing surface (e.g., from soil-track interface to soil-soil interface), increasing the soil thrust of dozer by about 1.3 to 1.6 times. The effect of grouser's shape ratio on the soil thrust of dozer differed with the relative density of the ground. As the shape ratios of grouser increased, soil thrust of dozer decreased at the relative density of 40% and increased at the relative density of 80%. Based on these results, it can be concluded that the shape ratio of grouser severely affects the dozer's performance; thus, careful consideration of the optimal shape ratio of grouser is of great importance in the mechanical design, evaluation, and optimization of the undercarriage of dozers.

• Korean Journal of Construction Engineering and Management
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• v.22 no.4
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• pp.29-40
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• 2021

Recently, interest in Building Information Modeling (BIM) has increased globally, and 3D modeling is a start for the application of BIM at construction sites. However, while many studies have been conducted on the efficiency of 3D modeling focused on civil facilities, there is a lack of research on the earthwork BIM. In particular, since 3D slope often has complex shapes depending on the ground models, the efficiency method for 3D slope are needed. This study analyzed the interfaces and procedures of other software to find out what functions users need. Then the functions to enter intervals between 3D faces, select multiple ground models, and improve the interface are reflected on the developed system and is able to efficiently perform modeling with only five steps, and reduce the number of clicks and inputs. As a result of conducting the test to verify the efficiency, using the developed system made skilled users complete modeling at least 1.8 times faster and unskilled people at least 2.4 times faster than using other software. This is expected to perform 3D slope modeling more efficiently, as well as to contribute to the activation of future BIM adoption for housing construction projects.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.242-248
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• 2017

This study was conducted to develop a cylindrical paperpot manufacturing equipment which is capable of continuously producing paperpots with a constant size. The equipment consists of the soil supply part, the paper supply part, the pot manufacturing part, the paperpot cutting part and its process for manufacturing paperpot from the soil supply to the paperpot cutting is continuously performed. As a result of the performance test using this equipment, we suggest that the optimal moisture content and injection pressure to supply soil are 50%~60%, and 0.5 Mpa respectively. Moreover the appropriate temperature for adhesive strength is $150{\sim}160^{\circ}C$ taking into account the performance of device and adhesion time. Also, considering the cutting speed and safety, it is appropriate to adopt a straight blade having a clean plan at a minimum angle of $30^{\circ}$. In addition, the manufacturing capacity of the developed equipment was 3300 pots per hour.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.1
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• pp.45-63
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• 2019

The number of domestic construction company is expanding every year while the construction workers' exposure to disaster risk is increasing due to technological advancements and popularity of high-rise buildings. In particular, the industry faces greater fatalities and severe large scale accidents because of construction industry characteristics including influx of foreign workers with different language and culture, large number of aged workers, outsourcing, high place work, heavy machine construction. The construction industry is labor-intensive, which is to be completed under given timeline and consists of unique working environment with a lot of night shifts. In addition, when a fixed construction budget is not secured, there is less investment in safety management resulting in poor risk management at the construction site. Taking account that the construction industry has higher accident risk rate and fatality rate, risky and unique working environment, and various labor pool from foreign to aged workers, preemptive safety management through risk factor identification is a mandatory requirement for the construction industry and site. The study analyzes about 8,500 cases of construction accidents that occurred over the past 10 years and identified risk factor by construction industry sector to secure a systematic insight for risk management. Based on interrelation analysis between accident types, work types, original cause materials and assailing materials, there is correlation between each analysis factor and work industry. Especially for work types, there is great correlation between work tasks and industry type. For reinforced concrete and earthwork are among the most frequent types of accidents, and they are not only high in frequency of accidents, but also have a high risk in categories of occurrence.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.203-216
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• 1994

The laboratory methods for compaction of soil (KSF 2312) and for moisture of soil (KSF 2306) in combination with the soil density in place by the sand-cone method (KSF 2311) are generally used for compaction control of soils. However, these methods have limitations in number of test and in accuracy. ]n addition, they are time-consuming. Therefore, they are not adequate for speedy control of embankment compaction in a project with huge amount of earthwork. The RI (Radioisotope) gauges for measurement of soil density and/or of soil moisture are widely used for the compaction control of soils in many countries. But in Korea, they have had a limited usage and available informations for uses of RI gauges are insufficient. Therefore, this study promotes efficient and safe use of RI gauges in geotechnical engineering. In this paper, fundamental aspects such as the priciples of RI gauges, gauge inspection techniques and the applicability and limitations of RI gauges for field usage were reviewed. And a new calibration curves suitable for the Korean soils were suggested.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.485-487
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• 2009

The Spatial Image contents of Geomorphology 3-D environment is focused by the requirement and importance in the fields such as, national land development plan, telecommunication facility management, railway construction, general construction engineering, Ubiquitous city development, safety and disaster prevention engineering. The currently used DEM system using contour lines, which embodies geographic information based on the 2-D digital maps and facility information has limitation in implementation in reproducing the 3-D spatial city. Moreover, this method often neglects the altitude of the rail way infrastructure which has narrow width and long length. This As the results, We confirmed the solutions of varieties application for railway facilities management using 3-D spatial image contents and database design. Also, I suggested that U-city using topographical modeling about matching methods of high density elevation value using 3-D aerial photo with laser data are best approach for detail stereo modeling and simulation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.4
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• pp.343-350
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• 2000

This study deals with the Definition of the Earth-volume quantity and direction of throwing down stones (Q.R.R) into the Breakwater using Real-time DGPS & Echo-Sounding method. Generally, the buoy in the center line of Breakwater has been set up so as to throw down stones in the correct area. After throwing stones down there, surveyors have been surveying the depth and direction of stones with rod and sounding lead. The method, however, is not effective because of long time and a lot of human power, in addition it is incorrect. This paper has studied on the solution of those problems using Real-time DGPS & Echo-Sounding data to calculate the earth-volume quantity, direction and depth of throwing down stones. This paper says the effective and economical methods using Real-time DGPS & Echo-Sounding data there.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.115-122
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• 2004

This study identifies various risk factors associated with activities of early construction stage, then establishes the Risk Breakdown Structure(RBS) by classifying the risks into the three groups; Common risks, risks for Earth works, and risks for Foundation works. The Common risks are identified and classified by considering various aspects of the early construction stage such as financial, political, constructional aspects, etc. The risks for Earth works and Foundation works are identified in detail by surveying technical specifications, relevant claim cases and interviewing with experts. These risks are classified based on the Wok Breakdown Structure(WBS) of the early construction stage. The WBS presented in this study classifies the works of early construction stage into four categories; excavation, sheeting works, foundation works, footing works. This study suggests a risk analysis method using fuzzy theory for construction projects. Construction risks are generally evaluated as vague linguistic value by subjective decision making. Fuzzy theory is a proper method to quantify vague conditions of construction activities. Therefore, this study utilizes fuzzy theory to analyse construction risks. The weight of risks is estimated by reflecting the interrelationship among risk factors from absolute weights obtained by fuzzy measure into the relative weights by Analytical Hierarchy Process(AHP). The interrelationship is estimated by Sugeno-fuzzy measure.