• Journal of Korean Society of Water and Wastewater
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• v.25 no.5
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• pp.651-658
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• 2011

Nitrate is a common contaminant in industrial wastewater and ground water. The maximum contaminant level set by EPA for nitrate of 10 mg/L as N. In this study, nitrate was removed using bipolar ZVI packed bed electrolytic cell that maximized the contact area between each electrode and contaminants under 600 V. Also this study investigates the simultaneously deals with removal of ammonia by operating air stripping tower. In addition to the air stripping also helped to precipitate iron ions to the form of iron oxides. Bipolar ZVI packed bed electrolytic cell was also effective in removing coliform by electrical power. In the continuous experiments for the simulated wastewater (initial nitrate for 25 mg/L as N), maximum 96.3% removal of nitrate was achieved in the applied 600 V at the flow rate of 6 mL/min.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.261-264
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• 2005

For concrete structures immersed in seawater, the concentration of chloride used to estimate the chloride diffusion coefficient can be defined as the seawater chloride concentration. However, for seashore concrete structures which are not coming into direct contact with seawater, establishing the interface concentration of chloride becomes delicate. In addition, concrete structures are greatly affected by salt attack primarily due to airborne sea salt like it can be seen through the corrosion of rebar. This study intends to investigate characteristics on the salinity of airborne sea salt by height. Salinity measurement devices were installed at height of 2, 10 and 19m on the seashore water tower located in the area of Samchuk in the Eastern coast. Analysis results of the decrease of salinity with respect to the height above the ground at a distance of 30m from the seashore showed that the reduction reached about 40$\%$ at a height of 10m and 60$\%$ at 20m.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.10
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• pp.2142-2149
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• 2002

Contacting with ground in the post-card area size only, tire supports entire automobile weight. As well, it characterizes most of automobile running performance. Among the design parameters, the carcass contour becomes a key design factor. This paper deals with the time-effective optimal design of tire crown contour in order to improve the tire wear performance by employing a back-propagation neural network model.

• Journal of the Korean Institute of Rural Architecture
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• v.17 no.4
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• pp.75-82
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• 2015

The elderly rate in South Korea in 2015 is over 13.1%. Especially, the elderly rate in rural area is high. Senior community project in rural that is being promoted by the government. This study's purpose is to provide the reserch group-home for the elderly in Japan rural area. And this paper provided planning of group-home for the elderly in Korea rural area. For this study, respective 5senior housing of Korea and Japan were chosen as respresenting two nations, and every manager was interviewed on housing pattern. This study suggests the planning material as following. First, the effectiveness of the group-home are big. Especially, the elderly was far healthier. Design point is public space(living room, small living room, etc). Maybe, healthy group-home concept is that would be design by Korean traditional housing. Also important public space design is that would be inner courtyard-house, wood floor, Deachong, etc. Two group-homes will construct elderly welfare facilities in between. Otherwise that is need layout of a big public space. In the case of vacant house can used by considering of scale, structure, site condition. Closed school can used through so easy remodeling too. More often than not complex type(hospital, community heath center) was appeared in Japan rural area. In the case of Korea, recommend complex type in community health center and public building. In this case, considering communication, access, contact, group-home keeps on ground floor. In this paper, we hope to take a lesson from group-home planning source for the elderly in Korea rural area.

• The Journal of Korean Physical Therapy
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• v.23 no.6
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• pp.15-22
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• 2011

Purpose: This research investigated falls due to obstacles that occur among elderly people by assessing changes in the values of plantar foot force, peak force, and plantar foot pressure in elderly subjects while they were stepping over obstacles of different heights. Methods: The subjects were 20 elderly people aged 70-80 years; Pressure was measured on flat ground(0 cm), and after installing obstacles of 8 cm and 12 cm using the F-scan system, which is a resistance-type pressure sensor. A one-way analysis of variance was performed to compare pressure on each part of the foot according to various heights after collecting data using the Tekscan program. The least significant difference test was used for the post-hoc analysis, A p-value <0.05 was considered significant. Results: The force value for the toe area (parts 1, and 2) and contact pressure increased significantly with the 12 cm obstacle (p<0.05). The peak force value and the peak contact pressure for part 1 increased significantly with the 12 cm obstacle (p<0.05). Conclusion: Larger changes appeared in the functions and structure of the foot while subjects walked over obstacles of different heights compared to flatland walking. This result suggests that people have safety strategies to prevent falls, and that there is a need for a more realistic approach through practice to overcome obstacles of various heights to prevent falls.

• Journal of Ocean Engineering and Technology
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• v.24 no.3
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• pp.72-78
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• 2010

This paper presents a design approach of driving system for tidal flat vehicle. Firstly, topographic and geological survey of tidal flat zone was accomplished. 'Anac' located in the west-south coast of South Korea was chosen for the survey area. From the survey, the basic design data such as distribution of gullies size and bearing pressure was obtained. To figure out the shape of driving system, numerical simulations were carried out. Through the numerical dynamic simulations using $Recurdyn^{TM}$, the performance of various concepts of driving system was analyzed. From the results, we propose the conceptual design with the functions: a) low contact pressure, b) powerful driving force transmission, c) adaptation to the ground undulation. To satisfy these functional requirements, the driving system adopts rubber tracks, sprockets, tires and suspensions. The static structural analysis of the frame structure was executed as well, from which the detailed design was drawn out. To validate the performance of the designed driving system, the test vehicle which has gasoline engine of 27HP and mechanical transmission was constructed. The driving tests of the vehicle were performed twice at the "Anac" area, and unveiled its capability.

• Journal of the Korea Concrete Institute
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• v.28 no.1
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• pp.95-104
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• 2016

Flexural strength of concrete ground slab reinforced with steel fiber is evaluated using the equivalent flexural strength ratio of steel fiber reinforced concrete based on the yield line theory. Recently, the European standard specifies that the tensile performance of the steel fiber reinforced concrete be evaluated directly from the residual flexural strength after the cracking of concrete. Thus, in the study, an experiment was carried out to evaluate the conventional equivalent flexural strength ratio and the residual flexural strength of the steel fiber reinforced concrete. Then the design flexural strength was investigated according to the location of a point load, based on the ratio of the radius of contact area of the load to the radius of relative stiffness. Design flexural capacity obtained from ACI 360R-10 was smaller than that from TR 34 (2003 & 2013). In addition, TR 34 (2013), which evaluates the design flexural capacity based on the residual flexural strength, showed slightly smaller value than TR 34 (2003).

• Journal of the Society of Disaster Information
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• v.13 no.3
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• pp.305-312
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• 2017

In our society, the advanced, advanced, and information industries have continued to grow and now live in the era of the fourth industrial revolution. As the industry develops, the load of the users has also increased so much that it is deepened by the energy shortage phenomenon and the construction of additional energy facilities is required. Therefore, energy plant construction work is being actively carried out in the coastal area. In particular, it is common to build a plant in the ground by filling the coast with soil in other regions, reflecting the fact that Korea is lacking in the country when constructing power plants, gas and petrochemical plants. Current domestic grounding designs are designed or constructed to suit only the use of grounding resistors based on the electrical equipment design technical standards. However, in the case of a plant facility constructed in the untested buried soil, when the lightning current and the abnormal current are inputted, the facility operator or the user due to the elevation of the ground potential is seriously exposed to the risk of electric shock disaster. In this paper, we analyze the ground resistivity of the landfilled soil and use a computer program (CDEGS) based on KS C IEC 61936-1, We analyze the contact voltage and stratification voltage and propose a grounding design optimized for plant installation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.6
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• pp.138-145
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• 2023

A study using numerical analysis techniques was conducted to examine the scour effect of pier-type dolphin structures installed in the domestic marine environment, and the effect of scour on horizontal bearing capacity was examined. In this study, we designed the berthing structures, taking into account the environmental and ground conditions of the target maritime area, and after calculating the predicted scour area, stability evaluation was performed by removing the ground elements of the area. The increase in scour depth was found to induce a direct decrease in horizontal bearing capacity due to soil loss in contact with the foundation, establishing a relationship that increases horizontal displacement. However, in the foundation designed to withstand the design load by reflecting the safety rate, the increase in horizontal displacement formed by possible scour is not large, which did not have a dominant effect on the horizontal bearing capacity of the foundation. In the future, research is required to analyze the impact of each factor and formalize evaluation and design techniques to evaluate the scour safety of marine foundations and pier-type structures installed in various ground conditions and structural formats.

• The Journal of Engineering Geology
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• v.26 no.1
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• pp.51-61
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• 2016

New building methods are needed to aid increased inner-city redevelopment and industrial construction. A particular area of improvement is the efficient use of cut slopes, with the minimization of associated problems. A retaining wall of precast panels can resist the horizontal earth pressure by increasing the shear strength of the ground and reinforcing it through contact with the panels. Precast panels allow quick construction and avoid the problem of concrete deterioration. Other problems to be solved include the digging of borrow pits, the disposal of material cut from the slope, and degradation of the landscape caused by the exposed concrete retaining wall.This study suggest the methods of improvement of an existing precast panel wall system by changing the appearance of the panels to that of natural rock and improving the process of adhering the panel to a vertical slope. The panels were tested in the laboratory and in the field. The laboratory test verified their specific strength and behavior, and the field test assessed the panels' ground adherence at a vertical cutting. Reinforcement of the cutting slope was also measured and compared with the results of 3D numerical analysis. The results of laboratory test, identified that the shear bar increase the punching resistance of panel. And as a results of test construction, identified the construct ability and field applicability of the panel wall system adhered to in-situ ground. In addition to that, extended measurement and numerical analysis, identified the long-term stability of panel wall system adhered to in-situ ground.