• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.643-643
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• 2012

Increasing energy prices and growing concerns about global warming address the need to improve energy self-sufficiency in many industrial and municipal sectors. Wastewater treatment plants (WWTPs) are representative of energy-consuming facilities in Korea, accounting for 5% of national energy consumption. We present renewable energy technologies and energy self-sufficiency scenarios in a municipal WWTP ($30,000m^3d^{-1}$) located in Yongin, South Korea. By employing photovoltaics (PV, 135 kW), small hydropower turbine (10 kW), and thermal energy from treated effluent (25 RT: refrigeration ton) within the WWTP, a total of 142 tonne of oil equivalent (toe) of energy was estimated to be generated, accounting for $365ton\;CO_2\;yr^{-1}$ of greenhouse gas emission reduction. Core renewable technologies under consideration include 1) hybrid solar PV system consisting of fixed PV, dual-axis PV, and building integrated PV, 2) low-head small hydropower plant specifically designed for treated effluent, 3) effluent heat recovery system for heating and air conditioning. In addition to these core technologies, smart operation and management scheme will be presented for enhancing overall energy savings and distribution within the WWTP.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.2
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• pp.87-92
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• 2009

Objects：The purpose of this study is to investigate the values of foot pressure of the stance phase during a gait cycle in hemiplegic gait. Method：42 patients who had a stroke and 42 healthy adults were evaluated by the RSscan system to analyze the stance phase of hemiplegic gait. The stance phase was evaluated as plantar foor pressure. Results：1) Foot plantar pressure of toe area, affected side and less affected side showed low distribution of the plantar foot pressure which is lower than plantar foot pressure of normal adults(p<0.05). 2) Foot plantar pressure of metatarsal area, showed significantly differences among hemiplesic patient's affected side and less affected side and distribution of plantar foot pressure of normal adults(p<0.05). 3) Foot plantar pressure of heel area, hemiplesic patients' affected side and less affected side showed lower distribution of the plantar foot pressure than plantar foot pressure of normal adults(p<0.05). Conclusion：The results of this study suggest that not only affected side but also less affected side in hemiplegic patients showed significantly differences in distribution of the plantar foot pressure of normal adults.

• Journal of the Korean Society of Physical Medicine
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• v.3 no.3
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• pp.169-176
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• 2008

Purpose : Tandem stance is a clinical measure of standing balance considered to assess postural steadiness in a heel-to-toe position by a temporal measurement. The aim of this study is to investigate postural steadiness and to explore the weight distribution between legs during 25s of quiet stance and tandem stance(right foot was leading) in healthy young adults. Methods : 107 healthy young adults(mean age 21.1 years) are participated. Weight distribution beneath both feet and sway distance were recorded while the subjects performed 25s of quiet stance and tandem stance. Results : Subjects placed more weight on the rear leg in tandem stance and on the left foot in quiet stance. So, quiet stance and tandem stance is not a task for equal weight bearing. Subjects show larger sway distance in anteroposterior direction of tandem stance than quiet stance. Conclusion : The results of this study will be useful to researchers and clinicians using tandem stance measures to evaluate postural steadiness and to predict fall. The results suggest that tandem stance is useful to treat of weight distribution and to improve of balace in elderly adults and stroke patients.

• Archives of Reconstructive Microsurgery
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• v.19 no.2
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• pp.88-92
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• 2010

The forefoot reconstruction is a challenging field for plastic surgeons. Weight bearing tolerability and stability are important factor of choosing reconstruction methods, but cosmetic aspect has to be considered. 51 year old man visited our clinic with extensive degloving injury on right forefoot by roller. The soft tissue defect started from metatarsal area to the toe tip including nails. We harvested the anterolateral thigh flap and transferred it to the forefoot defect area with nerve coaptation. The flap was successful without skin necrosis or other complications. Secondary flap debulking surgery was performed after ten months from initial operation. Patient was satisfied with functional and cosmetic outcomes. The patient was able to wear shoes and walk with adequate sensory recovery. As there is few report about reconstruction of forefoot soft tissue defects, we report a unique case of the anterolateral thigh innervated free flap reconstruction in degloving injury.

• Earthquakes and Structures
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• v.10 no.3
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• pp.717-733
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• 2016

Trapezoidal Cemented Sand and Gravel Dam, namely Trapezoid CSG, is a new type of dam. Due to lack of dynamic studies in the field of CSG dam, this research was performed to analyze Trapezoidal CSG dam using dynamic Finite element method with ABAQUS Software. To investigate possible earthquake-induced damages, fragility curves are plotted based on damage index, the length of the cracks created at the dam base and the area of cracked elements in the dam. The seismic analysis indicated that minimum and maximum tensions are generated in the heel and toe of the dam, respectively. According to the fragility curves, with increase in PGA, the possibility of the exceeding the defined limit state is increased. However, the rate of increment is significantly reduced after PGA=0.4 g. Also, the same result is achieved for the second limit state. The "area of cracked elements" is more conservative criterion than the "crack length at the dam base", especially at PGA<0.4 g. As conclusion, CSG dams, despite of being made of poor materials in comparison with concrete dams, show good resistance, and even in some situations, better performance than the weighted concrete dams.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.2 s.140
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• pp.129-135
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• 2005

At present, fatigue design of welded structures is primarily based on a nominal stress or hot spot stress approach with a series of classified weld S-N curves. Although well accepted by major industries, the nominal stress based fatigue design approach is cumbersome in terms of securing a series of S-N curves corresponding to each class of joint types and loading modes. The hot spot stress based fatigue design has a difficulty of finding a proper stress through the global model, the midium size model, and the detail model of ship structure. Also, it is difficult to link proper displacements within three different mesh size models. Recently, the structural stress is proposed as a mesh-size insensitive structural stress definition that gives a stress state at weld toe with relatively large mesh size. However, this method requires an experimental validation in obtaining the fatigue strength of weldments. Therefore, in this study, a series of experiment is performed for various sizes of weldments.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.215-220
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• 2006

Along with socioeconomic development and improving standard of living, the heat demand for heating and cooling in residential and commercial sectors is expected to expand rapidly, reaching over 43 million TOE by 2010 in Korea(about 80% increase compared with that in 1995). Since most of this heat demand is loop temperature below $60^{\circ}C$, the utilization of 'unused energy' is surely one of very effective measures to both environmental preservation and energy conservation. 'Unused energy' in this paper is implicated as 'temperature differential energy' available from treated sewage water, useful and abundant heat source for heat pump(cooler in summer and warmer in winter than outside air). An analysis was carried out to estimate the energy potential of treated sewage water for heat pump heat source. Some analysis were taken to study the characteristics of a heat pump system using the treated sewage water as heat source.

• The Journal of Information Systems
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• v.30 no.3
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• pp.159-175
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• 2021

Purpose The purpose of this study was to find the effect of the determinants on the Big data utilization in industry. The determinants of Big data utilization were deduced by reviewing theoretical background and discussions on Big data related researches. Research model and proposed hypothesis were constructed from TOE framework and UTAUT model. Design/methodology/approach The research was conducted to collect a sample data from the experts involved in the Big data projects in industry. In addition, interviews and online survey were performed to get sample data. Exploratory factor analysis was conducted to verify the grouping of these questionnaire items and confirmatory factor analysis was done to verify the validity and reliability of the measurement model. Finally, research hypothesis was verified and theoretical and practical implications were proposed for further studies. Findings The results show that the technical factor have a significant effect on the expectancy factor and the behavioral factor. The organizational factor have a significant effect on the behavioral factor. In addition, the expectancy factor was significant on the behavioral factor and the intention-to-use of Big data system.

• Geomechanics and Engineering
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• v.17 no.1
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• pp.109-118
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• 2019

The movement of soil along a slope during rainfall can cause serious economic damage and can jeopardize human life. Accordingly, predicting slope stability during rainfall is a major issue in geotechnical engineering. Due to rainwater penetrating the soil, the negative pore water pressure will decrease, in turn causing a loss of shear strength in the soil and ultimately slope failure. More seriously, many constructions such as houses and transmission towers built in/on slopes are at risk when the slopes fail. In this study, the numerical simulation using 2D finite difference program, which can solve a fully coupled hydromechanical problems, was used to evaluate the effects of soil properties, rainfall conditions, and the location of a foundation on the slope instability and slope failure mechanisms during rainfall. A slope with a transmission tower located in Namyangju, South Korea was analyzed in this study. The results showed that the correlation between permeability and rainfall intensity had an important role in changing the pore water pressure via controlling the infiltrated rainwater. The foundation of the transmission tower was stable during rainfall because the slope failure was estimated to occur at the toe of the slope, and did not go through the foundation.

• Journal of Information Technology Services
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• v.18 no.1
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• pp.91-112
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• 2019

The IoT environment has led to explosive growth of existing enterprise data, and how to utilize such big data is becoming an important issue in the management field. In this paper, major factors affecting the decisions of companies to utilize big data have been studied. And also, the effect of big data utilization on the management quality is studied empirically. During this process, we have studied the difference according to the award of Korean national quality award. As a result of the study, we confirmed that the five factors such as cost from technology, organization and environment perspective, compatibility, company size, chief officer support, and competitor pressure are key factors influencing big data utilization. Also, it was confirmed that the use of big data for management activities has an important influence on the six management quality factors based on MBNQA, and that the management quality level of Korean national quality award companies is relatively high. This paper provides practical implications for companies' use of big data because it demonstrates for the first time that big data utilization has an impact on management quality improvement.