• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.1-10
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• 2022

Recently, due to the frequent occurrence of localized torrential rains and heat waves caused by abnormal climates. For this reason, it is necessary to develop an economical and eco-friendly rainwater detention facility that can secure the groundwater level through rainwater detention as well as flood prevention against concentrated rainfall by simultaneously implementing rainwater permeation and storage. In this study, the structural safety of an eco-friendly rainwater infiltration type detention facility made using eco-friendly inorganic binders including red clay was examined. Static analysis considering the constant load and additional vertical load and dynamic analysis considering the seismic spectrum were performed. As a result, it was found that the eco-friendly prefabricated rainwater infiltration type detention facility developed in this study has a maximum stress of about 68.1% to 75.4% and a maximum displacement of about 0.9% to 9.6% under the same load and seismic conditions compared to the existing PE block rainwater detention facility. It was confirmed that the eco-friendly prefabricated rainwater infiltration type detention facility secured excellent structural stability.

• Membrane Journal
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• v.32 no.5
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• pp.357-365
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• 2022

Recently, as the demand for secondary batteries for electric vehicles has rapidly increased, the efficient production of lithium compounds is attracting great attention. Bipolar membrane electrodialysis (BPED) is known as an eco-friendly, economical, and efficient electrochemical lithium compound production process. Since the efficiency of the BPED depends on the performance of the bipolar membrane (BPM), the selection of the BPM is very important. In this study, the characteristics of BPMs suitable for the BPED for electrochemical LiOH production were derived by comparative analyses of BP-1E (Astom) and FBM (Fumatech), which are the most widely used commercial BPMs in the world. Through systematical evaluation, it was confirmed that reducing membrane ion transfer resistance and co-ion leakage among the characteristics of BPM is the most important, and BP-1E has better performance than FBM in this respect.

• Journal of the Korean Geotechnical Society
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• v.24 no.10
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• pp.93-103
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• 2008

For conventional gravity type offshore structures constructed on the soft ground, which is located on the western and/or southern Korea, the excessive consolidation settlements are caused by the self-weight of the structures and so additional ground treatment methods are generally needed. Several types of improved foundation systems utilizing buoyancy applicable to even the soft ground were introduced for economical and efficient design of the offshore structure. In this study, a series of numerical simulations on the consolidation and lateral behaviors of breakwaters with the improved foundation systems utilizing buoyancy were carried out. From the results of numerical simulations it is found that the foundation systems utilizing buoyancy are efficient for reducing the maximum consolidation settlements without reducing lateral safety.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.831-837
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• 2008

Korean construction industry faces diverse social and economical changes. Labor shortage, Free Trade Agreements (FTA), high oil prices alert industry practitioners to the new challenges and opportunities. It is time to make novel approaches for significant improvement of industry performance. Korean government and companies have plans for interdisciplinary research and development efforts. To this end, technology evaluation and market needs analysis should be extensively carried out prior to research initiation. Research programs developed in this way are presented in term of budget estimate, research scope and timeline. A framework for construction technology valuation methodology is also suggested to evaluate the holistic technology value and return on investment of research, development and commercialization.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6C
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• pp.241-253
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• 2010

For seismic design of a vertical shaft, three-dimensional Finite Element (FE) analyses were performed to evaluate the accurate response of a vertical shaft and to apply a Response Displacement Method (RDM). Special attention is given to the evaluation of seismic base and response displacement of surrounding soil, estimation of load and loading method. Based on the result, it was found that shear wave velocity of seismic base greater than 1500m/s was appropriate for the seismic design. It was also found that double cosine method which evaluates a response displacement of surrounding soil was most appropriate to consider the characteristic of multi-layered soil. Finally, shape effect of the structure was considered to clarify the dynamic behavior of vertical shaft and it would be more economical vertical shaft design when a vertical shaft was analyzed by using RDM.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2C
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• pp.41-49
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• 2009

Due to the increased size of civil infrastructure and the cost of materials, the needs exists for utilizing large sized cast-inplace piles in lieu of conventional precast piles. Among them, the barrette pile has become more commonly used in fields where a diaphragm wall is the retaining wall, to improve workability and economical efficiency, and to ensure hole stability under deep soil layers. In this paper, the bearing capacity and displacement characteristics of the barrette pile are evaluated by using the bi-directional loading test data obtained from four different sites. In addition, the design value of pile shaft resistance, ${\beta}$, is assessed with previous literatures and load transfer analysis. Finally, numerical analyses were performed to analyze the load-displacement behavior, and the interface effect on the piles, using the 3-dimensional finite element method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2D
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• pp.181-190
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• 2010

The purpose of this study is to propose an effective approach of making route decisions for the large-scale national project (i.e. the KTX Gyeongbu line between Daegu and Busan) by analyzing the conflicts that had occurred in the process of selecting the routes and stations. This study investigated policy making processes and conflicts during the construction of the KTX Gyeongbu line. The five contentious issues were 1) selecting the route between Daegu~Busan line, 2) developing a new route through Gyeongju areas, 3) making decisions of the first and second phases of construction, 4) setting up an extra station in Ulsan, and 5) conflicts of the Mt. Cheonseong route in Yangsan. In terms of analyzing these issues, the current study focuses on dealing with notions of technical, economical, legal, social, and practical rationality. Based on such analyses and implications, this study proposes a relatively reasonable model of line decision making especially for long-distance intercity routes. It also turns out that the large-scale project like the development of KTX Gyeongbu line should be conducted after receiving enough quantitative evaluation by reviewing relevant technical research studies and economic analyses, and having social agreements to prevent plausible conflicts.

• Clinical and Experimental Vaccine Research
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• v.12 no.1
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• pp.70-76
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• 2023

Purpose: Typhoid remains a major health problem, especially in the developing world. Furthermore, the emergence of multidrug-resistant and extensively drug-resistant strains of Salmonella typhi added a sense of urgency to develop more effective typhoid vaccines, one of which is bacterial ghosts (BGs), prepared by both genetic and chemical means. The chemical method includes incubation with numerous agents for a short time at their minimum inhibitory or minimum growth concentrations. This study included the preparation of BGs by a sponge-like reduced protocol (SLRP). Materials and Methods: Critical concentrations of sodium dodecyl sulfate, NaOH, and H₂O₂ were used. Moreover, high-quality BGs were visualized by scanning electron microscope (SEM). Subculturing was used to confirm the absence of vital cells. Besides, the concentrations of the released DNA and protein were estimated spectrophotometrically. In addition, the integrity of cells was proved by visualizing Gram-stained cells using a light microscope. Furthermore, a comparison between the immunogenicity and safety of the prepared vaccine and the available whole-cell killed vaccine was established. Results: Improved preparation of high-quality BGs of S. typhi, visualized by SEM, revealed punctured cells with intact outer shells. Moreover, the absence of vital cells was confirmed by subculturing. At the same time, the release of respective amounts of proteins and DNA is another evidence of BGs' production. Additionally, the challenge test provided evidence that the prepared BGs are immunogenic and have the same efficacy as the whole cell vaccine. Conclusion: The SLRP provided a simple, economical, and feasible method for BGs preparation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.1
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• pp.193-202
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• 2008

This paper investigates experimentally the confining effect, strengthening capacity and rebound rate of sprayed Fiber-Reinforced-Polymer (SFRP). From the method, resin and chopped fibers are sprayed separately from the nozzle with high pressure, and then they are attached to the concrete surface, so structure could be repaired. To evaluate the strengthening effect of sprayed FRP, cylindrical specimens and beam specimens were strengthening with SFRP. As main material of FRP, glass fiber and polyester resin are used. To investigate the optimum condition of sprayed FRP, the effects of fiber length, coating thickness, fiber volume ratio and concrete strength were examined. Capacities of sprayed FRP method were also compared to the FRP sheet method. In case of the sprayed FRP, rebound rate is important parameter considering economical efficiency and constructibility, so rebound rate of was discussed. From the test results, optimum conditions of sprayed FRP were determined. SFRP method showed superior strengthening capacities than FRP sheet method.

• Quality Improvement in Health Care
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• v.1 no.2
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• pp.44-59
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• 1994

Medical consumers(patients) want evening-clinic because of busy work. For patient's convenience and improving service, hospital should accept it. Considering payment system and patient's demand, personnel expenses, hospital can not accept. The practice of shift system to accept patient's demand and hospital's economic aspect was made. To analysis the effect of the system and probability to alternative to evening clinic this study was done. This study was composed of basal study, intervention, evaluation of effect. The basal study were composed of studying demand on evening clinic, the number of beds, doctors employee, the time table of practice and work, and the number of patients at arrival time. The intervention composed of changing of practice time, changing of working time by the number of patients at arrival time, increasing of employee. The evaluation of effect were composed of evaluating the number of patient at time, the effect of shift system, the comparison of the number of in and out patients and questionnairing the practice of shift system. In the practice time at 2 shift system First team works 7-15 hours and Second team 12-20 hours. there are no lunch and supper time. At 18-20 hours the number of patients were 25-30. The number of patient a depart were 6-7. The number of out-patient increase in 13% and inpatient increase in 10% before the system. Doctors(100%), employee(94.6%), and patients(86.4%) approved this system. The advantage of this system were utilization of surplus time, lengthen the practice time, even distribution of patients and shortening of waiting time, rapid treatment of emergent patients. The disadvantage of this system were shortage of manpower, not all depart practice, continuity of practice, no lunch and supper time, irregular rounding. At present because of small Demanding on evening clinic, this shift system was economical. To succeed this study more effectively all depart in hospital participate. But because of economical reason it is impossible for hospital to do it. If the government assist the economic loss that all depart participate in this system it is very helpful for hospital to succeed in implementing this system more early.