• Korean Journal of Construction Engineering and Management
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• v.10 no.6
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• pp.135-145
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• 2009

The main goal of construction projects from the past has been enhancing efficiency by reducing cost and time. but, seeing the current condition of safety management of many construction companies nowadays, it is true that not much attention has been paid to safety management for a long time. However, there are paradigm shift from the cost and term of works to safety management in the construction industry, from this circumstance the safety management is evaluated more importantly. Though less accident happens compared to past, the accidents are getting greater because construction projects nowadays are bigger and more complex and monetary loss from the accidents are increasing. Also, the severity is getting greater and even fatal. For this reason, more improved safety management is very necessary. Therefore, we are to propose more efficient system for safety management in this thesis. Technical parts for developing system include many technique such as Real Time Locating system, and other techniques like Monitoring module based on BIM, Data Mart, Alarm are also applied together. Through this system, in the construction site, safety management is performed more effectively and widely because the system can manage the human resource and fluid situation. Also, safety manager can conduct more systematically and advanced safety management through human resource dominated safety management.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.261-266
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• 2007

In this research, we studied an estimating method in client's sight to estimate the total construction cost which is based on the historical cost data at the early stage of the office buildings as a public phase. It is very difficult to analyze the estimation accurately and logically. When a client estimates a project, he/she has to consider there are many issues at the planning step, according as office buildings become gradually diversified as well as their roles continuously extended. Therefore, those are usually make problems for wasting the budget in accordance with the cost estimation errors. Moreover, many kinds of public construction projects, especially such as school, office, sports complex, and the others, have been invested the private finances defined as BTL(Build Transfer Lease) method that are required to manage the detailed process more strictly from initial planning. In order to make an effective planning, the long-term users amount and the building life cycle at the beginning of project should be considered previously and then it may enable to achieve an appropriate project plan. But actually considering overall variables in a building planning is impossible. Accordingly, suggesting a regression model based on the historical cost data from many similar types of office building to support client's role known as estimating the total cost at the early stage. And then performing the test against the proposed model to research the reasonability as using the historical cost data of Japan office buildings.

• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.1-8
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• 2000

It is required that gas accidents should be managed carefully as the consumption of fuel gas increases and high pressure gas process becomes more complex, which may cause a catastrophic accident. Factors to cause accidents were investigated through a systematic analysis of gas accidents between 1995 and 1998, which could be applied to prepare countermeasures to reduce gas accidents. As a result, it was suggested that the effective countermeasures to gas accidents should be kept applied, while new countermeasures were suggested in the field of increasing or not-decreasing number of accident. Totally 2,027 of accidents were reported during this term, and were found to decrease by about $12\%$ every year from 1996. The number of fuel gas such as LPG and city gas accident took up $96\%$, and most of accidents occurred at end-user's facility such as residential house and restaurant business. According to the kind of gas and facility, trend of accident by cause varies, while dominant causes are defective installation, appliance failure, or user's carelessness. Intentional accidents by fuel gas was excluded in this study because of its occurring mechanism and will be analyzed further elsewhere, although it took up $15\%$ and increased by $38\%$ every year.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.1
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• pp.39-50
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• 2003

This study aims to figure out water quality impacts due to sudden disturbances of sediments during dike construction in land reclamation for the northern part of the Siwhaho Lake where heavily deteriorated settlements from upstream loadings are outstanding. We exploit a 3-D water quality model CE-QUAL-ICM combined with a hydrodynamic model TIDE3D. Simulations are done accounting water-sediment interaction in a 4-$\sigma$ layers. Long-term simulation for 1-year shows that bottom layers around the disturbance location are only affected and marks very high concentration. Complete vertical mixing appears at least 5km apart to downward due to complex effects of geometry, bathymetry and river inflows. It should be addressed that existing condition of the Siwhaho Lake stands for high concentration of COD and TP in winter and spring due to relatively high incoming loadings, however the effect of sediment disturbances yields reverse phenomena, i.e., impacts of dike construction arise greatly in summer and fall. Refined grid system consisting of 150m${\times}$150m rectangular grid, which is doubled system compared to previous study (Suh et al.,2002), gives affordable results by reducing flux differences through a cell especially in front of gate.

• Korean Journal of Community Nutrition
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• v.19 no.5
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• pp.479-489
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• 2014

Objectives: This study intended to determine significant factors that influence the health-related quality of life ("HRQoL"; EuroQol 5 Dimension health-related quality of life (EQ_5D) & EuroQol visual analogue scale (EQ_VAS)) of the elderly in Korea. Methods: This study was based on 3,903 subjects aged 65 years or more who participated in the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V), 2010~2012. The HRQoL was analyzed by various factors (general characteristics, health habits, mental health, chronic diseases, nutrient intakes). SPSS statistics for complex samples (Windows ver. 21.0) was used. Results: The HRQoL was higher in the males, those with higher educational level or higher income level while it was lower in those belong to single households. In particular, the EQ_5D was significantly higher in the group who reported walking practice, moderate physical activity (male), and the group who reported no vigorous physical activity (female). The EQ_VAS was significantly higher in the group who reported walking practice. Both EQ_5D and EQ_VAS were significantly lower in the group with stress, melancholy, suicidal thinking, and osteoarthritis. EQ_5D was significantly lower in the group with < 75% Estimated Energy Requirements (EER) in energy intake, and with < Estimated Average Requirements (EAR) in iron or niacin intake. A stepwise regression analysis revealed that i) higher educational level (male), and good self-rated health status significantly increased the EQ_5D, ii) age, alcohol intake (male), melancholy (female), suicidal thinking, osteoarthritis, and niacin intake deficiency (male) significantly decreased the EQ_5D, iii) higher income level (male) and good self-rated health status significantly increased the EQ_VAS, and iv) age (male), stress, suicidal thinking (female) and osteoarthritis significantly decreased the EQ_VAS. Conclusions: This study suggested that general characteristics, mental health, osteoarthritis, and niacin intake were associated with the HRQoL. Prospective research of long-term control is needed to establish the causal relationship between factors and the HRQoL.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1126-1139
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• 2014

World is experiencing abnormal weather caused by urbanization and industrialization increasing greenhouse gas and one of these phenomenon domestically happening is flood and drought. The increase of green-house gases is due to urbanization and industrialization acceleration which are causing abnormal climate changes such as the El Nino and a La Nina phenomenon. It is expected that there will be many difficulties in water management, especially considering the topography and seasonal circumstances in Korea. Unlike in the past, a variety of water conservation initiatives have been undertaken like the river-management flow and water capacity expansion projects. To meet the increasing demand for water resources, new environmentally-friendly small and medium-sized dams have been built. Therefore, the development of a new paradigm for water resources management is essential. This study shows that additional security is needed for potential water resources through diversion tunnels and is very important to consider for future water supplies and situations. Using RCP 6.0 and RCP 8.5 in representative concentration pathway climate change scenario, specific hydrologic data of study basin was produced to analyze past observed basin rainfall tendency which showed both scenario 5%~9% range increase in rainfall. Through sensitivity analysis using objective function, population in highest goodness was 1000 and cross rate was 80%. In conclusion, it is expected that the results from this study will help to make long-term and stable water supply plans by using the potential water resource evaluation model which was applied in this study.

• Journal of Chest Surgery
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• v.44 no.1
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• pp.9-17
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• 2011

Background: A peripheral extracorporeal membrane oxygenator (p-ECMO) has been developed to support patients who are dying due to a serious cardiopulmonary condition. This analysis was planned to define the clinical situation in which the patient benefits most from a p-ECMO. Material and Methods: Between June 2007 and Aug 2009, a total of 41 adult patients used the p-ECMO. There were 23 males and 18 females (mean age $54.4{\pm}15.1$ years). All patients had very unstable vital signs with hypoxia and complex cardiac problems. We divided the patients into 4 groups. In the first group, a p-ECMO was used as a bridge to cardiac operation. In the second group, patients did not have the opportunity to undergo any cardiac procedures; nevertheless, they were treated with a p-ECMO. In the third group, patients mostly had difficulty in weaning from CPB (cardiopulmonary bypass) after cardiac operation. The fourth group suffered from many complications, such as pneumonia, bleeding, infections, and LV dysfunction with underlying cardiac problems. All cannulations were performed by the Seldinger technique or cutting down the femoral vessel. A long venous cannula of $DLP^{(R)}$ (Medtronic Inc, Minneapolis, MN) or $RMI^{(R)}$ (Edwards Lifesciences LLC, Irvine, CA) was used together with a 17~21 Fr arterial cannula and a 21 Fr venous cannula. As a bypass pump, a Capiox emergency bypass system ($EBS^{(R)}$; Terumo, Tokyo, Japan) was used. We attempted to maintain a flow rate of $2.4{\sim}3.0\;L/min/m^2$ and an activated clotting time (ACT) of around 180 seconds. Results: Nine patients survived by the use of the p-ECMO. Ten patients were weaned from a p-ECMO but they did not survive, and the remainder had no chance to be weaned from the p-ECMO. The best clinical situation to apply the p-ECMO was to use it as a bridge to cardiac operation and for weaning from CPB after cardiac operation. Conclusion: Various clinical results were derived by p-ECMO according to the clinical situation. For the best results, early adoption of the p-ECMO for anatomical correction appears important.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.719-724
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• 2009

Background: As the patients who undergo heart transplantation have achieved better survival in recent years, growing number of recipients are at a risk for experiencing surgical complications in addition to rejection and infection. In this paper, we report on our experience with the surgical complications that occurred in heart transplant recipients. Material and Method: From April 1994 to September 2003, 37 heart transplantations were performed at our center by a single surgeon. The indications for transplantation were dilated cardiomyopathy, ischemic cardiomyopathy, valvular cardiomyopathy and familial hypertrophic cardiomyopathy. Result: Twenty postoperative complications required surgeries in 15 patients (41%). The types of operations required were; redo-sternotomy for bleeding (5), pericardiostomy for effusion (4), implantation of a permanent pacemaker (1), right lower lobe lobectomy for aspergilloma (1), removal of urinary stone (1), cholecystectomy for gall bladder stone (1), drainage of a perianal abscess (1), paranasal sinus drainage (1), total hip replacement (1), partial gingivectomy due to gingival hypertrophy (1), urethrostomy (1), herniated intervertebral disc operation (1) and total hysterectomy for myoma uteri (1). The locations of the complications were mediastinal in 10 (27%) cases and extramediastihalin 10 (27%) cases. Conclusion: The relatively high incidence of extrathoracic complications associated with heart transplantation emphasizes the importance of a multidisciplinary approach to the improve long-term survival when managing those complex patients.

• Membrane Journal
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• v.16 no.4
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• pp.294-302
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• 2006

Silver polymer electrolytes are very promising membrane materials for the separation of olefin/paraffn mixtures. Olefin molecules are known to be transported through reversible complex formation with silver ions entrapped iii polymer matrix. However, they have poor long-term stability, which is very important fur the industrial application; the selectivity through the membrane decreases gradually with time mostly due to the reduction of silver ions ($Ag^+$) into silver nanoparticles ($Ag^0$). In this study, the stability of silver polymer electrolyte was investigated for poly(vinyl pyrrolidone) (PVP) and $AgBF_4$ system containing a surfactant, i.e. $C_{18}H_{35}(OCH_2CH_2)_{20}OH$ (Brij98) as a stabilizer. The reduction behavior of silver ions to silver nanoparticles in PVP was also investigated by atomic force microscopy (AFM) and UV-visible spectroscopy. It was found that the growth of silver nanoparticles was slower and selectivity of polymer electrolyte for propylene in propylene/propane was maintained longer time when Brij98 was added as a stabilizer.

• Tunnel and Underground Space
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• v.21 no.5
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• pp.394-405
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• 2011

In this paper, we applied coupled non-isothermal, multiphase fluid flow and geomechanical numerical modeling using TOUGH-FLAC coupled analysis to study the complex thermodynamic and geomechanical performance of underground lined rock caverns (LRC) for compressed air energy storage (CAES). Mechanical stress in concrete linings as well as pressure and temperature within a storage cavern were examined during initial and long-term operation of the storage cavern for CAES. Our geomechanical analysis showed that effective stresses could decrease due to air penetration pressure, and tangential tensile stress could develop in the linings as a result of the air pressure exerted on the inner surface of the lining, which would result in tensile fracturing. According to the simulation in which the tensile tangential stresses resulted in radial cracks, increment of linings' permeability and air leakage though the linings, tensile fracturing occurred at the top and at the side wall of the cavern, and the permeability could increase to $5.0{\times}10^{-13}m^2$ from initially prescribed $10{\times}10^{-20}m^2$. However, this air leakage was minor (about 0.02% of the daily air injection rate) and did not significantly impact the overall storage pressure that was kept constant thanks to sufficiently air tight surrounding rocks, which supports the validity of the concrete-lined underground caverns for CAES.