• Korean Chemical Engineering Research
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• v.47 no.1
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• pp.65-71
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• 2009

In this study, performance and economic analysis of natural gas/syngas fueled 100 MWth chemical-looping combustion (CLC) combined cycle plant were performed. Net efficiency of both cases was 53~54%, corresponding to previous research. We used Chemical Engineering Plant Cost Index and Guthrie method to evaluate plant cost. For syngas fueled CLC combined cycle plant, the plant cost was higher since lower heating value(LHV) of syngas was lower than that of natural gas and cost of electricity(COE) was also higher since the cost of syngas was higher than that of natural gas. By sensitivity analysis, it was shown that the cost of syngas should be less than 5.3 $/GJ in order to make COE lower than 5.8 ¢/kWh which was COE of natural gas fueled CLC combined cycle plant.

• Journal of the Society of Disaster Information
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• v.12 no.1
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• pp.10-18
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• 2016

This study presented a new NOS model through the following suggestions to apply the construction work planing and management to NOS(Network Operating System). First, This study presented CIMS(construction information classification system) reflected the characteristics of facility classification - functional component classification - functional component classification - work classification - resource classification. Based on this system. this study presented how to establish PMMB(performance measurement management baseline) with proposed master target equation which analyzed the trend of performance measurement management baseline and proposed work target equation which analyzed the execution results. Finally, this study presented NOS model that can be applied to fixed price method and cost plus fee method through the theoretical verification of executive performance analysis method.

• Korea Journal of Hospital Management
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• v.11 no.1
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• pp.54-90
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• 2006

Medical clinics are core institutes that cover the primary medical care in Korea. Financial viability of the clinics is essential for them to conduct their roles and functions, and can be improved by increasing their operating profitability. On this ground, this study aimed at finding important factors that affect the operating profitability, and thereby at suggesting strategic alternatives that can contribute to the improvement of the profitability. Operating margin was set as a dependent variable, and such factors as general management conditions, number of visits, medical revenue, marketing activities, input resources, medical cost as independent variables. Nineteen hypotheses related to the variables were established and tested using data collected from 138 sample clinics for the year 2003. The results of the study are as follows : Firstly, such variables as percent ratio of the depreciation plus rent costs to total administration costs, type of clinical department manifested whether medical, surgical, or quasi-surgical, percent ratio of the interior facility investment to total fixed assets, and total number of outpatient visit are important factors that affect, positively or negatively, the medical profitability of the clinics. Secondly, following measures are needed to be established and implemented to improve the medical profitability. (1) Administration costs share 53.2% of the total medical costs, and depreciation plus rent costs 16.3% of the total administration costs. This implies that such measures as reinforcement of marketing activities, establishment of the cooperative utilizing system of the facility and equipment, or group practice are needed to increase cost-effectiveness. (2) Occupancy rate of the clinics with inpatient bed is as low as 45.5%, causing high fixed costs and low medical profitability. For its improvement, the resource input structure should be reorganized. Thirdly, in the future, a study that can increase sample representativeness of the study and explanation power of the variables should be performed for each type of clinical department to find more specific determinant factors and to contribute to the improvement of the medical profitability of the clinics.

• Journal of the Korean housing association
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• v.17 no.4
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• pp.101-109
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• 2006

The purpose of this study was to suggest ways on reducing the cooling and heating energy cost of the officetel building with the multiple glazing windows according to Life Cycle Costing. This study consisted of an hour-by hour energy simulation program and further data from the EnergyPlus V1-2-2 to the four pane type windows that were applied with 2 low-e polyester film and krypton gas to the officetel model building. It was determined that the four panes type windows that had 2 low-e polyester film and krypton gas applied to, them showed a cooling and heating cost reduction over traditional double glazed windows that were filled with air. According to this study, as well as the information from chart 4.5 and the LCC it was determined that the present value of the four panes of windows that had 2 low-e polyester film and krypton gas applied to them showed. a 11.4% reduction in heating and cooling in comparison to the traditional double glazed windows that were filled with air.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.5
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• pp.534-544
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• 1997

The permittivity distribution of a two-dimensional high-contrast object with large size, which leads to the global minimum of cost function, is reconstructed by iteratively using the hybrid algorithm of Levenberg-magquardt algorithm(LMA) plus Genetic Algorithm(GA). The scattered fields calculated in a cost function are expanded in angular spectral modes, of which only effective propagating modes are used. The definition of cost function based on the effective propagating modes enables us to formulate the minimum number of incident waves for the reconstruction of object. It is numerically shown that LMA has an advantage of fast convergence but can't reconstruct a high-contrast object with large size and GA can reconstruct a high-contrast object with large size but has an disadvantage of slow convergence, whereas an inverse scattering technique using the hybrid algorithm adopts only advantages of LMA and GA.

• Journal of the Korea Institute of Building Construction
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• v.14 no.5
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• pp.467-476
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• 2014

According to the expanding of construction machinery works, the number of civil complaints demanding compensations are increasing continuously from surrounding residents due to the noise from construction fields. However, the noise is usually managed restrictedly during the construction phase rather than prevented in advance. So, the efforts to solve the noise problem are occurring only after complaints have been made. Also, excessive cost and time consuming in order to solve the complaints negatively affects to construction companies. Therefore, the purpose of this study is to develop an optimized scheduling process model for controlling the noise in construction field by considering the planned time, cost, and the number of equipment before construction. In addition, this process model is expected to provide a useful information about the cost comparison between the original planned cost plus compensation and the optimized cost considering noise limitation so that the site managers can manage their projects effectively.

• Environmental and Resource Economics Review
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• v.27 no.1
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• pp.1-28
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• 2018

This study investigates the strategic environmental corporate social responsibility (ECSR) of polluting duopoly when two firms have different production costs and compete with prices. We then examine an endogenous timing game in choosing ECSR and its effects on environmental damage and social welfare. The followings are the main findings: First, sequential choice of ECSR is strategic complements and it provides late adopter advantage irrespective of cost difference. Second, sequential choice of ECSR is the equilibrium of endogenous timing game. In particular, an efficient firm-leading ECSR is the payoff dominance equilibrium when cost difference is significant. Finally, environmental damage and social welfare depend on the social cost of pollution. In particular, an efficient firm-leading ECSR is socially desirable when social cost is high. However, an inefficient firm-leading ECSR increases environmental damage irrespective of social cost and it reduces social welfare when cost difference is significant.

• Current Research on Agriculture and Life Sciences
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• v.32 no.4
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• pp.231-235
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• 2014

This study performed a benefit cost analysis of an automatic eggshell crack detection system. Based on various cost benefit analysis methods, including the net present value (NPV), internal rate of return (IRR), and benefit cost ratio (B/C Ratio), the automatic eggshell crack detection system was confirmed to have economic validity. The NPVs were 175,035,645 won at a 5% discount rate and 129,082,393 won at a 10% discount rate. Plus, the IRRs were 0.686 at a 5% discount rate and 0.660 at a 10% discount rate. Finally, the B/C ratios were 1.981 at a 5% discount rate and 1.900 at a 10% discount rate.

• Journal of Mechanical Science and Technology
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• v.16 no.8
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• pp.1053-1063
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• 2002

This paper presents a robust nonlinear controller for a f degree of freedom (DOF) parallel manipulator in the task space coordinates. The proposed control strategy requires information on orientations and translations in the task space unlike the joint space or link space control scheme. Although a 6 DOF sensor may provide such information in a straightforward manner, its cost calls for a more economical alternative. A novel indirect method based on the readily available length information engages as a potential candidate to replace a 6 DOF sensor. The indirect approach generates the necessary information by solving the forward kinematics and subsequently applying alpha-beta-gamma tracker With the 6 DOF signals available, a robust nonlinear task space control (RNTC) scheme is proposed based on the Lyapunov redesign method, whose stability is rigorously proved. The performance of the proposed RNTC with the new estimation scheme is evaluated via experiments. First, the results of the estimator are compared with the rate-gyro signals, which indicates excellent agreement. Then, the RNTC with on-line estimated 6 DOF data is shown to achieve excellent control performance to sinusoidal inputs, which is superior to those of a commonly used proportional-plus-integral-plus-derivative controller with a feedforward friction compensation under joint space coordinates and the nonlinear controller under task space coordinates.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2737-2740
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• 2012

The use of plants to remove toxic metals from soil (phytoremediation) is emerging as a cost-effective alternative to conventional methods for the removal of heavy metals from contaminated soil. Indian mustard (Brassica juncea) was used as the plant to accumulate high tissue concentrations of lead when grown in contaminated soil. For this study, the application of an electric field combined effectively with EDTA-enhanced phytoremediation. A stimulation of direct and alternating electric potential was compared and EDTA-enhanced phytoremediation of lead using Indian mustard has been performed. The effects of experimental parameters such as operating voltage with different concentration of EDTA, the number of graphite electrodes, and cultivation period on the removal of toxic metal were studied. Shoot lead accumulations in Indian mustard increased as the concentration of EDTA and dc electric potential was increased. Two to four folds was increased when EDTA plus a dc electric potential was applied, compared to an ac electric potential. The maximum lead accumulation in the shoots was achieved by applying EDTA plus dc electric potential with 6 graphite electrodes.