• Corrosion Science and Technology
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• v.23 no.3
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• pp.246-254
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• 2024

Recently, coal-fired power plants are experiencing many problems that they have never experienced before due to an increase in flexible operation. In particular, a two-phase flow accelerated corrosion on water wall tubes in a boiler has not been detected overseas or domestically. There is no response plan to deal with such corrosion problem either. However, oxide film damage and tube material corrosion due to a two-phase flow accelerated corrosion are being discovered on water wall boiler tubes of domestic coal-fired power plants recently. If this situation is severe, it can cause enormous damage such as tube rupture. Therefore, in this paper, in order to prepare a response plan for a two-phase flow accelerated corrosion on water wall tubes in the future, differences between a two-phase flow accelerated corrosion and a single-phase flow accelerated corrosion were investigated and an example of discovery of a two-phase flow accelerated corrosion on water wall tubes was presented.

• Journal of Environmental Policy
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• v.9 no.2
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• pp.111-133
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• 2010

Environmental conservation plan, notwithstanding their feasibility and potential utility in construction of environment-friendly spaces, has long been perceived in practice as "declarative" and a "formality." Such perceptions are largely the result of the failure to provide spatial planning that is directly relevant to development of the space in question, and to sufficiently interconnect with urban development plan. This demonstrates the need for ways to link disparate plans, i.e. to enact "spatial environment plan." In response to these issues, this study proposes the systematization of spatial environment data as a necessary prerequisite to the establishment of spatial environment plan, which would provide both linkages with other plans, and ensure the applicability of environmental conservation plan. To this end, this study analyzed existing environmental data, and then proposed systems for links with spatial environment plan. In respect of this, the study examined spatial data systems, and then classified applicable spatial according to each environmental medium. The study also produced spatial information and planning items that can be included in spatial environment plans for each of the nine environmental media, and then constructed a system that could link the existing spatial information system, current spatial environment data, and spatial environment management plan. Furthermore, the study proposed matters for improvement in the construction of spatial environmental data to ensure the activation of spatial environment plan. The construction of a systematic spatial database, by facilitating the smooth establishment of spatial environment plan, can enhance and upgrade environmental conservation plan, while contributing to enhanced linkages with related spatial plans.

• Structural Monitoring and Maintenance
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• v.5 no.3
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• pp.345-361
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• 2018

The set of processes performed to determine the dynamic characteristics of the constructed structures is named experimental modal analysis. Using experimental modal analysis and interpreting its results, structural failure can be assessed and then it would be possible to plan for their repair and maintenance. The purpose of the experimental modal analysis is to determine the resonance frequencies, mode shapes and Mode damping for the structure. Diverse methods for determining the shape of the mode by various researchers have been presented. There are pros and cons for each of these methods. This paper presents a method for determining the mode shape of the structures using the response spectrum in the experimental modal analysis. In the first part, the principles of the proposed method are described. Then, to check the accuracy of the results obtained from the proposed method, single and multiple degrees of freedom models were numerically and experimentally investigated.

• Textile Coloration and Finishing
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• v.8 no.2
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• pp.35-42
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• 1996

Peroxodisulfates are being developed as low temperature bleaching agents for cotton fabrics to save the thermal energy. In this research we used the colar difference meter to determine the whiteness which peroxide booster will possibly make an effect on cotton fabric at the low temperature process using consist of temperature with different conditions agents, such as sodium hydroxide, sodium peroxodisulfate and potassium peroxodisulfate. The peroxide bleaching follows a laboratory experiments, using a statistical plan for three variables: the concentrations of hydrogen peroxide and sodium hydroxide and the temperature of bathing. The purpose of this research was to use the response surface analysis method to evaluate the relative importance of factors providing optimum whiteness. A ridge analysis of the data on whiteness response results in 3-D response surface diagrams for optimizing the concentrations of hydrogen peroxide and sodium hydroxide at about 42~52$^{\circ}C$.

• Journal of KSNVE
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• v.9 no.5
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• pp.949-954
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• 1999

Speed-up and mass reduction of railway vehicle usually causes increased of the interior noise. One of the best ways to control the interior noise is to identify the noise level radiated from each of parts in the cabin. In this paper, we describe the method to estimate the interior noise nad evaluate the noise contribution to each of parts. This method is based that the sound pressure can be calculated by using the frequency response function and acceleration. According to analysis of the noise contribution, we validated that the noise radiated from the floor is the higher in the cabin. We also measured the noise distribution for the side and floor by using the microphone array in order to analyze the effect of the noise flowing into the cabin from the outdoors. Finally, we presented the plan of the interior noise reduction based on the noise levels radiated from each of parts.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2285-2290
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• 2008

Even though efficiency of coal-fired power plant is proportional to operating temperature, increasement of operating temperature is limited by a technological level of each power plant component. It is an alternative plan to increase operating pressure up to ultra super critical point for efficiency enhancement. It is difficult to control process of power plant in ultra super critical point because that point has highly nonlinear characteristics. In this paper, new control logic, Unit Response Optimizer Controller(URO Controller) which is based on Fuzzy logic and Model Predictive Controller, is introduced for better performance. Then its performance is tested and analyzed with design guideline.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.2
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• pp.151-162
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• 2014

This study proposes an optimization model to plan the patient distribution and medical resource allocation considering the diverse characteristics of disaster. For reflecting the particularity of disaster response, we configured a few scenarios such as availability of emergency surgery of non-major medical staff and the change in number of patients estimated reflecting the uncertainty, urgency and convergence of disaster. And we finally tested the effects of the scenarios' combination on the objective function defined as maximum number of survival patients. Our experimental results are expected to highlight the significance of the proposed model as well as the applicability of scenarios under disaster response.

• Coupled systems mechanics
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• v.6 no.1
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• pp.55-74
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• 2017

The evaluation of torsional effects on multistory buildings remains an open issue, despite considerable research efforts and numerous publications. In this study, a large number of multiple test structures are considered with normally distributed topological attributes, in order to quantify the statistically derived relationships between the torsional criteria and response parameters. The linear regression analysis results, depict that the center of twist and the ratio of torsion (ROT) index proved numerically to be the most reliable criteria for the prediction of the modal rotation and displacements, however the residuals distribution and R-squared derived for the ductility demands prediction, was not constant and low respectively. Thus, the assessment of the torsional parameters' contribution to the nonlinear structural response was investigated using artificial neural networks. Utilizing the connection weights approach, the Center of Strength, Torsional Stiffness and the Base Shear Torque curves were found to exhibit the highest impact numerically, while all the other torsional indices' contribution was investigated and quantified.

• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.1-9
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• 2023

The purpose of this study is to examine the disaster management system of local governments by diagnosing the current status of disaster management experts in Korea, deriving problems and improvement measures, and looking at local governments' total labor cost system. The status and status of disaster management personnel were compared and analyzed to find ways to improve the local government's disaster management response system under the Framework Act on Disaster and Safety Management in Korea. Considering Korea's reality, because national security and disaster management exist together, we devised a plan to improve on-site response capabilities and seek solutions by deriving the problems of the currently operating security and safety-related organizations.

• The Korean Journal of Applied Statistics
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• v.21 no.5
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• pp.791-799
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• 2008

Ansim Flat DATA Plan is a DATA additional service product related to DATA call in a mobile telephone company A. Up to now, the company A is selling it by outbound TM after targeting customers which used data within specific price band. In this paper, we propose a targeting method applying score model combining response rate and retention rate by data mining. The suggested target model is to find customers more likely not only to respond to outbound TM but also to retain Ansim Flat DATA Plan. The proposed targeting method is expected to improve both from 23.7% to 38.8% in the response rate and from 53.2% to 61.4% in the retention rate.