• Proceedings of the KSME Conference
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• 2000.04a
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• pp.13-18
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• 2000

Nowadays, 60 percent of thermal power plants already have been operated over their own design life. These operations of old power plant over their design life have caused a fracture accident of degradation a loss of economic and human. Therefore, the new life assessment and prediction technology is necessary to improve the safety and reliability of high pressure and high temperature power plant facilities. In this paper, innovative electrochemical test method have been used and results have been compared to the conventional test. Finally, the electrochemical test is applied to the in-field HP turbine and a database is currently in progress for the development of the life assessment standard and procedure.

• Proceedings of the IEEK Conference
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• summer
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• pp.128-132
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• 2004

In this paper, we propose a new image quality assessment scheme considering the human visual perception characteristics. A subjective quality assessment is obtained by the response of the receptive field in the primary visual cortex and a human's eye can't focus on all of the visual range in a moment. Take advantage of two facts above, we apply Gabor wavelet transform, which is well fit the receptive field in the cortex, to divided constant sized subblocks. Then a local distortion of the subblocks and a global distortion for the entire image are calculated in order. The proposed method has been evaluated using video test sequences provided by the Video Quality Experts Group (VQEG). The experimental results show that good correlation with human perception is obtained using the proposed metric, which is what we called GPSNR.

• Journal of Korea Multimedia Society
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• v.22 no.9
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• pp.1091-1107
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• 2019

The purpose of this study is to technology impact assessment uncertainties and influences of factors for the coexistence technology in MR and to derive the ripple effect of the target technology in many different application fields. This survey is to evaluate the impact of new technologies on economy, society, culture, ethics and environment in advance and to reflect the results in policy research. As a result, we analyzed the positive and negative impacts predicted by the coexistence technology in MR in edutainment field by word cloud analysis. The purpose of these study is to strengthen the intrinsic intent of technology assessment on the edutainment fields to strengthen positive impacts and minimize adverse impacts by identifying the various factors affecting society when the coexistence technology in MR was commercialized as well as by evaluating the positive and negative impacts from a more balanced view.

• The Mathematical Education
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• v.47 no.4
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• pp.487-503
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• 2008

In this paper, descriptive assessment method for middle school mathematics was evaluated by developing a framework for designing and grading problems for descriptive assessment and analyzing the effectiveness of the problems. The new descriptive assessment problems were developed by reviewing the current 7th National Mathematics Curriculum of Korea and aligned mathematics textbooks to define a set of problem design principles and evaluation framework for the assessment strategy. The developed problems were first pilot tested and then revised based on the feedback from the test. The final version was field tested by 100 students in 7th grade middle school. After the field test, the problems were graded by two middle school math teachers and one math education researcher to determine the overall correlation between graders and also to analyze effectiveness of the evaluation framework of the test. This result of this study is expected to assist in the further development of descriptive problems and grading framework by providing a reference work for teachers to better understand the process and the limitations of executing the new assessment strategy.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.69-75
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• 2009

Water stress has become a major concern in agriculture. Korea suffers from limited agricultural water supply, and wastewater reuse has been recommended as an alternative solution. A study was performed to examine the effects of microorganism concentration in the ponded-water of a paddy rice field with reclaimed-water irrigation for evaluating the microbial risk to farmers and neighborhood children. Most epidemiological studies were performed based on an upland field, and they may not directly applicable to paddy fields. Beta-Poisson model was used to estimate the microbial risk of pathogen ingestion. Their risk value increased significantly high level after irrigation and precipitation. It implies that agricultural activities such as plowing, and fertilizing, and precipitation need be practiced a few days after irrigation considering health risks. The results about field application of the microbial risk assessment using E. coli showed difference according to monitoring time and treatment plot. Result of the microbial risk assessment showed that risk values of ground-water and reclaimed secondary wastewater irrigation were lower than directly use of wastewater treatment plants' effluent. This paper should be viewed as a first step in the application of quantitative microbial risk assessment of E. coli to wastewater reuse in a paddy rice farming.

• Journal of the Korean Solar Energy Society
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• v.40 no.5
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• pp.1-12
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• 2020

To assess the performance and characteristics of colored building-integrated photovoltaic (BIPV) modules, a comparative assessment of empirical performance was conducted on colored BIPV modules (gray, blue, and orange) and general BIPV module. These modules were installed on the south-facing slope (30°) for comparative assessment through a field test. Monitoring data were collected every 10 min from December 20, 2019 to January 21, 2020 and used to performance and characteristics analysis. Performance ratio and module efficiency were utilized during performance indexing for comparative assessment. For general BIPV modules, the operational efficiency was analyzed at 16.63%, whereas for colored BIPV modules, 13.70% (gray), 15.12 % (blue), and 14.49% (orange) were analyzed. It was discovered that the efficiency reduction caused by transmission losses owing to the application of colored cover glasses were 17.74% (gray), 9.05% (blue), and 9.86 % (orange), under field testing conditions. These values turned on an additional 7% reduction in efficiency for gray BIPV modules, compared to the degradation resulting from transmission drop (gray: 10.87%, blue: 8.99%, and orange: 9.02%) calculated using the efficiency of each module in standard test conditions (STC). Performance ratio analysis resulted in the following values: 0.92 for general BIPV modules, and 0.85 (gray), 0.91 (blue), and 0.91 (orange) for colored BIPV modules. As demonstrated by the above results, modules with a colored cover glass may differ in their operational performance depending on their color, unlike general modules. Therefore, in addition to the performance evaluation under STC, additional factors of degradation require consideration through field test.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1997.11a
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• pp.117-122
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• 1997

This paper presents a study on the fuzzy based approach for the safety assessment of human body under ELF electric and magnetic(EM) field considering power system states. The analysis of ELF EM field based on quasi-static method is introduced. UP to the present, the analysis of ELF EM field has been conducted with the consideration of one transmission line, or a power line model only In this paper, however, the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes and the states are classified into two types, normal state resulting from normal operation and emergency state from outages. In order to analyze the uncertainty in the normal state, the Monte Carlo Simulation, a statistic approach was introduced and line current and bus voltage distribution are calculated by a contingency analysis method, in the emergency state. To access the safety of human body, the approach based on fuzzy linguistic variable is adopted to overcome the shortcomings of the assessment by a crisp set concept. In order to validate the usefulness of the approach suggested herein, the case study using a sample system with 765(kV) was done. The results are presented and discussed.

• Earthquakes and Structures
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• v.15 no.5
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• pp.487-498
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• 2018

Buckling-restrained braces are passive control devices with high level of energy dissipation ability. However, they suffer from low post-yield stiffness which makes them vulnerable to severe ground motions, especially near-field earthquakes. Among the several methods proposed to improve resistance of BRB frames, mega-brace configuration can be a solution to increase frame lateral strength and stiffness and improve distribution of forces to prevent large displacement in braces. Due to the limited number of research regarding the performance of such systems, the current paper aims to assess seismic performance of BRB frames with mega-bracing arrangement under near-field earthquakes via a detailed probabilistic framework. For this purpose, a group of multi-story mega-BRB frames were modelled by OpenSEES software platform. In the first part of the paper, simplified procedures including nonlinear pushover and Incremental Dynamic Analysis were conducted for performance evaluation. Two groups of near-fault seismic ground motions (Non-pulse and Pulse-like records) were considered for analyses to take into account the effects of record-to-record uncertainties, as well as forward directivity on the results. In the second part, seismic reliability analyses are conducted in the context of performance based earthquake engineering. Two widely-known EDP-based and IM-based probabilistic frameworks are employed to estimate collapse potential of the structures. Results show that all the structures can successfully tolerate near-field earthquakes with a high level of confidence level. Therefore, mega-bracing configuration can be an effective alternative to conventional BRB bracing to withstand near-field earthquakes.

• The Journal of Korean Medicine
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• v.38 no.1
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• pp.21-33
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• 2017

Objectives: The purpose of this study is to present the needs for New Health Technology in Korean medicine field and suggest the strategy to raise the application and selection rate. Methods: In this study, we reviewed the application status of New Health Technology application from April 27, 2007 to June 30, 2016. And we analyzed the assessment methods, procedures, and failure factors through the two Research stage technologies reports in Korean medicine field. Results: In Korean medicine field, the application status of New Health Technology is very small as 2% of the whole applications. Moreover, 62.9% of the applied technology were either an existing technology or an early technology, so did not enter the assessment process. Two technologies categorized as Research stage technology also had failed to adopt New Health Technology because they were lacking evidences or need more research to prove effectiveness. Conclusions: In order to develop New Health Technology in Korean medicine, more efforts should be made to activate research that can prove the safety and effectiveness of medical technology, and to create a quantitative or qualitative basis for the results of the research. Also, it is necessary to increase researchers' awareness of New Health Technology. And the strategy to positively utilize the "Limited Approval" to promote clinical studies.

• Smart Structures and Systems
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• v.31 no.4
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• pp.311-323
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• 2023

Ever since ancient times, earthquakes have been a major threat to the civil infrastructures and the safety of human beings. The majority of casualties in earthquake disasters are caused by the damaged civil infrastructures but not by the earthquake itself. Therefore, the efficient and accurate post-earthquake assessment of the conditions of structural damage has been an urgent need for human society. Traditional ways for post-earthquake structural assessment rely heavily on field investigation by experienced experts, yet, it is inevitably subjective and inefficient. Structural response data are also applied to assess the damage; however, it requires mounted sensor networks in advance and it is not intuitional. As many types of damaged states of structures are visible, computer vision-based post-earthquake structural assessment has attracted great attention among the engineers and scholars. With the development of image acquisition sensors, computing resources and deep learning algorithms, deep learning-based post-earthquake structural assessment has gradually shown potential in dealing with image acquisition and processing tasks. This paper comprehensively reviews the state-of-the-art studies of deep learning-based post-earthquake structural assessment in recent years. The conventional way of image processing and machine learning-based structural assessment are presented briefly. The workflow of the methodology for computer vision and deep learning-based post-earthquake structural assessment was introduced. Then, applications of assessment for multiple civil infrastructures are presented in detail. Finally, the challenges of current studies are summarized for reference in future works to improve the efficiency, robustness and accuracy in this field.