• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.3
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• pp.121-128
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• 2018

Severe earthquakes can cause damage to society both socially and economically. An appropriate initial response can alleviate damage from severe earthquakes. In order to formulate an appropriate initial response, it is necessary to identify damage situations in societies; however, it is difficult to grasp this information immediately after an earthquake event. In this study, an earthquake damage assessment methodology for buildings is proposed for estimating damage situations immediately after severe earthquakes. A response spectrum database is constructed to provide response spectra at arbitrary locations from earthquake measurements immediately after the event. The fragility curves are used to estimate the damage of the buildings. Earthquake damage assessment is performed from the response spectrum database at the building scale to provide enhanced damage condition information. Earthquake damage assessment for Gyeongju city and Pohang city were conducted using the proposed methodology, when an earthquake occurred on September 12, 2016, and November 15, 2017. Results confirm that the proposed earthquake damage assessment effectively represented the earthquake damage situation in the city to decide on an appropriate initial response by providing detailed information at the building scale.

• Journal of the Korean School Mathematics Society
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• v.17 no.2
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• pp.275-290
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• 2014

This study aims to examine how secondary mathematics teachers perceive and how they use constructed-response assessment in their mathematics classrooms. For this purpose, we conducted a survey in Seoul, Inchun, and Gyeonggi-do; 189 teachers participated in the survey. Results from the data analysis suggest as follows: a) the secondary mathematics teachers participated in the survey seem to consider the primary goals of assessment through constructed-response items as evaluating student achievement and the development of students' thinking and creativity; b) the teachers perceive that constructed-response assessment would promote students' mathematical thinking and problem solving skills; c) in general, constructed-response items were included in both performance assessment(less than 20 percent) and paper-and-pencil test(20 to 40 percent); and d) constructed-response items were primarily used as a part of regular examination, rather than as an independent assessment.

• Earthquakes and Structures
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• v.14 no.5
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• pp.389-398
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• 2018

The seismic isolation system makes a structure isolated from ground motions to protect the structure from seismic events. Seismic isolation techniques have been implemented in full-scale buildings and bridges because of their simplicity, economic effectiveness, inherent stability and reliability. As for the responses of an isolated structure due to seismic events, it is well known that the most uncertain aspects are the seismic loading itself and structural properties. Due to the randomness of earthquakes and uncertainty of structures, seismic response distributions of an isolated structure are needed when evaluating the seismic fragility assessment (or probabilistic seismic safety assessment) of an isolated structure. Seismic response time histories are useful and often essential elements in its design or evaluation stage. Thus, a large number of non-linear dynamic analyses should be performed to evaluate the seismic performance of an isolated structure. However, it is a monumental task to gather the design or evaluation information of the isolated structure from too many seismic analyses, which is impractical. In this paper, a new methodology that can evaluate the seismic fragility assessment of an isolated structure is proposed by using stochastic response database, which is a device that can estimate the seismic response distributions of an isolated structure without any seismic response analyses. The seismic fragility assessment of the isolated nuclear power plant is performed using the proposed methodology. The proposed methodology is able to evaluate the seismic performance of isolated structures effectively and reduce the computational efforts tremendously.

• The Mathematical Education
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• v.53 no.1
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• pp.131-146
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• 2014

This study examines whether there is discrepancy between elementary and middle school mathematics teachers' beliefs and practices in constructed-response assessment and how their beliefs and practices are interrelated. Analyzing the responses of 212 elementary teachers and 189 middle school mathematics teachers to the questionnaire, we found that there is lack of consistency among elementary and middle school teachers' beliefs, practices, and expected benefits regarding constructed-response assessment. In addition, there was a weak correlation between each group of teachers' beliefs and expected benefits about constructed-response assessment. The results from this study imply that such inconsistency in elementary and middle school teachers' beliefs and practices regarding assessments may determine the effects of constructed-response assessment.

• Journal of Elementary Mathematics Education in Korea
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• v.16 no.1
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• pp.63-95
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• 2012

Since performance assessment was implemented for 10 years, a survey has been carried out from 212 elementary school teachers in Seoul area in terms of their perception and status about descriptive assessment. As results, most of teachers agreed strongly that using constructed-response items is necessary for assessment, and they showed that purpose of using constructed-response items in their mathematics classrooms was to evaluate accurately student achievement in accordance with learning objectives in mathematics and they referred mainly to items which they modified from problems or items in the textbook when they generate constructed-response items. In addition, they considered level of difficulty in creating constructed-response items mostly. Moreover, they indicated that the effects of assessment through constructed-response items would be improvement of students' problem solving and reasoning skills.

• Journal of the Earthquake Engineering Society of Korea
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• v.17 no.2
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• pp.89-95
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• 2013

Structures in a nuclear power system are designed to be elastic even under an earthquake excitation. However a structural component such as an isolator shows inelastic behavior inherently. For the seismic assessment of nonlinear structures, response history analysis should be performed. In this study, the response of base isolation system was analyzed by response history analysis for the seismic performance assessment. Firstly, several seismic assessment criteria for a nuclear power plant structure were reviewed for the nonlinear response history analysis. Based on these criteria, the spectrum matched ground motion generation method modifying a seed earthquake ground motion time history was adjusted. Using these spectrum matched accelerograms, the distribution of displacement responses of the simplified base isolation system was evaluated. The resulting seismic responses excited by the modified ground motion time histories and the synthesized time history generated by stochastic approach were compared. And the response analysis of the base isolation system considering the different intensities in each orthogonal direction was performed.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.137-137
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• 2002

Biologically Based Dose-Response (BBDR) models were developed using biomarkers for cancer risk assessment. To establish the relationship among biomarkers, exposure dose and tumor response, biomarkers in the lung, liver, stomach or blood were measured after a single or continuous administration of selected carcinogen (; BaP) in mice or rats.(omitted)

• 대한예방의학회:학술대회논문집
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• 1994.02a
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• pp.412-415
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• 1994

The fundamental assumption that thresholds exist for noncarcinogenic toxic effects of chemicals is reviewed; this assumption forms the basis for the no-observed-effect level/ safety-factor (NOEL/SF) approach to risk assessment for such effects. The origin and evolution of the NOEL/SF approach are traced, and its limitations are discussed. The recently proposed use of dose-response modeling to estimate a benchmark dose as a replacement for the NOEL is explained. The possibility of expanding dose-response modeling of non carcinogenic effects to include the estimation of assumed thresholds is discussed. A new method for conversion of quantitative toxic responses to a probability scale for risk assessment via dose-response modeling is outlined.

• The Korean Journal of Emergency Medical Services
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• v.22 no.3
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• pp.47-54
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• 2018

Purpose: The purpose of this study was to present evidence for quality management based on analysis of patient transportation and response intervals among emergency medical squads. Methods: The chi-square test was used to determine whether mental status and patient assessment affected direct medical control and hospital destination. One way analysis of variance was used to compare response intervals depending on mental status and patient assessment using data drawn from 1172 prehospital care reports. Results: There was a statistically significant relationship between mental status and direct medical control (p<.001); there was a statistically significant relationship between patient assessment and hospital destination (p=.011). However, there was no statistically significant relationship between mental status and hospital destination. The interval from arrival at the patient's side to departure from the scene showed a statistically significant difference (p<.001, p<.001), however, it took the longest time (16.8 minutes) in unresponsive patients. It showed a statistically significant difference (p<.001) in the interval from arrival at patient's side to departure from the scene depending on patient assessment; however, it took the longest time (9.6 minutes) in emergency patients. Conclusion: There was call for direct medical control based on patient assessment; however, patient transportation and response intervals were not appropriate.

• Journal of The Korean Association For Science Education
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• v.35 no.1
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• pp.121-130
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• 2015

Identifying students' achievement level and reflecting it on educational policy making or instructional improvement by analyzing the results of nationwide standardized assessment is an integral part of accountability in education. On the basis of this premise, we analyzed the characteristics of National Assessment of Educational Achievement (NAEA) items for middle school science subject conducted from 2010 to 2013 by using the option response rate distribution curve, the fittest graph estimated from the response rate of correct/incorrect options by achievement score. Furthermore, we classified the type of option response rate curve in terms of correct and incorrect options. Results of the analysis of option response curve showed that five types of correct option response curve (S-shaped, J-shaped, straight-shaped, F-shaped, and step-shaped) and 4 types of incorrect option response curve (down-slope, flat, mound, and up-slope) were identified. The most common type of items was the combination of S-shaped correct option response curve and down-slope incorrect option response curve, which are considered as appropriate items to discriminate the students according to achievement level. Moreover, correct option response was found to be correlated with incorrect option response. Based on the results, we also discussed some implications on teaching-learning method and classroom assessment in science education.