• Journal of the Korean Society of Safety
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• v.22 no.5
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• pp.71-76
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• 2007

Failures of equipments for train control systems are linked directly to extensive damages of human lives or financial losses from the increasing uses of train control equipments utilizing computers. Then safety activities for assuring safety and reliability are needed during the system life-cycle. Risk analysis is important phase to increase safety from determining the risk presented by the identified hazard. In this paper, we investigated several methods for risk estimation of safety activities, and then we drew a comparison between original methods to suggest optimized one in the application to train control systems. In the result of the comparison, we had plan to propose the risk analysis method called Best-Practice(BP) risk method combining advantages of the qualitative and the quantitative analysis. In addition, we attempted to apply the BP-risk method to domestic train control systems handling in Korea.

• Journal of the Korean Society of Safety
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• v.35 no.6
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• pp.61-77
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• 2020

In order to establish a conceptual basis and future research direction of safety leadership, this study reviewed domestic and foreign research trends related to safety leadership through systematic literature review methods. The literature search was conducted by combining terms related to safety leadership without limiting the period databases. A total of 195 documents were found, of which the final 59 were used for analysis. As a results, the safety leadership study was the most frequent in relations among variables. The most leadership types were based on transactional leadership and transformational leadership. In addition, studies have been conducted to categorize safety leadership as an independent concept. Safety leadership was mainly studied in the fields of safety engineering, disaster prevention, and business administration. Quantitative studies were mainly conducted to research methods. Based on the results, the research trend related to safety leadership was discussed, and suggestions for future research direction was presented.

• Journal of the Ergonomics Society of Korea
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• v.27 no.2
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• pp.15-24
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• 2008

As users increasingly recognize the importance of safety and the Product Liability comes into effect, a company should take responsibility of protecting the users who use its product. In order to produce a safe product and satisfy the needs of users, it is critical for develope opriately and understand the characteristics of the product accurately. Furthermore, a safe product can be realized by considering a safety level of the product in a whole product development process. However, in general, product development projects hardly evaluate the safety of a product in the product planning step. In addition, most of safety evaluation methods which are applied in the product planning step have a tendency to be qualitative because a detailed product design step. Therefore, this research aims at enhancing the performance of the safety evaluation process by applying quantitative methods such as 'AHP' and 'Fuzzy'. AHP can help analysts derive the weight of safety factors. Fuzzy is applied to evaluate the degree of safety of product elements in this paper. The proposed method will be able to improve the safety level of a product by using the quantitative methods in the product planning step.

• School Mathematics
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• v.17 no.4
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• pp.571-591
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• 2015

Even though fractions make up one of the most important concepts in the domain of numbers in elementary math, it is difficult to teach or learn them due to their different quantity concepts and notation methods from natural numbers and their various concepts. The didactic transposition of fractions is thus important, and there is a need to examine the didactic concepts of fractions used in the South Korean textbooks for its research. This study compared elementary math textbooks among South Korea, Taiwan, and China and investigated differences in the instructional time and order of fraction concepts in the textbooks according to their didactic concepts and also differences in the instructional methods according to quantitative concepts.

• Journal of Biomedical Engineering Research
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• v.22 no.4
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• pp.311-319
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• 2001

Statistical reconstruction methods in the context of a Bayesian framework have played an important role in emission tomography since they allow to incorporate a priori information into the reconstruction algorithm. Given the ill-posed nature of tomographic inversion and the poor quality of projection data, the Bayesian approach uses regularizers to stabilize solutions by incorporating suitable prior models. In this work we show that, while the quantitative performance of the standard filtered backprojection (FBP) algorithm is not as good as that of Bayesian methods, the application of spline-regularized smoothing to the sinogram space can make the FBP algorithm improve its performance by inheriting the advantages of using the spline priors in Bayesian methods. We first show how to implement the spline-regularized smoothing filter by deriving mathematical relationship between the regularization and the lowpass filtering. We then compare quantitative performance of our new FBP algorithms using the quantitation of bias/variance and the total squared error (TSE) measured over noise trials. Our numerical results show that the second-order spline filter applied to FBP yields the best results in terms of TSE among the three different spline orders considered in our experiments.

• Journal of Power Electronics
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• v.19 no.1
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• pp.158-167
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• 2019

This research comparatively studies three kinds of flux regulation methods, namely, stored capacitor discharge pulse (SCDP), constant current source pulse (CCSP), and quantitative flux regulation pulse (QFRP), which are used for hybrid permanent magnet (PM) axial field flux-switching memory machines (HPM-AFFSMMs). Through an analysis of the operation principle and the series hybrid PM flux regulation mechanism of the objective machine, the circuit topologies and flux regulation process of these flux regulation methods are addressed in detail. On the basis of a simulation, the flux regulation characteristics of the researched machine during the magnetization and demagnetization processes are comparatively evaluated. Then, machine performance, including back EMF, direct and quadrature axis inductances, and magnetization and demagnetization characteristics, is quantitatively investigated. Results show that the QFRP enables the HPM-AFFSMM to achieve a less harmonic component of back EMF by approximately 7.28% and 7.97% at the magnetization and demagnetization states, respectively, and a more complete magnetization process than the SCDP and CCSP.

• Journal of Haehwa Medicine
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• v.28 no.2
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• pp.20-28
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• 2019

Objectives : Hwangryunhaedok-tang. a traditional Korean herbal medicine, has been widely used for the treatment. This study is purposed to analyze the research trend of Hwangryunhaedok-tang in Korea for developing further research plan. Methods : A search of Korean research database( OASIS, RISS, Korean traditional knowledge portal, NDSL) was conducted to find studies for Hwangryunhaedok-tang. We analyzed studies by publish date, speciality, study method, and field of study. Result : 1. 2.65 papers were published annually on average. 2. After analyzing for the speciality of the journal, most of the papers were published in Traditional Korean Medicine. 3. After analyzing for the study method, in vivo was 33.96%, in vitro was 32.08% and quantitative inspection was 13.21% 4. After analyzing for the subject of the studies, beneficial effect was 81.13%, quantitative and qualitative analysis was 13.21%, toxicity was 3.77% 5. Papers on beneficial effect were classified by the type of diseases. Hwangryunhaedok-tang was most used in skin disease. Conclusions : Hwangryunhaedok-tang is effective in various category of diseases. This study will be useful to future researchers and clinicians to conduct a study on Hwangryunhaedok-tang.

• Research in Community and Public Health Nursing
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• v.29 no.2
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• pp.155-169
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• 2018

Purpose: The purpose of this study is to review the quantitative research literature on measuring caring in order to identify overall trends in measuring caring. Methods: Fifty three papers were selected from four databases including RISS4U, DBpia, KISS, and Korea Med. Results: The number of measuring caring papers has increased since 2000. Approximately 60 % of the total papers were descriptive and correlative design researches with convenience sampling. Jean Waston's theory was the most popular conceptual framework, but much of the research tended to be conducted without any conceptual framework. In that kind of research, 'caring' terms were used without definition. The most frequently used term for the concept of caring was nurses' caring behaviors. Also, 'nurses' was one of the most popular subjects. Thirty six measuring caring instruments were used. Twenty were developed in foreign countries and translated into Korean. The others were developed originally in Korean. Interpersonal Caring Technique - Communication Skills Scale, based on the interpersonal process model, was the most frequently used tool. Among the translated instruments, Coates' Caring Efficacy Scale was the most popular. Some instruments were used without validation. Conclusion: These results provide basic data on measuring caring and indicate directions for further research. In particular, validation studies of measuring caring instruments are needed.

• Journal of Periodontal and Implant Science
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• v.47 no.1
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• pp.13-19
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• 2017

Purpose: The purpose of this study was to examine whether periodontal pocket could be satisfactorily visualized by optical coherence tomography (OCT) and to suggest quantitative methods for measuring periodontal pocket depth. Methods: We acquired OCT images of periodontal pockets in a porcine model and determined the actual axial resolution for measuring the exact periodontal pocket depth using a calibration method. Quantitative measurements of periodontal pockets were performed by real axial resolution and compared with the results from manual periodontal probing. Results: The average periodontal pocket depth measured by OCT was $3.10{\pm}0.15mm$, $4.11{\pm}0.17mm$, $5.09{\pm}0.17mm$, and $6.05{\pm}0.21mm$ for each periodontal pocket model, respectively. These values were similar to those obtained by manual periodontal probing. Conclusions: OCT was able to visualize periodontal pockets and show attachment loss. By calculating the calibration factor to determine the accurate axial resolution, quantitative standards for measuring periodontal pocket depth can be established regardless of the position of periodontal pocket in the OCT image.

• The Korean Journal of Community Living Science
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• v.25 no.4
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• pp.449-460
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• 2014

This study examines research trends in Korean journal articles covering the role of fathers with young children. For this study, 45 research papers published from 2000 to present were analyzed according to research periods, research topics, research types, data collection methods, and data analysis methods. First, the largest number of papers was written since 2010. Second, the largest number of papers in terms of research topics focused on the father's child-rearing involvement and behavior. Third the most frequently used research type was the quantitative study. Fourth, the most frequently used data collection method was the questionnaire method. Fifth, the most frequently used data analysis method was the frequency and mean method. Future research should consider broader age groups of father and children by using various types of data collection and analysis methods. In addition, it should be useful to scrutinize general research trends in Korean journal articles highlighting the importance of roles of fathers with young children in a rapidly changing society.