• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.2
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• pp.113-119
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• 2024

Existing reinforced concrete buildings with seismically deficient column details affect the overall behavior depending on the failure type of column. This study aims to develop and validate a machine learning-based prediction model for the column failure modes (shear, flexure-shear, and flexure failure modes). For this purpose, artificial neural network (ANN), K-nearest neighbor (KNN), decision tree (DT), and random forest (RF) models were used, considering previously collected experimental data. Using four machine learning methodologies, we developed a classification learning model that can predict the column failure modes in terms of the input variables using concrete compressive strength, steel yield strength, axial load ratio, height-to-dept aspect ratio, longitudinal reinforcement ratio, and transverse reinforcement ratio. The performance of each machine learning model was compared and verified by calculating accuracy, precision, recall, F1-Score, and ROC. Based on the performance measurements of the classification model, the RF model represents the highest average value of the classification model performance measurements among the considered learning methods, and it can conservatively predict the shear failure mode. Thus, the RF model can rapidly predict the column failure modes with simple column details.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.347-361
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• 2023

Water utilities are making various efforts to reduce water losses from water networks, and an essential part of them is to recognize the moment when a pipe burst occurs during operation quickly. Several physics-based methods and data-driven analysis are applied using real-time flow and pressure data measured through a SCADA system or smart meters, and methodologies based on machining learning are currently widely studied. Water utilities should apply various approaches together to increase pipe burst detection. The most intuitive and explainable water balance method and its procedure were presented in this study, and the applicability and detection performance were evaluated by applying this approach to water supply pipelines. Based on these results, water utilities can establish a mass balance-based pipe burst detection system, give a guideline for installing new flow meters, and set the detection parameters with expected performance. The performance of the water balance analysis method is affected by the water network operation conditions, the characteristics of the installed flow meter, and event data, so there is a limit to the general use of the results in all sites. Therefore, water utilities should accumulate experience by applying the water balance method in more fields.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.2
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• pp.63-73
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• 2018

Academia and research institutes mainly use qualitative methods that rely on expert judgments to understand and predict research trends and science and technology trends. Since such a technique has the disadvantage of requiring much time and money, in this study, science and technology trends were predicted using keyword network analysis. To that end, 13,618 AI (Artificial Intelligence) patent abstracts were analyzed using keyword network analysis in three separate lots based on the period of the submission of each abstract: analysis period 1 (January 1, 2002 - December 31, 2006), analysis period 2 (January 1, 2007 - December 31, 2011), and analysis period 3 (January 1, 2012 - December 31, 2016). According to the results of frequency analyses, keywords related to methods in the field of AI application appeared more frequently as time passed from analysis period 1 to analysis period 3. In keyword network analyses, the connectivity between keywords related to methods in the field of AI application and other keywords increased over time. In addition, when the connected keywords that showed increasing or decreasing trends during the entire analysis period were analyzed, it could be seen that the connectivity to methods and management in the field of AI application was strengthened while the connectivity to the field of basic science and technology was weakened. According to analysis of keyword connection centrality, the centrality value of the field of AI application increased over time. According to analysis of keyword mediation centrality during analysis period 3, keywords related to methodologies in the field of AI application showed the highest mediation value. Therefore, it is expected that methods in the field of AI application will play the role of powerful intermediaries in AI hereafter. The technique presented in this paper can be employed in the excavation of tasks related to regional innovation or in fields such as social issue visualization.

• Journal of Korean Academy of Nursing
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• v.37 no.6
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• pp.1013-1019
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• 2007

Purpose: This study was to determine the current trend of nursing research as exploring both quantitative and qualitative methodologies, and to provide the explicit direction to improve the quality of published papers. Methods: Total of 366 articles published between 2004 and 2006 was reviewed using the criteria of analysis. Results: There was more number of quantitative studies than qualitative studies. More studies were conducted with subjects who had health problems, and studies that targeted women and elderly population have been significantly increased. In quantitative methodology, utilization of experimental and quasi-experimental designs has been increased, however descriptive study was dominant as yet. In qualitative methodology, studies using grounded theory and phenomenology were frequently published. It was noted that theoretical framework and rational for sample size were rarely presented in quantitative study. Philosophical position and the process of preparation for study, which guided the research, were not clearly described in qualitative study. Conclusion: The findings of this review suggest that published studies have been improved and diversified, however, detailed and clear evaluation tool that assesses study process and method should be developed as a way to further improve the quality of published papers.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.1
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• pp.61-72
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• 2018

Objectives The authors propose a new checklist model adapted for safety miniscalpel acupuncture procedure of cervical and lumbar spine. Methods On the basis of available literature and expert opinion, a prototype checklist was developed. The checklist was adapted on the basis of observation of daily practice. Results The checklist has three parts: 1. prevention and management of healthcare associated infections, 2. verification list before and after miniscalpel acupuncture treatment, 3. adverse event monitoring after procedure. We presented a summary checklist based on the above contents. Conclusions We propose the first patient safety checklist for minicalpel acupuncture treatment of cervical and lumbar spine. The checklist will be complemented using further research methodologies.

• International Journal of Automotive Technology
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• v.8 no.1
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• pp.93-102
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• 2007

The frontal crash optimization of an engine room member using the response surface method was studied. The engine room member is composed of the front side member and the sub-frame. The thicknesses of the panels on the front side member and the sub-frame were selected as the design variables. The purpose of the optimization was to reduce the weight of the structure, under the constraint that the objective quantity of crash energy is absorbed. The response surface method was used to approximate the crash behavior in mathematical form for optimization procedure. To research the effect of the regression method, two different methodologies were used in constructing the response surface model, the least square method and the moving least square method. The optimum with the two methods was verified by the simulation result. The precision of the surrogate model affected the optimal design. The moving least square method showed better approximation than the least square method. In addition to the deterministic optimization, the reliability-based design optimization using the response surface method was executed to examine the effect of uncertainties in design variables. The requirement for reliability made the optimal structure be heavier than the result of the deterministic optimization. Compared with the deterministic optimum, the optimal design using the reliability-based design optimization showed higher crash energy absorption and little probability of failure in achieving the objective.

• Molecules and Cells
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• v.42 no.1
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• pp.87-95
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• 2019

Long interspersed element-1 (LINE-1 or L1) is an autonomous retrotransposon, which is capable of inserting into a new region of genome. Previous studies have reported that these elements lead to genomic variations and altered functions by affecting gene expression and genetic networks. Mounting evidence strongly indicates that genetic diseases or various cancers can occur as a result of retrotransposition events that involve L1s. Therefore, the development of methodologies to study the structural variations and interpersonal insertion polymorphisms by L1 element-associated changes in an individual genome is invaluable. In this study, we applied a systematic approach to identify human-specific L1s (i.e., L1Hs) through the bioinformatics analysis of high-throughput next-generation sequencing data. We identified 525 candidates that could be inferred to carry non-reference L1Hs in a Korean individual genome (KPGP9). Among them, we randomly selected 40 candidates and validated that approximately 92.5% of non-reference L1Hs were inserted into a KPGP9 genome. In addition, unlike conventional methods, our relatively simple and expedited approach was highly reproducible in confirming the L1 insertions. Taken together, our findings strongly support that the identification of non-reference L1Hs by our novel target enrichment method demonstrates its future application to genomic variation studies on the risk of cancer and genetic disorders.

• Restorative Dentistry and Endodontics
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• v.38 no.1
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• pp.2-10
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• 2013

A common failure in endodontic treatment of the permanent maxillary first molars is likely to be caused by an inability to locate, clean, and obturate the second mesiobuccal (MB) canals. Because of the importance of knowledge on these additional canals, there have been numerous studies which investigated the maxillary first molar MB root canal morphology using in vivo and laboratory methods. In this article, the protocols, advantages and disadvantages of various methodologies for in-depth study of maxillary first molar MB root canal morphology were discussed. Furthermore, newly identified configuration types for the establishment of new classification system were suggested based on two image reformatting techniques of micro-computed tomography, which can be useful as a further 'Gold Standard' method for in-depth morphological study of complex root canal systems.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.190-194
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• 2007

In most countries, mobile subscribers are already experiencing 3G-like services. At the moment of launching 3G services, lots of studies showed estimates of the number of subscribers for 3G services, using long-term demand curves, econometric methods or survey methodologies. Those studies mainly focused on the potential number of subscribers and the point of rapid growth rather than precise estimates for the services. Even though we've already experienced parts of 3G services, full length of 3G services are expecting in near future. Therefore, now we need to have more accurate estimates for 3G services. While we thought that 3G services were moved from 2G, in real place 3G services are being evolved from 2G services. In the process of evolving, regulators' policy affects service demand and diffusion significantly. For the more accurate estimates, we need to consider policy issues which influence service diffusion practically in real place. This study aims to present a model which shows better estimates for 3G services with consideration on policy issues, such as numbering issues, price regulation, and competition policy. The consideration can provide more accurate estimates for 3G services with service providers. The methodology could help academicians In forecasting of similar telecommunications services as well.

• Herbal Formula Science
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• v.24 no.4
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• pp.367-376
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• 2016

Objectives : The purpose of this study was to investigate the interpretation of the Gwibi-tang(歸脾湯, GBT) prescription in order to obtain the traditional significance. Methods : We have analyzed the interpretation on the GBT prescription through translations and comparisons based on classic books about the oriental medical prescriptions. Results : 1. The source of GBT in Dongeuibogam(東醫寶鑑) is Guchiryuyo(口齒類要), Jeongcheryuyo(正體類要) and Gyojubuinyangbang(校註婦人良方) etc. 2. Meaning of "GwiBi(歸脾)" in the GBT name is returning to the Bi(脾) which is origin of generating Gi(氣) and Blood(血). 3. GBT is composed of Sagunja-tang(四君子湯), Hwanggi-tang(黃芪湯) and Danggwibohyeol-tang(當歸補血湯) etc. 4. According to wide range of symptom, GBT can be varied by adding or subtracting herbs. Conclusions : In this study, we have demonstrated various methodologies. This paper will be useful to the future researchers and clinicians to conduct a study on herbal medicines such as the GBT.