• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.3
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• pp.47-57
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• 2023

In this study, pull-out tests were performed to investigate the effects of stirrup spacing, rebar diameter, and corrosion rate on bond strength of deformed bars in reinforced concrete. Twelve pull-out specimens with different stirrup spacing, rebar diameter, and corrosion rate were prepared following the RILEM RC6 guidelines. The test results showed that the bond strength of specimens with stirrups increased when the corrosion rate was less than 3%, whereas it decreased when the corrosion rate was more than 3%. On the other hand, the bond strength of specimens without stirrups decreased as the corrosion rate increased. The effect of rebar diameter was less significant compared to those of stirrup spacing and corrosion rate. A bond strength model for pull-out specimens was proposed considering stirrup ratio and corrosion rate, and the model showed the lowest error among the previous models.

• Journal of the Korea Convergence Society
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• v.7 no.6
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• pp.259-266
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• 2016

The purpose of this study is to explore the feasibility of establishing the elderly protection system for the elderly in the local community, and to explore the linkage model and action strategy. In Korea, there is a need to build a comprehensive elderly care system so that elderly people can have appropriate counseling and support programs in the community, as the elderly increase their diverse needs (leisure, housing, employment). In this study, we set up a linkage model of elderly care system and suggested two ways to practice it. First, it is suggested that it is desirable to focus on the formation of the elderly protection system in the community, and divide the practice process into three stages: organization, practice, and organization. Second, it is necessary to apply the long-term care professional manpower which can play a central role such as care manager and nursing care provider in order to apply the community organizing model of the elderly protection system and stable operation of long-term care insurance for the elderly. In addition, a social welfare council and a private network should be established to form a social welfare council, the establishment of related legal provisions, and the education of care managers. Therefore, it is necessary to establish basic data through this study, to establish diverse strategies and plans for the elderly protection system, and to promote it in a phased manner.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.33-41
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• 2018

The purpose of this study is to develop more accurate and robust emotion prediction neural network (EPNN) model by combining heart rate variability (HRV) and neural network. For the sake of improving the prediction performance more reliably, the proposed EPNN model is based on various types of activation functions like hyperbolic tangent, linear, and Gaussian functions, all of which are embedded in hidden nodes to improve its performance. In order to verify the validity of the proposed EPNN model, a number of HRV metrics were calculated from 20 valid and qualified participants whose emotions were induced by using money game. To add more rigor to the experiment, the participants' valence and arousal were checked and used as output node of the EPNN. The experiment results reveal that the F-Measure for Valence and Arousal is 80% and 95%, respectively, proving that the EPNN yields very robust and well-balanced performance. The EPNN performance was compared with competing models like neural network, logistic regression, support vector machine, and random forest. The EPNN was more accurate and reliable than those of the competing models. The results of this study can be effectively applied to many types of wearable computing devices when ubiquitous digital health environment becomes feasible and permeating into our everyday lives.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.264-264
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• 2017

국외의 상수도 원격검침 시스템 내 데이터 전송방식은 도시 규모, 계량기의 밀도, 전력공급 여부 및 통신망의 설치 여부 등을 종합적으로 고려하여 결정되었다. 대부분의 스마트워터미터 제조업체들은 계량기의 부호기가 공급하는 판독 내용(데이터)을 전송할 검침단말기와 근거리 통신망(neighborhood area network)을 연계하여 개발 및 판매하였으며, 자체 소유 통신 프로토콜을 사용하여 라디오 주파수(RF) 통신 기술을 사용하고 있다. 광역통신망(wide area network)의 경우, 노드(말단의 계량기 및 센서)들과 이에 연결된 통신망 들을 포함한 네트웍의 배열이나 구성이 스타(star), 메쉬(mesh), 버스(bus), 나무(tree) 등의 형태로 통신망이 구성되어 있으나, 스타와 메쉬형 통신망 구성형태가 가장 널리 활용되는 것으로 조사되었다. 시스템 통합운영관리 업체들인 IBM, Oracle, Itron 등은 용수 인프라 관리 또는 통합네트워크 솔루션 등의 통합 물관리 시스템(integrated water management system)을 개발하여 현장적용을 하고 있으며, 원격검침 시스템을 통해 고객들의 현재 소비량과 과거 누적 소비량, 누수 감지 서비스 및 실시간 요금 고지 등을 실시간으로 웹 포털과 앱을 통해 제공하고 있다. 또한, 일부 제조업체들은 도시 용수공급/소비 관리자가 주민의 용수사용량을 모니터링하여 일평균 용수사용량 및 사용 경향을 파악하고, 누수를 검지하여 복구 및 용수 사용 지속가능성 지수를 제시하고, 실시간으로 주민의 용수사용량 관련 데이터를 모니터링하여 용수공급의 최적화를 위한 의사결정지원 서비스를 용수공급자에게 제공하고 있다. 최근에는 인공지능을 활용해 가정용수의 용도별(세탁용수, 화장실용수, 샤워용수, 식기세척용수 등) 사용량 곡선을 패터닝하여 profiling 기법을 도입해, 스마트워터미터에서 용수사용량이 통합되어 검지될 시 용수사용량의 세부 용도별 re-profiling 기법을 도입하여 가정용수내 과소비되는 지점을 도출 후 절감을 유도하는 기술이 개발 중이다. 또한, 미래 용수 사용량 예측을 위해 다양한 시계열 자료를 분석하는 선형 종속 모형(자기회귀모형, 자기회귀이동평균모형, 자기회귀적분이동평균모형 등)과 비선형 종속 모형(Fuzzy Logic, Neural Network, Genetic Algorithm 등)을 활용한 예측기능이 구축되어 상호 비교하여 최적의 용수사용량 예측 도구를 제공되고 있다.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.571-576
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• 2014

Convergence refers to create a new one by combining the different elements of two or more. Currently convergence has expanded academy, industry and education from the concept of combining heterogeneous inter-technology. The most important key to the convergence in success is to derive ideas for problem solving. However, the idea derivation is done in companies to hire professional people for letting the innovation of corporate planning and new product in most cases. It is hard to get the expected results of convergence's variety. In this research, the creation of the general public for their ideas is main focus on developing a curriculum. Development models are: 1) strengthening the internal capacity for creative thinking, 2) curriculum meets the consumer 3) an understanding of convergence technology 4) creative ideas and planning ability is composed of four concepts. It is expected that convergence man power having the creative idea is trained in case of applying the proposed education model to the convergence education.

• Journal of Industrial Convergence
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• v.20 no.12
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• pp.179-186
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• 2022

This study aims to develop a predictive model to suggest a used sales price to sellers and buyers when trading used tablet PCs. For model development, we analyzed the real used tablet PC transaction data and additionally collected detailed product information. We developed several predictive models and selected the best predictive model among them. Specifically, we considered a multiple linear regression model using the used sales price as a dependent variable and other variables in the integrated data as independent variables, a multiple linear regression model including interactions, and the models from stepwise variable selection in each model. The model with the best predictive performance was finally selected through cross-validation. Through this study, we can predict the sales price of used tablet PCs and suggest appropriate used sales prices to sellers and buyers.

• Journal of Convergence for Information Technology
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• v.10 no.9
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• pp.229-236
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• 2020

The purpose of this study was to investigate the current status of unmet medical need using data from the Korea Health Panel study from 2009 to 2013 (excluding 2010), and to analyze the trends of unmet medical need and related factors. The subjects of this study were 11,598 in 2009, 11,035 in 2011, 10,584 in 2012, 10,099 in 2013, and 7,144 people in panel data, and conducted frequency analysis, chi-square test and generalized estimating equation. As a result of the analysis by year, it was found that women, under middle school graduation, medical aid, the lowest household income and low subjective health status experienced more unmet medical need. As a result of analysis using generalized estimating equation, women, under 40 years of age, under elementary school graduation, lowest quartile household income, subjective health status of less than 20 points, and activity restrictions are more likely to experience unmet medical need. Based on these results, we intend to provide basic data for establishing policies on the use of medical services.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.197-205
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• 2020

The present study analyzed the effector that has an influence on continuance intention to use YouTube that is a prime platform to distribute visual contents. Whether the dispersion of information communication technology succeeds or not is determined by a more extent which user uses active and continued than adopts fast. From this point of view, we employed partial least square(PLS) path modeling to analyze structural causality among constructs in the post-adoption model(PAM). As a result, all paths given in PAM except for the path 'confirmation-satisfaction' were validated. Especially, confirmation mediated with satisfaction than perceived usefulness has a more effect on continuance intention. Finally, we described the limitation of the present study and the suggestion for future research.

• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.271-279
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• 2020

Squats and lunges are important exercises for strengthening the trunk and lower body among various free weight exercises. It should be achieved safe and effective excise through establishing of theoretical basis for exercise posture and standard movement. Therefore, it's necessary to develop the exercise model in order to prepare the scientific countermeasures for the prevent injuries and error movement through optimal exercise movement. For this purpose, it is effective to use appropriate instruments for motion compensation according to the optical motion and error motion. In this paper, we develop a motion model analysis system based on dynamic motion through the four-point load cell for dynamic motion analysis. Proposed analytical method, the optimal and the error motion numerical data is obtained through the dynamic motion analysis. And we verified that dynamic movement is simplified to establish the motion modeling according to the classification motion and the numerical quantification data for analyzing.

• Convergence Security Journal
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• v.12 no.6
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• pp.51-59
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• 2012

This paper presents a new learning model, "BoX(Battle of X)", which is based on a concept from the culture of B-Boys who enjoy the race of "distributed cognition" to win in their contests. The "battle" means a contest and "X" means a course to which our learning model can be applied. The goal of this paper is to present a learning model that allow students to be in a state of learning-flow and provides them with the ability of creative problem solving simultaneously. The key of the "BoX" implementation is to design a principle that controls contests between students to maximize distributed cognitive activities for reducing individual's cognitive load. This paper also presents how-to of "BoX" implementation and its effects. Through the analysis on learning achievement of students during one year course of IT education, we have confirmed that the "BoX" model provides students with higher learning achievement and learning-flow level in comparison with traditional learning model.