• Earthquakes and Structures
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• v.12 no.4
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• pp.425-436
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• 2017

Vibration control using a tuned mass damper (TMD) is an effective technique that has been verified using analytical methods and experiments. It has been applied in mechanical, automotive, and structural applications. However, the damping of a TMD cannot be adjusted in real time. An excessive mass damper stroke may be introduced when the mass damper is subjected to a seismic excitation whose frequency content is within its operation range. The semi-active tuned mass damper (SATMD) has been proposed to solve this problem. The parameters of an SATMD can be adjusted in real time based on the measured structural responses and an appropriate control law. In this study, a stiffness-controllable TMD, called a leverage-type stiffness-controllable mass damper (LSCMD), is proposed and fabricated to verify its feasibility. The LSCMD contains a simple leverage mechanism and its stiffness can be altered by adjusting the pivot position. To determine the pivot position of the LSCMD in real time, a discrete-time direct output-feedback active control law that considers delay time is implemented. Moreover, an identification test for the transfer function of the pivot driving and control systems is proposed. The identification results demonstrate the target displacement can be achieved by the pivot displacement in 0-2 Hz range and the control delay time is about 0.1 s. A shaking-table test has been conducted to verify the theory and feasibility of the LSCMD. The comparisons of experimental and theoretical results of the LSCMD system show good consistency. It is shown that dynamic behavior of the LSCMD can be simulated correctly by the theoretical model and that the stiffness can be properly adjusted by the pivot position. Comparisons of experimental results of the LSCMD and passive TMD show the LSCMD with less demand on the mass damper stroke than that for the passive TMD.

• Journal of the Korean Wood Science and Technology
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• v.46 no.3
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• pp.285-296
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• 2018

As a study for the verification of heat treated wood according to ISPM No. 15, the spectroscopic characteristics of the heat treated wood surface were analyzed. Various functional groups were observed on the IR spectrum, but it was difficult to find any particular difference between wood species, heat treatment time and storage period. HBI (hydrogen-bonding intensity) shows the change of the heat treated wood according to the storage time, but the change of wood with the heat treatment time was hard to be observed. On the PCA score plot, however, it was possible to sort the wood according to the heat treatment time of 60 minutes or 90 minutes in the species. The standards for classification of heat-treated wood in PCA were aromatic rings in lignin and C-H bending in cellulose, and these components were able to classify heat-treated wood by ISPM No. 15.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.321-327
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• 2019

The purpose of this study is to develop a smart device-based Language Rehabilitation Program (LRP) to improve communication ability for the patients with language disability. The content of the LRP includes a variety of semantic categories and grammatical elements and consists of 17 semantic categories, 29 tasks and 3780 items to improve comprehension/production ability at word level, semantic category level, sentence level and discourse level. We developed LRP as a Windows-base management program and an Android-base language rehabilitation application. LRP was developed into an application for smart devices, providing real-time delivery of training contents, measurement and database of training task results, and patient progress and monitoring. A follow-up study will be conducted on the verification of the language rehabilitation effect using LRP by patients with language disability.

• Journal of the Korea Society of Computer and Information
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• v.20 no.8
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• pp.121-128
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• 2015

This study aimed to investigate the effects of an unplugged robot education system capable of computerless coding education. Specifically, this study compared this education system with PicoCricket, an educational robot that can also be used with elementary students in lower grades, using assessment tools on perceived usefulness and ease. Using random sampling and randomized assignment for more objective validation, 30 participants were assigned to the unplugged robot education system group (experimental group) and 30 participants were assigned to the PicoCricket group (control group), for a total of 60 study participants. The research procedure included verification of the equivalence of the two groups by conducting a pretest after a 2-hour basic training session on algorithms and programming. The experimental and control groups learned the same content using different educational tools in accordance with software training guidelines for a total of 12 hours. Then, the difference in perceived usefulness and ease between the two groups was examined using a post-treatment test. The study results showed that scores on both dependent variables, perceived usefulness and perceived ease, were significantly higher in the experimental group than the control group. Moreover, scores on all sub-variables of the dependent variables were significantly higher in the experimental group than the control group. These results suggest that learners using the unplugged robot education system found it more useful and easier to use than learners using the existing educational robot, PicoCricket. This study's findings are significant, as according to the technology acceptance model, the perceived usefulness and ease of an educational tool are important variables that determine the acceptance of the tool (i.e., persistence of learning).

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.199-206
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• 2020

This study was conducted for the purpose of developing a measurement tool for success and failure factors of education and training of Korean bodyguards. conducted a meeting from the fully open questionnaire at first, and then formed the semi-structured questionnaire, finally carried out the survey from the closed questionnaire and analyzed data from SPSS 21.0, AMOS 21.0 and developed the measurements. It was conducted from May, 2019 to December, 2019. This survey was conducted of 150 security guards after the verification of the content validity though the pilot survey and presented the success attribution factors and standards on the basis of the result form this survey. As a result, the success factors of the training of the bodyguards were accidental education (5 item), vocational mental education (2 item), vocational mental education (2 item), work ability enhancement education (2 item), realistic practical education (2 item) ), Including 4 items, 11 items, The failure factors consisted of 12 item of three factors: formal education and training (5 item), lack of leadership qualities (4 item), and lack of education (3 item).

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.3
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• pp.39-61
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• 2021

This study aims to examine the effect of the Mindfulness for YouTube users. Recently, video sharing platforms have grown rapidly with YouTube, and YouTube has grown rapidly despite the emergence of various video sharing platforms. Which YouTube represents these changes, provides an environment where anyone can make and distribute videos. And through these advantages, many viewers are coming in and more creators are making videos. The purpose of this study is to understand the influence factors of YouTube service in Korea and to clarify the causal relationship between the factors that affect the continued use intention through usefulness, confirmation, and satisfaction. For this reason, presented a research model that applied key variables of the Mindfulness theory, which emphasized that users should be aware of their emotions. In order to empirical verification the research model of this study, a questionnaire was conducted for university students and general office workers who had experience using YouTube. As a result, first decentered attention has been shown that has no positive effect on perceived usefulness and confirmation. Second, non-judgmental acceptance has benn shown that has a postitive effect on perceived usefulness and confirmation. Third, current self-perception has been shown that has no positive effect on perceived usefulness and confirmation. Fourth, concentration has been shown that has no positive effect on perceived usefulness and confirmation. And Mindfulness has been shown that has a positive effect on satisfaction and perceived usefulness. Through this, it is important to use YouTube to use what users feel is important, and it is important to determine whether the video is helpful to them when accepting content and make them expect the next video.

• The Journal of Bigdata
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• v.6 no.1
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• pp.13-22
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• 2021

The purpose of this study is to develop and demonstrate a framework for evaluating the maturity of big data for effective data strategy establishment and efficient investment of companies. By supplementing the shortcomings of the evaluation developed so far, a framework was developed to evaluate the maturity of a company's big data in an integrated process. As a result, four evaluation areas of 'Vision and Strategy', 'Management', 'Analysis' and 'Utilization', assessment items for each area, detailed content, and criteria for each stage were derived. This was verified through a survey of entrepreneurs, and the maturity level of big data of domestic companies was confirmed. As a future research direction, it is proposed to develop detailed assessment factors according to the characteristics of each industry, to develop a data utilization framework according to the assessment results, and to improve validity and reliability through adjustment of verification targets.

• Journal of Fashion Business
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• v.25 no.3
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• pp.51-70
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• 2021

The study aims to evaluate changes in textiles for automotive interior and suggest directions that the textile-development should take in order to achieve sustainability, and enter a circular economy system in the future. The main content and results of the study are as follows: First, we cover the overall sustainability study in the fashion and textile fields; in particular, the certification system is well established through the provision of information on the whereabouts of products to consumers and verification by external environmental auditors. Second, we considered the criteria of C2C in order to derive the necessary criteria for sustainability certification in the field of textiles. Third, we looked at the latest development trends of textile materials for automobile interiors which were divided into three categories: natural originated materials, circular economic consideration materials, and functional supplementary lightweight materials. In addition, we identified to what extent the trend of changes aggregated in the examples was satisfied and what was lacking when applied to the Basic criterion of C2C. As such, this study links and applies the sustainability criteria pursued in the fashion and textile fields to the textile for automotive interior materials, suggesting a direction for the textile field for automotive internal materials in the future. Based on the results of this study, it is hoped that studies on textiles for automotive interior considering the net economy will continue, and practical development in the industry will be realized.

• Journal of Korean Society of Rural Planning
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• v.25 no.2
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• pp.99-117
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• 2019

Environmental impact assessment (EIA), which predicts, evaluates, and manages the influences on natural landscape, plays a role of monitoring natural resources for systematic management of natural landscape. However, the function of verification and correction of the system is still insufficient and feed-back, one of the most important features of EIA follow-up, has not been introduced in Korea's EIA system yet. As a procedure, it is required to check if the opinions of the evaluators are properly reflected to the outcomes of the project through a reviewing process after assessing environmental impacts of a development project. In reality, despite the awareness about the importance of follow-up inspection of the conformity with, the system mainly focuses on the agreement during the planning stage of the development project and fails to continuously manage after its completion. There have been various preceding studies related to prediction, evaluation, and management of environmental impacts on natural landscape for better management. They primarily dealt with the problems in the EIA process and suggested improvement measures, including directions for institutional development, step-by-step goals, and operation methods, to address the problems which arise in the EIA follow-up process. However, suggested measures are not actively applied with the focus only put on institutional operation, there are virtually no standardized methods to predict and assess landscape changes due to the development project and to manage landscape after the project. Against this backdrop, this study aims to explore the existing methods to analyze the impacts natural landscape and to establish a system where landscape management is continued after the development project. To this end, we will suggest reducing methods according to the predicted changes in landscape for post-project management of natural landscape. Characteristics of reduction methods by project type were examined through reviewing the guide to natural landscape rating and the importance of development project impacts on natural landscape by type of reduction was evaluated through questionnaire for experts. Evaluated types of reduction are classified and presented by characteristics of each development project and content of reduction type.

• Journal of muscle and joint health
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• v.28 no.1
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• pp.30-40
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• 2021

Purpose: This study aims to present nurses' legal conflicts and legal basis through the precedent analysis of a crime of professional negligence resulting in death and injury for the past 20 years and provide vital references to cultivate the correct and high-level legal consciousness of nurses. Methods: This study was conducted in five stages of the systematic content analysis method. It amalyses the precedents of a crime of nurses' professional negligence resulting in death and injury from 2000 to 2020. The application system for the provision of the written judgment was used to collect precedents. A total of 67 cases were analyzed in this study, and they were classified according to the type of nursing error, and the contents were systematically analyzed. Results: A total of 52 cases (77.5%) of nursing errors were caused by independent nursing practices. They were classified as 38 cases (A1) in the violation of patient supervision obligations, 12 cases in the violation of progress observation obligations (A2), one case in the violation of medical equipment inspection obligations (A3), and one case in the violation of explanation and verification obligations. Among the non-independent nursing practices (code B), B1 was 10 cases related to administrative acts, one blood transfusion accident (B2), and one anesthesia accident (B3). Conclusion: To prevent nurses from being involved in legal confits, the advocation of systematic training such as nurses' legal obligations and judgment grounds through case-based learning from the recent precedent analysis and promote nurses' legal perspective, and preventive activities are essential.