• Smart Structures and Systems
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• v.15 no.3
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• pp.627-643
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• 2015

Negative stiffness, previously emulated by active or semi-active control for cable vibration mitigation, is realized passively using a self-contained highly compressed spring, the negative stiffness device (NSD).The NSD installed in parallel with a viscous damper (VD) in the vicinity of cable anchorage, enables increment of damper deformation during cable vibrations and hence increases the attainable cable damping. Considering the small cable displacement at the damper location, even with the weakening device, the force provided by the NSD-VD assembly is approximately linear. Complex frequency analysis has thus been conducted to evaluate the damping effect of the assembly on the cable; the displacement-dependent negative stiffness is further accounted by numerical analysis, validating the accuracy of the linear approximation for practical ranges of cable and NSD configurations. The NSD is confirmed to be a practical and cost-effective solution to improve the modal damping of a cable provided by an external damper, especially for super-long cables where the damper location is particularly limited. Moreover, mathematically, a linear negative stiffness and viscous damping assembly has proven capability to represent active or semi-active control for simplified cable vibration analysis as reported in the literature, while in these studies only the assembly located near cable anchorage has been addressed. It is of considerable interest to understand the general characteristics of a cable with the assembly relieving the location restriction, since it is quite practical to have an active controller installed at arbitrary location along the cable span such as by hanging an active tuned mass damper. In this paper the cable frequency variations and damping evolutions with respect to the arbitrary assembly location are then evaluated and compared to those of a taut cable with a viscous damper at arbitrary location, and novel frequency shifts are observed. The characterized complex frequencies presented in this paper can be used for preliminary damping effect evaluation of an adaptive passive or semi-active or active device for cable vibration control.

• Journal of Practical Engineering Education
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• v.8 no.1
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• pp.23-29
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• 2016

Our society is endemic in safety insensitivity, yet we have been concerned for safety education and disaster drill since the Sewol Ferry accident. However, the practical training costs very high, and it has its limit to increase reality. Recently, industry fields put emphasis on virtual reality (VR) as alternatives, so various contents are invented by using advantages of VR. The paper explores crucial application in 3-dimensional simulation for fire drill, suggests novel design, and contemplates about educative result through designing process. In order to construct and materialize the suggested system, practical 3D spatial information model and various disaster-drill scenarios are necessary. Also, to apply game elements for augmentation in users' utility, educations based on computer science and visual art are inevitable, which requires skills in programing and modeling respectively. Thus, this study investigates educational effect of convergence field through the suggested system designing process.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1643-1653
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• 2021

This study is to investigate the effect of beauty lifestyle on the quality of life of middle-aged women. For this study, 417 middle-aged women aged 35-65 years living in Seoul, Gyeonggi, Gwangju, Sejong, and Daejeon were conducted from February 27, 2021 to March 14, 2021. As a result of this study, the correlation of quality of life of middle-aged women according to beauty lifestyle was positively correlated in the order of show-off type, appearance-seeking type, practicality-seeking type, and fashion-seeking type. In addition, it was found that the practical pursuit of beauty lifestyle and the pursuit of show-off affect the quality of life of middle-aged women. Therefore, it is necessary to develop customized communication information and marketing strategies for beauty products based on the ambivalent perspective that pursues economic efficiency and luxury for the practical and flaunting types that can have a positive impact on the quality of life of middle-aged women.

• ETRI Journal
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• v.23 no.4
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• pp.158-167
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• 2001

We examine the diffusion layers of some block ciphers referred to as substitution-permutation networks. We investigate the practical and provable security of these diffusion layers against differential and linear cryptanalysis. First, in terms of practical security, we show that the minimum number of differentially active S-boxes and that of linearly active S-boxes are generally not identical and propose some special conditions in which those are identical. We also study the optimal diffusion effect for some diffusion layers according to their constraints. Second, we obtain the results that the consecutive two rounds of SPN structure provide provable security against differential and linear cryptanalysis, i.e., we prove that the probability of each differential (resp. linear hull) of the consecutive two rounds of SPN structure with a maximal diffusion layer is bounded by $p^n(resp.q^n)$ and that of each differential (resp. linear hull) of the SDS function with a semi-maximal diffusion layer is bounded by $p^{n-1}(resp. q^{n-1})$, where p and q are maximum differential and linear probabilities of the substitution layer, respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 1992.07a
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• pp.55-66
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• 1992

The energy and momentum coefficients ${\alpha}$ and ${\beta}$ are measures of homogenerity of velocity distribution in a chanel section. They indicate the effect of energy and momentum transport. However, in most practical applications, they are assumed to be unity due to the difficulty in estimating them. Efforts have been made in this study to estimate these coefficients and to develop equations for practical applications. The Prandtl-von Karman logarithmic equation as being used today has limitations and far-reaching assumptions. Therefore, this paper uses Chiu's velocity distribution equation which seems to be capable of serving as such an alternative, to estimate the velocity distribution and the energy and momentum coefficients, ${\alpha}$ and ${\beta}$ results are compared with those computed by other existing equations. For practical applications, this paper also uses Chiu's equation along with the Mannig's equation to calculate ${\alpha}$, ${\beta}$ without velocity data

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.854-861
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• 2005

Studied accuracy and practical use possibility of joint measurement that using 3D laser scanner to rock slope. Measured joint of Rock slope and comparison applied 3 dimension laser scanner and clinometer. 3D laser scanning system preserves on computer calculating to 3 dimension coordinate scaning laser to object. and according to laser measurement method of interior, produce correct vector value from charge-coupled device(CCD) or laser reciver and telegram register and time measuring equipment. Create of object x, y, z point coordinates to 3 dimension space of computer. Such 3 dimension point datum (Point Clouds) forms relocate position informations that exist to practical space to computer space. Practical numerical values related between each other. Compared joint distribution and direction that measured by laser scanner and clinometer. By the result, Distribution of joint projected almost equally. Could get more joint datas by measurement of 3 dimension scanner than measured by clinometer. Therefore, There is effect that objectification of rock slope investigation data, shortening of investigation periods, investigation reduction of cost. could know that it is very effective method in joint measuring.

• Korean Journal of Childcare and Education
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• v.16 no.2
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• pp.119-139
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• 2020

Objective: This study aims to identify career decisions based on the variables associated with child care practice and to identify how each factor in the child care teacher's career decisions affects the prospective child care teacher's career decisions affects the prospective child care teacher's career decisions, and to what extent they are able to explain their career decisions to the prospective child care teacher. Methods: Data were analyzed through partial correlation and hierarchical regression. Results: Both the institutional and school variables involved in child care practices were found to have significant static implications for career decisions. The relative explanatory power of these variables has been shown to be significant in practical satisfaction. Conclusion/Implications: The results of the study that the practical satisfaction level, which is the institutional variable related to child care practice, significantly affects the career decisions of prospective child care teachers, recognize the importance of the child care practice in practical institutions where prospective child care teachers practice and suggest appropriate child care practice based on their understanding of the trainee.

• Geomechanics and Engineering
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• v.17 no.2
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• pp.133-143
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• 2019

An optimal hydraulic section is critical for irrigated water conservancy in seasonal frozen ground due to a large proportion of water leakage, as investigated by in-situ surveys. This is highly correlated with the frost heave of underlain soils in cold season. This paper firstly derived a practical model for frost heave of clayey soils, with temperature dependent thermal indexes incorporating phase change effect. A model test carried out on clay was used to verify the rationality of the model. A novel approach for optimizing the cross-section of irrigation canals in cold regions was suggested with live updated geometry characterized by three unique geometric constraints including slope of canal, ratio of practical flow section to the optimal and lining thickness. Allowable frost heave deformation and tensile stress in canal lining are utilized as standard in computation iterating with geometry updating while the construction cost per unit length is regarded as the eventual target in optimization. A typical section along the Jinghui irrigation canal was selected to be optimized with the above requirements satisfied. Results prove that the optimized hydraulic section exhibits smaller frost heave deformation, lower tensile stress and lower construction cost.

• Journal of Korea Multimedia Society
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• v.24 no.7
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• pp.953-965
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• 2021

The research of combining virtual reality technology with the design elements of children's picture book education is a relatively new topic in virtual reality technology in recent years. Based on the combination of picture book design elements with virtual reality technology and the development of a children's picture book teaching game, this article analyzes the effectiveness of the application of virtual reality technology in children's teaching, and explores the usability of picture book design elements in teaching [1]. Through literature research methods, practical research methods and investigation research methods, this paper lucubrates the application of virtual reality technology in the design elements of children's picture book education so as to provide adequate theoretical and practical support for the research theme. The spatial positioning, vision, sound, and functional requirements of children's picture book games play a leading role in teaching. Practical statistics have proved that it is easier to promote children's mastery of teaching knowledge in a virtual environment. Moreover, use VR's game management function and setting function to solve the boringness of traditional education methods and the limitations of the teaching environment. The feasibility of game operation provides a virtual teaching platform system for children's education, and the teaching effect is remarkable.

• Journal of Distribution Science
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• v.22 no.8
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• pp.77-86
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• 2024

Purpose: This study investigates the psychological mechanisms of comparison within the design context of retail stores, products, and advertising. The research aims to expand the understanding of comparison psychology, encompassing social, cognitive, perceptual, and self-comparisons and their application in design practices. Research Design, Data, and Methodology: The study employs a comprehensive review of psychological theories related to comparison psychology. They were selected through extensive research on literature pertaining to design psychology and consumer behavior. The research integrates insights from psychology, marketing, consumer behavior, and design theory, supported by various design examples of retail stores, products, and advertising, to demonstrate the practical applications. Results: The findings reveal that comparison psychology significantly impacts consumer preferences and user experiences. For instance, the assimilation effect and prospect theory highlight how comparisons shape value judgments and design perceptions. Practical examples are used to illustrate the profound influence of comparative judgments in design. Conclusion: The study advocates for a "psychologically-informed approach" to design, promoting designs that are not only aesthetically pleasing and functionally sound but also psychologically aligned. By bridging the gap between psychological theories and practical design implementations, the research provides valuable insights for designers, marketers, and psychologists, enhancing the psychological efficacy of design.