• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2D
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• pp.113-118
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• 2010

This paper presents an analysis of the instability phenomenon on motorways, with the aim of arriving at the definition of a control strategy suitable for keeping the flow stable. By using some results of the motorway reliability theory, a relationship and some flow characteristics is obtained, which shows that the existence of a reliability threshold critical for flow stability. The macroscopic flow characteristics corresponding to this threshold are very different in different situations, so that this control of flow stability requires the analysis of speed and density microscopic process surveyed on a cross section of the motorway carriage ways to be controlled. A method is presented, based on integrated moving average(IMA) analysis in real time of these processes, by which it is possible to detect the approach of instability before its effects become manifest, and to single out the proper control strategy in different situations.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.1-10
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• 2023

The purpose of this study is to explore ways to nurture creative and fusion-type talents centered on ANT. In order to nurture creative and convergence-type talents centered on ANT, first, it is necessary to utilize Kao's Law in the network formation stage. Second, it is necessary to utilize the strong power of weak ties in the network formation stage. Third, in order to cause a stir in the stage of raising questions among the four stages of translation, the ability to ask questions must be developed. Fourth, education in various creative problem-solving techniques is needed to throw a stir. Fifth, in order to successfully intervene in the second stage of the four stages of translation, the stage of attracting attention, communication and critical thinking skills must be trained. Suggestions for follow-up research are: First, it is necessary to compare and analyze the four stages of translation and the stage of the creative problem-solving model presented by ANT. Second, it is expected that there will be follow-up studies that apply specific cases centering on ANT.

• 한국노년학
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• v.29 no.1
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• pp.1-20
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• 2009

The purpose of the current research is to reconstruct the process in which changes in elderly support take place from the perspective of the elderly in rural areas. Six elderly couples were interviewed three times with the use of Schütze's 'autobiographical-narrative interview'. The entire interviews consisted of 17 sessions. Interviewed data was analyzed, following the method of Schütze's 'autobiographical-narrative interview analysis'. Research findings were as follows: Elderly support as experienced by the current elderly couples is mainly 'family support', which turned out to be 'dual structural shift' in the process of modernization. That is, there has been an 'internal structural shift' from 'family support on intergenerational, mutual support dimension' to 'family support on intragenerational self-support dimension' on the one hand. An 'external structural shift' has been noticed that realizes the 'socialization of family support' on the other hand. Additionally, a 'discrepancy' was captured between support norm and support behavior as occurred in the process of 'dual structural shift'. Perception on the 'dual structural shift' has proven 'ambivalent'. On the basis of these results, a critical discussion of modernization theory ensued, along with some implications for practice.

• Steel and Composite Structures
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• v.44 no.4
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• pp.451-471
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• 2022

In the present paper, the static bending and buckling responses of functionally graded carbon nanotubes-reinforced composite (FG-CNTRC) beam under various boundary conditions are investigated within the framework of higher shear deformation theory. The significant feature of the proposed theory is that it provides an accurate parabolic distribution of transverse shear stress through the thickness satisfying the traction-free boundary conditions needless of any shear correction factor. Uniform (UD) and four graded distributions of CNTs which are FG-O, FG-X, FG- and FG-V are selected here for the analysis. The effective material properties of FG-CNTRC beams are estimated according to the rule of mixture. To model the FG-CNTRC beam realistically, an efficient Hermite-Lagrangian finite element formulation is successfully developed. The accuracy and efficiency of the present model are demonstrated by comparison with published benchmark results. Moreover, comprehensive numerical results are presented and discussed in detail to investigate the effects of CNTs volume fraction, distribution patterns of CNTs, boundary conditions, and length-to-thickness ratio on the bending and buckling responses of FG-CNTRC beam. Several new referential results are also reported for the first time which will serve as a benchmark for future studies in a similar direction. It is concluded that the FG-X-CNTRC beam is the strongest beam that carries the lowest central deflection and is followed by the UD, V, Λ, and FG-O-CNTRC beam. Besides, the critical buckling load belonging to the FG-X-CNTRC beam is the highest, followed by UD and FG-O.

• Tribology and Lubricants
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• v.40 no.1
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• pp.8-16
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• 2024

This study conducts numerical modeling and eigen-analysis of a rod-fastened rotor, which is mainly used in aircraft gas turbine engines in which multiple disks are in contact through curvic coupling. Nayak's theory is adopted to calculate surface parameters measured from the tooth profile of the curvic coupling gear. Surface parameters are important design parameters for predicting the stiffness between contact surfaces. Based on the calculated surface parameters, elastoplastic contact analysis is performed according to the interference between two surfaces based on the Greenwood-Williamson model. The equivalent bending stiffness is predicted based on the shape and elastoplastic contact stiffness of the curvic coupling. An equation of motion of the rod-fastened rotor, including the bending stiffness of the curvic coupling, is developed. Methods for applying the bending stiffness of a curvic coupling to the equation of motion and for modeling the equation of motion of a rotor that includes both inner and outer rotors are introduced. Rotordynamic analysis is performed through one-dimensional finite element analysis, and each element is modeled based on Timoshenko beam theory. Changes in bending stiffness and the resultant critical speed change in accordance with the rod fastening force are predicted, and the corresponding mode shapes are analyzed.

• Advances in nano research
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• v.16 no.5
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• pp.473-487
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• 2024

The current study employs the nonlocal Timoshenko beam (NTB) theory and von-Kármán's geometric nonlinearity to develop a non-classic beam model for evaluating the nonlinear free vibration of bi-directional functionally-graded (BFG) nanobeams. In order to avoid the stretching-bending coupling in the equations of motion, the problem is formulated based on the physical middle surface. The governing equations of motion and the relevant boundary conditions have been determined using Hamilton's principle, followed by discretization using the differential quadrature method (DQM). To determine the frequencies of nonlinear vibrations in the BFG nanobeams, a direct iterative algorithm is used for solving the discretized underlying equations. The model verification is conducted by making a comparison between the obtained results and benchmark results reported in prior studies. In the present work, the effects of amplitude ratio, nanobeam length, material distribution, nonlocality, and boundary conditions are examined on the nonlinear frequency of BFG nanobeams through a parametric study. As a main result, it is observed that the nonlinear vibration frequencies are greater than the linear vibration frequencies for the same amplitude of the nonlinear oscillator. The study finds that the difference between the dimensionless linear frequency and the nonlinear frequency is smaller for CC nanobeams compared to SS nanobeams, particularly within the α range of 0 to 1.5, where the impact of geometric nonlinearity on CC nanobeams can be disregarded. Furthermore, the nonlinear frequency ratio exhibits an increasing trend as the parameter µ is incremented, with a diminishing dependency on nanobeam length (L). Additionally, it is established that as the nanobeam length increases, a critical point is reached at which a sharp rise in the nonlinear frequency ratio occurs, particularly within the nanobeam length range of 10 nm to 30 nm. These findings collectively contribute to a comprehensive understanding of the nonlinear vibration behavior of BFG nanobeams in relation to various parameters.

• Asia pacific journal of information systems
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• v.29 no.2
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• pp.308-327
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• 2019

The concept of sharing economy has received rich attention in recent years. As a typical type of business model in the sharing economy, online short rent has been paid attention by both industry and academia. In this study, we find trust to be a critical determinant to the success of online short rent platforms. Based on three dimensions of trust theory, i.e., ability, benevolence and integrity, we investigate the factors influencing tenant' willingness to participate in online short rent. We further examine the extent to which trust can influence the number of sales and comments of rooms listed at online short-term rent platforms, which can represent tenant' willingness to participate in the sharing economy. The results show that the trust dimensions represented by a landlord's personal characteristics have significant positive correlations with the number of sales and comments. For example, the real name authentication and the sesame score can represent the trust integrity; online replay ratio and the average confirmation time representing the trust sincerity, and the order acceptance ratio representing the trust ability. On this basis, we proposed some recommendations for both platforms and landlords. For example, the landlords can improve the tenants' trust by authenticating his/her real name, replying actively and timely. For platforms, when they make housing list ranking rules, they can take the landlord's personal attributes that may affect trust into consideration. Moreover, platforms can also allow landlords to supply value-added services to improve service quality and ultimately promote the virtuous circle of the platform ecosphere. Through conducting the empirical research on a particular application of the sharing economy, we aim to fill the research gap of this field in China and provide theoretical and practical contributions to the future development of online short rent.

• (The)Study of the Eastern Classic
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• no.55
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• pp.223-264
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• 2014

Yeoncheon Hong Seok-joo(淵泉 洪奭周: 1774-1842) faithfully followed a policy of restoration of literary style of king Jeongjo. He was an young vassal after 1794 and influenced by Jeongjo because Yeoncheon was around the king. Furthermore, he had comparatively favorable working period as a vassal(仕宦期, 1795-1836) after death of Jeongjo(1800) while establishing his own academic viewpoint. Therefore, a study about art theory of Yeoncheon Hong Seok-joo is one about logical system to accept various desires for change of then while not getting rid of scope of Neo-Confucianism after Jeongjo. It is catched that exchange of Hong Seok-joo and Jeong Yak-yong was made relating to study of Sangseo. Hong Seok-joo and Jeong Yak-yong absorbed in study of Sangseo, which is come from putting importance on 6 scriptures (經) among studies of scriptures by both of them. Through this, they aimed to re-discover ideology of original Confucian studies as one for cultivating oneself and governing people (修己治人之學). Dasan and Yeoncheon have something in common that they were young vassals who were cultivated as a guarding power for Jeongjo centered on Gyujanggak. They were largely fit to view of literature(文體觀) of Jeongjo. Hong Seok-joo distinguished function of prose(文) and poetry(詩) into teaching moral(明敎) and moving people(感人) in the category of Mun-yi-jae-do(文以載道) based on thoughts of 'literature is linguistic device for Taoism '(道本文末)' which is a core concept of literature theory based on Neo-Confucianism. He gave a careful attention on instructional and social function in prose while on emotional understanding that puts importance on temper and the secrets of nature in poetry. Hong Seok-joo regarded moral impression and edification through this as a core of artistic creation based on Segyoseol(世敎說). Furthermore, expressions such as 'Heunggwangunwon(興觀群怨)' or 'Yeohangguyo(閭巷謳謠) which are mentioned as important elements in his artistic works put importance on actual existence of objective things in artistic activity and this is connected to an attitude to require description fit to fact. So, it is assumed that such expression style aimed for features of genre painting in painting arts. Understanding of the study of ancient documents by Yeoncheon developed from critical perspective. He criticized the study of ancient documents, saying it as first, Pasoijisul(破碎之術), second, Dotaekjisul(塗澤之術), third, Hoimojisul(毁侮之術). Jeong Yak-yong criticized ' theory on the Odes' from viewpoint of theory of Mun-yi-jae-do(文以載道) based on Neo-Confucianism. He stressed political and social function of Sipeon and general poetry in "the Odes" and reinterprets discourses about poetry of Zhu Xi based on his own opinion. He says that poems of national fashion do political and social criticism. The theory of national fashion by Jeong Yak-yong clearly discloses his thoughts that stress practical role of noblemen in the social and political context.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.447-456
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• 2020

Korean society is facing the 2017 regime and the era of the fourth industrial revolution. University education is trying to select agendas that focuses on public interest and innovation, which are key words, for change. Unlike recent efforts, practical changes are insufficient. There is a relative lack of discussion on the essence and theory of university education in South Korea. This study looked at the current location of Korean university education and discussed the essential direction from a point of view on critical pedagogy. So far, Korean university education has operated under the control of neo-liberalism for more than 20 years since the May 31 educational reform in 1995. Democracy and deindustrialization, the direction pursued by the 2017 regime and the Fourth Industrial Revolution, differs from neo-liberalism. Therefore, it is necessary to reflect on neo-liberalism and seek a subsequent turn of direction. Henry Giroux has been critical of the neo-liberalistic policy of American education, which has been a major discourse since 1980, and has discussed proposals for various changes. In particular, it provides clear coordinates for the features of human resources as educated people. For example, they are intellectuals, border intellectuals, and public intellectuals. These intellectuals have independent, autonomous, active, self-reliant characteristics and have a duty and accountability to pursue for public interests. It is also closely related to the 2017 regime and the Fourth Industrial Revolution. Along with this discussion, university education seems to need serious and rigorous discussion and consideration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8176-8186
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• 2015

This research was conducted for the purpose of developing a high-fidelity simulation education program, applying it to clinical field and analyzing this program's effect on nursing college students in order to solve problems being caused from the gap between the adult nursing theoretical class and practical education. As the analysis method, this study developed a scenario including an algorithm for caring hyperkalemia patients, the evaluation check list, and debriefing according to the adult nursing theoretical class's learning goal and measured the high-fidelity simulation program's effect in using the non-equivalent control group pre-test and post-test design. As the results from the analysis, there secured the simulation education program's general properties and dependent variable's homogeneity in the experimental group and the control group. The nursing simulation practice program for hyperkalemia patients showed slight effect on the experimental group compared to the control group in fields such as nursing practice ability, problem solving ability, critical thinking skills, self-confidence of nursing, and knowledge. (t=-83.313, p<.001, t=-3.169, p=.003, t=-2.473, p=.017, t=-4.036, p<.001, t=-5.044, p<.001). High-Fidelity simulation programs in conjunction with an adult nursing theory classes of nursing students nursing practice ability, problem solving ability, critical thinking skills, self-confidence of nursing, and knowledge. This simulation program may be an effective educational method for nursing practice and also support improved quality of nursing education.