• Structural Engineering and Mechanics
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• v.63 no.4
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• pp.471-480
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• 2017

This paper investigates free vibration characteristics of a rotating functionally graded (FG) beam in hygro environments. In the present study, material properties of the FG beam vary continuously through thickness direction according to the power-law which approximates material properties of FG beam. The governing differential equations of motion are derived based on Euler-Bernoulli beam theory and using the Hamilton's principle which solved utilizing a semi-analytical technique called the Differential Transform Method (DTM). In order to verify the competency and accuracy of the current analysis, a comparative study with previous researches are performed and good agreement is observed. Influences of Several important parameters such as power-law exponent, hygro environment, rotational speed and slenderness ratio on natural frequencies are investigated and discussed in detail. It is concluded that these effects play significant role on dynamic behavior of rotating FG beam in the hygro environments. Numerical results are tabulated in several tables and figures that can be serving as benchmarks for future analyses of rotating FG beams in the hygro environments.

• The Journal of Information Systems
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• v.18 no.1
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• pp.25-46
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• 2009

According to adaptive structuration theory, faithfulness of appropriation(FOA), and consensus on appropriation(COA) are variables for measuring appropriation in use of IT. FOA is the level of interpreting and using the intentions of the IT designers objectively and COA is the level of agreement on ways of using IT among or with user group independently of designers' intention. In traditional theories of IT adoption, computer self-efficacy(CSE), self evaluation on abilities of using computer, has been considered as one of the important individual differences. which would influence on beliefs of using IT. Therefore, considering the relationship among CSE, FOA, COA and attitude, we can hypothesize that CSE would play a moderation varaible among appropriation related variables relationships, FOA-attitude and COA-attitude. The objective of this study is an analysis of CSE's moderation effects in causality relationship among appropriation measuring variables. For this purpose, we propose a research model where there are four hypotheses for moderation effects of CSE on the relationships between appropriation variables. We test these hypotheses by sampling ERP and groupware users. In result, our proposed hypotheses except moderation effect of COA-usefulness are accepted. Main contribution of this study is to identify the relationship between CSE and AST. This study implies that very careful consideration of users' CSE is necessary in order to perform managerial activities based on FOA and COA in IT management department.

• Journal of Information Science Theory and Practice
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• v.8 no.2
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• pp.18-31
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• 2020

Cognitive biases can influence human information behaviour and decisions made in information behaviour and use. This study aims to identify the biases involved in some aspects of information behaviour and the role they play in information behaviour and use. Twenty-five semi-structured face-to-face interviews were conducted in an exploratory qualitative study with graduate (MA and PhD) students who were at the stage of their dissertation/thesis research. Eisenberg & Berkowitz Big6^TM Skills for Information Literacy was adopted as a framework for interviews and the analysis was done using grounded theory coding method. The findings revealed the presence of twenty-eight biases in different stages of information behaviour, including availability bias (affects the preference for information seeking strategies), attentional bias (leads to biased attention to some information), anchoring effect (persuades users to anchor in special parts of information), confirmation bias (increases the tendency to use information that supports one's beliefs), and choice-supportive bias (results in confidence in information seeking processes). All stages of information seeking were influenced by some biases. Biases might result in a lack of clarity in defining the information needs, failure in looking for the right information, misinterpretation of information, and might also influence the way information is presented.

• Structural Engineering and Mechanics
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• v.66 no.2
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• pp.249-262
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• 2018

In this paper, reaction of functionally graded (FG) thick nanoplates resting on a viscoelastic foundation to a moving nanoparticle/load is investigated. Nanoplate is assumed to be thick by using second order shear deformation theory and small-scale effects are taken into account in the framework of Eringen's nonlocal theory. Material properties are varied through the thickness using FG models by having power-law, sigmoid and exponential functions for material changes. FG nanoplate is assumed to be on a viscoelastic medium which is modeled using Kelvin-Voight viscoelastic model. Galerkin, state space and fourth-order Runge-Kutta methods are employed to solve the governing equations. A comprehensive parametric study is presetned to show the influence of different parameters on mechanical behavior of the system. It is shown that material variation in conjunction with nonlocal term have a significant effect on the dynamic deformation of nanoplate which could be used in comprehending and designing more efficient nanostructures. Moreover, it is shown that having a viscoelastic medium could play an important role in decreasing these dynamic deformations. With respect to the fresh studies on moving atoms, molecules, cells, nanocars, nanotrims and point loads on different nanosctructures using scanning tunneling microscopes (STM) and atomic force microscopes (AFM), this study could be a step forward in understanding, predicting and controlling such kind of behaviors by showing the influence of the moving path, velocity etc. on dynamic reaction of the plate.

• Journal of Biosystems Engineering
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• v.34 no.2
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• pp.89-94
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• 2009

Aerial application using an agricultural unmanned helicopter was suggested for an alternative against current pesticide application methods. Centrifugal clutches play important roles in the performance and safety of the helicopter operation. A previous study analyzed and verified the power transfer theory of the guide type centrifugal clutch. Based on the clutch theory, optimal designs of the clutch became possible and feasible using a simulation method. Design criteria of the clutch were the power transfer capacity of 24.66 kW(33.5 PS) at the rated engine speed and the engaging range speed of 3,000${\sim}$3,500 rpm. Various designs were accomplished using the simulation. An optimal clutch was simulated by determining the values of spring constant and mass of friction sector, which were 94,700 N/m and 123.7 g, respectively. The design performed the power capacity of 24.86 kW(33.8 PS) and engagement speed of 3,069 rpm, meeting the design criteria. Using the designed clutch, an efficient transfer of the power would be possible for the unmanned agricultural helicopter.

• Structural Engineering and Mechanics
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• v.70 no.1
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• pp.55-66
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• 2019

This work deals with the size-dependent wave propagation analysis of functionally graded (FG) anisotropic nanoplates based on a nonlocal strain gradient refined plate model. The present model incorporates two scale coefficients to examine wave dispersion relations more accurately. Material properties of FG anisotropic nanoplates are exponentially varying in the z-direction. In order to solve the governing equations for bulk waves, an analytical method is performed and wave frequencies and phase velocities are obtained as a function of wave number. The influences of several important parameters such as material graduation exponent, geometry, Winkler-Pasternak foundation parameters and wave number on the wave propagation of FG anisotropic nanoplates resting on the elastic foundation are investigated and discussed in detail. It is concluded that these parameters play significant roles on the wave propagation behavior of the nanoplates. From the best knowledge of authors, it is the first time that FG nanoplate made of anisotropic materials is investigated, so, presented numerical results can serve as benchmarks for future analysis of such structures.

• BMB Reports
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• v.52 no.1
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• pp.13-23
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• 2019

Aging is accompanied by a time-dependent progressive deterioration of multiple factors of the cellular system. The past several decades have witnessed major leaps in our understanding of the biological mechanisms of aging using dietary, genetic, pharmacological, and physical interventions. Metabolic processes, including nutrient sensing pathways and mitochondrial function, have emerged as prominent regulators of aging. Mitochondria have been considered to play a key role largely due to their production of reactive oxygen species (ROS), resulting in DNA damage that accumulates over time and ultimately causes cellular failure. This theory, known as the mitochondrial free radical theory of aging (MFRTA), was favored by the aging field, but increasing inconsistent evidence has led to criticism and rejection of this idea. However, MFRTA should not be hastily rejected in its entirety because we now understand that ROS is not simply an undesired toxic metabolic byproduct, but also an important signaling molecule that is vital to cellular fitness. Notably, mitochondrial function, a term traditionally referred to bioenergetics and apoptosis, has since expanded considerably. It encompasses numerous other key biological processes, including the following: (i) complex metabolic processes, (ii) intracellular and endocrine signaling/communication, and (iii) immunity/inflammation. Here, we will discuss shortcomings of previous concepts regarding mitochondria in aging and their emerging roles based on recent advances. We will also discuss how the mitochondrial genome integrates with major theories on the evolution of aging.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.9
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• pp.121-130
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• 2021

In the mobile industry, customer complaints play a significant role in retaining customer loyalty to the services provided. Thanks to user complaints, mobile service providers can effectively identify problems and then propose solutions to adapt or improve their services. Hence, it's critical to understand the relationship between consumer complaints and satisfaction with mobile services. While several studies have shown that customer satisfaction is an intermediary variable that explains customer complaint intention, there have been few studies on the relationship between pre-determinants of their satisfaction, leaving a gap in our understanding of customer complaint intention. To demonstrate an in-depth approach to this matter, authors revisit justice theory and suggest trust and perceived responsibility variables be combined into a research model. A cross-section survey was conducted to collect data from 265 mobile services users of the three biggest mobile service providers in Kien Giang Province, Vietnam. This study employed Structural Equation Modeling (SEM) method to analyze the samples collected. The result showed that customer complaint intention is affected by distributive justice, interactional justice, trust but not procedural justice. Additionally, the moderating role of the perceived responsibility variable to the relationship between customer satisfaction and complaint intention is also proved.

• Analyses & Alternatives
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• v.2 no.1
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• pp.71-106
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• 2018

The 19th CPC National Congress has a key historical significance in the development of China's constitution. It will also play a decisive role in the history of the seventy years'constitutional change in New China. XiJinping's new socialist thought with Chinese characteristics established in the report of 19th CPC National Congress will be written in the preface of the March 2018 National People's Congress's constitutional amendment. The fifth revision of 1982 Constitution will touch on many issues such as the leadership of the CPC into the constitution, the abolition of the tenure of the president, the constitutional oath system, and the reform of the national supervisory system. In addition, the constitutionality review system, the establishment of the National Security Council, the constitutional status of socialist public property and private property and the adjustment of major economic system has become a hot topic in the theory field. In the history node towards a socialist country ruled by law, the theory and practice of the China indeed have the academic ideas, value position and path model differences, which will delay the Chinese constitutional development, but also is the necessary pain in the process of moving towards the rule of law in China. Indeed, how to the development and where to go in the future of Chinese constitutionalism itself has sample value, which deserves rational attention and in-depth inquiry from Chinese and Western academics.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.559-564
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• 2006

The purpose of this study is to minimize negative effect of VMS travel time information service by sensitivity analysis, which forecasts the change in link traffic volume. As a result, strategies for providing travel information that can change driving patterns for minimizing travel time were found. The framework for analysis is recently expanded with the application of game theory. According to the experiment, the algorithm generated for travel time information service reduces total travel time and yields travel patterns that is very close to the system optimization. Also, this study found that the route the travel time service information is provided about could play the important role.