• Title/Summary/Keyword: physical theory

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Assessment of Questionnaire of Physical Activity at Workplace Based on the Social Cognitive Theory (PAWPQ-SCT): A Psychometric Study in Iranian Gas Refinery Workers

  • Kamel Ghobadi;AhmadAli Eslami;Asiyeh Pirzadeh;Seyed Mohammad Mazloomi;Fatemeh Hosseini
    • Safety and Health at Work
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    • v.14 no.4
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    • pp.358-367
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    • 2023
  • Background: This study aimed to develop and assess the psychometric features of the Physical Activity at Workplace Questionnaire (PAWPQ) based on the Social Cognitive Theory (SCT) to evaluate employees' physical activity (PA) behaviors at the workplace. Methods: This psychometric cross-sectional study was conducted on 455 employees working in one of the gas refineries in Iran. The participants were selected using the proportional stratified sampling method in 2019. The data collection tools were a demographic information questionnaire, the short form of the International Physical Activity Questionnaire (IPAQ), and a questionnaire developed based on the SCT, whose psychometric features were confirmed in terms of validity and reliability. Data were analyzed using SPSS22 and AMOS20 software. Results: The first version of PAWPQ-SCT had 74 items. After evaluating content and face validity, nine items were removed. The results of the content validity index (0.98), content validity ratio (0.86), and impact score (3.62) were acceptable for the whole instrument. In exploratory factor analysis, after removing seven items-58-item final version of the scale-six factors could explain 73.54% of the total variance. The results of structural equation modeling showed the acceptable fit of the model into the data (RMSEA = 0.052, CFI = 0.917, NFI = 0.878, TLI = 0.905, IFI = 0.917, CMIN/DF = 2.818). Cronbach's alpha coefficient and Intraclass Correlation were 0.90 and 0.86, respectively. Conclusion: This study confirmed that the psychometric features of the 58-item final version of PAWPQSCT constructs were acceptable in a sample of Iranian employees. This questionnaire can be used as a valid and reliable tool to evaluate Iranian employees' PA behaviors and develop effective educational interventions for workers and managers.

Apparel Quality Evaluation Process bused on Means- Bnd Chain Theory: A Theoretical Study (수단-목적 사슬 이론을 이용한 의복품질 평가과정에 잔한 이론적 연구)

  • 오현정;이은영
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.4
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    • pp.452-459
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    • 1998
  • The purpose of this study was to discover a conceptual framework and evaluation process of apparel quality by means-end chain theory. The theoretical study was conducted to find out a conceptual framework and build a hypothetical evaluation process model of apparel quality. Apparel quality was perceived associative network called a means-end chain and was evaluated in several stages. A conceptual framework of apparel quality evaluation was organized into hierarchical relationships among four different dimensions: physical attribute, physical function, instrumental performance, and expressive performance. The means-end structure linked tangible physical attributes and function to more abstract instrumental and expressive performance. A hypothetical evaluation process model linked dimensions of apparel quality to the selected means-end relationship. Different consumers had different means-end chains for the same apparel. Therefore different subjects are likely to have different evaluation paths. From this study we can suggest an evaluation process model of apparel quality.

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Thermal post-buckling analysis of a laminated composite beam

  • Akbas, Seref D.
    • Structural Engineering and Mechanics
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    • v.67 no.4
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    • pp.337-346
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    • 2018
  • The purpose of this study is to investigate thermal post-buckling analysis of a laminated composite beam subjected under uniform temperature rising with temperature dependent physical properties. The beam is pinned at both ends and immovable ends. Under temperature rising, thermal buckling and post-buckling phenomena occurs with immovable ends of the beam. In the nonlinear kinematic model of the post-buckling problem, total Lagrangian approach is used in conjunction with the Timoshenko beam theory. Also, material properties of the laminated composite beam are temperature dependent: that is the coefficients of the governing equations are not constant. In the solution of the nonlinear problem, incremental displacement-based finite element method is used with Newton-Raphson iteration method. The effects of the fibber orientation angles, the stacking sequence of laminates and temperature rising on the post-buckling deflections, configurations and critical buckling temperatures of the composite laminated beam are illustrated and discussed in the numerical results. Also, the differences between temperature dependent and independent physical properties are investigated for post-buckling responses of laminated composite beams.

Physical Modeling of a Sanjo Gayageum (산조 가야금의 물리적 모델링)

  • 정의필;조상진
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.7
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    • pp.521-531
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    • 2004
  • In this paper we developed the Physical modeling of the Sanio Gayageum using the improved digital waveguide theory. The frequency characteristics of the Gayageum body is implemented by an inverse filtering and the impulse response of the body. We obtained the synthesis sounds of the unit sound for the Gayageum using the simulation of the straight-line fits by the changes of the fundamental frequencies depending on the Amok location. Finally. we could obtain the virtual Sanio Gayageum sounds similar to the actual Gayageum by tuning the Amok positions.

Nonlinear thermal displacements of laminated composite beams

  • Akbas, Seref D.
    • Coupled systems mechanics
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    • v.7 no.6
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    • pp.691-705
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    • 2018
  • In this paper, nonlinear displacements of laminated composite beams are investigated under non-uniform temperature rising with temperature dependent physical properties. Total Lagrangian approach is used in conjunction with the Timoshenko beam theory for nonlinear kinematic model. Material properties of the laminated composite beam are temperature dependent. In the solution of the nonlinear problem, incremental displacement-based finite element method is used with Newton-Raphson iteration method. The distinctive feature of this study is nonlinear thermal analysis of Timoshenko Laminated beams full geometric non-linearity and by using finite element method. In this study, the differences between temperature dependent and independent physical properties are investigated for laminated composite beams for nonlinear case. Effects of fiber orientation angles, the stacking sequence of laminates and temperature on the nonlinear displacements are examined and discussed in detail.

Body action impacts the stability of nanomedicine tools in the drug delivery

  • Peng Zou;Wei Zhao;Jinpeng Dong;Yinyin Cao
    • Advances in nano research
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    • v.14 no.3
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    • pp.247-259
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    • 2023
  • Muscle strength and hypertrophy are equivalent when low-intensity resistance exercise is paired with blood flow restriction. This paper deals with the impact of physical exercise in the form of body activities on drug delivery using nanodevices. The body's actions impact the blood flow since the nano drug delivery devices are released into the bloodstream, and physical exercise and all the activities that change the blood flow influence the stability of these nanodevices. The nanodevice for the drug delivery purpose is modeled via nonuniform tube structures based on the high-order beam theory along with the nonlocal strain gradient theory. The nanodevice is made by a central nanomotor as well as two nanoblade in the form of truncated conical nanotubes carrying the nanomedicine. The mathematical simulation of rotating nanodevices is numerically solved, and the effect of various parameters on the stability of nanodevices has been studied in detail after the validation study.

The Synesthetic Presence and Physical Movement of Nong-ak as Seen Through Affect Theory (정동 이론으로 본 농악의 공감각적 현존과 신체 운동)

  • Kwon, Eun-Young
    • (The) Research of the performance art and culture
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    • no.40
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    • pp.5-35
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    • 2020
  • Affect is intensity and quality that are generated as the physical body senses the outside world. Of experienced affect, notions that are granted meaning and interpretation are emotions. Affect theory distinguishes emotion and affect and by focusing on affect, it provides methods with which to analyze physical body responses and changes and it presents new possibilities to performing arts research that uses the physical body as a medium. Nong-ak is art that concentrates mainly on the occurrence of affect rather than 'representation'. Nong-ak is a performance type in which sound, color, texture, and physical movement overlap and exist in a synesthetic way. Here, physical things such as instruments, props, costumes, and stage devices are gathered together with non-physical things such as rhythm, mood, and atmosphere around human bodies. The physical body is stimulated by these things, displays tendencies that suit performances, and becomes 'the body without an image' as it immerses itself into the performance, acting while displaying 'quasi-corporeality'. The body, which moves automatically as if without consciousness, appears more easily within groups. To transition individuals of everyday life to 'the body without an image', Nong-ak executes the group physical exercise of 'Jinpuri'. Such physical exercise builds up affect by increasing nonverbal communion and communication and brings out the creativity of individuals within mutual trust and a sense of belonging. Affect and emotion stirred up by Nong-ak act as confirmation and affirmation of the existence, vitality, and ability of one's self and groups. Such affirmation recalls Nong-ak as a meaningful and important value from group dimensions and perceives it as a performance form that should be preserved and passed on.

Review of the Hidden Rays of Diffraction

  • Kim, Se-Yun
    • Journal of electromagnetic engineering and science
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    • v.15 no.1
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    • pp.1-5
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    • 2015
  • A high-frequency analysis technique, called the hidden rays of diffraction (HRD), is reviewed in this paper. The physical optics and the rigorous diffraction coefficients of a perfectly conducting wedge illuminated by a plane wave are compared. The physical existence of hidden rays on the shadow boundary is explained in view of the geometric theory of diffraction (GTD). In particular, a systematic tracing of hidden rays and its visualization are precisely described by introducing the concept of the supplementary boundary. The physical meaning of the null-field condition in the complementary region is also explained.

Physical knowledge in children: Children's developing understanding of object motion (아동의 물리지식: 물체의 운동에 대한 아동의 이해와 발달)

  • Park Sunmi
    • Korean Journal of Cognitive Science
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    • v.15 no.4
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    • pp.31-47
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    • 2004
  • This study was carried out to examine the development of physical knowledge in children. Eighty children aged 3- to 11-year-old and 16 adults were participated in this study. Participants' knowledge about failing, sliding and sinking/floating objects was investigated to understand what kind of knowledge they had, whether their knowledge was organized as theory and what was the nature of the developmental change in physical knowledge. Results showed that, for falling object task children of all age had correct knowledge about object's falling phenomena. However, there were age differences in children's understanding of the cause of object's falling. As the children's age decreased, the frequency of explanation referring to the absence of supper rather than the gravity as the cause of falling phenomena increased. For the sliding object task, children of all age could predict the motion of sliding object correctly. But only a few 9- and 11-year-old children could understand the effect of object weight and relations between gravity, frictional force and their interactions. Children under age 7 showed no evidence of possessing these knowledge. For sinking or floating object task, children of all age and even adults showed difficulties in understanding the sinking or float phenomena per se. For the cause of these phenomena although a few 9- and 11-year-old children referred to buoyancy as the cause, they had no correct knowledge about the buoyancy. This was also true for the adults. As a conclusion, the results of this study suggested that, not 3, but as young as 5-year-old children's physical knowledge exited as a form of naive theory in terms of their use as a causal devise in explaining the cause of object motion. However, even the theory of 9- and 11-year-old children was lack of the abstractness and coherence, which were also important characteristics of a theory. Finally, developmental change in physical knowledge proceeded toward more frequent and consistent use of physical knowledge as causal device and more abstract and coherently organized theory.

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A REVIEW ON THE MATHEMATICAL ASPECTS OF FLUID FLOW PROBLEMS IN AN INFINITE CHANNEL WITH ARBITRARY BOTTOM TOPOGRAPHY

  • Chakrabarti, A.;Martha, S.C.
    • Journal of applied mathematics & informatics
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    • v.29 no.5_6
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    • pp.1583-1602
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    • 2011
  • A special system of partial differential equations (PDEs) occur in a natural way while studying a class of irrotational inviscid fluid flow problems involving infinite channels. Certain aspects of solutions of such PDEs are analyzed in the context of flow problems involving multiple layers of fluids of different constant densities in a channel associated with arbitrary bottom topography. The whole analysis is divided into two parts-part A and part B. In part A the linearized theory is employed along with the standard Fourier analysis to understand such flow problems and physical quantities of interest are derived analytically. In part B, the same set of problems handled in part A are examined in the light of a weakly non-linear theory involving perturbation in terms of a small parameter and it is shown that the original problems can be cast into KdV type of nonlinear PDEs involving the bottom topography occurring in one of the coefficients of these equations. Special cases of bottom topography are worked out in detail and expressions for quantities of physical importance are derived.