• Title/Summary/Keyword: Capture Effects

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Estimating dose-response curves using splines: a nonparametric Bayesian knot selection method

  • Lee, Jiwon;Kim, Yongku;Kim, Young Min
    • Communications for Statistical Applications and Methods
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    • 제29권3호
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    • pp.287-299
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    • 2022
  • In radiation epidemiology, the excess relative risk (ERR) model is used to determine the dose-response relationship. In general, the dose-response relationship for the ERR model is assumed to be linear, linear-quadratic, linear-threshold, quadratic, and so on. However, since none of these functions dominate other functions for expressing the dose-response relationship, a Bayesian semiparametric method using splines has recently been proposed. Thus, we improve the Bayesian semiparametric method for the selection of the tuning parameters for splines as the number and location of knots using a Bayesian knot selection method. Equally spaced knots cannot capture the characteristic of radiation exposed dose distribution which is highly skewed in general. Therefore, we propose a nonparametric Bayesian knot selection method based on a Dirichlet process mixture model. Inference of the spline coefficients after obtaining the number and location of knots is performed in the Bayesian framework. We apply this approach to the life span study cohort data from the radiation effects research foundation in Japan, and the results illustrate that the proposed method provides competitive curve estimates for the dose-response curve and relatively stable credible intervals for the curve.

Effect of moving load on dynamics of nanoscale Timoshenko CNTs embedded in elastic media based on doublet mechanics theory

  • Abdelrahman, Alaa A.;Shanab, Rabab A.;Esen, Ismail;Eltaher, Mohamed A.
    • Steel and Composite Structures
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    • 제44권2호
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    • pp.255-270
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    • 2022
  • This manuscript illustrates the dynamic response of nanoscale carbon nanotubes (CNTs) embedded in an elastic media under moving load using doublet mechanics theory, which not considered before. CNTs are modelled by Timoshenko beam theory (TBT) and a bottom to up modelling nano-mechanics is simulated by doublet mechanics theory to capture the size effect of CNTs. To explore the influence of the CNTs configurations on the dynamic behaviour, both armchair and zigzag configurations are considered. The governing equations of motion and the associated boundary conditions are obtained using the Hamiltonian principle. The Navier solution methodology is applied to obtain the solutions for both orientations. Free vibration and forced response under moving loads are considered. The accuracy of the developed procedure is verified by comparing the obtained results with available previous algorithms and good agreement is observed. Parametric studies are conducted to demonstrate effects of doublet length scale, CNTs configurations, moving load velocities as well as the elastic media parameters on the dynamic behaviours of CNTs. The developed procedure is supportive in the design and manufacturing of MEMS/NEMS made from CNTs.

Nonlinear finite element analysis of ultra-high performance fiber reinforced concrete beams subjected to impact loads

  • Demirtas, Gamze;Caglar, Naci;Sumer, Yusuf
    • Structural Engineering and Mechanics
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    • 제82권1호
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    • pp.81-92
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    • 2022
  • Ultra-high performance fiber reinforced concrete (UHPFRC) is a composite building material with high ductility, fatigue resistance, fracture toughness, durability, and energy absorption capacity. The aim of this study is to develop a nonlinear finite element model that can simulate the response of the UHPFRC beam exposed to impact loads. A nonlinear finite element model was developed in ABAQUS to simulate the real response of UHPFRC beams. The numerical results showed that the model was highly successful to capture the experimental results of selected beams from the literature. A parametric study was carried out to investigate the effects of reinforcement ratio and impact velocity on the response of the UHPFRC beam in terms of midpoint displacement, impact load value, and residual load-carrying capacity. In the parametric study, the nonlinear analysis was performed in two steps for 12 different finite element models. In the first step, dynamic analysis was performed to monitor the response of the UHPFRC beam under impact loads. In the second step, static analysis was conducted to determine the residual load-carrying capacity of the beams. The parametric study has shown that the reinforcement ratio and the impact velocity affect maximum and residual displacement value substantially.

Experimental study on vibration serviceability of cold-formed thin-walled steel floor

  • Bin Chen;Liang Cao;Faming Lu;Y. Frank Chen
    • Steel and Composite Structures
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    • 제46권4호
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    • pp.577-589
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    • 2023
  • In this study, on-site testing was carried out to investigate the vibration performance of a cold-formed thin-walled steel floor system. Ambient vibration, walking excitation (single and double persons), and impulsive excitation (heel-drop and jumping) were considered to capture the primary vibration parameters (natural frequencies, damping ratios, and mode shapes) and vertical acceleration response. Meanwhile, to discuss the influence of cement fiberboard on structural vibration, the primary vibration parameters were compared between the systems with and without the installation of cement fiberboard. Based on the experimental analysis, the cold-formed thin-walled steel floor possesses high frequency (> 10 Hz) and damping (> 2%); the installed cement fiberboard mainly increases the mass of floor system without effectively increasing the floor stiffness and may reduce the effects of primary vibration parameters on acceleration response; and the human-structure interaction should be considered when analyzing the vibration serviceability. The comparison of the experimental results with those in the AISC Design Guide indicates that the cold-formed thin-walled steel floor exhibits acceptable vibration serviceability. A crest factor 𝛽rp (ratio of peak to root-mean-square accelerations) is proposed to determine the root-mean-square acceleration for convenience.

Urban Greening: A Sustainable Method for Particulate Matter (PM) Reduction

  • Sanghee Park;Myeong Ja Kwak;Jongkyu Lee;Yea Ji Lim;Handong Kim;Su Gyeong Jeong;Joung-a Son;Hanna Chang;Sun Mi Je;Chang-Young Oh;Kyongha Kim;Su Young Woo
    • 한국산림과학회지
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    • 제112권1호
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    • pp.1-10
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    • 2023
  • Urbanization and industrialization associated with rapid economic development have resulted in air pollution in urban areas, which adversely affects human health and the environment around the world. Growing awareness of the health effects of airborne particulate matter (PM) has led to the emergence of urban greening as a promising eco-friendly, nature-based solution to reduce the concentration of PM (especially PM2.5) to which individuals are exposed, thereby promoting public health. In this review, we highlight fundamental insights about PM and recent research on the ability of urban greening to capture PM. Reports from the scientific literature on PM published from 1992 to 2021 were retrieved from Google Scholar. Here, we explore some of the main complex relationships between leaf traits and the ability to retain PM for research or management to optimize greenspaces.

Social Media Performance: From the Perspective of Social Media Apathetic Behavior

  • Inwon Kang;Sungjoon Yoo
    • Journal of Korea Trade
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    • 제26권3호
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    • pp.1-22
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    • 2022
  • Purpose - Social media platforms have presented individuals with an opportunity to create and maintain their social relationship through the use of social media services. However, such social relationship has a negative influence on users' interest in social media. Design/methodology - Using structural equation modeling, this study seeks to examines the effects of different social media conflicts (individual and social conflicts) on users' psychological internal state, especially user apathetic behavior Findings - The findings confirm that, among social media conflicts, social-related conflict, especially social interaction overload has a negative effect on cognitive resonance, while individual conflict has the highest effect on cognitive dissonance. Also, cognitive dissonance has a much greater effect than cognitive resonance on user resistance, this means that users' negative perception of social media has a greater influence on their resistance. Lastly, user's resistance was found to have a positive influence on user's apathetic behavior. Originality/value - In other to capture social media Apathetic behavior, this study focus on social media conflict perspective, which includes social-related conflict and individual conflict, which are found to influence users' internal states towards social media and further induce social media behavior. This study is unique because it is among the first to explore social media apathetic behavior by focusing on the influence of both external social media conflict and internal state. Also, this study proposed that social related conflict has a higher negative influence on WeChat user than individual related conflict.

Measurement of the applicability of various experimental materials in a medically relevant reactor neutron source part two: Study of H3BO3 and B-DTPA under neutron irradiation

  • Ezddin Hutli;Peter Zagyvai
    • Nuclear Engineering and Technology
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    • 제55권7호
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    • pp.2419-2431
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    • 2023
  • Experiments related to Boron Neutron Capture Therapy (BNCT) accomplished at the Institute of Nuclear Techniques (INT), Budapest University of Technology and Economics (TUB) are presented. Relevant investigations are required before designing BNCT for vivo applications. Samples of relevant boron compounds (H3BO3, BDTPA) usually employed in BNCT were investigated with neutron beam. Channel #5 in the research reactor (100 kW) of INT-TUB provides the neutron beam. Boron samples are mounted on a carrier for neutron irradiation. The particle attenuation of several carrier materials was investigated, and the one with the lowest attenuation was selected. The effects of boron compound type, mass, and compound phase state were also investigated. To detect the emitted charged particles, a traditional ZnS(Ag) detector was employed. The neutron beam's interaction with the detector-detecting layer is investigated. Graphite (as a moderator) was employed to change the neutron beam's characteristics. The fast neutron beam was also thermalized by placing a portable fast neutron source in a paraffin container and irradiating the H3BO3. The obtained results suggest that the direct measurement approach appears to be insufficiently sensitive for determining the radiation dose committed by the Alpha particles from the 10B (n,α) reaction. As a result, a new approach must be used.

Prefrontal Cortex Activation during Diaphragmatic Breathing in Women with Fibromyalgia: An fNIRS Case Report

  • Hyunjoong Kim;Jihye Jung;Seungwon Lee
    • Physical Therapy Rehabilitation Science
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    • 제12권3호
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    • pp.334-339
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    • 2023
  • Objective: The present study is designed to delve deeper into the realm of fibromyalgia (FM) symptom management by investigating the effects of diaphragmatic breathing on the prefrontal cortex (PFC) in women diagnosed with FM. Using functional near-infrared spectroscopy (fNIRS), the study aims to capture real-time PFC activation patterns during the practice of diaphragmatic breathing. The overarching objective is to identify and understand the underlying neural mechanisms that may contribute to the observed clinical benefits of this relaxation technique. Design: A case report Methods: To achieve this, a twofold approach was adopted: First, the patient's breathing patterns were meticulously examined to detect any aberrations. Following this, fNIRS was employed, focusing on the activation dynamics within the PFC. Results: Our examination unveiled a notable breathing pattern disorder inherent to the FM patient. More intriguingly, the fNIRS analysis offered compelling insights: the ventrolateral prefrontal cortex (VLPFC) displayed increased activation. In stark contrast, regions of the anterior prefrontal cortex (aPFC) and orbitofrontal cortex (OFC) manifested decreased activity, especially when benchmarked against typical activations seen in healthy adults. Conclusions: These findings, derived from a nuanced examination of FM, underscore the condition's multifaceted nature. They highlight the imperative to look beyond conventional symptomatology and appreciate the profound neurological and physiological intricacies that define FM.

Application of Risk Information Seeking and Processing Model to the Health Preventive Behavior: How Risk Susceptibility and Political Identity affect Vaccination

  • SoYoung Lee;Seoyeon Hong;Bokyung Kim
    • International Journal of Internet, Broadcasting and Communication
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    • 제15권4호
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    • pp.9-20
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    • 2023
  • In the aftermath of the COVID-19 pandemic, the importance of collective efforts in promoting health preventive behaviors is accentuated, bringing sociopolitical factors into focus. To fully capture psychological drivers of health preventive behaviors in risk situations, anchored on the Model of Risk Information Seeking and Processing (RISP; Griffin, Dunwoody, and Neuwirth 1999), in retrospect of the recent COVID-19 pandemic, we explored whether and how individuals' vaccination behaviors are predicted by RISP-related variables (information insufficiency, affective responses, perceived information gathering capacity, subjective norms) and one's political identity. Findings from a survey of 705 adult participants in the U.S. showed that the effects of one's risk information insufficiency on his or her information seeking and affective response regarding the pandemic, which is also related to their risk susceptibility perceptions. More importantly, the impact of political identity on one's perceived risk susceptibility, and its association with vaccination behaviors are also identified. The findings of this study provide valuable insights for the development of effective health communication strategies for preventive health behaviors.

The Historical Achievement of the South Korean Music Industry

  • Woo-Jun JANG
    • 한류연구
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    • 제3권1호
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    • pp.7-13
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    • 2024
  • The study aims to examine the development of the South Korean music industry over time in order to capture the evolution process of the industry from its initial stages to its current state as one of the world's leading music markets. Based on the above consideration, a systematic literature review was conducted in order to provide an overview of the achievements of the South Korean music industry with the help of PRISMA method. The reason for doing this is to ensure that the process of selecting, filtering and collecting literature from different sources is not only efficient and time-saving but also rigid and coherent. This paper will explore the various elements that have defined the industry, including culture, technology, marketing and government policies and regulations (Jang & Song, 2017). Furthermore, it will inquire the effects of the K-pop cultural export on other industries, whether it be tourism, fashion, consumer goods, and more, thereby illustrating its vast significance. In more detail, this study aims to give an adequate idea about the historical accomplishments of the South Korean music industry in the global music map, identify factors that facilitated the enhancement of the industry and examine the significance of the findings and their applications for the industry's progression and development in the future.