• Title/Summary/Keyword: Uncertain Measure

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Reliability-Based Shape Optimization Under the Stress Constraints (응력 제한조건하의 신뢰성 기반 형상 최적설계)

  • Oh, Young-Kyu;Park, Jae-Yong;Im, Min-Gyu;Park, Jae-Yong;Han, Seog-Young
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.4
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    • pp.469-475
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    • 2010
  • The objective of this study is to integrate reliability analysis into shape optimization problem using the evolutionary structural optimization (ESO) in the application example. Reliability-based shape optimization is formulated as volume minimization problem with probabilistic stress constraint under minimization max. von Mises stress and allow stress. Young's modulus, external load and thickness are considered as uncertain variables. In order to compute reliability index, four methods, i.e., reliability index approach (RIA), performance measure approach (PMA), single-loop singlevector (SLSV) and adaptive-loop (ADL), are used. Reliability-based shape optimization design process is conducted to obtain optimal shape satisfying max. von Mises stress and reliability index constraints with the above four methods, and then each result is compared with respect to numerical stability and computing time.

A system model for reliability assessment of smart structural systems

  • Hassan, Maguid H.M.
    • Structural Engineering and Mechanics
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    • v.23 no.5
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    • pp.455-468
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    • 2006
  • Smart structural systems are defined as ones that demonstrate the ability to modify their characteristics and/or properties in order to respond favorably to unexpected severe loading conditions. The performance of such a task requires a set of additional components to be integrated within such systems. These components belong to three major categories, sensors, processors and actuators. It is wellknown that all structural systems entail some level of uncertainty, because of their extremely complex nature, lack of complete information, simplifications and modeling. Similarly, sensors, processors and actuators are expected to reflect a similar uncertain behavior. As it is imperative to be able to evaluate the impact of such components on the behavior of the system, it is as important to ensure, or at least evaluate, the reliability of such components. In this paper, a system model for reliability assessment of smart structural systems is outlined. The presented model is considered a necessary first step in the development of a reliability assessment algorithm for smart structural systems. The system model outlines the basic components of the system, in addition to, performance functions and inter-relations among individual components. A fault tree model is developed in order to aggregate the individual underlying component reliabilities into an overall system reliability measure. Identification of appropriate limit states for all underlying components are beyond the scope of this paper. However, it is the objective of this paper to set up the necessary framework for identifying such limit states. A sample model for a three-story single bay smart rigid frame, is developed in order to demonstrate the proposed framework.

The Concept of Hope of Stroke Patient: A Review of the Literature for Nursing (뇌졸중 환자의 희망에 대한 이론적 고찰)

  • Kim, Lee-Sun;Huang, Bo-Sun
    • Research in Community and Public Health Nursing
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    • v.6 no.2
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    • pp.212-233
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    • 1995
  • Cerebrovascular diseases in Korea is an important health problem since mortality and mobidity have been increasing rapidly. Cerebrovascular diseases marked the 2nd rank of cause specific death rate in 1993. The ploblem of emotion after a stroke has received very little attention from the nursing profession until recently. Even the frequency of the emotional disorder after stroke is uncertain, and there has been very little research. Emotional disorder after stroke was related to limited social function, guilty conscience, helplessness, hopelessness, powerlessness, alienation, and damage of self-image. In the stroke patient, hope may be related to a rehabilitation or enhancing physical condition. Inspiring hope is necessary when stroke patients are unable to mobilize energy on their own behalf and perceive limited or no person choices available. Inspiring hope is an intervention that can be used with many nursing diagnoses, especially when feelings of helplessness, hopelessness, powerlessness, and depression are present. The nurse can inspire hope by understanding the hoping process. On the basis of this literature review, the following suggestions are prosed. 1) Qualitative studies on hope have been done to indentify variables that affect maintenance of hope in the chronically ill patients. 2) In the development of an instrument to measure hope, the validity, reliability, and cultural property of the hope have been estabilished.

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Background and Activities of the Samsung Ombudsperson Commission in Korea

  • Lee, Cheolsoo;Kang, Seong-Kyu;Kim, Hyunwook;Kim, Inhee
    • Journal of Preventive Medicine and Public Health
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    • v.52 no.4
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    • pp.265-271
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    • 2019
  • Objectives: The Samsung Ombudsperson Commission was launched as an independent third-party institution following an agreement among Samsung Electronics, Supporters for Health and Right of People in Semiconductor Industry (Banolim in Korean, an independent NGO), and the Family Compensation Committee, in accordance with the industry accident prevention measure required by the settlement committee to address the issues related to employees who allegedly died from leukemia and other diseases as a result of working at Samsung's semiconductor production facilities. Methods: The Commission has carried out a comprehensive range of activities to review and evaluate the status of the company's occupational accidents management system, as well as occupational safety and health risk management within its facilities. Results: Based on the results of this review, termed a comprehensive diagnosis, the Commission presented action plans for improvement to strengthen the company's existing safety and health management system and to effectively address uncertain risks in this area going forward. Conclusions: The Commission will monitor the execution of the suggested tasks and provide advice and guidance to ensure that Samsung's semiconductor and liquid crystal display production lines are safer.

High-z Universe probed via Lensing by QSOs (HULQ): How many QSO lenses are there?

  • Taak, Yoon Chan;Im, Myungshin
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.77.3-77.3
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    • 2019
  • Aims. The evolution of scaling relations between SMBHs and their host galaxies becomes uncertain at high redshifts. The HULQ project proposes to use gravitational lensing to measure the masses of QSO host galaxies, an otherwise difficult goal. SMBH masses of QSOs are relatively easy to determine using either reverberation mapping or the single-epoch method. These measurements, if made for a substantial number of QSOs at various redshifts, will allow us to study the co-evolution of SMBHs and their host galaxies. To determine the feasibility of this study, we present how to estimate the number of sources lensed by QSO hosts, i.e. the number of deflector QSO host galaxies (hereafter QSO lenses). Method and results. Using SMBH masses measured from SDSS DR14 spectra, and the M_BH - Sigma relation, the Einstein radii are calculated as a function of source redshift, assuming singular isothermal sphere mass distributions. Using QSOs and galaxies as sources, the probability of a QSO host galaxy being a QSO lens is calculated, depending on the limiting magnitude. The expected numbers of QSO lenses are estimated for ongoing and future wide-imaging surveys, and additional factors that may affect these numbers are discussed.

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The Effect of Institutional Capability on Entrepreneurship Education: An Empirical Study of Vietnamese Universities

  • NGUYEN, Trong Luan;NGUYEN, Trung Hau;THACH, Thao Vy;TRAN, Doan Vy;HOANG, Nguyen Huong Giang;PHAM, Ngoc Phuong Trang
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.1
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    • pp.363-372
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    • 2022
  • Entrepreneurs are valuable assets for any country. Rather than being confronted with new obstacles, they should be fostered and nurtured. Entrepreneurial firms have the power to influence how we live and work, in addition to producing jobs and contributing to economic progress. Entrepreneurs have the ability to change the world by creating diversified skill sets and profitable businesses that are vital to the advancement of our economies. How does one go about being a successful business, though? More resources are believed to be needed to create entrepreneurial environments in higher education that foster progressive ideas and innovation while also providing students with the practical knowledge and skills they need to navigate the troublesome, difficult, and uncertain situations that come with owning a business. This article will outline the scales of components from which to measure variables impacting universities' ability to encourage entrepreneurial behavior among students, based on the aforementioned significance of universities. This article is based on a survey of 507 students from different universities and backgrounds in Vietnam. The research methods used are Cronbach's alpha test and Structural Equation Modeling. From the research results, it can be seen that the university's environment plays a significant role in fostering entrepreneurial behavior among students.

A novel Metropolis-within-Gibbs sampler for Bayesian model updating using modal data based on dynamic reduction

  • Ayan Das;Raj Purohit Kiran;Sahil Bansal
    • Structural Engineering and Mechanics
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    • v.87 no.1
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    • pp.1-18
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    • 2023
  • The paper presents a Bayesian Finite element (FE) model updating methodology by utilizing modal data. The dynamic condensation technique is adopted in this work to reduce the full system model to a smaller model version such that the degrees of freedom (DOFs) in the reduced model correspond to the observed DOFs, which facilitates the model updating procedure without any mode-matching. The present work considers both the MPV and the covariance matrix of the modal parameters as the modal data. Besides, the modal data identified from multiple setups is considered for the model updating procedure, keeping in view of the realistic scenario of inability of limited number of sensors to measure the response of all the interested DOFs of a large structure. A relationship is established between the modal data and structural parameters based on the eigensystem equation through the introduction of additional uncertain parameters in the form of modal frequencies and partial mode shapes. A novel sampling strategy known as the Metropolis-within-Gibbs (MWG) sampler is proposed to sample from the posterior Probability Density Function (PDF). The effectiveness of the proposed approach is demonstrated by considering both simulated and experimental examples.

The Impact of Manual Therapy on Pain Catastrophizing in Chronic Pain Conditions: A Systematic Review and Meta-analysis

  • Hyunjoong Kim;Seungwon Lee
    • Physical Therapy Rehabilitation Science
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    • v.12 no.2
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    • pp.177-184
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    • 2023
  • Objective: Manual therapy is a commonly utilized approach in managing chronic pain, but its specific impact on pain catastrophizing remains uncertain. The objective of this systematic review and meta-analysis was to examine the effects of manual therapy on pain catastrophizing in individuals with chronic pain. Design: A systematic review and meta-analysis Methods: A comprehensive search was conducted in electronic databases to identify relevant studies published from 2014 onwards. Studies that evaluated the impact of manual therapy on pain catastrophizing in individuals with chronic pain were incorporated. The risk of bias in the selected studies was evaluated using the Cochrane tool for risk of bias in qualitative analysis. For the quantitative analysis, RevMan 5.4 software was utilized, employing a random-effects model as the analysis model. The effect measure used in the analysis was the standardized mean difference (SMD). Results: In total, 26 studies were collected, and following the screening process, three of them were incorporated into the final analysis. The included studies involved a total of 153 patients with chronic pain. The interventions comprised various manual therapy techniques targeting different areas of the body. Pain catastrophizing and pain intensity were the primary outcomes of interest. The meta-analysis revealed a significant reduction in pain catastrophizing scores following manual therapy intervention compared to control conditions (SMD = -0.91, 95% CI: -1.25 to -0.58). However, heterogeneity between the studies was observed. Conclusions: Despite the limited quantity and heterogeneity of studies, it has been demonstrated that manual therapy intervention is effective in reducing pain catastrophizing in individuals with chronic pain.

Evaluation of Arabinofuranosidase and Xylanase Activities of Geobacillus spp. Isolated from Some Hot Springs in Turkey

  • Sabriye, Canakci;Inan, Kadriye;Murat, Kacagan;Belduz, Ali Osman
    • Journal of Microbiology and Biotechnology
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    • v.17 no.8
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    • pp.1262-1270
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    • 2007
  • Some hot springs located in the west of Turkey were investigated with respect to the presence of thermophilic microorganisms. Based on phenotyping characteristics and 16S rRNA gene sequence analysis, 16 of the isolates belonged to the genus Geobacillus and grew optimally at about $60^{\circ}C$ on nutrient agar. 16S rRNA gene sequence analysis showed that these isolates resembled Geobacillus species by ${\ge}97%$, but SDS-PAGE profiles of these 16 isolates differ from some of the other species of the genus Geobacillus. However, it is also known that analysis of 16S rRNA gene sequences may be insufficient to distinguish between some species. It is proposed that recN sequence comparisons could accurately measure genome similarities for the Geobacillus genus. Based on recN sequence analysis, isolates 11, IT3, and 12 are strains of G stearothermophilus; isolate 14.3 is a strain of G thermodenitrificans; isolates 9.1, IT4.1, and 4.5 are uncertain and it is required to make further analysis. The presence of xylanase and arabinofuranosidase activities, and their optimum temperature and pH were also investigated. These results showed that 7 of the strains have both xylanase and arabinofuranosidase activities, 4 of them has only xylanase, and the remaning 5 strains have neither of these activities. The isolates 9.1, 7.1, and 3.3 have the highest temperature optima ($80^{\circ}C$), and 7.2, 9.1, AO4, 9.2, and AO17 have the highest pH optima (pH 8) of xylanase. Isolates 7.2, AO4, AC15, and 12 have optimum arabinofuranosidase activities at $75^{\circ}C$, and only isolate AC15 has the lowest pH of 5.5.

NIR - a Tool for Evaluation of Milling Procedure

  • Gergely, Sziveszter;Handzel, Lidia;Zoltan, Andrea;Salgo, Andras
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1125-1125
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    • 2001
  • Micro-scale test methods are producing small-sample size where the conventional physical and chemical tests can not be used (high standard deviation, uncertain sampling conditions, low repeatability). Different small-scale test methods were developed recently for determination of physico-chemical, functional, rheological properties of wheat or wheat dough using miniaturized instruments with sophisticated sample preparation/handling and mechanics (RVA, 2 g mixograph, micro-Z-arm mixer, small-scale noodle maker, micro-baking method etc.). The small-scale methodologies can be used as basic research tools or as technology supported measurements and can be also essential in the early selection for quality traits in breeding programs. The milling as a sample preparation step is essential procedure providing good quality flour or semolina samples from small amount of grain (5-10 g) in a reproducible and reliable way. The aim of present study was to use NIR as quality control tool, and to evaluate the recently developed and manufactured micro-scale lab mill (FQC-2000) produced by Inter-Labor Co. Ltd., Hungary. The milling characteristics of the new instrument were compared to other laboratory mills and the effects of milling action on the chemical composition of fractions were analysed. The fractions were tested with both chemical and near infrared spectroscopic methods. The micro-scale milling resulted significantly different yields, particle size distributions and different fractions from compositional point of view. The near infrared spectra were sensitive enough to distinguish the fractions obtained by different milling procedures. Quantitative NIR calibration equations were developed and tested in order to measure the chemical composition of characteristic milling fractions. Special qualification procedure the PQS (Polar Qualification System) method was used for detecting the differences between fractions obtained by macro and micro-milling procedures. The results and the limitations of PQS method in this application will be discussed.

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