• Steel and Composite Structures
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• v.33 no.2
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• pp.195-208
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• 2019

Based on a four-variable shear deformation shell theory, the free vibration analysis of functionally graded graphene platelet-reinforced composite (FGGPRC) doubly-curved shallow shells with different boundary conditions is investigated in this work. The doubly-curved shells are composed of multi nanocomposite layers that are reinforced with graphene platelets. The graphene platelets are uniformly distributed in each individual layer. While, the volume faction of the graphene is graded from layer to other in accordance with a novel distribution law. Based on the suggested distribution law, four types of FGGPRC doubly-curved shells are studied. The present shells are assumed to be rested on elastic foundations. The material properties of each layer are calculated using a micromechanical model. Four equations of motion are deduced utilizing Hamilton's principle and then converted to an eigenvalue problem employing an analytical method. The obtained results are checked by introducing some comparison examples. A detailed parametric investigation is performed to illustrate the influences of the distribution type of volume fraction, shell curvatures, elastic foundation stiffness and boundary conditions on the vibration of FGGPRC doubly-curved shells.

• Educational Technology International
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• v.6 no.2
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• pp.43-58
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• 2005

The purpose of this study was to investigate the impact of organizational learning culture on job satisfaction and organizational commitment. Two streams of scholarly work have provided the theoretical foundations for this study. The first stream comes from the literature on learning organization. The second stream of the theoretical foundation comes from an extensive literature on attitude-intention-behavior relationships. In addition, this study was tested three alternative models. Alternative model 1 employed job satisfaction as the mediating commitments variable between learning culture and organizational commitment. Alternative model 2 used organizational commitment as the mediating variable between learning culture and job satisfaction. Finally, alternative model 3 specified a direct impact of learning culture on both job satisfaction and organizational commitment, and reciprocal linkages between these two variables. The results of this study support the hypothesized relations among an organization's learning culture, job satisfaction, and organizational commitment. The findings of this study are various congruent with a widely accepted hypothesis that job satisfaction serves as an appraisal function in evaluating various work environments and determining emotional responses such as organizational commitment. Organizational learning culture is one of the important factors that organizations cannot overlook. Therefore, the findings of this study provide a new direction for researchers seeking to explain the complex relations among these central organizational variables.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.922-932
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• 2024

This paper presents the design features and preliminary design analysis results of the Wielenga Innovation Static Salt Reactor (WISSR). The WISSR incorporates features that make it both flexible and inherently safe. It is based on innovative technology that controls a nuclear reactor by moving molten salt fuel into or out of the core. The reactor is a low-pressure, fast spectrum transuranic (TRU) burner reactor. Inherent shutdown is achieved by a large negative reactivity feedback of the liquid fuel and by the expansion of fuel out of the core. The core is made of concentric, thin annular fuel chambers containing molten fuel salt. A molten salt coolant passes between the concentric fuel chambers to cool the core. The core has both fixed and variable volume fuel chambers. Pressure, applied by helium gas to fuel reservoirs below the core, pushes fuel out of a reservoir and up into a set of variable volume chambers. A control system monitors the density and temperature of the fuel throughout the core. Using NaCl-(TRU,U)Cl₃ fuel and NaCl-KCl-MgCl₂ coolant, a road-transportable compact WISSR core design was developed at a power level of 1250 MWt. Preliminary neutronics and thermal-hydraulics analyses demonstrate the technical feasibility of WISSR.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.28 no.1
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• pp.70-79
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• 2024

Backgrounds/Aims: After pancreatoduodenectomy (PD), an early oral diet is recommended; however, the postoperative nutritional management of PD patients is known to be highly variable, with some centers still routinely providing parenteral nutrition (PN). Some patients who receive PN experience clinically significant complications, underscoring its judicious use. Using a large cohort, this study aimed to determine the proportion of PD patients who received postoperative nutritional support (NS), describe the nature of this support, and investigate whether receiving PN correlated with adverse perioperative outcomes. Methods: Data were extracted from the Recurrence After Whipple's study, a retrospective multicenter study of PD outcomes. Results: In total, 1,323 patients (89%) had data on their postoperative NS status available. Of these, 45% received postoperative NS, which was "enteral only," "parenteral only," and "enteral and parenteral" in 44%, 35%, and 21% of cases, respectively. Body mass index < 18.5 kg/m² (p = 0.03), absence of preoperative biliary stenting (p = 0.009), and serum albumin < 36 g/L (p = 0.009) all correlated with receiving postoperative NS. Among those who did not develop a serious postoperative complication, i.e., those who had a relatively uneventful recovery, 20% received PN. Conclusions: A considerable number of patients who had an uneventful recovery received PN. PN is not without risk, and should be reserved for those who are unable to take an oral diet. PD patients should undergo pre- and postoperative assessment by nutrition professionals to ensure they are managed appropriately, and to optimize perioperative outcomes.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.1
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• pp.161-169
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• 2013

As research cooperation was increased nowadays, This study seeks to explores the performance determinants of research cooperation. Toward this end, this study is focused on generating such determinants as interfirm trust, commitment and corporate capability based on previous studies and existing literature. We define openness, management ability and consideration as sub-variable of interfirm trust, corporate capability was composed of R&D capability, financial capability, management capability and absorptive capacity. Commitment had no sub-variable. Also, this study was composed of two dependent variables, aiming to explore differential performance of research cooperation. Results of the empirical analyses are as follows. First, corporate capability was significant impact on research cooperation. Second, interfirm trust and commitment was not significant to research cooperation. Finally, performance differentiation between two dependent variable was not proved in this study.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.2
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• pp.85-96
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• 2015

Korea is one of low-ranked countries in women's economic participation rate among OECD nations because well-educated females are not participating in economic activities. Regardless of current state of our society, opening a business is being considered as a effective method for job creation. Also, increasing the number of female business founders can lead to female job creation which promotes even growth of foundation and job creation and augments women's economic activity rate. Therefore, this study suggests the direction of foundation and inspires foundation factors and aims at increasing social re-participation through vitalization of business foundation by women in career discontinuity. For this study, I carried out a survey targeting career interrupted women who have attained entrepreneurial education using five- point scale by Likert and analyzed with SPSS Windows 18.0. The analysis set up 3 hypotheses with independent variables of psychological traits, entrepreneurial education and entrepreneurial environment and the dependent variable of entrepreneurial intention of the career interrupted women. Also, I looked if there is the modify effect when psychological traits and entrepreneurial education affect the entrepreneurial intention with entrepreneurial environment as a moderating variable. To summarize the positive analysis result, Firstly, all psychological traits, entrepreneurial education and entrepreneurial environment had similar positive affects on career interrupted women's entrepreneurial intention. Secondly, when psychological traits and entrepreneurial education affect the entrepreneurial intention, entrepreneurial environment had similar effects as a moderating effect. This study implies that psychological traits, entrepreneurial education and entrepreneurial environment are all important for the career interrupted women's entrepreneurial intention. There are so many women who are going through both professional experience and personal network's severance. Therefore, optimized entrepre neurship education must be provided to help those women return to economic activity considering their psychological traits. Additionally, we should put emphasis on producing the entrepreneurial environment that can positively convert others' perceptions and construct those women's personal network. There seems to be more productive information for the strategies which can induce those women's actual business foundation if the social problems of the women who have highly willing to open a business are treated in the future. Also, considering that psychological traits, entrepreneurial education and entrepreneurial environment all have effect on entrepreneurial intentions, there should be more related follow-up study on this.

• Structural Engineering and Mechanics
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• v.48 no.1
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• pp.17-39
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• 2013

In the present paper, a coaxial rotating smeared crack model is proposed for mass concrete in three-dimensional space. The model is capable of applying both the constant and variable shear transfer coefficients in the cracking process. The model considers an advanced yield function for concrete failure under both static and dynamic loadings and calculates cracking or crushing of concrete taking into account the fracture energy effects. The model was utilized on Koyna Dam using finite element technique. Dam-water and dam-foundation interactions were considered in dynamic analysis. The behavior of dam was studied for different shear transfer coefficients considering/neglecting fracture energy effects. The results were extracted at crest displacement and crack profile within the dam body. The results show the importance of both shear transfer coefficient and the fracture energy in seismic analysis of concrete dams under high hydrostatic pressure.

• Journal of the Korean Society of Safety
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• v.29 no.6
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• pp.81-86
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• 2014

Composite materials have high specific stiffness, specific strength than existing concrete or steel materials. It has superior dynamic properties when utilizing advantages of material such as Non-corrosive, light weight, non-conducting and it has superior mold ability which can make variable shapes. Thus, in the construction, for using composite materials as construction materials, the study carried out static strength of fiber right angle direction and fatigue performance of FRP deck member. The study is going to deduct S-N curve by analyzing the results comparatively and estimate long-term durability. From now on, the study is going to provide interpretation of FRP member and basic data of design basis, furthermore providing foundation technique of composite materials' application of structural frame is the goal of this study.

• Structural Engineering and Mechanics
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• v.61 no.2
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• pp.295-316
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• 2017

Element based differential quadrature method (EDQM) has been applied to analyze static, stability and free vibration of non-homogeneous orthotropic rectangular plates of variable or stepped thickness. The Young's modulus and the density are assumed to vary in exponential form in X-direction whereas the thickness is assumed to vary linear, parabolic or exponential variation in one or two directions. In-plane loading is assumed to vary linearly. Various combinations of clamped, simply supported and free edge conditions (regular and irregular boundary) have been considered. Continuous plates could also be handled with ease. In this paper, formulation for equilibrium, buckling and free vibration problems is discussed and several numerical examples are solved using EDQM and compared with the published results.

• Structural Engineering and Mechanics
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• v.66 no.6
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• pp.693-701
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• 2018

This paper develops a nonlocal strain gradient plate model for vibration analysis of graphene sheets under thermal environments. For more accurate analysis of graphene sheets, the proposed theory contains two scale parameters related to the nonlocal and strain gradient effects. Graphene sheet is modeled via a two-variable shear deformation plate theory needless of shear correction factors. Governing equations of a nonlocal strain gradient graphene sheet on elastic substrate are derived via Hamilton's principle. Differential quadrature method (DQM) is implemented to solve the governing equations for different boundary conditions. Effects of different factors such as temperature rise, nonlocal parameter, length scale parameter, elastic foundation and aspect ratio on vibration characteristics a graphene sheets are studied. It is seen that vibration frequencies and critical buckling temperatures become larger and smaller with increase of strain gradient and nonlocal parameter, respectively.