Search results

The purpose of this paper is to investigate the first three stochastic natural frequencies of skewed sandwich plates, considering uncertain system parameters. To conduct the sensitivity analysis for checking the criticality of input parameters.

The theoretical formulation is developed based on higher-order-zigzag theory in accordance with the radial basis function (RBF) and stochastic finite element (FE) model. A cubic function is considered for in-plane displacement over thickness while a quadratic function is considered for transverse displacement within the core and remains constant in the facesheet. RBF is used as a surrogate model to achieve computational efficiency and accuracy. In the present study, the individual and combined effect of ply-orientation angle, skew angle, number of lamina, core thickness and material properties are considered for natural frequency analysis of sandwich plates.

Results presented in this paper illustrates that the skewness in the sandwich plate significantly affects the global dynamic behaviour of the structure. RBF surrogate model coupled with stochastic FE approach significantly reduced the computational time (more than 1/18 times) compared to direct Monte Carlo simulation approach.

The stochastic results for dynamic stability of sandwich plates show that the inevitable source uncertainties present in the input parameters result in significant variation from the deterministic value demonstrates the need for inclusive design paradigm considering stochastic effects. The present paper comprehensively establishes a generalized new RBF-based FE approach for efficient stochastic analysis, which can be applicable to other complex structures too.

Considering that uncertain factors widely exist in engineering practice, an adaptive collocation method (ACM) is developed for the structural fuzzy uncertainty analysis.

ACM arranges points in the axis of the membership adaptively. Through the adaptive collocation procedure, ACM can arrange more points in the axis of the membership where the membership function changes sharply and fewer points in the axis of the membership where the membership function changes slowly. At each point arranged in the axis of the membership, the level-cut strategy is used to obtain the cut-level interval of the uncertain variables; besides, the vertex method and the Chebyshev interval uncertainty analysis method are used to conduct the cut-level interval uncertainty analysis.

The proposed ACM has a high accuracy without too much additional computational efforts.

A novel ACM is developed for the structural fuzzy uncertainty analysis.

Advanced computational methods help to solve complex engineering problems via finite-element simulation. However, uncertainties during the process occurred due to the nature of geometry, material properties, loading, and boundary conditions. These inaccuracies affect the accuracy of results obtained from the analysis. This paper aims to analyse the uncertainty parameters of a finite element model in Excel-Visual Basic Application (VBA) by applying a random simulation method.

This study focuses on a finite element model with a different mesh. Young's Modulus, E, Poisson's ratio, and load, L are the uncertainty input parameters considered random variables.

Results obtained proved that the finite element model with the most nodes and elements has better solution convergence.

Random simulation method is a tool to perform uncertainty analysis of a finite element model.

This paper aims to accomplish friction stir welding (FSW) of Al–Li alloy AA8090 to determine optimal settings of the process parameters for higher tensile strength and higher micro-hardness (MH) to achieve the objective of adequate butt-joint strength.

An empirical relation is implemented to govern the utmost influence parameters, i.e. tool rotation speed (TRS), tool transverse speed (TTS) and dwell time (DT). Taguchi grey relational analysis (GRA) was applied for multi-response optimization of response parameters. The grey relational grades (GRs) have been calculated for both the responses MH and ultimate tensile strength to get optimal parametric settings. The variance test has been performed to check the adequacy of the model.

The Taguchi L9 orthogonal array design was used in establishing the relation between input parameter and output parameter (tensile and MH). TTS and DT have been predicted to be the two most important parameters that influence the extreme quality features of joints by using friction stir welding. Scanning electron microscopy fractography shows the ductile failure of the welded joints.

The experimental trials provided the followings results, maximum ultimate tensile strength (UTS) of 219 MPa and MH 107.1 HV under 1,400 rpm of TRS, 40 mm/min of TTS and 8 s of DT founded the optimum value through GRA.

Achieving reliable instrument reprocessing requires finding the right balance among cost, productivity, and safety. However, there have been few attempts to comprehensively examine sterile processing department (SPD) work systems. We considered an SPD as an example of a socio-technical system – where people, tools, technologies, the work environment, and the organization mutually interact – and applied work systems analysis (WSA) to provide a framework for future intervention and improvement.

The study was conducted at two SPD facilities at a 700-bed academic medical center servicing 56 onsite clinics, 31 operating rooms (ORs), and nine ambulatory centers. Process maps, task analyses, abstraction hierarchies, and variance matrices were developed through direct observations of reprocessing work and staff interviews and iteratively refined based on feedback from an expert group composed of eight staff from SPD, infection control, performance improvement, quality and safety, and perioperative services. Performance sampling conducted focused on specific challenges observed, interruptions during case cart preparation, and analysis of tray defect data from administrative databases.

Across five main sterilization tasks (prepare load, perform double-checks, run sterilizers, place trays in cooling, and test the biological indicator), variance analysis identified 16 failures created by 21 performance shaping factors (PSFs), leading to nine different outcome variations. Case cart preparation involved three main tasks: storing trays, picking cases, and prioritizing trays. Variance analysis for case cart preparation identified 11 different failures, 16 different PSFs, and seven different outcomes. Approximately 1% of cases had a tray with a sterilization or case cart preparation defect and 13.5 interruptions per hour were noted during case cart preparation.

While highly dependent upon the individual skills of the sterile processing technicians, making the sterilization process less complex and more visible, managing interruptions during case cart preparation, improving communication with the OR, and improving workspace and technology design could enhance performance in instrument reprocessing.

In the academic field of business management, several potential theories were established during the last decades to explain companies' decisions, organizational behavior, consumer patterns, and internationalization, among others. As a result, businesses and scholars were able to analyze and decide based on theoretical approaches to explain the current conditions of the market. Secondary research was conducted to collect more than 36 management theories. This chapter aims to develop the most famous theories related to business applied in the international field. The novelty of this chapter relies on the compilation of recognized previous research studies from the academic literature and evidence in international business.

The purpose of this study was to examine purchasing intentions in online sports ticketing websites. Based on previous research related to business-to-consumer (B2C) e-commerce, this study developed a conceptual model to test the effect of perceived risk, trust and the Technology Acceptance Model (TAM) on purchase intentions in online secondary ticket websites. College students (N = 251) from the northeastern region of the United States were chosen as the sample. Structural Equation Modeling (SEM) was used to investigate the proposed relationships among four major components (i.e. perceived risk, trust, TAM and behavioural intention). The results showed that there were positive effects of key TAM constructs (i.e. perceived usefulness and ease of use) and trust on purchasing intention, but perceived risk was not a significant indicator of purchase intention.

Studies in psychology have long revealed that making personal choice involves multiple motivational consequences. It has only been recent, however, that the literature on neuroscience started to examine the neural underpinnings of personal choice and motivation. This chapter reviews this sparse, but emergent, body of neuroscientific literature to address possible neural correlates underlying personal choice. By conducting the review, we encourage future systematic research programs that address this topic under the new realm of “autonomy neuroscience.” The chapter especially focused on the following motivational aspects: (i) personal choice is rewarding, (ii) personal choice shapes preference, (iii) personal choice changes the perception of outcomes, and (iv) personal choice facilitates motivation and performance. The reviewed work highlighted different aspects of personal choice, but indicated some overlapping brain areas – the striatum and the ventromedial prefrontal cortex (vmPFC) – which may play a critical role in motivational processes elicited by personal choice.

This paper examines job satisfaction and participation in decision making in three home health aide facilities with different organizational structures (worker-owned for-profit, for-profit with no participation or ownership by workers, and nonprofit).

More than 600 surveys were completed by home health aides across the three facilities. The author also engaged in participant observation during training sessions and other meetings and conducted a small number of interviews with caregivers and agency management.

Home health aides at the worker-owned, participative decision making organization were significantly more satisfied with their jobs than those at the other agencies. Results for the other agencies were not significantly distinguishable from one another.

This study involved respondents from one of each type of business. A study across several of each type of organization would allow more focus on the effects of the structural characteristics of the organizations.

In the United States, the work that home health aides perform provides a valuable service to society. On behalf of caregivers and those for whom they provide care, conditions of the work need improvement. If participative democratic workplaces provide better outcomes, they should receive more attention from lawmakers, the business community, and researchers.

This research highlights the working conditions of the people (primarily women) who perform this work. The poor compensation received is a reminder of inequality in opportunity for some workers and of the value placed on this type of caring labor.

This research is unique in its focus on work environment and outcomes in home health care across nonprofit, for-profit, and worker-owned for-profit organizations. The findings of different job satisfaction outcomes from the others in the worker-owned organization and similar outcomes in the nonprofit and conventional for-profit organizations are also unique.

Since the publication of the report “To Err Is Human: Building a Safer Health System” by the US Institute of Medicine in 2000, much has changed with regard to patient safety. Many of the more recent initiatives to improve patient safety target the behavior of health care staff (e.g., training, double-checking procedures, and standard operating procedures). System-based interventions have so far received less attention, even though they produce more substantial improvements, being less dependent on individuals’ behavior. One type of system-based intervention that can benefit patient safety involves improvements to hospital design. Given that people’s working environments affect their behavior, good design at a systemic level not only enables staff to work more efficiently; it can also prevent errors and mishaps, which can have serious consequences for patients. While an increasing number of studies have demonstrated the effect of hospital design on patient safety, this knowledge is not easily accessible to clinicians, practitioners, risk managers, and other decision-makers, such as designers and architects of health care facilities. This is why the Swiss Patient Safety Foundation launched its project, “More Patient Safety by Design: Systemic Approaches for Hospitals,” which is presented in this chapter.