Search results

A dual integral formulation for a cracked bar under torsion is derived, and a dual boundary element method is implemented. It is shown that as the thickness of the crack becomes thinner, the ill‐posedness for the linear algebraic matrix becomes more serious if the conventional BEM is used. Numerical experiments for solution instability due to ill‐posedness are shown. To deal with this difficulty, the hypersingular equation of the dual boundary integral formulation is employed to obtain an independent constraint equation for the boundary unknowns. For the sake of computational efficiency, the area integral for the torsion rigidity is transformed into two boundary integrals by using Green’s second identity and divergence theorem. Finally, the torsion rigidities for cracks with different lengths and orientations are solved by using the dual BEM, and the results compare well with the analytical solutions and FEM results.

This chapter provides an overview of the status of applied econometric research in hospitality and tourism management and outlines the econometric toolsets available for quantitative researchers using empirical data from the field. Basic econometric models, cross-sectional models, time-series models, and panel data models are reviewed first, followed by an evaluation of relevant applications. Next, econometric modeling topics that are germane to hospitality and tourism research are discussed, including endogeneity, multi-equation modeling, causal inference modeling, and spatial econometrics. Furthermore, major feasibility issues for applied researchers are examined based on the literature. Lastly, recommendations are offered to promote applied econometric research in hospitality and tourism management.

The purpose of this paper is to detect the degenerate scale of a 2D bending plate analytically and numerically.

To avoid the time-consuming scheme, the influence matrix of the boundary element method (BEM) is reformulated to an eigenproblem of the 4 by 4 matrix by using the scaling transform instead of the direct-searching scheme to find degenerate scales. Analytical degenerate scales are derived from the boundary integral equation (BIE) by using the degenerate kernel only for the circular case. Numerical results of the direct-searching scheme and the eigen system for the arbitrary shape are also considered.

Results using three methods, namely, analytical derivation, the direct-searching scheme and the 4 by 4 eigen system, are also given for the circular case and arbitrary shapes. Finally, addition of a constant for the kernel function makes original eigenvalues (2 real roots and 2 complex roots) of the 4 by 4 matrix to be all real. This indicates that a degenerate scale depends on the kernel function.

The analytical derivation for the degenerate scale of a 2D bending plate in the BIE is first studied by using the degenerate kernel. Through the reformed eigenproblem of a 4 by 4 matrix, the numerical solution for the plate of an arbitrary shape can be used in the plate analysis using the BEM.

The efficient speed controller is found to be an important requirement to run the motor for the brushless direct current (BLDC) motor. This requirement is considered as superior, as it may increase the operating speed and system efficiency. In the existing methods, proportional plus integral (PI) controller has been included because of its simple architecture. But the PI controller produces load disturbance, control complexity and some parametric (Proportional plus integral) variations. The purpose of this proposed controller is to overcome the problems produced by PI controller in BLDC motor.

The proposed BLDC motor is developed with fixed order H-infinity controller. In this architecture, both the weight functions and transfer functions were included to design the controller. This controller has been included in this BLDC to detect the rotor position. The optimal position of rotor is identified by introducing particle swarm optimization algorithm.

The torque that obtained in the motor is highly reduced by this proposed controller and also enhances the speed. The BLDC motor is modelled in a MATLAB environment.

The performance of the torque, speed and back electro-motive force is analysed and compared with the existing controllers such as fuzzy proportional plus integral plus derivative, sensing algorithm and fuzzy proportional plus derivative controller.

Simulation results show that the proposed technique gives better results than the other existing controllers.

This paper aims to present a nonlinear finite element model (FEM) of the Brushless DC (BLDC) motor and the application of the optimal linear–quadratic control-based method to determine the excitation voltage and current waveform considering the minimization of the energy injected to the input circuit and energy lost. The control problem is designed and analyzed using the feedback gain strategy for the infinite time horizon problem.

The method exploits the distributed parameters, nonlinear FEM of the device. First, dynamic equations of the BLDC motor are transformed into a suitable form that makes an ARE (algebraic Riccati equation)-based control technique applicable. Moreover, in the controller design, a Bryson scaling method is used to obtain desirable properties of the closed-loop system. The numerical techniques for solving ARE with the gradient damping factor are proposed and described. Results for applied control strategy are obtained by simulations and compared with measurement.

The proposed control technique can ensure optimal dynamic response, small steady-state error and energy saving. The effectiveness of the proposed control strategy is verified via numerical simulation and experiment.

The authors introduced an innovative approach to the well-known control methodology and settled their research in the newest literature coverage for this issue.

The purpose of the paper is to present a frequency-changing technique to realize a fast start-up radio frequency (RF) energy harvester.

First, a simple analysis of the input impedance of the rectifier circuit is presented, and based on the analysis, it is shown how the input impedance of the rectifier is changed during the rectifier charging. Then, the frequency-changing technique is presented in which the variation of the rectifier input reactance (capacitance) is partly compensated by changing the frequency of the transmitted RF signal. A harvester consisting of a four-stage rectifier and a simple series matching inductor, implemented based on Schottky diode, is employed to verify the technique.

With the input available power of −12 dBm, the simulated and the measured results prove that the proposed frequency-changing method compared to the typical fixed-frequency method shows more than 30 per cent decrease in the transient time to reach 0.5 V output voltage, while the final harvested output voltage is unchanged.

A frequency-changing technique is presented.

The purpose of this paper is to evolve a framework for assessing the efficiencies of municipal solid waste management (MSWM) services.

Stochastic frontier analysis (SFA), a deterministic parametric frontier technique, has been employed for benchmarking of the MSWM services across municipalities in 22 cities in the state of Madhya Pradesh, India.

This paper reviews the solid waste management status and applies SFA to evaluate the relative performances of the services in terms of seven models, of which two models were found significant and acceptable based on the null hypothesis, significance of elasticity of variables, and an absence of data heteroskedasticity. The paper discusses the results in the context of various indicators, and finds that a large number of MSWM municipalities exhibit relative inefficiencies, implying that most municipalities can achieve higher levels of outputs by deploying fewer resources, thereby improving performances without necessarily increasing municipal spendings.

The work suggests some of the changes at the policy level that would affect the way in which solid waste is managed currently in India, and hence the work has social implications whereby the lives of a billion people will be improved through improved solid waste management services.

To the best of the author's information, advanced benchmarking techniques such as SFA have seldom been applied for evolving the efficiencies of solid waste management municipalities, primarily because the sanitation services are yet to take the shape of an industry in the developing world. Lack of availability of data and non‐transparent functions of these services prevent further exploration into estimating the inefficiencies of these service utilities. The paper will be of use to policy makers, solid waste managers, administrators, and sector regulators.

Practicing flexible revenue management (RM) at hotels during Covid-19 is essential. The well-performed hotels ponder how to transform the target from revenue to net profits. This paper aims, first, to develop a value stream mapping (VSM) model for a productive RM based on six key drivers: organizational culture, demand forecasting, dynamic distribution channels, competition breakdown, dynamic and customized pricing and daily reviewing, and, second, to examine the nexus between RM and hotel’s efficiency during Covid-19 using the wavelet analysis (WA) to visualize this relationship’s time and frequency-based lead–lag dynamics.

Using time-series data, a multiple case study of 31 luxury hotels in Egypt was applied based on semi-structured interviews and self-administered questionnaires.

The first phase results showed that consensus toward the RM framework was achieved, regardless of current challenges, indicating that RM managers and scholars could use it. In Phase 2, the WA confirmed a positive correlation and significant influence between Covid-19 and RM practices at most business cycle frequencies. Furthermore, overall high causal relationships between RM practices and hotel efficiency were discovered in the short and medium terms and through different occurrence cycles. Though, the dynamic pricing in the long term was apart from this relationship. The causal effects between Covid-19 and hotel efficiency are not observable in the long-run spectra, indicating that resilience efforts with Covid-19 perhaps mitigated the impact.

Hotel managers could use the RM model developed from this study during the downturn to improve efficiency. The outcome may lead to the recovery of the hotel market and the whole economy. WA maps display possible directions for hotel managers to be more efficient based on the time and frequency domains.

This study shows opportunities for RM implementation during Covid-19 based on the VSM and the WA approaches in hotels.

The purpose of this paper is to mainly investigate what factors drive growth for independent hotel firms on an island.

Two steps were followed. First, to identify hotels demonstrated significant growth; 92 independent hotels in North Cyprus were analyzed via a self-report questionnaire. Second, key growth factors were examined in five hotels showing the growth over years among the independent hotels via in-depth, semi-structured interviews, focus group interviews, and observations.

The study findings revealed 16 important growth factors for hotels, including active risk taking, education, family history, networks of contacts, other business interests, family investing friends, key employee partners, customer concentration, autonomy, innovativeness, proactiveness, competitive aggressiveness, location, desire to succeed, age of founders, and state support where are strong, weak, and interrelated relationships among these factors. These findings allow factors to be categorized into new groups, namely, strategic and tactical factors. The research findings unveil new factors referred to as “political conflict – pursuing different strategy and opportunities,” importance of second generations affect and entrepreneur’s metacognitive strategies, “informal networking.”

More research should also be undertaken for entrepreneurs or managers who formulate and implement strategies to enter new markets or to tackle turbulent and/or unstable environments.

This study reveals that one factor on its own cannot influence the growth of hotels. Rather, successful growth depends on the entrepreneur’s ability to combine all factors in harmony.

Given that there is limited empirical evidence on the growth of independent hotels on islands, this study made an important attempt to contribute to the entrepreneurship literature in the hospitality management and family business fields via micro-level approaches concerning the factors influencing hotels’ growth on an island. This is one of the first studies presenting and discussing empirical findings on growth factors for small hotels on an island, and brings a new perspective by grouping factors as strategic and tactical factors.

The purpose of this paper is to provide an enhanced version of quality function deployment (QFD) that captures customers’ present and future preferences, accurately prioritizes product specifications and eventually translates them into desirable quality products. Under rapidly changing environments, customer requirements and preferences are constantly changing and evolving, rendering essential the realization of the dynamic role of the “Voice of the Customer (VoC)” in the design and development of products.

The proposed methodological framework incorporates a Multivariate Markov Chain (MMC) model to describe the pattern of changes in customer preferences over time, the Fuzzy AHP method to accommodate the uncertainty and subjectivity of the “VoC” and the LP-GW-AHP to discover the most important product specifications in order to structure a robust QFD method. This enhanced QFD framework (MMC-QFD-LP-GW-Fuzzy AHP) takes into consideration the dynamic nature of the “VoC” captures the actual customers’ preferences (WHATs) and interprets them into design decisions (HOWs).

The integration of MMC models into the QFD helps to handle the sequences of customers’ preferences as categorical data sequences and to consider the multiple interdependencies among them.

In this study, a MMC model is introduced for the first time within QFD, in an effort to extend the concept of listening to further anticipating to customer wants. Gaining a deeper understanding of current and future customers’ preferences could help organizations to design products and plan strategies that more effectively and efficiently satisfy them.