Search results

The purpose of this paper is to develop a preventive maintenance (PM) model for auxiliary components whose failures may not necessarily correspond to system failure but rather to faster system degradation.

The concept of load sharing was utilized to build a suitable Markov model for the problem. Regression analysis was used to estimate the various transition rates of the model. A real field application was used to illustrate the model.

Models addressing the design of an optimal PM strategy for such a problem are rare in the literature. The load‐sharing concept was borrowed and found very useful to model this problem. Regression analysis based on real field data was also found to be useful to estimate the model transition rates.

This paper addresses a problem that is not given enough attention in the currently available literature. Available models assume that a PM activity will restore the equipment to an as new, or at least to a better, condition. There exist situations, however, where a PM activity does not amend any damage but instead slows down further deterioration.

The purpose of this paper is to address reported weaknesses with existing equipment reliability improvement methods through their integration into the Six‐Sigma DMAIC methodology.

The evaluation was done by assessing the weaknesses of traditional methods such as reliability centered maintenance (RCM), evaluating what Six‐Sigma could potentially offer to close the gaps, and testing potential improvements through an example application.

It is concluded that Six‐Sigma addresses many RCM flaws and weaknesses. It is also concluded that Six‐Sigma, if integrated with other reliability techniques, can produce results that are far more objective and dependable.

Six‐Sigma, however, still bears its own cons and limitations. It requires good data which are sometimes unavailable. Six‐Sigma is also lengthier and consumes more resources per single problem since it focuses at one problem at a time.

The introduction of Six‐Sigma into equipment reliability/maintenance applications is quite original since this methodology has traditionally been limited to manufacturing and only recently to administrative processes. The outcome is of significant value as it opens up a new perspective into the development of reliability improvement measures for plant equipment.

This paper investigates the validity of the expectations hypothesis for the term structure of interest rates in the context of the deposit interest rates in Kuwait. The data set covers average inter local bank interest rates on deposits of Kuwaiti Dinar (KD) with maturity of one, three and six months from the period June 1994 to August 2008. We utilize Johansen procedures to examine the relationship between spot and forward rates. Our findings show that the spot and forward rates are cointegrated for all cases, the one month interest rates, the three month interest rates as well as the six month interest rates. The explanation of this relationship indicates that the expectations hypothesis of the term structure of interest rates is accepted for the case of Kuwait.

This paper aims to investigate the effect of governance mechanisms and firm performance on chief executive officer (CEO) compensation in relation to the Jordanian business environment. This study also examines the moderating role of gender diversity.

The sample is drawn from the annual reports of 68 Jordanian firms between 2015 and 2019. This paper uses the ordinary least square regression. It also uses the generalised method of moments approach to control any endogeneity issue and analyses the data in depth. In addition, it uses a dynamic model to address concerns regarding causality in the study’s models.

The results show that governance mechanisms and firm performance have an impact on CEO compensation. Furthermore, the outcomes indicate that gender diversity significantly and positively moderates the association between firm performance and CEO compensation. These findings enhance and support agency theory in the context of Jordan.

The study’s results have significant implications for policymakers, shareholders, investors, academicians and the public in the developing Jordanian market. The findings also support more monitoring and inspection to prevent the occurrence of opportunistic management behaviour and ensure that CEO remuneration packages are appropriately designed.

This study provides a unique understanding by explaining the impact of governance and performance on CEO compensation in a developing country such as Jordan. Besides that, the current study extends prior studies in Jordan significantly.

This paper aims to integrate Islamic and mainstream economics framework towards a more realistic understanding of Muslim consumption behaviour.

The model incorporates some of the Islamic institutions like period-wise deduction of Zakat from endowments. It also includes bequests which could be significant given the Islamic injunctions on inheritance distribution and the significance placed on the institution of family. Furthermore, the model integrates the assumption that consumption opportunity set will axiomatically filter out the prohibited consumption goods from the consumption set in both contemporaneous and inter-temporal consumption.

Zakat ensures contemporaneous redistribution from endowment surplus households (those having Zakatable endowments above Nisab) to endowment-deficient households (those having Zakatable endowments below Nisab). The lifetime resources are scaled down for endowment surplus households because of the payment of Zakat in both periods and leaving bequests in old-age period, while the lifetime resources are scaled up for endowment deficient households because of the receipt of Zakat in both periods and receiving the bequests in youth.

The authors show how some of the Islamic principles and institutions can be integrated in the mainstream economics framework, especially in research studies where the objective is to understand and describe reality rather than persuasion and idealization.

Assessment of outdoor thermal perception in urban spaces is of particular importance due to its financial, social and ecological consequences. Thermal perception includes four elements: thermal sensation votes (TSV), thermal preference (T_pref), overall thermal comfort (T_c) and thermal acceptability (T_accept). Thermal acceptability can offer a benchmark that specifies the acceptable thermal range (ATR), which is useful for urban planners, designers, and bio-meteorologists. ATR, however, can be defined either using direct or indirect measures. The purpose of this paper is to investigate the validity of the indirect measures of ATR, which are most commonly used in outdoor thermal comfort assessments.

This study was conducted in the context of Melbourne, which has an oceanic temperate climate (Cfb). Three sites forming RMIT University City Campus (RUCC) were selected as the case studies, which were located in the heart of Melbourne Central Business District. A field survey was conducted in RUCC during three seasons, from November 2014 (Spring) to May 2015 (Autumn), which consisted of concurrent field measurements and questionnaire surveys from 9:00 a.m. to 5:00 p.m.

In total, 1,059 valid questionnaires were collected from the three sites of RUCC. The results of comparative analysis between the different measures of ATR determination showed that the various elements of thermal perceptions expressed the users’ thermal judgements in different ways. Therefore, it was found that the instruction recommended by the thermal comfort standards on the definition of ATR failed to provide an appropriate estimation of ATR for outdoor built environments. The ATR, defined using TSV, therefore, was revised by the direct measure of thermal acceptability. The resulting range showed broader limits in acceptable thermal conditions in RUCC outdoor spaces users. Lastly, the results suggest that in the absence of directly measured acceptability of thermal conditions in field surveys, overall comfort is the most appropriate indirect measure to use.

Some indoor thermal comfort studies have used the alternatives for defining ATR. However, as the applicability of these four methods is yet to be fully explored in outdoor conditions with large weather variations, it is valuable to conduct a comparative analysis among these methods. This study also intended to understand the dynamics of comfort range under non-steady and non-uniform outdoor conditions. The resultant outcome has provided information on the relationship between different measures of thermal perceptions. Ultimately, this research aimed to explore the extent to which the indirect measures of acceptability are considered as a reliable source of information compared to the direct measure.

The present study aims to examine the effects of the Islamic sacred months, namely, Muḥarram, Rajab, Dhu al-Qaʿdah and Dhu al-Ḥijjah, on stock prices on the Iran and Iraq Stock Exchanges.

Using the infrastructure models of the capital market, the daily stock prices were calculated for the sacred and non-sacred months. As the data of this study are non-stationary, the AMIRA time-series model was used for better understanding of the model or future projections. The dependent variables of this study are the daily stock indexes for Iranian and Iraqi Stock Exchanges, and independent ones are the sacred and non-sacred months of a lunar year. Data were gathered daily from the financial statements of Iranian and Iraqi Stock Exchanges websites. To test the hypotheses under study, a five-year period from 2012 to 2016 was considered for both Iraqi and Iranian Stock Exchanges, which corresponds with the lunar calendar from 1433-1437AH.

The obtained results indicated that there is no significant difference in stock prices between the sacred months of Muḥarram, Rajab, Dhu al-Qaʿdah and Dhu al-Ḥijjah and other non-sacred months. However, the stock price in the Iranian Stock Exchange has a significant difference in Rajab and Dhu al-Qaʿdah with other non-sacred months.

The results of this study will reveal more than ever the role of Islamic sacred months for society and users of financial statements to make better financial decisions especially in Islamic emerging markets.

The purpose of this study is to investigate the effect of the considerable Ag₂SO₄ content on the electrical and dielectric properties of (AgPO₃)_1−x(Ag₂SO₄)_x ion glass system as well as to extract thermodynamic parameters.

Glass samples of (AgPO₃)_1-x(Ag₂SO₄)_x with different mole ratios of Ag₂SO₄ [x = 0.00, 0.10,0.15,0.20 and 0.25] have been synthesized and used. X-ray diffraction and differential thermal analysis were used to investigate structural and thermal properties, and then the electrical characterizations of the bulk glasses were performed in different frequency and temperature range.

For different ratios of Ag₂SO₄ on AgPO₃, the bulk conductivity is enhanced with increasing the amount of Ag₂SO₄ until the composition of x = 0.20, after which the conductivity decreases. The general behavior of both ε’ and ε” decreases with increasing frequency and increases with increasing temperature. Complex impedance analysis studied by Z‘−Z’ and Cole–Cole plot at different temperatures revealed that bulk resistance decreases with temperature.

The calculated values of activation free energy, enthalpy and entropy change for different compositions of (AgPO₃)_1-x(Ag₂SO₄)_x showed an increase in activation energy and enthalpy when Ag₂SO₄ ratio is increased in (AgPO₃)_1-x(Ag₂SO₄)_x composition up to 20%, and then there is a decrease in their values at x = 25%, which may be explained based on non-bridging oxygen.

This study aims to examine the impact of autonomous vehicles adoption motivations (i.e. technological, ecological and intrinsic motivation) on tourists’ pro-environmental behavior and verify the mediating role of tourists’ green self-image between the relationship of eco-friendly attitudes and autonomous vehicles adoption motivations.

The data from 586 national and international tourists were analyzed using the partial least squares method.

The findings revealed that eco-friendly attitude is a significant predictor of tourists’ green self-image; tourists’ green self-image is a significant predictor of autonomous vehicles adoption motivations; and autonomous vehicles adoption motivations are significant predictors of tourists’ pro-environmental behavior. In addition, tourists’ green self-image mediated the relationship between eco-friendly attitudes and autonomous vehicles adoption motivations.

These outcomes provide valuable guidance for the future development of green destination tourism and allow interesting implications for the tourism industry and autonomous vehicles adoption.

本研究探讨自动驾驶汽车采纳动机（即技术、生态和内在动机）对游客环保行为的影响, 并验证游客绿色自我形象在环保态度和自动驾驶汽车采纳动机之间的中介作用。

收集586份来自中国国内外游客的数据, 采用偏最小二乘法进行分析。

研究结果表明, 环保态度显著影响游客绿色自我形象, 进而影响自动驾驶汽车采纳动机, 带来游客的环保行为。此外, 游客的绿色自我形象在环保态度与自动驾驶汽车采纳动机之间起到中介作用。

本研究提出了游客绿色自我形象的概念, 将游客与环保人士的日常行为进行区分。研究结果为绿色目的地旅游业的未来发展提供了方向, 对旅游业和自动驾驶汽车的采纳产生影响。

Este estudio tiene como objetivo examinar el impacto de las motivaciones para la adopción de vehículos autónomos (es decir, motivaciones tecnológicas, ecológicas e intrínsecas) en el comportamiento proambiental de los turistas y verificar el papel mediador de la autoimagen ecológica de los turistas en la relación entre las actitudes ecológicas. y las motivaciones para la adopción de vehículos autónomos.

Se analizaron los datos de 586 turistas nacionales e internacionales mediante el método de mínimos cuadrados parciales.

Los hallazgos revelaron que la actitud ecológica es un predictor importante de la autoimagen ecológica de los turistas; la autoimagen ecológica de los turistas es un predictor importante de las motivaciones para la adopción de vehículos autónomos; y las motivaciones para la adopción de vehículos autónomos son predictores importantes del comportamiento proambiental de los turistas. Además, la autoimagen ecológica de los turistas medió la relación entre las actitudes ecológicas y las motivaciones para la adopción de vehículos autónomos.

Estos resultados proporcionan una orientación valiosa para el desarrollo futuro del turismo de destino ecológico y permiten implicaciones interesantes para la industria turística y la adopción de vehículos autónomos.