Crosstalk in misaligned free space optical interconnects: modelling and simulation

We introduce convenient model and an optimization scheme to optimize the signal-to-crosstalk ratio (SCR) in a free space optical interconnects (FSOIs) system that uses microlenses with finite circular apertures. In this model, we consider both the stray light crosstalk and the crosstalk due to the diffraction at the microlens apertures to evaluate the SCR. Using cylindrical form of Collins diffraction integral and the Laguerre–Gaussian (LG) beam model, we derive an approximate closed form formula for the optical field of a multimode LG beam propagating through circular apertured FSOIs by expanding the hard edge circular aperture function of the microlens in terms of complex Gaussian functions. The analyses indicate that the size of the detector is an important factor to optimize the SCR for both the apertured and the unapertured misaligned FSOIs system. The effect of higher order mode of the laser source on the SCR is also considered.

Linking Ontology, Epistemology And Research Methodology

The purpose of this paper is to offer insights that can help researchers to link ontology, epistemology and research methodology. This paper outlines the links among ontology, epistemology and research methodology by exploring ontological, epistemological and methodological perspectives in the research. It discusses how ontological and epistemological issues influence research methodology by providing a clear understanding for different research methodologies based on ontology and epistemology. Furthermore, attention is given to research aspects such as the elements of research process, research philosophy, research approach, research strategy, the choice of method, and research design

Employees’ Service Innovation Behavior and New Service Development in Four- and Five-Star Hotels

This study aims to explore the impact of Employee Service Innovation Behavior (ESIB) on New Service Development (NSD) among hotels’ employees. A research model was proposed in which one hypothesis was developed. The empirical data were collected from employees who are working in four- and five-star hotels in Jordan. A total of 332 questionnaires were returned and the data were analyzed using a single regression to determine the relationship between ESIB and NSD. The results supported the proposed model that there is a significant relationship between ESIB and NSD, and it also found that service innovation performance is exited in the hotel industry. The theoretical and managerial implications were drawn based on the study findings, and recommendations for future researchers were made, and limitations and conclusions are discussed

Employees’ perspectives of service quality in hotels

Although the importance of service quality has been recognised, few studies have addressed service quality in hotels from the perspective of employees. Therefore, this study aims to measure the service quality of four and five-star hotels in Jordan from the employees’ perspective based on the SERVQUAL model. The current study was carried out by measuring the data gathered according to a five-point Likert scale. A quantitative survey method was applied, and therefore the SERVQUAL instrument was used to measure service quality. Data obtained from a sample of 238 respondents drawn from ten four- and five-star hotels in Jordan were analysed with the SPSS software based on descriptive statistics. The study’s findings indicated that service quality of five-star hotels in Jordan was higher than that of four-star hotels.Keywords: service quality, SERVQUAL, work environment, competitive advantage, hotel industr

Improvement of misalignment tolerance in free-space optical interconnects

In this paper, the use of micro lenses with non-uniform transmittance apertures as an alternative to those with uniform transmittance apertures in optical communication systems is proposed. In particular, we consider the use of micro lenses with tapered Gaussian transmittance profiles to improve the misalignment tolerance in optical interconnects. We study the effects of utilizing Gaussian transmittance profiles on the propagation of light beams and the signal to crosstalk ratio of misaligned optical systems. Moreover, we consider the use of uniform transmittance profiles in optical systems for the sake of comparison. To this end, the crosstalk optical noise is modeled at the plane of the detectors array considering the two scenarios of uniform and Gaussian apertures. This was possible after finding the optical field for both scenarios at the of the detectors array. Numerical results clearly demonstrate the significant improvement in decreasing the crosstalk and increasing the signal to crosstalk ratio in the considered optical systems upon utilizing the Gaussian profiles

Bandwidth density optimization of misaligned optical interconnects

In this paper, the bandwidth density of misaligned free space optical interconnects (FSOIs) system with and without coding under a fixed bit error rate is considered. In particular, we study the effect of using error correction codes of various codeword lengths on the bandwidth density and misalignment tolerance of the FSOIs system in the presence of higher order modes. Moreover, the paper demonstrates the use of the fill factor of the detector array as a design parameter to optimize the bandwidth density of the communication. The numerical results demonstrate that the bandwidth density improves significantly with coding and the improvement is highly dependent on the used codeword length and code rate. In addition, the results clearly show the optimum fill factor values that achieve the maximum bandwidth density and misalignment tolerance of the system

Concept, opportunities and challenges of urban tourism in the Arab world: Case studies of Dubai, Cairo and Amman

This paper aims to provide a better understanding of the current situation of urban tourism with referring to the experiences of the Arab World. By using bibliographic documentation and descriptive-analytic method, this paper addresses the main opportunities, impediments, and challenges of urban tourism in three Arab cities (Dubai, Cairo and Amman). This paper indicates that the three cities have many opportunities stemming from their location and their rich tourism resources. Moreover, urban tourism in these cities should confront some internal (country based) and external (global and regional) challenges such as seasonality, pollution, congestion, competition, funding and instability. Some recommendations and policy implications were suggested. The paper concludes, by arguing, that common internal and external challenges need to be addressed in a systematic manner within the broader cultural and tourism policy context in which urban tourism is now implicated. There is a lack of literature on urban tourism within the Arab countries, which is attributed to that tourism in the Arab world is heritage dominated type. Therefore, this research also attempts to bridge the gap in the existing literature about urban tourism in the Arab cities

Proverbs, Anti-Proverbs and Language Learning

Proverbs express public wisdom and reflect public attitudes. In the traditional definition they are untouchable when it comes to form. Like other idiomatic expressions, they are learnt as whole, indivisible chunks. As such, they should be included in language classes, if a native-like mastery is to be achieved since they constitute an indispensible component of one’s linguistic repertoire. Recent studies have shown that proverbial form is not as “holy” as tradition holds it. Speakers “commit” different kinds of transformations to popular proverbs, their sanctity notwithstanding. Examples of different types of mutations are discussed in this paper and categorized under the headings of: sound imitation, word play, stunting (or cropping), combining more than one proverb, and introducing a completely new “proverb”. These different types are seen to produce proverb-like statements which could eventually turn into proverbs proper. This paper argues that all such transformations have a purpose not unlike the purpose of proverbs proper: they are often utilized by their users to “decorate” their texts with what sounds like traditionally accepted truths very similar to the truths expressed by proverbs.Inclusion of this part of language in language classes becomes integral to the process of teaching since knowledge of these expressions, like that of other idiomatic expressions, is essential for perfecting a learner’s mastery of a target language

Hope: Toward Conceptual Maturity in Nursing

Purpose: to explore the contextual usage of the concept of hope within the discipline of nursing across two different contexts: spinal cord injury and cancer from the patient's perspective. Method: the Pragmatic Utility approach was utilized for surplus clarification and advancement of the concept. Findings: there is no consistency in the way the concept of hope is conceptualized across two contexts, a number of overlapping concepts were found, and the concepts' operationalization is limited. Nursing Implications and Conclusion: despite a considerable attention to the concept of hope, there is no consensus on the definition of hope. Refinement and clarification of the concept of hope will improve nursing practice through providing nurses who deal with patients suffering from chronic illnesses and their families with better understanding and helping them to design strategies to inspire hope across life span. Future studies to enhance the measurement of the concept of hope is needed. Keywords: Cancer, Concept Maturity, Hope, Spinal Cord Injury

Focus Groups in Hospitality Research Why are they not used in Jordan?

The purpose of this study is to identify the reasons for the lack of focus groups in Jordan by conducting a focus group with twenty four Academics from Jordanian Universities. Focus groups are commonly used for academic purposes and taught at colleges and universities. The outcome of focus groups for marketing, especially in the tourism industry, is a beneficial learning tool. Focus groups, however, are rarely used for a number of reasons. This research tool is foreign to university students, and unless they study abroad, they are not exposed to a wide range of research and education tools. There are barriers that exist with focus groups. These barriers include: government and educational funding, cultural limitations, personal expectations, teaching materials and resources. Following this research, the recommendations are to have focus groups implemented in Jordanian school systems and to conduct focus group training sessions, encourage students to use them as a research tool and explain the link between focus groups and the hospitality industry. By limiting curriculums in Jordanian education systems, students will not have the proper knowledge or skills once they graduate to compete with markets outside of Jordan. Recommendations are discussed based on the author’s research findings