German-Jordanian University

About: German-Jordanian University is a education organization based out in Amman, Jordan. It is known for research contribution in the topics: Fading & Photovoltaic system. The organization has 565 authors who have published 1368 publications receiving 14252 citations.

Index Modulation Techniques for Next-Generation Wireless Networks

Abstract: What is index modulation (IM)? This is an interesting question that we have started to hear more and more frequently over the past few years. The aim of this paper is to answer this question in a comprehensive manner by covering not only the basic principles and emerging variants of IM, but also reviewing the most recent as well as promising advances in this field toward the application scenarios foreseen in next-generation wireless networks. More specifically, we investigate three forms of IM: spatial modulation, channel modulation and orthogonal frequency division multiplexing (OFDM) with IM, which consider the transmit antennas of a multiple-input multiple-output system, the radio frequency mirrors (parasitic elements) mounted at a transmit antenna and the subcarriers of an OFDM system for IM techniques, respectively. We present the up-to-date advances in these three promising frontiers and discuss possible future research directions for IM-based schemes toward low-complexity, spectrum- and energy-efficient next-generation wireless networks.

Smart Cities: A Survey on Data Management, Security, and Enabling Technologies

Abstract: Integrating the various embedded devices and systems in our environment enables an Internet of Things (IoT) for a smart city. The IoT will generate tremendous amount of data that can be leveraged for safety, efficiency, and infotainment applications and services for city residents. The management of this voluminous data through its lifecycle is fundamental to the realization of smart cities. Therefore, in contrast to existing surveys on smart cities we provide a data-centric perspective, describing the fundamental data management techniques employed to ensure consistency, interoperability, granularity, and reusability of the data generated by the underlying IoT for smart cities. Essentially, the data lifecycle in a smart city is dependent on tightly coupled data management with cross-cutting layers of data security and privacy, and supporting infrastructure. Therefore, we further identify techniques employed for data security and privacy, and discuss the networking and computing technologies that enable smart cities. We highlight the achievements in realizing various aspects of smart cities, present the lessons learned, and identify limitations and research challenges.

Global warming: review on driving forces and mitigation

Abstract: Global warming is one of the major consequences of the human activities where the overuse of fossil fuels as energy resources caused the increase in the concentration of the greenhouse gases (GHGs), such as CO2, CH4, N2O, and water vapor, in the atmosphere causing the increase in the average surface temperature of the earth. This article reviews the driving forces of global warming and highlights the major contributors to this phenomenon and presents some of the mitigation techniques. Water vapor is responsible for two-third of the global warming; however, CO2 is considered as the controlling factor of the global warming. In other words, if the concentration of CO2 did not increase, global warming would not have happened. Scientists claim that doubling or halving the CO2 in the atmosphere causes the change in the average surface temperature of the earth by +3.8 C or −3.6 C, respectively. However, this amount of change depends on the change in the humidity of the air which in return depends on the air’s temperature. Conversely, even though the other GHGs such as CH4 and N2O have stronger ability to absorb the radiation, their contribution in the global warming is insignificant because of their low concentration in the atmosphere compared with CO2. The adoption of the mitigation and adaptation strategies at the same time is the most effective economic and technical solution for the global warming issue. © 2018 American Institute of Chemical Engineers Environ Prog, 2018

Consumer attitudes towards online shopping

Abstract: Purpose – The purpose of this paper is to examine consumer attitudes toward online shopping in Jordan. The paper introduces an integrated model which includes trust, perceived benefits, perceived web quality, and electronic word of mouth (eWOM) along with their relationships in order to examine their effects on consumer attitudes toward online shopping. Design/methodology/approach – A structured and self-administered online survey was employed targeting online shoppers of a reputable online retailer in Jordan; i.e. MarkaVIP. A sample of 273 online shoppers was involved in the online survey. A series of exploratory and confirmatory factor analyses were used to assess the research constructs, unidimensionality, validity, and composite reliability. Structural path model analysis was also used to test the hypothesized relationships of the research model. Findings – The empirical findings of this study indicate that consumer attitudes toward online shopping is determined by trust and perceived benefits. Trust ...

Supercritical drying of aerogels using CO2: Effect of extraction time on the end material textural properties

Abstract: Aerogel technology provides high added-value lightweight materials with outstanding textural properties (i.e., high surface area and open porosity). Aerogels are obtained from wet gels by using a suitable drying technology, usually supercritical drying process, able to avoid the pore collapse phenomenon in order to keep intact the porous texture of the wet material. In this sense, the study of the kinetic profile of the gel supercritical drying is regarded as a key aspect to be considered in the specific case of the design of aerogel-based systems. In this work, the drying profile with supercritical carbon dioxide (scCO 2 ) of alcogels (in ethanol) was determined using a customized supercritical fluid extraction equipment. The drying of alcogels from different precursors (inorganic-silica-, organic-starch-), densities (silica aerogel of densities 0.08 and 0.15 g/cm 3 ) and morphologies (cylindrical monoliths, microspheres) was studied. Depending on the nature of the gel precursor, the extent of drying (i.e., drying time duration) gave significant differences in the end textural properties of the dried gel.