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The aim of this work is to miniaturize a microstrip patch antenna resonating at 3 GHz. For this purpose, defected ground structure (DGS) has been employed to shift the resonance frequency of an initial microstrip antenna from 5.7 GHz to 3 GHz by disturbing the antenna's current distribution. The proposed DGS is incorporated in the ground plane under the patch antenna to improve its performances. Finally, a miniaturization up to 50%, with respect to the conventional microstrip antenna, is successfully accomplished. A prototype of the antenna was fabricated with the FR4 substrate and tested. The measurements results were in good agreement with simulation results.

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and a visiting professor working with the Institute for Systems Engineering Research/MSU/U.S. Army Corps of Engineers. Dr. Jaradat received a PhD in Engineering Management and Systems Engineering from Old Dominion University in 2014. His main research interests include systems engineering and management systems, systems thinking and complex system exploration, system of systems, virtual reality and complex systems, systems simulation, risk, reliability and vulnerability in critical infrastructures with applications to diverse fields ranging from the military to industry. His publications appeared in several ranking journals including the IEEE Systems Journal, and the Computers & Industrial Engineering Journal. His total awarded projects exceed $ 4.2 M including National Science Foundation

This study utilized the application of authentic Virtual Reality (VR) to replicate the real-world complex system scenarios of a large retail supply chain. The proposed VR scenarios were developed based on an established systems thinking instrument that consists of seven dimensions: level of complexity, independence, interaction, change, uncertainty, systems’ worldview, and flexibility. However, in this study, we only developed the VR scenarios for the first dimension, level of complexity, to assess an individual’s Systems Thinking Skills (STS) when he or she engages in a turbulent virtual environment. The main objective of this study was to compare a student’s STS when using traditional ST instruments versus VR scenarios for the complexity dimension. The secondary aim was to investigate the efficacy of VR scenarios utilizing three measurements: Simulation Sickness Questionnaire (SSQ), System Usability Scale (SUS), and Presence Questionnaire (PQ). In addition to the three measures, NASA TLX assessment was also performed to assess the perceived workload with regards to performing the tasks in VR scenarios. The results show students’ preferences in the VR scenarios are not significantly different from their responses obtained using the traditional systems skills instrument. The efficacy measures confirmed that the developed VR scenarios are user friendly and lie in an acceptable region for users. Finally, the overall NASA TLX score suggests that users require 36% perceived work effort to perform the activities in VR scenarios.