Design and Optimization of Micro-Machined Sierpinski Carpet Fractal Antenna Using Ant Lion Optimization

This study investigates the optimized Sierpinski carpet fractal patch antenna and also explores the possibility of the integration of the proposed design with monolithic microwave integrated circuits. The optimization process has been performed using an ant lion optimization algorithm to achieve the required operating frequency and impedance matching. Further, due to surface waves excitation in the high index substrates used for the antenna design, the performance of the antenna degrades. Therefore, a process of micro-machining has been adopted to overcome this limitation. The micro-machining process creates an air cavity underneath the patch which further creates the low index environment in the patch antenna causing drastic improvement in the performance parameters along with the compatibility with monolithic microwave integrated circuits. The design shows multiple resonance frequencies in X-band and Ku-band. The proposed micro-machined design shows the resonance at 7.9 GHz, 9.6 GHz, 13.6 GHz, and 19 GHz with a maximum gain of 6 dBi.&nbsp

Novel Design of High Performance of MIMO antenna for 5G Bio-Telemetry applications

A MIMO antenna with 4 L-shaped elements and 2 E-shaped elements for the ISM band and also for wireless communication is proposed in the paper. This antenna contains 4 L slots in an H manner and 2 E slots are cut in the H slot. The dimensions of this proposed antenna are 40*30*1.6mm^3. The substrate used in this antenna is an FR4 substrate with a permittivity of 4.4. The operating frequency of this antenna is 2.4GHz and 5.1GHz.  All four L-shaped elements are placed in an orthogonal manner. The maximum gain is -4.4dB and the minimum gain is -16.2. The efficiency of this proposed antenna is 2.45. The radiation efficiency is 2.45dB and 75%. Fed can be provided using CPW. There is no need to concentrate on the isolation issue as we do not have several notches. This antenna is probably the most efficient antenna for the ISM band and also for wireless communication as a single-notch antenna is able to resonate at both frequencies. &nbsp

The Application of Improved Bacteria Foraging Algorithm to the Optimization of Aviation Equipment Maintenance Scheduling

Taking the aviation equipment scheduled maintenance as a prototype, this paper improves a bionic global random search algorithm - bacteria foraging optimization algorithm to solve the task-scheduling problem. Inspired by gene mutation, the activity of bacteria is dynamically adjusted to make good bacteria more capable of action. In addition, a bacterial quorum sensing mechanism is established, which allows bacteria to guide their swimming routes by using their peer experience and enhance their global search capability. Its application to the engineering practice can optimize the scheduling of the maintenance process. It is of great application value in increasing the aviation equipment maintenance efficiency and the level of command automation. In addition, it can improve the resource utilization ratio to reduce the maintenance support cost

A Review on Antenna Technologies for Ambient RF Energy Harvesting and Wireless Power Transfer: Designs, Challenges and Applications

Radio frequency energy harvesting (RFEH) and wireless power transmission (WPT) are two emerging alternative energy technologies that have the potential to offer wireless energy delivery in the future. One of the key components of RFEH or WPT system is the receiving antenna. The receiving antenna's performance has a considerable impact on the power delivery capability of an RFEH or WPT system. This paper provides a well-rounded review of recent advancements of receiving antennas for RFEH and WPT. Antennas discussed in this paper are categorized as low-profile antennas, multi-band antennas, circularly polarized antennas, and array antennas. A number of contemporary antennas from each category are presented, compared, and discussed with particular emphasis on design approach and performance. Current design and fabrication challenges, future development, open research issues of the antennas and visions for RFEH and WPT are also discussed in this review

Energy-efficient resource allocation scheme based on enhanced flower pollination algorithm for cloud computing data center

Cloud Computing (CC) has rapidly emerged as a successful paradigm for providing ICT infrastructure. Efficient and environmental-friendly resource allocation mechanisms, responsible for allocatinpg Cloud data center resources to execute user applications in the form of requests are undoubtedly required. One of the promising Nature-Inspired techniques for addressing virtualization, consolidation and energyaware problems is the Flower Pollination Algorithm (FPA). However, FPA suffers from entrapment and its static control parameters cannot maintain a balance between local and global search which could also lead to high energy consumption and inadequate resource utilization. This research developed an enhanced FPA-based energy efficient resource allocation scheme for Cloud data center which provides efficient resource utilization and energy efficiency with less probable Service Level Agreement (SLA) violations. Firstly, an Enhanced Flower Pollination Algorithm for Energy-Efficient Virtual Machine Placement (EFPA-EEVMP) was developed. In this algorithm, a Dynamic Switching Probability (DSP) strategy was adopted to balance the local and global search space in FPA used to minimize the energy consumption and maximize resource utilization. Secondly, Multi-Objective Hybrid Flower Pollination Resource Consolidation (MOH-FPRC) algorithm was developed. In this algorithm, Local Neighborhood Search (LNS) and Pareto optimisation strategies were combined with Clustering algorithm to avoid local trapping and address Cloud service providers conflicting objectives such as energy consumption and SLA violation. Lastly, Energy-Aware Multi-Cloud Flower Pollination Optimization (EAM-FPO) scheme was developed for distributed Multi-Cloud data center environment. In this scheme, Power Usage Effectiveness (PUE) and migration controller were utilised to obtain the optimal solution in a larger search space of the CC environment. The scheme was tested on MultiRecCloudSim simulator. Results of the simulation were compared with OEMACS, ACS-VMC, and EA-DP. The scheme produced outstanding performance improvement rate on the data center energy consumption by 20.5%, resource utilization by 23.9%, and SLA violation by 13.5%. The combined algorithms have reduced entrapment and maintaned balance between local and global search. Therefore, based on the findings the developed scheme has proven to be efficient in minimizing energy consumption while at the same time improving the data center resource allocation with minimum SLA violation

Large space structures and systems in the space station era: A bibliography with indexes (supplement 04)

Bibliographies and abstracts are listed for 1211 reports, articles, and other documents introduced into the NASA scientific and technical information system between 1 Jul. and 30 Dec. 1991. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems

Towards Oxide Electronics:a Roadmap

At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore's law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and heterostructures, in sectors as data storage and computing, optics and plasmonics, magnonics, energy conversion and harvesting, and power electronics

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion

Fluctuation-induced interactions and nonlinear nanophotonics

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 293-329).We present theoretical and numerical methods for studying Casimir forces and nonlinear frequency conversion in nanophotonic media consisting of arbitrary geometries and materials. The first section of the thesis focuses on the study of various geometry-enabled resonant effects leading to strong nonlinear interactions. The starting point of this work is a coupled-mode theory framework for modeling a wide range of resonant nonlinear frequency-conversion processes in general geometries, ameliorating the need for repeated and expensive finite-difference time-domain simulations. We examine the predictions of the theory for two particular nonlinear processes: harmonic generation and difference-frequency generation. Our results demonstrate strong enhancement of nonlinear interactions at a "critical" input power leading to 100% frequency conversion, among many other interesting dynamical effects. Using a quantum-mechanical description of light, based on cavity quantum electrodynamics, similar enhancement effects are demonstrated at the single-photon level, leading to the possibility of achieving all-optical switching of a single signal photon by a single gating photon in a waveguide-cavity geometry consisting of pumped four-level atoms embedded in a cavity. Finally, we describe how one may tailor the geometry of certain materials to enhance their nonlinear susceptibilities by exploiting a consequence of the Purcell effect. The second section of the thesis, the main contribution of this work, presents a new formulation for studying Casimir forces in arbitrary geometries and materials that directly exploits efficient and well-developed techniques in computational electromagnetism. To begin with, we present the step-by-step conceptual development of our computational method, based on a well-known stress tensor formalism for computing Casimir forces. A proof-of- concept finite-difference frequency-domain implementation of the stress-tensor method is described and checked against known results in simple geometries. Building on this work, we then describe the basic theoretical ingredients of a new technique for determining Casimir forces via antenna measurements in tabletop experiments. This technique is based on a (derived) correspondence between the complex-frequency deformation of the Casimir frequency-integrand for any given geometry and the real-frequency classical electromagnetic response of the same geometry, but with dissipation added everywhere. This correspondence forms the starting point of a numerical Casimir solver based on the finite-difference time-domain method, which we describe and then implement via an off-the-shelf time-domain solver, requiring no modifications. These numerical methods are then used to explore a wide range of geometries and materials, of various levels of complexity: First, a four-body piston-like geometry consisting of two cylinders next to adjacent walls, which exhibits a non-monotonic lateral Casimir force (explained via ray optics and the method of images); Second, a zipper-like, glide-symmetric structure that leads to a net repulsive force arising from a competition between attractive interactions. Finally, we examine a number of geometries consisting of fluid-separated objects and find a number of interesting results. These include: stable levitation and suspension of compact objects, dispersion-induced orientation transitions, and strong non-zero temperature Casimir effects.by Alejandro Rodriguez-Wong.Ph.D

Annual Report 2013 - Institute of Ion Beam Physics and Materials Research

The year 2013 was the third year of HZDR as a member of the Helmholtz Association (HGF), and we have made progress of integrating ourselves into this research environment of national Research centers. In particular, we were preparing for the evaluation in the framework of the so-called program oriented funding (POF), which will hopefully provide us with a stable funding for the next five years (2015 – 2019). In particular, last fall we have submitted a large proposal in collaboration with several other research centers. The actual evaluation will take place this spring. Most of our activities are assigned to the program “From Matter to Materials and Life” (within the research area “Matter”). A large fraction of this program is related to the operation of large-scale research infrastructures (or user facilities), one of which is our Ion Beam Center (IBC). The second large part of our research is labelled “in-house research”, reflecting the work driven through our researchers without external users, but still mostly utilizing our large-scale facilities such as the IBC, and, to a lesser extent, the free-electron laser. Our in-house research is performed in three so-called research themes, as depicted in the schematic below. What is missing there for simplicity is a small part of our activities in the program “Nuclear Waste Management and Safety” (within the research area “Energy”)