Electromagnetic Metamaterials: Transmission Line Theory and Microwave Applications. By Christophe Caloz and Tatsuo Itoh.

This paper puts forth a vision and an architecture for a community knowledge evolution system. We propose augmenting a multimedia document repository (digital library) with innovative knowledge evolution support, including computer-mediated communications, community process support, decision support, advanced hypermedia features, and conceptual knowledge structures. These tools, and the techniques developed around them, would enable members of a virtual community to learn from, contribute to, and collectively build upon the community's knowledge and improve many member tasks. The resulting Collaborative Knowledge Evolution Support System (CKESS) would provide an enhanced digital library infrastructure serving as an ever-evolving repository of the community's knowledge, which members would actively use in everyday tasks and regularly update.

/pdf/toward-virtual-community-knowledge-evolution-2we4pcxb03.pdf

Toward Virtual Community Knowledge Evolution

A system facilitates the secure access, and update of patient record information and the creation and navigation of image menus supporting the location and access of desired patient record data by a user. A method for use by a portable processing device for accessing patient record information involves receiving user entered information identifying at least one patient record to be acquired and a content portion of a patient record to be acquired. A patient record repository is accessed by generating a URL link including an address of the repository and containing fields incorporating the information identifying the content portion and the patient record. The generated URL link is communicated to an application used for accessing the repository and the identified patient record content portion is received in response to the communication.

System and user interface for accessing and processing patient record information

This paper describes a program of research designed to understand how knowledge-sharing and learning can be supported in virtual communities. To conduct this research, we propose the development of a series of knowledge sharing tools and procedures followed by a rigorous evaluation of the use of these tools in real virtual community environments. The paper starts with a brief examination of relevant theory in knowledge management and learning. This leads to a comprehensive set of research questions. To investigate these questions, we next propose a set of tools for supporting collaboration, knowledge sharing and learning for distributed communities. Evaluation is also a vital element of this research.

/pdf/towards-knowledge-sharing-and-learning-in-virtual-jjiomov5se.pdf

Towards knowledge-sharing and learning in virtual professional communities

As a general and rigid mathematical tool, wavelet theory has found many applications and is constantly developing. This article reviews the development history of wavelet theory, from the construction method to the discussion of wavelet properties. Then it focuses on the design and expansion of wavelet transform. The main models and algorithms of wavelet transform are discussed. The construction of rational wavelet transform (RWT) is provided by examples emphasizing the advantages of RWT over traditional wavelet transform through a review of the literature. The combination of wavelet theory and neural networks is one of the key points of the review. The review covers the evolution of Wavelet Neural Network (WNN), the system architecture and algorithm implementation. The review of the literature indicates the advantages and a clear trend of fast development in WNN that can be combined with existing neural network algorithms. This article also introduces the categories of wavelet-based applications. The advantages of wavelet analysis are summarized in terms of application scenarios with a comparison of results. Through the review, new research challenges and gaps have been clarified, which will serve as a guide for potential wavelet-based applications and new system designs.

https://ieeexplore.ieee.org/ielx7/6287639/6514899/09785993.pdf

A Review of Wavelet Analysis and Its Applications: Challenges and Opportunities

The universal filtered multi-carrier (UFMC) technique has been proposed as a prominent waveform candidate for fifth generation (5G) communication techniques. However, UFMC systems exhibit a high peak-to-average power ratio (PAPR), which causes serious degradation in the performance of the system. Therefore, this paper puts forward an effective hybrid PAPR reduction method to reduce the high PAPR of the UFMC system. The proposed hybrid scheme consists of a combination of precoding and non-linear companding techniques (NLCTs). A comparative analysis of the performance of different precoding methods, NLCTs, and hybrid methods are investigated in terms of the cumulative distribution function of the PAPR and the bit error rate (BER). The simulation results show that the proposed hybrid UFMC system has better PAPR reduction performance compared to conventional NLC and precoded UFMC systems. Moreover, the BER analysis of the UFMC system verifies that the proposed hybrid technique shows better BER performance compared to conventional companding techniques.

/pdf/performance-analysis-of-hybrid-peak-to-average-power-ratio-31fxkuzrew.pdf

Performance Analysis of Hybrid Peak to Average Power Ratio Reduction Techniques in 5G UFMC Systems

Filtered orthogonal frequency division multiplexing (F-OFDM) is one of the most prominent waveform candidates when it comes to fifth-generation (5G) wireless communication and beyond. This paper analyzes the performance of the F-OFDM system in terms of the peak-to-average power ratio (PAPR) and bit error rate (BER). The F-OFDM system exhibits a high PAPR, which introduces earnest deterioration in its performance. Consequently, an efficient PAPR-reduction technique has been recommended to reduce the effect of the high value of PAPR of the F-OFDM system. The prospective two-piecewise companding (TPWC) scheme effectively reduces the peak power by analyzing large and small amplitudes individually, so its outcome has both piecewise linear and continuous characteristics. The performances of different PAPR reduction techniques are compared in terms of PAPR complementary cumulative distribution functions and BERs. It is shown that the proposed TPWC transform can significantly reduce PAPR with reduced computational complexity compared with conventional companding techniques.

/pdf/performance-analysis-of-the-two-piecewise-linear-companding-4wzuphvjkq.pdf

Performance Analysis of the Two-Piecewise Linear Companding Technique on Filtered-OFDM Systems

Using a dynamic hypermedia engine (DHE), we propose to automate the following features for database systems, both on and off the Web. First we automatically generate links based on the database's relational (physical) schema and its original (non-normalized) entity-relationship specification. Second, the application developer can specify which kinds of database elements are related to diverse elements in the same or different database application, or even another software system. Our current DHE prototype illustrates these for a relational database management system. We propose integrating data warehousing applications into the DHE. We also propose incorporating data mining as a new kind of automated link generation. Passing the application element selected by a user, a data mining system that would discover interesting relationships for that element. DHE would then map each relationship to a link.

/pdf/towards-hypermedia-support-for-database-systems-170dcpxwfj.pdf

Towards hypermedia support for database systems

In this paper, two different patch antenna geometries are proposed for wireless sensor applications involving electromagnetic propagation from inside the jet engine to our designed relaying antenna at the rim of the inlet. First, an enhanced modified version of our earlier proposed two-element circular patch antenna array is proposed. We follow with a fresh new design based on two-element array of hybrid rectangular circular patch antenna geometry. Both antenna designs are discussed in light of basic governing equations enabling initial design calculations, intuitions behind selecting the design elements based on desired propagation characteristics, simulation results, as well as fabrication and experimental measurements. Because of the environmental constraints, the proposed antennas need to be an extremely low profile and ultrathin. The proposed relaying antennas are designed to have a dual-beam pattern, one of which is directed toward the inside of the jet engine. The antennas are simulated using HFSS as well as fabricated and measured inside an anechoic chamber. Experimental results, which sufficiently agree well with the simulation results, demonstrate the achievement of the desired characteristics by fabricated antennas for deployment on jet engines.

Patch Antenna Array Designs for Wireless Communication Applications Inside Jet Engines

Using full wave analysis in `Ansys® HFSS', we obtain the electric field distribution inside a jet engine containing one set of 24 blades due to the excitation provided by a simple Hertzian dipole. Hertzian dipole illuminates the structure by radiating continuous wave field. The real and imaginary components of the electric field along the engine axis for various excitation positions are extracted and analyzed statistically. Our results show that the real and imaginary field components along the engine's main axis are dependent Gaussian distributions with different means and variances. These results provide a novel general statistical modeling for the field distribution inside the engine. This statistical approach to electromagnetic analysis avoids all the sophisticated engine details.

http://www.qu.edu.qa/offices/vpcao/graduates/GRADvocate/documents/dd130.pdf

A. Krishna

Papers

Performance Analysis of Hybrid Peak to Average Power Ratio Reduction Techniques in 5G UFMC Systems

Performance Analysis of the Two-Piecewise Linear Companding Technique on Filtered-OFDM Systems

Towards hypermedia support for database systems

Patch Antenna Array Designs for Wireless Communication Applications Inside Jet Engines

On the statistical distribution of electric field inside jet engines