New Approach of Efficiency Improvement in 10 dB Doherty Power Amplifier for 4G LTE and 5G Wireless Applications

In this research article, the design procedure and comparative analysis of the 10 dB Doherty power amplifier (DPA) with single and double auxiliary amplifier for maximum efficiency has been presented. A new Doherty amplifier structure with parallel two auxiliary amplifiers based on conventional design having optimum value of load resistance of 3.162 ohm has been proposed with higher efficiency of 85.803% and analyzed with n-tone sinusoidal signal. The proposed Doherty power amplifier can achieve drain efficiency of 83.299% & with single and 85.803% with dual auxiliary amplifier at the output power back, off of 10 dB from the saturated power point. The simulated outputs are matched with mathematically derived design values. The simulated n-tone time response shows that the proposed design of DPA can able to handle different modulation standards at different frequencies with compatible structure.

Enhancing Creative Redesign through Multi-Modal Design Heuristics for Additive Manufacturing

When designing for Additive Manufacturing (AM), designers often need assistance in breaking out of their conventional manufacturing mind-set. Previously, Blösch-Paidosh and Shea (2019) derived Design Heuristics for AM (DHAM) to assist designers in doing this during the early phases of the design process. This work proposes a set of 25 multi-modal cards and objects to accompany each of the Design Heuristics for AM and studies their effect through a series of controlled, novice user studies conducted using both teams and individuals who redesign a city E-Bike. The resulting AM concepts are analyzed in terms of the quantity of design modifications relevant for AM, AM-flexibility, novelty, and variety. It is found that the DHAM cards and objects increase the inclusion of AM concepts, AM modifications, and the unique capabilities of AM in the concepts generated by both individuals and teams. They also increase the creativity of the concepts generated by both individuals and teams, as measured through a series of defined metrics. Further, the objects in combination with the cards are more effective at stimulating the generation of a wider variety of designs than the cards alone. Future work will focus on studying the use of the DHAM cards and objects in an industrial setting.

Design and Evaluation of a New Resin-Filled GFRP Pipe Connection System for Butt Splicing of FRP Bars

Fiber-reinforced polymer (FRP) bars are one of the promising alternatives for steel bars used in concrete structures under corrosion or non-magnetic environments due to the unique physical properties of FRP materials. When compared with steel bars, FRP bars are difficult to be spliced in field application due to their anisotropy and low shear and compressive strengths. In view of this, the paper presents a new non-metallic connection system (i.e., resin-filled glass fiber-reinforced polymer (GFRP) pipe connection system) for the butt splicing of FRP bars. With the proposed connection system and a simplified trilinear interfacial bond-slip model, a set of design formulas were derived based on the requirement that the proposed connection system should provide a load transfer capacity beyond the tensile capacity of the spliced FRP bars (i.e., to fulfill the high tensile strength of FRP materials). Besides, considering the fabrication error-induced load transfer capacity reduction of the connection system in field application, a correction factor was introduced in the paper to compensate for the reduced load transfer capacity by increasing the FRP bar anchorage length. At last, to estimate the effectiveness of the proposed connection system and the derived design formulas, nine specimens were fabricated with a kind of commercially available basalt fiber-reinforced polymer (BFRP) bars and the designed connection system and tested under unidirectional tension to study their tensile performance. With the comparison between the tested and theoretical results, the effectiveness of the proposed connection system and the derived design formulas are verified.

Challenge-derived design practices for a semantic gazetteer for medieval and early modern places

In recent years gazetteers based on semantic web technologies were discussed as an effective way to describe, formalize and standardize place data by using contextual information as a method to structure and distinguish places from each other. While research concerning semantic gazetteers with regard to historical places has pointed out the importance of enabling the creation of a global and epoch-spanning gazetteer, we want to emphasize the importance of taking a domain oriented approach as well – in our case, focusing on places set in medieval and early modern times. By discussing the topic from the historians’ perspective, we will be able to identify a number of challenges that are specific to the semantic representation of places set in these time periods. We will then do a survey of existing gazetteer projects that are taking historical places into account. This will enable us to find out which technologies and practices already exist, that can meet the demands of a gazetteer that considers the time specific geographic, social and administrative structures of medieval and early modern times. Finally we will develop a catalogue of design practices for such a semantic gazetteer. Our recommendations will be derived from these existing solutions as well as from our epoch-specific challenges identified before.

A microstrip switched-band impedance transformer for frequency-dependent complex load

This study presents a simple switched-band impedance transformer using microstrip lines. The proposed circuit is suitable for loads with frequency-dependent complex impedances at two arbitrary operating frequencies. The transformer comprises two cascaded microstrip lines and two detachable shunt stepped-impedance stubs, which are separately connected to the main line via switching diodes such that provide good matching at one of the two operating frequencies and suppress unwanted signal at the other frequencies. The structure contains several user-set parameters such that designers can create a smaller circuit. The circuit parameters, except the user-set ones, are obtained using the derived design formula. The numerical simulations and experimental results agree well such that validate the proposed structure and the design formula.

Programmable FFT Processor using Dual RAM and ROM Technologies for Future 5G Communications

The high-throughput programmable Fast Fourier transform processor supports the usage of 2-stream 1024/2048/4096-point Fast Fourier Transforms and 1-to 4- stream 64/128-point Fast Fourier Transform for 4G,wireless local networks and for 5G.The proposed architecture which was designed is a well-intentionedfour-bank single-port SRAM which is being working in four-word data width, the design which is proposed gives us sixteen memory pathways . where the data is accessed up to this extent where it can be used in upcoming 5G. The radix-16 butterfly process element comprises of 2 cascaded parallel, pipelined radix-4 butterfly units which is specified. The projected memory-addressing methodology will effectively wear down single-port, merged-bank memory with high-radix process components. Comparing with typical memory based Fast Fourier Transform styles, the derived design has higher performance in expressions of area and power consumption. The architecture which is projected occupies the tiniest area of around1.21mm2 .The processor supports 1966MS/s 4096-point FFT and frequency of 1GHz.The Electronic design automation synthesis results show the power consumption is 32.16mW.The SQNR performance analysis is 42.14 dB.

Virtual Course of Accessibility of the Tecnológico Nacional de México and IT Aguascalientes

This chapter described an analysis and those derived design improvements for an accessibility course offered by Tecnológico Nacional de México/IT Aguascalientes (ITA). The course is addressed to train professors for awareness and implementation of educational strategies that allow an accessible and inclusive learning environment. Enhancements found were oriented to makes easier teachers' tasks when generating strategies for the creation of accessible educational content. All suggestions were derived from a usability analysis of both interactive elements and the structure of the course on the on-line learning platform Moodle. The study was performed by implementing several international standards and design guides such as the traditional web content accessibility guidelines (WCAG).

Pressure Hull Design Methods for Unmanned Underwater Vehicles

This paper describes design methods for the plastic hull of an Unmanned Underwater Vehicle (UUV), with a particular focus on its cylindrical body and nearly spherical domes at the ends. With the proposed approach, the methodologies reported in the literature were compared, and suitable modifications and improvements were investigated and implemented to extend the classical theories and data to this case study. The investigated underwater vehicle, named FeelHippo, was designed and assembled by the Department of Industrial Engineering of the University of Florence. Its main hull is composed of an extruded PMMA (PolyMethyl MethAcrylate) cylinder and two thermoformed PMMA domes. Breakage of the hull results in destructive phenomena, namely, yielding and buckling. An experimental campaign and FEM (Finite Element Method) analysis were carried out to complete the theoretical study, and the collapse pressures were compared with the derived design values. In conclusion, the proposed innovative method is a lean and effective technique for designing underwater hull domes and predicting the collapse pressures.

Perceptions of Spatiality: Supramodal Meanings and Metaphors in Therapeutic Environments

This paper explores the perceptions of the spatiality of individuals who self-harm, with the aim of understanding the design aspects which foster supportive therapeutic environments. Analysis of responses found that there were key similarities in areas of perception of architectural interior space, refuting the commonly held view that all architectural response is purely subjective, and that subjective experience cannot be shared. Three examples of perceptions of interior therapeutic environments are discussed to highlight how the perceptions of spatiality of individuals who self-harm consists of a particular cluster of spatial understandings, behaviours and focuses, manifesting as a strong emotional overtone overlaid onto built environments. This includes common kinds of triggers and emotional reactions provoked by aspects of the built environment. This paper discusses architectural aspects in relation to subjectivity in perception, constructs of interiority, and the role of supramodal engagement in influencing perceptual responses to interior space. By understanding how individuals who self-harm experience a space, a greater comprehension of the design of these environments delivering mental health services may be enabled. This paper tables a series of research-derived design suggestions to facilitate supportive therapeutic spaces. This paper also proposes a series of further research directions to explore the relationships between constructs of interiority, the physical interior space, and the therapeutic function for which they are designed.