Full Hybrid Research Articles

Impact of CSI Knowledge on the Codebook-Based Hybrid Beamforming in Massive MIMO

Hybrid beamforming, which consists of an RF precoder and a baseband precoder, has been proposed to reduce the number of RF chains at the massive multiple input multiple output (MIMO) base station (BS). This paper studies the impact of channel state information (CSI) on the capacity of massive MIMO systems with codebook-based hybrid beamforming , where the RF precoder is selected from a finite size codebook. Two types of CSI at the BS (CSIT) are commonly assumed: full instantaneous CSIT and hybrid CSIT (channel statistics plus the low-dimensional effective channel matrix). With full instantaneous CSIT, both the RF and baseband precoders are adaptive to the full instantaneous CSI at the fast timescale. With hybrid CSIT, the RF precoder is adaptive to channel statistics only, and the baseband precoder is adaptive to the instantaneous effective channel, yielding lower implementation complexity by sacrificing some capacity. We derive asymptotic sum capacity expressions under these two types of CSIT. We find that, in codebook-based hybrid beamforming systems, exploiting the full instantaneous CSIT can only achieve a marginal SNR gain and hybrid CSIT is sufficient to achieve the first-order gain provided by the massive MIMO for most of the cases. We also propose fast and slow timescale RF precoding algorithms, which asymptotically achieve the capacity under full instantaneous CSIT and hybrid CSIT, respectively.

Evolution of Useless Iron Rust into Uniform α-Fe2O3 Nanospheres: A Smart Way to Make Sustainable Anodes for Hybrid Ni–Fe Cell Devices

The large amount of iron rust yielded in steel industries is undoubtedly a useless and undesired product since its substantial formation and recycle/smelting would give rise to enormous financial costs and environmental pollution issues. To best reuse such rusty wastes, we herein propose a smart and applicable method to convert them into uniform α-Fe2O3 nanospheres. Only after a simple and conventional hydrothermal treatment in HNO3 solution, nearly all of the iron rust can evolve into sphere-like α-Fe2O3 products with a typical size of ∼30 nm. When serving as actives for electrochemical energy storage, the in situ generated α-Fe2O3 nanospheres exhibit prominent anodic performance, with a maximum specific capacity of ∼269 mAh/g at ∼0.3 A/g, good rate capabilities (∼67.3 mAh/g still retains even at a high rate up to 12.3 A/g), and negligible capacity degradation among 500 cycles. Furthermore, by paring with activated carbons/Ni cathodes, a unique full hybrid Ni–Fe cell is constructed. The assembled full de...

Control strategy for all the mode-switches of hybrid electric vehicle

This article focuses on the mode-switch control of a new type of full hybrid electric vehicle with a torque-limiting clutch and an overrunning clutch. The working mode regions of hybrid electric vehicle are divided according to the characteristics of the engine and motor. The target-required torque of the power source in each working mode is determined by a rule-based control strategy for optimal system efficiency. To reduce the torque fluctuation and improve the ride comfort of the vehicle, the coordinated torque control strategy has been proposed during the mode-switch process. The fuzzy control strategy of the oil pressure loaded on the torque-limiting clutch has been put forward. To improve the ride comfort during the mode-switch, the motor has been used for compensation of the rest of the vehicle-required torque according to the clutch-transmitted torque and the output torque of the engine. The dynamic model of the system in each mode-switch has also been established. The simulation has been conducted using MATLAB/Simulink platform for all the mode-switches. Furthermore, the experiment of the motor-assisted engine starting process with the proposed control strategy has been carried out. The result of the experiment is consistent with that of the simulation, and the control strategy proposed in this article is effective for the mode-switch control.

The Conometric Concept: Definitive Fixed Lithium Disilicate Restorations Supported by Conical Abutments.

The use of the conical coupling connection to support definitive restorations was evaluated in cases involving full acrylic resin or hybrid acrylic resin-composite prostheses. The aim of this study was to evaluate the performance of definitive fixed partial prostheses made with lithium disilicate and supported by coupling connection abutments and healed implants. The prostheses were placed in the posterior regions of partially edentulous patients; 65 patients received fixedlithium disilicate restorations splinted with conical coupling connectionsto two implants. Implants were placed into healed sites and fresh extraction sockets. The prostheses were placed after healing periods of 3 months: restorations were followed yearly for 3 years. At each follow-up visit, peri-implant bone levels and pocket depths were recorded. Esthetic, functional, and biologic United States Public Health Services (USPHS) parameters modified by the FDI World Dental Federation study design were assessed at the last follow-up appointments. Two prostheses (3.07%) fractured: one was related to framework design error; one was caused by a car accident. Three patients reported small chips: these restorations were immediately polished. No significant difference involving peri-implant bone and probing levels between the experimental times were found. None of the prostheses became loose. The results of this research indicated that abutment-prostheses coupling connections were successful within the timeframe of this study.

Antenna Selection and Hybrid Beamforming for Simultaneous Wireless Information and Power Transfer in Multi-Group Multicasting Systems

In this paper, low-cost alternatives to full digital beamforming, namely, antenna selection and hybrid beamforming, are proposed for simultaneous wireless information and power transfer in a multi-group multicasting scenario. The joint problem can be outlined as the design of beamformer weight vectors and power splitting ratios in order to satisfy both signal-to-interference-plus-noise -ratio and harvested power constraints at each user with minimum transmission power. We first develop an efficient algorithm for antenna selection by converting the original mixed integer programming problem into a continuous one and adapting feasible point pursuit-successive convex approximation. Second, a new hybrid beamforming structure is presented for multi-group multicasting. Both continuous and discrete-phase hybrid beamformers are considered in this content. Two algorithms for continuous-phase case are developed by employing two competing techniques. In addition, a special two-bit discrete-phase hybrid beamformer design is considered for practical systems. The integer constraints are converted into linear equality and inequalities for this specific structure and an efficient algorithm is designed. The proposed algorithms are compared for different scenarios revealing some interesting characteristics of each technique.

Experimental Study on Seismic Performance of New RCS Connection

This paper deals with an experimental study on seismic performance of a new type of exterior RCS connection, in which a steel profile embedded inside RC column is directly welded to the steel beam. A full scale exterior hybrid joint was built and tested under reversed-cyclic loading at the University of Transport and Communications of Vietnam. Seismic performance in term of load bearing capacity, story drift capacity, ductility, energy dissipation and stiffness degradation were evaluated. The test specimen showed a good response to cyclic load reversals. The experimental results indicated that the test specimen performed in a ductile manner and the stiffness degradation during the cycles performed was gradual. It was concluded that the studied RCS joint could be used as dissipative element in the structures of ductility class medium (DCM).

Well-to-wheel costs, primary energy demand, and greenhouse gas emissions for the production and operation of conventional and alternative vehicles

This study provides a comprehensive comparison of well-to-wheel (WTW) energy demand, WTW GHG emissions, and costs for conventional ICE and alternative passenger car powertrains, including full electric, hybrid, and fuel cell powertrains. Vehicle production, operation, maintenance, and disposal are considered, along with a range of hydrogen production processes, electricity mixes, ICE fuels, and battery types. Results are determined based on a reference vehicle, powertrain efficiencies, life cycle inventory data, and cost estimations. Powertrain performance is measured against a gasoline ICE vehicle. Energy carrier and battery production are found to be the largest contributors to WTW energy demand, GHG emissions, and costs; however, electric powertrain performance is highly sensitive to battery specific energy. ICE and full hybrid vehicles using alternative fuels to gasoline, and fuel cell vehicles using natural gas hydrogen production pathways, are the only powertrains which demonstrate reductions in all three evaluation categories simultaneously (i.e., WTW energy demand, emissions, and costs). Overall, however, WTW emission reductions depend more on the energy carrier production pathway than on the powertrain; hence, alternative energy carriers to gasoline for an ICE-based fleet (including hybrids) should be emphasized from a policy perspective in the short-term. This will ease the transition towards a low-emission fleet in Switzerland.

Inverse full state hybrid projective synchronization for chaotic maps with different dimensions

A new synchronization scheme for chaotic (hyperchaotic) maps with different dimensions is presented. Specifically, given a drive system map with dimension n and a response system with dimension m, the proposed approach enables each drive system state to be synchronized with a linear response combination of the response system states. The method, based on the Lyapunov stability theory and the pole placement technique, presents some useful features: (i) it enables synchronization to be achieved for both cases of n < m and n > m; (ii) it is rigorous, being based on theorems; (iii) it can be readily applied to any chaotic (hyperchaotic) maps defined to date. Finally, the capability of the approach is illustrated by synchronization examples between the two-dimensional Hénon map (as the drive system) and the three-dimensional hyperchaotic Wang map (as the response system), and the three-dimensional Hénon-like map (as the drive system) and the two-dimensional Lorenz discrete-time system (as the response system).

A new approach to study the coexistence of some synchronization types between chaotic maps with different dimensions

When synchronizing chaotic systems, an interesting phenomenon that may occur is the coexistence of several synchronization types. Referring to discrete-time chaotic (hyperchaotic) systems, this paper presents a new approach to rigorously study the coexistence of some synchronization types between maps with different dimensions. By exploiting a Lyapunov-based approach, the paper first analyzes the coexistence of full state hybrid projective synchronization and generalized synchronization when the drive system is a three-dimensional map and the response system is a two-dimensional map. Successively, the coexistence of three different synchronization types is illustrated, i.e., inverse projective synchronization, inverse generalized synchronization and Q–S synchronization are proved to coexist between two-dimensional drive systems and three-dimensional response systems. Finally, by exploiting a pole placement technique, the coexistence of antiphase synchronization and dislocated full state hybrid projective synchronization is proved to be achieved between three-dimensional drive system maps and two-dimensional response system maps. Since synchronization is achieved in finite time, this last case represents an example of dead beat coexistence of some synchronization types in maps with different dimensions. Several numerical examples of coexistence of synchronization types are illustrated, with the aim to show the effectiveness of the novel approach developed herein.

Perspectives of electric mobility: Total cost of ownership of electric vehicles in Germany

The transport sector is a major source of greenhouse gas emissions worldwide as well as in Germany and is therefore able to contribute significantly to the achievement of climate protection goals. With this in mind and the steadily increasing electricity generation from renewable energy sources in Germany, electrically driven vehicles can be an attractive option to reach the climate targets of the EU and the German government. The target of the German government to have at least one million electric vehicles registered by 2020 seems currently far from realisation. For this reason, this article analyses the total cost of ownership (TCO) of electric passenger vehicles in Germany on a component-based approach and gives an estimation about the further development until 2050. To represent the German market, we investigate different vehicle sizes, user types and drive technologies. Furthermore, we show the CO2 abatement potential offered by different types of electric vehicles. Finally, we analyse buyer's premiums as an incentive to accelerate the uptake of electric vehicles on German roads.In result, even without governmental subsidies, full and mild hybrid electric vehicles are already an economic option for a wide range of vehicle sizes and user types. To achieve nowadays cost competitiveness for full electric vehicle powertrains, considerable buyer's premiums are necessary. For plug-in hybrid electric vehicles and battery electric vehicles, the premiums range from about 8,600 to 32,400 EUR2010/vehicle depending on the vehicle size and user type. Eventually, following the future cost estimations, full electric vehicles can reach economic viability from 2030 onwards for many of the investigated vehicles and users.

SU-F-T-616: Comparison of Different Techniques Using RTOG0631 Guidelines in Spine SBRT

Purpose: Stereotactic body radiosurgery (SBRT) for spine metastases involves irradiation using a single high dose fraction. The purpose of this study was to investigate a Hybrid VMAT/IMRT technique which combines volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) for spine SBRT in terms of its dosimetric quality and treatment efficiency using Radiation Therapy Oncology Group (RTOG) 0631 guidelines. Methods: 7 fields IMRT, 2 full arcs VMAT and Hybrid VMAT/IMRT were created for ten previously treated patients. The Hybrid VMAT/IMRT technique consisted of 1 full VMAT arc and 5 IMRT fields. Hybrid VMAT/IMRT plans were compared with IMRT and VMAT plans in terms of the dose distribution, spinal cord sparing, homogeneity, conformity and gradient indexies, monitor unit (MU) and beam on time (BOT). RTOG 0631 recommendations were applied for treatment planning. All plans were normalized and prescribed to deliver 18.0 Gy in a single fraction to 90% of the target volume. Results: The Hybrid VMAT/IMRT technique significantly improved target dose homogeneity and conformity compared with IMRT and VMAT techniques. Providing sharp dose gradient Hybrid VMAT/IMRT plans spare the spinal cord and healthy tissue more effectively. Although, both MU and BOT slightly increased in Hybrid VMAT/IMRT plans there is no statistically meaningful difference between VMAT and Hybrid VMAT/IMRT plans. Conclusion: In IMRT, a smaller volume of healthy tissue can be irradiated in the low dose region, VMAT plans provide better target volume coverage, favorable dose gradient, conformity and better OAR sparing and also they require a much smaller number of MUs and thus a shorter treatment time than IMRT plans. Hybrid plan offers a sinergy through combination of these two techniques with slightly increased number of MU and thus more treatment time.

Electron and chemical reservoir corrections for point-defect formation energies

The formation energies of semiconductor point defects are nowadays predicted much more accurately by density functional theory than a decade ago, thanks to the use of modern hybrid functionals. The drawback is the high computational effort compared to the traditional local density approximation (LDA) or generalized gradient approximation (GGA). In this work, the authors trace back the main variations between the functionals to differences in the position of the bulk valence-band maximum, as well as in the reference energies for the chemical potential obtained with each functional. For point defects relevant for $p$-type GaN, these differences are accounted for by corrections, reducing the maximum disagreement between the different functionals from more than 2 eV to below 0.2 eV. The correction scheme should be useful for performing high-throughput calculations in cases where full hybrid functional calculations are prohibitively expensive.

A hybrid formulation for the numerical simulation of condensed phase explosives

In this article we present a new formulation and an associated numerical algorithm, for the simulation of combustion and transition to detonation of condensed-phase commercial- and military-grade explosives, which are confined by (or in general interacting with one or more) compliant inert materials. Examples include confined rate-stick problems and interaction of shock waves with gas cavities or solid particles in explosives. This formulation is based on an augmented Euler approach to account for the mixture of the explosive and its products, and a multi-phase diffuse interface approach to solve for the immiscible interaction between the mixture and the inert materials, so it is in essence a hybrid (augmented Euler and multi-phase) model. As such, it has many of the desirable features of the two approaches and, critically for our applications of interest, it provides the accurate recovery of temperature fields across all components. Moreover, it conveys a lot more physical information than augmented Euler, without the complexity of full multi-phase Baer–Nunziato-type models or the lack of robustness of augmented Euler models in the presence of more than two components. The model can sustain large density differences across material interfaces without the presence of spurious oscillations in velocity and pressure, and it can accommodate realistic equations of state and arbitrary (pressure- or temperature-based) reaction-rate laws. Under certain conditions, we show that the formulation reduces to well-known augmented Euler or multi-phase models, which have been extensively validated and used in practice. The full hybrid model and its reduced forms are validated against problems with exact (or independently-verified numerical) solutions and evaluated for robustness for rate-stick and shock-induced cavity collapse case-studies.

Development of High Voltage Wire for New Structure Motor in Full Hybrid Vehicle

Development of High Voltage Wire for New Structure Motor in Full Hybrid Vehicle

Hybrid laser-metal active gas welding of S460ML steel plates: Weldability and consequences of dropping on weld quality

This work investigates the weldability of S460ML steel using a hybrid laser-metal active gas (MAG) process and the effect of dropping on material properties. Dropping is the creation of regularly scattered drops on the back side of thick plates during full penetration hybrid laser-MAG welding. As these drops can reach several millimeters in diameter, it is an unacceptable defect since it lowers esthetic properties. Besides the geometrical aspect, mechanical properties are also affected by dropping. In order to check the consequences of dropping on weld quality: metallographic, mechanical, and dilution analyses have been performed. Results confirm the good weldability of S460ML using hybrid welding with proper welding parameters. If dropping occurs, it enhances heterogeneity in chemistry and microstructure, and welding defects such as porosity and undercuts. However, these properties and defects remain tolerable. Drops can be removed by grinding, making the weld acceptable.

New generation of hybrid carbon/Ni(OH)2 electrochemical capacitor using functionalized carbon electrode

Abstract Tailoring carbon based negative electrode by grafting electroactive 9,10-phenanthrenequinone molecules on porous carbon drastically improves the performance of a carbon/Ni(OH)2 hybrid electrochemical capacitor. The grafted-quinone moieties add a Faradaic contribution to the double layer capacitance of carbon leading to a significant increase of the charge stored by the full devices. Good cyclability is ensured due to the strong bond between 9,10-phenanthrenequinone molecules and the carbon surface. More importantly, by increasing the total capacity, the grafting improves the energy density of the full hybrid device while maintaining fast charge/discharge kinetics and thus without affecting the power density.

Analysis of fuel consumption and pollutant emissions of regulated and alternative driving cycles based on real-world measurements

Discrepancies between real-world use of vehicles and certification cycles are a known issue. This paper presents an analysis of vehicle fuel consumption and pollutant emissions of the European certification cycle (NEDC) and the proposed worldwide harmonized light vehicles test procedure (WLTP) Class 3 cycle using data collected on-road. Sixteen light duty vehicles equipped with different propulsion technologies (spark-ignition engine, compression-ignition engine, parallel hybrid and full hybrid) were monitored using a portable emission measurement system under real-world driving conditions. The on-road data obtained, combined with the Vehicle Specific Power (VSP) methodology, was used to recreate the dynamic conditions of the NEDC and WLTP Class 3 cycle. Individual vehicle certification values of fuel consumption, CO2, HC and NOx emissions were compared with test cycle estimates based on road measurements. The fuel consumption calculated from on-road data is, on average, 23.9% and 16.3% higher than certification values for the recreated NEDC and WLTP Class 3 cycle, respectively. Estimated HC emissions are lower in gasoline and hybrid vehicles than certification values. Diesel vehicles present higher estimated NOx emissions compared to current certification values (322% and 326% higher for NOx and 244% and 247% higher for HC+NOx for NEDC and WLTP Class 3 cycle, respectively).

Coordinated control strategies for a full hybrid electric vehicle with single motor during mode changes

This paper presents the coordinated control strategies for a full hybrid vehicle with single motor during mode changes. The mode changes between various driving modes are firstly divided into three types according to the similar characteristics of mode transitions. For the first type of mode change, a coordinated control strategy expressed as the combination of clutch pressure fuzzy control and motor torque compensation is proposed. For the second type of mode change, a coordination control strategy of motor speed closed-loop control and clutch pressure control is developed. The coordinated control strategy expressed as the engine throttle opening rate control and motor torque compensation is adopted for the third type of mode change. Performance of these proposed control strategies is validated by experimental tests based on the test bench of the full hybrid drivetrain. The results show a remarkable improvement in drivability of the full hybrid vehicle during mode changes.

INFLUENCE OF FINISH LINE DESIGN ON THE VERTICAL MARGINAL DISCREPANCY OF ENAMIC HYBRID CERAMIC: IN VITRO STUDY

Aim of the study: The aim of this study was to evaluate the effect of finish line design (chamfer and shoulder) on the vertical marginal gap distance, and fracture resistance of Hybrid ceramic (Vita Enamic, VITA Zahnfabrik, Bad Sackingen, Germany). Materials and Methods: Two stainless steel dies were machine milled to simulate a tooth preparation for a ceramic crown of a mandibular second molar with two finish line configurations 1mm chamfer and 1 mm shoulder. Each die was 6-mm in height, 8-mm in cervical diameter, 6mm in occlusal diameter and had a total occlusal convergence of 16o. Digitalization of both dies and milling of hybrid restorations was made using CAD-CAM technology. Sixteen full coverage hybrid ceramic crowns were constructed from milled Vita Enamic hybrid ceramic blocks. The samples were divided into two equal groups’ eight samples for each finish line tested.-Group Ac: eight samples (n=8) with Chamfer finish line.Group Bs: eight samples (n=8) with Shoulder finish line. All restorations were positioned onto a digital-microscope, magnification 50 X, and the images were captured and transferred to a IBM personal computer equipped with the Image-tool software to measure the vertical marginal gap distance. Results: The results showed a statistically significant difference between the two groups (Ac, Bs) where the mean values were (35.44μm and 48.36μm) respectively at p=0.002. Conclusions: the vertical marginal gap values of both finish line designs are within the clinically accepted range

Barrett′s mucosa segmentation in endoscopic images using a hybrid method: Spatial fuzzy c-mean and level set

Barrett's mucosa is one of the most important diseases in upper gastrointestinal system that caused by gastro-esophagus reflux. If left untreated, the disease will cause distal esophagus and gastric cardia adenocarcinoma. The malignancy risk is very high in short segment Barrett's mucosa. Therefore, lesion area segmentation can improve specialist decision for treatment. In this paper, we proposed a combined fuzzy method with active models for Barrett's mucosa segmentation. In this study, we applied three methods for special area segmentation and determination. For whole disease area segmentation, we applied the hybrid fuzzy based level set method (LSM). Morphological algorithms were used for gastroesophageal junction determination, and we discriminated Barrett's mucosa from break by applying Chan-Vase method. Fuzzy c-mean and LSMs fail to segment this type of medical image due to weak boundaries. In contrast, the full automatic hybrid method with correlation approach that has used in this paper segmented the metaplasia area in the endoscopy image with desirable accuracy. The presented approach omits the manually desired cluster selection step that needed the operator manipulation. Obtained results convinced us that this approach is suitable for esophagus metaplasia segmentation.