scholarly journals Switched Capacitor DC-DC Converters: A Survey on the Main Topologies, Design Characteristics, and Applications

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2231
Author(s):  
Alencar Franco de Souza ◽  
Fernando Lessa Tofoli ◽  
Enio Roberto Ribeiro
Keyword(s):  
Voltage Regulation ◽  
Inherent Difficulty ◽  
Practical Applications ◽  
Dc Power ◽  
Higher Power ◽  
Voltage Doubler ◽  
Converter Design ◽  
Design Characteristics ◽  
And Performance ◽  
Full Charge

This work presents a review of the main topologies of switched capacitors (SCs) used in DC-DC power conversion. Initially, the basic configurations are analyzed, that is, voltage doubler, series-parallel, Dickson, Fibonacci, and ladder. Some aspects regarding the choice of semiconductors and capacitors used in the circuits are addressed, as well their impact on the converter behavior. The operation of the structures in terms of full charge, partial charge, and no charge conditions is investigated. It is worth mentioning that these aspects directly influence the converter design and performance in terms of efficiency. Since voltage regulation is an inherent difficulty with SC converters, some control methods are presented for this purpose. Finally, some practical applications and the possibility of designing DC-DC converters for higher power levels are analyzed.

Картофелекопатель с ротационной сепарирующей поверхностью

2018 ◽  
Author(s):  
V.M. Alakin ◽  
G.S. Nikitin
Keyword(s):  
Performance Data ◽  
Pilot Studies ◽  
Research Results ◽  
Operating Modes ◽  
Analysis Of Results ◽  
Design Characteristics ◽  
And Performance ◽  
Definition Of

Приведены результаты исследований экспериментального картофелекопателя с ротационной сепарирующей поверхностью. Особое внимание уделяется обоснованию конструктивных параметров и определению рабочих характеристик нового сепарирующего устройства. На основе анализа результатов экспериментальных исследований определены наиболее оптимальные режимы работы экспериментального картофелекопателя.Research results of an experimental potato digger with rotational separating web are published in this article. Special attention is paid to definition of design characteristics and performance data of the new separating device. Admissible operating modes are defined on the basis of the analysis of results of pilot studies of the experimental potato digger.

Local Calibration of Pavement Mechanistic-Empirical Faulting Reliability using Pavement Management Data

2021 ◽  
pp. 036119812110013
Author(s):  
Lucio Salles de Salles ◽  
Lev Khazanovich
Keyword(s):  
Model Calibration ◽  
Prediction Models ◽  
Plain Concrete ◽  
Performance Model ◽  
Pavement Management ◽  
Pavement Design ◽  
Reliability Model ◽  
Transverse Joint ◽  
Design Characteristics ◽  
And Performance

The Pavement ME transverse joint faulting model incorporates mechanistic theories that predict development of joint faulting in jointed plain concrete pavements (JPCP). The model is calibrated using the Long-Term Pavement Performance database. However, the Mechanistic-Empirical Pavement Design Guide (MEPDG) encourages transportation agencies, such as state departments of transportation, to perform local calibrations of the faulting model included in Pavement ME. Model calibration is a complicated and effort-intensive process that requires high-quality pavement design and performance data. Pavement management data—which is collected regularly and in large amounts—may present higher variability than is desired for faulting performance model calibration. The MEPDG performance prediction models predict pavement distresses with 50% reliability. JPCP are usually designed for high levels of faulting reliability to reduce likelihood of excessive faulting. For design, improving the faulting reliability model is as important as improving the faulting prediction model. This paper proposes a calibration of the Pavement ME reliability model using pavement management system (PMS) data. It illustrates the proposed approach using PMS data from Pennsylvania Department of Transportation. Results show an increase in accuracy for faulting predictions using the new reliability model with various design characteristics. Moreover, the new reliability model allows design of JPCP considering higher levels of traffic because of the less conservative predictions.

Advances in MXene Films: Synthesis, Assembly, and Applications

2021 ◽  
Author(s):  
Xiaohua Li ◽  
Feitian Ran ◽  
Fan Yang ◽  
Jun Long ◽  
Lu Shao
Keyword(s):  
Spin Coating ◽  
Reaction Mechanisms ◽  
Membrane Separation ◽  
Synthesis Methods ◽  
Metal Carbides ◽  
Max Phases ◽  
Practical Applications ◽  
Coating Methods ◽  
And Performance ◽  
Important Form

AbstractA growing family of two-dimensional (2D) transition metal carbides or nitrides, known as MXenes, have received increasing attention because of their unique properties, such as metallic conductivity and good hydrophilicity. The studies on MXenes have been widely pursued, given the composition diversity of the parent MAX phases. This review focuses on MXene films, an important form of MXene-based materials for practical applications. We summarized the synthesis methods of MXenes, focusing on emerging synthesis strategies and reaction mechanisms. The advanced assembly technologies of MXene films, including vacuum-assisted filtration, spin-coating methods, and several other approaches, were then highlighted. Finally, recent progress in the applications of MXene films in electrochemical energy storage, membrane separation, electromagnetic shielding fields, and burgeoning areas, as well as the correlation between compositions, architecture, and performance, was discussed.

A Comprehensive Review on Reconfigurable Drones: Classification, Characteristics, Design and Control Technologies

2021 ◽  
pp. 1-27
Author(s):  
Saddam Hocine Derrouaoui ◽  
Yasser Bouzid ◽  
Mohamed Guiatni ◽  
Islam Dib
Keyword(s):  
Fault Tolerant ◽  
Control Strategies ◽  
Cluttered Environments ◽  
Viable Solution ◽  
Promising Solution ◽  
Design Characteristics ◽  
And Performance ◽  
Control Technologies ◽  
And Control ◽  
Near Future

Recently, reconfigurable drones have gained particular attention in the field of automation and flying robots. Unlike the conventional drones, they are characterized by a variable mechanical structure in flight, geometric adaptability, aerial reconfiguration, high number of actuators and control inputs, and variable mathematical model. In addition, they are exploited to flight in more cluttered environments, avoid collisions with obstacles, transport and grab objects, cross narrow and small spaces, decrease different aerial damages, optimize the consumed energy, and improve agility and maneuverability in flight. Moreover, these new drones are considered as a viable solution to provide them with specific and additional functionalities. They are a promising solution in the near future, since they allow increasing considerably the capabilities and performance of classical drones in terms of multi-functionalities, geometric adaptation, design characteristics, consumed energy, control, maneuverability, agility, efficiency, obstacles avoidance, and fault tolerant control. This paper explores very interesting and recent research works, which include the classification, the main characteristics, the various applications, and the existing designs of this particular class of drones. Besides, an in-depth review of the applied control strategies will be presented. The links of the videos displaying the results of these researches will be also shown. A comparative study between the different types of flying vehicles will be established. Finally, several new challenges and future directions for reconfigurable drones will be discussed.

scholarly journals Design of the VISTA-ITL Test Facility for an Integral Type Reactor of SMART and a Post-Test Simulation of a SBLOCA Test

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Hyun-Sik Park ◽  
Byung-Yeon Min ◽  
Youn-Gyu Jung ◽  
Yong-Cheol Shin ◽  
Yung-Joo Ko ◽  
...  
Keyword(s):  
System Analysis ◽  
Cooling System ◽  
Heat Removal ◽  
Test Facility ◽  
Integral Type ◽  
Type Reactor ◽  
Integral Effect ◽  
Post Test ◽  
Design Characteristics ◽  
And Performance

To validate the performance and safety of an integral type reactor of SMART, a thermal-hydraulic integral effect test facility, VISTA-ITL, is introduced with a discussion of its scientific design characteristics. The VISTA-ITL was used extensively to assess the safety and performance of the SMART design, especially for its passive safety system such as a passive residual heat removal system, and to validate various thermal-hydraulic analysis codes. The VISTA-ITL program includes several tests on the SBLOCA, CLOF, and PRHRS performances to support a verification of the SMART design and contribute to the SMART design licensing by providing proper test data for validating the system analysis codes. A typical scenario of SBLOCA was analyzed using the MARS-KS code to assess the thermal-hydraulic similarity between the SMART design and the VISTA-ITL facility, and a posttest simulation on a SBLOCA test for the shutdown cooling system line break has been performed with the MARS-KS code to assess its simulation capability for the SBLOCA scenario of the SMART design. The SBLOCA scenario in the SMART design was well reproduced using the VISTA-ITL facility, and the measured thermal-hydraulic data were properly simulated with the MARS-KS code.

scholarly journals DC/DC Boost Converter Controller

2018 ◽  
Vol 3 (3) ◽  
pp. 53-59 ◽  
Author(s):  
José Ferreira
Keyword(s):  
Linear System ◽  
Output Voltage ◽  
Voltage Regulation ◽  
Boost Converter ◽  
System Stability ◽  
Comparative Approach ◽  
System State ◽  
And Performance ◽  
Time Linear ◽  
Variant System

The DC/DC boost converter is described as a time variant system. State-Space is one of the methods used to approach a time variant system to an invariant time linear system. The present document focuses on a comparative approach of output voltage regulation and system stability and performance. For this document, there were made MatLab tests of PI and PD controllers, with and without fuzzy control.

Mobile Web Services for P2P Computing

2010 ◽  
pp. 133-157
Author(s):  
Fahad Aijaz
Keyword(s):  
Web Services ◽  
Performance Optimization ◽  
Mobile Nodes ◽  
P2p Computing ◽  
Mobile Web Services ◽  
Mobile Web ◽  
Service Oriented Computing ◽  
Service Oriented ◽  
Design Characteristics ◽  
And Performance

The Information Technology (IT) and Telecommunication (TelCo) sectors face enormous integration challenges, due to the prominent heterogeneity in existing systems. Service-oriented computing tackles such challenges by providing a fundamental platform that facilitates the convergence of distinct domains based on Web Services (WSs). With the mobility and technological advancements, service-oriented computing has been pushed towards the mobile sector enabling P2P Mobile Web Services (MobWSs) provisioning. In this work, we investigate the interaction, architecture and design characteristics of MobWSs for P2P computing. Here, the two MobWS interaction strategies are presented followed by the architectural discussion, enfolding server and client side components, of a resource-oriented MobWS framework. We follow REST design principles to propose an efficient way of architecting P2P MobWS systems, as an alternative to SOAP, enabling significant payload reduction and performance optimization in mobile servers. The detailed performance evaluation is also presented and compared to SOAP based on real-time measurements. By analyzing performance characteristics, we show that REST is a promising technique to architect P2P MobWS systems for resource-constraint mobile nodes.

Performing with Structure

2020 ◽  
pp. 287-331
Author(s):  
Daphne Leong
Keyword(s):  
Long Range ◽  
Third Culture ◽  
Practical Applications ◽  
Pitch Structure ◽  
And Performance

This chapter poses the question of how one synthesizes analysis and performance. Its centerpiece is Leathwood’s analysis of local frictions and long-range connections in the pitch structure of Carter’s Changes; his demonstration of their embodiment in guitaristic timbres, tactile shapes, and kinesthetic moves; and his modeling of how such knowledge might be internalized to inspire vital and free performances. “Improvising Changes: Exercises for Guitarists” and an accompanying video provide practical applications. Leong’s Prelude and Postlude frame Leathwood’s material and highlight how a “third culture” of analysis and performance can be inhabited and passed on—modeled and taught in studio and classroom.

Cost Breakdown of 2.5D and 3D Packaging

2016 ◽  
Vol 2016 (DPC) ◽  
pp. 000324-000341 ◽  
Author(s):  
Chet Palesko ◽  
Amy Palesko
Keyword(s):  
High Performance ◽  
Cost Model ◽  
High Price ◽  
Future Cost ◽  
The Future ◽  
3D Packaging ◽  
Long Time ◽  
Design Characteristics ◽  
And Performance ◽  
The Cost

2.5D and 3D packaging can provide significant size and performance advantages over other packaging technologies. However, these advantages usually come at a high price. Since 2.5D and 3D packaging costs are significant, today they are only used if no other option can meet the product requirements, and most of these applications are relatively low volume. Products such as high end FPGAs, high performance GPUs, and high bandwidth memory are great applications but none have volume requirements close to mobile phones or tablets. Without the benefit of volume production, the cost of 2.5D and 3D packaging could stay high for a long time. In this paper, we will provide cost model results of a complete 2.5D and 3D manufacturing process. Each manufacturing activity will be included and the key cost drivers will be analyzed regarding future cost reductions. Expensive activities that are well down the learning curve (RDL creation, CMP, etc.) will probably not change much in the future. However, expensive activities that are new to this process (DRIE, temporary bond/debond, etc.) provide good opportunities for cost reduction. A variety of scenarios will be included to understand how design characteristics impact the cost. Understanding how and why the dominant cost components will change over time is critical to accurately predicting the future cost of 2.5D and 3D packaging.

Assessing Patient Participation Burden Based on Protocol Design Characteristics

2019 ◽  
pp. 216847901986728
Author(s):  
Kenneth Getz ◽  
Venkat Sethuraman ◽  
Jessica Rine ◽  
Yaritza Peña ◽  
Sharma Ramanathan ◽  
...  
Keyword(s):  
Online Survey ◽  
Protocol Design ◽  
Retention Rates ◽  
Cross Sectional ◽  
Perceived Burden ◽  
Study Results ◽  
Design Characteristics ◽  
And Performance ◽  
Viable Approach ◽  
Patient Burden

Background: Although a number of studies have quantitatively measured investigative site burden to administer increasingly complex protocol designs, robust scholarly research has not been performed to quantify the burden that patients face as participants in clinical trials. Methods: This paper presents the results of a cross-sectional pilot study conducted by the Tufts Center for the Study of Drug Development and ZS Associates among nearly 600 patients via an online survey conducted between February and March 2019. Respondents rated the perceived burden of 60 commonly administered protocol procedures. The association and relationship between overall patient burden—derived from aggregating mean perceived burden ratings for individual procedures—and performance (eg, screen failure and retention rates, clinical trial cycle times) for a cross-sectional sample of 137 individual protocols was assessed. Descriptive statistics, significance tests, and univariate analyses were performed. Results: Strong positive, statistically significant associations were observed between a composite measure of patient burden and protocol-specific design and performance measures, most notably study visits above the tolerable mean and the study conduct duration from first patient first visit to last patient last visit. Conclusions: The study results suggest a new and viable approach to optimize protocol design and improve patient engagement.

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