Modular parallel inverter technology can enhance the power level and redundancy of wireless power transfer (WPT) systems, contributing to standardized production. It serves as an effective method for realizing high-power systems. However, inappropriate selection of compensation components can negatively affect the system’s efficiency, power factor, and the flexibility of modularization. This paper analyzes two key properties of modular-parallel-inverter WPT (MPI-WPT) systems: module number flexibility and modular deviation suppression. Firstly, to assess the modular deviation suppression of the system, its definition and calculation method are provided. Secondly, the expansion condition to achieve modular flexibility is examined, highlighting that the modular system needs to be a fully resonant system. Subsequently, an expansion design methodology from a single WPT system to an MPI-WPT system is proposed, ensuring the preservation of the original properties of the system during its extension. Finally, the parallel characteristics of MPI-WPT systems were experimentally verified.

The metaverse gradually evolves into a virtual world containing a series of interconnected sub-metaverses. Diverse digital resources, including identities, contents, services, and supporting data, are key components of the sub-metaverse. Therefore, a Domain Name System (DNS)-like system is necessary for efficient management and resolution. However, the legacy DNS was designed with security vulnerabilities and trust risks due to centralized issues. Blockchain is used to mitigate these concerns due to its decentralized features. Additionally, it supports identity management as a default feature, making it a natural fit for the metaverse. While there are several DNS alternatives based on the blockchain, they either manage only a single type of identifiers or isolate identities from other sorts of identifiers, making it difficult for sub-metaverses to coexist and connect with each other. This article proposes a M ulti- I dentifier management and resolution S ystem (MIS) in the metaverse, supporting the registration, resolution, and inter-translation functions. The basic MIS is portrayed as a four-tier architecture on a consortium blockchain due to its manageability, enhanced security, and efficiency properties. On-chain data is lightweight and compressed to save on storage while accelerating reading and writing operations. The resource data is encrypted based on the attributes of the sub-metaverse in the storage tier for privacy protection and access control. For users with decentralization priorities, a modification named EMIS is built on top of Ethereum. Finally, MIS is implemented on two testbeds and is available online as the open-source system. The first testbed consists of 4 physical servers located in the UK and Malaysia while the second is made up of 200 virtual machines (VMs) spread over 26 countries across all 5 continents on Google Cloud. Experiments indicate that MIS provides efficient reading and writing performance than the legacy DNS and other public blockchain-based workarounds including EMIS and Ethereum Name Service (ENS).

DIscusses the development, research, and commercialization of the electric vehicle from 1898 through 1930.

With the more stringent regulations on emissions and fuel economy, global warming, and constraints on energy resources, the electric, hybrid, and fuel cell vehicles have attracted more and more attention by automakers, governments, and customers. Research and development efforts have been focused on developing novel concepts, low-cost systems, and reliable hybrid electric powertrain. This paper reviews the state of the art of electric, hybrid, and fuel cell vehicles. The topologies for each category and the enabling technologies are discussed.

With ever-increasing oil prices, there is fast growing interest in hybrid electric vehicles (HEVs) globally. Thus, it is a pressing need for researchers to develop emerging energy-efficient devices for various kinds of HEVs, including the micro hybrids, mild hybrids, and full hybrids. In this paper, three key emerging energy-efficient technologies are identified and discussed: 1) the thermoelectric waste-heat recovery and temperature control systems for all hybrids, especially micro hybrids; 2) the integrated-starter-generator for mild hybrids; and 3) the electronic continuously variable transmission propulsion for full hybrids

In a world where environment protection and energy conservation are growing concerns, the development of electric vehicles (EV) and hybrid electric vehicles (HEV) has taken on an accelerated pace. The dream of having commercially viable EVs and HEVs is becoming a reality. EVs and HEVs are gradually available in the market. This paper will provide an overview of the present status of electric and hybrid vehicles worldwide and their state of the art, with emphasis on the engineering philosophy and key technologies. The importance of the integration of technologies of automobile, electric motor drive, electronics, energy storage, and controls and also the importance of the integration of society strength from government, industry, research institutions, electric power utilities, and transportation authorities are addressed. The challenge of EV commercialization is discussed.

This paper presents a general method for transformations of an object between 2D and 3D which can be used efficiently in computer-aided garment design. A uniform triangular spring–mass-based deformable model is employed. Both 2D-to-3D and 3D-to-2D transformations can be implemented in the same model. An efficient collision detection method is also discussed. © 1998 John Wiley & Sons, Ltd.

Cellular phone network speech quality monitoring is a regular task performed by the cellular service providers. Objective speech quality measures are needed in such tasks to provide a reasonably accurate estimate of subjective quality of the network. We performed an experiment to collect real distorted data, conducted a survey to obtain subjective quality measure of the collected speech samples and studied the statistical correlation of 32 objective speech quality measures with the subjective measures. Four of the objective measures were found to be good. Synchronization was found to be important.

The cellular phone is becoming an important means of mobile wireless communication, especially in metropolitan areas. One of the important operating considerations of the cellular phone service providers is the maintainence of the speech quality of the cellular phone network. Subjective evaluation by repeated listening tests at various sites within the coverage area is impractical due to its intrinsic laborious and expensive nature. As a result, it would be much desirable to have an automatic objective evaluation system which applies a good objective speech measure to estimate the statistical average of subjective opinions of the typical conversational speech sentences sent through the cellular network. While extensive work was done for objective speech measures for languages such as English, Japanese, French, and other western languages, little has been done for Chinese. In addition, little has been done to quantify speech quality in the wireless environment.