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Article
Publication date: 15 May 2024

Dangshu Wang, Zhimin Guan, Jing Wang, Menghu Chang, Licong Zhao and Xinxia Wang

This study aims to solve the problem of high output voltage fluctuation and low efficiency caused by the misalignment of the magnetic coupling structure in the wireless charging…

Abstract

Purpose

This study aims to solve the problem of high output voltage fluctuation and low efficiency caused by the misalignment of the magnetic coupling structure in the wireless charging system for electric vehicles. To address these issues, this paper proposes a dual LCC-S wireless power transfer (WPT) system based on the double-D double-layer quadrature (DDDQ) coil, which can realize the anti-misalignment constant voltage output of the system.

Design/methodology/approach

First, this paper establishes the equivalent circuit of a WPT system based on dual LCC-S compensation topology and analyzes its constant-voltage output characteristics and the relationship between system transmission efficiency and coupling coefficient. 1. Quadruple D (Ahmad et al., 2019) and double-D quadrature pad (DDQP) (Chen et al., 2019) coils have good anti-misalignment in the transverse and longitudinal directions, but the magnetic induction intensity in the center of the coils is weak, making it difficult for the receiving coil to effectively couple to the magnetic field energy. 2. Based on the double-D quadrature (DDQ) structure coil that can eliminate the mutual inductance between coupling coils and cross-coupling, Gong et al. (2022a) proposed a parameter optimized LCC-LC series-parallel hybrid topology circuit, which ensures that the output current fluctuation is controlled within 5% only when the system is misaligned within the 50% range along the X direction, achieving constant current output with anti-misalignment. The magnetic coupling structure’s finite element simulation model is established to analyze the change in magnetic induction intensity and the system’s anti-misalignment characteristics when the coil offsets along the x and y axes. Finally, an experimental prototype is developed to verify the constant voltage output performance and anti-misalignment performance of the system, and the proposed anti-misalignment system is compared with the systems in existing literature, highlighting the advantages of this design.

Findings

The experimental results show that the system can achieve a constant voltage output of 48V under a time-varying load, and the output voltage fluctuates within ±5% of the set value within the range of ±60 mm lateral misalignment and ±72 mm longitudinal misalignment.

Originality/value

Based on the dual LCC-S WPT system, the mutual inductance between the same side coils is reduced by adding decoupling coils, and the anti-misalignment characteristics and output power of the system are improved in a certain range. It is aimed at improving the stability of the system output and transmission efficiency.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 21 May 2024

Mohammad Malmir, Farhad Hosseinzadeh Lotfi, Reza Kazemi Matin and Mahnaz Ahadzadeh Namin

The purpose of this paper is to evaluate the efficiency of a series network system with undesirable and unreturnable simultaneously.

Abstract

Purpose

The purpose of this paper is to evaluate the efficiency of a series network system with undesirable and unreturnable simultaneously.

Design/methodology/approach

The research was conducted by applying data envelopment analysis (DEA) approach to measure the efficiency score of a system and substages with an undesirable output of the second and third stages separately. For each case, new production technology was introduced, and based on them, novel DEA models were proposed.

Findings

One of the most important issues in the development of a country is the banking industry. In this study, 51 branches of commercial banks as a three-stage system with undesirable and unreturnable outputs in the second stage are considered. Then, the efficiency of each branch and substages is measured by using proposed models.

Originality/value

The efficiency of a three-stage network in the presence of undesirable and unreturnable outputs was assessed. In this model, Kousmanen’s technology was used.

Details

Journal of Modelling in Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1746-5664

Keywords

Article
Publication date: 13 May 2024

Lian Bai and Dong Cai

Distributed photovoltaic (DPV) projects generally have output risks, and the production effort of the supplier is often private information, so the buyer needs to design the…

Abstract

Purpose

Distributed photovoltaic (DPV) projects generally have output risks, and the production effort of the supplier is often private information, so the buyer needs to design the optimal procurement contract to maximise its procurement utility.

Design/methodology/approach

Based on the principal-agent theory, we design optimal procurement contracts for DPV projects with fixed payments and incentive factors under three situations, i.e. symmetry information, asymmetry information without monitoring and asymmetry information with monitoring. We obtain the optimal production effort and expected utility of the supplier, the expected output and expected utility of the buyer and analyse the value of the information and monitoring.

Findings

The results show that under asymmetric information without monitoring, risk-averse suppliers need to take some risk due to output risk, which reduces the optimal production effort of the supplier and the expected output and expected utility of the buyer. Therefore, when the monitoring cost is below a certain threshold value, the buyer can introduce a procurement contract with monitoring to address the asymmetry information. In addition, under asymmetric information without monitoring, the buyer should choose a supplier with a low-risk aversion.

Originality/value

Considering the output risk of DPV projects, we study the optimal procurement contract design for the buyer under asymmetric information. The results provide some theoretical basis and management insights for the buyer to design optimal procurement contracts in different situations.

Details

Kybernetes, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 17 April 2024

Bingwei Gao, Hongjian Zhao, Wenlong Han and Shilong Xue

This study proposes a predictive neural network model reference decoupling control method for the coupling problem between the leg joints of hydraulic quadruped robots, and…

Abstract

Purpose

This study proposes a predictive neural network model reference decoupling control method for the coupling problem between the leg joints of hydraulic quadruped robots, and verifies its decoupling effect..

Design/methodology/approach

The machine–hydraulic cross-linking coupling is studied as the coupling behavior of the hydraulically driven quadruped robot, and the mechanical dynamics coupling force of the robot system is controlled as the disturbance force of the hydraulic system through the Jacobian matrix transformation. According to the principle of multivariable decoupling, a prediction-based neural network model reference decoupling control method is proposed; each module of the control algorithm is designed one by one, and the stability of the system is analyzed by the Lyapunov stability theorem.

Findings

The simulation and experimental research on the robot joint decoupling control method is carried out, and the prediction-based neural network model reference decoupling control method is compared with the decoupling control method without any decoupling control method. The results show that taking the coupling effect experiment between the hip joint and knee joint as an example, after using the predictive neural network model reference decoupling control method, the phase lag of the hip joint response line was reduced from 20.3° to 14.8°, the amplitude attenuation was reduced from 1.82% to 0.21%, the maximum error of the knee joint coupling line was reduced from 0.67 mm to 0.16 mm and the coupling effect between the hip joint and knee joint was reduced from 1.9% to 0.48%, achieving good decoupling.

Originality/value

The prediction-based neural network model reference decoupling control method proposed in this paper can use the neural network model to predict the next output of the system according to the input and output. Finally, the weights of the neural network are corrected online according to the predicted output and the given reference output, so that the optimization index of the neural network decoupling controller is extremely small, and the purpose of decoupling control is achieved.

Details

Robotic Intelligence and Automation, vol. 44 no. 2
Type: Research Article
ISSN: 2754-6969

Keywords

Article
Publication date: 25 March 2024

Boyang Hu, Ling Weng, Kaile Liu, Yang Liu, Zhuolin Li and Yuxin Chen

Gesture recognition plays an important role in many fields such as human–computer interaction, medical rehabilitation, virtual and augmented reality. Gesture recognition using…

Abstract

Purpose

Gesture recognition plays an important role in many fields such as human–computer interaction, medical rehabilitation, virtual and augmented reality. Gesture recognition using wearable devices is a common and effective recognition method. This study aims to combine the inverse magnetostrictive effect and tunneling magnetoresistance effect and proposes a novel wearable sensing glove applied in the field of gesture recognition.

Design/methodology/approach

A magnetostrictive sensing glove with function of gesture recognition is proposed based on Fe-Ni alloy, tunneling magnetoresistive elements, Agilus30 base and square permanent magnets. The sensing glove consists of five sensing units to measure the bending angle of each finger joint. The optimal structure of the sensing units is determined through experimentation and simulation. The output voltage model of the sensing units is established, and the output characteristics of the sensing units are tested by the experimental platform. Fifteen gestures are selected for recognition, and the corresponding output voltages are collected to construct the data set and the data is processed using Back Propagation Neural Network.

Findings

The sensing units can detect the change in the bending angle of finger joints from 0 to 105 degrees and a maximum error of 4.69% between the experimental and theoretical values. The average recognition accuracy of Back Propagation Neural Network is 97.53% for 15 gestures.

Research limitations/implications

The sensing glove can only recognize static gestures at present, and further research is still needed to recognize dynamic gestures.

Practical implications

A new approach to gesture recognition using wearable devices.

Social implications

This study has a broad application prospect in the field of human–computer interaction.

Originality/value

The sensing glove can collect voltage signals under different gestures to realize the recognition of different gestures with good repeatability, which has a broad application prospect in the field of human–computer interaction.

Details

Sensor Review, vol. 44 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 1 September 1999

Michael Di Francesco

This paper is based on work undertaken for the Commonwealth Department of Finance and Administration and reports on recent developments within the Australian public sector of…

1274

Abstract

This paper is based on work undertaken for the Commonwealth Department of Finance and Administration and reports on recent developments within the Australian public sector of performance measurement in policy advice output. It outlines the role of performance information in an accrual‐based outcomes and outputs management framework, examines the merits of a model for developing criteria for “good” performance information and explores how these design principles might be applied to policy advice output. The paper identifies the key attributes of policy advice output from the perspective of both providers and clients and their linkage to proposed performance indicators, and concludes by surveying the political and accountability problems associated with specifying and measuring policy advice in government.

Details

International Journal of Public Sector Management, vol. 12 no. 5
Type: Research Article
ISSN: 0951-3558

Keywords

Article
Publication date: 17 October 2008

Ping He and Zhongsheng Hua

To develop a method of compensation analysis based on the additive data envelopment analysis model.

583

Abstract

Purpose

To develop a method of compensation analysis based on the additive data envelopment analysis model.

Design/methodology/approach

It is a common assumption in current target setting literature that outputs of decision making units (DMUs) are generated simultaneously. In practice, outputs of DMUs may be generated consecutively, and targets of posterior outputs may need to be adjusted to keep a DMU efficient when the anterior output cannot reach the previously set output target. The proposed method determines a compensation rate among consecutive outputs, which is applied to keep a DMU efficient when the decrease of an anterior output exceeds its stability region. This compensation analysis is also extended to consecutive inputs.

Findings

Sufficient and necessary conditions for preserving efficiency upon output compensation are presented.

Research limitations/implications

The compensation analysis when multiple anterior outputs decrease from their previously set targets is the main limitation, and needs further investigation.

Practical implications

The paper is a useful method for decision maker to set target consecutively.

Originality/value

The paper defines a new target setting (adjusting) problem, in which targets of posterior outputs may need to be adjusted to keep a DMU efficient if an anterior output of the DMU decreases from its previously set target. Theoretical analyses of the compensation analysis are provided.

Details

Kybernetes, vol. 37 no. 9/10
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 7 September 2010

Xiaoyun Liu, Wanchun Luo, Xuefeng Mao, Xiuqing Wang and Xian Xin

The paper aims to assess the impact of agricultural output changes on the general price level over time with China as an example.

1800

Abstract

Purpose

The paper aims to assess the impact of agricultural output changes on the general price level over time with China as an example.

Design/methodology/approach

A simple numerical global general equilibrium (GE) model of two regions (China and the rest of the world) and three commodities (agriculture, manufacturing goods, and services) is used to assess the impacts of agricultural output changes on the overall economy price changes. The numerical GE model of this paper consists of production, final consumption, and market clear conditions. The results are generated with the GE model calibrated to aggregated China's input‐output tables of 1987, 1997, and 2005.

Findings

The results suggest that China witnessed a declining influence of agricultural output changes on general price changes. The contribution of given agricultural output change on the general price change in 2005 was merely less than 60 percent of that in 1987, which in turn implies that macro policies targeting to curb general inflation via boosting agricultural output will be less effective as those of 20 years ago.

Practical implications

China's policy makers should rely less and less on promoting agricultural output policies to fight against general inflation and should resort to non‐agricultural policies.

Originality/value

The paper argues that the influence of agriculture on the China's general price indices has been weakening along with China's economic development with a numerical GE model calibrated to aggregated China's input‐output tables of 1987, 1997, and 2005.

Details

China Agricultural Economic Review, vol. 2 no. 3
Type: Research Article
ISSN: 1756-137X

Keywords

Article
Publication date: 12 August 2014

Bing Xu and Xiaowen Hu

– The purpose of this paper is to find alternative strategies to change negative output gaps in China.

Abstract

Purpose

The purpose of this paper is to find alternative strategies to change negative output gaps in China.

Design/methodology/approach

A path Philips curves approach is proposed to investigate output gaps, which develops hybrid Philips curves with the control variables of money, house prices and interest rates.

Findings

An alternative strategy to stop the decline in output gaps rate is to perform interest rate, house price, and money growth rate about 3, 1 and 15 percent, respectively. The results also indicate that only one of monetary increase, changes in interest rates, and house price adjustments are difficult to change the negative output gap.

Practical implications

Alternative strategies cannot only change the negative output gap, but also succeed in pushing the inflation rate down to 3 percent.

Originality/value

This study provides a new path Philips curves to simulate how the macroscopic control variables influence output and inflation. It provides a useful insight for stopping the decline in output gaps.

Details

Management Decision, vol. 52 no. 7
Type: Research Article
ISSN: 0025-1747

Keywords

Article
Publication date: 1 January 1992

Philip Lawler

Examines the effects of a monetary expansion on certain keymacroeconomic variables, in particular the nominal exchange rate,competitiveness, and domestic output and employment…

Abstract

Examines the effects of a monetary expansion on certain key macroeconomic variables, in particular the nominal exchange rate, competitiveness, and domestic output and employment, using a modified version of the Dornbusch (Journal of Political Economy, 1976) model. Dornbusch′s original analysis of the implications of sticky prices was conducted on the basis of two alternative assumptions concerning the supply side of the economy, a fixed (full‐employment) level of output and (in his Appendix) continuous goods market clearing, maintained by instantaneous output adjustment. Neither of these assumptions appears particularly satisfactory and the model presented here attempts to address the issue by assuming output to be instantaneously fixed, but to respond gradually to excess demand or supply in the goods market. The structure of the resulting model is such as to imply a third‐order dynamic adjustment process which is solved explicitly. Two principal conclusions follow from the analysis. First, despite the fact that the monetary expansion inevitably reduces the domestic interest rate, nominal exchange rate overshooting need not result. Second, the dynamics of adjustment are considerably more complicated than in the original Dornbusch model and may, in fact, be cyclical in nature.

Details

Journal of Economic Studies, vol. 19 no. 1
Type: Research Article
ISSN: 0144-3585

Keywords

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