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1 – 10 of over 12000Contemporary stochastic optimal control by synergy of the probability density evolution method (PDEM) and conventional optimal controller exhibits less capability to guarantee…
Abstract
Purpose
Contemporary stochastic optimal control by synergy of the probability density evolution method (PDEM) and conventional optimal controller exhibits less capability to guarantee economical energy consumption versus control efficacy when non-stationary stochastic excitations drive hysteretic structures. In this regard, a novel multiscale stochastic optimal controller is invented based on the wavelet transform and the PDEM.
Design/methodology/approach
For a representative point, a conventional control law is decomposed into sub-control laws by deploying the multiresolution analysis. Then, the sub-control laws are classified into two generic control laws using resonant and non-resonant bands. Both frequency bands are established by employing actual natural frequency(ies) of structure, making computed efforts depend on actual structural properties and time-frequency effect of non-stationary stochastic excitations. Gain matrices in both bands are then acquired by a probabilistic criterion pertaining to system second-order statistics assessment. A multi-degree-of-freedom hysteretic structure driven by non-stationary and non-Gaussian stochastic ground accelerations is numerically studied, in which three distortion scenarios describing uncertainties in structural properties are considered.
Findings
Time-frequency-dependent gain matrices sophisticatedly address non-stationary stochastic excitations, providing efficient ways to independently suppress vibrations between resonant and non-resonant bands. Wavelet level, natural frequency(ies), and ratio of control forces in both bands influence the scheme’s outcomes. Presented approach outperforms existing approach in ensuring trade-off under uncertainty and randomness in system and excitations.
Originality/value
Presented control law generates control efforts relying upon resonant and non-resonant bands, and deploys actual structural properties. Cost-function weights and probabilistic criterion are promisingly developed, achieving cost-effectiveness of energy demand versus controlled structural performance.
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Stewardship theory is an emergent approach for explaining leadership behavior, challenging the assumptions of agency theory and its dominance in corporate governance literature…
Abstract
Purpose
Stewardship theory is an emergent approach for explaining leadership behavior, challenging the assumptions of agency theory and its dominance in corporate governance literature. This study revisits the agency and stewardship theories by seeking to answer whether chief executive officers (CEOs) in China are committed stewards or opportunistic agents.
Design/methodology/approach
Based on 5,165 observations of 1,036 listed companies in China over the period 2005–2010, the results suggest that the corporate governance mechanisms developed from the agency theory in the West are not necessarily applicable in the Chinese context.
Findings
This study supports the stewardship theory in its findings that empowering CEOs through the practice of CEO duality and longer CEO tenure have a positive effect on firm value in China. Additionally, the positive relationships between CEO duality, CEO tenure and firm value are strengthened by the number of executive directors on the board, and weakened by the number of independent directors on the board.
Practical implications
One size does not fit all. Leadership behaviors in China do not follow the agency assumptions inherent in Western practices, rather they favor the conditions of positive leadership expressed by the stewardship theory. Assuming that the motivations of managers in emerging markets such as China are similar to those in the West may lead to a poor fit between governance policies and the institutional context.
Originality/value
As one of the few studies to connect the theoretical debate between the agency and stewardship theories, this study presents new evidence to support the stewardship theory, thereby strengthening its theoretical importance and relevance in corporate governance literature.
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Peng Li and Huizhen Chen
The purpose of this paper is to propose a multi-criteria decision-making model based on the case-based reasoning (CBR) method for interval-valued probabilistic linguistic term set…
Abstract
Purpose
The purpose of this paper is to propose a multi-criteria decision-making model based on the case-based reasoning (CBR) method for interval-valued probabilistic linguistic term set (IVPLTS), which can cluster different categories of building suppliers for targeted management.
Design/methodology/approach
First, a new score function and distance measure for IVPLTS are proposed. Second, a green building supplier evaluation criterion system is constructed from five aspects: operation management, green management, cooperation potential, service level and product information. Finally, the IVPLTS-CBR model is used to evaluate the green building suppliers and groups them into three preset categories.
Findings
The feasibility and validity of the proposed method are verified by comparing with the advanced TOPSIS method and the IVPLTS-based VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method. The compared results show that the proposed method is more consistent with the actual situation and has strong theoretical significance and practical value.
Research limitations/implications
This paper presents a new method for clustering construction suppliers. Decision makers can use this method to classify construction suppliers into different categories, so that they can be targeted management. In this way, suppliers can be better guided and motivated to accelerate the green transformation and contribute their share to achieve the strategic goal of carbon neutral and carbon peak as soon as possible.
Originality/value
A new score function and distance measure for IVPLTS are proposed. Besides, a novel IVPLTS-CBR method is applied to rank and cluster building suppliers.
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Yong Yang, Youqing Fan and Jianfeng Jia
In the face of external paradoxical requirements, the cognitive framework of managers and employees use to perceive, interpret and reconstruct information is important to ease…
Abstract
Purpose
In the face of external paradoxical requirements, the cognitive framework of managers and employees use to perceive, interpret and reconstruct information is important to ease anxiety and improve job performance. The Yin-Yang balancing of eastern philosophical thought is particularly good at explaining and predicting changes and conflict environments. For this reason, this study aims to propose the eastern construction of the paradoxical cognitive framework based on the Yin-Yang balancing theory and its antecedent framework.
Design/methodology/approach
This paper contrasts the similarity and differences between Chinese and Western philosophy’s thoughts on paradoxes. On this basis, the eastern construction of the paradoxical cognitive framework is proposed. Then, the paper puts forward the antecedent framework of managers’ cognitive framework and employees’ paradoxical cognitive framework.
Findings
This paper proposes the eastern construction of the paradoxical cognitive framework includes the following three dimensions: the unity-in-diversity of paradoxical elements, the asymmetric balance of paradoxical elements and mutual transformation of paradoxical elements. In addition, this paper proposes an antecedent framework of the eastern construction of the paradoxical cognitive framework – the paradoxical requirement of organizational environment exerts a direct impact on managers’ and employees’ paradoxical cognitive framework; managers’ paradoxical cognitive framework has a positive impact on paradoxical leadership; paradoxical leadership exerts an indirect impact on employees’ paradoxical cognitive framework through the collective paradoxical cognitive framework; paradoxical leadership directly affects employees’ paradoxical cognitive framework.
Research limitations/implications
This paper focuses on comparing the similarities and differences of the individual paradoxical cognitive framework in Chinese and Western cultures and proposes the eastern construction of the paradoxical cognitive framework and its antecedent framework. Future research needs to further verify the theoretical framework proposed in this paper.
Originality/value
This paper makes a detailed comparison of the paradox views in Chinese and Western philosophy. It is the first to propose the eastern construction of the paradoxical cognitive framework and its antecedent framework, laying a theoretical foundation for future empirical research.
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Jiawen Chen, Xiaotao Yao and Linlin Liu
This paper aims to examine how a firm’s capability affects its political networking in emerging economies and how the institutional environment influences the relationship between…
Abstract
Purpose
This paper aims to examine how a firm’s capability affects its political networking in emerging economies and how the institutional environment influences the relationship between a firm’s capability and its political networking.
Design/methodology/approach
The authors test the theoretical model by analyzing a database from a World Bank survey in China.
Findings
The results show a nonlinear (U-shaped) relationship between a firm’s capability and its efforts in political networking. The relationship between a firm’s capability and political networking is contingent on the institutional environment, as reflected in institutional development and industry regulation.
Originality/value
This study elucidates political networking in emerging economies and contributes to research on corporate political strategy.
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Zhong-Xin Li, Peng Li and Ke-Chao Wang
The purpose of this paper is to propose a fast, accurate and efficient algorithm for assessment of transient behavior of grounding grids buried in horizontal multilayered earth…
Abstract
Purpose
The purpose of this paper is to propose a fast, accurate and efficient algorithm for assessment of transient behavior of grounding grids buried in horizontal multilayered earth model considering soil ionization effect.
Design/methodology/approach
The purpose of this paper is to develop a numerical simulation method to calculate the lightning impulse response of the grounding grid buried in a horizontal multilayered earth model. The mathematical model about the hybrid method based on PI basic function belonging to time domain is proposed in the paper; the mode can precisely calculate the lightning current distribution and lightning impulse response to grounding grids buried in horizontal multilayered soil model considering soil ionization effect. To increase computing efficiency, quasi-static complex image method (QSCIM) and its time-domain Green’s function closed form are introduced in the model.
Findings
The hybrid model is rather stable, with the respect to the number of elements used and with excellent convergence rate. In addition, because this mathematical model belongs to the time domain algorithm, it is very powerful for the simulation of soil ionization caused by high amplitude lightning current.
Research limitations/implications
To increase computing efficiency, QSCIM and its time domain Green's function closed form are introduced in the model.
Practical implications
The mathematical model about the hybrid method based on PI basic function can precisely calculate the lightning current distribution and lightning impulse response to grounding grids buried in horizontal multilayered soil model considering the soil ionization effect.
Social implications
Considering the soil ionization effect, the simulation calculation of lightning impulse response of substation grounding grid buried in the actual horizontal multilayered earth can effectively support the scientific and efficient design of lightning protection performance of substation grounding grid.
Originality/value
The hybrid model in time domain is originally developed by the authors and used to precisely calculate the lightning current distribution and lightning impulse response to grounding grids buried in horizontal multilayered soil model considering soil ionization effect. It is simple and very efficient and can easily be extended to arbitrary grounding configurations.
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Lin Shi, Guicheng Shi and Huanguang Qiu
The purpose of this paper is to provide a better understanding of the development of intelligent agriculture (IA) in China, which is an important tendency in advancing the…
Abstract
Purpose
The purpose of this paper is to provide a better understanding of the development of intelligent agriculture (IA) in China, which is an important tendency in advancing the agricultural productivity in the coming era.
Design/methodology/approach
Considering publications as featured evidence of an emerging phenomenon, the authors review publications of IA. Specifically, the use of term, definition and examples of IA, both English and Chinese literature, and government policies of China are all reviewed. Additionally, the authors use basic statistical and thematic analysis to help synthesizing the literature and drawing conclusions. Findings from various sources of publications supplement with each other.
Findings
IA in China has shown three main characteristics: unbalanced geographic distribution, an early stage of the trend and attention mainly focused on a limited range of technologies. Compared with the development of IA in other countries, such as Japan, India and the USA, featured with diversified properties, similarities and differences of IA development in China and in other countries are also discussed.
Originality/value
This general review contributes by uncovering the emergence of IA, identifying its general definition with a comprehensive set of practical examples and pointing out the present characteristics and problems of IA development in China. The general review provides a necessary summary for the policy makers and researchers to have a systematic understanding of IA and better promote its future development. At last, the paper calls for a process-based strategy with different goals at different stages, a sustainable mechanism coordinated by multiple participants, and a localized consideration for relevant policy making.
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Peng Li, Xingguang Duan, Guangli Sun, Xiang Li, Yang Zhou and Yunhui Liu
This paper aims to develop a climbing robot to help people inspect lamps of high-mast lighting.
Abstract
Purpose
This paper aims to develop a climbing robot to help people inspect lamps of high-mast lighting.
Design/methodology/approach
The robot consists of driving mechanism, suspension mechanism and compression mechanism. The driving mechanism is realized by link chains and sprockets, which are arranged opposite to each other, to form a dual caterpillar mechanism. The compression mechanism squeezes the caterpillar, and rubber feet “grasps” the steel rope to generate enough adhesion forces. The suspension mechanism is used to compensate the contraction or extension of the chains. The robot is equipped with a DC motor with a rated power of 250 W and a wireless module to communicate with the operator’s console. The dynamic model of the robot and the control strategy is derived, and the stability of the controller is proofed.
Findings
The payload experiment shows the robot can afford up to 3.7 times payload versus its own weight. Even when the payload is 30 kg, the robot can maintain a speed of the 1 m/s. The experiments also show that the tracking error of the robot reaches zero.
Practical implications
The proposed moving mechanism has a high load/weight ratio, which is a verified solution for the cable inspection purpose.
Originality/value
A rope climbing robot for high mast lighting inspection is proposed. The developed mechanism can reach a speed of 1 m/s with the payload of 30 kg, while its own weight is only 15.6 kg. The payload/weight ratio of the robot is 2.24; this value is rather good in many climbing robots reported in other renowned journal.
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Xiaojun Wu, Peng Li, Jinghui Zhou and Yunhui Liu
Scattered parts are laid randomly during the manufacturing process and have difficulty to recognize and manipulate. This study aims to complete the grasp of the scattered parts by…
Abstract
Purpose
Scattered parts are laid randomly during the manufacturing process and have difficulty to recognize and manipulate. This study aims to complete the grasp of the scattered parts by a manipulator with a camera and learning method.
Design/methodology/approach
In this paper, a cascaded convolutional neural network (CNN) method for robotic grasping based on monocular vision and small data set of scattered parts is proposed. This method can be divided into three steps: object detection, monocular depth estimation and keypoint estimation. In the first stage, an object detection network is improved to effectively locate the candidate parts. Then, it contains a neural network structure and corresponding training method to learn and reason high-resolution input images to obtain depth estimation. The keypoint estimation in the third step is expressed as a cumulative form of multi-scale prediction from a network to use an red green blue depth (RGBD) map that is acquired from the object detection and depth map estimation. Finally, a grasping strategy is studied to achieve successful and continuous grasping. In the experiments, different workpieces are used to validate the proposed method. The best grasping success rate is more than 80%.
Findings
By using the CNN-based method to extract the key points of the scattered parts and calculating the possibility of grasp, the successful rate is increased.
Practical implications
This method and robotic systems can be used in picking and placing of most industrial automatic manufacturing or assembly processes.
Originality/value
Unlike standard parts, scattered parts are randomly laid and have difficulty recognizing and grasping for the robot. This study uses a cascaded CNN network to extract the keypoints of the scattered parts, which are also labeled with the possibility of successful grasping. Experiments are conducted to demonstrate the grasping of those scattered parts.
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Josep M. Argilés-Bosch, Josep Garcia-Blandon and Mónica Martinez-Blasco
This paper undertakes an empirical analysis of the impact of absorbed and unabsorbed slack, employing three different measures for each slack type, on firm profitability. We find…
Abstract
This paper undertakes an empirical analysis of the impact of absorbed and unabsorbed slack, employing three different measures for each slack type, on firm profitability. We find that unabsorbed slack has a more favorable influence on future firm profitability than absorbed slack. While all the absorbed slack indicators have a significant negative influence on future profitability, the three unabsorbed slack indicators present positive, negative, and non-significant influences, respectively. The fewer constraints of unabsorbed slack on the redeployment to exploit new opportunities point to its comparative advantage over absorbed slack. We find evidence for the differential impact of absorbed versus unabsorbed slack on profitability in firms with lower levels of slack, which suggests firms prefer to withdraw resources from current business and redeploy them to develop new and more favorable business opportunities.
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