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1 – 10 of over 2000Biao Ma, Liang Yu, Man Chen, He Yan Li and Liang Jie Zheng
This paper aims to investigate the thermal characteristics of the clutch hydraulic system under various oil flow conditions. Increasing the oil flow is one of the most…
Abstract
Purpose
This paper aims to investigate the thermal characteristics of the clutch hydraulic system under various oil flow conditions. Increasing the oil flow is one of the most important approaches to reduce the clutch temperature. However, the effect of the oil flow on the clutch temperature remains to be explored.
Design/methodology/approach
The thermal resistance network model and the lumped parameter method are used to study the thermal characteristics of the clutch hydraulic system. The predicted temperature variations of the clutch and the oil are compared with experimental data.
Findings
Results demonstrate that the larger the friction power is, the higher the temperatures of the clutch and the oil are. However, the temperature growth rates of the clutch and oil present different trends: the former decreases gradually and the latter increases constantly. Additionally, increasing the oil flow within a certain range gives rise to the decrease of clutch temperature and the increase of oil temperature; nevertheless, their variation trends are gradually weakening. When the oil flow is large enough, it brings a slight effect on the clutch temperature rise.
Originality/value
This paper extends the knowledge into the oil flow supply of the clutch hydraulic system. The conclusions can provide a theoretical guidance for the oil management of the transmission system. Additionally, the thermal resistance network model is also effective and efficient for other hydraulic equipment to predict the temperature variation.
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Abstract
Purpose
This paper aims to study and compare the friction stability of wet paper-based clutches with regard to the radial grooves (RG) and waffle grooves (WG).
Design/methodology/approach
This paper presents an experimental study of a wet clutch concerning the effect of groove patterns on the friction torque and surface temperature. The friction stabilities of RG and WG are investigated with the applied pressure, rotating speed and automatic transmission fluid (ATF) temperature taken into consideration.
Findings
The friction torque and surface temperature of WG are larger than those of RG under the same operating condition. The friction torque difference between RG and WG grows with the increase of applied pressure and narrows with the increase of ATF temperature. Additionally, their temperature difference expands via increasing the rotating speed and ATF temperature or reducing the applied pressure; in this way, not only the variable coefficient difference between RG and WG can be narrowed, but also the friction stability of the clutch can be improved dramatically.
Originality/value
This paper explains the thermodynamic differences between RG and WG; moreover, it is verified experimentally that WG has a better friction stability than RG.
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Haixu Yang, Feng Zhu, Haibiao Wang, Liang Yu and Ming Shi
The purpose of this paper is to describe the structure of nonlinear dampers and the dynamic equations, and nonlinear realization principles and optimize the parameters of…
Abstract
Purpose
The purpose of this paper is to describe the structure of nonlinear dampers and the dynamic equations, and nonlinear realization principles and optimize the parameters of nonlinear dampers. Using the finite element method to analyze the seismic performance of the frame structure with shock absorber.
Design/methodology/approach
The nonlinear shock absorber was installed in a six-storey reinforced concrete frame structure to study its seismic performance. The main structure was designed according to the eight degree seismic fortification intensity, and the time history dynamic analysis was carried out by Abaqus finite element software. EL-Centro, Taft and Wenchuan seismic record were selected to analyze the seismic response of the structure under different magnitudes and different acceleration peaks.
Findings
Through the principle study and parameter analysis of the nonlinear shock absorber, combined with the finite element simulation results, the shock absorption performance and shock absorption effect of the nonlinear energy sink (NES) nonlinear shock absorber are given as follows: first, the damping of the NES shock absorber is satisfied, and the linear spring stiffness and nonlinear stiffness of the shock absorber are based on the relationship k1=kn×kl2, so that the spring design length is fixed, and the linear stiffness of the shock absorber can be obtained. The nonlinear shock absorber has the characteristics of high rigidity and frequency bandwidth, so that the frequency is infinitely close to the frequency of the main structure, and when the mass of the shock absorber satisfies between 0.056 and 1, a good shock absorption effect can be obtained, and the reinforced concrete with the shock absorber is obtained. The frame structure can effectively reduce the seismic response, increase the natural vibration period of the structure and reduce the damage loss of the structure. Second, the spacer and each additional shock absorber have a small difference in shock absorption effect. After the shock absorber parameters are accurately calculated, the number of installations does not affect the shock absorption effect of the structure. Therefore, the shock absorber is properly constructed and accurately calculated. Parameters can reduce costs.
Originality/value
New shock absorbers reduce earthquake-induced damage to buildings.
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Liang-Wei Kuo, Hsin-Yu Liang and Yung-Jang Wang
Building upon the framework of the tradeoff model of capital structure and motivated by the equity market timing theory, we examine whether equity misvaluation is a source…
Abstract
Building upon the framework of the tradeoff model of capital structure and motivated by the equity market timing theory, we examine whether equity misvaluation is a source of adjustment “costs” that will affect a firm’s leverage adjustment speed toward target. We also investigate whether the quality of a firm’s long-term growth options will influence the decisions of managers to exploit the mispriced equity to converge to the optimum. Using a sample of listed Taiwanese firms during 1992–2014 and employing the market-to-book decomposition as developed by Rhodes-Kropf, Robinson, and Viswanathan (2005), we find that overleveraged and overvalued firms demonstrate faster adjustment speed than overleveraged but undervalued firms. Furthermore, controlling for the misvaluation status, high-growth firms converge to target faster than their low-growth counterparts. The effect of growth options on the relation between equity mispricing and adjustment speed does not mirror the effect of financing deficits. With the detailed financial information of the local companies across a rather long time series, this study provides incremental inputs to the literature of capital structure from the determinants of target leverage, the estimation of leverage adjustment speeds, to the identification of the sources of adjustment costs in an emerging market where institutional environment is strikingly different from the US.
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Elías Moreno and Luís Raúl Pericchi
We put forward the idea that for model selection the intrinsic priors are becoming a center of a cluster of a dominant group of methodologies for objective Bayesian Model…
Abstract
We put forward the idea that for model selection the intrinsic priors are becoming a center of a cluster of a dominant group of methodologies for objective Bayesian Model Selection.
The intrinsic method and its applications have been developed in the last two decades, and has stimulated closely related methods. The intrinsic methodology can be thought of as the long searched approach for objective Bayesian model selection and hypothesis testing.
In this paper we review the foundations of the intrinsic priors, their general properties, and some of their applications.
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Yu‐Liang Chi, Tien‐Yu Hsu and Wei‐Pang Yang
The purpose of this study is to describe a framework of ontological techniques to restrengthen current content management systems of a natural science museum. The…
Abstract
Purpose
The purpose of this study is to describe a framework of ontological techniques to restrengthen current content management systems of a natural science museum. The ontological approach is utilized to extend the service level from information to knowledge.
Design/methodology/approach
Two ontologies have been established to perform vascular plant and herbal drug knowledge bases that further facilitate knowledge integration and inference. Furthermore, this study presented ontology development processes, including knowledge acquisition, representation, and retrieval.
Findings
Empirical lessons related to development techniques are concluded as follows: first, the formal concept analysis can be used as a knowledge acquisition approach to acquire concepts and attributes from expertise. Second, the Ontology Web Language represents an XML‐based language which provides formal logic expressions for describing knowledge concepts. Finally, the Jena APIs can be further developed as an ontology reasoner to facilitate knowledge inference and retrieval.
Research limitations/implications
The development of ontological knowledge base is time‐consuming and requires seamless collaboration among specialists, knowledge engineers, and information systems.
Practical implications
Empirical lessons indicate that ontological techniques provide potential approaches for library and museum communities to apply for next generation knowledge building.
Originality/value
This study indicates that ontological techniques have excellent potential for knowledge building.
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Shuqing Li, Li Ding, Xiaowei Ding, Huan Hu and Yu Zhang
With the continuous change of research contents and methods of intelligence science, its integration with other disciplines is also deepening. The purpose of this paper is…
Abstract
Purpose
With the continuous change of research contents and methods of intelligence science, its integration with other disciplines is also deepening. The purpose of this paper is to further explore the interdisciplinary research characteristics of intelligence science in theoretical depth and application value.
Design/methodology/approach
This paper summarizes and explores in two aspects. The first is a large number of literature review, mainly combined with the historical characteristics of the development of intelligence science researches in China and international comparison. The second is to refine the discipline construction ideas suitable for the development of contemporary intelligence science.
Findings
From the perspective of the historical development of discipline relevance, the development characteristics and positioning of intelligence science in China are introduced, with the comparison of many disciplines including information technology, library science, information science, data science, management science and other disciplines. In order to better meet the practical needs of intelligence service in the new era, this paper mainly analyzes the construction method of intelligence science research system and the relocation of intelligence science research content.
Originality/value
This paper summarizes the historical characteristics and international comparison of the development of intelligence science in China. It proposes the development characteristics and orientation of intelligence science in China from the perspective of historical development of discipline relevance. It also proposes the discipline construction ideas suitable for the development of contemporary intelligence science.
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Yu‐Liang Chi and Hsiao‐Chi Chen
The purpose of this paper is to demonstrate how the semantic rules in conjunction with ontology can be applied for inferring new facts to dispatch news into corresponding…
Abstract
Purpose
The purpose of this paper is to demonstrate how the semantic rules in conjunction with ontology can be applied for inferring new facts to dispatch news into corresponding departments.
Design/methodology/approach
Under a specific task domain, the proposed design comprises finding a glossary from electronic resources, gathering organization functions as controlled vocabularies, and linking relationships between the glossary and controlled vocabularies. Web ontology language is employed to represent this knowledge as ontology, and semantic web rule language is utilized to infer implicit facts among instances.
Findings
Document dispatching is highly domain dependent. Human perspectives being adopted as predefined knowledge in understanding document meanings are important. Knowledge‐intensive approaches such as ontology can model and represent expertise as reusable components. Ontology and rules together extend inference capabilities in semantic relationships between instances.
Practical implications
Empirical lessons reveal that ontology with semantic rules can be utilized to model human subjective judgement as knowledge bases. An example, including ontology and rules, based on news dispatching is provided.
Originality/value
An organization can classify and deliver documents to corresponding departments based on known facts by following the described procedure.
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Liqun Xiang, Yongtao Tan, Xin Jin and Geoffrey Shen
This study aims to identify the stakeholders and critical factors (CFs) of promoting age-friendly communities (AFCs), discuss the relationship between the stakeholders and…
Abstract
Purpose
This study aims to identify the stakeholders and critical factors (CFs) of promoting age-friendly communities (AFCs), discuss the relationship between the stakeholders and CFs and develop a preliminary framework for the briefing stage of promoting AFCs in urban China.
Design/methodology/approach
Stakeholders and CFs were identified through literature review and document analysis. The Delphi method was used to screen the extracted stakeholders and CFs. The focus group methodology was applied to obtain evaluation matrices of relationships between stakeholders and CFs. A two-mode social network was formed to analyse the evaluation matrices generated.
Findings
Results of the analyses indicate that local governments and policymaking institutions, together with project investors, obtained high prioritisations in the stakeholders' group, whilst senior citizens and caregivers appear to rank last. For CFs, communities' environmental factors receive the most attention from stakeholders.
Research limitations/implications
Results of the analyses can only show similarities of the participating stakeholders' opinions on their concerns, and provide researchers and practitioners with initial ideas on analysing stakeholders and CFs at the briefing stage of promoting AFCs. For a specific project, the concerns and prioritisations would change. Diverse voices are necessary and case studies are in need.
Practical implications
Challenges in promoting AFCs in urban China are discussed, and a preliminary framework of the briefing stage is developed for practitioners to follow when promoting AFCs.
Originality/value
This study discusses which CFs should be considered priorities and what consensuses are generally reached by stakeholders. CFs are utilised to interpret stakeholders' relationships, influences and concerns on AFC projects when conducting the social network analysis (SNA).
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