Zhang Yi, Zhang Xiaodong, Chang Xueping and Wu Qian
This paper aims to clarify the relationship between the cone bit seal failure and the down-hole drilling fluid pressure and high temperature that occur during ultra-deep well…
Abstract
Purpose
This paper aims to clarify the relationship between the cone bit seal failure and the down-hole drilling fluid pressure and high temperature that occur during ultra-deep well drilling. It proposes that the contact pressure distribution under low pressure conditions is favourable for lubrication and the seal inner wear is serious under high pressure conditions. Furthermore, the more reliable cone bit seal can be obtained using the back propagation (BP) neural network and genetic algorithm (GA) to reduce the drilling cost.
Design/methodology/approach
The wear morphologies of the seal surface were analyzed using Contour GT-K to determine the seal contact pressure distribution. Then, the influences of the drilling fluid pressure and high temperature on the metal seal interface were analyzed using finite element method. The structural parameters of the seal under high pressure were optimized based on the BP neural network and GA.
Findings
This paper proposes that the inner seal contact pressure increases rapidly with an increase in the drilling fluid pressure. The design parameters of the seal components should be adjusted reasonably to ensure that the outer contact pressure is greater than the inner contact pressure, which is advantageous for forming a lubricant film on the inner side of the seal. The uneven temperature distribution of the seal surface will further aggravate seal failure.
Originality/value
Study on the bit seal with good property is significant in drilling application, and the optimized seal can prolong the cone bit life.
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Xueping Zhen, Shuangshuang Xu, Dan Shi and Fangjun Liu
This study aims to explore the government’s subsidy preference and pricing decisions of a manufacturer who produces traditional and green product simultaneously under different…
Abstract
Purpose
This study aims to explore the government’s subsidy preference and pricing decisions of a manufacturer who produces traditional and green product simultaneously under different government subsidy policies.
Design/methodology/approach
The authors establish a model consisting of a government, a set of heterogeneous consumers and a manufacturer. Three government subsidy policies are investigated without government subsidy (NS), government subsidy to consumer (CS) and government subsidy to the manufacturer (MS).
Findings
The results show that the government subsidy can increase both the green product’s demand and the manufacturer’s profit. The subsidy level and government’s utility under the CS policy are equal to those under the MS policy. Furthermore, if the government’s subsidy level is exogenous, there exists a Pareto improvement region when social welfare for unit greenness level is high. That is, if the government’s subsidy level under the CS policy is higher than that under the MS policy, both government and manufacturer prefer the CS policy; otherwise, they prefer the MS policy.
Research limitations/implications
This paper considers the market where there is a monopoly green manufacturer and a government that only provides subsidy policy. In fact, competition from traditional manufacturers and carbon taxes are also worth exploring in future research.
Practical implications
This study provides some suggestions for government subsidy and provides guidance for the manufacturer’s pricing decisions under different government subsidy policies.
Originality/value
This paper is the first to compare government subsidy to consumer with a government subsidy to the manufacturer and investigate the pricing decisions of a manufacturer who produces traditional and green product simultaneously by considering an endogenous subsidy level of government.
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Xueping Xiong, Jie Tian and Hongxin Ruan
As a major agricultural province in central China, Hubei Province mainly carries out the peasant household credit investigation system through rural credit cooperatives (RCCs)…
Abstract
Purpose
As a major agricultural province in central China, Hubei Province mainly carries out the peasant household credit investigation system through rural credit cooperatives (RCCs). The purpose of this paper is to evaluate the efficiency of the peasant household credit investigation system in Hubei RCCs and provide some evidence and ideas to the formulation of relevant policies.
Design/methodology/approach
First, this paper briefly reviews the related literature of the efficiency in credit investigation system; second, the paper gives a brief description of the data envelopment analysis (DEA) model and designs the indicators for efficiency evaluation; third, the paper accounts data sources and processing methods; and finally, the paper performs the empirical analysis and draws a conclusion.
Findings
The paper finds that the efficiency of the resource allocation in both regions is unoptimistic, the general efficiency is somewhat low, and it shows the trend of declination. The efficiency of pure technology in two regions represents the adverse trend. Every year's average scale efficiency in both regions is higher than the pure technology efficiency.
Originality/value
The main contributions of this paper include the first use of DEA model to practically evaluate the efficiency of credit investigation system based on 54 samples of RCCs in Hubei Province and the horizontal and vertical comparisons of the results. The conclusions of this paper not only make the efficiency of credit investigation system in the province's 54 credit cooperatives comparable but also has a great application value to the actual decision‐making departments in formulating credit policies, and each credit cooperative in further building the credit investigation system according to its own conditions. Moreover, it has certain reference value to other similar studies.
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This chapter builds on the authors’ research into the internationalization of China’s higher education (HE) as soft power with “Chinese characteristics” (Lo & Pan, 2020). It…
Abstract
This chapter builds on the authors’ research into the internationalization of China’s higher education (HE) as soft power with “Chinese characteristics” (Lo & Pan, 2020). It rethinks the “Chinese characteristics” in contemporary China’s internationalization of HE as soft power, by contextualizing them in the historico-cultural rootedness that legitimizes the sense of Chinese exceptionalism in the Party-state’s global re-emergence. It also sheds light on the tension and paradox therein through analyzing the conflicts generated by the Party-state’s attempts at re-globalizing the Chinese world order alongside the Westphalian system. In addition to integrating the soft-power concepts coined by Joseph Nye (1990) with the dimensional perspectives on the internationalization of HE framed by Jane Knight (1997), this study also puts in China’s perspectives that stand in contrast to, and yet in confluence with, some of the current norms and values being espoused by the West. In so doing, it demonstrates the potentiality of employing comparative lenses that cut across times, spaces and cultures in the research into internationalization of HE as soft power with national characteristics.
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Madjid Tavana and Vahid Hajipour
Expert systems are computer-based systems that mimic the logical processes of human experts or organizations to give advice in a specific domain of knowledge. Fuzzy expert systems…
Abstract
Purpose
Expert systems are computer-based systems that mimic the logical processes of human experts or organizations to give advice in a specific domain of knowledge. Fuzzy expert systems use fuzzy logic to handle uncertainties generated by imprecise, incomplete and/or vague information. The purpose of this paper is to present a comprehensive review of the methods and applications in fuzzy expert systems.
Design/methodology/approach
The authors have carefully reviewed 281 journal publications and 149 conference proceedings published over the past 37 years since 1982. The authors grouped the journal publications and conference proceedings separately accordingly to the methods, application domains, tools and inference systems.
Findings
The authors have synthesized the findings and proposed useful suggestions for future research directions. The authors show that the most common use of fuzzy expert systems is in the medical field.
Originality/value
Fuzzy logic can be used to manage uncertainty in expert systems and solve problems that cannot be solved effectively with conventional methods. In this study, the authors present a comprehensive review of the methods and applications in fuzzy expert systems which could be useful for practicing managers developing expert systems under uncertainty.