Rui Xi, Jiangyou Yu, Le Cao, Xiaojiang Zheng and Jun Guo
Most solder paste printers are configured to periodically clean the stencil to maintain printing quality. However, a periodical cleaning control may result in excessive cleaning…
Abstract
Purpose
Most solder paste printers are configured to periodically clean the stencil to maintain printing quality. However, a periodical cleaning control may result in excessive cleaning operations. The purpose of this paper is to develop a control method to schedule stencil cleaning operations appropriately.
Design/methodology/approach
A hybrid failure rate model of the stencil printing process with age reduction factor and failure rate increase factor is presented. A stencil cleaning policy based on system reliability is introduced. An optimization model used to derive the optimal stencil cleaning schedule is provided.
Findings
An aperiodic stencil cleaning control with good adaptability is achieved. A comparative analysis indicates that aperiodic control has better printing system reliability than traditional periodical control under the same cleaning resource consumption.
Originality/value
Periodical cleaning control commonly used in industrial printing process often results in excessive cleaning operations. By incorporating the printing system reliability, this paper develops an aperiodic stencil cleaning control method based on hybrid failure rate model of the stencil printing process. It helps to reduce unnecessary cleaning operations while keeping printing quality stable.
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JiangYou Yu, Le Cao, Hao Fu and Jun Guo
Stencil cleaning is an important operation in solder paste printing process. Frequent cleaning may interrupt printing process and increase idle time, as well as loss for…
Abstract
Purpose
Stencil cleaning is an important operation in solder paste printing process. Frequent cleaning may interrupt printing process and increase idle time, as well as loss for performing cleaning. This paper aims to propose a method to optimize the stencil cleaning time and reduce unnecessary cleaning operations and losses.
Design/methodology/approach
This paper uses a discrete-time, discrete-state homogeneous Markov chain to model the stencil printing performance degradation process, and the quality loss during the stencil printing process is estimated based on this degradation model. A stencil cleaning decision model based on renewal reward theorem is established, and the optimal cleaning time is obtained through a balance between quality loss and the loss on idle time.
Findings
A stencil cleaning decision model for solder paste printing is established, and numerical simulation results show that there exists an optimal stencil cleaning time which minimizes the long-term loss.
Originality/value
Stencil cleaning control is very important for solder paste printing. However, there are very few studies focusing on stencil cleaning control. This research contributes to developing a model to optimize the stencil cleaning time in solder paste printing process.
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Haiqing Hu and Tian Wu
Strengthening the combination of technology and finance can significantly promote the development of economy and society. Urbanization is a crucial standard to measure the…
Abstract
Strengthening the combination of technology and finance can significantly promote the development of economy and society. Urbanization is a crucial standard to measure the economic and social development of a country and region, and urban regional planning based on science and technology finance has always been the focus of both domestic and foreign research institutions. Thus, this paper takes Mianyang, the first city of science and technology, as the object of research, and from the angle of the development process of Mianyang, investigates the three stages of the construction and development of this science and technology city. This study analyzes the characteristics of regional planning of Mianyang City and sums up the idea of relying on the old city to build another new district, which boosts the development of science and technology as well as the economy. From two specific angles (i.e., urban spatial function region planning and urban and rural planning), this paper thoroughly studies a multiscale planning scheme of Mianyang’s urban area in recent years by researching the local policy, system, finance, and society. Empirical measurement proves that reasonable planning and construction of the science and technology city Mianyang can accelerate the development process of the western region, effectively promoting the economic development of the surrounding areas of Sichuan and remarkably improving the overall quality of the regional economy of both Chongqing and Sichuan Provinces.
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Jianbo Huang, Hengyi Su and Hanqi Wu
Merchant guild culture derives from business practices associated with medieval and early modern merchant guilds. This study aims to investigate the nexus between merchant guild…
Abstract
Purpose
Merchant guild culture derives from business practices associated with medieval and early modern merchant guilds. This study aims to investigate the nexus between merchant guild culture and firm internationalization as well as the factors that moderate this nexus.
Design/methodology/approach
Based on the distribution of the ten merchant guilds in China and data on Chinese listed companies, this study uses the geographical proximity-based method to measure the intensity of merchant guild culture, which is the nearest distance between the ten merchant guilds’ origins and each firm’s registered address.
Findings
This study provides robust evidence that merchant guild culture positively relates to the degree of firm internationalization. It also documents that this nexus is stronger for firms with overseas background executives and those situated in highly marketized regions.
Practical implications
The findings of this study have valuable implications for both governments and firms. Governments can leverage local cultures to promote the internationalization of domestic firms, particularly in emerging economies with rich cultural heritage. Firms can further enhance their internationalization efforts by hiring more executives with overseas backgrounds.
Originality/value
This study advances the imprinting literature, provides a novel perspective on the antecedents of firm internationalization and expands research on the contemporary value of historical business culture.
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Jian Wang, Chenqi Situ and Mingzhu Yu
This paper aims to study a dynamic post-disaster emergency planning (PDEP) problem in an integrated network through the investigation of the selection of shelters, medical centers…
Abstract
Purpose
This paper aims to study a dynamic post-disaster emergency planning (PDEP) problem in an integrated network through the investigation of the selection of shelters, medical centers and distribution centers (DCs), and the allocation of evacuees and injured people. The resource and people assignment in multiple periods are considered.
Design/methodology/approach
A mathematical formulation is provided for the PDEP problem. The authors decompose the model into two sub-models as follows: the primary model is an integer programming model and the subproblem is a nonlinear programming model with continuous variables. The simulated annealing is used to solve the primary problem, and particle swarm optimization (PSO) mixed with beetle antennae search (BAS) is used to solve the subproblem.
Findings
The paper finds that BAS can increase the stability of PSO and keep the advantages of PSO’s rapid convergence. By implementing these algorithms on emergency planning after the Wenchuan earthquake that happened in China in 2008, this paper finds that the priority of different levels of injured people is influenced by several factors. Even within the same disaster, the priority of different levels of injured can be inconsistent because of the differences in resource levels.
Originality/value
The authors integrate the shelters, medical centers and DCs as a system, and simultaneously, consider evacuees and injured people and different resource assignments. The authors divide the injured people into three levels and use survival rate function to simulate the survival conditions of different people. The authors provide an improved PSO algorithm to solve the problem.
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Gholamreza Sepehri, Naser Haj‐Akbari, Ehsan Sepehri and Motahareh Mohsen‐Beigi
Few reports considering drug use among earthquake survivors exist. The present study aims to examine the Bam earthquake's impact on prescribing patterns and drug use among…
Abstract
Purpose
Few reports considering drug use among earthquake survivors exist. The present study aims to examine the Bam earthquake's impact on prescribing patterns and drug use among residents five years post‐disaster.
Design/methodology/approach
In this study, 297,104 prescriptions, issued by general practitioners in Bam city in 2008, were investigated for drugs/prescriptions, drug name, drug category, using WHO appropriate general practice prescribing indicators.
Findings
Mean drugs per prescription was 3.1. Drugs affecting the central nervous system were the most frequently used among Bam residents, representing 25.1 per cent, followed by antimicrobials, respiratory, cardiovascular and gastrointestinal tract drugs. Benzodiazepines were the most frequently used central nervous system drugs (15.8 per cent) followed by narcotic analgesics and tricyclic antidepressants. Penicillins (6.4 per cent) and cephalosporines (2.3 per cent) were the most frequently used antimicrobial drugs.
Originality/value
Results emphasize increased drug use for psychological disturbances and the need for strategies to improve mental health among disaster survivors.