Search results

1 – 3 of 3
Open Access
Article
Publication date: 28 April 2020

Jialin Zou, Kun Wang and Hongbo Sun

Crowd network systems have been deemed as a promising mode of modern service industry and future economic society, and taking crowd network as the research object and exploring…

Abstract

Purpose

Crowd network systems have been deemed as a promising mode of modern service industry and future economic society, and taking crowd network as the research object and exploring its operation mechanism and laws is of great significance for realizing the effective governance of the government and the rapid development of economy, avoiding social chaos and mutation. Because crowd network is a large-scale, dynamic and diversified online deep interconnection, its most results cannot be observed in real world, and it cannot be carried out in accordance with traditional way, simulation is of great importance to put forward related research. To solve above problems, this paper aims to propose a simulation architecture based on the characteristics of crowd network and to verify the feasibility of this architecture through a simulation example.

Design/methodology/approach

This paper adopts a data-driven architecture by deeply analyzing existing large-scale simulation architectures and proposes a novel reflective memory-based architecture for crowd network simulations. In this paper, the architecture is analyzed from three aspects: implementation framework, functional architecture and implementation architecture. The proposed architecture adopts a general structure to decouple related work in a harmonious way and gets support for reflection storage by connecting to different devices via reflection memory card. Several toolkits for system implementation are designed and connected by data-driven files (DDF), and these XML files constitute a persistent storage layer. To improve the credibility of simulations, VV&A (verification, validation and accreditation) is introduced into the architecture to verify the accuracy of simulation system executions.

Findings

Implementation framework introduces the scenes, methods and toolkits involved in the whole simulation architecture construction process. Functional architecture adopts a general structure to decouple related work in a harmonious way. In the implementation architecture, several toolkits for system implementation are designed, which are connected by DDF, and these XML files constitute a persistent storage layer. Crowd network simulations obtain the support of reflective memory by connecting the reflective memory cards on different devices and connect the interfaces of relevant simulation software to complete the corresponding function call. Meanwhile, to improve the credibility of simulations, VV&A is introduced into the architecture to verify the accuracy of simulation system executions.

Originality/value

This paper proposes a novel reflective memory-based architecture for crowd network simulations. Reflective memory is adopted as share memory within given simulation execution in this architecture; communication efficiency and capability have greatly improved by this share memory-based architecture. This paper adopts a data-driven architecture; the architecture mainly relies on XML files to drive the entire simulation process, and XML files have strong readability and do not need special software to read.

Details

International Journal of Crowd Science, vol. 4 no. 2
Type: Research Article
ISSN: 2398-7294

Keywords

Article
Publication date: 11 October 2021

Jialin Song, Yiyi Su, Taoyong Su and Luyu Wang

The purpose of this paper is, from a resource accumulation and resource allocation perspective, to examine the variant effects of government subsidies among firms with varying…

Abstract

Purpose

The purpose of this paper is, from a resource accumulation and resource allocation perspective, to examine the variant effects of government subsidies among firms with varying levels of market power and to test how industry competition moderates the relationship between market power and allocative efficiency of government subsidies.

Design/methodology/approach

This study explores the relationship between government subsidies and firm performance from a resource-based view. The authors study the moderating role of market power and three-way interaction between subsidy, market power and industry competition on firm performance. The authors test their hypotheses using a sample of Chinese A-share manufacturing firms from 2006–2019. The authors apply firm-level panel data regressions and conduct a series of robustness tests. The marginal effect of market power and industry competition is explored via three-way moderator effect models.

Findings

This study finds that government subsidies are negatively related to firm performance. Market power, on average, strengthens the negative effect of government subsidies on performance, but such a reinforcement effect is neutralized when industry competition is intense. Government subsidies are least efficiently used when firms have market power and industry competition is low. In addition, the authors use different forms of firm performance and a various of robustness tests to verify their assumptions.

Originality/value

This paper contributes to the literature as follows. First, the authors look into subsidy–performance problem from the perspective of the resource-based view and contribute to explaining and mitigating the divergence of current findings on the subsidy–performance relationship. Second, the authors introduce market power and industry competition as moderators to study how resource allocative efficiency affects the subsidy–performance relationship. Third, the authors propose that managerial incentives have played an important role in the allocation of government subsidies, which enriches management practices.

Details

Chinese Management Studies, vol. 16 no. 5
Type: Research Article
ISSN: 1750-614X

Keywords

Open Access
Article
Publication date: 17 May 2022

Hao Li, Jialin Sun and Guotang Zhao

With the help of multi-body dynamics software UM, the paper uses Kik–Piotrowski model to simulate wheel-rail contact and Archard wear model for rail wear.

Abstract

Purpose

With the help of multi-body dynamics software UM, the paper uses Kik–Piotrowski model to simulate wheel-rail contact and Archard wear model for rail wear.

Design/methodology/approach

The CRH5 vehicle-track coupling dynamics model is constructed for the wear study of rails of small radius curves, namely 200 and 350 m in Guangzhou East EMU Depot and those 250 and 300 m radius in Taiyuan South EMU Depot.

Findings

Results show that the rail wear at the straight-circle point, the curve center point and the circle-straight point follows the order of center point > the circle-straight point > the straight-circle point. The wear on rail of small radius curves intensifies with the rise of running speed, and the wearing trend tends to fasten as the curve radius declines. The maximum rail wear of the inner rail can reach 2.29 mm, while that of the outer rail, 10.11 mm.

Originality/value

With the increase of the train passing number, the wear range tends to expand. The rail wear decreases with the increase of the curve radius. The dynamic response of vehicle increases with the increase of rail wear, among which the derailment coefficient is affected the most. When the number of passing vehicles reaches 1 million, the derailment coefficient exceeds the limit value, which poses a risk of derailment.

Details

Railway Sciences, vol. 1 no. 1
Type: Research Article
ISSN: 2755-0907

Keywords

1 – 3 of 3