Dian Wang, Chuanjin Huang, Ning Hu and Qiang Wei
The purpose of this paper is to clarify the influence of low earth orbit space environment on the wear mechanism of TC4 alloy material and crank rocker mechanism.
Abstract
Purpose
The purpose of this paper is to clarify the influence of low earth orbit space environment on the wear mechanism of TC4 alloy material and crank rocker mechanism.
Design/methodology/approach
In this study, friction experiments were carried out on TC4 alloy friction discs and crank rocker mechanisms, both before and after exposure to atomic oxygen and proton irradiation. Nanoindentation, grazing incidence X-ray diffraction (GIXRD), and X-ray photoelectron spectroscopy were employed to systematically characterize alterations in mechanical properties, surface phase, and chemical composition.
Findings
The results show that the wear mechanism of TC4 alloy friction disc is mainly adhesive wear in vacuum environment, while the wear mechanism of crank rocker mechanism includes not only adhesive wear but also abrasive wear. Atomic oxygen exposure leads to the formation of more oxides on the surface of TC4 alloy, which form abrasive particles during the friction process. Proton irradiation will lead to a decrease in fatigue performance and an increase in hardness on the surface of TC4 alloy, thus causing fatigue wear on the surface of TC4 alloy, and more furrows appear on the crank rocker mechanism after proton irradiation. In the three environments, the characteristics of abrasive wear of the crank rocker mechanism are more obvious than those of the TC4 alloy friction disc.
Originality/value
These results highlight the importance of understanding the subtle effects of atomic oxygen and proton irradiation on the wear behavior of TC4 alloy and provide some insights for optimizing its performance in space applications.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2024-0051/
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Zhixue Liao, Xinyu Gou, Qiang Wei and Zhibin Xing
Online reviews serve as valuable sources of information, reflecting tourists’ attentions, preferences and sentiments. However, although the existing research has demonstrated that…
Abstract
Purpose
Online reviews serve as valuable sources of information, reflecting tourists’ attentions, preferences and sentiments. However, although the existing research has demonstrated that incorporating online review data can enhance the performance of tourism demand forecasting models, the reliability of online review data and consumers’ decision-making process have not been given adequate attention. To address the aforementioned problem, the purpose of this study is to forecast tourism demand using online review data derived from the analysis of review helpfulness.
Design/methodology/approach
The authors propose a novel “identification-first, forecasting-second” framework. This framework prioritizes the identification of helpful reviews through a comprehensive analysis of review helpfulness, followed by the integration of helpful online review data into the forecasting system. Using the SARIMAX model with helpful online review data sourced from TripAdvisor, this study forecasts tourist arrivals in Hong Kong during the period from August 2012 to June 2019. The SNAÏVE/SARIMA model was used as the benchmark model. Additionally, artificial intelligence models including long short-term memory, back propagation neural network, extreme learning machine and random forest models were used to assess the robustness of the results.
Findings
The results demonstrate that online review data are subject to noise and bias, which can adversely affect the accuracy of predictions when used directly. However, by identifying helpful online reviews beforehand and incorporating them into the forecasting process, a notable enhancement in predictive performance can be realized.
Originality/value
First, to the best of the authors’ knowledge, this study is one of the first to focus on the data issue of online reviews on tourism arrivals forecasting. Second, this study pioneers the integration of the consumer decision-making process into the domain of tourism demand forecasting, marking one of the earliest endeavors in this area. Third, this study makes a novel attempt to identify helpful online reviews based on reviews helpfulness analysis.
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Wei‐qiang Sun, Jin‐sheng Li and Pei‐lin Hong
Multicasting is a necessity for a broadband metro‐area‐network. Discusses the security problems with current multicast protocols. To make the multicast delivery infrastructure…
Abstract
Multicasting is a necessity for a broadband metro‐area‐network. Discusses the security problems with current multicast protocols. To make the multicast delivery infrastructure more secure and reliable, a stateful multicast access control mechanism, based on MAPE, is proposed. This mechanism expands the current forwarding procedure of a layer 2 switch so that stateful multicast access control can be carried out at the very edge of the metro area network. The architecture of MAPE is discussed in detail, as well as the states maintained and messages exchanged. Further explains that the scheme is flexible and scalable.
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Wei Qiang Lim, Mutharasu Devarajan and Shanmugan Subramani
This paper aims to study the influence of the Cu-Al2O3 film-coated Cu substrate as a thermal interface material (TIM) on the thermal and optical behaviour of the light-emitting…
Abstract
Purpose
This paper aims to study the influence of the Cu-Al2O3 film-coated Cu substrate as a thermal interface material (TIM) on the thermal and optical behaviour of the light-emitting diode (LED) package and the annealing effect on the thermal and optical properties of the films.
Design/methodology/approach
A layer-stacking technique has been used to deposit the Cu-Al2O3 films by means of magnetron sputtering, and the annealing process was conducted on the synthesized films.
Findings
In this paper, it was found that the un-annealed Cu-Al2O3–coated Cu substrate exhibited low value of thermal resistance compared to the bare Cu substrate and to the results of previous works. Also the annealing effect does not have a significant impact on the changes of properties of the films.
Research limitations/implications
It is deduced that the increase of the Cu layer thickness can further improve the thermal properties of the deposited film, which can reduce the thermal resistance of the package in system-level analysis.
Practical implications
The paper suggested that the Cu-Al2O3–coated Cu substrate can be used as alternative TIM for the thermal management of the application of LEDs.
Originality value
In this paper, the Cu substrate has been used as the substrate for the Cu-Al2O3 films, as the Cu substrate has higher thermal conductivity compared to the Al substrate as shown in previous work.
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Peipei Liu and Wei-Qiang Huang
This study is the first that aims to investigate international transmission channels of sovereign risk among G20 and explore its influential factors by applying the…
Abstract
Purpose
This study is the first that aims to investigate international transmission channels of sovereign risk among G20 and explore its influential factors by applying the multidimensional SAR model.
Design/methodology/approach
Multiple spatial weight matrices can capture the contiguity of spatial units from various dimensions, which could be exploited to improve the precision of inference as well as prediction accuracy. To the best of the authors’ knowledge, this is the first study to investigate international transmission channels of sovereign risk among G20 and explore its influential factors by applying the multidimensional SAR model.
Findings
With network structure analysis, this study finds that they contain different information content from the perspective of graphical display, node strength and correlation. Developed and emerging countries all play major roles in trade connection, while only developed countries play major roles in financial linkage. Second, by applying the multidimensional SAR model, only the spatial autocorrelation coefficients for trade and financial linkages are significant during the full sample period, which is in sharp contrast to published studies using the SAR model with a single matrix. Third, the spillover channels that play major roles in various periods are different. Only trade channel plays a role during crisis periods and it is the most important. Fourth, the spatial correlation among countries greatly amplifies the shock’s impacts on one market. And spatial effect for developed countries is larger than those for emerging countries, while the mean spatial effect of a unit shock in the USA on emerging countries is slightly greater than that on developed countries.
Originality/value
Multiple spatial weight matrices can capture the contiguity of spatial units from various dimensions, which could be exploited to improve the precision of inference as well as prediction accuracy. To the best of the authors’ knowledge, this is the first study to investigate international transmission channels of sovereign risk among G20 and explore its influential factors by applying the multidimensional SAR model.
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Qiang Wei, Sheng Li, Xinyu Gou and Baofeng Huo
The rapid development of e-commerce has caused not only explosive growth of the express delivery industry, but also ever-greater operational pressures. Models from the sharing…
Abstract
Purpose
The rapid development of e-commerce has caused not only explosive growth of the express delivery industry, but also ever-greater operational pressures. Models from the sharing economy may provide new ideas for operational improvement. The purpose of this paper is to consider an optimization method that reduces costs and increases efficiency. The proposed method enables a shared distribution system based on revenue-sharing and cooperative investment contracts.
Design/methodology/approach
The authors design a two-echelon supply chain (SC) of the shared distribution system with one shared distribution company and N express companies. In this SC, the express companies provide only inter-city transportation, and they outsource internal-city transportation to a shared distribution company. This distribution system differs from that of the traditional express delivery industry. The traditional system of delivery requires large numbers of empty trips (with no load to deliver), because the operating mode of urban distribution has been the franchise. To offer greater efficiency and performance, the authors introduce the sharing economy mode of express delivery. The authors examine the potential of a joint optimal decision-making strategy that involves revenue-sharing and cooperative investment contracts based on an order flow proportion (OFP) and a revenue-sharing factor (RSF). In this shared distribution system, the most important innovation is that all of the express companies jointly invest in and establish a shared distribution company based on OFP or RSF principles.
Findings
The profitability of an SC with revenue-sharing contracts based on an OFP system is much higher than that of a decentralized SC, and it is very close to the profitability of a centralized SC. In SCs with revenue-sharing contracts that are based on RSFs, there are many possible combinations of RSFs that can increase the overall profitability. The analyses indicate that the OFP system offers the best solution in designing revenue-sharing contracts based on RSFs.
Practical implications
This study indicates that revenue-sharing contracts based on both OFP and RSF principles can increase overall SC returns by 0.21 to 0.44 percent. In sum total, this improvement could mean a 0.84 to 1.76bn Yuan increase in revenues for the 400+ bn-Yuan express delivery industry.
Originality/value
The authors find that a combination of equity investment and SC coordination contracts makes the cooperation between SC members much more stable. Through this kind of shared distribution system, the scale of economy can further reduce the costs and increase the efficiency of the express delivery industry.
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Reviewing a dozen of fiscal stimulus packages in developed countries, this paper analyzes one common strategy that has found widespread support in these stimulus packages and its…
Abstract
Purpose
Reviewing a dozen of fiscal stimulus packages in developed countries, this paper analyzes one common strategy that has found widespread support in these stimulus packages and its relevance for developing countries: investing in broadband and next‐generation networks, as a counter‐cyclical tool to create jobs and provide the foundation for economic recovery and long‐term sustained growth.
Design/methodology/approach
The paper looks at the various impacts broadband investment is expected to have: short‐term job creation and aggregate demand effects, and long‐term productive activities in other sectors of the economy. Moreover, broadband investment is more fiscally sound than other public spending stimulus options, in the sense of coming closer to, or in some cases actually being, self‐financing.
Findings
Several factors highlight the potential of broadband infrastructure as an important area of public investment during economic downturn, an option also open to policymakers in developing countries. Spending initiatives on next‐generation telecommunications networks at a time when labor market conditions are particularly weak can help preserve jobs and head off a potential burden on social safety nets. Bringing forward longer‐term aggregate spillover effects of broadband can improve the productivity of the entire economy and is consistent with enhancing longer‐run growth and development. Public support also “crowds in” private investment when access to private financing is decreasing and more expensive.
Originality/value
This is one of the few studies with a focus on the emerging broadband network, its impact on economy and the role of the public sector in rolling out next‐generation networks, during economic downturn and in general. A detailed summary of broadband initiatives in more than a dozen developed countries is provided in the paper.
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Ming Ren, Qiang Wei, Shuangjie Li and Guoqing Chen
The purpose of this paper is to present an intelligent data-driven framework which provides an effective group-buying aggregation service and thus offers a new opportunity for…
Abstract
Purpose
The purpose of this paper is to present an intelligent data-driven framework which provides an effective group-buying aggregation service and thus offers a new opportunity for personalized services in recommendation and advertisement.
Design/methodology/approach
The work presented in the paper analyzes the aggregated group-buying data and creates a compact view of the data which eliminates the potential redundancy and noise. In doing this, the dependencies are discovered from the data in a reverse engineering way. A noise-tolerant method is appreciated, as noise and exception is inevitable in massive data.
Findings
The paper finds that, through the implementation of the intelligent framework, the aggregator will provide a compact view of the group-buying data to customers. According to the empirical study, a 38 percent average decrease of redundancy and noise in the searching results is achieved through the newly built views and corresponding data.
Originality/value
The paper presents the innovative process of discovering the dependencies and creating views in a data-driven and noise-tolerant way. The proposed intelligent framework improves the aggregation performance and forms the basis of personalized services.
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Qianwen Zhou and Xiaopeng Deng
Despite the knowledge transfer between projects has received increasing attention from scholars, few scholars still conduct comprehensive research on inter-project knowledge…
Abstract
Purpose
Despite the knowledge transfer between projects has received increasing attention from scholars, few scholars still conduct comprehensive research on inter-project knowledge transfer from both horizontal and vertical perspectives. Besides, knowledge transfer is affected by multiple antecedent conditions, and these factors should be combined for analysis. Therefore, this paper aims to explore the key factors influencing knowledge transfer between projects using the fuzzy-set qualitative comparative analysis (fsQCA) method from both horizontal and vertical perspectives and how these factors combine to improve the effectiveness of knowledge transfer (EKT) between projects.
Design/methodology/approach
First, nine factors affecting knowledge transfer between projects were identified, which were from the four dimensions of subject, relationship, channel, and context, namely temporary nature (TN), time urgency (TU), transmit willingness (TW), receive willingness (RW), trust (TR), project-project transfer channels (PPC), project-enterprise transfer channels (PEC), organizational atmosphere (OA), and motivation system (MS). Then, the source of the samples was determined and the data from the respondents was collected for analysis. Following the operation steps of the fsQCA method, variable calibration, single condition necessity analysis, and configuration analysis were carried out. After that, the configurations of influencing factors were obtained and the robustness test was conducted.
Findings
The results of the fsQCA method show that there are five configurations that can obtain better EKT between projects. Configuration 3 (∼TN * ∼TU * TW * RW * TR * ∼PPC * PEC * MS) has the highest consistency, indicating that it has the highest degree of the explanatory variable subset. Configuration 1 (∼TN * ∼TU * TW * RW * PEC * OA * MS) has the highest coverage, meaning that this configuration can explain most cases. Also, the five configurations were divided into three types: vertical transfer, horizontal-vertical transfer, and channel-free transfer category.
Originality/value
Firstly, this study explores the key factors influencing knowledge transfer between projects from four dimensions, which presents the logical chain of influencing factors more clearly. Then, this study divided the five configurations obtained into three categories according to the transfer direction: vertical, horizontal-vertical, and channel-free transfer, which gives implications to focus on both horizontal knowledge transfer (HKT) and (VKT) when studying knowledge transfer between projects. Lastly, this study helps to realize the exploration of combined improvement strategies for EKT, thereby providing meaningful recommendations for enterprises and project teams to facilitate knowledge transfer between projects.
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Yanan Guo, Yuegang Tang, Shaoqing Wang, Weiwei Li, Xiaolei Yu, Xukun Lu and Qiang Wei
A detailed analytical study of Leping bark liptobiolith in Jiangxi was conducted to determine its petrographic characteristics and depositional environment based on coal…
Abstract
A detailed analytical study of Leping bark liptobiolith in Jiangxi was conducted to determine its petrographic characteristics and depositional environment based on coal petrography and geochemistry. Results indicate that barkinite mainly occurs in the middle and lower coal sea4ms, whereas less barkinite and more vitrinite occur in the middle and upper coal seams. Coal facies analysis of bark liptobiolith was performed to determine its characteristics under various depositional conditions, such as the presence of a water table and gelification during coal formation. Results indicate that the environmental evolution of bark liptobiolith begins from brackish-marine swamp facies (barkinite-rich coal seam) and ends in back barrier swamp facies (barkinite-poor coal seam).