Search results

The purpose of this paper is to use the wavelet neural network and genetic algorithm to study the effects of polyalphaolefin, TMP108 and OCP0016 on the kinematic viscosity, viscosity index and pour point of lubricating oil.

Wavelet neural network is used to train the known samples, test the unknown samples and compare the obtained results with those obtained with a traditional empirical formula.

It is found that the wavelet neural network prediction value is closer to the experimental value than the traditional empirical formula calculation value.

The results show that the wavelet neural network can be used to study the physical and chemical indexes of lubricating oil.

The purpose of this paper is to review the literature on information technology adoption in organizations to understand the need of integrated models for technology adoption. It further makes an attempt to identify key parameters to integrate technology acceptance model (TAM) and technology-organization-environment (TOE) framework for firm level technology adoption. This integration is intended to improve predictive power of resulting model.

The research papers are accessed from the popular databases from 2000 to 2012. The selected papers have addressed technology adoption in context of recent technologies such as e-commerce, ERP, RFID, EDI and knowledge management, etc. The paper attempts to review the studies based on TAM model and TOE framework to identify relevant set of variables for the adoption of these technologies in organizations.

TAM and its extended versions have high capability to explain the technology adoption while the significance of TOE framework is similarly recognized in explaining technology adoption. This review presents a holistic picture of a set of variables which can be used in the adoption of similar technologies in future. Further, the study has advocated the integration of TAM model and TOE framework to improve their explanatory power in technology adoption. The identified set of variables of TAM model and TOE framework can be used to integrate the two. Guidelines for integrating the two are also explained.

This study provides a platform for studying adoption of similar technologies using integration of TAM and TOE.

The researchers and managers can use the set of variables identified for adoption of similar technologies in organizations.

The review presents a set of variables which can be used to study adoption of similar technologies in future.

The increasing social media use has been widely recognized for its adverse effects, such as social media fatigue. With the continuously increasing friends on social media, the dissimilarity of individuals in terms of age, personality, and values has increased. It is unclear whether perceived dissimilarity with others is associated with social media fatigue. The authors attempted to bridge this gap by constructing a “perception–emotion–behavioral” research framework. This study investigated the influence of individual perceived dissimilarity on social media fatigue. The authors further investigated the mechanisms mediating the three dimensions of social anxiety in the model.

This study examined the mechanisms by which individual perceived dissimilarity influences social media fatigue, particularly using WeChat application. A field survey study conducted in China with 408 subjects of WeChat app users was used in this study to analyze the study model.

The obtained results demonstrate that individual perceived dissimilarity has a significant positive effect contributing to social media fatigue, perceived dissimilarity is positively correlated to social anxiety. Social anxiety positively affects social media fatigue, and social anxiety partially mediates the positive effect between perceived dissimilarity and social media fatigue.

First, the study confirmed the influence of perceived dissimilarity on social media fatigue, which may enrich the antecedent mechanisms of social media fatigue. Second, the authors demonstrated the social anxiety-mediated development of fatigue. The findings provide an in-depth understanding of users' fatigue. Third, the findings of this study provide valuable insights for preventing of social media fatigue.

Corporate social responsibility (CSR) has received considerable research attention globally over the past decade. Although a growing number of prior studies have investigated the various dimensions of CSR in general terms, few studies have investigated the critical role that CSR can play in the internationalization process of firms.

Using S&P 500 companies during 2004-2014, the authors found that the level of CSR commitment raises the level of reliability of firm and allows further international penetration. Moreover, better regulatory quality of host country is at actual support of internationalization only when considering the short term.

Better regulatory quality of host country is at actual support of internationalization only when considering the short term.

The authors build on internationalization theory and CSR and examine the relationship between firms’ level of internationalization and CSR commitment.

The purpose of this research paper is to examine predictors of impulsive buying intentions among youngsters from a hedonic shopping perspective. Recent theoretical work suggests that impulsive buying can function as a form of different hedonic shopping value dimensions such as fun, social interactions, novelty, escapism and outside appreciation.

The present research empirically tests a theoretical model of impulse buying intentions by examining the associations between hedonic shopping value dimensions and intentions in the presence of situational characteristics as moderators. A survey of 333 youngsters aged 15 to 23 is conducted using a structured questionnaire. Constructs are measured using established scales.

Results indicate that the impulsive buying intentions of youngsters are positively associated with all the five dimensions of hedonic shopping value. Situational characteristics of money and time availability positively moderate this relationship. Task definition negatively moderates the association between impulsive buying intention and hedonic shopping value dimensions.

Two major theoretical implications result from this study. First, the study enabled the conceptualization of a theoretical framework of impulse buying intentions by including five dimensions of hedonic shopping value as important factors in young consumers’ impulse behavior buying intentions. Further, it includes the moderating effects of all the three aspects of situational characteristics in the same model.

The marketers can make use of the shopping value dimensions and the situational characteristics moderators to design and implement marketing strategies so that sales via impulse buying are maximized.

This study provides novel insights on the complex process of impulsive buying by youngsters by expanding the application of the hedonic shopping motives in the presence of situational factors as moderating variables.

Mobile ad hoc networks rely on cooperation to perform essential network mechanisms such as routing. Therefore, network performance depends to a great extent on giving participating nodes an incentive for cooperation. The level of trust among nodes is the most frequently used parameter for promoting cooperation in distributed systems. There are different models for representing trust, each of which is suited to a particular context and leads to different procedures for computing and propagating trust. The goal of this study is to analyze the most representative approaches for mobile ad hoc networks. It aims to obtain a qualitative comparison of the modeling approaches, according to the three basic components of a trust model: information gathering, information scoring and ranking, and action execution.

The paper identifies the different tasks required by a trust system and compares the way they are implemented when the system model itself is based on information theory, social networks, cluster concept, graph theory and game theory. It also provides a common nomenclature for the models. The study concentrates exclusively on the trust models themselves, without taking into account other aspects of the original articles that are beyond the scope of this analysis.

The study identifies the main components that a trust model must provide, and compares the way they are implemented. It finds that the lack of unity in the different proposed approaches makes it difficult to conduct an objective comparison. Finally, it also notices that most of the models do not properly manage node reintegration.

The best of our knowledge, the study is the first that uses information scoring and ranking as classification key. According to this key, approaches can be classified as based on information theory, clusters and social network theory, and cooperative and non‐cooperative game theory. It also provides a common nomenclature for all of them. Finally, the main contribution of the paper is to provide an analysis of the most representative approaches and present a novel qualitative comparison.

This paper aims to solve the lubrication failures in the turning arm bearing of RV reducer, give some help in perfecting the bearing structure design and provide theoretical basis for the reducer’s performance improvement.

The paper establishes a mixed lubrication analysis model to study performance parameters. According to the discretization of parameters and iteration of equations, numerical simulation and theoretical analysis are achieved in computational process.

Considering influences of contact load, real rough surface and realistic geometry of RV reducer turning arm roller bearing, the mixed lubrication analysis model is established to study the ratio of oil film thickness, pressure distribution and maximum von Mises stress in different speeds, temperatures and fillets. The results of mixed lubrication show that reasonable round corner modification, increase in temperature and speed, decrease of surface roughness and lubricant types can improve the lubrication performance.

The mixed lubrication analysis model is established to study the influences of contact load, real rough surface and realistic geometry of RV reducer turning arm roller bearing. Different speed, temperature, lubricant and fillet modification are also considered in the research to analyze oil film thickness, pressure distribution and maximum von Mises stress. These studies can optimize structural design of bearing and direct engineer operations.

Regarding the assembly of the fuselage panel, this paper aims to illustrate a design of pre-assembly tooling of the fuselage panel for the automatic drilling riveting machine. This new prototype of pre-assembly tooling can be used for different types and sizes of fuselage panels. Also, apply to the automated drilling and riveting machine of the fuselage panels.

Based on the different structures of the fuselage panel, the position of the preassembly tooling components, location of the clamp and position of the fuselage panel are determined. After that, the overall structure of the preassembly tooling is designed, including the movable frame and the cardboard. The cardboard positioning module and the clamping module formulate a detailed design scheme of preassembly tooling for the fuselage panel. The structure of the pre-assembled tooling is optimized by static analysis. The result of the overall design is optimized by using MATLAB and CATIA-V5 software, and the results meet the condition of the design requirements.

The traditional assembly process of the fuselage is to install the fuselage panel on the preassembly tooling for positioning the hole and then install it on the automated drilling and riveting tooling for secondary tooling. Secondary tooling can consume assembly errors of the fuselage panel. The new prototype of flexible tooling design for the fuselage panel not only avoids the secondary tooling error of the fuselage panel but also meets the preassembly of different types of fuselage panels.

The further development of the flexible tooling design of the fuselage panel is to reduce the error of sliding tooling due to friction of the sliding components. Because if the assembly cycle is increased, the sliding parts will lose material due to corrosion. As a result, the repeated friction force is the root cause of the positioning error of sliding parts. Therefore, it is necessary to engage less corrosive material. Also, the lubricant may be used to reduce the corrosion in minimizing the positioning error of the sliding tool components. In addition, it is important to calculate the number of assembly cycles for efficient fuselage panel assembly.

According to the structure and assembly process characteristics of the fuselage panel, the fuselage panel preassembly tooling can optimize the assembly process of the fuselage panel and have certain practical application values.

This paper aims to provide a comprehensive analysis of the state of the art in energy efficiency for autonomous mobile robots (AMRs), focusing on energy sources, consumption models, energy-efficient locomotion, hardware energy consumption, optimization in path planning and scheduling methods, and to suggest future research directions.

The systematic literature review (SLR) identified 244 papers for analysis. Research articles published from 2010 onwards were searched in databases including Google Scholar, ScienceDirect and Scopus using keywords and search criteria related to energy and power management in various robotic systems.

The review highlights the following key findings: batteries are the primary energy source for AMRs, with advances in battery management systems enhancing efficiency; hybrid models offer superior accuracy and robustness; locomotion contributes over 50% of a mobile robot’s total energy consumption, emphasizing the need for optimized control methods; factors such as the center of mass impact AMR energy consumption; path planning algorithms and scheduling methods are essential for energy optimization, with algorithm choice depending on specific requirements and constraints.

The review concentrates on wheeled robots, excluding walking ones. Future work should improve consumption models, explore optimization methods, examine artificial intelligence/machine learning roles and assess energy efficiency trade-offs.

This paper provides a comprehensive analysis of energy efficiency in AMRs, highlighting the key findings from the SLR and suggests future research directions for further advancements in this field.

This study aims to propose an approach to assess the security of supply (SS) in a coal-fired electricity generation supply chain subject to public price regulation in Brazil. This study characterizes the Brazilian scenario of coal-fired electricity generation, which represents less than 3.5% of the energy sources.

Data from six mining companies that supply a coal plant were analyzed in a case study. The risks were characterized and objectively estimated through a synthetic multidimensional index. Structural changes in the earnings before interest, taxes, depreciation, amortization and exploration indicator time series of coal companies (CC) were statistically detected.

Empirical evidence demonstrates that the supply chain has a low disruption risk (SS index equal to 0.74). However, when suppliers are individually analyzed, 48.64% of all coal shows moderated disruption risk, and 2.51% is under high risk. In addition, this study finds a drop in the financial results of CC related to public regulation of coal prices. This impacts the security of coal supply.

This study discusses the influence of legal and regulatory policy risks in a coal power generation supply chain and the implications of the SS index as a management tool.

A novel SS index is presented and empirically operationalized, and its dimensions – environmental, occupational, operational, economic-financial and supply capacity – are analyzed.