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A numerical study has been conducted for the characteristics of the periodically fully developed turbulent flow and heat transfer in a channel with transverse opposite‐positioned fins. The Reynolds number range is 2 × 10⁴ to 7 × 10⁴. K‐ε model and wall function method were adopted during the calculation. The influence of the thermal boundary condition of the fin to the heat transfer has been verified. For the studied configuration the prominent feature that differs from the similar laminar heat transfer is the phenomenon of secondary peak of the Nusselt number distribution. Assessment of heat transfer enhancement under the constraint of the same pump power reveals that the effect of the configuration of the relative fin height, e/H, equal to 0.1 is superior to those of e/H equal to 0.15 and 0.2. Comparing with the results of the channel with rod disturbances, the studied configuration possesses nearly the same heat transfer enhancement effect. Transient simulations to cases with big fin have also been conducted to assure the validity of the steady algorithm.

While recognizing networking as a powerful means of school turnaround, most studies focus on governments’ and schools’ roles in promoting collaborative turnaround rather than the complexity of external providers and their behaviors. This study explores multiple external providers’ complex roles in networked school turnaround.

This study employed a qualitative case study approach and collected data through document analysis, observation and interviews in a Shanghai public junior secondary school’s turnaround network.

This study revealed three patterns in external providers’ interactions with the school (direction leader, solution supplier and method instructor) corresponding to three types of external providers (universities, private enterprises and public institutions). While providing support at different levels (i.e. macro, meso and micro), different external providers shared common strategies for addressing policy requirements and school needs and co-constructing turnaround strategies.

This study offers new insights into external providers’ supporting roles in Chinese school turnaround and expands the scant international knowledge base on external providers in educational improvement.

This paper aims to investigate how perceived working conditions affect employee performance, including safety compliance and task performance, through employee well-being (i.e. job satisfaction) in the context of the coal mining sector in China.

This paper uses the job demands-resources model to test the relationships between working conditions, including job demands (work pressure as a challenge demand and perceived risks and hazards in the workplace and ineffectiveness of the safety system as hindrance demands), job resources (interpersonal harmony), job satisfaction and performance. This study adopts a two-wave design with a three-month lag to reduce possible common method bias.

Employees who experienced high level of challenge demands, e.g. time pressure workload, reported higher levels of task performance, and this positive relationship seemed to be robust. There is a direct effect of perceived ineffectiveness of the safety system on task performance, while the relationship between perceived risks and hazards and task performance was fully mediated by job satisfaction. Challenge demands, i.e. work pressure, did not impact much on employees’ well-being, and thus job satisfaction did not mediate the relationship between work pressure and performance. Perceived ineffectiveness of the safety system was negatively associated with safety compliance. This result is not surprising since a lack of effective safety system reflects management’s ignorance of workplace safety, which demotivates employees to enact safe behaviors. In contrast, the presence and implementation of an effective safety system would be interpreted by employees as management exhibiting a high level of commitment. Work pressure was positively not negatively related to safety compliance. One possible explanation for this finding is that the effects of work pressure on safety compliance behaviors might be dependent on contextual factors such as safety climate. Interpersonal harmony moderated the relationships between work pressure and employee performance (both safety compliance and task performance) and the relationship between perceived risks and hazards and task performance, but the role of interpersonal harmony appeared more complex. There was no significant correlation between challenging job demands and individual employee performance when there were higher levels of interpersonal harmony. The relationship between perceived risks and hazards, a hindrance job demand and task performance became positive as interpersonal harmony increased but negative as interpersonal harmony decreased.

This paper provides a robust integrative theoretical framework that better explains the various types of job demands and job resources in the working environment of coal mining sector in China and their relationships to employee performance. The findings also offer valuable guidance for managers trying to identify effective ways to enhance employee performance and safety in the workplace.

A chaotic system is a nonlinear deterministic system that displays complex, noisy‐like and unpredictable behavior. The interest in chaotic systems lies mostly upon their complex, unpredictable behavior, and extreme sensitivity to initial conditions as well as parameter variations. Based on wavelet neural network's (WNN) online approximation ability, the purpose of this paper is to propose an adaptive Gaussian wavelet neural control (AGWNC) system to control a chaotic system.

The proposed AGWNC system is composed of a wavelet neural controller and a compensation tangent controller. The wavelet neural controller utilizes a Gaussian WNN to mimic an ideal controller, and the compensation tangent controller is designed to compensate the approximation error between the ideal and the wavelet neural controllers. The controller parameters of the proposed AGWNC can online tune in the Lyapunov sense, thus the uniformly ultimately bounded stability of closed‐loop system can be guaranteed.

The proposed AGWNC system is applied to a chaotic system. Simulation results are used to demonstrate the effectiveness and performance of the proposed AGWNC scheme. Simulation results show that not only the favorable control performance can be achieved but also the control efforts without any chattering phenomena. Moreover, all controller parameters can be online tuning by the derived adaptive laws based on the Lyapunov function.

The proposed AGWNC approach is interesting for the design of an intelligent control scheme. The main contributions of this paper are: the overall closed‐loop control system is globally stable in uniform ultimate boundedness; the tracking error can be asymptotically attenuated to a desired small level around zero by appropriate chosen parameters and learning rates; and the AGWNC system can achieve favorable tracking performance.

This paper seeks to propose a new approach for tackling the uncertainty and imprecision of identifying suitable supplier offers, evaluating these offers and choosing the best alternatives in bi‐negotiation. In a build‐to‐order supply chain, the handling of uncertainties is addressed by a real time information sharing system and appropriate supplier selection.

A methodology integrated analytic hierarchy process (AHP) with bi‐negotiation agents based on the multi‐criteria decision‐making approach and software agent technique is then developed to take into account both qualitative and quantitative factors in supplier selection.

During the decision‐making between buyer and suppliers, the AHP process matches product characteristics with supplier characteristics. Next, agents assist the user in the debate to negotiate a joint representation of the supplier chosen and automatically justify proposals with this joint representation.

This study focused on a multi‐attribute negotiation mechanism including qualitative conditions, which enables automated negotiation on multiple attributes. Finally, a fuzzy membership function represented the joint representation's cognition for each condition such as quantity, price, quality, and delivery for the outsourced component. A case study in a high‐end computer manufacturing company is given to demonstrate the potential of the methodology.

Mobile robots become more and more important for many potential applications such as navigation and surveillance. The paper proposes an image processing scheme for moving object detection from a mobile robot with a single camera. It especially aims at intruder detection for the security robot on either smooth paved surfaces or uneven ground surfaces.

The core of the proposed scheme is the template matching with basis image reconstruction for the alignment between two consecutive images in the video sequence. The most representative template patches in one image are first automatically selected based on the gradient energies in the patches. The chosen templates then form a basis matrix, and the instances of the templates in the subsequent image are matched by evaluating their reconstruction error from the basis matrix. For the two well-aligned images, a simple and fast temporal difference can thus be applied to identify moving objects from the background.

The proposed template matching can tolerate in rotation (±10°) and (±10°) in scaling. By adding templates with larger rotational angles in the basis matrixes, the proposed method can be further extended for the match of images from severe camera vibrations. Experimental results of video sequences from a non-stationary camera have shown that the proposed scheme can reliably detect moving objects from the scenes with either minor or severe geometric transformation changes. The proposed scheme can achieve a fast processing rate of 32 frames per second for an image of size 160×120.

The basic approaches for moving object detection with a mobile robot are feature-point match and optical flow. They are relatively computational intensive and complicated to implement for real-time applications. The proposed template selection and template matching are very fast and easy to implement. Traditional template matching methods are based on sum of squared differences or normalized cross correlation. They are very sensitive to minor displacement between two images. The proposed new similarity measure is based on the reconstruction error from the test image and its reconstruction from the linear combination of the templates. It is thus robust under rotation and scale changes. It can be well suited for mobile robot surveillance.

The purpose of this paper is to study the reliability of sintered nano-silver joints on bare copper substrates during high-temperature storage (HTS).

In this study, HTS at 250 °C was carried out to investigate the reliability of nano-silver sintered joints. Combining the evolution of the microstructure and shear strength of the joints, the degradation mechanisms of joints performance were characterized.

The results indicated that the degradation of the shear properties of sintered nano-silver joints on copper substrates was attributed to copper oxidation at the silver/copper interface and interdiffusion of interfacial elements. The joints decreased by approximately 57.4% compared to the original joints after aging for 500 h. In addition, severe coarsening of the silver structure was also an important cause for joints failure during HTS.

This paper provides a comparison of quantitative and mechanistic evaluation of sintered silver joints on bare copper substrates during HTS, which is of great importance in promoting the development of sintered silver technology.

This study aims to examine the solvency and performance persistence of defined benefit private and public pension plans (DBPPs) in the Republic of Congo.

The authors use the 2 × 2 contingency table approach and the time product ratio (TPR)-based cross-product ratio (CPR) on data covering ten years from 2011 to 2020, with variable funded ratios and excess returns, to determine the solvency and performance persistence of defined benefit pension plans.

The authors document a lack of solvency and performance persistence in DBPP funds. They conclude that the solvency and performance of DBPP funds are not repetitive. The previous year's private and public defined benefit pension funds’ results do not repeat in the current year. Hence, the current solvency and performance of defined benefit pension funds are not good predictors of future funds' solvency and performance.

To the best of the authors’ knowledge, this study is the first to combine solvency and performance to examine the persistence of defined benefit pension plans in sub-Saharan Africa.

Electromagnetic noise of permanent magnet synchronous motor (PMSM) seriously affects the sound quality of electric vehicles (EVs). This paper aims to present a comprehensive process for the electromagnetic noise analysis and optimization of a water-cooled PMSM.

First, the noises of an eight-pole 48-slot PMSM in at speeds up to 10,000 rpm are measured. Furthermore, an electromagnetic-structural-acoustic model of the PMSM is established for multi-field coupling simulations of electromagnetic noises. Finally, the electromagnetic noise of the PMSM is optimized by using the multi-objective genetic algorithm, where a multi-objective function related to the slot width of PMSM stator is defined for radial electromagnetic force (REF) optimization.

The experimental results show that main electromagnetic noises are the 8n-order (n = 1, 2, 3, …) and 12-order noises. The simulated results show that the REFs are mainly generated by the 8n-order (n = 1, 2, 3, 4, 5, 6) vibrations, especially those of the 8th, 16th, 24th and 32th orders. The 12-order noise is a mechanical noise, which might be caused by the bearings and other structures of the PMSM. Comparing the simulated results before and after optimization, both the REFs and electromagnetic noises are effectively reduced, which suggests that an appropriate design of stator slot is important for reducing electromagnetic noise of the PMSM.

In view of applications, the methods proposed in this paper can be applied to other types of PMSM for generation mechanism analysis of electromagnetic noise, optimal design of PMSM and thereby noise improvement of EVs.

This study aims to test a theoretical model of co-creation dynamics, service innovation and competitive advantage. The authors explore the dynamics of collaboration between travel agents and their suppliers in co-creating value for their customers. A research model is proposed to examine the relationship among six co-creation elements (co-creation dynamics), service innovation, competitive advantage and two antecedents: technology adoption and environmental change and the moderating effects of trust.

An empirical survey was performed based on travel agencies in Taiwan and Malaysia. A total of 105 valid responses from Taiwan and 102 valid responses from Malaysia were received. SPSS and partial least square were used to analyze the data.

A new six-element construct of co-creation dynamics was suggested. All the proposed effects were found significant in which trust enhanced the effect of elements of innovation for Taiwan travel agencies. However, in contrast to the proposed hypotheses, technology adoption had no direct effect, whereas trust had no moderating effect for Malaysia travel agencies.

This study suggests that managers should include co-creation approaches with partners and customers while developing new services. The identification of areas that may be lacking can allow managers to develop capabilities to improve business co-creation competency.

This study links the relational view with service-dominant logic that emphasizes business co-creation and service innovation as operant resources and a key fundamental source for competitive advantage. This study also looks at interpreting business co-creation and discusses whether business co-creation affects service innovation in the hospitality and tourism industry.