Hong Xiao, Yugang Duan, Zhongbo Zhang and Ming Li
This paper aims to investigate an approach for mental fatigue detection and estimation of assembly operators in the manual assembly process of complex products, with the purpose…
Abstract
Purpose
This paper aims to investigate an approach for mental fatigue detection and estimation of assembly operators in the manual assembly process of complex products, with the purpose of founding the basis for adaptive transfer and demonstration of assembly process information (API), and eventually making the manual assembly process smarter and more human-friendly.
Design/methodology/approach
The proposed approach detects and estimates the mental state of assembly operators by electroencephalography (EEG) signal recording and analysis in an engine assembly experiment. When the subjects perform assembly tasks, their EEG signal is recorded by a portable EEG recording system called Emotiv EPOC+ headset. The feature set of the EEG signal is then extracted by calculating its power spectrum density (PSD), followed by data dimension reduction based on principal component analysis (PCA). The dimension-reduced data are classified by using support vector machines (SVMs), and hence, the mental state of assembly operators can be estimated during the assembly process.
Findings
The experimental result shows that the proposed approach is able to estimate the mental state of assembly operators within an acceptable accuracy range, and the PCA-based dimension reduction method performs very well by representing the high-dimensional EEG feature set with just a few principal components.
Originality/value
This paper provides theoretical and experimental basis for the API transfer and demonstration based on human cognition. It provides a new idea to seek balance between the improvement of production efficiency and the sustainable utilization of human resources.
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Keywords
Duan Yugang, Zhou Yuan, Tang Yiping and Li Dichen
The purpose of this paper is to improve the mechanical and thermal properties of photosensitive resin for rapid prototyping (RP) by modifying with nano‐TiO2.
Abstract
Purpose
The purpose of this paper is to improve the mechanical and thermal properties of photosensitive resin for rapid prototyping (RP) by modifying with nano‐TiO2.
Design/methodology/approach
The silane coupling agent was selected to treat the surface of anatase nano‐TiO2 particles. The IR spectrum showed that the hydroxyl (−OH) group on the surface of nano‐TiO2 reacted with the coupling agent effectively. The effects of TiO2 content on the curing depth and viscosity of the photosensitive resin were studied by experiments. The mechanical properties including tensile strength, tensile modulus, flexural strength and hardness were tested according to ASTM standards. The thermal stability of modified photosensitive resin was tested by differential scanning calorimetry.
Findings
The comprehensive performance of the modified photosensitive resin was good when TiO2 content was at 0.25 per cent, the tensile strength was increased by 89 per cent from 25.26 to 47.82 MPa, the tensile modulus increased by 18 per cent from 2,001 to 2,362 MPa, the flexural strength and the hardness increased by 6 and 5 per cent, respectively. In addition, the plasticity and heat stability of modified photosensitive resin were also improved obviously.
Originality/value
The paper provides a low‐cost method to greatly improve the performance of photosensitive resin for RP. The modified photosensitive resin prepared according to the formulas in this paper has been successfully employed in RP equipment of Xi'an Jiaotong University, China.
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Liu Xiaomei, Yao Yao, Aws AlHares, Yasir Shahab and Sun Yue
To investigate the impact of tax enforcement on (a) debt aggressiveness (DEA) and (b) dynamic adjustment of capital structure in Chinese listed firms.
Abstract
Purpose
To investigate the impact of tax enforcement on (a) debt aggressiveness (DEA) and (b) dynamic adjustment of capital structure in Chinese listed firms.
Design/methodology/approach
The authors estimate the target capital structure by employing the different models. This study uses data of Chinese A-share listed firms from year 1998 to 2015.
Findings
The study suggests that the greater the intensity of tax enforcement, the more radical the listed companies' debt policy. The macroeconomic status and nature of property rights have significant moderating effect on the positive relationship between tax enforcement and DEA of listed companies. Further, tax enforcement has a significant impact on the dynamic adjustment of capital structure.
Practical implications
Research conclusions are conducive to tax administration departments to understand the economic consequences of tax enforcement and further promote tax administration efficiency. Additionally, listed companies can rationally adjust their capital structure to strengthen tax enforcement.
Originality/value
This research helps extend the influencing factors of corporate debt decision-making and capital structure dynamic adjustment to the level of tax enforcement and provide new evidence on the effects of tax enforcement on corporate capital structure.
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Bhavin Shah and Gaganpreet Singh
In order to achieve competitive advantage over the physical marketplace, the e-retailers are insisted on endowing with lenient return policies. The piece-wise…
Abstract
Purpose
In order to achieve competitive advantage over the physical marketplace, the e-retailers are insisted on endowing with lenient return policies. The piece-wise returns-and-reordering process incurs excessive buffering and unwanted logistics costs which raises overall fulfillment charges. The objective of this study is to re-design e-retail distribution policy by providing temporal storage at logistics service provides' (LSP) location. The impact of recurrent returns on pricing and profit margins are also investigated over time continuum.
Design/methodology/approach
A framework is developed to reduce the non-value added (NVA) storage and distribution efforts by providing collaborative buffering between LSP and e-retailer. The knapsack based buffering approach is tested and compared with traditional e-retail distribution practices. The revenue sharing concept is mathematically modelled and implemented in GAMS, which finally validated through multiple return scenarios.
Findings
The proposed model outperforms the existing one under all scenarios with different configuration settings of re-ordering, profit margins, and buffer time windows. The distribution cost is found, linearly related to the necessary product buffering space. The findings help to re-design sustainable return policies for individual products so that maximum customer value can be yield with minimum costs.
Research limitations/implications
This study helps to determine the NVA efforts incurred while storing and delivering multi-time returned products to ensure desired service levels. The revenue sharing model provides pricing strategies for e-retail practitioners deciding which product should store in what quantity for how much time at the shipping agency location so that it fulfils the re-ordering at least waiting and sufficient buffering.
Originality/value
The proposed model extends the role of LPSs as temporary buffer providers to reduce returns-and-reordering fulfilment efforts in the e-retail network. This Collaborative framework offers an opportunity to amend the distribution contracts and policies time by time that enhances e-retailer's performance and customer satisfaction.