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Changes of customer requirements (CRs) are inevitable disturbances for products which will lead to product obsolescence or frequent redesign. The property of product defending and recovering from the shock of ever-changing CRs is resilience. It is beneficial for designers to explore and evaluate product resilience towards changing CRs. Fortunately, various resilience assessment methods in engineering realm have offered some significant insights. Motivated by the deficiencies of the existing studies and the advantages of engineering resilience assessment methods, product resilience towards changing CRs is measured. Firstly, joint customer satisfaction is defined by integrating competition analysis and importance analysis. Secondly, the evolution trends of CRs are depicted and captured based on a modified grey model and polynomial fitting, respectively. Then, a three-stage model considering absorption, adaptation, and recovery is established to evaluate product resilience. Lastly, a case study of an electric vehicle is implemented to elucidate the utility and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Product structural properties are fundamental in product structure optimisation and design. Due to the inevitable evolution of products, product structural properties also change accordingly. Although the evolution of the product structure has been preliminarily investigated, it is mainly analyzed from the viewpoint of commonalities for product generations, and the evolution trend of product structure across product generations has not been well explored. To provide product development direction for designers, this study aims at uncovering the evolution characteristics of product structural properties based on the time-dependent network model. Firstly, weighted time-dependent networks are constructed to represent the cross-generation product structures. Secondly, product structural properties (including complexity, importance, and robustness) are analyzed benefited from topology similarities between product structures and complex networks. Thirdly, 25 generations of iPhones are selected to analyze the evolution characteristics of product structural properties. The results show that in the evolution of product structures, the complexity of the product is decreasing while core components are becoming more complex owing to scale-free property. And the core components are always important in each product generation. Additionally, the evolving product structural networks are highly robust in random failure of components (RFC) and vulnerable in the failure of core components (FCC). [ABSTRACT FROM AUTHOR]

More and more customers place emphasis on the product obsolescence instead of the product quality, which is driven by changing customer requirements, developing technology and evolving market environments. The product redesign is the prior design strategy to respond to the factors that cause product obsolescence. In this study, the necessary assessment of a product redesign is modelled as the product obsolescence assessment problem based on the Information Axiom. First, the customer-expected functional requirement (FR) and the existing FR of a product are characterised as the design range and the system range, respectively. The information content, which is defined to assess the degree of product obsolescence, is then calculated. In the process of calculating information content, the integral characterised by fuzzy bounds is a challenging problem. To solve this issue, this study proposes a defuzzification method to convert fuzzy bounds into crisp numbers. Finally, the assessment of product obsolescence for a crawler crane is performed as an example to elaborate on the effectiveness of the developed approach. [ABSTRACT FROM AUTHOR]

Objective. To investigate the clinical values of preoperative use of antibiotics in transanal endoscopic microsurgery (TEM). Methods: Thirty patients undergoing TEM surgery to treat rectal neoplasms in our hospital were selected in this study. All patients were randomly divided into two groups: antibiotic group that antibiotics were used before and after surgery, and control group that antibiotics were only used after surgery. Several markers were evaluated before and after surgery in all patients, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), changes procalcitonin (PCT), white blood cell count (WBC), neutrophils (NE%) and temperature (T). Results: The patients in the antibiotic group at the first and third days after surgery showed lower values of ESR, CRP, WBC, NE% and T than the control group (p < 0.05), furthermore, the WBC and NE% were significantly decreased at the third day after surgery compared with the first day after surgery. For the PCT, there was a significant difference in the first day after surgery between the two groups (p < 0.05), but no significant difference was observed between them at the third day after surgery (p > 0.05). Conclusion: The preoperative use of antibiotics in TEM surgery to treat rectal neoplasms may become an effective method to reduce inflammation and prevent infecting after surgery, which will be verified by an amount of studies on large sample. [ABSTRACT FROM AUTHOR]

Changes of customer requirements inevitably occur in the process of product design and manufacturing, which results in substantial costs in product development. Enterprises have to update product configuration schemes to meet new customer requirements and maintain competitiveness. Recent studies have attempted to solve this problem with the 'two-stage' model (optimisation of change propagation and update scheme). They have largely ignored the correlation between the two stages, which leads to extra costs in practice. Therefore, this paper proposes a master-slave coordinated optimisation model, in which the design of update scheme was the leader and the optimisation of change propagation path was the follower. The upper optimisation model was constructed to obtain a change propagation path with the minimum propagation range. And the lower optimisation model was constructed to obtain a product configuration update scheme with the highest satisfaction. Meanwhile, the diversity of the optimal update scheme from the lower model was fed back to the upper model, and the change propagation probability was adjusted. This causes further changes in the process of change propagation. Finally, cases of sanitation vehicles and motorbike engines were taken to verify the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

In this article, we propose a method for change detection in high-resolution remote-sensing images by means of level set evolution and support vector machine (SVM) classification, which combined both the pixel-level method and the object-level method. Both pixel-based change features and object-based ones are extracted to improve the discriminability between the changed class and the unchanged class. At the pixel level, the change detection problem is formulated as a segmentation issue using level set evolution in the difference images. At the object level, potential training samples are selected from the segmentation results without manual intervention into the SVM classifier. Thereafter, the final changes are obtained by combining the pixel-based changes and the object-based changes. A chief advantage of our approach is being able to select appropriate samples for SVM classifier training. Furthermore, our proposed method helps improve the accuracy and the degree of automation. We systematically evaluate it with various Satellite Pour l’Observation de la Terre (SPOT) 5 images and aerial images. Experimental results demonstrate the accuracy of our proposed method. [ABSTRACT FROM PUBLISHER]

As the product life cycle progresses, the impact of product design change gradually extends from design to production and supply. Companies must minimise the impact of design change dissemination to improve delivery speed and enhance corporate competitiveness. Considering that design change will causes change in other links of product, enterprises need to establish an evaluation index system to explore the influence of multiple fields on the change propagation intensity. Therefore, this paper proposes an optimisation model of design change propagation routing based on multi-domain network collaboration for enterprises to evaluate intensity of change propagation. Firstly, component, production and supply networks are constructed based on complex network theory and mapped to multi-domain networks. Secondly, the optimisation model of change propagation routing is established. By quantifying the change propagation probability, node crucial, change cost and change time, the minimum value of change propagation intensity of multi-domain network collaborative design is calculated. Finally, taking the medical call system as an example, the hybrid genetic ant colony algorithm is used to find the optimal change propagation routing of multi-domain network collaboration, which demonstrates the effectiveness of the proposed method and provides a reference for enterprises to minimise the impact of product design change propagation. [ABSTRACT FROM AUTHOR]

The Guizhou high-sulfur coal and its demineralized coal were rapidly pyrolyzed in a drop tube furnace under an argon atmosphere at the high temperatures ranging from 700°C to 1200°C. The effects of temperature and minerals on the transformations between various forms of sulfur, including sulphidic sulfur and thiophenic sulfur, were studied using X-ray photoelectron spectroscopy (XPS) during rapid pyrolysis. The total sulfur content was determined by the infrared-red sulfur analyzer (ISA) and confirmed by XPS analysis. The total sulfur retention in chars did not simply decrease with increasing temperature but increased at a specific temperature in both raw coal and demineralized coal. Thiophenic sulfur was the primary sulfur compound found on the char surface during rapid pyrolysis at different temperatures. Sulfur in different forms decomposed and transformed at high temperatures and this was evidenced by the complete decomposition of sulphidic sulfur at 1000°C and the increase of thiophenic sulfur content at 1100°C. These results indicate that other forms of sulfur could transform into thiophenic sulfur. [ABSTRACT FROM AUTHOR]

Users have higher demands on product with the developing e-commerce and the increasing online shopping. Enterprises must design products that meet user demands accurately and quickly to improve user satisfaction and increase product competitiveness. In the face of ever-changing user demands, enterprises need to predict the changing trend of user demands, so as to design products more in line with user demands and reduce the market risk of new product development. Therefore, this paper proposes a Grey-Markov model of user demands prediction based on online reviews for enterprises to predict the monthly changing trend of user demands in advance. Firstly, LDA topic model and sentiment analysis are used to get user attention values and user satisfaction values. Secondly, The Grey-Markov model of user demands prediction was established. According to two dimensions of the attention and satisfaction of user demands, the values of user demands are predicted, and the division of user demand improvement sequence is used to balance the scheme of product optimisation. Finally, taking the demand prediction and optimisation design of smartphones and automobiles for examples to illustrate the effectiveness of the proposed method and to provide a reference for manufacturing enterprises to optimise product design. [ABSTRACT FROM AUTHOR]

A highly efficient electrode material is required to explore and apply to microbial electrolysis cell (MEC) with high hydrogen evolution reaction (HER) efficiency. Pt/C was one of the most efficient catalysts for hydrogen production in current lab research, but it was expensive and some chemicals in wastewater were prone to Pt poisoning, which was a great limitation in application. Thus, a cheap and effective nickel(II) Oxide/Y (NiO/Y) material was prepared by using Y zeolites as carrier loaded with NiO in this study, which was used in MEC to evaluate the hydrogen evolution performance in comparison with Pt/C. The results indicated that NiO/Y composites showed a competitive HER performance to Pt/C. The linear sweep voltammetry (LSV) tests and Tafel plots showed that the NiO/Y composites exhibited the best catalytic activity for HER. In the MEC tests, the NiO/Y composites cathode was comparable with the Pt/C cathode in terms of current densities and energy efficiency. The coulombic efficiency, cathodic energy efficiency rate and hydrogen production rate obtained with NiO/Y cathode MEC was 85.88 ± 6.5%, 228.39 ± 3.2% and 0.83 ± 0.05 m3/m3d under, respectively, which were slightly higher than those obtained with the Pt/C cathode MEC. It was concluded that even with the cheap Y zeolites as the supports, the NiO/Y materials showed the superior performance, which was attributed to a good dispersing of the active component of NiO on the large specific surface area of Y zeolites and the fast escape of hydrogen bubbles from microporous and mesoporous structure of Y zeolites. [ABSTRACT FROM AUTHOR]

Top-down design (TDD) and modular product design (MPD) are two popular design strategies for development of complex products. Although integration of these two design strategies can improve the quality and efficiency for the development of complex products, it is difficult to implement the TDD and MPD strategies simultaneously due to the lack of tools that can handle modelling of the inheritance mechanism from the abstract design descriptions to the detailed design descriptions within TDD and modelling of the relatively independent design descriptions as groups within MPD. A new multi-skeleton modelling approach is introduced in this research for layout design of complex products based on TDD and MPD. First, through studies on the inheritance mechanism between design descriptions on different levels in the hierarchical product modelling architecture and the interface relationships between different modules, design information is classified into five categories: locations, interface features, design spaces, key features and kinematic constraints. Second, these different types of design information are modelled using three types of skeletons: location skeletons, interface skeletons and published skeletons. Third, a multi-skeleton modelling scheme is introduced for the development of product descriptions from relative abstract levels to more detailed levels recursively in TDD manner with relatively independent modules. This multi-skeleton modelling approach can be used to propagate changes of product descriptions on different levels, to improve design efficiency by reusing and modifying the existing modules, and to evaluate the design at early design stage without detailed design descriptions. In addition, the multi-skeleton model can be implemented in most CAD systems. A case study is used to illustrate the effectiveness of the new multi-skeleton modelling approach. [ABSTRACT FROM PUBLISHER]

A new change-detection method for remote sensing images based on a conditional random field (CRF) model is proposed in this paper. The method artfully uses memberships of Fuzzy C-means as unary potentials in the fully connected CRF (FCCRF) model without training parameters, and pairwise potentials of the CRF model are defined by a linear combination of Gaussian kernels, with which a highly efficient approximate inference algorithm can be used. The proposed FCCRF model is expressed on the complete set of pixels in both the observed multitemporal images, which can incorporate long range contextual information of remote-sensing images and enable greatly refined change-detection results. Experimental results demonstrate that the proposed approach leads to more accurate pixel-level change-detection performance and is more robust against noise than traditional algorithms. [ABSTRACT FROM AUTHOR]