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This study aims to assess the use of variational quantum imaginary time evolution for solving partial differential equations using real-amplitude ansätze with full circular entangling layers. A graphical mapping technique for encoding impulse functions is also proposed.

The Smoluchowski equation, including the Derjaguin–Landau–Verwey–Overbeek potential energy, is solved to simulate colloidal deposition on a planar wall. The performance of different types of entangling layers and over-parameterization is evaluated.

Colloidal transport can be modelled adequately with variational quantum simulations. Full circular entangling layers with real-amplitude ansätze lead to higher-fidelity solutions. In most cases, the proposed graphical mapping technique requires only a single bit-flip with a parametric gate. Over-parameterization is necessary to satisfy certain physical boundary conditions, and higher-order time-stepping reduces norm errors.

Variational quantum simulation can solve partial differential equations using near-term quantum devices. The proposed graphical mapping technique could potentially aid quantum simulations for certain applications.

This study shows a concrete application of variational quantum simulation methods in solving practically relevant partial differential equations. It also provides insight into the performance of different types of entangling layers and over-parameterization. The proposed graphical mapping technique could be valuable for quantum simulation implementations. The findings contribute to the growing body of research on using variational quantum simulations for solving partial differential equations.

The purpose of this paper is to investigate the nonlinear dynamics of the aircraft assembly lines. An approach for modeling and analyzing the production rate of an aircraft assembly line is introduced using the chaos theory.

First, two key system variables including reliability and learning ability are considered to control the dynamics model. The discrete-time dynamics equation of the production rate is established as a function of the reliability and the learning rate. Then an improved Gauss-learning curve is proposed and applied to aircraft assembling condition. Finally, the bifurcation diagrams and the maximal Lyapunov exponents are used and applied to the experimental study to analyze the dynamic behavior under different combinations of parameters.

On the basis of the experimental study, it is shown that chaotic behavior really exists in the aircraft assembly lines. The reliability and the Gauss-learning curve can nonlinearly affect the production rate.

This paper applied nonlinear dynamics and chaotic theory to the production analyses of the aircraft assembly lines for the first time. The proposed model has been successfully applied to a practical case, and the result justifies its advantage as well as feasibility to both theory and engineering application.

This paper aims to study vehicle-type strategies for the manufacturer's car sharing by accounting for consumers' behavior and the subsidy.

The authors develop a game model, in which a monopoly manufacturer that can produce gasoline vehicles (GVs) or energy vehicles (EVs) not only sells vehicles in the sales market, but also rents them out in the sharing market by the self-built platform. The manufacturer strategically chooses which type of vehicles based on consumers' behavior and whether the government provides the EVs’ subsidy.

When consumers' low-carbon awareness is relatively high or the marginal cost is low, the manufacturer chooses EVs. The manufacturer chooses GVs when the low-carbon awareness and the marginal cost are low. Only when the low-carbon awareness and the subsidy are not too low, the manufacturer who originally chose GVs launches EVs. When the low-carbon awareness is high, the excessive subsidy discourages the manufacturer from entering the sharing market. If the government provides the subsidy, the manufacturer launches high-end EVs. Otherwise, the manufacturer launches low-end EVs. Moreover, the subsidy increases consumer surplus and social welfare since the high subsidy makes EVs’ sharing market demand be negative.

This study enriches the literature on vehicle-type strategies for the manufacturer's car sharing, owns a practical significance to guide the manufacturer's operation management in the car sharing market and provides advice on whether the government should provide EVs’ subsidy.

Modeling and analysis of dimensional variation propagation is a crucial support technology for variation reduction, product/process design evaluation and recognition of variation source. However, owing to the multi-deviation (i.e. part deviations and fixture deviations) and multi-interaction (i.e. part-to-part interaction, part-to-fixture interaction and station-to-station interaction) in assembly processes, it is difficult for designers to describe or understand the variation propagation (or accumulation) mechanism clearly. The purpose of this paper is to propose a variation propagation modeling and analysis (VPMA) method based on multiple constraints aiming at a single station.

Initially, part-to-part constraints (PPCs) and part-to-fixture constraints (PFCs) are applied for the multi-interaction of assembly, and multiple constraints graph (MCG) model is proposed for expressing PPCs, PFCs, parts, as well as the variation propagation relation among them. Then, locating points (LPs) are adopted for representing the deviations in constraints, and formulas for calculating the deviations of LPs are derived. On that basis, a linearized relation between LPs’ deviations and part’s locating deviations is derived. Finally, a wing box is presented to validate the proposed method, and the results indicate the methodology’s feasibility.

MCG is an effective tool for dimensional VPMA, which is shown as an example of this paper.

Functions of geometric constraints in dimensional variation propagation are revealed, and MCG is proposed to formulize dimensional variation propagation.

This paper aims to clarify the size and morphology of transition metal dichalcogenides has an impact on lubrication performance of Cu-based composites. This study is intended to show that Cu-based electrical contact materials containing Nb_0.91Ti0.09Se₂ have better electrical and tribological properties than those containing NbSe₂. The tribological properties of Cu-based with different Ti-dopped NbSe₂ content were also discussed.

The NbSe₂ and Nb_0.91Ti_0.09Se₂ particles were fabricated by thermal solid state reaction method. The powder metallurgy technique was used to fabricate composites with varying Nb_0.91Ti_0.09Se₂ mass fraction. The phase composition of Cu-based composites was identified by X-ray diffraction, and the morphology of NbSe₂/Nb_0.91Ti_0.09Se₂ and the worn surface of composites were characterized by scanning electron microscopy and transmission electron microscopy. In addition, the tribological properties of composites were appraised using a ball-on-disk multi-functional tribometer. The data of friction coefficient and resistivity were analyzed and the corresponding conclusion was drawn.

In comparison with the pure copper, Cu-based composites containing Nb_0.91Ti_0.09Se₂/NbSe₂ had a lower friction coefficient, illustrating the Nb_0.91Ti_0.09Se₂ with nano-size particles prepared in this work is a perfect choice for the fabrication of excellent electrical contact composites. Compared to composites with NbSe₂, composites containing Nb_0.91Ti_0.09Se₂ have better tribological and electrical properties.

Because of the use of thermal solid state reaction method, the size of NbSe₂ and Nb_0.91Ti_0.09Se₂ is relatively large. Therefore, the fabrication of finer particles of Nb_0.91Ti_0.09Se₂ is encouraged.

In this paper, the authors discuss the tribological and electrical properties of Cu-based composites, and the value of optimum obtained as Nb_0.91Ti_0.09Se₂ content is 15 Wt.%.

The purpose of this paper is to assess the effectiveness of the Silk Road Economic Belt (SREB) strategy and its role of industrial productivity in China.

To identify the causal effect of this strategy on industrial sustainable development, the authors first use the slacks-based measure model to calculate industries’ total-factor productivity (TFP) considered with CO₂ emissions as undesirable output on the provincial level. Then, the authors use the PSM-DID method to identify the difference of TFPs between provinces and industries before and after the implementation of SREB strategy.

However, the authors find that there is no difference or even a relative decrease in TFPs of industries in target provinces after the implementation of the strategy, which reveals that the SREB strategy does not play a positive role of the industries’ sustainable development in years of 2014 and 2015.

The value of this result is to identify the short-term impact of SREB strategy and to seek for probable causes and appropriate solutions.

Design is a time-consuming process for mechanical production. Some design structures frequently occur in different products and can be shared by multiple assembly models. Thus, identifying these structures and adding them to a design knowledge library significantly speed up the design process. Most studies addressing this issue have traditionally focused on part models and have not extended to assembly models. This paper aims to find a method for common design structure discovery in assembly models.

Computer-aided design models have a great deal of valuable information defined by different designers in the design stages, especially the assembly models, which are actually carriers of information from multiple sources. In this paper, an approach for discovering a common design structure in assembly models is proposed by comparing information from multiple sources. Assembly models are first represented as attribute connection graphs (ACGs), in which we mainly consider topological information and various attributes of parts and connections. Then, we apply a K-means clustering method based on a similarity analysis of different attributes to classify the parts and connections and transform ACGs of assemblies into type code graphs (TCGs). After this, a discovery algorithm that improves upon fast frequent subgraph mining is used to identify common design structures in assemblies.

A new method was developed for discovering common design structures in assembly models, considering the similarity of information from multiple sources and allowing some differences in the details to keep both commonalities and individualities of common design structures.

Experiments show that the proposed method is efficient and can produce a reasonable result.

This discovery method helps designers find common design structures from different assembly models and shorten the design cycle. It is an effective approach to build a knowledge library for product design that can shorten the design cycle.

This paper aims to conduct an empirical study to investigate whether an industry’s position affects the transmission of information and economic shocks.

This paper conducts an empirical study of inventory performance based on a large panel of 71 industries in the manufacturing, wholesale and retail sectors over a 10-year period (2007–2016).

It is found that the position of a focal industry in the supply chain network moderates the impacts of macroeconomic uncertainty shocks and shocks from supplier/customer industries on the focal industry’s inventory. On the one hand, more central industries are more sensitive to macroeconomic uncertainty shocks as well as spillover shocks from their supplier and customer industries. On the other hand, uncertainty shocks from more central industries have higher impact on their partner industries than those from less central industries.

A manager needs to take into account the network positions of suppliers/customers in supply network when making inventory decisions. For example, when sharing information with partners, the network position of a partner affects how important its information is.

The key novelty of this paper is the introduction of network structure that represents the supplier–customer relationships in the entire economy, and the modeling of uncertainty shocks transmitted through the supply chain network.

The purpose of this paper is to consider relative navigation – a vital technology to satellites formation flying, and to propose a new concept for relative navigation determination along with a technical approach for its practical implementation.

The determination of relative orbit is considered with the relative distance elevation and azimuth measurements about formation flying while the primary satellite is in a circle or ellipse orbit. This measurement is obtained by laser range finder and the estimations of the intersatellite relative position and velocity are obtained by utilizing the unscented Kalman filter instead of extended Kalman filter.

The simulation results show that the error of the relative position and velocity can be estimated with the order of cm and mm/s, respectively, under the effect of J2, converge faster than EKF, and then demonstrate that the approach is feasible.

The paper proposes a new concept for relative navigation determination and describes a technical approach for its practical implementation.

Purpose: This paper uses performance theory to explore how wine-tourism experiences are orchestrated by wine tour guides to encourage engagement of consumers. It describes how such orchestration is built on material elements such as landscapes, architecture, vineyards, production facilities, and wine tastings.

Design/methodology/approach: A multi-layer ethnographic research on wine-tourism was employed. The interviews, observations, and field notes were analyzed through the lens of performance theory. A constant comparative method was used to identify emergent patterns, and a hermeneutic method was used to interpret the data.

Findings: The paper builds on performance theory and delineates the ways in which guides co-create intense experiences with participants. It portrays how tour guides often adjust their theatrical scripts to consumers’ unique needs through creative variations: surprise treats, activities, and personal stories. When guides take pleasure in tours, participants do as well, resulting in memorable co-created experiences. The tours feature processes such as pitching and relation-building techniques that call upon identity, morality, and materiality scripts, which ultimately build a sense of social obligation among participants toward tour guides and winery staff.

Originality/value: From a theoretical perspective, the paper adds value to the discussion of performance in tourism by suggesting that the service blueprint, architecture, and employee training are only part of the story. This paper shows how consumer engagement and interactions between participants, guides, architecture, and landscapes are essential elements of memorable experiences.

Research limitations: Like other studies, there are limitations to our study as well. Our study only included one-day wine tours. A broader investigation of strategic alliances between tour companies and wineries, and how wine tourists experience and sustain a sense of social obligations to the wineries they visit, will provide further insights into how wine-tourism functions as a co-creative emergent form of consumption involving individuals, products, and processes.