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The purpose of this paper is to propose a multi-feature, multi-metric and multi-loop tightly coupled LiDAR-visual-inertial odometry, M³LVI, for high-accuracy and robust state estimation and mapping.

M³LVI is built atop a factor graph and composed of two subsystems, a LiDAR-inertial system (LIS) and a visual-inertial system (VIS). LIS implements multi-feature extraction on point cloud, and then multi-metric transformation estimation is implemented to realize LiDAR odometry. LiDAR-enhanced images and IMU pre-integration have been used in VIS to realize visual odometry, providing a reliable initial guess for LIS matching module. Location recognition is performed by a dual loop module combined with Bag of Words and LiDAR-Iris to correct accumulated drift. M³LVI also functions properly when one of the subsystems failed, which greatly increases the robustness in degraded environments.

Quantitative experiments were conducted on the KITTI data set and the campus data set to evaluate the M³LVI. The experimental results show the algorithm has higher pose estimation accuracy than existing methods.

The proposed method can greatly improve the positioning and mapping accuracy of AGV, and has an important impact on AGV material distribution, which is one of the most important applications of industrial robots.

M³LVI divides the original point cloud into six types, and uses multi-metric transformation estimation to estimate the state of robot and adopts factor graph optimization model to optimize the state estimation, which improves the accuracy of pose estimation. When one subsystem fails, the other system can complete the positioning work independently, which greatly increases the robustness in degraded environments.

The purpose of this paper is to solve the problems of poor mechanical properties, high surface roughness and waste support materials of thin-walled parts fabricated by flat-layered additive manufacturing process.

This paper proposes a curved-layered material extrusion modeling process with a five-axis motion mechanism. This process has advantages of the platform rotating, non-support printing and three-dimensional printing path. First, the authors present a curved-layered algorithm by offsetting the bottom surface into a series of conformal surfaces and a toolpath generation algorithm based on the geodesic distance field in each conformal surface. Second, they introduce a parallel five-axis printing machine consisting of a printing head fixed on a delta-type manipulator and a rotary platform on a spherical parallel machine.

Mechanical experiments show the failure force of the five-axis printed samples is 153% higher than that of the three-axis printed samples. Forming experiments show that the surface roughness significantly decreases from 42.09 to 18.31 µm, and in addition, the material consumption reduces by 42.90%. These data indicate the curved-layered algorithm and five-axis motion mechanism in this paper could effectively improve mechanical properties and the surface roughness of thin-walled parts, and realize non-support printing. These methods also have reference value for other additive manufacturing processes.

Previous researchers mostly focus on printing simple shapes such as arch or “T”-like shape. In contrast, this study sets out to explore the algorithm and benefits of modeling thin-walled parts by a five-axis machine. Several validated models would allow comparability in five-axis printing.

The purpose of this paper is to shed light on the effect of high‐level human capital investment, using tertiary education as the proxy, on the urban‐rural income gap in China.

Using a panel dataset covering 28 provinces of China over the period from 1988 to 2007, this paper employs Hansen's method and two‐step GMM‐SYS estimator to estimate the threshold regression model and the dynamic fixed‐effect panel model, respectively.

The urban‐rural income gap is found to be related to high‐level human capital investment in an inverted U‐shaped pattern with respect to economic development level. The estimated threshold turning point is around 20,000 RMB GDP per capita. This estimate is sufficiently robust to model specifications and variants of the dependent variable.

The authors forecast that high‐level human capital investment could play a role in bridging the urban‐rural income gap at the national level by 2014, when China's GDP per capita assumes an annual growth rate of 7.5 percent.

This, it is believed, is the first research to find an inverted U‐shaped pattern for high‐level human capital investment and urban‐rural income gap nexus in China.

As the information asymmetry and credit rationing are existing, SMEs are finding it difficult to gain bank credit. Trade credit, as a one off substitution, gives another access to SME finance. The purpose of this paper is to examine the effects between inter‐corporate relationships (including the direct‐relationship and indirect‐relationship) and trade credit.

Following the mainstream of qualitative and quantitative research, this paper examines the relationship between SMEs and their analysis of the commercial credit financing. In the empirical research, through text‐analysis to build the variable of “the number of unions that enterprises take part in”. First, find the relate union through “baidu and googel” by the keywords of enterprise's name and the Union; then two persons select and determine which the enterprise may take part in and calculate the number. For that which cannot make sure, ask the third person. Learning from the HHI‐index, the paper calculates according to the amount and times of the enterprise related transactions to build the variable of “the concentration of enterprises related transactions”. Based on three years panel data (from 2007 to 2009) of 196 small and medium listed companies, this paper establishes the empirical models and examines the effects between inter‐corporate relationship and trade credit through the random effect model.

The paper finds that: SMEs must pay attention to inter‐enterprise relationship management. Without the power and status owned by large enterprises, SMEs have to learn how to survive in the complex and changing environment. The managers of SMEs have to develop their skills to manage the inter‐enterprise relationship. It finds the effects between inter‐enterprise relationship and trade credit seem like a “U” shape. SMEs should take part in associations wittingly and establish the relationship with the others, as all economic activities are embedded in the social network. This research shows that participating in the business associations, especially provincial associations, has a positive impact to gain trade credit.

This paper breaks through the traditional SMEs' financing theories. In this paper, the individual level theories have been extended to the organizational level. This paper also expands the study of the social capital theory and gives a more tolerable empirical test.

Under the trend of global economic integration and the new context of stagflation, frequent fluctuations in international interest rates are exerting far-reaching impacts on the world economy. In this paper, the transmission mechanism of the impact of fluctuations in international interest rates (specifically, the American interest rate) on the bankruptcy risk in China's pillar industry, the construction industry (which is also sensitive to interest rates), is examined.

Using an improved contingent claims analysis, the bankruptcy risk of enterprises is calculated in this paper. Additionally, an individual fixed-effects model is developed to investigate the mediating effects of international interest rates on the bankruptcy risk in the Chinese construction industry. The heterogeneity of subindustries in the industrial chain and the impact of China's energy consumption structure are also analysed in this paper.

The findings show that fluctuations in international interest rates, which affect the bankruptcy risk of China's construction industry, are mainly transmitted through two major pathways, namely, commodity price effects and exchange rate effects. In addition, the authors examine the important impact of China's energy consumption structure on risk transmission and assess the transmission and sharing of risks within the industrial chain.

First, in the research field, the study of international interest rate risk is extended to domestic-oriented industries. Second, in terms of the research content, this paper is focused on China-specific issues, including the significant influence of China's energy consumption structure characteristics and the risk contagion (and risk sharing) as determined by the current development of the Chinese construction industry. Third, in terms of research methods a modified contingent claim analysis approach to bankruptcy risk indicators is adopted for this study, thus overcoming the problems of data frequency, market sentiment and financial data fraud, which are issues that are ignored by most relevant studies.

The purpose of this paper is to investigate the tribological properties of the WC/TiC-Co substrate under different loading conditions under three impact abrasive wear conditions.

The three body collisional wear behavior of Co alloy with WC and TiC at three impact energy was studied from 1 to 3 J. Meanwhile, the microstructure, hardness, phase transformation and wear behavior of these specimens were investigated by scanning electron microscopy, Rockwell hardness (HRV), EDS and impact wear tester. The resulting wear rate was quantified by electronic balance measurements under different pressures.

The specific wear rate increases with the increase of the nonlinearity of the impact energy and the increase in the content of WC or TiC. The effect of TiC on wear rate is greater than that of WC, but the hardness is smaller. The wear characteristics of the samples are mainly characterized by three kinds of behavior, such as cutting wear, abrasive wear and strain fatigue wear. The WC-Co with fewer TiC samples suffered heavier abrasive wear than the more TiC samples under both low and high impact energy and underwent fewer strain fatigue wears under high impact energy.

The experimental results show that the wear resistance of the Co alloy is improved effectively and the excellent impact wear performance is achieved. The results can be used in cutting tools such as coal mine cutting machines or other fields.

Fun at workplace is considered an important initiative to build co-working communities, and this study aims to study its role in promoting the innovative behaviour of co-workers [members of co-working spaces (CWS)] and the mechanism of its influence.

Based on the theory of social exchange and resource conservation, the authors conducted a qualitative study to explore the four dimensions of workplace fun and a quantitative study to empirically analyse the relationship between community embeddedness, organisational embeddedness, workplace fun and creativity of co-workers, taking K-space as an example.

Workplace fun is positively correlated with co-workers' creativity. Community embeddedness plays a complete mediating role between workplace fun and organisational embeddedness. Community embeddedness and organisational embeddedness play a chain-mediating role between workplace fun and creativity.

This study explores the process and impact of fun on employee creativity in a shared office environment by clarifying the composition of fun in CWS workplaces and the transmission mechanism of fun through informal community embeddedness and formal organisational embeddedness, expanding the research perspective on the factors influencing employee creativity in the new office model and enriching the research findings on the impact of fun at work on job performance.

This paper aims to focus on the tracking of a moving magnetic target by using total field magnetometers and to present a tracking method based on the gradient of a magnetic anomaly. In the tracking, it is assumed that the motion of the target is equivalent to a first-order Markov process. And the unit direction vector of the magnetic moment from the gradient of the magnetic anomaly can be obtained. According to the unit direction vector, the inverse problem is turned into an optimization problem to estimate the parameters of the target. The particle swarm optimization algorithm is used to solve this optimization problem. The proposed method is validated by the numerical simulation and real data. The parameters of the target can be calculated rapidly using the proposed method. And the results show that the estimated parameters of the mobile target using the proposed method are very close to the true values.

The authors focus on the tracking of a moving magnetic target by using total field magnetometers and present a tracking method based on the gradient of a magnetic anomaly.

The paper provides an effective method for tracking the magnetic target based on an array with total field sensors.

Comparing with a vector magnetic sensor, the measurement of the scalar magnetic sensor is almost not influenced by its orientation. In this paper, a moving magnetic target was tracked by using total field magnetometers and a tracking method presented based on the gradient of a magnetic anomaly.

This paper seeks to fill the literature gap that lacks of exploring negotiation strategy with competing partners under asymmetric production-cost information. The purpose of this paper is to examine firms’ optimal contract negotiation strategies in buyer–supplier–supplier triads where there are concurrent negotiations between the retailer and two competing manufacturers.

The authors consider a two-echelon supply chain, in which the retailer has the option of segmented or unified negotiation policy, whereas the two competing manufacturers can withhold or share production cost information in the negotiation. Based on game theory, the authors derive the manufacturers’ optimal wholesale prices and the retailer’s optimal retail prices with eight possible scenarios. Optimal strategic choices and operational decisions are then explored through the comparative analysis of equilibriums of eight possible scenarios.

The authors find that the retailer will adopt different negotiation strategies depending on manufacturers’ decisions on sharing or withholding their production-cost information. When both manufacturers share their production-cost information, the retailer will adopt a unified negotiation policy. The high-efficiency manufacturer should adopt the same information-sharing strategy as the low-efficiency manufacturer in order to gain more profit.

The modelling helps to bring further clarity in supply chain contract negotiation by offering a conceptual framework to enhance our understanding of the effects of information-sharing strategy and negotiation policy in the negotiation process form the perspectives of all engaging parties. Managerial insights derived from the research will enable retailers and manufacturers to make informed and better strategic and operational decisions to improve market competitiveness.

Internet-famous food (also known as “online celebrity” food) is very popular in the digital age. This study aims to investigate consumer attitudes and understand consumer behavior towards Internet-famous food.

The authors collected 136,835 online comments regarding “Internet-famous food” from Dianping platform between 2016 and 2019 using a web scraper. A sentiment lexicon for Internet-famous food was constructed, and sentiment analysis is further conducted to understand consumer attitudes. Additionally, the authors use topic analysis and time series analysis to study consumer behavior.

Sentiment analysis showed that the number of consumers' comments decreased over time with the attitudes being overall positive, and the Internet-famous food industry has a positive prospect; time series analysis showed that the consumption of Internet-famous food was not affected by the season; topic analysis showed that consumers' comments on Internet-famous food were rich with a large variety, covering food categories, brand, quality, service, environment and price.

To the authors’ knowledge, limited research has focused on public opinions regarding “Internet-famous food”. This is the first study on consumer behavior towards Internet-famous food. This article provides a unique insight into the purchasing behavior and attitude of Chinese Internet-famous food consumers through text mining.