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With the development of tourism industry, online travel agencies (OTA) have gradually become an important channel for tourism product supplies and sales. Some OTAs provide consumers with a platform for tourism guidance and online travel sharing. They not only satisfy some tourists’ desire to share their experiences but also provide reference for more consumers to choose travel products. This process is the process of value co-creation by customers and online travel companies. This study is conducted under DART theory, a theoretical framework of value co-creation composed of four dimensions, namely dialog, access, risk-assessment, and transparency. Brand equity is divided into four aspects: brand loyalty, brand awareness, customer perceived value, and brand image. This study uses the structural equation model to investigate the impact of customer value co-creation behavior on brand equity of online travel enterprises and interprets the process and mechanism of customer value co-creation behaviors for online travel business brand equity, which provides more efficient strategies and methods for platform interaction and value co-creation.

The purpose of this paper is to put forward a path planning method in complex environments containing dynamic obstacles, which improves the performance of the traditional A* algorithm, this method can plan the optimal path in a short running time.

To plan an optimal path in a complex environment with dynamic and static obstacles, a novel improved A* algorithm is proposed. First, obstacles are identified by GoogLeNet and classified into static obstacles and dynamic obstacles. Second, the ray tracing algorithm is used for static obstacle avoidance, and a dynamic obstacle avoidance waiting rule based on dilate principle is proposed. Third, the proposed improved A* algorithm includes adaptive step size adjustment, evaluation function improvement and path planning with quadratic B-spline smoothing. Finally, the proposed improved A* algorithm is simulated and validated in real-world environments, and it was compared with traditional A* and improved A* algorithms.

The experimental results show that the proposed improved A* algorithm is optimal and takes less execution time compared with traditional A* and improved A* algorithms in a complex dynamic environment.

This paper presents a waiting rule for dynamic obstacle avoidance based on dilate principle. In addition, the proposed improved A* algorithm includes adaptive step adjustment, evaluation function improvement and path smoothing operation with quadratic B-spline. The experimental results show that the proposed improved A* algorithm can get a shorter path length and less running time.

The purpose of this paper is to analyze the changes in its importance due to the maintenance and repair of components.

In this paper, a concept of time-varying importance measure is proposed to solve the problem of component importance change caused by maintenance. When the system is broken-down, the probability difference between the component works well after repairing and the component break down before repairing is solved, this difference is measured as an index of time-varying importance method. Then, the approach has been verified by the CNC machine tool.

The paper provides a method to analyze the importance of changes of components in the system due to maintenance. The time-varying importance measure can evaluate the component importance anytime during its whole life span, and it has the ability to find out the most responsible component for a system failure in the actual production process. What is more, it provides guidance for the next maintenance work.

The proposed method can guide the next maintenance time according to the change of component performance caused by each maintenance activity of the manufacturing system, and avoid the waste of resources caused by repeated maintenance.

This paper aims to improve the meshing effect of the gear teeth. It is recommended to analyze the deformation difference between the inner and outer surfaces of the flexspline. The purpose of this paper is to modify the profile of the flexspline based on the deformation difference to improve the transmission accuracy and operating life of the harmonic drive.

In this paper, ring theory is used to calculate the deformation difference of the inner and outer surfaces of the flexspline, and the actual tooth profile of the flexspline is corrected based on the deformation difference. Then, the flexspline is divided into multiple sections along the axial direction, so that the three-dimensional tooth profile of the flexspline is modified to improve the gear tooth meshing effect.

This paper proves the effect of the deformation difference between the inner and outer surfaces of the flexspline on the tooth backlash, which affects the transmission accuracy and life of the harmonic drive. It is recommended to modify the tooth profile of the flexspline based on the deformation difference, so as to ensure the tooth meshing effect.

This paper provides a new way for the optimization of the three-dimensional tooth profile design of the harmonic drive.

Fatigue and creep are the key factors for the failure of polymethyl methacrylate (PMMA) in the engineering structure, so a great of quantity attention is focused on the life prediction under the creep and fatigue conditions. This paper aims to mainly summarize the traditional life assessment method (S–N curve), life assessment method based on crazing density and life assessment method based on transmittance. S–N curve and classical creep curve are introduced on the traditional life assessment method; the variation of the craze density with the logarithm of cyclic numbers is given in different fatigue load. A linear relationship is obtained, and a higher stress leads to a higher slope, suggesting a faster growth of craze. Furthermore, a craze density model is purposed to describe this relationship; the variation of craze density with the time at different creep load is given. The craze density has two obvious stages. At the first stage, craze density ranged from approximately 0.02 to 0.17, and a linear relationship is obtained. In the following stage, a nonlinear relationship appears till specimen rupture, a new creep life model is proposed to depict two stages. The relationship between transmission and time under creep load is shown. With increasing of time, the transmittance shows a nonlinear decrease. Through polynomial nonlinear fitting, a relationship between the transmittance and residual life can be obtained. To provide reference for the life assessment of transparent materials, the paper compares three life assessment methods of PMMA.

This paper uses the traditional life assessment method (S–N curve), life assessment method based on crazing density, life assessment method based on transmittance.

The variation of the craze density with the logarithm of cyclic numbers is given in different fatigue loads. A linear relationship is obtained, and a higher stress leads to a higher slope, suggesting a faster growth of craze. Furthermore, a craze density model is proposed to describe this relationship, and the variation of craze density with the time at different creep loads is given. The craze density has two obvious stages. The relationship between transmission and time under creep load is shown. With increasing of time, the transmittance shows a nonlinear decrease. Through polynomial nonlinear fitting, a relationship between the transmittance and residual life can be obtained.

Fatigue and creep are the key factors for the failure of PMMA in the engineering structure, so a great of quantity attention is focused on the life prediction under the conditions of creep and fatigue. This paper mainly summarizes traditional life assessment method (S–N curve), life assessment method based on crazing density and life assessment method based on transmittance.

Hull block assembly is a vital task in ship construction. It is necessary to obtain the actual poses of the assembly features to guide further block alignment. Traditional methods use single-point measurement, which is time-consuming and may lead to loss of key information. Thus, large-scale scanning is introduced for data acquisition, and this paper aims to provide a precise and robust method for retrieving poses based on point set registration.

The main problem of point registration is to find the correct transformation between the model and the scene. In this paper, a vote framework based on a new point pair feature is used to calculate the transformation. First, a special edge indicator for multiplate objects is proposed to determine the edges. Subsequently, pair features with an edge description are noted for every point. Finally, a voting scheme based on agglomerative clustering is implemented to determine the optimal transformation.

The proposed method not only improves registration efficiency but also maintains high accuracy compared to several commonly used approaches. In particular, for objects composed of plates, the results of pose estimation are more promising because of the compact pair feature. The multiple ship longitudinal localization experiment validates the effectiveness in real scan applications.

The proposed edge description performs a better detection for the edges of multiplate objects. The pair feature incorporating the edge indicator is more discriminative than the original template, resulting in better robustness to outliers, noise and occlusions.

This study aims to demonstrate a modified wire arc additive manufacturing (AM) named non-transferring arc and wire AM (NTA-WAM). Here, the build plate has no electrical arc attachment, and the system’s arc is ignited between tungsten electrode and filler wire.

The effect of various deposition conditions (welding voltage, travel speed and wire feed speed [WFS]) on bead characteristics is studied through response surface methodology (RSM). Under optimum deposition condition, a single-bead and thin-layered part is fabricated and subjected to microstructural, tensile testing and X-ray diffraction study. Moreover, bulk texture analysis has been carried out to illustrate the effect of thermal cycles and tensile-induced deformations on fibre texture evolutions.

RSM illustrates WFS as a crucial deposition parameter that suitably monitors bead width, height, penetration depth, dilution, contact angle and microhardness. The ferritic (acicular and polygonal) and lath bainitic microstructure is transformed into ferrite and pearlitic micrographs with increasing deposition layers. It is attributed to a reduced cooling rate with increased depositions. Mechanical testing exhibits high tensile strength and ductility, which is primarily due to compressive residual stress and lattice strain development. In deposits, ϒ-fibre evolution is more resilient due to the continuous recrystallisation process after each successive deposition. Tensile-induced deformation mostly favours ζ and ε-fibre development due to high strain accumulations.

This modified electrode arrangement in NTA-WAM suitably reduces spatter and bead height deviation. Low penetration depth and dilution denote a reduction in heat input that enhances the cooling rate.

The purpose of this paper is to investigate and minimize the printing-related defects in the surface mount assembly (SMA) process.

This paper uses an experimental approach to explore process parameter and printing defects during the SMA process. Increasing printing performance, various practices of solder paste (Ag3.0/Cu0.5/Sn) storage and handling are suggested. Lopsided paste problem is studied by varying squeegee pressure and the results are presented. Unfilled pads problems are observed for ball grid array (BGA) and quad flat package (QFP) which is mitigated by proper force tuning. In this paper, a comparative study is conducted which evaluates the manifestation of printing offset due to low-grade stencil. The input/output (I/O) boards were oxidized when the relative humidity was maintained beyond 70 per cent for more than 8 h. This pad oxidation problem is overcome by proper printed circuit board (PCB) handling procedures. When the unoptimized line is used, the paste wedged in the stencil and influences the performance of the screen printer, for this reason, an optimized line is proposed that minimize the printing defects.

The key findings are as follows: in the SMA process, printing quality is directly associated with solder paste quality. Experimentally, it is observed that a considerable variance in solder deposition occurred when the front and rear squeegee have different configurations. High-grade and unsoiled stencil results in superior paste deposition and less distinction. Insufficient solder paste and bridge problems also occur in printing when PCB pads are oxidized. Optimized line resolves solder paste clog issues, associated with stencil’s aperture. The cooling arrangement on the conveyor, after reflow, explicates hot jig problem. Control environmental conditions minimized static charges and printing defects.

The preceding studies emphasis mostly on the squeegee pressure, while other important parameters are not completely investigated. Moreover, it is very imperative to concurrently measure all parameters while varying the environmental conditions. This study highlights and provides an experimental approach to various PCB printing defects, and a comparative study has been conducted that concurrently measure all process parameters.

The downstream insulin signaling, such as phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) pathway, is an important step for skeletal glucose disposal through the translocation of glucose transporter (GLUT)-4. In addition, the master of energy regulator adenosine monophosphate-activated kinase (AMPK) is also involved in GLUT-4 translocation, independent from the PI3K/Akt pathway. Fermented cassava tuber or gatot is a traditional food from Indonesia with antihyperglycemic properties. However, the molecular mechanism leading to this effect is unclear. Therefore, this paper aims to evaluate whether the antidiabetic activity of gatot is through PI3K/Akt dependent or AMPK pathway.

Diabetes mellitus was induced in 20 male Wistar rats by intraperitoneal injection of 65 mg/kg body weight streptozotocin and 230 mg/kg body weight nicotinamide. Diabetic rats were randomly allocated into four groups; negative control, positive control (metformin 100 mg/kg body weight), fermented cassava diet replacing 50% of carbohydrate (FC-50) and 100% of carbohydrate (FC-100) in the diet. Serum glucose, insulin and lipid profile were analyzed before and after four weeks of intervention. Genes expression of PI3K subunit alpha, PI3K subunit beta, PI3K regulatory subunit, Akt and AMPK were analyzed using real time polymerase chain reaction (PCR). GLUT-4 protein expression was performed using immunohistochemistry.

There is a significant difference (p = 0.000) in serum glucose, insulin, total cholesterol, triglyceride, high density lipoprotein (HDL)-cholesterol and LDL-cholesterol between groups. Skeletal AMPK gene expression was higher and significantly different between FC-100 (p = 0.006) and healthy control groups. No significant difference was observed in the messenger ribonucleic acid (mRNA) expression of the PI3K/Akt pathway among groups. GLUT-4 expression was highly expressed in a positive control group followed by FC-100.

This paper did not characterize the bioactive component that is responsible for increasing mRNA expression of AMPK. This paper also did not analyze the phosphorylation of PI3K/Akt and AMPK that are important in activating the protein.

To the best of the authors’ knowledge, this is the first study that showed the antidiabetic activity of traditional fermented food is through AMPK-dependent activity.