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This study aims to solve the problem of the existing metal foreign object (MFO) detecting systems, which are not sensitive to the small size MFO in wireless charging region of electric vehicle (EV) because of the extremely complex signal noise in the process of wireless charging of EV.

A method for MFO detection based on the principle that MFOs can cause mistuned resonance of detection coil resonant circuit is proposed. The general scheme of detecting system is proposed. The design method for detection coils which is effective to small MFOs detection in large-area region of wireless charging of EV is presented. The design of time-sharing driving circuit and amplifying circuit of high frequency exciting signal for detection coils is introduced. The design scheme of signal processing circuit (including filter and rectifier) of detection coil terminal voltage is also proposed.

The influence of exciting frequency of detection coils on detecting sensitivity and the anti-noise feature of system are analyzed according to the experiment results.

The experiment of MFO detection indicates that the proposed method can effectively detect the coin-sized small MFO in the process of wireless charging of EV.

This paper aims to present a multiscale fuzzy optimization (FO) method to optimize both the density distribution and macrotopology of a uniform octet-truss lattice structure.

The design formulae for the strut radii are presented based on the effective mechanical properties obtained from the representative volume element. The proposed basic lattice material is applied in a normalization process to determine the material model with penalization. The solid isotropic material with penalization (SIMP) method is extended to solve the minimum compliance problem using the optimality criteria. The evolutionary deletion process is proposed to delete elements corresponding to thin-strut unit cells and to obtain the optimal macrotopology.

Both numerical cases indicate that the FO results significantly improved in structural performance compared with the results of the conventional SIMP. The deleting threshold controls the macrotopology of the graded-density lattice structures with negligible effects on the mechanical properties.

This paper presents one of the first multiscale optimization methods to optimize both the relative density and macrotopology of uniform octet-truss lattices. The material model and corresponding optimality criteria of octet-truss lattices are proposed and implemented in the optimization.

Existing calibration methods mainly focus on the camera laser-plane calibration of a single laser-line length, which is not convenient and cannot guarantee the consistency of the results when several three-dimensional (3D) scanners are involved. Thus, this study aims to provide a unified step for different laser-line length calibration requirements for laser profile measurement (LPM) systems.

3D LPM is the process of converting physical objects into 3D digital models, wherein camera laser-plane calibration is critical for ensuring system precision. However, conventional calibration methods for 3D LPM typically use a calibration target to calibrate the system for a single laser-line length, which needs multiple calibration patterns and makes the procedure complicated. In this paper, a unified calibration method was proposed to automatically calibrate the camera laser-plane parameters for the LPM systems with different laser-line lengths. The authors designed an elaborate planar calibration target with different-sized rings that mounted on a motorized linear platform to calculate the laser-plane parameters of the LPM systems. Then, the camera coordinates of the control points are obtained using the intersection line between the laser line and the planar target. With a new proposed error correction model, the errors caused by hardware assembly can be corrected. To validate the proposed method, three LPM devices with different laser-line lengths are used to verify the proposed system. Experimental results show that the proposed method can calibrate the LPM systems with different laser-line lengths conveniently with standard steps.

The repeatability and accuracy of the proposed calibration prototypes were evaluated with high-precision workpieces. The experiments have shown that the proposed method is highly adaptive and can automatically calibrate the LPM system with different laser-line lengths with high accuracy.

In the repeatability experiments, there were errors in the measured heights of the test workpieces, and this is because the laser emitter had the best working distance and laser-line length.

By using this proposed method and device, the calibration of the 3D scanning laser device can be done in an automatic way.

The calibration efficiency of a laser camera device is increased.

The authors proposed a unified calibration method for LPM systems with different laser-line lengths that consist of a motorized linear joint and a calibration target with elaborately designed ring patterns; the authors realized the automatic parameter calibration.

This paper aims to develop a climbing robot to help people inspect lamps of high-mast lighting.

The robot consists of driving mechanism, suspension mechanism and compression mechanism. The driving mechanism is realized by link chains and sprockets, which are arranged opposite to each other, to form a dual caterpillar mechanism. The compression mechanism squeezes the caterpillar, and rubber feet “grasps” the steel rope to generate enough adhesion forces. The suspension mechanism is used to compensate the contraction or extension of the chains. The robot is equipped with a DC motor with a rated power of 250 W and a wireless module to communicate with the operator’s console. The dynamic model of the robot and the control strategy is derived, and the stability of the controller is proofed.

The payload experiment shows the robot can afford up to 3.7 times payload versus its own weight. Even when the payload is 30 kg, the robot can maintain a speed of the 1 m/s. The experiments also show that the tracking error of the robot reaches zero.

The proposed moving mechanism has a high load/weight ratio, which is a verified solution for the cable inspection purpose.

A rope climbing robot for high mast lighting inspection is proposed. The developed mechanism can reach a speed of 1 m/s with the payload of 30 kg, while its own weight is only 15.6 kg. The payload/weight ratio of the robot is 2.24; this value is rather good in many climbing robots reported in other renowned journal.

Multi-robot laser-based simultaneous localization and mapping (SLAM) in large-scale environments is an essential but challenging issue in mobile robotics, especially in situations wherein no prior knowledge is available between robots. Moreover, the cumulative errors of every individual robot exert a serious negative effect on loop detection and map fusion. To address these problems, this paper aims to propose an efficient approach that combines laser and vision measurements.

A multi-robot visual laser-SLAM is developed to realize robust and efficient SLAM in large-scale environments; both vision and laser loop detections are integrated to detect robust loops. A method based on oriented brief (ORB) feature detection and bag of words (BoW) is developed, to ensure the robustness and computational effectiveness of the multi-robot SLAM system. A robust and efficient graph fusion algorithm is proposed to merge pose graphs from different robots.

The proposed method can detect loops more quickly and accurately than the laser-only SLAM, and it can fuse the submaps of each single robot to promote the efficiency, accuracy and robustness of the system.

Compared with the state of art of multi-robot SLAM approaches, the paper proposed a novel and more sophisticated approach. The vision-based and laser-based loops are integrated to realize a robust loop detection. The ORB features and BoW technologies are further utilized to gain real-time performance. Finally, random sample consensus and least-square methodologies are used to remove the outlier loops among robots.

Previous research about online recommendation systems has focused largely on their impact on customers' purchase decisions regarding the products being recommended, but it has mostly ignored how they may affect focal product evaluation. This research aimed to examine the influence of recommendation type (i.e. substitute-based vs complement-based) on focal product evaluation dependent on the brand image (i.e. warm vs competent).

Four laboratory experiments were conducted. Study 1 adopted an implicit association task. Studies 2 and 3 used a 2 (image: warmth vs competence) × 2 (product display: complements vs substitutes) between-subjects experimental design. Study 4 used a 2 (decision stage) × 2 (image) × 2 (product display) × continuous (need for cognition) between-subjects design.

Study 1 demonstrated a general “complementation (competition)—warmth (competence)” association. Studies 2 and 3 found that when a focal product had a warm (competent) image, complement-based (substitute-based) recommendations led customers to evaluate it more favorably than substitute-based (complement-based) recommendations. Study 3 further demonstrated that processing fluency mediates the above effect. Study 4 showed that this effect relies on heuristic processing and disappears for those who are in the screening stage or have a high need for cognition.

Theoretically, this research extends the understanding of the stereotype content model of focal product brand image, the feelings-as-information process, and moderating roles of processing stage and need for cognition in e-commerce contexts. Practically, the findings provide online retailers a guideline for customizing their recommendation systems.

The purpose of this paper is to determine: how much the residual curvature could be formed in sintered nano‐silver assembly when it is cooled to room temperature from the sintering temperature (normally 275°C); how the cyclic temperature load affects the residual curvature or stresses in sintered joint. Then the stress level and the reliability of sintered nano‐silver for high‐temperature applications can be understood.

5 mm * 2.5 mm silicon chip was bonded with 96 per cent Al₂O₃ substrate by sintering nanosilver paste. An optical system was developed to measure the curvature of the sintered assemblies. Reliability of the sintered assemblies was evaluated by temperature cycling of −40∼125°C. Finite element analysis was employed to simulate the behavior of the joint subjected to the temperature cycling from −40°C to 125°C by ANSYS. SEM images were taken to investigate the impact of temperature cycling on the reliability of sintered silver attachment.

This residual bending at room temperature was found concave towards the substrate (alumina) side. Also, with the bondline thickness increasing, the residual curvature decreases obviously. The severity of the residual bending in all the structures was mitigated to some extent with increasing number of cycles. There is no crack in the joint with the thickness of 25 μm. The drop of the residual curvature of the samples with bondline of 25 μm is caused mainly by stress relaxation in sintered silver before 300 cycles. Sample with thicker bondline is more susceptible to thermal cycling for the structure bonded with nanosilver than that with thinner bondline. The poor quality of bonding is due to the thicker sintered joint, which means that sintered nanosilver is not suitable for die‐attachment requiring thick bondline.

The paper describes: how a precise optical system was developed to measure the residual curvature of the sintered assemblies; how the evolution of the residual curvature of the sintered assembly with the temperature cycling was obtained by both experiment and simulation; and how microstructures of the sintered silver joint were analyzed for as‐sintered assembly and the sintered assembly after temperature cycling.

The purpose of this paper is to investigate the relationship between corporate governance mechanism and firm value of the listed companies in China. Does the better corporate governance lead to the higher firm value? Or does the higher firm value make it easy to choose a better governance mechanism? Or they affect each other? In other words, this paper tries to answer whether the corporate governance mechanism is only decided by institutional arrangement, or by market choice according to firm value or performance or by the interaction of institutional arrangement and market choice? It tries to answer whether institutional arrangement maximizes the firm value, or an invisible hand pushes them to arrive at its maximum.

This paper establishes an analytic framework of simultaneous equations based on causality, which includes five endogenous variables: ownership of larger shareholders, managerial ownership, director compensation, debt financing and firm value. It adopts 1,644 data samples from 274 Chinese listed companies in Shanghai and Shenzhen Stock Exchange during 2007- 2012 after the non-tradable shares reform. Ordinary least squares (OLS) estimation of single equation, 2SLS and 3SLS estimation of simultaneous equations are respectively done to show the differences of these three kinds of estimations.

The empirical results show that differences exist among OLS, 2SLS and 3SLS estimation. Finally, 3SLS estimation should be adopted because the OLS and 2SLS estimation are biased. There are endogenous relationships between corporate governance mechanism and firm value. Through the 3SLS estimation, it is found that first, ownership concentration and firm value affect each other positively. Second, managerial ownership and firm value affect each other positively; third, director compensation and firm value affect each other negatively, while director compensation and firm performance affect each other positively. Finally, debt financing level and firm value are negatively related to each other.

It means that ownership of large shareholders, managerial ownership, director compensation and debt financing in the Chinese listed companies are found to have a root in the interaction between institutional arrangement and market choice. It is also found that adverse selection occurs when creditors loan to the listed companies. Managerial compensation is positively related to accounting profit, but it is negatively related to firm value because managers increase profit due by earning management. This could only increase the accounting profits and obtain huge cash compensation, but not increase firm value and even harm the interests of shareholders.

This paper not only shows the difference between OLS and 2SLS estimation but also compares the estimation of 2SLS and 3SLS in terms of empirical methods. It gives answers to the following questions: whether the relationship is one-way causality or bilateral causality between ownership concentration, managerial ownership, director compensation and firm value; whether governance mechanism affects firm value by institutional arrangement, or market drives both of them to strike a balance by an invisible hand. In other words, does it make them arrive at equilibrium through the competitive selection process when shareholders, directors, managers and creditors attempt to maximize themselves of their interests?

This paper aims to use nano-silver paste to design a new bonding method for super-large-area direct-bonded-aluminum (DBA) plates. It compared several frequently used bonding methods and proved the feasibility of an optimized low-pressure-assisted double-layer-printed silver sintering technology for large-area bonding to increase the thermal conductivity of power electronic modules with high junction temperature, higher power density and higher reliability.

The bonding profile was optimized by using transparent glasses as substrates. Thus, the bonding qualities could be directly characterized by optical observation. After sintering, the bonded DBA samples were characterized by nondestructive X-ray computed tomography system, scanning electron microscopy equipped with an energy dispersive spectrometer. Finally, bonding stress evolution was characterized by shear tests.

Low-pressure-assisted large-area double-layer-printed bonding process consisting of six-step was successfully developed to bond DBA substrates with the size of 50.8 × 25.4 mm. The thickness of the sintered-silver bond-line was between 33  and 74 µm with the average porosity of 12.5 per cent. The distribution of shear strength along the length of DBA/DBA bonded sample was from 9.7  to 18.8 MPa, with average shear strength of 15.5 MPa. The typical fracture primarily propagated in the sintered-silver layer and partially along the Ni layer.

The bonding stress needs to be further improved. Meanwhile, the thermal and electrical properties are encouraged to test further.

If nano-silver paste can be used as thermal interfacial material for super-large-area bonding, the thermal performance will be improved.

The paper accelerated the use of nano-silver paste for super-large-area DBA bonding.

The proposed bonding method greatly decreased the bonding pressure.