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Approaches maintenance management in a systematic way so as to achieve its business objectives. From a managerial point of view, this so‐called object/objective‐oriented maintenance management (OOMM) is an integral process of asset (equipment) management with behavior‐based maintenance (BBM) as a major element. Within the OOMM concept, the objective‐approach focuses on the managing of the maintenance processes so as to achieve the business objectives, and the object‐approach emphasizes the object (asset or equipment) and the behavioral failures. Furthermore, combined together, the two approaches reflect the basic characteristics of the maintenance process. Also, both sides affect and influence each other, and are inseparable within OOMM. BBM addresses the monitoring and controlling of the technical and economic behavior of a piece of equipment in two ways.

The purpose of this paper is to develop a novel MEMS vector hydrophone with the key features of smaller size, better consistency, higher sensitivity and directional reception, and to develop a highly effective and economical obstacle avoidance sonar system. Currently, the typical vector hydrophones are resonant vector hydrophones based on the accelerometer, which greatly increases the volume and constrains the detection sensitivity. Also, because the system is composed of a number of devices, its size is difficult to be reduced.

A novel double T-shape MEMS vector hydrophone is proposed with a fish’s lateral line organs as prototypes. The structure size and layout location of the piezoresistors were determined by simulation analysis, and the double T-shape microstructure was fabricated integrally by MEMS manufacturing technology, after which, the acoustic package of the microstructure was completed and the prototype was produced. Finally, the packaged hydrophone was calibrated in a standing wave field in the first-class national-defense underwater acoustic calibration station of China. Also, the design and test of an obstacle avoidance sonar system based on the vector hydrophone were completed.

The calibration data show that the double T-shape vector hydrophone has a flat frequency response curve, exhibits a sensitivity of −180 dB (1 kHz, 0 dB reference 1 V/uPa) and shows a good directivity pattern in the form of an “8” shape. The test results of the obstacle avoidance sonar system further verify the feasibility of detecting underwater acoustic signals.

The next work is to increase the sensitivity by optimizing the microstructure and to realize orientation by organizing array.

The hydrophone has the advantages of smaller size, lower cost and directional reception. It can be used to develop highly effective and economical obstacle avoidance sonar system, thus solving the problems of water transport efficiency and traffic safety. The hydrophone has broad application prospects and a huge market potential in the civilian fields.

The MEMS technology and innovative bionic microstructure enable the miniaturization and low cost of the hydrophone. The hydrophone is easy to form array and can narrow the array aperture greatly. So, the hydrophone can be widely used in civil sonar systems.

Human-induced marine environmental noise, such as commercial shipping and seismic exploration, is concentrated in the low-frequency range. Meanwhile, low-frequency sound signals can achieve long-distance propagation in water. To meet the requirements of long-distance underwater detection and communication, this paper aims to propose an micro-electro-mechanical system (MEMS) flexible conformal hydrophone for low-frequency underwater acoustic signals. The substrate of the proposed hydrophone is polyimide, with silicon as the piezoresistive unit.

This paper proposes a MEMS heterojunction integration process for preparing flexible conformal hydrophones. In addition, sensors prepared based on this process are non-contact flexible sensors that can detect weak signals or small deformations.

The experimental results indicate that making devices with this process cannot only achieve heterogeneous integration of silicon film, metal wire and polyimide, but also allow for customized positions of the silicon film as needed. The success rate of silicon film transfer printing is over 95%. When a stress of 1 Pa is applied on the x-axis or y-axis, the maximum stress on Si as a pie-zoresistive material is above, and the average stress on the Si film is around.

The flexible conformal vector hydrophone prepared by heterogeneous integration technology provides ideas for underwater acoustic communication and signal acquisition of biomimetic flexible robotic fish.

A unified framework for solving the bending, buckling and vibration problems of rectangular thin plates (RTPs) with four free edges (FFFF), including isotropic RTPs, orthotropic rectangular thin plates (ORTPs) and nano-rectangular plates, is established by using the symplectic superposition method (SSM).

The original fourth-order partial differential equation is first rewritten into Hamiltonian system. The class of boundary value problems of the original equation is decomposed into three subproblems, and each subproblem is given the corresponding symplectic eigenvalues and symplectic eigenvectors by using the separation variable method in Hamiltonian system. The symplectic orthogonality and completeness of symplectic eigen-vectors are proved. Then, the symplectic eigenvector expansion method is applied to solve the each subproblem. Then, the symplectic superposition solution of the boundary value problem of the original fourth-order partial differential equation is given through superposing analytical solutions of three foundation plates.

The bending, vibration and buckling problems of the rectangular nano-plate/isotropic rectangular thin plate/orthotropic rectangular thin plate with FFFF can be solved by the unified symplectic superposition solution respectively.

The symplectic superposition solution obtained is a reference solution to verify the feasibility of other methods. At the same time, it can be used for parameter analysis to deeply understand the mechanical behavior of related RTPs. The advantages of this method are as follows: (1) It provides a systematic framework for solving the boundary value problem of a class of fourth-order partial differential equations. It is expected to solve more complicated boundary value problems of partial differential equations. (2) SSM uses series expansion of symplectic eigenvectors to accurately describe the solution. Moreover, symplectic eigenvectors are orthogonal and directly reflect the orthogonal relationship of vibration modes. (3) The SSM can be carried to bending, buckling and free vibration problems of the same plate with other boundary conditions.

The purpose of this paper is to propose a smooth double-spline interpolation method for six-degree-of-freedom rotational robot manipulators, achieving the global C2 continuity of the robot trajectory.

This paper presents a smooth double-spline interpolation method, achieving the global C2 continuity of the robot trajectory. The tool center positions and quaternion orientations are first fitted by a cubic B-spline curve and a quartic-polynomial-based quaternion spline curve, respectively. Then, a parameter synchronization model is proposed to realize the synchronous and smooth movement of the robot along the double spline curves. Finally, an extra u-s function is used to record the relationship between the B-spline parameter and its arc length parameter, which may reduce the feed rate fluctuation in interpolation. The seven segments jerk-limited feed rate profile is used to generate motion commands for algorithm validation.

The simulation and experimental results demonstrate that the proposed method is effective and can generate the global C2-continuity robot trajectory.

The main contributions of this paper are as follows: guarantee the C2 continuity of the position path and quaternion orientation path simultaneously; provide a parameter synchronization model to realize the synchronous and smooth movement of the robot along the double spline curves; and add an extra u-s function to realize arc length parameterization of the B-spline path, which may reduce the feed rate fluctuation in interpolation.

This paper aims to study the joint decision making of advance selling and service cancelation for service provides with limited capacity when consumers are overconfident.

For the case in which consumers encounter uncertainties about product valuation and consumption states in the advance period and are overconfident about the probability of a good state, we study how the service provider chooses the optimal sales strategy among the non-advance selling strategy, the advance selling and disallowing cancelation strategy, and the advance selling and allowing cancelation strategy. We also discuss how overconfidence influences the service provider’s decision making.

The results show that when service capacity is sufficient, the service provider should adopt advance selling and disallow cancelation; when service capacity is insufficient, the service provider should still implement advance selling but allow cancelation; and when service capacity is extremely insufficient, the service provider should offer spot sales. Moreover, overconfidence weakens the necessity to allow cancelation under sufficient service capacity and enhances it under insufficient service capacity but is always advantageous to advance selling.

The obtained results provide managerial insights for service providers to make advance selling decisions.

This paper is among the first to explore the effect of consumers’ overconfidence on the joint decision of advance selling and service cancelation under capacity constraints.

The purpose of this paper is to present a novel nitrile butadiene rubber (NBR) packaging structure, which can solve the problems of the low sensitivity, narrow frequency band and fluctuating frequency response curve of the MEMS bionic vector hydrophone.

A 0.05-mm-thick NBR sound-transparent cap was designed by theoretical analysis and simulation to reduce the signal attenuation caused by the packaging structure, and the frequency band of the hydrophone has been extended to 4 kHz. In this work, the vector hydrophone was fabricated by the MEMS technology and packaged with the NBR sound-transparent cap. The performance indicators were calibrated in the National Defence Underwater Acoustics Calibration Laboratory of China.

The results show that the sensitivity of NBR-packaged hydrophone reaches −170 dB (±2 dB), and the difference is less than 1 dB compared to bare chip. And the frequency band is 50 Hz-4 kHz. The hydrophone also has good directional pattern in the form of an 8-shape, and the pressure-resisting ability is more than 2 MPa.

The packaging structure significantly increases the sensitivity of the hydrophone and broadens the frequency band, providing a new method in the packaging design for MEMS hydrophone.

During the early 1970s, faced with the serious demographic situation, China began to fully implement the policy of family planning in urban and rural regions. Nowadays, the problems of pension and medical care for aged parents confronted by the first generation of the one‐child family have begun to gradually appear. Meanwhile, China's population and the family planning are also faced with some problems that are difficult to solve, including unbalanced fertility rate of urban and rural population, the gender imbalance, the difficulty of the risk diversification in a one‐child family, as well as the profound contradiction between the stability of the family planning policy and the drive of administrative measures. Therefore, it is necessary to establish the integrated‐scheduled life security system of the one‐child family in urban and rural areas, in order to overcome the problems and to promote the transformation of the family planning policy. The purpose of this paper is to discuss the life security system for China's one‐child families.

The life security system for the one‐child family proposed by this paper consists of three issues: the basic security based on the level of social security, the additional security of the policy insurance and the supplementary security of the commercial insurance. The paper begins with the history of the family planning policy in the first section and then go through some relevant articles regarding complementary measures such as maternity insurance, rural endowment insurance that only focused on one aspect of issues associated with the family planning. In section three, four typical problems are listed for the purpose of following discussion of corresponding solutions which are full of deficiency in section four. In part five, the integrated planning of the life security system for Chinese one‐child family is elaborated with risk and fund management. In the last part, we conclude that the family planning policy maintains stable, whereas measures to be taken are adjusted along with changeable new problems.

The policy insurance plays an increasingly important role in dealing with the life security of older people in one‐child families. It may be better to promote the kind of insurance.

The paper comprehensively discusses the life security system for Chinese families in compliance with the family planning policy.

This paper aims to evaluate the efficiency and mechanism of three kinds of expired nitroimidazole antibiotics as corrosion inhibitor for mild steel in 1M HCl.

Evaluation was carried out by weight loss and electrochemical techniques. The surface morphology and the composition of the elements of adsorption layer are studied by scanning electron microscopy and energy dispersive spectrometer.

The experimental results reveal that the maximum value of inhibition efficiency appear at an extreme point of concentration with the increase of concentration of the inhibitors. Ornidazole has better corrosion inhibition than metronidazole but not as tinidazole. The inhibitors all act as cathodic type corrosion inhibitor. The adsorption of ornidazole, metronidazole and tinidazole on mild steel obeys Langmuir adsorption isotherm and belongs to chemisorption of electron donating. Combined with the molecular structure of the corrosion inhibitor and the experimental structure, the authors propose a detailed mechanism analysis.

The expired nitroimidazole antibiotics as corrosion inhibitor for mild steel in hydrochloric acid solution is first studied. It provides a way to deal with expired drugs, thereby reducing environmental pollution. The study explored the inhibition mechanism affecting by comparison different structure of three kinds of expired nitroimidazole antibiotics molecular, providing theoretical support for the preparation of the new inhibitor.