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As one of the important structures of composite materials, polymethacrylimide (PMI) foam sandwich structure is prone to debonding and delamination defects during manufacturing and service, which seriously affects the mechanical properties of materials. Therefore, it is necessary to detect the defects of foam sandwich structure. A linear frequency modulation infrared thermal wave nondestructive testing system was built to study the correlation between the geometric characteristics (diameter and depth) of the defect and the surface temperature signal and its influence on the detection effect. The image sequence is processed by principal component analysis, discrete Fourier transform, thermal wave signal reconstruction, and other algorithms. Studies have shown that the larger the defect diameter, the shallower the depth, easy to detect defects, detection effect is good. The detection system can effectively detect and identify debonding and de-lamination defects. The thermal wave signal reconstruction method is superior to the principal component analysis method and the discrete Fourier transform method in the signal-to-noise ratio index, which improves the quality of the image and is conducive to the effective identification of the image surface defect information.

In order to further improve the surface quality in LS-WEDM, a new procedure as Gas-liquid Combined Multiple Cut (the finishing is in gas) is presented and has carried on the contrast experiment to conventional WEDM multi cutting processing in the paper. the single factor and orthogonal experimental design method were used to study Effects of pulse duration, pulse interval, peak current, servo voltage and servo feed on roughness in finishing in gas, By range analysis, analysis of variance and the binary table the optimum level of the above five factors was found in consideration of the above five factors interaction. The paper provides basis for advanced study of finishing process of LS-WEDM.

This study proposed an integrated framework of applying refined Kano's model and Kano-CKM (Customer Knowledge Management) model in classifying customer requirements of Taiwan High Speed Rail in Taiwan. The traditional Kano's model does not take into account the degree of importance of quality attributes. Thus, customer requirements can be deployed more precisely, namely highly attractive, less attractive, high value-added, low value-added, critical, necessary, potential, and care-free, by refined Kano's model. On the other hand, the hybrid Kano-questionnaire of Kano-CKM model could reduce the number of questions in the survey. This study shows how refined Kano's model and Kano-CKM model can be integrated to extract more information by simplifying the surveying process in the case of Taiwan High Speed Rail. Therefore, when the type of Kano's category for a particular item is determined, the strategy can be made based on different Kano's categories. This proposed approach is to integrate refined Kan...

Using cutting speed and the roughness as index, the five factors as pulse duration, peak current, offset, ratio of pulse interval to pulse duration and worktable feed were chosen in dry finishing. Based on the single factor experiment, the central composite design (CCD) method is used to study the effects of the five factors and their interactions on cutting speed and the surface roughness and develop empirical models for cutting speed and roughness Ra. Significant order influencing cutting speed and roughness are found. The results of the verification test show that Ra regression model and cutting speed regression model have high reliability, and can achieve significant prediction effect.

This paper aims at getting the finishing process models in HS-WEDM in gas. Using cutting speed and the roughnessRaas index, the five factors of pulse-on time, peak current, offset, pulse interval ratio and worktable feed were chosen in dry finishing. The effects of the five factors and their interaction on cutting speed and the Surface roughnessRaand empirical models for cutting speed and roughnessRawere developed by performing a designed experiment based on the central composite design (CCD) experiments, significant order influencing cutting speed and roughness were found. The results of the verification test show thatRaRegression Model and Cutting Speed Regression Model have high reliability, and can achieve significant prediction effect, more accurate mathematical models are provided for the further HS-WEDM process research.

Ergodicity is the outstanding character of chaos system, and chaotic variables can be used to approach global optimal point. Aiming at the control requirements for position and speed of mobile robot, a compact PID controller parameters optimization strategy based on mutative scale chaos optimization algorithm is proposed. The Kinematics model of the soccer robot system is introduced, and the strategy of chaos optimization PID controller parameters is discussed. This optimal solution needs no prior knowledge, searches the whole parameter’s space efficiently and finds the optimal parameter, according to the given performance criteria. Simulation results show that this strategy is feasible and effective.

Evolutionary game theory originated as an application of the mathematical theory of games to biological contexts, having the advantages of truly reflecting the diversity and complexity to provide theoretical basis to study macro-control group behavior. The evolutionary game theory-based modeling and stability analysis of subsidy policy on safety investment in SMEs is studied, and the simulation about the effect of the alteration of the ratio on the evolvement results is executed. The results indicate that the safety subsidy of local governments can enhance SMEs’ enthusiasm to invest. It has excellent significance to study further how to achieve equilibrium between SMEs and local governments using evolutionary game theory, and to provide theoretical basis to study operation mode of subsidy policy on safety investment in SMEs.

This paper investigates a new process of wire electrical discharge machining (WEDM) as gas-liquid combined multiple cut. High-speed WEDM (HS-WEDM) finishing was compared in atmosphere and emulsion. Dry finishing has shorter discharge gap, better straightness and surface roughness and much higher material MRR than that in emulsion. Influences of wire winding speed and no load worktable feed on machined surface quality in dry and wet conditions were discussed. The better straightness obtained in gas is explained by analyzing forces acting on wire electrode. When first cut and second cut were performed both in emulsion liquid, and third cut was done in atmosphere, the surface roughness is improved compared with conventional WEDM.

This study investigates the dry WEDM in multiple cut. To improve surface quality with high-speed WEDM (HS-WEDM), a new procedure as Gas-liquid Combined Multiple Cut (roughing is processed in dielectric liquid, and semi-finishing is in liquid or gas, while the finishing is in gas) is presented. Effects of pulse duration, peak current, offset, worktable feed and wire length on roughness and removal rate for dry semi-finishing were studied were studied with L16(45) design, and significant order inflluncing roughness and removal rate were found. Experiment results show that multiple cut with dry WEDM in semi-finishing and finishing can improve surface roughness significantly.

This study investigates the dry wire electrical discharge machining (WEDM) in multiple cut. To improve surface quality with high-speed WEDM (HS-WEDM), a new procedure as Gas-liquid Combined Multiple Cut (roughing is processed in dielectric liquid, and semi-finishing is in liquid or gas, while the finishing is in gas) is presented. Effects of pulse duration, pulse interval, peak current, offset, wire winding speed and wire length on roughness, straightness and removal rate had been studied in dry and wet conditions. Experiment results show that multiple cut with dry WEDM in semi-finishing and finishing can improve surface roughness significantly.

This paper studies the surface quality of mould steel with high-speed wire electrical discharge machining (WEDM) method, which is conducted in gas to improve the accuracy of finish cut, and compares the surface quality in atmosphere and in emulsion dielectric. Experiment results showed that WEDM in atmosphere offers advantages such as better surface roughness and higher material removal rate. The relationship about winding speed and worktable feed on WEDMed surface quality in semi-finishing cut and finishing cut had been obtained. Morover, a new attemption was successful in applying dry WEDM in multiple cut to improve surface roughness.

Utilizing gas as the dielectric instead of dielectric liquid has enabled the development of dry wire electrical discharge machining (dry WEDM) technology for finishing cut. Experiment results showed that Low-Speed WEDM (LS-WEDM) in gas offers advantages such as better straightness, and shorter discharge gap. This paper studies on influence of different gas dielectrics, wire winding speed and pulse duration on the WEDMed surface quality (discharge gap, straightness, surface roughness, removal rate) in finishing. New attempt of applying dry WEDM as the 4th cut had been proved feasible in improving conventional multiple cut surface quality of LS-WEDM.

Chitosan nitrate (CTS-HNO 3 ) as an electrorheological (ER) material was synthesized by a simple method. The nontoxic and facile chitosan (CTS) as a substrate of the materials, as well as nitric acid were chosen as starting materials. The ER properties of the suspensions of the CTS and CTS-HNO 3 materials were researched. The CTS-HNO 3 suspension has much better ER performance than the CTS suspension. The ER effect (relative shear stress, τ r = τ E / τ 0 ) of the CTS-HNO 3 suspension (25 wt%) in silicon oil under a dc electric field reached 94 at a shear rate of 14.5 s −1 , which is eight times higher than that of the CTS suspension, where τ E and τ 0 are the shear stresses at the electric field strengths of 4.2 and 0.0 kV/mm, respectively. The formation of chitosan nitrate helped to decrease effectively the shear stress at zero electric field, and to enhance the ER effect of chitosan material markedly. The influence of the surface energy, conductivity, dielectric constant and dielectric loss tangent on the ER property of the particle materials was investigated, and the results indicate that surface energy played a predominant role. Moreover, the magnitude of the ER effect of the CTS-HNO 3 suspension was closely related to the shear rate. In addition, the chitosan nitrate had better thermal stability. The properties of CTS-HNO 3 are advantageous in its application as an ER material.

The purpose of this study was to establish a quantitative method with which to assess the post-operative recurrence of chronic subdural haematoma (CSDH).CT scans were reviewed from 44 consecutive patients with CSDHs who underwent burr hole drainage between July 2008 and January 2012. The area of the haematoma was quantified according to the mean haematoma density (MHD) using computer-based image analysis of pre-operative brain CT scans. MHD as well as other variables of patients with and without post-operative recurrences was statistically compared.Post-operative recurrence was noted in six of the 44 patients that underwent surgical procedures. Among these variables, high MHD, separated type and bilateral and skull base involvement of CSDHs were shown to be significantly related to post-operative recurrence (p0.05). Controlling for separated type in logistic regression analysis revealed the OR of MHD as statistically significant indicators with a p value of less than 0.05 (OR = 1.243; 95% CI = 1.003-1.54).This study provides statistical proof that MHD is a significant, independent, prognostic factor for the post-operative recurrence of CSDH. As such, consideration of MHD could aid in the prediction of post-operative prognosis of CSDHs.

Because of the features of small size and lack funds of small and medium-sized enterprise (Abbr. SMEs) in our country, it has seriously effect on the safety situation of our country, and their own healthy growth. The evolutionary game theory-based modeling and stability analysis of subsidy policy on safety investment in SMEs is studied, and the operation mode of subsidy policy on safety investment is introduced. It indicates that the safety subsidy of local governments can enhance SMEs' enthusiasm to invest. In the operation process of subsidy policy in SMEs, the key factor is that the SMEs in time pay enough injury insurance, and the subsidized enterprises to invest matched funds to control safety risk. For relevant departments of local governments, supervision and law execution should be enhanced to ensure the operation effect. It has excellent significance to study further how to achieve equilibrium between SMEs and local governments using evolutionary game theory, and to provide theoretical basis to study operation mode of subsidy policy on safety investment in SMEs.

In recent years, the problem of the frequent accidents in the SMEs has been a community-wide focus, which is rooted in the market failure caused by the seriously underestimated of the value of human life, Thus leading to the SME owners' lack of power and pressure in safety input. So assessing the value of human life is of great significant, also is a basic perspective for analysis of production safety management of SMEs. In this paper, on the basis of an overview of the relevant literature, using the condition-valuation approach to estimate the employees' life value and the related factors affecting their willingness to accept for compensation is also analyzed.

Safety in small and medium-sized enterprises is a major problem in China, representing about 70% of serious industrial and trade accidents in 2005. By retrospective analysis of previous related research to safety performance, this paper advanced to assess safety performance in small and medium-sized enterprises by using the ‘initiative’ indicators together with ‘passive’ indicators. The research designed an indicator system of safety performance and developed an assessment model with linguistic assessment information which is solved by LWM operator and HLWA operator. Real example shows that using ‘initiative’ indicators together with ‘passive’ indicators to assess safety performance in small and medium-sized enterprises is forward-looking and the assessment model is reliable.