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On-machine measurement is a high-efficient measure method in NC machining, and there are pre-travel errors during measurement. What is more, these errors tend to present anisotropy, and affect the measurement accuracy. This paper aimed at measuring the anisotropy of probe’s pre-travel error. First, the standard ball is measured by changing the probe angle with the same machine tool moving direction, and the pre-travel errors with different probe angles under the same machine tool errors are obtained. Then, the machine tool backlash errors are measured and compensated, and the pre-travel errors with different probe angle are obtained. Finally, the mathematical model of pre-travel error is established. The method proposed in this paper can be used to determine probe’s pre-travel error with anisotropy.

It is becoming a development direction to study green forming process in mechanical. The processing technology of machining deep hole in relative thin sheet is a kind of green mechanical processing technology in this paper. The process uses the friction between driller and workpiece and plasticity of workpiece to form hole. The new technological process not only saves material, but also saves man-hours, and the workpiece has a good piece of assembly. In this paper, the forming process of deep hole on thin sheet was simulated, and some effect factors of forming hole were studied, such as the stress, temperature and shape of forming area, etc. The forming simulation is proved to be feasible by the test in this paper. The study results are useful to improve the machining parameters, and laid a foundation for further research on forming deep holes process on thin sheet metal by friction heat.

Bayesian method was introduced and leaded into the vehicle fault data processing. The parameter estimation and the selection of the optimal distribution model based on Bayesian method were studied, and an example was given. The references are provided for the application of Bayesian method in the large complicated systems, such as vehicle equipments.

It is difficult to identify whether the ECS of a engine can overcome the HEMP environment, and if there are influences existing, how it will be affected and what extent it can. On the basis of discussing the occurring mechanics and characteristics of HEMP, a route to study the effects of the engine ECS under HEMP environment has been researched. Through the simulation of the HEMP, a laboratory test has been designed and carried out, and the influence of the engine ECS under HEMP has been analyzed. The research indicated that the engine ECS is susceptibility to the HEMP, the main damage mode is soft and transiency damage, it can make the control signal confusion and can even result in the suspension of work, but it can not make permanent hard damage to the ECS, and there are no evidence to show that the HEMP can result in an accumulation damage to the tested engine ECS.

This paper reviews shearography and its applications for testing of aircraft composite structures and honeycomb-based specimen. Shearography is a laser-based interferometry in conjunction with the digital imaging processing technique for full-field measurement of surface deformation. It reveals defects in an object by looking for defect-induced deformation anomalies. It does not require special vibration isolation, and with the development of a small and mobile measuring device (portable inspection system), it can be employed easily in field/factory environments.

Based on the principle of a screw seal, a new type of seal consisting of a series of screw seals was developed and named as an axial pumping baffle seal. A theoretical analysis model was presented for such a seal which was developed to be used in nuclear coolant pumps. The feasibility of sealing high-pressure medium for such a seal had been proved. The variation of leakage rate and pressure distribution between a tooth and a sleeve with the number of seal stages and the geometrical parameters of screws was studied. The sealing mechanism was presented. The results showed that such a new seal maybe replace the first stage seal of a series mechanical seal used in a nuclear pump. When the number of screw seals is about 9, the reliability is ensured by the cooperation of the “attack” of the screw seal and the “defense” of the 180° sharp back bend.

Experiments of four reinforced concrete (RC) two-span T-beams were introduced. During the experiment, one T-beam was normal temperature control T-beam, and the other three T-beams were heated 75 minutes under ISO-834 standard fire (ISO 834, 1975). Among these three T-beams, One T-beam was unstrengthened control T-beam, and the other two T-beams were strengthened with carbon fiber reinforced polymer (CFRP) sheets. The same test setup was used to loading tests of four T-beams. The results showed that the midspan yield load, ultimate load, stiffness and ductility of the fire-damaged continuous T-beams decreased comparing with these of the normal temperature control T-beam, while ductility and stiffness dropped more sharply. External strengthening with CFRP sheets was found to increase the load capacity and stiffness of T-beams, but the ductility of Tbeams dropped. The way of strengthening using CFRP influenced the moment redistribution of the fire-damaged continuous Tbeams. Tensile rupture of the CFRP sheets was the only failure mode for the strengthened T-beams. The way of moment redistribution of T-beam changed greatly because of the influence of fire. Different from the normal temperature T-beam, the fire-damaged continuous T-beams had obvious moment redistribution at the beginning of the loading because of the variable stiffness along the length of the T-beams. The relationship between stiffness ratio and moment ratio of the continuous beams was deduced as well.

Since almost large die surfaces are free-form surfaces, currently, these are almost manually implemented. In order to overcome this barrier, floating polishing is a feasible polishing technology. The contact friction between polishing disk and workpiece is a key problem of floating polishing technology. This paper tries to study the contact friction between polishing disk and workpiece with ANSYS analysis software. At first, the paper focuses on the contact friction between polishing disk and plane workpiece by ANSYS analysis software, then focuses on the contact friction between polishing disk and cylinder and sphere workpiece with the software. The analysis results show the hypothesis of full friction condition is feasible. The research results will be used for developing the floating polishing.

The intelligent control of simulation target with infrared imaging target in the indoor and outdoor environment can effectively and quantitatively evaluated the parameters such as the minimum resolution temperature difference（MRTD）and spatial resolution of airborne forward looking infrared, infrared detection and tracking, infrared alarm, and etc. This paper focused on introducing the working principles of the intelligent control simulation target of Infrared imaging target, studying the thermal radiation characteristics of the infrared target surface material, analyzing the influences of the infrared radiation energy distribution, and developing the intelligent control simulation target with IR imaging target for hardware-in-the-loop simulation test. The intelligent control simulation target which area was 5 ㎡ and concluded 44 infrared targets including two kinds of infrared targets ,0.25ｍ×0.25ｍ, and 0.25m×0.5m, achieved 1℃～10℃ temperature simulation of target and the background, and temperature control precision better than 0.5℃. Field test requirements were achieved by actual test.

In order to provide a set of field test equipment for the infrared system of modern weapon equipments and other optics instruments, a set of large-scale resistance-type infrared target system was designed. First, the large-scale infrared target was designed in modular construction. It was decomposed into several independent and controllable units. Then the working principle of the system was introduced. Three modes of thermal exchange (conduction, convection and radiation) and the computing methods for each mode were given under thermal equilibrium conditions through modeling and simulating. Periphery electro-circuit and control software were carried out as well. Finally, the performance of the system was tested. Meanwhile novel ways of temperature compensation to improve the uniformity of the surface temperature of the target was introduced. The experimental results show that the infrared target could meet test requirements for infrared imaging weaponry which wavelengths from 8 μm to 14 μm. The temperature control precision can reach 0.5ms. In conclusion, the infrared target system can satisfy requirements of reliability, high precision, as well as strong anti-jamming and stabilization.

A novel bend-insensitive long-period fiber grating (LPFG) sensor written using focused CO 2 laser pulses is demonstrated, for the first time, to our knowledge. It is found that the central wavelength shift of such a LPFG is only −0.018 nm even for a curvature of 1.1 m −1 at the most bend-insensitive position of the LPFG. Experimental results show that the bend sensitivity of the central wavelength of the LPFG has a periodic distribution along its circular directions. Such a bend-insensitive sensor could be used to solve the problem of cross-sensitivity between bend and other measurands, such as temperature, strain or refractive index, which is an unsolved problem for LPFG sensors in practice. In addition, the bend sensitivity of the LPFG can be adjusted by selecting its circular positions.

Simultaneous strain and temperature measurement for advanced 3-D braided composite materials using fibre-optic sensor technology is demonstrated, for the first time. These advanced 3-D braided composites can virtually eliminate the most serious problem of delamination for conventional composites. A tandem in-fibre Bragg-grating (FBG)/extrinsic Fabry-Perot interferometric sensor (EFPI) system with improved accuracy has been used to facilitate simultaneous temperature and strain measurement in this work. The non-symmetric distortion of the optical spectrum of the FBG, due to the combination of the FBG and the EFPI, is observed for the first time. Experimental and theoretical studies indicate that this type of distortion can affect the measurement accuracy seriously and it is mainly caused by the modulation of the periodic output of the EFPI. A simple method has been demonstrated to improve the accuracy for detection of the wavelength-shift of the FBG induced by temperature change. A strain accuracy of ∼ ±20 μe and a temperature accuracy of ∼ ±1 °C have been achieved, which can meet the requirements for practical applications of 3-D braided composites. © 2002 Elsevier Science Ltd. All rights reserved.

By applying Fourier mode coupling (FMC) theory to the Bragg gratings (BGs) with the effects of Gaussian-apodization, phase shift, superstructure, and linear chirp, the calculations of their reflectivities are fast and accurately achieved, and compared with the practical cases and those on the transfer matrix (TM) method used widely. The results indicate that the FMC theory can be used for the real-time analysis and control in the design and fabrications of nonuniform BG and its mask, of which the efficiency is about several-thousand times that of the TM method.

Cell therapy has shown its power to promote diabetic chronic wound healing. However, problems of scar formation and loss of appendages have not yet been solved. Our study aims to explore the potential of using embryonic skin cells (ESkCs) to repair diabetic wounds. Circular wound was created on the back of the diabetic mice, and ESkCs stained with CM-DIL were transplanted into the wound. Wound area was recorded at the day 4, 7, 11, and 14 after transplantation. The tissue samples were obtained at week 1, 2, and 3, and the tissue sections were stained by transforming growth factor β1 (TGF-β1), TGF-β3, vascular endothelial growth factor (VEGF), and CD31. The new skin formed on the wound of the diabetic mice with ESkC treatment at week 1 but not on the wounds of the non-treatment group. The histological scores of diabetic group with ESkC treatment were significantly better than the non-treatment group ( P

Experiments of seven reinforced concrete (RC) two-span T-beams were introduced. During the experiments, one T-beam was normal temperature control T-beam, and the other six T-beams were heated under ISO-834 standard fire. All T-beams had the same geometrical dimensions and reinforcement as well as the loading and support arrangement. The fire-damaged T-beams were classified into two groups according to the fire exposure time. Different fire exposure time including 60 minutes and 75 minutes were investigated. In each group, one T-beam was unstrengthened fire-damaged control T-beam, and the other two T-beams were strengthened with carbon fiber reinforced polymer (CFRP) sheets after fire. The results showed that midspan yield load, ultimate load, stiffness and ductility of the fire-damaged T-beams decreased comparing with these of the normal temperature control T-beam, while ductility and stiffness dropped more sharply. External strengthening with CFRP sheets was found to increase the load capacity and stiffness of T-beams, but the ductility of T-beams dropped. Different from the normal temperature T-beam, the fire-damaged T-beams had obvious moment redistribution at the beginning of the loading because of the variable stiffness along the length of the T-beams. The moment redistribution of fire-damaged RC continuous T-beams changed greatly because of the influence of fire. Under the same heating curve, fire exposure time was one important factor that influences the moment redistribution of fire-damaged RC continuous T-beams. The way of strengthening using CFRP influenced the moment redistribution of the fire-damaged RC continuous T-beams. Tensile rupture of the CFRP sheets was the main failure mode for the strengthened fire-damaged RC continuous T-beams. The relationship between stiffness ratio and moment ratio of the continuous beams was deduced as well.

A novel technique for simultaneous measurement of static strain, temperature and vibration in health monitoring of structures is demonstrated using an integrated in-fibre Bragg grating (FBG)/extrinsic Fabry-Perot interferometer (EFPI) sensor. The EFPI sensor provides static strain and vibration information simultaneously by using the channel-spectrum method and the low-coherence interferometric technique, respectively. The FBG sensor is used for temperature measurement. The experimental results show that a static-strain accuracy of ±20µe, a temperature accuracy of ±1°C and a vibration resolution of 1 nm have been achieved with a good repeatability.

Aiming at the problem of existing component composition little attention to their reliability, a trusted component composition approach is proposed based on neuron component. The method which simulates the information transmission behavior of biological neurons completes message transmission and composition between components. First, it proposes the concept of neuron component and connector. Then the method sets the parameters of component threshold and calculates it using cloud model theory. After defining the states and states transition of the component, it puts forward four operation rules and utilizing them to complete the component composition with graphics mode. Finally, taking simple calculator as an example shows the effectiveness of the method.

This paper presents the field programmable gate array (FPGA) implementation of the Advanced Encryption Standard (AES) with handshake protocol to resistant differential power analysis (DPA). DPA is a powerful side-channel analysis (SCA) attack. A SCA attack takes advantage of implementation specific characteristics to recover the secret parameters involved in the computation. We propose a DPA-resistant design method with handshake protocol to make the power traces misaligned. AES algorithm was implemented in Xilinx Spartan III-E FPGA device using the structure of handshake protocol. At last, an experiment platform was built to prove that the design has ability to resistant the differential power analysis.

To make software system adapt the change of user's demand, the environmental variation in running period and to make the software system better satisfy user's application request, a service-oriented dynamic evolution model named SOEM model is proposed in this article. Firstly, based on analyses existing evolution method, introduce the SOA to software evolution. Then give the formal description of a series of concept in service-oriented software evolution process. Define the ruler of service-oriented evolution and the process that based on this evolution ruler. Finally apply SOEM model in a process management system and it has proved that this model has the good ability of evolution.

Predictive Control Systems are usually designed through "trade-off". Tuning parameters are selected according to experiences. Simulations are often required to test the design results. This is not suitable for the industrial users. In this paper, the dynamical behaviour and the closed-loop robustness of the generalized dynamic matrix control systems are quantitatively analysed based on the internal model control structure. For a class of industrial processes, analytical results about the system dynamics and robustness are obtained. A software packet is developed for the industrial users to design the predictive control systems automatically.

In this letter, we present a novel sensor approach allowing fast measurement of temperature. It consists of a chirped fibre Bragg grating (CFBG) and an extrinsic Fabry-Perot interferometric sensor (EFPI) in series. Both EFPI and CFBG are well integrated to provide local strain and temperature information respectively, using wavelength-division-multiplexed (WDM) technique. As the wavelength-shift of the CFBG is detected via intensity variation, the speed for temperature measurement can be very high (

In this paper, a single long-period fiber grating (LPFG) element written by focused high-frequency CO2 laser pulses is demonstrated for simultaneous measurement of transverse load and temperature, for the first time, to our knowledge. Temperature and transverse load can be directly measured by detecting the resonant wavelength shift and the resonant peak amplitude change of the LPFG respectively, as there are two special circular orientations along the fiber axis where the resonant peak amplitude change of the LPFG has a linear relationship with the load applied and is insensitive to the resonant wavelength shift. Such a sensor could solve the cross-sensitivity problem between transverse load and temperature due to the unique feature of this type of LPFG, i.e. the wavelength-load-sensitivity of the LPFG strongly depends on loading orientations due to the non-uniform distribution of the refractive index on the cross-section of the LPFG caused by the thermal shock effect and other effects of the high-frequency CO2 laser pulses exposure method used.

A novel fibre-optic sensing system used for temperature- strain discrimination is presented. This system consists of an extrinsic Fabry-Perot interferometric sensor (EFPI) and a chirped in-fibre Bragg grating (CFBG) in series. The EFPI and the CFBG are wavelength-division multiplexed to provide strain and temperature information, respectively. The wavelength-shift of the CFBG induced by temperature change at the 1.55μm region is interrogated with an intensity- based scheme, allowing fast measurement of temperature. The cavity length change of the EFPI is measured at the 1.3μm region, allowing strain to be measured without cross-talk from the temperature sensor, i.e, the CFBG. Experimental results show that the achieved accuracies for strain and temperature measurement are ±20μe and ±2°C, respectively.

In this paper, we describe low-noise Er-doped optical fiber amplifiers (EDFAs) achieved byexploring novel long period fibre gratings (LPFGs) written by high-frequency CO2 laser pulses. This new LPFG fabrication technique is based on the thermal shock effect of high-frequency CO2 laser pulses at several kHz. By inserting such a LPFG in the Er-doped fibre, the ASE (Amplified Spontaneous Emission) noise of the EDFA has been reduced considerably. Two low-noise EDFAshave been constructed and demonstrated. The ASE noise of the two EDFAs used as a pre-amplifier and an in-line amplifier has been successfully reduced from 4.0dB to 3.5dB and from 4.8dB to4.3dB with a small-signal gain increase of7dB for the in-line amplifier, respectively. Keywords: Er-doped optical fiber amplifiers (EDFAs), ASE noise filters, In-fiber gratings. 1. INTRODUCTION Er-doped optical fibre amplifiers (EDFAs) with a low noise figure are critical for realizing high-performance optical fibre communication systems, especially for pre- and in-line amplifiers.

Analytic solutions (ASs) for the spectral responses of waveguide devices with raised-cosine-apodized (RCA) gratings are presented. The waveguide devices include short- and long-period RCA-gratings, RCA-grating-based interferometers as Fabry—Perot, Mach—Zehnder and Michelson interferometers. The calculations based on the analytic solutions are demonstrated and compared with those based on the transfer matrix (TM) method preferred, which has confirmed that the AS-based analysis is with enough accuracy and several thousands times the efficiency of the TM method.

A novel theory, namely, Fourier mode coupling (FMC) theory for fiber Bragg gratings (FBGs) is proposed in this paper. During analyzing coupled modes of FBGs, the Fourier transform relations among the amplitude coefficients of coupled modes are found for the first time. The general expressions of reflective and transmissive spectra of FBGs are deduced from the combination of Fourier transform with the well-known coupled-mode theory. In the proposed FMC theory, the spectral characteristics of the FBG are achieved by the calculation of coupled modes in the spatial domain spectrum, which is the Fourier transform result of refractive index perturbation in the FBG. The FBG spectrum based on the FMC theory is simulated here, and compared with those obtained from the coupled mode theory and pure Fourier transform. The comparison shows that the FMC theory for and the derived spactra of FBGs are in accordance with the coupled mode theory and the practical spectra of the FBG respectively. The FMC theory has many features, these being simple, clear, direct, accurate and fast, which could be used as a universal tool for fast spectrum analysis of any FBG with an arbitrary distribution of refractive index perturbation along the fiber axis.

A novel theory, namely, Fourier mode coupling (FMC) theory for long-period fiber gratings (LPFGs) is proposed in this paper. During analyzing the co-propagating coupling between the core mode and cladding modes in LPFGs, the Fourier transform relations among the amplitude coefficients of co-propagating coupled-modes are found for the first time, to the best of authors’ knowledge. The general expressions of the coupling and transmission spectra of LPFGs are also deduced from the combination of Fourier transform with the well-known coupled-mode theory. In the proposed FMC theory, the spectral characteristics of the LPFGs without over-coupling are derived from the calculation of co-propagating mode coupling in the spatial domain spectrum, which is the Fourier transform result of refractive index perturbation in the LPFG. According to the FMC theory, the spectra of the LPFGs in different perturbation amplitudes and lengths are numerically simulated here. A measured transmission spectrum is also compared with the calculated transmission spectra based on the FMC theory and the coupled mode theory, respectively. The comparison shows that the FMC theory and the derived spectra for LPFGs are in consistance with the coupled-mode theory and the practical spectra of LPFGs respectively. The FMC has many features, these being simple, fast and accurate, which could be employed for spectrum analysis of any LPFG with an arbitrary distribution of refractive index perturbation along the fiber axis.