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To evaluate the quality of the laser direct part marked Data Matrix symbols on titanium alloy substrates, the quality assessment methods at home and abroad were compared. A new quality assessment method of combining the effect of the laser on substrate materials and symbol grade of laser marked Data Matrix was put forward. Depending on previous research works, orthogonal experiment results were analyzed again and a modified nonlinear mathematics model was established. Analysis results indicate that this modified model can explain 90.6% of symbol contrast change and it is statistically significant. So it is better than previous linear regression model and can be used to estimate the quality of laser marked Data Matrix symbols on titanium alloy substrates. The nonlinear mathematics model can also explain the laser parameters influence on the symbol contrast.

Laser color marking experiments on titanium alloy substrates were carried out to investigate the impact of selected laser processing parameters on the resulting colors. The CIE L*a*b* color space was used to quantify these colors. The surface roughness of the marked color areas was measured by using a TR200 hand-held surface roughness instrument. The relationships between laser parameters and CIE L*a*b* values and surface roughness of the colors were obtained. Results clearly showed that different colors ranging from blue and gray to yellow were produced. Some colors can be obtained by different sets of parameters, while some colors can only be produced by a specific combination of process parameters due to the existence of different forms of heat input and thermal process. The b* value increased to the maximum which represented yellow then decreased. The surface roughness of color areas decreased with the increase of focal plane offset, scanning velocity, or hatch space.

KDP (KH2PO4) crystal is a kind of excellent nonlinear optical crystals, which has been widely used in nonlinear optical and Inertial Confinement Fusion (ICF) engineering. KDP crystal with the characteristics of low hardness, high brittleness, easy deliquescence and temperature-sensitive is easy to crack during the crystal growth, taken out from crystallizer, and the process of slicing. Stress concentration caused by the initial internal stress redistribution and the growth defect in KDP crystal is an important reason of KDP crystal cracking during sawing process. The numerical simulation model of the KDP crystal containing spherical cavity defect and sawing with fixed abrasive wire saw is established by finite element method in this paper. The effects of initial internal stress, spherical cavity defect on sawing stress are investigated. The maximum tensile stress near the defect during the sawing process is simulated and analyzed. The results show that sawing stress changes smoothly during sawing process, and the fixed abrasive wire saw slicing belongs to low stress cutting way. The sawing stress at sawing kerf is increased obviously. The crystal defect leads to local stress concentration during sawing process. The coupling effect of sawing stress with initial internal stress and the effect of stress concentration are enhanced when the sawing kerf approaches to the defect.

The paper presents a circuit topology favorable to drive piezoelectric actuators for high frequency servo valve. It begins with a short overview of different energy-saving PZA drive types and their tradeoff between efficiency and circuit complexity. Then the mechanical structure and equivalent model of the piezoelectric servo valve are described. And the circuit topology including an energy-saving oscillator, an efficient DC bias power and a repetitive controller especially for tracking reciprocating motion, is proposed. The efficiency-improved PZA drive is then derived from the above design. Finally, the drive together with the servo valve is tested in the simulation experiments.

This paper presents a new rate-dependent model for piezoelectric actuators. The proposed method directly utilizes a modified rate-dependent Prandtl-Ishlinskii hysteresis model to characterize the hysteresis and frequency effect of piezoelectric Actuators quickly and efficiently. To identify the model parameters, the least square method is adopted. Based on the identified model parameters, the rate-dependent model for Piezoelectric Actuators is established. By comparing the rate-dependent model with the real output of the Piezoelectric Actuators, the result shows that the new rate-dependent model could characterizes the hysteresis and frequency effect of Piezoelectric Actuator, which clearly demonstrates the effectiveness of the proposed Rate-Dependent Prandtl-Ishlinskii Model.

Objective A diagnostic model was established to discriminate infectious diseases from non-infectious diseases. Methods The clinical data of patients with fever of unknown origin (FUO) hospitalized in Xiangya Hospital Central South University, from January, 2006 to April, 2011 were retrospectively analyzed. Patients enrolled were divided into two groups. The first group was used to develop a diagnostic model: independent variables were recorded and considered in a logistic regression analysis to identify infectious and non-infectious diseases (αin = 0.05, αout = 0.10). The second group was used to evaluate the diagnostic model and make ROC analysis. Results The diagnostic rate of 143 patients in the first group was 87.4%, the diagnosis included infectious disease (52.4%), connective tissue diseases (16.8%), neoplastic disease (16.1%) and miscellaneous (2.1%). The diagnostic rate of 168 patients in the second group was 88.4%, and the diagnosis was similar to the first group. Logistic regression analysis showed that decreased white blood cell count (WBC < 4.0×109/L), higher lactate dehydrogenase level (LDH > 320 U/L) and lymphadenectasis were independent risk factors associated with non-infectious diseases. The odds ratios were 14.74, 5.84 and 5.11 (P ≤ 0.01) , respectively. In ROC analysis, the sensitivity and specificity of the positive predictive values was 62.1% and 89.1%, respectively, while that of negative predicting values were 75% and 81.7%, respectively (AUC = 0.76, P = 0.00). Conclusions The combination of WBC < 4.0×109/L, LDH > 320 U/L and lymphadenectasis may be useful in discriminating infectious diseases from non-infectious diseases in patients hospitalized as FUO.

The modified Reynolds equation is established on the basis of critical shear stress model, in which the circumferential and axial wall slip of sleeve and journal surface is considered. Cavitation is treated using modified Elrod algorithm that simplifies the solution of modified Reynolds equation in the full-film region. The modified Reynolds equations considering wall slip and cavitation effect for two-dimensional sleeve bearing are established. The results show that wall slip decreases oil film pressure, carrying capacity, friction drag and temperature rise but increases end leakage and cavitation region. The obtained results using the mass-conserving boundary condition are compared with the Reynolds boundary condition. Copyright © 2014 John Wiley & Sons, Ltd.

This paper presents a novel image acquisition technology for raised characters. First, laser stripes modulated with height information of raised character are captured using the 3D vision technique; then, laser stripes are combined into agrating image, in which are complete character images with grating background; Finally, a rational design Gabor kernel is applied to filter thegrating image. Through this way, the background was removed and the grayscale images of the raised characters are reserved. Experiments show that the proposed method can get the well-separated character images. Also, it is more simple and efficient than the existing methods.

Background: Assessment of hepatic fibrosis stage in patients with chronic hepatitis B (CHB) is indispensable for prognosis evaluation and therapeutic regime. Noninvasive tests are fast, safe and cheap and need low technical requirements for diagnosing hepatic fibrosis in CHB patients. Objectives: Using the latent class model with a random-factor to estimate relative accuracy of noninvasive tests for the diagnosis of hepatic fibrosis without a gold standard in a large population with CHB. Patients and Methods: A total of 544 patients with CHB were assessed for fibrosis stage by four noninvasive tests containing liver stiffness measurement (LSM), aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis index based on 4 factors (FIB-4) and globulin and platelet (GP). The diagnostic evaluation was made by the latent class method with random effect which analyzed the clinical data above to assess the accuracy of four ways of noninvasive diagnosis. Results: The latent class model with random effect permitted to conciliate the observed data and estimates of test performances. For significant fibrosis, the specificity/sensitivity were 83.24%/91.59% (APRI), 90.05%/95.57% (FIB-4), 75.11%/66.01% (LSM) and 71.13%/98.33% (GP), respectively. For cirrhosis, the specificity/sensitivity were 84.04%/17.91% (APRI), 89.86%/17.09 (FIB-4), 78.64%/37.07% (LSM) and 82.28%/37.07% (GP), respectively. Conclusions: FIB-4 confirmed the best value for diagnosis of significant fibrosis. APRI had a sub-optimal diagnosis accuracy for significant fibrosis. LSM showed the most balance diagnosis value for cirrhosis with the highest sensitivity and moderate specificity.

Objective: To investigate the association between the change of IGF-2 level in serum after transcatheter arterial chemoembolization (TACE) and hepatocellular carcinoma (HCC) progression, especially in relation to metastasis. Methods: IGF-2 in serum was measured by quantitative sandwich enzyme-linked immunosorbent assaybefore, 3 days and 4 weeks after TACE in 60 patients with HCC. The occurrence of HCC metastasis was also evaluated, 3 months after TACE. Results: (1) The average serum level of IGF-2 in the 60 patients with HCC was 136.5 ± 87.3 pg/ml; (2) A tendency for increase was observed with heterogenous uptake of octreotide and portal vein thrombosis. Metastatic foci were found in 37/38 patients in the group with IGF-2 increasing (97.0%), in contrast to 3/22 (13.6%) patients with IGF-2 decrease. Conclusion: The increase of IGF-2 level in serum appears to be associated with the occurrence of metastatic HCC after TACE and chemotherapy.

To inspect the surface quality of steel bar, we designed an automatic system including linear camera and laser. Through the comparison among kinds of cameras, we select linear CCD to our system. The laser is also chosen by us with its high luminance and performance. Through a series of computation, we select the appropriate camera lens to our device. At last, we draw the whole detection system. This device has been used well and provides a good foundation for prospective image processing.

Because of shortcomings of images of motion objects in deep space，including non-uniform distribution of background pixels，low SNR, general 1ow picture quality and small size，a novel image segmentation algorithm based on the combination of image gradient and its variance is adopted. An algorithm to compute the correlation coefficient based on the small region template matching is presented. The algorithm overcomes the disadvantages of correlation disturbed frequently by noise, and size difference, besides it also reduces the computational complexity and improves the speed of the system．Experiments show that the algorithm has great accuracy，high speed，and good stability，and can meet the requirements of a real-time system.

A new inspection algorithm based on local annular contrast (LAC) for steel bar surface defects is presented. Because of little fluctuation of gray value inside the defects, traditional gradient detection methods could not find the defects accurately and often mistake the boundary of the bright region in center for defects. The LAC-based algorithm doesn’t have this disadvantage. Defects in images can be found due to their large contrast with local annular background (LAB). After average filter to steel bar surface image, the noise could be smoothed to a great extent but the contrast between defects and LAB changes very little. Then the LAC-based algorithm is applied to inspect defects. Experimental results show that the proposed algorithm needs only 13 ms to inspect one steel bar surface image and its detection accuracy exceeds 95%.

A new algorithm based on local gradient is proposed to inspect steel rod surface defects. The local gradient method can weaken the effect of noise in steel rod surface image. Then the open operation of morphology theory is employed to remove the retaining noise. Experiments show that this algorithm is effective to inspect steel rod surface defects and is time-saving.

This paper studies of laser parameters for direct-part marking Data Matrix symbols on aluminum alloy by using Nd:YAG laser. Different laser parameters and the resultant can affect the barcode grade profoundly. The experiment focuses on all interval values of the vector step, inter-step time, laser Q frequency and laser Q release time. From the experiment results, the relationship between laser parameters and barcodes grade was found, and thus determined the optimal laser parameters. By analyzing the higher and the lower power density processing module SEM images and EDS data, it was found that the microstructure and micro-components of formations that created by the interaction between the laser and the aluminum alloy can affect the barcodes grade level significantly. We also found that the interaction between the laser and the aluminum alloy can be divided into four stages.

Different laser parameters and the interactional production can affect the barcode grade profoundly. In order to mark barcodes on aluminum alloy with a laser effectively, it is important to search out the optimum parameters and establish a relationship between critical laser parameters and the quality of the symbol. In this research, a Nd:YAG laser was utilized to produce 3136 Data Matrix symbols onto aluminum substrates. The experiment focuses on all interval values of the vector step, inter-step time, laser Q frequency and laser Q release time. From the experiment results, the optimized parameters are the vector step of 0.005~0.009 mm, the inter-step time of 29~43 μs, laser Q frequency of 7~10 KHz, and laser Q release time of 13~19 μs. And then, by analyzing the higher and the lower power density processing module SEM images and EDS data, it was found that the microstructure and micro-components of formations that created by the interaction between the laser and the aluminum alloy can affect the barcodes grade level significantly.

Rolling steel surface defect inspection technology based on machine vision is more and more widely used. The latest progress of vision-based real-time inspection algorithm for rolling steel surface defect at home and abroad is introduced, and several key issues are analyzed. Finally, the current domestic research emphases and development trends are proposed.

Laser current is a key parameter in laser direct-part marking symbols on a substrate. Different laser current can create enormous impact on bar code contrast, but the influencing regularities are unclear. In this paper, a new significance test method based on the multivariate nonlinear model was proposed to investigate the influencing regularities. First, the multi-element nonlinear stepwise regression model between the laser current, the laser line spacing and symbol contrast was established, and then the model significance test was employed to evaluate the influence between the two factors and symbol contrast. Finally, the influencing regularities were found by comparing the influence between the laser current and the laser line spacing. These regularities are that along with the laser current value increasing the influence of laser current on symbol contrast decreases and that the effect is much smaller and can even be neglected when the laser current reaches or exceeds a certain value. This certain value is 15 A in the Nd:YAG laser Direct-part marking symbols on the aluminum alloy experiments.

Objective To determine whether preoperative inspiratory muscle training was associated with a significant difference in the rate of postoperative pulmonary adverse outcomes in patients undergoing cardiothoracic or upper abdominal surgery using trial sequential analysis to correct for the risk of random errors. Methods We systematically reviewed the Excerpta Medica database, PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Central Register of Controlled Trials for randomized controlled trials evaluating inspiratory muscle training before cardiothoracic or upper abdominal surgery. Outcome measures included postoperative pulmonary complications, length of hospital stay, maximum inspiratory pressure, and quality of life. A random-effects model was used to estimate relative risks with 95% confidence intervals (CIs). We used trial sequential analysis to calculate a diversity-adjusted required information size for meta-analysis. Results Thirteen randomized controlled trials were included in the meta-analysis for a total of 784 patients. Compared with the standard care group, the inspiratory muscle training group exhibited significantly decreased postoperative pulmonary complications (risk ratio, 0.59; 95% CI, 0.47-0.74). Trial sequential analysis indicated that the cumulative Z curve crossed both the conventional boundary and the trial sequential monitoring boundary for benefit. The length of hospital stay was reduced in the inspiratory muscle training group (mean difference, −1.15 days; 95% CI, −2.10 to 0.20), and the maximum inspiratory pressure was significantly improved at the end of the preoperative training (mean difference, 13.66; 95% CI, 3.88-23.44). The quality of life outcome was unavailable in most of the studies. Conclusions Preoperative inspiratory muscle training resulted in significantly improved maximum inspiratory pressure and was associated with decreased postoperative pulmonary complications.

A method of vibration analysis for mechanical fault detection based on adaptive noise canceling(ANC) and envelope analysis was presented. The adaptive filtering was used for noise canceling and feature extraction from vibration signal measured for the detection. The envelope analysis based on analytic wavelet was also used for the fault detection. Experiment shows that the method proposed in this paper is very effective for reducing noise, and for vibration analysis to discriminating the fault types with a high accuracy.

In this paper, we propose an improved method of phase generated carrier (PGC) combined with 3×3 coupler to extend dynamic range and compensate low-frequency drift of modulation depth. The small amplitude signal(≤10 -2 rad) is figured out by the PGC method to keep the minimum phase resolution and the large amplitude signal(≥10rad) can be calculated by the 3×3 fixed phase difference algorithm to extend the maximum amplitude of the dynamic range. We can get the same result to the signal with the normal amplitude(10 -2 rad≤D≤10rad) by any two kinds of methods. Furthermore, the modulation carrier wave amplitude and frequency information can be monitored by the 3×3 auxiliary algorithm to compensate low-frequency drift of modulation depth and keep the system stability as a feedback. According to the result, the interferometer is able to resolve 2.0 ×10 -5 rad/√Hz with a dynamic range of 182.2dB@10Hz frequency and 2Mbps sample rates.

In this paper, we present an improved fixed phased demodulation method combined with phase generated carrier (PGC) and ellipse fitting algorithm (EFA) to enhance the phase resolution and suppress the total harmonic distortion (THD) caused by the laser intensity disturbance (LID) of modulation phase. We make the subtraction operation to the outputs of the two 1×2 couplers to get the differential signals without DC offset, which is used to achieve the fixed phase demodulation. The EFA is applied to construct the standard quadrature signals with the two signals. The last output is utilized to finish the small amplitude (

This paper focus on the strain characteristic of the fiber-optic flexural disk accelerometer based on the multilayer sensing fiber coils. The strain state is analyzed in theory, and by using the simulation software, we built the simulation model and obtain the strain distribution of the multilayer sensing fiber coils in different bonding position of the flexural disk. The strain theoretical model agrees well with the strain distribution obtained by the simulation model. According to the results, a flexural disk accelerometer is produced. Experiment results show that the phase sensitivity is 6814rad/g, which is equivalent to the acceleration sensitivity of 15ng/Hz1/2.

A method of simultaneous evaluation for two branches of a multi-functional integrated optic chip (MFIOC) with a dual channel system is proposed. The difference between the two branches of the MFIOC can be tested simultaneously with a high precision. In the system, the chip is used as a 1×2 splitter and its two branches are combined by a 2×2 coupler. The characteristic peaks of the two branches are distinguished by selecting proper length of the extended fibers which connected to each polarization-maintaining (PM) pigtails. Temperature responses of the two branches of the MFIOC are experimented. Results show that the dual channel system can simultaneously measure the characteristics of the two branches of MFIOC with resolution of over -85 dB and dynamic range of 85dB.

In accordance with the obvious characteristics of the pressed raised character image and the shortages of the template matching method.a new method of using the general radial-basis function neural network (GRBFN) for testing the quality of the pressed character is presented. The structures and training methods of GRBFN are fully analyzed, as well as the functionality of hidden layer, excited focus and area. The results show the checker based on GRBFN has highly checking ratio for the label pressed raised characters. It is suited to the quality testing of raised characters.

This paper will be devoted to build a mathematical model of this kind based on the computer-controlled AC servo feed system of a common XY worktable. First, a practical AC servo worktable system is analyzed and its linear theoretical mathematical model is given. Second, the parameter in this model is identified in terms of the actual measured output data and reference signal by using an ARX model by using RLS identification method. Then, by using servo “simulation” techniques, a very accurate model of the servo drive can be constructed. Based on this model, it is possible to observe the effect on performance by changing the factors such as backlash, friction, servo-loop gains. Hence, a deep understanding of dynamics of the computer-controlled AC servo feed system of a common XY worktable is obtained. It is expected that this paper will lay reliable foundation for the further work—friction compensation, so that the precision of the system will be improved in the end.

Hemorrhagic fever with renal syndrome (HFRS) is caused by hantavirus infection, which was characterized by abrupt high fever, systemic hemorrhage, hypotension and renal damage. Although multiple system organ damage was not uncommon, but multiple organ system failure were rare. Hereafter we report one case with simultaneous renal, heart and liver failure. In this case, we received some experience and lessons.

A white light temporal interferometric technique for measurement of the quasi-distributed birefringence dispersion (BD) in a polarization maintain (PM) device with high accuracy based on weighted least square (WLS) method is presented. It is verified theoretically and experimentally that the accuracy of WLS method and the conventional ordinary least square (OLS) method both are proportional to the signal-to-noise ratio (SNR) of interferogram, whereas the WLS method holds a higher scaling factor because it is more suitable for heteroscedastic model that has unequal error variance. The experiment results show a repeatability of ~4.6 × 10(-5) ps/nm @ 1550 nm with WLS method for 100 sets of data, and ~4.3 × 10(-4) ps/nm with OLS method, for an interferogram with SNR of 30 dB. Besides, WLS method without iterative operation is carried out by using power spectrum of interferogram as weight value. The feasibility of this technique is demonstrated by distinguishing the quasi-distributed BD of every part for a packaged Y-waveguide with two 1m-long PM pigtails.

According to the finite differential method, the influences of the spiral angle and eccentricity ratios on moving of cavities of novel spiral oil wedge hybrid journal bearing are presented. Numerical results show that moving of cavities is great related with spiral angle and eccentricity ratios, then the change of them make moving direction of cavities entirely inverse, and make the rupture location great different. And that it makes us know well the position of the cavities erosion before the test measurement.