Real and Complex Analysis

The current status of enterprise equipment management and maintenance management is briefly described.Through analysis of system functional requirements of the production site.the framework of a statistical analysis system of production line fault based on network and the function modules are presented in detail.The system database structure is designed by using MYSQL.The fault prediction model based on RBF Neural network is proposed.Based on B/S structure,Microsoft Visual Studio2008 c # as a programming language with MySQL database,the production line fault statistical analysis system based on network is developed.The system is applied in the statistics and analysis of a camshaft production line failure and proved the effectiveness.It also provides a practical tool for production line equipment maintenance and management for the enterprise.

Statistical analysis system of production line fault based on internet

The materials used in the study consisted of 720 small clear specimens of nominal dimensions 20 x 20 x 60 mm, of Turkish Red Pine (Pinus brutia) Lebanon cedar (Cedrus libani), Oriental beech (Fagus oriantalis), and English oak (Quercus robur ) from Turkey. The specimens were grouped into 4 batches of 15 specimens each and were tested in the ETH laboratories in Zurich, Switzerland. The influence of EMC was studied over four batches of 15 specimens each, conditioned for 6-8 weeks before testing at a temperature of 20 ± 2oC and at four different relative humidities (50%, 65%, 85%, and 95%). Time of flight value was measured with an ultrasonic commercial device Steinkamp BP-V. Measurements were made end to end directions (L, R, T) on each specimen, with a constant sensor coupling pressure. According to the time results of ultrasound devices, the wave velocities (length/time) and Edyn were calculated. Samples were also tested in uniaxial compression in order to determine E values in three orthotropic directions using a Zwick Z 100 universal testing machine. A load cell with 100-kN maximum capacity was used for compression tests performed in all directions. The feed rate was defined in such a way that the failure of the specimen should be reached in 90 (±30) s. The strains were evaluated using the digital image correlation DIC technique. Wood MC was determined by the oven-drying method. The R values between E and Edyn ranged from 0.79 to 0.96 for the species tested. Moisture content seems to be an influencing factor on sound velocities.

Proceedings: 19th International Nondestructive Testing and Evaluation of Wood Symposium

The American Society for Testing and Materials, through the Optically Pumped Laser Section - Committee F1.02, is developing standard test methods and practices for optical testing, evaluation, and fabrication. These standards are developed within a framework of producer, user, and general interest persons by obtaining a consensus. Each test method is subjected to round-robin testing and carries with it a validated precision statement. This paper describes these optical test methods and invites suggestions and contributions of effort in the Section toward additional optical and laser standards. Nine ASTM standards are reprinted for easy reference by optical scientists.

Optical Standards And The American Society For Testing And Materials (ASTM)

Whole Timber Construction: A State of the Art Review

Two important wood properties are stiffness (modulus of elasticity or MOE) and bending strength (modulus of rupture or MOR). In the past, MOE has often been modeled as a Gaussian and MOR as a lognormal or a two or three parameter Weibull. It is well known that MOE and MOR are positively correlated. To model the simultaneous behavior of MOE and MOR for the purposes of wood system reliability calculations, we introduce a bivariate Gaussian–Weibull distribution and the associated pseudo-truncated Weibull. We use asymptotically efficient likelihood methods to obtain an estimator of the parameter vector of the bivariate Gaussian–Weibull, and then obtain the asymptotic distribution of this estimator.

/pdf/asymptotically-efficient-estimation-of-a-bivariate-gaussian-o1boxk4cor.pdf

Asymptotically Efficient Estimation of a Bivariate Gaussian–Weibull Distribution and an Introduction to the Associated Pseudo-truncated Weibull

Approximately 375 Douglas-fir and ponderosa pine logs, 3 to 6 inches in diameter, were tested in third-point bending and in compression parallel to the grain. The moisture content at time of test was about 14 percent. Good correlations were found between the modulus of elasticity (MOE) in static bending and those obtained by transverse vibration. Good correlations were also found between modulus of rupture (MOR) and MOE. A species independent relationship was established between ultimate compression stress parallel to the grain and MOR. A mechanical grading system previously developed for 9-inch diameter logs was shown applicable to small-diameter logs.

https://www.fpl.fs.fed.us/documnts/pdf2008/fpl_2008_green004.pdf

Grading and properties of small-diameter Douglas-fir and ponderosa pine tapered logs

https://www.fpl.fs.fed.us/documnts/fplrp/fpl_rp671.pdf

An Evaluation of a Proposed Revision of the ASTM D 1990 Grouping Procedure

Two important wood properties are the modulus of elasticity (MOE) and the modulus of rupture (MOR). In the past, the statistical distribution of the MOE has often been modeled as Gaussian, and that of the MOR as lognormal or as a two- or three-parameter Weibull distribution. It is well known that MOE and MOR are positively correlated. To model the simultaneous behavior of MOE and MOR for the purposes of wood system reliability calculations, we introduce a bivariate Gaussian–Weibull distribution and the associated univariate pseudo-truncated Weibull (PTW). We note that theoretical arguments suggest that the strength distributions of grades of lumber are likely to be PTW rather than Weibull. We describe a Web-based program that fits bivariate Gaussian–Weibull data sets (and thus fits PTW distributions to MOR data). We present data that demonstrate that strength distributions of visual grades of lumber are not Weibull and do display at least some of the characteristics of PTW data. Finally, we demonstrate via simulation that if we fit a Weibull distribution to PTW data (as is often done), we can obtain very poor estimates of probabilities of failure.

https://www.fpl.fs.fed.us/documnts/pdf2014/fpl_2014_verrill001.pdf

Reliability Implications in Wood Systems of a Bivariate Gaussian–Weibull Distribution and the Associated Univariate Pseudo-truncated Weibull

Standing stress wave measurements were taken on 274 small-diameter Douglas-fir trees in western Montana. Stand, site, and soil measurements collected in the field and remotely through geographical information system (GIS) data layers were used to model dynamic modulus of elasticity (DMOE) in those trees. The best fit linear model developed resulted in an adjusted R 2 = 0.52 for predictions of individual tree DMOE and an R 2 = 0.85 for predictions averaged on a stand basis. The linear model used was mean annual increment -1 , total tree height, and a GIS-based estimate of soil bulk density. Logical models were also developed to predict membership in dichotomous DMOE categories with 71-82% selected trees meeting their respective DMOE criteria. The inverse relationship between soil bulk density and DMOE could be explained by the soil-tree moisture interactions know as least limiting water range.

https://www.fpl.fs.fed.us/documnts/pdf2013/fpl_2013_morrow001.pdf

Cherilyn A. Hatfield

Papers

Asymptotically Efficient Estimation of a Bivariate Gaussian–Weibull Distribution and an Introduction to the Associated Pseudo-truncated Weibull

Grading and properties of small-diameter Douglas-fir and ponderosa pine tapered logs

An Evaluation of a Proposed Revision of the ASTM D 1990 Grouping Procedure

Reliability Implications in Wood Systems of a Bivariate Gaussian–Weibull Distribution and the Associated Univariate Pseudo-truncated Weibull

Prediction of wood quality in small-diameter douglas-fir using site and stand characteristics