Changchun NO.1 Machine Tool Plant

The Changchun No.1 Machine Tool Plant was established in 1958. It is a key enterprise of the Ministry of the Machine Building Industry, the largest grinder producing plant in northeast China and a leading plant producing cam-shaft grinders in China. The plant stands on a site of 200.000 sqm. It has 3.000 staff and workers, with engineers and technicians accounting for 12.8%. and 600 items of production equipment and precision

DK7732-1 Electric Spark CNC Wire-Cuffing Machine

The machine tool is one of the new products developed and produced by the Shanghai No.8 Machine Tool Plant. It adopts a lift adjustable wiretrame and molybdenum filament tensioning mechanism with large cutting thickness and high machining precision. It is equipped with an advanced IBM-PC 386 microcomputer-controlled system, with strong performance and CRT display. Man/

A computational model to identify fertility-related proteins using sequence information

Fertility is the most crucial step in the development process,which is controlled by many fertility-related proteins,including spermatogenesis-,oogenesis-and embryogenesis-related proteins.The identification of fertility-related proteins can provide important clues for studying the role of these proteins in development.Therefore,in this study,we constructed a two-layer classifier to identify fertility-related proteins.In this classifier,we first used the composition of amino acids(AA)and their physical and chemical properties to code these three fertility-related proteins.Then,the feature set is optimized by analysis of variance(ANOVA)and incremental feature selection(IFS)to obtain the optimal feature subset.Through five-fold cross-validation(CV)and independent data tests,the performance of models constructed by different machine learning(ML)methods is evaluated and compared.Finally,based on support vector machine(SVM),we obtained a two-layer model to classify three fertility-related proteins.On the independent test data set,the accuracy(ACC)and the area under the receiver operating characteristic curve(AUC)of the first layer classifier are 81.95%and 0.89,respectively,and them of the second layer classifier are 84.74%and 0.90,respectively.These results show that the proposed model has stable performance and satisfactory prediction accuracy,and can become a powerful model to identify more fertility related proteins.

An automated approach to calculating the maximum diameters of multiple cutters and their paths for sectional milling of centrifugal impellers on a 4_(1/2)-axis CNC machine

Power generators and chemical engineering compressors include heavy and large centrifugal impellers. To produce these impellers in high-speed machining, a 4?-axis milling machine(or a 4-axis machine plus an indexing table) is often used in the industry, which is more rigid than a5-axis milling machine. Since impeller blades are designed with complex B-spline surfaces and impeller channels spaces vary significantly, it is more efficient to use multiple cutters as large as possible to cut a channel in sections and a blade surface in patches, instead of only using a small cutter to machine a whole blade and a channel. Unfortunately, no approach has been established to automatically calculate the largest diameters of cutters and their paths, which include the indexing table angles. To address this problem, an automated and optimization approach is proposed. Based on the structure of a 4?-axis machine, a geometric model for a cutter gouging/interfering the impeller is formulated, and an optimization model of the cutter diameter in terms of the indexing table angle is established at a cutter contact(CC) point on a blade surface. Then, the diameters of the tools,their orientations, and the indexing table angles are optimized, and each tool's paths are generated for machining its corresponding impeller section. As a test, an impeller is efficiently machined with these tools section by section; thus, this approach is valid. It can be directly used in the industry to improve efficiency of machining centrifugal impellers.