基于iMachining和PM软件的智能高效粗加工方法研究

针对传统数控铣削加工效率低、加工参数主要依靠经验以及机床和刀具加工潜力发挥不足的弊端,利用SolidCAM软件提供的iMachining加工策略,完成数控铣削粗加工的自动编程。同时,针对iMachining在刀具轨迹自动生成时某些部位切削力突变的情况,利用Production Module软件提供的刀具轨迹分析功能,对刀具承受切削力突变的部位进行优化处理。通过以上方式进行数控铣削粗加工编程,有效提高了数控铣削加工效率,充分发挥了机床和刀具的潜力,提高了刀具的使用寿命和机床切削的稳定性。

A product module mining method for PLM database

Modular technology can effectively support the rapid design of products, and it is one of the key technologies to realize mass customization design. With the application of product lifecycle management(PLM) system in enterprises, the product lifecycle data have been effectively managed. However, these data have not been fully utilized in module division, especially for complex machinery products. To solve this problem, a product module mining method for the PLM database is proposed to improve the effect of module division. Firstly, product data are extracted from the PLM database by data extraction algorithm. Then, data normalization and structure logical inspection are used to preprocess the extracted defective data. The preprocessed product data are analyzed and expressed in a matrix for module mining. Finally, the fuzzy c-means clustering(FCM) algorithm is used to generate product modules, which are stored in product module library after module marking and post-processing. The feasibility and effectiveness of the proposed method are verified by a case study of high pressure valve.

基于Production Module 3D数控铣削仿真技术在钛合金主吊挂加工中的应用

在钛合金主吊挂支架的铣削过程中,采用Production Module 3D软件对数控程序、材料、刀具及工件的综合分析,得到了在整个数控程序下的温度峰值、进给力、切削力及材料去除率等数据。然后采用完善数控程序中的吃刀量、切削速度及进给量来使加工过程中温度、切削力等符合要求,使负载平衡,降低振动。最终刀具的使用寿命提高20%,加工周期降低22%。

Time-Frequency Bandwidth Product Estimation of Sinusoidal Non-Linear Chirp Keying Scheme

Sine Non-linear Chirp Keying(SNCK) is a kind of high-efficient modulation scheme, which provides a potential new beamforming method in communication and radar systems. It has been proved to have advantages in some parameter estimation issues over conventional modulation schemes. In this paper, a novel transform termed as Discrete Sinusoidal Frequency Modulation transform(DSFMT) is proposed. Then, the DSFMT of SNCK signal is deduced and classified into three types, based on which, the time-bandwidth product is estimated by the proposed algorithm. Simulation results show that the noise has a signifi cant impact on the localization of the peak value and the time-bandwidth product can be estimated by using local ratio values when.

Recent progress in random metric theory and its applications to conditional risk measures

The purpose of this paper is to give a selective survey on recent progress in random metric theory and its applications to conditional risk measures.This paper includes eight sections.Section 1 is a longer introduction,which gives a brief introduction to random metric theory,risk measures and conditional risk measures.Section 2 gives the central framework in random metric theory,topological structures,important examples,the notions of a random conjugate space and the Hahn-Banach theorems for random linear functionals.Section 3 gives several important representation theorems for random conjugate spaces.Section 4 gives characterizations for a complete random normed module to be random reflexive.Section 5 gives hyperplane separation theorems currently available in random locally convex modules.Section 6 gives the theory of random duality with respect to the locally L0-convex topology and in particular a characterization for a locally L0-convex module to be L0-pre-barreled.Section 7 gives some basic results on L0-convex analysis together with some applications to conditional risk measures.Finally,Section 8 is devoted to extensions of conditional convex risk measures,which shows that every representable L∞-type of conditional convex risk measure and every continuous Lp-type of convex conditional risk measure(1 ≤ p < +∞) can be extended to an L∞F(E)-type of σ,λ(L∞F(E),L1F(E))-lower semicontinuous conditional convex risk measure and an LpF(E)-type of T,λ-continuous conditional convex risk measure(1 ≤ p < +∞),respectively.

SEARCH FOR TRANSLESION SYNTHESIS MODULATORS FROM NATURAL PRODUCTS:ANALYTICAL DEVELOPMENT, VALIDATION AND APPLICATIONS

DNA translesion synthesis(TLS)is a DNA damage tolerance mechanism that relies on a series of specialized DNA polymerases able to bypass a lesion on a DNA template strand during replication or post-repair synthesis.TLS DNA polymerases pursue replication by inserting a base opposite this lesion,correctly or incorrectly