三鞍座硫回收冷凝器的强度计算

通过对非对称布置三鞍座硫回收冷凝器的受力分析及简化,提出了计算各支座反力和轴向弯矩的数学公式,供设计时参考。     

A genetic strategy to design cellular automata based block ciphers

We propose an evolutionary computation approach to design a fast and secure block cipher using non-uniform second-order cellular automata. We build a flexible block ciphering model that permit the construction of a huge space of possible instances defined each one by a finite set of elementary transition rules. The constructed space is explored using a genetic algorithms strategy in order to find an optimal solution with respect to the strict avalanche criterion used as fitness measurements. The genetically designed cipher is benchmarked experimentally using conventional statistical tests, and shown to have very admissible characteristics leading to a very acceptable level of cryptographic security. Moreover, performances analysis shows that the designed cipher permit to achieve a high encryption/decryption speed, and compete many of the existing standardized ciphers.     

Parallel operation of CartaBlanca on shared and distributed memory computers

We describe the parallel performance of the pure Java CartaBlanca code on heat transfer and multiphase fluid flow problems. CartaBlanca is designed for parallel computations on partitioned unstructured meshes. It uses Java's thread facility to manage computations on each of the mesh partitions. Inter‐partition communications are handled by two compact objects for node‐by‐node communication along partition boundaries and for global reduction calculations across the entire mesh. For distributed calculations, the JavaParty package from the University of Karlsruhe is demonstrated to work with CartaBlanca. Copyright © 2004 John Wiley & Sons, Ltd.     

Irreducible constituents of monomial representations

We describe an algorithm for obtaining the central primitive idempotents of the algebra associated with a monomial representation. As a consequence, we obtain its irreducible constituents. This is implemented in Magma, using an algorithm based on Dixon’s modular approach. In the case of permutation representations, we get a simplified version of the algorithms of Michler and Weller.     

基于进化计算的兴趣建模

为实现对个体的兴趣建模,提出基于进化计算的建模(Evolutionary Computation Based Modeling,ECBM)方法。该方法采用定性和定量相结合的方式对个体的兴趣系统进行建模,首先通过定性分析构建个体的兴趣模型框架,然后通过进化计算(Evolutionary Computation)方法对模型参数自动进化。实验结果表明,ECBM能够通过数据驱动模式优化模型参数,并利用更新信息进化模型,使其不断逼近真实系统。     

A faster parameterized algorithm for set packing

We present an efficient parameterized algorithm for the (k,t)-set packing problem, in which we are looking for a collection of k disjoint sets whose union consists of t elements. The complexity of the algorithm is O(²O(t)nNlogN). For the special case of sets of bounded size, this improves the O(k(ck)n) algorithm of Jia et al. [J. Algorithms 50 (1) (2004) 106].     

并行计算和稀疏存储在模糊积分上的应用

近年来很多学者开展了模糊积分的相关研究,并将模糊积分应用于各种分类问题,而模糊测度的确定则是模糊积分计算的重点和难点。本文将并行计算和稀疏存储应用在模糊积分求解上,分别解决模糊积分计算中的时间复杂度和空间复杂度问题,并提出一种高效率模糊积分算法—基于并行和稀疏框架的模糊积分(Parallel and Sparse Frame Based Fuzzy Integral,简称PSFI)。实验表明,随着计算资源的增加,PSFI算法的加速比和效率下降较低。在变量存储上,PSFI算法在较多特征的数据集上对存储空间减少数千倍。最后,本文提出的PSFI算法相比之前提出的多重模糊积分(Multiple Nonlinear Integral, MNI)算法,有较高的分类准确率。     

基于安全多方计算的车载网隐私保护机制

为了解决当前车载网隐私保护机制的安全性和效率问题,基于安全多方计算理论和匿名认证协议,提出了一种新的车载网节点隐私保护方案.该方案利用线性方程组的求解理论,采用安全高效的茫然传输机制,避开了传统的计算复杂的公钥密码算法.对方案的安全性和效率分析的结果表明,新方案不仅能够解决车载网中发送者隐私、接收者隐私、匿名性、共谋攻击、重放攻击等多种安全问题,而且认证效率也得到了有效提高,在计算性能受限的物联网环境中,具有理论和应用价值.     

Connectionism,Learning and Meaning

There is an apparent anomaly in the notion that connectionism, which is fundamentally a new technology, has considerable philosophical significance. Nonetheless, connectionism has been widely viewed as having implications for symbol grounding, notions of structured representation and compositionality, as well as the issue of nativism. In this paper, we consider each of these issues in detail and find that the current state of connectionism does not warrant the magnitude of many of the philosophical conclusions drawn from it. We argue that connectionist models are no more 'grounded' than their classical counterparts. In addition, since connectionist representations typically are ascribed content through semantic interpretation based on correlation, connectionism is prone to a number of well known philosophical problems facing any kind of correlational semantics. However, we suggest that philosophy may be ill advised to ignore the development of connectionism, particularly if connectionist systems prove to be able to learn to handle structured representations.     

有效降低厚板料冲裁模冲裁力的方法

介绍了厚板冲裁模冲裁力计算及通过波浪型刃口及阶梯型凸模的应用有效降低冲裁力,最终满足机床使用要求,并介绍了厚板修边冲孔模具结构的设计及模具的工作过程。