On the decoding of binary cyclic codes with the Newton identities

We revisit in this paper the concept of decoding binary cyclic codes with Gröbner bases. These ideas were first introduced by Cooper, then Chen, Reed, Helleseth and Truong, and eventually by Orsini and Sala. We discuss here another way of putting the decoding problem into equations: the Newton identities. Although these identities have been extensively used for decoding, the work was done manually, to provide formulas for the coefficients of the locator polynomial. This was achieved by Reed, Chen, Truong and others in a long series of papers, for decoding quadratic residue codes, on a case-by-case basis. It is tempting to automate these computations, using elimination theory and Gröbner bases.Thus, we study in this paper the properties of the system defined by the Newton identities, for decoding binary cyclic codes. This is done in two steps, first we prove some facts about the variety associated with this system, then we prove that the ideal itself contains relevant equations for decoding, which lead to formulas.Then we consider the so-called online Gröbner basis decoding, where the work of computing a Gröbner basis is done for each received word. It is much more efficient for practical purposes than preprocessing and substituting into the formulas. Finally, we conclude with some computational results, for codes of interesting length (about one hundred).     

基于相互认证和3DES加密的智能卡远程支付系统认证方案

针对现有基于智能卡支付系统的安全方案存在密码暴露、信息泄露和身份认证等问题,提出一种新的基于相互认证和3DES加密的智能卡远程支付系统认证方案。分析基于二次剩余的支付认证方案的不足,在注册、登录、身份认证和密码更改阶段对其进行改进,避免密码暴露攻击,提高密码更改阶段的安全性,同时结合3DES加密算法对支付信息进行加密处理。性能分析表明,该方案能有效抵御多种攻击,且用户能够自由地修改密码,同时可对用户信息进行匿名保护。与现有智能卡支付认证方案相比,该方案提高了支付系统的安全性能且具有较小的计算复杂度。     

PLC顺控指令在废渣回收系统中的应用

废渣回收系统的逻辑控制是典型的顺序控制,利用PLC可以简便、准确地实现该控制,以西门子S7-200小型PLC为例,介绍了顺序控制的编程方法和优点.     

新型Rabin签名方案

提出一种基于二次剩余问题的新型Rabin签名方案.该方案对明文空间几乎没有限制,可能抵 抗选择密文攻击,其描述也更为简单,同时还具有更高的实现效率,在签名检验时仅需作一次 模乘运算.     

减压渣油评价中的人工神经网络分析方法

介绍了渣油评价中人工神经分析方法,其目标是以少量的关键参数推演出渣油评价所需的并试图通过改变网络输入参数来确定不同性质指标对推演渣油其他参数的影响程度。文中给出了人工神经网络方法与多元线性回归方法的对比,表明人工神经网络用于模拟减压渣油的评价方法和实验过程的可行性,并为该方法用于仿真实验过程指出应用前景。     

Crystallization characteristic of glass-ceramic made from electrolytic manganese residue

Electrolytic manganese residue (EMR) is a waste from electrolytic manganese industry that contains high concentration of toxic substances. Since the EMR disposal in landfill sites has a serious environmental impact, new ways of EMR utilization are being sought. Considering the melting of EMR to a glass at high temperature was a relatively less energy-intensive process, EMR was first made into a base glass and then the ground base glass was heat-treated in a certain procedure to make a glass-ceramic and the crystallization process was studied. It was determined by X-ray diffraction (XRD) that the primary crystalline phases of the EMR glass-ceramic were diopside and anorthite, which formed the surface crystallization mechanism with a crystallization activation energy of 429 kJ/mol. Scanning electron microscopy (SEM) observation showed that a layer of small spherical particles with an average size of about 0.5 μm were covered on the glass matrix surface, and among them there were some big particles. The low melting temperature and crystallization activation energy make it promising to reuse EMR for glass-ceramic production.     

利用粉煤灰滤渣制备NaP1型沸石及其吸附Cu~(2+)的研究

以固体废弃物粉煤灰为原料,经过煅烧和水热反应生成粉煤灰滤渣前驱体,通过添加工业硅粉来调整反应物的Si/Al摩尔比,采用水热法合成了NaP1型沸石。通过X射线衍射仪、扫描电子显微镜和傅立叶转换红外光谱仪对所合成沸石的物相、显微结构和化学基团进行了观察与分析,并对其吸附铜离子的性能进行了研究。结果表明,Si/Al摩尔比为3∶1的粉煤灰滤渣和氢氧化钠溶液在90℃下可以水热合成得到结晶度较高的NaP1型沸石;NaP1型沸石对于铜离子具有较高的吸附量,初期其吸附速度较快,30min时吸附量为52.8mg/g,之后吸附速度稍有减缓,吸附时间为60min时接近吸附饱和,饱和吸附量可达到82.7mg/g。     

国内外农药使用与残留控制体系

分析了联合国、美国、欧盟、日本等国际组织及国外对农药使用与残留控制的机制,阐述了国际组织和发达国家对农药使用及残留控制体系的发展趋势.介绍了我国对农药使用和残留控制的现状,提出了加强我国对农药使用和残留控制在制度、措施、标准等方面的建议.