A FRAMEWORK FOR REAL-VALUED CIPHER SYSTEMS

Most cipher systems designed thus far are binary-valued or integer-valued cipher systems. Their security relies on the assumption that one-way functions exist. Though the existence of one-way functions has not been proved yet, most cryptographic researchers believe that one-way functions exist. In addition, many candidates for one-way functions have been proposed. Therefore, the key step for developing real-valued cipher systems is to define real one-way functions and to propose candidates for them. In this paper, based on computational complexity theory over the real field, we give two definitions of real one-way functions; one is for digital one-way functions and the other is for general one-way functions. Candidates for these two classes of one-way functions are also proposed. Moreover, we present two examples to demonstrate that the candidates for both digital one-way functions and general one-way functions can be applied to construct secure real-valued cipher systems.     

城市快速轨道交通接运公交路线网规划

合理的接运公交线网规划是城市快速轨道交通系统充分发挥作用的保证,其关键环节是接运站点的选取和接运路线的优化。接运站点以它可能为轨道路线接运的最大客运周转量来选取;接运路线以接运效率最大为目标搜索优化     

风险、等效边际成本与投资规模

用金融期权的分析方法研究了非完全竞争市场条件下风险、企业的等效边际成本和投资规模之间的关系,并讨论了需求弹性和企业商品的市场占有率的影响．研究表明风险促使企业降低等效边际成本,导致边际成本随资本量递减企业增加投资,递增企业减少投资．需求弹性和企业商品的市场占有率对等效边际成本和投资规模也有明显的影响．     

武器装备体系组合规划的高维多目标优化决策

针对武器装备体系组合规划问题中存在多类相互冲突的高维多目标问题(目标数 ≥ 5),提出了一种三阶段的集成优化决策方法. 首先运用目的规划技术将高维多目标问题转换为一般多目标优化模型(目标数 ≤ 3); 然后提出一种多目标差分进化算法,用于搜索属于决策者关心区间的非劣解集; 最后提出基于预测优化的理想点算法,可生成精确满足决策者偏好的最佳折衷解. 通过某侦察装备体系组合规划示例,证明了各算法模块的优势和该方法的整体有效性,可为武器装备发展和顶层规划提供决策支持.     

Discovering non-terminating inputs for multi-path polynomial programs

This paper investigates the termination problems of multi-path polynomial programs （MPPs） with equational loop guards. To establish sufficient conditions for termination and nontermination simultaneously, the authors propose the notion of strong/weak non-termination which under/over- approximates non-termination. Based on polynomial ideal theory, the authors show that the set of all strong non-terminating inputs （SNTI） and weak non-terminating inputs （WNTI） both correspond to tile real varieties of certain polynomial ideals. Furthermore, the authors prove that the variety of SNTI is computable, and under some sufficient conditions the variety of WNTI is also computable. Then by checking the computed SNTI and WNTI varieties in parallel, termination properties of a consid- ered MPP can be asserted. As a consequence, the authors establish a new framework for termination analysis of MPPs.     

一类G-框架及其对偶的若干性质

在一个新的Hilbert空间上定义了G-框架及G-对偶框架,并且讨论了他们的性质,改进和推广了其他学者的成果.     

12CaO·7Al2O3型精炼合成渣物性与脱硫试验

对近两年从国外发展起来的新型精炼合成渣 12 Ca O· 7Al2 O3的烧成工艺、物性和脱硫能力进行了试验研究。结果表明 ,该渣系原料来源广泛 ,成本较低 ;以 12 Ca O· 7Al2 O3为低熔点相 ,具有较低的熔化温度 ,在精炼温度下具有较好的流动性 ;由于具有很高的碱度和 Al2 O3含量 ,因而具有较强的脱硫能力和吸附铝脱氧产物的能力 ,并且在精炼过程中还可配加大量石灰 ,进一步提高其脱硫能力 ,尤其适用于铝脱氧钢     

New crystal structure of molecular complex 1-piperidine carboxylate-piperidinium-H<Subscript>2</Subscript>O studied by X-ray single crystal diffraction

Piperidine absorbs CO2 and H2O in air to form a molecular complex： piperidium-l-piperidinecarboxylate-H2O. The structure of the complex was characterized by X-ray single crystal diffraction. The crystal structure was determined to be triclinic, space group P1^-with a=0.648 6（8） nm, b=0.809 200） nm, c= 1.357 1（16） nm, a=96.96706）°, β =102.506（15）°,γ=104.202 05）°, Z=2. The complex is stabilized via five hydrogen bonds between the three components, N-O electrostatic interaction and O-O interaction （electron transfer） betweenl-piperidinecarboxylate and H2O. Due to electron transference of carbamate ion, the oxygen atom in water molecule is strongly negatively charged and the O-H bond is considerably shorter than that of the free molecule of water. The formation of the molecular complex is a reversible process and will decompose upon heating. The mechanism of formation and stabilization is further investigated herein.     

探讨大体积混凝土的施工技术

随着现代建筑技术的不断发展,大体积混凝土的应用越来越广泛.大体积混凝土逐渐成为构成大型设施或构筑物主体的重要组成部分.笔者结合实践经验,对建筑工程中大体积混凝土的施工技术进行探讨.     

时间反演联合接收端人工噪声的安全传输方案

针对时间反演(time reversal, TR)技术无法较好地解决聚焦区内非法用户窃听的问题,提出了一种TR技术联合接收端人工噪声的物理层安全传输方案。首先,利用时间反演技术的空时聚焦性提高合法用户接收端的信噪比(signal to noise ratio, SNR)。其次,通过在接收端加入人工噪声来干扰非法用户对合法用户保密信息的窃听,以聚焦区内外系统安全性能为基础,推导出保密信干噪比(signal to interference plus noise ratio, SINR)、可达保密速率和误码率(bit error rate, BER)的解析表达式。最后,通过仿真分析证明了所提方案能提高系统的SINR和可达保密速率,同时还能降低合法用户的BER,使系统拥有更好的安全性能。