CRYPTOPOST™ A cryptographic application to mail processing

A public key cryptography protocol is designed for the authentication of documents. When applied to the authentication of postage on mail envelopes it permits the development of a universal automated and standardized mail processing and postage verification system. The mail processing automation problem is present, and the protocol solution and characteristics of the proposed cryptographic CRYPTOPOST system are described. Partial details of one implementation are disclosed.     

专用通信网的作用及发展趋势

专用通信网是对公网的种补充，从它产生之日起，就为满足一些部门和企业的特殊需要发挥着重要作用。但随着社会的发展和技术的进步，专网的地位和作用也会发生一定的变化。本文在对专网的地位和作用进行分析的基础上，揭示了专网未来的发展趋势，并着重指出，许多企业将会用虚拟专用网取代传统专用网。     

A variant of Digital Signature Algorithm

In this paper we present a variant of the Digital Signature Algorithm based on a factorization problem and two discrete logarithm problems. We prove that our signature scheme is at least as secure as the original Digital Signature Algorithm and withstands all known attacks.      

公共资本投资的随机内生增长模型

本文假设公共资本是宏观经济的一部分,由此建立一个随机内生增长模型,把公共资本作为宏观经济变量并进入个人效用.分析了经济达均衡时税收,政府投资,个人投资对经济增长率和社会福利的影响.同时还求出子最优的增长率和个人资本与财富比,消费和财富比.     

Continuous spatial public goods game with self and peer punishment based on particle swarm optimization

How cooperative behavior emerges and evolves in human society remains a puzzle. It has been observed that the sense of guilt rooted from free-riding and the sense of justice for punishing the free-riders are prevalent in the real world. Inspired by this observation, two punishment mechanisms have been introduced in the spatial public goods game which are called self-punishment and peer punishment respectively in this paper. In each situation, we have introduced a corresponding parameter to describe the level of individual tolerance or social tolerance. For each individual, whether to punish others or whether it will be punished by others depends on the corresponding tolerance parameter. We focus on the effects of the two kinds of tolerance parameters on the cooperation of the population. The particle swarm optimization (PSO)-based learning rule is used to describe the strategy updating process of individuals. We consider both of the memory and the imitation in our model. Via simulation experiments, we find that both of the two punishment mechanisms could facilitate the promotion of cooperation to a large extent. For the self-punishment and for most parameters in the peer punishment, the smaller the tolerance parameter, the more conducive it is to promote cooperation. These results can help us to better understand the prevailing phenomenon of cooperation in the real world.     

对普遍服务成本补偿机制的经济分析

普遍服务是电信管制机构强制实行的一项电信政策，旨在促进并维持社会公众能够获取经济上可以承受的电信业务。从经济学的角度将普遍服务的本质归纳为收入再分配和社会的外部性。管制机构必须实行有效的管制机制（内部补贴和外部补贴）来实施普遍服务政策。运用经济学原理分别对这两种机制进行了评述。最后阐述了普遍服务的拍卖方式，并认为这是一种较好的解决办法。从经济学的角度看，普遍服务实际上是对市场经济的一种扭曲。因此，随着市场的不断完善和科学技术的不断进步，各种电信管制政策（包括电信普遍服务）最终会减弱直至走向消亡。     

通信传输技术九十年代新动向

本文概述九十年代通信技术的新动向,主要讲卫星通信、移动通信、光纤通信以及公用和专用通信网传输技术的发展趋势。文中着重指出各种有前途的新技术,包括卫星通信的星上点波束天线,小孔径天线地面终端,与ISDN兼容;数字移动通信的蜂窝微区(micro-cell),个人便携通信的无线接入交换网;光纤通信的掺铒光纤放大器,DFB调谐单频激光管,多量子阱(MQW),光电子集成,外差检测,密集FDM多路载波通信;以及公用通信网数字化、综合化、宽带化组成B-ISDN,同步光纤网,同步数字体系,异步转移方式;专用通信网的局域网(LAN和MAN),光纤分布数据接口,分隙环(slotted ring),分布排队双总线等新建议。     

72型分光光度计的调修及故障排除

从日常维修工作的实际需要出发,重点介绍了72型分光光度计的调正、常见故障及排除方法。     

可公开验证的动态秘密分享机制

基于背包公钥密码体制,提出了一个公开可验证的动态秘密分享方式.此秘密分享方式中每个分享者的子秘密可以重复使用;特别地,它能在恢复秘密的过程中及时地检查出不诚实者.