Power Allocation Strategy for Secret Key Generation Method in Wireless Communications

Secret key generation (SKG) is an emerging technology to secure wireless communication from attackers. Therefore, the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wireless channels’ uncertainty. However, the physical layer secret key generation (PHY-SKG) depends on two fundamental parameters, i.e., coherence time and power allocation. The coherence time for PHY-SKG is not applicable to secure wireless channels. This is because coherence time is for a certain period of time. Thus, legitimate users generate the secret keys (SKs) with a shorter key length in size. Hence, an attacker can quickly get information about the SKs. Consequently, the attacker can easily get valuable information from authentic users. Therefore, we considered the scheme of power allocation to enhance the secret key generation rate (SKGR) between legitimate users. Hence, we propose an alternative method, i.e., a power allocation, to improve the SKGR. Our results show 72% higher SKGR in bits/sec by increasing power transmission. In addition, the power transmission is based on two important parameters, i.e., epsilon and power loss factor, as given in power transmission equations. We found out that a higher value of epsilon impacts power transmission and subsequently impacts the SKGR. The SKGR is approximately 40.7% greater at 250 from 50 mW at epsilon = 1. The value of SKGR is reduced to 18.5% at 250 mW when epsilonis 0.5. Furthermore, the transmission power is also measured against the different power loss factor values, i.e., 3.5, 3, and 2.5, respectively, at epsilon = 0.5. Hence, it is concluded that the value of epsilon and power loss factor impacts power transmission and, consequently, impacts the SKGR.     

地学文献馆际互借模式分析

馆际互借是图书情报机构面向读者的新型服务方式,是资源共享的一种最有效形式。应利用各种手段,广泛宣传这种服务,让读者了解馆际互借服务,以便用最快捷的方式获得所需文献,最大限度地满足读者的需求。本文在总结分析馆际互借重要性、国内外地学文献馆际互借现状与存在问题的基础上,结合信息技术发展现状,提出了完善规章制度、推进信息共享和加强馆际互借的宣传等我国地学文献馆际互借的发展对策,并就中国地质图书馆在其中作用进行了论述,以期能对地学文献共享有所帮助。     

YKA7232型数控蜗杆砂轮磨齿机控制系统设计

ＹＫＡ７２３２型数控蜗杆砂轮磨齿机采用１６位ＳＴＤ总线工业控制机和光栅和光电编码器元件，可进行６轴控制４轴联动的全交流伺服闭环控制。文章介绍了机床系统硬件和软件的构成，特点及功能。     

面向多租户的门户资源管理框架

为了提高企业信息门户中间件平台的资源利用率,提出了一个面向多租户架构的资源管理框架。针对门户应用场景中资源的特点,在建立资源模型的基础上,通过元数据描述租户与资源的映射关系,并针对不同类型的资源,提供相应的资源共享和隔离机制。在提高资源利用率的同时,向资源使用者屏蔽对租户敏感资源的访问细节,简化多租户环境中逻辑资源的管理问题。将该框架应用于OncePortal门户中间件,并在此基础上进行了实验分析,结果表明了框架的可行性和有效性。     

频谱可用性和保护带宽共享度感知的弹性光网络生存性多路径策略

针对弹性光网络频谱利用率降低和带宽阻塞率高等问题,该文提出一种频谱可用性和保护带宽共享度感知的生存性多路径策略(M-SDSAA)。首先,该策略对业务采用单路径路由,通过区分业务的持续时间,分别采用首次命中和末端命中的工作路径频谱分配方式,并且为不同大小共享频谱块设定不同链路权重值。若单路径路由或频谱分配失败,引入多路径传输策略,自适应选择消耗频隙数少的策略,并且引入共享保护机制,提高保护带宽共享度。最后,当业务阻塞时,且存在单路径业务的保护路径预置在频隙消耗次优的路径,则启动重配置机制进一步降低阻塞率,将该业务重配置到保护频隙消耗最少的路径。仿真结果表明所提算法能有效地提高频谱利用率,降低网络的带宽阻塞率。     

基于非局域性正交乘积态的动态量子秘密共享方案

当前的量子秘密共享(QSS)存在资源制备开销较大、安全性不强的问题,该文提出一种基于正交乘积态的可验证量子秘密共享方案弥补上述不足,且多方成员能动态地加入或退出秘密共享。该方案将正交乘积态的粒子分成两个序列,第1个序列在多个参与者之间传输,前一个参与者对其执行嵌入份额值的酉算子后传输给下一个参与者,直到全部份额聚合完成;对于另一个序列,只有最后一个参与者(验证者)对接收到的粒子执行Oracle算子。然后,验证者对两个序列中的粒子对执行全局测量,得到秘密值的平方剩余。最后,借鉴Rabin密码中密文与明文之间非单一映射的思想,验证者联合Alice验证测量结果的正确性,并从测量结果确定出秘密值。安全性分析表明,该方案能抵抗常见的外部攻击和内部攻击,且验证过程具有强安全性;由于非局域性正交乘积态以两个序列分开传输,因此增强了秘密重构过程的安全性。性能分析表明,该方案使用正交乘积态作为信息载体,量子资源开销较小,且将正交乘积基的维度从低维拓展到d维,参与者人数能动态地增加和减少,使得方案具有更好的灵活性和通用性。     

<Emphasis Type="Italic">t</Emphasis>-resilient functions and the partial exposure problem

The Wire-Tap Channel II introduced by L. H. Ozarow, A.D. Wyner was the first instance of a Partial Exposure Problem. General Exposure-Resilient Functions (ℓ-ERF) are known to be appropriate to provide a solution to the Partial Exposure Problem as long as random secret chains are to be protected. It is known that a perfect ℓ-ERF is nothing but a t-resilient function for t = n − ℓ, where n is the length of the exposed symbol-chain and t the largest number of symbols that an adversary is able to observe. We here manage to adapt the use of t-resilient functions for protecting messages against partial exposure. A solution to that problem had been given by the perfect local pseudo-random generator introduced by Maurer and Massey which is based upon a t-resilient function, but its use needs a secret key shared by the sender and the receiver. We are able to provide solutions to protect messages against Partial Exposure without using secret keys, for various ranges of parameters. Moreover low complexity algorithms are devised to that end.     

网格GIS系统设计及其在遥感图像处理上的应用

随着地学数据特别是遥感数据与日剧增,许多数据却因为数据量大、处理困难而得不到有效利用。因此,如何更好地发展计算机网络技术,使得海量数据能够得到更好的共享与应用成为了困惑广大计算机专业及地学工作者的一大难题,网格计算提供了此问题的解决途径。以网格计算及其在GIS的应用为主线,首先分析了网格技术的特点,并进一步结合其在GIS中的应用给出了网格GIS的应用前景。同时以局域网为单位,结合网格设计的思想,借助中间件技术,讨论了基于局域网络的网格GIS系统的实现技术,并列举了所需的几项关键技术。特别就当前GIS所面临     

West 8:大众文化图景下的当代景观

West8通过他们的设计观念及作品表明．面对商业主义消费社会大众文化的平庸化侵蚀，当代景观的塑造需要一种乐观主义精神以及对于建筑、规划景观、工业设计等多学科领域的充分整合。     

Home-based communication system for older adults and their remote family

As in many Latin–American countries, in Mexico many older adults live alone as a result of the migration of one or more of their relatives, mostly to the USA. Thus, not only do they live alone, but they might seldom see these relatives for long periods, even though they often depend on them financially. With the goal of designing appropriate communication technology for seniors and their relatives experiencing this situation, we conducted interviews and evaluated scenarios and prototypes to reveal the practical ways they maintain emotional ties despite the distance. Based on those findings, we envisioned a communication system through which seniors and their relatives can maintain close social ties by sharing information, personal reminiscences and stories. We found that older adults perceived the system as a richer, natural form of communication with their relatives that could facilitate their integration into the networks that currently connect members of their families.