FSE2R: An Improved Collision-Avoidance-based Energy Efficient Route Selection Protocol in USN

The 3D Underwater Sensor Network (USNs) has become the most optimistic medium for tracking and monitoring underwater environment. Energy and collision are two most critical factors in USNs for both sparse and dense regions. Due to harsh ocean environment, it is a challenge to design a reliable energy efficient with collision free protocol. Diversity in link qualities may cause collision and frequent communication lead to energy loss; that effects the network performance. To overcome these challenges a novel protocol Forwarder Selection Energy Efficient Routing (FSE2R) is proposed. Our proposal’s key idea is based on computation of node distance from the sink, Residual Energy (RE) of each node and Signal to Interference Noise Ratio (SINR). The node distance from sink and RE is computed for reliable forwarder node selection and SINR is used for analysis of collision. The novel proposal compares with existing protocols like H2AB, DEEP, and E2LR to achieve Quality of Service (QoS) in terms of throughput, packet delivery ratio and energy consumption. The comparative analysis shows that FSE2R gives on an average 30% less energy consumption, 24.62% better PDR and 48.31% less end-to-end delay compared to other protocols.     

Captured Kriegsmarine Enigma Documents at Bletchley Park

Abstract

The discovery of intercepts in the Japanese “Orange Translations” regarding the sinking of merchant ships (marus) bearing allied POWs led to the conclusion that the Joint Intelligence Center Pacific Ocean Area (JICPOA) gave latitudes and longitudes of these vessels to the Commander, Submarine Force, Pacific (ComSubPac) knowing that POWs would be killed. An examination of the “Orange Translations” reveals that most of the intercepts are from the Japanese Water Transport Code (2468) system, not the “Maru Code” (JN-11). The author concludes that while JICPOA provided ComSubPac with convoy coordinates, they were unaware of the presence of POWs on the marus.     

1.5 V Sub‐mW CMOS Interface Circuit for Capacitive Sensor Applications in Ubiquitous Sensor Networks

In this paper, a low‐power CMOS interface circuit is designed and demonstrated for capacitive sensor applications, which is implemented using a standard 0.35‐μm CMOS logic technology. To achieve low‐power performance, the low‐voltage capacitance‐to‐pulse‐width converter based on a self‐reset operation at a supply voltage of 1.5 V is designed and incorporated into a new interface circuit. Moreover, the external pulse signal for the reset operation is made unnecessary by the employment of the self‐reset operation. At a low supply voltage of 1.5 V, the new circuit requires a total power consumption of 0.47 mW with ultra‐low power dissipation of 157 μW of the interface‐circuit core. These results demonstrate that the new interface circuit with self‐reset operation successfully reduces power consumption. In addition, a prototype wireless sensor‐module with the proposed circuit is successfully implemented for practical applications. Consequently, the new CMOS interface circuit can be used for the sensor applications in ubiquitous sensor networks, where low‐power performance is essential.     

一种高性能的网络文件访问协议的研究与实现

随着网络上的数据呈爆炸性的增长，融合NAS和SAN技术的USN(统一存储网)正成为新的研究热点。针对传统文件共享协议的缺点，实现了一个新的基于USN的文件共享协议(File Access Protocol，FAP)，详细介绍了这种FAP协议的设计方案，并进行了相应的试验测试和性能分析。     

基于三方传送的USN的设计和实现

USN（统一存储网）为用户同时提供File I／O和Block I／O服务,实现了NAS和SAN的统一。采用三方传送协议实现USN可以达到以下目的：元数据服务器集中管理存储设备实现了存储空间的动态共享,提高了存储空间的利用率;合理地分配信用保证了数据共享的一致性;利用密钥分配方案生成信用在保证存储安全的同时而不增加元数据服务器的过重的负担;元数据通道和数据通道的分离,提高了USN的I／O性能。实验证明该方法是可行的。     

DETERMINATION OF TRACE ELEMENTS OF EMBOLI (CLOT) IN THE CARDIOVASCULAR SYSTEMS OF PATIENTS BY ENERGY DISPERSIVE X-RAY FLUORESCENCE ANALYSIS

ABSTRACT

An energy dispersive x-ray fluorescence analysis is applied for determining the spatial distribution of elemental concentrations of emboli in the vascular system. The fluorescent Kα x-rays of elements were detected so that the elemental concentration could be determined for these elements. For this measurement, Am-241 and Fe-55 radioisotopes were used for excitation of samples and a Si(Li) detector together with an ND66B multichannel analyzer was used for counting of Kα x-rays.     

Cross‐Layer Cooperative Scheduling Scheme for Multi‐channel Hybrid Ubiquitous Sensor Networks

The multi‐scenario topology of multi‐channel hybrid ubiquitous sensor networks (USNs) is studied and a novel link auto‐diversity cross‐layer cooperative scheduling scheme is proposed in this paper. The proposed scheme integrates the attributes of the new performance evaluation link auto‐diversity air‐time metric and the topology space in the given multi‐scenario. The proposed scheme is compared with other schemes, and its superiority is demonstrated through simulations. The simulation results show that relative energy consumption, link reception probability, and end‐to‐end blocking probability are improved. The addressing ratio of success with unchanged parameters and external information can be increased. The network can tolerate more hops to support reliable transportation when the proposed scheme is implemented. Moreover, the scheme can make the network stable. Therefore, the proposed scheme can enhance the average rate performance of the hybrid USN and stabilize the outage probability.     

水下传感器网络目标跟踪时的非短视比特优化分配算法

由于水下传感器网络(Underwater Sensor Network,USN)的能量、带宽有限,传输原始量测数据前需要进行量化处理。面向目标跟踪,在传输比特数据量的约束下,提出了非短视量化比特分配算法。首先,推导了量化量测下的条件后验克拉美罗下界,并将其设为优化目标,建立了比特分配优化模型。在此基础上,提出了一种双层近似动态规划的算法来实现比特分配的优化,在所设时间窗内利用第一层近似动态规划分配各个时刻的比特,并利用第二层近似动态规划在各分支上实现水下传感器节点的比特分配,进一步提升了计算效率。仿真结果表明,所提算法在满足实时性的要求下具有更稳定的跟踪性能。     

数字图书馆系统的网络存储技术研究

主要对几种常用的网络存储技术DAS、NAS、SAN进行了分析,并在此基础上提出了我国数字图书馆在现有国情下适合的一种组合的网络存储方式。     

一种高性能的USN文件服务器的研究与实现

随着网络上的数据呈爆炸性的增长，融合NAS和SAN技术的USN(统一存储网)正成为新的研究热点．针对传统文件服务器的缺点，我们实现了一个新的基于USN的文件服务器UsnFS(USN-based File Server)，在文中，我们详细介绍了这种文件服务器的设计方案，并进行了相应的试验测试和性能分析．