A blockchain-empowered authentication scheme for worm detection in wireless sensor network

Wireless Sensor Network(WSN)is a distributed sensor network composed a large number of nodes with low cost,low performance and self-management.The special structure of WSN brings both convenience and vulnerability.For example,a malicious participant can launch attacks by capturing a physical device.Therefore,node authentication that can resist malicious attacks is very important to network security.Recently,blockchain technology has shown the potential to enhance the security of the Internet of Things(IoT).In this paper,we propose a Blockchain-empowered Authentication Scheme(BAS)for WSN.In our scheme,all nodes are managed by utilizing the identity information stored on the blockchain.Besides,the simulation experiment about worm detection is executed on BAS,and the security is evaluated from detection and infection rate.The experiment results indicate that the proposed scheme can effectively inhibit the spread and infection of worms in the network.

模拟Worms的游戏设计与实现

本课题的目标是仿照Team17的Worms2D系列游戏产品,开发一款2D游戏,了解整个游戏开发流程,设计一款2D游戏引擎,封装了Direct3D9的部分图形绘制接口、图形控制接口、音效接口,并在此基础上实现一款2D射击游戏.

WORMS评分中滑膜炎症与膝骨性关节炎中医证型的关联性研究

目的:探讨膝骨性关节炎性滑膜炎与膝骨关节炎中医证型的相关性。方法:自2015年1月至2018年6月,选取213例膝骨关节炎的患者,进行中医辨证分型,其MRI影像进行WORMS评分,同时做WORMS评分中滑膜炎和中医证型的相关性分析。结果:213例患者中,风寒湿痹证25例(占11.7%),风湿热痹证84例(占39.4%),瘀血痹阻证43例(占20.2%),肝肾亏虚证61例(占28.6%);在WORMS评分中,滑膜炎评分为0分的12例(占5.6%),1分的60例(占28.2%),2分的50例(占23.5%),3分的91例(占42.7%);相关性分析中,差异有统计学意义,WORMS评分中滑膜炎3分组更容易发生在风湿热痹证中(χ^2=137.286,P=0.000)。结论:膝骨性关节炎滑膜炎患者临床上以风湿热痹型(39.4%,84/213)为主,这对于相关治疗有一定的指导意义。

Modeling and Defending Passive Worms over Unstructured Peer-to-Peer Networks

Passive worms can passively propagate through embedding themselves into some sharing files, which can result in significant damage to unstructured P2P networks. To study the passive worm behaviors, this paper firstly analyzes and obtains the average delay for all peers in the whole transmitting process due to the limitation of network throughput, and then proposes a mathematical model for the propagation of passive worms over the unstructured P2P networks. The model mainly takes the effect of the network throughput into account, and applies a new healthy files dissemination-based defense strategy according to the file popularity which follows the Zipf distribution. The simulation results show that the propagation of passive worms is mainly governed by the number of hops, initially infected files and uninfected files. The larger the number of hops, the more rapidly the passive worms propagate. If the number of the initially infected files is increased by the attackers, the propagation speed of passive worms increases obviously. A larger size of the uninfected file results in a better attack performance. However, the number of files generated by passive worms is not an important factor governing the propagation of passive worms. The effectiveness of healthy files dissemination strategy is verified. This model can provide a guideline in the control of unstructured P2P networks as well as passive worm defense.

New Localities and Palaeoscolecid Worms from the Cambrian(Stage 4,Series 2)Guanshan Biota in Kunming,Yunnan,South China

The Guanshan Biota from the Cambrian Stage 4 Wulongqing Formation is a typical Burgess-shale type Lagerst？tte that had witnessed the Cambrian explosion. Here we report two new localities of the Guanshan Biota, which is located at Baimei village, south of Kunming and Xinglong village, Wuding County, Yunnan Province respectively. Both localities produce soft-body fossils and several new taxa, e.g. a new species of palaeoscolecidans （Palaeoscolex xinglongensis sp. nov.） reported herein. The comparative study of the new species with similar form not only indicates that there is a diversification of palaeoscolecid species in Guanshan Biota, but also strengthens the ties between the older Chengjiang Biota and the younger Kaili Biota （and also the coeval Burgess Shale community）. Three paleoecological features, including high diversity, little disparity and richness of palaeoscolecid worms, are summarized as a case study to represent the differences between Guanshan and Chengjiang Biota.

Global dynamics of a novel multi-group model for computer worms

In this paper, we study worm dynamics in computer networks composed of many autonomous systems. A novel multigroup SIQR （susceptible-infected-quarantined-removed） model is proposed for computer worms by explicitly considering anti-virus measures and the network infrastructure. Then, the basic reproduction number of worm R0 is derived and the global dynamics of the model are established. It is shown that if R0 is less than or equal to 1, the disease-free equilibrium is globally asymptotically stable and the worm dies out eventually, whereas, if R0 is greater than 1, one unique endemic equilibrium exists and it is globally asymptotically stable, thus the worm persists in the network. Finally, numerical simulations are given to illustrate the theoretical results.

Instant Messaging Worms Propagation Simulation and Countermeasures

Instant messaging （IM） has become one of the most popular online communication tools among consumer and enterprise IM users. It provides instant message delivery, as well as convenient file transfer services. The increasing popularity and functionalities of IM programs have made it increasingly attractive for attackers, especially for worm writers. IM contact list offers worm an easy way of finding potential victims so that the worm could achieve a surprising spreading speed. This paper first presents our experimental results of simulating IM worm propagation in the logical network defined by IM contact lists, which is reported to be a scale-free network. Then, the existing proposals for detecting and containing IM worm epidemics are discussed. At last, a new algorithm for this purpose is presented, which is based on the observation of the bi-directional nature of IM worm traffic, and its advantages and possible improvements in implementation are analyzed. The simulation results show the proposed algorithm is of significant effect on restricting IM worm propagation.

Simulating Greedy Propagation of P2P Worms

Greedy propagation policy for unstructured P2P worms employs the neighboring node list of each node in peer-to-peer （P2P） network to speed up the propagation of P2P worms. After describing the technique background of P2P worms, the algorithm of greedy propagation is addressed. Simulating design for this novel propagation policy is also described. Then, the effects of the greedy propagation policy on spreading speed, convergence speed, and attacking traffic in static P2P worms are simulated and discussed. The primary experimental results show that the greedy propagation is harmful and can bring severe damages to P2P network.

An Immunization Strategy for Social Network Worms Based on Network Vertex Influence

Along with the rapid development of social networks, social network worms have constituted one of the major internet security problems. The root of worm is the inevitable software vulnerability during the design and implementation process of software. So it is hard to completely avoid worms in the existing software engineering systems. Due to lots of bandwidth consumption, the patch cannot be transmitted simultaneously by the network administrator to all hosts. This paper studies how to prevent the propagation of social network worms through the immunization of key nodes. Unlike existing containment models for worm propagation, a novel immunization strategy is proposed based on network vertex influence. The strategy selects the critical vertices in the whole network. Then the immunization is applied on the selected vertices to achieve the maximal effect of worm containment with minimal cost. Different algorithms are implemented to select vertices. Simulation experiments are presented to analyze and evaluate the performance of different algorithms.

Research in Computer Viruses and Worms

Viruses and worms have become so common that most computer users now accept them as a fact of life.This paper introduces the definitions and difference of the computer viruses and worms.Some main research problems about the computer viruses and worms in recent years are also summarized and discussed in detail.Finally the developing trend of the computer virus and worms is proposed.

Research and Development of P2P Worms

With the development and the application of many popular peer-to-peer （P2P） systems such as eMule and BitTorrent, worms probably employ the features of these P2P networks to put them at risk. Some features, such as the local routing table and the application routing mechanism, are helpful to quickly distribute the P2P worms into the networks. This paper aims to give a comprehensive survey of P2P worms. The definition and the classification of P2P worms are discussed firstly. Then, the research and development of P2P worms, including experimental analysis, propagation modeling, and defensive approaches, are addressed and analyzed in detail.

Comparison of Two Pour-On Formulations of Ivermectin against Gastrointestinal Worms, Fleas and Lice in Naturally Infected Stray Dogs

The aim of the present study was to evaluate the efficacy of two commercial pour-on ivermectin formulations against intestinal parasites (IP), fleas and lice in naturally infested stray dogs. Eighteen crossbreed dogs with eggs of IP as well as adult fleas and lice were included in the trial. On day 0, the dogs were randomly divided into 3 groups of 6 animals each: a group receiving a single pour-on treatment with 0.5% ivermectin (500 mcg/kg), a group treated similarly with 0.2% iver-mectin (200 mg/kg), and a control group. Fecal and skin analyses were carried out on days 0, 7, 14, 21 and 28 to determine the reduction of eggs and the number of fleas and lice. Weight gain was also measured on day 28. On day 30, the dogs were humanely sacrificed in order to count adult IP. Efficacy was measured as the percentage of the reduction of eggs per gram fecal mass (EPGF), of adult IP, fleas and lice relative to the control group. For the eggs of IP, ivermectin at 0.5% showed an efficacy of 100% against ascarids and 79% against Ancylostoma caninum. ivermectin at 0.2% removed 90.2% of the ascarids and 50.4% of A. caninum. For adult IP, the efficacy of 0.5% iver-mectin against Toxocara canis and A. caninum was 100%, and for 0.2% ivermectin it was 62.4% and 76.4% for T. canis and A. caninum, respectively. Both compounds were 100% effective against lice and 96% and 71.1% efficacious against fleas, respectively. However, neither treatment was effective against Dypilidium caninum. Weight gain in treated dogs was statistically different from that of the controls (p < 0.05). We concluded that 0.5% pour-on ivermectin showed better efficacy than 0.2% pour-on ivermectin in the reduction of eggs and adult intestinal parasites and fleas;it was similarly efficacious against lice.

Research on the Propagation Models and Defense Techniques of Internet Worms

Internet worm is harmful to network security,and it has become a research hotspot in recent years.A thorough survey on the propagation models and defense techniques of Internet worm is made in this paper.We first give its strict definition and discuss the working mechanism.We then analyze and compare some repre-sentative worm propagation models proposed in recent years,such as K-M model,two-factor model,worm-anti-worm model（WAW）,firewall-based model,quarantine-based model and hybrid benign worm-based model,etc.Some typical defense techniques such as virtual honeypot,active worm prevention and agent-oriented worm defense,etc.,are also discussed.The future direction of the worm defense system is pointed out.

侧链含有不同电子受体的聚咔唑衍生物的合成及其WORM型存储性能

利用Suzuki偶联反应合成了3种侧链含有不同电子受体的可溶性D-A型聚咔唑衍生物：聚[（9-（2-己基葵基）-9 H-咔唑）-（9-（4-硝基苯基）-9 H-咔唑）]（PCz-NO2）、聚[（9-（2-己基葵基）-9 H-咔唑）-（4-（9 H-咔唑-9-基）苯甲醛）]（PCz-CHO）和聚[（9-（2-己基葵基）-9 H-咔唑）-（4-（9 H-咔唑-9-基）苯甲腈）]（PCz-CN）。基于这3种聚合物的存储器件（器件结构：Al（200nm）/高分子（90nm）/氧化铟锡（ITO）均表现出典型的电双稳电子开关效应和非易失性一次写入多次读出（WORM）型存储性能。随着共轭聚合物光学带隙的增加[2.26eV（PCz-NO2）→2.79eV（PCzCHO）→3.20eV（PCz-CN）],相应器件的启动阈值电压逐渐增大（-1.70V→-1.81V→-1.89V）;而电流开关比（ON/OFF）则依次减小（6.63×10^4→4.08×10^4→5.68×10^3）。含氰基的聚咔唑衍生物需要的开启电压最大,展现出来的电流开关比在3种聚合物中则最小。

WORM存储技术及其在医院中的应用

本文简要介绍了WORM存储技术的基本概念,指出了基于光盘、磁带和磁盘的WORM技术的实现方法和各自的优缺点,讨论了医疗信息的特征和在医院信息化建设中应用WORM存储技术的必要性和迫切性,并给出了在医院中运用WORM技术的设计方案和应注意的问题。

Contact Toxicity and Antifeedant Activity of Aconitum flavum Extract against Cabbage Worm

[ Objective] The paper was to study the contact toxicity and antifeedant activity of Aconitum flavum against cabbage worm. [ Method ] In- sect dipping method was adopted to determine the contact toxicity of the extracts of A. fiavum extracted from five polar solvents including ethanol, petroleum ether, ether, ethyl acetate, n-butanol and water; leaf dish method was adopted to determine the antifeedant activities of five solvent ex- tracts including ethanol, petroleum ether, ether, ethyl acetate, n-butanol and water against cabbage worm, [ Result] Extracts of A. flavum had high contact toxicity against cabbage worm. When the concentration was 100.00 mg/ml, the corrected mortality at 48 h roached 97.24%, and the insec- ticidal activities of five solvent extracts against cabbage worm in sequence were water 〉 n-butanol 〉 ethyl acetate 〉 ether 〉 petroleum ether, the cor- rected mortality of water extract at 48 h was 95.87% ; the antifeedant activities of five solvent extracts in sequence were water 〉 n-butanol 〉 ethyl ac- etate 〉 ether 〉 petroleum ether. [ Conclusion] Extracts of A. flavum had strong contact toxicity and antifeedant activity against cabbage worm, and the active ingredients with contact toxicity and antifeedant activity might be a kind of polar compound.

一种WORM光盘文件存储系统的设计

本文讨论了ＷＯＲＭ光盘构成文件存储系统时由于写一次特性引起的各种处理方式。给出了一种存档后备式文件系统的设计。详细说明了其层次结构、文卷结构、文件结构，以及用户界面、层内部界面等设计。同时给出了速度及可靠性的设计考虑。

Win32.SQLExp.Worm蠕虫病毒分析与对策

分析了Win32.SQLExp.Worm蠕虫病毒原理,并给出相应解决方案。

Parametric Analysis of the End Face Engagement Worm Gear

A novel specific type of worm drive, so-called end face engagement worm gear（EFEWD）, is originally presented to minimize or overcome the gear backlash. Different factors, including the three different types, contact curves, tooth profile, lubrication angle and the induced normal curvature are taken into account to investigate the meshing characteristics and create the profile of a novel specific type of worm drive through mathematical models and theoretical analysis. The tooth of the worm wheel is very specific with the sine-shaped tooth which is located at the alveolus of the worm and the tooth profile of a worm is generated by the meshing movement of the worm wheel with the sine-shaped tooth, but just the end face of the worm（with three different typical meshing types） is adapted to meshing, and therefore an extraordinary manufacturing methods is used to generate the profile of the end face engagement worm. The research results indicates that the bearing contacts of the generated conjugate hourglass worm gear set are in line contacts, with certain advantages of no-backlash, high precision and high operating efficiency over other gears and gear systems besides the end face engagement worm gear drive may improve bearing contact, reduce the level of transmission errors and lessen the sensitivity to errors of alignment. Also, the end face engagement worm can be easily made with superior meshing and lubrication performance compared with the conventional techniques. In particular, the meshing and lubrication performance of the end face engagement worm gear by using the end face to meshing can be increased over 10% and 7%, respectively. This investigate is expect to provide a new insight on the design of the future no-backlash worm drive for industry.