Powe宿命论量表的汉化及信效度检验

目的:汉化Powe宿命论量表(Powe Fatalism Inventory, PFI),并在结直肠癌高危人群中进行信效度检验。方法:依据Beaton跨文化调试指南对量表进行翻译、回译、跨文化调试及预试验形成中文版Powe宿命论量表。于2022年9月18日—2023年2月18日选取348例云南省10所医院的肿瘤科及其中1所医院的普外科和消化内科40~74岁的结直肠癌高危人群进行问卷调查,验证量表的信效度。结果:中文版Powe宿命论量表共4个维度,15个条目,分别为先定(7个条目)、死亡的必然性(3个条目)、悲观(3个条目)、恐惧(2个条目)。总量表的Cronbach′s α系数为0.853,各维度的Cronbach′s α系数为0.582~0.836;总量表的折半信度为0.845,总量表的重测信度为0.823,各维度的重测信度为0.514~0.794。验证性因子分析结果显示,模型拟合度良好。结论:中文版Powe宿命论量表具有良好的信度和效度,可以用来测量结直肠癌高危人群的癌症宿命论水平。

PowerPoint课件中插入Flash动画及其存取与播放

本文总结了PowerPoint课件中插入Flash动画及其存取与播放的一些方法技巧。

用PowerPoint制作平抛运动的演示课件

本文介绍应用PowerPoint 2003制作平抛运动的演示课件,给出了详细的制作过程和方法,课件效果较好,制作过程简单易学,对于只学习过PowerPoint的教师不失为一个较好的方法。

Research on Impact Mechanism and Power System of Urbanization in West China

Based on the current situation of urbanization development in West China, this paper analyses main factors responsible for sluggish urbanization in West China as follows: impact of environment factor, impact of population quality and quantity, lagging of public product service, stagnancy of technological development, backwardness of slow growth, and rigidity of system building. And then this paper analyses the restriction mechanism of urbanization in West China: at the superficial level, the constraints of urbanization in West China arise from the shortage of capital; at the profound level, the backward culture contributes to the constraints of urbanization in West China. The thread of resolving restriction mechanism of urbanization in West China is put forward from system, economy and culture. On the basis of this thread, we construct the power system for the development of urbanization in West China. The power system for urbanization in West China should be propelled by "four forces", namely, pull of external forces, cohesive strength of regional market environment, expansion power inside countryside, traction of industrial structure adjustment. Innovation is the engine of impetus for urbanization in West China; spatial clustering and modernization of industry is the major driving force for urbanization; the government behaviour, driving of foreign investment, great projects and other forces are supplementary power. Via the main power, we should take the market as medium to achieve the role of power in promoting urbanization.

Predictive power of statistical significance

A statistically significant research finding should not be defined as a P-value of 0.05 or less, because this definition does not take into account study power. Statistical significance was originally defined by Fisher RA as a P-value of 0.05 or less. According to Fisher, any finding that is likely to occur by random variation no more than 1 in 20 times is considered significant. Neyman J and Pearson ES subsequently argued that Fisher's definition was incomplete. They proposed that statistical significance could only be determined by analyzing the chance of incorrectly considering a study finding was significant(a Type Ⅰ?error) or incorrectly considering a study finding was insignificant(a Type Ⅱ error). Their definition of statistical significance is also incomplete because the error rates are considered separately, not together. A better definition of statistical significance is the positive predictive value of a P-value, which is equal to the power divided by the sum of power and the P-value. This definition is more complete and relevant than Fisher's or Neyman-Peason's definitions, because it takes into account both concepts of statistical significance. Using this definition, a statistically significant finding requires a P-value of 0.05 or less when the power is at least 95%, and a P-value of 0.032 or less when the power is 60%. To achieve statistical significance, P-values must be adjusted downward as the study power decreases.

PowerPlex 16 HS试剂盒在陈旧血样DNA检验中的应用

PowerPlex16HS系统是对16个STR基因座进行联合扩增试剂盒，对PCR抑制物的耐受性较强，适于直接扩增^[1-2]。本文作者在公安部的打拐专项行动中，采用该试剂盒，对保存近10年的300份陈旧血样进行DNA检验，取得了较好的效果。

Game theory attack pricing for mining pools in blockchain-based IoT

The malicious mining pool can sacrifice part of its revenue to employ the computing power of blockchain network.The employed computing power carries out the pool mining attacks on the attacked mining pool.To realize the win-win game between the malicious mining pool and the employee,the paper proposes an Employment Attack Pricing Algorithm(EAPA)of mining pools in blockchain based on game theory.In the EAPA,the paper uses mathematical formulas to express the revenue of malicious mining pools under the employment attack,the revenue increment of malicious mining pools,and the revenue of the employee.It establishes a game model between the malicious mining pool and the employee under the employment attack.Then,the paper proposes an optimal computing power price selection strategy of employment attack based on model derivation.In the strategy,the malicious mining pool analyzes the conditions for the employment attack,and uses the derivative method to find the optimal utilization value of computing power,employees analyze the conditions for accepting employment,and use the derivative method to find the optimal reward value of computing power.Finally,the strategy finds the optimal employment computing power price to realize Nash equilibrium between the malicious mining pool and the employee under the current computing power allocation.The simulation results show that the EAPA could find the employment computing power price that realizes the win-win game between the malicious mining pool and the employee.The EAPA also maximizes the unit computing power revenue of employment and the unit computing power revenue of honest mining in malicious mining pool at the same time.The EAPA outperforms the state-of-the-art methods such as SPSUCP,DPSACP,and FPSUCP.

A Systematic Literature Review on Blockchain Consensus Mechanisms’ Security: Applications and Open Challenges

This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is to comprehensively investigate prominent mechanisms’security features and vulnerabilities,emphasizing their security considerations,applications,challenges,and future directions.The existing literature offers valuable insights into various consensus mechanisms’strengths,limitations,and security vulnerabilities and their real-world applications.However,there remains a gap in synthesizing and analyzing this knowledge systematically.Addressing this gap would facilitate a structured approach to understanding consensus mechanisms’security and vulnerabilities comprehensively.The study adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines and computer science standards and reviewed 3749 research papers from 2016 to 2024,excluding grey literature,resulting in 290 articles for descriptive analysis.The research highlights an increased focus on blockchain consensus security,energy efficiency,and hybrid mechanisms within 60%of research papers post-2019,identifying gaps in scalability,privacy,and interoperability for future exploration.By synthesizing the existing research and identifying the key trends,this SLR contributes to advancing the understanding of blockchain consensus mechanisms’security and guiding future research and structured innovation in blockchain systems and applications.

面向能源区块链的分布式电力交易系统设计

研究能源区块链驱动的分布式电力交易系统设计。通过整合POW共识算法的电力交易工作流程、能源区块链平台的架构探索以及优化电力交易流程,探讨分布式电力市场的可行性和经济潜力。研究结果表明,太阳能光伏发电功率与挖矿成本之间存在密切联系,需要根据光照和功率波动调整电力交易策略以降低成本。改进的连续双向拍卖模式通过智能合约提高了交易效率,同时区块链技术确保了交易的安全和透明性,可以为未来电力市场的可持续性和创新提供参考。

RPFT:基于PoW的高效率共识算法

随着区块链技术的发展,作为其核心技术的共识算法也成为了很多学者的研究热点,良好的共识算法可以有效解决区块链的安全性、扩展性、能耗代价和性能效率等问题.本文选取Raft共识算法作为研究对象,针对Raft算法领导者选举中由于投票分裂而造成选举延时问题,提出了一种基于PoW的高效率共识算法--RPFT共识算法.该算法首先利用PoW共识算法成功选取出高效率的副领导者节点;其次为每一个节点赋予一个等待时间,并根据节点行为调整等待时间;最后,引入等待时间选举模型,结合PoW共识算法优化Raft算法投票选举,快速选举出高效的领导者节点.实验结果表明,新提出的RPFT算法对比Raft算法在选举速度上提高了75%左右;在共识效率方面,RPFT算法共识效率提高了40%.

面向POW共识的日蚀攻击动态防御机制

日蚀攻击是区块链系统中一种恶意攻击手段,攻击者通过垄断受害节点网络,达到欺骗、控制目的。从实际区块链应用中得知,目前为止还没有防御日蚀攻击的好方法,因此为了解决该问题,设计了一种针对POW共识区块链系统的日蚀攻击动态防御模型,其基于节点间互相评价机制。具体来说,通过综合客户端之间互相评价的结果,基于kademlia算法和设计的等级值评估机制,为每个节点评估、存储一个等级,节点根据等级值和等级限定值之间的关系选择正常对等节点作为邻居,以避免恶意节点。经过实验证明,该方法可以有效抵御日蚀攻击。该方法改进了先前提出的一系列防御策略,无需对区块链系统协议、网络等进行更改,能够较高概率地成功抵御日蚀攻击,并且模型产生的开销也很小,非常适合实际部署。

Hybrid Smart Contracts for Securing IoMT Data

Data management becomes essential component of patient healthcare.Internet of Medical Things(IoMT)performs a wireless communication between E-medical applications and human being.Instead of consulting a doctor in the hospital,patients get health related information remotely from the physician.The main issues in the E-Medical application are lack of safety,security and priv-acy preservation of patient’s health care data.To overcome these issues,this work proposes block chain based IoMT Processed with Hybrid consensus protocol for secured storage.Patients health data is collected from physician,smart devices etc.The main goal is to store this highly valuable health related data in a secure,safety,easy access and less cost-effective manner.In this research we combine two smart contracts such as Practical Byzantine Fault Tolerance with proof of work(PBFT-PoW).The implementation is done using cloud technology setup with smart contracts(PBFT-PoW).The accuracy rate of PBFT is 90.15%,for PoW is 92.75%and our proposed work PBFT-PoW is 99.88%.

高压直流换流站分合闸控制装置故障分析

为了减少直流输电系统投切交流滤波器过程中产生的带有直流分量的涌流和操作电压,以及减少投切换流变压器和站用变压器产生的励磁涌流,兴仁换流站采用了分合闸控制POW装置控制其分合。介绍了POW装置的工作原理、控制策略,讨论了实际运行中POW装置出现的多种故障,分析了POW装置出现故障的原因,并对POW装置的运行维护提出了建议。结合一年的运行经验,对比未安装之前,投切交流滤波器减少了60%操作电压,投切变压器减少了80%的励磁涌流。结果表明,使用POW装置效果较好。

基于新型区块的售票系统的设计与实现

以电影院售票系统为例,将区块链技术应用于传统电影院售票系统,设计并实现了基于新型区块的电影院售票系统。在以太坊上实验结果表明,新型区块存储的数据量高于传统区块存储数据量3.95倍。基于新型区块的电影院售票系统,改进了传统电影院售票系统存在的数据被篡改、虚假票房、偷税漏税等缺陷,为区块链技术在售票系统中的应用提供参考。

一种基于区块链PoS共识算法的改进研究

区块链共识算法保证了区块链中的区块按时间戳有序生成,算法优劣直接影响区块链系统性能。PoS共识算法是一种区块链公有链采用的主流共识算法,但生成区块的时间具有随机性,有些情况下区块间隔时间过长,不能满足商业应用场景需要;针对PoS共识算法生成区块的速度存在的性能局限,改进设计的Silkworm算法,通过智能合约对最快生成区块时间和最慢生成区块时间进行定义,结合Raft算法进行主节点选举;在有交易的情况下,当PoS共识算法未在定义的最快时间内生成区块时,Silkworm算法确保由主节点自动快速生成区块;在无交易情况下,当PoS共识算法未在定义的最慢时间内生成区块时,Silkworm算法也由主节点生成区块。而当主节点关闭或出故障时,PoS共识算法仍然生效正常生成区块。通过实验验证:Silkworm算法能较大提升基于PoS共识算法的区块链的性能,保证了区块链的安全性和健壮性,更能满足商业应用场景的需要。

区块链技术与应用前瞻综述

区块链技术是一种去中心化、去信任化的分布式数据库技术方案。该数据库由参与系统的所有节点集体维护,具有去中心化、不可篡改、透明、安全等特性。区块链技术归功于比特币应用,它作为比特币的底层技术支持,是比特币系统的核心支撑。区块链技术具有广阔的发展前景,从关键技术、内容、原理、瓶颈、应用和前景几个方面进行介绍,对相关研究问题进行探讨。

The Research and Development to Glasses to See the Cancer Cells

Cancer cells are notoriously difficult to see,even under high-powered magnification(放大).The glasses are designed to make it easier for surgeons to distinguish cancer cells from healthy cells,helping to ensure that no stray tumor cells are left behind during surgery."We’re in the early stages of this technology,and more development and testing will be done,but we’re certainly

基于有向无环图的高效区块链共识算法

针对传统区块链共识算法存在效率低和大量资源浪费的问题,提出一种使用基于ID分类的有向无环图数据结构取代传统区块链链式数据结构的算法,解决了传统区块链项目无法在短时间内确认大量交易的问题.该算法使用基于ID分类的有向无环图数据结构能更简单地达成共识,适用于多用户在同一时间进行交易确认.该共识算法与传统区块链项目相比能在更短的时间内确认交易,从而可节省大量的硬件资源,且提升区块链对交易的处理效率.

基于Go语言的区块链模型设计与实现

研究区块链技术原理、特点及POW工作量证明算法,构建基于Go语言的区块链模型,实现挖矿、交易数据打包、区块上链等操作。为了保证交易数据的安全性,模型对区块数据哈希校验,检验数据是否被篡改。在仿真实验中,使用Postman软件对指定端口进行post和get操作,实验结果证明,模型能完成工作量计算,能够实现交易数据上链等操作。

基于信用模型的工作量证明算法

提出了一种基于信用模型的共识协议。首先,该共识协议借鉴了个人信用风险评估的思想,设计了一种基于BP神经网络的节点信用度模型。其次,构造了一种分片轮转模型,它可以根据节点的信用度高低分割搜索空间产生新区块,同时对协议所面临的可能攻击进行分析,修复了协议存在的漏洞。最后,仿真实验表明共识协议既能有效地降低新区块产生过程中重复计算的巨大资源消耗,也能抑制大型矿池的产生,使整个区块链系统变得更加安全可靠。