Asymmetric image encryption algorithm based on a new three-dimensional improved logistic chaotic map

Based on some analyses of existing chaotic image encryption frameworks and a new designed three-dimensional improved logistic chaotic map(3D-ILM),an asymmetric image encryption algorithm using public-key Rivest–Shamir–Adleman(RSA)is presented in this paper.In the first stage,a new 3D-ILM is proposed to enhance the chaotic behavior considering analysis of time sequence,Lyapunov exponent,and Shannon entropy.In the second stage,combined with the public key RSA algorithm,a new key acquisition mathematical model(MKA)is constructed to obtain the initial keys for the 3D-ILM.Consequently,the key stream can be produced depending on the plain image for a higher security.Moreover,a novel process model(NPM)for the input of the 3D-ILM is built,which is built to improve the distribution uniformity of the chaotic sequence.In the third stage,to encrypt the plain image,a pre-process by exclusive OR(XOR)operation with a random matrix is applied.Then,the pre-processed image is performed by a permutation for rows,a downward modulo function for adjacent pixels,a permutation for columns,a forward direction XOR addition-modulo diffusion,and a backward direction XOR addition-modulo diffusion to achieve the final cipher image.Moreover,experiments show that the the proposed algorithm has a better performance.Especially,the number of pixels change rate(NPCR)is close to ideal case 99.6094%,with the unified average changing intensity(UACI)close to 33.4634%,and the information entropy(IE)close to 8.

Balanced Functional Maps for Three-Dimensional Non-Rigid Shape Registration

Three-dimensional(3D)shape registration is a challenging problem,especially for shapes under non-rigid transformations.In this paper,a 3D non-rigid shape registration method is proposed,called balanced functional maps(BFM).The BFM algorithm generalizes the point-based correspondence to functions.By choosing the Laplace-Beltrami eigenfunctions as the function basis,the transformations between shapes can be represented by the functional map(FM)matrix.In addition,many constraints on shape registration,such as the feature descriptor,keypoint,and salient region correspondence,can be formulated linearly using the matrix.By bi-directionally searching for the nearest neighbors of points’indicator functions in the function space,the point-based correspondence can be derived from FMs.We conducted several experiments on the Topology and Orchestration Specification for Cloud Applications(TOSCA)dataset and the Shape Completion and Animation of People(SCAPE)dataset.Experimental results show that the proposed BFM algorithm is effective and has superior performance than the state-of-the-art methods on both datasets.

应用Carto3电解剖标测系统指导射频消融治疗室性心律失常

目的报告应用Carto 3电解剖标测系统指导射频消融治疗室性心律失常中的初步体验。方法采用Carto 3与CartoXP系统,以单一专用导管行心室电解剖重建,激动顺序、起搏与拖带标测,实施射频消融。观察消融的即刻成功率、成功靶点的分布、并发症,手术时间及X线曝光时间、随访复发情况。比较Carto 3与CartoXP系统两组数据。结果共入选22例患者,每组各11例,Carto 3组即刻成功11例,成功消融部位:右室流出道间隔部5例,右室流出道游离壁2例,三尖瓣环1例,主动脉二尖瓣连接处1例,左后分支处1例,右室流出道游离壁+左冠窦1例。CartoXP组即刻成功11例,成功消融靶点均位于右室流出道,两组均未见并发症。术后随访1～6个月无1例复发。Carto 3组与CartoXP组比较,手术时间(57±29 min vs 62±10 min,P<0.01)与X线投照时间(5.23±5.42 min vs 8.45±2.33 min,P<0.01)明显缩短。结论应用Carto 3电解剖标测系统可快速重建心脏电解剖结构,提高消融治疗室性心律失常的效率。

Carto3系统指导射频消融治疗流出道室性心律失常的效果

目的探讨应用carto3电解剖标测系统指导射频消融治疗流出道室性心律失常的效果。方法选择2011年1月至2012年10月住院治疗的室性心律失常患者50例，按人院时间先后分为Carto3组和cartoXP组，各25例。前者采用carto3电解剖标测系统，后者采用carto XP电解剖标测系统，以单一专用导管行心室电解剖重建，激动顺序、起搏与拖带标测，实施射频消融。观察2组消融的即刻成功率、成功靶点的分布、并发症、手术时间、x线曝光时间及随访复发情况。结果①carto3组即刻成功24例，失败1例。成功消融部位：右心室流出道问隔部14例，右心室流出道游离壁5例，肺动脉瓣上1例，左冠状窦2例，主动脉和二尖瓣环连接处1例，二尖瓣环1例；失败者为心脏扩大伴心功能不全患者，考虑其为心外膜起源室性早搏；手术时间（55±25）min，X线投照时间（6±3）min。②canoXP组即刻成功24例，失败1例。成功消融靶点：右心室流出道间隔部18例，右心室流出道游离壁3例，右冠状窦2例，左冠状窦1例；失败者为左心室流出道室性早搏，考虑其位于左右心室流出道之间，消融能量不能达到；手术时间（67±15）min，X线投照时间为（9±5）min。2组均无并发症，即刻成功率均为96．0％（24／25）。Carto3组手术及x线投照时间均明显短于Caao XP组，差异均有统计学意义（均P〈0．01）。结论应用Carto3电解剖标测系统可快速重建心脏电解剖结构，提高消融治疗室性心律失常的效率。

采用CARTO 3 Version 6.0系统指导心房颤动消融术后房性心动过速的标测和消融

目的采用CARTO 3 Version 6.0系统指导心房颤动(简称房颤)消融术后房性心动过速(简称房速)标测中的应用经验和技巧。方法2020年7月至2020年12月因房速行导管消融术的11例患者(以上患者均曾接受房颤导管消融术)。术中放置6F十极冠状静脉窦电极导管,在CARTO 3 Version 6.0系统指引下,利用PENTARAY高密度标测电极进行三维电解剖标测,在扩展的“早接晚”(EEML)功能中设置高阈值为75%~80%,对应的低阈值为25%~20%精准确认房速的关键部位及消融靶点,消融终止心动过速,验证消融线阻滞且心动过速不再自发及诱发则手术成功。结果11例术中均为房速心律,EEML能够提供清晰的瘢痕阻滞区,明确其房速机制,经标测后证实其中8例为单源性房速,余3例可经心房刺激诱发或自行转化出2种以上不同机制的房速。房速平均周长为(256.5±37.1)ms。肺静脉相关房速4例,其余包括顶部依赖折返2例、二尖瓣环折返1例,左房瘢痕相关折返性房速3例,右房瘢痕相关折返性房速1例。首次消融中所有患者房速终止并无法再次诱发。中位数随访时间8个月,1例房速复发并接受第二次消融,证实为顶部依赖折返,1例复发房颤。消融术中未出现严重并发症。结论CARTO 3 Version 6系统提供的EEML功能为识别瘢痕造成的阻滞区提供了更直观的手段。房颤消融术后房速的机制多样,通常与此前房颤消融造成的瘢痕有关。

Sampling Designs for Validating Digital Soil Maps: A Review

Sampling design(SD) plays a crucial role in providing reliable input for digital soil mapping(DSM) and increasing its efficiency.Sampling design, with a predetermined sample size and consideration of budget and spatial variability, is a selection procedure for identifying a set of sample locations spread over a geographical space or with a good feature space coverage. A good feature space coverage ensures accurate estimation of regression parameters, while spatial coverage contributes to effective spatial interpolation.First, we review several statistical and geometric SDs that mainly optimize the sampling pattern in a geographical space and illustrate the strengths and weaknesses of these SDs by considering spatial coverage, simplicity, accuracy, and efficiency. Furthermore, Latin hypercube sampling, which obtains a full representation of multivariate distribution in geographical space, is described in detail for its development, improvement, and application. In addition, we discuss the fuzzy k-means sampling, response surface sampling, and Kennard-Stone sampling, which optimize sampling patterns in a feature space. We then discuss some practical applications that are mainly addressed by the conditioned Latin hypercube sampling with the flexibility and feasibility of adding multiple optimization criteria. We also discuss different methods of validation, an important stage of DSM, and conclude that an independent dataset selected from the probability sampling is superior for its free model assumptions. For future work, we recommend: 1) exploring SDs with both good spatial coverage and feature space coverage; 2) uncovering the real impacts of an SD on the integral DSM procedure;and 3) testing the feasibility and contribution of SDs in three-dimensional(3 D) DSM with variability for multiple layers.

A novel hybrid cryptosystem based on DQFrFT watermarking and 3D-CLM encryption for healthcare services

Quaternion algebra has been used to apply the fractional Fourier transform(FrFT)to color images in a comprehensive approach.However,the discrete fractional random transform(DFRNT)with adequate basic randomness remains to be examined.This paper presents a novel multistage privacy system for color medical images based on discrete quaternion fractional Fourier transform(DQFrFT)watermarking and three-dimensional chaotic logistic map(3D-CLM)encryption.First,we describe quaternion DFRNT(QDFRNT),which generalizes DFRNT to handle quaternion signals effectively,and then use QDFRNT to perform color medical image adaptive watermarking.To efficiently evaluate QDFRNT,this study derives the relationship between the QDFRNT of a quaternion signal and the four components of the DFRNT signal.Moreover,it uses the human vision system's(HVS)masking qualities of edge,texture,and color tone immediately from the color host image to adaptively modify the watermark strength for each block in the color medical image using the QDFRNT-based adaptive watermarking and support vector machine(SVM)techniques.The limitations of watermark embedding are also explained to conserve watermarking energy.Second,3D-CLM encryption is employed to improve the system's security and efficiency,allowing it to be used as a multistage privacy system.The proposed security system is effective against many types of channel noise attacks,according to simulation results.

经主动脉窦消融成功的室性心律失常体表心电图特点

目的分析经主动脉窦消融成功的室性心律失常体表心电图特点。方法 36例频发室性早搏/非持续性室性心动过速(PVCs/NSVT)的患者经主动脉逆行途径,在CARTO三维电解剖标测指导下,在主动脉根部-左室流出道衔接部进行三维解剖重建、激动顺序标测和指导消融,且消融成功(1例部分成功),并分析其体表心电图特点。结果 36例患者,经左冠窦消融成功30例(83.3%),右冠窦6例(16.7%)。PVCs在体表心电图均表现心电轴下偏的反复单一形态的QRS波形。经左冠窦消融成功的PVCs/NSVT,Ⅰ导联为R、Rs、rS、r、q或rsr波,Ⅱ、Ⅲ、aVF导联均为高振幅R波,胸前导联PVCs R波移行区位于V_1~V_3导联,且PVCs移行区均早于窦性心律移行区,V_1导联表现为R、Rs、RS、rS或qr波,V_1或V_2导联R/S波幅指数2.64±2.03,R波时限指数0.62±0.12,Ⅲ导联与Ⅱ导联R波振幅比(RⅢ/RⅡ)1.09±0.18,aVL导联与aVR导联QS波振幅比(QSaVL/QSaVR)1.32±0.46。经右冠窦消融成功的PVCs/NSVT,Ⅰ导联为R、Rs、r波,Ⅱ、Ⅲ、aVF导联均为高振幅R波,胸前导联PVCs R波移行区位于V_1~V_3导联,V_1导联表现为R、Rs、rS波,V_1或V_2导联R/S波幅指数0.51±0.38,R波时限指数0.55±0.26,RⅢ/RⅡ0.95±0.23,QSaVL/QSaVR1.12±0.39。PVCs经左冠窦消融成功的V_1或V_2导联R/S波幅指数要高于右冠窦(P<0.05)。结论经左冠窦消融成功的室性心律失常多于右冠窦。体表心电图的相关特征有助于决策主动脉窦内的室性心律失常的具体消融部位。