基于近似测量算法Sketch的高精度区块链异常检测机制

区块链存在网络动态性强和其管理困难等问题,使得区块链普遍存在DDoS攻击和账户接管等异常现象.现有区块链异常检测方法多从所有区块链账户中提取历史交易信息和交易频率等特征加以分析以甄别异常.然而,随着区块链数据规模的不断扩大,现有方法在提取特征时面临内存消耗高、检测精度低的挑战.为此,提出了一种高检测精度、低内存开销的区块链异常检测机制,该机制采用近似测量算法将区块链异常检测转化为异常交易账户检测,包括区块内异常账户和跨区块异常账户.对于区块内异常账户,即仅存在于单个区块内的异常账户,使用Sketch算法进行账户识别,精度高.而对于存在于多个区块且难以通过单个区块信息检测到的跨区块异常账户,则通过聚合和分析多区块信息进行账户的准确检测.使用包含88847个区块的真实区块链数据评估上述机制.实验结果表明,与现有代表性方法对比,所提出的机制将区块链异常检测的召回率最高提升了6.3倍,F1分数最高提升了4.4倍.因此,提出的高精度区块链异常检测机制对于规范区块链交易行为、维护系统安全性具有意义.

基于Sketch的重要DNS查询缓存方法

在网络信息技术快速发展背景下,域名系统作为互联网应用的入口,其性能和安全对网络服务的质量尤为关键。然而,从缓存的角度来看,当前域名解析器的域名缓存项管理机制尚不完善。为此,提出了一种基于Sketch技术的域名缓存管理方法,创新地引入了“重要度”评估指标,将网络测量方法应用于缓存管理,实现对缓存项的时间和频率两方面特征的综合度量,满足动态划定重要域名需求。实验结果表明,该缓存方法能够从真实网络环境产生的海量域名查询请求中,针对性地将重要域名添加到缓存予以保护,平均解析时间相比现有域名缓存解决方案减少超过18%。所提方法不仅能够对域名缓存实施更灵活的操作,提高域名系统的用户侧可用性和管理侧可维护性,更为域名缓存管理的研究提供了新的视角和解决方案。

基于Count Sketch的预处理贪婪Kaczmarz方法

在贪婪Kaczmarz方法中,通过对系数矩阵进行正交三角分解引入右预处理子能够提高贪婪Kaczmarz方法的收敛速率。但在系数矩阵的行数远大于列数的情况下,正交三角分解的成本过高。为降低预处理的成本,通过引入Count Sketch变换,提出了基于Count Sketch的预处理贪婪Kaczmarz方法,并对新方法进行了收敛性分析。理论分析说明了新方法在系数矩阵条件数较大时比已有方法具有更好的收敛速率。数值实验验证了新方法的有效性。

Sketch软件在UI设计中的应用研究

随着移动智能设备的普及和各类App的迭代发展,用户对产品的用户界面(User Interface,UI)期望越来越高。为了追求良好的设计效果,越来越多的计算机图像处理软件被运用到UI设计行业。作为一款专门为数字产品的设计而生的软件,目前,Sketch已经基本替代Photoshop,被广泛地应用于UI设计领域。基于此,文章从Sketch软件在UI设计中的实际应用角度出发,介绍了UI设计与Sketch软件的基本内容,分析了Sketch软件在设计应用中的主要优势和一般步骤。

IntervalSketch:面向数据流的间隔项近似统计方法

流式数据库在数据库中的占比逐渐增加,在流式数据库的数据流中提取所需信息是一项重要任务。文中研究了数据流的间隔项,并将其应用到了网络场景中。其中间隔项指在数据流中以固定时间间隔到达的元素对,这是第一项在数据流中定义和统计间隔项的工作。为了高效统计间隔项的top-K,提出了IntervalSketch。IntervalSketch首先基于模拟退火对数据流分块以加快统计速度,其次利用Sketch进行间隔项的存储,最后通过特征分组存储策略降低Sketch存储间隔项的空间开销,提升了统计间隔项的精度。IntervalSketch在两个真实数据集上进行了大量对比实验,实验结果表明,在同样内存的情况下,IntervalSketch明显优于基线方案,其中处理时间为基线方案的1/3~1/2,平均绝对误差、平均相对误差约为基线方案的1/3。

PeakSketch:检测网络流中的top-k流的无偏和通用草图

通过对现有Sketch结构的研究,提出一种新的Sketch结构:PeakSketch,本文将其应用于三种任务:检测top-k频繁流,检测top-k重变化流,检测top-k持久流,从理论上证明了PeakSketch可以提供无偏估计,并且给出了算法的误差界。实验结果表明,PeakSketch的各项性能优秀,在检测top-k频繁流任务中,PeakSketch的吞吐量显著提升,特别是在分配内存小于200 kB以下时,吞吐量最高提升可以达到50%,准确率最高提升一倍,PeakSketch也展现突出的性能。

基于多层Sketch的SDN网络流量测量技术研究

针对大流检测、突变流检测和基数估计等的网络流量测量对保障网络安全具有重要意义.但当前相关研究存在实时性不足、测量精度不高等问题.针对上述问题,设计了一种基于多层Sketch(multiple layer sketch, ML Sketch)的网络流量测量模型.首先,该模型采用自主设计的ML Sketch结构,使用分类存储结构提高了流量测量的精度.其次,在SDN(software defined network)环境下利用流量实时回放技术,模拟了流量的动态发生场景.最后,在SDN控制平面实现了对大流、突变流和基数估计类流量的实时动态检测.在UNSW-NB15上的实验结果表明,与传统Sketch结构相比,所设计的ML Sketch结构在F1_Score指标上最高提高4.81%,相关误差最高降低81.12%,验证了该模型的有效性.

基于Sketch Engine检索工具的日语近义词辨析——以「願う」「祈る」为例

基于在线语料库检索工具Sketch Engine,利用其目标语料库Japanese Web 2011 (jaTenTen11)中的词语索引功能与词汇素描差异功能,考察了近义词「願う」「祈る」的词语搭配规律及语义特征。通过考察「願う」与「祈る」这两个动词与宾格名词的共现显著性,并通过分布图直观清晰地呈现它们的分布情况,发现「願う」与物质性名词或动作性名词搭配,表“希望对方给予建议”或“请求某人做某事”之义;「祈る」多与状态性名词搭配,如与身体状况和农业生产丰收相关的名词搭配,带有宗教色彩。这种研究方法不仅克服了传统近义词辨析中可能存在的主观性和片面性,还使得研究结果更加客观、直观且具有说服力。 Based on the online corpus retrieval tool Sketch Engine, the word indexing function and vocabulary sketching difference function of its target corpus Japanese Web 2011 (jaTenTen11) were used to investigate the word collocation rules and semantic features of synonyms “Negau” and “Inoru”. By examining the co-occurrence significance of the verbs “Negau” and “Inoru” with objective nouns, and presenting their distribution clearly and intuitively through a distribution map, it was found that “Negau” is paired with material or action nouns to express the meaning of “hoping for advice from the other party” or “requesting someone to do something”;“Inoru” is often paired with situa-tional nouns, such as those related to physical condition and agricultural production, with religious connotations. This research method not only overcomes the subjectivity and one sidedness that may exist in traditional synonym analysis, but also makes the research results more objective, in-tuitive, and persuasive.

基于Sketch Engine的日语“准备”类近义词辨析——以「準備」和「用意」为例

在日语中,「準備」和「用意」是学习者容易混淆的一对近义词。本研究利用Sketch Engine平台的Japanese Web 2011语料库,系统收集了这两个词作为名词及サ变动词使用时的大量词语搭配实例,并进一步考察了它们在表达准备行为时的不同语义倾向。本研究不仅有利于日语学习者准确理解和使用这两个词,还可为日语教学提供较为具体的指导建议。In Japanese, “準備(junbi)” and “用意(yōi)” are considered near-synonyms that are frequently confused by learners. This study employed the Japanese Web 2011 corpus accessible through the Sketch Engine platform to systematically gather a substantial number of lexical collocations for these terms when employed as nouns and in their suru-verb forms. We further examined their distinct semantic nuances when expressing preparatory actions. Our research not only assists Japanese language learners in accurately understanding and utilizing these terms but also offers specific guidance for Japanese language instruction.

基于高职应用型人才培养的教学研究——以SketchUp草图大师课程为例

该文以SketchUp草图大师课程为例,阐述了教学改革中高职应用型人才培养的必要性和可行性,分析了现阶段高职院校课程教学中存在的问题,并针对存在的问题提出了具体的解决措施。在此基础上,从学生能力培养、课堂教学质量提升以及教学团队建设等方面探索了课程改革效果,并总结课程改革的实施过程。

基于Google Earth和Sketch Up的虚拟校园建设

笔者利用地图发布平台Google Earth获取待建虚拟校园的基础平面数据,选取Sketch Up在基础平面数据上快速有效地建立虚拟校园三维模型,并将其无缝地运行在Google Earth上,从而实现虚拟校园的网上发布,可以进行数据的快速浏览和共享.

A novel molybdenite depressant for efficient selective flotation separation of chalcopyrite and molybdenite

A novel small molecule depressant(M-DEP)was used to separate chalcopyrite and molybdenite via flotation.The results showed that M-DEP had an excellent selective depression on molybdenite,while had little effect on the flotation of chalcopyrite.The adsorption capacity of M-DEP on the surface of molybdenite was greater than that on chalcopyrite surface.The adsorption of M-DEP reduced the floatability of molybdenite and had less effect on the floatability of chalcopyrite,which was due to its different adsorption modes on the surface of the two minerals.Furthermore,the interaction between chalcopyrite and M-DEP was mainly chemical interaction,and almost all of the adsorbed M-DEP molecules were removed and replaced by sodium butyl xanthate(SBX).By contrast,hydrophobic interaction was the main way in which M-DEP was adsorbed on the molybdenite surface with little chemical interaction,which was less interfered by SBX addition.Therefore,M-DEP had a super selective depression on molybdenite.The study provided a novel depressant and approach for the deep separation of chalcopyrite and molybdenite via flotation.

Functional analysis of the novel mitochondrial tRNA^(Trp)and tRNA^(Ser(AGY))variants associated with type 2 diabetes mellitus

BACKGROUND Mutations in mitochondrial tRNA(mt-tRNA)genes that result in mitochondrial dysfunction play important roles in type 2 diabetes mellitus(T2DM).We previously reported a large Chinese pedigree with maternally inherited T2DM that harbors novel mt-tRNA^(Trp)A5514G and tRNA^(Ser(AGY))C12237T variants,however,the effects of these mt-tRNA variants on T2DM progression are largely unknown.AIM To assess the potential pathogenicity of T2DM-associated m.A5514G and m.C12237T variants at genetic,molecular,and biochemical levels.METHODS Cytoplasmic hybrid(cybrid)cells carrying both m.A5514G and m.C12237T variants,and healthy control cells without these mitochondrial DNA(mtDNA)variants were generated using trans-mitochondrial technology.Mitochondrial features,including mt-tRNA steady-state level,levels of adenosine triphosphate(ATP),mitochondrial membrane potential(MMP),reactive oxygen species(ROS),mtDNA copy number,nicotinamide adenine dinucleotide(NAD+)/NADH ratio,enzymatic activities of respiratory chain complexes(RCCs),8-hydroxy-deoxyguanine(8-OhdG),malondialdehyde(MDA),and superoxide dismutase(SOD)were examined in cell lines with and without these mt-tRNA variants.RESULTS Compared with control cells,the m.A5514G variant caused an approximately 35%reduction in the steady-state level of mt-tRNA^(Trp)(P<0.0001);however,the m.C12237T variant did not affect the mt-tRNA^(Ser(AGY))steady-state level(P=0.5849).Biochemical analysis revealed that cells with both m.A5514G and m.C12237T variants exhibited more severe mitochondrial dysfunctions and elevated oxidative stress than control cells:ATP,MMP,NAD+/NADH ratio,enzyme activities of RCCs and SOD levels were markedly decreased in mutant cells(P<0.05 for all measures).By contrast,the levels of ROS,8-OhdG and MDA were significantly increased(P<0.05 for all measures),but mtDNA copy number was not affected by m.A5514G and m.C12237T variants(P=0.5942).CONCLUSION The m.A5514G variant impaired mt-tRNA^(Trp)metabolism,which subsequently caused mitochondrial dysfunction.The m.C12237T variant did not alter the steady-state level of mt-tRNA^(Ser(AGY)),indicating that it may be a modifier of the m.A5514G variant.The m.A5514G variant may exacerbate the pathogenesis and progression of T2DM in this Chinese pedigree.

Fatty acid binding protein 5 is a novel therapeutic target for hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)is an aggressive subtype of liver cancer and is one of the most common cancers with high mortality worldwide.Reprogrammed lipid metabolism plays crucial roles in HCC cancer cell survival,growth,and evolution.Emerging evidence suggests the importance of fatty acid binding proteins(FABPs)in contribution to cancer progression and metastasis;however,how these FABPs are dysregulated in cancer cells,especially in HCC,and the roles of FABPs in cancer progression have not been well defined.AIM To understand the genetic alterations and expression of FABPs and their associated cancer hallmarks and oncogenes in contributing to cancer malignancies.METHODS We used The Cancer Genome Atlas datasets of pan cancer and liver hepatocellular carcinoma(LIHC)as well as patient cohorts with other cancer types in this study.We investigated genetic alterations of FABPs in various cancer types.mRNA expression was used to determine if FABPs are abnormally expressed in tumor tissues compared to non-tumor controls and to investigate whether their expression correlates with patient clinical outcome,enriched cancer hallmarks and oncogenes previously reported for patients with HCC.We determined the protein levels of FABP5 and its correlated genes in two HCC cell lines and assessed the potential of FABP5 inhibition in treating HCC cells.RESULTS We discovered that a gene cluster including five FABP family members(FABP4,FABP5,FABP8,FABP9 and FABP12)is frequently co-amplified in cancer.Amplification,in fact,is the most common genetic alteration for FABPs,leading to overexpression of FABPs.FABP5 showed the greatest differential mRNA expression comparing tumor with non-tumor tissues.High FABP5 expression correlates well with worse patient outcomes(P<0.05).FABP5 expression highly correlates with enrichment of G2M checkpoint(r=0.33,P=1.1e-10),TP53 signaling pathway(r=0.22,P=1.7e-5)and many genes in the gene sets such as CDK1(r=0.56,P=0),CDK4(r=0.49,P=0),and TP53(r=0.22,P=1.6e-5).Furthermore,FABP5 also correlates well with two co-expressed oncogenes PLK1 and BIRC5 in pan cancer especially in LIHC patients(r=0.58,P=0;r=0.58,P=0;respectively).FABP5high Huh7 cells also expressed higher protein levels of p53,BIRC5,CDK1,CDK2,and CDK4 than FABP5low HepG2 cells.FABP5 inhibition more potently inhibited the tumor cell growth in Huh7 cells than in HepG2 cells.CONCLUSION We discovered that FABP5 gene is frequently amplified in cancer,especially in HCC,leading to its significant elevated expression in HCC.Its high expression correlates well with worse patient outcome,enriched cancer hallmarks and oncogenes in HCC.FABP5 inhibition impaired the cell viability of FABP5high Huh7 cells.All these support that FABP5 is a novel therapeutic target for treating FABP5high HCC.

基于Sketch Up的大学校园三维图的设计与实现

Sketch Up(以下称SU)是Google公司运营的一套直接面向设计方案创作过程的三维图设计工具,中文名"草图大师",用其结合Arc Gis等对大学校园三维图的设计并上传互联网共享,可以进行数据的快速浏览.

基于Sketch Up与VRP的交互式虚拟数字校园构建与实现

结合Sketch Up建模软件和VRP可视化仿真应用软件,实现了南京信息工程大学虚拟数字校园模型构建与交互式浏览;讨论了校园3维模型构建中的数据需求、数据获取方法,以及用VRP实现交互式浏览应注意的一些问题。

3Ds Max与Sketch Up联合三维建模方法

三维软件建模凭借它真实的场景展现和其直观的视觉感受,成了三维地理信息系统(geographic information system,GIS)领域的主要研究方向。三维软件建模法构建的模型真实、美观,能非常精细地表现地物的特征和细节。通过对3Ds Max和Sketch Up两种不同三维软件建模方法的比较分析,总结出两种软件各自的优势,然后将两者的优点相结合,能更加快速完整地进行三维模型构建。通过对联合建模方法的研究,能够为三维软件建模提供一种更为简洁的方法,从而缩短建模的时间,减少人力消耗。

基于Sketch Engine检索工具的英语同义词辨析——以assure和ensure为例

英语中含有诸多同义词,学习者在习得这类词汇时经常会遇到辨析困难。而利用在线SketchEngine工具辨析英语同义词能有效解决这一问题。以辨析英语同义词assure和ensure为例,运用在线Sketch Engine工具进行检索和对比分析,能得到更加客观、可靠的辨析结果。两词有着共同的正式语体倾向,部分相似的类联接,其宾语搭配词的语义韵也趋向一致,但两词在具体语域中分布差异明显。另外,部分类联接、搭配词等方面也存在明显差异。

Sketch Up结合Cinema 4D在园林设计中的应用

在分析传统园林设计制图程序和制图软件的不足以及分析Sketch Up和Cinema 4D软件无缝结合的基础上,提出Sketch Up结合Cinema 4D的园林绘图模式。明确提出利用Sketch Up和Cinema 4D软件结合能够快速、优质地表达园林设计内容。

Analyzing the Adaptation of Rebecca from the Novel to the Film in Light of the Black-and-White

Classical Chinese aesthetics is based on Chinese philosophy.The characteristic of classical Chinese aesthetics regards“artistic conception”as one of the basic aesthetic categories.Chinese art speaks highly of the charm of the black-and-white.During the adaptation,there is the same beauty in the black-and-white photography and the“color without color”of Chinese paintings.The“artistic conception”is similar between them from the aesthetic perspective.Therefore,the unique“artistic conception”of the novel should be mastered,if the adapter aims to retain the“soul”of it.In other words,film adaptation not only considers“similarity in form”,but also draws much attention to“similarity in spirit”.The latter is the essence of film adaptation.