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Outlier-DivideConquer:近似聚集查询中离群分治取样算法 被引量:1
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作者 胡文瑜 孙志挥 张柏礼 《南京大学学报(自然科学版)》 CAS CSCD 北大核心 2011年第5期524-531,共8页
取样是一种通用有效的近似技术,利用取样技术进行近似聚集查询处理是决策支持系统和数据挖掘实现技术中的常用方法.如何正确有效地给出近似查询结果并最小化近似查询误差是近似查询处理的关键和目标.在深入研究近似聚集查询取样方法的... 取样是一种通用有效的近似技术,利用取样技术进行近似聚集查询处理是决策支持系统和数据挖掘实现技术中的常用方法.如何正确有效地给出近似查询结果并最小化近似查询误差是近似查询处理的关键和目标.在深入研究近似聚集查询取样方法的基础上,本文提出了一个有误差确界且只需单遍扫描数据集的离群分治取样Outlier-DivideConquer算法,该算法在聚集属性内部存在高方差分布时能克服随机均匀取样局限,可显著降低近似查询误差,且执行效率优于同类算法.最后通过与传统均匀取样算法的实验比较验证了Outlier-DivideConquer算法的有效性和正确性. 展开更多
关键词 数据挖掘 决策支持 近似聚集查询 均匀取样 离群分治
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一种面向海量数据的spilt-and-conquer方法
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作者 温焜 兰晓然 《统计与决策》 CSSCI 北大核心 2018年第16期74-76,共3页
Lasso是一种能很好进行变量选择的方法,已被广泛应用。但面对高维海量数据集的时候会存在计算机消耗过大的情况。针对这种情况,文章提出一种spilt-and-conquer方法。首先把高维数据集均分成K份,进行变量选择,把每份选择出来的特征集进... Lasso是一种能很好进行变量选择的方法,已被广泛应用。但面对高维海量数据集的时候会存在计算机消耗过大的情况。针对这种情况,文章提出一种spilt-and-conquer方法。首先把高维数据集均分成K份,进行变量选择,把每份选择出来的特征集进行合并后再进行变量选择。为了验证方法的优越性,使用了六组数据集进行实验。最后通过SVM、随机森林、神经网络的预测结果表明,spilt-and-conquer方法,在处理高维海量数据时具有很好的特性,并很大程度上节省了运行时间。 展开更多
关键词 spilt-and-conquer方法 变量选择 高维数据
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Joy Lies in the Process of Conquering the Peak
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《China Today》 2001年第10期66-67,共2页
关键词 Joy Lies in the Process of conquering the Peak LI
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CONQUERING DIFFICULTIES,MAKING ACHIEVEMENT
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作者 王玉 《杂技与魔术》 2007年第6期35-,共1页
When mentioned creating the acrobatic drama Swan Like, vice president of China Acrobats Association Ning Genfu had the following remarks"We are acrobatics people and we all know how difficult it is to create,to t... When mentioned creating the acrobatic drama Swan Like, vice president of China Acrobats Association Ning Genfu had the following remarks"We are acrobatics people and we all know how difficult it is to create,to train,to organize and to package an acrobatic drama."So in this sense we could regard the acrobatic drama"Dunhuang Goddess"as a big success,because it was produced by Gansu Acrobatic Troupee from the northwest of China and which didn't have a fairly solid foundation in creating before.It was a big... 展开更多
关键词 conquerING DIFFICULTIES MAKING ACHIEVEMENT
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征途漫漫COMMAND CONQUER
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作者 庄晓 《数字生活》 2007年第4期90-95,共6页
《Command & Conquer》自1995年上市以来,全系列产品,包括续作和其他的副产品,总共售出了2300万套以上。这也是游戏史上唯一的资料片还有资料片的游戏系列。虽然,曾经辉煌的Westwood已经不在,但是, Command & Conquer依然拥有... 《Command & Conquer》自1995年上市以来,全系列产品,包括续作和其他的副产品,总共售出了2300万套以上。这也是游戏史上唯一的资料片还有资料片的游戏系列。虽然,曾经辉煌的Westwood已经不在,但是, Command & Conquer依然拥有者强悍的生命力,而最新的游戏也在2007年三月由EA推出,RTS的王者归来,将给我们带来怎样的惊喜? 展开更多
关键词 COMMAND conquer 资料片 RTS 游戏风格 王者归来 游戏引擎
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在权化的完备度量空间上解Divide&Conquer算法
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作者 黄梦桥 龙环 马昌社 《模糊系统与数学》 北大核心 2018年第5期113-120,共8页
每一个弱权化的度量空间可以序嵌入到一个度量空间的形式球中,并且这种嵌入是拓扑连续的。本文证明权化的完备度量空间上的收缩的弱Lipschitz函数的一个不动点定理,此不动点定理可以用来解Divide&Conquer算法。
关键词 偏度量 弱Lipschitz函数 Divide&conquer算法
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Optimal constrained multi-degree reduction of Bézier curves with explicit expressions based on divide and conquer 被引量:3
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作者 Lian ZHOU Guo-jin WANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第4期577-582,共6页
We decompose the problem of the optimal multi-degree reduction of Bézier curves with corners constraint into two simpler subproblems, namely making high order interpolations at the two endpoints without degree re... We decompose the problem of the optimal multi-degree reduction of Bézier curves with corners constraint into two simpler subproblems, namely making high order interpolations at the two endpoints without degree reduction, and doing optimal degree reduction without making high order interpolations at the two endpoints. Further, we convert the second subproblem into multi-degree reduction of Jacobi polynomials. Then, we can easily derive the optimal solution using orthonormality of Jacobi polynomials and the least square method of unequally accurate measurement. This method of 'divide and conquer' has several advantages including maintaining high continuity at the two endpoints of the curve, doing multi-degree reduction only once, using explicit approximation expressions, estimating error in advance, low time cost, and high precision. More importantly, it is not only deduced simply and directly, but also can be easily extended to the degree reduction of surfaces. Finally, we present two examples to demonstrate the effectiveness of our algorithm. 展开更多
关键词 Bezier curves Multi-degree reduction Divide and conquer
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Parallel divide and conquer bio-sequence comparison based on Smith-Waterman algorithm 被引量:4
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作者 ZHANGFa QIAOXiangzhen LIUZhiyong 《Science in China(Series F)》 2004年第2期221-231,共11页
Tools for pair-wise bio-sequence alignment have for long played a central role in computation biology. Several algorithms for bio-sequence alignment have been developed. The Smith-Waterman algorithm, based on dynamic ... Tools for pair-wise bio-sequence alignment have for long played a central role in computation biology. Several algorithms for bio-sequence alignment have been developed. The Smith-Waterman algorithm, based on dynamic programming, is considered the most fundamental alignment algorithm in bioinformatics. However the existing parallel Smith-Waterman algorithm needs large memory space, and this disadvantage limits the size of a sequence to be handled. As the data of biological sequences expand rapidly, the memory requirement of the existing parallel Smith- Waterman algorithm has become a critical problem. For solving this problem, we develop a new parallel bio-sequence alignment algorithm, using the strategy of divide and conquer, named PSW-DC algorithm. In our algorithm, first, we partition the query sequence into several subsequences and distribute them to every processor respectively, then compare each subsequence with the whole subject sequence in parallel, using the Smith-Waterman algorithm, and get an interim result, finally obtain the optimal alignment between the query sequence and subject sequence, through the special combination and extension method. Memory space required in our algorithm is reduced significantly in comparison with existing ones. We also develop a key technique of combination and extension, named the C&E method, to manipulate the interim results and obtain the final sequences alignment. We implement the new parallel bio-sequences alignment algorithm, the PSW-DC, in a cluster parallel system. 展开更多
关键词 biological sequence alignment dynamic programming divide and conquer parallel.
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GetArtemisininsByAnymeans (GABA): artemisinins path to conquer diabetes go through GABA receptors
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作者 Xiaojie Bai Suneng Fu 《Science Bulletin》 SCIE EI CAS CSCD 2017年第6期383-385,共3页
Diabetes is a chronic disease of elevated blood glucose levels that affects more than 400 million people worldwide.Complications of diabetes affect the neuronal and the vascular systems and causes diabetic kidney dise... Diabetes is a chronic disease of elevated blood glucose levels that affects more than 400 million people worldwide.Complications of diabetes affect the neuronal and the vascular systems and causes diabetic kidney disease,cardiovascular disease,hypertension,retinopathy,peripheral neuropathy,and diabetic food diseases.Diabetes is caused by either the body’s inability to 展开更多
关键词 GABA cell artemisinins path to conquer diabetes go through GABA receptors Get Artemisinins By Anymeans
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A Divide-and-Conquer Strategy for Embedding a Distance-Net Point Set Into E^n and Its Application
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作者 周加农 刘立 《Science China Mathematics》 SCIE 1994年第10期1189-1199,共11页
A divide-and-conquer strategy is given for embedding a distance-net point set into Euclidean space En, and the problem of embedding a bounded distance-net point set into E3 and its application to the macromolecular co... A divide-and-conquer strategy is given for embedding a distance-net point set into Euclidean space En, and the problem of embedding a bounded distance-net point set into E3 and its application to the macromolecular conformation with Nuclear Magnetic Resonance data are discussed. 展开更多
关键词 distance-net point set DIVIDE-AND-conquer strategy EMBEDDING with bounded DISTANCES macromolecular conformation.
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Coalition-based downlink resource allocation for LTE system with divide-and-conquer approach
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作者 GAO Xiang LI Xi +1 位作者 JI Hong LI Yi 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2012年第6期1-5,共5页
To take advantage of the multiuser diversity resulted from the variation in channel conditions among the users, it has become an interesting and challenging problem to efficiently allocate the resources such as subcar... To take advantage of the multiuser diversity resulted from the variation in channel conditions among the users, it has become an interesting and challenging problem to efficiently allocate the resources such as subcarriers, bits, and power. Most of current research concentrates on solving the resource-allocation problem for all users together in a centralized way, which brings about high computational complexity and makes it impractical for real system. Therefore, a coalitional game framework for downlink multi-user resource allocation in long term evolution (LTE) system is proposed, based on the divide-and-conquer idea. The goal is to maximize the overall system data rate under the constraints of each user's minimal rate requirement and maximal transmit power of base station while considering the fairness among users. In this framework, a coalitional formation algorithm is proposed to achieve optimal coalition formation and a two-user bargaining algorithm is designed to bargain channel assignment between two users. The total computational complexity is greatly reduced in comparison with conventional methods. The simulation results show that the proposed algorithms acquire a good tradeoff between the overall system throughout and fairness, compared to maximal rate and max-min schemes. 展开更多
关键词 LTE resource allocation DIVIDE-AND-conquer coalitional game bargaining solution
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N-Box ConQuer和flashlink机箱
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《世界广播电视》 2004年第5期112-112,共1页
关键词 挪威网络公司 N-Box conquer flashlink 机箱
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Conquering Qomolangma
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作者 TANG YUANKAI 《Beijing Review》 2007年第44期40-41,共2页
The torch relay of the 2008 Olympics will reach the highest point on earth,the summit of the Qomolangma(Mt. Everest).Ensuring it keeps burning there amid thin air,high winds and freezing temperatures has been a diffic... The torch relay of the 2008 Olympics will reach the highest point on earth,the summit of the Qomolangma(Mt. Everest).Ensuring it keeps burning there amid thin air,high winds and freezing temperatures has been a difficult task 展开更多
关键词 conquering Qomolangma
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Doctor Yamei Hu: A Chinese pioneer dedicated to conquering childhood leukemia
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作者 Huyong Zheng 《Pediatric Investigation》 2018年第4期205-206,共2页
At 95 years of age, Dr. Yamei Hu, an academician of the Chinese Academy of Engineering (CAE), has seen her greatest wish fulfilled: to establish China's National Children's Leukemia/Cancer Foundation and the N... At 95 years of age, Dr. Yamei Hu, an academician of the Chinese Academy of Engineering (CAE), has seen her greatest wish fulfilled: to establish China's National Children's Leukemia/Cancer Foundation and the National Children's Hematology Oncology Center. Dr. Hu's purpose has always been simple: to allow more children with leukemia to receive effective treatment and to have hope for a new life. 展开更多
关键词 DOCTOR Yamei HU conquering CHILDHOOD leukemia HEMATOLOGY ONCOLOGY Center
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A Tibetan Woman Has Conquered Mt. Qumolangma
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作者 ZHANG XIAOPING LI LI 《Women of China》 1995年第8期62-64,共3页
KUN Sang, which means "perfect" in Tibetan, is the name of an ordinary Tibetan woman. Obviously, it contains her parents’ wishes for her. Kun Sang, the heroine of this article, is a mountaineer and conquero... KUN Sang, which means "perfect" in Tibetan, is the name of an ordinary Tibetan woman. Obviously, it contains her parents’ wishes for her. Kun Sang, the heroine of this article, is a mountaineer and conqueror of the highest peak of the world. 展开更多
关键词 A Tibetan Woman Has conquered Mt Qumolangma
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杨宗艳基于五脏生克规律论治肺癌经验
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作者 刘坤 王辉 杨宗艳 《辽宁中医杂志》 CAS 北大核心 2024年第10期15-18,共4页
肺癌是威胁人民健康的重大疾病,发病率和死亡率均居恶性肿瘤之首。肺癌属于中医“肺积”“息贲”等范畴。杨宗艳主任认为:肺癌的发生、发展是动态演变的过程。正气不足、肺脏亏虚是肺癌的主要病因。五脏功能紊乱,痰、瘀、毒胶结是肺癌... 肺癌是威胁人民健康的重大疾病,发病率和死亡率均居恶性肿瘤之首。肺癌属于中医“肺积”“息贲”等范畴。杨宗艳主任认为:肺癌的发生、发展是动态演变的过程。正气不足、肺脏亏虚是肺癌的主要病因。五脏功能紊乱,痰、瘀、毒胶结是肺癌发生、发展的基本病机。肺脏与他脏生克失宜,是肺癌病机演变的内在规律。肺癌的治疗,当立足肺脏本身,考量肺脏与他脏的关系状态,依照五行生克,补不足,损有余:清心火,润肺金;培脾土,生肺金;疏肝木,护肺金;滋肾水,固肺金,并灵活选用扶正、化痰、祛瘀、解毒方药,恢复肺脏与他脏常正关系,消解相互胶着的痰、瘀、毒。 展开更多
关键词 肺癌 五脏 五行 生克 经验
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灌溉机器人全覆盖路径规划方法
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作者 王臻卓 陈金林 +2 位作者 任婷婷 杨科科 任宁宁 《节水灌溉》 北大核心 2024年第9期53-58,共6页
灌溉机器人全覆盖行动的各个任务具有较为明显的空间并行性,随着全覆盖范围扩大,在对覆盖区域进行分解阶段,需要充分考虑将整个区域空间分解为哪些区域。但是,灌溉机器人受到视觉感知区域限制,准确匹配和衔接路块间最近端点的难度较大,... 灌溉机器人全覆盖行动的各个任务具有较为明显的空间并行性,随着全覆盖范围扩大,在对覆盖区域进行分解阶段,需要充分考虑将整个区域空间分解为哪些区域。但是,灌溉机器人受到视觉感知区域限制,准确匹配和衔接路块间最近端点的难度较大,导致局部路点的连通和线路衔接出现差错,难以有效全覆盖。为了有效解决这一问题,提出一种灌溉机器人全覆盖路径规划方法。通过快速搜索随机算法展开需要覆盖区域的边界检测,考虑视觉传感器的感知范围受限因素,采用灰度质心法展开区域视图边界提取,根据提取结果建立地图。在地图上建立线段序列,通过曼哈顿最小距离原则连接地图上的部分路径线段,形成多个弓形线路块。使用分治算法匹配和衔接各个弓形线路块间最近端点对,引入改进A*算法对全局以及局部路点的连通和线路衔接,实现灌溉机器人的全覆盖路径规划。实验结果表明:针对简单灌溉区域,该方法的路径重复率为0.041%,灌溉覆盖率为98.90%;针对复杂灌溉区域,该方法的路径重复率为0.017%,灌溉覆盖率为99.87%。这说明针对不同的灌溉环境,该方法均可以实现理想的路径规划,不仅可以最大限度地实现全覆盖,并有效地减少路径冗余程度,可以获取理想的灌溉机器人全覆盖路径规划方案。 展开更多
关键词 灌溉机器人 全覆盖线路 路径规划 快速搜索随机算法 边界提取 分治算法
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由义尊与义方彝等周初铜器论及西周早期年代
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作者 朱凤瀚 《河北师范大学学报(哲学社会科学版)》 2024年第1期8-15,共8页
近年新见义尊、义方彝是一组商人大族■族贵族义受武王赏赐后所作的青铜器,同组还有一件圆鼎和两件方鼎。西周初年的义器铭文中的闰月历日可为武王克商年的判定提供参考。何尊与新见的贝毳尊卣、德方鼎等器均述成王迁宅于成周之事,迁宅... 近年新见义尊、义方彝是一组商人大族■族贵族义受武王赏赐后所作的青铜器,同组还有一件圆鼎和两件方鼎。西周初年的义器铭文中的闰月历日可为武王克商年的判定提供参考。何尊与新见的贝毳尊卣、德方鼎等器均述成王迁宅于成周之事,迁宅至迟于成王五祀三月已完成。铭文中有“新邑”一词的青铜器,年代均应早于何尊所铭成王五祀。新出青铜器使得西周早期诸王年代的考订已突破夏商周断代工程所定年限,武王克商年有必要再重新考虑。以周初诸王在位王年,向前可推拟武王克商之年。以成王在位三十二年计,武王克商应为公元前1076年。以成王在位三十七年计,则武王克商年是公元前1081年。 展开更多
关键词 周初铜器 何尊 武王克商年 西周早期王年
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基于改进算法YOLOv5+的混凝土轨枕裂纹检测 被引量:1
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作者 令雅莉 杨桂芹 +1 位作者 张又元 王小鹏 《铁道标准设计》 北大核心 2024年第4期70-77,87,共9页
基于既有研究成果在对混凝土轨枕裂纹检测效率不足的基础上,提出一种改进算法YOLOv5+,主要以YOLOv5网络模型为基础,对混凝土轨枕裂纹进行高效检测。首先,采用分治标签的策略来增大裂纹在标签中的实际占比,从而解决混凝土轨枕裂纹尺度变... 基于既有研究成果在对混凝土轨枕裂纹检测效率不足的基础上,提出一种改进算法YOLOv5+,主要以YOLOv5网络模型为基础,对混凝土轨枕裂纹进行高效检测。首先,采用分治标签的策略来增大裂纹在标签中的实际占比,从而解决混凝土轨枕裂纹尺度变化大的问题,使网络更利于提取有效特征;其次,将YOLOv5网络结构中SPP模块的最大池化层改为平均池化层,减少裂纹漏检的现象;同时,在YOLOv5骨干网络中嵌入SE注意力模块(Squeeze and Excitation,SE)提高对细小裂纹的检测能力;最后,结合新的检测尺度与特征融合网络,降低微小裂纹的漏检现象。实验结果表明,以YOLOv5网络模型为基础的改进算法YOLOv5+,除了召回率Recall变化不大外,精确率Precision提高6.5%,平均精度均值mAP提升8%,帧率FPS也有所提升,能够满足实时性的检测需求。 展开更多
关键词 混凝土轨枕 裂纹检测 分治标签 平均池化 注意力模块 YOLOv5+
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基于误差分治的神经网络验证
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作者 董彦松 刘月浩 +4 位作者 董旭乾 赵亮 田聪 于斌 段振华 《软件学报》 EI CSCD 北大核心 2024年第5期2307-2324,共18页
随着神经网络技术的快速发展,其在自动驾驶、智能制造、医疗诊断等安全攸关领域得到了广泛应用,神经网络的可信保障变得至关重要.然而,由于神经网络具有脆弱性,轻微的扰动经常会导致错误的结果,因此采用形式化验证的手段来保障神经网络... 随着神经网络技术的快速发展,其在自动驾驶、智能制造、医疗诊断等安全攸关领域得到了广泛应用,神经网络的可信保障变得至关重要.然而,由于神经网络具有脆弱性,轻微的扰动经常会导致错误的结果,因此采用形式化验证的手段来保障神经网络安全可信是非常重要的.目前神经网络的验证方法主要关注分析的精度,而易忽略运行效率.在验证一些复杂网络的安全性质时,较大规模的状态空间可能会导致验证方法不可行或者无法求解等问题.为了减少神经网络的状态空间,提高验证效率,提出一种基于过近似误差分治的神经网络形式化验证方法.该方法利用可达性分析技术计算非线性节点的上下界,并采用一种改进的符号线性松弛方法减少了非线性节点边界计算过程中的过近似误差.通过计算节点过近似误差的直接和间接影响,将节点的约束进行细化,从而将原始验证问题划分为一组子问题,其混合整数规划(MILP)公式具有较少的约束数量.所提方法已实现为工具NNVerifier,并通过实验在经典的3个数据集上训练的4个基于ReLU的全连接基准网络进行性质验证和评估.实验结果表明,NNVerifier的验证效率比现有的完备验证技术提高了37.18%. 展开更多
关键词 神经网络 模型抽象 符号传播 线性近似 分治
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