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Vector Product and an Integrable Dynamical System
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作者 Willi-Hans Steeb Yorick Hardy Igor Tanski 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第12期992-994,共3页
We study an autonomous system of first order ordinary differential equations based on the vector product. We show that the system is completely integrable by constructing the first integrals.The connection with Nambu ... We study an autonomous system of first order ordinary differential equations based on the vector product. We show that the system is completely integrable by constructing the first integrals.The connection with Nambu mechanics is established.The extension to higher dimensions is also discussed. 展开更多
关键词 integrable system vector product Nambu mechanics
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AN ALGORITHM FOR DETERMINING CONCAVE VERTEX OF OBJECT BASED ON VECTOR PRODUCT
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作者 Fu Rong Shen Hong 《Journal of Electronics(China)》 2010年第2期212-217,共6页
Concave vertex of an object is an important parameter for analyzing an object’s shape. A new algorithm for searching concave vertex is proposed in this paper. The new algorithm requires tracking the border firstly,an... Concave vertex of an object is an important parameter for analyzing an object’s shape. A new algorithm for searching concave vertex is proposed in this paper. The new algorithm requires tracking the border firstly,and then uses sampling border to obtain coordinates sequence of discrete boundary points. Each sampling point of the discrete border is determined to be either concave or convex according to the value of vector product. Two inflexions can be searched by the change of concavo-convex trend. The region between two inflexions is defined as concave area. The values of distance are calculated between all boundary points on the concave area and a straight line connected by two inflexions. The boundary point corresponding to the greatest distances is max concave vertex,or the object’s concave vertex. Experimental results have proved that the new algorithm can extract the max concave vertexes of an object accurately and reliably. 展开更多
关键词 vector product Concave vertex Convex vertex INFLEXION
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The Sivers Asymmetry of Vector Meson Production in Semi-Inclusive Deep Inelastic Scattering
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作者 Yongjie Deng Tianbo Liu Ya-Jin Zhou 《Chinese Physics Letters》 2025年第6期38-51,共14页
The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productio... The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productions,we perform a calculation of the Sivers asymmetry within the transverse momentum-dependent factorization.Our results are consistent with the COMPASS data,supporting the universality of the Sivers function in the semi-inclusive deep inelastic scattering process for different final-state hadrons within current experimental uncertainties.While different parametrizations of the Sivers function from global analyses allow describing the data equally well,we obtain very different predictions on the Sivers asymmetry ofρand K^(*)productions at electron-ion colliders,which therefore are expected to provide further constraints. 展开更多
关键词 Sivers asymmetry transverse single spin asymmetry pion kaon productionswe sivers function semi inclusive deep inelastic scattering compass datasupporting calculation sivers asymmetry vector meson production
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NONEMPTY INTERSECTION THEOREMS AND SYSTEM OF GENERALIZED VECTOR EQUILIBRIUM PROBLEMS IN PRODUCT G-CONVEX SPACES 被引量:3
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作者 丁协平 《应用数学和力学》 EI CSCD 北大核心 2004年第6期563-571,共9页
By using an existence theorems of maximal elements for a family of set-valued mappings in G-convex spaces due to the author, some new nonempty intersection theorems for a family of set-valued mappings were established... By using an existence theorems of maximal elements for a family of set-valued mappings in G-convex spaces due to the author, some new nonempty intersection theorems for a family of set-valued mappings were established in noncompact product G-convex spaces. As applications, some equilibrium existence theorems for a system of generalized vector equilibrium problems were proved in noncompact product G-convex spaces. These theorems unify, improve and generalize some important known results in literature. 展开更多
关键词 集值映象组 非空交定理 广义矢量平衡问题组 乘积G凸空间
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Solution for slab forging with bulge between two parallel platens by strain rate vector inner-product integration and series expansion 被引量:3
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作者 赵德文 王磊 +1 位作者 刘相华 王国栋 《中国有色金属学会会刊:英文版》 EI CSCD 2005年第5期1009-1013,共5页
A new linear integration was developed. First, effective strain rate for slab forging with bulge was expressed in terms of two-dimensional strain rate vector, and its inner-product was integrated term by term. Second,... A new linear integration was developed. First, effective strain rate for slab forging with bulge was expressed in terms of two-dimensional strain rate vector, and its inner-product was integrated term by term. Second, a summation process of term by term integrated results and a formula of the bulging were introduced, and an analytical solution of stress effective factor was obtained. It is proved that the expression of power by the above linear integration is the same as that of traditional immediate integration. Also, the solution was simplified by series expansion and compared by slab forging test with the others. It turns out that the calculated result of total forging pressure is basically in agreement with measured value in the actual press test. 展开更多
关键词 金属加工 压力加工 应力 线性整合 速率
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Rolling With Simplified Stream Function Velocity and Strain Rate Vector Inner Product 被引量:2
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作者 ZHAO De-wen, ZHANG Shun-hu, LI Can-ming, SONG Hong-yu, WANG Guo-dong (State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, Liaoning, China) 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2012年第3期20-24,共5页
The dual-stream function velocity field is reduced in order to analyze two-dimensional plate broadside roll- ing in roughing. The strain rate vector inner product and integral mean value theorem, as well as coqine vec... The dual-stream function velocity field is reduced in order to analyze two-dimensional plate broadside roll- ing in roughing. The strain rate vector inner product and integral mean value theorem, as well as coqine vector inner product are used respectively in plastic deformation power, friction losses and shear power. A theoretical solution of roll torque and separating force for the rolling is obtained and the calculated results by the solution are compared with those measured in broadside rolling on-line. It shows that both the force and torque calculated are higher than those of measured, but the maximum relative error between them is no more than 11%. 展开更多
关键词 broadside roiling roll separating force strain rate vector inner product analytical solution
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NONEMPTY INTERSECTION THEOREMS AND SYSTEM OF GENERALIZED VECTOR EQUILIBRIUM PROBLEMS IN PRODUCT G-CONVEX SPACES 被引量:4
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作者 DINGXie-ping 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2004年第6期618-626,共9页
By using an existence theorems of maximal elements for a family of set-valued mappings in G-convex spaces due to the author, some new nonempty intersection theorems for a family of set-valued mappings were established... By using an existence theorems of maximal elements for a family of set-valued mappings in G-convex spaces due to the author, some new nonempty intersection theorems for a family of set-valued mappings were established in noncompact product G-convex spaces. As applications, some equilibrium existence theorems for a system of generalized vector equilibrium problems were proved in noncompact product G-convex spaces. These theorems unify, improve and generalize some important known results in literature. 展开更多
关键词 family of set-valued mapping nonempty intersection theorem system of generalized vector equilibrium problem product G-convex space
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Inner-product of strain rate vector through direction cosine in coordinates for disk forging 被引量:1
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作者 赵德文 金文忠 +1 位作者 王磊 刘相华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2006年第6期1320-1324,共5页
A new linear integration for plastic power was proposed.The effective strain rate for disk forging with bulge was expressed in terms of two-dimensional strain rate vector,and then its direction cosines were determined... A new linear integration for plastic power was proposed.The effective strain rate for disk forging with bulge was expressed in terms of two-dimensional strain rate vector,and then its direction cosines were determined by the ratio of coordinate increments.Furthermore,inner-product of the vector for plastic power was term integrated by term and summed.Thereafter,through a formula for determination of bulge an analytical solution of stress effective factor was obtained.Finally,through compression tests,the calculated results of above formula were compared with those of Avitzur’s approximate solution and total indicator readings of the testing machine.It is indicated that the calculated compression forces are basically in agreement with the measured ones if the pass reduction is less than 13.35%.However,when the reduction gets up to 25.34% and 33.12%,the corresponding errors between the calculated and measured results also get up to 6% and 13.5%,respectively. 展开更多
关键词 DISK FORGING bulge strain rate vector direction COSINE inner-product analytical solution
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Reliability-based multidisciplinary design optimization using incremental shifting vector strategy and its application in electronic product design 被引量:10
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作者 Z.L.Huang Y.S.Zhou +2 位作者 C.Jiang J.Zheng X.Han 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2018年第2期285-302,共18页
Use of multidisciplinary analysis in reliabilitybased design optimization(RBDO) results in the emergence of the important method of reliability-based multidisciplinary design optimization(RBMDO). To enhance the effici... Use of multidisciplinary analysis in reliabilitybased design optimization(RBDO) results in the emergence of the important method of reliability-based multidisciplinary design optimization(RBMDO). To enhance the efficiency and convergence of the overall solution process,a decoupling algorithm for RBMDO is proposed herein.Firstly, to decouple the multidisciplinary analysis using the individual disciplinary feasible(IDF) approach, the RBMDO is converted into a conventional form of RBDO. Secondly,the incremental shifting vector(ISV) strategy is adopted to decouple the nested optimization of RBDO into a sequential iteration process composed of design optimization and reliability analysis, thereby improving the efficiency significantly. Finally, the proposed RBMDO method is applied to the design of two actual electronic products: an aerial camera and a car pad. For these two applications, two RBMDO models are created, each containing several finite element models(FEMs) and relatively strong coupling between the involved disciplines. The computational results demonstrate the effectiveness of the proposed method. 展开更多
关键词 Reliability-based design optimization(RBDO) Multidisciplinary design optimization(MDO) Incremental shifting vector(ISV) Decoupling algorithm Electronic product
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Automatic Product Image Classification with Multiple Support Vector Machine Classifiers
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作者 贾世杰 孔祥维 满红 《Journal of Shanghai Jiaotong university(Science)》 EI 2011年第4期391-394,共4页
For the task of visual-based automatic product image classification for e-commerce,this paper constructs a set of support vector machine(SVM) classifiers with different model representations.Each base SVM classifier i... For the task of visual-based automatic product image classification for e-commerce,this paper constructs a set of support vector machine(SVM) classifiers with different model representations.Each base SVM classifier is trained with either different types of features or different spatial levels.The probability outputs of these SVM classifiers are concatenated into feature vectors for training another SVM classifier with a Gaussian radial basis function(RBF) kernel.This scheme achieves state-of-the-art average accuracy of 86.9%for product image classification on the public product dataset PI 100. 展开更多
关键词 product image classification support vector machine(SVM) multiple SVM classifier
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考虑乘客自主选择的区段交替响应式城乡公交调度
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作者 姜晓红 李家伟 +2 位作者 华晶雯 仲韫豪 邢吉平 《交通运输系统工程与信息》 北大核心 2025年第2期201-213,共13页
为有效应对农村地区公交服务覆盖率低导致居民出行不便的问题,增强乘客作为出行主体的选择权,本文提出一种利用现有城乡公交固定线路资源,考虑乘客自主选择的区段交替响应式调度方法。该方法将乡村运营区段划分为两个交替响应的小区段,... 为有效应对农村地区公交服务覆盖率低导致居民出行不便的问题,增强乘客作为出行主体的选择权,本文提出一种利用现有城乡公交固定线路资源,考虑乘客自主选择的区段交替响应式调度方法。该方法将乡村运营区段划分为两个交替响应的小区段,通过向量积法确定需求响应站点;设计两阶段调度模型,采用即时处理订单的方式实现实时响应,将已被服务的需求响应站点设为“临时固定站点”加速模型求解;并构建涵盖从出行需求产生到选择出发时间、上车站点、服务车次,以及拒单后二次选择等全过程的自主选择机制。以江苏省宿迁市泗阳县4路城乡公交为例,设计不同客流强度下的数值实验。实验结果表明:区段交替响应在大客流场景下,每个需求响应站点的平均下车人数为3.76人;不同客流强度下,自主选择机制使15.79%~34.50%的乘客做出个性化选择,至高提升13.51%的票价收入;通过收取服务票价的方式均衡额外成本,平均每增加1%的行驶距离可提升1.53%的票价收入。结果表明:区段交替响应可有效集中出行时间相似且到达站点在同一个区段内的乘客,减少运营成本;考虑乘客自主选择可完整刻画乘客出行全过程行为,并提高系统收入。 展开更多
关键词 智能交通 区段交替响应 两阶段调度 城乡公交 乘客选择 向量积法
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面向不确定度的机床系统正交鲁棒设计方法
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作者 韦进文 郭志俊 李东旭 《机电工程》 北大核心 2025年第4期780-788,共9页
针对数控机床加工中存在不确定度从而影响机床加工精度的问题,依据广义叉积(GCP)鲁棒定理所明确的“叉矩阵(CM)正交则积向量(PV)鲁棒性最强”,提出了一种新的机床控制系统鲁棒设计方法。首先,采用了牛顿法建立了机床的动力学模型,并利... 针对数控机床加工中存在不确定度从而影响机床加工精度的问题,依据广义叉积(GCP)鲁棒定理所明确的“叉矩阵(CM)正交则积向量(PV)鲁棒性最强”,提出了一种新的机床控制系统鲁棒设计方法。首先,采用了牛顿法建立了机床的动力学模型,并利用阶跃响应方法分析了不确定度对控制系统性能的影响;其次,详细阐述了GCP鲁棒定理,并将其应用于机床的控制系统设计,即用差分方程系数构造CM、输入输出序列构造PV,得到了系统的GCP形式;然后,在状态空间对系统进行了状态反馈设计,建立了满足CM正交条件的方程组,通过求解该正交方程组确定了控制器参数;最后,采用了蒙特卡洛法(MCM)仿真与加工实验,对该方法的有效性进行了验证。研究结果表明:采用该方法的正交鲁棒系统具有强鲁棒性,对比传统的极点配置系统和滑模控制系统,实验加工误差的期望值分别降低了40.4%和12.3%。该方法能有效抑制不确定度的影响,可为机床控制系统鲁棒设计提供参考。 展开更多
关键词 不确定度 广义叉积 叉矩阵 积向量 正交鲁棒设计 蒙特卡洛法 控制系统性能
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基于机器学习的油藏动态分析研究
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作者 王小燕 谢文昊 +1 位作者 李娟妮 王亦鑫 《现代电子技术》 北大核心 2025年第14期117-122,共6页
针对油藏开发过程中,传统储量预测方法精度低、复杂度高,以及人工分析信息滞后导致不能及时发现潜力井等问题,提出一种智能化油藏动态分析方法,实现油藏开发问题的实时精确处理。在油田生产过程采集的20个参数中,利用皮尔逊相关系数最... 针对油藏开发过程中,传统储量预测方法精度低、复杂度高,以及人工分析信息滞后导致不能及时发现潜力井等问题,提出一种智能化油藏动态分析方法,实现油藏开发问题的实时精确处理。在油田生产过程采集的20个参数中,利用皮尔逊相关系数最终选用当前年产油量、含水、体积液量、累产油量、排量、冲次和泵效共7个参数表征油田生产能力。然后基于回归的支持向量机模型,利用不同核函数下的SVR模型对油田月产油量进行预测,最终选定超参数d=2、C=54的二阶多项式核函数下的SVR模型作为最优的油田月产量预测模型,该模型预测结果的平均绝对误差为-0.0061,均方误差为-0.1028。实验结果表明,智能化油藏动态分析方法在勘探数据分析的基础上,能够准确地动态预测油藏,优化勘探规划结构并提高油藏发现效率。 展开更多
关键词 智能油田 油藏动态分析 油田产量预测 支持向量机模型 核函数 皮尔逊相关系数
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CHO细胞表达基因工程抗体的研究进展
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作者 邓思棋 朱元源 +5 位作者 徐璐 李芳韬 赵俊杰 刘业兵 邬静 邹兴启 《中国兽医科学》 北大核心 2025年第4期520-527,共8页
基因工程抗体为肿瘤、自身免疫性疾病和感染性疾病等提供了新的治疗途径,具有重要的临床使用价值。该抗体属第三代抗体,通过抗体基因改造、DNA重组和蛋白表达技术,在合适的宿主细胞中转录和翻译而进行生产。它具有可塑性强、制备周期短... 基因工程抗体为肿瘤、自身免疫性疾病和感染性疾病等提供了新的治疗途径,具有重要的临床使用价值。该抗体属第三代抗体,通过抗体基因改造、DNA重组和蛋白表达技术,在合适的宿主细胞中转录和翻译而进行生产。它具有可塑性强、制备周期短、操作简单、生产成本低廉等优点。目前,大多数批准上市的治疗性抗体是由中国仓鼠卵巢细胞(CHO)生产的,它能提供复杂的翻译后修饰,使抗体药物具备活性和稳定性。在开发抗体药物的过程中,现有的生产平台仍然面临抗体产量低、质量和稳定性不一致、生产成本高等挑战。本文将综述基因工程抗体的类型、CHO细胞以及重组表达载体的设计策略等,旨在优化表达系统,为提高抗体表达量和降低生产成本提供参考,以满足未来日益增长的生物医药需求。 展开更多
关键词 基因工程抗体 CHO细胞 重组表达载体 生产力
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面向国产RISC-V芯片的高效高精度求和与点积算法
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作者 李骥 邱琪 +4 位作者 张翔 肖调杰 孟祥飞 龚春叶 冯超超 《小型微型计算机系统》 北大核心 2025年第11期2798-2806,共9页
RISC-V作为一种新兴的开源精简指令集架构,是后摩尔时代处理器技术发展与创新的关键之一.浮点求和与点积运算是数值运算的基础组成部分,在众多领域应用广泛.目前RISC-V架构尚未适配兼具高精度和高效率的求和与点积运算算法,这是因为现... RISC-V作为一种新兴的开源精简指令集架构,是后摩尔时代处理器技术发展与创新的关键之一.浮点求和与点积运算是数值运算的基础组成部分,在众多领域应用广泛.目前RISC-V架构尚未适配兼具高精度和高效率的求和与点积运算算法,这是因为现有优化方案难以良好地平衡运算精度和效率,要么侧重于低精度算法效率,要么通过牺牲效率实现高精度运算.本文利用RVV(RISC-V Vector instruction set extension,RVV)矢量扩展指令,设计并实现了一种基于无误差变换技术的高效、高精度求和与点积算法.首先避免使用规约指令以防止运算精度降低,实现并优化两类运算基于RVV的向量化算法;其次根据算法中的数据依赖关系,对寄存器配置参数进行优化.最后针对算法核心步骤进行汇编优化,增加指令级并行度,提高流水线利用率.实验结果表明,与两类运算操作的原始算法相比,优化后的算法运算效率分别提高了4.4和4.2倍.优化后的算法与多精度库MPFR中的四精度算法有相同精度,但其运算效率明显优于后者,其计算速度与OpenBLAS的双精度计算速度相当. 展开更多
关键词 RISC-V 点积 求和 无误差变换 高精度 向量化
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Solution of the Matrix Second Semi-Tensor Product Equation A ∘ l X ∘ l B=C
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作者 Hao Zhang 《Journal of Applied Mathematics and Physics》 2024年第10期3261-3280,共20页
In this paper, the solution of the matrix second semi-tensor product equation A∘lX∘lB=Cis studied. Firstly, the solvability of the matrix-vector second semi-tensor product equation is investigated. At the same time,... In this paper, the solution of the matrix second semi-tensor product equation A∘lX∘lB=Cis studied. Firstly, the solvability of the matrix-vector second semi-tensor product equation is investigated. At the same time, the compatibility conditions, the sufficient and necessary conditions and the specific solution methods for the matrix solution are given. Secondly, we further consider the solvability of the second semi-tensor product equation of the matrix. For each part, several examples are given to illustrate the validity of the results. 展开更多
关键词 Matrix Equation The Second Semi-Tensor product Compatibility Condition Sufficient and Necessary Conditions vectorIZATION
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基于高维语义向量的同群企业识别方法研究
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作者 王伟 陈逢文 王冰 《管理学报》 北大核心 2025年第9期1626-1635,共10页
为精准界定市场边界并揭示企业间隐性关系网络,提出一种基于高维语义向量的同群企业识别方法:①应用神经网络语言模型对上市公司年报中的产品文本进行向量化表示,生成能够刻画企业经济相关性的高维语义向量;②基于资源依赖理论,将经济... 为精准界定市场边界并揭示企业间隐性关系网络,提出一种基于高维语义向量的同群企业识别方法:①应用神经网络语言模型对上市公司年报中的产品文本进行向量化表示,生成能够刻画企业经济相关性的高维语义向量;②基于资源依赖理论,将经济相关性较高的企业识别为焦点企业的同群企业。继而采用线性均值模型检验方法的有效性,研究显示:该方法在解释焦点企业绩效与决策行为方面明显优于传统行业分类,且同群企业变动频率更高。通过股价联动性指标开展稳健性检验,进一步验证了此方法在刻画企业间经济相关性上的优势,并探讨了同群企业数量对相关性度量的影响机制。 展开更多
关键词 同群企业 经济相关性 产品文本语义 高维语义向量 企业关系网络
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标准模型下效率更高的身份基匹配加密 被引量:1
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作者 陈洁 楚乔涵 +1 位作者 杜秋妍 高莹 《软件学报》 北大核心 2025年第2期698-714,共17页
身份基匹配加密是一种新型的密码学原语,允许接收者与发送者双方都可以指定对方的身份,只有身份匹配时才可与之通信.这项加密技术提供了一种非交互式的秘密握手协议以摆脱实时互动,进一步提高参与者的隐私性.在标准模型下基于SXDH假设,... 身份基匹配加密是一种新型的密码学原语,允许接收者与发送者双方都可以指定对方的身份,只有身份匹配时才可与之通信.这项加密技术提供了一种非交互式的秘密握手协议以摆脱实时互动,进一步提高参与者的隐私性.在标准模型下基于SXDH假设,提出素数阶群上的身份基匹配加密方案,实现短参数,降低解密时的配对次数,是目前效率最高的身份基匹配加密方案.此外,还提出第1个标准模型下基于SXDH假设的等值策略的内积匹配加密方案.技术路线如下,首先构造合数阶群上的方案,然后通过DPVS技术将方案模拟到素数阶群中,并降低所需的对偶基维数,进一步减小参数大小.最后,替换身份基匹配加密的第1层策略,构造出等值策略的内积匹配加密方案. 展开更多
关键词 身份基匹配加密 内积匹配加密 对偶配对向量空间 SXDH假设
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基于RISC-V Matrix指令集扩展的LLM矢量点积加速研究
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作者 陈煦豪 胡思鹏 +3 位作者 刘洪超 刘伯然 唐丹 赵地 《计算机科学》 北大核心 2025年第5期83-90,共8页
鉴于边缘AI的高性能与低功耗需求,基于RISC-V指令集架构,针对边缘设备数字信号处理的实际问题,设计了一种边缘AI的专用指令集处理器,在有限的硬件开销下,提升了边缘AI的执行效率,降低了边缘AI的能量消耗,能够满足边缘AI应用中进行高效... 鉴于边缘AI的高性能与低功耗需求,基于RISC-V指令集架构,针对边缘设备数字信号处理的实际问题,设计了一种边缘AI的专用指令集处理器,在有限的硬件开销下,提升了边缘AI的执行效率,降低了边缘AI的能量消耗,能够满足边缘AI应用中进行高效大语言模型(LLM)推理计算的需求。针对大语言模型的特性,基于RISC-V指令集扩展了自定义指令完成矢量点积计算,在专用的矢量点积加速硬件上进行大语言模型的运算加速;基于开源高性能RISC-V处理器核“香山”nanhu版本架构,实现了矢量点积专用指令集处理器nanhu-vdot,其在高性能处理器“香山”(nanhu版本)的基础上增加了矢量点积计算单元以及流水线处理逻辑;对nanhu-vdot进行FPGA硬件测试,在几乎没有增加额外的硬件资源和功耗消耗的前提下,矢量点积运算速度相比标量方法提高4倍以上,使用软硬件协同方案进行第二代生成式预训练(Generative Pre-Trained-2,GPT-2)模型推理,相比纯软件实现,速度提高了约30%。 展开更多
关键词 指令集扩展 矢量点积 软硬件协同 大语言模型推理
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基于支持向量回归改进的温带草原总初级生产力估算
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作者 曹云刚 赵俊 +3 位作者 杜蒲英 曾雅慧 张成利 杨秀春 《草业科学》 北大核心 2025年第9期2153-2165,共13页
植被生产力是衡量生态系统应对气候变化和人类活动影响的重要指标。本研究的主要目的是提高总初级生产力(GPP)估算的准确性,以满足精确生态监测的迫切需要。为此,本研究在光能利用率模型的基础上,提出了优化的GPP估算模型:CASA_SVR。植... 植被生产力是衡量生态系统应对气候变化和人类活动影响的重要指标。本研究的主要目的是提高总初级生产力(GPP)估算的准确性,以满足精确生态监测的迫切需要。为此,本研究在光能利用率模型的基础上,提出了优化的GPP估算模型:CASA_SVR。植被冠层光合有效辐射占比(FPAR)是光能利用率模型的重要参数,CASA_SVR模型结合支持向量回归算法(SVR),利用归一化植被指数(NDVI)和修正土壤调整植被指数(MSAVI)改进了FPAR的估算。结果表明:1)CASA_SVR模型估算GPP的R^(2)为0.71(P<0.001),比CASA模型提高0.19,RMSE和MAE均有所降低。同样,与VPM模型相比,VPM_SVR模型也有改善,R^(2)值增加0.25,RMSE和MAE均有所降低,凸显了将SVR纳入GPP估算模型以及引入MSAVI优化FPAR计算的作用。2)与CASA模型相比,利用CASA_SVR模型估算草甸草原、典型草原和荒漠草原的GPP,RMSE值分别降低7.11、2.31和10.41 g∙(m^(2)∙month)^(−1)。CASA_SVR模型能够显著改善草地的GPP估算,与传统模型和现有的MODIS产品相比,RMSE降低明显,且CASA_SVR在不同草原类型中表现出更广泛的适用性和更高的准确性。 展开更多
关键词 温带草原 总初级生产力 陆地资源卫星 支持向量回归 光合有效辐射占比 土壤植被指数 光能利用效率模型
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