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排序方式: 共有733条查询结果,搜索用时 17 毫秒
1.
在分析单一MU(Most Uncertainty)采样缺陷的基础上,提出一种"全局最优搜寻"方法 GOS(Global Optimal Search),并结合MU共同完成查询选择。GOS+MU方法中,GOS着眼全局寻找目标,在应用环境能提供的训练样本数量有限、分类器受训不充分时,该方法选择的对象学习价值高,能快速推进分类器学习进程;MU则能够在GOS采样失效情形下,利用分类器当前训练成果,选择查询不确定性最强的样本补充训练集。通过对网络商品的用户评论进行分类仿真,并比较其他采样学习方法的效果,证明了GOS+MU方法在压缩学习成本、提高训练效率方面的有效性。 相似文献
2.
针对领域自适应问题中源域和目标域的联合分布差异最小化问题,提出两阶段领域自适应学习方法.在第一阶段考虑样本标签和数据结构的判别信息,通过学习一个共享投影变换,使投影后的共享空间中边缘分布的差异最小.第二阶段利用源域标记数据和目标域非标记数据学习一个带结构风险的自适应分类器,不仅能最小化源域和目标域条件分布差异,还能进一步保持源域和目标域边缘分布的流形一致性.在3个基准数据集上的实验表明,文中方法在平均分类准确率和Kappa系数两项评价指标上均表现较优. 相似文献
3.
条件概率关系数据库模型 总被引:1,自引:0,他引:1
现实世界中大量存在着的不确定性信息,关系数据库模型仅视它们为空值,有必要增强其处理这类信息的能力,文章在总结前人工作的基础上推广关系数据库模型,创建有效处理随机型不确定性信息的条件概念关系数据库模型,该模型通过在关系模式中增加一个条件概率测度属性,为每条记录指定适当的条件概率的途径,来表示不确定性信息。文中以对象码为基本工具,创建了条件概率关系结构;以特征函数为基本工具,定义了一套基于该结构的代数运算规则。条件概率的语意比概率的语意广泛,灵活,因而该模型能有效克服概率关系模型的许多不足。 相似文献
4.
DVB条件接收系统中独立加扰器的设计与实现 总被引:2,自引:0,他引:2
本文介绍DVB条件接收系统的基本结构,详细分析了条件接收系统的工作原理,并给出条件接收系统中独立加扰器SAS(Stand Alone Scrambler)的具体实现方案。 相似文献
5.
Parthasarathy P. Tirumalai Meng Lee Michael S. Schlansker 《The Journal of supercomputing》1991,5(2-3):119-136
Modulo scheduling theory can be applied successfully to overlap Fortran DO loops on pipelined computers issuing multiple operations per cycle both with and without special loop architectural support. This paper shows that a broader class of loops—REPEAT-UNTIL, WHILE, and loops with more than one exit, in which the trip count is not known beforehand—can also be overlapped efficiently on multiple-issue pipelined machines. The approach is described with respect to a specific machine model, but it can be extended to other models. Special features in the architecture, as well as compiler representations for accelerating these loop constructs, are discussed. Performance results are presented for a few select examples.An earlier version of this paper was presented at Supercomputing '90. 相似文献
6.
Marek Gondzio 《Software》1987,17(3):215-226
Every microprocessor-based system needs powerful debugging tools. Debugging power strongly depends on a mechanism of control exchange between the debugger and an application program. Several implementation methods of such a mechanism are briefly described and compared in this paper. It is shown that conditional breakpoints facilitate a semantics-oriented approach to program debugging. Some debugging techniques derived from elementary control-exchange mechanisms are proposed. Most of the techniques discussed are implemented in the MD-86 debugger designed for the Intel 8086 microprocessor. The debugger itself is also briefly described. 相似文献
7.
Abstract. Large sample properties of the least‐squares and weighted least‐squares estimates of the autoregressive parameter of the explosive random‐coefficient AR(1) process are discussed. It is shown that, contrary to the standard AR(1) case, the least‐squares estimator is inconsistent whereas the weighted least‐squares estimator is consistent and asymptotically normal even when the error process is not necessarily Gaussian. Conditional asymptotics on the event that a certain limiting random variable is non‐zero is also discussed. 相似文献
8.
A mechanism of synchronization of components of distributed systems in which communications are based on a common time schedule
for all system components is illustrated by examples of simple Time-Triggered Protocols. For parametric linear models of synchronization,
the optimization problem is considered for a parameter that should exclude the overlapping of messages in communication channels.
The results of using numeric methods for estimation of the optimal value of this parameter are described.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 24–32, May–June 2006. 相似文献
9.
条件函数依赖(Conditional Functional Dependeny,CFD)是对函数依赖(Functional Depencency,FD)加入语义约束扩展而来,它在数据库一致性检测、数据清洗方面更优于后者.讨论了条件函数依赖的相关概念及其基本性质,讨论如何将它应用于数据清洗,并对已提出的基于CFD的数据清洗方案提出改进措施,并通过实验说明改进措施的可行性. 相似文献
10.
Martina Mazzariol Giovanni Camussi Maria Felice Brizzi 《International journal of molecular sciences》2021,22(8)
Extracellular vesicles (EV) are microparticles released in biological fluids by different cell types, both in physiological and pathological conditions. Owing to their ability to carry and transfer biomolecules, EV are mediators of cell-to-cell communication and are involved in the pathogenesis of several diseases. The ability of EV to modulate the immune system, the coagulation cascade, the angiogenetic process, and to drive endothelial dysfunction plays a crucial role in the pathophysiology of both autoimmune and renal diseases. Recent studies have demonstrated the involvement of EV in the control of renal homeostasis by acting as intercellular signaling molecules, mediators of inflammation and tissue regeneration. Moreover, circulating EV and urinary EV secreted by renal cells have been investigated as potential early biomarkers of renal injury. In the present review, we discuss the recent findings on the involvement of EV in autoimmunity and in renal intercellular communication. We focused on EV-mediated interaction between the immune system and the kidney in autoimmune diseases displaying common renal damage, such as antiphospholipid syndrome, systemic lupus erythematosus, thrombotic microangiopathy, and vasculitis. Although further studies are needed to extend our knowledge on EV in renal pathology, a deeper investigation of the impact of EV in kidney autoimmune diseases may also provide insight into renal biological processes. Furthermore, EV may represent promising biomarkers of renal diseases with potential future applications as diagnostic and therapeutic tools. 相似文献