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排序方式: 共有6125条查询结果,搜索用时 8 毫秒
71.
多通道信号源是多路采集系统自检与测试系统的重要组成部分,为提高信号源的通用性,可靠性,可扩展性及小型化,结合PXI总线技术,设计出多通道信源卡;详细介绍了波形再生硬件模块,外部SRAM存储波形模块及满足设计要求边沿时间短的矩形波的软硬件设计,同时使用VHDL语言编写了数据通信协议模块,实现FPGA与计算机之间的正常通信。 相似文献
72.
针对通用BP网络对于高纬度、大数据量训练收敛困难的问题,在使用动量因子、自适应调整学习速率等方法的基础,引入约束聚类,构造集成神经网络,以提高网络的训练速度及诊断效果;首先,采用约束聚类算法将训练样本集划分为若干个规模相当的子样本集,分别训练生成相应子网络;此外,在诊断过程中除各子网络的输出变量外,还加入了诊断数据相对各子训练样本集的隶属度因子;最后通过一个实际电路板25维采样数据、38类故障的BP网络诊断实例验证了算法的可行性。 相似文献
73.
74.
提出一种利用小波变换提取模拟电路故障特征和基于支持向量机状态分类的模拟电路故障自动识别和诊断方法。首先讨论小波变换的基本原理和支持向量机原理及其多分类算法,同时着重研究支持向量机的一种改进型一对多故障分类算法,然后实现在小波变换上,采用分布式多SVM分类器识别单相桥式整流模拟电路的故障。实验证明,该方法能准确有效地对模拟电路故障进行识别和诊断。 相似文献
75.
76.
基于ATmega128的调光控制器方案设计 总被引:1,自引:0,他引:1
现有的模拟调光控制器大多采用拉杆、旋钮、开关等对模拟信号进行变换,控制精度不高,体积较大,且只能实现对灯具的通断控制。本文结合PC上位机、ATmega128单片机及AD7226芯片实现一种高精度的模拟调光控制器,通过上位机的调光控制软件可以对灯具实现多种灯光效果的变换。 相似文献
77.
音体美专业学生的计算机课程教学,是困扰教师教学的难题。本文通过对该类专业学生教学过程和实验设计的探讨,从多个角度介绍解决这些困扰的方法和策略,试图运用这些手段,克服教学中的困难和阻碍,以达到较理想的教学目标。 相似文献
78.
In this paper, we consider a distribution system where a warehouse is responsible for replenishing the inventories at multiple retailers by a fleet of vehicles of limited capacity. If a distribution policy of the system involves split deliveries, that is, the inventory of at least one retailer is replenished by using multiple vehicle routes, the coordination of the deliveries can further reduce the inventory cost of the retailer. We consider the coordination where two split deliveries are realized by direct shipping and multiple-stop shipping, respectively. To the best of our knowledge, this kind of coordination was never studied in the literature but can find its application in inventory routing problems. This paper proposes and analyses a class of coordination policies for the split deliveries which can reduce the inventory costs of the retailers without increasing transportation costs. A non-linear programming model is established for formulating the class of polices. Because the optimal coordination policy corresponding to an optimal solution of the model may be hard to find and/or implement, two simple but effective coordination policies are proposed. The inventory cost savings realized by the two policies are evaluated analytically and algorithmically. Our theoretical analysis and computational experiments show that both policies are effective. Under certain conditions, they can save 50% of the inventory costs at the retailers without increasing transportation costs. 相似文献
79.
The aims were to evaluate the inter-method reliability of a registration sheet for patient handling tasks, to study the day-to-day variation of musculoskeletal complaints (MSC) and to examine whether patient handling tasks and psychosocial factors were associated with MSC.Nurses (n = 148) fulfilled logbooks for three consecutive working days followed by a day off. Low back pain (LBP), neck/shoulder pain (NSP), knee pain (KP), psychosocial factors (time pressure, stress, conscience of the quality of work) and patient transfers and care tasks were reported.The logbook was reliable for both transfer and care tasks. The numbers of nurses reporting MSC and the level of pain increased significantly during the three working days (15%-30% and 17%-37%, respectively) and decreased on the day off. Stress and transfer task were associated with LPB and transfer tasks were associated with KP.Our results confirm a relationship between work factors and MSC and indicate that logs could be one way to obtain a better understanding of the complex interaction of various nursing working conditions in relation to MSC. 相似文献
80.
A structured P2P network based on the small world phenomenon 总被引:1,自引:0,他引:1
In this paper, we propose a new structured P2P overlay network, named SW-Uinta(small-world). In order to reduce the routing
latency, we firstly construct the Uinta network in which both physical characteristics of network and data semantic are considered.
Furthermore, based on Uinta, a nondeterministic caching strategy is employed to allow for poly-logarithmic search time while
having only a constant cache size. Compared with the deterministic caching strategy proposed by previous P2P systems, the
nondeterministic caching strategy can reduce communication overhead for maintaining the routing cache table. Cache entries
in the cache table of peer nodes can be updated by subsequent queries rather than only by running stabilization periodically.
In the following, a novel cache replacement scheme, named the SW cache replacement scheme, is used to improve lookup performance,
which has proved to satisfy the small-world principle. So we call this network SW-Uinta(small-world). After that, according
to the theoretical analysis, it can be proved that SW-Uinta(small-world) can get O((log 2
N)/k) search time with O(k) cache size. Lastly, the performance of SW-Uinta(small-world) is compared with those of other structured P2P networks such
as Chord and Uinta. It shows that SW-Uinta(small-world) can achieve improved object lookup performance and reduce maintenance
cost.
相似文献
Hai Jin (Corresponding author)Email: |