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1.
This paper concerns recombinations which produce offspring from two parents. We assume an infinite population and regard recombinations as transformations of stochastic variables represented as chromosomes. We then formalize recombinations with the probability density functions of stochastic variables represented as the parameters and describe the change of the probability density functions of chromosomes before and after recombination. Our formalization includes various proposed recombinations, such as multi-point, uniform, and linear crossover, as well as BLX-alpha. We also derive certain properties of the operators, such as diversification and decorrelation.  相似文献   

2.
在Linux系统中,进程作为实体自始至终运行在系统之中,进程使用系统的资源,而进程的调度更是影响系统的性能:进程响应时间尽可能快,后台进程的吞吐量尽可能高,进程"饿死"现象尽可能避免,低优先级和高优先级进程需要尽可能调和.本文从Linux 2.4.0内核角度分析影响进程调度的各个因素和调度处理流程,以及在SMP(Symmetric Multi Processing)的进程调度处理.  相似文献   

3.
摘要:设计基于SNMP和其它协议的网络拓扑发现算法,实现三层交换机和路由器为网关的网络拓扑的快速发现,尽可能地发现完整的网络,且对网络带来的额外负栽和开销尽可能小。  相似文献   

4.
该文介绍了计划体系在ERP系统中地位、作用以及计划体系在ERP系统设计实施过程中常遇缺陷对常遇问题进行了分析,并提出解决方案。阐述了计划体系在ERP的核心地位,以及MPS,MRP核心计划在整个计划体系的作用以及运作模式,最后总结了ERP实施过程中的难点提出了几点解决方案。  相似文献   

5.
A new planar split dual gate (PSDG) MOSFET device, its characteristics and experimental results, as well as the three dimensional device simulations, are reported here for the first time. Both theoretical calculation and 3D simulation, as well as the experiment data, show that the two independent split dual gates can provide dynamical control of the device characteristics, such as threshold voltage (Vt) and sub-threshold swing (SS), as well as the device saturated current. The PSDG MOSFET transistor leakage current (loft) can be reduced as much as 78% of the traditional single gate MOSFET. The PSDG is fabricated and fully compatible with our conventional 0.18 μm logic process flow.  相似文献   

6.
This paper provides a comprehensive review of research efforts in the emerging field of micro devices assembly (MDA) as well as identifies future directions for research. The general domain dealing with both manual and automated assembly of micro devices can be referred to as MDA. The study of computer-based methods to accomplish the assembly of micron-sized parts can be described as Automated MDA (AMDA). The primary focus of this paper is to provide an overview of concepts related to MDA as well as a review of various segments of MDA research including study of the role of interactive forces at the micro level, the design of innovative gripping and assembly techniques as well as the use of information technology (IT) based approaches.  相似文献   

7.
The issues arising in hybrid or simultaneous external as well as internal stabilization of linear systems with saturating actuators are considered. Four different stabilization problems are studied. Roughly, these problems are (1) simultaneous semi-global external as well as semi-global internal stabilization, (2) simultaneous semi-global external as well as global internal stabilization, (3) simultaneous global external as well as semi-global internal stabilization, and (4) simultaneous global external as well as global internal stabilization. As evident from the literature, the requirement of internal stabilization alone either in the global or semi-global sense demands that the linear part of the given system be (a) stabilizable, and (b) has all its poles in the closed left half complex plane for continuous-time systems while it has all its poles inside and/or on the unit circle for discrete-time systems. This implies that the posed simultaneous stabilization problems are solvable at best only under the conditions (a) and (b). Under such conditions, we construct here explicit state as well as measurement feedback controllers for all the four problems in the case of continuous-time systems, and for the problems (1), (2) and (4) in the case of discrete-time systems. The design methodologies used to construct appropriate feedback laws are based on by now familiar low-gain and low-and-high gain design concepts or certain scheduled versions of them.  相似文献   

8.
度量学习通过更真实的刻画样本之间的距离,来提高分类和聚类的精度。GMML(Geometric Mean Metric Learning)在学习度量矩阵[A]时,使得在该度量下同类点之间的距离尽可能小,不同类点之间的距离尽可能大。GMML用来学习的训练样本均为目标类数据,而对于现实存在的为数众多的同领域非目标类数据,即Universum数据并未加以利用,不免造成信息的浪费,针对此,提出一种新的度量学习算法--融入Universum学习的GMML(U-GMML)。U-GMML期望得到一个新的度量矩阵[A],使得同类点之间的距离尽可能小,不同类点之间的距离尽可能大,且Universum数据与目标类数据的距离尽可能大,从而使得所学习的度量矩阵[A]更有利于分类。真实数据集上的实验结果验证了该算法的有效性。  相似文献   

9.
The open thermodynamic system has been identified as an imprecise dynamical observer and as a rotator, each one with a heuristic function of behavior. These two identification models have been obtained by isolation of the open system. They have been determined as patterns with interpretation of the internalized plan and of the oscillations in the open system. The imprecise dynamical observer has been constructed by perceiving the internalized plan as a fuzzy controller of the speed of a mobile robot, by structuring the internalized plan as a dynamical observer and interpreting the internalized plan as a heuristic function for the remaining path to a goal. The rotator has been constructed by perceiving the oscillations as movement along a cycle, by structuring the oscillations as an autoregressive model and by interpreting the oscillations as a heuristic function for the remaining energy to a goal.  相似文献   

10.
A problem of determining optimal periodic test input signals for estimating weighting functions of continuous-time systems is considered by an information theory approach. Under appropriate assumptions, the amount of information provided by the measurements in a period is calculated in terms of the corresponding periodic test input signals. By taking the amount of information as a criterion function, the existence of optimal test input signals and the condition for optimality are studied under energy constraint. It is shown that, in the case of observing sampled outputs, an input signal of as small auto-correlation as possible and, at the same time, of as largo energy as possible is optimal, while, in the case of observing outputs continuously, an input signal of as flat a spectrum as possible and, at the same time, of as large energy as possible is optimal. As an example, the optimality of an M-sequence signal is examined.  相似文献   

11.
随着体验经济时代的来临,商品包装的价值已与消费体验密不可分。文章以消费体验理论为基础和指导,以茶叶便携包装为研究对象,界定白领女性为受众群体。通过对白领女性的消费心理和行为的研究总结出人群对茶叶包装的特征要求,并以此作为茶叶便携包装的研究依据,进行包装设计特征总结、设计表现方法分析和设计要素定义。  相似文献   

12.
We analyze the worst-case ratio of natural variations of the so-called subset sum heuristic for the bin packing problem, which proceeds by filling one bin at a time, each as much as possible. Namely, we consider the variation in which the largest remaining item is packed in the current bin, and then the remaining capacity is filled as much as possible, as well as the variation in which all items larger than half the capacity are first packed in separate bins, and then the remaining capacity is filled as much as possible. For both variants, we show a nontrivial upper bound of 13/9 on the worst-case ratio, also discussing lower bounds on this ratio.  相似文献   

13.
Wearable computing: toward humanistic intelligence   总被引:1,自引:0,他引:1  
Over the past 20 years, wearable computing has emerged as the perfect tool for embodying humanistic intelligence (HI). HI is intelligence that arises when a human is part of the feedback loop of a computational process in which the human and computer are inextricably intertwined. It is common in the field of human-computer interaction to think of the human and computer as separate entities. (indeed, the term "HCI" emphasizes this separateness by treating the human and computer as different entities that interact.) However, in HI theory, we prefer not to think of the wearer and the computer with its associated I/O apparatus as separate entities. Instead, we regard the computer as a second brain and its sensory modalities as additional senses, in which synthetic synesthesia merges with the wearer's senses. When a wearable computer functions in a successful embodiment of HI, the computer uses the human's mind and body as one of its peripherals, just as the human uses the computer as a peripheral. This reciprocal relationship is at the heart of HI.  相似文献   

14.
提出一种基于传感器最优配置的等价空间故障检测方法.针对线性时不变动态系统,给出了传感器最优配置问题的描述,以及基于传感器最优配置的故障检测多目标优化问题的描述.在系统可供测量的N个变量中,选择能获得关于系统故障尽可能多信息的m个变量作为测量变量,在满足对故障具有尽可能高的灵敏度,同时对扰动等未知信号具有尽可能强的鲁棒性的条件下,使整个系统测量成本达到最低.仿真算例说明了所提出设计方法及算法的有效性.  相似文献   

15.
An image analysis method and its validation are presented for tracking the displacements of parallel mechanical force sensors. Force is measured using a combination of beam theory, optical microscopy, and image analysis. The primary instrument is a calibrated polymeric microbeam array mounted on a micromanipulator with the intended purpose of measuring traction forces on cell cultures or cell arrays. One application is the testing of hypotheses involving cellular mechanotransduction mechanisms. An Otsu-based image analysis code calculates displacement and force on cellular or other soft structures by using edge detection and image subtraction on digitally captured optical microscopy images. Forces as small as 250+/-50 nN and as great as 25+/-2.5 microN may be applied and measured upon as few as one or as many as hundreds of structures in parallel. A validation of the method is provided by comparing results from a rigid glass surface and a compliant polymeric surface.  相似文献   

16.
Parallel programming of high-performance computers has emerged as a key technology for the numerical solution of large-scale problems arising in computational science and engineering (CSE). The authors believe that principles and techniques of parallel programming are among the essential ingredients of any CSE as well as computer science curriculum. Today, opinions on the role and importance of parallel programming are diverse. Rather than seeing it as a marginal beneficial skill optionally taught at the graduate level, we understand parallel programming as crucial basic skill that should be taught as an integral part of the undergraduate computer science curriculum. A practical training course developed for computer science undergraduates at Aachen University is described. Its goal is to introduce young computer science students to different parallel programming paradigms for shared and distributed memory computers as well as to give a first exposition to the field of computational science by simple, yet carefully chosen sample problems.  相似文献   

17.
We study data-driven Web applications provided by Web sites interacting with users or applications. The Web site can access an underlying database, as well as state information updated as the interaction progresses, and receives user input. The structure and contents of Web pages, as well as the actions to be taken, are determined dynamically by querying the underlying database as well as the state and inputs. The properties to be verified concern the sequences of events (inputs, states, and actions) resulting from the interaction, and are expressed in linear or branching-time temporal logics. The results establish under what conditions automatic verification of such properties is possible and provide the complexity of verification. This brings into play a mix of techniques from logic and model checking.  相似文献   

18.
Real-time active database systems (RTADB) have attracted the attention of researchers in recent times. Such systems are envisioned as control systems for environments as diverse as process control, network management and automated financial trading. Sensors distributed throughout the system report the state of the system to the database. Unacceptable state reports typically results in corrective actions being triggered with deadlines. Thus RTADB's incorporate both real-time as well as active characteristics. We study buffer management in RTADB. Buffer management is recognized as not being a well studied area in real-time systems. As a result of our work, we postulate PAPER, a new buffer management scheme that relies on two strategies: prefetching and priority based buffer replacement. We report the result of studies of the performance of PAPER, as compared to that of existing buffer management algorithms. The insights derived from this paper impact both real-time database systems as well as real-time, active database systems  相似文献   

19.
矿井宽带无线传输技术研究   总被引:2,自引:3,他引:2  
提出了矿井宽带无线传输技术是解决采掘工作面移动监控、监视和语音通信需求的关键技术。提出了矿井宽带无线传输应满足传输带宽宽、便于接入有线宽带网络、中继设备少、体积小、发射功率小、电磁兼容性好、安全性好、传输协议标准化、电源电压波动适应能力强等要求。提出了漏泄通信不能用作矿井宽带无线传输技术,但可用于煤矿井下局部通信等;感应通信不能用作矿井宽带无线传输技术,但可用于煤矿井下救灾通信等;透地通信不能用作矿井宽带无线传输技术,但可用于煤矿井下避难硐室等应急通信;小灵通、CDMA、GSM、Bluetooth不能用作矿井宽带无线传输技术;RFID不能用作矿井宽带无线传输技术,但可用于煤矿物联网、矿用设备管理和防碰撞等;ZigBee不能用作矿井宽带无线传输技术,但可用于煤矿井下人员、胶轮车、电机车等动目标精确定位和矿用传感器无线传输等;UWB不能用作矿井宽带无线传输技术,但可用于煤矿井下生命探测、防碰撞、煤矿井下人员和胶轮车等动目标精确定位等;WCDMA、CDMA2000、TD-SCDMA等3G不能用作矿井宽带无线传输技术,但可用于煤矿井下语音移动通信等。提出了矿井宽带无线传输技术宜采用WiFi,4G有可能成为未来矿井宽带无线传输技术。  相似文献   

20.
基于FPGA和DSP的人民币图像鉴别平台设计   总被引:1,自引:0,他引:1  
实现了一种高速采集、实时处理、适用于新国标A类机的人民币图像鉴别处理平台。该平台采用ADC量化CIS的输出作为系统输入,FPGA、DSP作为处理核心,得到的人民币信息被发送到鉴别仪的主控模块作为真假币的判别依据。该系统可以以子系统形式整合到鉴别仪中,具有很好的应用前景、良好的可升级性和鲁棒性。  相似文献   

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