Estimation of capability index based on bootstrap method

A process capability index C_pmk is recently proposed to measure the degree of process capability of a system. C_pmk is a generalized version of the existing indices C_p, C_pk, and, C_pm, which have been studied extensively in the last few years. In this paper, we present the estimators of C_pmk and derive its asymptotic distribution. We also utilize the asymptotic variance of the estimator of C_pmk to derive the two-sided confidence interval for C_pmk based on a percentile-t bootstrap method. Our new confidence intervals are shown to outperform the ones based on the percentile and standard bootstrap method by simulation.     

Functional verification of instruction processing units through control flow modeling

The design verification of state-of-the-art high-performance microprocessors has become a significant challenge for test engineers. Deep pipelines, multiple execution units, out-of-order and speculative execution techniques, typically found in such microprocessors, contribute much to this complexity. Conventional methods, which treat the processor as a logic state machine or apply architectural level tests, fail to provide coverage of all possible corner cases in the design. This paper presents a functional verification method for modern microprocessors, which is based on innovative models of the microprocessor architecture, intended to cover the testing of all corner cases. In order to test the models presented in this work, an architecture independent coverage measurement system has been developed. The models were tested with both random code and real world applications in order to determine which of the two achieves higher coverage.     

模糊PID双组份流量控制方法研究

针对目前变转速泵流量控制系统主要是对单个流量的执行机构进行速度控制,控制过程中会出现动态响应慢、控制精度低、无法实现双组份变比例流量控制等问题,特别是流量控制系统具有很大的滞后性、非线性和强耦合性,采用传统的PID控制无法满足工程要求的现状,提出采用简单预测的模糊控制和积分分离的PID控制方法,控制系统通过简单预测的方法快速接近理想流量比,然后采用带积分分离的模糊PID控制减小超调量。该方法具有响应速度快、精度高的优点。实验和工程实践结果表明该方法可提供在不同压力下不同的流量比。     

多路恢复数据流并行传输与控制方法

为有效缩短灾难恢复时间,提出了一种多路恢复数据流并行传输与控制方法(MRPTC).首先,待恢复服务器与多个备用服务器建立连接,将当前破损数据与原始的完好数据(备份数据)做差异比较,获得两者的差异数据,然后从各备用服务器处动态并行下载差异数据的不同部分,再在本地进行拼合,获得完整的数据,从而实现数据的快速恢复.该方法具有多点协同差异恢复、恢复速度快、带宽利用率高、传输网络要求低等优点.理论分析和实验结果表明,该方法是快速灾难恢复的一种有效的新途径.     

宽带信号源个数估计频域bootstrap方法

针对宽带和非平稳信号,在未知信源类型及其它任何统计特性条件下,基于bootstrap方法,利用样本频域协方差矩阵的特征值特性,结合多假设检验过程,提出一种新的信源个数估计方法.理论分析和仿真实验表明该算法的有效性.     

In vivo validation of a one-dimensional finite-element method for predicting blood flow in cardiovascular bypass grafts

Current practice in vascular surgery utilizes only diagnostic and empirical data to plan treatments and does not enable quantitative a priori prediction of the outcomes of interventions. We have previously described a new approach to vascular surgery planning based on solving the governing equations of blood flow in patient-specific models. A one-dimensional finite-element method was used to simulate blood flow in eight porcine thoraco-thoraco aortic bypass models. The predicted flow rate was compared to in vivo data obtained using cine phase-contrast magnet resonance imaging. The mean absolute difference between computed and measured flow distribution in the stenosed aorta was found to be 4.2% with the maximum difference of 10.6% anda minimum difference of 0.4%. Furthermore, the sensitivity of the flow rate and distribution with respect to stenosis and branch losses were quantified.     

腐蚀生产线上槽液流量的控制方法及应用

铝电解电容器阳极箔的腐蚀生产线上 ,主腐蚀槽槽液的流量是一个关键控制量。根据法拉第电解定律 ,定量地阐述了主腐蚀槽槽液流量的控制方法。结合实际情况 ,讨论了该控制方法的局限性和有效性。     

基于控制流序位比对的智能Fuzzing测试方法

在国际前沿技术EFS(evolutionary fuzzing system)的研究基础上,提出基于控制流序位比对算法的智能Fuzzing测试方法。根据遗传算法的内在属性演算得到基于序列比对的适应度函数,并有效地计算出需要搜索的程序逻辑空间。最后给出了该方法与2种传统Fuzzing方法的测试性能的实验结果比对,证明了该方法能够充分利用遗传算法属性中并行性进行智能地程序逻辑学习,具有逻辑覆盖面广、搜索导向性强的优点,能够提高漏洞挖掘能力。     

Research of traffic flow multi-objectives intelligent control method for junction network

Junction network is a special type of roadwork pattern that scatters and distributes around the specific zone of metropolitan and in that contains different grade and functional roads of arterial road, urban freeway and expressway. Intelligent control is new development where the control problem is to find the combination of control measures that result for the best road performance and control effectiveness. The problems of multi-objective coordinated metering and evaluation for local ramp is considered. This paper discusses the optimal coordination of mainline and ramp, a modified ramp latency model is posed using the method of queuing theory, and a ramp control with better mechanism compare to artificial neural network using radical based function-support vector machine algorithm is designed. With in-situ traffic flow data of Beijing ring and radial freeway during high-density period, three known and the designed novel methodologies are compared, the intensive simulations show the effectiveness of the proposed approach, particularly at the aspect of minimize reduplicated waiting time for junction network. using these methodologies demonstrates the comparative control efficiency and accuracy.     

Cost-effective three-phase FRM drive with four switches and bootstrap gate control circuitry

A cost-effective three-phase flux reversal machine (FRM) drive topology, which consists of four main switches with bootstrap gate control circuitry, is proposed. A design guide for a proper profile of bootstrap charging and discharging voltages is proposed by considering the switching sequence for four-switch drives. The proposed design scheme, which considers the switching sequence of a fourswitch drive, is verified by a laboratory prototype 100 W FRM.     

Mathematical simplification of a PET blood flow model

The positron emission tomography (PET) H(2)(15)O bolus injection model for cerebral blood flow (CBF) requires calculation of a certain double integral that, when calculated, provides the pixel values of a reconstructed image (PET number) in terms of the tissue flow, the arterial input function, a decay constant for (15)O, the partition coefficient and a camera calibration constant that relates the flow-dependent integrated tissue activity to the measured PET number (cts/pixel). The tissue activity is assumed to be zero at the time of injection. A mathematical simplification, changing the order of integration, enabled the integration with respect to time to be performed analytically before the integration of the arterial input function. As a result of this simplification, only single integrals remain to be calculated numerically; cubic spline integration was used to calculate numerically these remaining integrals. This technique increases the accuracy and speed of evaluating blood flow without making simplifying assumptions. Similar simplifications may be applicable to other physiological models.     

Robust parameter-estimation using the bootstrap method for the2-parameter Weibull distribution

This paper proposes bootstrap robust estimation methods for the Weibull parameters; it applies bootstrap estimators of order statistics to the parametric estimation procedure. Estimates of the Weibull parameters are equivalent to the estimates using the extreme value distribution. Therefore, the bootstrap estimators of order statistics for the parameters of the extreme value distribution are examined. Accuracy and robustness for outliers are examined by Monte Carlo experiments which indicate adequate efficiency of the proposed reliability estimators for data with some outliers     

DS域中一种补偿CIR体现公平性的流量控制方法

本文针对CIR因素引发的不公平性问题，基于公平性原则给出了一个补偿CIR的通信量调整方法。在这种方法下，为较高CIR付费的用户能享受不低于为较低CIR付费的用户的超出带宽，并且通过模拟验证了算法的公平性。     

Optimal flow control of a stochastic fluid-flow system

This paper is concerned with the optimal flow control of an ATM switching element in a broadband-integrated services digital network. We model the switching element as a stochastic fluid-flow system with a finite buffer, a constant output rate, and Markov-modulated fluid input. There is a cost of holding fluid and a reward for admitting the fluid to the buffer. We study the optimal flow control policies that minimize the fetal expected discounted cost. We analyze the problem by two different approaches and show that the optimal policy is of the turnpike type with the turnpike levels dependent on the states of the Markov-modulated source. We also state sufficient conditions under which the optimal turnpike levels are monotonic functions of the states of the Markov-modulated source     

Assessing the value of a lead-free solder control plan using cost-based FMEA

While the transition to lead-free electronics, which began nearly a decade ago, is complete for most commercial products, many safety, mission and infrastructure critical systems that were originally exempt from RoHS and WEEE are only now transitioning. For these types of products qualification is very expensive and the consequences of failure can be catastrophic, therefore carefully engineered control plans are needed when technology or process changes are required. A control plan is a set of activities that a manufacturer can choose or be required to perform to ensure product performance. This paper uses cost-based FMEA to determine the projected cost of failure consequence for a technology insertion control plan for the adoption of lead-free solder for the assembly of electronic systems in critical applications that previously used tin–lead solder. A case study of the lead-free implementation of a power supply demonstrates the return on investment of the control plan for the same product under to different risk scenarios.     

A control method to reduce the standard deviation of flow time inwafer fabrication

This paper proposes a control, method for reducing flow time variability in a wafer fabrication facility with multiple wafer types. We employ stochastic Petri nets to model and analyze the machine module, and define operation due dates using a novel utilization index metric. An operation due date (OPNDD) rule for lot dispatch is proposed and evaluated against other lot dispatch policies     

Advanced control strategy for a digital mass flow controller

Mass flow controllers are complex mechatronic devices, the design of which involves many techniques and skills in various scientific domains. Due to the slow response time of the sensors embedded in such devices, it is critically important to control gas flow variations in processes used in semiconductor industry. This paper shows how a digital controller for MFCs can be mathematically computed once the dynamic characteristics of the open-loop system have been identified. The proposed control method goes beyond prior art control methods as it explicitly takes into account the dynamics of the sensor, computes the digital controller appropriate to the order of the open-loop model and imposes a desired closed-loop transient response. The simulations performed and experimental results obtained with this new type of digital controller were very promising.     

Convergence of REM flow control at a single link

Various TCP congestion control schemes can be interpreted as approximately carrying out a certain basic algorithm to maximize aggregate source utility, different schemes corresponding to different choices of utility functions. The basic algorithm consists of a link algorithm that updates a congestion measure based on its traffic load, and a source algorithm that adapts the source rate to congestion in its path. Though convergent, this algorithm can lead to large equilibrium backlogs. This problem can be eliminated by modifying the basic algorithm to include backlog in the update of the congestion measure. This article proves that the modified algorithm converges when the network can be modeled as a single bottleneck link. Moreover, in equilibrium, the source rates are matched to the link capacity while the buffer is cleared     

Window flow control on a trunked byte-stream virtual circuit

The throughput versus window-size behavior of the sliding window protocol is studied on a trunked byte-stream virtual circuit. For the case studied, the node service discipline is processor sharing, background traffic is Poisson with exponentially distributed message lengths, propagation times are a significant fraction of the total delay, and the channel error rate is negligible. Analytic models are compared to the results of simulation. For small windows, the throughput is controlled by the ratio of window size to roundtrip propagation time. For large windows, the throughput is controlled by the background traffic level, the number of hops, and the ratio of window size to background message length     

Multiuser rate-based flow control

Flow and congestion control allow the users of a telecommunication network to regulate the traffic that they send into the network in accordance with the quality of service that they require. Flow control may be performed by the network, as is the case in asynchronous transfer mode (ATM) networks (the available bit rate (ABR) transfer capacity), or by the users themselves, as is the case in the Internet [transmission control protocol/Internet protocol (TCP/IP)]. We study both situations using optimal control and dynamic game techniques. The first situation leads to the formulation of a dynamic team problem, while the second one leads to a dynamic noncooperative game, for which we establish the existence and uniqueness of a linear Nash equilibrium and obtain a characterization of the corresponding equilibrium policies along with the performance costs. We further show that when the users update their policies in a greedy manner, not knowing a priori the utilities of the other players, the sequence of policies thus generated converges to the Nash equilibrium. Finally, we study an extension of the model that accommodates multiple traffic types for each user, with the switching from one type of traffic to another being governed by a Markov jump process. Presentation of some numerical results complements this study