共查询到20条相似文献,搜索用时 9 毫秒
1.
A process capability index Cpmk is recently proposed to measure the degree of process capability of a system. Cpmk is a generalized version of the existing indices Cp, Cpk, and, Cpm, which have been studied extensively in the last few years. In this paper, we present the estimators of Cpmk and derive its asymptotic distribution. We also utilize the asymptotic variance of the estimator of Cpmk to derive the two-sided confidence interval for Cpmk 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. 相似文献
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Rami FeigShlomo Weiss 《Microelectronics Journal》2002,33(3):285-299
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. 相似文献
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Steele BN Wan J Ku JP Hughes TJ Taylor CA 《IEEE transactions on bio-medical engineering》2003,50(6):649-656
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. 相似文献
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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。 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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 相似文献
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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。 相似文献
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Rajagopal S. Kulkarni V.G. Stidham S. Jr. 《Selected Areas in Communications, IEEE Journal on》1995,13(7):1219-1228
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 相似文献
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《Microelectronics Reliability》2015,55(6):969-979
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. 相似文献
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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 相似文献
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Pierre Couturier 《Mechatronics》2009,19(4):443-449
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. 相似文献
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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 相似文献
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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 相似文献
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Multiuser rate-based flow control 总被引:1,自引:0,他引:1
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 相似文献