A Theoretical Foundation for the Development of Process Capability Indices and Process Parameters Optimization under Truncated and Censoring Schemes

Process capability indices (PCIs) provide a measure of the output of an in-control process that conforms to a set of specification limits. These measures, which assume that process output is approximately normally distributed, are intended for measuring process capability for manufacturing systems. After implementing inspections, however, non-conforming products are typically scrapped when units fail to meet the specification limits; hence, after inspections, the actual resulting distribution of shipped products that customers perceive is truncated. In this research, a set of customer-perceived PCIs is developed focused on the truncated normal distribution, as an extension of traditional manufacturer-based indices. Comparative studies and numerical examples reveal considerable differences among the traditional PCIs and the proposed PCIs. The comparison results suggest using the proposed PCIs for capability analyses when non-conforming products are scrapped prior to shipping to customers. The confidence interval approximations for the proposed PCIs are also developed. A simulation technique is implemented to compare the proposed PCIs with its traditional counterparts across multiple performance scenarios. The robust parameter design (RPD), as a systematic method for determining the optimum operating conditions that achieve the quality improvement goals, is also studied within the realm of censored data. Data censoring occurs in time-oriented observations when some data is unmeasurable outside a predetermined study period. The underlying conceptual basis of the current RPD studies is the random sampling from a normal distribution, assuming that all the data points are uncensored. However, censoring schemes are widely implemented in lifetime testing, survival analysis, and reliability studies. As such, this study develops the detailed guidelines for a new RPD method with the consideration of type I-right censoring concepts. The response functions are developed using nonparametric methods, including the Kaplan-Meier estimator, Greenwood\u27s formula, and the Cox proportional hazards regression method. Various response-surface-based robust parameter design optimization models are proposed and are demonstrated through a numerical example. Further, the process capability index for type I-right censored data using the nonparametric methods is also developed for assessing the performance of a product based on its lifetime

Cumulative sum quality control charts design and applications

Includes bibliographical references (pages 165-169).Classical Statistical Process Control Charts are essential in Statistical Control exercises and thus constantly obtained attention for quality improvements. However, the establishment of control charts requires large-sample data (say, no less than I 000 data points). On the other hand, we notice that the small-sample based Grey System Theory Approach is well-established and applied in many areas: social, economic, industrial, military and scientific research fields. In this research, the short time trend curve in terms of GM( I, I) model will be merged into Shewhart and CU SUM two-sided version control charts and establish Grey Predictive Shewhart Control chart and Grey Predictive CUSUM control chart. On the other hand the GM(2, I) model is briefly checked its of how accurate it could be as compared to GM( I, 1) model in control charts. Industrial process data collected from TBF Packaging Machine Company in Taiwan was analyzed in terms of these new developments as an illustrative example for grey quality control charts

Inspecting for Weapons Production a Modest Computer Simulation

We have tried to present an experiment in the detection of illegal weapons production, using a rather modest and simplified computer simulation. Three inspection schemes are defined by their ability to detect evasion and to avoid false alarms, and their effects are simulated using Monte Carlo methods. Because the model is not a fully dynamic one, it employs delayed rather than more or less instantaneous feedback; the full intensity of the inspection-evasion interaction is moderated. Furthermore, the model makes a number of assumptions which are justified only in so preliminary an analysis. For simu lation techniques such as that presented here to play a really useful role in the design of inspection systems and exercise a practical effect on the negotiations for disarma ment, this pilot project must be considerably surpassed in complexity and sophistication. Proceeding on the basis of data gathered during the computer simulation, we out lined a sequence of procedures whereby the potential signatories to a weapons produc tion ban agreement might be able to sort out and compare the relative costs of alterna tive inspection systems outlined. We have quite consciously sought to combine such disparate material and strategic-political factors as installation and operating cost on the one hand and successful evasion or false detection cost on the other. Two caveats are thus in order. First, such 'combining of utilities' may be a perfectly reasonable procedure, but we cannot afford to forget that certain of our inputs are based on political judgements of a most crucial sort. Second, and equally important, the calcula tions suggested here incorporate only a small portion of all the variables that must be considered in selecting a man-machine inspection system upon which a nation's security may well depend.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69022/2/10.1177_002234336500200102.pd

Chain: A Dynamic Double Auction Framework for Matching Patient Agents

In this paper we present and evaluate a general framework for the design of truthful auctions for matching agents in a dynamic, two-sided market. A single commodity, such as a resource or a task, is bought and sold by multiple buyers and sellers that arrive and depart over time. Our algorithm, Chain, provides the first framework that allows a truthful dynamic double auction (DA) to be constructed from a truthful, single-period (i.e. static) double-auction rule. The pricing and matching method of the Chain construction is unique amongst dynamic-auction rules that adopt the same building block. We examine experimentally the allocative efficiency of Chain when instantiated on various single-period rules, including the canonical McAfee double-auction rule. For a baseline we also consider non-truthful double auctions populated with zero-intelligence plus"-style learning agents. Chain-based auctions perform well in comparison with other schemes, especially as arrival intensity falls and agent valuations become more volatile

Design of SkSP-R Variables Sampling Plans

In this paper, we present the designing of the skip-lot sampling plan including the re-inspection  called SkSP-R. The plan parameters of the proposed plan are determined through a  nonlinear optimization problem by minimizing the average sample number satisfying both the producer's risk and the consumer's risks. The proposed plan is shown to perform better than the existing sampling plans in terms of the average sample number. The application of the proposed plan is explained with the help of illustrative examples.En este artículo, se presenta el diseño de un plan de muestreo de lotes incluyendo reinspección llamado SkSP-R. Los parámetros del plan propuesto se determinan a través de un problema de optimización no lineal que minimiza el número de muestras promedio óptimo que satisface el riesgo del productor a un nivel de calidad aceptable y el riesgo del consumidor a un nivel de calidad límite. El plan propuesto se desempeña mejor que otros planes de muestreo existentes en términos del número de muestras promedio. Se presenta una aplicación del plan propuesto con la ayuda de tabulados

Development and demonstration of an on-board mission planner for helicopters

Mission management tasks can be distributed within a planning hierarchy, where each level of the hierarchy addresses a scope of action, and associated time scale or planning horizon, and requirements for plan generation response time. The current work is focused on the far-field planning subproblem, with a scope and planning horizon encompassing the entire mission and with a response time required to be about two minutes. The far-feld planning problem is posed as a constrained optimization problem and algorithms and structural organizations are proposed for the solution. Algorithms are implemented in a developmental environment, and performance is assessed with respect to optimality and feasibility for the intended application and in comparison with alternative algorithms. This is done for the three major components of far-field planning: goal planning, waypoint path planning, and timeline management. It appears feasible to meet performance requirements on a 10 Mips flyable processor (dedicated to far-field planning) using a heuristically-guided simulated annealing technique for the goal planner, a modified A* search for the waypoint path planner, and a speed scheduling technique developed for this project

Capacidade dos sistemas de medição para tarefas de inspeção 100% /

Tese (Doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico

Development of a Wireless Real-Time Productivity Measurement System for Rapid Bridge Replacement

Increased attention has been paid to rapid bridge replacement, one of the critical components of the nation’s transportation network, since the terrorist attacks on September 11, 2001. To enhance the capability of rapid replacement of damaged bridges after extreme events, a prototype wireless real-time productivity measurement system has been developed. The developed system has a potential not only to improve the accuracy of construction schedule but also to strengthen the communication and coordination among parties involved in the replacement process after extreme events by providing accurate productivity information in real time. To validate the developed system, field experiments were conducted at three construction sites. Results of data analyses indicate that it is feasible to use the developed system to measure on-site productivity in real time; and productivity measurements were accurate and could be shared among all parties involved in the replacement process

THE COMPARATIVE STUDY ON EXPECTED TOTAL QUALITY COST BETWEEN TRADITIONAL SINGLE SAMPLING PLAN AND ECONOMICAL DESIGN

In the quality inspection practice of the consumer electronics industry, MIL-STD-105E sampling table is viewed as the basis for sampling plans. This traditional quality inspection plan determine the sample size and reject rule based on the size of lot, consumer�s and producer's risk and average quality level (AQL). Traditional sampling plan does not consider internal and external quality costs. However, quality costs were considered in many previous researches, but the comparison between traditional and economical design of single sampling plan is rare from now. This paper discusses the sampling test before the receiving inspection which is vendor simulated buyers. Includes the costs of inspection, rework, replacement, and external failure cost are considered. We compare the quality economical design with traditional single sampling plan under the total quality cost. This paper can be regarded as a reference for future studies and practical applications