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The Consequences of Implementing Statistical Process Control

Description: This study evaluated the changes which occur in manufacturing organizations in the plastic molding industry which implement statistical process control (SPC). The study evaluated changes in product quality, consistency, cost, changes in employee attitudes, and changes in the organization structure which occur after the implementation of SPC. The study was conducted in two phases. Phase 1 consisted of an exploratory field study of a single manufacturing company. Phase 2 consisted of a field survey of three manufacturing companies in the same industry. An unexpected opportunity to evaluate the differences in effects of successful and unsuccessful SPC implementations occurred during the field survey. One plant, whose management assessed their SPC program as being unsuccessful, reported no economic or quality benefits from SPC. Neither did this plant report any changes in the attitudes or behavior of their employees. Neither of these findings was surprising since this plant was the only one of the four study plants which implemented SPC as a quality control program with no participation from the production department. The three plants whose management assessed their SPC programs as being successful reported reduced product variation and a decrease in the proportion of defective product produced as a result of SPC. No consistent evidence was found concerning a reduction in the material required per product resulting from SPC. No consistent evidence was found linking changes in employee attitudes and behavior to the implementation of SPC. The field study found a significant change in the employees1 attitudes toward management but no change in their attitudes toward the company. The field survey found no evidence of change in either dimension. Evidence was found for a change to a more organic structure during SPC training and to a more mechanistic structure during SPC implementation. The final form of the organization was more organic than …
Date: August 1990
Creator: Sower, Victor E.
Partner: UNT Libraries

Proceedings of the 1981 Symposium on Instrumentation and Control for Fossil-Energy Processes: June 8-10, 1981 Sheraton-Palace Hotel, San Francisco, California

Description: Compiled proceedings of the fifth Symposium on Instrumentation and Control for Fossil-Energy Processes, covering process control involved in the conversion of fossil fuels into synthetic fuels.
Date: January 1982
Creator: Argonne National Laboratory
Partner: UNT Libraries Government Documents Department

An Adaptive System for Process Control

Description: Abstract: Researchers at the U.S. Bureau of Mines (USBM) have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by loosely modeling the search procedures of natural genetics. FLC's are rule-based systems that efficiently manipulate a problem environment by modeling the "rule-of-thumb" strategy used in human decisionmaking. Together, GA's and FLC's include all of the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a cont element to manipulate the problem environment, an analysis element to recognize changes in the problem environment, and an adaptive element to adjust to the changes in the problem environment. The control system also employs a computer simulation of the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented; all results are from the physical laboratory system and not from a computer simulation.
Date: 1995
Creator: Karr, Charles L.; Gentry, E. J. & Stanley, D. A.
Partner: UNT Libraries Government Documents Department

Help for the Developers of Control System Cyber Security Standards

Description: A Catalog of Control Systems Security: Recommendations for Standards Developers (Catalog), aimed at assisting organizations to facilitate the development and implementation of control system cyber security standards, has been developed. This catalog contains requirements that can help protect control systems from cyber attacks and can be applied to the Critical Infrastructures and Key Resources of the United States and other nations. The requirements contained in the catalog are a compilation of practices or various industry bodies used to increase the security of control systems from both physical and cyber attacks. They should be viewed as a collection of recommendations to be considered and judiciously employed, as appropriate, when reviewing and developing cyber security standards for control systems. The recommendations in the Catalog are intended to be broad enough to provide any industry using control systems the flexibility needed to develop sound cyber security standards specific to their individual security requirements.
Date: May 1, 2008
Creator: Evans, Robert P.
Partner: UNT Libraries Government Documents Department

Statistical process control (SPC) for coordinate measurement machines

Description: The application of process capability analysis, using designed experiments, and gage capability studies as they apply to coordinate measurement machine (CMM) uncertainty analysis and control will be demonstrated. The use of control standards in designed experiments, and the use of range charts and moving range charts to separate measurement error into it's discrete components will be discussed. The method used to monitor and analyze the components of repeatability and reproducibility will be presented with specific emphasis on how to use control charts to determine and monitor CMM performance and capability, and stay within your uncertainty assumptions.
Date: January 4, 2000
Creator: Escher, R. N.
Partner: UNT Libraries Government Documents Department

Photovoltaic Cz Silicon Module Improvements; Final Subcontract Report, 9 November 1995 - 8 November 1998

Description: This report describes work that focused on reducing the cost per watt of Cz silicon photovoltaic modules under Siemens Solar Industries' (SSI) DOE/NREL Photovoltaic Manufacturing Technology (PVMaT) 4A subcontract. SSI researchers deployed new module designs, realized improvements in yield of more than 25%, and implemented statistical process control (SPC). They have described yield improvements in detail and reported on the deployment of SPC in critical process steps. The sum of all improvements resulted in a greater than 17% cost per watt reduction in manufacturing.
Date: June 17, 1999
Creator: Jester, T. L.
Partner: UNT Libraries Government Documents Department

Process Control System Cyber Security Standards - An Overview

Description: The use of cyber security standards can greatly assist in the protection of process control systems by providing guidelines and requirements for the implementation of computer-controlled systems. These standards are most effective when the engineers and operators, using the standards, understand what each standard addresses. This paper provides an overview of several standards that deal with the cyber security of process measurements and control systems.
Date: May 1, 2006
Creator: Evans, Robert P.
Partner: UNT Libraries Government Documents Department

Study of the State-of-the-Art of Instrumentation for Process Control and Safety in Large-Scale Coal Gasification, Liquefaction, and Fluidized-Bed Combustion Systems

Description: A study has been carried out to determine the state-of-the-art of instrumentation which is available for process control and safety in planned demonstration and commercial scale coal gasification, liquefaction, and fluidized-bed combustion systems. The study identified available instrumentation which will perform satisfactorily in these systems and pinpointed deficiencies for which instruments must be developed. The identified deficiencies fall into the same few categories for all processes considered. These categories are presented with associated physical parameters found in the various processes studied. Development of instruments to meet these deficiencies is recommended along with development of control valves and optimal control schemes in order to assure the possibility of automatic control of the large scale coal conversion and combustion systems.
Date: 1976
Creator: O'Fallon, N. M.; Beyerlein, R. A.; Managan, W. W.; Karplus, H. B. & Mulcahey, T. P.
Partner: UNT Libraries Government Documents Department

Emerging standards with application to accelerator safety systems

Description: This paper addresses international standards which can be applied to the requirements for accelerator personnel safety systems. Particular emphasis is given to standards which specify requirements for safety interlock systems which employ programmable electronic subsystems. The work draws on methodologies currently under development for the medical, process control, and nuclear industries.
Date: August 1, 1997
Creator: Mahoney, K.L. & Robertson, H.P.
Partner: UNT Libraries Government Documents Department

Summary of the ecl2 Workshop

Description: We summarize the ECL2 workshop on electron cloud clearing, which was held at CERN in early March 2007, and highlight a number of novel ideas for electron cloud suppression, such as continuous clearing electrodes based on enamel, slotted structures, and electrete inserts.
Date: April 9, 2007
Creator: Fischer, W.
Partner: UNT Libraries Government Documents Department

Final Report, Distillation Column Flooding Predictor

Description: The Flooding Predictor is an advanced process control strategy comprising a patented pattern-recognition methodology that identifies pre-flood patterns discovered to precede flooding events in distillation columns. The grantee holds a U.S. patent on the modeling system. The technology was validated at the Separations Research Program, The University of Texas at Austin under a grant from the U. S. Department of Energy, Inventions & Innovation Program. Distillation tower flooding occurs at abnormally high vapor and/or liquid rates. The loss in tray efficiencies is attributed to unusual behavior of liquid inventories inside the column leading to conditions of flooding of the space in between trays with liquid. Depending on the severity of the flood condition, consequences range from off spec products to equipment damage and tower shutdown. This non-intrusive pattern recognition methodology, processes signal data obtained from existing column instrumentation. Once the pattern is identified empirically, it is modeled and coded into the plant's distributed control system. The control system is programmed to briefly "unload" the tower each time the pattern appears. The unloading takes the form of a momentary reduction in column severity, e.g., decrease bottom temperature, reflux or tower throughput. Unloading the tower briefly at the pre-flood state causes long-term column operation to become significantly more stable - allowing an increase in throughput and/or product purity. The technology provides a wide range of value between optimization and flooding. When a distillation column is not running at capacity, it should be run in such a way ("pushed") that optimal product purity is achieved. Additional benefits include low implementation and maintenance costs, and a high level of console operator acceptance. The previous commercial applications experienced 98% uptime over a four-year period. Further, the technology is unique in its ability to distinguish between different flooding mechanisms within the same tower, e.g., liquid and …
Date: May 31, 2003
Creator: Dzyacky, George E.
Partner: UNT Libraries Government Documents Department

Project B: Improved Liquid Steel Feed For Slab Casters

Description: This report describes the completion of the development of an electromagnetic valve to control liquid steel flow for improved liquid steel feeding for slab casters. Achievements result from a joint research effort between Westinghouse Science and Technology Center, North American Refractories and U.S. Steel. This effort is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. Department of Energy (DOE) and fifteen North American steel makers.
Date: October 1, 1998
Creator: Isaacson, Brent S.; Slepian, Mike & Richter, Thomas
Partner: UNT Libraries Government Documents Department

Wet-Etch Figuring Optical Figuring by Controlled Application of Liquid Etchant

Description: WET-ETCH FIGURING (WEF) is an automated method of precisely figuring optical materials by the controlled application of aqueous etchant solution. This technology uses surface-tension-gradient-driven flow to confine and stabilize a wetted zone of an etchant solution or other aqueous processing fluid on the surface of an object. This wetted zone can be translated on the surface in a computer-controlled fashion for precise spatial control of the surface reactions occurring (e.g. chemical etching). WEF is particularly suitable for figuring very thin optical materials because it applies no thermal or mechanical stress to the material. Also, because the process is stress-free the workpiece can be monitored during figuring using interferometric metrology, and the measurements obtained can be used to control the figuring process in real-time--something that cannot be done with traditional figuring methods.
Date: February 13, 2001
Creator: Britten, J
Partner: UNT Libraries Government Documents Department

Adaptive control of femtosecond pulse propagation in optical fibers

Description: We present an adaptive control loop that synthesizes fs-pulses that are self-correcting for higher order nonlinear effects when launched in a conventional single-mode fiber, nearly preserving the initial (t{approx}200 fs) pulse duration.
Date: January 1, 2001
Creator: Omenetto, F. G. (Fiorenzo G.); Taylor, Antoinette J.,; Moores, M. D. (Mark D.) & Reitze, David H.
Partner: UNT Libraries Government Documents Department

Evaluation and Development of a Prototype Electrokinetic Sonic Amplitude (ESA) System for On-Line Measurement of Charge in Papermaking Process Streams

Description: The papermaking industry uses an abundance of chemicals to control the process of papermaking. These chemicals are used to control everything from paper strength to brightness. Due to the natural variability of products used in papermaking, the chemistry of the process is heavily monitored. Cationic (charge) demand is one of the most important parameters in process control of papermaking. High variations in cationic demand result in off-spec final product or paper breaks resulting in wasted production and downtime. Both of these results are costly for papermakers due to high energy consumption and loss of revenue. Currently, cationic demand is measured off-line in a laboratory setting with a heavily diluted specimen taking up to hours for results. The industry need is for an on-line, real-time measurement of cationic demand at higher consistencies to provide control feedback for the addition of cationic demand at higher consistencies to provide control feedback for the addition of cationic polymers for finely-tuned control of the paper process. Electrokinetic sonic amplitude (ESA) is a method for measuring particle charge and size, which has been employed in the semiconductor industry for several years. While this technology is generally geared for smaller particles (micron size) instead of paper fibers (millimeter size), this project researched the idea of using ESA to measure cationic demand in a real-time setting at high pulp consistencies. Within the scope and schedule of this project, the feasibility of the ESA technology for use in an on-line instrument was inconclusive. Further engineering is required to generate a sufficient ESA signal from the paper pulp to obtain reliable and consistent measurements. Future research in this area will help to further tailor the technology for application to paper streams. The ESA technology continues to remain a viable option for on-line charge demand measurements in the papermaking process and …
Date: August 12, 2005
Creator: Tucker, Brian J. & Good, Morris S.
Partner: UNT Libraries Government Documents Department

PowerLight Corporation Lean Manufacturing, PV Manufacturing R&D Phase I Report: 6 December 2001--31 March 2003

Description: PowerLight Corporation (PowerLight) has completed Phase I of its PV Manufacturing R&D subcontract, ''PowerGuard Lean Manufacturing,'' Subcontract No. NDO-1-30628-04. The overall technical goal of this project was to reduce the cost of PowerGuard manufacturing while simultaneously improving product quality. This will enable PowerLight to scale up production capacity as the market for PowerGuard continues to grow. Through the introduction of world-class lean manufacturing techniques, PowerLight was to cut out waste in the manufacturing process of PowerGuard. The manufacturing process was to be overhauled with an objective of removing as much as possible those steps that do not add value to the product. Quality of finished goods was also to be improved through the use of statistical process control and error-proofing in the manufacturing process. Factory operations were also to be addressed to streamline those factory activities that support the manufacturing process. This report de tails the progress made toward the above listed goals during the first phase of this subcontract.
Date: June 1, 2005
Creator: Hargis, L. & Botkin, J.
Partner: UNT Libraries Government Documents Department

Proceedings of the 1978 Symposium on Instrumentation and Control for Fossil Demonstration Plants : June 19-21, 1978, Newport Beach Marriott, Newport Beach, California

Description: This conference covers various aspects of fossil-fuel power plants based on coal or coal-conversion products, as well as the process control equipment involved in the conversion or combustion processes.
Date: June 1978
Creator: Argonne National Laboratory
Partner: UNT Libraries Government Documents Department
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