A Multi-Exchange Neighborhood Search Heuristic for an Integrated Clustering and Machine Setup Model for PCB Manufacturing

In the manufacture of printed circuit boards, electronic components are attached to a blank board by one or more pick-and-place machines. Frequent machine setups, though time consuming, can reduce overall processing time. We consider the Integrated Clustering and Machine Setup (ICMS) model, which incorporates this tradeoff between processing time and setup time and seeks to minimize the sum of the two. Solving this model to optimality is intractable for very large-scale instances. We show that ICMS is NP-hard and consequently propose and test a heuristic based on multi-exchange neighborhood search structures. Initial numerical results are very encouraging. Keywords: Printed circuit board assembly, feeder slot assignment, product clustering, integer programming, computational complexity, heuristics

Automated decision making and problem solving. Volume 2: Conference presentations

Related topics in artificial intelligence, operations research, and control theory are explored. Existing techniques are assessed and trends of development are determined

Coal Quality Management Model for a Dome Storage (DS-CQMM)

Coal quality (ash, sulfur, moisture and BTU) is one of the key aspects for both coal mines and power plants. Mines invest time as well as economic and technological resources in order to manage coal quality for final use in power plants. In order to deliver uniform coal quality to the power plant, there is a need for a real-time monitoring of coal quality from the mine to the coal stockpiles. The specific problem represents the process of stacking the coal inside the enclosed facility such as a dome. The process of stacking coal inside a dome generates the unique geometry of the stockpile due to the physical constraints caused by the circular shape and walls of dome, and height and length of stacker. The reclaiming process also creates a particular shape of the stockpile. The specific challenge to the mine is to know spatial distribution of coal quality parameters, volume and tonnage in such formed stockpile.;The objective of this research was to develop a custom-made and integrated Coal Quality Management Model for a Dome Storage (DS-CQMM). The DS-CQMM merges existing technology in surface mines, such as coal analyzers, along with automation technologies, information technologies (IT), mathematical models, and different programming languages.;The DS-CQMM is organized into four major sections: Delay Time Application, Stacker Application, Reclaimer Application, and Live Stockpile Application. A sub-process called Volume Calculation is embedded in Stacker Application, while an additional feature called Forecast Tool is included in the Reclaimer Application. The Delay Time Application calculates the time that a batch of coal takes to reach the boom of the stacker from the coal analyzer through the belt conveyor system. The Stacker Application retrieves the information provided by the Delay Time Application and Distributed Control System (DCS) database using a mathematical model. This model is specifically designed for this purpose in order to assign a unique location to coal that is being stacked into the mathematically-discretized dome storage. The volume of the stacked coal is calculated by using the mathematical model and dome discretization. Finally, tonnage is determined and assigned along with coal quality tags. Once the coal is stacked into the dome, the Reclaimer Application displays the ranges of every quality tag within the stockpile. For more accurate representation, coal quality is shown in numerical values in the Forecast Tool using different tables. The Forecast Tool has the capability of calculating the average of each quality tag and the total summation of the tonnage of the coal that will be reclaimed by selecting the desired cells and showing the values in a display window. After reclaiming the coal, the Reclaimer Application retrieves required data from the DCS database and builds the shape of the remaining stockpile. The Reclaimer Application shows the distribution of the coal quality of the remaining stockpile. The Live Stockpile Application is developed for a special part of the dome that was originally designed to serve as an emergency reclaimer in case of failure or maintenance of the mobile reclaimer. The Live Stockpile Application has two parts: stacking and reclaiming. Using the same concept and mathematical model of the Stacker Application, the stacking part of the Live Stockpile Application is developed, while new concepts and mathematical models are developed for the reclaiming part. Both parts show the same graphical outputs as the Stacker and Reclaiming Applications. The DS-CQMM model was developed for a surface coal mine in the southern United States

Third CLIPS Conference Proceedings, volume 1

Expert systems are computed programs which emulate human expertise in well defined problem domains. The potential payoff from expert systems is high: valuable expertise can be captured and preserved, repetitive and/or mundane tasks requiring human expertise can be automated, and uniformity can be applied in decision making processes. The C Language Integrated Production Systems (CLIPS) is an expert system building tool, developed at the Johnson Space Center, which provides a complete environment for the development and delivery of rule and/or object based expert systems. CLIPS was specifically designed to provide a low cost option for developing and deploying expert system applications across a wide range of hardware platforms. The development of CLIPS has helped to improve the ability to deliver expert systems technology throughout the public and private sectors for a wide range of applications and diverse computing environments

Measurements, Models, Systems and Design

531 s.