This paper describes an analysis performed to assess the fidelity, scalability, and performance of the Sage(©) Fab Advisor™ semiconductor fab simulation engine executing two years of fab operations across a range of lot sizes. We describe the demand and fab operations models used, as well as the tools and methodology used in conducting the analysis. Our results were validated against a well-known model running on a well-known toolset, showing performance to be very competitive with that model. Further, we show that our engine's performance, running this model, scales almost linearly from 25 wafer lot sizes down to single wafer lot sizes. That is, simulation time increases roughly linearly with respect to the number of lots being processed.

The introduction of emerging technologies into existing manufacturing facilities is not necessarily encouraged by the people responsible for the output of the facilities. Any "new" technology carries risks and people responsible for delivering manufactured products are, by nature, risk-adverse. This paper demonstrates the advantage of evaluating the impact of attempting to introduce a new technology into an existing facility before actually attempting the introduction. The first part of the analysis examines the impact on the total product delivery for a comparable volume of two facilities, one with the traditional processes and one with the new process replacing existing ones. Based on these results, a conclusion can be reached if there are sufficient benefits to consider pursuing the development and introduction of the new techniques. An example is employed that evaluates the introduction of nano-imprint.

Wafers in a 300-mm semiconductor fabrication facility are transported throughout the factory in carriers called front opening unified pods (FOUPs). Two standard capacities of FOUPs are 25 and 13 wafers. This paper describes a simulation study designed to compare the performance of a factory employing different FOUP capacities. The main performance measure considered is work-in-process (WIP) and the resulting cycle time. Batching policy, order arrival rate, average order size, the automated material handling system (AMHS) and the number of batch tools largely effect the performance of the models. Most of the empirical results show that the 25-wafer FOUP capacity provides a lower WIP level in a moderately loaded semiconductor factory.

The odorous compound 2-acetyl-1-pyrroline (2AP) was the cause of an undesirable ''mousy'' odor that developed when raw pearl millet grits were wetted and slowly dried. The 2AP in millet was identified by comparing gas chromatography (GC) retention times, odor at the GC sniffing port, mass spectra, and vapor-phase infrared spectra with those of 2AP from Jasmine and Indian Basmati aromatic rices. Identification of 2AP in aromatic rices had been reported previously. The odor of 2AP at the sniffing port was similar to the undesirable odor in bulk samples of wetted millet grits and was the key factor in identifying 2AP as the odorous component. Both blue and yellow raw millet grits produced 2AP and the mousy odor.

The effects of the geosynchronous thermal environment on the surface accuracy of a tetrahedral-truss support structure for a high-frequency microwave antenna concept for Earth-science monitoring have been studied. The thermal environment and the slow rotation of the spacecraft relative to the Sun result in long exposure to both heating and cooling conditions and, consequently, in severe temperature extremes. Resulting transient temperatures ranged from 150 to - 180-degrees-C and were strongly influenced by the shadow cast by the reflector surface. The use of truss element surface coatings achieved mixed success in alleviating thermal problems. Multilayer insulation or a Sun shield worked best in reducing surface distortions, but the distortions still exceeded the required surface accuracy. Surface accuracy requirements could only be met by customization of surface coatings and element expansion characteristics.

AN operations analysis and planning tool (OPSMODEL) has been developed by Computer Sciences Corporation for NASA Langley Research Center to provide realistic modeling and simulation of on-orbit crew operations for a space station. The IBM PC compatible program produces a quantitative measure of the effectiveness of the on-orbit crew's activities under alternative space station designs, technologies, and operational policies. The OPSMODEL also supports engineering and cost analyses and operations planning activities. The simulation can be monitored on-line with the focus and level of detail selected by the user. Other outputs include engineering performance indicators, such as crew times and space station status, cost performance organized according to work breakdown structure, and various data products extracted from a time-tagged event log recorded during the simulation run.

Correlation of the Perkin-Elmer Corporation portable wear metal analyzer, version two (PWMA-2) and the Baird Corporation A/E35U-3 spectrometric oil analysis data is accomplished by curve fitting of data from aircraft, bearing test rigs, and organometallic oil samples analyzed on both instruments. Each of nine wear metal elements (iron, silver, aluminum, chromium, copper, magnesium, nickel, silicon and titanium) was separately fitted to linear, logarithmic, power law and low order polynomial curves. Power law curve fits were best for most of the elements, especially in the important low concentration (0–5 ppm) range, where U.S. Air Force gas turbine aircraft engines typically operate. The power law curve was applied to all the elements to construct correlation algorithms, with a general uncertainty in correlation values of about 0.5–1 ppm or 10%, whichever was the greater. The coefficients of determination for the power law curve fits ranged from 0.935 for aluminum to 0.993 for iron. The fit for silicon was poor for any type of curve (the best coefficient of determination was 0.564 for the power law curve fit) and therefore correlation of silicon values is not recommended.

Previous investigators assumed that ferrographic area coverage data were linearly related to the quantity of sample analyzed. However, theoretical examination of ferrographic deposition of wear debris and treatment of published data confirm that coverage varies with sample quantity by a power law relationship. Imrpved normalization and wear trending procedures based upon power curve fitting of area covered measurements vs. sample quantities are developed. The new procedures should increase confidence and reliability in both ferrographic measurement and wear severity index trending.

Theme T techniques for determining boundary-layer transition in flight have been compared using data from the NASA Re-entry F experiment. The methods define transition from a rise either in the temperature history at a given sensor location or in the laminar heating-rate distribution at a given altitude. Since there are no previous comparisons of these techniques, the results of this study are considered to be a major contribution to the state-of-the-art.

National Municipal ReviewVolume 45, Issue 4 p. 194-198 News in Review Home renewal center pioneers Elsie S. Parker, Search for more papers by this authorRobert L. Wright, Search for more papers by this author Elsie S. Parker, Search for more papers by this authorRobert L. Wright, Search for more papers by this author First published: April 1956 https://doi.org/10.1002/ncr.4110450411AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Volume45, Issue4April 1956Pages 194-198 RelatedInformation

Journal Article Linguistics and the Preparation of the High School English Teacher Get access Robert L. Wright Robert L. Wright 1Robert L. Wright — Director of Writing Improvement Service, Michigan State University, East Lansing, Michigan Search for other works by this author on: Oxford Academic Google Scholar Journal of Communication, Volume 6, Issue 3, September 1956, Pages 119–123, https://doi.org/10.1111/j.1460-2466.1956.tb02480.x Published: 07 February 2006