Improving reuse of semiconductor equipment through benchmarking, standardization, and automation

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering; in conjunction with the Leaders for Manufacturing Program at MIT, 2006.Includes bibliographical references (p. 91-92).The 6D program at Intel® Corporation was set up to improve operations around capital equipment reuse, primarily in their semiconductor manufacturing facilities. The company was faced with a number of challenges, including differing work flows across multiple locations, lack of centralized work flow management, discontinuous inventory information, and other opportunities for cost reduction. The internship was set up to benchmark and explore potential for integration of best known methods, accumulated both inside and outside the company. Based on interviews, research and quantitative analysis, opportunities were identified for reuse of equipment shipping crates, improvement in warehouse inventory management, and changes in labor models to facilitate better knowledge capture and dissemination. As a result of this study Intel® Corporation may realize significant improvement in the areas mentioned in terms of cost reduction, process improvement and knowledge management. By using a flexible approach to problem identification and generating organizational interest in the improvements, recommendations were well received and should lead to eventual adoption.by Jacob Silber.S.M.M.B.A

Porcelain Surface Roughness, Color and Gloss Changes after Orthodontic Bonding

The purpose of this study was to evaluate the alteration in surface characteristics after orthodontic debonding of two types of porcelain systems commonly used in prosthetic dentistry. For this purpose, porcelain specimens were fabricated from low-fusing (n = 20) and high-fusing (n = 20) porcelain. The baseline surface roughness, color, and gloss were evaluated using profilometry, color shade index, and gloss study. All specimens were bonded with brackets and debonded using a testing machine at a rate of 0.1 mm/minute crosshead speed. The porcelain surfaces were polished using a 12-fluted carbide composite removal bur (low-fusing, n = 20; high-fusing, n = 20). In addition, half of each porcelain group was further polished using a series of Sof-Lex discs (low-fusing, n = 10; high-fusing, n = 10). The postdebond porcelain surface characteristics roughness, color, and gloss were reevaluated and compared with baseline measurements. The results were analyzed with two-way analysis of variance and Tukey multiple comparisons test, with porcelain type (low-fusing or high-fusing) and polishing protocol (carbide bur or carbide bur and discs) serving as discriminate variables at α = 0.05 level of significance. Bonding and debonding increased all roughness parameters tested; however, no change was revealed between the two polishing protocols. Similarly, gloss and color index changes were significantly altered after resin grinding, regardless of the polishing method used. No difference was identified between the two porcelain types with respect to roughness, color index, or gloss. Orthodontic bonding alters the porcelain surfaces, and postdebond polishing does not restore the surface to the prebond state

Personal Identification Based on Patterns of Missing, Filled, and Unrestored Teeth

Dental comparison of antemortem and postmortem records provides one of the best avenues for establishing personal identification in the forensic sciences. The types of antemortem dental evidence are extensive (including treatment notes, odontograms, radiographs, casts, photographs, etc.) and in many instances a positive identification can be established strictly on a dental comparison. Perhaps the best form of antemortem dental evidence is the radiograph, which provides a detailed odontoskeletal record of a specific individual at a specific point in the past. Unfortunately, antemortem radiographic evidence is not always available during forensic comparisons. For example, at the U.S. Army Central Identification Laboratory, Hawaii (CILHI), dental radiographs are not commonly available when performing antemortem/postmortem comparisons of military personnel missing from past conflicts, especially those missing from WWII or the Korean War. In these instances, as well as some modern forensic cases, antemortem dental information may only be available in the form of handwritten charts and notes derived from the missing individual’s health documents. While these charts are susceptible to human error (not generally a concern with radiographs), dental information of this type that accurately documents an individual’s dental condition can be essential for establishing a link to an unidentified set of remains. Obviously, documents that are incomplete or inaccurate, on the other hand, will not assist in the identification process and could actually hinder the effort. The goal of this dissertation is to validate the use of non-radiographic dental evidence for identification purposes. Statistically, there are trillions of possible combinations of missing, filled, and unrestored teeth within the adult mouth. This quantity of possible combinations suggests that an individual’s dental health pattern should often be of sufficient uniqueness to be used for identification. While the statistical model of possible combinations is mathematically plausible, it does not necessarily represent reality. Each of the 32 teeth in the adult dentition cannot be considered to be at the same risk for loss or disease. Dental morphology will dictate that molars, based on their large surface area, will be more susceptible to decay than other teeth, such as canines or incisors. Furthermore, all dental patterns are not equiprobable, signifying that some patterns will occur more frequently than others and statistical calculations of the total number of possible combinations of dental characteristics are not useful and are potentially misleading. Thus the theoretical number of possible dental health permutations should not be cited to justify the diversity of dental patterns for identification purposes. In order to adequately address the issue of diversity in dental patterns, large datasets are needed for analysis. As part of this dissertation, four datasets were compiled that represent distinct demographic or temporal groups from the United States. These datasets are referred to as WWII-Korea, Southeast Asia, Modern Military, and Modern Civilian. With the exception of the Modern Civilian data, all other datasets consist of U.S. military personnel. The WWII-Korea and Southeast Asia datasets are composed of individuals missing in action from these conflicts, while the Modern Military and Modern Civilian data were originally collected as part of large dental health studies (the 1994 and 2000 Tri-Service Comprehensive Oral Health Surveys and the 1988-1994 National Health and Nutrition Examination Survey). Only permanent teeth were considered during this research, excluding third molars. Initially, it was necessary to explore the accuracy of the dental evidence, specifically the military dental charts from WWII, the Korean War, and the Southeast Asia Conflict. In order to gauge the accuracy of the dental records, the Decayed, Missing, and Filled Teeth (DMFT) index was used to compare the WWII-Korea and Southeast Asia datasets with published results from temporally and demographically similar populations. The DMFT (Klein and Palmer 1937) is a popular index that is reported in many studies of dental health. Distinct variation between the published DMFT scores and those derived from the datasets used in this dissertation is likely indicative of incomplete/inaccurate recordation of treatment within the military dental records. As another test of the accuracy of antemortem dental records, a sample of dental charts was gathered from identified service members who were originally missing from WWII, the Korean War, or the Southeast Asia Conflict. The identification cases had been processed through either the CILHI or the CILTHAI (Central Identification Laboratory, Thailand) and were not part of the datasets used in this dissertation. The antemortem dental records were compared with the postmortem dental findings and the accuracy was assessed as a ratio of corresponding characteristics. It was found that the WWII and Korea records had an overabundance of individuals with “perfect teeth” (defined as the absence of decay and extraction throughout the mouth). In general, the WWII and Korea records were found to either be thoroughly documented or very poor, with the poor records lacking any documentation of treatment. The Southeast Asia cases were found to show excellent antemortem-postmortem congruence. Next, the overall diversity of dental patterns formed by missing, filled, and unrestored teeth was explored for each of the datasets. As part of this process, the four datasets were transformed into two formats regarding the coding of fillings. Each dataset was coded in a detailed format in which all fillings were designated by the affected tooth surface. In the generic format, fillings were treated as either present or absent with a single code (i.e. there was no surface information coded). The diversity of dental patterns in both the detailed and generic formats was compared to the diversity found in mitochondrial DNA (mtDNA) sequences. The results of this dissertation show that the diversity of dental patterns, regardless of the data format, is on a scale that is comparable, if not superior, to mtDNA. Dental patterns were validated as an excellent means of forensic identification. At this point it was essential to explore the diversity of specific dental patterns and to derive a method for quantifying the frequency that a specific pattern could be expected to occur. It was found that a method of empirical comparison to a relevant reference dataset is the most useful approach to the quantification of dental pattern frequency since this removes subjectivity and standards based on arbitrary points of concordance. This technique is nearly identical to the manner that mtDNA sequence frequencies are reported. Based on empirical comparison, it is possible to compare dental patterns formed by any combination of teeth and their characteristics. Postmortem loss is not a hindrance to the technique. It was found that very common dental treatment would often form a very unique dental pattern when all of the evidence is analyzed as a whole. This may be counterintuitive to many dentists. Furthermore, if numerous teeth are available in the postmortem analysis, the generic format of the data is sufficient to create very individualistic dental patterns. In situations of extensive postmortem loss, the detailed format will be critical to the establishment of individualistic patterns. Prior to this research, forensic odontologists did not have a technique for assessing the strength of an antemortem-postmortem match between non-radiographic dental evidence. Up to this point, the comparison has usually been based on the subjective judgment of the dentist, which cannot be statistically quantified. Through empirical comparison with a large, representative dataset, dental patterns can now be objectively assessed. Patterns that may be initially hypothesized to be common in the general population could actually be shown to be extremely rare and individualistic based on empirical comparison to a reference dataset. By attaching an empirically derived probability value (the expected frequency that a specific pattern would be found in the population), matches based on dental patterns can be quantified in a manner that is easily defensible in a court of law. Two important points need to be understood as part of this research: 1) The end result of this research is not to create a database that can be used to match a dental pattern to a specific individual. Rather once an association to an individual has been made, the technique allows the significance of the dental pattern match to be quantified. 2) The use of non-radiographic dental evidence alone, asdiscussed in this dissertation, is not sufficient to establish a positive identification. It is anticipated that the evidence, in conjunction with other circumstantial evidence, can be used to form a very strong association between a missing individual and an unidentified set of remains that is beyond reasonable doubt

Bond Strength of Direct and Indirect Bonded Brackets After Thermocycling

Thermocycling simulates the temperature dynamics in the oral environment. With direct bonding, thermocycling reduces the bond strength of orthodontic adhesives to tooth structure. The purpose of this study was to evaluate the shear bond strengths (SBS) of one direct and two indirect bonding methods/adhesives after thermocycling. Sixty human premolars were divided into three groups. Teeth in group 1 were bonded directly with Transbond XT. Teeth in group 2 were indirect bonded with Transbond XT/Sondhi Rapid Set, which is chemically cured. Teeth in group 3 were indirect bonded with Enlight LV/Orthosolo and light cured. Each sample was thermocycled between 5°C and 55°C for 500 cycles. Mean SBS in groups 1, 2, and 3 were not statistically significantly different (13.6 ± 2.9, 12.3 ± 3.0, and 11.6 ± 3.2 MPa, respectively; P \u3e .05). However, when these values were compared with the results of a previous study using the same protocol, but without thermocycling, the SBS was reduced significantly (P = .001). Weibull analysis further showed that group 3 had the lowest bonding survival rate at the minimum clinically acceptable bond-strength range. The Adhesive Remnant Index was also determined, and group 2 had a significantly (P \u3c .05) higher percentage of bond failures at the resin/enamel interface

Public Schools\u27 Pyrrhic Victories Over Parental Rights

This article explores the historical roots of parental rights in education, and then demonstrates that Professors Uerling and Strope are quite correct when they declare parental rights in public education to be almost extinct. Next, it examines the stark contrasts between the rights of public school parents and those of parents who choose private and home schooling. Finally, this article suggests that since the constitutionality of educational choice, including choices involving religious schools, has been established beyond any legitimate question, public school advocates and courts should rethink their position concerning parental rights within public education lest they contribute to the demise of the very system which they seek to save from the subversive influence of those committed parents who give both students and tax dollars to the schools

Data-driven design of targeted gene panels for estimating immunotherapy biomarkers

We introduce a novel data-driven framework for the design of targeted gene panels for estimating exome-wide biomarkers in cancer immunotherapy. Our first goal is to develop a generative model for the profile of mutation across the exome, which allows for gene- and variant type-dependent mutation rates. Based on this model, we then propose a new procedure for estimating biomarkers such as Tumour Mutation Burden and Tumour Indel Burden. Our approach allows the practitioner to select a targeted gene panel of a prespecified size, and then construct an estimator that only depends on the selected genes. Alternatively, the practitioner may apply our method to make predictions based on an existing gene panel, or to augment a gene panel to a given size. We demonstrate the excellent performance of our proposal using an annotated mutation dataset from 1144 Non-Small Cell Lung Cancer patients.Comment: 21 pages, 10 figure

Heat acclimation does not protect trained males from hyperthermia-induced impairments in complex task performance

This study evaluated if adaptation to environmental heat stress can counteract the negative effects of hyperthermia on complex motor performance. Thirteen healthy, trained males completed 28 days of heat acclimation with 1 h daily exercise exposure to environmental heat (39.4 ± 0.3 °C and 27.0 ± 1.0% relative humidity). Following comprehensive familiarization, the participants completed motor-cognitive testing before acclimation, as well as after 14 and 28 days of training in the heat. On all three occasions, the participants were tested, at baseline (after ~15 min passive heat exposure) and following exercise-induced hyperthermia which provoked an increase in core temperature of 2.8 ± 0.1 °C (similar across days). Both cognitively dominated test scores and motor performance were maintained during passive heat exposure (no reduction or difference between day 0, 14, and 28 compared to cool conditions). In contrast, complex motor task performance was significantly reduced in hyperthermic conditions by 9.4 ± 3.4% at day 0; 15.1 ± 5.0% at day 14, and 13.0 ± 4.8% at day 28 (all p < 0.05 compared to baseline but not different across days). These results let us conclude that heat acclimation cannot protect trained males from being negatively affected by hyperthermia when they perform complex tasks relying on a combination of cognitive performance and motor function