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考慮兩階段相依製程下量測誤差對指數加權移動平均管制圖之效應研究 / Effects of Measurement Error on EWMA Control Charts for Two-Step Process何漢葳, Ho, Han-Wei Unknown Date (has links)
無 / In this article, a two-step process is considered to investigate the effects of measurement errors on EWMA
and cause-selecting EWMA control charts. At the end of current process, a pair of imprecise measurements of in-coming quality and out-going quality is randomly taken with individual units.
The linear relationship between in-coming quality and out-going quality is assumed and four possible states of the process are defined with respective distributions of in-coming and out-going
qualities derived. The EWMA control chart with measurement error is then constructed to monitor small-scale shift in mean for the previous process while the cause-selecting control chart, or EWMA control chart based on residuals, including measurement error, is proposed to diagnose the state of current process.
Based on sensitivity analysis, the presence of imprecise measurement diminishes the power of both the EWMA and the proposed control charts and affects the detectability of process disturbances. Further, applications of proposed control charts are demonstrated through a numerical example to show some possible misuses of control charts. If the process mean shifts in a small scale when a single assignable cause occurs on each step, the proposed cause-selecting control chart is more sensitive than other control charts. The Hotelling T^2 control chart is also compared to illustrate the diagnostic advantage outweighed by proposed cause-selecting control chart.
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Improvements in ranked set samplingHaq, Abdul January 2014 (has links)
The main focus of many agricultural, ecological and environmental studies is to develop well designed, cost-effective and efficient sampling designs. Ranked set sampling (RSS) is one of those sampling methods that can help accomplish such objectives by incorporating prior information and expert knowledge to the design. In this thesis, new RSS schemes are suggested for efficiently estimating the population mean. These sampling schemes can be used as cost-effective alternatives to the traditional simple random sampling (SRS) and RSS schemes. It is shown that the mean estimators under the proposed sampling schemes are at least as efficient as the mean estimator with SRS. We consider the best linear unbiased estimators (BLUEs) and the best linear invariant estimators (BLIEs) for the unknown parameters (location and scale) of a location-scale family of distributions under double RSS (DRSS) scheme. The BLUEs and BLIEs with DRSS are more precise than their counterparts based on SRS and RSS schemes. We also consider the BLUEs based on DRSS and ordered DRSS (ODRSS) schemes for the unknown parameters of a simple linear regression model using replicated observations. It turns out that, in terms of relative efficiencies, the BLUEs under ODRSS are better than the BLUEs with SRS, RSS, ordered RSS (ORSS) and DRSS schemes.
Quality control charts are widely recognized for their potential to be a powerful process monitoring tool of the statistical process control. These control charts are frequently used in many industrial and service organizations to monitor in-control and out-of-control performances of a production or manufacturing process. The RSS schemes have had considerable attention in the construction of quality control charts. We propose new exponentially weighted moving average (EWMA) control charts for monitoring the process mean and the process dispersion based on the BLUEs obtained under ORSS and ODRSS schemes. We also suggest an improved maximum EWMA control chart for simultaneously monitoring the process mean and dispersion based on the BLUEs with ORSS scheme. The proposed EWMA control charts perform substantially better than their counterparts based on SRS and RSS schemes. Finally, some new EWMA charts are also suggested for monitoring the process dispersion using the best linear unbiased absolute estimators of the scale parameter under SRS and RSS schemes.
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Universal Interface Between Telemetry Processors and Chart RecordersBrimbal, Michel, Kelly, Fred 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / Chart recorders currently in use on telemetry ranges are connected to telemetry processors via a series of Digital to Analog Converters (DAC) systems. A new modular interface system receives data directly from the processor broadcast bus and distributes them to up to ten digital chart recorders. This interface is programmed from a computer to assign individual tags to each one of the display channels. This system eliminates DAC's and patch panels. It simplifies display system operation, speeds up transition from test to test and reduces maintenance costs.
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The Effect of Two Attending Surgeons on Patients with Large Curve Adolescent Idiopathic Scoliosis Undergoing Posterior Spinal FusionBosch, Liam Christian 01 June 2017 (has links)
A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Surgical correction of Adolescent Idiopathic Scoliosis (AIS) carries a substantial risk of complication. The literature supports improved perioperative outcomes through the two surgeon strategy in other complex orthopedic procedures. Does the presence of 2 versus 1 attending surgeons affect the perioperative morbidity of posterior spinal fusion (PSF) in patients with AIS curves greater than 70°? We reviewed the database from a large regional children’s hospital of all patients with AIS curves greater than 70° who underwent PSF from 2009‐2014 and divided the cohort into single versus 2‐surgeon groups (28 vs. 19 cases, respectively). We analyzed cases for length of surgery, estimated blood loss, and length of stay. The groups were identical when comparing age, gender, spinal levels fused, and average ASA score. However, the average Cobb angle in the single surgeon group was significantly less than in the 2 surgeon group at 78.4 vs 84.0 degrees, respectively (p=0.049). Mean operative time for single versus 2 surgeons was 238 (SD 48) vs 212 (SD 46) minutes (p=0.078). Mean percent estimated blood loss was 26% (SD 14.1) for single surgeon vs 31% (SD 14.9) for 2 surgeons (p=0.236), and mean estimated blood loss for single surgeon vs 2 surgeons was 830ml (SD 361) vs 1045ml (SD 346) (p=0.052). Mean length of stay was significantly decreased in the 2 surgeon group at 5.16 days (SD 1.7) versus the single surgeon group at 6.82 days (SD 6.82) (p=0.002). The use of 2 surgeons in AIS deformity correction at an experienced regional children’s hospital did not improve clinical outcomes. The average length of stay was reduced in the two‐surgeon group, but there was no significant impact on blood loss or operative time. However, this study does not rule out the potential for positive impact with a two‐surgeon strategy, and given previous supportive data in the literature, this approach should further evaluated to determine its effect on improving perioperative outcomes.
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Patterns Of Asthma Exacerbation Related To Climate And Weather In The Northeast Kingdom Of VermontCampbell, Quincy McKenzie 01 January 2016 (has links)
Asthma is a chronic respiratory disease characterized by long- and short-term inflammation and bronchospasm susceptible to multiple triggers that affects patients across the lifespan. Asthma management is a primary care priority in Vermont, where there continues to be an above-average prevalence of asthma among both children and adults as compared to other states. However, many of Vermont's children and especially adults with asthma are not participating in regular check-ups for asthma management that would best prevent exacerbation of asthma symptoms. Several climate and weather elements including, but not limited to, extreme temperatures and particulate matter are known asthma triggers. Vermont's high per capita use of old woodstoves, pockets of poverty and cold winters are all factors that might collide to adversely impact residents' asthma. Insights into how climate and weather might be related to peak periods of acute asthma exacerbation (AAE) among individuals living in the rural Northeast Kingdom of Vermont (NEK) could provide valuable, regionally focused public health information to primary care providers on the front lines of asthma management.
The objective of this research was to examine the potential relationship between the climate and weather of the NEK and visits for asthma exacerbation in the primary care setting. The research began with a retrospective chart review including visits to five different clinic sites in the NEK between 2009-2014 with the ICD-9 code for asthma exacerbation (493.xx) as the primary diagnosis. When visits were individually validated as an AAE, the clinic site, date of visit, and the patients' age and sex were documented. These validated visits were then analyzed against weather and climate data including temperature and air quality. Results suggest that while diurnal shifts and air quality do not show a strong relationship with AAEs in this area, colder days do appear to correlate to when patients visit primary care clinics in the NEK for AAEs.
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Statistically monitoring inventory accuracy in large warehouse and retail environmentsHuschka, Andrew January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / John English / This research builds upon previous efforts to explore the use of Statistical Process Control (SPC) in lieu of cycle counting. Specifically a three pronged effort is developed. First, in the work of Huschka (2009) and Miller (2008), a mixture distribution is proposed to model the complexities of multiple Stock Keeping Units (SKU) within an operating department. We have gained access to data set from a large retailer and have analyzed the data in an effort to validate the core models. Secondly, we develop a recursive relationship that enables large samples of SKUs to be evaluated with appropriately with the SPC approach. Finally, we present a comprehensive set of type I and type II error rates for the SPC approach to inventory accuracy monitoring.
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Textbook diagrams illustrating phases of the moon: Grade 10 learners' interpretation in relation to spatial abilityMosoloane, Retselisitsoe Ananias 14 February 2013 (has links)
Many textbooks have diagrams illustrating astronomy concepts. However, research shows that sometimes learners struggle to obtain information illustrated in diagrams. This study investigated learners‘ ability to interpret diagrams illustrating phases of the Moon. Three constructs formed a theoretical framework used to design the study and interpret results: a theory associated with design and interpretation of diagrams, spatial ability theory which explains how people mentally manipulate objects in space, and the theory of models which proposes issues to take into consideration when using models (e.g. diagrams) in classrooms. I collected and processed data in three phases.
In the first phase, I administered a diagnostic test to 75 learners, investigating their ideas about concepts associated with phases of the Moon. In addition, I administered six spatial ability tests to these learners, investigating their mastery of spatial ability skills needed to understand concepts associated with phases of the Moon. Results show that all the learners lacked background knowledge of these concepts. Furthermore, most of the learners lacked spatial ability skills needed to understand these concepts. I used these results to select 10 learners for participation in the third phase of the study. Five of these learners had high spatial ability skills while the other five had low spatial ability skills.
During the second phase of the study, I analyzed 28 diagrams illustrating phases of the Moon to investigate the extent to which their composition (i) might enable learners to perceive all diagrammatic information, (ii) might enable learners to understand information for which the diagrams are intended, and (iii) complies with context of intended learners. Results show that only few diagrams were designed in a way that might hinder perception of information. However, most diagrams were designed in a way that might hinder understanding of intended information, and many did not comply with context of intended viewers. These results enabled me to select four diagrams having the fewest design problems to be used in the third phase of the study.
In the third phase, I interviewed the ten learners selected during the first phase, to investigate their ability to interpret diagrams illustrating phases of the Moon. The learners were generally able to interpret aspects of diagrams which required the diagrams to be perceived in two-dimensional space. However, they struggled to interpret aspects of the diagrams which required perception and mental manipulation of the components of the Earth-Moon-Sun system in three-dimensional space. The high spatial-ability learners were better able to cope with tasks requiring mental manipulation of the Earth-Moon-Sun system in space than their low spatial ability counterparts. These results suggest the existence of a link between spatial ability and learners‘ interpretation of these diagrams.
Teachers should be informed about these findings to help them understand how usage of the diagrams might hinder leaning. This information might help them use diagrams that have fewer design problems. Also, teacher trainers should be informed about these findings, to help them caution pre-service teachers about problems found in textbook diagrams. In addition, publishers should be informed about findings of this study to help them improve quality of diagrams in school textbooks. Furthermore, researchers should investigate strategies that can help learners (particularly those with low spatial ability skills) to better cope with aspects of diagrams which require mental manipulation of the Earth-Sun-Moon system in space.
Keywords
Astronomy, phases of the Moon, diagram design, diagram interpretation, spatial ability.
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\"Análise da qualidade de prontuários odontológicos para fins de identificação humana através da auto-avaliação\" / Quality analysis of dental charts, for human identification purpose, through professionals´self-assessmentMeo, Ilka Corrêa de 18 October 2006 (has links)
A qualidade de um prontuário odontológico tem relação direta com sua capacidade em suprir determinadas necessidades dentro da prática profissional. Entre as características desta documentação encontramos a sua capacidade de funcionar como evidência de grande valor em casos de identificação humana, principalmente em casos onde há destruição dos corpos encontrados (carbonização, putrefação avançada, afogamentos e mutilações), onde fica dificultada a realização da identificação através da dactiloscopia ou o reconhecimento pelos familiares. Com a queda no número de tomadas radiográficas realizadas durante o tratamento odontológico e a diminuição da incidência de cárie na população em geral, o detalhamento da documentação escrita elaborada pelo cirurgião-dentista torna-se imprescindível para possibilitar a sua comparação com dados postmortem por ocasião de uma perícia de identificação humana. Dessa forma, este trabalho teve como proposta realizar uma avaliação da qualidade dos prontuários elaborados por cirurgiões-dentistas. Além disso, foi também realizada uma comparação entre a qualidade da documentação elaborada por profissionais recém-formados e profissionais formados há mais de 5 anos, como uma tentativa de estabelecer o tempo de formação do profissional como um fator relevante na elaboração do prontuário. Para tanto, foi realizado um questionário com perguntas referentes à rotina de elaboração da documentação odontológica a uma amostra não probabilística de 132 profissionais, tendo sido utilizada para sua análise a observação quantitativa das tendências das respostas. Observou-se que há grande deficiência no conhecimento dos profissionais quanto ao preenchimento desta documentação, além do desconhecimento da relevância que esta pode apresentar em casos de identificação humana. Quando da comparação levando em consideração o tempo de formado, de modo geral, o desempenho dos dois grupos apresentou-se bastante semelhante, não se refletindo assim, na qualidade final da documentação elaborada, o tempo de formação do indivíduo. / The quality of a dental chart has direct relation with its capacity in supplying definitive necessities of the professional practice. Among the characteristics of this documentation we find its capacity to function as evidence of great value in cases of human identification, especially in cases presenting massive destruction of the bodies (carbonization, advanced decomposition, drowning and mutilation), making it difficult to accomplish the identification through dactyloscopy or even the recognition by the family members. With the decrease in the number of radiographic takes carried out through the dental treatment and the reduction of the incidence of caries in the population in general, the detailing of written documentation elaborated by the dentist becomes essential to make possible its comparison with postmortem data in a forensic identification. Thus, our goal was to evaluate the quality of the dental charts made by graduated dentists. Moreover, we made also a comparison between the quality of the documentation elaborated by newly graduated professionals and professionals graduated for more than 5 years, as an attempt to establish the time of graduation as a relevant factor in the elaboration of the written documentation. For that, a non probabilistic sample of 132 professionals was submitted to a questionnaire with questions referring to the routine elaboration of the dental documentation, having been used for its analysis the quantitative observation of the trends of the answers. It was noticed that there is a great deficiency in the professionals´ knowledge in producing this documentation, and also of its importance in cases of human identification. Regarding the time of graduation, generally, the performance of the two groups presented very similarly, what led us to the conclusion that it does not reflect in the final quality of the documentation.
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A self-starting statistical control chart methodology for data exhibiting linear trendMcClurg, Brian Matthew 01 May 2016 (has links)
Traditional quality control charts are designed to monitor and control a quality characteristic for processes with a stable in-control state in which enough data is available to estimate the process parameters prior to a production run. For many processes we desire the ability to monitor a quality characteristic that has an in-control state not stable such as a degradation or deterioration process that exhibits a linear trend as its in-control state. In addition, there are many times when sufficient sampling for in-control parameter estimation is not possible before the production run due to cost or collection time. We therefore desire a self-starting charting scheme that monitors both in-control and out of control linear trends. We present here the needed results so that a process with the in-control linear trend can be charted to detect slope and intercept shifts, when accurate information on in-control parameters is not available. We propose a Q chart scheme, a EWMA Q chart, and a EWMA Q chart with delay parameter d that utilizes results from statistical process control and linear regression. The developed control chart schemes are tested through simulation studies and applied to real data examples.
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Strategies for the use of interactive multimedia to train extension workers in developing countriesWijekoon, R. R. A., University of Western Sydney, Faculty of Performance, Fine Arts and Design, School of Design January 1999 (has links)
A key feature of recent agricultural extension programs has been the focus on increased participation for local, rural communities in the overall decision-making process. This move towards increasing community participation has raised expectations in terms of communication: communication between central research facilities and rural communities, between rural communities and central research facilities, and amongst the rural communities themselves. In order to provide effective communication along each of these channels, attention is turning to the extension trainers deployed in the field. For extension trainers this emerging communication role is distinct from, and supplementary to, the conventional technical training function. The thesis highlights the lack of effective training in communication skills in existing extension training programs. It identifies the flip chart as the most widely used visual aid for farmer training, and the overhead projector as the most widely used visual aid for in-service training. The thesis develops a comprehensive set of training competencies and content for teaching those two technologies, derived from individual task analyses and an extensive literature review. A range of strategic alternatives for the delivery of those competencies in a developing country are then formulated and examined. Central to the different strategies considered is the use of interactive multimedia as a key delivery technology. Two proprietary CDROMs have been designed and produced specifically to the support training in the design and production skills for overhead projector and flip chart technologies. The design, content and production of the CDROMs is described, and both technical and user evaluations are presented. The two CDROMs have been field-tested in Sri Lanka, across a broad range of strategic alternatives. The outcome is a set of guidelines and specific structures for training programs in overhead projector and flip chart technologies. The guidelines are generic and broadly applicable. The case studies also indicate a particular subset of preferred strategies for the future deployment of interactive multimedia-based training in developing countries. Most specifically, the thesis indicates a balance between and the need for mix of interactive multimedia modules along with face-to-face training support / Doctor of Philosophy (PhD)
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