1 |
Variable Sampling Rate Control Charts for Monitoring Process VarianceHughes, Christopher Scott 20 May 1999 (has links)
Industrial processes are subject to changes that can adversely affect product quality. A change in the process that increases the variability of the output of the process causes the output to be less uniform and increases the probability that individual items will not meet specifications.
Statistical control charts for monitoring process variance can be used to detect an increase in the variability of the output of a process so that the situation can be repaired and product uniformity restored. Control charts that increase the sampling rate when there is evidence the variance has changed gather information more quickly and detect changes in the variance more quickly (on average) than fixed sampling rate procedures. Several variable sampling rate procedures for detecting increases in the process variance will be developed and compared with fixed sampling rate methods.
A control chart for the variance is usually used with a separate control chart for the mean so that changes in the average level of the process and the variability of the process can both be detected. A simple method for applying variable sampling rate techniques to dual monitoring of mean and variance will be developed. This control chart procedure increases the sampling rate when there is evidence the mean or variance has changed so that changes in either parameter that will negatively impact product quality will be detected quickly. / Ph. D.
|
2 |
Rule based decision support for marine collision avoidance in an integrated bridge environmentTucker, Stephen Michael January 1998 (has links)
No description available.
|
3 |
The application of use cases in systems analysis and design specificationRatcliffe, Martyn January 2003 (has links)
No description available.
|
4 |
Celiac Disease in the Hispanic Population at Maricopa Integrated Health SystemMassimo, Lauren 23 May 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. / Celiac disease (CD) is an autoimmune gastrointestinal disorder that has been well studied amongst non‐Hispanic white populations. Data specifically describing the disease in the U.S. Hispanic population is limited and available studies that do report prevalence and incidence within this population reveal discrepancies. The aim of this study is to estimate the incidence of CD and to define common presenting symptoms in Hispanics in Phoenix, AZ. Data was collected via a retrospective chart review from Maricopa Integrated Health System (MIHS), an organization caring for a patient population that is >50% Hispanic, between 2004‐2013. The study population is both adult and pediatric patients that had received the ICD‐9 code 579.0. The total number of non‐repeat patients seen at MIHS each year between 2004‐2013 was also determined and broken down by race for incidence calculations. During this 10‐year period, 29 total patients were diagnosed with CD at MIHS. The overall yearly incidence increased from 1 in 44,011 patients in 2004 to 1 in 27,948 in 2013. Of the 29 diagnosed, 52% were Caucasian, 34% Hispanic, 7% Asian and 7% African American. The yearly incidence in Hispanic patients also increased from 0 in 2004 to 1 in 58,302 in 2007 to 1 in 25,826 in 2013. Although diagnosis was greater in females of both races, Hispanic patients were diagnosed at a younger age than Caucasians (22 vs. 31 y/o, respectively). The most common diagnostic approach was serological testing combined with duodenal biopsy. The 3 most common gastrointestinal presenting symptoms in Caucasians were diarrhea, abdominal pain and nausea/vomiting, while those in Hispanics were constipation, bloating/abdominal distention and diarrhea. At the time of diagnosis, at least 1/3rd of both Caucasian and Hispanic patients had presented with another autoimmune disorder. Other associated conditions were neurological symptoms and iron‐deficiency anemia. Data from this study suggests that CD in the Hispanic population may be more common in Phoenix than the overall population in the U.S. as described in the literature. It also suggests that Hispanic patients may have different presenting symptoms than do Caucasians. The reason behind the increase in CD incidence in Hispanics is unclear, although increased physician awareness and diagnosis may play a role. Further research and awareness of CD in the Hispanic population may be necessary to optimize diagnosis & treatment of the condition.
|
5 |
Comparing Different Forms of Childhood Maltreatment as Risk Factors for Adult Cardiovascular Disease and DepressionPanchanathan, Amritha 23 May 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. / Research has shown an association between childhood maltreatment and risk factors for cardiovascular disease and depression. The purpose of this study is to examine the total and unique effects of various forms of childhood maltreatment on the development of risk factors for cardiovascular disease and depression in both women and men. Data for this study will be obtained from retrospective chart review and from an already established research database at a private healthcare facility specializing in the treatment of trauma and addiction. All information will pertain to participants’ admission to the healthcare facility and will include self‐report data on childhood maltreatment and symptoms of depression, as well as retrospective chart review data regarding physiological metrics of risk for cardiovascular disease (blood pressure, cholesterol, diabetes). Results from 290 patients indicated that emotional abuse and emotional neglect were the leading predictors of negative outcomes with emotional neglect being a significant predictor of adult depression even after controlling for age, gender, and marital status. Younger participants and women reported higher levels of depression. However, the gender‐specific regressions showed that younger age and emotional neglect remained significant predictors of depression, with the percent variance explained by the model being greater among men compared to women. This greater effect size among men was driven by a stronger association between younger age and depression in men than in women. Childhood emotional abuse was associated with greater risk for coronary heart disease, even after controlling for gender and marital status. Gender‐specific analyses showed that, for men, childhood physical neglect emerged as a significant predictor of coronary heart disease risk after controlling for marital status. Contrary to predictions, among women, none of the five types of childhood maltreatment emerged as a significant predictor of coronary heart disease risk. Moreover, depression was inversely associated with risk for coronary heart disease. In other words, higher levels of depression were consistently associated with lower levels of coronary heart disease risk. This was attributed to the fact that younger people reported higher levels of depression, but younger age was also associated with lower levels of coronary heart disease risk. Furthermore, the results of this study can be used to develop screening tools, based on childhood maltreatment severity and type, for depression and cardiovascular disease.
To what degree are specific types of childhood abuse and neglect (i.e., emotional, physical, or sexual) risk factors for depression and cardiovascular disease and how are these risks moderated by gender? Hypotheses: 1) It is expected that higher levels of childhood neglect and abuse (all forms taken together) will be related to higher levels of depressive symptoms and greater risk for cardiovascular disease. 2) Comparing five basic forms of neglect and abuse, it is anticipated that emotional abuse will have the strongest association with elevations in depression and cardiovascular risk. 3) It is hypothesized that the relation between childhood maltreatment and cardiovascular risk will be stronger in women compared to men.
|
6 |
An evaluation of the bioclimatic chart for choosing design strategies for a thermostatically-controlled residence in selected climatesVisitsak, Sopa 15 May 2009 (has links)
To be successful in sustainable building design, architects must consider energy
efficient design strategies in the early design stage. Unfortunately, many architects still
rely on simplified analysis, synthesis techniques, and historical examples. Although,
building energy simulations are becoming more common in the design of buildings,
architects rarely use simulation in the early design stage.
The “Bioclimatic” charts have been used in the early design stage to define
potential building design strategies to achieve indoor thermal comfort. Currently, many
architects use the Givoni-Milne bioclimatic design chart (Milne and Givoni, 1979),
which was developed based on principle reasoning and heuristics. There have been many
attempts to develop computerized programs to further the bioclimatic analysis; however,
there have been very limited efforts to test and evaluate the design strategies of the chart
using simulations of a thermostatically-controlled building.
Therefore, the purpose of this research is to promote comfortable buildings that
reduce energy use through appropriate building design strategies. The objectives of the
research are to develop a more accurate bioclimatic chart for a thermostaticallycontrolled
residence by testing and evaluating the Givoni-Milne bioclimatic chart. The
analysis is performed with DOE-2.1e program (Winkelmann, 1993) and TMY2 weather
data (Marion and Urban, 1995) for several climates. To achieve these objectives, four
main tasks were accomplished: 1) investigate the Givoni-Milne Bioclimatic Chart using
representative weather data from several climates, 2) analyze and modify the design
strategy boundaries using DOE-2 program and TMY2 weather data to simulate the effects of varied conditions of a thermostatically-controlled residence in different
climates, 3) compare these new design strategy boundaries to the original Givoni-Milne
design strategy boundaries, and 4) develop general guidelines for the new bioclimatic
chart.
In summary, there were some differences in the results from the Givoni-Milne
bioclimatic chart and the DOE-2 simulation results. These results imply that without
further modification, the G-M Chart may have only a limited use for a thermostaticallycontrolled
residence. Therefore, to improve the usefulness of the bioclimatic chart the
new bio-climatic chart for choosing design strategies for a thermostatically-controlled
residence in the hot-humid climate of Houston, Texas, was developed. This new
bioclimatic chart for a thermostatically-controlled residence will be a useful tool for
architects and engineers in the early design stage. Similar versions of the new
bioclimatic for other climates could then be developed.
|
7 |
An evaluation of the bioclimatic chart for choosing design strategies for a thermostatically-controlled residence in selected climatesVisitsak, Sopa 10 October 2008 (has links)
To be successful in sustainable building design, architects must consider energy
efficient design strategies in the early design stage. Unfortunately, many architects still
rely on simplified analysis, synthesis techniques, and historical examples. Although,
building energy simulations are becoming more common in the design of buildings,
architects rarely use simulation in the early design stage.
The "Bioclimatic" charts have been used in the early design stage to define
potential building design strategies to achieve indoor thermal comfort. Currently, many
architects use the Givoni-Milne bioclimatic design chart (Milne and Givoni, 1979),
which was developed based on principle reasoning and heuristics. There have been many
attempts to develop computerized programs to further the bioclimatic analysis; however,
there have been very limited efforts to test and evaluate the design strategies of the chart
using simulations of a thermostatically-controlled building.
Therefore, the purpose of this research is to promote comfortable buildings that
reduce energy use through appropriate building design strategies. The objectives of the
research are to develop a more accurate bioclimatic chart for a thermostaticallycontrolled
residence by testing and evaluating the Givoni-Milne bioclimatic chart. The
analysis is performed with DOE-2.1e program (Winkelmann, 1993) and TMY2 weather
data (Marion and Urban, 1995) for several climates. To achieve these objectives, four
main tasks were accomplished: 1) investigate the Givoni-Milne Bioclimatic Chart using
representative weather data from several climates, 2) analyze and modify the design
strategy boundaries using DOE-2 program and TMY2 weather data to simulate the effects of varied conditions of a thermostatically-controlled residence in different
climates, 3) compare these new design strategy boundaries to the original Givoni-Milne
design strategy boundaries, and 4) develop general guidelines for the new bioclimatic
chart.
In summary, there were some differences in the results from the Givoni-Milne
bioclimatic chart and the DOE-2 simulation results. These results imply that without
further modification, the G-M Chart may have only a limited use for a thermostaticallycontrolled
residence. Therefore, to improve the usefulness of the bioclimatic chart the
new bio-climatic chart for choosing design strategies for a thermostatically-controlled
residence in the hot-humid climate of Houston, Texas, was developed. This new
bioclimatic chart for a thermostatically-controlled residence will be a useful tool for
architects and engineers in the early design stage. Similar versions of the new
bioclimatic for other climates could then be developed.
|
8 |
Analyse von Schnittstellenkompatibilität von Steuergeräten auf Basis von MSC-BeschreibungenMa, Zheng. Glockner, Matthias, January 2008 (has links)
Chemnitz, Techn. Univ., Diplomarb., 2008.
|
9 |
Flowgrapher : generation of conceptual graphs from flowcharts /Venkatasubramanian, Ramprasad. January 1994 (has links)
Report (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaf 59). Also available via the Internet
|
10 |
Statistical Monitoring of Risk Factors for VICU Patients through Spectral Analysis of Heart Rate VariabilityLai, Ju-Ja 19 June 2001 (has links)
Spectral analysis of heart rate variability (HRV) has been applied
in many medical research to study autonomic nervous system
activity. In these studies, the researchers found that (i) ratio
of low frequency (LF) to high frequency (HF) spectrum power is a
useful measure of sympathetic/parasympathetic balance, and (ii)
low heart rate variability is an important risk factors for
patients. Therefore, continuous monitoring of the ratio and heart
rate variability have the potential to early detect physiological
deterioration of patients. This thesis consists of the following
two parts. In the first part, we establish control charts
monitoring heart rates and low HRV. Numerical method is applied
to compute exact control limits of the EWRMS and EWMV charts. The
distribution of the conventional LF/HF ratio statistic is
difficult to derive, significant of alterations in HRV parameters
can not be assessed efficiently. We resolve this problem in the
second part, a new equivalently useful ratio statistic is proposed
whose distribution can be derived more easily. Based on the
derived distribution, the probability control limits of the
proposed statistic are calculated. In application, we construct
Shewhart charts of the newly proposed ratio statistic and EWRMS,
EWMV charts of the heart rate variability to monitor the risk
factors of patients in vascular intensive care unit. Furthermore,
we define a risk score which combining the two risk factors
together, heart rate variability and LF/HF spectrum power ratio.
The results show that the higher risk scores corresponding to
patients after operation in severer condition.
|
Page generated in 0.0458 seconds