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Propensity Score for Causal Inference of Multiple and Multivalued TreatmentsGu, Zirui 01 January 2016 (has links)
Propensity score methods (PSM) that have been widely used to reduce selection bias in observational studies are restricted to a binary treatment. Imai and van Dyk extended PSM to estimate non-binary treatment effect using stratification with P-Function, and generalized inverse treatment probability weighting (GIPTW). However, propensity score (PS) matching methods on multiple treatments received little attention, and existing generalized PSMs merely focused on estimates of main treatment effects but omitted potential interaction effects that are of essential interest in many studies. In this dissertation, I extend Rubin’s PS matching theory to general treatment regimens under the P-Function framework. From theory to practice, I propose an innovative distance measure that can summarize similarities among subjects in multiple treatment groups. Based on this distance measure I propose four generalized propensity score matching methodologies. The first two methods are extensions of nearest neighbor matching. I implemented Monte Carlo simulation studies to compare them with GIPTW and stratification on P-Function methods. The next two methods are extensions of the nearest neighbor caliper width matching and variable matching. I define the caliper width as the product of a weighted standard deviation of all possible pairwise distances between two treatment groups. I conduct a series of simulation studies to determine an optimal caliper width by searching the lowest mean square error of average causal interaction effect. I further compare the ones with optimal caliper width with other methods using simulations. Finally, I apply these methods to the National Medical Expenditure Survey data to examine the average causal main effect of duration and frequency of smoking as well as their interaction effect on annual medical expenditures. Using proposed methods, researchers can apply regression models with specified interaction terms to the matched data and simultaneously obtain both main and interaction effects estimate with improved statistical properties.
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Exercise-induced laryngeal obstruction : Prevalence, laryngeal findings and evaluation of treatmentNorlander, Katarina January 2017 (has links)
Exercise-induced laryngeal obstruction (EILO) is one of many different causes for adolescents to experience dyspnoea during exercise. Objective exercise-testing with continuous video laryngoscopy is crucial for a correct diagnosis since it is difficult to differentiate EILO from other exercise related conditions in the airways only on the symptomatology. The main symptom in EILO is inspiratory stridor arising from an obstruction at the laryngeal level during ongoing exercise which quickly resolves after the exercise has stopped. EILO is often misdiagnosed as exercise-induced bronchoconstriction (EIB), which is obstruction in the peripheral airways that typically arises after cessation of exercise. From a previous survey investigating self-reported exercise-induced dyspnoea in all 12-13-year-old adolescents in Uppsala (n=3,838, response rate 60.2%) a subset of 150 randomly selected adolescents (103 with dyspnoea and 47 controls) performed standardized treadmill exercise-tests for EIB and EILO. During the exercise-test for EIB the subjects breathed dry air according to the current recommended guidelines. EIB was defined as a decrease in FEV1 ≥10% from baseline. EILO was diagnosed during a continuous laryngoscopy exercise (CLE) test by use of the CLE-score method and was defined as an obstruction of grade 2 at either glottic or/and supraglottic laryngeal level. The estimated prevalence of EIB in the general population was 19.2% and the estimated prevalence of EILO was 5.7%. No gender differences were detected. A diagnostic software program for EILO, EILOMEA, was compared with the CLE-score and the methods were found to be compatible. EILOMEA was used to map and compare laryngeal response patterns in adolescents with exercise-induced dyspnoea (EIB and/or EILO), in adolescents with dyspnoea but without a diagnosis of EIB or EILO, and in healthy controls, all of whom had performed the CLE-test. No differences were seen between the healthy controls and the adolescents with dyspnoea without a diagnosis. Only adolescents diagnosed with EILO showed a significant different laryngeal response pattern which strongly suggests that the diagnostic procedure is reliable. In a follow-up study of patients referred for investigation of exercise-induced dyspnoea, we investigated the outcome of surgical vs. conservative treatment of EILO-positive subjects and subjects tested negative for the diagnosis, regarding the level of exercise-induced dyspnoea and physical activity. Surgically treated patients had less breathing problems and were more physically active than both conservatively treated patients and patients who were tested negative.
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The effect of Stravinsky's ballets on the role of the conductorBaxter, Hannah January 2014 (has links)
This thesis explores Stravinsky's effect on the role of the conductor, employing a combination of score analysis, performance analysis, aesthetics and historicism. Stravinsky is widely regarded as one of the most influential composers of the Twentieth Century, and this now 'mythic' influence is perceived by many to have transformed the conductor's work. I investigate how true this assumption is, and whether The Rite of Spring in particular is responsible for any developments. The compound methodology allows for the study of rhythm, structure, harmony, instrumentation, hermeneutics and staging. My seven case studies (The Firebird, Petrushka, The Rite of Spring, Les Noces, Apollo, Stravinsky Violin Concerto, and Agon) are all ballets, which also places spotlight on a commonly neglected genre in music. This allows for the consideration of choreography - an additional influencing factor that is bypassed in most musicological and conducting literature. Moreover, the study of Stravinsky's ballets, as they span the composer's entire career, can serve as a useful lens through which to view the composer's repertoire as a whole. Therefore the findings of the thesis can be indicative of Stravinsky's broader influence on the conductor. The conclusions drawn were that although it is impossible to refute Stravinsky's overall impact on the conductor's work (particularly in relation to his comtemporaries), there are numerous overrated areas of impact. Furthermore, The Rite of Spring is not solely responsible for these changes. In fact, it overshadows the challenges present throughout Stravinsky's repertoire, which manifest themselves in the innovative choreography, instrumentation, rhythm and anti-interpretative devices.
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Balanced Score Card para optimizar el planeamiento estratégico para Maccaferri de Perú S.A.C. periodo 2016-2017Mallma Cordero, Juan Blas January 2018 (has links)
El objetivo general de la investigación es demostrar como el balanced score card optimizará el planeamiento estratégico para Maccaferri de Perú S.A.C. periodo 2016-2017.
Para la investigación el tipo de estudio fue descriptivo. Se utilizó el método deductivo-explicativo.
Entre los resultados más importantes resaltan: que; la comunicación de estrategias en forma clara que proyecta ejecutar Maccaferri S.A.C para el periodo 2016-2017 influye significativamente en permitirle cumplir con su visión institucional
The general objective of the research is to demonstrate how the balanced score card will optimize the strategic planning for Maccaferri of Peru S.A.C. 2016-2017 period.
For the investigation, the type of study was descriptive. The deductive-explanatory method was used.
Among the most important results stand out: that; The communication of strategies in a clear form that Maccaferri S.A.C plans to execute for the 2016-2017 period has a significant influence on enabling it to fulfill its institutional vision.
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Evaluating the Impact of an Early Warning Scoring System in a Community Hospital SettingConner, Christine 01 January 2018 (has links)
Failure to recognize and respond to early signs of deterioration in hospitalized patients can have significant implications associated with delays in treatment. This lack of recognition was the impetus for rapid response teams in the United States and the recommendation by the Institute of Healthcare Improvement for use of early warning scores. This project was designed to evaluate the pilot implementation of an early warning score on 2 units in a community hospital in the Northeast. The practice-focused question was used to explore how patient outcomes changed following implementation of an early warning score (EWS) compared to patient outcomes associated with a rapid response team alone. The translating evidence into practice model informed this project. Supporting evidence from existing hospital data was collected for rapid response, code blue, and mortality. Analysis using the chi-square test of homogeneity compared post-implementation with baseline data. The findings indicated the differences between the proportions were not statistically significant, indicating the metrics did not change appreciably following the implementation of the early warning score. While the evaluation analytics of this pilot did not demonstrate significant change in the outcome measures post-implementation, the results may be useful for the facility when performing a future evaluation of the EWS. It is possible that the results of the 2 units were not representative of the facility, and it is therefore recommended to repeat the evaluation using data from the entire facility for a longer period. Increasing the capacity for early recognition in decline has implications for social change through improvement in safety and quality of health care for all hospitalized patients.
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Black Aggie: A Tale of American FolkloreElliott, Gabrielle O'rean 23 April 2014 (has links)
<italic>Black Aggie: A Tale of American Folklore<italic> is a musical work written for wind symphony and synthesizer. The piece has the possibility to be performed in two different ways. It can either be performed by a live wind symphony or can be played as an electronic realization with media. The piece was inspired by the legend of Black Aggie - a peculiar grave statue with a series of fantastical stories surrounding her existence. The media presentation is to be played along with the live or synthesized performance. The media consists of photographs and footage of key elements in Black Aggie's legend. All of the media was manipulated with <italic>Photoshop<italic> and transferred to the video editing software <italic>iMovie<italic>. The realization of the music was created using <italic>Finale, Logic Pro,<italic> and <italic>East West Symphonic Gold<italic>. The music and the media together create a vivid depiction of Black Aggie's legend. / Mary Pappert School of Music; / Music Theory / MM; / Thesis;
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Essays on Treatment Effects EvaluationGuo, Ronghua 06 September 2012 (has links)
The first chapter uses the propensity score matching method to measure the average impact of insurance on health service utilization in terms of office-based physician visits, total number of reported visits to hospital outpatient departments, and emergency room visits. Four matching algorithms are employed to match propensity scores. The results show that insurance significantly increases office-based physician visits, and its impacts on reported visits to hospital outpatient departments and emergency room visits are positive, but not significant. This implies that physician offices will receive a substantial increase in demand if universal insurance is imposed. Government will need to allocate more resources to physician offices relative to outpatient or emergency room services in the case of universal insurance in order to accommodate the increased demand.
The second chapter studies the sensitivity of propensity score matching methods to different estimation methods. Traditionally, parametric models, such as logit and probit, are used to estimate propensity score. Current technology allows us to use computationally intensive methods, either semiparametric or nonparametric, to estimate it. We use the Monte Carlo experimental method to investigate the sensitivity of the treatment effect to different propensity score estimation models under the unconfoundedness assumption. The results show that the average treatment effect on the treated (ATT) estimates are insensitive to the estimation methods when index function for treatment is linear, but logit and probit model do better jobs when the index function is nonlinear.
The third chapter proposes a Cross-Sectionally Varying (CVC) Coefficient method to approximate individual treatment effects with nonexperimental data, the distribution of treatment effects, the average treatment effect on the treated and the average treatment effect. The CVC method reparameterizes the outcome of no treatment and the treatment effect in terms of observable variables, and uses these observables together with a Bayesian estimator of their coefficients to approximate individual treatment effects. Monte Carlo simulations demonstrate the efficacy and applicability of the proposed estimator. This method is applied to two datasets: data from the U.S. Job Training Partnership ACT (JTPA) program and a dataset that contains firms’ seasoned equity offerings and operating performances.
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towards silos and smokestacks for OrchestraJenkins, Derek 16 September 2013 (has links)
towards silos and smokestacks takes its name from the Silos and Smokestacks Heritage Area. In 1996, the northeast third of Iowa became a federally designated heritage area to pass on the story of American agriculture to younger generations. I spent much of my childhood growing up in Iowa. On my many trips through the state, two contrary aspects in the surrounding landscape caught my fascination. First, there are the vast cornfields that expand outwards for miles fading off beyond the horizon. Second, this countryside is home to countless grain silos and billowing smokestacks of small Midwestern cities. These monoliths can be seen miles away like small islands within Iowa’s rolling agricultural oceans. As I drew closer to these structures, they would slowly grow into colossal pillars giving a vertical, albeit fleeting, dimension to the scenery before disappearing once again into the distance. This piece is an attempt to juxtapose this sense of vastness and the monoliths that interrupt the sprawling “amber waves of grain” through the use of spatial aspects and ever expanding register.
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Analyzing the Management in Nutraceutical Industry in Taiwan¡GTaking G Company as an ExampleLi, Yen-Chang 30 August 2010 (has links)
Abstract
Balance Score Card (BSC) has been adopted broadly in organization performance evaluation as well as strategy development and evaluation, especially when the business environment is growingly competitive. The effectiveness of BSC has been shown through its practice in many large-size companies by enhancing cross divisional communications.
However, for 90% of companies in Taiwan are small and medium sized and these companies contributed over 70% of job opportunities, it is important to investigate whether BSC can provide such effectiveness for these Taiwanese firms. Thus, this research develops a case study of an emerging company. By observing the decision and introduction of BSC to the company, this research has found below conclusions:
1. Small and medium sized firms are simpler, thus easier to focus and result to shorter introduction time of BSC.
2. BSC has provided effective design of indicators to connect strategy and actions and further provide good means for management team to evaluate performance and report to the board.
3. In the development phase of SMEs, the financial phase of BSC reminds the firms to emphasize the growth of revenue. With the help of BSC, management team can balance the focus of customer value, internal process and organizational learning.
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Effects of conventional or low bull to female ratio and utilization of reproductive tract scores in extensively-managed, natural mating breeding groupsRathmann, Ryan James 25 April 2007 (has links)
The current study involved two experiments which were conducted at the Texas
A&M Agricultural Research and Extension Center in Uvalde (semi-arid environment)
from 2002 to 2004. In experiment one, Bonsmara bulls (n = 19; 20-24 mo of age) were
joined with multiparous, crossbred females (n =586) for 90 d in 2003 and 2004. Bulls
were allotted by selected physical traits, seminal traits, social rank, and serving capacity
to one of two bull to female ratio (BFR) treatments: Conventional (1:21-1:29; n = 6
pastures) or Low (1:47-1:52; n = 2 pastures) BFR. Pregnancy rate (P = 0.33), calving
rate (P = 0.26), and calving date (P = 0.22) did not differ between Conventional and Low
BFR treatments. Post-breeding evaluation of bulls in 2002 (n = 16) indicated that social
rank, but not seminal traits, was significantly correlated with pre-breeding values (P <
0.05). The current study demonstrates that Low BFR can be utilized in single- and multisire,
90-d breeding pastures of up to 2,090 ha without adversely affecting reproductive
performance.
In experiment two, yearling, one-half or three-quarter Bonsmara heifers (n = 106;
11-14 mo of age) were palpated per rectum and assigned a reproductive tract score (RTS)
immediately prior to the beginning of the breeding season. Reproductive performance was measured in their two subsequent breeding years in order to estimate the value of the
RTS system in extensively-managed, natural mating, 90-d breeding season programs.
RTS was positively correlated (p < 0.01) with frame score (r = 0.25), age (r = 0.31),
weaning weight (r = 0.47), and the weight of the heifer on the day of RTS exam (r =
0.56). The RTS means by dam parity also differed (P < 0.03). A lower (P < 0.01)
percentage of females conceived during each of their first two breeding seasons for
heifers of RTS 1 and 2 (65.2%) than for heifers of RTS 3, 4, and 5 (91.2%). Females
with a RTS of 1 had a lower pregnancy rate over each of their first two breeding seasons,
conceived later during their first breeding season, weaned lighter first calves, and
remained lighter each year for fall body weight and body condition score than did heifers
with RTS of 2 to 5 (P < 0.05). Collectively, the results of the current study indicate that
heifers with a RTS of 1 immediately prior to a 90-d breeding season should be culled.
Consideration should also be given to eliminating RTS 2 heifers, but further studies will
be needed to confirm the potential economic advantage of this practice.
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