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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

THE INFLUENCE OF STATE-LEVEL RENEWABLE ENERGY POLICY INSTRUMENTS ON ELECTRICITY GENERATION IN THE UNITED STATES: A CROSS-SECTIONAL TIME SERIES ANALYSIS

Park, Sunjoo 12 September 2013 (has links)
No description available.
192

Correlation of Selected Trunk and Hip Muscle Cross-Sectional Areas with Incidence and Severity of Low Back Pain in Adult Males and Females

Amabile, Amy Helen 19 September 2016 (has links)
No description available.
193

Propensity Score Matching in Observational Studies with Multiple Time Points

Li, Chih-Lin 28 September 2011 (has links)
No description available.
194

Adherence in patients with heart failure. Relationships to symptom burden and hospitalization frequency : A cross-sectional survey study

Moe, Helen January 2024 (has links)
Aim: The aim of the study was to investigate the degree of adherence and non-adherence to treatment regimen in the population with heart failure, as well as to explore relationships to symptom burden and hospitalization-frequency. Introduction: Heart failure – a chronic disease with a somber prognosis and high mortality, incidence and prevalence increasing world-wide. Adherence to treatment regimen mitigates symptom flare-up, increases life quality and impedes hospitalizations. Non-adherence is a global problem, historically underestimated and difficult to measure. The level of non-adherence to medical treatment in the heart failure-population is about 50 %, degree of non-adherence from a wider perspective implicates a gap of knowledge. Methods: A cross-sectional survey-study was conducted via the electronic survey: ”Living with heart failure”. Selection was consecutive, based on patients visiting the Cardiac outpatient-clinic, in a Swedish University Hospital. Data was transferred to descriptive statistics using the statistical processing program SPSS. Results: 479 individuals participated, non-adherent were 73,6 % and adherent 26,4 %. There was a significant difference between symptom burden among the non-adherent and the adherent. A trend also appeared between low hospitalization-frequency, high degree of adherence and low symptom burden, an equivalent trend among the most frequently hospitalized which exhibited the lowest degree of adherence and the most severe symptom burden. Conclusion: The results pinpoint the need to further draw attention to non-adherence, repeatedly representing the majority of the population. With a patient-centered approach nurses/caregivers could have an empowering effect on the patient´s ability to health literacy and thus promote conditions for adherence.
195

Experiments on special-shaped CFST stub columns under axial compression

Ren, Q-X., Han, L-H., Lam, Dennis, Hou, C. January 2014 (has links)
This paper is an attempt to study the behavior of axially loaded concrete filled steel tubular (CFST) stub columns with special-shaped cross-sections, i.e. triangular, fan-shaped, D-shaped, 1/4 circular and semi-circular. A total of forty-four specimens including CFST stub columns and reference hollow steel tubular stub columns were tested. The effects of the changing steel tube wall thickness and the infill of concrete on the behavior of the composite columns were investigated. The results showed that the tested special-shaped CFST stub columns behaved in a ductile manner, and the composite columns showed an outward local buckling model near the middle section. Generally, the failure modes of these five kinds of special-shaped specimens were similar to those of the square CFST stub columns. Finally, simplified model for predicting the cross-sectional strength of the special-shaped CFST sections was discussed and proposed.
196

Predicting Future Age-Related Cognitive Delcine: Processing Speed and Frontal Lobe Functioning

Kitner-Triolo, Melissa Hughes 19 May 2000 (has links)
The present study assessed the impact of aging on cognitive functioning over six to 16 years in exceptionally healthy individuals (20 to 79 years) drawn from the Baltimore Longitudinal Study of Aging. The first study (N = 380 women, 757 men) examined the relationship between age and speed of processing as measured by five reaction time (RT) tasks (simple reaction time to complex reaction time involving varying amounts of inhibitory and working memory processing). Unlike previous research, this study additionally assessed the impact of processing speed, working memory, inhibitory processing, and interference RT measures in predicting future performance 6-16 years later (N=103) on (1) mental status (Blessed Information-Memory-Concentration, Mini-Mental State Examination), and prefrontal mediated neuropsychological tests (Trail Making A and B; verbal and category fluency; WAIS digits forward and backwards, California Verbal Learning Test proactive interference index). Regression analyses assessed which theoretical approach, speed of processing (Salthouse, 1996) or prefrontal cortex (Hasher & Zacks, 1988; West, 1996), better explained cognitive change. Age-related cognitive slowing was observed for initial RT tasks. Especially among the oldest studied (62-79 years of age), slower speed of processing was accelerated by task complexity. Increases in response time were substantially steeper for older as opposed to younger participants. Men were faster than women were on simple RT and a RT task that involved inhibitory processing. A 6-9 year age decline in speed of processing only occurred among individuals over 60 years. RT omission and commission errors showed similar results. Hierarchical regression analyses determined that RT tasks involving inhibitory control, working memory and interference were most predictive of future prefrontal-mediated cognitive performance (Trail Making B, digit span backwards, letter and category fluency). Prediction of the prefrontal outcome measures of Trail Making A and digit span forward performance from simple reaction time was mediated by the RT measures (inhibitory control, working memory and interference), but not the other way around. Thus, the data most strongly support the Inhibitory Deficit (Hasher & Zacks, 1988) and Prefrontal Cortex Function (West, 1996) theories. There was little support for the processing speed theory (Salthouse, 1996). / Ph. D.
197

Two Essays on Asset Pricing

Hur, Jungshik 01 May 2007 (has links)
This dissertation consists of two chapters. The first chapter shows that the measurement errors in betas for stocks induce corresponding measurement errors in alphas and a spurious negative covariance between the estimated betas and alphas across stocks. This negative covariance between the estimated betas and alphas results in a violation of the independence assumption between the independent variable (betas) and error terms in the Fama-MacBeth regressions of tests of the CAPM, thereby creating a downward bias in the estimated market risk premiums. The procedure of using portfolio returns and betas does not necessarily eliminate this bias. Depending upon the grouping variable used to form portfolios, the negative covariance between estimated betas and alphas can be increased, decreased, and can even be made positive. This paper proposes two methods for correcting the downward bias in the estimated market risk premium. The estimated market risk premiums are consistent with the CAPM after the proposed corrections. The second chapter provides evidence that when the ex-post market risk premium is positive (up markets), the relation between returns and betas is positive, significant, and consistent with the CAPM. However, when the ex-post market risk premium is negative (down markets), the negative relation between betas and returns is significant, but stronger than what is implied by the CAPM. This strong negative relation offsets the positive relation, resulting in an insignificant relation between returns and betas for the overall period. The negative relation between size and returns, after controlling for beta differences, is present only when the ex-post market risk premium is negative, and is responsible for the negative relation for the overall period. This paper decomposes the negative relation between size and returns after controlling for beta differences into the intercept size effect (relation between alphas of stocks and their size) and the residual size effect (relation between residuals of stocks and their size). The asymmetrical size effect between up and down market is being driven by the residual size effect. Long term mean reversion in returns explains, in part, the negative relation between size and returns during down markets. / Ph. D.
198

Cross-Sectional Stiffness Properties of Complex Drone Wings

Muthirevula, Neeharika 05 January 2017 (has links)
The main purpose of this thesis is to develop a beam element in order to model the wing of a drone, made of composite materials. The proposed model consists of the framework for the structural design and analysis of long slender beam like structures, e.g., wings, wind turbine blades, and helicopter rotor blades, etc. The main feature consists of the addition of the coupling between axial and bending with torsional effects that may arise when using composite materials and the coupling stemming from the inhomogeneity in cross-sections of any arbitrary geometry. This type of modeling approach allows for an accurate yet computationally inexpensive representation of a general class of beam-like structures. The framework for beam analysis consists of main two parts, cross-sectional analysis of the beam sections and then using this section analysis to build up the finite element model. The cross-sectional analysis is performed in order to predict the structural properties for composite sections, which are used for the beam model. The thesis consists of the model to validate the convergence of the element size required for the cross-sectional analysis. This follows by the validation of the shell models of constant cross-section to assess the performance of the beam elements, including coupling terms. This framework also has the capability of calculating the strains and displacements at various points of the cross-section. Natural frequencies and mode shapes are compared for different cases of increasing complexity with those available in the papers. Then, the framework is used to analyze the wing of a drone and compare the results to a model developed in NASTRAN. / Master of Science
199

Tangled Up in Metrics : A Study on Equity Premiums in Europe

Persson, Oskar, Lindblom, Simon January 2024 (has links)
Investing has become increasingly popular among individuals in recent years,this has led to multiple investing strategies formalizing. One of them being factorinvesting, a strategy where investors search for companies with certain strongfirm specific financial metrics through screening. Many researchers try to findwhich these metrics are, and which of them has an effect on the cross-sections ofstock returns. This study examines the relationship between the three metrics,earnings-to-price, dividend yield, debt over equity and the European stock marketbetween January 2010 to December 2022. This is done by using the two-stageregression model suggested by Fama and Macbeth (1973). Our results show thatthere is an anomaly in the European stock market and that there is a firmcharacteristic risk associated with these metrics. This suggests that when lookingat individual firms, investors are willing to pay a premium for the metrics studiedin this paper and it is therefore important to take them into account whenscreening for individual companies. As the previous research is mainly focusedon the American stock market and emerging markets in Europe, our thesis fills agap by providing a view on factor premiums in the European market as a whole.
200

Prescribed opioids in primary care: cross-sectional and longitudinal analyses of influence of patient and practice characteristics

12 November 2019 (has links)
Yes / Objectives: To examine trends in opioid prescribing in primary care, identify patient and general practice characteristics associated with long-term and stronger opioid prescribing, and identify associations with changes in opioid prescribing. Design: Trend, cross-sectional and longitudinal analyses of routinely recorded patient data. Setting: 111 primary care practices in Leeds and Bradford, UK. Participants: We observed 471 828 patient-years in which all patients represented had at least 1 opioid prescription between April 2005 and March 2012. A cross-sectional analysis included 99 847 patients prescribed opioids between April 2011 and March 2012. A longitudinal analysis included 49 065 patient-years between April 2008 and March 2012. We excluded patients with cancer or treated for substance misuse. Main outcome measures: Long-term opioid prescribing (4 or more prescriptions within 12 months), stronger opioid prescribing and stepping up to or down from stronger opioids. Results: Opioid prescribing in the adult population almost doubled for weaker opioids over 2005–2012 and rose over sixfold for stronger opioids. There was marked variation among general practices in the odds of patients stepping up to stronger opioids compared with those not stepping up (range 0.31–3.36), unexplained by practice-level variables. Stepping up to stronger opioids was most strongly associated with being underweight (adjusted OR 3.26, 1.49 to 7.17), increasing polypharmacy (4.15, 3.26 to 5.29 for 10 or more repeat prescriptions), increasing numbers of primary care appointments (3.04, 2.48 to 3.73 for over 12 appointments in the year) and referrals to specialist pain services (5.17, 4.37 to 6.12). Compared with women under 50 years, men under 50 were less likely to step down once prescribed stronger opioids (0.53, 0.37 to 0.75). Conclusions: While clinicians should be alert to patients at risk of escalated opioid prescribing, much prescribing variation may be attributable to clinical behaviour. Effective strategies targeting clinicians and patients are needed to curb rising prescribing, especially of stronger opioids. / e National Institute for Health Research (NIHR) under its Research for Patient Benefit Programme (Grant Reference Number PB-PG- 1010-23041).

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