156 research outputs found
Blending Two Automatic Playlist Generation Algorithms
We blend two existing automatic playlist generation algorithms. One algorithm is built to smoothly transition between a start song and an end song (Start-End). The other infers song similarity based on adjacent occurrences in expertly authored streams (EAS). First, we seek to establish the effectiveness of the Start-End algorithm using the EAS algorithm to determine song similarity, then we propose two playlist generation algorithms of our own: the Unbiased Random Walk (URW) and the Biased Random Walk (BRW). Like the Start-End algorithm, both the URW algorithm and BRW algorithm transition between a start song and an end song; however, issues inherent to the Start-End algorithm lead us to believe that our algorithms may create playlists with smoother transitions between songs
Model Development and Assessment of the Gate Network in a High-Performance SiC Power Module
The main objective of this effort is to determine points of weakness in the gate network of a high-performance SiC power module and to offer remedies to these issues to increase the overall performance, robustness, and reliability of the technology. In order to accomplish this goal, a highly accurate model of the gate network is developed through three methods of parameter extraction: calculation, simulation, and measurement. A SPICE model of the gate network is developed to analyze four electrical issues in a high-speed, SiC-based power module including the necessary internal gate resistance for damping under-voltage and over-voltage transients, the disparity in switching loss between paralleled devices due to propagation delay, a high-frequency oscillatory behavior on gate voltage due to die-to-die interactions, and current equalization in the kelvin-source signal path. In addition, the analysis of parameter variance between paralleled MOSFETs and the effects of mismatched threshold voltage and on-state resistance on switching loss and junction temperature are investigated. Finally, three Miller Clamp topologies are simulated and assessed for effectiveness culminating in a solution for parasitic turn-on in high dv/dt systems such as those utilizing high-performance SiC power modules
Transmission of Stereo Audio Signals with Lasers
An alternative method for transmitting audio signals via the use of laser technology was presented here. The primary focus of this document is on the audio amplifier subsystem including the design, simulation, and performance results. Simulations using the PSPICE computer simulation software were utilized to investigate the theoretical designs of the audio amplifier subsystem. The audio amplifier was examined in three junctures including the noise-canceling input stage, the high voltage gain cell, and the low impedance driver. Through the design procedure using theoretical calculations, simulations using PSPICE computer software, and examination of the finished product with an oscilloscope, the audio amplifier was greatly investigated and verified for desired functionality. In addition, the pulse-width modulation technique was examined and implemented with precision 555 timers in order to transmit audio signals via laser
Neighborhood Factors that Contribute to Alcohol Use and Loneliness in HIV Positive Patients
Background: Neighborhood factors contribute to substance abuse and increased health risk behavior. Alcohol use has adverse consequences as it may interfere with antiretroviral medication adherence. In addition, studies have shown that those who are HIV positive have decreased social network size, limited social support, and social isolation as well as decreased treatment adherence. It is hypothesized that participants with high neighborhood density of alcohol outlets combined with increased feelings of loneliness will be more likely to drink.
Methods: Participants included 85 patients from an HIV treatment clinic in Jacksonville. Interviewer-administered measures included the Alcohol Use Disorders Identification Test (AUDIT) and UCLA Loneliness Scale. Geographical Information Systems was used to map participant residential area and surrounding neighborhood factors. This study collected cross-sectional, retrospective data. Multi-linear regression using UCLA scores and geographic alcohol outlets availability were used as predictors of drinking behavior.
Results: UCLA scores (β = 0.088, p = .012) and number of alcohol outlets (β = 0.040, p = .028) were significant predictors of AUDIT scores. UCLA scores and number of alcohol outlets accounted for 10.4% (R2 = .104) of variance of AUDIT scores.
Conclusion: There was co-occurrence of alcohol use and self-reported loneliness among patients currently in treatment for HIV. There also appears to be a relationship with neighborhood factors, alcohol use, and loneliness but further research is needed
Social vs. practical problems in attaining a colonoscopy: Different patient profiles?
Background: Colonoscopy is an effective procedure for identifying precancerous polyps and cancerous lesions, but it is unlike other cancer screening tools in that it requires sedation and thus assistance from at least one other individual. The intent of this paper was to identify logistical problems in completing the colonoscopy and to examine their relationships with sociodemographic characteristics.
Methods: All eligible patients (n = 2500) from two academic-affiliated colonoscopy centers (one free standing, one hospital-based) were invited to participate in an onsite, pre-colonoscopy survey; patients agreeing to participate (n = 1841, RR = 73.6%) received a $5.00 gift card. Multiple correspondence analysis (MCA) was used to identify the underlying dimensional structure of the problems. Bivariate statistics were performed to compare demographic variables and health literacy levels among patients reporting problems. Multivariate logistic regression with a backwards conditional solution was used to determine the demographic variables independently associated with problems.
Results: Multiple correspondence analyses indicated two dimensions of problems (social and practical). Using logistic regression, social problems (e.g., finding someone to accompany the patient) were associated with not living in the same home as the driver, not working due to disability, and younger age. Practical problems (e.g., making an appointment) were associated with “other” minority race, poorer health, lower health literacy, and younger age.
Conclusion: Patients experience different problems completing the colonoscopy based on socio-demographics. Particularly at risk are patients who find it difficult to navigate the system, are of younger age, or who may have smaller social networks
Un análisis cuantitativo del uso de Plaguicidas en los campesinos colombianos: percepción del control y la confianza en este uso
ABSTRACT: This study aims to explore how campesino non
pesticide users differ in their knowledge, attitudes and beliefs,
and perceptions of control and confidence surrounding
pesticide use compared to pesticide users. Methodology:
we collected 79 questionnaires with adult (male and female)
rural agricultural campesinos in San Cristobal, Antioquia,
Colombia. We examined the campesinos’ perceptions on
pesticides’ harm for human health and the environment, as
well as their beliefs, attitudes, perceived control, and perceived
confidence related to pesticide use. Results: The findings
differed between two campesino groups sampled: pesticide
users and agroecological adherents. Pesticide users showed
lower perceptions of pesticide harm for human health and the
environment, lower perceived control about stopping pesticide
use (an increase of one unit in control decreases the logit of
using pesticides by 74%), and lower confidence about stopping
pesticide use than agroecological adherents (an increase of
one unit in confidence decreases the logit of using pesticides
by 64%). Discussion: Several individual factors influence
the occupational safety and health of campesinos, including
perceived control and confidence. We recommend that future
public health and educational interventions should improve
safety training and confidence so campesinos can gain control
of the process for implementing behavioral change related to
pesticide use reduction.RESUMEN: Este estudio pretende explorar como los campesinos no usuarios de plaguicidas difieren en su conocimiento, actitudes y creencias y percepciones de control y confianza en torno al uso de plaguicidas comparado con usuarios de plaguicidas. MetodologĂa: Colectamos 79 cuestionarios con hombres y mujeres adultas que son campesinos agricultores en San CristĂłbal, Antioquia, Colombia. Examinamos las percepciones de estos campesinos sobre el daño de los plaguicidas sobre la salud humana y el medio ambiente. TambiĂ©n se exploraron sus creencias, actitudes, percepciones de control y confianza relacionadas con el uso de los plaguicidas. Resultados: Los hallazgos difieren entre los dos grupos de campesinos muestreados: usuarios y no usuarios de plaguicidas. Los usuarios de pesticidas experimentaron menores percepciones del daño de los plaguicidas sobre la salud humana y el medio ambiente, menor percepciĂłn del control acerca de parar el uso de plaguicidas (el incremento de una unidad en control disminuyĂł el logit de usar pesticidas en un 74%), y menor confianza acerca de parar el uso de pesticidas comparado
con los no usuarios de plaguicidas (el aumento de una unidad
en la confianza, disminuyĂł el logit de usar pesticidas en un
64%). DiscusiĂłn: Varios factores individuales influencian la
salud ocupacional y la salud de los campesinos incluyendo
la percepciĂłn del control y la confianza. Recomendamos que
futuras intervenciones educativas en salud pĂşblica aumenten el
entrenamiento sobre prácticas seguras y la confianza. Asà los
campesinos pueden ganar control en el proceso de implementar
cambios en su comportamiento relacionado con la reducciĂłn
del uso de pesticidas
Lightweight Formal Methods for Improving Software Security
This research examines how software specifications could be used to build more-secure software. For this project, we analyzed known vulnerabilities for open source projects to identify the corrective actions required to patch the vulnerability. For each vulnerability, we then augmented the program with formal assertions in an attempt to allow a static analysis tool to find the vulnerability. Using the information gathered from these assertions, we hope to determine which assertions are most effective at finding vulnerabilities with today\u27s tools and evaluate new assertions that could be added to the static analysis tool to help uncover more vulnerabilities. My work focuses on a common vulnerability type across multiple projects. In particular, I am examining if vulnerabilities caused by missing authentication could be prevented with proper tool usage
Evaluating preferences for colorectal cancer screening in individuals under age 50 using the Analytic Hierarchy Process
In 2021, the United States Preventive Services Task Force updated their recommendation, stating that individuals ages 45-49 should initiate screening for colorectal cancer. Since several screening strategies are recommended, making a shared decision involves including an individual’s preferences. Few studies have included individuals under age 50. In this study, we use a multicriteria decision analysis technique called the Analytic Hierarchy Process to explore preferences for screening strategies and evaluate whether preferences vary by age. Participants evaluated a hierarchy with 3 decision alternatives (colonoscopy, fecal immunochemical test, and computed tomography colonography), 3 criteria (test effectiveness, the screening plan, and features of the test) and 7 sub-criteria. We used the linear fit method to calculate consistency ratios and the eigenvector method for group preferences. We conducted sensitivity analysis to assess whether results are robust to change and tested differences in preferences by participant variables using chi-square and analysis of variance. Of the 579 individuals surveyed, 556 (96%) provided complete responses to the AHP portion of the survey. Of these, 247 participants gave responses consistent enough (CR < 0.18) to be included in the final analysis. Participants that were either white or have lower health literacy were more likely to be excluded due to inconsistency. Colonoscopy was the preferred strategy in those < 50 and fecal immunochemical test was preferred by those over age 50 (p = 0.002). These results were consistent when we restricted analysis to individuals ages 45-55 (p = 0.011). Participants rated test effectiveness as the most important criteria for making their decision (weight = 0.555). Sensitivity analysis showed our results were robust to shifts in criteria and sub-criteria weights. We reveal potential differences in preferences for screening strategies by age that could influence the adoption of screening programs to include individuals under age 50. Researchers and practitioners should consider at-home interventions using the Analytic Hierarchy Process to assist with the formulation of preferences that are key to shared decision-making. The costs associated with different preferences for screening strategies should be explored further if limited resources must be allocated to screen individuals ages 45-49.https://doi.org/10.1186/s12913-021-06705-
Evidence of emerging hookah use among university students: a cross-sectional comparison between hookah and cigarette use
Measuring changes in self-concept: a qualitative evaluation of outcome questionnaires in people having acupuncture for their chronic health problems
BACKGROUND: Changes in self-concept are an important potential outcome for many interventions for people with long-term conditions. This study sought to identify and evaluate outcome questionnaires suitable for quantifying changes in self-concept in people with long-term conditions, in the context of treatment with acupuncture and Chinese medicine. METHODS: A literature search was followed by an evaluation of three questionnaires: The Wellbeing Questionnaire W-BQ12, the Patient Enablement Instrument (PEI), and the Arizona Integrative Outcome Scale (AIOS). A convenience sample of 23 people completed the questionnaires on two occasions and were interviewed about their experience and their questionnaire responses. All acupuncturists were interviewed. RESULTS: Changes in self-concept were common and emerged over time. The three questionnaires had different strengths and weaknesses in relation to measuring changes in self-concept. The generic AIOS had face validity and was sensitive to changes in self-concept over time, but it lacked specificity. The PEI was sensitive and specific in measuring these changes but had lower acceptability. The sensitivity of the W-BQ12 was affected by initial high scores (ceiling effect) and a shorter timescale but was acceptable and is suitable for repeated administration. The PEI and W-BQ12 questionnaires worked well in combination. CONCLUSION: Changes in self-concept are important outcomes of complex interventions for people with long-term illness and their measurement requires carefully evaluated tools and long-term follow-up. The literature review and the analysis of the strengths and weaknesses of the questionnaires is a resource for other researchers. The W-BQ12 and the PEI both proved useful for this population and a larger quantitative study is planned
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