Welfare Participation and Depression Among Youth and Young Adults in the United States and China

Globally, depression is one of the most common mental disorders among youth and young adults, occurring at similar rates in countries with dissimilar cultures, such as the United States and China. Despite cultural differences, both the United States and China have systems of public welfare that create a social safety net and provide at least a minimal standard of living. Although many studies have documented the prevalence of mental health issues among adult welfare recipients, little empirical research has examined the prevalence of depression among youth and young adults who were raised in welfare recipient families. To address this gap in the knowledge, this dissertation uses welfare participation as a marker of low socioeconomic status with the aim of creating a nuanced understanding of the relationship between welfare participation and youth depression in the United States and China. The first paper presents a systematic review of 15 reports that evaluated the relationship of welfare participation with the prevalence of youth depression in the United States. Results from four descriptive studies had mixed findings, whereas the remaining comparison studies consistently showed an association between welfare participation and elevated risk of depression. The second paper used the U.S. Add Health data to investigate the relationship between childhood welfare participation and depression during young adulthood. Results showed childhood welfare participation to be positively related to self-reported depression score in young adulthood. However, no significant relationship between childhood welfare participation and clinical diagnoses of depression was observed. Additionally, subgroup analyses (i.e., by poor, near-poor, and non-poor groups and by gender) indicated that the higher depression scores were significant only for the poor group, whereas only the near-poor group had a significantly higher probability of being diagnosed with depression. Moreover, female young adults raised in families that received welfare had significantly higher depression scores. The third paper used data from a national survey conducted in China to examine the relationship between participating the Dibao welfare program and depression among Chinese youth. Results showed that Dibao-recipient youth had significantly higher depression scores compared to non-recipient youth. Moreover, subgroup analyses showed significantly higher depression scores among 4 groups of Dibao-recipient youth: those living in rural areas, those with a child, females with a child, and rural female with a child. Overall, the findings presented across these 3 papers are consistent and suggest youth from welfare recipient families have a higher vulnerability to depression. Each of the papers includes a discussion of the implications for social work practice and future research.Doctor of Philosoph

An Auto-Parallelizer for Distributed Computing in Haskell

One of the main challenges in distributed computing is building interfaces and APIs that allow programmers with limited background in distributed systems to write scalable, performant, and fault-tolerant applications on large clusters. In this demonstration, we designed and implemented a Haskell auto-parallelizer with a simple yet powerful interface by taking advantage of the default purity of Haskell functions. Finally, we benchmarked our implementation on a set of examples to illustrate the potential for future work in this direction.Comment: 2 pages excluding title page and reference page. 2 figures. This work was submitted to the 28th ACM SIGPLAN International Conference on Functional Programming, Haskell Symposium. This work was accepted for oral presentation and was presented on Sep 8, 202

The influence of childhood welfare participation on adulthood substance use: evidence from the National Longitudinal Study of Adolescent to Adult Health

The associations between early life-socioeconomic status and health, specifically substance use, is well substantiated. The vulnerabilities associated with adversity in childhood, particularly poverty, can have a cumulative effect on an individual’s risk and resilience throughout the life course. While several studies substantiate the relationship between substance use and welfare participation, less known is the impact of and prevalence of behavioral health problems later in life among young adults who were welfare recipients before age 18

Household Financial Assets Inequity and Health Disparities Among Young Adults: Evidence from the National Longitudinal Study of Adolescent to Adult Health

Introduction: Research has established a strong relationship between financial resources and health outcomes. Yet, little is known about the effects of assets disparities on health outcomes, especially during the critical period when adolescents transition to adults. Methods: Using data from the National Longitudinal Study of Adolescent to Adult Health (n = 10,861), this study investigated the relationships between three household total assets value groups (low, moderate, and high assets) and three net worth groups (negative, neutral, and positive) on young adults’ general health, obese, and depression. Results: Both assets and debts were related to young adults’ health status, young adults with more assets and positive net worth have higher probability to report a better level of both general health and depression. Young adult’s obesity was found to be associated with net worth but not with assets. Conclusions and Implications: Our work connects health promotion with poverty alleviation to address the challenge of health disparity. A better understanding of different forms of financial resources (e.g., income, assets, and debts) and their dynamic relationships with health outcomes will contribute to developing effective asset-based interventions for promoting health status. Particularly, current policy and practice should consider the importance of resolving and clearing debt

School Lunch Participation and Youth School Failure: A Multi-Racial Perspective

In the United States, students from low-socioeconomic status and minority ethnic groups graduate from high school at lower rates than their peers. Limited studies exist about the risk and protective factors that affect the disproportionate graduation rates by income and ethnicity. Using the 2016 Arizona Youth Survey data (N = 32,178), this study aims to explore the relationship between the National School Lunch Program (NSLP) participation and school failure, and other risk and protective factors from a multi-racial perspective. Logistic regressions were conducted on the total sample and the six ethnic subsamples (i.e., White, Latino, Black, American Indian, Asian/Pacific Islander, and Mixed). Results showed a significant difference in school failure between free lunch participants and nonparticipants for the total youth sample and for the White, Latino, Black and Mixed subsamples. However, a significant difference in school failure between free lunch participants and reduced price lunch participants was only found for the total sample but not for any of the six ethnic subsamples. Significant risk factors across most ethnic groups include the participant being suspended from school and peer suspension/dropout. Protective factors across most ethnic groups were family management and school commitment. Findings highlight the need for more culturally responsive interventions to target school failure for low-income students across ethnic groups

Wavelet packet decomposition-based fault diagnosis scheme for SRM drives with a single current sensor

Power converters are a key, but vulnerable component in switched reluctance motor (SRM) drives. In this paper, a new fault diagnosis scheme for SRM converters is proposed based on the wavelet packet decomposition (WPD) with a dc-link current sensor. Open- and short-circuit faults of the power switches in an asymmetrical half-bridge converter are analyzed in details. In order to obtain the fault signature from the phase currents, two pulse-width modulation signals with phase shift are injected into the lower-switches of the converter to extract the excitation current, and the WPD algorithm is then applied to the detected currents for fault diagnosis. Moreover, a discrete degree of the wavelet packet node energy is chosen as the fault coefficient. The converter faults can be diagnosed and located directly by determining the changes in the discrete degree from the detected currents. The proposed scheme requires only one current sensor in the dc link, while conventional methods need one sensor for each phase or additional detection circuits. The experimental results on a 750-W three-phase SRM are presented to confirm the effectiveness of the proposed fault diagnosis scheme

Independent current control of dual parallel SRM drive using a public current sensor

Switched reluctance motors (SRMs) have been considered a potential candidate for automotive applications due to its rare-earth-free feature and wide speed range. Conventionally, a current sensor is installed in each phase for the current regulation control, which will considerably add the cost and volume to multimotor drives. This paper proposes an independent current control technique for dual parallel SRM drives using only one current sensor. In order to identify the individual motor currents from the public current, a pulse injection scheme is developed accordingly. Two pulses are individually injected into the lower transistors of the dual converter in the excitation regions and the fixed current sampling points triggered by the injected pulse are presented for motor current identification. The independent current control for the dual SRM can be directly implemented by the public current sensing, although the motor parameters are different. The developed system requires only one current sensor without additional hardware or reduced system performance. The simulation and experimental results on parallel 750 W and 150 W three-phase 12/8 SRM drives are presented to confirm the effectiveness of the proposed method. With this scheme, the dual-motor drive can be more compact and cost effective for traction drive applications

Investigation of skewing effects on the vibration reduction of three-phase switched reluctance motors

Switched reluctance motors (SRMs) are gaining in popularity because of their robustness, low cost, and excellent high-speed characteristics. However, they are known to cause vibration and noise primarily due to the radial pulsating force resulting from their double-saliency structure. This paper investigates the effect of skewing the stator and/or rotor on the vibration reduction of the three-phase SRMs by developing four 12/8-pole SRMs, including a conventional SRM, a skewed rotor-SRM (SR-SRM), a skewed stator-SRM (SS-SRM), and a skewed stator and rotor-SRM (SSR-SRM). The radial force distributed on the stator yoke under different skewing angles is extensively studied by the finite-element method and experimental tests on the four prototypes. The inductance and torque characteristics of the four motors are also compared, and a control strategy by modulating the turn-ON and turn-OFF angles for the SR-SRM and the SS-SRM are also presented. Furthermore, experimental results validate the numerical models and the effectiveness of the skewing in reducing the motor vibration. Test results also suggest that skewing the stator is more effective than skewing the rotor in the SRMs

Online sensorless position estimation for switched reluctance motors using one current sensor

This paper proposes an online sensorless rotor position estimation technique for switched reluctance motors (SRMs) using just one current sensor. It is achieved by first decoupling the excitation current from the bus current. Two phase-shifted pulse width modulation signals are injected into the relevant lower transistors in the asymmetrical half-bridge converter for short intervals during each current fundamental cycle. Analog-to-digital converters are triggered in the pause middles of the dual pulse to separate the bus current for excitation current recognition. Next, the rotor position is estimated from the excitation current, by a current-rise-time method in the current-chopping-control mode in a low-speed operation and a current-gradient method in the voltage-pulse-control mode in a high-speed operation. The proposed scheme requires only a bus current sensor and a minor change to the converter circuit, without a need for individual phase current sensors or additional detection devices, achieving a more compact and cost-effective drive. The performance of the sensorless SRM drive is fully investigated. The simulation and experiments on a 750-W three-phase 12/8-pole SRM are carried out to verify the effectiveness of the proposed scheme

Online sensorless position estimation for switched reluctance motors using one current sensor

This paper proposes an online sensorless rotor position estimation technique for switched reluctance motors (SRMs) using just one current sensor. It is achieved by first decoupling the excitation current from the bus current. Two phase-shifted pulse width modulation signals are injected into the relevant lower transistors in the asymmetrical half-bridge converter for short intervals during each current fundamental cycle. Analog-to-digital converters are triggered in the pause middles of the dual pulse to separate the bus current for excitation current recognition. Next, the rotor position is estimated from the excitation current, by a current-rise-time method in the current-chopping-control mode in a low-speed operation and a current-gradient method in the voltage-pulse-control mode in a high-speed operation. The proposed scheme requires only a bus current sensor and a minor change to the converter circuit, without a need for individual phase current sensors or additional detection devices, achieving a more compact and cost-effective drive. The performance of the sensorless SRM drive is fully investigated. The simulation and experiments on a 750-W three-phase 12/8-pole SRM are carried out to verify the effectiveness of the proposed scheme