Phd Dissertation

Time, Work and Organizational Commitment.

Publication Date

January 1, 1980

Author(s)

Abstract

Organizational scholars usually treat commitment either as a calculative or a moral form of organizational involvement. There has been a parallel schism with respect to etiology, with commitment being seen either as the result of investments in the organizational role or as reciprocation with the organization for the fulfillment of important needs. The latter view implies that individual differences in need structure will act as a moderator. The research is based, in part, on a theory which holds that the saliency of different needs varies with job tenure. Questionnaire data were collected from 881 employees in two hospitals and 28 bank branches to determine whether job tenure moderates the relative impacts of existence, relatedness and growth need fulfillment on organizational commitment. The study also compared the relative utility of the investments and reciprocation models of etiology, vis-a-vis both calculative and moral commitment. Both etiological models accounted for non-redundant variance in organizational commitment. While support was stronger for the reciprocation model, there was a relative gain in support for the investments model when calculative commitment was the dependent variable. No support was found for the hypothesized job-tenure phased differences in the impacts of needs on commitment. Subsidiary analyses of job satisfaction, role stress and manifest need strengths indicated basic patterns in the participant sample at variance with the underlying model of time and work. Non-supportive results were discussed in this context.

Suggested Citation
Harold Leroy Angle (1980) Time, Work and Organizational Commitment.. PhD Dissertation. University of California, Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/1go3t9q/alma991035092847104701.

research report

The Impact of Labor-Management Relations on Productivity and Efficiency in Urban Mass Transit

Abstract

The study investigates associations between the labor-management relationship and selected indicators of urban mass transit performance. Four components of performance are analyzed: service efficiency; service effectiveness; employee withdrawal (i.e. turnover, absenteeism and tardiness); and adaptability. Measures of these four dependent variables are related to several controllable aspects of the labor-management relationships: the legal framework that constrains labor-management interaction; labor and management organization; the relationship climate between labor and management (i.e. containment-aggression, accommodation, or cooperation); and the makeup of the collective agreement. The focus of the empirical research is on fixed-route bus systems, and on the bargaining unit that represents the transit operators in those systems. Data was collected from organizational archives, personal interviews, questionnaires, and on-site observations at 28 transit properties.

Suggested Citation
James L. Perry, Harold A. Angle and Mark Pittel (1979) The Impact of Labor-Management Relations on Productivity and Efficiency in Urban Mass Transit. Final Report DOT/RSPA/DPB-50-79-7. ITS-Irvine. Available at: https://hdl.handle.net/2027/mdp.39015041110290.

presentation

Calibration and Validation of Generalized Bathtub Model with Boston's Blue Bike Data

Suggested Citation
Jingnan Liu (2022) “Calibration and Validation of Generalized Bathtub Model with Boston's Blue Bike Data”. 2022 ITS-Irvine Emerging Scholars Transportation Research Showcase, ITS-Irvine, 28 October. Available at: https://youtu.be/Rpdf6-T_fCk?t=3742.

presentation

Exploring how infrastructure access and the built environment affect bicycling safety in OC & Housing affordability in Los Angeles County

Suggested Citation
Casey Chung (2023) “Exploring how infrastructure access and the built environment affect bicycling safety in OC & Housing affordability in Los Angeles County”. 2023 ITS-Irvine Emerging Scholars Transportation Research Showcase, ITS-Irvine, 7 March. Available at: https://youtu.be/OCt7zCBv5nk?t=1252.

presentation

Equity in Transit Agencies and TNC Partnerships: Exploring the Benefits from Service Zone Placement

Suggested Citation
Dylan Ando (2023) “Equity in Transit Agencies and TNC Partnerships: Exploring the Benefits from Service Zone Placement”. 2023 ITS-Irvine Emerging Scholars Transportation Research Showcase, ITS-Irvine, 7 March. Available at: https://youtu.be/OCt7zCBv5nk?t=3182.

presentation

Accessibility of Mental Health Facilities in Disaster-Prone Areas

Suggested Citation
Carissa Ann Kelly (2025) “Accessibility of Mental Health Facilities in Disaster-Prone Areas”. 2025 ITS-Irvine Emerging Scholars Transportation Research Showcase I, ITS-Irvine, 10 October. Available at: https://youtu.be/tizg3bjVN50?t=4337.

presentation

Optimal Fare Policy and Fleet-sizing for Integrated Fixed and Microtransit Systems

Abstract

Integrating microtransit with fixed-route transit (FRT) can improve travelers’ mobility by leveraging microtransit’s flexibility and FRT’s capacity. However, the high operating costs of microtransit pose a challenge, calling for careful evaluation of the trade-offs between mobility gains and operational costs. This presentation introduces a modeling approach and solution procedure to identify Pareto-optimal designs. The focus is on design parameters of practical interest, namely, fare policies and microtransit fleet size. To explore these trade-offs, a bi-level and bi-objective (i.e., minimize taxpayer subsidy and maximize mobility-based consumer welfare) modeling framework is developed, featuring an agent-based transportation system simulation model at the lower level and a multi-objective Bayesian Optimization (BO) model at the upper level. The modeling and solution approach is applied to Lemon Grove, California (a suburban area in San Diego County). Results reveal a diverse set of solutions along the Pareto frontier, indicating that naive microtransit fare strategies are suboptimal. Notably, Pareto-optimal designs feature a 50–100% discount for microtransit-to-FRT transfers, as well as peak-period fare multipliers between 1.8x and 3.5x to manage time-varying demand effectively.

Suggested Citation
Ritun Saha (2025) “Optimal Fare Policy and Fleet-sizing for Integrated Fixed and Microtransit Systems”. 2025 Emerging Scholars Research Showcase I, ITS-Irvine, 10 October. Available at: https://youtu.be/tizg3bjVN50?t=5267.

published journal article

Fuse It or Lose It? Analyzing the Effects of Sensor Diversity on Multimodal Ensembles for Autonomous Vehicle Perception

IEEE Transactions on Intelligent Transportation Systems

Publication Date

January 1, 2025

Author(s)

Trier Mortlock, Luke Chen, Jonathon M. Smereka, Pramod Khargonekar, Mohammad Al Faruque
Suggested Citation
Trier Mortlock, Luke Chen, Jonathon M. Smereka, Pramod Khargonekar and Mohammad Abdullah Al Faruque (2025) “Fuse It or Lose It? Analyzing the Effects of Sensor Diversity on Multimodal Ensembles for Autonomous Vehicle Perception”, IEEE Transactions on Intelligent Transportation Systems, pp. 1–12. Available at: 10.1109/TITS.2025.3612873.

published journal article

Climate anxiety among adolescents in a pediatric emergency department

Environmental Research: Health

Publication Date

December 1, 2025

Author(s)

Raymen Rammy Assaf, Shelby K Shelton, Tricia Morphew, Susan Clayton, Jun Wu

Abstract

Abstract A changing climate indirectly threatens health by acting as a stressor from perceived threats to well-being. Few studies assess youth-centered climate anxiety in clinical settings. The emergency department (ED) is a prominent source of adolescent mental health triage. The primary objective was to understand demographic and clinical predictors of climate anxiety among ED pediatric patients. Secondarily, to externally validate an abbreviated version of the climate change anxiety scale (CCAS). In this cross-sectional study, data was collected from 2023 to 2024 in a single-center pediatric ED, with 860 patients ages 12–17 years approached via convenience sampling; 116 did not complete study surveys. Exposures included demographic factors (age, gender, race, ethnicity, insurance payor), chief complaint type (mental health or medical), temporal season, and General Anxiety Disorder–7 (GAD-7) score. The main outcome was climate anxiety, measured on the CCAS. 744 participants, with 79.8% presenting with medical complaints and 28.1% reporting climate anxiety. Females had 1.49 times higher odds of experiencing greater climate anxiety compared to males (95% CI 1.05, 2.12), p =.027. Having public health insurance increased the odds of experiencing climate anxiety (OR = 1.82, 95% CI 1.21, 2.73), p =.004, as well as warm seasonality (OR = 1.51, 95% CI (1.07, 2.13), p =.018. Participants with moderate or severe GAD-7 had five times higher odds of elevated climate anxiety than those with minimal generalized anxiety ( p <.001). The CCAS-short form (CCAS-S) demonstrated high sensitivity (91.4%–96.8%) and specificity (85%–95.5%) in detecting mild to severe levels of distress compared to the full CCAS. A four-tiered threshold of CCAS-S severity showed excellent reliability (quadratic weighted kappa = 0.838). We identified clinical predictors of climate anxiety and externally validated the CCAS-S in a large pediatric cohort. Given the increasing impact of the changing climate on human health, we advocate utilizing the tool alongside routine pediatric mental health assessments.

Suggested Citation
Raymen Rammy Assaf, Shelby K Shelton, Tricia Morphew, Susan Clayton and Jun Wu (2025) “Climate anxiety among adolescents in a pediatric emergency department”, Environmental Research: Health, 3(4), p. 045001. Available at: 10.1088/2752-5309/ae09d2.