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- Genre: Case studies
- Genre: Diaries
- Creators: Arizona State University
- Resource Type: Text
Description
Daily dairies and other intensive measurement methods are increasingly used to study the relationships between two time varying variables X and Y. These data are commonly analyzed using longitudinal multilevel or bivariate growth curve models that allow for random effects of intercept (and sometimes also slope) but which do not address the effects of weekly cycles in the data. Three Monte Carlo studies investigated the impact of omitting the weekly cycles in daily dairy data under the multilevel model framework. In cases where cycles existed in both the time-varying predictor series (X) and the time-varying outcome series (Y) but were ignored, the effects of the within- and between-person components of X on Y tended to be biased, as were their corresponding standard errors. The direction and magnitude of the bias depended on the phase difference between the cycles in the two series. In cases where cycles existed in only one series but were ignored, the standard errors of the regression coefficients for the within- and between-person components of X tended to be biased, and the direction and magnitude of bias depended on which series contained cyclical components.
ContributorsLiu, Yu (Author) / West, Stephen G. (Thesis advisor) / Enders, Craig K. (Committee member) / Reiser, Mark R. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Informal public transport is commonplace in the developing world, but the service exists in the United States as well, and is understudied. Often called "dollar vans", New York's commuter vans serve approximately 120,000 people every day (King and Goldwyn, 2014). While this is a tiny fraction of the New York transit rider population, it is comparable to the total number of commuters who ride transit in smaller cities such as Minneapolis/St Paul and Phoenix. The first part of this study reports on the use of commuter vans in Eastern Queens based on a combination of surveys and a ridership tally, all conducted in summer 2016. It answers four research questions: How many people ride the vans? Who rides the commuter vans? Why do they ride commuter vans? Do commuter vans complement or compete against formal transit? Commuter van ridership in Eastern Queens was approximately 55,000 with a high percentage of female ridership. Time and cost savings were the main factors influencing commuter van ridership. Possession of a MetroCard was shown to negatively affect the frequency of commuter van ridership. The results show evidence of commuter vans playing both a competing and complementary role to MTA bus and subway transit. The second part of this study presents a SWOT analysis results of commuter vans, and the policy implications. It answers 2 research questions: What are the main strengths, weaknesses, opportunities and threats of commuter vans in Eastern Queens? and How do the current policies, rules and regulations affect commuter van operation? The SWOT analysis results show that the commuter van industry is resilient, performs a necessary service, and, with small adjustments that will help reduce operating costs and loss of profits have a chance of thriving in Eastern Queens and the rest of New York City. The study also discusses the mismatch between policy and practice offering recommendations for improvement to ensure that commuter vans continue to serve residents of New York City.
ContributorsMusili, Catherine (Author) / Salon, Deborah (Thesis advisor) / King, David (Committee member) / Kelley, Jason (Committee member) / Arizona State University (Publisher)
Created2017
Description
Bicycle sharing systems (BSS) operate on five continents, and they change quickly with technological innovations. The newest “dockless” systems eliminate both docks and stations, and have become popular in China since their launch in 2016. The rapid increase in dockless system use has exposed its drawbacks. Without the order imposed by docks and stations, bike parking has become problematic. In the areas of densest use, the central business districts of large cities, dockless systems have resulted in chaotic piling of bikes and need for frequent rebalancing of bikes to other locations. In low-density zones, on the other hand, it may be difficult for customers to find a bike, and bikes may go unused for long periods. Using big data from the Mobike BSS in Beijing, I analyzed the relationship between building density and the efficiency of dockless BSS. Density is negatively correlated with bicycle idle time, and positively correlated with rebalancing. Understanding the effects of density on BSS efficiency can help BSS operators and municipalities improve the operating efficiency of BSS, increase regional cycling volume, and solve the bicycle rebalancing problem in dockless systems. It can also be useful to cities considering what kind of BSS to adopt.
ContributorsCui, Wencong (Author) / Kuby, Michael (Thesis advisor) / Salon, Deborah (Committee member) / Thigpen, Calvin (Committee member) / Arizona State University (Publisher)
Created2018
Description
ABSTRACT
This research reveals how governments cut budgets during fiscal crises and what pattern may emerge based on the cuts. It addresses a significant gap in literature by looking into the details of an agency for a full recession period to explain how cutback requirements were met. Through investigating a large Arizona state agency during the 2008 recession in the United States, the research reveals that cutback management is a stage-by-stage process lagging the immediate deterioration of the state’s economy and that patterns found among cuts are more often rational than not.
Cutbacks in this agency proceeded through three stages: the beginning, middle and the end period of cuts. In each stage, the author used descriptive analysis, process map analysis and cause and effect analysis to explore the features of cuts made. These methods of analysis were used to break down an annual budget reduction into original appropriation budget cuts, mid year reductions and the final budget cuts required to end the fiscal year in balance. In addition, the analytical methods permitted more detailed analysis of specific appropriation line items. The information used was secondary data collected from seven fiscal years around the recession and from various sources, including budgetary materials, legislation, accounting materials and many program reports related to budget cuts.
The findings suggested that across-the-board cuts are implemented at the beginning of cutback stage mainly to non-mandatory programs without jeopardizing the core functions of the agency. Later, in the middle period of the recession, selective cuts are made on large programs. Fund transfers and excess balance transfers are also preferred to reduce the budgets of other restricted funds. At the end stage of budget cuts, new revenue sources are established to support programs which had relied on general fund revenues in the past.
Overall, the cutback process observed in this research reflects decremental and rational patterns of decision making, contrasting with the randomness observed in previous research on cutback management. Across the board cuts are decremental; the remainders are rational, even strategic decisions. This investigation reminds researchers to be aware of the context and the level of observation when analyzing cutbacks.
This research reveals how governments cut budgets during fiscal crises and what pattern may emerge based on the cuts. It addresses a significant gap in literature by looking into the details of an agency for a full recession period to explain how cutback requirements were met. Through investigating a large Arizona state agency during the 2008 recession in the United States, the research reveals that cutback management is a stage-by-stage process lagging the immediate deterioration of the state’s economy and that patterns found among cuts are more often rational than not.
Cutbacks in this agency proceeded through three stages: the beginning, middle and the end period of cuts. In each stage, the author used descriptive analysis, process map analysis and cause and effect analysis to explore the features of cuts made. These methods of analysis were used to break down an annual budget reduction into original appropriation budget cuts, mid year reductions and the final budget cuts required to end the fiscal year in balance. In addition, the analytical methods permitted more detailed analysis of specific appropriation line items. The information used was secondary data collected from seven fiscal years around the recession and from various sources, including budgetary materials, legislation, accounting materials and many program reports related to budget cuts.
The findings suggested that across-the-board cuts are implemented at the beginning of cutback stage mainly to non-mandatory programs without jeopardizing the core functions of the agency. Later, in the middle period of the recession, selective cuts are made on large programs. Fund transfers and excess balance transfers are also preferred to reduce the budgets of other restricted funds. At the end stage of budget cuts, new revenue sources are established to support programs which had relied on general fund revenues in the past.
Overall, the cutback process observed in this research reflects decremental and rational patterns of decision making, contrasting with the randomness observed in previous research on cutback management. Across the board cuts are decremental; the remainders are rational, even strategic decisions. This investigation reminds researchers to be aware of the context and the level of observation when analyzing cutbacks.
ContributorsLiu, Xiaoqing (Author) / Miller, Gerald J (Thesis advisor) / Eden, Catherine R (Committee member) / Cayer, N Joseph (Committee member) / Lan, Zhiyong (Committee member) / Arizona State University (Publisher)
Created2018
Description
Advancements in marine and aerospace technology drive legal reform in admiralty and air law. The increased accessibility and affordability of these technologies demand and motivate lawmakers and federal agencies to anticipate potential threats to peoples’ rights and resources in the seas and skies. Given the recent applications of unmanned aircraft in the public and private sectors, developments in aircraft and air law are rapidly becoming more relevant to American Indian and Alaska Native tribes. In anticipation of legal reform, tribal nations are taking steps to assert, expand, and secure their air rights before agencies or the courts attempt to divest their sovereign authority. An analysis of two case studies through a lens of water and federal Indian law locates spaces in American jurisprudence that have the legal foundation and structural capacity to support a greater presence of Indigeneity in airspace. Research findings from these studies answer the following inquiries about tribal airspace sovereignty: where does Indigeneity reside in the US national airspace system and domestic air law, how are tribal air rights strengthened or weakened by American jurisprudence, what strategies do tribes employ to exercise their sovereignty in airspace, and how are tribes planning for future developments in aircraft and air law? Answers lead to proof of how meaningful consultation through collaborative rulemaking produces far greater mutual benefits than burdens for federal agencies and tribes, and much more. Most importantly, these discoveries celebrate a diverse and accumulative strategic legacy of strengthening and expanding tribal sovereignty in the face of imminent threats and possibilities in tribal airspace.
ContributorsKnight, Shelly Lynn (Author) / Vicenti Carpio, Myla (Thesis advisor) / Martinez, David (Committee member) / Riding In, James (Committee member) / Arizona State University (Publisher)
Created2019
Description
The comparison of between- versus within-person relations addresses a central issue in psychological research regarding whether group-level relations among variables generalize to individual group members. Between- and within-person effects may differ in magnitude as well as direction, and contextual multilevel models can accommodate this difference. Contextual multilevel models have been explicated mostly for cross-sectional data, but they can also be applied to longitudinal data where level-1 effects represent within-person relations and level-2 effects represent between-person relations. With longitudinal data, estimating the contextual effect allows direct evaluation of whether between-person and within-person effects differ. Furthermore, these models, unlike single-level models, permit individual differences by allowing within-person slopes to vary across individuals. This study examined the statistical performance of the contextual model with a random slope for longitudinal within-person fluctuation data.
A Monte Carlo simulation was used to generate data based on the contextual multilevel model, where sample size, effect size, and intraclass correlation (ICC) of the predictor variable were varied. The effects of simulation factors on parameter bias, parameter variability, and standard error accuracy were assessed. Parameter estimates were in general unbiased. Power to detect the slope variance and contextual effect was over 80% for most conditions, except some of the smaller sample size conditions. Type I error rates for the contextual effect were also high for some of the smaller sample size conditions. Conclusions and future directions are discussed.
A Monte Carlo simulation was used to generate data based on the contextual multilevel model, where sample size, effect size, and intraclass correlation (ICC) of the predictor variable were varied. The effects of simulation factors on parameter bias, parameter variability, and standard error accuracy were assessed. Parameter estimates were in general unbiased. Power to detect the slope variance and contextual effect was over 80% for most conditions, except some of the smaller sample size conditions. Type I error rates for the contextual effect were also high for some of the smaller sample size conditions. Conclusions and future directions are discussed.
ContributorsWurpts, Ingrid Carlson (Author) / Mackinnon, David P (Thesis advisor) / West, Stephen G. (Committee member) / Grimm, Kevin J. (Committee member) / Suk, Hye Won (Committee member) / Arizona State University (Publisher)
Created2016