Hospital Treatment Rates and Spill-Over Effects: Does Ownership Matter?

This paper studies the effect of hospital ownership on treatment rates allowing for spatial correlation among hospitals. Competition among hospitals and knowledge spillovers generate significant externalities which we try to capture using the spatial Durbin model. Using a panel of 2342 hospitals in the 48 continental states observed over the period 2005 to 2008, we find significant spatial correlation of medical service treatment rates among hospitals. The paper also shows mixed results on the effect of hospital ownership on treatment rates that depends upon the market structure where the hospital is located and which varies by treatment type

A Finite Exact Representation of Register Automata Configurations

A register automaton is a finite automaton with finitely many registers ranging from an infinite alphabet. Since the valuations of registers are infinite, there are infinitely many configurations. We describe a technique to classify infinite register automata configurations into finitely many exact representative configurations. Using the finitary representation, we give an algorithm solving the reachability problem for register automata. We moreover define a computation tree logic for register automata and solve its model checking problem.Comment: In Proceedings INFINITY 2013, arXiv:1402.661

Essays on Health and Medical Care

This dissertation consists of two essays that explain health outcomes and medical care in the United States. Health care has been a major concern of economists and policy makers. Policy intervention is one of the key factors that affect health outcomes, especially among low-income families. Welfare programs such as Medicaid and cash assistance are conventionally implemented to assist low-income families. The effectiveness of these efforts to improve health outcomes and medical utilization among low-income families is not entirely clear. As to the supply side of health care, the results of previous studies on how hospitals provide the services are mixed. Additionally, hospitals may compete to attract patients and generate spillover effects. Quality of hospitals may in turn differ by market. My two essays apply econometrics models to investigate the effects of public policies and hospital quality on health and medical care. Specifically, the first essay examines whether welfare programs affect the health outcomes and medical utilization of children in the low-income families, and if so, which policy has the strongest effect on them. The second essay explores how the spillover effects impact the treatment rates of hospitals. The first essay examines the effect of the Temporary Aid to Needy Families (TANF) program on children\u27s health outcomes using data from the Survey of Income and Program Participation (SIPP) over the period 1994 to 2005. The TANF policies have been credited with increased employment for single mothers and a dramatic drop in welfare caseload. Our results show that these policies also had a significant effect on various measures of children\u27s health and medical utilization especially among low-income families. These health measures include a rating of the child\u27s health status reported by the parents; the number of days an illness or injury kept the child in bed; the number of times that parents consulted a doctor; and the number of nights that the child stayed in a hospital. The second essay addresses the effect of hospital ownership on treatment rates allowing for spatial correlation among hospitals. Competition among hospitals and knowledge spillovers generate significant externalities which we try to capture using the spatial Durbin model. Using a panel of 2342 hospitals in the 48 continental states observed over the period 2005 to 2008, we find significant spatial correlation of medical service treatment rates among hospitals. We also get mixed results on the effect of hospital ownership on treatment rates that depends upon the market structure where the hospital is located and which varies by treatment type

An investigation of a bistable oscillator used in a phase modulated control circuit

A primary component in the investigation of phase modulated control systems is bistable oscillator which converts a constant oscillation signal to control the system. The oscillator is feedback type that utilizes a feedback capacitance and resistance in each feedback path to change its frequency. The theoretical behavior of bistable oscillator was investigated and the non-dimensional results were set for convenience in determining the oscillation period. The control circuit which based on the oscillator was also presented a form of suitable circuit for direct application to practical control problems --Abstract, page ii

Detection of Early-Stage Enterprise Infection by Mining Large-Scale Log Data

Recent years have seen the rise of more sophisticated attacks including advanced persistent threats (APTs) which pose severe risks to organizations and governments by targeting confidential proprietary information. Additionally, new malware strains are appearing at a higher rate than ever before. Since many of these malware are designed to evade existing security products, traditional defenses deployed by most enterprises today, e.g., anti-virus, firewalls, intrusion detection systems, often fail at detecting infections at an early stage. We address the problem of detecting early-stage infection in an enterprise setting by proposing a new framework based on belief propagation inspired from graph theory. Belief propagation can be used either with "seeds" of compromised hosts or malicious domains (provided by the enterprise security operation center -- SOC) or without any seeds. In the latter case we develop a detector of C&C communication particularly tailored to enterprises which can detect a stealthy compromise of only a single host communicating with the C&C server. We demonstrate that our techniques perform well on detecting enterprise infections. We achieve high accuracy with low false detection and false negative rates on two months of anonymized DNS logs released by Los Alamos National Lab (LANL), which include APT infection attacks simulated by LANL domain experts. We also apply our algorithms to 38TB of real-world web proxy logs collected at the border of a large enterprise. Through careful manual investigation in collaboration with the enterprise SOC, we show that our techniques identified hundreds of malicious domains overlooked by state-of-the-art security products

Deepen the understanding for school bully-victims : the reasons for bully-victims' role formations, role transitions, and role terminations

C

Are the global REIT markets efficient by a new approach?

This study uses a panel KSS test by Nuri Ucar and Tolga Omay (2009), with a Fourier function based on the sequential panel selection method (SPSM) procedure proposed by Georgios Chortareas and George Kapetanios (2009) to test the efficiency of REIT markets in 16 countries from 28 March 2008 to 27 June 2011. A Fourier approximation often captures the behavior of an unknown break, and testing for a unit root increases its power to do so. Moreover, SPSM can determine the mix of I(0) and I(1) series in a panel setting to clarify how many and which are random walk processes. Our empirical results demonstrate that REIT markets are efficient in all sampled countries except the UK. Our results imply that investors in countries with efficient REIT markets can adopt more passive portfolio strategies

An analysis of the debate between economic gobalization and regionalization based on Rawls’s theory of justice

Driven by globalization, international economic integration has become unavoidable. Within this broader trend, two distinctive modes of international regime building can be identified globalism and regionalism. Globalism, illustrated using the case of the World Trade Organization (WTO), pushes forward global economic integration using established norms. In contrast, regionalism involves gradual expansion of regional integration mechanisms based on interests of member states. This study assesses these two development modes with justice as a concept of moral rightness. To this effect, Rawls’s theory of justice is applied to evaluate standards of justice in international regimes. Based on Rawls’s two principles of justice, three assessment criteria are developed: (1) equal qualification principle, (2) equal opportunity principle, and (3) difference principle. These criteria are applied for comparative analysis of justice in the development of global and regional regimes in order to develop a model for international regimes that is consistent with the concept of justice. A comparison of (1) qualifications for membership; (2) fairness of decision making mechanisms, and (3) institutionalization of differential treatment shows that justice in global regimes is superior to that in regional regimes. In other words, in terms of the philosophy of moral rightness, states should pursue integration based on the principles of globalism

Fire extinguisher

Fire extinguisher is a safety product that can be found almost everywhere, yet it is the one product that everyone often neglect. In order to understand more about fire extinguishers, we must first know the different classes of fire and then the suitable type of fire extinguishers used. Table 1 summarises the classes of fire and its sources (Fire Extinguisher Types - Fire Protection Equipment & System, March 5, 2019). Table 2, on the other hand, summarises the types of fire extinguishers and the fires suitable to be used for (Surrey Fire & Safety Ltd., April 6, 2018)