Browsing by Subject "efficiency"

Now showing 1 - 5 of 5
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    The Effect of Charter Schools on Districts’ Student Composition, Costs, and Efficiency: The Case of New York State
    (Elsevier, 2019) Buerger, Christian; Bifulco, Robert; School of Public and Environmental Affairs
    Charter schools can influence a school district's costs by reducing economies of scale and by changing the share of high cost students a district serves, but might also increase the district's efficiency through competition. Utilizing data for New York State school districts from 1998/99 to 2013/14, we estimate difference-in-differences models to assess the effect of charter schools on enrollment and student composition. Then, we estimate an expenditure function, using data prior to the charter school program, to measure the costs associated with reaching a given performance standard for students in various need categories and different enrollments. Next, using the entire data set, we run a second expenditure function to determine changes in efficiency associated with charter school entry. We find that charter schools increase the cost of providing education, and that these cost increases are larger than short-run efficiency gains, but are offset by efficiency gains in the long term.
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    Inference about the slope in linear regression: an empirical likelihood approach
    (Springer, 2017) Müller, Ursula U.; Peng, Hanxiang; Schick, Anton; Mathematical Sciences, School of Science
    We present a new, efficient maximum empirical likelihood estimator for the slope in linear regression with independent errors and covariates. The estimator does not require estimation of the influence function, in contrast to other approaches, and is easy to obtain numerically. Our approach can also be used in the model with responses missing at random, for which we recommend a complete case analysis. This suffices thanks to results by Müller and Schick (Bernoulli 23:2693–2719, 2017), which demonstrate that efficiency is preserved. We provide confidence intervals and tests for the slope, based on the limiting Chi-square distribution of the empirical likelihood, and a uniform expansion for the empirical likelihood ratio. The article concludes with a small simulation study.
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    Procedural Economy in Pre-trial Procedure: Developments in Germany and the United States
    (2016) Boyne, Shawn Marie; Robert H. McKinley School of Law
    In this article, I compare pre-trial procedures in Germany and the United States and probe the extent to which prosecutor’s decision-making practices deviate from each system’s normative goals. In both countries, the daily practice of the key players in both criminal justice systems continues to shift as the result of ever-increasing resource constraints and a varied array of organizational incentives. These shifts have created areas of both convergence and divergence. On the one-hand, in an era in both countries in which the number of cases resolved through a full-fledged public trial is decreasing, the course of pre-trial practice has become more outcome-determinative. Faced with a heavy caseload, a German prosecutor who receives a file in which the initial facts appear to be weak, may dismiss the case right out of the gate. On the other hand, carrying the mantle of a “party” rather than as an “organ of justice,” an American prosecutor who views the same investigation file may be more likely to seek some level of conviction through a plea agreement. Viewed solely through the goal of “finding the truth,” the shortened investigation process in both cases raises questions about whether the outcome fulfilled the retributive and rehabilitative objectives of the criminal law. On the other hand, in an era of tight resources, both outcomes appear to efficiently resolve the dispute at issue. In both cases, the shortened process also impacts, and perhaps undercuts, the traditional role of the fact-finder, be it a jury in the United States or a German judicial panel. Consequently, in many cases, bureaucrats in both countries are functioning as the arbiters of justice rather than simply as the head of the investigation process. This shift in institutional roles casts doubt on the degree to which the normative vision underlying each system’s path to “truth” informs prosecutors’ practice routines. By highlighting this development, this chapter will explore the widening disconnect between the law in action and these two normative visions of the truth-finding process. I then describe how some facets of pre-trial practice in both in both countries today undermine the objective to find the truth. After highlighting these problematic features, I suggest that the way to right the ship is, not to strengthen the law, but to more closely examine the organizational incentives that guide prosecutorial decision-making today.
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    Reconfiguration of a Wind Turbine with Hydrostatic Drivetrain to Improve Annual Energy Production
    (IEEE, 2015-09) Deldar, Majid; Izadian, Afshin; Anwar, Sohel; Department of Mechanical Engineering, School of Engineering and Technology
    Abstract: Hydrostatic transmission systems (HTS) have shown potential in replacing gearbox in conventional wind turbines. However, the general perception about these systems is that they suffer from low efficiencies, specifically at low wind speeds. This paper presents a novel technique that can improve the annual energy production (AEP) beyond that of a conventional wind turbine. By optimizing the operating conditions and the design of the wind turbine, the performance and efficiency of a HTS can be improved. A side-by-side comparison with the conventional wind turbines is provided to highlight the benefits of the proposed methodology. One of the findings of this research is that, rotor, hydrostatic pump, motor and their operations' planning must be optimized together to achieve higher AEP. The reconfigured turbines are shown to provide up to 8 percent AEP increase for a 750 kW plant and up to 10 percent increase for 1500 kW plants using the proposed drivetrain configurations.
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    What delays your case start? Exploring operating room inefficiencies
    (Springer, 2021-06) Athanasiadis, Dimitrios I.; Monfared, Sara; Whiteside, Jake; Banerjee, Ambar; Keller, Donna; Butler, Annabelle; Stefanidis, Dimitrios; Surgery, School of Medicine
    Introduction Improving operating room (OR) inefficiencies benefits the OR team, hospital, and patients alike but the available literature is limited. Our goal was, using a novel surgical application, to identify any OR incidents that cause delays from the time the patient enters the OR till procedure start (preparatory phase). Materials and methods We conducted an IRB approved, prospective, observational study between July 2018 and January 2019. Using a novel surgical application (ExplORer Surgical) three observers recorded disrupting incidents and their duration during the preparatory phase of a variety of general surgery cases. Specifically, the number and duration of anesthesia delays, unnecessary/distracting conversations, missing items, and other delays were recorded from the moment they started until they stopped affecting the normal workflow. Results Ninety-six OR cases were assessed. 20 incidents occurred in 18 (19%) of those cases. The average preparatory duration for all the cases was 20.7 ± 8.6 min. Cases without incidents lasted 19.5 ± 7.4 min while cases with incidents lasted 25.9 ± 11.2 min, p = 0.03. The average incident lasted 3.7 min, approximately 18% of the preparatory phase duration. Conclusion The use of the ExplORer Surgical app allowed us to accurately record the incidents happening during the preparatory phase of various general surgery operations. Such incidents significantly prolonged the preparatory duration. The identification of those inefficiencies is the first step to targeted interventions that may eventually optimize the efficiency of preoperative preparation.