Affirmative action policies are widely used in the school choice programs in many countries. However, the perverse comparative statistics of affirmative action policies for the minority students, the purported benefic...
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Affirmative action policies are widely used in the school choice programs in many countries. However, the perverse comparative statistics of affirmative action policies for the minority students, the purported beneficiaries, has been shown to be a quite common phenomenon by recent studies. Dogan (2016) recently analyzes this issue in the deferred acceptance algorithm with minority reserves, advocated by Hafalir et al. (2013) as an alternative approach of implementing affirmative action in practice. Following Dogan (2016), we propose a new mechanism to solve this problem utilizing the concept of under-demanded schools and show further, how this method recovers the efficiency losses in the original mechanism. (C) 2017 Elsevier B.V. All rights reserved.
BACKGROUNDThe ordering process at Stanford Health Care involved twice-daily shipments predicated upon current stock levels from the blood center to the hospital transfusion service. Manual census determination is time...
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BACKGROUNDThe ordering process at Stanford Health Care involved twice-daily shipments predicated upon current stock levels from the blood center to the hospital transfusion service. Manual census determination is time consuming and error prone. We aimed to enhance inventory management by developing an informatics platform to streamline the ordering process and reallocate staff productivity. STUDY DESIGN AND METHODSThe general inventory accounts for more than 50 product categories based on characteristics including component, blood type, irradiation status, and cytomegalovirus serology status. Over a 5-month calibration period, inventory levels were determined algorithmically and electronically. An in-house software program was created to determine inventory levels, optimize the electronic ordering process, and reduce labor time. A 3-month pilot period was implemented using this program. RESULTSThis system showed noninferiority while saving labor time. The average weekly transfused:stocked ratios for cryoprecipitate, plasma, and red blood cells, respectively, were 1.03, 1.21, and 1.48 before the pilot period, compared with 0.88, 1.17, and 1.40 during (p=0.28). There were 27 (before) and 31 (during) average STAT units ordered per week (p=0.86). The number of monthly wasted products due to expiration was 226 (before) and 196 (during) units, respectively (p=0.28). An estimated 7 hours per week of technologist time was reallocated to other tasks. CONCLUSIONAn in-house electronic ordering system can enhance information fidelity, reallocate and optimize valuable staff productivity, and further standardize ordering. This system showed noninferiority to the labor-intensive manual system while freeing up over 360 hours of staff time per year.
Approaches used in modern numerical simulations of the dynamics of dust and gas in circumstellar disks are tested. The gas and dust are treated like interpenetrating continuous media that can exchange momentum. A stif...
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Approaches used in modern numerical simulations of the dynamics of dust and gas in circumstellar disks are tested. The gas and dust are treated like interpenetrating continuous media that can exchange momentum. A stiff coupling between the gas and dust phases is typical for such disks, with the dust stopping time much less than the characteristic dynamical time scale. This imposes high demands on the methods used to simulate the dust dynamics. A grid-based, piecewise-parabolic method is used as the basic algorithm for solving the gas-dynamical equations. Numerical solutions obtained using various methods to compute the momentum exchanges are presented for the case of monodisperse dust. Numerical solutions are obtained for shock tube problem and the propagation of sound waves in a gas-dust medium. The studied methods are compared in terms of their ability to model media with (a) an arbitrary (short or long) dust stopping time, and (b) an arbitrary dust concentration in the gas (varying the dust to gas mass ratio from 0.01 to 1). A method for computing the momentum exchange with infinite-order accuracy in time is identified, which makes it possible to satisfy the conditions (a) and (b) with minimal computational costs. A first-order method that shows similar results in the test computations is also presented. It is shown that the proposed first-order method for monodisperse dust can be extended to a regime when the dust is polydisperse;i.e., a regime represented by several fractions with different stopping times. Formulas for computing the gas and dust velocities for polydisperse dust with each fraction exchanging momentum with the gas are presented.
BACKGROUNDSuspected transfusion reaction (STR) investigations are foundational for biovigilance. Diagnostic evaluations performed by blood banks may prolong turnaround times (TATs) for final STR results reporting. We ...
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BACKGROUNDSuspected transfusion reaction (STR) investigations are foundational for biovigilance. Diagnostic evaluations performed by blood banks may prolong turnaround times (TATs) for final STR results reporting. We identified a quality improvement opportunity using diagnostic testing reflex algorithms and our hospital's patient electronic health record to enhance TATs regarding one aspect of STR results reporting. STUDY DESIGN AND METHODSWe conducted a descriptive quality improvement study of reported STR cases investigated by our hospital's blood bank from March 1, 2014, to December 31, 2016, using data obtained from consult reports/quality improvement databases examining the number and types of diagnostic algorithm reflex activations performed and the TATs for an electronic provisional diagnosis reporting (PDXR) related to them. RESULTSA total of 461 STR events occurred during the study interval, of which 150 involved no reflex testing. In the remainder of cases (n=311), a total of 448 reflex activations occurred. In those cases in which PDXR occurred (n=446), the median PDXR TAT during the first month of implementation was 325 minutes, which progressively decreased to 70 minutes or less approximately 1 year after implementation. By the last quarter of 2015, median TATs were 60 minutes or less in length, where they remained for the duration of the study. CONCLUSIONTechnologists using targeted diagnostic reflex arcs to expedite laboratory testing along with STR electronic PDXR improve communication and timely results/information dissemination, potentially aiding bedside hemotherapy-related clinical decision making.
Motivation: Biodiversity databases now comprise hundreds of thousands of sequences and trait records. For example, the Open Tree of Life includes over 1 491 000 metazoan and over 300 000 bacterial taxa. These data pro...
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Motivation: Biodiversity databases now comprise hundreds of thousands of sequences and trait records. For example, the Open Tree of Life includes over 1 491 000 metazoan and over 300 000 bacterial taxa. These data provide unique opportunities for analysis of phylogenetic trait distribution and reconstruction of ancestral biodiversity. However, existing tools for comparative phylogenetics scale poorly to such large trees, to the point of being almost unusable. Results: Here we present a new R package, named 'castor', for comparative phylogenetics on large trees comprising millions of tips. On large trees castor is often 100-1000 times faster than existing tools.
Ryo Kikuuwe and Hideo Fujimoto introduce the Proxy-based sliding mode control (PSMC), which is a control algorithm intended for position control of robotic systems. This paper implements PSMC at the Cartesian space of...
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ISBN:
(纸本)9781728131863
Ryo Kikuuwe and Hideo Fujimoto introduce the Proxy-based sliding mode control (PSMC), which is a control algorithm intended for position control of robotic systems. This paper implements PSMC at the Cartesian space of a movable platform of 2 degree of freedom (2-DOF). Numerical co-simulations in Matlab/Simulink ® and MSC-ADAMS ® framework demonstrate the good performance of the system in motion control application.
In this paper, a backstepping controller is presented for quadrotor system to follow a predefined trajectory without the knowledge of dynamic parameters in the control algorithms. By dividing the quadrotor systems int...
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ISBN:
(纸本)9781538679012;9781538679265
In this paper, a backstepping controller is presented for quadrotor system to follow a predefined trajectory without the knowledge of dynamic parameters in the control algorithms. By dividing the quadrotor systems into several subsystems, the idea of nominal control input is presented to modify the quadrotor input force and torque. Subsequently, the backstepping control technique is developed for the nominal controls with the adaptive laws to estimate unknown dynamic parameters. Both the mass and moment of inertia are coped with by using adaptive laws. Stability and tracking performance of the proposed closed-loop system are proved by using Lyapunov theorem that the tracking errors converge to the origin asymptotically. Numerical examples are presented to show the quadrotor system tracking a desired trajectory efficiently.
For decades, many countries have developed a variety of multifingered dexterous hands. However, most of the multi-finger-fingers that have come out at present aim to achieve high dexterity, with a large number of join...
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ISBN:
(数字)9781728141923
ISBN:
(纸本)9781728141930
For decades, many countries have developed a variety of multifingered dexterous hands. However, most of the multi-finger-fingers that have come out at present aim to achieve high dexterity, with a large number of joints, a very complex structure, high degree of freedom, tedious control algorithm and high cost, which is unrealistic for practical application. Therefore, this paper designed an artificial muscle-driven[1] three-finger dexterous hand, which has good flexibility[2], very light quality, large input-output ratio, low manufacturing cost, can complete complex grasping and operating tasks, high dexterity advantages.
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