Current Matching Research Articles

RETRACTED: Transfer printing of fully formed microscale InGaP/GaAs/InGaNAsSb cell on Ge cell in mechanically-stacked quadruple-junction architecture

Abstract To bypass the requirements of epitaxial and current matching in monolithic stacks, we have finished the transfer printing of fully formed, thin-film microscale triple-junction (3J) solar cells with band gaps of 1.9/1.4/1 eV onto Ge cell to obtain a four-terminal quadruple-junction architecture. Meanwhile, AFM results suggest that both 3J cell and Ge cell have smooth surfaces, in favor of transfer printing with thin adhesive. In addition, the electrical, optical and thermal measurements have confirmed that the TiO2/SiO2/TiO2 film serves as an electrically-insulating, optically-transparent and thermally-conductive interface material. Moreover, colorized infrared optical images of an assembled 3J/Ge cell before and after thermal cycling confirm the interface bonding with high uniformity and indicate no degradation and high thermal stability of interface bonding. Due to the logarithmic increase of Voc with illumination intensity, the efficiency of both 3J cell and Ge cell from 1 sun and 330 suns have kept increasing from 31.3% to 41.4% and from 0.71% to 1.45%, respectively.

Modeling and implementation of tandem polymer solar cells using wide‐bandgap front cells

AbstractTandem device architectures offer a route to greatly increase the maximum possible power conversion efficiencies (PCEs) of polymer solar cells, however, the complexity of tandem cell device fabrication (such as selecting bandgaps of the front and back cells, current matching, thickness, and recombination layer optimization) often result in lower PCEs than are observed in single‐junction devices. In this study, we analyze the influence of front cell and back cell bandgaps and use transfer matrix modeling to rationally design and optimize effective tandem solar cell structures before actual device fabrication. Our approach allows us to estimate tandem device parameters based on known absorption coefficients and open‐circuit voltages of different active layer materials and design devices without wasting valuable time and materials. Using this approach, we have investigated a series of wide bandgap, high voltage photovoltaic polymers as front cells in tandem devices with PTB7‐Th as a back cell. In this way, we have been able to demonstrate tandem devices with PCE of up to 12.8% with minimal consumption of valuable photoactive materials in tandem device optimization. This value represents one of the highest PCE values to date for fullerene‐based tandem solar cells.

Assigning Refugees to Landlords in Sweden: Efficient, Stable, and Maximum Matchings*

AbstractIn this paper, we investigate the problem of finding housing for refugees once they have been granted asylum. In particular, we demonstrate that market design can play an important role in a partial solution to the problem. More specifically, we investigate a specific matching system, and we propose an easy‐to‐implement mechanism that finds an efficient, stable, and maximum matching. Such a matching guarantees that housing is efficiently provided to a maximum number of refugees, and that no refugee prefers another specific landlord to their current match when, at the same time, that specific landlord prefers that refugee to their own current match.

Spectral response measurements of each subcell in monolithic triple-junction GaAs photovoltaic devices

Multijunction photovoltaic devices have gained attention for both solar cells and wireless power transmission. Herein, we present the spectral response of each subcell in a monolithic triple-junction photovoltaic device composed of only GaAs subcells with different thicknesses, which clarifies current matching among the GaAs subcells under simulated solar illumination conditions. In addition, the spectral response curves of each subcell show that the power-dependent spectral responses under laser illumination with wavelengths of 405, 660, and 785 nm are explained by the top GaAs subcell, which has a slightly lower shunt resistance and experiences the effects of luminescent coupling.

Nanopillars assisted multilayer antireflection coating for photovoltaics with multiple bandgaps

A nanopillar assisted multilayer antireflection (AR) coating that combines the Ta2O5/SiO2 multilayer with SiO2 nanopillars was investigated to improve the light absorption of quadruple-bandgap photovoltaics. After clarifying that the performance of the traditional multilayer AR coating is restricted by the available refractive index of the top layer, periodic SiO2 rhombic nanopillars that work in the subwavelength regime were used to vary its effective index from 1 to 1.46. Then, the effective index and thickness of SiO2 nanopillars were optimized together with the Ta2O5/SiO2 stack using the global optimization algorithm to further reduce the reflection loss. When the SiO2 nanopillars have an effective index of 1.15 and a thickness of 108 nm, the best AR performance was achieved with a reflectance of 3.9% in the target spectral range of 300–1700 nm. Using laser interference lithography and ion assisted deposition technologies, the nanopillar assisted AR coating was realized with a reflectance of 4.5%. Compared to the traditional multilayer AR coating, this hybrid approach can not only achieve better AR performance but also reduce the disparities of the reflection loss among different bandgaps, which helps us to effectively improve the current matching and enhance the overall efficiency of quadruple-bandgap photovoltaics.

Applying to Orthopaedic Residency and Matching Rates: Analysis and Review of the Past 25 Years.

The competitiveness of orthopaedics and recent changes in the residency application process have resulted in increased costs to both applicants and programs. Our purpose was to investigate changes in the orthopaedic residency application process between 1992 and 2017. Also, we aimed to determine an ideal number of applications that each student can submit without jeopardizing his or her probability of matching into an orthopaedic residency slot while concurrently reducing the excessive number of applications that are received by program selection committees. Retrospective data from both the Electronic Residency Application Service (ERAS) and the National Resident Matching Program (NRMP) were collected and analyzed for changes in the characteristics of applications, applicants, and programs over the study period. Using these data, the probability of matching into orthopaedics through the years was calculated and compared in order to propose an ideal number of applications for a medical student to submit to match into an orthopaedic residency. Over the study period of 25 years, there has been an increase in the number of residency positions offered and a decrease in the number of applicants per offered position among U.S. senior medical students. Nonetheless, the average number of submitted applications per applicant significantly increased from 1992 to 2017, from 28 to 80 applications (p < 0.001). As a result, the overall costs to apply and review applications also have increased. There was no association between the increased number of submitted applications and the match rate. Our analysis showed that 50 applications per student offer is the most effective option without compromising the overall applicant match rate. Based on these data, we suggest encouraging students to limit the number of applications that they submit. This limit could reduce the cost for both applicants and programs while likely maintaining the current match rate and competitiveness of the specialty.

Contemporary Assessment of Match Violations within Urology: an Opportunity for Ethical Leadership.

The primary aim of this review is to: (1) adequately define Match violations, (2) thoroughly examine the nature and scope of Match violations in the American Urologic Association (AUA) Urology Match, and (3) propose and recommend policy guidelines, including consequences for applicants and programs, as it pertains to Match violations. These recommendations are intended to affect change at the level of the AUA and Society of Academic Urology (SAU) that more effectively mitigates future violations, intentional or not. There is a paucity of specific guidelines published by the AUA on what constitutes a Match violation. Furthermore, in contrast to the National Resident Matching Program (NRMP), the AUA is surprisingly lenient in their existing guidelines. The Match violations most frequently reported were programs asking applicants illegal and restricted questions as well as inappropriate post-interview communication between applicants and programs. Review of current Match policies and violations suggest several areas for improvement, particularly regarding the specificity of AUA guidelines to define Match violations, the asking of illegal interview questions, and post-interview communication. The obligation to uphold a fair and equitable Match is an ethical imperative for the urologic community.

Interestingness Calculation for Cricket Summary Generation

This paper analyses the way how to make cricket summary automation more efficient. Thus, from the score card details, by adding various interestingness factors to make the summary more interesting to the user is the solution. That can be achieved by considered both the history of the teams and the current match details and analyzed by the system.

EDITORIAL COMMENT

The rapid growth in reconstructive urology has resulted in the proliferation of fellowships and increased resident exposure to reconstructive urological cases, driving further interest in the field. This article characterizes the early results of the Society of Genitourinary Reconstructive Surgeons (GURS) fellowship match. This study is important because it opens the GURS match to future study. However, there are several things this article does not do. A comparative analysis of prematch graduates was not performed and this survey was not designed to determine if the current match is better.

Two-terminal mechanical perovskite/silicon tandem solar cells with transparent conductive adhesives

Herein, we demonstrate a novel two-terminal perovskite/silicon mechanical tandem solar cell, fabricated by bonding a silicon cell upside down on a perovskite cell using a transparent conductive adhesive (TCA). The TCA consists of Ag-coated poly(methyl 2-methylpropenoate) microparticles embedded in a polymer adhesive. The Ag microparticles serve as an electrical current path, and the polymer adhesive mechanically bonds two sub-cells. The specific contact resistance and transmittance of the TCA layer were determined to be 5.46 × 10−2 Ω∙cm2 and >97.0%, respectively. Through an optical simulation, the current of the perovskite top cell was predicted to match the current of the p-type Si bottom cell with an Al back-surface field (BSF) layer when the thickness of MAPbI3 was 150 nm. The tandem cell fabricated under the optimal current matching conditions exhibited a current density of 15.43 mA cm-2, an open-circuit voltage of 1.59 V, and a fill factor of 79%, resulting in a steady-state efficiency of 19.4%. To the best of our knowledge, our result is the highest efficiency among two-terminal mechanical perovskite/silicon tandem cells. The unique structure of this tandem cell facilitates an excellent long-term stability without encapsulation in humid environment.

Theoretical Analysis of Two‐Terminal and Four‐Terminal Perovskite/Copper Indium Gallium Selenide Tandem Solar Cells

Perovskite/copper indium gallium selenide (CIGS) tandem solar cells represent an attractive configuration to obtain ultrahigh efficiency. A detailed theoretical analysis is crucial for further improving the performance of tandem solar cells. Herein, four‐terminal and two‐terminal perovskite/CIGS tandem solar cells are intensively researched. For four‐terminal perovskite/CIGS tandem solar cell, the optimal thicknesses of CH3NH3PbI3 and CIGS are 0.5 and 3 μm, respectively, according to the simulation result. Reducing the thickness of TiO2 and Spiro‐OMeTAD can minimize the short‐wavelength parasitic absorption and long‐wavelength parasitic absorption, respectively. Meanwhile, using antireflection coating, such as 100 nm MgF2, is beneficial to increase the photon absorption. For two‐terminal perovskite/CIGS tandem solar cells, the thicknesses of perovskite and CIGS are tuned to meet the current matching. To further improve the efficiency of two‐terminal tandem cells, FTO thickness is reduced to minimize reflection, and the optimal doping concentration of CIGS (1 × 1018 cm−3) is used. In addition, results show that the quality of perovskite films should be improved by enlarging the grain size to decrease the trap states at grain boundary. Finally, the optimal efficiency of two‐terminal CH3NH3PbI2Br/CIGS tandem solar cells reaches 31.13%.

Enhancing Game Agent Pathfinding Through Dynamic Graph Reweighting

This paper proposes a computationally inexpensive algorithm that utilizes player data to optimize nonplayer character pathfinding in a competitive, multiplayer environment and focuses on imitating the player behavior. The algorithm’s input consists of player statistics gathered during the current and previous matches with additional time and space context, similar in design to influence maps. The input is then enriched with two additional, novel variables, allowing easy online fine-tuning of the output. The obtained result influences the final edge values of the map graph. Any known pathfinding algorithm that works with digraphs can then be utilized to control the agent. This paper contains exemplary results obtained when analyzing input on a map modeled after an existing map in the video game Unreal Tournament.

Self-Similar Expansion Model of Cylindrical Flux Ropes Combined with an Alfvén Wave Current System

Magnetic flux ropes in space are generally connected to some regions electromagnetically. We consider the whole closed current system of the expanding flux ropes including the electric current associated with them. By combining the theories regarding the self-similar expansion of cylindrical flux ropes and the Alfven wave current system, we examine conditions under which the electric current matches. These matching conditions are satisfied when the time dependence of the current flowing in the closed circuit agrees with that which maintains the expanding flux rope. In consequence, we encountered three possible forms of expansion. The two-step eruption of solar filaments may be interpreted as a transition from one form of expansion to another. If this process works, increasing the diffusion outside of the flux rope is necessary to trigger the transition.

Voluntary Adoption of an All In Match Policy in the Medical Specialties Matching Program: Advantages and Disadvantages.

Voluntary Adoption of an All In Match Policy in the Medical Specialties Matching Program: Advantages and Disadvantages.

Intra-aortic balloon pump and survival with favorable neurological outcome after out-of-hospital cardiac arrest: A multicenter, prospective propensity score-matched study

ObjectivesThis study aimed to evaluate whether intra-aortic balloon pump (IABP) use in nontraumatic out-of-hospital cardiac arrest (OHCA) patients who achieved return of spontaneous circulation (ROSC) is associated with favorable neurological outcome after OHCA. BackgroundThe association between the IABP use in OHCA patients and favorable neurological outcome has not been extensively evaluated. MethodsThe Comprehensive Registry of Intensive Cares for OHCA Survival (CRITICAL) study, a multicenter, prospective observational registry in Osaka, Japan, included consecutive nontraumatic OHCA patients aged ≥18 years who achieved ROSC from July 2012 to December 2016. The primary outcome was 1-month survival with favorable neurological outcome. Logistic regression analysis was used to evaluate the association between the IABP use or non-IABP use and favorable neurological outcome using one-to-one propensity score (PS) matching analysis. ResultsAmong the 2894 eligible patients, 10.4% used IABP, and 89.6% did not use IABP. In all patients, the proportion of 1-month survival with favorable neurological outcome was higher in the IABP use group than in the non-IABP use group (30.7% [92/300] vs. 13.2% [342/2594]). However, in PS-matched patients, the proportions of 1-month survival with favorable neurological outcome were almost consistent, and there were no significant differences between the IABP use group and the non-IABP use group (37.3% [59/158] vs. 41.1% [65/158]; adjusted odds ratio, 0.97; 95% confidence interval, 0.48–1.96). ConclusionsIn this population, the current PS matching analysis did not reveal any association between the IABP use and 1-month survival with favorable neurological outcome among adult patients with ROSC after OHCA.

A novel design of double junction CZTS/CdS solar cell with transparent intermediate layer

In this paper, a novel double junction CZTS/CdS solar cell is proposed, where Copper Zinc Tin Sulfide (CZTS) and Cadmium Sulfide (CdS) are applied as top and bottom cells. Zinc Telluride (ZnTe) and Zinc Selenide (ZnSe) are used as Anti-Reflection Coating (ARC) layers in order to decrease the reflection of solar radiant beams. Zinc Oxide (ZnO) layer is used between the top cell and the bottom cell as a transparent intermediate layer which increases the current flow. Current density matching was established between short-circuit current densities in top cell and bottom, and the short-circuit current density of 22.2 mA/cm2 was reached in the solar cell. The maximum power conversion efficiency of 48.05% and maximum fill factor of 84.56% was obtained by optimizing double junction CZTS/CdS solar cell with changing the thickness of CZTS and CdS layers and doping concentration of each solar cell layer.

The Pediatric Match Frenzy: An Overview and an Approach for Mentoring Medical Students

Applying for a pediatric residency position has become an increasingly stressful event and recently medical educators have described it as a “Match Frenzy.” Match statistics demonstrate increased competition for pediatric residency positions and a record number of applications. Faculty who mentor medical students are now challenged to counsel them through the intensified process and pediatric residency programs are now forced to navigate the rising number of applications. We define the Match Frenzy and its implications, review historical and current match statistics, and describe a data-driven approach to the problem. Through mitigating the frenzy surrounding this process, we can help students and residency programs better allocate their precious resources.

Maximum Matching on Trees in the Online Preemptive and the Incremental Graph Models

We study the Maximum Cardinality Matching (MCM) and the Maximum Weight Matching (MWM) problems, on trees and on some special classes of graphs, in the online preemptive and the incremental graph models. In the Online Preemptive model, the edges of a graph are revealed one by one and the algorithm is required to always maintain a valid matching. On seeing an edge, the algorithm has to either accept or reject the edge. If accepted, then the adjacent edges are discarded, and all rejections are permanent. In this model, the complexity of the problems is settled for deterministic algorithms (McGregor, in: Proceedings of the 8th international workshop on approximation, randomization and combinatorial optimization problems, and proceedings of the 9th international conference on randomization and computation: algorithms and techniques, APPROX’05/RANDOM’05, Springer, Berlin, pp. 170–181, 2005; Varadaraja, in: Automata, languages and programming: 38th international colloquium, ICALP 2011, Zurich, Switzerland, proceedings, part I, pp. 379–390, 2011. https://doi.org/10.1007/978-3-642-22006-7_32 ). Epstein et al. (in: 30th international symposium on theoretical aspects of computer science, STACS 2013, Kiel, Germany, pp. 389–399, 2013. https://doi.org/10.4230/LIPIcs.STACS.2013.389 ) gave a 5.356-competitive randomized algorithm for MWM, and also proved a lower bound on the competitive ratio of $$(1+\ln 2) \approx 1.693$$ for MCM. The same lower bound applies for MWM. In the Incremental Graph model, at each step an edge is added to the graph, and the algorithm is supposed to quickly update its current matching. Gupta (in: 34th international conference on foundation of software technology and theoretical computer science, FSTTCS 2014, 15–17 Dec 2014, New Delhi, India, pp. 227–239, 2014. https://doi.org/10.4230/LIPIcs.FSTTCS.2014.227 ) proved that for any $$\epsilon \le 1/2$$ , there exists an algorithm that maintains a $$(1+\epsilon )$$ -approximate MCM for an incremental bipartite graph in an amortized update time of $$O\left( \frac{\log ^2 n}{\epsilon ^4}\right) $$ . No $$(2-\epsilon )$$ -approximation algorithm with a worst case update time of O(1) is known in this model, even for special classes of graphs. In this paper we show that some of the results can be improved for trees, and for some special classes of graphs. In the online preemptive model, we present a 64 / 33-competitive randomized algorithm (which uses only two bits of randomness) for MCM on trees. Inspired by the above mentioned algorithm for MCM, we present the main result of the paper, a randomized algorithm for MCM with a worst case update time of O(1), in the incremental graph model, which is 3 / 2-approximate (in expectation) on trees, and 1.8-approximate (in expectation) on general graphs with maximum degree 3. Note that this algorithm works only against an oblivious adversary. We derandomize this algorithm, and give a $$(3/2+\epsilon )$$ -approximate deterministic algorithm for MCM on trees, with an amortized update time of $$O(1/\epsilon )$$ . We also present a minor result for MWM in the online preemptive model, a 3-competitive randomized algorithm (that uses only O(1) bits of randomness) on growing trees (where the input revealed upto any stage is always a tree, i.e. a new edge never connects two disconnected trees).

Preventing Infant Maltreatment with Predictive Analytics: Applying Ethical Principles to Evidence-Based Child Welfare Policy

Infant maltreatment is a devastating social and public health problem. Birth Match is an innovative policy solution to prevent infant maltreatment that leverages existing data systems to rapidly predict future risk through linkage of birth certificate and child welfare data then initiate a child protection response. Birth Match is one example of child welfare policy that capitalizes on recent advances in computing technology, predictive analytics, and algorithmic decision making. We apply frameworks from business and computer science as a case study in ethical decision-making in child welfare policy. Current Birth Match policy applications appear to lack key aspects of transparency and accountability identified in the frameworks. Although technology holds promise to help solve intractable social problems such as fatal infant maltreatment, the decision to deploy such policy innovations must consider ethical questions and tradeoffs. Technological advances hold great promise for prevention of fatal infant maltreatment, but numerous ethical considerations are lacking in current implementation and should be considered in future applications.

Simulation study for the current matching optimization in In0.48Ga0.52N/In0.74Ga0.26N dual junction solar cells

Abstract In this paper indium gallium nitride (InGaN) is used to design and optimize a dual junction (DJ) solar cell, which is series-connected via a tunnel diode, with a careful analysis of the current matching between the top and the bottom sub-cells. In particular, a bandgap combination of 1.76eV/1.13eV for an In0.48Ga0.52N/In0.74Ga0.26N structure is adopted and several numerical simulation results are presented. The doping concentration and the base thickness of each sub-cell are considered as fitting parameters in order to determine an accurate current matching condition. The In0.48Ga0.52N-based n++/p++ tunnel junction behavior is also taken into account. A maximum short circuit current density of 19.543 mA/cm2 is obtained for a 1 μm-thick base in both the sub-cells, and a p/n doping ratio of 5 × 1018 cm−3/5 × 1015 cm−3 and 1.9 × 1019 cm−3/1.9 × 1016 cm−3 for the top and the bottom cell, respectively. The optimized DJ solar cell exhibits an open circuit voltage of 1.713 V, a fill factor of 82.49%, and a conversion efficiency of 28.78%. The external quantum efficiency and the current (power) density-voltage characteristics of different devices are investigated in detail.