Fair Match Research Articles

Sense of Freedom in the Golden Years: Disentangling the Complex Ties Between Community Safety Concerns and Depressive Symptoms in Later Life.

This study investigates the "Negative Spillover Effect"-a conceptual framework that highlights the correlation between older adults' community safety concerns and depressive symptoms. It explores the moderating influence of the sense of freedom in this relationship. Through the analysis of data from 3408 participants in the China Labor-force Dynamics Survey, employing a two-stage least squares regression approach, the study uncovers the intricate role of the sense of freedom in influencing the depressive symptoms of older adults based on their community safety concerns. The sense of freedom serves as a protective factor against the adverse psychological effects of community safety concerns when they are strong. However, this protective role diminishes when coupled with a low perception of the fair match between labor input and living condition rewards. The study underscores the importance of addressing and mitigating the negative spillover effect to foster sustainable and equitable community development. Reducing these adverse effects is essential for enhancing the mental health and well-being of the older demographic.

"Smart University" project: fair matching of students to academic trajectories

"Smart University" project: fair matching of students to academic trajectories

Designing Service Menus for Bipartite Queueing Systems

Designing Fair and Incentive-Compatible Matching Systems Many service systems face the challenge of dynamically matching customers who have heterogeneous preferences with an available pool of service providers in a fair and equitable manner. The first come, first served (FCFS) service discipline offers a straightforward and fair approach to allocate arriving customers to available servers and manage congestion. However, FCFS may limit the ability of service providers to reach an efficient allocation based on the individual preferences of customers and the characteristics of servers. In “Designing Service Menus for Bipartite Queuing Systems,” Caldentey, Hillas, and Gupta develop a queueing framework to address this dynamic matching problem. Their proposed methodology enables service providers to offer a menu of different service classes, each served by a distinct pool of servers. By thoughtfully designing this menu, a service provider can encourage self-interested customers to select service classes in a way that optimizes the trade-off between quality of matching and waiting time delays.

Shape reconstruction of axisymmetric Taylor bubbles using conductivity probes through a scheme of combined experiment and theory.

A simple measurement scheme is proposed to reconstruct the geometry of an axisymmetric void propagating through a conducting liquid using a pair of parallel wire conductivity probes. An experimental study allows for obtaining the time variation of the resistance of the film surrounding the void. Analytical modeling and numerical simulation has been adopted to correlate the resistance between the wire electrodes and the film thickness. Finally, the shape of the void can be estimated by combining the predicted resistance-film thickness relationship and the measured time variation of resistance. For validation, this scheme has been used to reconstruct the shape of a rising Taylor bubble. There is a fair match between the reconstructed shape of the bubble and its photographic image. The probable errors in the measurement scheme have been discussed and assessed mathematically.

Match experiences affect interest: Impacts of matchmaking and performance on churn in a competitive game

This study assessed how matchmaking and match results affect player churn in a multiplayer competitive game. In competitive games, matchmaking is crucial in gathering players with similar skills and creating balanced player-versus-player matches. Players are highly motivated when they win matches, whereas losing matches is demotivating, leading to churn. We performed a two-way fixed effects estimation using our panel data to analyze the relationship between players' churn and match experience. The panel data retrieved 42 days of server-side in-game logs, comprising approximately six million matches played by more than 262k players in the casual commercial game “Everybody's Marble.” The experimental results indicate that churn is positively influenced by being matched with stronger opponents. Interestingly, being matched with weaker opponents decreases the possibility of churn more than fair matches (being matched with equally skilled opponents). Furthermore, large differences in opponents' skill levels positively influence churn, while more frequent and consecutive wins negatively influence it. The results also reveal that consecutive losses can affect churn differently, depending on the players' level. This study provides theoretical and practical implications for researchers who want to understand the factors that affect user churn and game developers who want to maximize user retention rates in commercial games.

Fractured reservoirs: An extensive geomechanical integrity approach

There is no more challenging task for today oil and gas production companies than simulating the production behavior of naturally fractured reservoirs fields. These reservoirs are highly prosperous at their early stage of production, only to decline afterward. Previous behavior has risen awareness of the geomechanics role in controlling deliverability of those reservoirs. Hasdrubal is a naturally fractured reservoir field located in offshore Tunisia. Recently, the field has manifested serious integrity and water coning issues. An integrity study was necessary to accurately determine the ever-changing stress settings and properly assimilate their impact on the production trend. Thus, former geomechanical investigations of the field were revisited to acquire a strong understanding of the reservoir and so develop an appropriate Mechanical Earth Models that assimilate the current stresses state and mechanical properties. The rock-mechanical characteristics was subsequently up-scaled to an Intact Three-Dimensional Geomechanical Model that incorporates the geomechanical properties along with the faults network. The homogenization concept was then adopted to generate the homogenized rock properties that were then populated over the latest model in order to establish the Three-Dimensional Homogenized Geomechanical Model (3D-HGM). The 3D-HGM was deployed to investigate the invasive impact of the fractures on field deliverability and ultimately generate a reactivation potential map of the faults at current and future conditions, which showed again the reactivation of most of faults intercepted by the well notably the ones responsible of water production. A justification that the former investigation studies were not in position to offer it as they were grounded only on the 1D modelling approaches (i.e. intact model). Previous observation was confirmed through the built of a two dimensional finite model for the problematic well A1ST thus allowing us to compute displacement of the fault's walls and accordingly interpret the new values of permeability associated to the different faults of the field. The up-to-date permeabilities were introduced to the dynamic reservoir model hence to estimate production trend of the A1ST1 well. A fair matching with field production data was achieved, proving again the reliability of the integral approach developed in this study in modelling the Hasdrubal field with high accuracy.

Frequency-reconfigurable variode enabled metasurface reflector loaded antenna

A compact high gain frequency reconfigurable metasurface reflector (MSR) loaded antenna using a varactor diode is proposed in this paper. In comparison to a traditional antenna, a metamaterial (MTM) loaded with CSRR is used to achieve a size reduction up to 70%. The ground plane of the proposed slotted decagon antenna has been loaded with a complementary split-ring resonator (CSRR). With dimensions of 0.24 λ × 0.24 λ × 0.013 λ (λ represents the center frequency at 2.40 GHz) the antenna is extremely compact. The antenna is designed on an FR4 substrate with εr = 4.4 & 1.6 mm of thickness. The investigation shows that utilization of the MSR structure has significantly increased gain compared to the decagon antenna without MSR. The MSR-loaded antenna dimension is 0.48 λ × 0.47λ × 0.013 λ (λ represents the center frequency at 2.40 GHz). Frequency reconfigurability is introduced by placing a varactor diode on the patch’s upper side. Changing the varactor’s DC reverse bias voltage from 0 to 10 V causes its resonance frequency to shift from 2420 to 2550 MHz, giving it a tuning ratio of 1.35. The proposed antenna offers efficiency ranges from 70%–80% over the operating bands. Except for a small deviation, there is a fair match between measured and simulated values. The antenna can be used in a variety of current and future communication systems.

Repeatedly matching items to agents fairly and efficiently

We consider a novel setting where a set of items is matched to the same set of agents repeatedly over multiple rounds. Each agent gets exactly one item per round, which brings interesting challenges to finding efficient and/or fair repeated matchings. A particular feature of our model is that the value of an agent for an item in some round depends on the number of rounds in which the item has been used by the agent in the past. We present a set of positive and negative results about the efficiency and fairness of repeated matchings. For example, when items are goods, an adaptation of the well-studied fairness notion of envy-freeness up to one good (EF1) can be satisfied under certain conditions. Furthermore, it is intractable to achieve fairness and (approximate) efficiency simultaneously, even though they are achievable separately. For mixed items, which can be goods for some agents and chores for others, we propose and study a new notion of fairness that we call swap envy-freeness (swapEF).

Pseudotetrahedral C2-symmetrical Co/Zn(II)-achiral Schiff base complexes with Δ/Λ-chirality induction at-metal as a racemic mixture

Reaction of achiral Schiff base ligands 1-((X-phenylimino)methyl)naphthalen-2-ol {X = 2-ethyl (HL1) or 4-methyl (HL2)} with cobalt(II) or zinc(II) acetate provided the corresponding bis[1-((X-phenylimino)methyl)naphthalen-2-olato-k2N,O]cobalt(II) or zinc(II) {X = 2-ethyl: M = Co (1) and Zn (2) or X = 4-methyl: M = Co (3) and Zn (4)} complexes. The molecules crystallize in the centrosymmetric space groups R–3 (1) and P–1 (3 or 4). Molecular structures determinations showed coordination of two molecules of the N,O-chelate ligands to the metal ion and formation of pseudotetrahedral complexes with C2-symmetry. Furthermore, coordination of two unsymmetrical achiral N,O-chelates induces Λ/Δ-chirality at the metal atom as a racemic mixture in the centrosymmetric space groups. Structural analyses further reveal that incorporation of 2-ethyl (1) or 4-methyl (3 or 4) group on the N-bound phenyl ring leads to an increase of both the O1-M-O2 and N1-M-N2 bond angles on going from 1 to 3 or 4, with the N1-M-N2 angle increasing to a much greater extent. The fair matching of the experimental and simulated powder X-ray diffraction patterns confirms the phase purity of bulk microcrystalline sample. Differential scanning calorimetry (DSC) results suggest an irreversible phase transformation from solid crystals to isotropic-liquids and subsequent thermal stability of the complexes. Cyclic voltammograms indicate a quasi-reversible two one electron charge transfer processes for 1 or 3 in N,N-dimethylformamide (DMF). Optimized geometry and excited state properties by density functional theory (DFT) and time dependent-density functional theory (TD-DFT) calculations correspond well to the experimental results.

Evaluation of rapid visual screening assessment of existing buildings using nonlinear numerical analysis

Different methodologies are available in the literature to perform seismic assessment of existing buildings. Amongst the simplified ones, Rapid Visual Screening (RVS) methodologies have been recently developed and proposed. RVS methods are simplified procedures that can be implemented rather quickly for preliminary assessment of building vulnerability without the need to perform a detailed model and numerical analysis. Their application is particularly useful in regions characterised by high seismicity or where an important share of the buildings was not designed according to seismic provisions. The outcome of RVS methods is a safety index, based on the data from simplified forms that are filled during visual inspection of the buildings. For this reason, the accuracy of the results could be significantly affected by building features that cannot be considered by such forms. To address this issue and to evaluate the effectiveness of RVS methods, this paper focuses on the comparison between the results of a specific RVS method and those from advanced numerical modelling and nonlinear analyses of masonry-infilled reinforced concrete buildings. Several case-study buildings were selected from a database developed in the framework of a recently concluded European project, which focused on the seismic risk assessment of residential buildings in Northern Algeria, a seismic prone region. The buildings are analysed using detailed structural finite element models, through both nonlinear static and dynamic analysis, considering also the influence of mechanical and geometrical properties of the masonry infills. The comparison results show that, despite the significant variability observed in the RVS vulnerability assessment outcomes, there is a fair overall match with the nonlinear analysis results, confirming the utility of RVS methods at an initial assessment stage, as well as the need for further extended validation research efforts.

Fair Matching under Constraints: Theory and Applications

Abstract This paper studies a general model of matching with constraints. Observing that a stable matching typically does not exist, we focus on feasible, individually rational, and fair matchings. We characterize such matchings by fixed points of a certain function. Building on this result, we characterize the class of constraints on individual schools under which there exists a student-optimal fair matching, the matching that is the most preferred by every student among those satisfying the three desirable properties. We study the numerical relevance of our theory using data on government-organized daycare allocation.

Concussion in Canadian Youth Ice Hockey: What Is Needed to Decrease the Burden?

Concussion in Canadian Youth Ice Hockey: What Is Needed to Decrease the Burden?

Palaeobiogeography, palaeoecology, and sequence stratigraphy of the Upper Jurassic carbonate succession of the Lar Formation, central Alborz Zone, Iran

Foraminifera, ammonites, and calcareous dinoflagellates were used for stratigraphy and, together with microfacies, for the assessment of the palaeoenvironmental conditions of the Upper Jurassic deposits in the central Alborz Zone of northern Iran. The Lar Formation (Lar Fm.) in the Polur section is of latest Oxfordian to early Kimmeridgian age. The ammonite Subnebrodites planula and the calcareous dinoflagellate Colomisphaera nagyi have been introduced as new biomarkers of the lower Kimmeridgian in the central Neo-Tethys. The distribution of calcareous dinoflagellates reflects possible dispersal routes along a narrow seaway between the western Neo-Tethys and the Alborz Zone in the central Neo-Tethys. The Terebella-Crescentiella associations of the Lar Fm. represent a low-energy setting under dysoxic conditions in the Central Neo-Tethys Ocean. The benthic foraminiferal assemblages in this formation show a high dominance of infaunal taxa and r-selected strategists. This assemblage is reminiscent of eutrophic conditions and low oxygen levels in the lower part of the Lar Fm. Good preservation of the hexactinellid sponges in the upper part of the Lar Fm. also indicates an oxygen-minimum zone. Three third-order depositional sequences can be distinguished in the study area based on six microfacies. Depositional sequence 1 (DS1) is composed mainly of argillaceous limestone and medium- to thick-bedded limestone, corresponding to an outer ramp-to-middle ramp environment. Depositional sequence 2 (DS2) comprises breccia limestone and thick-bedded limestone facies in its lower part and thin-bedded limestone to massive limestone in its upper part. The breccia limestone facies may be associated with subaerial exposure and reworking of previously deposited sediment during a relative sea level fall. The thin-bedded limestone to massive limestone of DS2 consists mainly of bioclastic mudstone to wackestone (outer ramp). These represent an deep-water outer homoclinal ramp facies. Depositional sequence 3 (DS3) consists mainly of massive limestone to thick-bedded limestone with a bioclastic peloidal microbial Crescentiella packstone (middle ramp). The relative stratigraphic positions of DSs1–3 and sequence boundaries in the uppermost Oxfordian to lower Kimmeridgian of the Polur area show a fair match to the upper Oxfordian to lower Kimmeridgian sequences (JOx7, JOx8, JKi1 and JKi2) on the global sea level curve.

Matching and Scheduling of Student-Company-Talks for a University IT-Speed Dating Event

In this paper, the IT-speed dating of a German university is considered, where students have talks with different companies in order to find a suitable internship. The goal is to create a good and fair matching of students and companies for these talks, based on student preferences, and to schedule the resulting talks in order to maintain the given time horizon and minimize the necessary room changes for the students. We solved the problem in two steps. First, we modeled the matching problem as an extended version of the capacitated transportation problem and solved it using a modified stepping stone method. Second, we present two approaches to solve the scheduling problem. A Monte Carlo tree search procedure generates time-constrained schedules with minimal duration, while a genetic algorithm generates longer schedules with individual pauses and fewer room changes. The approaches led to significantly more talks with valuable content, a shorter duration, and greater satisfaction of all participants.

Unique strength-ductility balance of AlCoCrFeNi2.1 eutectic high entropy alloy with ultra-fine duplex microstructure prepared by selective laser melting

• A highly densed AlCoCrFeNi 2.1 eutectic high entropy alloy with ultra-fine structure and remarkable strength-ductility balance is fabricated by selective laser melting (SLM). • The ultra-fine grains and heterogeneous eutectic structures are introduced into the AlCoCrFeNi 2.1 due to the rapid solidification. • The SLM-ed AlCoCrFeNi 2.1 presents an excellent match of high tensile strength (1271 MPa), yield strength (966 MPa), and good ductility (22.5%) at room temperature. • A fan blade with smooth and bright surface is successfully produced with gas-atomized powders. As a typical dual-phase eutectic high entropy alloy (EHEA), AlCoCrFeNi 2.1 can achieve the fair matching of strength and ductility, which has attracted wide attention. However, the engineering applications of as-cast AlCoCrFeNi 2.1 EHEAs still face challenges, such as coarse grain and low yield strength resulting from low solidification rate and temperature gradient. In this study, selective laser melting (SLM) was introduced into the preparation of AlCoCrFeNi 2.1 EHEA to realize unique strength-ductility balance, with emphasis on investigating the effects of processing parameters on its eutectic microstructure and properties. The results show that the SLM-ed samples exhibit a completely eutectic structure consisting of ultra-fine face-centered cubic (FCC) and ordered body-centered cubic (B2) phases, and the duplex microstructure undergoes a morphological evolution from lamellar structure to cellular structure as laser energy input reducing. The SLM-ed AlCoCrFeNi 2.1 EHEA presents an excellent match of high tensile strength (1271 MPa), yield strength (966 MPa), and good ductility (22.5%) at room temperature, which are significantly enhanced by the ultra-fine grains and heterogeneous structure due to rapid solidification rate and high temperature gradient during SLM. Especially, the yield strength increment of ∼50% is realized with no loss in ductility as compared with the as-cast samples with the same composition. On this basis, the precise complex component with excellent mechanical properties is well achieved. This work paves the way for the performance improvement and complex parts preparation of EHEA by microstructural design using laser additive manufacturing.

Hydrodynamic coefficients from forced and decay heave motion tests of a scaled model of a column of a floating wind turbine equipped with a heave plate

This paper describes the results of an experimental campaign aimed at the determination of heave hydrodynamic coefficients for a column of a floating wind turbine platform, equipped with a solid heave plate. The tests are carried out with an experimental system that allows performing both heave forced oscillation tests and heave decay tests. A specific characteristic of the system is the reduced mechanical friction, thanks to the use of air bushings. A series of forced oscillation and decay experiments have been carried out with such a model, and the hydrodynamic coefficients obtained in both types of tests are compared. Results show correlation between both methods if the mean of the peaks of the decay process is chosen to represent its Keulegan–Carpenter number (KC), with a fair matching of the results in the KC range where both methods are applicable. With the objective of conducting an uncertainty assessment which can be relevant for the full-scale extrapolation of results, non-dimensional added mass and damping coefficients are proposed. They incorporate the primitive relevant variables and are shown to lead to a notable collapse of the various results in the form of curves with small differences among them. With these coefficients, an uncertainty assessment is carried out, propagating to those coefficients the uncertainties of the primitive variables in place. Such non-dimensional coefficients are useful to develop simple models to estimate the dimensional ones to be used in numerical simulations of the full scale system. The estimated uncertainties can serve to define design safety margins for the values of such coefficients.

A Planar Four-Element UWB Antenna Array with Stripline Feeding Network

This paper proposes a four-element ultrawideband (UWB) planar antenna array with elliptical-shaped radiators and a stripline excitation network designed for the 6–8.5 GHz UWB frequency band allowed in Europe by the European Commission. The designed antenna array has a symmetrical structure in which the radiators are placed along one line in the central conducting layer, arranged between two layers of a dielectric. Radiating elements are fed by the stripline excitation network that provides uniform power distribution. The dimensions of the elliptical radiators’ axes are 14 mm × 16 mm. Two variants of array are proposed. The distance between the radiators’ centers is L = 19 mm for a shorter variant and L = 24 mm for a longer one. The presented antenna array structures have a size of 81 mm × 41 mm and 96 mm × 41 mm. These arrays present a measured gain of 6.4–10.6 dBi for the shorter variant and 8.5–10.8 dBi for the longer one and a fair impedance matching. The measured |S11| is less than −8.7 dB and −9.7 dB for the shorter and longer corresponding variants.

P-doped TiO2-MWCNTs nanocomposite thin films with enhanced photocatalytic activity under visible light exposure

From a sustainability standpoint, TiO2 semiconductor photocatalyst has a lot of potential in water purification. However, due to TiO2's high band gap and rapid recombination rate of electron/hole (e−/h+) pairs, visible light exposure is not practicable. To overcome these limitations, this study investigated the effects of phosphorous (P) doping and multi-walled carbon nanotubes (MWCNTs) insertion in the TiO2 matrix. The thin films form of the photocatalyst was focused on to avoid the challenges associated with the usage of powder form photocatalyst. Thin films of TiO2, TiO2/MWCNTs and phosphorous (P)-doped TiO2/MWCNTs composites have been satisfactorily prepared on glass substrates by a newly developed facile sol-gel drop coating (SGDC) method. Characterization of the prepared samples for morphology, structure, and other properties was done by using Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), and Ultraviolet–Visible (UV–Vis) absorption spectroscopy. The XRD pattern of all thin films exhibited an anatase phase of the TiO2 crystal lattice, and calculation of lattice parameters revealed a fair match of lattice values of P-doped TiO2/MWCNTs thin films with the standard value of the same. The photocatalytic activity was estimated by the degradation of methylene blue (MB) dye in water under visible light exposure. The efficiency percentage of the as synthesized P-doped TiO2/MWCNTs thin films was more than doubled when compared to pure TiO2 and MWCNTs-TiO2. The enhancement of photocatalytic activity of P-doped TiO2/MWCNTs thin films is due to the photo-induced electron absorption effect by MWCNTs and the electron trap effect by P, a non-metal within the TiO2 matrix. Additionally, P doping within TiO2 also lowers the band gap, which in turn helps to exhibit pronounced photo-catalytic activity in the visible light region. A first-order kinetics model fitted the experimental photodegradation data well. The findings of the study suggest that P-doped TiO2/MWCNTs composite thin films prepared by the SGDC method can be widely applied in waste water treatment using visible light exposure.

Design of a Compact Novel Stub Loaded Pentaband Bandpass Filter for Next Generation Wireless RF Front Ends

This paper presents a compact novel pentaband bandpass filter using a dual path stub loaded step impedance resonator (SLSIR). The proposed topology consists of a dual path λ/4 and 2λ/3 long uniform impedance resonator centered separated by 2λ/3 open and λ/12 short circuit stubs respectively. The superposition of signals from the two transmission routes results in a fifth-order pentaband bandpass response with six finite frequency transmission zeroes and out-of-band rejection of 11dB from 12 GHz up to 20 GHz. The filter produces five frequency bands at 1.06 GHz, 3.24 GHz, 5.36 GHz, 8.55 GHz and 10.78 GHz with fractional bandwidth (FBW) of 25.59%, 22.22%, 19.48%, 16.03% and 17.17% respectively. The proposed design is fabricated on a high-frequency substrate with a physical size of (0.23λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>g</i></sub> × 0.14 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>g</i></sub> ). The new pentaband bandpass filter has a simple and compact design with good electrical performance. A fair match can be found between the simulated and experimental results.

A comparison of models of linear collisions between spherical particles in the pendular regime

This study examines granular collisions between spherical particles coated with a thin layer of viscous liquid, such that the capillary number is high and viscous forces dominate. Measurements were performed using high-speed particle tracking velocimetry. The measurements were used to examine four theoretical models that describe the collisions. The viscous force scales with the inverse of the separation distance between particles. The models limit the viscous force by setting a minimum approach distance. A fair match between experiments and simulations was obtained for all models by fitting this minimum approach distance. However, in some cases, to achieve a good match to the experiments, the minimum approach distance had to be set to a non-physical value. The best, and most physically reasonable, agreement was obtained when the viscous force accounted for the curvature of the surface and the minimum approach distance was determined using an empirically-fitted glass transition pressure model.