Mitigating the risk of tanking in multi-stage tournaments

Multi-stage tournaments consisting of a round-robin group stage followed by a knockout phase are ubiquitous in sports. However, this format is incentive incompatible if at least 2 teams from a group advance to the knockout stage where the brackets are predetermined. A model is developed to quantify the risk of tanking in these contests. The suggested approach is applied to the 2022 FIFA World Cup to uncover how its design could have been improved by changing group labelling (a reform that has received no attention before) and the schedule of group matches. Scheduling is found to be a surprisingly weak intervention compared to previous results on the risk of collusion in a group. The probability of tanking, which is disturbingly high around 25%, cannot be reduced by more than 3 percentage points via these policies. Tournament organisers need to consider more fundamental changes against tanking

The fairness of the group draw for the FIFA World Cup

Several sports tournaments contain a round-robin group stage where the teams are assigned to groups subject to some constraints. Hence, the organisers usually use a computer-assisted random draw to avoid any dead end, a situation when the teams still to be drawn cannot be assigned to the remaining empty slots. This procedure is known to be unfair: the feasible allocations are not equally likely, that is, the draw does not have a uniform distribution. We quantify the implied unfairness of the 2025 FIFA World Cup draw and evaluate its effect on the probability of qualification for the knockout stage for each national team. The official draw order of Pot 1, Pot 2, Pot 3, Pot 4 turns out to be a significantly better option than the 23 other draw orders with respect to the unwanted distortions. Nonetheless, the non-uniform draw distorts the probability of qualification by more than one percentage point for two countries. Our results call attention to the non-negligible role of draw order and make it possible for policymakers to decide whether using fairer draw mechanisms is justified

On variants of a load-balancing problem with unit-load jobs

In this paper, we reconsider an offline load-balancing problem with unit-time jobs that require one unit from a common resource throughout their execution. In the unit-time case, the jobs have to be assigned to time-slots such that a separable convex function of the load of the resource has to be minimized. Variants of this problem have been studied extensively in the literature under different names. We briefly discuss these problems and give a new implementation for one of them with a better worst-case time complexity than any of the known methods. We also consider the more general preemptive problem in which the execution of the jobs can be interrupted and resumed later. Furthermore, we divide the time horizon into disjoint time intervals, and for each interval, a separable convex cost function is given. The jobs have to be scheduled within their feasible intervals preemptively such that the total cost is minimized, where the cost is determined separately for each interval by the corresponding cost function. We show how to solve this problem in polynomial time by a single minimum-cost-flow computation. For the preemptive problem with one cost function only, we propose a proprietary algorithm for finding a feasible solution which is optimal for any convex cost function. We also present some qualitative computational results

Slowed epigenetic aging in Olympic champions compared to non-champions

The lifestyle patterns of top athletes are highly disciplined, featuring strict exercise regimens, nutrition plans, and mental preparation, often beginning at a young age. Recently, it was shown that physically active individuals exhibit slowed epigenetic aging and better age-related outcomes. Here, we investigate whether the extreme intensity of physical activity of Olympic champions still has a beneficial effect on epigenetic aging. To test this hypothesis, we examined the epigenetic aging of 59 Hungarian Olympic champions and of the 332 control subjects, 205 were master rowers. We observed that Olympic champions exhibit slower epigenetic aging, applying seven state-of-the-art epigenetic aging clocks. Additionally, male champions who won any medal within the last 10 years showed slower epigenetic aging compared to other male champions, while female champions exhibited the opposite trend. We also found that wrestlers had higher age acceleration compared to gymnasts, fencers, and water polo players. We identified the top 20 genes that showed the most remarkable difference in promoter methylation between Olympic champions and non-champions. The hypo-methylated genes are involved in synaptic health, glycosylation, metal ion membrane transfer, and force generation . Most of the hyper-methylated genes were associated with cancer promotion. The data suggest that rigorous and long-term exercise from adolescence to adulthood has beneficial effects on epigenetic aging

The allocation of FIFA World Cup slots based on the ranking of confederations

Qualifications for several world championships in sports are organised such that distinct sets of teams play in their own tournament for a predetermined number of slots. Inspired by a recent work studying the problem with the tools from the literature on fair allocation, this paper provides an alternative approach based on historical matches between these sets of teams. We focus on the FIFA World Cup due to the existence of an official rating system and its recent expansion to 48 teams, as well as to allow for a comparison with the already suggested allocations. Our proposal extends the methodology of the FIFA World Ranking to compare the strengths of five confederations. Various allocations are presented depending on the length of the sample, the set of teams considered, as well as the frequency of rating updates. The results show that more European and South American teams should play in the FIFA World Cup. The ranking of continents by the number of deserved slots is different from the ranking implied by FIFA policy. We recommend allocating at least some slots transparently, based on historical performances, similar to the access list of the UEFA Champions League

Statistical overview of the Sniffin’ sticks olfactory test from the perspectives of anosmia and hyposmia

The Sniffin’ Sticks test is evaluated by summing the scores of threshold, discrimination, and identification subtests to establish an olfactory diagnosis (anosmia , hyposmia , normosmia). However, variations in thresholds, ranges and inconsistencies have been observed. Statistical analyses (distributions, quantiles), protocol simulation, and implementations of the Sniffin’ Sticks test were conducted. This study contributes a statistical revision: determining a cut-off point for the total TDI score, optimising the number of alternatives in the identification subtest, and equalising correct responses (frequency, balanced in time, subsequent pairs). The upper score threshold used to diagnose anosmia is lower than the typical first-order error thresholds applied in comparable assessments ( anosmia ≤ 16.75 points, hyposmia ≥ 17 points at 90% confidence level). In the culturally adapted 16-pen Sniffin’ Sticks identification tests, the frequency of correct responses was aligned with that of the original test. However, the equalisation of the frequency of adjacent correct response pairs and the temporal occurrence of correct responses was not met in any test. The order of all correct answers that simultaneously satisfied all three matching conditions was determined. The practical significance of the results is that the recommended protocol of the Sniffin’ Sticks test system can be implemented in clinical practice with minimal modification

Polynomial Time Coverability Analysis in Discrete State Chemical Reaction Network Subclasses

In this paper the coverability problem of discrete state Chemical Reaction Networks (d-CRNs) is considered. We study certain sub-classes of d-CRN reaction network structures and prove that the coverability relation is implied by the reachability property in another reaction network class in which the reachability problem is proven to be decidable in polynomial time. We make use of the equivalent Petri net representation of d-CRNs and the concept of dual graph to obtain networks for which the reachability relation can be decided in polynomial time. Making use of the reachability relations of the dual graph, we provide theoretical guarantee for the coverability property in the initial network. This way sufficient condition is obtained for d-CRN coverability with polynomial time complexity. The studied sub-classes of d-CRNs include subconservative network structures, in addition, complexes composed of more than one species are allowed as well. The basic concepts and the new results are illustrated on several examples

Exact particle flow Daum-Huang filters for mobile robot localization in occupancy grid maps

In this paper, we present a novel localization algorithm for mobile robots navigating in complex planar environments, a critical capability for various real-world applications such as autonomous driving, robotic assistance, and industrial automation. Although traditional methods such as particle filters and extended Kalman filters have been widely used, there is still room for assessing the capabilities of modern filtering techniques for this task. Building on a recent localization method that employs a chamfer distance-based observation model, derived from an implicit measurement equation, we explore its potential further by incorporating exact particle flow Daum–Huang filters to achieve superior accuracy. Recent advancements have spotlighted Daum–Huang filters as formidable contenders, outshining both the extended Kalman filters and traditional particle filters in various scenarios. We introduce two new Daum–Huang-based localization algorithms and assess their tracking performance through comprehensive simulations and real-world trials. Our algorithms are benchmarked against various methods, including the widely acclaimed Adaptive Monte–Carlo Localization algorithm. Overall, our algorithm demonstrates superior performance compared to the baseline models in simulations and exhibits competitive performance in the evaluated real-world application

Scenario-Optimization-Based Velocity Planning of Autonomous Vehicles for Interacting With Pedestrians

This paper presents a velocity planning method for autonomous vehicles (AVs) to guarantee safe interactions with pedestrians at unsignalized crosswalks and with surrounding vehicles on the AV's route. The method is structured within a hierarchical framework that includes robust control, a learning-based component, and a supervisory element. The learning-based component is trained using reinforcement learning techniques to reduce traveling time, minimize control interventions, and set the priority ratio between the AV and pedestrians. The supervisory element employs scenario optimization, using statistical data on pedestrian motions to ensure collision avoidance. A complex game-theory-based pedestrian model is formulated and analyzed in order to evaluate the effectiveness of the proposed velocity planning method. Extensive simulations are performed using the high-precision traffic simulator software SUMO. These simulations evaluate various aspects of the velocity planner, including computation time, traveling time, control interventions, and parameter settings. The results demonstrate the method's ability to achieve real-time implementation while maintaining safety and performance objectives. © 2025 IEEE