Showing papers on "Tournament published in 2020"

The Positive Impact of Teams Games Tournament Learning Model Assisted with Video Media on Students’ Mathematics Learning Outcomes

Abstract: The low of Mathematics learning outcomes of the fifth-grade students are the main problem in this study. It is because the teacher has not implemented a learning model that can enable students in the learning process, the lack of use of media in the learning process provided by the teacher, students study Mathematics rarely, and the lack of concentration in receiving Mathematics. This study aimed to determine the effect of the video media assisted Teams Games Tournament (TGT) learning model on the Mathematics learning outcomes of the fifth-grade students. This research was a quasi-experimental with using non-equivalent post-test only control group design. The population of this research was 137 students. This study applied an intact group technique so the research sample of fifth grade students was 52 students. The students’ Mathematics learning outcomes were collected by using an objective test method through 24 multiple choice questions. The research hypothesis was tested using t-test. Based on the results of data analysis, the researcher obtained tcount = 14,354 > ttable = 2,021 (at a significance level 5%). The result of hypothesis test indicated that there was a significant difference on students’ Mathematics learning outcomes. Thus, it can be concluded that the video media assisted Teams Games Tournament (TGT) significantly influences the mathematics learning outcomes.

On the Structure of Stable Tournament Solutions

Abstract: A fundamental property of choice functions is stability, which, loosely speaking, prescribes that choice sets are invariant under adding and removing unchosen alternatives. We provide several structural insights that improve our understanding of stable choice functions. In particular, (i) we show that every stable choice function is generated by a unique simple choice function, which never excludes more than one alternative, (ii) we completely characterize which simple choice functions give rise to stable choice functions, and (iii) we prove a strong relationship between stability and a new property of tournament solutions called local reversal symmetry. Based on these findings, we provide the first concrete tournament---consisting of 24 alternatives---in which the tournament equilibrium set fails to be stable. Furthermore, we prove that there is no more discriminating stable tournament solution than the bipartisan set and that the bipartisan set is the unique most discriminating tournament solution which satisfies standard properties proposed in the literature.

Do tournament incentives motivate chief executive officers to be socially responsible

Abstract: This study aims to investigate the question concerning whether tournament incentives motivate chief executive officers (CEOs) to be socially responsible.,Data from all A-share Chinese companies listed on the Shanghai and Shenzhen stock exchanges for the period from 2010 to 2015 are used. To draw inferences from the data, ordinary least squares (OLS) regression and cluster OLS are used as a baseline methodology. To control for the possible issue of endogeneity, firm-fixed-effects regression, two-stage least squares regression and propensity score matching are used.,A reliable evidence is found that tournament incentives motivate CEOs to be more socially responsible. Additional analysis reveals that the positive effect of CEO tournament incentives on corporate social responsibility performance (CSRP) is more pronounced in state-owned firms than it is in non-state-owned firms. The study’s findings are consistent with tournament theory and the conventional wisdom hypothesis, which proposes that better incentives lead to competitiveness, which improves financial and social performance.,The study’s findings have implications for companies and regulators who wish to enhance CSRP by giving tournament incentives to top managers. Investment in social responsibility may reduce the conflict between executives and employees and improve the corporate culture.,This study contributes to the existing literature by providing the first evidence that CEOs’ tournament incentives play a vital role in CSRP. The study’s findings contribute to tournament theory.

Vertex ordering problems in directed graph streams

Abstract: We consider directed graph algorithms in a streaming setting, focusing on problems concerning orderings of the vertices. This includes such fundamental problems as topological sorting and acyclicity testing. We also study the related problems of finding a minimum feedback arc set (edges whose removal yields an acyclic graph), and finding a sink vertex. We are interested in both adversarially-ordered and randomly-ordered streams. For arbitrary input graphs with edges ordered adversarially, we show that most of these problems have high space complexity, precluding sublinearspace solutions. Some lower bounds also apply when the stream is randomly ordered: e.g., in our most technical result we show that testing acyclicity in the p-pass random-order model requires roughly n1+1/p space. For other problems, random ordering can make a dramatic difference: e.g., it is possible to find a sink in an acyclic tournament in the one-pass random-order model using polylog(n) space whereas under adversarial ordering roughly n1/p space is necessary and sufficient given Θ(p) passes. We also design sublinear algorithms for the feedback arc set problem in tournament graphs; for random graphs; and for randomly ordered streams. In some cases, we give lower bounds establishing that our algorithms are essentially space-optimal. Together, our results complement the much maturer body of work on algorithms for undirected graph streams.

Smooth approximations and CSPs over finitely bounded homogeneous structures.

Abstract: We develop the novel machinery of smooth approximations, and apply it to confirm the CSP dichotomy conjecture for first-order reducts of the random tournament, various homogeneous graphs including the random graph, and for expansions of the order of the rationals. Apart from obtaining these dichotomy results, we show how our new proof technique allows to unify and significantly simplify the previous results from the literature. For all but the last structure, we moreover characterize those CSPs which are solvable by local consistency methods, again using the same machinery.

Meta-Analysis of Teams Games Tournament Learning Model with Spinning Wheel Media-Based on Local Wisdom Toward Students’ Learning Outcomes

Abstract: Research that examines the effect of cooperative learning teams games tournament types on student learning outcomes has been done a lot, but the results of these studies have not received further study to be summarized and tested again the effectiveness of the effect of the learning model used. This study aims to analyze the effect of the use of a team games tournament type cooperative learning model with spinning wheel media-based local wisdom on the learning outcomes of elementary school students. The method used in this research is meta-analysis. The collection of data through online searches using the Google Scholar platform as many as 15 articles were collected with the details of 10 articles representing the learning models of team’s games tournaments and spinning wheel media while the remaining 5 articles are educational articles based on local wisdom. All articles are then analyzed with differences and similarities in data and then reprocessed using SPSS Version 25 using paired sample t-test and showing the Sig. (2-tailed), i.e. (0, 019) <α (0.05). So, H0 is rejected and it can be concluded that there is a significant difference from before and after the use of the learning model that assisted team’s tournament games wheel media in science subjects.

Teams Games Tournament Assisted by Question Card Increases Student Knowledge Competence in Science Learning

Abstract: The low competence of students' science knowledge is caused by the lack of optimal use of innovative learning models and the lack of using learning media. The purpose of this study was to examine the effect of the Teams Games Tournament learning model assisted by the Media Question Card on the scientific competence of science students in fourth grade elementary. This type of research was a quasi-experimental research design with a nonequivalent control group design. The population of this study was the fourth-grade students with a total of 392 students. The sample was determined by a random sampling technique. The sample in this study was class IV with a total sample of class 34 students as the experimental group and class IV with a class sample of 33 students as the control group. The science competency data collection was done by the test method and the instrument used was an ordinary multiple-choice objective test. The data obtained were analyzed using a t-test. The results of the analysis showed that there were significant differences in the learning models of team’s games tournament assisted by the media question card to the scientific competence of science with conventional learning of fourth-grade students. Based on the results of data analysis obtained tcount = 3.245 at a significance level of 5% and dk = 65 obtained ttable = 1.997 so tcount = 3.25> ttable = 1.997. Based on the testing criteria, it is rejected and accepted. Thus, it can be concluded, the Teams Games Tournament learning model assisted by the Question Card media influences the science knowledge competence of fourth-grade.

Tournament Incentives and Acquisition Performance

Abstract: This paper examines the impact of promotion-based tournament incentives on corporate acquisition performance. Measuring tournament incentives as the compensation ratio between the CEO and other senior executives, we show that acquirers with greater tournament incentives experience lower announcement returns. Further analysis shows that the negative effect is driven by the risk-seeking behavior of senior executives induced by tournament incentives. Our results are robust to alternative identification strategies. Our evidence highlights that senior executives, in addition to the CEO, play an influential role in acquisition decisions.

2-approximating feedback vertex set in tournaments

Abstract: A tournament is a directed graph T such that every pair of vertices is connected by an arc. A feedback vertex set is a set S of vertices in T such that T − S is acyclic. We consider the Feedback Vertex Set problem in tournaments. Here the input is a tournament T and a weight function w : V(T) → N and the task is to find a feedback vertex set S in T minimizing w(S) = ∑v∈S w(v). Rounding optimal solutions to the natural LP-relaxation of this problem yields a simple 3-approximation algorithm. This has been improved to 2.5 by Cai et al. [SICOMP 2000], and subsequently to 7/3 by Mnich et al. [ESA 2016]. In this paper we give the first polynomial time factor 2 approximation algorithm for this problem. Assuming the Unique Games conjecture, this is the best possible approximation ratio achievable in polynomial time.

Surprises in Knockout Tournaments

Abstract: Sometimes the second-best player in a knockout tournament is more likely to win that to finish second. We characterize this surprising situation, under certain natural conditions.

Strategic Manipulations in Round-Robin Tournaments

Abstract: We study round-robin tournaments with four symmetric players and two identical prizes where players compete against each other in games modeled as an all-pay contest. We demonstrate that in this common structure players may have an incentive to manipulate the results, namely, depending on the outcomes of the first round, a player may have an incentive to lose in the second round in order to maximize his expected payoff in the tournament.

Tighter Bounds on Directed Ramsey Number R(7)

Abstract: Tournaments are orientations of the complete graph, and the directed Ramsey number $R(k)$ is the minimum number of vertices a tournament must have to be guaranteed to contain a transitive subtournament of size $k$, which we denote by $TT_k$. We include a computer-assisted proof of a conjecture by Sanchez-Flores that all $TT_6$-free tournaments on 24 and 25 vertices are subtournaments of $ST_{27}$, the unique largest TT_6-free tournament. We also classify all $TT_6$-free tournaments on 23 vertices. We use these results, combined with assistance from SAT technology, to obtain the following improved bounds: $34 \leq R(7) \leq 47$.

Tournament solutions based on cooperative game theory

Abstract: A tournament can be represented as a set of candidates and the results from pairwise comparisons of the candidates. In our setting, candidates may form coalitions. The candidates can choose to fix who wins the pairwise comparisons within their coalition. A coalition is winning if it can guarantee that a candidate from this coalition will win each pairwise comparison. This approach divides all coalitions into two groups and is, hence, a simple game. We show that each minimal winning coalition consists of a certain uncovered candidate and its dominators. We then apply solution concepts developed for simple games and consider the desirability relation and the power indices which preserve this relation. The tournament solution, defined as the maximal elements of the desirability relation, is a good way to select the strongest candidates. The Shapley–Shubik index, the Penrose–Banzhaf index, and the nucleolus are used to measure the power of the candidates. We also extend this approach to the case of weak tournaments.

Effects of an International Tournament on Heart Rate Variability and Perceived Recovery in Elite Water Polo Players.

Abstract: Botonis, PG, Smilios, I, Platanou, TI, and Toubekis, AG. Effects of an international tournament on heart rate variability and perceived recovery in elite water polo players. J Strength Cond Res XX(X): 000-000, 2020-The purpose of the study was to evaluate the effects of an international tournament participation in vagal-related heart rate variability and perceived recovery among elite water polo players. Nine elite water polo players participated in an intensified training week (pretournament) and then traveled abroad to take part in an international tournament including 3 high-competitive matches during a 4-day period. Internal workload was measured after training or competition. Morning, postwakening natural logarithm of the root mean square of successive differences (lnRMSSD) and measures of perceived recovery were obtained pretournament and daily during the tournament. Logarithm of the root mean square of successive differences was also measured 30 minutes after the completion of each match of the tournament. Logarithm of the root mean square of successive differences was suppressed after the first match (p = 0.03, d = -0.75), compared with the first morning of the tournament, rebounded the following morning (p = 0.03, d = 0.87), and remained unaltered until the third match. In the last morning of the tournament, LnRMSSD was higher compared with the first postmatch measurement (p = 0.002, d = 1.57) and tended to be higher than pretournament (p = 0.09, d = 0.81). Perceived recovery and internal workloads were lower in the tournament days compared with pretournament (p < 0.001, d = 2.0 and p < 0.001, d = 14.0, respectively). In conclusion, heart rate variability may stabilize and progressively increase by the end of a tournament, as compared with a pretournament training period, reflecting an enhanced parasympathetic reactivation may be due to the reduced training load. By contrast, perceived recovery was suppressed indicating that other factors may also influence the overall recovery of the players.

Cycles of a given length in tournaments

Abstract: We study the asymptotic behavior of the maximum number of directed cycles of a given length in a tournament: let $c(\ell)$ be the limit of the ratio of the maximum number of cycles of length $\ell$ in an $n$-vertex tournament and the expected number of cycles of length $\ell$ in the random $n$-vertex tournament, when $n$ tends to infinity. It is well-known that $c(3)=1$ and $c(4)=4/3$. We show that $c(\ell)=1$ if and only if $\ell$ is not divisible by four, which settles a conjecture of Bartley and Day. If $\ell$ is divisible by four, we show that $1+2\cdot\left(2/\pi\right)^{\ell}\le c(\ell)\le 1+\left(2/\pi+o(1)\right)^{\ell}$ and determine the value $c(\ell)$ exactly for $\ell = 8$. We also give a full description of the asymptotic structure of tournaments with the maximum number of cycles of length $\ell$ when $\ell$ is not divisible by four or $\ell\in\{4,8\}$.

Robust bounds on choosing from large tournaments.

Abstract: Tournament solutions provide methods for selecting the “best” alternatives from a tournament and have found applications in a wide range of areas. Previous work has shown that several well-known tournament solutions almost never rule out any alternative in large random tournaments. Nevertheless, all analytical results thus far have assumed a rigid probabilistic model, in which either a tournament is chosen uniformly at random, or there is a linear order of alternatives and the orientation of all edges in the tournament is chosen with the same probabilities according to the linear order. In this work, we consider a significantly more general model where the orientation of different edges can be chosen with different probabilities. We show that a number of common tournament solutions, including the top cycle and the uncovered set, are still unlikely to rule out any alternative under this model. This corresponds to natural graph-theoretic conditions such as irreducibility of the tournament. In addition, we provide tight asymptotic bounds on the boundary of the probability range for which the tournament solutions select all alternatives with high probability.

Simulating competitiveness and precision in a tournament structure: a reaper tournament system

Abstract: This paper explores a new perspective of finding the best tournament structures by focusing on two aspects (apart from the number of matches): competitiveness development and ranking precision. Competitiveness development emphasizes the importance of participants’ motivation while keeping the matches exciting whereas ranking precision reflects the persuasiveness of tournament result to its participants. To address competitiveness development, this paper proposes a new method that visualizes tournament structures using a tree-like graphical model called progress tree. In addition, ranking precision is addressed by considering the similarities and qualities of the ranking process by the sorting algorithm during the ranking process. With respect to these two aspects, several well-known tournament structures such as the single elimination, double elimination, Round-Robin, and Swiss systems were analyzed. Although each tournament has its own pros and cons, none of them can thoroughly convince all participants of the tournament results while keeping the matches strongly motivating. As such, a new tournament structure called Reaper tournament system with its variants, are proposed. The Reaper tournament system with its variants were evaluated on simulated football matches and validated with real-world data of previous football tournaments. Thence, practical insights into tournament structures are obtained and possible future works are discussed.

Tournament Incentives and Acquisition Performance

Abstract: This paper examines the impact of promotion-based tournament incentives on corporate acquisition performance. Measuring tournament incentives as the compensation ratio between the CEO and other senior executives, we show that acquirers with greater tournament incentives experience lower announcement returns. Further analysis shows that the negative effect is driven by the risk-seeking behavior of senior executives induced by tournament incentives. Our results are robust to alternative identification strategies. Our evidence highlights that senior executives also play an influential role in acquisition decisions in addition to the CEO.

A paradox of tournament seeding

Abstract: We analyse a mathematical model of seeding for sports contests with round-robin qualifying tournaments. The sufficient conditions for incentive compatibility are found to be quite restrictive: if each team is considered with its own coefficient (usually a measure of its past performance), only one or all of them should qualify from every round-robin tournament. Consequently, the standard draw system creates incentives for tanking as each team prefers to qualify with teams having a lower coefficient in order to face weaker opponents on average in the next stage. Major football competitions are shown to suffer from this weakness. Strategyproofness can be guaranteed by giving to each qualified team the highest coefficient of all teams that are ranked lower in its round-robin tournament for seeding purposes. Our proposal is illustrated by the 2020/21 UEFA Champions League.

Refining Tournament Solutions via Margin of Victory

Abstract: Tournament solutions are frequently used to select winners from a set of alternatives based on pairwise comparisons between alternatives. Prior work has shown that several common tournament solutions tend to select large winner sets and therefore have low discriminative power. In this paper, we propose a general framework for refining tournament solutions. In order to distinguish between winning alternatives, and also between non-winning ones, we introduce the notion of margin of victory (MoV) for tournament solutions. MoV is a robustness measure for individual alternatives: For winners, the MoV captures the distance from dropping out of the winner set, and for non-winners, the distance from entering the set. In each case, distance is measured in terms of which pairwise comparisons would have to be reversed in order to achieve the desired outcome. For common tournament solutions, including the top cycle, the uncovered set, and the Banks set, we determine the complexity of computing the MoV and provide worst-case bounds on the MoV for both winners and non-winners. Our results can also be viewed from the perspective of bribery and manipulation.

Approximately Strategyproof Tournament Rules: On Large Manipulating Sets and Cover-Consistence

Abstract: We consider the manipulability of tournament rules, in which n teams play a round robin tournament and a winner is (possibly randomly) selected based on the outcome of all binom{n}{2} matches. Prior work defines a tournament rule to be k-SNM-α if no set of ≤ k teams can fix the ≤ binom{k}{2} matches among them to increase their probability of winning by >α and asks: for each k, what is the minimum α(k) such that a Condorcet-consistent (i.e. always selects a Condorcet winner when one exists) k-SNM-α(k) tournament rule exists? A simple example witnesses that α(k) ≥ (k-1)/(2k-1) for all k, and [Jon Schneider et al., 2017] conjectures that this is tight (and prove it is tight for k=2). Our first result refutes this conjecture: there exists a sufficiently large k such that no Condorcet-consistent tournament rule is k-SNM-1/2. Our second result leverages similar machinery to design a new tournament rule which is k-SNM-2/3 for all k (and this is the first tournament rule which is k-SNM-(<1) for all k). Our final result extends prior work, which proves that single-elimination bracket with random seeding is 2-SNM-1/3 [Jon Schneider et al., 2017], in a different direction by seeking a stronger notion of fairness than Condorcet-consistence. We design a new tournament rule, which we call Randomized-King-of-the-Hill, which is 2-SNM-1/3 and cover-consistent (the winner is an uncovered team with probability 1).

The Influence of Teams Games Tournament (TGT) Model in Mastery of German Language Vocabulary

Abstract: This study aims to (1) describe the mastery of the vocabulary of the German language in students by using the learning lecturer variation model, (2) describe students German vocabulary who studied by using the learning model Teams Games Tournament, (3) determine the significant difference between students that use Teams Games Tournament learning model and students who are taught using lecturer variation model. This research used a quasi-experimental design with non-equivalent control group design forms and analyzed using a t-test. The population was class X IPA at SMAN 11 Makassar, totaling 252 students. The sample was selected using random sampling techniques. Class X IPA 1 includes 33 students as an experimental class and class X IPA 3 which includes 33 students as the control class. The results of the data analysis showed that the t-count > t table is 3.27> 1,999. It can be concluded that there are significant differences between students that learned German vocabulary by using the learning model Teams Games Tournament and students be taught using the lecture learning model varies.

Preference Graph of Potential Method as a Fuzzy Graph

Abstract: An autocatalytic set (ACS) is a graph. On the other hand, the Potential Method (PM) is an established graph based concept for optimization purpose. Firstly, a restricted form of ACS, namely, weak autocatalytic set (WACS), a derivation of transitive tournament, is introduced in this study. Then, a new mathematical concept, namely, fuzzy weak autocatalytic set (FWACS), is defined and its relations to transitive PM are established. Some theorems are proven to highlight their relations. Finally, this paper concludes that any preference graph is a fuzzy graph Type 5.

The “Cinderella Effect”: The Value of Unexpected March Madness Runs as Advertising for the Schools:

Abstract: This study looks at the impact of a university making a surprise (“Cinderella”) run in the men’s NCAA basketball tournament. Our results suggest that surprise success in the tournament has little t...

Decomposing tournaments into paths

Abstract: We consider a generalisation of Kelly's conjecture which is due to Alspach, Mason, and Pullman from 1976. Kelly's conjecture states that every regular tournament has an edge decomposition into Hamilton cycles, and this was proved by Kuhn and Osthus for large tournaments. The conjecture of Alspach, Mason, and Pullman asks for the minimum number of paths needed in a path decomposition of a general tournament (Formula presented.). There is a natural lower bound for this number in terms of the degree sequence of (Formula presented.) and it is conjectured that this bound is correct for tournaments of even order. Almost all cases of the conjecture are open and we prove many of them.

Investigating the Effect of Teams-Games-Tournament (TGT) Technique Towards Students’ Speaking Skill

Abstract: This study aimed to investigate the effect of Teams-Games-Tournament (TGT) Technique towards students’ speaking skill. Type of this research was a quantitative research with quasi-experimental design. 60 students of XI grade at SMA Negeri 9 Padang were choosed as the sample of this research which divided into two groups, experimental and control group. Both of this groups consisted of 30 students. The Teams-GamesTournament (TGT) Technique was used in the experimental group and the traditional technique was used in the control group to teach speaking. The data of this research were collected by using speaking test. It was used to obtain the students’ speaking score. Then, the data was analyzed by using t-test formula with the significance alpha 0.05. The findings of the research showed that Teams-Games-Tournament (TGT) Technique give a better effect on students’ speaking skill when compared with the effects of traditional technique. It was proved by the value of tobserved that was 2.446 which was higher than the value of ttable which was 1.671. The data indicated that the students taught by using Teams-Games-Tournament (TGT) Technique achieved significantly better scores in speaking than those taught by using the traditional technique.

On the restricted isometry property of the Paley matrix

Abstract: In this paper, we prove that the Paley graph conjecture implies that the Paley matrix has restricted isometry property (RIP) beating the square-root bottleneck for the sparsity level. Moreover, we show that the RIP of the Paley matrix implies an improved bound on the size of transitive subtournaments in the Paley tournament.