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International audience; This paper studies a novel multi-access coded caching (MACC) model where the topology between users and cache nodes is a generalization of those already studied in previous work, such as combinatorial and cross-resolvable design topologies. Our goal is to minimize the worst-case transmission load in the delivery phase from the server over all possible user requests. By formulating the access topology as two classical combinatorial structures, t-design and t-group divisible design, we propose two classes of coded caching schemes for a flexible number of users, where the number of users can scale linearly, polynomially or exponentially with the number of cache nodes. In addition, our schemes can unify most schemes for the shared link network and unify many schemes for the multi-access network except for the cyclic wrap-around topology.

Accepted paper to ISIT 2023 without proofs; International audience; In this paper, we study the computation of the ratedistortion-perception function (RDPF) for discrete memoryless sources subject to a single-letter average distortion constraint and a perception constraint that belongs to the family of fdivergences. For that, we leverage the fact that RDPF, assuming mild regularity conditions on the perception constraint, forms a convex programming problem. We first develop parametric characterizations of the optimal solution and utilize them in an alternating minimization approach for which we prove convergence guarantees. The resulting structure of the iterations of the alternating minimization approach renders the implementation of a generalized Blahut-Arimoto (BA) type of algorithm infeasible. To overcome this difficulty, we propose a relaxed formulation of the structure of the iterations in the alternating minimization approach, which allows for the implementation of an approximate iterative scheme. This approximation is shown, via the derivation of necessary and sufficient conditions, to guarantee convergence to a globally optimal solution. We also provide sufficient conditions on the distortion and the perception constraints which guarantee that our algorithm converges exponentially fast. We corroborate our theoretical results with numerical simulations, and we draw connections with existing results.

In typical coded caching scenarios, the content of a central library is assumed to be of interest to all receiving users. However, in a realistic scenario the users may have diverging interests which may intersect to various degrees. What happens for example if each file is of potential interest to, say, $40\,\%$ of the users and each user has potential interest in $40\,\%$ of the library? What if then each user caches selfishly only from content of potential interest? In this work, we formulate the symmetric selfish coded caching problem, where each user naturally makes requests from a subset of the library, which defines its own file demand set (FDS), and caches selfishly only contents from its own FDS. For the scenario where the different FDSs symmetrically overlap to some extent, we propose a novel information-theoretic converse that reveals, for such general setting of symmetric FDS structures, that selfish coded caching yields a load performance which is strictly worse than that in standard coded caching., Comment: 6 pages. Submitted to 2022 IEEE International Symposium on Information Theory (ISIT). arXiv admin note: substantial text overlap with arXiv:2109.04807

Recently, Muralidhar et al. proposed a novel multi-access system model where each user is connected to multiple caches in a manner that follows the well-known combinatorial topology of combination networks. For such multi-access topology, the same authors proposed an achievable scheme, which stands out for the unprecedented coding gains even with very modest cache resources. In this paper, we identify the fundamental limits of such multi-access setting with exceptional potential, providing an information-theoretic converse which establishes, together with the inner bound by Muralidhar et al., the exact optimal performance under uncoded prefetching., Comment: 5 pages, 1 figure. Submitted to 2022 IEEE International Symposium on Information Theory (ISIT). arXiv admin note: substantial text overlap with arXiv:2110.07426

Through this study, sportsmanship orientation of hearing impairedvolleyball players were tried to beexamined in terms of some variants. While the set ofresearch consisted of four-team Turkish 2017-2018 season Hearing ImpairedVolleyball 1st League, the sample group was of forty male sportsmen agedbetween 26,75 ± 7,59 who played in this league. For data collection, ademographic form including personal information and the MultidimensionalSportsmanship Orientation Scale (MSOS) which was developed by Vallerand and hisfriends (1997) and transcripted into Turkish by Sezen-BALÇIKANLI (2010) wereused. For normality test (Shapiro Wilk Test) seeing that data wasn’t proving anormal distribution for all dimensions, Mann Whitney-U and Kruskal Wallis testsare used instead which are non-parametric analysis methods. As a result, whilethere weren’t significant changes among hearing impaired volleyball players’sportsmanship attitudes in terms of sportsmanship experiences, educationlevels, parental education levels and age groups (p>0,05), inmulti-dimensional sportsmanship orientation scale it can be said thatcontribution to values of sportsmanship orientation for all sub-dimensions justas compliance with social norms, respect to rules and management, commitment tosocial responsibilities and respect for opponent is more among athletes over 26years old regarding those between 17-25 years old; among those who has 4 years or moreexperience in sportmanship regarding those who has less experience and it ismore again among those who are primary school graduates regarding high schooland university graduates., Bu araştırma ile işitme engelli voleybolcuların sportmenlik yönelimleri bazıdeğişkenler açısından incelenmeye çalışılmıştır. Araştırmanın evrenini 2017-2018 sezonu Türkiye İşitme Engelliler Voleybol1. Ligi oluştururken, örneklem grubunu ise bu lige katılan dört takımdan yaşlarıortalamaları 26,75 ± 7,59 kırk erkek sporcu oluşturmaktadır.Verilerin toplanmasında kişisel bilgilerin yer aldığı demografik form ileVallerand ve arkadaşları (1997) tarafından geliştirilen ve Türkçe’ye uyarlamasıSezen-BALÇIKANLI (2010) tarafından yapılan Çok Boyutlu Sportmenlik YönelimiÖlçeği (MSOS) kullanılmıştır. Normallik testinde (Shapiro Wilk Testi) verilertüm boyutlarda normal dağılım göstermediği için non-parametrik analiz yöntemlerindenMann Whitney-U ve Kruskal Wallis testleri kullanılmıştır.Sonuç olarak; işitme engellivoleybolcuların sportmenlik yönelimlerinde sporculuk tecrübesi, eğitimdüzeyi, ebevyn eğitim düzeyi ve yaş gruplarına göre anlamlı değişimlerbulunmazken (p>0,05), çok boyutlusportmenlik yönelimi ölçeği sosyal normlara uyum, kurallara ve yönetime saygı,sosyal sorumluluklara bağlılık ve rakibe saygı alt boyutlarının tamamında 26 veüzeri yaş grubundaki sporcuların 17-25 yaş grubundaki sporculara göre, 4 yıl veüzeri sporculuk geçmişine sahip sporcuların daha az sporculuk süresine sahipsporculara göre ve ilköğretim mezunu sporcuların orta ve yükseköğretim mezunusporculara göre sportmenlik yönelim değerlerine daha fazla olumlu katkıdabulundukları söylenilebilir.