Approximation Algorithms for the Highway Problem under the Coupon Model

When a store sells items to customers, the store wishes to determine the prices of the items to maximize its profit. Intuitively, if the store sells the items with low (resp. high) prices, the customers buy more (resp. less) items, which provides less profit to the store. So it would be hard for the store to decide the prices of items. Assume that the store has a set V of n items and there is a set E of m customers who wish to buy those items, and also assume that each item i \in V has the production cost d_i and each customer e_j \in E has the valuation v_j on the bundle e_j \subseteq V of items. When the store sells an item i \in V at the price r_i, the profit for the item i is p_i=r_i-d_i. The goal of the store is to decide the price of each item to maximize its total profit. In most of the previous works, the item pricing problem was considered under the assumption that p_i \geq 0 for each i \in V, however, Balcan, et al. [In Proc. of WINE, LNCS 4858, 2007] introduced the notion of loss-leader, and showed that the seller can get more total profit in the case that p_i < 0 is allowed than in the case that p_i < 0 is not allowed. In this paper, we consider the line and the cycle highway problem, and show approximation algorithms for the line and/or cycle highway problem for which the smallest valuation is s and the largest valuation is \ell or all valuations are identical.Comment: 13 pages, 5 figure

Magnetic ordering in the JeffJ_{\rm eff} = 0 Nickelate NiRh2_2O4_4 prepared via a solid-state metathesis

In spinel-type nickelate NiRh$_2$O$_4$, magnetic ordering is observed upon the sample synthesized via kinetically controlled low-temperature solid-state metathesis, as opposed to previously-reported samples obtained through conventional solid-state reaction. Our findings are based on a combination of bulk susceptibility and specific heat measurements that disclose a N$\'e$el transition temperature of $T_N$ = 45 K in this material, which might feature spin-orbit entanglement in the tetragonally-coordinated $d^8$ Mott insulators. The emergence of magnetic ordering upon alteration of the synthesis route indicates that the suppression of magnetic ordering in the previous sample was rooted in the cation-mixing assisted by the entropy gain that results from high-temperature reactions. Furthermore, the $J_{\rm eff}$ = 0 physics, instead of solely the spin-only $S = 1$, describes the observed enhancement of effective magnetic moment well. Overseeing all observations and speculations, we propose that the possible mechanism responsible for the emergent magnetic orderings in NiRh$_2$O$_4$ is the condensation of $J_{\rm eff}$ = 0 exciton, driven by the interplay of the tetragonal crystal field and superexchange interactions.Comment: 7 pages, 5 figures, accepted in Physical Review Material

The Impact of social media on intercultural identity formation: the case of Algerian learners in the U.S

Abstract: In the globalised world nowadays, understanding culture is no more challenging due to the feasibility of virtual communication, which is fundamental among individuals whose language and culture differ. Regardless of their distance, people’s cultural differences are now creatively portrayed across various situations; interactions have enabled them to connect, adjust their ideas and thoughts, and express their worries and interests. Individuals can easily maintain and establish relationships across cultural boundaries, develop their intercultural communication, and use social media to explore the world around them. In this respect, they possess new identities through interacting with other groups, reflecting on their experiences, and acquiring values, norms, and ways of communicating with others to become more integrated into the host culture. In light of this, many researchers are interested in examining the connection between social media and intercultural identity. Thus, the present study sheds light on two main categories, which are - the impact of social networking on intercultural communication, and the influence of social media and the acculturation process on intercultural identity (ICI) formation. In-depth interviews of Algerian learners of U.S. universities are conducted. The study concludes that social media use influences significantly how Algerian students in the United States model an ICI. Directions for more research in this area are also explored. Keywords: Acculturation, Intercultural Communication, Intercultural Identity, Social Medi

Contribution à la modélisation probabiliste des propriétés géo-mécaniques des sols pour l’analyse de la fiabilité structurelle des fondations et conduites enterrées

This present study synthesizes a numerical approach to optimize foundation systems design and underground pipes based on the combination of elastoplastic soil behavior and probabilistic modeling of its geo-mechanical characteristics. Also, this work allows quantifying the effects of soil spatial variability on the mechanical and structural reliability of civil engineering infrastructures anchored at shallow depths in the ground. The illustrated simulations are based on simultaneous combination of the elastoplastic soil behavior and its spatial variability. The obtained results show that the probabilistic analysis of the spatial variability of soil properties into structure numerical modeling has a significant effect on the structural responses of civil engineering infrastructures, mainly if the structure length is relatively significant.Cette présente étude synthétise une approche numérique permettant d’optimiser la conception des systèmes de fondation et des conduites souterraines sur la base de la combinaison entre le comportement élastoplastique du sol et la modélisation probabiliste de ses caractéristiques géo-mécaniques. Ce travail permet aussi de quantifier l’influence de la variabilité spatiale de ces propriétés géo-mécaniques sur la fiabilité mécanique et structurelle des infrastructures ancrées à faible profondeur dans le sol. Les simulations présentées sont basées sur la prise en compte simultanée de l’aspect élastoplastique du sol et la variabilité spatiale de ses propriétés géo-mécaniques. Les résultats montrent que l’analyse probabiliste de variabilité spatiale des propriétés du sol dans la modélisation numérique, présente une influence considérable sur les réponses des infrastructures d’autant plus, si l’ouvrage en question possède une longueur relativement importante.Cette présente étude synthétise une approche numérique permettant d’optimiser la conception des systèmes de fondation et des conduites souterraines sur la base de la combinaison entre le comportement élastoplastique du sol et la modélisation probabiliste de ses caractéristiques géo-mécaniques. Ce travail permet aussi de quantifier l’influence de la variabilité spatiale de ces propriétés géo-mécaniques sur la fiabilité mécanique et structurelle des infrastructures ancrées à faible profondeur dans le sol. Les simulations présentées sont basées sur la prise en compte simultanée de l’aspect élastoplastique du sol et la variabilité spatiale de ses propriétés géo-mécaniques. Les résultats montrent que l’analyse probabiliste de variabilité spatiale des propriétés du sol dans la modélisation numérique, présente une influence considérable sur les réponses des infrastructures d’autant plus, si l’ouvrage en question possède une longueur relativement importante

Identity and Acculturation: the Case for Algeria

Abstract: This article examines the intricate relationship between identity and acculturation in Algeria, a nation of significant historical and cultural importance in North Africa. Amidst rapid cultural diversity and change, Algeria grapples with the complexities of identity. The study advocates a multidimensional approach, considering personal, relational, and social dimensions. Algeria's identity is portrayed as multifaceted, shaped by personal values, relationships, and group memberships. Acculturation processes, including unidimensional, bi-dimensional, and multidimensional models, are explored to understand how Algerians navigate cultural adaptation. The historical context, including colonization and independence, defines Algeria's identity. Post-independence challenges involve reconciling a unified national identity with cultural diversity, particularly among Berber and Kabyle populations. Globalization and modernization present both opportunities and challenges, leading to a proposed modified acculturation model integrating a tri-dimensional identity approach. Embracing these multidimensional models is crucial for appreciating Algeria's cultural diversity amid globalization and modernization, necessitating further nuanced research. Keywords: Algeria, Identity, Acculturation, Multiculturalism, Globalizatio