Modeling the relationship between network operators and venue owners in public Wi-Fi deployment using non-cooperative game theory

Wireless data demands keep rising at a fast rate. In 2016, Cisco measured a global mobile data traffic volume of 7.2 Exabytes per month and projected a growth to 49 Exabytes per month in 2021. Wi-Fi plays an important role in this as well. Up to 60% of the total mobile traffic was off-loaded via Wi-Fi (and femtocells) in 2016. This is further expected to increase to 63% in 2021. In this publication, we look into the roll-out of public Wi-Fi networks, public meaning in a public or semi-public place (pubs, restaurants, sport stadiums, etc.). More concretely we look into the collaboration between two parties, a technical party and a venue owner, for the roll-out of a new Wi-Fi network. The technical party is interested in reducing load on its mobile network and generating additional direct revenues, while the venue owner wants to improve the attractiveness of the venue and consequentially generate additional indirect revenues. Three Wi-Fi pricing models are considered: entirely free, slow access with ads or fast access via paid access (freemium), and paid access only (premium). The technical party prefers a premium model with high direct revenues, the venue owner a free/freemium model which is attractive to its customers, meaning both parties have conflicting interests. This conflict has been modeled using non-cooperative game theory incorporating detailed cost and revenue models for all three Wi-Fi pricing models. The initial outcome of the game is a premium Wi-Fi network, which is not the optimal solution from an outsider's perspective as a freemium network yields highest total payoffs. By introducing an additional compensation scheme which corresponds with negotiation in real life, the outcome of the game is steered toward a freemium solution

Sedimentation of particulate matter in the south-west lagoon of New Caledonia : spatial and temporal patterns

Suspended and sedimented particulate materials were assessed monthly at five sites on the south-west lagoon of New Caledonia, from May 1986 to April 1987. Sedimentation of particulate matter was measured using sediment traps for 24 h. Resuspension, which accounted for more than 80% of the total sedimentation, was distinguished to calculate net sedimentation values. The mean net sedimentation rate for the lagoon varied according to the site from 0.481 to 1.157 gC/m2/day with a general mean value of 0.756 gC/m2/day. An increasing gradient from the reef to the shore stations was observed for both suspended and sedimented particles. The standing stocks and the fluxes of suspended particles were maximal in February, during the warm season associated with maximal rainfall, and minimal in August. The high C/N ratio in sedimented material compared to suspended particles indicated that organic matter degradation had occurred preferentially in the water column. The mean particulate organic carbon flux was about twice the lagoon pelagic primary production ; sedimented plant material only accounted for a small part of the organic carbon flux. The major source of sedimented organic carbon was therefore allochthonous and derived both from the reef and the shore. The latter seemed to predominate. Relative uncoupling between benthos and pelagos is suggested. (Résumé d'auteur

KAJIAN PENGGUNAAN METODE PENAJAMAN CITRA (PAN-SHARPENING) WORLDVIEW-2 (Studi Lokasi : Kabupaten Jombang)

Penggabungan citra (image fusion) dapat dijadikan sebagai alat bantu penting dalam evaluasi data penginderaan jauh dengan ketersediaan data citra multisensor, multitemporal, multifrekuensi dan multiresolusi dari satelit observasi bumi. Hal ini tentu saja sangat membantu pelaksanaan aplikasi citra penginderaan jauh dalam hal pengukuran, pemetaan, pantauan dan pemodelan dengan lebih efisien dibandingkan pemetaan secara konvensional. Pan-sharpening adalah salah satu teknik yang tepat untuk menggabungkan detil geometri (spasial) dan detil warna (spektral) pada pasangan citra awal sehingga didapatkan citra multispektral baru dengan informasi spasial dan spektral yang lebih tajam. Bertujuan untuk membandingkan beberapa metode pan sharpening. Adapun metode pan sharpening yang dilakukan adalah Metode HSV, Brovey, Gram-Schmidt dan PCA. Hasil penelitian ini dapat menunjukkan bahwa dengan menggunakan metode Pan-Sharpening dari data citra pankromatik dengan resolusi spasial 0,5m dan data citra multispektral dengan resolusi spasial 2.0m dapat mempertajam citra hasil klasifikasi dan membantu dalam identifikasi objek. Kata Kunci : Image fusion, Pan-Sharpening, HSV, Brovey, Gram-Schmidt dan PC

Optimizing the investments in mobile networks and subscriber migrations for a telecommunication operator

We consider the context of a telecommunications company that is at the same time an infrastructure operator and a service provider. When planning its network expansion, the company can leverage over its knowledge of subscribers dynamic to better optimize the network dimensioning, therefore avoiding unnecessary costs. In this work, the network expansion represents the deployment and/or reinforcement of several technologies (e.g. 2G,3G,4G), assuming that subscribers to a given technology can be served by this technology or older ones. The operator can influence subscribers dynamic by subsidies. The planning is made over a discretized time horizon while some strategic guidelines requirements are demanded at the end of the time horizon. Following classical models, we consider that the behavior of customers follows an S-shape piecewise constant function. We propose a Mixed-Integer Linear Programming formulation and a heuristic algorithm for the multi-year planning problem. The scalability of the formulation and the quality of the heuristic are assessed numerically on real instances for a use-case with two generations

AGN STORM 2. I. First results: A Change in the Weather of Mrk 817

We present the first results from the ongoing, intensive, multiwavelength monitoring program of the luminous Seyfert 1 galaxy Mrk 817. While this active galactic nucleus was, in part, selected for its historically unobscured nature, we discovered that the X-ray spectrum is highly absorbed, and there are new blueshifted, broad, and narrow UV absorption lines, which suggest that a dust-free, ionized obscurer located at the inner broad-line region partially covers the central source. Despite the obscuration, we measure UV and optical continuum reverberation lags consistent with a centrally illuminated Shakura–Sunyaev thin accretion disk, and measure reverberation lags associated with the optical broad-line region, as expected. However, in the first 55 days of the campaign, when the obscuration was becoming most extreme, we observe a de-coupling of the UV continuum and the UV broad emission-line variability. The correlation recovered in the next 42 days of the campaign, as Mrk 817 entered a less obscured state. The short C IV and Lyα lags suggest that the accretion disk extends beyond the UV broad-line region. Unified

Compl\ue9ments \ue0 l\u27\ue9tude syst\ue9matique des Ischnomesidae (Isopodes Asellotes) de l\u27Atlantique. Description de quatre esp\ue8ces nouvelles

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