Coalition Formation Game for Cooperative Cognitive Radio Using Gibbs Sampling

This paper considers a cognitive radio network in which each secondary user selects a primary user to assist in order to get a chance of accessing the primary user channel. Thus, each group of secondary users assisting the same primary user forms a coaltion. Within each coalition, sequential relaying is employed, and a relay ordering algorithm is used to make use of the relays in an efficient manner. It is required then to find the optimal sets of secondary users assisting each primary user such that the sum of their rates is maximized. The problem is formulated as a coalition formation game, and a Gibbs Sampling based algorithm is used to find the optimal coalition structure.Comment: 7 pages, 2 figure

Reply to comments on ‘On the steadiness of separating meandering currents’

The authors thank Nof et al. for their comments on the authors’ paper ‘‘On the steadiness of separating meandering currents.’’ The authors’ paper was motivated by a series of papers by Nof et al. Under a certain set of conditions (reduced gravity, steady state, no meridional velocity at outflow, and parallel outflow), Nof et al. showed that a separating and retroflecting frictionless current cannot be steady because of a momentum imbalance. The main conclusion of the authors’ paper was that they agree with the Nof et al. result that a momentum imbalance exists and extended the proof to all possible configurations of retroflecting currents, even including friction. The authors’ results point to a new mechanism for the generation of variability in the ocean that is not related to dynamical instability of the flow. The main claim in the comments is that the authors incorrectly argued in the appendix that the steadystate solutions presented by Nof et al. in several papers fulfill the extra constraint u2 5g9h. In the original paper, the authors showed that it follows from the geostrophic assumption stated implicitly in all these Nof et al. papers, because the flow is assumed to be parallel. Nof et al. now argue that the flow is only approximately geostrophic in all Nof et al. papers. The authors show in this reply that for steady weakly meandering outflows approximate geostrophy does lead to a momentum imbalance paradox as Nof et al. claim. However, for a steady strongly meandering outflow, approximate geostrophy is not enough and one has to use the method explored by van Leeuwen and De Ruijter to derive a momentum imbalance paradox

STRATEGI KOMUNIKASI BPJS KETENAGAKERJAAN DALAM MENINGKATKAN JUMLAH PENGGUNA JASA PROGRAM BPJS KETENAGAKERJAAN DI KOTA BANDA ACEH

Jaminan sosial sudah menjadi salah satu kebutuhan bagi masyrakat yang Indonesia saat ini. Penggunaan jaminan sosial bertujuan untuk memproteksi diri dari masalah ekonomi apabila terjadi sesuatu kepada penggunanya. Salah satu jaminan sosial yang sudah menjadi program Pemerintah Indonesia adalah Program Jaminan Sosial BPJS Ketenagakerjaan. Penelitian ini membahas tentang bagaimana strategi komunikasi yang digunakan BPJS Ketenagakerjaan dalam meningkatkan jumlah pengguna jasa program jaminan sosial BPJS Ketenagakerjaan di Kota Banda Aceh. Menggunakan pendekatan penelitian kualitatif deskriptif, peneliti menganalisis hasil penelitian dengan bantuan teori AIDDA. Subjek dalam penelitian ini adalah karyawan BPJS Ketenagakerjaan yang berperan penting dalam mengatur strategi komunikasi dimasyarakat dan peserta BPU (Bukan Penerima Upah) program BPJS Ketenagakerjaan. Hasil penelitian menunjukkan bahwa strategi komunikasi yang digunakan oleh BPJS Ketenagakerjaan cabang Banda Aceh sudah efektif, dikarenakan telah memenuhi kriteria dari teori AIDDA. Hasil dari teori AIDDA pada strategi komunikasi BPJS Ketenagakerjaan dimana Attention (perhatian) adalah BPJS Ketenagakerjaan melakukan kegiatan promosi dan iklan di media cetak, radio, dan baliho. Interest (ketertarikan) adalah BPJS Ketenagakerjaan menciptakan daya tarik peserta dari sosialisasi-sosialisasi dengan bahasa yang mudah dipahami. Desire (keinginan) adalah BPJS Ketenagakerjaan memunculkan keinginan peserta untuk bergabung dari nilai iuran kecil tapi manfaat yang besar. Decision (keputusan) adalah BPJS ketenagakerjaan berusaha semaksimal mungkin memaparkan manfaat yang akan diterima sebagai bentuk asuransi dan proteksi dalam bekerja sehingga mendapat keputusan untuk penggunaan program tersebut. Action (tindakan) adalah mempermudah peserta dalam pendaftaran dan pembayaran uang iuran tiap bulannya. Dengan straegi komunikasi ini menimbulkan pemahaman yang baik dimata peserta dan akhirnya tertaik mendaftar program jaminan sosial BPJS Ketenagakerjaan.Kata Kunci: Jaminan Sosial, BPJS Ketenakerjaan, Teori AIDD

Cognitive Hierarchy Theory for Distributed Resource Allocation in the Internet of Things

In this paper, the problem of distributed resource allocation is studied for an Internet of Things (IoT) system, composed of a heterogeneous group of nodes compromising both machine-type devices (MTDs) and human-type devices (HTDs). The problem is formulated as a noncooperative game between the heterogeneous IoT devices that seek to find the optimal time allocation so as to meet their quality-of-service (QoS) requirements in terms of energy, rate and latency. Since the strategy space of each device is dependent on the actions of the other devices, the generalized Nash equilibrium (GNE) solution is first characterized, and the conditions for uniqueness of the GNE are derived. Then, to explicitly capture the heterogeneity of the devices, in terms of resource constraints and QoS needs, a novel and more realistic game-theoretic approach, based on the behavioral framework of cognitive hierarchy (CH) theory, is proposed. This approach is then shown to enable the IoT devices to reach a CH equilibrium (CHE) concept that takes into account the various levels of rationality corresponding to the heterogeneous computational capabilities and the information accessible for each one of the MTDs and HTDs. Simulation results show that the proposed CHE solution keeps the percentage of devices with satisfied QoS constraints above 96% for IoT networks containing up to 10,000 devices without considerably degrading the overall system performance.Comment: To appear in IEEE Transactions on Wireless Communications, 201

The Social Medium Selection Game

We consider in this paper competition of content creators in routing their content through various media. The routing decisions may correspond to the selection of a social network (e.g. twitter versus facebook or linkedin) or of a group within a given social network. The utility for a player to send its content to some medium is given as the difference between the dissemination utility at this medium and some transmission cost. We model this game as a congestion game and compute the pure potential of the game. In contrast to the continuous case, we show that there may be various equilibria. We show that the potential is M-concave which allows us to characterize the equilibria and to propose an algorithm for computing it. We then give a learning mechanism which allow us to give an efficient algorithm to determine an equilibrium. We finally determine the asymptotic form of the equilibrium and discuss the implications on the social medium selection problem

The Dot-com Meltdown and the Web

Presents findings from a survey conducted between August and September 2001. Looks at how the collapse of the dot-com economy has had tangible effects on personal lives, and how online Americans have made quick adjustments to the changing Web environment

Technical Note: Is radiation important for the high amplitude variability of the MOC in the North Atlantic?

International audienceRadiation is of fundamental importance to climate modeling and it is customary to assume that it is also important for the variability of North Atlantic Deep Water (NADW) formation and the meridional overturning cell (MOC). Numerous articles follow this scenario and incorporate radiation into the calculation. Using relatively old heat-flux maps based on measurements taken in the nineteen sixties, Sandal and Nof (2007) recently suggested that, even though the radiation terms are of the same order as the other heat-flux terms, they are not important for the variability of the NADW and the MOC. They proposed that only sensible and latent heat fluxes are important for the long-term variability of the convection, i.e., for processes such as Heinrich events, which supposedly correspond to turning convection on-and-off in the Atlantic. Here, we place this suggestion on a firmer ground by presenting new and accurate up-to-date heat flux maps that also suggest that the radiation is of no major consequence to the NADW variability. Also, we attribute the relative importance of sensible and latent heat fluxes and the contrasting negligible role of radiation to the fact that the latent and sensible heat fluxes are primarily proportional to the difference between the sea surface and the air temperature whereas the radiation is primarily proportional to the sea surface temperature, i.e., radiation is approximately independent of the atmospheric temperature. Due the small heat capacity ratio of air/water (1/4), the difference between the ocean temperature and the air temperature varies dramatically between the state of active and inactive MOC, whereas the ocean temperature by itself varies very modestly between a state of active and inactive convection