The Core in a Normal Form Game

Due to the externalities, in normal form games a deviation changes the payoff of all players inducing a retaliation by the remaining or residual players. The stability of an outcome depends on the expectations potential deviators have about this reaction, but so far no satisfactory theory has been provided. The present paper continues the work of Tulkens and Chander (1997) where deviators consider residual equilibria, but we allow coalitions to form, moreover introduce consistency between the residual solution and the solution of the original game. Optimistic and pessimistic considerations produce a pair of cores. These cores are compared to some existing cooperative concepts such as the g- and r-cores and the equilibrium binding agreements. In our final section we discuss the predominance of the grand coalition and suggest a generalisation of the normal form where such a precedence can be removed.

PENERAPAN ALGORITME C4.5 DALAM KLASIFIKASI KOMENTAR SPAM DI INSTAGRAM

Agus Salim (2021): Penerapan Algoritme C4.5 Dalam Klasifikasi Komentar Spam di Instagram. Komentar spam merupakan komentar yang sama sekali tidak relevan dengan topik tertentu sehingga membuat ketidaknyamanan pada pengguna, komentar spam tersebut berupa iklan barang atau promosi yang sama sekali tidak berkaitan dengan postingan yang dikomentari. Penelitian ini bertujuan untuk mengetahui bagaimana menerapkan algoritme C4.5 dalam mengklasifikasi komentar spam di media sosial (dalam hal ini Instagram). Dengan adanya penelitian ini diharapkan dapat menjadi salah satu referensi untuk menemukan metode yang sesuai dalam pengembangan selanjutnya untuk mengatasi komentar spam. Dengan menggunakan data sebanyak 1200 data, dimana 600 merupakan data spam dan 600 data tidak spam. Algoritme C4.5 telah diuji menggunakan confusion matrix dengan perbandingan 70:30, 80:20, 90:10 dan dilakukan validasi data silang dengan k-fold cross validation. Hasil pengujian 70:30 memiliki akurasi rata-rata 83.59% dengan k-fold bernilai 4, pengujian 80:20 memiliki akurasi rata-rata 83.08% dengan k-fold bernilai 5, dan pengujian 90:10 memiliki akurasi rata-rata 82.58% dengan k-fold bernilai 10. Akurasi tertinggi terdapat pada perbandingan 80:20 fold ke 5 yaitu sebesar 87.08%. Dengan demikian dapat disimpulkan bahwa algoritme C4.5 dapat diterapkan untuk mengklasifikasi komentar spam di Instagram. Kata Kunci: Algoritme C4.5, Instagram, Klasifikasi, Komentar Spa

Statics and kinetics at the nematic­-isotropic interface: effects of biaxiality

We use the Landau-de Gennes theory of a nematic liquid crystal to investigate anew aspects of the properties of the interface between the isotropic and nematic liquid crystal phases of the same fluid. The equations of the static interface have been solved, both numerically and using asymptotic analysis, with an emphasis on the effect of inclusion of the order parameter biaxiality on the physical properties. We have compared the results of the exact solutions to the commonly used de Gennes ansatz, which assumes positive and uniform unixiality through the interface. Although the de Gennes ansatz in general gives good results, when bend and splay elastic constants dominate over the twist constants, it can lead to errors of up to 10% in the surface energy. The asymptotic analysis also shows that, by contrast with the de Gennes ansatz, the order parameter wings in the isotropic phase exhibit negative order parameter, with principal axis perpendicular to the surface. For moving interfaces, using an approximation which at this stage does not yet include hydrodynamic coupling, we have compared our results with the analogue of the de Gennes ansatz used by the present authors in an earlier paper. We find that including biaxiality leads to larger effects in the dynamic than in the static properties, and that whereas this is essentially a perturbation to the energy, the velocity of the moving interface can be significantly slowed down. The slowing down effects are strongly correlated with surface biaxiality, but both effects seem to be diminished when the isotropic phase is advancing

GLOBAL AND STRICT CURVE FITTING METHOD

To find a global and smooth curve fitting, cubic B­Spline method and gathering­ line methods are investigated. When segmenting and recognizing a contour curve of character shape, some global method is required. If we want to connect contour curves around a singular point like crossing points, merging separated contours together which lies apart crossing the singular point is necessary. For this pur pose, cubic B­Spline method and new line­gathering method are investigated and proposed. The result is that cubic B­Spline method is rather too easy to bend. Easy to bend feature can cover singular point smoothly, so is not good to detect singular points. Gathering­line method is to represent the contour by overlapped line segments. By overlapping lines, arcs can be represented in natural way. Some investigations and experimental results are shown

Undeniable Signatures Based on Characters: How to Sign with One Bit

We present a new undeniable signature scheme which is based on the computation of characters. Our signature scheme offers the advantage of having an arbitrarily short signature. Its asymptotic complexity is attractive: the asymptotic complexity of all algorithms (even the key setup) are quadratic in the size of the modulus n in bits when the other parameters are fixed. The practical complexity can be quite low depending on parameter and variant choices. We present also a proof of security of our scheme containing the standard security requirements of an undeniable signature

Analytic extensions and Cauchy-type inverse problems on annular domains. I: theoretical aspects and stability results

We consider the Cauchy issue of recovering boundary values on the inner circle of a two-dimensional annulus from available overdetermined data on the outer circle, for solutions to the Laplace equation. Using tools from complex analysis, Hardy classes and approximation, we establish stability properties and error estimates, as well as a recovery scheme, illustrated by some numerical computations

One-Hop Delay Estimation in 802.11 Ad Hoc Networks Using the OLSR Protocol

In this report, we present an estimation of the one-hop delay in 802.11 wireless network using the OLSR routing protocol. Our approach consists in modeling the 802.11 Mac sublayer while taking advantage of statistics obtained through the use of OLSR. We model each node as a discrete time M/G/1 queue. The Mac service time distribution is derived by modeling the exponential backoff function and deducing the collision probability and the channel occupancy from OLSR statistics. Our model is verified through simulations using the ns-2 tool