Influence of the Ground-State Topology on the Domain-Wall Energy in the Edwards-Anderson +/- J Spin Glass Model

We study the phase stability of the Edwards-Anderson spin-glass model by analyzing the domain-wall energy. For the bimodal distribution of bonds, a topological analysis of the ground state allows us to separate the system into two regions: the backbone and its environment. We find that the distributions of domain-wall energies are very different in these two regions for the three dimensional (3D) case. Although the backbone turns out to have a very high phase stability, the combined effect of these excitations and correlations produces the low global stability displayed by the system as a whole. On the other hand, in two dimensions (2D) we find that the surface of the excitations avoids the backbone. Our results confirm that a narrow connection exists between the phase stability of the system and the internal structure of the ground-state. In addition, for both 3D and 2D we are able to obtain the fractal dimension of the domain wall by direct means.Comment: 4 pages, 3 figures. Accepted for publication in Rapid Communications of Phys. Rev.

Fractal dimension of domain walls in the Edwards-Anderson spin glass model

We study directly the length of the domain walls (DW) obtained by comparing the ground states of the Edwards-Anderson spin glass model subject to periodic and antiperiodic boundary conditions. For the bimodal and Gaussian bond distributions, we have isolated the DW and have calculated directly its fractal dimension $d_f$. Our results show that, even though in three dimensions $d_f$ is the same for both distributions of bonds, this is clearly not the case for two-dimensional (2D) systems. In addition, contrary to what happens in the case of the 2D Edwards-Anderson spin glass with Gaussian distribution of bonds, we find no evidence that the DW for the bimodal distribution of bonds can be described as a Schramm-Loewner evolution processes.Comment: 6 pages, 5 figures. Accepted for publication in PR

Generalization properties of finite size polynomial Support Vector Machines

The learning properties of finite size polynomial Support Vector Machines are analyzed in the case of realizable classification tasks. The normalization of the high order features acts as a squeezing factor, introducing a strong anisotropy in the patterns distribution in feature space. As a function of the training set size, the corresponding generalization error presents a crossover, more or less abrupt depending on the distribution's anisotropy and on the task to be learned, between a fast-decreasing and a slowly decreasing regime. This behaviour corresponds to the stepwise decrease found by Dietrich et al.[Phys. Rev. Lett. 82 (1999) 2975-2978] in the thermodynamic limit. The theoretical results are in excellent agreement with the numerical simulations.Comment: 12 pages, 7 figure

Analisis Faktor-faktor Eksternal Yang Mempengaruhi Keputusan Konsumen Dalam Memilih Belanja Di Assalaam Hypermarket

The purpose of this study was to determine the influence of cultural, reference groups, family and social class factors, either partially or simultan to consumer decision in choosing shopping in Assalaam Hypermarket. The analytical tool used in this study were: Multiple linear regression test, Test t, Test F and The coefficient of determination (R2) or Adjusted R Square. The results of data analysis concludes that the cultural, reference groups, family and social class variables influence the purchasing decisions of consumers on Assalam Hypermarket, either partially or simultan, Cultural Variables become the dominant factor in the purchase decision. Suggestions that emerged in this study were The management should pay more attention to factors such as cultural community grows in accordance with decisions of private consumption, the reference group is able to provide encouragement to consume, the number of family members and their effects on individual consumption decisions, and social class potential segments that many make purchases at Assalam hypermarket and the manager also acan develop a plan of activities to encourage consumers to get used to make purchases at Assalam hypermarket. Keywords: Cultural, Reference Group, Family, Social Class, Consumer Decision Making

Pengaruh Arus Terhadap Sebaran Material Padatan Tersuspensi Di Pantai Sigandu, Kabupaten Batang

Pantai Sigandu terletak di Kabupaten Batang, Propinsi Jawa Tengah merupakan daerah yang mulai berkembang dengan aktifitas industri dan wisata disamping kegiatan nelayan. Kegiatan ini tentunya akan berdampak negatif terhadap kondisi perairan. Salah satunya adalah semakin meningkatnya konsentrasi padatan tersuspensi di perairan wilayah tersebut. Sebaran MPT di perairan laut sangat di pengaruhi oleh arus dan sumber MPT itu sendiri. Kandungan MPT yang tinggi akan sangat mengganggu produktivitas perairan. Berkaitan dengan hal tersebut perlu dikaji hubungan antara keadaan hidrooseanografi dan sebaran material padatan tersuspensi agar pola sebaran MPT dapat diketahui dan dianalisa secara tepat. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh arus laut terhadap sebaran MPT di perairan Pantai Sigandu, Kabupaten Batang. Penelitian ini dilakukan 2 tahap, pengukuran lapangan dan proses pemodelan hidrodinamika 2D. Pengukuran lapangan yang meliputi pengukuran dan pengambilan data pasang surut, data sampel air, dan data arus pada tanggal 4 Mei - 7 Mei 2012, sedangkan pemodelan yang dilaksanakan di Laboratorium Komputasi Jurusan Ilmu Kelautan pada bulan Juli – Agustus 2012. Berdasarkan hasil penelitian diketahui pola sebaran MPT berbeda pada setiap lapisan kedalaman. Konsentrasi MPT pada lapisan 0,2 D berkisar antara 27 mg/l – 127 mg/l. Sedangkan pada lapisan kedalaman 0,6 D, nilai konsentrasi MPT cukup bervariasi sekitar 43 mg/l – 147 mg/l. Pada lapisan 0,8 D mempunyai nilai konsentrasi MPT sekitar 47 mg/l - 157 mg/l. Pada setiap lapisan kedalaman nilai konsentrasi MPT di daerah dekat pantai cenderung tersebar menyusur pantai dan relatif lebih tinggi dengan kedalaman yang dangkal. Hasil penelitian menunjukkan bahwa arus mempengaruhi pola sebaran MPT, tetapi penurunan konsentrasi MPT banyak dipengaruhi oleh letak stasiun. Tingginya nilai konsentrasi MPT di lapisan dasar dibandingkan di permukaan karena adanya resuspensi sedimen dan pergerakkan arus di lapisan dasar. Sedangkan besarnya MPT di muara sungai karena adanya penumpukkan material padatan yang disebabkan oleh pergerakkan arus dan pengaruh pasang surut

Levy ratchets with dichotomic random flashing

Additive symmetric L\'evy noise can induce directed transport of overdamped particles in a static asymmetric potential. We study, numerically and analytically, the effect of an additional dichotomous random flashing in such L\'evy ratchet system. For this purpose we analyze and solve the corresponding fractional Fokker-Planck equations and we check the results with Langevin simulations. We study the behavior of the current as function of the stability index of the L\'evy noise, the noise intensity and the flashing parameters. We find that flashing allows both to enhance and diminish in a broad range the static L\'evy ratchet current, depending on the frequencies and asymmetry of the multiplicative dichotomous noise, and on the additive L\'evy noise parameters. Our results thus extend those for dichotomous flashing ratchets with Gaussian noise to the case of broadly distributed noises.Comment: 15 pages, 6 figure