581 research outputs found
Fixed-parameter tractability for the subset feedback set problem and the S-cycle packing problem
AbstractWe investigate generalizations of the following well-known problems in the framework of parameterized complexity: the feedback set problem and the cycle packing problem. Our problem setting is that we are given a graph and a vertex set S called “terminals”. Our purpose here is to consider the following problems:1.The feedback set problem with respect to the terminals S. We call it the subset feedback set problem.2.The cycle packing problem with respect to the terminals S, i.e., each cycle has to contain a vertex in S (such a cycle is called an S-cycle). We call it the S-cycle packing problem. We give the first fixed parameter algorithms for the two problems. Namely;1.For fixed k, we can either find a vertex set X of size k such that G−X has no S-cycle, or conclude that such a vertex set does not exist in O(n2m) time, where n is the number of vertices of the input graph and m is the number of edges of the input graph.2.For fixed k, we can either find k vertex-disjoint S-cycles or conclude that such k disjoint cycles do not exist in O(n3) time
PERMIAN FUSULINACEANS OF THE SURMAQ FORMATION IN THEABADEH REGION, CENTRAL IRAN
Fusulinaceans consisting of 56 species belonging to 30 genera are distinguished from the Surmaq Formation distributed in the Abadeh region, central Iran. Among them, 23 species, including three species newly proposed: Parafusulina tarazi, Skinnerella abadehensis, and Sphaerulina iranensis, are systematically described and discussed. Many microphotographs of fusulinaceans are illustrated so as to understand their wide intraspecific variation and to compare them with other faunas from the Tethyan regions. The Surmaq Formation is biostratigraphically divided into six zones from lower to upper: Darvasites ordinatus, Pseudofusulina quasifusuliniformis, Eopolydiexodina persica, Afghanella schencki, Neoschwagerina occidentalis, and Chusenella abichi. The first zone is probably Yakhtashian, the second is possibly Kubergandian, the third to fifth are Murgabian, and the last is Midian in age, based on the stratigraphic distribution and faunal correlation of neoschwagerinids and schwagerinids in Middle Permian formations of the Tethyan regions. Schwagerinids are dominant in these six zones, whereas almost all neoschwagerinids and verbeekinids are restricted to the fourth and fifth zones. Middle Permian fusulinacean faunas in South West Asian and Mediterranean Sea regions are well represented by those of the Surmaq Formation, and paleobiogeographically assignable to Province A (Western Tethyan Province). Fusulinacean faunas of Province A are largely different from those in Province B (Eastern Tethyan Province) by the very rare occurrence of typical Colania and Lepidolina, and from Province C (Panthalassan Province) by the presence of Afghanella and Sumatrina. 
TeV Scale Mirage Mediation and Natural Little SUSY Hierarchy
TeV scale mirage mediation has been proposed as a supersymmetry breaking
scheme reducing the fine tuning for electroweak symmetry breaking in the
minimal supersymmetric extension of the standard model. We discuss a moduli
stabilization set-up for TeV scale mirage mediation which allows an
extra-dimensional interpretation for the origin of supersymmetry breaking and
naturally gives an weak-scale size of the Higgs B-parameter. The set-up
utilizes the holomorphic gauge kinetic functions depending on both the heavy
dilaton and the light volume modulus whose axion partners are assumed to be
periodic fields. We also examine the low energy phenomenology of TeV scale
mirage mediation, particularly the constraints from electroweak symmetry
breaking and FCNC processes.Comment: 44 pages, 14 figures; added references, extended discussions in
section
Edge state on hydrogen-terminated graphite edges investigated by scanning tunneling microscopy
The edge states that emerge at hydrogen-terminated zigzag edges embedded in
dominant armchair edges of graphite are carefully investigated by
ultrahigh-vacuum scanning tunneling microscopy (STM) measurements. The edge
states at the zigzag edges have different spatial distributions dependent on
the - or -site edge carbon atoms. In the case that the defects
consist of a short zigzag (or a short Klein) edge, the edge state is present
also near the defects. The amplitude of the edge state distributing around the
defects in an armchair edge often has a prominent hump in a direction
determined by detailed local atomic structure of the edge. The tight binding
calculation based on the atomic arrangements observed by STM reproduces the
observed spatial distributions of the local density of states.Comment: 9 pages, 11 figures, accepted for Physical Review
Phenomenology of NMSSM in TeV scale mirage mediation
We study the next-to-minimal supersymmetric standard model (NMSSM) with the
TeV scale mirage mediation, which is known as a solution for the little
hierarchy problem in supersymmetry. Our previous study showed that 125 GeV
Higgs boson is realized with O(10) % fine-tuning for 1.5 TeV gluino (1 TeV
stop) mass. The term could be as large as 500 GeV without sacrificing the
fine-tuning thanks to a cancellation mechanism. The singlet-doublet mixing is
suppressed by . In this paper, we further extend this analysis. We
argue that approximate scale symmetries play a role behind the suppression of
the singlet-doublet mixing. They reduce the mixing matrix to a simple form that
is useful to understand the results of the numerical analysis. We perform a
comprehensive analysis of the fine-tuning including the singlet sector by
introducing a simple formula for the fine-tuning measure. This shows that the
singlet mass of the least fine-tuning is favored by the LEP anomaly for
moderate . We also discuss prospects for the precision measurements
of the Higgs couplings at LHC and ILC and direct/indirect dark matter searches
in the model.Comment: 47 pages, 46 figures, version accepted by JHE
IoT measurements of the winter environment around Lake Izunuma, Miyagi
The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc
A Neural Correlate of Predicted and Actual Reward-Value Information in Monkey Pedunculopontine Tegmental and Dorsal Raphe Nucleus during Saccade Tasks
Dopamine, acetylcholine, and serotonin, the main modulators of the central nervous system, have been proposed to play important roles in the execution of movement, control of several forms of attentional behavior, and reinforcement learning. While the response pattern of midbrain dopaminergic neurons and its specific role in reinforcement learning have been revealed, the role of the other neuromodulators remains rather elusive. Here, we review our recent studies using extracellular recording from neurons in the pedunculopontine tegmental nucleus, where many cholinergic neurons exist, and the dorsal raphe nucleus, where many serotonergic neurons exist, while monkeys performed eye movement tasks to obtain different reward values. The firing patterns of these neurons are often tonic throughout the task period, while dopaminergic neurons exhibited a phasic activity pattern to the task event. The different modulation patterns, together with the activity of dopaminergic neurons, reveal dynamic information processing between these different neuromodulator systems
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