45,797 research outputs found
An Exact Algorithm for TSP in Degree-3 Graphs via Circuit Procedure and Amortization on Connectivity Structure
The paper presents an O^*(1.2312^n)-time and polynomial-space algorithm for
the traveling salesman problem in an n-vertex graph with maximum degree 3. This
improves the previous time bounds of O^*(1.251^n) by Iwama and Nakashima and
O^*(1.260^n) by Eppstein. Our algorithm is a simple branch-and-search
algorithm. The only branch rule is designed on a cut-circuit structure of a
graph induced by unprocessed edges. To improve a time bound by a simple
analysis on measure and conquer, we introduce an amortization scheme over the
cut-circuit structure by defining the measure of an instance to be the sum of
not only weights of vertices but also weights of connected components of the
induced graph.Comment: 24 pages and 4 figure
Sputtered Gold as an Effective Schottky Gate for Strained Si/SiGe Nanostructures
Metallization of Schottky surface gates by sputtering Au on strained Si/SiGe
heterojunctions enables the depletion of the two dimensional electron gas
(2DEG) at a relatively small voltage while maintaining an extremely low level
of leakage current. A fabrication process has been developed to enable the
formation of sub-micron Au electrodes sputtered onto Si/SiGe without the need
of a wetting layer.Comment: 3 pages, 3 figure
Dynamical behavior of interacting dark energy in loop quantum cosmology
The dynamical behaviors of interacting dark energy in loop quantum cosmology
are discussed in this paper. Based on defining three dimensionless variables,
we simplify the equations of the fixed points. The fixed points for interacting
dark energy can be determined by the Friedmann equation coupled with the
dynamical equations {in Einstein cosmology}. But in loop quantum cosmology,
besides the Friedmann equation, the conversation equation also give a constrain
on the fixed points. The difference of stability properties for the fixed
points in loop quantum cosmology and the ones in Einstein cosmology also have
been discussed.Comment: 7 pages, 5 figure
On the kinks and dynamical phase transitions of alpha-helix protein chains
Heuristic insights into a physical picture of Davydov's solitonic model of
the one-dimensional protein chain are presented supporting the idea of a
non-equilibrium competition between the Davydov phase and a complementary,
dynamical- `ferroelectric' phase along the chainComment: small latex file with possible glue problems, just go on !, no
figures, small corrections with respect to the published text, follow-up work
to cond-mat/9304034 [PRE 47 (June 1993) R3818
An Intrinsic Integrity-Driven Rating Model for a Sustainable Reputation System
In the era of digital markets, the challenge for consumers is discerning
quality amidst information asymmetry. While traditional markets use brand
mechanisms to address this issue, transferring such systems to internet-based
P2P markets, where misleading practices like fake ratings are rampant, remains
challenging. Current internet platforms strive to counter this through
verification algorithms, but these efforts find themselves in a continuous
tug-of-war with counterfeit actions.
Exploiting the transparency, immutability, and traceability of blockchain
technology, this paper introduces a robust reputation voting system grounded in
it. Unlike existing blockchain-based reputation systems, our model harnesses an
intrinsically economically incentivized approach to bolster agent integrity. We
optimize this model to mirror real-world user behavior, preserving the
reputation system's foundational sustainability. Through Monte-Carlo
simulations, using both uniform and power-law distributions enabled by an
innovative inverse transform method, we traverse a broad parameter landscape,
replicating real-world complexity. The findings underscore the promise of a
sustainable, transparent, and formidable reputation mechanism. Given its
structure, our framework can potentially function as a universal, sustainable
oracle for offchain-onchain bridging, aiding entities in perpetually
cultivating their reputation. Future integration with technologies like Ring
Signature and Zero Knowledge Proof could amplify the system's privacy facets,
rendering it particularly influential in the ever-evolving digital domain.Comment: 36 pages,13 figure
High sensitivity microwave detection using a magnetic tunnel junction in the absence of an external applied magnetic field
In the absence of any external applied magnetic field, we have found that a
magnetic tunnel junction (MTJ) can produce a significant output direct voltage
under microwave radiation at frequencies, which are far from the ferromagnetic
resonance condition, and this voltage signal can be increase by at least an
order of magnitude by applying a direct current bias. The enhancement of the
microwave detection can be explained by the nonlinear resistance/conductance of
the MTJs. Our estimation suggests that optimized MTJs should achieve
sensitivities for non-resonant broadband microwave detection of about 5,000
mV/mW
Quartification with T' Flavor
In the simplest (non-quiver) unified theories, fermion families are often
treated sequentially and a flavor symmetry may act similarly. As an alternative
with non-sequential flavor symmetry, we consider a model based on the group
(T'*Z_2)_global * [SU(3)^4]_local which combines the predictions of T' flavor
symmetry with the features of a unified quiver gauge theory. The model
accommodates the relationships between mixing angles separately for neutrinos,
and for quarks, which have been previously predicted with T'. This quiver
unification theory makes predictions of several additional gauge bosons and
bifundamental fermions at the TeV scale.Comment: 8 pages, LaTex; added references and clarifie
Reciprocal relationships in collective flights of homing pigeons
Collective motion of bird flocks can be explained via the hypothesis of many
wrongs, and/or, a structured leadership mechanism. In pigeons, previous studies
have shown that there is a well-defined hierarchical structure and certain
specific individuals occupy more dominant positions --- suggesting that
leadership by the few individuals drives the behavior of the collective.
Conversely, by analyzing the same data-sets, we uncover a more egalitarian
mechanism. We show that both reciprocal relationships and a stratified
hierarchical leadership are important and necessary in the collective movements
of pigeon flocks. Rather than birds adopting either exclusive averaging or
leadership strategies, our experimental results show that it is an integrated
combination of both compromise and leadership which drives the group's movement
decisions.Comment: 7 pages, 5 figure
- …