33,617 research outputs found
Lattice Statistics in Three Dimensions: Exact Solution of Layered Dimer and Layered Domain Wall Models
Exact analyses are given for two three-dimensional lattice systems: A system
of close-packed dimers placed in layers of honeycomb lattices and a layered
triangular-lattice interacting domain wall model, both with nontrivial
interlayer interactions. We show that both models are equivalent to a 5-vertex
model on the square lattice with interlayer vertex-vertex interactions. Using
the method of Bethe ansatz, a closed-form expression for the free energy is
obtained and analyzed. We deduce the exact phase diagram and determine the
nature of the phase transitions as a function of the strength of the interlayer
interaction.Comment: 22 pages in Revtex, 6 PS files, submitted to PR
Recommended from our members
Studying RFID adoption by SMES in the Taiwanese IT industry
With the advent of Radio Frequency Identification (RFID), organisations have the opportunity to rethink how their organisation will operate and integrate in the supply chain. Especially for Small to Medium Sized Enterprises (SMEs), that they have limited resources adopting such an innovative technology (i.e. RFID) can be daunting. Literature indicates that SMEs that deal with implementation have so far only a few guidelines regarding specific opportunities and risks. This research is therefore trying to fill the gap by employing Exploratory Factor Analysis (EFA) techniques and utilising a questionnaire survey with the aim of exploring the factors that affect SMEs’ RFID adoption in the Taiwan Information Technology (IT) manufacturing industry. In doing so, the adoption factors which are classified into 3 different adopters categories named ready adopter (cost and management), initiator adopter (competitiveness and process efficiency) and unprepared adopter (IT management difficulties, IT implementation difficulties and cost of implementation) using EFA technique. A SMEs RFID adoption model is then proposed. It is anticipated that the findings of this research will not only enhance the research in RFID adoption in SMEs, but can also act as a reference for practitioners in the industry and researchers in the academic field
Exact Solution of a Three-Dimensional Dimer System
We consider a three-dimensional lattice model consisting of layers of vertex
models coupled with interlayer interactions. For a particular non-trivial
interlayer interaction between charge-conserving vertex models and using a
transfer matrix approach, we show that the eigenvalues and eigenvectors of the
transfer matrix are related to those of the two-dimensional vertex model. The
result is applied to analyze the phase transitions in a realistic
three-dimensional dimer system.Comment: 11 pages in REVTex with 2 PS figure
Exact solution of a lattice model of flux lines in superconductors
We consider a statistical mechanical model describing flux lines in type II superconductors by embedding the flux lines on a lattice wound on torus. The lines are nonintersecting and each loop of lines is associated with a fugacity z = -1. It is shown that the exact solution of this model leads to a second-order transition between the Meissner and the superconducting states as well as a first-order transition between the superconducting and the normal states
The clinical utility of contrast enhanced whole-heart coronary MRA with 32-channel coil at 3T scanner in the era of 64 and more-slice CT
A Soluble Free-Fermion Model in d Dimensions
We consider a vertex model in d dimensions characterized by lines which run
in a preferred direction. We show that this vertex model is soluble if the
weights of vertices with intersecting lines are given by a free-fermion
condition, and that a fugacity -1 is associated to each loop of lines. The
solution is obtained by mapping the model into a dimer problem and by
evaluating a Pfaffian. We also determine the critical point and the singular
behavior of the free energy.Comment: 19 pages, REVTEX, 6 figure
Geometries for Possible Kinematics
The algebras for all possible Lorentzian and Euclidean kinematics with
isotropy except static ones are re-classified. The geometries
for algebras are presented by contraction approach. The relations among the
geometries are revealed. Almost all geometries fall into pairs. There exists correspondence in each pair. In the viewpoint of
differential geometry, there are only 9 geometries, which have right signature
and geometrical spatial isotropy. They are 3 relativistic geometries, 3
absolute-time geometries, and 3 absolute-space geometries.Comment: 40 pages, 7 figure
Perceptual Zero-Tree Coding with Efficient Optimization for Embedded Platforms
This study proposes a block-edge-based perceptual zero-tree coding (PZTC) method, which is implemented with efficientoptimization on the embedded platform. PZTC combines two novel compression concepts for coding efficiency and quality:block-edge detection (BED) and the low-complexity and low-memory entropy coder (LLEC). The proposed PZTC wasimplemented as a fixed-point version and optimized on the DSP-based platform based on both the presented platformindependentand platform-dependent optimization technologies. For platform-dependent optimization, this study examinesthe fixed-point PZTC and analyzes the complexity to optimize PZTC toward achieving an optimal coding efficiency.Furthermore, hardware-based platform-dependent optimizations are presented to reduce the memory size. Theperformance, such as compression quality and efficiency, is validated by experimental results
Rebrightening of XRF 030723: further evidence for a two-component jet in gamma-ray burst
Optical afterglows from two-component jets under various configurations are
investigated numerically. Generally, the light curve is characterized by a
rapid rebrightening when the observer is off-axis with respect to the narrow
component, with the amplitude and peak time depending on detailed parameters.
We further show that the optical afterglow of XRF 030723, especially its
notable and rapid rebrightening, can be well explained by a typical
two-component jet. This X-ray flash, together with GRB 030329, strongly hints
the two-component jet model as a unified picture for X-ray flashes and
gamma-ray bursts. With a narrow but ultra-relativistic inner outflow and a wide
but less energetic outer ejecta, a two-component jet will be observed as a
typical gamma-ray burst if our line of sight is within the angular scope of the
narrow outflow. Otherwise, if the line of sight is within or slightly beyond
the cone of the wide component, an X-ray flash will be detected.Comment: 1 figure inserted and references added, 19 pages, ApJ in pres
- …