Quantum Impurity in Luttinger Liquid: Universal Conductance with Entanglement Renormalization

We study numerically the universal conductance of Luttinger liquids wire with a single impurity via the Muti-scale Entanglement Renormalization Ansatz (MERA). The scale invariant MERA provides an efficient way to extract scaling operators and scaling dimensions for both the bulk and the boundary conformal field theories. By utilizing the key relationship between the conductance tensor and ground-state correlation function, the universal conductance can be evaluated within the framework of the boundary MERA. We construct the boundary MERA to compute the correlation functions and scaling dimensions for the Kane-Fisher fixed points by modeling the single impurity as a junction (weak link) of two interacting wires. We show that the universal behavior of the junction can be easily identified within the MERA and argue that the boundary MERA framework has tremendous potential to classify the fixed points in general multi-wire junctions.Comment: 14 pages, 18 figure

High Efficiency Concurrent Embedded Block Coding Architecture for JPEG 2000

[[abstract]]Embedded block coding with optimized truncation (EBCOT) is the most important part of JPEG 2000. Due to the bit level operation and the three-pass scanning technique, the EBCOT may take more than 50% operation time in the JPEG 2000. This paper presents a high efficiency concurrent EBCOT(HECEBC) entropy encoder hardware architecture. The proposed HECEBC can concurrently process the four samples in a stripe column. Furthermore this architecture can be extended to process several stripe columns concurrently for the JPEG 2000 to accomplish high resolution applications in real time. Besides, the HECEBC uses the technique of concentrated context window to stabilize the Context-Decision (CX-D) output to relax the load in between the arithmetic encoder (AE) and the parallel-in-serial-out (PISO) buffer to triple the EBC performance.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

Effective Application of Improved Profit-Mining Algorithm for the Interday Trading Model

Many real world applications of association rule mining from large databases help users make better decisions. However, they do not work well in financial markets at this time. In addition to a high profit, an investor also looks for a low risk trading with a better rate of winning. The traditional approach of using minimum confidence and support thresholds needs to be changed. Based on an interday model of trading, we proposed effective profit-mining algorithms which provide investors with profit rules including information about profit, risk, and winning rate. Since profit-mining in the financial market is still in its infant stage, it is important to detail the inner working of mining algorithms and illustrate the best way to apply them. In this paper we go into details of our improved profit-mining algorithm and showcase effective applications with experiments using real world trading data. The results show that our approach is practical and effective with good performance for various datasets

What influences geography teachers' usage of geographic information systems? A structural equation analysis

Understanding the usage of the geographic information system (GIS) among geography teachers is a crucial step in evaluating the current dissemination of GIS knowledge and skills in Taiwan's educational system. The primary contribution of this research is to further our understanding of the factors that affect teachers' GIS usage. The structural equation model was employed to analyze the data collected from 725 senior high school geography teachers. This was done using a survey questionnaire inspired by the Technology Acceptance Model (TAM), which postulates the importance of how teachers perceived the usefulness and ease of use of GIS. Further, this study investigates the direct effect of GIS workshop attendance on actual GIS usage and assesses whether GIS workshop attendance mediates the relationship between perceived ease of use, perceived usefulness, and actual usage. Structural equation modeling results suggest that the perceived usefulness of adopting GIS is vital as it directly affects teachers' attendance at GIS training, and can further prompt their application of GIS in lectures. The perceived ease of GIS use does not influence actual usage directly, but does affect teachers' GIS usage in teaching through perceived usefulness and workshop attendance. Finally, workshop attendance can increase teachers' usage of GIS and mediate the association between perceived usefulness and actual usage