29726375
Collaborative Education Model and Its Application in E-learning
This paper presents a collaborative education model and its application in e-learning. This work is distinguished by three contributions. One is the proposition of three goals of e-learning in "source, transmit and quality" views. The second one is the proposition of collaborative education model including model of studying process, model of studying environment and six collaborative scenarios. The last one is the proposition of a collaborative e-learning implementation architecture.
17507770
An Improved Level Set for Liver Segmentation and Perfusion Analysis in MRIs
Determining liver segmentation accurately from MRIs is the primary and crucial step for any automated liver perfusion analysis, which provides important information about the blood supply to the liver. Although implicit contour extraction methods, such as level set methods (LSMs) and active contours, are often used to segment livers, the results are not always satisfactory due to the presence of artifacts and low-gradient response on the liver boundary. In this paper, we propose a multiple-initialization, multiple-step LSM to overcome the leakage and over-segmentation problems. The multiple-initialization curves are first evolved separately using the fast marching methods and LSMs, which are then combined with a convex hull algorithm to obtain a rough liver contour. Finally, the contour is evolved again using global level set smoothing to determine a precise liver boundary. Experimental results on 12 abdominal MRI series showed that the proposed approach obtained better liver segmentation results, so that a refined liver perfusion curve without respiration affection can be obtained by using a modified chamfer matching algorithm and the perfusion curve is evaluated by radiologists.
15935457
A Design of Data Rebuilding for Decision Support in E-Government System
The E-Government System is composed of three networks and one database. The business network within government offices (the Internal Net), the resource network in central and local administrations and departments (the External Net), the public information network (PIN) relying on the Internet. It is necessary to rebuild data in the three networks of the system in order to construct an effective electronic information database. In data rebuilding, a data exchange platform is set up to enable data sharing between the three networks. The data exchange platform is implemented in a structure that combines the intelligent decision support system (IDSS) and data warehouse (DW).
7335001
Pivotbrowser: a tag-space image searching prototype
We propose a novel iterative searching and refining prototype for tagged images. This prototype, named PivotBrowser, captures semantically similar tag sets in a structure called pivot. By constructing a pivot for a textual query, PivotBrowser first selects candidate images possibly relevant to the query. The tags contained in these candidate images are then selected in terms of their tag relevances to the pivot. The shortlisted tags are clustered and one of the tag clusters is used to select the results from the candidate images. Ranking of the images in each partition is based on their relevance to the tag cluster. With the guidance of the tag clusters presented, a user is able to perform searching and iterative query refinement.
116588251
On-line evolutionary exponential family mixture
This paper deals with evolutionary clustering, which refers to the problem of clustering data with distribution drifting along time. Starting from a density estimation view to clustering problems, we propose two general on-line frameworks. In the first framework, i.e., historical data dependent (HDD), current model distribution is designed to approximate both current and historical data distributions. In the second framework, i.e., historical model dependent (HMD), current model distribution is designed to approximate both current data distribution and historical model distribution. Both frameworks are based on the general exponential family mixture (EFM) model. As a result, all conventional clustering algorithms based on EFMs can be extended to evolutionary setting under the two frameworks. Empirical results validate the two frameworks.
16710673
BCM Mechanism Based on Infinite-horizon Growth Model in E-commerce
Applying Romer model to Business Continuity Management (BCM) of E-commerce will greatly improve the reliability and security of E-commerce. There are three levels in Mechanism of Business Continuity Management Mechanism Based on infinite-hotizon growth model such as Hardware, the resource Database and. The appliance of the Mechanism in an online-book store is proven it’s efficiency.
120992950
A mathematical model for bifurcations in a Belousov-Zhabotinsky reaction
Abstract In our investigation we find that there are three stages during the whole lifespan of a Belousov–Zhabotinsky (BZ) system with 1,4-cyclohexanedione (CHD) and ferroin: transitional period (TP), induction period (IP), and main period (MP). When the system goes from the TP to the IP, there is a bifurcation from monostability (orange steady-state) to bistability (both orange and blue steady-states). When the system shifts from the IP to the MP, a different bifurcation occurs from the bistability back to the monostability (orange steady-state). A reduction step before the second bifurcation propagates slower than oxidation steps and pulses during the whole lifespan of the medium. This sharp difference of propagation speed has not been observed in other BZ systems, and cannot be interpreted by the prototype Oregonator model. We construct here an Oregonator-type model that simulates the two bifurcations and the propagation speed difference of the two kinds of step before the second bifurcation. Furthermore, our model demonstrates other bifurcations that are not observable in experiment. Our discovery not only unfolds a new aspect of the well-studied BZ reaction, but also leads to a new demand for further understanding of a reaction–diffusion equation system as the corresponding ordinary differential equation system bifurcates.