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181.
Visual secret sharing (VSS) is a variant form of secret sharing, and is efficient since secret decoding only depends on the human vision system. However, cheating in VSS, first showed by Horng et al., is a significant issue like a limelight. Since then, plenty of studies for cheating activities and cheating prevention visual secret sharing (CPVSS) schemes have been introduced. In this paper, we revisit some well-known cheating activities and CPVSS schemes, and then categorize cheating activities into meaningful cheating, non-meaningful cheating, and meaningful deterministic cheating. Moreover, we analyze the research challenges in CPVSS, and propose a new cheating prevention scheme which is better than the previous schemes in the aspects of some security requirements. 相似文献
182.
Mingxing He Shi-Jinn Horng Pingzhi Fan Muhammad Khurram Khan Ray-Shine Run Jui-Lin Lai Rong-Jian Chen Adi Sutanto 《Expert systems with applications》2011,38(10):12018-12027
Phishing attack is growing significantly each year and is considered as one of the most dangerous threats in the Internet which may cause people to lose confidence in e-commerce. In this paper, we present a heuristic method to determine whether a webpage is a legitimate or a phishing page. This scheme could detect new phishing pages which black list based anti-phishing tools could not. We first convert a web page into 12 features which are well selected based on the existing normal and fishing pages. A training set of web pages including normal and fishing pages are then input for a support vector machine to do training. A testing set is finally fed into the trained model to do the testing. Compared to the existing methods, the experimental results show that the proposed phishing detector can achieve the high accuracy rate with relatively low false positive and low false negative rates. 相似文献
183.
Chyouhwa Chen Shi-Jinn Horng Chin-Pin Huang 《Expert systems with applications》2011,38(10):12388-12397
Association rule mining is one of the most important techniques for intelligent system design and has been widely applied in a large number of real applications. However, classical mining algorithms cannot process very large databases in a reasonable amount of time. The sampling approach that processes a subset of the whole database is a viable alternative. Obviously, such an approach cannot extract perfectly accurate rules. Previous works have tried to improve the accuracy by removing “outliers” from the initial sample based on global statistical properties in the sample. In this paper, we take the view that the initial sample may actually consist of multiple possibly overlapping subsets or clusters. It is more reasonable to apply data clustering techniques to the initial sample before outlier removal is performed on the resulting clusters, so that outliers are removed based on local properties of individual clusters. However, clustering transactional data with very high dimensions is a difficult problem by itself. We solve this problem by interpreting locality sensitive hashing as a means for data clustering. Previously proposed algorithms may be then optionally used to remove the outliers in the individual clusters. We propose several concrete algorithms based on this general strategy. Using an extensive set of synthetic data and real datasets, we evaluate our proposed algorithms and find that our proposals exhibit better accuracy or execution time, or both, than previously proposed algorithms. 相似文献
184.
185.
This paper accomplished a three-dimensional computational analysis of the methanol reformer with steam reforming by the Arrhenius form of reaction model and SIMPLE-C algorithm. The performance enhancement and non-isothermal reactant transport of the cylindrical reformer wrapped with a porous sheath were investigated. The parameters, including temperature of internal heater (TH), porosity (ε), and thickness of porous sheath (RP), on methanol conversion, hydrogen, carbon monoxide, carbon dioxide productions, temperature and velocity fields with the same inlet conditions have been investigated. The results present that higher methanol conversion and richer hydrogen production occur as temperature of heater, porosity, and porous sheath thickness increase. As temperature of internal heater is equal to 250 °C, employing a porous sheath with ε = 0.9 and RP = 10 mm to wrap a reformer results in the maximum enhancements of 35.71% in methanol conversion and 21.18% in hydrogen production. Besides, a porous sheath with ε = 0.5 and RP = 10 mm leads to the maximum reduction of 2.23% in carbon monoxide produced from the reformer at TH = 300 °C. 相似文献
186.
S.Y. Yang C.S. HoC.L. Lee B.Y. ShihH.E. Horng Chin-Yih Hong H.C. Yang Y.H. ChungJ.C. Chen T.C. Lin 《Food chemistry》2012,131(3):1021-1025
The application of the assay methodology, called immunomagnetic reduction, using bio-functionalized magnetic nanoparticles as labeling markers for chloramphenicol was investigated. The reduction in the alternative-current (ac) magnetic susceptibility χac of magnetic nanoparticles caused by the association between magnetic nanoparticles and chloramphenicol was detected as a function of the concentration of chloramphenicol. In this study, the characterizations used to detect chloramphenicol, such as low-detection limit and interference, were also conducted. Furthermore, the extracting processes for chloramphenicol from shrimp were explored. Thus, the platform for detecting chloramphenicol residue in shrimp via immunomagnetic reduction was demonstrated. Such platform showed features of a 0.1-ppb low-detection limit, low interference from other kinds of antibiotics, and easy operation. 相似文献
187.
188.
The anionic polymerization of methyl methacrylate was performed in tetrahydrofuran (THF) at ?78°C, using sec‐butyllithium/1,1‐diphenylethylene (DPE) as the initiation system. The effects of polymerization time and initiator concentration on the branching reaction were studied. High vacuum was used to prevent contamination during the polymerization. Gel permeation chromatography (GPC) was used to characterize the branching effect qualitatively. Experimental results indicated that the monomer conversion reached more than 98% in a polymerization time of 10 min. The branching reaction occurred after high monomer conversion, resulting in a tail of high molecular weight in the GPC trace. This branching effect, observed by GPC, increased with polymerization time. Rapid termination was thus probably required immediately after all of the monomer was consumed in the preparation of a well‐defined PMMA without a high‐molecular‐weight tail in this diphenylbutylllithium/THF/?78°C system. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
189.
Porous silicon carbide (SiC) was synthesized by carbothermal reduction method. In this method, the sucrose and the tetarethoxysilane (TEOS) were used as carbon resource and silicon resource. The surface area and pore volume of the obtained SiC was 157 m2/g and 0.46 cm3/g, respectively. Then the Pt/SiC was prepared by incipient impregnation method for the CO oxidation. The result shows that the catalyst exhibits relatively high catalyst activity, and makes it likely that SiC will become the subject of intense research as a potential new catalyst support material. 相似文献
190.
Huang S.-H. Horng R.-H. Wen K.-S. Lin Y.-F. Yen K.-W. Wuu D.-S. 《Photonics Technology Letters, IEEE》2006,18(24):2623-2625
A novel flip-chip structure of GaN-sapphire light-emitting diodes (LEDs) was developed to improve the external quantum efficiency, where the sapphire substrate was textured and shaped with beveled sidewalls using a wet etching technique. The forward voltage of the conventional flip-chip and shaped flip-chip GaN LEDs were 2.84 and 2.85 V at 20 mA, respectively. This indicates that the GaN LED was not destroyed during the sapphire wet etching process. It was found that the output power increased from 9.3 to 14.2 mW, corresponding to about 52% increases in the external quantum efficiency. The results agree well with the simulation data that the shaped flip-chip GaN LED can provide better light extraction efficiency than that of the conventional flip-chip sample 相似文献