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25 September 2009, Volume 2009 Issue 5 Previous Issue    Next Issue

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Context aware computing(Chinese) GU Jun-zhong 2009, 2009 (5):  1-20.  Abstract ( 3354 )   PDF (3326KB) ( 4429 )   Save An overview of the basic concepts concerning context aware computing and a survey of the up-to-date researches were presented in this paper. Context and its spectrum were well formed and defined. Based on the evolution of computing modes, context aware computing as well as context aware systems was analyzed. As application examples, realizations of location based service and context aware web searching were discussed. Related Articles | Metrics

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Modified exemplar-based image inpainting algorithm(Chinese) TANG Xiao-na;CHEN Ji-guo;SHEN Chao-min;ZHANG Gui-xu 2009, 2009 (5):  21-28.  Abstract ( 2849 )   PDF (4206KB) ( 1454 )   Save This paper changed the searching scope of the original exemplar-based image inpainting from the whole image domain into a user-defined domain, which guarantees that the suitable structure is inpainted, and thereby efficiently improved inpainting results. Meanwhile, the original fixed size of the exemplar was also changed into an automatically adjusted size, which significantly improved the searching speed. This algorithm has been successfully applied to remotely sensed data. Related Articles | Metrics

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Study on the photocatalytic property of ZnO nanorod/PVC composite (Chinese) DONG Peng-fei;HAN Jing;SHAO Qi-wei;CHENG Rong-ming 2009, 2009 (5):  29-39,8.  Abstract ( 3025 )   PDF (2053KB) ( 1352 )   Save Composite precursor was synthesized by mixing ZnO nanorod which was attained by hydrothermal method and polyvinyl chloride solution, ZnO nanorod/PVC composite was prepared by calcinating the precursor at appropriate temperature. Also, the composite was characterized by XRD, TEM, SEM, IR, UV-Vis and ESR. We studied on the photocatalytic property of ZnO nanorod and its composite under visible light, and evaluated the effect of preparations using methyl orange(MO) as a probe reaction. The experiments showed the optimum conditions for preparing this composite are: the mass ratio of ZnO nanorod and PVC is 1∶1, calcined temperature is 250 ℃ and calcined time is 1 h. Otherwise, the composite can degrade MO up to 88% under illumination with 15 W home light for 3 h when the concentration of MO is 10 mg/L, and the dose of photocatalyst is 0.5 g/L. The results above indicated that ZnO nanorod/PVC composite has good photocatalytic property under visible light. Related Articles | Metrics

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Improved enzyme immobilization for enhanced bioelectrocatalyticactivity of glucose sensor (Chinese) DU Wei-jie;LOU Lei;ZHU Zi-qiang;WANG Yi-ting;ZHU Jian-zhong 2009, 2009 (5):  37-44.  Abstract ( 2910 )   PDF (1391KB) ( 1921 )   Save A highly sensitive and stable glucose sensor based on the synergic action of multi wall carbon nanotube (MWCNTs) and ZnO nanoparticles was developed. Glucose oxidase (GOx) was firmly immobilized on the ZnO nanoparticles surface due to their large difference in the isoelectric point (IEP), while the ZnO nanoparticles were deposited on the negatively charged MWCNTs layer. A cationic polydiallyldimethylammonium chloride (PDDA) layer was coated on the GOx layer. The unique sandwich-like layer structure (PDDA/GOx/ZnO/MWCNTs) formed by self-assembling provides a favorable microenvironment to keep the bioactivity of GOx and to prevent enzyme molecule leakage. Amperometric detection of glucose was carried out at 100 mV (vs. Ag/AgCl) in 0.05 mol/L phosphate buffer solution (pH 6.8); a wide linear response range of 0.1 to 16 mmol/L was measured by a sensor with 0.5 units GOx; a sensitivity of 50.2 mA•cm-2•mol-1 and a detection limit of 250 nmol/L (3σ) were measured by a sensor with 2.0 units GOx. Results obtained from the glucose sensor directly in human blood serum were compared with ones obtained by spectrometry by a local hospital. On testing 100 samples of serum, the correlation coefficient reaches 0.997. Related Articles | Metrics

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Approach to planning for an organized evacuation (Chinese) ZHENG Yan-fei;LI Xiang 2009, 2009 (5):  45-52.  Abstract ( 3047 )   PDF (1856KB) ( 1679 )   Save In response to extreme disasters, it is necessary to evacuate people to safe places. This paper presented a new approach to planning for an organized evacuation based on the shortest path algorithm. Experiments were conducted and the results demonstrated that both average waiting time and total evacuation time are shortened with this algorithm. The approach can be applied by decision making authorities in planning for disaster prevention and mitigation. Related Articles | Metrics

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Application of PCR-DGGE to analyze the effect of temperatureon structure of nitrifying bacteria in A2/O system (Chinese) TAO Fang;HUANG Yan;GAO Shang;HUANG Min-sheng;CHEN Cheng 2009, 2009 (5):  53-62.  Abstract ( 2934 )   PDF (2591KB) ( 2200 )   Save The effects of temperature on the structure of nitrifying bacteria in A2/O system were studied for the purpose of technique improvements and system regulations. Total microbial DNA was extracted from samples which were collected from reactor, then target DNA fragments were amplified from the total DNA using specific bacterial primer. The target DNA were used for denaturing gradient gel electrophoresis(DGGE) analysis. Results indicated that the changes of temperature could affect the community structure and the Shannon diversity index of nitrifying bacteria. The structure of AOB community was stable when the temperature was higher than 25 ℃, the removal rate of NH4+-N was over 95% in this condition; The structure of Nitrobacter community was stable when the temperature was higher than 20 ℃, the removal rate of NH4+-N can reach 95% in this condition; The structure of Nitrospira community changed greatly when the temperature changed, comparatively speaking, the community structure was most stable when the temperature was between 15 ℃ to 20 ℃, the removal rate of NH4+-N was between 75% to 95% in this condition. Related Articles | Metrics

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Study on ecological benefits of urban near-natural forests (Chinese) YIN Jun-guang;PENG Yuan;ZHANG Jun-guo;DA Liang-jun; 2009, 2009 (5):  63-74.  Abstract ( 3107 )   PDF (2722KB) ( 1974 )   Save This paper focused on the ecological benefits of the near-natural forest in Pudong Shanghai, and contrasted it with the evergreen broad-leaf forests in Tiantong National Park and also with plant communities in urban areas. Several indices were selected in the investigation, including concentration of air anion, air temperature and humidity, air microorganisms and soil microorganisms. We got the following results. The air anion in near-natural forest were much higher than that in the contrast communities in urban areas, but much lower than that in the evergreen broad-leaf forests in Tiantong National Forest Park. The distribution of air bacteria, air fungus, and air actinomycete were definitely different. The average of air bacteria concentrations of urban near-natural forest was lower than contrast sample plots, but air fungi and actinomycete was higher. Near-natural forest was approaching natural forest better than contrast plant communities in urban area by its numbers of soil microorganisms. Related Articles | Metrics

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Distribution of soil heavy metal and pollution evaluation in Chongming Island (Chinese) ZHOU Yan-;LI De-zhi-;SONG Yun-;LI Hong-;KE Shi-zhen-;WANG Chun-ye-;SUN Yu-bing-;LI Li-ke-;ZHAO Lu-qing- 2009, 2009 (5):  75-84.  Abstract ( 4464 )   PDF (1446KB) ( 2196 )   Save The distribution maps of heavy metals in soils of Chongming county were drawn using Kriging method in the geo-statistic module of ArcGIS，and the degrees of pollution were evaluated using the single-facter pollution index (SPI) and comprehensive pollution index (CPI).The results showed that the degrees of pollution of heavy metals in soils of Chongming County were Cd>Zn>Cu>Cr>Pb. Among the heavy metals, Cd was the major one. The average SPI of Cd in the soil samples was 1.05, reaching the light degree of pollution.The comprehensive pollution index of 5 heavy metals including all soil samples, ranged from 0.22 to 2.59 with an average of 0.88, reaching the alarm degree of pollution. However, The overall situation of heavy metals in soils were relatively clean, because there were still 72.39% of soil samples showing the cleanness. Related Articles | Metrics

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Spatio-temporal variation of main soil nutrientsin three islands in Chongming (Chinese) SONG Yun -;LI De-zhi-;ZHOU Yan-;LI Hong-;KE Shi-zhen-;SUN Yu-bing-;WANG Chun-ye-;ZHAO Lu-qing-;LI Li-ke- 2009, 2009 (5):  85-93.  Abstract ( 3183 )   PDF (1757KB) ( 2082 )   Save According to the data of organic matter (OM), total nitrogen (TN), available phosphrus (AP) and available potassium (AK) of topsoil samples (0~20 cm) collected from 135 sites in 2007, the spatial distribution characteristics of the main soil nutrients in three islands in Chongming，Chongming island， Changxing island and Hengsha island，were analyzed using the methods of geostatistics and overlay analysis in the software of ArcGIS 9.1. The results showed that the areas with higher OM and TN were mainly distributed in Chengqiao town and Bao town, and the values of both indices declined gradually towards northwest and northeast. The distribution trends of AP and AK were basically complementary. When comparing the values of 1980 and 2007 in terms of all these indexes, OM and TN did not change significantly, whereas AP increased rapidly and AK decreased. The results further revealed the unbalance in soil fertilization. Related Articles | Metrics

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Isolation and identification of a 10-hydroxycamptothecin-producingendophytic fungus from Camptotheca acuminate Decne (Chinese) MIN Chang-li;YUAN Ping 2009, 2009 (5):  94-99.  Abstract ( 3286 )   PDF (1035KB) ( 1702 )   Save Six endophytic fungi isolated from Camptotheca acuminate Decne were cultured in taper flask under shaking. The organic extracts of mycelium were analyzed with thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). The results showed one of the strains produced the 10-hydroxycamptothecin (HCPT) with output of 410 μg/L and was named XK002. Morphological observation indicates that XK002 belongs to Mycelia sterlia. Related Articles | Metrics

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On the problem of transversal selection (Chinese) GUAN Zhi-zhong;LIU Yong-ming 2009, 2009 (5):  100-106.  Abstract ( 3950 )   PDF (647KB) ( 2037 )   Save The Hungarian method by matching is efficient in solving assignment problems. And its method by matrix is easy to handle and popular. But the latter method would fail in some special cases due to improper selection of zeros for transversal when there are more than one to choose. A general selection method of transversal was given based on the Hungarian method by matching. The MATLAB routine of our method was also given. Related Articles | Metrics

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Pricing forward starting call option in a jump diffusion model WANG Wei;WANG Wen-sheng;WANG Shuai 2009, 2009 (5):  107-117.  Abstract ( 3003 )   PDF (204KB) ( 1566 )   Save By the way of change of measure, a closed solution of pricing formula of European forward starting call option was given in a double exponential jump diffusion model. Moreover, a problem of pricing forward call option when the log jump size has a general distribution was also considered. Related Articles | Metrics

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Credibility models with error uniform dependence WEN Li-min; WANG Wei; YU Xue-li 2009, 2009 (5):  118-126，.  Abstract ( 2964 )   PDF (296KB) ( 1812 )   Save Firstly, the errors were assumed to be uniformly dependent in normal-normal cases and the Bayes premiums were derived in this model which show that it is the exact credibility. Secondly, the Bühlmann’s credibility models with uniform dependence were built, and the corresponding credibility estimators were derived. In addition, the models were extended to Bühlmann-Straub credibility in which the natural weights among contracts were introduced. However, the credibility estimators of individual premium under Bühlmann-Straub model have only the generalized form of "credibility". Related Articles | Metrics

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Proof procedure of some theories in statistical analysis of global symmetry (Chinese) Pan Changyuan;Ma Hainan;;Chen Xueping;Zhang Yingshan 2009, 2009 (5):  127-137.  Abstract ( 2888 )   PDF (314KB) ( 1264 )   Save This research guaranteed orthogonal symmetry demonstration to any system function,ensured the formula of demonstration to system function variance.They are the kernel and foundation stone of statistical analysis of global symmetry.By studying how these symmetry functions work in the whole system function,the symmetry of system function can be understood better.As illustrated by the examples,it showed the symmetry of system function clearly by using the Monte-Carlo calculated value of contribution rate as the global sensitivity index of symmetry function. Related Articles | Metrics

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Solutions to some Diophantine equations over mathbf{Q}(\sqrt{-3} WANG Yong-liang 2009, 2009 (5):  138-141.  Abstract ( 2518 )   PDF (144KB) ( 1505 )   Save By using Fermat’s method of descent, this paper proved that Diophantine equations { x^{4}-y^{4}=z^{2}} and { x^{4}+4y^{4}=z^{2}} have no non-trivial solutions over {\mathbf{Q}}(\sqrt{-3}), which implies that the Fermat Equation also has no non-trivial solutions in this field for n =4. Related Articles | Metrics