Cloud detection from thermal infrared images using a segmentation technique

In this paper, a fast and accurate method is proposed for two cloud detection tests on thermal infrared (IR) data obtained from satellite images over sea; an IR gross cloud test and a spatial coherence test. The proposed method is based on a regional segmentation technique. After the segmentation of an IR image, small regions were regarded as cloudy due to their high spatial variability in temperature. This technique preserved the spatial resolution of the detected cloud image which would be degraded by the conventional spatial coherence test. It also reduced the computation dramatically, compared to the conventional spatial coherence test. An accurate temperature threshold between clear sea and clouds was determined directly from the segmented image. This post-determined threshold was found to be more accurate than pre-determined temperature thresholds. Since this algorithm does not require any human interaction, it can be combined with other tests in an automatic cloud detection algorithm.     

Efficient and secure source authentication scheme for multicast user authentication

Multicast technology application has been widely utilized in broadband internet. Source authentication is one of the most needs for many multicast applications transferring real-time information such as stream video and online news. Because multicast current services provided to the group members are changed dynamically, data transferring by a group member is not used by the recipient. In order to verify the identity of the sender who sent the packet and to make sure that the data have not been tampered, an optimized source authentication scheme has been proposed to transfer the authentication information not to the next-door packet. The proposed method for multiple packets authenticates the source with a limited number of electronic signatures. The proposed method can reduce overhead compared to the method by adding a digital signature for every packet. In addition, by sending the generated electronic signature to the first packet and the last packet, it prevents the loss of consecutive packets, as well as a source authentication can be provided in real-time services.     

Corrosion performance of high pressure die-cast Al-6Si-3Ni and Al-6Si-3Ni-2Cu alloys in aqueous NaCl solution

The corrosion performance of high pressure die-cast Al-6Si-3Ni (SN63) and Al-6Si-3Ni-2Cu (SNC632) alloys in 3.5% (mass fraction) NaCl solution was investigated. X-ray diffraction (XRD) and microstructural studies revealed the presence of single phase Si and binary Al₃Ni/Al₃Ni₂ phases along the grain boundary. Besides, the single Cu phase was also identified at the grain boundaries of the SNC632 alloy. Electrochemical corrosion results revealed that, the SNC632 alloy exhibited nobler shift in corrosion potential (?_corr), lower corrosion current density (J_corr) and higher corrosion resistance compared to the SN63 alloy. Equivalent circuit curve fitting analysis of electrochemical impedance spectroscopy (EIS) results revealed the existence of two interfaces between the electrolyte and substrate. The surface layer and charge transfer resistance (R_ct) of the SNC632 alloy was higher than that of the SN63 alloy. Immersion corrosion test results also confirmed the lower corrosion rate of the SNC632 alloy and substantiated the electrochemical corrosion results. Cu addition improved the corrosion resistance, which was mainly attributed to the absence of secondary Cu containing intermetallic phases in the SNC632 alloy and Cu presented as single phase.     

Correlation Between Oxidative Deterioration of Unsaturated Lipid and n-Hexanal during Storage of Brown Rice

n-Hexanal in the headspace over cooked brown rice stored at 5°C and 35°C for 0, 4, 8 and 12 months was determined by a gas chromatographic method using modified direct vapor injection. The off-flavors of stored brown rice were evaluated by n-hexanal and oxidized linoleic acid analysis. The amount of n-hexanal was found to be linearly proportional to the amount of oxidized linoleic acid (correlation coefficient, 0.99). Therefore, the simple and rapid method of vapor injection gas chromatography can be used for determining n-hexanal in the headspace vapor over cooked brown rice. Thus, the off-flavor of the stored brown rice resulting from lipid oxidation can be detected indirectly.     

Limonoids in Pummelos [Citrus grandis (L.) Osbeck]

Juice and seeds from 16 cultivars of mature pummelo fruits were analyzed for limonoid content. Pummelo juice contained an average of 18 ppm limonin and 29 ppm total limonoid glucosides. Compared to other juices, ptmnnelo contained very high concentrations of limonin and very low concentrations of limonoid glucosides. Limonin, nomilin, obacunone and trace amounts of deacetyhromilin were found in pummelo seeds. The 17–β-D-glucopyranoside derivatives (glucosides) of nomilin, nomilinic acid and obacunone were also present. Total limonoid aglycone concentration in the seeds ranged from 773 ppm to 9,900 ppm and total limonoid glucosides ranged from 130 ppm to 1,912 ppm.     

旋转浓缩-蓄热氧化法处理涂装废气的中试研究

用旋转浓缩-蓄热氧化(RC-RTO)系统对某车轮厂涂装废气进行了中试处理研究,以废气处理前后总挥发性有机物(T-VOCs)浓度及苯、甲苯、乙苯、对二甲苯、邻二甲苯浓度的变化为指标,考察了RC转速对吸附性能、RTO氧化效果的影响.结果表明,RC转速对吸附效果及进入RTO单元浓缩气体中VOCs浓度有较大的影响,RC转速过高或过低均不利于系统稳定高效的运行.系统在RC转速为3r/h的条件下连续运行1个月,期间系统不需外加能源即可维持热量平衡,且RC单元及RTO单元排气中5种VOC物质浓度均远低于国家规定的排放标准(GB16297-1996).