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1.
Bio-cryptography is an emerging security technology which combines cryptography with biometrics. A good bio-cryptosystem is required to protect the privacy of the relevant biometric data as well as achieving high recognition accuracy. Fingerprints have been widely used in bio-cryptosystem design. However, fingerprint uncertainty caused by distortion and rotation during the image capturing process makes it difficult to achieve a high recognition rate in most bio-cryptographic systems. Moreover, most existing bio-cryptosystems rely on the accurate detection of singular points for fingerprint image pre-alignment, which is very hard to achieve, and the image rotation transformation during the alignment process can cause significant singular point deviation and minutiae changes. In this paper, by taking full advantage of local Voronoi neighbor structures (VNSs), e.g. local structural stability and distortion insensitivity, we propose an alignment-free bio-cryptosystem based on fixed-length bit-string representations extracted from modified VNSs, which are rotation- and translation-invariant and distortion robust. The proposed alignment-free bio-cryptosystem is able to provide strong security while achieving good recognition performance. Experimental results in comparison with most existing alignment-free bio-cryptosystems using the publicly-available databases show the validity of the proposed scheme. 相似文献
2.
Stephen Ridout Milos Dusek Chris Bailey Chris Hunt 《Microelectronics Reliability》2006,46(12):2122-2130
This paper presents both modelling and experimental test data to characterise the performance of four non-destructive tests. The focus is on determining the presence and rough magnitude of thermal fatigue cracks within the solder joints for a surface mount resistor on a strip of FR4 PCB. The tests all operate by applying mechanical loads to the PCB and monitoring the strain response at the top of the resistor. The modelling results show that of the four tests investigated, three are sensitive to the presence of a crack in the joint and its magnitude. Hence these tests show promise in being able to detect cracking caused by accelerated testing. The experimental data supports these results although more validation is required. 相似文献
3.
Milos Bandjur Nikola Sekulovic Mihajlo Stefanovic Aleksandra Golubovic Petar Spalevic Dejan Milic 《ETRI Journal》2013,35(4):722-725
In this letter, a wireless communication system with microdiversity and macrodiversity reception in gamma‐shadowed Rician fading channels is considered. Exact and rapidly converging infinite‐series expressions for the average level crossing rate and average fade duration at the output of the system are provided. Numerical results are presented graphically to illustrate the proposed mathematical analysis and to examine the effects of the system's parameters on the quantities considered. 相似文献
4.
Tetiana Borzda Christoph Gadermaier Natasa Vujicic Peter Topolovsek Milos Borovsak Tomaz Mertelj Daniele Viola Cristian Manzoni Eva A. A. Pogna Daniele Brida Maria Rosa Antognazza Francesco Scotognella Guglielmo Lanzani Giulio Cerullo Dragan Mihailovic 《Advanced functional materials》2015,25(22):3351-3358
The 2D semiconductor MoS2 in its mono‐ and few‐layer form is expected to have a significant exciton binding energy of several 100 meV, suggesting excitons as the primary photoexcited species. Nevertheless, even single layers show a strong photovoltaic effect and work as the active material in high sensitivity photodetectors, thus indicating efficient charge carrier photogeneration. Here, modulation spectroscopy in the sub‐ps and ms time scales is used to study the photoexcitation dynamics in few‐layer MoS2. The results suggest that the primary photoexcitations are excitons that efficiently dissociate into charges with a characteristic time of 700 fs. Based on these findings, simple suggestions for the design of efficient MoS2 photovoltaic and photodetector devices are made. 相似文献
5.
A method is presented for near-Earth spacecraft or aviation vehicle‘s attiude rate cstimation by using relative Doppler frequency shift of the Global Positioning System(GPS)carrier.It comprises two GPS receiving antennas,a signal processing circuit and an algorithm.The whole system is relatvely simple,the cost and weight,as well power consumption,are very low. 相似文献
6.
This paper reports on experimental results of aqueous heterophase polymerizations with monomers of quite different solubility in water ranging from the water-soluble 2-hydroxyethyl methacrylate to lauryl methacrylate with solubility in water of only about 10−4 mM. A calorimetric study revealed the strong influence of both the hydrophilicity of the monomer and the stirrer speed on the rate of polymerization in the absence of surfactants. In order to obtain maximum latex yield and high efficiency (which is a measure considering colloidal properties, polymerization recipe, and polymerization parameters) the initiator-surfactant combination must be properly chosen in dependence on the hydrophilicity of the monomer. Results are presented for sodium alkyl sulfates or disodium-N-stearoyl-l-glutamate as surfactant and potassium peroxodisulfate, or poly(ethylene glycol)-azo- compounds, or 2,2′-azobis(N-2′-methylpropanoyl-2-amino-alkyl-1)-sulfonates as initiators. 相似文献
7.
Ivana M. Radovic Dusica B. Stojanovic Aleksandar Kojovic Milos Petrovic Petar S. Uskokovic Vesna J. Radojevic 《Polymer-Plastics Technology and Engineering》2017,56(11):1188-1195
The study presents a novel method for protection of the first- and the second-generation Grubbs’ catalyst, by incorporation in poly(styrene) fibers through electrospinning technique. Both catalysts are sensitive to the presence of the amine hardeners in the epoxy-based self-healing composites and require protection from deactivation to retain their ability to promote polymerization reaction of the healing agent. Comparison of healing efficiencies of both catalysts suggested that poly(styrene) fibers offer better protection and dispersion for the first-generation Grubbs’ catalyst, although all the samples exhibited high-healing efficiency. Difference in stereoselectivity between two catalysts was also indicated. 相似文献
8.
Soini HA Linville SU Wiesler D Posto AL Williams DR Novotny MV 《Journal of chemical ecology》2012,38(2):145-156
We investigated head- and cheek-rubbing behavior in four species of large felines, lions (Leo panther), leopards (Panthera pardus), tigers (Panthera tigris), and cougars (Puma concolor), in captivity. Preliminary behavioral observations found that lions and tigers, but not leopards and cougars, showed behavioral
responses to cardboard rubbing samples from head and cheek areas from conspecific felines, compared to the blank cardboard
controls. In this context, surface samples on the facial areas of each species were collected to analyze volatile organic
compounds that could be involved in the facial marking of felines. Previously developed stir bar surface sampling methodology
was used. From all cheek and forehead samples, 100 volatile organic compounds were identified or tentatively identified. Among
these, 41 have been previously reported to be present in feline urine and marking secretions. Several new compounds were identified
on facial surfaces. Some of the compounds showed substantial quantitative differences among the species. One compound, that
has not been reported previously in mammals, 3-acetamidofuran, was found in all investigated species. It was synthesized and
tested for behavioral responses. No responses were elicited in a preliminary test. Future research will test other potential
signaling compounds and their mixtures for ability to elicit behavioral responses. 相似文献
9.
Helena A. Soini Donald Wiesler Sachiko Koyama Christophe Féron Claude Baudoin Milos V. Novotny 《Journal of chemical ecology》2009,35(5):580-589
Whereas the house mouse (Mus domesticus) has been studied extensively in terms of physiology/behavior and pheromonal attributes, the evolutionarily related mound-building
mouse (Mus spicilegus) has received attention only recently due to its divergent behavioral traits related to olfaction. To date, no chemical studies
on urinary volatile compounds have been performed on M. spicilegus. The rationale for our investigations was to determine if there are differences in urinary volatiles of intact and castrated
M. spicilegus males and to explore further whether this species could utilize the same or structurally similar pheromones as the male house
mouse, M. domesticus. The use of capillary gas chromatography/mass spectrometry (GC-MS) together with sorptive stir bar extraction sampling enabled
quantitative comparisons between the intact and castrated M. spicilegus urinary profiles. Additionally, through GC-MS and atomic emission (sulfur-selective) detection, we identified qualitative
molecular differences between intact M. spicilegus and M. domesticus. A series of volatile and odoriferous lactones and the presence of coumarin were the unique features of M. spicilegus, as was the notable absence of 2-sec-butyl-4,5-dihydrothiazole (a prominent M. domesticus male pheromone) and other sulfur-containing compounds. Castration of M. spicilegus males eliminated several substances, including δ-hexalactone and γ-octalactone, and substantially decreased additional compounds,
suggesting their possible role in chemical communication. Some other M. domesticus pheromone components were also found in M. spicilegus urine. These comparative chemical analyses support the notion of metabolic similarities as well as the uniqueness of some
volatiles for M. spicilegus, which may have a distinct physiological function in reproduction and behavior. 相似文献
10.
The evaluation of antioxidant power of glycosidically bound volatile aglycones from savory shows that these compounds possess antioxidative activity comparable to that of the essential oil, but less effective compared to the well-known antioxidant butylated hydroxytoluene (BHT) and alpha-tocopherol. Thus, since the glycosides are able to release their aglycones by enzymatic hydrolysis, they could be considered as possible precursors of antioxidant substances in savory. 相似文献