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51.
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Nowadays video surveillance systems are widely deployed in many public places. However, the widespread use of video surveillance
violates the privacy rights of the people. Many authors have addressed the privacy issues from various points of view. In
this paper we propose a novel, on-demand selectively revocable, privacy preserving mechanism. The surveillance video can be
tuned to view with complete privacy or by revoking the privacy of any subset of pedestrians while ensuring complete privacy
to the remaining pedestrians. We achieve this by tracking the pedestrians using a novel Markov chain algorithm with two hidden
states, detecting the head contour of the tracked pedestrians and obscuring their faces using an encryption mechanism. The
detected pedestrian face/head is obscured by encrypting with a unique key derived from a master key for the privacy preservation
purpose. The performance evaluations on many challenging surveillance scenarios show that the proposed mechanism can effectively
and robustly track as well as identify multiple pedestrians and obscure/unobscure their faces/head in real time. 相似文献
53.
Emmanuel Benoist Jean-Jacques Hébrard 《Annals of Mathematics and Artificial Intelligence》2003,37(3):251-272
The enlarged Horn formulas generalize the extended Horn formulas introduced by Chandru and Hooker (1991). Their satisfying truth assignments can be generated with polynomial delay. Unfortunately no polynomial algorithm is known for recognizing enlarged Horn formulas or extended Horn formulas. In this paper we define the class of simple enlarged Horn formulas, a subclass of the enlarged Horn formulas, that contains the simple extended Horn formulas introduced by Swaminathan and Wagner (1995). We present recognition algorithms for the simple enlarged Horn formulas and the simple extended Horn formulas whose complexity is bounded by the complexity of the arborescence-realization problem. 相似文献
54.
Yannis Theodoridis Dimitris Papadias Emmanuel Stefanakis Timos Sellis 《Data & Knowledge Engineering》1998,27(3):2108
This paper defines direction relations (e.g., north, northeast) between two-dimensional objects and shows how they can be efficiently retrieved using B-, KDB- and R- tree-based data structures. Essentially, our work studies optimisation techniques for 2D range queries that arise during the processing of direction relations. We test the efficiency of alternative indexing methods through extensive experimentation and present analytical models that estimate their performance. The analytical estimates are shown to be very close to the actual results and can be used by spatial query optimizers in order to predict the retrieval cost. In addition, we implement modifications of the existing structures that yield better performance for certain queries. We conclude the paper by discussing the most suitable method depending on the type of the range and the properties of the data. 相似文献
55.
In this paper, a method for robust design of a neural network (NN) model for prediction of delamination (Da), damage width (Dw), and hole surface roughness (Ra) during drilling in carbon fiber reinforced epoxy (BMS 8-256) is presented. This method is based on a parametric analysis of neural network models using a design of experiments approach. The effects of number of neurons (N), hidden layers (L), activation function (AF), and learning algorithm (LA) on the mean square error (MSE) of model prediction are quantified. Using the aforementioned method, a robust NN model was developed that predicted process-induced damage with high accuracy. 相似文献
56.
Sofia Papadaki Magdalini Krokida Dimitrios Economides Emmanuel Koukios 《Drying Technology》2014,32(12):1500-1511
This article presents a study of the effect of drying methods on dyeing capacity of widespread European flora dyestuff plant materials. The natural colorants, derived from the selected plant materials, were applied on chemical pulp in order to examine their dyeability. In this work, three different drying methods were examined—the natural, the air-, and the freeze-drying method—in various conditions. The plant materials that were dried naturally show weak dyeing results in comparison with the air- and freeze-dried materials. Freeze drying significantly improved the dyeing capacity of dyestuff plant materials with high initial moisture content. On the other hand, air drying at low temperature and high relative humidity improved the dyeing capacity of plant materials with low initial moisture content. 相似文献
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Antifungal activity of five different essential oils in vapour phase for the control of Colletotrichum gloeosporioides and Lasiodiplodia theobromae in vitro and on mango
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Anand Babu Perumal Periyar Selvam Sellamuthu Reshma B. Nambiar Emmanuel Rotimi Sadiku 《International Journal of Food Science & Technology》2016,51(2):411-418
Mango fruit has high commercial value; however, major postharvest losses are encountered throughout the supply chain due to postharvest diseases. These results lead to the search for natural fungicide for postharvest diseases control. The antifungal effects of five essential oils (thyme, clove, cinnamon, anise and vitex) were assessed by disc volatilisation method. Thyme oil vapours at 5 μL per Petriplate, and clove and cinnamon oil at 8 μL per Petriplate showed 100% growth inhibition of mango pathogens in vitro. GC/MS analysis of essential oil showed thymol (23.88), o‐cymol (23.88) and terpinolene (23.88) as the major constituents of thyme oil. Clove and cinnamon oils contain 3‐allyl‐2‐methoxyphenol (37.42%) and benzofuran 3‐methyl (17.97%), respectively. Thyme oil as a fumigant at 66.7 μL L?1 showed a significant (P < 0.05) inhibition on postharvest pathogens of mango fruits stored at 25 °C for 6 days. Results of our study suggest the possibility of using thyme oil as an alternate natural fungicide to manage postharvest diseases in mango. 相似文献
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Multimedia Tools and Applications - Robust tracking of moving objects is still an open problem in computer vision. The problem and its difficulty depend on many factors, which includes the... 相似文献