Search results for "processi"
showing 10 items of 9638 documents
Agroecology as a challenge for the competitiveness of small scale agriculture
2018
L'agroecologia viene spesso presentata come un'alternativa agli attuali sistemi di produzione diffusi, sebbene ci siano molte domande sulla reale possibilità di una produzione alimentare sufficiente- mente elevata per una popolazione in crescita. L' analisi sviluppata in questo paper è basata sulla ricer- ca scientifica degli ultimi vent'anni e sulle l'attività delle ONG, dei movimenti degli agricoltori e delle organizzazioni governative di diversi contesti. L'obiettivo è quello di fornire un panorama dei princi- pali argomenti in discussione per una transizione agroecologica dei sistemi alimentari mondiali, individ- uando alcune sfide prioritarie e immaginando chi saranno i partecipanti qu…
<title>Multiresolution description of range images through 2D quincunx wavelet analysis</title>
1999
In this paper, we present a method for performing a multi- scale analysis on range images by using the wavelet transform, that is capable of revealing multi-resolution information. An accurate non-contact optical system based upon laser triangulation is used to determine the depth information of the object being scanned. The resulting range image is treated as a gray-level image by using a multi- resolution approach based on the generalization of the cascade algorithm using the quincunx wavelet transform. The quincunx wavelet assures very fine analysis. This method allows reconstruction of non-subsampled images that correspond to decompositions previously done at chosen scales. Multi-resolu…
Stochastic Graph Filtering Under Asymmetric Links in Wireless Sensor Networks
2018
Wireless sensor networks (WSN s) are often characterized by random and asymmetric packet losses due to the wireless medium, leading to network topologies that can be modeled as random, time-varying and directed graphs. Most of existing works related to graph filtering in the context of WSNs assume that the probability of delivering an information from one node to a neighbor node is the same as in the reverse direction. This assumption is not realistic due to the typical link asymmetry in WSNs caused by interferences and background noise. In this work, we analyze the problem of applying stochastic graph filtering over random time-varying asymmetric network topologies. We show that it is poss…
Outsourcing information systems: A strategic partnership with risks
1993
Abstract As information processing and telecommunications technology increase in sophistication and complexity, organizations are finding it more difficult to manage their information systems (IS) for business success. Growing numbers are now sharing these responsibilities and risks with outsourcing vendors. American Standard, Eastman Kodak, General Dynamics, Metropolitan Life, and Young & Rubicam are prominent companies which have outsourced some or all of their IS activities. They are looking to gain competitive advantages by cutting costs and focusing internal resources on core activities. However, compromises in management control and data security, the potential of hidden costs, and th…
Channel Modeling and System Concepts for Future Terahertz Communications: Getting Ready for Advances Beyond 5G
2020
Future terahertz (THz) communications will utilize the frequency spectrum around 300 GHz. This technology provides a promising solution for future high-data-rate communications due to the high available bandwidth. However, the unfavorable channel characteristics are a major barrier for the realization of THz communications. To address the challenges caused by the unfavorable propagation conditions, the world?s first THz communication standard includes a channel-modeling document (CMD).
A statistical model for magnitudes and angles of wavelet frame coefficients and its application to texture retrieval
2014
Abstract This paper presents a texture descriptor based on wavelet frame transforms. At each position in the image, and for each resolution level, we consider both vertical and horizontal wavelet detail coefficients as the components of a bivariate random vector. The magnitudes and angles of these vectors are computed. At each level the empirical histogram of magnitudes is modeled by a Generalized Gamma distribution, and the empirical histogram of angles is modeled by a different version of the von Mises distribution that accounts for histograms with 2 modes. Each texture is characterized by few parameters. A new distance is presented (based on the Kullback–Leibler divergence) that allows g…
Three-dimensional ultrasonography in prenatal diagnosis
1995
Within the past five years, 3D ultrasonography has developed to the degree that it offers both the patient and the examiner an entirely new visual experience in prenatal diagnosis. With the system described here (Kretz-technik, Austria), any desired plane can be displayed within the stored volume, and within seconds a high-quality 3D surface or transparent image can be calculated and displayed on the ultrasound monitor without need for an external workstation. All of this can be performed routinely in the clinical setting. Since 1989 we have routinely examined a total of 458 fetuses (242 normal and 216 with anomalies) between 16 and 38 weeks of gestation, supplementing our conventional 2D u…
Southeast Asia as a Linguistic Area
2006
The languages belonging to the families of Mon-Khmer, Tai, Sinitic, Hmong-Mien, and Chamic (Malayo-Polynesian) spoken in mainland Southeast Asia share a considerable number of properties due to contact-induced convergence. General characteristics of the languages in this area are the lack of obligatory grammatical categories and the central role of pragmatics (indeterminateness), syllabic morphology, and relatively flexible correlations between word class and syntactic positions (versatility). The following properties will be described in some more detail: word order, numeral classifiers, cooccurrence patterns of the verb with coverbs, tense-aspect-modality markers and directional verbs, an…
A Digital Watermarking Algorithm Based on Quantization of the DCT: Application on Medical Imaging
2013
International audience; The objective of this paper is to elaborate a new watermarking algorithm applied to the medical imaging. This algorithm must be invisible, robust and has a rate, relatively high, integrating data. The proposed method uses the standard JPEG compression for the integration of medical data. The insertion block is inserted just after the quantization phase. To control identification and eventually the correction (if possible) of the inserted data, we use a series of turbocodes to recover the inserted data, after application of several attacks. The simulation studies are applied on MRI medicals images.
Automatic detection of cervical cells in Pap-smear images using polar transform and k-means segmentation
2016
We introduce a novel method of cell detection and segmentation based on a polar transformation. The method assumes that the seed point of each candidate is placed inside the nucleus. The polar representation, built around the seed, is segmented using k-means clustering into one candidate-nucleus cluster, one candidate-cytoplasm cluster and up to three miscellaneous clusters, representing background or surrounding objects that are not part of the candidate cell. For assessing the natural number of clusters, the silhouette method is used. In the segmented polar representation, a number of parameters can be conveniently observed and evaluated as fuzzy memberships to the non-cell class, out of …