Search results for " sistemi"
showing 10 items of 1888 documents
Restoration of out of focus images based on circle of confusion estimates
2002
In this paper a new method for a fast out-of-focus blur estimation and restoration is proposed. It is suitable for CFA (Color Filter Array) images acquired by typical CCD/CMOS sensor. The method is based on the analysis of a single image and consists of two steps: 1) out-of-focus blur estimation via Bayer pattern analysis; 2) image restoration. Blur estimation is based on a block-wise edge detection technique. This edge detection is carried out on the green pixels of the CFA sensor image also called Bayer pattern. Once the blur level has been estimated the image is restored through the application of a new inverse filtering technique. This algorithm gives sharp images reducing ringing and c…
Acquisition of New Knowledge to Manage Conversation in TutorJ
2009
This paper presents new conversation modules developed for TutorJ to support the use of meta-cognitive strategies in the learners. TutorJ is an Intelligent Tutoring System able to interact with users to assess their skills, and improve their knowledge in a specific domain. New models are devoted to plan the conversation and to acquire new knowledge from semi-structured data sources. Conversation planning is based on probabilistic techniques. Knowledge acquisition is based on retrieval, transformation and alignment of data from wikis to enrich the replies to students questions.
The Sound Design Toolkit
2017
The Sound Design Toolkit is a collection of physically informed sound synthesis models, specifically designed for practice and research in Sonic Interaction Design. The collection is based on a hierarchical, perceptually founded taxonomy of everyday sound events, and implemented by procedural audio algorithms which emphasize the role of sound as a process rather than a product. The models are intuitive to control – and the resulting sounds easy to predict – as they rely on basic everyday listening experience. Physical descriptions of sound events are intentionally simplified to emphasize the most perceptually relevant timbral features, and to reduce computational requirements as well. Keywo…
Automatic concept maps generation in support of educational processes
2014
A VLE is a system where three main actors can be devised: the teacher in the role of instructional designer, the tutor, and the stu- dent. Instructional designers need easy interaction for specifying the course domain structure to the system, and for controlling how well the learning materials agree to such a structure. Tutors need tools for having a holistic perception of the evolution of single students and/or groups in the VLE during the learning process. Finally, students need self regulation in terms of controlling their learning rate, reflect on their learning strategies, and comparing with other people in the class. In this work we claim that sharing an implicit representation of the…
Intelligent Agents supporting user interactions within self regulated learning processes
2010
The paper focuses on the main advantages in the defnition and utilization of an open and modular e-learning software platform to support highly cognitive tasks performed by the main actors of the learning process. We present in detail the integration inside the platform of two intelligent agents devoted to talking with the student and to retrieving new information sources on the Web. The process is triggered as a reply to the system’s perception that the student feels discontented with the presented contents. The architecture is detailed, and some conclusions about the growth of the platform’s overall performance are expressed.
Automatic Volumetric Liver Segmentation Using Texture Based Region Growing
2010
In this paper an automatic texture based volumetric region growing method for liver segmentation is proposed. 3D seeded region growing is based on texture features with the automatic selection of the seed voxel inside the liver organ and the automatic threshold value computation for the region growing stop condition. Co-occurrence 3D texture features are extracted from CT abdominal volumes and the seeded region growing algorithm is based on statistics in the features space. Each CT volume is composed by 230 slices, having 512 x 512 pixels as spatial resolution, and 12-bit gray level resolution. In this initial feasible study, 5 healthy volunteer acquisitions has been used. Tests have been p…
Mathematical Patterns and Cognitive Architectures
2014
Mathematical patterns are an important subclass of the class of patterns. The main task of this paper is examining a particular proposal concerning the nature of mathematical patterns and some elements of the cognitive architecture an agent should have to recognize them.
A Graph-Based Method for PET Image Segmentation in Radiotherapy Planning: A Pilot Study
2013
Target volume delineation of Positron Emission Tomography (PET) images in radiation treatment planning is challenging because of the low spatial resolution and high noise level in PET data. The aim of this work is the devel- opment of an accurate and fast method for semi-automatic segmentation of me- tabolic regions on PET images. For this purpose, an algorithm for the biological tumor volume delineation based on random walks on graphs has been used. Va- lidation was first performed on phantoms containing spheres and irregular in- serts of different and known volumes, then tumors from a patient with head and neck cancer were segmented to discuss the clinical applicability of this algo- rith…
Body Area Networks and Healthcare
2014
Derived from Wireless Sensor Networks, Body Area Networks, comprise a wide range of typologies with sensor nodes placed on, close to, or implanted in the body that measure physiological signs. The availability of compact mobile computing devices makes it possible to integrate traditional healthcare with new powerful means. New paradigms in public health are arising from these developments, such as e-health and mHealth, and new converging applications can be envisioned. Physiological data acquisition provided by BANs may give care providers a unobtrusive real-time view on patient’s health. On the other hand, the patient may be informed, assisted and even given the proper treatment by care pr…
Computer assisted diagnosis (CAD) in mammography. Comparison of diagnostic accuracy of a new algorithm (Cyclopus(R), Medicad) with two commercial sys…
2008
The study compares the diagnostic accuracy (correct identification of cancer) of a new computer-assisted diagnosis (CAD) system (Cyclopus) with two other commercial systems (R2 and CADx). Cyclopus was tested on a set of 120 mammograms on which the two compared commercial systems had been previously tested. The set consisted of mammograms reported as negative, preceding 31 interval cancers reviewed as screening error or minimal sign, and of 89 verified negative controls randomly selected from the same screening database. Cyclopus sensitivity was 74.1% (R2=54.8%; CADx=41.9%) and was higher for interval cancers reviewed as screening error (90.9%; R2=54.5%; CADx=81.8%) compared with those revie…