WATCHING PEOPLE: ALGORITHMS TO STUDY HUMAN MOTION AND ACTIVITIES

Nowadays human motion analysis is one of the most active research topics in Computer Vision and it is receiving an increasing attention from both the industrial and scientific communities. The growing interest in human motion analysis is motivated by the increasing number of promising applications, ranging from surveillance, human–computer interaction, virtual reality to healthcare, sports, computer games and video conferencing, just to name a few. The aim of this thesis is to give an overview of the various tasks involved in visual motion analysis of the human body and to present the issues and possible solutions related to it. In this thesis, visual motion analysis is categorized into three major areas related to the interpretation of human motion: tracking of human motion using virtual pan-tilt-zoom (vPTZ) camera, recognition of human motions and human behaviors segmentation. In the field of human motion tracking, a virtual environment for PTZ cameras (vPTZ) is presented to overcame the mechanical limitations of PTZ cameras. The vPTZ is built on equirectangular images acquired by 360° cameras and it allows not only the development of pedestrian tracking algorithms but also the comparison of their performances. On the basis of this virtual environment, three novel pedestrian tracking algorithms for 360° cameras were developed, two of which adopt a tracking-by-detection approach while the last adopts a Bayesian approach. The action recognition problem is addressed by an algorithm that represents actions in terms of multinomial distributions of frequent sequential patterns of different length. Frequent sequential patterns are series of data descriptors that occur many times in the data. The proposed method learns a codebook of frequent sequential patterns by means of an apriori-like algorithm. An action is then represented with a Bag-of-Frequent-Sequential-Patterns approach. In the last part of this thesis a methodology to semi-automatically annotate behavioral data given a small set of manually annotated data is presented. The resulting methodology is not only effective in the semi-automated annotation task but can also be used in presence of abnormal behaviors, as demonstrated empirically by testing the system on data collected from children affected by neuro-developmental disorders

Methodological approach for evaluating the geo-exchange potential: VIGOR Project

In the framework of VIGOR Project, a national project coordinated by the Institute of Geosciences and Earth Resources (CNR-IGG) and sponsored by the Ministry of Economic Development (MiSE), dedicated to the evaluation of geothermal potential in the regions of the Convergence Objective in Italy (Puglia, Calabria, Campania and Sicily), is expected to evaluate the ability of the territory to heat exchange with the ground for air conditioning of buildings. To identify the conditions for the development of low enthalpy geothermal systems collected and organized on a regional scale geological and stratigraphic data useful for the preparation of a specific thematic mapping, able to represent in a synergistic and simplified way the physical parameters (geological, lithostratigraphic, hydrogeological, thermodynamic) that most influence the subsoil behavior for thermal exchange. The litho-stratigraphic and hydrogeological database created for every region led to the production of different cartographic thematic maps, such as the thermal conductivity (lithological and stratigraphical), the surface geothermal flux, the average annual temperature of air, the climate zoning, the areas of hydrogeological restrictions. To obtain a single representation of the geo-exchange potential of the region, the different thematic maps described must be combined together by means of an algorithm, defined on the basis of the SINTACS methodology. The purpose is to weigh the contributions of the involved parameters and to produce a preliminary synthesis map able to identify the territorial use of geothermal heat pump systems, based on the geological characteristics and in agreement with the existing regulatory constraints

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

Pedestrian Tracking in 360 Video by Virtual PTZ Cameras

Since the data acquired by a PTZ camera change while adjusting the pan, tilt and zoom parameters, the results of tracking algorithms are difficult to reproduce; such diffi- culty limits the development and the comparison of tracking algorithms with PTZ cameras. The recently introduced 360- degree cameras acquire spherical views of the environment, generally stored as equirectangular images. Each pixel of an equirectangular image corresponds to a point on the spherical surface. A gnomonic projection can be used to project the points on the spherical surface onto a plane tangent to the sphere. Such tangent plane can be interpreted as the image plane of a virtual PTZ camera oriented towards the point of tangency. This paper proposes a framework to simulate PTZ cameras from 360-degree video enabling, in this way, the development and comparison of PTZ-based tracking algorithms. Furthermore, within the above mentioned framework, this paper presents a novel pedestrian tracking algorithm for 360- degree videos. The proposed algorithm aims at estimating the pan, tilt and zoom parameters required to control the virtual camera in such a way that the target is always at the center of the virtual camera view. The proposed method belongs to the category of tracking-by-detection algorithms; it also exploits the use of a dynamic memory to store the appearance models of the best past target detections. Preliminary results on a publicly available benchmark demonstrate the viability of the proposed approach

Hop: Histogram of patterns for human action representation

This paper presents a novel method for representing actions in terms of multinomial distributions of frequent sequential patterns of different length. Frequent sequential patterns are series of data descriptors that occur many times in the data. This paper proposes to learn a codebook of frequent sequential patterns by means of an apriori-like algorithm, and to represent an action with a Bag-of-Frequent-Sequential-Patterns approach. Preliminary experiments of the proposed method have been conducted for action classification on skeletal data. The method achieves state-of-the-art accuracy value in cross-subject validation

Particle Filtering for Tracking in 360 Degrees Videos Using Virtual PTZ Cameras

360 degrees cameras are devices able to record spherical images of the environment. Such images can be used to generate views of the scene by projecting the spherical surface onto planes tangent to the sphere. Each of these views can be considered as the output of a virtual PTZ (vPTZ) camera with specific pan, tilt and zoom parameters. This paper proposes to formulate the visual tracking problem as the one of selecting, at each time, the vPTZ camera to foveate on the target from the unlimited set of simultaneously generated vPTZ camera views. Assuming that the selected vPTZ camera is a stochastic variable, the paper proposes to model the posterior distribution of the underlying stochastic process by means of a set of particles each representing a vPTZ camera view. Experiments on a publicly available dataset show that the proposed tracking strategy is viable and achieves state-of-the-art performance

Childhood maltreatment and clinical response to mood stabilizers in patients with bipolar disorder

The association between childhood maltreatment (CM) and clinical response to mood stabilizers has been scarcely investigated in bipolar disorder (BD). Therefore, we assessed whether CM affects the response to lithium or anticonvulsant treatments in BD patients

Childhood maltreatment and clinical response to mood stabilizers in patients with bipolar disorder

The association between childhood maltreatment (CM) and clinical response to mood stabilizers has been scarcely investigated in bipolar disorder (BD). Therefore, we assessed whether CM affects the response to lithium or anticonvulsant treatments in BD patients