Search results for "Caliza"

Attenuation of NF-κB Signaling Response to UVB Light during Cellular Senescence

1999

The ability of cells to adapt to environmental stresses undergoes a progressive reduction during aging. NF-kappaB-mediated signaling is a major defensive system against various environmental challenges. The aim of this study was to find out whether replicative senescence affects the response of the NF-kappaB signaling pathway to UVB light in human WI-38 and IMR-90 fibroblasts. The exposure of early passage fibroblasts to UVB light inhibited the proliferation and induced a flat phenotype similar to that observed in replicatively senescent fibroblasts not exposed to UVB light. The UVB radiation dose used (153 mJ/cm2) did not induce apoptosis in either early or late passage WI-38 fibroblasts. …

Contrasting Internationalization Paths of Product- and Service-oriented Software Firms

2019

The internationalization of software firms has been widely researched topic over the last two decades. However, the most of the studies have treated software firms as a homogeneous group, ignoring the fact that software firms actually differ greatly in terms of having either a product or a service orientation. Based on earlier literature, we hypothesized that software product firms would show a tendency to internationalize earlier and at a smaller size than software service firms, and that product firms would show a greater tendency to target countries that are both geographically and culturally distant. In fact, we found no support for most of our hypotheses, with relatively strong and sta…

Seismic Network Evaluation through Simulation: an application to the Italian RSNC-INGV

2010

Palermo 2010 - Underwater seismic monitoring of the epicenter area of the 6 September 2002 Palermo Earthquake

2011

Accessibility urban and central business

2012

The structures and facilities of large dimensions, such as shopping malls centers and leisure facilities are an important component in the expansion of contemporary cities and urban planning. Urban planning and transport have to be involved in the strategic role of policy related to business planning, this is the aim the city has to requalify the suburbs and large marginal areas. This study analyzes the characteristics and the dynamics that influence the mobility demand and the impact that these greet attractors have on mobility itself.

A phase-field model for strain localization

2018

Strain localization in quasi-brittle materials occurs when a material is subjected to a high level of mechanical solicitations and inelastic strains develop in relatively narrow zone where micro-cracks appear. The gradual evolution of the micro-cracks results in the formation of localized bands up to the development of stress-free cracks. The localized zone or plastic band is generally associated to a faster growth of strain and is characterized by inelastic phenomena such as opening and propaga- tion of cracks, initiation and growth of voids. Conversely, outside of this zone, the material unloads elastically. Extensive research has been carried out to address issues related to the modeling…

INDOOR LOCALIZATION USING COGNITIVE RADIOS AND SOFTWARE-DEFINED WIRELESS NETWORKS

WMPS: A Positioning System for Localizing Legacy 802.11 Devices

2012

The huge success of location-aware applications calls for the quick development of a positioning system alternative to GPS for indoor localization based on existing technologies such as 802.11 wireless networks. In this paper we propose WMPS, the Wireless MAC Processor Positioning System, that is a localization system running on off-the-shelf 802.11 Access Points and based on time-of-flight ranging of users’ standard terminals. We prove through extensive experiments that propagation delays can be measured with the accuracy required by indoor applications despite the different noise components that can affect the result, like latencies of the hardware transreceivers, multi- path, ACK jitters…

A hybrid observer for localization from noisy inertial data and sporadic position measurements

2023

We propose an asymptotic position and speed observer for inertial navigation in the case where the position measurements are sporadic and affected by noise. We cast the problem in a hybrid dynamics framework where the continuous motion is affected by unknown continuous-time disturbances and the sporadic position measurements are affected by discrete-time noise. We show that the peculiar hybrid cascaded structure describing the estimation error dynamics is globally finite-gain exponentially ISS with gains depending intuitively on our tuning parameters. Experimental results, as well as the comparison with an Extended Kalman Filter (EKF), confirm the effectiveness of the proposed solution with…

A machine learning approach for user localization exploiting connectivity data

2016

The growing popularity of Location-Based Services (LBSs) has boosted research on cheaper and more pervasive localization systems, typically relying on such monitoring equipment as Wireless Sensor Networks (WSNs), which allow to re-use the same instrumentation both for monitoring and for localization without requiring lengthy off-line training. This work addresses the localization problem, exploiting knowledge acquired in sample environments, and extensible to areas not considered in advance. Localization is turned into a learning problem, solved by a statistical algorithm. Additionally, parameter tuning is fully automated thanks to its formulation as an optimization problem based only on co…