1,157 research outputs found
RISK, CAPITALIZATION AND SURVIVAL OF YOUNG FIRMS: EMPIRICAL SURVEY ON ITALIAN COMPANIES
Young businesses are very vulnerable during first stage of life. There are many causes that can lead to premature extinction of companies. The purpose of this paper is to verify if the level of risk that enterprises face in their first year of life affects their survival. To this end, an empirical survey has been carried out on Italian companies established in 2009, 2010 and 2011. In order to reduce the influence of under capitalization on the survival of the firms in the first stage of life, only companies with a share capital ≥ €50,000 were included in the sample. Furthermore, only companies not belonging to a private or public group were included in the sample. This is to in order to eliminate the influence of the financial strength of the public and/or private holding on the survival of the companies examined. The study has highlighted that these companies with a strong capitalization (with a share capital ≥ €50,000) have very high survival rates at five years; furthermore, their survival is not affected by an operating and financial risk higher than average. Therefore, the high vulnerability rate of young firms seems to be mainly caused by under capitalization rather than the risk rate they face
A CSI Dataset for Wireless Human Sensing on 80 MHz Wi-Fi Channels
In the last years, several machine learning-based techniques have been proposed to monitor human movements from Wi-Fi channel readings. However, the development of domain-adaptive algorithms that robustly work across different environments is still an open problem, whose solution requires large datasets characterized by strong domain diversity, in terms of environments, persons and Wi-Fi hardware. To date, the few public datasets available are mostly obsolete - as obtained via Wi-Fi devices operating on 20 or 40 MHz bands - and contain little or no domain diversity, thus dramatically limiting the advancements in the design of sensing algorithms. The present contribution aims to fill this gap by providing a dataset of IEEE 802.11 ac channel measurements over an 80 MHz bandwidth channel featuring notable domain diversity, through measurement campaigns that involved thirteen subjects across different environments, days, and with different hardware. Novel experimental data is provided by blocking the direct path between the transmitter and the monitor, and collecting measurements in a semi-anechoic chamber (no multi-path fading). Overall, the dataset - available on IEEE DataPort [1] - contains more than thirteen hours of channel state information readings (23.6 GB), allowing researchers to test activity/identity recognition and people counting algorithms
V-MAD: Video-based Morphing Attack Detection in Operational Scenarios
In response to the rising threat of the face morphing attack, this paper
introduces and explores the potential of Video-based Morphing Attack Detection
(V-MAD) systems in real-world operational scenarios. While current morphing
attack detection methods primarily focus on a single or a pair of images, V-MAD
is based on video sequences, exploiting the video streams often acquired by
face verification tools available, for instance, at airport gates. Through this
study, we show for the first time the advantages that the availability of
multiple probe frames can bring to the morphing attack detection task,
especially in scenarios where the quality of probe images is varied and might
be affected, for instance, by pose or illumination variations. Experimental
results on a real operational database demonstrate that video sequences
represent valuable information for increasing the robustness and performance of
morphing attack detection systems
Experimental and computational investigation of heat transfer in channels filled by woven spacers
Models of woven-type spacer-filled channels were investigated by Computational Fluid Dynamics (CFD) and parallel experiments in order to characterize the performance of Membrane Distillation (MD) modules. The case of overlapped spacers was analysed in a companion paper. Experiments were based on a non-intrusive technique using Thermochromic Liquid Crystals (TLC) and digital image processing, and provided the distribution of the local convective heat transfer coefficient on a thermally active wall. CFD simulations ranged from steady-state conditions to unsteady and early turbulent flow, covering a Reynolds number interval of great practical interest in real MD applications. A specific spacer aspect ratio (pitch-to-channel height ratio of 2) and two different spacer orientations with respect to the main flow (0° and 45°) were considered. Among the existing studies on spacer-filled channels, this is one of the first dealing with woven spacers, and one of the very few in which local experimental and computational heat transfer results are compared. Results suggest a convenience in adopting the 45° orientation for applications that can be operated at very low Reynolds numbers, since convenience decreases as the Reynolds number increases
Smart valorization of waste biomass: Exhausted lemon peels, coffee silverskins and paper wastes for the production of levulinic acid
In recent years, the replacement of fossil resources with renewable ones has focused great interest, expecially as regards the production of new valuable bio-products and bio-fuels, in progressive replacement of the traditional petroleum-based ones.The Waste Management Policy strongly encourages the valorization of waste biomasses into added-value bio-chemicals, instead of their traditional combustion for energy recovery or, even worse, of their landfill disposal. In this context, the acid-catalysed hydrothermal conversion of negative-value bio-wastes into levulinic acid (LA) represents a smart exploitation possibility, already developed and optimized on pilot-scale, and widely adaptable to different kinds of feedstocks. In this work, the LA production was investigated starting from two bio-wastes deriving from industrial Italian food-processing, e.g.exhausted lemon peels and coffee silverskins, together with that of a clean cellulose powder, which derives from the cutting operations occurring during the tissue paper production. The effect of the main reaction parameters on the LA synthesis, in particular the concentration of the acid catalyst, the biomass loading, the reaction temperature/time and, additionally, the effect of an upstream milder acid pretreatment, was investigated and discussed. Moreover, in the case of coffee silverskin, a preliminary extraction step of the water-soluble phenolics has further improved the fractionation and exploitation of this waste biomass. These compounds have been proposed as natural antioxidants, which represent very valuable niche products for nutraceutical uses. The described examples confirm the feasibility of an integrated valorization of the waste biomass, well in agreement with the Biorefinery concept
Implementation and Review of the Axisymmetric Equilibrium System of RFX-Mod2 within the MARTe2 Framework
A major refurbishment of the toroidal complex of the RFX-mod device is in progress and it will include the removal of the Inconel vacuum vessel and a modification of the stainless steel supporting structure to be made vacuum-tight. The axisymmetric equilibrium control in RFX-mod was responsible for the control of the plasma current, horizontal and vertical position along with its stability and the plasma shape. The new implementation framework, both hardware and software, is described. The system has been fully reviewed and modified, if needed, for its prospective use in RFX-mod2. In order to run tests in an operation-like context, the updated system has also been implemented in the MARTe2 framework, to be deployed for the real-time applications of RFX-mod2. The results of the previous versions were reproduced and the cycle-time requirements were met
Fertility-Sparing Treatment for Early-Stage Cervical Cancer ≥ 2 cm: A Problem with a Thousand Nuances—A Systematic Review of Oncological Outcomes.
BACKGROUND: Fertility-sparing treatments (FSTs) have played a crucial role in the management of early-stage cervical cancer (ECC). The guidelines have recognized various approaches, depending on the tumor stage and other risk factors such as histotype and lymphovascular positivity. Much more debate has centered around the boundary within which these treatments should be considered. Indeed, these are methods to be reserved for ECC, but tumor size may represent the most significant limitation. In particular, there is no consensus on the strategy to be adopted in the case of ECC ≥ 2 cm. Therefore, this systematic review was to collect the literature evidence regarding the management of these patients. METHODS: Following the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we systematically searched the Pubmed and Scopus databases was conducted in April 2022, from the date of the first publication. We made no limitation on the country. We included all studies containing data on disease-free survival, overall survival, recurrence rate (RR), or complete response rate (CRR) to chemotherapy. RESULTS: Twenty-six studies fulfilled the inclusion criteria, and 691 patients were analyzed regarding FST. Surgery-based FST showed an RR of between 0 and 42.9%, which drops to 12.9% after excluding the vaginal or minimally invasive approaches. Furthermore, papers regarding FST based on the neoadjuvant chemotherapy (NACT) approach showed a CRR of between 21.4 and 84.5%, and an RR of between 0 and 22.2% CONCLUSION: This paper focused on the significant heterogeneity present in the clinical management of FST of ECC ≥ 2 cm. Nevertheless, from an oncological point of view, approaches limited to the minimally invasive or vaginal techniques showed the highest RR. Vice versa, the lack of standardization of NACT schemes and the wealth of confounders to be attributed to the histological features of the tumor make it difficult, if not impossible, to set a standard of treatment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1245/s10434-022-12436-w
Radiomics analysis in gastrointestinal imaging: a narrative review
Background and Objective: To present an overview of radiomics radiological applications in major
gastrointestinal oncological non-oncologic diseases, such as colorectal cancer, pancreatic cancer, gastro-
oesophageal cancer, gastrointestinal stromal tumor (GIST), hepatocellular carcinoma (HCC), intrahepatic
cholangiocarcinoma (ICC), and non-oncologic diseases, such as liver fibrosis, nonalcoholic steatohepatitis,
and inflammatory bowel disease.
Methods: A search of PubMed databases was performed for the terms “radiomic”, “radiomics”, “liver”,
“small bowel”, “colon”, “GI tract”, and “gastrointestinal imaging” for English articles published between
January 2013 and July 2022. A narrative review was undertaken to summarize literature pertaining to
application of radiomics in major oncological and non-oncological gastrointestinal diseases. The strengths
and limitation of radiomics, as well as advantages and major limitations and providing considerations for
future development of radiomics were discussed.
Key Content and Findings: Radiomics consists in extracting and analyzing a vast amount of quantitative
features from medical datasets, Radiomics refers to the extraction and analysis of large amounts of
quantitative features from medical images. The extraction of these data, integrated with clinical data, allows
the construction of descriptive and predictive models that can build disease-specific radiomic signatures.
Texture analysis has emerged as one of the most important biomarkers able to assess tumor heterogeneity
and can provide microscopic image information that cannot be identified with the naked eye by radiologists.
Conclusions: Radiomics and texture analysis are currently under active investigation in several institutions
worldwide, this approach is being tested in a multitude of anatomical areas and diseases, with the final aim
to exploit personalized medicine in diagnosis, treatment planning, and prediction of outcomes. Despite
promising initial results, the implementation of radiomics is still hampered by some limitations related to the
lack of standardization and validation of image acquisition protocols, feature segmentation, data extraction,
processing, and analysi
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