232 research outputs found
Epidemics of Liquidity Shortages in Interbank Markets
Financial contagion from liquidity shocks has being recently ascribed as a
prominent driver of systemic risk in interbank lending markets. Building on
standard compartment models used in epidemics, in this work we develop an EDB
(Exposed-Distressed-Bankrupted) model for the dynamics of liquidity shocks
reverberation between banks, and validate it on electronic market for interbank
deposits data. We show that the interbank network was highly susceptible to
liquidity contagion at the beginning of the 2007/2008 global financial crisis,
and that the subsequent micro-prudential and liquidity hoarding policies
adopted by banks increased the network resilience to systemic risk---yet with
the undesired side effect of drying out liquidity from the market. We finally
show that the individual riskiness of a bank is better captured by its network
centrality than by its participation to the market, along with the currently
debated concept of "too interconnected to fail"
Decompose et Impera: tensor methods in high-dimensional data
This thesis is written with the scope of exploring multiway data. Multiway
data, also referred to as tensor data, is a collection of data points in multidimensional matrices. At a first glance one may think that these objects
are only a convenient representation of a datasets. They are not just a col-
lection of data, they have their own structure. For this reason, multiway
data need specific models to be correctly analysed. In this spirit, I developed
my personal idea on data analysis which can be represented by following
statement:
\It is not the data that should fit models, but models that should fit the data"
However, this should not be taken literary I do think that models are im-
portant: giving a structure to our techniques is necessary. Nevertheless, I do
think that data should be the main driver.This means that instead of trimming data at our necessity to fit existing models, researchers should develop
new models to re
ect the complexity of the data.
The purpose of this work is to provide an overview of tensor methods applied
to Economics and Finance. Yet, the most important aspect of this thesis are
ideas and applications rather than the mathematical content. New models
are proposed and fitted to data in order to test their performance and get
insights from the datasets analysed.
The description of the tensor methods provided in this thesis is not intended
to be complete but rather restricted to the model applicable to the analysed
data
Surgical Implications of Ischemia Reperfusion Damage and Future Perspectives.
Flaps are often used in plastic and reconstructive surgery, and random pattern flaps were the first to be described. The indications for their use are numerous and include post-traumatic loss of su..
Skin graft donor site: a procedure for a faster healing
Background: The authors want to evaluate the efficacy of fibrillary tabotamp dressing in skin graftdonor site. A comparison was made with Vaseline gauzes. Tabotamp is an absorbable haemostatic product of Ethicon (Johnson and Johnson) obtained by sterile and oxidized regenerated cellulose (Rayon). It is used for mild to moderate bleeding. Materials and methods: 276 patients were subject to skin graft and divided into two group: Group A and Group B. The donor site of patients in Group A was medicated with fibrillary tabotamp, while the patients of Group B were medicated only with Vaseline gauze. We recorded infection, timing of healing, number of dressing change, the pain felt during and after the dressing change with visual analog scale (VAS) and a questionnaire. Results: Patients allocated in Group A healed faster than the Group B. Questionnaires and VAS analysis showed lower pain felt, lower intake of pain drugs and lower infection rate in the Group A than the Group B. Analysis of coast showed lower dressing change in Group A than the Group B. Conclusion: We believe that the use of tabotamp is a very viable alternative to improve healing. (www.actabiomedica.it)
- …