879 research outputs found
Effects of variations of load distribution on network performance
This paper is concerned with the characterization of the relationship between
topology and traffic dynamics. We use a model of network generation that allows
the transition from random to scale free networks. Specifically, we consider
three different topological types of network: random, scale-free with \gamma =
3, scale-free with \gamma = 2. By using a novel LRD traffic generator, we
observe best performance, in terms of transmission rates and delivered packets,
in the case of random networks. We show that, even if scale-free networks are
characterized by shorter characteristic-path- length (the lower the exponent,
the lower the path-length), they show worst performances in terms of
communication. We conjecture this could be explained in terms of changes in the
load distribution, defined here as the number of shortest paths going through a
given vertex. In fact, that distribu- tion is characterized by (i) a decreasing
mean (ii) an increas- ing standard deviation, as the networks becomes
scale-free (especially scale-free networks with low exponents). The use of a
degree-independent server also discriminates against a scale-free structure. As
a result, since the model is un- controlled, most packets will go through the
same vertices, favoring the onset of congestion.Comment: 4 pages, 4 figures, included in conference proceedings ISCAS 2005,
Kobe Japa
Communication models with distributed transmission rates and buffer sizes
The paper is concerned with the interplay between network structure and
traffic dynamics in a communications network, from the viewpoint of end-to-end
performance of packet transfer. We use a model of network generation that
allows the transition from random to scale-free networks. Specifically, we are
able to consider three different topologycal types of networks: (a) random; (b)
scale-free with \gamma=3; (c) scale free with \gamma=2. We also use an LRD
traffic generator in order to reproduce the fractal behavior that is observed
in real world data communication. The issue is addressed of how the traffic
behavior on the network is influenced by the variable factors of the
transmission rates and queue length restrictions at the network vertices. We
show that these factors can induce drastic changes in the throughput and
delivery time of network performance and are able to counter-balance some
undesirable effects due to the topology.Comment: 4 pages, 5 figures, IEEE Symposium on Circuits and Systems, Island of
Kos, Greece, 200
A Prototype Mild-solar-Hybridization Kit: Design and Challenges
Abstract This paper deals with the development of an automotive hybridization kit (equipment, along with associated techniques and methodologies), aimed at converting conventional cars into hybrid solar vehicles (Mild-Solar-Hybrid). The main aspect of the projects consists into the integration of state-of-the-art components (in-wheel motors, photovoltaic panels, batteries), and into the development of an optimal controller for the power management. A prototype of the hybridizing equipment – patented by the University of Salerno (Italy)- is installed on a FIAT Grande Punto. A mild parallel hybrid structure is obtained by substituting/integrating the rear wheels with 7 kW in-wheel motors and adding a lithium battery to manage on-board energy. Thus, the vehicle can operate in electric mode (when ICE is switched off or disconnected by the front wheels) or in hybrid mode (when the ICE drives the front wheels and the rear in-wheel motors operate in traction mode or in generation mode, corresponding to a positive or negative torque). The battery can be recharged both by rear wheels, when operating in generation mode, and by photovoltaic panels. The vehicle is also equipped with an EOBD gate (On Board Diagnostics protocol), which allows accessing data such as pedal position, vehicle speed, engine speed, manifold pressure and other variables. The Vehicle Management Unit (VMU), which is part of the invention and implements control logics compatible with typical drive styles of conventional-car users, receives the data from OBD gate, from battery (SOC estimation) and drives in-wheel motors by properly acting on the electric node. The paper, focused on the main aspects of prototype design and realization, also provides insights on control issues related to the integration of the above-mentioned components, drivability and safety
Endoscopic sinus surgery in individuals with facial pain due to chronic maxillary sinusitis ? a functional controlled study
Objective: To measure the intra-sinus pressure and the maxillary sinus functional efficiency (MSFE) in individuals with chronic facial pain after conservative or conventional endoscopic maxillary surgery, as well as in controls. Method: Sinus manometry was performed 5 times during inhalation. Results: The resemblance of pressure values comparing those treated with minimally invasive surgery and controls was remarkable, while traditional surgery significantly decreased intrasinusal pressures. The MSFE was 100% in the three tested times for controls, close to that in those submitted to minimally invasive surgery (98.3%, 98.8%, and 98.0%) and significantly impaired after conventional surgery (48.8%, 52.1%, 48.5 %, p<0.01). All patients submitted to minimally invasive surgery remained pain-free after three months of surgery, relative to 46.7% of the submitted to conventional surgery (p<0.05). Conclusion: Minimally invasive sinus surgery is associated with functionality of the chambers that resemble what is found in normal individuals
Trans-Scleral Plugs Fixated FIL SSF IOL: A Review of the Literature and Comparison with Other Secondary IOL Implants
Purpose. To revise the current literature on FIL SSF (Carlevale) intraocular lens, previously known as Carlevale lens, and to compare their outcomes with those from other secondary IOL implants. Methods. We performed a peer review of the literature regarding FIL SSF IOLs until April 2021 and analyzed the results only of articles with a minimum of 25 cases and a follow-up of at least 6 months. The searches yielded 36 citations, 11 of which were abstracts of meeting presentations that were not included in the analysis because of their limited data. The authors reviewed 25 abstracts and selected six articles of possible clinical relevance to review in full text. Of these, four were considered to be sufficiently clinically relevant. Particularly, we extrapolated data regarding the pre- and postoperative best corrected visual acuities (BCVA) and the complications related to the procedure. The complication rates were then compared with those from a recently published Ophthalmic Technology Assessment by the American Academy of Ophthalmology (AAO) on secondary IOL implants. Results. Four studies with a total of 333 cases were included for results analysis. The BCVA improved in all cases after surgery, as expected. Cystoid macular edema (CME) and increased intraocular pressure were the most common complications, with an incidence of up to 7.4% and 16.5%, respectively. Other IOL types from the AAO report included anterior chamber IOLs, iris fixation IOLs, sutured iris fixation IOLs, sutured scleral fixation IOLs, and sutureless scleral fixation IOLs. There was no statistically significant difference in the rates of postoperative CME (p = 0.20), and vitreous hemorrhage (p = 0.89) between other secondary implants and the FIL SSF IOL, whereas the rate of retinal detachment was significantly less with FIL SSF IOLs (p = 0.04). Conclusion. The results of our study suggest the implantation of FIL SSF IOLs is an effective and safe surgical strategy in cases where there is a lack of capsular support. In fact, their outcomes seem to be comparable to those obtained with the other available secondary IOL implants. According to published literature, the FIL SSF (Carlevale) IOL provides favorable functional results with a low rate of postoperative complications
Behavioral aspects in children's brothers affected by Autism Spectrum Disorders
Introduction: Autistic Spectrum Disorder (ASD) is a permanent and complex disability arising within the first three years of life characterized by a socio-communicative disorder and by fixed interests and repetitive behaviors. The present pilot study aims to evaluate behavioral aspects in a small population of siblings of ASD children.
Material and methods: Population: 5 school-aged children (2 males, 3 females) (mean age 9.235 ± 2.041) were enrolled, as siblings of ASD children, and for comparison, 12 healthy (7 males, 5 females) children (average age 9,528 ± 3,351). All subjects underwent evaluation of the behavioral with Child Behavior Checklist (CBCL) scale.
Results: The two groups were statistically comparable by age (p = 0.86) and gender distribution (p = 0.87). From the behavioral point of view evaluated with the CBCL scale, siblings of ASD have a higher degree of overall problem (Total problems) compared to control children (p=0.003), in addition they have significantly higher scores in the subscales of behavior examined (Anxious/Depressed, Withdrawn, Somatic Complaints, Social, Thought, Attention, Delinquent, Aggressive) as well as a greater share of disturbances both internalizing (p=0.004) and externalizing (p = 0.007) (Table 1).
Conclusions: The present preliminary data confirm the need for a global management of the entire family structure for the correct management of Autistic Disorders
ADDICTIONS SUBSTANCE FREE DURING LIFESPAN
The addictions substance free is an umbrella definition comprises internet addiction, sexual addiction, gambling pathological, workholism, videogames and computer addiction. Actually, the technological addictions is frequent in young adolescents. The term Digital Natives indicates the children born in an information system of learning and communication different from that of the generations previous. This temporal range was strongly characterized by growing presence of technological communication toolsin daily life. The effects of hyper-exposition to technological tools tend to create a relational virtuality without a body is born,therefore, already within the family ties and during adolescence he moved to the digital socialization network. The technological object it interacts between the adolescent and the world of peers and adults, becoming the facilitator object that as the psychotropic substance, it conveys new modes of communicatio
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