966 resultados para tcp, tcp a ritrasmissione asimmetrica, omnet, inet, sistemi mobili
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The aim of this study was to evaluate the clinical, tomographic, and histological similarity within the use of HA+β-TCP (Boneceramic) alone or associated with enamel matrix derived (EMD) proteins in sinus lifting procedures with subsequent dental implant placement. We selected two patients with residual bony ridges between 3 mm and 5 mm in height in need of bone grafts. Six months later, eight implants were installed (two implants at each site). Biopsies were made, and the tissue was processed and stained with HE solution. Tomographic evaluation showed bone height gain up to 10.0 mm on average. Histology showed new bone formation for both groups, with similar bone density and trabecular interconnectivity. It can be concluded that the HA+β-TCP graft isolated or associated to EMD provided bone height gain in sinus lifting procedures, with similar clinical, tomographic and histological characteristics.
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The biological behavior of a new bioactive material composed of calcium-deficient hydroxyapatite, octacalcium phosphate, and beta-tricalcium phosphate was investigated by in vitro indirect and direct cytotoxicity, cell adhesion and proliferation tests, and by in vivo subcutaneous and bone implantation in rats. The results of the in vitro studies showed that the material is biocompatible and no cytotoxic. Slightly poorer initial cell adhesion and lower cell proliferation than in control was observed, which were attributed to the reactivity and roughness of the material surface, In vivo results showed that the material is biodegradable and bioactive in bone tissue, but only biocompatible and partially biodegradable in soft tissue.
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There is a wide range of video services over complex transmission networks, and in some cases end users fail to receive an acceptable quality level. In this paper, the different factors that degrade users' quality of experience (QoE) in video streaming service that use TCP as transmission protocol are studied. In this specific service, impairment factors are: number of pauses, their duration and temporal location. In order to measure the effect that each temporal segment has in the overall video quality, subjective tests. Because current subjective test methodologies are not adequate to assess video streaming over TCP, some recommendations are provided here. At the application layer, a customized player is used to evaluate the behavior of player buffer, and consequently, the end user QoE. Video subjective test results demonstrate that there is a close correlation between application parameters and subjective scores. Based on this fact, a new metrics named VsQM is defined, which considers the importance of temporal location of pauses to assess the user QoE of video streaming service. A useful application scenario is also presented, in which the metrics proposed herein is used to improve video services(1).
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Diapositive utilizate a lezione sugli argomenti: - connessione TCP - formato segmento TCP - macchina a stati finiti TCP - timer TCP
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La diffusione di Internet negli ultimi anni e lo sviluppo sempre crescente nell'ambito delle reti di telecomunicazione, hanno portato oggi ad una vera e propria esplosione della diffusione di nuove tecnologie di trasmissione. Inizialmente il protocollo di trasporto dati, TCP, non era stato pensata per operare in scenari diversi da quello della rete fissa. Con l'introduzione di nuovi scenari, come quello wireless, wimax e satellitare, si è notato come le prestazioni peggiorino in questi ambienti. Proprio per questo, il protocollo TCP ha subito parecchie modifiche negli anni e sono state realizzate alternative atte a migliorare l'inefficienza del protocollo. Le modifiche, a cui il TCP è stato sottoposto, sono basate su alcuni criteri di valutazione e l'introduzione di meccanismi come il controllo del flusso o il controllo di congestione in modo da migliorare le performance in ambienti “ostili”. Molti ricercatori si sono concentrati nello studio e modifica di questi nuovi meccanismi cercando di adattare al meglio il TCP secondo diversi scenari di rete, trascurando così altri criteri un pò meno noti. Dopo aver introdotto lo scenario con la descrizione del protocollo TCP, andremo a descrivere e illustrare questi “nuovi criteri” presentando alcuni recenti studi effettuati, in seguito andremo a presentare un nuova versione del protocollo chiamata Early Warning TCP e nell'ultimo capitolo andremo a presentare delle conclusioni degli studi presentati.
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Tesi relativa ai criteri di valutazione del protocollo TCP
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In questo lavoro si introduce il progetto di estrarre lo stack tcp-ip dal kernel di linux e farlo funzionare come una normale libreria in userspace. Si parlerà dei vantaggi di avere lo stack tcp-ip in userspace, di altri progetti simili, del motivo per cui si è scelto lo stack di linux, dei principali problemi incontrati nel corso del lavoro, del percorso seguito, e di come il risultato possa essere migliorato per renderlo uno strumento effettivamente utile.
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The primary objective of this study was to clinically and histologically evaluate periodontal wound healing/regeneration following surgical implantation of recombinant human growth/differentiation factor-5 (rhGDF-5) adsorbed onto a particulate ?-tricalcium phosphate (?-TCP) carrier rhGDF-5/?-TCP into periodontal defects in man.
Resumo:
To present the safety profile, the early healing phase and the clinical outcomes at 24 weeks following treatment of human intrabony defects with open flap debridement (OFD) alone or with OFD and rhGDF-5 adsorbed onto a particulate β-tricalcium phosphate (β-TCP) carrier. Twenty chronic periodontitis patients, each with at least one tooth exhibiting a probing depth ≥6 mm and an associated intrabony defect ≥4 mm entered the study. Ten subjects (one defect/patient) were randomized to receive OFD alone (control) and ten subjects OFD combined with rhGDF-5/β-TCP. Blood samples were collected at screening, and at weeks 2 and 24 to evaluate routine hematology and clinical chemistry, rhGDF-5 plasma levels, and antirhGDF-5 antibody formation. Plaque and gingival indices, bleeding on probing, probing depth, clinical attachment level, and radiographs were recorded pre- and 24 weeks postsurgery. Comparable safety profiles were found in the two treatment groups. Neither antirhGDF-5 antibody formation nor relevant rhGDF-5 plasma levels were detected in any patient. At 6 months, treatment with OFD + rhGDF-5/β-TCP resulted in higher but statistically not significant PD reduction (3.7 ± 1.2 vs. 3.1 ± 1.8 mm; p = 0.26) and CAL gain (3.2 ± 1.7 vs. 1.7 ± 2.2 mm; p = 0.14) compared to OFD alone. In the tested concentration, the use of rhGDF-5/β-TCP appeared to be safe and the material possesses a sound biological rationale. Thus, further adequately powered, randomized controlled clinical trials are warranted to confirm the clinical relevance of this new approach in regenerative periodontal therapy. rhGDF-5/β-TCP may represent a promising new techology in regenerative periodontal therapy.