Search results for "Imperfect"
showing 8 items of 158 documents
Moving RTS/CTS to the frequency domain: an efficient contention scheme for 802.11ax networks
2019
In this paper, we propose a contention mechanism based on the execution of multiple contention rounds in the frequency domain (ReCHo), which is designed to offer high throughput performance and robustness with respect to imperfect carrier sensing. The main idea is using narrow tones as signalling messages for performing channel access contentions and allowing the Access Point (AP) to echo these signals, in order to extend the sensing capabilities to all the stations associated to the AP. In particular, we refer to the emerging IEEE 802.11ax standard, showing how our scheme can boost performance of random access with respect to the current version of IEEE 802.11ax OFDMA Back-Off (OBO), even …
'Good to Repeat': Making Random Access Near-Optimal with Repeated Contentions
2020
Recent advances on WLAN technology have been focused mostly on boosting network capacity by means of a more efficient and flexible physical layer. A new concept is required at MAC level to exploit fully the new capabilities of the PHY layer. In this article, we propose a contention mechanism based on Repeated Contentions (ReCo) in frequency domain. It provides a simple-to-configure, robust and short-term fair algorithm for the random contention component of the MAC protocol. The throughput efficiency of ReCo is not sensitive to the number of contending stations, so that ReCo does not require adaptive tuning of the access parameters for performance optimization. Efficiency and robustness is …
Imperfections et hybridation générique dans « Les Employés » d’Honoré de Balzac
2020
L’imperfezione dell’essere umano e delle sue costruzioni sociali è al centro della Comédie humaine. Il presente articolo intende esplorare questo aspetto della produzione letteraria di Balzac attraverso l’analisi de Les Employés (1845), in cui la mediocrità del mondo burocratico viene esaminata in dettaglio. Nel romanzo, la mediocrità vince sul merito, ma la rappresentazione dell’imperfezione trascende la dimensione puramente narrativa: Les Employés è un grande laboratorio in cui l’ibridazione tra genere romanzesco e genere teatrale interroga i limiti della creazione letteraria. The imperfection of the human being and his social constructions is at the heart of the Comédie humaine. This art…
Essays on the economics of small business finance
2013
Die Hochenergetische Extrakorporale Stoßwellentherapie (ESWT) in der Behandlung von Pseudarthrosen
2008
PROBLEM The success rate of high-energy extracorporal shock wave therapy in the treatment of non-unions in comparison to the "golden standard" surgery is still unclear. METHOD In a prospective study, 3000 impulses with an energy density of 0.6 mJ/mm2 were applied with an experimental device to the pseudarthrosis in 52 patients. RESULTS The mean duration of pseudarthrosis was 13 months. A mean of 2.5 surgical interventions had already been performed. Bony union was achieved in 52% of our patients after an average of 3.3 months. Failures especially were found in the atrophic type of pseudarthrosis as well as in congenital bone disorders like fibrous dysplasia or osteogenesis imperfecta. No se…
Hyperplastic callus formation in osteogenesis imperfecta: CT and MRI findings.
1998
Hyperplastic callus formation is a noteworthy condition in patients with osteogenesis imperfecta because it often mimicks osteosarcoma on radiography. The findings of CT and MRI in hyperplastic callus formation have not been reported. In the presented case, MRI demonstrated contrast enhancement and edema of the surrounding soft tisssue, consistent with benign as well as malignant disease. Computed tomography showed a calcified rim of the lesion which may be a useful feature to rule out osteosarcoma in this condition.
El dolor crónico en las personas adultas con osteogénesis imperfecta y su relación con la personalidad, valoración, afrontamiento y calidad de vida: …
2022
La osteogénesis imperfecta (OI), popularmente conocida como la “enfermedad de los huesos de cristal”, es una patología congénita del tejido conectivo, de carácter hereditario, que afecta principalmente a la producción de colágeno. Presenta una etiología y clínica muy heterogénea, con amplia variedad fenotípica, aunque su principal característica es la elevada fragilidad ósea, que se traduce en fracturas frecuentes. Otras manifestaciones clínicas habituales en la patología son las escleras azuladas, dentinogénesis imperfecta, hiperlaxitud de ligamentos y piel, problemas de audición y visión y deformidades óseas. Su incidencia es de 1/15.000 a 1/ 20.000 recién nacidos, por lo que se considera…
The Effect of Predator Population Dynamics on Batesian Mimicry Complexes.
2022
Understanding Batesian mimicry is a classic problem in evolutionary biology. In Batesian mimicry, a defended species (the model) is mimicked by an undefended species (the mimic). Prior theories have emphasized the role of predator behavior and learning as well as evolution in model-mimic complexes but have not examined the role of population dynamics in potentially governing the relative abundances and even persistence of model-mimic systems. Here, we examined the effect of the population dynamics of predators and alternative prey on the prevalence of warning-signaling prey composed of models and mimics. Using optimal foraging theory and signal detection theory, we found that the inclusion …