Search results for "Location"

Kalman filter estimation of the contention dynamics in error-prone IEEE 802.11 networks

2008

In the last years, several strategies for maximizing the throughput performance of IEEE 802.11 networks have been proposed in literature. Specifically, it has been shown that optimizations are possible both at the medium access control (MAC) layer, and at the physical (PHY) layer. In fact, at the MAC layer, it is possible to minimize the channel wastes due to collisions and backoff expiration times, by tuning the minimum contention window as a function of the number n of competing stations. At the PHY layer, it is possible to improve the transmission robustness, by selecting a suitable modulation/coding scheme as a function of the channel quality perceived by the stations. However, the feas…

Energy-Efficient M2M Communications in for Industrial Automation

2020

M2M communication with autonomous data acquisition and exchange plays a key role in realizing the “control”-oriented tactile Internet (TI) applications such as industrial automation. In this chapter, we develop a two-stage access control and resource allocation algorithm. In the first stage, we introduce a contract-based incentive mechanism to motivate some delay-tolerant machine-type communication (MTC) devices to postpone their access demands in exchange for higher access opportunities. In the second stage, a long-term cross-layer online resource allocation approach is based on Lyapunov optimization, which jointly optimizes rate control, power allocation, and channel selection without pri…

Accuracy and the role of experience in dynamic computer guided dental implant surgery: an in-vitro study

2019

Background To compare the accuracy of implant placement using the conventional freehand method and a dynamic navigation system; to assess the role of the surgeon’s experience in implant placement using these two methods. Material and Methods A randomized in-vitrostudy was conducted. Six resin mandible models and 36 implants were used. Two researchers with differing clinical experience (novice and experienced) placed implants using either the Navident dynamic navigation system (navigation group) or the conventional freehand method (freehand group). Accuracy was measured by overlaying the real position in the postoperative CBCT on the virtual presurgical placement of the implant in a CBCT ima…

Sensor networks for cognitive radio : theory and system design

2008

Positron Annihilation in Polycrystalline Metals Deformed by Uniaxial Tension

2005

Angular distributions of the positron annihilation quanta were measured for polycrystalline samples deformed by uniaxial tension up to difierent deformation degrees. The S parameter as a function of the W parameter was determined. The data obtained for samples elongated up to difierent elongation degrees indicate that in the proportionality and limited proportionality regions the changes in the physical properties of samples are governed mainly by generation of vacancies and formation and kinetics of transformations of vacancy clusters occurring flrst of all on the grains of monocrystallites. In the region of plastic deformations the dominant defects are dislocations and vacancies and their…

Utility of island populations in re-introduction programmes--relationships between Arabian gazelles (Gazella arabica) from the Farasan Archipelago an…

2014

Understanding local adaptation and population differentiation is vital to the success of re-introduction initiatives. As other mammals living on islands, Arabian gazelles (G. arabica) show reduced body size on the Farasan archipelago, which we corroborated in this study through morphometric analyses of skulls. In the light of the steep population decline on the Arabian Peninsula – but stable population development on the archipelago – we tested the potential suitability of Farasan gazelles as a source for re-introductions on the mainland. We therefore investigated genetic differentiation between Farasan and mainland populations using eleven nuclear microsatellite loci and detected a distinc…

Further Investigation of Harmonic Priming in Long Contexts Using Musical Timbre as Surface Marker to Control for Temporal Effects

2004

Harmonic priming studies have reported facilitated processing for chords that are harmonically related to the prime context. Responses to the target (the last chord of an 8-chord sequence) were faster and more accurate when the target was strongly related, i.e., a tonic chord, to the preceding prime context than when it was less related, i.e., a subdominant chord. Results have been interpreted in terms of musical expectations and processing speed: the prime allows listeners to develop expectations for future events which lead to facilitated processing of the most strongly expected event. The present experiment investigated an alternative hypothesis suggesting that the harmonic structure of…

Optimal growth and land preservation

1997

A model of optimal economic growth with a constant population subject to a constraint on the availability of land is presented. It takes account of the dual character of land as a production factor and as a consumption good (environmental amenities) by determining the optimal intertemporal allocation of land between productive and recreational uses. An extension of the analysis for the case of a growing population with endogenous growth based on human capital accumulation shows that if the rate of discount is not very low then there exists a set of balanced growth paths compatible with a constant allocation of land. En este trabajo se presenta un modelo de crecimiento económico óptimo con u…

“The Limits” of Economic Growth in Romania

2014

Abstract A sustainable economic growth of GDP of 3-4% annually in Romania for the reduction of gaps in development was considered impossible by most institutions of various skill and opinion leaders, as well as of international financial bodies. The reasons cited were delayed public reforms, low growth potential as a result of the crisis, the overview status of the states in the Eurozone dependent on inside community trade and also the prospects for a lasting economic stagnation, the balance sheet effect, as a result of over indebtedness of firms and individuals that substantially reduced inclination towards investment and consumption. Contradicting these forecasts, in 2013, Romania's econo…

The nonmarket benefits of redeveloping dockland areas for recreational purposes: the case of Castellón, Spain

2003

As a consequence of the decline of central harbour sites and the relocation of port activities to the outskirts of cities, today waterfront redevelopment has become a key issue in the urban revitalisation policies of port cities. Although we are aware that city-port regeneration has strong links with the real estate market, our purpose here is very different. In particular, the contingent valuation method (CVM) has been applied in order to obtain the nonmarket benefits of the environmental and urban improvements derived from redeveloping some port-related areas for recreational and leisure purposes in the city of Castelloèn, Spain. To date, no previous study has attempted to apply this meth…