Search results for "BAND"

Integration of onshore and offshore seismic arrays to study the seismicity of the Calabrian Region: a two steps automatic procedure for the identific…

2014

Abstract. We plan to deploy in the Taranto Gulf some Ocean Bottom broadband Seismometer with Hydrophones. Our aim is to investigate the offshore seismicity of the Sibari Gulf. The seismographic network optimization consists in the identification of the optimal sites for the installation of the offshore stations, which is a crucial factor for the success of the monitoring campaign. In this paper, we propose a two steps automatic procedure for the identification of the best stations geometry. In the first step, based on the application of a set of a priori criteria, the suitable sites to host the ocean bottom seismic stations are identified. In the second step, the network improvement is eval…

Long term seismic noise acquisition and analysis in the Homestake Mine with tunable monolithic sensors

2009

In this paper we describe the scientific data recorded along one month of data taking of two mechanical monolithic horizontal sensor prototypes located in a blind-ended (side) tunnel 2000 ft deep in the Homestake (South Dakota, USA) mine chosen to host the Deep Underground Science and Engineering Laboratory (DUSEL). The two mechanical monolithic sensors, developed at the University of Salerno, are placed, in thermally insulating enclosures, onto concrete slabs connected to the bedrock, and behind a sound-proofing wall. The main goal of this experiment is to characterize the Homestake site in the frequency band 10-4 ÷ 30 H z and to estimate the level of Newtonian noise, providing also the ne…

The INGV's new OBS/H: Analysis of the signals recorded at the Marsili submarine volcano

2009

Abstract The ocean bottom seismometer with hydrophone deployed on the flat top of the Marsili submarine volcano (790 m deep) by the Gibilmanna OBS Lab (CNT–INGV) from 12th to 21st July, 2006, recorded more than 1000 transient seismic signals. Nineteen of these signals were associated with tectonic earthquakes: 1 teleseismic, 8 regional (located by INGV) and 10 small local seismic events (non located earthquakes). The regional events were used to determine sensor orientation. By comparing the signals recorded with typical volcanic seismic activity, we were able to group all the other signals into three categories: 817 volcano–tectonic type B (VT-B) events, 159 occurrences of high frequency t…

Temperature and Isotopic Mass Dependence of the Direct Band Gap in Semiconductors: LCAO Calculations

2000

Isoelectronic series of twofold coordinated Si, Ge, and Sn atoms in glassy SiO2: a luminescence study

1992

Abstract Luminescence centers causing optical absorption bands in the 5 eV region in oxygen-deficient pure (‘Si-doped’), as well as in Ge- and Sn-doped glassy SiO2 were studied. The spectral and particularly kinetic data show that in all cases luminescence centers with closely similar properties exist which constitute an isoelectronic series. They are attributed to defects, formed by electrically neutral twofold coordinated Si, Ge, and Sn atoms (T20 centers) in glassy SiO2. Twofold coordinated Si causes the characteristic ‘B2’ optical absorption band at 5.03 eV. Upon reaction with atomic hydrogen, T20 centers convert to the well known ‘H(I)’, ‘H(II)’ and ‘H(III)’ ESR-active defects. The alt…

Emancipation or simulation? The pedagogy of ignorance and action research in PETE

2021

Education is increasingly a bureaucratized, standardized and regulated service in which everything is decided by the ‘experts’. There is an abandonment of the concept of education centred on the su...

Gradient Scheduling Algorithm for Fair Delay Guarantee in Logarithmic Pricing Scenario

2008

In this paper we propose a packet scheduling scheme for ensuring delay as a Quality of Service (QoS) requirement. For customers, fair service is given while optimizing revenue of the network service provider. Gradient type algorithm for updating the weights of a packet scheduler is derived from a revenue-based optimization problem in the logarithmic pricing scenario. Algorithm is simple to implement. We compared algorithm with optimal brute-force method. The weight updating procedure is independent on the assumption of the connection's statistical behavior, and therefore it is robust against erroneous estimates of statistics.

A New Multicast Technique for Video Transmission over ABR Services in ATM Networks

2000

Multicast techniques are the only way to simultaneously provide flows of information from one source to several destinations. The intention of this paper is to study and to evaluate different multicast techniques using a video coder based on an adaptive video compression algorithm with subband coding and a best effort network service like ATM with the Available Bit Rate (ABR) service. This video transmission can adapt faster and easily to changing network conditions. In this way, we present an evaluation process for a determined network configuration. Thereafter we discuss the results obtained by simulation and propose for this video transmission a trade-off between these multicast techniqu…

Performance evaluation of differentiated access mechanisms effectiveness in 802.11 networks

2005

The IEEE 802.11e draft specification aims to extend the original 802.11 MAC protocol by introducing priority mechanisms able to manage bandwidth and resource allocation according to the QoS needs of real-time applications. Different strategies based on MAC parameter diversifications, such as contention window limits, contention window updating factor and silence monitoring time, can be pursued in order to provide service differentiation, also in the case of distributed access. In this paper, we investigate on the behaviour of each differentiation possibility under different load conditions and traffic requirements. Our results show that the most powerful mechanisms which provide service dif…

AREE DISMESSE ED ORTI URBANI: UN “VALORE SOCIALE COMPLESSO” NELLE CITTÀ Abandoned areas and urban gardens: a "complex social value" in the cities

2015

The contribution to the welfare of citizens that urban gardens can generate represents a "social use-value". The social value of horticulture in cities can be expressed by means of an appropriate set of indicators describing the produced values. The proposed work, which is the result of an interdisciplinary collaboration, highlights the potentiality of abandoned and degraded urban areas, and intends to outline a model for the assessment of the social value generated by the introduction of "urban gardens". The proposed model can be utilised for selecting the most suitable areas for the use in question, for monitoring the effects of policies for urban gardens on urban sustainability, and for …