Search results for "High-speed"
showing 10 items of 34 documents
La rete ferroviaria ad Alta Velocità in Corea del Sud [The High-Speed Rail network in South Korea]
2012
LA RETE FERROVIARIA AD ALTA VELOCITA’ IN COREA DEL SUD High speed rail in South Korea
The total social costs of constructing and operating a high-speed rail line using a case study of the Riyadh-Dammam Corridor, Saudi Arabia
2019
Introducing a High-Speed Rail technology between the Saudi Arabian cities starts raising many challenging issues of different nature ranging from technical to operational, which require huge investments in infrastructure, operations and maintenance. Background information about the development of HSR worldwide to date is included. However, the main aim of this paper is to determine a methodology to estimate the full cost of travel and provide insights into the working model developed to include the calculations of the total social costs of building a new HSR line for the Riyadh-Dammam corridor in Saudi Arabia and understand in what circumstances it is a suitable technology to use. The Sprea…
Design of the stabilization control system of a high-speed craft
2016
In this paper, the main causes of technical malfunction of a hydrofoil was analyzed. In particular, a preliminary analysis evaluates the economic impact for the navigation company of the periodical maintenance related to the keeping of the vessel in dry dock. The study demonstrated that the main critical points are focused on the fragility of the stabilization control system. The increasing of operating costs has motivated the realization of a study aimed at redesigning the stabilization system. The continuing failure of the stabilization system (usually in water-immersed) severely limits the use of the high-speed craft. The proposed design solution considers the positioning of the control …
VoIP end-to-end performance in HSPA with packet age aided HSDPA scheduling
2008
In this paper, we present an enhanced VoIP scheduling for the high speed downlink packet access (HSDPA) in UMTS, which takes the age of the VoIP packet into account. The downlink capacity can be significantly improved by this way, especially for shorter uplink transmission delay. In order to quantify the achievable performance improvement, we present results obtained from extensive system-level uplink and downlink simulations. Inter alia, it is shown that using the proposed scheme can lead to an increase in the downlink cell capacity of up to 16%. By applying the proposed method, the downlink performance can be improved considerably while the uplink performance remains the same, which ensur…
On Serving Cell Change Reliability in HSDPA Network
2009
In Wideband Code Division Multiple Access (WCDMA) networks the Signaling Radio Bearer (SRB) is transmitted downlink to inform the user i.a. when it needs to make a handover. When transmitting e.g. Voice over IP (VoIP) on High Speed Downlink Packet Access (HSDPA) SRB is mapped on HSDPA user data channel, High-Speed Downlink Shared Channel (HS-DSCH) in order to maximize voice capacity. The lack of support for soft handover (SHO) of HS-DSCH may compromise the reception of SRB and thus also a possible incoming serving HSDPA cell change command especially at the cell borders. This can lead to serious VoIP service degradation due to prolonged camping on a poor cell and in the worst case even to c…
Real-time acquisition of complex optical fields by binary amplitude modulation
2017
We describe, through simulations and experiments, a real-time wavefront acquisition technique using random binary amplitude masks and an iterative phase retrieval algorithm based on the Fresnel propagator. By using a digital micromirror device, it is possible to recover an unknown complex object by illuminating with this set of masks and simultaneously recording the resulting intensity patterns with a high-speed camera, making this technique suitable for dynamic applications.
Etude dynamique et structurale de biomolécules par microscopie à force atomique HS-AFM : application à une petite protéine de choc thermique sHsp
2012
The atomic force microscopy (AFM) gives access to the topography of organic and inorganic samplesat the atomic scale. The latest innovations offer the possiblity to understand the sample nano-mechanicalproperties (elasticity, adhesion...). Its feature set allows overcoming the demands of nanotechnology,both in the fields of physics, chemistry and biology.However, understanding biological processes require faster acquisitions for the atomic forcemicroscopy, less than a second per frame. As conventional equipment does not offer the possibility toovercome the constraint of time for dynamical studies, a prototype of high-speed atomic forcemicroscope (HS-AFM) was developed in partnership with Pr…
HSDPA Link Adaptation Improvement Based on Node-B CQI Processing
2007
In this paper HSDPA link adaptation (LA) based on Channel Quality Indicator (CQI) reports is optimised. A pre-processing of the last received CQI reports is done before the execution of the LA algorithm in the Node-B in order to obtain more profitable channel quality estimations and hence improve the LA performance. Different types of processing techniques are presented and assessed, considering from the simplest sample averaging to some more elaborated predictive algorithms. Results demonstrate that a non negligible enhancement in the LA performance can be obtained if medium and high speed users are considered.
FLUMO: FLexible Underwater MOdem
2019
The last years have seen a growing interest in underwater acoustic communications because of its applications in marine research, oceanography, marine commercial operations, the offshore oil industry and defense. High-speed communication in the underwater acoustic channel has been challenging because of limited bandwidth, extended multipath, refractive properties of the medium, severe fading, rapid time variation and large Doppler shifts. In this paper, we show an implementation of a flexible Software-Defined Acoustic (SDA) underwater modem, where modulation parameters are completely tunable to optimize performance. In particular, we develop the system architecture following two key ideas. …
Contributions to the new electronics of the AGATA gamma tracking detector. Design, implementation, test and integration of the digitizers control card
2013
154 páginas. Tesis Doctoral del Departamento de Ingeniería Electrónica de la Universidad de Valencia.