Search results for "NETWORKING"
showing 10 items of 1776 documents
The moderating effect of personal and situational characteristics in behavioural factors affecting ports of call
2017
This research aims to study the moderating effects of cruise passengers’ gender, age, education, and prior experiences on a Mediterranean port of call destination image formation and the influence ...
Cruise passengers' behavior at the destination: Investigation using GPS technology
2016
This paper aims at segmenting cruise passengers in order to identify passengers' profiles according to their behavior at destination. Through an integrated use of traditional survey instruments and of GPS technologies, a set of indicators for the analysis of passengers' mobility at destination is proposed. Data collected in the port of Palermo are used in order to investigate space-time activities of cruise passengers at the destination. Monothetic Analysis is used in order to segment passengers according to their behavior at destination, and groups are then compared in terms of socio-demographic characteristics and other variables collected through questionnaire-based survey. Results ident…
An integrated approach of analytical chemistry
1999
The tremendous development of physical methods of analysis offers an impressive number of tools to simultaneously determine a large number of elements and compounds at very low concentration levels. Todays Analytical Chemistry provides appropriate media to solve technical problems and to obtain correct information about chemical systems in order to take the most appropriate decisions for problem solving. In recent years the development of new strategies for sampling, sample treatment and data exploitation through the research on field sampling, microwaveassisted procedures and chemometrics, additionally the revolution of the analytical methodology provided by the development of flow analysi…
STUDIES ON THE CONSTRUCTION AND FUNCTIONING OF MACHINES FOR FERTILIZER DISTRIBUTION
1970
SUMMARY The researches were made on the machine of fertiliz er distribution MA 3,5, which has a capacity of 3,5 m 3 . It is used for transport and spreading solid chem ical fertilizers. It is tracted by tractor U 650 and is actioned from the p ower prize of tractor and from the right support wheels. This machine is formed of frame with catching equipment, bin, distribution equipment, transmision and mechanisms of adjustment and getting in function. The metal frame is supported by 2 pairs of wheels w ith tires, which afford a big mobility during work to the machine . . The distributor is of centrifugal type, formed of a horizontal disc with 6 pallets with adjusted position. Above the disc is…
Energy efficiency and CO2 emissions of port container terminal equipment: Evidence from the Port of Valencia
2019
Abstract Energy efficiency has emerged as a key point in port industry because of different factors such as the adoption of stronger environmental regulations and the increasing pressure of the local community on the surrounding ports. As gathering operational data from port terminals can be difficult due to privacy, studies on emissions and energy efficiency of these terminals are scarce. The following research provides key information about the real energy consumption and CO2 emissions of one of the most relevant container terminals in the Mediterranean area, located in Valencia, Spain. The results show that yard terminal tractors and rubber tyred gantry cranes (RTGs) are the main emissio…
Intelligent Sampling for Vegetation Nitrogen Mapping Based on Hybrid Machine Learning Algorithms
2021
Upcoming satellite imaging spectroscopy missions will deliver spatiotemporal explicit data streams to be exploited for mapping vegetation properties, such as nitrogen (N) content. Within retrieval workflows for real-time mapping over agricultural regions, such crop-specific information products need to be derived precisely and rapidly. To allow fast processing, intelligent sampling schemes for training databases should be incorporated to establish efficient machine learning (ML) models. In this study, we implemented active learning (AL) heuristics using kernel ridge regression (KRR) to minimize and optimize a training database for variational heteroscedastic Gaussian processes regression (V…
Reliability of Data Transmission of UAVs
2018
Drones have been recently an interesting subject of research due to their roles in accomplishing missions. Flying in a formation fleet, they form a cooperative communication system in order to improve the efficiency of the mission. For this reason, the reliability of the communication is essential to guarantee the overall performance of the fleet although the link conditions, the external factors and the hardware failures of a drone. The drones capture several images or videos of the geographical area of the mission and send them to other drones in the fleet or to the Ground Station Control (GSC). The importance is to ensure that all the data transmitted is received. In this article, we aim…
An explanation for unexpected 802.11 outdoor link-level measurement results
2008
This paper provides experimental evidence that "weird'/poor outdoor link-level performance measurements may be caused by driver/card-specific antenna diversity algorithms unexpectedly supported/activated at the WLAN transmitter side. We focus our analysis on the Atheros/MADWiFi card/driver case, and we observe that the transmit antenna diversity mechanisms remain by default enabled when the available antennas are not homogeneous in terms of gain or, even worse, when only a single antenna is connected. This may cause considerable performance impairments (large frame loss ratio), in conditions frequently encountered in outdoor link deployments. The negative impact of transmit antenna diversit…
A Battery-free Asset Monitoring System based on RF Wireless Power Transfer
2020
In the Internet of Things (IoT) era, asset monitoring represents an appealing implementation of Wireless Sensor Networks due to the enormous benefits associated with being able to monitor and record the exact position and transportation conditions of assets, personal objects, and the like. This kind of infrastructure enables the provision of increasingly advanced services, including the ability to measure the movement speed of a monitored asset using relatively inexpensive nodes with sensing capabilities and wireless transmission and reception. These nodes would ideally employ battery-free sensors that do not require any maintenance, but conventional power supply management systems cannot s…
New insights into the OCST problem
2009
This paper considers the Euclidean variant of the optimal communciation spanning tree (OCST) problem. Researches have analyzed the structure of the problem and found that high quality solutions prefer edges of low cost. Further, edges pointing to the center of the network are more likely to be included in good solutions. We add to the literature and provide additional insights into the structure of the OCST problem. Therefore, we investigate properies of the whole tree, such as node degrees and the Wiener index. The results reveal that optimal solutions are structured in a star-like manner. There are few nodes with high node degrees, these nodes are located next to the graph's center. The m…