Search results for "working"
showing 10 items of 2747 documents
Improved GNSS positioning exploiting a vehicular P2P infrastructure
2010
This paper considers the possibility to exploit external altitude measurements to improve the performance of a Kalman based GNSS receiver. The altitude measurements are provided by means of a peer to peer network, that is supposed to be based on the evolution of the 802.11 standard for the vehicular environment, namely the WAVE (802.11p). The performance of such a system are investigated for different characteristics of the aiding measurement and for a different number and disposals of the aiding peers. The aiding measurement is obtained starting from the altitude measurements that the other peers in the network send to the aided user. The experiments highlight the need for a parameter that…
Varieties of agencies during working life changes
2020
The aim of this study is to shed light on the varieties of workers´ agencies in working life change situations, which is an under-researched topic in the literature of workplace learning and in working life studies. The research questions are what kinds of agencies there are to be found when workers encounter changes and how the different kinds of agencies are connected together. The understanding of agency is grounded on the subject-centered socio-cultural approach, whereas the methodological approach is based on applying life-course perspective on research material consisting of 48 working life narratives written by Finnish adults. The narratives are analyzed by abductive content analysis…
Estimation of the Velocity of a Walking Person in Non-Stationary Indoor Environments from the Received RF Signal
2018
Accurate estimation of the time-variant (TV) velocity, i.e., TV speed and TV direction of motion, of walking persons in indoor environment is of great importance in a variety of wireless indoor applications. This paper presents a novel method for estimating the velocity of a walking person in three-dimensional indoor environments, which are assumed to be equipped with a distributed 3 × 3 multiple-input multiple-output (MIMO) system. The approach estimates the TV speed, TV vertical angle-of-motion (VAOM), and TV horizontal angle-of-motion (HAOM) by fitting the spectrogram of the complex channel gain of a non-stationary indoor channel model to the spectrogram obtained from the received radio …
Impact of Transport Costs on International Trade: The Case of Spanish Ceramic Exports
2003
This paper aims to investigate the determinants of maritime and overland transport costs and the role they play in deterring trade across countries. We estimate a transport cost function using data on maritime and overland transport of the ceramic sector (tiles) obtained from interviews held with Spanish logistics operators. We also study the relationship between transport costs and trade and estimate an import demand model for ceramic products. Additionally, we present a discussion on the sensitivity of trade flows and transportation costs to the existence of back-hauling, special conditions for transport and number of reloads.1 The study of modal transport (overland versus maritime) and i…
CVS: Using VLANs to Counteract the Effect of Topology Changes in Quasi-Static Mesh Access Networks
2006
Mesh networks are candidate to play the role of switched Ethernet LANs over extended areas and with a sensibly higher flexibility. Actually, mesh networks can exploit both Ethernet and wireless technologies, e.g. Wi-Fi and/or free-space optical links, to provide a high degree of redundancy in an access network, and to provide users with powerful means to connect with each other. By using such technologies, the mesh topology remains stable for hours, so that the mesh topology can be considered quasi-static. However, large meshes require a heavy overhead in the network control plane as for the management of end-to-end paths, which can change due to mobility of users and due to occasional fail…
Dynamic QoS management for multimedia real-time transmission in industrial environments
2007
The use of multimedia within industrial applications has become commonplace, targetting improved process monitoring and machine vision. In both cases, the multimedia information is commonly distributed and subject to time constraints that must be met across networks while avoiding untolerable interference over typical control flows. This can be achieved with Constant Bit-Rate (CBR) channels, typically supported by real-time protocols. However, the compressors used to reduce the amount of information to transfer generate Variable Bit-Rate (VBR) patterns. Adapting a VBR source to a CBR channel requires specific care in order to avoid wasting channel bandwidth or dropping video frames. This pa…
Nanoseconds Timing System Based on IEEE 1588 FPGA Implementation
2019
Clock synchronization procedures are mandatory in most physical experiments where event fragments are readout by spatially dislocated sensors and must be glued together to reconstruct key parameters (e.g. energy, interaction vertex etc.) of the process under investigation. These distributed data readout topologies rely on an accurate time information available at the frontend, where raw data are acquired and tagged with a precise timestamp prior to data buffering and central data collecting. This makes the network complexity and latency, between frontend and backend electronics, negligible within upper bounds imposed by the frontend data buffer capability. The proposed research work describ…
Switched Ethernet Networking over LEO Satellite
2005
Satellite onboard switching capabilities, and their possibility to enable "over-the-air" networks, are a strongly innovative achievement of modern satellite communication. The exploitation of satellite networking is especially relevant in the case of low Earth orbit satellites (LEO), where the reduced latency makes a LEO mesh network highly appealing and competitive with terrestrial solutions also in terms of performance. However, while the idea of a LEO mesh network is well understood, we are far from an ultimate answer on which is the best and more appropriate networking solution for moving LEO satellite network nodes. This paper promotes the adoption of existing layer-2 networking soluti…
LSOM: A Link State protocol Over MAC addresses for metropolitan backbones using Optical Ethernet switches
2003
This paper presents a new protocol named "Link State Over MAC" (LSOM) for Optical Ethernet switches to allow the use of active loop topologies, like meshes, in Metropolitan Area Networks (MAN) or even Wide Area Networks (WAN) backbone. In this respect, LSOM is an alternative to a ring topology as proposed in draft IEEE 802.17 Resilient Packet Ring (RPR) or a tree topology using IEEE802. 1D Rapid Spanning Tree Protocol (RSTP). LSOM provides higher scalability and is able to achieve better bandwidth utilization and lower latency than RSTP and RPR. Simulation results for 4-node and 9-node topologies show that LSOM can improve throughput over RPR by a factor of up to 1.7. Furthermore, full free…
Criminal networks analysis in missing data scenarios through graph distances
2021
Data collected in criminal investigations may suffer from issues like: (i) incompleteness, due to the covert nature of criminal organizations; (ii) incorrectness, caused by either unintentional data collection errors or intentional deception by criminals; (iii) inconsistency, when the same information is collected into law enforcement databases multiple times, or in different formats. In this paper we analyze nine real criminal networks of different nature (i.e., Mafia networks, criminal street gangs and terrorist organizations) in order to quantify the impact of incomplete data, and to determine which network type is most affected by it. The networks are firstly pruned using two specific m…