Temat: time of arrival - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Performance comparison of ToA and TDoA based tracking in underwater multipath environments using bernoulli filter
Autorzy:: Gunes, Ahmet
Tematy:: underwater target tracking
bernoulli filter
Time-of-Arrival
Time-Difference-of-Arrival
underwater multipath propagation; Pokaż więcej
Wydawca:: Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:: https://bibliotekanauki.pl/articles/32917889.pdf Link otwiera się w nowym oknie
Opis:: Underwater localization and tracking is a challenging problem and Time-of-Arrival and Time-Difference-of-Arrival approaches are commonly used. However, the performance difference between these approaches is not well understood or analysed adequately. There are some analytical studies for terrestrial applications with the assumption that the signal arrival times are not correlated. However, this assumption is not valid for underwater propagation. To present the distinct nature of the problem under the water, a high-fidelity simulation is required. In this study, Time-of-Arrival and Time-Difference-of-Arrival approaches are compared using a ray tracing based propagation model. Moreover, basic methods to mitigate the multipath propagation problem are also implemented for Bernoulli filters. Since the Bernoulli filter is a joint detection and tracking filter, the detection performance is also analysed. Comparisons are done for all combinations of filter and measurement approaches. The results can help to design underwater localization systems better suited to the needs.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: AIS R-mode trilateration for GPS positioning and timing insurance
Autorzy:: Shyshkin, O. V.
Konovets, V. I.
Koshevyy, V. M.
Tematy:: Automatic Identification System
Global Navigation Satellite System
Global Positioning System
positioning
navigation and timing
time division multiple access
R-mode
time of arrival
time difference of arrival; Pokaż więcej
Wydawca:: Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Powiązania:: https://bibliotekanauki.pl/articles/59123272.pdf Link otwiera się w nowym oknie
Opis:: Satellite navigation is the backbone of maritime navigation today. However, the technical vulnerability of on-board Global Navigation Satellite System (GNSS) receivers the satellite system greatly destabilizes maritime security due to the loss of ship’s position and accurate time. This article devoted to study an alternative method for obtaining coordinates and accurate time based on the use of automatic identification system (AIS) radio channels, so-called range mode (R-Mode). We use other AIS ship stations with reliable position data as reference stations and determine time of arrival for received AIS transmissions. To improve the accuracy of measuring signal arrival instance in the time difference of arrival (TDOA), that we utilize for trilateration, it is proposed signal oversampling and applying the fast Fourier transform (FFT) to the product of quadrature components of the baseband Gaussian minimum shift keying (GMSK) signal in the window of AIS time slot. To take into account the movement of other ships, appropriate coordinate corrections are foreseen, which can be calculated by dead reckoning or by the inertial navigation system of our ship. The proposed method is fully compatible with the existing AIS signals and may be employed in critical situations of locally limited (jamming, spoofing) GNSS abilities. It can be implemented as a separate unit, working for receiving in parallel with the mandatory AIS transponder.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: A cooperative positioning algorithm for DSRC enabled vehicular networks
Autorzy:: Efatmaneshnik, M.
Kealy, A.
Alam, N.
Dempster, A.
Tematy:: DSRC
Vanet
cooperative positioning
ranging
time of arrival
CRLB
Kalman filtering
robust positioning
pozycjonowanie
godzina przyjazdu
filtracja Kalmana; Pokaż więcej
Wydawca:: Stowarzyszenie Geodetów Polskich
Powiązania:: https://bibliotekanauki.pl/articles/129825.pdf Link otwiera się w nowym oknie
Opis:: Many of the safety related applications that can be facilitated by Dedicated Short Range Communications (DSRC), such as vehicle proximity warnings, automated braking (e.g. at level crossings), speed advisories, pedestrian alerts etc., rely on a robust vehicle positioning capability such as that provided by a Global Navigation Satellite System (GNSS). Vehicles in remote areas, entering tunnels, high rise areas or any high multipath/ weak signal environment will challenge the integrity of GNSS position solutions, and ultimately the safety application it underpins. To address this challenge, this paper presents an innovative application of Cooperative Positioning techniques within vehicular networks. CP refers to any method of integrating measurements from different positioning systems and sensors in order to improve the overall quality (accuracy and reliability) of the final position solution. This paper investigates the potential of the DSRC infrastructure itself to provide an intervehicular ranging signal that can be used as a measurement within the CP algorithm. In this paper, time-based techniques of ranging are introduced and bandwidth requirements are investigated and presented. The robustness of the CP algorithm to inter-vehicle connection failure as well as GNSS dropouts is also demonstrated using simulation studies. Finally, the performance of the Constrained Kalman Filter used to integrate GNSS measurements with DSRC derived range estimates within a typical VANET is described and evaluated.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Efficiency of a voluntary speed reduction algorithm for a ship’s great circle sailing
Autorzy:: Wang, H.
Mao, W.
Eriksson, L.
Tematy:: great circle sailing
algorithm, ship’s sailing route
route planning
Dynamic Programming (DP)
great circle route
great circle (orthodrome)
Estimated Time of Arrival (ETA); Pokaż więcej
Wydawca:: Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Powiązania:: https://bibliotekanauki.pl/articles/117253.pdf Link otwiera się w nowym oknie
Opis:: The great-circle is the shortest distance between two points on the surface of the earth. When planning a ship’s sailing route (waypoints and forward speeds) for a specific voyage, the great circle route is commonly considered as a reference route, especially for ocean-crossing seaborne transport. During the planning process, the upcoming sea weather condition is one of the most important factors affecting the ship’s route optimization/planning results. To avoid encountering harsh conditions, conventional routing optimization algorithms, such as Isochrone method and Dynamic Programming method, have been developed/implemented to schedule a ship’s optimal routes by selecting waypoints around the great circle reference route based on the ship’s operational performances at sea. Due to large uncertainties in sea weather forecast that used as inputs of these optimization algorithms, the optimized routes may have worse performances than the traditional great circle sailing. In addition, some shipping companies are still sailing in or making charting contracts based on the great circle routes. Therefore, in this study, a new optimization algorithm is proposed to consider the voluntary speed reduction with optimal speed configuration along the great circle course. The efficiency of this method is investigated by comparing these two methods for optimal route planning with respect to ETA and minimum fuel consumption. A container ship sailing in the North Atlantic with full-scale performance measurements are employed as the case study vessels for the comparison.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Enhancing IoT Performance via Using Mobility Aware for Dynamic RPL Routing Protocol Technique (MA-RPL)
Autorzy:: Zarzoor, Ahmed R.
Tematy:: internet of things
IoTs
routing protocol for low power and lossy networks
RPL
mobility aware
MA-RPL
time difference of arrival
TDoA; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2055261.pdf Link otwiera się w nowym oknie
Opis:: Nodes' aware-mobility in the Internet of Things (IoTs) stills open defy for researchers, due to the dynamic changing of routing path and networks’ resource limitations. Therefore, in this study a new method is proposed called Mobility Aware - “Routing Protocol for Low power and Lossy Networks” (MARPL), that consists of two phases: in the first phase splitting the entire network into sub areas based on reference nodes with “Time Difference of Arrival” (TDoA) technique. While, the second phase, is about managing mobile nodes (MNs) in RPL according to the sub areas' ID. The Cooja simulator software has been used to implement and assess MA-RPL method performance, according to the data packet metrics (lost packet, packet delivery ratio PDR), latency and nodes' power usage in comparison with two methods: Corona (Co-RPL) and Mobility Enhanced (ME-RPL). The simulation results have been shown that the MA-RPL method consumes less nodes' energy usage, gives less latency with minimum data packet loss in comparison with Co-RPL and MERPL.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Analiza zmian w profiu wezwań Zespołów Ratownictwa Medycznego Wojewódzkiej Stacji Pogotowia Ratunkowego w Rzeszowie w latach 2010–2013
Analysis of changes in the profie of calls to Emergency Medical Teams at Regional Ambulance Station in 2010–2013
Autorzy:: Gawełko, Jan
Wilk, Konrad
Tematy:: Zespoły podstawowe i specjalistyczne pogotowia ratunkowego
czas dojazdu ZRM
klasyfiacja pacjentów ZRM wg grup ICD-10
Rapid response and Urgent Transfer Emergency
Medical Teams time of arrival
the classifiation of emergency
patients according to ICD-10 groups; Pokaż więcej
Wydawca:: Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Powiązania:: https://bibliotekanauki.pl/articles/1395119.pdf Link otwiera się w nowym oknie
Opis:: Wstęp: zadaniem Zespołów Ratownictwa Medycznego jest udzielanie świadczeń zdrowotnych w razie wypadku, urazu, porodu, nagłego zachorowania lub nagłego pogorszenia stanu zdrowia oraz transport poszkodowanego. Realizacji tych zadań służy system Państwowego Ratownictwa Medycznego. cel badań: celem badań była analiza zmian w strukturze wezwań i wyjazdów ZRM w WSPR w Rzeszowie w latach 2010–2013. Materiał i metoda: metodą retrospektywnej analizy zbadano 87580 kart wyjazdu ZRM w WSPR w Rzeszowie z lat 2010–2013. Przeanalizowano częstość wyjazdów karetek pogotowia zespołów podstawowych i specjalistycznych, miejsca i pory zdarzenia, czas od przyjęcia zlecenia do przyjazdu na miejsce zdarzenia, postępowanie zespołu ratunkowego oraz kwalifiację przyczyn wyjazdów ZRM. Wyniki: w badanym okresie wezwania pilne stanowiły 88% wszystkich zgłoszeń, najczęściej ZRM wzywano do miejsca zamieszkania – 59%, największy odsetek pacjentów – 69% jest przekazywanych do szpitali ogólnych, do najczęstszych przyczyn wezwań zalicza się wg klasyfiacji ICD-10: zaburzenia oddychania R06, ból w gardle i klatce piersiowej R07, ból w okolicach brzucha i miednicy R10, złe samopoczucie, zmęczenie R53, omdlenie i zapaść R55. Odsetek zgonów pacjentów, do których wezwano ZRM wyniósł 2%, a w tym 77% zgonów nastąpiło przed przybyciem ZRM do pacjenta, 22% w trakcie udzielania pomocy, a 1% zgonów nastąpił w trakcie transportu. Wnioski: profi wyjazdów ZRM w latach 2010–2013 był zgodny z celami ustawowymi i statutowymi, czasy dotarcia ZRM do pacjenta różnią się w poszczególnych regionach kraju, czas dojazdu do miejsca wezwania był zgodny z celami ustawy, a odsetek dojazdów powyżej 20 minut wynikał z odległości miejsca wezwania (30–40 km), w przypadkach zakończonych zgonem pacjenta odsetek zgonu w trakcie udzielania pomocy był niski, a w trakcie transportu był bardzo niski i wynosił 1%. Rosnący odsetek chorych przekazanych do leczenia szpitalnego wymaga dalszych badań celem oceny liczby chorych przyjętych albo odesłanych z oddziału ratunkowego do domu.
Introduction: The task of Emergency Medical Teams is to provide health assistance in the event of an accident, injury, childbirth, sudden illness or sudden deterioration of health and transport of a victim. The State System of Emergency Medicine is intended to implement these tasks. Aim: The aim of this study was to analyze the changes in the structure of calls and trips of Emergency Medical Teams at Regional Ambulance Station in Rzeszów in 2010–2013. Material and Methods: Retrospective analysis of 87580 emergency logs of Emergency Medical Teams at Regional Ambulance Station in Rzeszów in 2010–2013. The frequency of urgent transfer vehicle and rapid response vehicle, place and time of the event, time since accepting the order to the arrival at the scene, conduct of the rescue team and the qualifiation of trip reasons were analyzed. Results: In the analyzed period urgent calls constituted 88% of all calls. Emergency Medical Teams were most frequently called to the place of patient’s residence – 59%. The largest percentage of patients (69%) were transferred to general hospitals. The most common causes of emergency calls according to ICD-10 were: breathing disorders (R06), pain in the throat and chest (R07), pain in the abdomen and pelvis (R10), malaise, fatigue (R53), syncope and collapse (R55). The proportion of deaths of patients to which Emergency Medical Teams were called amounted to 2%, including 77% of deaths before the arrival of Emergency Medical Teams, 22% in the course of the fist aid, and 1% of deaths occurred during the transport. conclusions: The profie of trips by Emergency Medical Teams in 2010-–2013 was in line with legal and statutory objectives, arrival times of Emergency Medical Teams varied in diffrent regions of the country, time of arrival at the scene was in line with the objectives of the Act, and the percentage of traveling time longer than 20 minutes resulted from a distance from the call (30–40 km). The percentage of patients’ death in the course of the fist aid was low and during transport was very low and amounted to 1%. Increasing proportion of patients transferred to hospital requires further research to assess the number of patients admitted or sent back home from A&E.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: The synchrosqueezing method in bearing estimation of stationary signals for passive sonar with towed array
Autorzy:: Czarnecki, K.
Leśniak, W.
Tematy:: reassignment method
time-frequency analysis
direction of arrival; Pokaż więcej
Wydawca:: Polskie Towarzystwo Akustyczne
Powiązania:: https://bibliotekanauki.pl/articles/332264.pdf Link otwiera się w nowym oknie
Opis:: In this paper a novel method of the bearing estimation in a passive sonar system with a towed array is introduced. The classical approach of the bearing estimation based on the spatial spectrum is extended by using the synchrosqeezing method that is a part of the reassignment method introduced by Kodera et al. The usage of this method leads to the precise bearing estimation. The proposed method requires a relatively small amount of computation, because of possibility of using the FFT algorithm. Moreover, method immunity against AWGN is tested for a selected sonar array having regard to the direction of arrival and the signal frequency.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: The busy period for the M^θ /G/1/m system with service time dependent of the queue length
Autorzy:: Zhernovyi, Y.
Kopytko, B.
Zhernovyi, K.
Tematy:: queueing system
group arrival of customers
service time dependent on the queue length; Pokaż więcej
Wydawca:: Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Powiązania:: https://bibliotekanauki.pl/articles/122898.pdf Link otwiera się w nowym oknie
Opis:: We consider the M^θ/G/1/m system wherein the service time depends on the queuelength and it is determined at the beginning of customer service. Using an approach basedon the potential method proposed by V. Korolyuk, the Laplace transforms for the distribution f the number of customers in the system on the busy period and for the distribution function of the busy period are found.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Bearing estimation using double frequency reassignment for a linear passive array
Autorzy:: Czarnecki, K.
Leśniak, W.
Tematy:: direction of arrival
DOA
instantaneous frequency
short-time Fourier transform
STFT
time-frequency reassignment
intercept and surveillance sonar
crest factor; Pokaż więcej
Wydawca:: Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:: https://bibliotekanauki.pl/articles/260131.pdf Link otwiera się w nowym oknie
Opis:: The paper demonstrates the use of frequency reassignment for bearing estimation. For this task, signals derived from a linear equispaced passive array are used. The presented method makes use of Fourier transformation based spatial spectrum estimation. It is further developed through the application of two-dimensional reassignment, which leads to obtaining highly concentrated energy distributions in the joint frequency-angle domain and sharp graphical imaging. The introduced method can be used for analysing, a priori, unknown signals of broadband, nonstationary, and/or multicomponent type. For such signals, the direction of arrival is obtained based upon the marginal energy distribution in the angle domain, through searching for arguments of its maxima. In the paper, bearing estimation of three popular types of sonar pulses, including linear and hyperbolic frequency modulated pulses, as well as no frequency modulation at all, is considered. The results of numerical experiments performed in the presence of additive white Gaussian noise are presented and compared to conventional digital sum-delay beamforming performed in the time domain. The root-mean-square error and the peak-to-average power ratio, also known as the crest factor, are introduced in order to estimate, respectively, the accuracy of the methods and the sharpness of the obtained energy distributions in the angle domain.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: The safety of the shipping and ports in the aspect of the tsunami events
Bezpieczeństwo żeglugi i portów w aspekcie wystąpienia tsunami
Autorzy:: Wiśniewski, B.
Wolski, T.
Tematy:: tsunami
bezpieczeństwo żeglugi i portów
czas przybycia tsunami
safety of shipping and ports
tsunami arrival time; Pokaż więcej
Wydawca:: Akademia Morska w Szczecinie. Wydawnictwo AMSz
Powiązania:: https://bibliotekanauki.pl/articles/359680.pdf Link otwiera się w nowym oknie
Opis:: The paper presents the influence of the tsunami on the safety of the shipping and seaports. The analysis based on the tsunami from 11 March 2011 on Japanese islands and coasts of Pacific. The paper describes the destruction caused by tsunami waves, both in port and coastal infrastructure. A list of casualties in dry bulk vessels and boats in Japan and in the U.S. coastis presented. Recommendations for ships with the warnings and messages before the tsunami are identified.
W artykule przeanalizowano wpływ fali tsunami na bezpieczeństwo żeglugi i portów morskich. Analiza oparta jest o tsunami z 11 marca 2011 r., które wystąpiło na wyspach japońskich i wybrzeżach Pacyfiku. Opisano zniszczenia wywołane falą tsunami w infrastrukturze portowej i brzegowej, a także przedstawiono wykaz strat wśród statków masowych i mniejszych jednostek w Japonii i u wybrzeży USA. Wskazano rekomendacje dla statków przy ostrzeżeniach przed tsunami i komunikatach.
Dostawca treści:: Biblioteka Nauki

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