Search results for: STOS TCP/IP

• Simulation model for assessment of IMS-based NGN call processing performance

  Publication

  • S. Kaczmarek
  • M. Kaszuba
  • M. Sac

  - Year 2012

  In current telecommunications it is assumed that demands of information society for quickly delivered services will be satisfied by Next Generation Network (NGN) architecture, which includes IP Multimedia Subsystem (IMS) elements. To guarantee Quality of Service (QoS), proper design and dimensioning of NGN is absolutely necessary, for which appropriate models have to be proposed. As NGN architecture is very complicated, the most...

• Extensions of ETSI performance measurements methodology for statistical results analysis =Rozszerzenia metodologii pomiarów wydajności zaproponowanej przez ETSI przy statystycznej analizy wyników

  Publication

  • S. Kaczmarek
  • M. Młynarczuk
  • M. Narloch
  • M. Sac

  - Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne - Year 2012

  Next Generation Network (NGN) architecture was proposed by International Telecommunication Union Telecommunication Standardization Sector (ITU-T) to deliver telecommunication services satisfying the needs of modern society for an access to information. The core of NGN service stratum are IP Multimedia Subsystem (IMS) elements acting as service controls units. To assess performance of IMS components, European Telecommunications...

• Message Inter-Arrival and Inter-Departure Time Distributions in IMS/NGN Architecture

  Publication

  • S. Kaczmarek
  • M. Sac

  - Year 2012

  Currently is it assumed that requirements of the information society for delivering multimedia services will be satisfied by the Next Generation Network (NGN) architecture, which includes elements of the IP Multimedia Subsystem (IMS) solution. In order to guarantee Quality of Service (QoS), NGN has to be appropriately designed and dimensioned. Therefore, proper traffic models should be proposed and applied. This requires determination...

• Are creative users more apt in reusing and adopting Open Government Data (OGD)? Gender differences

  Publication

  • C. H. Alexopoulos
  • S. Saxena
  • N. Rizun
  • R. Matheus
  • M. Janssen

  - Thinking Skills and Creativity - Year 2024

  Open Government Data (OGD) has been considered as a potent instrument for value creation and innovation by a range of stakeholders. Given that individual ingenuity is a function of individual and environmental factors, it is important to understand how the OGD adoption and usage is a factor of creative performance behaviors (CPB), viz., Problem Identification (PI), Information Search (IS), Idea Generation (IG) and Idea Promotion...

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• System monitoringu rozdzielnic kampusu Politechniki Gdańskiej

  Publication

  • K. Kwasigroch
  • M. Łukaszewicz
  • I. Mosoń

  - Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej - Year 2020

  W artykule opisano koncepcję, realizację programową oraz stanowisko testowe systemu monitoringu rozdzielnic kampusu Politechniki Gdańskiej. Zaproponowano realizację sprzętową oraz opracowano realizację programową systemu monitoringu rozdzielnic dla dwóch budynków: Gmachu Głównego i Centrum Obsługi Technicznej. Ważną cechą opracowanego rozwiązania jest jego skalowalność, gdyż docelowo system monitoringu będzie obejmował wszystkie...

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• A Survey of Fast-Recovery Mechanisms in Packet-Switched Networks

  Publication

  • M. Chiesa
  • A. Kamisinski
  • J. Rak
  • G. Retvari
  • S. Schmid

  - IEEE Communications Surveys and Tutorials - Year 2021

  In order to meet their stringent dependability requirements, most modern packet-switched communication networks support fast-recovery mechanisms in the data plane. While reactions to failures in the data plane can be significantly faster compared to control plane mechanisms, implementing fast recovery in the data plane is challenging, and has recently received much attention in the literature. This survey presents a systematic,...

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• Design of a Multidomain IMS/NGN Service Stratum

  Publication

  • S. Kaczmarek
  • M. Sac

  - Year 2018

  The paper continues our research concerning the Next Generation Network (NGN), which is standardized for delivering multimedia services with strict quality and includes elements of the IP Multimedia Subsystem (IMS). A design algorithm for a multidomain IMS/NGN service stratum is proposed, which calculates the necessary CSCF servers CPU message processing times and link bandwidths with respect to the given maximum values of mean...

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• Implementacja usług VoIP na platformie RIK

  Publication

  • R. Brendel
  • D. Bednarczyk
  • K. Nowicki

  - Year 2009

  W pracy przedstawiono strukturę platformy RIK (Rozproszonej Infrastruktury Komunikacyjnej) instalowanej na Wydziale ETI PG. Omówiono wymagania dla infrastruktury sieciowej Wydziału ETI umożliwiającej realizacje aplikacji VoIP. Opisano implementacje telefonów IP i usług VoIP w środowisku sieciowym na WETI PG. Scharakteryzowano środowisko programistyczne dla aplikacji VoIP. Zaprezentowano zaimplementowane na Wydziale ETI PG usługi:...

• Methods for evaluation packet delay distribution of flows using Expedited Forwarding PHB.

  Publication

  • S. Kaczmarek
  • M. Narloch

  - Year 2004

  Artykuł dotyczy problemu zapewnienia statystycznych gwarancji jakości obsługi dla strumieni czasu rzeczywistego korzystających z Expedited Forwarding Per Hop Behavior (EF PHB) w sieci IP Differentiated Services. Statystyczne podejście do określenia gwarancji jakościowych, oparte na obliczaniu prawdopodobieństwa że opóźnienie pakietów od końca do końca jest większe niż określona wielkość, pozwala lepsze wykorzystanie sieci niż poprzednio...

• Realizacja definiowanego programowo interfejsu radiowego NB-IoT

  Publication

  • O. Błaszkiewicz
  • J. Magiera
  • A. Olejniczak
  • P. Rajchowski
  • J. Sadowski
  • J. Stefański
  • K. Cwalina

  - Year 2022

  W niniejszym artykule przedstawiono sposób realizacji definiowanego programo-wo, uniwersalnego interfejsu radiowego do inteligentnych urządzeń IoT (Internet of Things) - DUCH IoT, pracującego zgodnie z międzynarodowymi standardami: LTE (Long Term Evolution) kat. NB1 (Narrowband) oraz LTE kat. NB2. Interfejs radiowy został za-implementowany w formie sprzętowo-programowego, frameworka z konfigurowalnym podziałem realizowanych funkcji...

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• Approximation of Message Inter-Arrival and Inter-Departure Time Distributions in IMS/NGN Architecture Using Phase-Type Distributions

  Publication

  • S. Kaczmarek
  • M. Sac

  - Journal of Telecommunications and Information Technology - Year 2013

  Currently it is assumed that requirements of the information society for delivering multimedia services will be satisfied by the Next Generation Network (NGN) architecture, which includes elements of the IP Multimedia Subsystem (IMS) solution. In order to guarantee Quality of Service (QoS), NGN has to be appropriately designed and dimensioned. Therefore, proper traffic models should be proposed and applied. This requires determination...

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• Quality measure of VoIP services in carrier grade systems

  Publication

  • S. Kaczmarek
  • M. Krajewski

  - Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne - Year 2010

  This paper describes passive measurement method of VoIP services quality in carrier grade systems, engaging slight system resources. Measurement is based on analyzing quality information in sender and receiver reports in RTCP packets sent by the end points of RTP session. Data is analyzed and stored by Session Boarder Controllers SBC. Objective evaluation of VoIP calls is based on quality information of IP connection and voice...

• Nuclear Co-generation: The Analysis of Technical Capabilities and Cost Estimates

  Publication

  • A. Reński
  • K. Duzinkiewicz
  • T. Minkiewicz
  • M. Jaskólski
  • A. Kaczmarek-Kacprzak

  - Acta Energetica - Year 2016

  This paper presents a concept of the parallel connection of a nuclear power plant fitted to provide heat for district heating application, with the CHP and heat plants existing in the supply region, in this case with the heating systems of Wejherowo and Gdynia. Presented variant proposes to add heat to a nuclear power plant’s total output by supplying heat exchangers with the steam from bleeders of low pressure (LP) turbine stage...

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• Traffic Model of IMS/NGN Architecture with Transport Stratum Based on MPLS Technology

  Publication

  • S. Kaczmarek
  • M. Kosek
  • M. Sac

  - International Journal of Electronics and Telecommunications - Year 2013

  Growing expectations for a fast access to information create strong demands for a universal telecommunication network architecture, which provides various services with strictly determined quality. Currently it is assumed that these requirements will be satisfied by Next Generation Network (NGN), which consists of two stratums and includes IP Multimedia Subsystem (IMS) elements. To guarantee Quality of Service (QoS) all NGN stratums...

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• Call Processing Performance in a Multidomain IMS/NGN with Asymmetric Traffic

  Publication

  • S. Kaczmarek
  • M. Sac

  - Year 2014

  In this paper we continue our research using the previously proposed analytical traffic model of a multidomain Next Generation Network (NGN), which is standardized for delivering multimedia services based on the IP Multimedia Subsystem (IMS). The aim of the model is to assess mean Call Set-up Delay (CSD) and mean Call Disengagement Delay (CDD), which are standardized call processing performance parameters. The output variables...

• Traffic model for evaluation of call processing performance parameters in IMS-based NGN

  Publication

  • S. Kaczmarek
  • M. Sac

  - Year 2012

  In the modern world requirements for accurate and fast information distribution are becoming more and more important, which creates a strong necessity for appropriate telecommunication network architecture. Proposition of such an architecture is the Next Generation Network (NGN) concept, which in order to guarantee Quality of Service (QoS), should be correctly designed and dimensioned. For this reason proper traffic models must...

• Zagadnienia inżynierii ruchu w sieciach NGN bazujących na IMS

  Publication

  • S. Kaczmarek
  • M. Sac

  - Year 2012

  Spełnienie wymagań dotyczących szybkości i dokładności dostarczania informacji powoduje konieczność wprowadzenia i poprawnego zaprojektowania sieci telekomunikacyjnych następnej generacji. W tym celu należy wskazać i zastosować odpowiednie modele ruchowe i metody inżynierii ruchu, czemu poświęcono niniejszą pracę. W pracy zaprezentowano standaryzację i architektury koncepcji IMS (IP Multimedia Subsystem) oraz bazujących na niej...

• Analytical Traffic Model for a Multidomain IMS/NGN Network Including Service and Transport Stratum

  Publication

  • S. Kaczmarek
  • M. Sac
  • M. Cieśliński

  - Year 2022

  This paper addresses the problem of modelling call processing performance (CPP) in a multidomain Next Generation Network (NGN) architecture including the elements of the IP Multimedia Subsystem (IMS) in service stratum and based on the Multiprotocol Label Switching (MPLS) technology in transport stratum. An analytical traffic model for such an architecture is proposed by integrating the formerly implemented submodels of service...

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• Quality Parameters in IMS/NGN Networks

  Publication

  • S. Kaczmarek
  • M. Sac

  - Year 2019

  The Next Generation Network (NGN) architecture, including elements of the IP Multimedia Subsystem (IMS) concept, is a proposition of a telecommunication network dedicated to the needs of current and future information society. The main goal of NGN is to provide Quality of Service (QoS), for which proper network design is necessary with respect to among others standardized call processing performance parameters, including expected...

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• Reliable routing and resource allocation scheme for hybrid RF/FSO networks

  Publication

  • J. Rak
  • W. Molisz

  - Year 2014

  Significant success of wireless networks in the last decade has changed the paradigms of communication networks design. In particular, the growing interest in wireless mesh networks (WMNs) is observed. WMNs offer an attractive alternative to conventional cable infrastructures, especially in urban areas, where the cost of new installations is almost prohibitive. Unfortunately, the performance of WMNs is often limited by the cluttered...

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• Performance Evaluation of a Multidomain IMS/NGN Network Including Service and Transport Stratum

  Publication

  • S. Kaczmarek
  • M. Sac

  - Applied Sciences-Basel - Year 2022

  The Next Generation Network (NGN) architecture was proposed for delivering various multimedia services with guaranteed quality. For this reason, the elements of the IP Multimedia Subsystem (IMS) concept (an important part of 4G/5G/6G mobile networks) are used in its service stratum. This paper presents comprehensive research on how the parameters of an IMS/NGN network and traffic sources influence mean Call Set-up Delay (E(CSD))...

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• Towards More Realistic Probabilistic Models for Data Structures: The External Path Length in Tries under the Markov Model

  Publication

  • K. Leckey
  • R. Neininger
  • W. Szpankowski

  - Year 2013

  Tries are among the most versatile and widely used data structures on words. They are pertinent to the (internal) structure of (stored) words and several splitting procedures used in diverse contexts ranging from document taxonomy to IP addresses lookup, from data compression (i.e., Lempel- Ziv'77 scheme) to dynamic hashing, from partial-match queries to speech recognition, from leader election algorithms to distributed hashing...

• Simulation model for evaluation of QOS dynamic routing

  Publication

  • M. Czarkowski
  • S. Kaczmarek

  - Year 2009

  Current informational networks use a large variety of technologies to support data exchange. Most of them are focused on IP protocol and include mechanisms which by definition should supply demanded QoS. One of those mechanisms is efficient path calculation - routing. Traffic offered to the network can change very rapidly in short term. Routing should support such traffic changes and all the time calculate valid paths in terms...

• Quality Expectations of Mobile Subscribers

  Publication

  • P. Falkowski-Gilski
  • J. Stefański

  - Journal of Telecommunications and Information Technology - Year 2015

  Mobile systems, by nature, have finite resources. Radio spectrum is limited, expensive and shared between many users and services. Mobile broadband networks must support multiple applications of voice, video and data on a single IP-based infrastructure. These converged services each have unique traffic holding and quality requirements. A positive user experience must be obtained through efficient partitioning of the available wireless...

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• Analiza algorytmów rutingu wspierających QoS w DiffServ

  Publication

  • M. Czarkowski
  • S. Kaczmarek

  - Year 2005

  W pracy podjęto tematykę związaną z opisem oraz analizą dostępnych algorytmów rutingu wspierających QoS dla specyficznej architektury sieci IP - DiffServ. Główną przyczyną jaka skłania do badania procedur rutingu QoS o wielu ograniczeniach (multi constrained routing) jest brak jak dotąd jednoznacznie sprecyzowanych, dokładnych metod pozwalających wyznaczyć drogi połączeniowe dla usług, dla których ma być gwarantowana jakość (QoS...

• Analiza algorytmów rutingu wspierających QoS w DiffServ.

  Publication

  • M. Czarkowski
  • S. Kaczmarek

  - Year 2004

  W artykule podjęto tematykę związaną z opisem oraz analizą dostępnych algorytmów rutingu wspierających QoS dla specyficznej architektury sieci IP - DiffServ. Główną przyczyną jaka skłania do badania procedur rutingu QoS o wielu ograniczeniach (multi constrained routing) jest brak jak dotąd jednoznacznie sprecyzowanych, dokładnych metod pozwalających wyznaczyć drogi połączeniowe dla usług, dla których ma być gwarantowana jakość...

• Analysis of IMS/NGN call processing performance using phase-type distributions

  Publication

  • S. Kaczmarek
  • M. Sac

  - Year 2013

  This work is a continuation of our research on the traffic model dedicated for design and analysis of the Next Generation Network (NGN), which is standardized for distribution of current and future multimedia services based on the IP Multimedia Subsystem (IMS). Our analytical and simulation models allow evaluation of mean Call Set-up Delay E(CSD) as well as mean Call Disengagement Delay E(CDD) in a single domain of IMS/NGN. Ensuring...

• Analysis of IMS/NGN Call Processing Performance Using Phase-Type Distributions Based on Experimental Histograms

  Publication

  • S. Kaczmarek
  • M. Sac

  - Advances in Intelligent Systems and Computing - Year 2018

  The paper describes our further research done with the proposed analytical and simulation traffic models of the Next Generation Network (NGN), which is standardized for delivering multimedia services with strict quality and includes elements of the IP Multimedia Subsystem (IMS). The aim of our models of a single IMS/NGN domain is to evaluate two standardized call processing performance parameters, which appropriate values are very...

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• Dynamiczne sieci VLAN z zastosowaniem mechanizmów silnego uwierzytelniania użytkowników oraz metod ochrony przesyłanych informacji

  Publication

  • G. Nagórski

  - Year 2010

  W pracy zaprezentowano definicje wirtualnych sieci LAN. Klasyfikację algorytmów sieci VLAN przeprowadzono używając kryterium przynależności tzn. port przełącznika, adres MAC, adres sieciowy, adres grupowy IP lub reguły logiczne. Opisano zasady tworzenia sieci VLAN w środowisku wieloprzełącznikowym z użyciem rozwiązań standardu 802.1Q lub protokółu ISL. Scharakteryzowano rozwiązania LANE oraz MPOA umożliwiającego integrację z siecią...

• User experience evaluation study on the quality of 1K, 2K, and 4K H.265/HEVC video content

  Publication

  • P. Falkowski-Gilski
  • T. Uhl
  • C. Hoppe

  - Zeszyty Naukowe Akademii Morskiej w Szczecinie - Year 2024

  Nowadays, most content creators focus on distributing rich media at the highest possible resolution. Currently, the majority of sold consoles, media players, computer hardware, as well as displays and TVs are advertised as 4K-compatible. The same trend is observed in the case of popular online streaming services and terrestrial TV broadcasts. Generally speaking, it is assumed that higher bitrates provide higher subjective judgements....

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• Thermodynamic and economic analysis of nuclear power unit operating in partial cogeneration mode to produce electricity and district heat

  Publication

  • M. Jaskólski
  • A. Reński
  • T. Minkiewicz

  - ENERGY - Year 2017

  This paper presents the methodology of techno-economic analysis for a nuclear unit operating in partial cogeneration mode and its application for the case study: a nuclear power plant planned in Poland. The research objectives were: to propose EPR, AP1000 and ESBWR nuclear condensing-extraction turbine systems modifications required for operation in cogeneration, to determine optimal heat production and heat transport line (HTL)...

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• Opóźnienie efektywne i jego zastosowanie do sterowania ruchem w sieciach pakietowych

  Publication

  • M. Narloch

  - Year 2006

  W rozprawie doktorskiej przeanalizowano problem zapewnienia gwarancji jakości usług (Quality of Service, QoS) w sieciach pakietowych, ze szczególnym uwzględnieniem usług o ściśle określonych wymaganiach opisujących opóźnienie pakietów i jego zmienność w sieciach z agregacją strumieni, takich jak np. sieć IP QoS z Differentiated Services (DiffServ) realizująca schemat obsługi Expedited Forwarding Per Hop Behavior (EF PHB) lub sieć...

• Open-Source Coprocessor for Integer Multiple Precision Arithmetic

  Publication

  • K. Rudnicki
  • T. Stefański
  • W. Żebrowski

  - Electronics - Year 2020

  This paper presents an open-source digital circuit of the coprocessor for an integer multiple-precision arithmetic (MPA). The purpose of this coprocessor is to support a central processing unit (CPU) by offloading computations requiring integer precision higher than 32/64 bits. The coprocessor is developed using the very high speed integrated circuit hardware description language (VHDL) as an intellectual property (IP) core. Therefore,...

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• Realizacja warstwy serwerów sterowania połączeniami dla ASON/GMPLS

  Publication

  • S. Kaczmarek
  • M. Młynarczuk
  • M. Narloch
  • M. Sac

  - Year 2010

  W materiale przedstawiono wyniki prac badawczych wykonanych w ramach projektu PBZ w podprojekcie Architektury i protokoły sieciowe. Obejmują krótką charakterystykę wytworzonych modeli analitycznych i symulacyjnych przeznaczonych do badania sieci pakietowych z gwarancją jakości klas usług dla technologii IP QoS, MPLS, OBS oraz uzyskane wyniki. Jednakże główny punkt ciężkości został położony na sieci z architekturą ASON/GMPLS dla...

• The influence of the UV irradiation on degradation of virgin rapeseed oils

  Publication

  • R. Pawłowicz
  • J. Gromadzka
  • M. Tynek
  • R. Tylingo
  • W. Wardencki
  • G. Karlovits

  - EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY - Year 2013

  This paper presents research which is a continuation of the investigations described earlier. The aim of these studies was to determine the influence of UV irradiation on flavor and the oxidative stability of different rapeseed oils varieties. For the purpose of this study, oil samples underwent accelerated deterioration for 4.5 h under a UV light test. In the obtained sample, characteristic values (peroxide (PV, 1.23–1.62 meq...

• Aplikacje i usługi a technologie sieciowe

  Publication

  • H. Krawczyk
  • S. Kaczmarek
  • K. Nowicki

  - Year 2018

  Obserwując tempo rozwoju technologii sieciowych oraz usług i aplikacji stajemy przed ogromnym dylematem jak wykorzystać istniejące możliwości by modernizować wybrane usługi i aplikacje zgodnie z ciągle zmieniającymi się potrzebami użytkowników. Bardzo często sygnalizowane nowe technologie czy aplikacje mają jednak czysto charakter biznesowy podporządkowany prawom marketingu i nie wnoszą wielu istotnych zmian. Dlatego jest ważne...

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• Implementation of failover and load balancing algorithms in SIP PBX High Availability system

  Publication

  • S. Kaczmarek
  • J. A. Litka
  • M. Krajewski

  - Year 2014

  Goal of the project was to design a High Availability SIP VoIP system that guarantees access to additional services like auto-attendent and automatic call distribution. The realization of the project required system to have load balancing and failover algorithms implemented. From the end users’ point of view the whole system had to figure as a single element. After taking under consideration the known methods of implementations...

• Outcomes of gynecologic cancer surgery during the COVID-19 pandemic: an international, multicenter, prospective CovidSurg-Gynecologic Oncology Cancer study

  Publication

  • C. Fotopoulou
  • T. Khan
  • J. Bracinik
  • N. Abu-Rustum
  • L. Chiva
  • A. Fagotti
  • K. Fujiwara
  • R. Ghebre
  • M. Gutelkin
  • T. Konney... and 4980 others

  - AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY - Year 2022

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• Effect of COVID-19 pandemic lockdowns on planned cancer surgery for 15 tumour types in 61 countries: an international, prospective, cohort study

  Publication

  • A. Adisa
  • E. AlAmeer
  • A. Costas-Chavarri
  • D. Morton
  • J. Simões
  • R. Sullivan
  • D. Nepogodiev
  • K. Siaw-Acheampong
  • E. Bywater
  • D. Chaudhry... and 4986 others

  - The Lancet Oncology - Year 2021

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• Elective surgery system strengthening: development, measurement, and validation of the surgical preparedness index across 1632 hospitals in 119 countries

  Publication

  • T. Abbott
  • M. Abou
  • D. Chaudhry
  • J. Davies
  • A. Desai
  • M. Fiore
  • J. Fitzgerald
  • A. Fowler
  • K. Futaba
  • R. Gujjuri... and 4373 others

  - The Lancet - Year 2022

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