Δημοσιεύσεις
Book Chapters
Christos Bouras; Vassilis Poulopoulos; Vassilis Tsogkas
Squeak Etoys: Interactive and Collaborative Learning Environment Book Chapter
In: Handbook of Research on SocialInteraction Technologies and Collaboration Software: Concepts and Trends, Chapter 37, pp. 417 - 427, IGI Global, 2010.
Abstract | Links | BibTeX | Ετικέτες:
@inbook{3132,
title = {Squeak Etoys: Interactive and Collaborative Learning Environment},
author = {Christos Bouras and Vassilis Poulopoulos and Vassilis Tsogkas},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/9805978-1-60566-368-5_ch037.pdf},
year = {2010},
date = {2010-01-01},
urldate = {2010-01-01},
booktitle = {Handbook of Research on SocialInteraction Technologies and Collaboration Software: Concepts and Trends},
pages = {417 - 427},
publisher = {IGI Global},
chapter = {37},
organization = {IGI Global},
abstract = {<p>Squeak Etoys is a free software program and media-rich authoring system with a user-friendly visual interface. The software is designed to help six to twelve year-old children learn through interaction and collaboration; it comes preinstalled on XO laptop computers distributed by the One Laptop Per Child Foundation. The goal of the One Laptop Per Child initiative is to create novel educational opportunities for the world?s children by providing each child with a book-size, light and portable computer for personal use at school and at home. This chapter elaborates on the educational dimensions of the XO laptop and the Etoys environment developed to empower teachers and students with the capacity for creative learning, exploration, interaction, and collaboration. The authors focus on how the hardware and software capabilities of XO laptops can be utilized to allow children to interact, work together on projects, and engage in computer simulations and games while learning mathematics, physics, chemistry, and geometry.</p>},
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<p>Squeak Etoys is a free software program and media-rich authoring system with a user-friendly visual interface. The software is designed to help six to twelve year-old children learn through interaction and collaboration; it comes preinstalled on XO laptop computers distributed by the One Laptop Per Child Foundation. The goal of the One Laptop Per Child initiative is to create novel educational opportunities for the world?s children by providing each child with a book-size, light and portable computer for personal use at school and at home. This chapter elaborates on the educational dimensions of the XO laptop and the Etoys environment developed to empower teachers and students with the capacity for creative learning, exploration, interaction, and collaboration. The authors focus on how the hardware and software capabilities of XO laptops can be utilized to allow children to interact, work together on projects, and engage in computer simulations and games while learning mathematics, physics, chemistry, and geometry.</p>
Christos Bouras; Antonios Alexiou; Vasileios Kokkinos; Evangelos Rekkas
The Multimedia Broadcast/Multicast Service of the Universal Mobile Telecommunications System Book Chapter
In: Selected Topics in Communication Networks and Distributed Systems, Chapter 2, pp. 43 - 78, World Scientific, 2010.
Abstract | Links | BibTeX | Ετικέτες: MBMS, UMTS
@inbook{3131,
title = {The Multimedia Broadcast/Multicast Service of the Universal Mobile Telecommunications System},
author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/mbms.pdf},
year = {2010},
date = {2010-01-01},
urldate = {2010-01-01},
booktitle = {Selected Topics in Communication Networks and Distributed Systems},
pages = {43 - 78},
publisher = {World Scientific},
chapter = {2},
organization = {World Scientific},
abstract = {The Universal Mobile Telecommunications System (UMTS) constitutes the premier third generation (3G) wireless technology that is dominating the global market. Multicasting is an efficient method of supporting group communication as it allows the transmission of packets to multiple destinations, using fewer network resources. The need for broadcasting and multicasting in UMTS led to the definition of the Multimedia Broadcast/Multicast Service (MBMS) framework, which targets the efficient utilization of radio and network resources of the UMTS network. This chapter introduces the key concepts of UMTS and in particular the MBMS framework of UMTS. Moreover, it investigates the power profiles of several transport channels (common and dedicated) which could be employed for the transmission of MBMS services to mobile users. Problems regarding the high power requirements for the realization of MBMS are also presented. The reader will become familiar with these problems and the proposed techniques/solutions.},
keywords = {MBMS, UMTS},
pubstate = {published},
tppubtype = {inbook}
}
The Universal Mobile Telecommunications System (UMTS) constitutes the premier third generation (3G) wireless technology that is dominating the global market. Multicasting is an efficient method of supporting group communication as it allows the transmission of packets to multiple destinations, using fewer network resources. The need for broadcasting and multicasting in UMTS led to the definition of the Multimedia Broadcast/Multicast Service (MBMS) framework, which targets the efficient utilization of radio and network resources of the UMTS network. This chapter introduces the key concepts of UMTS and in particular the MBMS framework of UMTS. Moreover, it investigates the power profiles of several transport channels (common and dedicated) which could be employed for the transmission of MBMS services to mobile users. Problems regarding the high power requirements for the realization of MBMS are also presented. The reader will become familiar with these problems and the proposed techniques/solutions.
Christos Bouras; Antonios Alexiou; Andreas Papazois
Congestion Control for Multicast Transmission over UMTS Book Chapter
In: Wireless Quality of Service: Techniques, Standards and Applications, Chapter 10, pp. 291 - 312, Auerbach Publications, Taylor & Francis Group, 2009.
Abstract | Links | BibTeX | Ετικέτες: Congestion Control, UMTS
@inbook{3129,
title = {Congestion Control for Multicast Transmission over UMTS},
author = {Christos Bouras and Antonios Alexiou and Andreas Papazois},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/9346final_chapter_with_pics.pdf},
year = {2009},
date = {2009-01-01},
urldate = {2009-01-01},
booktitle = {Wireless Quality of Service: Techniques, Standards and Applications},
pages = {291 - 312},
publisher = {Auerbach Publications, Taylor & Francis Group},
chapter = {10},
organization = {Auerbach Publications, Taylor & Francis Group},
abstract = {In this chapter, we present a novel mechanism for the multicast congestion control over Universal Mobile Telecommunications System (UMTS) networks. The proposed mechanism is based on the well known TCP-Friendly Multicast Congestion Control (TFMCC) scheme. TFMCC is an equation-based multicast congestion control mechanism intended to scale to groups of several thousand receivers. It is based on the concept of Current Limiting Receiver (CLR). The CLR is the receiver that the sender believes currently has the lowest expected throughput of the multicast group. The key challenge in the design of the new scheme lies in extending TFMCC in order to support the UMTS Terrestrial Radio-Access Network (UTRAN). Our major contribution is that the TFMCC mechanism was improved in order to cope with the packet losses caused by either the temporary or the permanent degradation of the wireless channel. One of the major advantages of the proposed scheme is that it introduces minor modifications in the UMTS nodes with respect to the computing power of the mobile terminals. Finally, we implement our approach in the ns-2 network simulator and we evaluate it under various conditions. The simulation results are presented along with their analysis.},
keywords = {Congestion Control, UMTS},
pubstate = {published},
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In this chapter, we present a novel mechanism for the multicast congestion control over Universal Mobile Telecommunications System (UMTS) networks. The proposed mechanism is based on the well known TCP-Friendly Multicast Congestion Control (TFMCC) scheme. TFMCC is an equation-based multicast congestion control mechanism intended to scale to groups of several thousand receivers. It is based on the concept of Current Limiting Receiver (CLR). The CLR is the receiver that the sender believes currently has the lowest expected throughput of the multicast group. The key challenge in the design of the new scheme lies in extending TFMCC in order to support the UMTS Terrestrial Radio-Access Network (UTRAN). Our major contribution is that the TFMCC mechanism was improved in order to cope with the packet losses caused by either the temporary or the permanent degradation of the wireless channel. One of the major advantages of the proposed scheme is that it introduces minor modifications in the UMTS nodes with respect to the computing power of the mobile terminals. Finally, we implement our approach in the ns-2 network simulator and we evaluate it under various conditions. The simulation results are presented along with their analysis.
Christos Bouras; Thrasivoulos Tsiatsos; Eleftheria Giannaka
An Integrated Architecture for Supporting Vocational Training Book Chapter
In: Architecture Solutions for e-Learning Systems, pp. 197 - 218, IDEA Group Publishing, 2008.
Abstract | Links | BibTeX | Ετικέτες:
@inbook{3128,
title = {An Integrated Architecture for Supporting Vocational Training},
author = {Christos Bouras and Thrasivoulos Tsiatsos and Eleftheria Giannaka},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/172311.pdf},
year = {2008},
date = {2008-01-01},
urldate = {2008-01-01},
booktitle = {Architecture Solutions for e-Learning Systems},
pages = {197 - 218},
publisher = {IDEA Group Publishing},
organization = {IDEA Group Publishing},
abstract = {<p>E-learning and Web-based training have evolved over time from a newborn trend for complementing the learning process to a major form of education and training for supporting mainly geographically scattered users. The basic aim of this chapter is the description of a platform for open and distance training, which is mainly focused at supporting the needs of Vocational Training Centers as well as of institutions providing life-long adult training and learning. In particular, the issues that this chapter focuses on are vocational education and training characteristics and requirements, the current situation and technological trends in ICT-supported VET, the development framework and processes while it also proposes basic vocational training services and the system architecture of the integrated platform. The presented platform aims to provide services of both synchronous and asynchronous and collaborative distance learning.</p>},
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<p>E-learning and Web-based training have evolved over time from a newborn trend for complementing the learning process to a major form of education and training for supporting mainly geographically scattered users. The basic aim of this chapter is the description of a platform for open and distance training, which is mainly focused at supporting the needs of Vocational Training Centers as well as of institutions providing life-long adult training and learning. In particular, the issues that this chapter focuses on are vocational education and training characteristics and requirements, the current situation and technological trends in ICT-supported VET, the development framework and processes while it also proposes basic vocational training services and the system architecture of the integrated platform. The presented platform aims to provide services of both synchronous and asynchronous and collaborative distance learning.</p>
Christos Bouras; Dimitris Primpas; Antonios Alexiou; J Papagiannopoulos
Metropolitan Broadband Networks: Design and implementation aspects and business models Book Chapter
In: Global Diffusion of Broadband Data Transmission: Factors Affecting the Adoption, Usage and Economics of Broadband, vol. 1, Chapter XIII, pp. 196 - 210, IDEA Group Publishing, 2008.
Abstract | Links | BibTeX | Ετικέτες:
@inbook{3127,
title = {Metropolitan Broadband Networks: Design and implementation aspects and business models},
author = {Christos Bouras and Dimitris Primpas and Antonios Alexiou and J Papagiannopoulos},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/4113Dwived196.pdf},
year = {2008},
date = {2008-01-01},
urldate = {2008-01-01},
booktitle = {Global Diffusion of Broadband Data Transmission: Factors Affecting the Adoption, Usage and Economics of Broadband},
volume = {1},
pages = {196 - 210},
publisher = {IDEA Group Publishing},
chapter = {XIII},
organization = {IDEA Group Publishing},
abstract = {<p>This chapter presents the design principles that cover the implementation of broadband infrastructure in the region of Western Greece, by examining all the necessary parameters that arise while implementing such a critical developmental project. The broadband infrastructure that is deployed is either based on optical fiber (on big municipalities) or on wireless systems (OFDM based and WiFi cells). Furthermore, we present as two case studies, all issues of the designing of the Metropolitan Area Network of Patras, the third biggest city of Greece and the Wireless Access Network of Messatida. The major target of the broadband networks is to interconnect the buildings of the public sector in the city and also deploy infrastructure (fibers or wireless systems) that will create conditions of competition in providing both access and content services in advantage of the end consumer. The usage of the broadband infrastructure by service providers will be based on the open availability of the infrastructure in a cost effective way. Finally, we present the main characteristics of a proposed business plan that ensures financial viability of the broadband infrastructure and guarantees the administration, growth, and exploitation of infrastructure.</p>},
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<p>This chapter presents the design principles that cover the implementation of broadband infrastructure in the region of Western Greece, by examining all the necessary parameters that arise while implementing such a critical developmental project. The broadband infrastructure that is deployed is either based on optical fiber (on big municipalities) or on wireless systems (OFDM based and WiFi cells). Furthermore, we present as two case studies, all issues of the designing of the Metropolitan Area Network of Patras, the third biggest city of Greece and the Wireless Access Network of Messatida. The major target of the broadband networks is to interconnect the buildings of the public sector in the city and also deploy infrastructure (fibers or wireless systems) that will create conditions of competition in providing both access and content services in advantage of the end consumer. The usage of the broadband infrastructure by service providers will be based on the open availability of the infrastructure in a cost effective way. Finally, we present the main characteristics of a proposed business plan that ensures financial viability of the broadband infrastructure and guarantees the administration, growth, and exploitation of infrastructure.</p>
Christos Bouras; Maria Nani
Using Open Source to Building and Accessing Learning Objects and Online Courses Book Chapter
In: Open Source for Knowledge and LearningManagement: Strategies beyond Tools, pp. 268 - 298, IDEA Group Publishing, 2007.
Abstract | Links | BibTeX | Ετικέτες:
@inbook{3126,
title = {Using Open Source to Building and Accessing Learning Objects and Online Courses},
author = {Christos Bouras and Maria Nani},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/758409Bouras_Nani.pdf},
year = {2007},
date = {2007-01-01},
urldate = {2007-01-01},
booktitle = {Open Source for Knowledge and LearningManagement: Strategies beyond Tools},
pages = {268 - 298},
publisher = {IDEA Group Publishing},
organization = {IDEA Group Publishing},
abstract = {As e-learning continuously gains the interest of the scientific community, industry, and government, a wide variety of learning technology products have been incorporated into the marketplace. Advances in information and communication technologies are in favor of the incorporation of innovative services and functionalities in such systems, though content creation and delivery remain the two key factors in any e-learning system. Therefore, in this chapter, we present the design and implementation of a tool targeted at building and accessing learning objects and online courses through the Web. This tool aims to facilitate instructors and trainers to easily develop accessible, reusable, and traceable learning content that can meet their distant students? needs for anytime and anyplace learning. Learners are able to access learning content, in addition to consulting, at any time, reports on their interactions within a course and get support by subject experts. Furthermore, all users can request to upgrade their role in the system and, thus, actively participate in the learning process. Special attention has been paid on the utilization of reliable and qualitative open source technologies and Web standards so that the proposed solution can form an easily accessible system.},
keywords = {},
pubstate = {published},
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As e-learning continuously gains the interest of the scientific community, industry, and government, a wide variety of learning technology products have been incorporated into the marketplace. Advances in information and communication technologies are in favor of the incorporation of innovative services and functionalities in such systems, though content creation and delivery remain the two key factors in any e-learning system. Therefore, in this chapter, we present the design and implementation of a tool targeted at building and accessing learning objects and online courses through the Web. This tool aims to facilitate instructors and trainers to easily develop accessible, reusable, and traceable learning content that can meet their distant students? needs for anytime and anyplace learning. Learners are able to access learning content, in addition to consulting, at any time, reports on their interactions within a course and get support by subject experts. Furthermore, all users can request to upgrade their role in the system and, thus, actively participate in the learning process. Special attention has been paid on the utilization of reliable and qualitative open source technologies and Web standards so that the proposed solution can form an easily accessible system.
Christos Bouras; Thrasivoulos Tsiatsos; Eleftheria Giannaka; Alexandros Panagopoulos; Maria Nani
An Integrated Platform for Educational Virtual Environments Book Chapter
In: Web-Based Intelligent e - Learning Systems: Technologies and Applications, Chapter XV, pp. 291 - 320, IDEA Group Publishing, 2006.
Abstract | Links | BibTeX | Ετικέτες:
@inbook{3122,
title = {An Integrated Platform for Educational Virtual Environments},
author = {Christos Bouras and Thrasivoulos Tsiatsos and Eleftheria Giannaka and Alexandros Panagopoulos and Maria Nani},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/81341159.pdf},
year = {2006},
date = {2006-01-01},
urldate = {2006-01-01},
booktitle = {Web-Based Intelligent e - Learning Systems: Technologies and Applications},
pages = {291 - 320},
publisher = {IDEA Group Publishing},
chapter = {XV},
organization = {IDEA Group Publishing},
abstract = {In this chapter, we present the design and implementation of an integrated platform for Educational Virtual Environments. This platform aims to support an educational community, synchronous online courses in multi-user three-dimensional (3D) environments, and the creation and access of asynchronous courses through a learning content management system. In order to offer synchronous courses, we have implemented a system called EVE-II, which supports stable event sharing for multi-user 3D places, easy creation of multi-user 3D places, H.323-based voice- over IP services fully integrated in a 3D space, as well as many concurrent 3D multi-user spaces.},
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In this chapter, we present the design and implementation of an integrated platform for Educational Virtual Environments. This platform aims to support an educational community, synchronous online courses in multi-user three-dimensional (3D) environments, and the creation and access of asynchronous courses through a learning content management system. In order to offer synchronous courses, we have implemented a system called EVE-II, which supports stable event sharing for multi-user 3D places, easy creation of multi-user 3D places, H.323-based voice- over IP services fully integrated in a 3D space, as well as many concurrent 3D multi-user spaces.
Christos Bouras; Agis Konidaris
Modeling Data Intensive Web Sites for Personalisation, Integrity and Performance Book Chapter
In: Information Modeling for Internet Applications, Chapter XII, pp. 259 - 276, IDEA Group Publishing, 2003.
Abstract | Links | BibTeX | Ετικέτες:
@inbook{3123,
title = {Modeling Data Intensive Web Sites for Personalisation, Integrity and Performance},
author = {Christos Bouras and Agis Konidaris},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/7151905.pdf},
year = {2003},
date = {2003-01-01},
urldate = {2003-01-01},
booktitle = {Information Modeling for Internet Applications},
pages = {259 - 276},
publisher = {IDEA Group Publishing},
chapter = {XII},
organization = {IDEA Group Publishing},
abstract = {This chapter presents a step-by-step approach to the design, implementation and management of a Data-Intensive Web Site (DIWS). The approach introduces five data formulation and manipulation graphs that are presented analytically. The core concept behind the modeling approach is that of “Web fragments,” that is an information decomposition technique that aids design, implementation and management of DIWS. We then present the steps that must be followed in order to “build” a DIWS based on Web fragments. Finally, we show how our approach can be used to ensure the basic DIWS user requirements of personalization, integrity and performance.},
keywords = {},
pubstate = {published},
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This chapter presents a step-by-step approach to the design, implementation and management of a Data-Intensive Web Site (DIWS). The approach introduces five data formulation and manipulation graphs that are presented analytically. The core concept behind the modeling approach is that of “Web fragments,” that is an information decomposition technique that aids design, implementation and management of DIWS. We then present the steps that must be followed in order to “build” a DIWS based on Web fragments. Finally, we show how our approach can be used to ensure the basic DIWS user requirements of personalization, integrity and performance.
Christos Bouras; Agis Konidaris; Afroditi Sevasti
Virtual Environments in Educational Networks Book Chapter
In: COMMUNICATIONS AND NETWORKING IN EDUCATION Learning in a Networked society, Edited by T. Downes and D. Watson, pp. 195 - 203, Kluwer Academic Publishers, 2000.
Abstract | Links | BibTeX | Ετικέτες:
@inbook{3124,
title = {Virtual Environments in Educational Networks},
author = {Christos Bouras and Agis Konidaris and Afroditi Sevasti},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/6551356.pdf},
year = {2000},
date = {2000-01-01},
urldate = {2000-01-01},
booktitle = {COMMUNICATIONS AND NETWORKING IN EDUCATION Learning in a Networked society, Edited by T. Downes and D. Watson},
pages = {195 - 203},
publisher = {Kluwer Academic Publishers},
organization = {Kluwer Academic Publishers},
abstract = {The field of Virtual Environments (VEs) is rapidly evolving into a new means of communication and accessing information, likely to overcome many existent technologies. However, being a new field makes the design and implementation of educational VEs an important aspect for scientific research in their educational potentials and the exploitation of existent technologies. New technologies in the field of VEs have appeared the establishment and combination of which, is yet to be investigated. This paper makes an effort to approach the issue of developing educational VEs introducing new aspects in the issues of interface, interaction with the user and functionality.},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
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The field of Virtual Environments (VEs) is rapidly evolving into a new means of communication and accessing information, likely to overcome many existent technologies. However, being a new field makes the design and implementation of educational VEs an important aspect for scientific research in their educational potentials and the exploitation of existent technologies. New technologies in the field of VEs have appeared the establishment and combination of which, is yet to be investigated. This paper makes an effort to approach the issue of developing educational VEs introducing new aspects in the issues of interface, interaction with the user and functionality.
Proceedings
Christos Bouras; Thrasivoulos Tsiatsos; Eleftheria Giannaka
An Object Driven Partitioning Approach for Distributed Virtual Environments Proceedings
2007.
Abstract | Links | BibTeX | Ετικέτες:
@proceedings{2912,
title = {An Object Driven Partitioning Approach for Distributed Virtual Environments},
author = {Christos Bouras and Thrasivoulos Tsiatsos and Eleftheria Giannaka},
url = {https://telematics.upatras.gr/7430pdcat2007_bouras/},
year = {2007},
date = {2007-12-01},
urldate = {2007-12-01},
pages = {153-154},
abstract = {Distributed virtual environments tend to become a de facto solution for large-scale networked virtual environments. One of the key issues and problems that need to be handled in the design of a scalable and effective distributed virtual environment system is the partitioning problem, which refers to the efficient assignment of the systems workload to the available resources of the system. This paper presents an object driven partitioning approach based on the partitioning algorithm of Lui & Chan, who proposed a three step technique for balancing the workload among the servers of the Distributed Virtual Environment.},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
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Distributed virtual environments tend to become a de facto solution for large-scale networked virtual environments. One of the key issues and problems that need to be handled in the design of a scalable and effective distributed virtual environment system is the partitioning problem, which refers to the efficient assignment of the systems workload to the available resources of the system. This paper presents an object driven partitioning approach based on the partitioning algorithm of Lui & Chan, who proposed a three step technique for balancing the workload among the servers of the Distributed Virtual Environment.
Book Sections
Christos Bouras; Kostas Stamos; Dimitris Primpas; Rute Sofia; Sheng Jiang
Survey of IPv4 Dependencies in Global Grid Foru Book Section
In: 2005.
@incollection{Bouras2005,
title = {Survey of IPv4 Dependencies in Global Grid Foru},
author = {Christos Bouras and Kostas Stamos and Dimitris Primpas and Rute Sofia and Sheng Jiang},
url = {https://bouras.upatras.gr/document/},
year = {2005},
date = {2005-01-01},
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Christos Bouras; Kostas Stamos; Dimitris Primpas; Rute Sofia; Sheng Jiang
Survey of IPv4 Dependencies in Global Grid Forum Sp Book Section
In: 2005.
@incollection{3156b,
title = {Survey of IPv4 Dependencies in Global Grid Forum Sp},
author = {Christos Bouras and Kostas Stamos and Dimitris Primpas and Rute Sofia and Sheng Jiang},
url = {Please contact us to obtain a copy of the document},
year = {2005},
date = {2005-01-01},
urldate = {2005-01-01},
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