Open Source Software for Digital Preservation Repositories: a Survey <s> INTRODUCTION <s> The difficulty and expense of preserving digital information is a potential impediment to digital library development. Preservation of traditional materials became more successful and systematic after libraries and archives integrated preservation into overall planning and resource allocation. Digital preservation is largely experimental and replete with the risks associated with untested methods. Digital preservation strategies are shaped by the needs and constraints of repositories with little consideration for the requirements of current and future users of digital scholarly resources. This article discusses the present state of digital preservation, articulates requirements of both users and custodians, and suggests research needs in storage media, migration, conversion, and overall management strategies. Additional research in these areas would help developers of digital libraries and other institutions with preservation responsibilities to integrate long-term preservation into program planning, administration, system architectures, and resource allocation. <s> BIB001 </s> Open Source Software for Digital Preservation Repositories: a Survey <s> INTRODUCTION <s> Internet of Things (IoT) has been recognized as a part of future internet and ubiquitous computing. It creates a true ubiquitous or smart environment. It demands a complex distributed architecture with numerous diverse components, including the end devices and application and association with their context. This article provides the significance of middleware system for (IoT). The middleware for IoT acts as a bond joining the heterogeneous domains of applications communicating over heterogeneous interfaces. First, to enable the better understanding of the current gap and future directions in this field a comprehensive review of the existing middleware systems for IoT is provided here. Second, fundamental functional blocks are proposed for this middleware system, and based on that feature wise classification is performed on the existing IoT-middleware. Third, open issues are analyzed and our vision on the research scope in this area is presented. <s> BIB002 </s> Open Source Software for Digital Preservation Repositories: a Survey <s> INTRODUCTION <s> Europe is the leading continent in terms of active adoption and use of Digital Libraries – particularly Institutional Repositories (IRs). Africa has not done poorly in this area with a steady increase from 19 repositories in 2008 to 46 in January, 2011 but there is need to raise awareness and channel efforts towards making IRs easily accessible to Africans through ubiquitous channels such as hand-helds and mobile devices. This paper reviews the features, architecture, design and implementation technologies of IRs. In addition, it highlights viable research areas that can be pursued by African researchers in the field of Digital Libraries. It also encourages research efforts to focus on areas that will be beneficial to Africa. <s> BIB003 </s> Open Source Software for Digital Preservation Repositories: a Survey <s> INTRODUCTION <s> The stated aim of many repositories is to provide permanent open access to their content. However, relatively few repositories have implemented practical action plans towards permanence. Repository managers often lack time and confidence to tackle the important but scary problem of preservation. Written by, and aimed at, repository managers, this paper describes how the JISC-funded KeepIt project has been bringing together existing preservation tools and services with appropriate training and advice to enable repository managers to formulate practical and achievable preservation plans. Three elements of the KeepIt project are described: 1. The initial, exploratory phase in which repository managers and a preservation specialist established the current status of each repository and its preservation objectives; 2. The repository-specific KeepIt preservation training course which covered the organisational and financial framework of repository preservation; metadata; the new preservation tools; and issues of trust between repository, users and services; 3. The application of tools and lessons learned from the training course to four exemplar repositories and the impact that this has made. The paper concludes by recommending practical steps that all repository managers may take to ensure their repositories are preservation-ready. <s> BIB004 </s> Open Source Software for Digital Preservation Repositories: a Survey <s> INTRODUCTION <s> In this paper, we studied the usage of H.264/AVC video compression tools by the flagship smartphones. The results show that only a subset of tools is used, meaning that there is still a potential to achieve higher compression efficiency within the H.264/AVC standard, but the most advanced smartphones are already reaching the compression efficiency limit of H.264/AVC. <s> BIB005
Information preservation can simply be defined as the set of processes to store, index and access information  . In recent years, the creation of digital content has grown exponentially. Gantz and Reinsel report that the so called digital universe will grow from 2005 to 2020 by a factor of 300, from 130 exabytes to 40,000 exabytes  . They also predict that the whole set of data will double roughly every two years from 2012 to 2020. Digital video is a good example of the current data deluge: the demand for increasing resolutions and higher frame rates, despite all improvements in compression, have substantially increased the size of video files. Smartphones, with all their data sensors, namely photo and video recording capabilities, are also major contributors to the current massive production of data BIB005 . The Internet of Things (IoT) is poised to generate increasing amount of data, even if IoT middleware can help by reducing the volume of data to store and preserve BIB002 . The sheer volume of digital information to preserve is immense and will continue to grow over the years. In fact, major trends like Big Data have fostered the perception of digital data as valuable assets, strengthening the need for digital data preservation and henceforth for proper digital repositories  . This way, the field of digital information preservation has to address a huge challenge. The panorama of information preservation has substantially changed with the advent of the digital era. In fact, when paper was the main medium globally adopted for storing knowledge and information, libraries were the obvious and natural places responsible for guarding, protecting and maintaining all information stored in printed formats, such as, books, papers or other. It was not until 1960's that archivists and librarians felt concerned about the preservation of electronic records. This fostered the emergence of the Machine Readable Records branch, formed at the National Archives in the USA  . In the early 1990's, materials started being ported from printed formats to digital ones, being "reborn" digital. This rose awareness for the need to address preservation to digital-only data. Indeed, if exposed to mild humidity conditions and kept in a moderate environment, paper is relatively easy to preserve, or at least has a lifetime measured in decades and thus preservation can be organized accordingly. In addition, techniques such as microfilming allowed for affordable and durable preservation of paper-based documents BIB001 . The same does not apply to digital formats. Even if the base of digital formats is simple binary 0 and 1, digital encompasses a rich set of various resources such as text, audio/video, images, computer programs, just to name a few. Besides the main data, additional information regarding the resources -format, software environment, operating systems, etc. -is required to properly preserve and access digital data. Digital formats are very fragile and even on controlled environments, there must be an active management to assure their good shape and longevity  BIB001 . The paper paradigm shift to the digital reality clearly reflected itself on other knowledge institutions, not only libraries and archives. Schools, universities and other institutions also found themselves in a situation where using paper as the main support for storing information was no longer the best choice, either because of storage space issues, preservation issues or simply because of the advance of technology.It no longer made sense to keep using outdated and less flexible means to keep information. However, if on one side there was already an awareness about the need to preserve digital information, on the other side, data repositories that followed or implemented those standards were scarce or inexistent. The logic step for these institutions was to develop their own solutions and implementations of digital preservation repositories. Their own premises and academic communities were the perfect audience to test and perfect them. Much of the software featured in this survey has its root from an academic reality. Today, we are facing yet another challenge: the Internet. In a world where the demand for being always connected is higher than ever before, the global network and its omnipresent nature make it the obvious choice to store and disseminate information and knowledge. With an exponential growth observed during the 1990's, the volume of information available on the Internet expanded as well. However, unlike printed formats, its ephemeral existence and highly volatile availability were shortly noticed. The very nature of the Internet makes it the perfect place to publish information that frequently is not available elsewhere. The awareness and need to ensure the preservation and long-term access to this information gave birth to web archiving  , an important subset of digital information preservation. Indeed, consisting in the collection of information available in the World Wide Web for future access, the process of harvesting that information is challenging due to its heterogeneous nature. For this purpose, the WARC standard  was created in 2009 by the International Internet Preservation Consortium (IIPC). Standing for Web ARChive, WARC specifies a method for combining multiple digital resources into an aggregate archival file together with related information to be used by web crawling software when harvesting information from websites  . The resulting WARC files are passible of being ingested and stored on digital repositories for preservation. However, according to a recent survey  , very few institutions are effectively downloading the WARC files generated by the web crawlers and storing them in local preservation systems or repositories. In spite of not being a common practice among institutions, there is a recognition for the need to perform preservation of web content. The main motivation for this paper is to help to fill a void: to the best of our knowledge, no up-todate survey exists for open source digital preservation software. From our research, the most recent one isdated November 2010  . Furthermore, none of the other studies focuses exclusively on digital repositories software (e.g. BIB003 and BIB004 ). Indeed, much of the scientific literature focuses on general purpose repositories. Instead, our work targets open source software repositories for digital information preservation. While they share some common requirements and properties, the two types of repositories are quite different. General-purpose repositories aim to ingest data and ensure means to store and make accessible the ingested data. On the other hand, a digital preservation repository needs to implementat least six high level services as defined by the Open Archive Information System (OAIS) reference model  , as we shall see later in Section 2.1. The main contribution of this paper is to present a wide-scale comparisons of leading open source software solutions that can appropriately store and preserve digital information. The paper highlights the main features of each system, the licensing model, the main preservation capabilities and which standards and protocols are supported. Furthermore, the survey provides an in-depth analysis of five of the most relevant open source solutions for digital information preservation. This way, the paper aims to provide a reference for anyone who aims to build a preservation-enabled digital library to make an informed choice. We believe that the paper is of interest even to potential clients of fee-based solutions, who can further compare their targeted commercial solutions with open source software ones. This document introduces the subject of digital information preservation by giving an historical framing,pointing out the reasons why institutions and organizations are concerned about the preservation of their digital assets. In section 2, the paper reviews the main models, standards and protocols for digital information preservation. Section 3 compares eleven open source solutions for digital information preservation. Section 4 provides for an in-depth analysis of five open source solutions selected from the set of software reviewed from section 3. Finally, Section 5 concludes the paper.