17,716 research outputs found
Storage Solutions for Big Data Systems: A Qualitative Study and Comparison
Big data systems development is full of challenges in view of the variety of
application areas and domains that this technology promises to serve.
Typically, fundamental design decisions involved in big data systems design
include choosing appropriate storage and computing infrastructures. In this age
of heterogeneous systems that integrate different technologies for optimized
solution to a specific real world problem, big data system are not an exception
to any such rule. As far as the storage aspect of any big data system is
concerned, the primary facet in this regard is a storage infrastructure and
NoSQL seems to be the right technology that fulfills its requirements. However,
every big data application has variable data characteristics and thus, the
corresponding data fits into a different data model. This paper presents
feature and use case analysis and comparison of the four main data models
namely document oriented, key value, graph and wide column. Moreover, a feature
analysis of 80 NoSQL solutions has been provided, elaborating on the criteria
and points that a developer must consider while making a possible choice.
Typically, big data storage needs to communicate with the execution engine and
other processing and visualization technologies to create a comprehensive
solution. This brings forth second facet of big data storage, big data file
formats, into picture. The second half of the research paper compares the
advantages, shortcomings and possible use cases of available big data file
formats for Hadoop, which is the foundation for most big data computing
technologies. Decentralized storage and blockchain are seen as the next
generation of big data storage and its challenges and future prospects have
also been discussed
Open semantic service networks
Online service marketplaces will soon be part of the economy to scale the provision of specialized multi-party services through automation and standardization. Current research, such as the *-USDL service description language family, is already deïŹning the basic building blocks to model the next generation of business services. Nonetheless, the developments being made do not target to interconnect services via service relationships. Without the concept of relationship, marketplaces will be seen as mere functional silos containing service descriptions. Yet, in real economies, all services are related and connected. Therefore, to address this gap we introduce the concept of open semantic service network (OSSN), concerned with the establishment of rich relationships between services. These networks will provide valuable knowledge on the global service economy, which can be exploited for many socio-economic and scientiïŹc purposes such as service network analysis, management, and control
Improving lifecycle query in integrated toolchains using linked data and MQTT-based data warehousing
The development of increasingly complex IoT systems requires large
engineering environments. These environments generally consist of tools from
different vendors and are not necessarily integrated well with each other. In
order to automate various analyses, queries across resources from multiple
tools have to be executed in parallel to the engineering activities. In this
paper, we identify the necessary requirements on such a query capability and
evaluate different architectures according to these requirements. We propose an
improved lifecycle query architecture, which builds upon the existing Tracked
Resource Set (TRS) protocol, and complements it with the MQTT messaging
protocol in order to allow the data in the warehouse to be kept updated in
real-time. As part of the case study focusing on the development of an IoT
automated warehouse, this architecture was implemented for a toolchain
integrated using RESTful microservices and linked data.Comment: 12 pages, worksho
Hypermedia-based discovery for source selection using low-cost linked data interfaces
Evaluating federated Linked Data queries requires consulting multiple sources on the Web. Before a client can execute queries, it must discover data sources, and determine which ones are relevant. Federated query execution research focuses on the actual execution, while data source discovery is often marginally discussed-even though it has a strong impact on selecting sources that contribute to the query results. Therefore, the authors introduce a discovery approach for Linked Data interfaces based on hypermedia links and controls, and apply it to federated query execution with Triple Pattern Fragments. In addition, the authors identify quantitative metrics to evaluate this discovery approach. This article describes generic evaluation measures and results for their concrete approach. With low-cost data summaries as seed, interfaces to eight large real-world datasets can discover each other within 7 minutes. Hypermedia-based client-side querying shows a promising gain of up to 50% in execution time, but demands algorithms that visit a higher number of interfaces to improve result completeness
Towards OpenMath Content Dictionaries as Linked Data
"The term 'Linked Data' refers to a set of best practices for publishing and
connecting structured data on the web". Linked Data make the Semantic Web work
practically, which means that information can be retrieved without complicated
lookup mechanisms, that a lightweight semantics enables scalable reasoning, and
that the decentral nature of the Web is respected. OpenMath Content
Dictionaries (CDs) have the same characteristics - in principle, but not yet in
practice. The Linking Open Data movement has made a considerable practical
impact: Governments, broadcasting stations, scientific publishers, and many
more actors are already contributing to the "Web of Data". Queries can be
answered in a distributed way, and services aggregating data from different
sources are replacing hard-coded mashups. However, these services are currently
entirely lacking mathematical functionality. I will discuss real-world
scenarios, where today's RDF-based Linked Data do not quite get their job done,
but where an integration of OpenMath would help - were it not for certain
conceptual and practical restrictions. I will point out conceptual shortcomings
in the OpenMath 2 specification and common bad practices in publishing CDs and
then propose concrete steps to overcome them and to contribute OpenMath CDs to
the Web of Data.Comment: Presented at the OpenMath Workshop 2010, http://cicm2010.cnam.fr/om
Features for Killer Apps from a Semantic Web Perspective
There are certain features that that distinguish killer apps from other ordinary applications. This chapter examines those features in the context of the semantic web, in the hope that a better understanding of the characteristics of killer apps might encourage their consideration when developing semantic web applications. Killer apps are highly tranformative technologies that create new e-commerce venues and widespread patterns of behaviour. Information technology, generally, and the Web, in particular, have benefited from killer apps to create new networks of users and increase its value. The semantic web community on the other hand is still awaiting a killer app that proves the superiority of its technologies. The authors hope that this chapter will help to highlight some of the common ingredients of killer apps in e-commerce, and discuss how such applications might emerge in the semantic web
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