1,416 research outputs found
SWI-Prolog and the Web
Where Prolog is commonly seen as a component in a Web application that is
either embedded or communicates using a proprietary protocol, we propose an
architecture where Prolog communicates to other components in a Web application
using the standard HTTP protocol. By avoiding embedding in external Web servers
development and deployment become much easier. To support this architecture, in
addition to the transfer protocol, we must also support parsing, representing
and generating the key Web document types such as HTML, XML and RDF.
This paper motivates the design decisions in the libraries and extensions to
Prolog for handling Web documents and protocols. The design has been guided by
the requirement to handle large documents efficiently. The described libraries
support a wide range of Web applications ranging from HTML and XML documents to
Semantic Web RDF processing.
To appear in Theory and Practice of Logic Programming (TPLP)Comment: 31 pages, 24 figures and 2 tables. To appear in Theory and Practice
of Logic Programming (TPLP
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
Evaluating Cache Coherent Shared Virtual Memory for Heterogeneous Multicore Chips
The trend in industry is towards heterogeneous multicore processors (HMCs),
including chips with CPUs and massively-threaded throughput-oriented processors
(MTTOPs) such as GPUs. Although current homogeneous chips tightly couple the
cores with cache-coherent shared virtual memory (CCSVM), this is not the
communication paradigm used by any current HMC. In this paper, we present a
CCSVM design for a CPU/MTTOP chip, as well as an extension of the pthreads
programming model, called xthreads, for programming this HMC. Our goal is to
evaluate the potential performance benefits of tightly coupling heterogeneous
cores with CCSVM
Performance and Interoperability In Solar
Ubiquitous computing promises to integrate computers into our physical environment, surrounding us with applications that are able to adapt to our dynamics. Solar is a software infrastructure designed to deliver contextual information to these applications. To serve the large number and wide variety of context-aware devices envisioned by ubiquitous computing, Solar must exhibit both high performance and the ability to interoperate with many computing platforms. We created a testing framework to measure the performance of distributed systems such as Solar, as well as a pluggable data-transfer mechanism to support the dissemination of information to heterogeneous applications. This paper explores the testing framework developed, analyzes its findings concerning the performance of the current Solar prototype, presents several optimizations to Solar and their effects, and finally discusses the design of the pluggable data-transfer mechanism
Microservices applied to Web and mobile applications internship
Microservices is a software architecture that has seen an increase in popularity and use in recent years.
Due to its simplicity and ease of implementation it is nowadays the standard reference for web services.
This report focuses on the general concepts of microservices and their real-world application.
The report was divided into three main points: (a) general concepts of microservices, (b) facial and
emotion recognition applied to an adaptive user interface using microservices and (c) restructure an
existing web application following a microservices architecture.
The first point, (a) general concepts of microservices, introduces the definition of a microservice and
what are the main traits that a microservice should have. The second point, (b) describes the
implementation of a mobile application with an adaptive user interface that uses microservices for facial
and emotional recognition. In this point it is possible to understand how to consume microservices
developed by third parties. The third point, (c) describes the restructuring of an existing web application,
through a microservices architecture, exemplifying the concepts mentioned in point (a) and small excerpts
of code from an open-source project to demonstrate its real-world code usage.Micro serviços é uma arquitetura de software que cresceu em popularidade e utilização nos anos mais
recentes. Devido à sua simplicidade e facilidade de implementação é hoje em dia o padrão referência para
serviços web. Este relatório foca os conceitos gerais de micro serviços e a sua aplicação num âmbito
profissional.
O relatório foi dividido em 3 pontos principais: (a) conceitos gerais de micro serviços, (b)
reconhecimento facial e de emoções aplicado a uma interface adaptativa de utilizador utilizando micro
serviços e (c) reestruturar uma aplicação web existente seguindo uma arquitetura de micro serviços.
O primeiro ponto, o (a) conceitos gerais de micro serviços, introduz a definição de um micro serviço e
quais as principais características que um micro serviço deve obedecer. No segundo ponto, (b) descreve-se
a implementação de uma aplicação mobile com uma interface adaptativa de utilizador recorrendo a micro
serviços para reconhecimento facial e de emoções. Neste ponto é possível compreender como consumir
micro serviços desenvolvidos por terceiros. No terceiro ponto, (c) descreve-se a reestruturação de uma
aplicação web existente, através de uma arquitetura de micro serviços, exemplificando os conceitos
mencionados no ponto (a) e pequenos excertos de código de um projecto open-source para demonstrar a
sua utilização
A Service-Oriented Approach for Network-Centric Data Integration and Its Application to Maritime Surveillance
Maritime-surveillance operators still demand for an integrated maritime picture better supporting international coordination for their operations, as looked for in the European area. In this area, many data-integration efforts have been interpreted in the past as the problem of designing, building and maintaining huge centralized repositories. Current research activities are instead leveraging service-oriented principles to achieve more flexible and network-centric solutions to systems and data integration. In this direction, this article reports on the design of a SOA platform, the Service and Application Integration (SAI) system, targeting novel approaches for legacy data and systems integration in the maritime surveillance domain. We have developed a proof-of-concept of the main system capabilities to assess feasibility of our approach and to evaluate how the SAI middleware architecture can fit application requirements for dynamic data search, aggregation and delivery in the distributed maritime domain
Enabling system artefact exchange and selection through a linked data layer
The use of different techniques and tools is a common practice to cover all stages in the systems development lifecycle, generating a very good number of system artefacts. Moreover, these artefacts are commonly encoded in different formats and can only be accessed, in most cases, through proprietary and non-standard protocols. This scenario can be considered a real nightmare for software or systems reuse. Possible solutions imply the creation of a real collaborative development environment where tools can exchange and share data, information and knowledge. In this context, the OSLC (Open Services for Lifecycle Collaboration) initiative pursues the creation of public specifications (data shapes) to exchange any artefact generated during the development lifecycle, by applying the principles of the Linked Data initiative. In this paper, the authors present a solution to provide a real multi-format system artefact reuse by means of an OSLC-based specification to share and exchange any artefact under the principles of the Linked Data initiative. Finally, two experiments are conducted to demonstrate the advantages of enabling an input/output interface based on an OSLC implementation on top of an existing commercial tool (the Knowledge Manager). Thus, it is possible to enhance the representation and retrieval capabilities of system artefacts by considering the whole underlying knowledge graph generated by the different system artefacts and their relationships. After performing 45 different queries over logical and physical models stored in Papyrus, IBM Rhapsody and Simulink, results of precision and recall are promising showing average values between 70-80%.The research leading to these results has received funding from the AMASS project (H2020-ECSEL grant agreement no 692474; Spain's MINECO ref. PCIN-2015-262) and the CRYSTAL project (ARTEMIS FP7-CRitical sYSTem engineering AcceLeration project no 332830-CRYSTAL and the Spanish Ministry of Industry)
Deploying SDN architecture in Open Optical Transport Networks
Pro udrženı́ tempa s rostoucı́mi požadavky na přenosovou rychlost, latenci a bezpečnost je nutné zvážit současnou koncepci řı́zenı́ sı́tı́. Software-Defined Networking (SDN) je jedno z možných řešenı́, ke kterému telekomunikačnı́ průmysl směruje. Tato práce představuje současný stav Software-Defined Networking a zaměřuje se na vybraná open-source řešenı́ v oblasti SDN kontrolerů, jako je ONOS či OpenDaylight. Hlavnı́m cı́lem této části práce je vysvětlit, jak může SDN pomoci vyřešit rostoucı́ požadavky na rozšı́řenı́ automatizace v otevřených optických sı́tı́ch. Praktická část této práce je rozdělená do dvou oblastı́. V rámci prvnı́ oblasti jsem se zabýval rozšı́řenı́m funkčnosti SDN kontroleru pro umožněnı́ konfigurace a řı́zenı́ optických komunikačnı́ch zařı́zenı́. Hlavnı́m přı́nosem je implementace nových funkcionalit SDN driveru pro Nokia 1830 PSS (ROADM) a rozšı́řenı́ funkcionality driveru pro Nokia 1830 PSI-2T (optický transpondér). Ve druhé části práce jsem se zabýval problematikou korelace alarmů v otevřených optických sı́tı́ch. Výsledkem je funkce pro korelaci alarmů ve formě SDN aplikace, kterou jsem dále otestoval na emulovaných optických zařı́zenı́ch pro prokázánı́ funkčnosti celého konceptu.With the rising demands on the network throughput, latency and security, legacy control networking concepts should be reconsidered. Software-Defined Networking (SDN) is one of the possible solutions, to which telecommunication industry is moving. This work presents current state-of-the-art in Software-Defined Networking and focuses on some open-source solutions of SDN controllers, like ONOS and OpenDaylight. Main focus is to understand how SDN can help to solve increasing demand for broader automation in Optical Transport Networks. The practical section is divided in two parts. Within the first part I focused on extending functionality of SDN controller to facilitate more efficient configuration and control of optical network devices. Main contribution was to implement additional features to SDN drivers for Nokia 1830 PSS (ROADM) and extend functionality of Nokia 1830 PSI-2T (Optical Transponder) driver. Second part is dedicated to the Alarm Correlation problematic in open optical networks. We designed, developed an Alarm Correlation function as a SDN application then we tested it on emulated optical devices to prove the concept
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