Unifying Distributed Processing and Open Hypertext through a Heterogeneous Communication Model

A successful distributed open hypermedia system can be characterised by a scaleable architecture which is inherently distributed. While the architects of distributed hypermedia systems have addressed the issues of providing and retrieving distributed resources, they have often neglected to design systems with the inherent capability to exploit the distributed processing of this information. The research presented in this paper describes the construction and use of an open hypermedia system concerned equally with both of these facets

Quality of experience aware adaptive hypermedia system

The research reported in this thesis proposes, designs and tests a novel Quality of Experience Layer (QoE-layer) for the classic Adaptive Hypermedia Systems (AHS) architecture. Its goal is to improve the end-user perceived Quality of Service in different operational environments suitable for residential users. While the AHS’ main role of delivering personalised content is not altered, its functionality and performance is improved and thus the user satisfaction with the service provided. The QoE Layer takes into account multiple factors that affect Quality of Experience (QoE), such as Web components and network connection. It uses a novel Perceived Performance Model that takes into consideration a variety of performance metrics, in order to learn about the Web user operational environment characteristics, about changes in network connection and the consequences of these changes on the user’s quality of experience. This model also considers the user’s subjective opinion about his/her QoE, increasing its effectiveness and suggests strategies for tailoring Web content in order to improve QoE. The user related information is modelled using a stereotype-based technique that makes use of probability and distribution theory. The QoE-Layer has been assessed through both simulations and qualitative evaluation in the educational area (mainly distance learning), when users interact with the system in a low bit rate operational environment. The simulations have assessed “learning” and “adaptability” behaviour of the proposed layer in different and variable home connections when a learning task is performed. The correctness of Perceived Performance Model (PPM) suggestions, access time of the learning process and quantity of transmitted data were analysed. The results show that the QoE layer significantly improves the performance in terms of the access time of the learning process with a reduction in the quantity of data sent by using image compression and/or elimination. A visual quality assessment confirmed that this image quality reduction does not significantly affect the viewers’ perceived quality that was close to “good” perceptual level. For qualitative evaluation the QoE layer has been deployed on the open-source AHA! system. The goal of this evaluation was to compare the learning outcome, system usability and user satisfaction when AHA! and QoE-ware AHA systems were used. The assessment was performed in terms of learner achievement, learning performance and usability assessment. The results indicate that QoE-aware AHA system did not affect the learning outcome (the students have similar-learning achievements) but the learning performance was improved in terms of study time. Most significantly, QoE-aware AHA provides an important improvement in system usability as indicated by users’ opinion about their satisfaction related to QoE

Exposing Rich Update Operations via REST APIs

Paari viimase aastaga on Representational State Transfer (REST) muutunud Application Programming Interface’i (API) disaini liidriks tänu lihtsusele ja mitmekülgsusele. See on hõlbustanud API’sid URL’ide juures, mis kasutavad selliseid HTTP meetodeid nagu GET, POST, PUT ja DELETE. See on viinud lihtsustatud mudelite toomiseni klientide tarkvara arendajatele. Siiski on kaks probleemi, mida REST ainuüksi ei lahenda. Esimene neist on standardiseeritud vastused. Enamikel ettevõtetest on oma API’d, tavaliselt JSON tüüpi vastusega, mis ühtib nende andmemudeliga. Hea näide on see, kui Twitter’i API klient ei ole võimeline otseselt ühendust võtma Reddit API’ga ja vastupidi. Seetõttu teevad paljud API kliendid peaaegu sama asja. Sellest tulenevalt leiame me olukorra, kus arvukad arendajad kordavad sedasama saavutust. Järgmine probleem on API’de sidumine. World Wide Web’i Consortsium’i (W3C) kohaselt JSON ei sisalda sisseehitatud toetust hüperlinkidele, mis moodustavad põhilise Web’i ehitusbloki. Nende kahe puudused tähendavad seda, et API lõpp-punktid on seotud API dokumentatsiooniga, seega on kasutajad sunnitud hoolikalt läbi lugema mitmeid lehekülgi API dokumentatsioone, et mõista API lõpp-punktide vahelist suhet ning saada aru, mis tegevused on vajalikud juurdepääsuks antud vahendile. Kokkuvõttes me näeme, et kaasaegsetel rakendustel, arendatud API’d, on uuenduste käsklused ühendatud meetoditega, mis manipuleerivad otseselt domeeniga. Selles uuringus arutleme uuendusi otsivate käskluste probleemi üle ja püüame leida võimalusi, et täiustada seda rikkalike uuendusmeetodite ja erinevaid lähenemisi kasutavate, uuendusi otsivate, käskluste kaudu. Esimese panusena selles uurimustöös, tuleb võtta hüpermeedia formaat Collection +JSON ja parendada seda nii, et see mahutaks rohkem uuenduste käsklusi läbi üheainsa REST uuenduse meetodi dünaamiliselt nii API’s kui kliendi tarkvaras. Lihtsalt öeldes me kooskõlastame REST’i lihtsuse Domain Driven Development and Command Query Responsibility Segregation’i (CQRS) rikkalike kontseptidega. Me loome märkustel põhineva ressursi pakkija, mis genereerib käsud dünaamiliselt kasutades jagatud kontrollijat ja liidest, mis vähendab koodi, mida vajatakse laadimisel valdkonna teenuse meetodina API’sse.In the past few years Representational State Transfer (REST) has emerged a leader of modern Application Programming Interface (API) design for its simplicity and versatility. This has facilitated APIs with URLs that make use of HTTP methods like GET, POST, PUT and DELETE. It has also led to producing intuitive models for client developers. However, there are two issues that REST doesn’t solve alone, the first issue being standardized responses. Most enterprises have their own custom APIs, usually a JSON response that maps clearly to their custom data model. A good example is when a Twitter API client is not able directly communicate with a Reddit API and vice versa. This leads to numerous API clients that do almost, but not quite the same thing. Hence we find numerous developers duplicating the same efforts. The second issue is linking. As put by the World Wide Web Consortium (W3C): JSON doesn’t include built-in support for hyperlinks, which fundamentally constitutes as a building block on the Web. Hence the drawbacks of the two is that the API endpoints are only linked by API documentation, thus users are forced to peruse through pages of API documentation to comprehend the relationships between the API endpoints and understand what actions are required to interact with a given resource. In summary, we find that in modern day applications, the APIs developed have their update operations mapped to methods that directly manipulate the domain. In this research we discuss the underlying problem with update queries and unearth ways to enhance them for richer update methods and queries using various approaches. The first contribution in this research is to take a hypermedia format namely Collection +JSON, and to enhance it to accommodate and expose multiple update commands and templates through a single REST update method dynamically, both in the API and the client. In simple words, we reconcile the simplicity of REST, with the ample concepts of Domain Driven Development and Command Query Responsibility Segregation (CQRS). We also implement an annotation based resource assembler that generates commands dynamically by using a generic controller and interface that reduces the implementation needed to inject domain service methods into the API

Conception and prototypical implementation of a CTI application exemplified on Zarafa Groupware and SIPFoundry's SipXecs

This project is about Computer Telephony Integration (CTI). The main objective of this project is to integrate a groupware into Voice-IP PBX system and make a “click to dial plugin” for the Zarafa Collaboration Platform (ZCP) which is on open source collaborative software. We have one mail client (Zarafa Webaccess) and we have to be able to call our contacts with one click. I will use one SipXecs server, which is an open source voice over IP telephony server, it works like PBX and it is responsible for IP phones ringing. Every user has one IP-phone and all this has to run for a local network and is useful for connecting multiple users on a local network for free, such as several offices within a business.Este proyecto consiste en la integración de la telefonía en los ordenadores, conocido con las siglas CTI. El objetivo principal es integrar un groupware con un sistema PBX Voice-IP y desarrollar una aplicación “click to dial” para Zarafa Collaboration Platform (ZCP), que es un software colaborativo de código abierto. Tendré un cliente de correo (Zarafa Webaccess) y que crearé un plugin para hacer posible las llamadas entre contactos con un sólo click. Usaré un servidor SipXecs, que es un servidor de telefonía IP de código abierto, el cual funciona como centralita (PBX) y es el responsable de gestionar las llamadas entre los usuarios. Cada usuario contará con un telefono IP y todo esto se probará en una red local. De esta manera podré conectar múltiples usuarios en una red de manera gratuita, como por ejemplo conectar varias oficinas con centralitas y telefonos IP dentro de una misma compañía.Ingeniería Técnica en Sistemas de Comunicació