7 research outputs found

    Semantic metadata for supporting exploratory OLAP

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    Cotutela Universitat Politècnica de Catalunya i Aalborg UniversitetOn-Line Analytical Processing (OLAP) is an approach widely used for data analysis. OLAP is based on the multidimensional (MD) data model where factual data are related to their analytical perspectives called dimensions and together they form an n-dimensional data space referred to as data cube. MD data are typically stored in a data warehouse, which integrates data from in-house data sources, and then analyzed by means of OLAP operations, e.g., sales data can be (dis)aggregated along the location dimension. As OLAP proved to be quite intuitive, it became broadly accepted by non-technical and business users. However, as users still encountered difficulties in their analysis, different approaches focused on providing user assistance. These approaches collect situational metadata about users and their actions and provide suggestions and recommendations that can help users' analysis. However, although extensively exploited and evidently needed, little attention is paid to metadata in this context. Furthermore, new emerging tendencies call for expanding the use of OLAP to consider external data sources and heterogeneous settings. This leads to the Exploratory OLAP approach that especially argues for the use of Semantic Web (SW) technologies to facilitate the description and integration of external sources. With data becoming publicly available on the (Semantic) Web, the number and diversity of non-technical users are also significantly increasing. Thus, the metadata to support their analysis become even more relevant. This PhD thesis focuses on metadata for supporting Exploratory OLAP. The study explores the kinds of metadata artifacts used for the user assistance purposes and how they are exploited to provide assistance. Based on these findings, the study then aims at providing theoretical and practical means such as models, algorithms, and tools to address the gaps and challenges identified. First, based on a survey of existing user assistance approaches related to OLAP, the thesis proposes the analytical metadata (AM) framework. The framework includes the definition of the assistance process, the AM artifacts that are classified in a taxonomy, and the artifacts organization and related types of processing to support the user assistance. Second, the thesis proposes a semantic metamodel for AM. Hence, Resource Description Framework (RDF) is used to represent the AM artifacts in a flexible and re-usable manner, while the metamodeling abstraction level is used to overcome the heterogeneity of (meta)data models in the Exploratory OLAP context. Third, focusing on the schema as a fundamental metadata artifact for enabling OLAP, the thesis addresses some important challenges on constructing an MD schema on the SW using RDF. It provides the algorithms, method, and tool to construct an MD schema over statistical linked open data sets. Especially, the focus is on enabling that even non-technical users can perform this task. Lastly, the thesis deals with queries as the second most relevant artifact for user assistance. In the spirit of Exploratory OLAP, the thesis proposes an RDF-based model for OLAP queries created by instantiating the previously proposed metamodel. This model supports the sharing and reuse of queries across the SW and facilitates the metadata preparation for the assistance exploitation purposes. Finally, the results of this thesis provide metadata foundations for supporting Exploratory OLAP and advocate for greater attention to the modeling and use of semantics related to metadata.El processament analític en línia (OLAP) és una tècnica àmpliament utilitzada per a l'anàlisi de dades. OLAP es basa en el model multi-dimensional (MD) de dades, on dades factuals es relacionen amb les seves perspectives analítiques, anomenades dimensions, i conjuntament formen un espai de dades n-dimensional anomenat cub de dades. Les dades MD s'emmagatzemen típicament en un data warehouse (magatzem de dades), el qual integra dades de fonts internes, les quals posteriorment s'analitzen mitjançant operacions OLAP, per exemple, dades de vendes poden ser (des)agregades a partir de la dimensió ubicació. Un cop OLAP va ser provat com a intuïtiu, va ser ampliament acceptat tant per usuaris no tècnics com de negoci. Tanmateix, donat que els usuaris encara trobaven dificultats per a realitzar el seu anàlisi, diferents tècniques s'han enfocat en la seva assistència. Aquestes tècniques recullen metadades situacionals sobre els usuaris i les seves accions, i proporcionen suggerències i recomanacions per tal d'ajudar en aquest anàlisi. Tot i ésser extensivament emprades i necessàries, poca atenció s'ha prestat a les metadades en aquest context. A més a més, les noves tendències demanden l'expansió d'ús d'OLAP per tal de considerar fonts de dades externes en escenaris heterogenis. Això ens porta a la tècnica d'OLAP exploratori, la qual es basa en l'ús de tecnologies en la web semàntica (SW) per tal de facilitar la descripció i integració d'aquestes fonts externes. Amb les dades essent públicament disponibles a la web (semàntica), el nombre i diversitat d'usuaris no tècnics també incrementa signifícativament. Així doncs, les metadades per suportar el seu anàlisi esdevenen més rellevants. Aquesta tesi doctoral s'enfoca en l'ús de metadades per suportar OLAP exploratori. L'estudi explora els tipus d'artefactes de metadades utilitzats per l'assistència a l'usuari, i com aquests són explotats per proporcionar assistència. Basat en aquestes troballes, l'estudi preté proporcionar mitjans teòrics i pràctics, com models, algorismes i eines, per abordar els reptes identificats. Primerament, basant-se en un estudi de tècniques per assistència a l'usuari en OLAP, la tesi proposa el marc de treball de metadades analítiques (AM). Aquest marc inclou la definició del procés d'assistència, on els artefactes d'AM són classificats en una taxonomia, i l'organització dels artefactes i tipus relacionats de processament pel suport d'assistència a l'usuari. En segon lloc, la tesi proposa un meta-model semàntic per AM. Així doncs, s'utilitza el Resource Description Framework (RDF) per representar els artefactes d'AM d'una forma flexible i reusable, mentre que el nivell d'abstracció de metamodel s'utilitza per superar l'heterogeneïtat dels models de (meta)dades en un context d'OLAP exploratori. En tercer lloc, centrant-se en l'esquema com a artefacte fonamental de metadades per a OLAP, la tesi adreça reptes importants en la construcció d'un esquema MD en la SW usant RDF. Proporciona els algorismes, mètodes i eines per construir un esquema MD sobre conjunts de dades estadístics oberts i relacionats. Especialment, el focus rau en permetre que usuaris no tècnics puguin realitzar aquesta tasca. Finalment, la tesi tracta amb consultes com el segon artefacte més rellevant per l'assistència a usuari. En l'esperit d'OLAP exploratori, la tesi proposa un model basat en RDF per consultes OLAP instanciant el meta-model prèviament proposat. Aquest model suporta el compartiment i reutilització de consultes sobre la SW i facilita la preparació de metadades per l'explotació de l'assistència. Finalment, els resultats d'aquesta tesi proporcionen els fonaments en metadades per suportar l'OLAP exploratori i propugnen la major atenció al model i ús de semàntica relacionada a metadades.On-Line Analytical Processing (OLAP) er en bredt anvendt tilgang til dataanalyse. OLAP er baseret på den multidimensionelle (MD) datamodel, hvor faktuelle data relateres til analytiske synsvinkler, såkaldte dimensioner. Tilsammen danner de et n-dimensionelt rum af data kaldet en data cube. Multidimensionelle data er typisk lagret i et data warehouse, der integrerer data fra forskellige interne datakilder, og kan analyseres ved hjælp af OLAPoperationer. For eksempel kan salgsdata disaggregeres langs sted-dimensionen. OLAP har vist sig at være intuitiv at forstå og er blevet taget i brug af ikketekniske og orretningsorienterede brugere. Nye tilgange er siden blevet udviklet i forsøget på at afhjælpe de problemer, som denne slags brugere dog stadig står over for. Disse tilgange indsamler metadata om brugerne og deres handlinger og kommer efterfølgende med forslag og anbefalinger, der kan bidrage til brugernes analyse. På trods af at der er en klar nytteværdi i metadata (givet deres udbredelse), har stadig ikke været meget opmærksomhed på metadata i denne kotekst. Desuden lægger nye fremspirende teknikker nu op til en udvidelse af brugen af OLAP til også at bruge eksterne og uensartede datakilder. Dette har ført til Exploratory OLAP, en tilgang til OLAP, der benytter teknologier fra Semantic Web til at understøtte beskrivelse og integration af eksterne kilder. Efterhånden som mere data gøres offentligt tilgængeligt via Semantic Web, kommer flere og mere forskelligartede ikketekniske brugere også til. Derfor er metadata til understøttelsen af deres dataanalyser endnu mere relevant. Denne ph.d.-afhandling omhandler metadata, der understøtter Exploratory OLAP. Der foretages en undersøgelse af de former for metadata, der benyttes til at hjælpe brugere, og af, hvordan sådanne metadata kan udnyttes. Med grundlag i disse fund søges der løsninger til de identificerede problemer igennem teoretiske såvel som praktiske midler. Det vil sige modeller, algoritmer og værktøjer. På baggrund af en afdækning af eksisterende tilgange til brugerassistance i forbindelse med OLAP præsenteres først rammeværket Analytical Metadata (AM). Det inkluderer definition af assistanceprocessen, en taksonomi over tilhørende artefakter og endelig relaterede processeringsformer til brugerunderstøttelsen. Dernæst præsenteres en semantisk metamodel for AM. Der benyttes Resource Description Framework (RDF) til at repræsentere AM-artefakterne på en genbrugelig og fleksibel facon, mens metamodellens abstraktionsniveau har til formål at nedbringe uensartetheden af (meta)data i Exploratory OLAPs kontekst. Så fokuseres der på skemaet som en fundamental metadata-artefakt i OLAP, og afhandlingen tager fat i vigtige udfordringer i forbindelse med konstruktionen af multidimensionelle skemaer i Semantic Web ved brug af RDF. Der præsenteres algoritmer, metoder og redskaber til at konstruere disse skemaer sammenkoblede åbne statistiske datasæt. Der lægges særlig vægt på, at denne proces skal kunne udføres af ikke-tekniske brugere. Til slut tager afhandlingen fat i forespørgsler som anden vigtig artefakt inden for bruger-assistance. I samme ånd som Exploratory OLAP foreslås en RDF-baseret model for OLAP-forespørgsler, hvor førnævnte metamodel benyttes. Modellen understøtter deling og genbrug af forespørgsler over Semantic Web og fordrer klargørelsen af metadata med øje for assistance-relaterede formål. Endelig leder resultaterne af afhandlingen til fundamenterne for metadata i støttet Exploratory OLAP og opfordrer til en øget opmærksomhed på modelleringen og brugen af semantik i forhold til metadataPostprint (published version

    DEVELOPING A JUSTICE-CENTRED STRATEGIC RESPONSE TO LOCAL TRANSITION DYNAMICS IN ELECTRICITY GENERATION: AN ACTION RESEARCH INQUIRY

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    Background Local policy, stakeholder pressures and the dynamics of the local transition landscape in Jamaica’s electricity generation market have favoured new gas and renewables investments, predicting the complete decline of Heavy Fuel Oil (HFO) used by the incumbent JEP group in the next decade. JEP’s central contention is its unfair exclusion from participating in the sector’s sustainability transformation and the significant transition risk. However, this transition is also impacted by market design, the sector’s structural and ideological underpinnings, path dependency and inertia. Energy poverty and other injustices contribute to stakeholder distrust. Research Objectives The JEP group must formulate an appropriate strategic response to these dynamics, and the Energy Justice paradigm is explored as an entrepreneurial logic for business model innovation to maintain JEP’s relevance to the sector. The strategic value of this improvisational approach is examined in the following research question: How can JEP’s adoption of a Justice-centered strategic response improve its outlook in future scenarios of the sector? Research Approach The inquiry deploys action learning to understand the strategic implications of this improvisational approach to resolving JEP’s exclusion from the market. JEP’s senior and middle managers engage in collaborative strategy-making workshops over two iterations of the action learning cycle. Participants focus on sustainability transitions and Energy Justice, multi-level, socio-technical analysis for problem framing, operationalising Energy Justice, and a strategic intervention based on value mapping and group model building to assess how this operationalisation can guide business model innovation. Actionable Knowledge An Energy Justice worldview can catalyse strategic learning and innovative strategy-making within an action research setting, providing a values-based entrepreneurial logic, managerial paradigm, and socio-technical strategic framework as a scaffold for reconfiguring an incumbent’s business model architecture and dynamic capabilities towards sustainability. This scaffolding demonstrates that local electricity’s sustainability transition and governance can be anchored in a shared, comprehensive, and inclusive framework for engaging private actors. Theoretical and Practical Implications Private actors and policymakers pursuing the development of a sustainability-driven electricity market in the Caribbean should promote Energy Justice as strategically important to mitigating the impact of the sector's underlying socio-technical challenges and its evolutionary fitness. KEYWORDS: Action learning, energy justice, sustainability transition, business model, group model buildin

    A social media analytics framework for decision-making in citizen relationship management

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    Globally social media has shown unprecedented levels of adoption and Social Media Analytics (SMA) is a rapidly growing topic. For governments, SMA holds the promise of providing tools and frameworks to collect, monitor, analyse and visualise social media data, usually driven by specific requirements from a target application. However, social media data is noisy and unstructured, and organisations struggle to extract knowledge from this data, and convert it into actual intelligence. This study argues that SMA can support intelligent decision-making for Citizen Relationship Management (CzRM). CzRM is a growing effort of governments around the world to strive to respond rapidly to their citizens by fostering a closer relationship thereby creating more effective and efficient service delivery. However, there is a little evidence in literature on empirical studies of any existing decision-making framework for CzRM and SMA adoption. In particular, there is a gap with regards incorporating SMA into decision-making for CzRM of governments, particularly in developing countries like South Africa. The aim of this study was to develop a framework that provides guidelines, including methods and tools, incorporating SMA into decision-making for CzRM in the Gauteng Provincial Government (GPG) and the Free State Provincial Government (FSPG) of South Africa. A Systematic Literature Review (SLR) and conceptual analysis method was conducted to design the Social Media Analytics Framework for Decision-making in the context of CzRM (the SMAF). The findings from the literature review revealed several benefits and challenges with SMA, in particular the shortage of skills, guidelines, methods and tools for SMA. These challenges were used to draft guidelines that were included in the framework, which consists of five components that can be used to derive intelligent information from SMA. The pragmatic philosophy and a case study design was used to generate an in-depth, multifaceted understanding of the underlying problems in the case of the GPG and the FSPG. The German North-West Metropolitan region was used as a third case study to provide a more global perspective and a case of a developed country in terms of Gross Domestic Product. The scope of the study was limited to social media posts by provincial citizens related to CzRM and service delivery. Both formative and summative evaluations of the proposed theoretical framework were conducted. The formative evaluation was conducted v | Page as an Expert Review to receive feedback of the framework from the experts in the field of Computer Science and Information Systems. The findings validated the framework and some minor improvements were made based on the experts’ recommendations. Focus Group Discussions (FGDs) with participants from government managers and decision makers in the three cases were conducted. Case documents for the three cases were collected and reviewed. All collected data was analysed using the Qualitative Content Analysis (QCA) method and common categories and themes were identified. Summative evaluations were conducted in the form of a Field Study, which consisted of an analysis of Twitter data from the three cases, and a closing FGD with Business Intelligence (BI) experts at the primary case of the e-Government department of the GPG. The findings revealed that SMA has been adopted in all three cases; however, while their strategies are comprehensive their implementations are very much in their early stages. The findings also highlighted the status of SMA in government and some potential gaps and areas for implementing the framework.Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 202

    Vereinigung von detaillierten Teilmodellen in einer flexiblen Enterprise Architecture zur übergreifenden Analyse: Ableitung des Bedarfs an Handlungen für einen durch Kennzahlen beschriebenen Untersuchungskontext

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    Modelle haben sich zu Dokumentationszwecken bewährt, existieren in der Praxis aber oftmals losgelöst voneinander. Durch die wachsende Komplexität in den Unternehmen reicht jedoch eine getrennte Betrachtung nicht mehr aus. Das Zusammenspiel der Unternehmensbestandteile muss bei Entscheidungen berücksichtigt werden. Eine Enterprise Architecture (EA) eignet sich zur Herstellung einer übergreifenden Sichtweise. Wobei hauptsächlich aggregierte Inhalte enthalten sind, die manuell erstellt werden. Damit ist die EA ein weiteres Datensilo. Durch das Fehlen detaillierter Informationen in der EA sind außerdem die Möglichkeiten einer ganzheitlichen Analyse begrenzt. Die vorliegende Arbeit entwickelt daher ein Gesamtkonzept, um Detailinhalte zu vernetzen und übergreifende Analysen zu ermöglichen. Insbesondere werden auch Datenwerte (z.B. Kosten) einbezogen. Eine Indirektstufe kann die Teilmodelle lose verknüpfen. Zugleich dient ein einfaches EA-Vokabular als neutrale Begriffsschicht. Mithilfe der Technologien des Semantic Web entsteht so eine integrierte Datenbasis. Sie positioniert sich als Ebene oberhalb der Datenquellen. Anschließend kann eine übergreifende Analyse erfolgen, in der alle Inhalte kombiniert werden. Zur Konkretisierung des Ansatzes fokussiert sich die Arbeit auf die Ableitung des Bedarfs an Handlungen. Mit der Importance-Performance-Analyse wird ein Verfahren aus dem Qualitätsmanagement von Dienstleistungen entliehen und auf die EA-Analyse übertragen. Die Berechnung basiert auf flexibel zu beschreibenden Kennzahlen, bei deren Definition das EA-Vokabular verwendet wird. Als Ergebnis werden Gesamtratings für alle Untersuchungsobjekte ausgewiesen. Sie sagen etwas über einen Handlungsbedarf und die Dringlichkeit aus. Auch die Analyse basiert auf Technologien des Semantic Web. Als Nachweis der Realisierbarkeit wurde der Ansatz in einem Prototyp umgesetzt. Außerdem wird ein praxisnaher Anwendungsfall einer Digitalisierungsinitiative bei einer Versicherung skizziert
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