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  • 2901.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Ilayperuma, Tharaka
    Designing consumer-aligned services using business value modelling2012Ingår i: International Journal of Organisational Design and Engineering (IJODE), ISSN 1758-9797, Vol. 2, nr 3, 317-342 s.Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Given the dominance of service industries in today's economy, service improvement and innovation have become major concerns of many enterprises. To address these challenges, the service design should start at the business level at which services can be identified to provide values in an economically viable way by satisfying consumers' preferences for quality aspects. However, high-level business concepts, like value offerings, are hardly linked to technology levels, such as SOA and web services. Relying on the model driven development (MDD) and ontology paradigms, the paper proposes a method that uses business value models to elicit and structure business services from a consumer-centric quality perspective and transforming the business service model further to a web service model. To facilitate major MDD aspects, such as semantic-level descriptions and automated transformations, these models are designed as ontologies. A case study from the Swedish eye-care health sector is used to ground the presented method.

  • 2902.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Ilayperuma, Tharaka
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Exploring value business models for e-service design2010Ingår i: Model-driven domain analysis and software development: architectures and functions / [ed] Janis Osis and Erika Asnina, Hershey: IGI Global, 2010, nr 2009, 232-253 s.Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Contemporary enterprises face strong pressures to increase competitiveness by engaging in alliances of several kinds. In a rapidly increasing degree, traditional organizational structures evolve towards online business using modern ICT – such as the Internet, semantic standards, process- and service-oriented architectures. For efficient applications of inter-organizational information systems, the alignment between business and ICT is a key factor. At the ICT level, Web services are used as the cornerstones for modeling the interaction points of Web applications. So far, development of Web services has focused on a technical perspective, such as the development of standards for message exchanges and service coordination. Thereby, business concepts, such as economic values exchanged among the cooperating actors, cannot be traced in Web service specifications. As a consequence, business and ICT models become difficult to keep aligned. To address this issue, we propose a MDA-based approach for design of software services which may be implemented using Web services and Web service coordinations. The proposal focuses on a value-explorative analysis and modeling of business services at the CIM level, and model transformations using UML 2 to the PIM level, by utilizing well-defined mappings.

  • 2903.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Johannesson, Paul
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Cooperation of Processes through Message Level Agreement2004Ingår i: Proceedings of the 16th International Conference on Advanced Information Systems Engineering (CAiSE’04), 2004, Vol. 3084, nr 2004Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]
    E-Business is constantly growing as organizations are trying to inte-grate electronically in order to automate exchange of information, goods and services. To construct inter-organizational processes, the involved enterprise processes have to be able to integrate their services directly, or by use of busi-ness-to-business interaction standards. A problem is that existing processes are so diverse in protocols, activity and message forms that it is impossible to start collaboration without comprehensive adaptations. In this paper, we propose a framework for interoperation of processes, which is based on requirements for equivalence of document exchanges. We argue that this level of equivalence is sufficient to enable existing enterprise processes to collaborate without internal redesign. The proposed framework is aimed to facilitate process collaboration by using a mediator layer to perform necessary adaptations, while minimizing requirements for process similarity.
  • 2904.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Johannesson, Paul
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Henkel, Martin
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Service-Based Processes: Design for Business and Technology2004Ingår i: In: the ACM Proceedings of the Second International Conference on Service Oriented Computing (ICSOC 2004), 2004, nr 2004Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]
    Composition of software services is a fundamental part in supporting enterprise business processes. Designed properly, executable processes can be used to closely support business processes by the integration of existing software services. In order to support business processes the design of the executable process must closely follow the business events and activities, as perceived by business actors. However, the design must also consider technical issues such as limitations in existing technology and systems. In this paper we examine how technical system constraints influence the realization of business processes. Based on this examination we present a set of realization types that describes the transformation from a business process into its realization as an executable process. We also propose design criteria that need to be adhered to in order to cater to both business and technical needs.
  • 2905.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Johannesson, Paul
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Kabilan, Vandana
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Using Multi-Tier Contract Ontology to deduce Contract Workflow Model for Enterprise Interoperability2005Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]
    Ontologies are being proposed as a medium for affecting enterprise application integration. Though it is widely accepted that ontologies can support inter- enterprise interoperability, the exact nature and extent to which ontology may be useful is uncertain. We promote the use of ontology in a two-fold way: first, as a knowledge base for fostering human-to-human shared understanding; second, as ‘Interlingua’ for promoting human-to-machine as well as semantics-to-execution specification. The proposed concept is described using a case scenario in the realm of legal business contracts, followed by their integration to the business domain, with an objective to model contract compliant business process models. With the case, we illustrate the use of Multi-Tier Contract Ontology (MTCO) to deduce a high level, partial business process model named the Contract Workflow Model (CWM). Such a model, from the business process perspective, may be used as a skeleton for designing internal business processes for each individual contracting party, or for mapping to existing processes.
  • 2906.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Kabilan, Vandana
    Contract-based Exception Handling Process Patterns2008Ingår i: Proceedings of the 7th International Conference on Information Systems and its Applications (ISTA 2008), Springer , 2008, Vol. 5Konferensbidrag (Refereegranskat)
  • 2907.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap. Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap. Informationssystem. Tillämpad IT med entreprenörskap.
    Kabilan, Vandana
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap. Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap. Data- och Systemvetenskap. Informationssystem.
    Contract-based Exception Handling Process Patterns2008Ingår i: Proceedings of the 7th International Conference on Information Systems and its Applications (ISTA 2008), 2008, Vol. 5, 531-543 s.Konferensbidrag (Övrigt vetenskapligt)
  • 2908.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Kabilan, Vandana
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Enabling Business Process Interoperability Using Contract Workflow Models2005Ingår i: 13th International Conference on Cooperative Systems (CooPIS05), 2005, Vol. 3760Konferensbidrag (Refereegranskat)
  • 2909.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Kirikova, MariteJohannesson, PaulStockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Advanced Information Systems Engineering: 27th International Conference, CAiSE 2015, Stockholm, Sweden, June 8-12, 2015, Proceedings2015Samlingsverk (redaktörskap) (Refereegranskat)
    Abstract [en]

    This book constitutes the proceedings of the 27th International Conference on Advanced Information Systems Engineering, CAiSE 2015, held in Stockholm, Sweden, in June 2015.

    The 31 papers presented in this volume were carefully reviewed and selected from 236 submissions. They were organized in topical sections named: social and collaborative computing; business process modeling and languages; high volume and complex information management; requirements elicitation and management; enterprise data management; model conceptualisation and evolution; process mining, monitoring and predicting; intra- and inter-organizational process engineering; process compliance and alignment; enterprise IT integration and management; and service science and computing. The book also contains the abstracts of 3 keynote speeches and 5 tutorials, presented at the conference.

  • 2910.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Kirikova, Marite
    Johannesson, Paul
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Preface to CAISE 20152016Ingår i: Information Systems, ISSN 0306-4379, E-ISSN 1873-6076, Vol. 62Artikel i tidskrift (Övrigt vetenskapligt)
  • 2911.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Pastor, Oscar
    Loucopoulos, Pericles
    On the Capability Notion in Business Informatics: [Opening]2014Ingår i: [Proceedings of] The 1st International Workshop on Capability-oriented Business Informatics (CoBI 2014) / [ed] Jelena Zdravkovic, Peri Loucopoulos, Oscar Pastor, 2014, 1-2 s.Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The business environments of today are changing rapidly, entailing complex anddynamic organizational constellations. Enterprises operating in these conditions needto have the capability to deliver their services in a variety of business contexts withsustainable quality and moreover to leverage them to competitive advantage. Latelythe notion of capability has gained a growing attention, due to a number of factors:the notion directs business investment focus, it can be used as a baseline for businessplanning, and it leads directly to service specification and design.

  • 2912.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Rychkova, Irina
    Speckert, Thomas
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Requirements for IT Governance in Organizations Experiencing Decentralization2015Ingår i: Information Systems Engineering in Complex Environments: CAiSE Forum 2014, Thessaloniki, Greece, June 16-20, 2014, Selected Extended Papers / [ed] Selmin Nurkan, Elias Pimenidis, Springer, 2015, 269-285 s.Konferensbidrag (Refereegranskat)
    Abstract [en]

    Decentralization of organizations and subsequent change of their management and operation styles requires changes in organization’s processes and heavily involves the IT. A case study in the Higher Education sector in Sweden has shown that Enterprise Architecture (EA) frameworks fit to primarily centralized organizational structures, and as such have shortcomings when used in decentralized organizations. Overcoming these deficiencies requires some new principles to be introduced and incorporated into the EA knowledge. In particular for IT governance, the case study showed that the peer-to-peer principles, such as peer production, can offer more suitable governance over current EA frameworks as they are able to better match the decentralized components of the university’s organizational structure.

  • 2913.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Rychkova, Irina
    Sorbonne, , .
    speckert, thomas
    OMICRON electronics, , .
    Requirements for IT Governance in Organizations Experiencing Decentralization2014Ingår i: CAiSE 2014 Forum, Springer , 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    Decentralization of organizations and subsequent change of their management and operation styles requires changes in organization’s processes and heavily involves IT. Enterprise Architecture (EA) frameworks fit to primarily centralized organizational structures, and as such have shortcomings when used in decentralized organizations. We illustrate this idea on the example of one organization in Higher Education sector that faces decentralization of its structure and has to adapt to it. Overcoming these deficiencies requires some new principles to be introduced and incorporated into the EA knowledge. In particular for IT governance, in this study we present how peer-to-peer principles, such as peer production, can offer more suitable governance over current EA frameworks as they are able to better match the decentralized components an organizational structure.

  • 2914.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Stirna, Janis
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Grabis, Janis
    A Comparative Analysis of Using the Capability Notion for Congruent Business and Information Systems Engineering2017Ingår i: Complex Systems Informatics and Modeling Quarterly, ISSN 2255-9922, nr 10, 1-20 s.Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The notion of capability has been gaining a growing attention in the business and information system (IS) engineering community due to a number of reasons: it facilitates focus on business investments, it can be used as a baseline for business planning, and it directly leads to service specification and design. It is not however widely known to what extent capability is considered in different modeling approaches, how it is defined, and what purpose it fulfills. This article analyzes how the notion of capability is included in the frameworks spanning from business-oriented such as Business Architecture and Business Value Modeling, to the alignment-oriented represented by Enterprise Architecture (EA), and Enterprise Modeling (EM). The results of the analysis have shown that capability has widespread presence in the frameworks and that its conceptual meaning is largely similar, while the intentions and the mechanisms of its use differ, which raises stimulating opportunities for new contributions and improvements in the field.

  • 2915.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Stirna, Janis
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Henkel, Martin
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Grabis, Janis
    Modelling Business Capabilities and Context Dependent Delivery by Cloud Service2013Ingår i: Advanced Information Systems Engineering: Proceedings / [ed] Camille Salinesi, Moira C. Norrie, Óscar Pastor, Springer Berlin/Heidelberg, 2013, 369-383 s.Konferensbidrag (Refereegranskat)
    Abstract [en]

    Contemporary business environments are changing rapidly, organizations are global, and cloud-based services have become a norm. Enterprises operating in these conditions need to have the capability to deliver their business in a variety of business contexts. Capability delivery thus has to be monitored and adjusted. Current Enterprise Modeling approaches do not address context-dependent capability design and do not explicitly support runtime adjustments. To address this challenge, a capability-driven approach is proposed to model business capabilities by using EM techniques, and to use model-based patterns to describe how software applications can adhere to changes in the execution context. A meta-model for capability design and delivery is presented with the consideration to delivering solutions as cloud services. The proposal is illustrated with an example case from an energy efficiency project. A supporting architecture for the capability development and the delivery in the cloud is also presented.

  • 2916.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Stirna, Janis
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Kirikova, Marite
    Karagiannis, Dimitri
    Winter, Robert
    Advanced Enterprise Modeling: Editorial2015Ingår i: Business & Information Systems Engineering, ISSN 1867-0202, Vol. 57, nr 1, 1-2 s.Artikel i tidskrift (Övrigt vetenskapligt)
  • 2917.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Stirna, JanisStockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.Kirikova, MariteKaragiannis, DimitrisWinter, Robert
    Advanced Enterprise Modeling2015Samlingsverk (redaktörskap) (Refereegranskat)
  • 2918.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Stirna, Janis
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Kirikova, Marite
    Karagiannis, Dimitris
    Winter, Robert
    BISE – Call for Papers Issue 1/20152013Ingår i: Business & Information Systems Engineering, ISSN 1867-0202, Vol. 5, nr 5, 361-361 s.Artikel i tidskrift (Refereegranskat)
  • 2919.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Stirna, Janis
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Kuhr, Jan-Christian
    Koç, Hasan
    Requirements Engineering for Capability Driven Development2014Ingår i: The Practice of Enterprise Modeling: 7th IFIP WG 8.1 Working Conference, PoEM 2014, Manchester, UK, November 12-13, 2014: proceedings / [ed] Ulrich Frank, Berlin: Springer, 2014, Vol. 197, 193-207 s.Konferensbidrag (Refereegranskat)
    Abstract [en]

    Lately, the notion of capability has emerged in IS engineering as an instrument to context dependent design and delivery of business services. Representing core business functionalities of an organization, capabilities, and capability driven IS development can be seen as both – a shift beyond and complement to the widely established service-oriented engineering paradigm where needs of customers form the leading modeling and design perspective. To ensure the needs of business stakeholders for variety of business contexts that an organization faces, and thus facilitate successful systems delivery, capability-driven development needs a well-defined method for requirements engineering, as well as its confirmation in practices. In this paper a process for specifying requirements capabilities and their designs is proposed. An application of the proposed approach to the area of Business Process Outsourcing (BPO) services. is carried out for the German company SIV.

  • 2920.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Svee, Eric-Oluf
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Giannoulis, Constantinos
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Capturing consumer preferences as requirements for software product lines2015Ingår i: Requirements Engineering, ISSN 0947-3602, E-ISSN 1432-010X, Vol. 20, nr 1, 71-90 s.Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Delivering great consumer experiences in competitive market conditions requires software vendors to move away from traditional modes of thinking to an outside- in perspective, one that shifts their business to becoming consumer-centric. Requirements engineers operating in these conditions thus need new means to both capture real preferences of consumers and then relate them to requirements for software customized in different ways to fit anyone. Additionally, because system development models require inputs that are more concrete than abstract, the indistinct values of consumers need to be classified and formalized. To address this challenge, this study aims to establish a conceptual link between preferences of consumers and system requirements, using software product line (SPL) as a means for systematically accommodating the variations within the preferences. The novelty of this study is a conceptual model of consumer preference, which integrates generic value frameworks from both psychology and marketing, and a method for its transformation to requirements for SPL using a goal-oriented RE framework as the mediator. The presented artifacts are grounded in an empirical study related to the development of a system for online education.

  • 2921.
    Zdravkovic, Jelena
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Zikra, Iyad
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Ilayperuma, Tharaka
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    An MDA Method for Service Modeling by Formalizing REA and Open-edi Business Frameworks with SBVR2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    Business frameworks offer great opportunities of communication between people for working on the enterprise system engineering processes, as well as for eliciting services that the enterprise can offer in collaboration contexts. However, these kinds of frameworks, such as Resource-Event-Agent and Open-edi, recently unified in Open-edi Business Ontology (OeBTO), lack formal representations. This fact considerably limits their use in system development, particularly in model-driven development methods where the efficiency of transformations is of great importance. In this paper we suggest a formalization of OeBTO using OMG’s standard Semantics of Business Vocabulary and Business Rules (SBVR), as a method for creating a service-centric business model. This makes it possible to provide the necessary formal logic foundation to allow automatic processing of the business model and its transformation to a system-level service model. An example from the bank loan business sector is used to argument the application of the method.

  • 2922.
    Zeynep, Ahmet
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Holmquist, Lars Erik
    Sharing mobile services - Beyond the app store model2010Ingår i: MobileHCI 2010, ACM Press , 2010Konferensbidrag (Övrigt vetenskapligt)
  • 2923.
    Zeynep, Ahmet
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Jonsson, Martin
    Holmquist, Lars Erik
    Sumon, Saiful Islam
    Supporting embodied exploration of physical concepts in mixed digital and physical interactive settings2011Ingår i: TEI 2011, ACM Press , 2011Konferensbidrag (Övrigt vetenskapligt)
  • 2924.
    Zeynep, Ahmet
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Cramer, Henriette
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Holmquist, Lars Erik
    SICS / Mobile Life, , .
    Rost, Mattias
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Gamification and location-sharing: Some emerging social conflicts2011Ingår i: CHI2011, Vancouver, Canada: ACM Press , 2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Location-sharing services such as foursquare are a prominent example of commercial apps that use gamification to increase user engagement. These gamification elements however have to coexist with a plethora of usage motivations. We here present selected observations on emerging conflicts between gamification elements and other usage motivations for location-sharing. We argue gamification needs to take into account the social context in which services operate and that conflicts within this context can both be detrimental and add to playfulness.

  • 2925.
    Zeynep, Ahmet
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Väänänen-Vainio Mattila, Kaisa
    Tampere University of Technology, , .
    Face to face makes a difference: Recommendation Practices of Users of Mobile Services2011Ingår i: UbiComp2011, Beijing, China: ACM Press , 2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The mobile app stores and markets provide companies, independent developers and researchers alike with possibilities to distribute innovative designs for mobile devices on a global scale. However, reaching a large numbers of users does not in itself ensure a large number of users adopting the mobile application or service. Large-scale adoption depends on additional factors such as novelty in service design, ease of use, enjoyable interaction, built-in mechanisms for further distribution of the mobile service as well as the practice of word-of-mouth recommendations. In this position paper we present the background and preliminary findings from a study aimed at investigating the motivations and practices by which users recommend mobile apps and services among their acquaintances. We discuss our perspective on distribution of mobile applications and services on a large scale and end this paper by suggesting questions for discussion and future research.

  • 2926. Zhang, Ji-hong
    et al.
    Chen, Xi
    Ding, Xiao-song
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap. Beijing Foreign Studies University, China.
    Degeneracy removal in cutting plane methods for disjoint bilinear programming2017Ingår i: Optimization Letters, ISSN 1862-4472, E-ISSN 1862-4480, Vol. 11, nr 3, 483-495 s.Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Disjoint bilinear programming has appeared in miscellaneous practical applications. Although deterministic approaches such as cutting plane methods for solving it have been proposed, the frequently encountered computational problem regarding degeneracy still remains. This paper proposes a distance-following approach in order to generate a conservative hyperplane from a degenerate local star minimizer located by the augmented mountain climbing procedure, cut off it, and thus enable a cutting plane method to proceed without too much additional computational workload.

  • 2927. Zhang, Pengyi
    et al.
    Liu, Chang
    Hansen, Preben
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    I Need More Time!: The Influence of Native Language on Search Behavior and Experience2016Ingår i: Working Notes of CLEF 2016 - Conference and Labs of the Evaluation forum: CEUR Proceedings / [ed] Krisztian Balog, Linda Cappellato, Nicola Ferro, Craig Macdonald, 2016, 1166-1182 s.Konferensbidrag (Refereegranskat)
  • 2928.
    Zhang, Xiaoxi
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    An experiment with random stories in pervasive games2008Studentuppsats (Examensarbete)
    Abstract [en]
    In this thesis, we investigate a model for interactive story telling based on which stories are generated randomly. We discuss whether it is fun to read a story in random order and whether this can be used in a pervasive game. Moreover, in order to prove the theoretical discussions, we present a new game - Shards – which is a pervasive game based on random storytelling. Storytelling is a very traditional activity, as are games. Sometimes people connect the two together, making storytelling into a playful activity. Examples of playful storytelling include many formats, such as random writing or multi-author storytelling, interactive storytelling and adventure games. In this thesis, we discuss the playful possibilities offered by reading stories in random order, the different kinds of stories that fit this reading mode, the possible forms to play with it, and finally present an authoring tool for such stories. To illustrate this idea, we present a new game, Shards. Literally, “Shards” means pieces or fragments. Here, the name refers to the pieces of stories we play with. In this game, the player tries to complete one story line. Every time he or she comes close to another participant, a new shard can be retrieved, until the story is finished or the player stops playing the game. ‘Shards’ requires stories that are written to be read in random order. The first part of the thesis investigates which kinds of stories are best suited for shards. From a brainstorming session, we obtained four stories in the form of Shards. The four stories are very different and offer different reading experiences when read randomly. Based on the initial idea of this game, one story was chosen as a model story to develop the game and the authoring system for the game. One conclusion we can draw from the brainstorming session is that certain story themes are better suited for this game than others. For example, crime stories would fit well with the game structure. The second part of the thesis describes two authoring tools that support story writers in generating stories for shards. The tools were implemented using Ruby for basic reading tools and TCL/TK for more advanced functionality. Both are web-based tools and were used by the author to maintain the story database. The basic tools allow for CRED (create, read, edit, delete, a standard of database operation), and the more advanced tools allow for VADE (view, add, delete, edit, a standard) with “read” but without “delete” and “edit”. The basic tool, using Ruby, is intended for backend service management, and the more advanced tool, using TCL/TK, draws a graphic interface for the end user. The final part of the thesis describes a brief user evaluation of the game and evaluates the authoring tools. Four people participated in this evaluation. They found that Shards was a fun game with a well-designed story. This shows that it is possible to create a game out of random story reading, and also that the authoring tool is usable as a tool to create such stories. In all, this thesis is about the first trying of random story reading, random story writing and the early stage of the pervasive game Shards.
  • 2929.
    Zhang, Yanqing
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Constructing Swedish Fashion Identity Exhibition Review: Svenskt Mode (Swedish Fashion): 2000–2015, Sven-Harry’s Art Museum, Stockholm, May 23–August 31, 20142015Ingår i: Fashion theory, ISSN 1362-704X, E-ISSN 1751-7419Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This is an exhibition review article. It describes the goal, the curatorship, display and exhibited objects. The exhibition focuses on Swedish fashion design and treats fashion as something in relation to art. It analyzes the exhibition as part of institutionalization of Swedish fashion system. Understanding fashion as a system rather than material clothing is the key point here.

  • 2930.
    Zhang, Yanqing
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Tech Fashion: Fashion Institutionalization in Digital Technology2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis explores aesthetization in general and fashion in particular in digital technology design and how we can design digital technology to account for the extended influences of fashion. The thesis applies a combination of methods to explore the new design space at the intersection of fashion and technology. First, it contributes to theoretical understandings of aesthetization and fashion institutionalization that influence digital technology design. We show that there is an unstable aesthetization in mobile design and the increased aesthetization is closely related to the fashion industry. Fashion emerged through shared institutional activities, which are usually in the form of action nets in the design of digital devices. “Tech Fashion” is proposed to interpret such dynamic action nets of institutional arrangements that make digital technology fashionable and desirable. Second, through associative design research, we have designed and developed two prototypes that account for institutionalized fashion values, such as the concept “outfit-centric accessory.” We call for a more extensive collaboration between fashion design and interaction design.

  • 2931.
    Zhang, Yanqing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Juhlin, Oskar
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Fashion as System or Action Net in ‘Fashion in All Things’: a Case in Color Design of Mobile Phones2012Ingår i: Fashion: Exploring Critical Issues / [ed] Barbara Brownie, Laura Petican, Johannes Reponen, Oxford: Inter-Disciplinary Press, 2012, nr 1, 263-270 s.Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Contemporary fashion has permeated into all things in life beyond clothes. Recently, fashion theories take on interests in organization and system. Kawamura proposes a fashion system through which clothing is transformed into the idea of fashion. Can this fashion system be used to analyze other things in fashion? We present a study using mobile phone, one of the most intimate gadgets to people, as a way to approach ‘fashion in all things’. We chose the color as a way to study the fashion aspect in mobile design. Through the empirical study, we find that the decision making of color in mobile industry is a collective process. It is greatly influenced by technology, materials, consumer lifestyle and trend. The trendy colors in mobile design are not defined by certain cultural or social institutions, but formulated by actions conducted by various actors in certain social context. Our study shows that fashion can embrace more than Kawamura’s system, e.g. the action net of color design in mobile technology. Although mobile design shares some similarities with clothing fashion, the concept of fashion-ology is very Parisian and deals with only clothing. It is not fully applicable to mobile industry. If we want to use a fashion system that can apply to fashion in all things, we should revisit the theory to reveal the general characteristics of the fashion world or build smaller theory for each category.

  • 2932.
    Zhang, Yanqing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Juhlin, Oskar
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Fashion in Mobile Phone Design – The Emergence of Beautification, Desirability and Variation through Institutional Collaboration2016Ingår i: Fashion Practice: the journal of design, creative process & the fashion industry, ISSN 1756-9370, E-ISSN 1756-9389, Vol. 8, nr 1, 63-84 s.Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study if and how fashion values, such as beautification, desirability through symbolic interaction, and high variation, are increasingly visible in mobile phone design. We unpack such possible inter-linkages by interviewing eight representatives of both industries. Their comments allow us to discuss whether a process of fashionalization is underway and, if so, how it is taking place. Our findings indicate that fashion values are visible in the design of mobile phones and are accounted for in design. Fashionalization can thus be seen as emanating from institutions related to clothing that extend to and become shared with the mobile industry, such as a shared dependency on trend agencies for color selection and joint events. This interaction, ad hoc and heterogeneous, resists being modeled as a “system,” which has been suggested as a way to explain institutional work within clothing fashion. Drawing on Barbara Czarniawska’s institutional theory, we propose conceptualizing the emerging institutional work in terms of “action nets.” This concept makes visible flexible, situated, and ad hoc activities rather than stable and fixed organizational entities.

  • 2933.
    Zhang, Yanqing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Juhlin, Oskar
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    The “life and death” of great Finnish fashion phone: A periodization of changing styles in Nokia phone design between 1992 and 20132016Ingår i: Mobile Media & Communication, ISSN 2050-1579, Vol. 4, nr 3, 385-404 s.Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Visual aesthetics is an essential part of our experience of mobile devices, but the ways in which it is accounted for in design have largely been overlooked. We investigate whether an aesthetization of mobile design is taking place and, if so, how it is being pursued through institutional practices in organizations. We conduct a visual analysis of all Nokia phone releases between 1992 and 2013 complemented by an interview series with key actors. The study reveals a continuous increase in aesthetic variation between 1998 and 2008, which is visible in the variation of colors, forms and materials. The period between 2003 and 2008, which we term the Grand period, marks the peak of aesthetization of Nokia’s devices. It exhibits great variation, and is visibly similar to aesthetics in the fashion industry. With the introduction of the slate form, we see a decrease in visual variation between 2009 and 2013. The interviews reveal how the visual design was driven by organizational strategies, such as customer segmentation in general, and an orientation toward the fashion industry, e.g. in the creation of a fashion segment. The study reveals how aesthetic variation is weaved into a complex innovation system with sometimes conflicting demands deriving from e.g. technology and user interaction.

  • 2934.
    Zhao, Jing
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Learning Predictive Models from Electronic Health Records2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The ongoing digitization of healthcare, which has been much accelerated by the widespread adoption of electronic health records, generates unprecedented amounts of clinical data in a readily computable form. This, in turn, affords great opportunities for making meaningful secondary use of clinical data in the endeavor to improve healthcare, as well as to support epidemiology and medical research. To that end, there is a need for techniques capable of effectively and efficiently analyzing large amounts of clinical data. While machine learning provides the necessary tools, learning effective predictive models from electronic health records comes with many challenges due to the complexity of the data. Electronic health records contain heterogeneous and longitudinal data that jointly provides a rich perspective of patient trajectories in the healthcare process. The diverse characteristics of the data need to be properly accounted for when learning predictive models from clinical data. However, how best to represent healthcare data for predictive modeling has been insufficiently studied. This thesis addresses several of the technical challenges involved in learning effective predictive models from electronic health records.

    Methods are developed to address the challenges of (i) representing heterogeneous types of data, (ii) leveraging the concept hierarchy of clinical codes, and (iii) modeling the temporality of clinical events. The proposed methods are evaluated empirically in the context of detecting adverse drug events in electronic health records. Various representations of each type of data that account for its unique characteristics are investigated and it is shown that combining multiple representations yields improved predictive performance. It is also demonstrated how the information embedded in the concept hierarchy of clinical codes can be exploited, both for creating enriched feature spaces and for decomposing the predictive task. Moreover, incorporating temporal information leads to more effective predictive models by distinguishing between event occurrences in the patient history. Both single-point representations, using pre-assigned or learned temporal weights, and multivariate time series representations are shown to be more informative than representations in which temporality is ignored. Effective methods for representing heterogeneous and longitudinal data are key for enhancing and truly enabling meaningful secondary use of electronic health records through large-scale analysis of clinical data.

  • 2935.
    Zhao, Jing
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Temporal weighting of clinical events in electronic health records for pharmacovigilance2015Ingår i: 2015 IEEE International Conference on Bioinformatics and Biomedicine: Proceedings / [ed] Jun (Luke) Huan et al., IEEE Computer Society, 2015, 375-381 s.Konferensbidrag (Refereegranskat)
    Abstract [en]

    Electronic health records (EHRs) have recently been identified as a potentially valuable source for monitoring adverse drug events (ADEs). However, ADEs are heavily under- reported in EHRs. Using machine learning algorithms to automatically detect patients that should have had ADEs reported in their health records is an efficient and effective solution. One of the challenges to that end is how to take into account temporality when using clinical events, which are time stamped in EHRs, as features for machine learning algorithms to exploit. Previous research on this topic suggests that representing EHR data as a bag of temporally weighted clinical events is promising; however, how to assign weights in an optimal manner remains unexplored. In this study, nine different temporal weighting strategies are proposed and evaluated using data extracted from a Swedish EHR database, where the predictive performance of models constructed with the random forest learning algorithm is compared. Moreover, variable importance is analyzed to obtain a deeper understanding as to why a certain weighting strategy is favored over another, as well as which clinical events undergo the biggest changes in importance with the various weighting strategies. The results show that the choice of weighting strategy has a significant impact on the predictive performance for ADE detection, and that the best choice of weighting strategy depends on the target ADE and, specifically, on its dose-dependency.

  • 2936.
    Zhao, Jing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Henriksson, Aron
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Learning temporal weights of clinical events using variable importance2016Ingår i: BMC Medical Informatics and Decision Making, ISSN 1472-6947, E-ISSN 1472-6947, Vol. 16, nr Suppl. 2, 71Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Longitudinal data sources, such as electronic health records (EHRs), are very valuable for monitoring adverse drug events (ADEs). However, ADEs are heavily under-reported in EHRs. Using machine learning algorithms to automatically detect patients that should have had ADEs reported in their health records is an efficient and effective solution. One of the challenges to that end is how to take into account the temporality of clinical events, which are time stamped in EHRs, and providing these as features for machine learning algorithms to exploit. Previous research on this topic suggests that representing EHR data as a bag of temporally weighted clinical events is promising; however, the weights were in that case pre-assigned according to their time stamps, which is limited and potentially less accurate. This study therefore focuses on how to learn weights that effectively take into account the temporality and importance of clinical events for ADE detection. Methods: Variable importance obtained from the random forest learning algorithm is used for extracting temporal weights. Two strategies are proposed for applying the learned weights: weighted aggregation and weighted sampling. The first strategy aggregates the weighted clinical events from different time windows to form new features; the second strategy retains the original features but samples them by using their weights as probabilities when building each tree in the forest. The predictive performance of random forest models using the learned weights with the two strategies is compared to using pre-assigned weights. In addition, to assess the sensitivity of the weight-learning procedure, weights from different granularity levels are evaluated and compared. Results: In the weighted sampling strategy, using learned weights significantly improves the predictive performance, in comparison to using pre-assigned weights; however, there is no significant difference between them in the weighted aggregation strategy. Moreover, the granularity of the weight learning procedure has a significant impact on the former, but not on the latter. Conclusions: Learning temporal weights is significantly beneficial in terms of predictive performance with the weighted sampling strategy. Moreover, weighted aggregation generally diminishes the impact of temporal weighting of the clinical events, irrespective of whether the weights are pre-assigned or learned.

  • 2937.
    Zhao, Jing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Henriksson, Aron
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Asker, Lars
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Boström, Henrik
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Detecting Adverse Drug Events with Multiple Representations of Clinical Measurements2014Ingår i: 2014 IEEE International Conference on Bioinformatics and Biomedicine (BIBM): Proceedings, IEEE Computer Society, 2014, 536-543 s.Konferensbidrag (Refereegranskat)
    Abstract [en]

    Adverse drug events (ADEs) are grossly under-reported in electronic health records (EHRs). This could be mitigated by methods that are able to detect ADEs in EHRs, thereby allowing for missing ADE-specific diagnosis codes to be identified and added. A crucial aspect of constructing such systems is to find proper representations of the data in order to allow the predictive modeling to be as accurate as possible. One category of EHR data that can be used as indicators of ADEs are clinical measurements. However, using clinical measurements as features is not unproblematic due to the high rate of missing values and they can be repeated a variable number of times in each patient health record. In this study, five basic representations of clinical measurements are proposed and evaluated to handle these two problems. An empirical investigation using random forest on 27 datasets from a real EHR database with different ADE targets is presented, demonstrating that the predictive performance, in terms of accuracy and area under ROC curve, is higher when representing clinical measurements crudely as whether they were taken or how many times they were taken by a patient. Furthermore, a sixth alternative, combining all five basic representations, significantly outperforms using any of the basic representation except for one. A subsequent analysis of variable importance is also conducted with this fused feature set, showing that when clinical measurements have a high missing rate, the number of times they were taken by one patient is ranked as more informative than looking at their actual values. The observation from random forest is also confirmed empirically using other commonly employed classifiers. This study demonstrates that the way in which clinical measurements from EHRs are presented has a high impact for ADE detection, and that using multiple representations outperforms using a basic representation.

  • 2938.
    Zhao, Jing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Henriksson, Aron
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Asker, Lars
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Boström, Henrik
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Predictive modeling of structured electronic health records for adverse drug event detection2015Ingår i: BMC Medical Informatics and Decision Making, ISSN 1472-6947, E-ISSN 1472-6947, Vol. 15, nr SIArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: The digitization of healthcare data, resulting from the increasingly widespread adoption of electronic health records, has greatly facilitated its analysis by computational methods and thereby enabled large-scale secondary use thereof. This can be exploited to support public health activities such as pharmacovigilance, wherein the safety of drugs is monitored to inform regulatory decisions about sustained use. To that end, electronic health records have emerged as a potentially valuable data source, providing access to longitudinal observations of patient treatment and drug use. A nascent line of research concerns predictive modeling of healthcare data for the automatic detection of adverse drug events, which presents its own set of challenges: it is not yet clear how to represent the heterogeneous data types in a manner conducive to learning high-performing machine learning models. Methods: Datasets from an electronic health record database are used for learning predictive models with the purpose of detecting adverse drug events. The use and representation of two data types, as well as their combination, are studied: clinical codes, describing prescribed drugs and assigned diagnoses, and measurements. Feature selection is conducted on the various types of data to reduce dimensionality and sparsity, while allowing for an in-depth feature analysis of the usefulness of each data type and representation. Results: Within each data type, combining multiple representations yields better predictive performance compared to using any single representation. The use of clinical codes for adverse drug event detection significantly outperforms the use of measurements; however, there is no significant difference over datasets between using only clinical codes and their combination with measurements. For certain adverse drug events, the combination does, however, outperform using only clinical codes. Feature selection leads to increased predictive performance for both data types, in isolation and combined. Conclusions: We have demonstrated how machine learning can be applied to electronic health records for the purpose of detecting adverse drug events and proposed solutions to some of the challenges this presents, including how to represent the various data types. Overall, clinical codes are more useful than measurements and, in specific cases, it is beneficial to combine the two.

  • 2939.
    Zhao, Jing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Henriksson, Aron
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Boström, Henrik
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Cascading Adverse Drug Event Detection in Electronic Health Records2015Ingår i: 2015 IEEE International Conference on Data Science and Advanced Analytics (DSAA): Proceedings, IEEE Computer Society, 2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    The ability to detect adverse drug events (ADEs) in electronic health records (EHRs) is useful in many medical applications, such as alerting systems that indicate when an ADE-specific diagnosis code should be assigned. Automating the detection of ADEs can be attempted by applying machine learning to existing, labeled EHR data. How to do this in an effective manner is, however, an open question. The issues addressed in this study concern the granularity of the classification task: (1) If we wish to predict the occurrence of ADE, is it advantageous to conflate the various ADE class labels prior to learning, or should they be merged post prediction? (2) If we wish to predict a family of ADEs or even a specific ADE, can the predictive performance be enhanced by dividing the classification task into a cascading scheme: predicting first, on a coarse level, whether there is an ADE or not, and, in the former case, followed by a more specific prediction on which family the ADE belongs to, and then finally a prediction on the specific ADE within that particular family? In this study, we conduct a series of experiments using a real, clinical dataset comprising healthcare episodes that have been assigned one of eight ADE-related diagnosis codes and a set of randomly extracted episodes that have not been assigned any ADE code. It is shown that, when distinguishing between ADEs and non-ADEs, merging the various ADE labels prior to learning leads to significantly higher predictive performance in terms of accuracy and area under ROC curve. A cascade of random forests is moreover constructed to determine either the family of ADEs or the specific class label; here, the performance is indeed enhanced compared to directly employing a one-step prediction. This study concludes that, if predictive performance is of primary importance, the cascading scheme should be the recommended approach over employing a one-step prediction for detecting ADEs in EHRs.

  • 2940.
    Zhao, Jing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Henriksson, Aron
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Boström, Henrik
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Detecting Adverse Drug Events Using Concept Hierarchies of Clinical Codes2014Ingår i: 2014 IEEE International Conference on Healthcare Informatics: Proceedings, IEEE Computer Society, 2014, 285-293 s.Konferensbidrag (Refereegranskat)
    Abstract [en]

    Electronic health records (EHRs) provide a potentially valuable source of information for pharmacovigilance. However, adverse drug events (ADEs), which can be encoded in EHRs with specific diagnosis codes, are heavily under-reported. To provide more accurate estimates for drug safety surveillance, machine learning systems that are able to detect ADEs could be used to identify and suggest missing ADE-specific diagnosis codes. A fundamental consideration when building such systems is how to represent the EHR data to allow for accurate predictive modeling. In this study, two types of clinical code are used to represent drugs and diagnoses: the Anatomical Therapeutic Chemical Classification System (ATC) and the International Statistical Classification of Diseases and Health Problems (ICD). More specifically, it is investigated whether their hierarchical structure can be exploited to improve predictive performance. The use of random forests with feature sets that include only the original, low-level, codes is compared to using random forests with feature sets that contain all levels in the hierarchies. An empirical investigation using thirty datasets with different ADE targets is presented, demonstrating that the predictive performance, in terms of accuracy and area under ROC curve, can be significantly improved by exploiting codes on all levels in the hierarchies, compared to using only the low-level encoding. A further analysis is presented in which two strategies are employed for adding features level-wise according to the concept hierarchies: top-down, starting with the highest abstraction levels, and bottom-up, starting with the most specific encoding. The main finding from this subsequent analysis is that predictive performance can be kept at a high level even without employing the more specific levels in the concept hierarchies.

  • 2941.
    Zhao, Jing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Henriksson, Aron
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Kvist, Maria
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap. Karolinska Institute, Sweden.
    Asker, Lars
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Boström, Henrik
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Handling Temporality of Clinical Events for Drug Safety Surveillance2015Ingår i: AMIA Annual Symposium Proceedings, ISSN 1559-4076, Vol. 2015, 1371-1380 s.Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Using longitudinal data in electronic health records (EHRs) for post-marketing adverse drug event (ADE) detection allows for monitoring patients throughout their medical history. Machine learning methods have been shown to be efficient and effective in screening health records and detecting ADEs. How best to exploit historical data, as encoded by clinical events in EHRs is, however, not very well understood. In this study, three strategies for handling temporality of clinical events are proposed and evaluated using an EHR database from Stockholm, Sweden. The random forest learning algorithm is applied to predict fourteen ADEs using clinical events collected from different lengths of patient history. The results show that, in general, including longer patient history leads to improved predictive performance, and that assigning weights to events according to time distance from the ADE yields the biggest improvement.

  • 2942.
    Zhao, Jing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Karlsson, Isak
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Asker, Lars
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Boström, Henrik
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Applying Methods for Signal Detection in Spontaneous Reports to Electronic Patient Records2013Ingår i: Proceedings of the  19th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, Association for Computing Machinery (ACM), 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Currently, pharmacovigilance relies mainly on disproportionality analysis of spontaneous reports. However, the analysis of spontaneous reports is concerned with several problems, such as reliability, under-reporting and insucient patient information. Longitudinal healthcare data, such as Electronic Patient Records (EPRs) in which comprehensive information of each patient is covered, is a complementary source of information to detect Adverse Drug Events (ADEs). A wide set of disproportionality methods has been developed for analyzing spontaneous reports to assess the risk of reported events being ADEs. This study aims to investigate the use of such methods for detecting ADEs when analyzing EPRs. The data used in this study was extracted from Stockholm EPR Corpus. Four disproportionality methods (proportional reporting rate, reporting odds ratio, Bayesian condence propagation neural network, and Gamma-Poisson shrinker) were applied in two dierent ways to analyze EPRs: creating pseudo spontaneous reports based on all observed drug-event pairs (event-level analysis) or analyzing distinct patients who experienced a drug-event pair (patient-level analysis). The methods were evaluated in a case study on safety surveillance of Celecoxib. The results showed that, among the top 200 signals, more ADEs were detected by the event-level analysis than by the patient-level analysis. Moreover, the event-level analysis also resulted in a higher mean average precision. The main conclusion of this study is that the way in which the disproportionality analysis is applied, the event-level or patient-level analysis, can have a much higher impact on the performance than which disproportionality method is employed.

  • 2943.
    Zhao, Jing
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Papapetrou, Panagiotis
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Asker, Lars
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Boström, Henrik
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Learning from heterogeneous temporal data from electronic health records2017Ingår i: Journal of Biomedical Informatics, ISSN 1532-0464, E-ISSN 1532-0480, Vol. 65, 105-119 s.Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electronic health records contain large amounts of longitudinal data that are valuable for biomedical informatics research. The application of machine learning is a promising alternative to manual analysis of such data. However, the complex structure of the data, which includes clinical events that are unevenly distributed over time, poses a challenge for standard learning algorithms. Some approaches to modeling temporal data rely on extracting single values from time series; however, this leads to the loss of potentially valuable sequential information. How to better account for the temporality of clinical data, hence, remains an important research question. In this study, novel representations of temporal data in electronic health records are explored. These representations retain the sequential information, and are directly compatible with standard machine learning algorithms. The explored methods are based on symbolic sequence representations of time series data, which are utilized in a number of different ways. An empirical investigation, using 19 datasets comprising clinical measurements observed over time from a real database of electronic health records, shows that using a distance measure to random subsequences leads to substantial improvements in predictive performance compared to using the original sequences or clustering the sequences. Evidence is moreover provided on the quality of the symbolic sequence representation by comparing it to sequences that are generated using domain knowledge by clinical experts. The proposed method creates representations that better account for the temporality of clinical events, which is often key to prediction tasks in the biomedical domain.

  • 2944.
    Zikra, Iyad
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Design and Implementation of a Service Registry for Sensor Actuator Networks2009Studentuppsats (Examensarbete)
  • 2945.
    Zikra, Iyad
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Implementing the Unifying Meta-Model for Enterprise Modeling and Model-Driven Development: An Experience Report2012Ingår i: The Practice of Enterprise Modeling: 5th IFIP WG 8.1 Working Conference, PoEM 2012. Proceedings / [ed] Kurt Sandkuhl, Ulf Seigerroth, Janis Stirna, Springer, 2012, 172-187 s.Konferensbidrag (Refereegranskat)
    Abstract [en]

    Model-Driven Development (MDD) is becoming increasingly popular as a choice for developing information systems. Tools that support the principles of MDD are also growing in number and variety of available functionality. MetaEdit+ is a meta-modeling tool used for developing Domain Specific Languages and is identified as an MDD tool. The Eclipse Modeling Framework (EMF) and Graphical Modeling Project (GMP) are two Eclipse projects that provide plug-ins to support the principles of MDD. In this paper, we report on our experience in using MetaEdit+ and the Eclipse plug-ins for developing a graphical editor for the unifying meta-model, which is an MDD approach that extends the traditional view of MDD to cover Enterprise Modeling. The two modeling environments are reviewed using functionality areas that are identified by the research community as necessary in MDD tools. This report will provide useful insights for researchers and practitioners alike concerning the use of MetaEdit+ and the Eclipse plug-ins as MDD tools.

  • 2946.
    Zikra, Iyad
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Integration of Enterprise Modeling and Model Driven Development: A Meta-Model and a Tool Prototype2014Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    The use of models for designing and developing Information Systems (IS) has changed in recent years. Models are no longer considered a peripheral documentation medium that is poorly maintained and often neglected. Rather, models are increasingly seen as essential parts of the final product—as central artifacts that drive and guide the development efforts. The knowledge that modelers rely on when designing models is represented as formal models and clearly defined rules for transforming the models. The flexibility, reliability, and effectiveness offered by the formal models and the transformations are making Model Driven Development (MDD) a popular choice for building IS. Models also serve in describing enterprise design, where enterprise-level models capture organizational knowledge and aid in understanding, improving, and growing the enterprise. Enterprise Modeling (EM) offers a structured and unified view of the enterprise, thereby enabling more informed and accurate decisions to be made.

    Many MDD approaches have been proposed to tackle a wide range of IS-related issues, but little attention is being paid to the source of the knowledge captured by the IS models. EM approaches capture organizational knowledge and provide the necessary input and underlying context for designing IS. However, the results produced by EM approaches need to be manually analyzed by modelers to create the initial MDD model. This interruption of the MDD process represents a gap between enterprise models and MDD models. Limited research has been done to connect EM to MDD in a systematic and structured manner based on the principles of model-driven development.

    This thesis proposes a unifying meta-model for integrating EM and MDD. The meta-model captures the inherent links that exist between organizational knowledge and IS design. This helps to improve the alignment between organizational goals and the IS that are created to support them. The research presented herein follows the guidelines of the design science research methodology. It starts with a state-of-the-art survey of the current relationship between MDD and prior stages of development. The findings of the survey are used to elicit a set of necessary properties for integrating EM and MDD. The unifying meta-model is then proposed as the basis for an integrated IS development approach that applies the principles of MDD and starts on the enterprise level by considering enterprise models in the development process. The design of the meta-model supports the elicited integration properties. The unifying meta-model is based on the Enterprise Knowledge Development (EKD) approach to EM. A prototype tool is developed to support the unifying meta-model, following a study to choose a suitable implementation environment. The use of the unifying meta-model is demonstrated through the implemented tool platform using an example case study, revealing its advantages and highlighting the potential for improvement and future development.

  • 2947.
    Zikra, Iyad
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Model-based Requirements for Integrating Cloud Services2016Ingår i: Proceedings of the CAiSE'16 Forum, at the 28th International Conference on Advanced Information Systems Engineering (CAiSE 2016) / [ed] Sergio España, Mirjana Ivanović, Miloš Savić, 2016, 65-72 s.Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cloud-based services provide an alternative to the in-house implementation of various types of functionality. Organizations rely on such services to minimize the need for long-term commitments and enhance scalability and ubiquitous access to the services. However, achieving complex tasks that require a combination of services is not well studied, despite the potential added value. This paper investigates the requirements encountered when integrating cloud-based services in the modern organization. The paper proposes a model-driven solution for capturing the requirements for integrating cloud-based services. The model is to be used within the larger context of the organizational design; modeling components used to describe requirements are related to other views of the organization. A prototype tool and an example business case are presented to illustrate how the requirements model can be elicited and designed. The models are capable of being transformed into an integration solution.

  • 2948.
    Zikra, Iyad
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    The Communicative Nature of Information Systems Integration as an Enabler for Business IT Alignment2017Ingår i: Business Information Systems Workshops: BIS 2016 International Workshops, Leipzig, Germany, July 6-8, 2016, Revised Papers / [ed] Witold Abramowicz, Rainer Alt, Bogdan Franczyk, Springer, 2017, 136-147 s.Konferensbidrag (Refereegranskat)
    Abstract [en]

    Patterns of systems integration strive to accommodate the diversity of business ecosystems, including novel Web- and cloud-based services. In this paper, we apply the principles of the language/action paradigm (LAP) to develop a decentralized integration pattern that supports dynamic integration of services. A model is proposed for designing the interacting systems as active and independent entities that seek to communicate with each other. Two modes are enabled in the communication model: an indirect mode, where systems interact via business processes; and a direct mode, where systems directly interface with each other, following four categories. The communication perspective of the proposed integration pattern contributes to realizing the vision of a marketplace for cloud services. It supports a more flexible alternative to centralized integra-tion patterns. The communication model builds on the improved alignment be-tween system design models and the overall organizational design offered by the unifying meta-model for enterprise modeling.

  • 2949.
    Zikra, Iyad
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    España, Sergio
    Ruiz, Marcela
    Pastor, Oscar
    Stirna, Janis
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Aligning Communication Analysis with the Unifying Meta-Model for Enterprise Modeling2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Enterprise Modeling (EM) captures and represents organizational know-ledge in models that cover different views of the enterprise. The models can be leveraged in the development of information systems. Investigating how to use them as input to Model-Driven Development (MDD) is an open challenge. This paper explores how a holistic EM approach, represented by a unifying meta-model, can benefit from integrating with Communication Analysis, a communication-oriented business process modeling and requirements engineering method. As a first step towards an integrated EM-enabled MDD approach, the unifying meta-model and Communication Analysis meta-model are aligned. A set of guidelines for trans-forming models conforming to the unifying meta-model to Communication Analysis models are formulated. The approach is illustrated using of a lab demo.

  • 2950.
    Zikra, Iyad
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Stirna, Janis
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Zdravkovic, Jelena
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutionen för data- och systemvetenskap.
    Analyzing the Integration between Requirements and Models in Model Driven Development2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    In Model Driven Development (MDD), models replace software code as the development artifact. At the same time, requirements represent the information that is elaborated in models. However, despite the tight relationship between models and requirements, only a few MDD approaches provide the necessary methodological guidelines and tool support to explicitly facilitate this relationship. In this paper, we analyze existing approaches for integrating requirements with models within MDD. Based on the analysis, we elicit a set of general properties that need to be fulfilled when considering the integration of requirements and models, and we assess the contribution of the considered approaches accordingly.

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