Digital Library of Gesellschaft für Informatik e.V.
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Advancing Customer Feedback Systems with Blockchain
No full textOrganizations have to adjust to changes in the ecosystem, and customer feedback systems (CFS) provide important information to adapt products and services to changing customer preferences. However, current systems are limited to single-dimensional rating scales and are subject to self-selection biases. The work contributes design principles for CFS and implements a CFS that advances current systems by means of contextualized feedback according to specific organizational objectives. The authors apply Design Science Research (DSR) methodology and report on a longitudinal DSR journey considering multiple stakeholder values by utilizing value-sensitive design methods. They conducted expert interviews, design workshops, demonstrations, and a four-day experiment in an organizational setup, involving 132 customers of a major Swiss library. In the process, the identified design principles and the implemented software artifact were validated qualitatively and quantitatively, leading to conclusions for their efficient instantiation. The authors found that i) blockchain technology can afford four design principles of effective CFS. Also, ii) combining DSR with value-sensitive design methods explicitly provides rationale for design principles in the form of identified important values. Moreover, iii) combining DSR with value-sensitive design methods makes the construction of software artifacts more efficient it terms of design time by restricting the design space of a software artifact to those options that align with stakeholder values. The findings of this work thus extend the knowledge about the design of CFS and offer both researchers a theoretical contribution to reasoning about design principles and managers and decision makers a guide for the efficient design of software artifacts
Presentation Attack Detection Using Time-of-Flight-Based rPPG and Depth Features
No full textWith the rising importance of biometric authentication in numerous security applications it is critical to implement Presentation Attack Detection (PAD) techniques to protect against counterfeit biometrics. We evaluate a PAD-approach that uses 3D Time-of-Flight (ToF) cameras to perform heart rate measurements based on remote photoplethysmography (rPPG) for PAD. Compared to
Red-Green-Blue (RGB)-camera based approaches, ToF technology provides advantages, including
integration of 3D depth information, insensitivity to electronic displays and independence from ambient light and robustness against its influence. We introduce a Spectral pulse Peak prominence Ratio (SPR) and motion based metric and evaluate their applicability to PAD and present first promising
results
Artifact-Centric Modeling and Implementation of Blockchain-Enabled Business Processes
No full textSmart contracts can be used to support the execution of cross-organizational business processes involving mutually distrusting participants. Model-driven engineering is often used to generate such contracts and requires an appropriate blockchain-enabled process modeling language. Although artifact-centric languages are recommended in this context to support the business objects, lifecycles and cross-organizational process dimensions, most approaches rely on activity-centric languages such as BPMN. The few artifact-centric ones lack integrated support for one or more of these dimensions. To address this issue, in this paper we apply the design science research methodology. The authors propose a set of requirements for artifact-centric and blockchain-enabled business process modeling languages. It is used to evaluate existing work and present the design and demonstration of the B-MERODE language as an improved solution. The models created with the language can be formally verified and used as input to automatically generate smart contracts supporting the required process dimensions
Abhängigkeiten im Lebenszyklus von OGD-Applikationen – Eine Analyse der Auswirkungen von Änderungen am Beispiel einer langlebigen Webapplikation
No full textOpen Government Data-Initiativen ermöglichen den Zugriff auf und die Nutzung von Daten der öffentlichen Verwaltung. Diese Angebote werden oftmals als Grundlage für unterschiedliche, häufig nicht-kommerzielle Applikationen genutzt. Die Nutzung unterliegt in der Regel nicht der Regelung durch einen Vertrag, sondern durch Richtlinien. Die bereitgestellten Daten und Angebote unterliegen jedoch einer dynamischen Veränderung, da sie sich fortentwickeln oder durch neue Angebote ersetzt werden. Die Art und Weise der Kommunikation solcher Änderungen in Bezug auf Daten oder Schnittstellen seitens der Anbieter von Open Government Data (OGD) ist in vielen Fällen nicht ausführlich dokumentiert. Dies impliziert, dass OGD-Applikationen, die von diesen Daten abhängen, eine kontinuierliche Überprüfung der Änderungen, Konsistenz und Verfügbarkeit gewährleisten müssen. Dies resultiert in einer suboptimalen Nutzung von OGD, sowie in nur wenigen langfristig existierenden Applikationen. Eine Webapplikation, die als Hobbyprojekt bereits seit 2015 existiert und für eine Großstadt mit mehr als einer Million Einwohner*innen Abfahrtszeiten von öffentlichen Verkehrsmitteln je Haltestelle in Echtzeit darstellt, dient als Basis für eine Analyse von Abhängigkeiten, Änderungen und deren Auswirkungen auf diese OGD-Applikation. Die Analyse hat ergeben, dass spezifische Änderungen seitens des OGD-Anbieters zu einer Nichtverfügbarkeit der Applikation führen können. Aus den identifizierten Abhängigkeiten wurden vier Typen abgeleitet, die sich in ihren Auswirkungen auf die OGD-Applikation und deren Verfügbarkeit unterscheiden. Auf dieser Grundlage wurden Handlungsempfehlungen für OGD-Anbieter und OGD-Nutzer*innen abgeleitet. Open Government Data initiatives enable access to and use of public administration data. These offerings can be used as the basis for various, often non-commercial applications. Their use is generally governed by guidelines rather than contracts. However, the data and offerings provided are subject to changes as they evolve or are replaced by new offerings. The way in which Open Government Data (OGD) providers communicate such changes to data or interfaces is often not thoroughly documented. This implies that OGD applications that depend on these offerings must ensure continuous monitoring of changes, consistency, and availability. This results in suboptimal use of OGD and only a few long-term applications. A web application, created by “hobbyists” that has existed since 2015 and displays real-time public transport departure times for each stop in a large city with more than one million inhabitants serves as the basis for an analysis of dependencies, changes and their effects on this OGD application. The analysis revealed that specific changes made by the OGD provider can lead to the unavailability of the application. Four types of dependencies were identified, differing in their impact on the OGD application and its availability. Based on these findings, recommendations for OGD providers and OGD users were derived
Ontology-Driven Automated Reasoning About Property Crimes
No full textThe classification of police reports according to the typification of the criminal act described in them is not an easy task. The reports are written in natural language and often present missing, imprecise, or even inconsistent information, or lack sufficient details to make a clear decision. Focusing on property crimes, the aim of this work is to assist judges in this classification process by automatically extracting information from police reports and producing a list of possible classifications of crimes accompanied by a degree of confidence in each of them. The work follows the design science research methodology, developing a tool as an artifact. The proposal uses information extraction techniques to obtain the data from the reports, guided by an ontology developed for the Spanish legal system on property crimes. Probabilistic inference mechanisms are used to select the set of articles of the law that could apply to a given case, even when the evidence does not allow an unambiguous identification. The proposal has been empirically validated in a real environment with judges and prosecutors. The results show that the proposal is feasible and usable, and could be effective in assisting judges to classify property crime reports