TemporalRI: subgraph isomorphism in temporal networks with multiple contacts

AbstractTemporal networks are graphs where each edge is associated with a timestamp denoting when two nodes interact. Temporal Subgraph Isomorphism (TSI) aims at retrieving all the subgraphs of a temporal network (called target) matching a smaller temporal network (called query), such that matched target edges appear in the same chronological order of corresponding query edges. Few algorithms have been proposed to solve the TSI problem (or variants of it) and most of them are applicable only to small or specific queries. In this paper we present TemporalRI, a new subgraph isomorphism algorithm for temporal networks with multiple contacts between nodes, which is inspired by RI algorithm. TemporalRI introduces the notion of temporal flows and uses them to filter the search space of candidate nodes for the matching. Our algorithm can handle queries of any size and any topology. Experiments on real networks of different sizes show that TemporalRI is very efficient compared to the state-of-the-art, especially for large queries and targets

Supervised temporal link prediction in large-scale real-world networks

Link prediction is a well-studied technique for inferring the missing edges between two nodes in some static representation of a network. In modern day social networks, the timestamps associated with each link can be used to predict future links between so-far unconnected nodes. In these so-called temporal networks, we speak of temporal link prediction. This paper presents a systematic investigation of supervised temporal link prediction on 26 temporal, structurally diverse, real-world networks ranging from thousands to a million nodes and links. We analyse the relation between global structural properties of each network and the obtained temporal link prediction performance, employing a set of well-established topological features commonly used in the link prediction literature. We report on four contributions. First, using temporal information, an improvement of prediction performance is observed. Second, our experiments show that degree disassortative networks perform better in temporal link prediction than assortative networks. Third, we present a new approach to investigate the distinction between networks modelling discrete events and networks modelling persistent relations. Unlike earlier work, our approach utilises information on all past events in a systematic way, resulting in substantially higher link prediction performance. Fourth, we report on the influence of the temporal activity of the node or the edge on the link prediction performance, and show that the performance differs depending on the considered network type. In the studied information networks, temporal information on the node appears most important. The findings in this paper demonstrate how link prediction can effectively be improved in temporal networks, explicitly taking into account the type of connectivity modelled by the temporal edge. More generally, the findings contribute to a better understanding of the mechanisms behind the evolution of networks.Algorithms and the Foundations of Software technolog

A Hybrid Simulation Framework of Consumer-to-Consumer Ecommerce Space

In the past decade, ecommerce transformed the business models of many organizations. Information Technology leveled the playing field for new participants, who were capable of causing disruptive changes in every industry. Web 2.0 or Social Web further redefined ways users enlist for services. It is now easy to be influenced to make choices of services based on recommendations of friends and popularity amongst peers. This research proposes a simulation framework to investigate how actions of stakeholders at this level of complexity affect system performance as well as the dynamics that exist between different models using concepts from the fields of operations engineering, engineering management, and multi-model simulation. Viewing this complex model from a systems perspective calls for the integration of different levels of behaviors. Complex interactions exist among stakeholders, the environment and available technology. The presence of continuous and discrete behaviors coupled with stochastic and deterministic behaviors present challenges for using standalone simulation tools to simulate the business model. We propose a framework that takes into account dynamic system complexity and risk from a hybrid paradigm. The SCOR model is employed to map the business processes and it is implemented using agent based simulation and system dynamics. By combining system dynamics at the strategy level with agent based models of consumer behaviors, an accurate yet efficient representation of the business model that makes for sound basis of decision making can be achieved to maximize stakeholders\u27 utility

The drivers of Corporate Social Responsibility in the supply chain. A case study.

Purpose: The paper studies the way in which a SME integrates CSR into its corporate strategy, the practices it puts in place and how its CSR strategies reflect on its suppliers and customers relations. Methodology/Research limitations: A qualitative case study methodology is used. The use of a single case study limits the generalizing capacity of these findings. Findings: The entrepreneur’s ethical beliefs and value system play a fundamental role in shaping sustainable corporate strategy. Furthermore, the type of competitive strategy selected based on innovation, quality and responsibility clearly emerges both in terms of well defined management procedures and supply chain relations as a whole aimed at involving partners in the process of sustainable innovation. Originality/value: The paper presents a SME that has devised an original innovative business model. The study pivots on the issues of innovation and eco-sustainability in a context of drivers for CRS and business ethics. These values are considered fundamental at International level; the United Nations has declared 2011 the “International Year of Forestry”

Editorial: Responsible Innovation (RI) in the midst of an innovation crisis

The concept of Responsible Innovation (RI) occupies a central place in the discourse on science and technology, especially in the context of the European Union (EU) but also within academia. This concept is guided by the idea of steering science and technology towards societally desirable outcomes, particularly in response to normative objectives such as Sustainable Development Goals (von Schomberg, 2019). Visions of RI typically propose that to innovate responsibly requires a permanent commitment to be anticipatory, reflective, inclusively deliberative, and responsive (Owen et al., 2012). They also emphasize the need for open access, gender equality, science education, ethical standard in conducting experiments, and democratic governance (European Commission, 2020). However, the societal purpose of RI fundamentally conflicts with the imperative of maximizing economic growth inherent in today’s innovation climate (von Schomberg, 2022). This conflict points to a crisis in which innovation struggles to serve public interests insofar private interests continue to be prioritized. The magnitude of this crisis is also reflected within the RI literature itself, where the political ambition to exceed the privatization wave is summoned to a techno-economic concept of innovation (von Schomberg & Blok, 2019). This issue of NOvation – Critical Studies of Innovation brings into question to what extent innovation necessarily relates to the market, whether it is possible to develop an alternative concept of innovation that is separated from economic ends, and how we can conceptualize, for example, a political understanding of innovation. What really is innovation? While all seven contributions share the aspiration to critically reflect on these questions, they each offer a distinct and original perspective in discussing the relation between innovation, technology, politics, economics, and responsibility

Organizational learning: what have we learned so far?

Organizational Learning represents one of the most hopeful and yet nebulous areas of human resource management literature. The term itself is used to represent a variety of meanings, and no one definition of organizational learning has been adopted by OL theorists. After over 25 years of attention by management gurus and the academic community, definitions remain unclear, evaluation remains problematic, and success stories are few and far between. This paper provides a review of the OL literature including some of the debate around the potential for Organizational Learning as an effective management practice. In conclusion the author suggests that before OL initiatives can transform organizations into empowered workplaces, there must be a more complete analysis of the context in which learning happens. This includes a discussion of the issues of power and empowerment within organizations, the diversity of employee experiences that inform their learning, and the role of gender in power and learning within organizations

Where in the world versus what’s on the web: an examination of web- based locational information for selected firms in the hospitality sector

Transactions between hospitality service providers and their customers are often facilitated by locational information obtained from web-based, map-serving business directories. This article reports the results of an examination of web-based locational information for a convenience sample of small hospitality service providers. To illustrate the transaction-jeopardizing potential of locational mis- information, the article juxtaposes assessments of the ‘importance of place’ with the state of web-based locational information for four of the service providers in the larger sample. Results suggest that directory-provided locational information often mis-informs and potentially mis-directs prospective customers

Tourism impacts and an ecotourism case study

This paper illustrates the complexity and the impacts of tourism choices and decisions in a region. A framework for analyzing tourism impacts is developed and operationalized into a mapping model for the decision variables. A qualitative case study focuses on the niche ecotourism sector. Findings indicate the framework is useful for a region to evaluate tourism strategy decisions