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For aiding computer security experts in their study, log files are a crucial piece of information. Especially the time domain is very important for us because in most cases, timestamps are the only linking points between events caused by attackers, faulty systems or simple errors and their corresponding entries in log files. With the idea of storing and analyzing this log information in graph databases, we need a suitable model to store and connect timestamps and their events. This paper aims to find and evaluate different approaches how to store timestamps in graph databases and their individual benefits and drawbacks.

We analyse three different approaches, how timestamp information can be represented and stored in graph databases. For checking the models, we set up four typical questions that are important for log file analysis and tested them for each of the models. During the evaluation, we used the performance and other properties as metrics, how suitable each of the models is for representing the log files’ timestamp information. In the last part, we try to improve one promising looking model.

We come to the conclusion, that the simplest model with the least graph database-specific concepts in use is also the one yielding the simplest and fastest queries.

Limitations to this research are that only one graph database was studied and also improvements to the query engine might change future results.

In the study, we addressed the issue of storing timestamps in graph databases in a meaningful, practical and efficient way. The results can be used as a pattern for similar scenarios and applications.

Data protection requirements heavily increased due to the rising awareness of data security, legal requirements and technological developments. Today, NoSQL databases are increasingly used in security-critical domains. Current survey works on databases and data security only consider authorization and access control in a very general way and do not regard most of today’s sophisticated requirements. Accordingly, the purpose of this paper is to discuss authorization and access control for relational and NoSQL database models in detail with respect to requirements and current state of the art.

This paper follows a systematic literature review approach to study authorization and access control for different database models. Starting with a research on survey works on authorization and access control in databases, the study continues with the identification and definition of advanced authorization and access control requirements, which are generally applicable to any database model. This paper then discusses and compares current database models based on these requirements.

As no survey works consider requirements for authorization and access control in different database models so far, the authors define their requirements. Furthermore, the authors discuss the current state of the art for the relational, key-value, column-oriented, document-based and graph database models in comparison to the defined requirements.

This paper focuses on authorization and access control for various database models, not concrete products. This paper identifies today’s sophisticated – yet general – requirements from the literature and compares them with research results and access control features of current products for the relational and NoSQL database models.

Authorization and access control have been a topic of research for several decades. However, existing definitions are inconsistent and even contradicting each other. Furthermore, there are numerous access control models and even more have recently evolved to conform with the challenging requirements of resource protection. That makes it hard to classify the models and decide for an appropriate one satisfying security needs. Therefore, this study aims to guide through the plenty of access control models in the current state of the art besides this opaque accumulation of terms meaning and how they are related.

This study follows the systematic literature review approach to investigate current research regarding access control models and illustrate the findings of the conducted review. To provide a detailed understanding of the topic, this study identified the need for an additional study on the terms related to the domain of authorization and access control.

The authors’ research results in this paper are the distinction between authorization and access control with respect to definition, strategies, and models in addition to the classification schema. This study provides a comprehensive overview of existing models and an analysis according to the proposed five classes of access control models.

Based on the authors’ definitions of authorization and access control along with their related terms, i.e. authorization strategy, model and policy as well as access control model and mechanism, this study gives an overview of authorization strategies and propose a classification of access control models providing examples for each category. In contrast to other comparative studies, this study discusses more access control models, including the conventional state-of-the-art models and novel ones. This study also summarizes each of the literature works after selecting the relevant ones focusing on the database system domain or providing a survey, a classification or evaluation criteria of access control models. Additionally, the introduced categories of models are analyzed with respect to various criteria that are partly selected from the standard access control system evaluation metrics by the National Institute of Standards and Technology.

The purpose of this chapter is to contribute to the theory building of transformative university by delivering two conceptual models for legitimizing entrepreneurial university with a transformative role in quadruple helix for sustainability governance structures as being nominated as “responsible facilitator.” This chapter draws many theoretical insights sourced from Entrepreneurial University (Etzkowitz, 1988), Institutional Theory (Scott, 1987), quadruple/quintuple helix (Carayannis & Campbell, 2009a, b) and Responsible Innovation (Owen, Macnaghten, & Stilgoe, 2012) in order to frame the resulting conceptual models of transformative university for sustainability and quadruple helix for sustainability governance. The conceptual models offer a new paradigm discussion for the changing role of universities in knowledge economy and opens up for further investigation of quadruple helix actors namely as transformative university, society, industry and government for strategic capital, social capital, economic capital and culture–human capital interventions in sustainability governance. The second model illustrates the key interventions of quadruple helix actors in four pillars of capital delivering concrete examples of activities. The originality of this chapter lies in its discourse articulating a multilayered approach for the institutionalization of entrepreneurial university embedded in a responsible innovation ecosystem based on individual, organizational and macro-level perspectives. Quadruple helix actors are nominated as “responsible facilitator,” “hybrid hub,” “agile regulator” and “pressure beneficiary” roles for their relevant place in sustainability governance structure.

This paper aims to examine the role of life satisfaction in consumers’ reaction to nostalgic music in an advertisement in terms of attitude toward the brand and purchase intention. It suggests that life satisfaction forms the lens through which individuals interpret and reconstruct past emotional experiences evoked by nostalgia. It further investigates the role of product category involvement in the interplay between life satisfaction and nostalgic music.

Two experiments were conducted. The first study featured a 2 (nostalgic vs non-nostalgic music) × 2 (high vs low involvement) between-subjects design and tested the research hypotheses with 208 consumers. The second study featured two involvement conditions (high vs low) and explored the underlying process behind the hypotheses. Linear regression was used to analyze the data in both studies.

For the low involvement product category, nostalgic music was more effective than non-nostalgic music for consumers with high life satisfaction, whereas non-nostalgic music was more effective for consumers with low life satisfaction levels. For the high involvement product category, life satisfaction did not moderate consumers’ reaction to nostalgic music.

This research suggests that past experiences evoked through nostalgic music are not static but are subject to bias and interpretation depending on an individual’s current mindset. Hence, the eventual effect of nostalgia is determined by how past events are reconstrued based on the individual’s current state.

This paper warns against the blind use of nostalgic appeals in advertising, points to the need to consider the audience’s state of mind, and suggests an opportunity to leverage life satisfaction influencers in designing effective advertising campaigns.

The findings have strong implications for public policymakers. The results are crucial as policymakers often use public service announcement (PSA) to change the attitude of the public toward some phenomena. Knowing the current state of life satisfaction in society, they can increase the efficiency of public service announcements by including a nostalgic song in them.

To the best of the authors’ knowledge, this research is the first one in the marketing literature that looks at the efficiency of nostalgic songs in advertisements. The authors tested the conceptual framework by using two studies and offered novel implications to both marketers and scholars.

This study investigates when and why negative organization-related career shocks affect career optimism, which is a positive career-planning attitude. The indirect effect of negative organization-related career shocks on career optimism via job insecurity and the role of perceived organizational career support as a first-stage moderator were investigated.

Three-wave time-lagged data from a sample of 728 employees in Switzerland was used. Time-lagged correlations, an indirect effect model and a conditional indirect effect model with bootstrapping were used to test the hypotheses.

First, this study showed a significant negative correlation between negative organization-related career shocks (T1) and career optimism (T3), a positive correlation between negative organization-related career shocks (T1) and job insecurity (T2) and a negative correlation between job insecurity (T2) and career optimism (T3). Second, findings revealed that negative organization-related career shocks (T1) have a negative indirect effect on career optimism (T3) via job insecurity (T2). Third, perceived organizational career support (T1) buffers the indirect effect of negative organization-related career shocks (T1) on career optimism (T3).

This study provides an initial examination of the relationship between negative organization-related career shocks and career optimism by applying assumptions from the JD-R model and Conservation of Resources theory. Implications about how to deal with negative career shocks in HRM and career counseling are discussed.

The purpose of this review is to integrate and organize past research findings on affective, normative and continuance occupational commitment (OC) within an integrative framework based on central life span concepts.

The authors identified and systematically analyzed 125 empirical articles (including 138 cases) that examined OC with a content valid measure to the here applied definition of OC. These articles provided information on the relationship between OC and four distinct life span concepts: chronological age, career stages, occupational and other life events, and occupational and other life roles. Furthermore, developmental characteristics of OC in terms of construct stability and malleability were reviewed.

The reviewed literature allowed to draw conclusions about the mentioned life span concepts as antecedents and outcomes of OC. For example, age and tenure is more strongly positively related to continuance OC than to affective and normative OC, nonlinear and moderating influences seem to be relevant in the case of the latter OC types. The authors describe several other findings within the results sections.

OC represents a developmental construct that is influenced by employees’ work- and life-related progress, associated roles, as well as opportunities and demands over their career. Analyzing OC from such a life span perspective provides a new angle on the research topic, explaining inconsistencies in past research and giving recommendation for future studies in terms of dynamic career developmental thinking.

To advance the learning of professional practices in teacher education and medical education, this conceptual paper aims to introduce the idea of representational scaffolding for digital simulations in higher education.

This study outlines the ideas of core practices in two important fields of higher education, namely, teacher and medical education. To facilitate future professionals’ learning of relevant practices, using digital simulations for the approximation of practice offers multiple options for selecting and adjusting representations of practice situations. Adjusting the demands of the learning task in simulations by selecting and modifying representations of practice to match relevant learner characteristics can be characterized as representational scaffolding. Building on research on problem-solving and scientific reasoning, this article identifies leverage points for employing representational scaffolding.

The four suggested sets of representational scaffolds that target relevant features of practice situations in simulations are: informational complexity, typicality, required agency and situation dynamics. Representational scaffolds might be implemented in a strategy for approximating practice that involves the media design, sequencing and adaptation of representational scaffolding.

The outlined conceptualization of representational scaffolding can systematize the design and adaptation of digital simulations in higher education and might contribute to the advancement of future professionals’ learning to further engage in professional practices. This conceptual paper offers a necessary foundation and terminology for approaching related future research.

Graphs are powerful tools which affect a reader’s impression and decision making. However, graphs in annual reports have a long tradition of being designed in order to give a more favourable impression of the company’s performance. The purpose of this paper is to add to the understanding of how large listed companies in Europe choose to use and misuse graphical representation.

This comprehensive study investigates annual reports of the top 50 European companies listed in the fortune 500 index. Company reports are analysed over a period of seven years resulting in 4,683 graphs. The authors investigate the development of the three major areas of impression management – selectivity, graphical measurement distortion and presentational enhancement – individually by company as well as collectively for the entire sample.

The main findings are that topics displayed, and how they are presented, significantly change over time and that graphs are much more likely to exaggerate positive trends than to understate them. Additionally, it can be found that longer time sequences (greater than five years) almost exclusively depict favourable trends (86 per cent) and graphical measurement distortions are applied on purpose for both key financial variables (KFV) as well as for non-KFV (around 30 per cent in all years).

The sample for this study are the biggest 50 companies in Europe. It is not clear, if these companies are a representative sample for all publicly traded companies in Europe. Further research is needed regarding small and medium size companies.

The findings show that companies primarily produce graphs in order to influence the perception of their stakeholders rather than to display the topics in accordance with the “true and fair view” principle that is requested by the IASB. However, standard setters like the IASB or the FASB have not yet released any particular information on how to use graphs correctly and avoid misleading information. This study should provide a solid base for further discussions in this regard as companies still use graphs to give a favourable impression of the company and deliberately misuse them in order to achieve this aim.

This study contributes to the research field of impression management by answering the quest for more longitudinal studies and offers an extended focus while examining not only KFV but all variables depicted in annual reports.