Addressing the Node Discovery Problem in Fog Computing

In recent years, the Internet of Things (IoT) has gained a lot of attention due to connecting various sensor devices with the cloud, in order to enable smart applications such as: smart traffic management, smart houses, and smart grids, among others. Due to the growing popularity of the IoT, the number of Internet-connected devices has increased significantly. As a result, these devices generate a huge amount of network traffic which may lead to bottlenecks, and eventually increase the communication latency with the cloud. To cope with such issues, a new computing paradigm has emerged, namely: fog computing. Fog computing enables computing that spans from the cloud to the edge of the network in order to distribute the computations of the IoT data, and to reduce the communication latency. However, fog computing is still in its infancy, and there are still related open problems. In this paper, we focus on the node discovery problem, i.e., how to add new compute nodes to a fog computing system. Moreover, we discuss how addressing this problem can have a positive impact on various aspects of fog computing, such as fault tolerance, resource heterogeneity, proximity awareness, and scalability. Finally, based on the experimental results that we produce by simulating various distributed compute nodes, we show how addressing the node discovery problem can improve the fault tolerance of a fog computing system

From passion to performance : entrepreneurial passion in the creative industries

Entrepreneurship drives progress, innovation, growth, and prosperity. Passion, in turn, motivates and energizes people to pursue meaningful activities on a sustained basis. In following their passion and in interacting with their proximal environments, people build up competencies, knowledge, experience, and social relations, which may result in peak performance. When passion develops and relates to the creation, discovery and exploitation of entrepreneurial opportunities, entrepreneurial passion emerges. The current state of research shows that entrepreneurial passion is a source of motivation, inspiration, creativity, and perseverance. In the cultural and creative industries, entrepreneurship often begins from a passion for an artistic or creative work that is pursued as a hobby or leisure activity, which professionalizes over time. Thereby, passion for a creative or artistic activity can also create tensions between ideational and economic-organizational imperatives in entrepreneurial contexts. However, how, and why an artistic or creative passion develops into an entrepreneurial one and how it affects entrepreneurial success is unchartered territory. Hence, the aim of this dissertation is to investigate and explain the development of passion and its effect on entrepreneurial performance of creative people whose venturing ambitions are primarily driven by a non-entrepreneurial passion. The first study identifies the current state of literature on entrepreneurship in the cultural and creative industries. The review elaborates the phenomenon of a non-entrepreneurial passion as central feature of creative industries entrepreneurship and outlines its potential for future research. The second study presents a review of the state of research on passion in the entrepreneurial context and develops a theory-based approach that explains how passion emerges, and how it can extend to entrepreneurship and lead to entrepreneurial performance. Based on 11 semi-structured interviews with successful entrepreneurs whose life paths are characterized by passion for music, the third study follows this assumption and generates mental maps using the Conceptual Causal Mapping method. The results explain the development of real-life passion over time, its current constitution and embeddedness within the personal, social, and entrepreneurial life context and the relation of passion to performance. Based on the person-environment fit theory, the final study develops a model that substantiates the positive effects of life context fit on entrepreneurial passion and performance. Life context fit is operationalized using personal project analysis and the hypotheses were tested on a sample of 406 creative entrepreneurs using partial least squares structural equation modeling. The results demonstrate the effect of life context fit on entrepreneurial passion and its successive translation into performance in four subsegments that can be classified as artepreneurs, culturepreneurs, creative entrepreneurs, and lifestyle entrepreneurs. However, contrary to expectations, the analyses also indicate that neither the life context fit, nor the domains of entrepreneurial passion have uniform positive outcomes. Rather, these relations occur with compounded positive and negative effects. These results are surprising as the extant literature has found nearly consistent positive outcomes of passion on performance. Post-hoc analyses reveal the varying constitutions of life contexts and the existence of previously unmeasurable domains of entrepreneurial passion for products, for people, and for a social cause among creative practitioners and help explaining the positive and negative combination effects in the segments. Overall, this dissertation contributes to the cultural and creative industries literature, the state of research on passion in entrepreneurship and psychology, and the literature whose epistemological interest aim at capturing and explaining entrepreneurial contexts and environments. Findings reveal (a) the central importance, development, and impact of passion among creative and cultural entrepreneurs, (b) the influence of life context on passion and performance, and (c) the interplay of combined positive and adverse effects of the domains of entrepreneurial passion and their impact on entrepreneurial performance.Unternehmertum gilt als prägendes Element für Fortschritt, Innovation, Wachstum und Wohlstand. Leidenschaft wiederum treibt Menschen dazu an, bedeutsame Aktivitäten dauerhaft zu verfolgen. Dabei werden Kompetenzen, Wissen, Erfahrungen und Kontakte in Interaktion mit der Umwelt aufgebaut, die zu individuellen Höchstleistungen führen können. Wenn beides zusammenkommt und sich Leidenschaft auf das Verfolgen und Nutzen von unternehmerischen Gelegenheiten bezieht, entsteht unternehmerische Leidenschaft. Der gegenwärtige Stand der Forschung zeigt, dass unternehmerische Leidenschaft eine Quelle von Motivation, Inspiration, Kreativität und Durchhaltevermögen ist, die das Denken und Handeln von Menschen bestimmt und positiv auf ihre persönliche Entwicklung und unternehmerische Performanz wirkt. In der Kultur- und Kreativwirtschaft beginnt Unternehmertum häufig aus einer Leidenschaft für eine künstlerische oder kreative Tätigkeit heraus, die als Hobby oder Freizeitaktivität verfolgt und über die Jahre hinweg professionalisiert wird. Dabei entstehen häufig Spannungen und Konflikte zwischen ideellen und ökonomisch-organisatorischen Imperativen. Wie und warum sich aus einer künstlerisch-kreativen eine unternehmerische Leidenschaft entwickelt und wie sie auf unternehmerischen Erfolg wirkt, ist jedoch nahezu unerforscht. Daher ist es das Ziel dieser Dissertation, die Entwicklung von Leidenschaft und ihre Wirkung auf den unternehmerischen Erfolg von Kreativschaffenden, deren Ambitionen von einer nicht-unternehmerischen Leidenschaft bestimmt sind, zu untersuchen und zu erklären. Die erste Studie ermittelt den gegenwärtigen Stand der Literatur zu Unternehmertum in der Kultur- und Kreativwirtschaft. Die zweite Studie stellt eine Aufarbeitung des Forschungsstandes zum Thema Leidenschaft im unternehmerischen Kontext dar und entwickelt einen theoriebasierten Ansatz, der erklärt, wie Leidenschaft entstehen, sich auf Unternehmertum ausweiten und zu unternehmerischem Erfolg führen kann. Die dritte Studie knüpft daran an und generiert mentale Karten mit der Methode des Conceptual Causal Mapping auf der Basis von 11 halbstrukturierten Interviews mit erfolgreichen Unternehmern, deren Lebenswege von einer ausgeprägten Leidenschaft für Musik bestimmt sind. Die Studie zeigt erstmals, wie sich real gelebte Leidenschaft entwickelt und konstituiert, wie sie in den persönlichen, sozialen und unternehmerischen Lebenskontext von Individuen eingebettet ist und wie unternehmerischer Erfolg davon mitbestimmt ist. In der abschließenden Studie wird auf Basis der Person-Environment-Fit-Theorie ein Modell entwickelt, das die positive Wirkung von passenden Lebenskontexten auf die gegenwärtig messbaren Domänen unternehmerischer Leidenschaft und auf unternehmerischen Erfolg begründet. Lebenskontext-Fit wurde mithilfe der Personal Project Analysis operationalisiert und die Hypothesen an einem Sample von 406 kreativschaffenden Unternehmern mittels Strukturgleichungsmodellierung (Methode der kleinsten Quadrate) getestet. Die Ergebnisse belegen die Wirkung des Lebenskontexts auf unternehmerische Leidenschaft und deren sukzessive Übersetzung in Performanz, allerdings nicht im Gesamtsample, sondern in vier Segmenten, die als Künstlerunternehmer, Kulturunternehmer, Kreativunternehmer und Lifestyle-Unternehmer klassifiziert werden konnten. Anders als erwartet zeigen die Analysen, dass weder die Passung des Lebenskontexts noch die Domänen der unternehmerischen Leidenschaft einheitlich positiv wirken, sondern kombinierte positive und negative Effekte haben können. Das sind überraschende Ergebnisse, da die bestehende Forschungsliteratur bisher nahezu übereinstimmend positive Effekte von Leidenschaft auf Performanz festgestellt hat. Über Post-hoc-Analysen können die variierenden Konstitutionen von Lebenskontexten und die Ausprägungen der bisher noch nicht messbaren Domänen von unternehmersicher Leidenschaft für Produkte, für Menschen und für einen sozialen Zweck bei Kreativschaffenden nachgewiesen und die Wirkungskombinationen erklärt werden. Insgesamt leistet diese Dissertation einen Beitrag zur Literatur der Kultur- und Kreativwirtschaft, zum Stand der Forschung über Leidenschaft in Unternehmertum und Psychologie sowie zu dem Strang der Entrepreneurship-Literatur, deren erkenntnistheoretisches Interesse in der Erfassung und Erklärung von unternehmerischen Kontexten und Umgebungen liegt. Die Studienergebnisse zeigen (a) die zentrale Bedeutung, Entwicklung und Wirkung von Leidenschaft bei Kreativschaffenden, (b) den Einfluss des Lebenskontexts auf Leidenschaft und Performanz, und (c) das Zusammenspiel von kombinierten positiven und negativen Domänen der Leidenschaft und ihre Auswirkungen auf unternehmerischen Erfolg

Elastic Business Process Management: State of the Art and Open Challenges for BPM in the Cloud

With the advent of cloud computing, organizations are nowadays able to react rapidly to changing demands for computational resources. Not only individual applications can be hosted on virtual cloud infrastructures, but also complete business processes. This allows the realization of so-called elastic processes, i.e., processes which are carried out using elastic cloud resources. Despite the manifold benefits of elastic processes, there is still a lack of solutions supporting them. In this paper, we identify the state of the art of elastic Business Process Management with a focus on infrastructural challenges. We conceptualize an architecture for an elastic Business Process Management System and discuss existing work on scheduling, resource allocation, monitoring, decentralized coordination, and state management for elastic processes. Furthermore, we present two representative elastic Business Process Management Systems which are intended to counter these challenges. Based on our findings, we identify open issues and outline possible research directions for the realization of elastic processes and elastic Business Process Management.Comment: Please cite as: S. Schulte, C. Janiesch, S. Venugopal, I. Weber, and P. Hoenisch (2015). Elastic Business Process Management: State of the Art and Open Challenges for BPM in the Cloud. Future Generation Computer Systems, Volume NN, Number N, NN-NN., http://dx.doi.org/10.1016/j.future.2014.09.00

Combined wavelet domain and motion compensated filtering compliant with video codecs

In this paper, we introduce the idea of using motion estimation resources from a video codec for video denoising. This is not straightforward because the motion estimators aimed for video compression and coding, tolerate errors in the estimated motion field and hence are not directly applicable to video denoising. To solve this problem, we propose a novel motion field filtering step that refines the accuracy of the motion estimates to a degree that is required for denoising. We illustrate the use of the proposed motion estimation method within a wavelet-based video denoising scheme. The resulting video denoising method is of low-complexity and receives comparable results with respect to the latest video denoising methods

The Cognitive Profile of Math Difficulties: A Meta-Analysis Based on Clinical Criteria

Math difficulties (MD) manifest across various domain-specific and domain-general abilities. However, the existing cognitive profile of MD is incomplete and thus not applicable in typical settings such as schools or clinics. So far, no review has applied inclusion criteria according to DSM or ICD, summarized domain-specific abilities or examined the validity of response time scores for MD identification. Based upon stringent clinical criteria, the current meta-analysis included 34 studies which compared cognitive performances of a group with MD (n = 680) and a group without MD (n = 1565). Criteria according to DSM and ICD were applied to identify MD (percentile rank <= 16, age range 8-12 years, no comorbidities/low IQ). Effect sizes for 22 abilities were estimated and separated by their level and type of scoring (AC = accuracy, RT = response time). A cognitive profile of MD was identified, characterized by distinct weaknesses in: (a) computation (calculation [AC], fact retrieval [AC]), (b) number sense (quantity processing [AC], quantity-number linking [RT], numerical relations [AC]), and (c) visual-spatial short-term storage [AC]. No particular strength was found. Severity of MD, group differences in reading performance and IQ did not significantly moderate the results. Further analyses revealed that (a) effects are larger when dealing with numbers or number words than with quantities, (b) MD is not accompanied by any weakness in abilities typically assigned to reading, and (c) weaknesses in visual-spatial short-term storage emphasize the notion that number and space are interlinked. The need for high-quality studies investigating domain-general abilities is discussed

Signals from the Yolk Cell Induce Mesoderm, Neuroectoderm, the Trunk Organizer, and the Notochord in Zebrafish

AbstractWe have analyzed the role of the zebrafish yolk cell in the processes of mesoderm induction and establishment of the organizer. By recombining blastomere-free yolk cells and animal cap tissue we have shown that the yolk cell itself can induce mesoderm in neighboring blastomeres. We further demonstrate the competence of all blastomeres to form mesoderm, suggesting the endogenous mesoderm inducing signal to be locally restricted. Ablation of the vegetal third of the yolk cell during the first 20 min of development does not interfere with mesoderm formation in general, but results in completely ventralized embryos. These embryos lack the notochord, neuroectoderm, and the anterior-most 14–15 somites, demonstrating that the ablation affects the formation of the trunk-, but not the tail region of the embryo. This suggests the presence of a trunk organizer in fish. The dorsalized mutant swirl (zbmp-2b) shows expanded dorsal structures and missing ventral structures. In contrast to the phenotypes obtained upon the ablation treatment in wild-type embryos, removal of the vegetal-most yolk in swirl mutants results in embryos which do form neuroectoderm and anterior trunk somites. However, both wild-type and swirl mutants lack a notochord upon vegetal yolk removal. These ablation experiments in wild-type and swirl mutant embryos demonstrate that in zebrafish dorsal determining factors originate from the vegetal part of the yolk cell. These factors set up two independent activities: one induces the notochord and the other is involved in the formation of the neuroectoderm and the trunk region by counteracting the function of swirl. In addition, these experiments show that the establishment of the anteroposterior axis is independent of the dorsoventral axis