Simulating Blockchain Consensus Protocols in Julia: Proof of Work vs Proof of Stake

Consensus protocols constitute an important part in virtually any blockchain stack as they safeguard transaction validity and uniqueness. This task is achieved in a distributed manner by delegating it to certain nodes which, depending on the protocol, may further utilize the computational resources of other nodes. As a tangible incentive for nodes to verify transactions many protocols contain special reward mechanisms. They are typically inducement prizes aiming at increasing node engagement towards blockchain stability. This work presents the fundamentals of a probabilistic blockchain simulation tool for studying large transaction volumes over time. Two consensus protocols, the proof of work and the delegate proof of stake, are compared on the basis of the reward distribution and the probability bound of the reward exceeding its expected value. Also, the reward probability as a function of the network distance from the node initiating the transaction is studied

Online reservation systems in e-Business: Analyzing decision making in e-Tourism

Tourism is one of the fastest growing industries worldwide and in general, the Internet continues to gain importance in the tourism sector. The study focuses on exploration of knowledge of online booking systems and on the views of local students-users concerning the booking rate based on these online systems. Another perspective of this project is to investigate the decision-making process (emotion-focused) that they follow in order to choose a tourist destination via online booking systems. For the purposes of this study, three scales were administered E-WOM and Accommodation Scale, Emotion-Based Decision-Making Scale and Trait Emotional Intelligence Scale. Then, survey data were collected, preprocessed and analyzed based on Data Mining techniques evaluating the results. More specifically, classification and association algorithms were utilized to manage to describe hidden patterns. E-Tourism will continue to be oriented towards the consumers and the technology that surrounds them, providing dynamic communication in electronic business

Online reservation systems in e-Business: analyzing decision making in e-Tourism

Tourism is one of the fastest growing industries worldwide and in general, the Internet continues to gain importance in the tourism sector. The study focuses on exploration of knowledge of online booking systems and on the views of local students-users concerning the booking rate based on these online systems. Another perspective of this project is to investigate the decision-making process (emotion-focused) that they follow in order to choose a tourist destination via online booking systems. For the purposes of this study, three scales were administered E-WOM and Accommodation Scale, Emotion-Based Decision-Making Scale and Trait Emotional Intelligence Scale. Then, survey data were collected, preprocessed and analyzed based on Data Mining techniques evaluating the results. More specifically, classification and association algorithms were utilized to manage to describe hidden patterns. E-Tourism will continue to be oriented towards the consumers and the technology that surrounds them, providing dynamic communication in electronic business

Strategic management of hotel multinationals: environment - management - performance

Traditionally, tourism was placed second as a priority in the agenda of investors, policy makers, and academics. Nowadays, a significant reappraisal of its role in socioeconomic development is taking place, which values tourism as a source for earning export revenues, generating large numbers of jobs, promoting economic growth and a more services-oriented economy not only in developing but also in developed countries (UNCTAD, 2007). According to World Tourism Organization (WTO), the European Union (EU) numbered six Member States among the top 10 countries in the world welcoming the largest number of international tourist arrivals. Within the EU, receipts from international tourism in 2008 were highest in Spain, France, and Italy, followed by Greece and Portugal Previous studies have attempted to explain destination and/or firm strategic positions by focusing on (mostly demand side factors) prices, exchange rates, qualitative and other institutional factors. Supply side factors and in particular company strategy contact and performance have not been taking explicitly into consideration. However, important pioneer research has been done regarding the globalization of the service sector and the hotel industry (Dunning and McQueen 1981, 1982; Boddewyn et al., 1986; Li and Guisinger, 1992; Dunning and Kundu, 1995; Constractor and Kundu, 1995). The topic under scrutiny is, therefore, to investigate whether MNEs operating in Greece, France, Spain, Portugal and Italy perform differently than domestically owned firms. In particular, we seek to identify the relevant factors that may explain the performance implications of foreign ownership for a large cross section of firms in Greek, French, Spanish, Portugues and Italian industries, controlling for a number of factors affecting firms’ performance. A closely related topic is to examine whether MNEs perform well per se, or their relative superior performance is a consequence of the detrimental effect they may exercise on domestic profitability. Additionally, we will try to determine the relative importance of the firm and destination effects using a multilevel approach and hierarchical linear models.Παραδοσιακά, ο τουρισμός καταλάμβανε τη δεύτερη θέσω ως προτεραιότητας στην ατζέντα των επενδυτών, των φορέων χάραξης πολιτικής καθώς και στην ατζέντα της ακαδημαϊκής κοινότητας. Σήμερα, μια σημαντική επανεκτίμηση του ρόλου του τουρισμού στην κοινωνικοοικονομική ανάπτυξη λαμβάνει χώρα, η οποία εκτιμά τον τουρισμό ως πηγή για την απόκτηση εσόδων από τις εξαγωγές, δημιουργώντας μεγάλο αριθμό θέσεων εργασίας, προώθηση της οικονομικής ανάπτυξης και μια πιο προσανατολισμένη στις υπηρεσίες οικονομία, όχι μόνο στις αναπτυσσόμενες αλλά και στις ανεπτυγμένες χώρες (UNCTAD, 2007). Σύμφωνα με τον Παγκόσμιο Οργανισμό Τουρισμού (WTO), η Ευρωπαϊκή Ένωση (ΕΕ) αριθμούσε έξι κράτη μέλη μεταξύ των κορυφαίων 10 χωρών του κόσμου καλωσορίζοντας τον μεγαλύτερο αριθμό διεθνών τουριστικών αφίξεων. Εντός της ΕΕ, τα έσοδα από το διεθνή τουρισμό το 2008 ήταν υψηλότερα στην Ισπανία, τη Γαλλία και την Ιταλία, ακολουθούμενη από την Ελλάδα και την Πορτογαλία. Προηγούμενες μελέτες έχουν προσπαθήσει να εξηγήσουν τον τουριστικό προορισμό λαι/ή τη την στρατηγική της εταιρείας, εστιάζοντας σε (ως επί το πλείστον) παράγοντες από πλευράς της ζήτησης, των τιμών, των συναλλαγματικών ισοτιμιών, ποιοτικών και άλλων θεσμικών παραγόντων. Παράγοντες από την πλευρά των προμηθειών και ιδίως την στρατηγική επαφή της εταιρείας και την επίδοσή της δεν έχουν ληφθεί ρητά υπόψη. Ωστόσο, σημαντική και πρωτοπόρος έρευνα έχει γίνει σχετικά με την παγκοσμιοποίηση του τομέα των υπηρεσιών και της ξενοδοχειακής βιομηχανίας (Dunning and McQueen 1981, 1982; Boddewyn et al., 1986; Li and Guisinger, 1992; Dunning and Kundu, 1995; Constractor and Kundu, 1995). Το υπό εξέταση θέμα, ως εκ τούτου ερευνήθηκε εάν οι πολυεθνικές εταιρείες που λειτουργούν στην Ελλάδα, τη Γαλλία, την Ισπανία, την Πορτογαλία και την Ιταλία έχουν διαφορετική απόδοση από ό,τι αν λειτουργούσαν στη χώρα προέλευσης της μητρικής τους εταιρείας. Ειδικότερα, επιδιώχθηκε να εντοπιστούν παράγοντες που μπορούν να εξηγήσουν τις επιπτώσεις των επιδόσεων της ξένης ιδιοκτησίας για μια μεγάλη διατομή των επιχειρήσεων στην Ελλάδα, τη Γαλλία, την Ισπανία, την Ιταλία και την Πορτογαλία, ελέγχοντας έναν σημαντικό αριθμό παραγόντων που επηρεάζουν την απόδοση των επιχειρήσεων. Ένα θέμα επίσης που εξετάστηκε είναι το κατά πόσο οι πολυεθνικές εταιρείες έχουν καλύτερη επίδοση ή οι σχετικά ανώτερες επιδόσεις τους είναι συνέπεια της αρνητικής επίδοσης που έχουν οι εγχώριες πολυεθνικές επιχειρήσεις. Επιπλέον, προσδιορίζουμε την σημαντική επίπτωση που έχουν τα χαρακτηριστικά της εταιρείας και ο προορισμός χρησιμοποιώντας μια πολυεπιπέδη προσέγγιση και ιεραρχικά γραμμικά μοντέλα

Online reservation systems in e- Business: Analyzing decision making in e-Tourism

International audienceTourism is one of the fastest growing industries worldwide and in general, the Internet continues to gain importance in the tourism sector. The study focuses on exploration of knowledge of online booking systems and on the views of local students-users concerning the booking rate based on these online systems. Another perspective of this project is to investigate the decision-making process (emotion-focused) that they follow in order to choose a tourist destination via online booking systems. For the purposes of this study, three scales were administered E-WOM and Accommodation Scale, Emotion-Based Decision-Making Scale and Trait Emotional Intelligence Scale. Then, survey data were collected, preprocessed and analyzed based on Data Mining techniques evaluating the results. More specifically, classification and association algorithms were utilized to manage to describe hidden patterns. E-Tourism will continue to be oriented towards the consumers and the technology that surrounds them, providing dynamic communication in electronic business