Productivity, Product Differentiation and Profitability: A Comparison between the Chemical and the Textile Industries in Greece

The purpose of this study is to investigate the relationship between the profitability of the firm and its Research and Development expenditures. We separate Research and Development expenditures in two main categories, Research and Development that focuses on the product differentiation and Research and Development, which concerns improvements in production process. The latter leads to a more efficient production, which can be measured by labour productivity. We estimate our model using cross section analysis and test the impact of the two aforementioned variables upon firm’s profitability. Our model was applied to Greek Chemical industry and to Greek Textile industry, for a data set of 124 enterprises of the chemical sector 139 enterprises in the textiles sector in the year 2001. Our findings support the positive influence of productivity on profitability is present in both manufacturing sectors, although not at an equal weight

Measuring sponsorship effects on consumer purchasing intentions

In this paper the role of sponsorship in achieving the managerial goals of a firm is studied. In addition, it is examined whether sponsorship can be attributed to the Public Relation Theory and Practice. A survey is conducted and a questionnaire was distributed to consumers living in Athens in order to examine whether firms, which use sponsorship as a strategic tool aiming to form relationships with the consumers, actually achieve their goal. The questionnaires which were distributed to the consumers were statistically processed using SPSS. Various aspects which may affect a firm’s managerial decision in undertaking sponsorships are analyzed. The obtained results are also used to investigate whether there is a connection between the organizational goals (related to sponsorship) and consumers’ behavioral/purchasing intentions

Effectiveness of Bank Sponsorship: The case of Greece

Despite the increase of the amounts invested on sponsorship worldwide, the research undertaken in order to evaluate sponsorship effectiveness on consumer perception is insufficient. This study examines the answers given from a sample of 112 high educated young people who live in Greece and have been exposed to sponsorship activities undertaken by the six larger Banks of Greece. The analysis reached interesting conclusions concerning the way Greek consumers understand the concept of bank sponsorship

Risks associated with next generation access networks investment scenarios

The deployment of next generation access networks (NGAs) is investigated from technical, regulatory and investment perspectives. A brief review of the possible network architectures and deployment scenarios of NGAs is provided. Risk calculations of these NGA scenarios are performed based on a fully detailed techno-economic model. Furthermore, the effectiveness of the European Commission's Recommendation on regulated access to NGAs, aiming to tackle the regulatory trade-off between encouraging investments and promoting competition, is discussed

Techno‐economic analysis of 5G immersive media services in cloud‐enabled small cell networks: the neutral host business model

Fifth generation (5G) envisages a “hyperconnected society” with an enormous number of interconnected devices, anywhere and at any time. Edge computing plays a pivotal role in this vision, enabling low latency, large traffic volumes, and improved quality of experience. The advent of 5G and edge computing encourages vertical industries to develop innovative services, which can meet the challenging demands coming from consumers. However, economic feasibility is the ultimate factor that determines the viability of a new service. Hence, effective techniques for the economic assessment of such services are needed. This paper analyzes the provision of immersive media services in crowded events, through a cloud‐enabled small cell network owned by a neutral host, and offered in multitenancy to different mobile network operators. We initially develop a planning model to predict the required compute, storage, and radio resources. Taking into account dynamic factors such as service penetration and price evolution, we then provide a number of economic indices, such as net present value, internal rate of return, and expected payback period to assess the viability of a potential investment in a 5G infrastructure for immersive media services. The presented analysis will guide small cell network operators in the provision of 5G innovative media services

Assessment of socio-techno-economic factors affecting the market adoption and evolution of 5G networks: Evidence from the 5G-PPP CHARISMA project

5G networks are rapidly becoming the means to accommodate the complex demands of vertical sectors. The European project CHARISMA is aiming to develop a hierarchical, distributed-intelligence 5G architecture, offering low latency, security, and open access as features intrinsic to its design. Finding its place in such a complex landscape consisting of heterogeneous technologies and devices, requires the designers of the CHARISMA and other similar 5G architectures, as well as other related market actors to take into account the multiple technical, economic and social aspects that will affect the deployment and the rate of adoption of 5G networks by the general public. In this paper, a roadmapping activity identifying the key technological and socio-economic issues is performed, so as to help ensure a smooth transition from the legacy to future 5G networks. Based on the fuzzy Analytical Hierarchy Process (AHP) method, a survey of pairwise comparisons has been conducted within the CHARISMA project by 5G technology and deployment experts, with several critical aspects identified and prioritized. The conclusions drawn are expected to be a valuable tool for decision and policy makers as well as for stakeholders

Transmission limitations in all optical networks due to non-linear effects

In this thesis, transmission limitations in all-optical networks due to nonlinear effects and especially Four-Wave Mixing (FWM) are studied. An accurate analysis of the statistical nature of the FWM noise was carried out using Monte Carlo (MC) and Multicanonical MC (MCMC) simulations. Such an analysis is of great importance in network design and modeling since FWM is an important source of noise in dense wavelength-division multiplexing (DWDM) networks that employ nonzero-dispersion fibers (NZDF). In these systems, FWM causes the dominant nonlinear distortion, especially if high input powers, narrow channel spacing and dispersion compensation are used. The MCMC method was also applied to study the impact of IP traffic burstiness on the performance of an IP over ΜΡλS-based DWDM network limited by FWM and ln-band crosstalk. Furthermore, two new methods based on a hybrid amplitude-/frequency-shift keying (ASK/FSK) modulation and pulse prechirping are proposed for the suppression of the FWM effect The next chapter addresses the issue of the choice of optical modulation format in a multispan WDM system using G 655 fiber. Finally, in the last chapter of this thesis, an optical delay line based on the propagation of optical slow light solitons in Coupled Resonator Optical Waveguides (CROWs) is proposed.Στη παρούσα διδακτορική διατριβή μελετώνται οι περιορισμοί μετάδοσης λόγω μη γραμμικών φαινομένων και ιδιαίτερα λόγω της μίξης τεσσάρων κυμάτων (Four-Wave Mixing - FWM). Αρχικά έγινε ακριβής ανάλυση της στατιστικής φύσης του θορύβου FWM χρησιμοποιώντας την μέθοδο Monte Carlo (MC) και για πρώτη φορά σε οπτικούς θορύβους τη μέθοδο Multicanonical Monte Carlo (MCMC). Η ανάλυση αυτή είναι εξαιρετικής σημασίας για τη σχεδίαση και μοντελοποίηση οπτικών δικτύων. Σε αυτά τα συστήματα, ο θόρυβος FWM αποτελεί την κυρία πηγή μη γραμμικής παραμόρφωσης ιδιαίτερα όταν χρησιμοποιούνται ίνες μη μηδενικής διασποράς (NZDF), υψηλή ισχύς εισόδου, μικρή απόσταση μεταξύ των καναλιών και αντιστάθμιση διασποράς. Η μέθοδος MCMC χρησιμοποιήθηκε επίσης για την μελέτη της επίδρασης της κίνησης IP κατά ριπάς στις επιδόσεις ενός δικτύου IP πάνω από ΜΡλS-DWDM που περιορίζεται από τους θορύβους FWM και ενδοκαναλικής διαφωνίας. Στη συνέχεια, προτάθηκαν δυο νέες μέθοδοι για την αντιμετώπιση του θορύβου FWM η υβριδική διαμόρφωση ASK/FSK και η επιβολή οπτικού τρυλλίσματος στον πομπό. Επίσης μελετήθηκε το θέμα της επιλογής του καταλληλότερου σχήματος οπτικής διαμόρφωσης σε συστήματα WDM με πολλά τμήματα ίνας και ίνες χαμηλής διασποράς (G 655). Τέλος, προτάθηκε και μελετήθηκε μια γραμμή καθυστέρησης που βασίζεται στη διάδοση σολιτονίων αργού φωτός μέσα σε έναν κυματοδηγό συζευγμένων αντηχείων (Coupled Resonator Optical Waveguide - CROW)

Econometric analysis of financial returns

After failing to reject the null of a unit root in the classical dividend-price ratio (dp), we show that a cointegrating relationship between dividends and prices exists. We then define the modified dividend-price ratio (mdp), as the long run trend deviation between log dividends and prices. Using S&P 500 data for the periods (1926-2009), (1926-2012) and (1965-2012), we show that mdp provides substantially improved forecasting results over the classical dp ratio. Out of sample, while the classical dp ratio cannot outperform the “mean” benchmark for any useful horizon, an investor who employs the modified dp ratio will do better in forecasting 3-5-and 7-year returns with a coefficient of determination of 15%, 32% and 36% respectively. The results remain robust for the second and third data interval. In sample, the coefficient of determination of mdp reaches the 70% for the subsample and 45% for the larger samples. Moreover, when both ratios are present in a multivariate setting, the classical dividend price ratio fails to bring any extra information about future returns. Thus, in the presence of the modified ratio, the only thing left for the classical dividend-price ratio to predict is its forward looking value.Βασικό ερευνητικό αντικείμενο της παρούσας διδακτορικής διατριβής αποτελεί η τροποποίηση της μερισματικής απόδοσης, ώστε να παρουσιάζει καλύτερα αποτελέσματα όσον αφορά την πρόβλεψη των αποδόσεων, τόσο εντός όσο και εκτός δείγματος, σε σχέση με την κλασική μερισματική απόδοση. Η σύνθεση της τροποποιημένης μερισματικής απόδοσης βασίζεται στη παραδοχή της ύπαρξης συνολοκλήρωσης ανάμεσα στα μερίσματα και τις τιμές, ικανοποιώντας τη βασική σχολή θεμελιώδους σκέψης. Χρησιμοποιώντας δεδομένα για τον δείκτη S&P 500 για τα χρονικά διαστήματα (1926-2009), (1926-2012) και (1965-2012), καταλήξαμε στα εξής συμπεράσματα για την εκτός δείγματος ανάλυση: Στο πρώτο διάστημα η τροποποιημένη μερισματική απόδοση μπορεί να ερμηνεύσει το 15%, το 32% καθώς και το 36% της μεταβλητότητας των μελλοντικών αποδόσεων σε ορίζοντα τριών (3), πέντε (5) και επτά (7) ετών αντίστοιχα, κάτι το οποίο δεν μπορεί να επιτευχθεί με την κλασσική μερισματική απόδοση. Τα εν λόγω ποσοστά ανέρχονται στο 7%, στο 26% και στο 31% για το δεύτερο διάστημα και παραμένουν ανάλογα και για το τρίτο διάστημα. Όσον αφορά την εντός δείγματος ανάλυση, η τροποποιημένη μερισματική απόδοση παρουσιάζει μεγαλύτερα ποσοστά ερμηνείας της διακύμανσης των μελλοντικών αποδόσεων, σε σχέση με την κλασική μερισματική απόδοση, που αγγίζουν το 70% για το διάστημα (1965-2012) και το 49% για τα ευρύτερα διαστήματα. Επιπλέον, παρούσας της τροποποιημένης μερισματικής απόδοσης, η μερισματική απόδοση μπορεί να προβλέψει μόνο τον παράγοντα ορθολογικής φούσκας (δηλαδή την μελλοντική σταθμισμένη μερισματική απόδοση), παρουσιάζοντας με αυτόν τον τρόπο μία τεχνητή ικανότητα πρόβλεψης των αποδόσεων σε μεγαλύτερους χρονικούς ορίζοντες από αυτούς που υποδηλώνονται με βάση την τροποποιημένη μερισματική απόδοση