Ο ταχύτατα εξελισσόμενος τομέας των δικτύων κινητών επικοινωνιών έχει επιφέρει μία ιδιαίτερα αυξανόμενη απαίτηση για ασύρματη, πολυμεσική επικοινωνία. Στη ραγδαία εξέλιξη του τομέα αυτού συμβάλουν τα μέγιστα και οι απαιτήσεις της σύγχρονης αγοράς για ένα ενοποιημένο και λειτουργικό σύστημα κινητής τηλεφωνίας παρέχοντας παράλληλα πληθώρα ευρυζωνικών υπηρεσιών ψηφιακού περιεχομένου στους πελάτες - χρήστες του. Είναι γεγονός ότι τα τελευταία χρόνια τα δίκτυα επικοινωνιών τρίτης γενιάς (3G) - Universal Mobile Telecommunication System (UMTS) γνωρίζουν μεγάλη άνθηση και η χρήση τους έχει επεκταθεί στις περισσότερες ευρωπαϊκές χώρες, όπως και στην Ελλάδα. Τα νέα αυτά κινητά δίκτυα αντικαθιστούν τα υπάρχοντα κινητά δίκτυα δεύτερης γενιάς και επιπλέον προσφέρουν προηγμένες υπηρεσίες στους κινητούς χρήστες. Ωστόσο, η αδήριτη ανάγκη για μεγαλύτερες (ευρυζωνικές) ταχύτητες πρόσβασης οδήγησε στην περαιτέρω ανάπτυξη των 3G δικτύων και στην υιοθέτηση νέων τεχνολογιών, με κυριότερο εκπρόσωπο τους την τεχνολογία High Speed Packet Access (HSPA). Η τεχνολογία HSPA αποτελεί τη φυσιολογική μετεξέλιξη του UMTS, η οποία πολλές φορές συναντάται και ως 3.5G ή 3G+, προκειμένου να δηλώσει την αναβάθμιση του 3G (UMTS) προτύπου. Ωστόσο, παρά το γεγονός ότι η τεχνολογία HSPA αναμένεται να προσφέρει τη δυνατότητα παροχής πληθώρας ευρυζωνικών υπηρεσιών, το 3rd Generation Partnership Project (3GPP), που αποτελεί τον οργανισμό που προτυποποιεί τις νέες τεχνολογίες και ορίζει τις προδιαγραφές τους, ήδη μελετά και επεξεργάζεται νέες τεχνολογίες που θα επικρατήσουν την αμέσως επόμενη δεκαετία στην αγορά των κινητών επικοινωνιών. Το νέο αυτό project αποκαλείται Long Term Evolution (LTE) και στοχεύει στην επίτευξη ακόμη υψηλότερων ρυθμών μετάδοσης σε συνδυασμό με την αξιοποίηση μεγαλύτερου εύρος ζώνης. Κύρια προοπτική του LTE αποτελεί η διασφάλιση της ανταγωνιστικότητας και η επικράτηση του προτύπου στο χρονικό ορίζοντα της επόμενης δεκαετίας. Κατά συνέπεια, η αγορά κινητών επικοινωνιών σταδιακά μεταλλάσσεται προς τη δημιουργία δικτύων κινητών επικοινωνιών επόμενης γενιάς, με απώτερο σκοπό την επίτευξη της αποκαλούμενης «Κινητής Ευρυζωνικότητας» (Mobile Broadband). Ταυτόχρονα με την εκτεταμένη εξάπλωση των δικτύων κινητών επικοινωνιών επόμενης γενιάς καθώς και τις αυξημένες δυνατότητες των κινητών συσκευών, οι πάροχοι πολυμεσικού περιεχομένου και υπηρεσιών ενδιαφέρονται όλο και περισσότερο για την υποστήριξη της πολυεκπομπής (multicasting) δεδομένων στα δίκτυα αυτά με σκοπό την αποτελεσματική διαχείριση και επαναχρησιμοποίηση των διαθέσιμων πόρων του δικτύου. Επιπρόσθετα, οι χρήστες των κινητών δικτύων έχουν πλέον την απαίτηση να προσπελαύνουν εφαρμογές και υπηρεσίες οι οποίες μέχρι σήμερα μπορούσαν να διατεθούν αποκλειστικά από τα συμβατικά ενσύρματα δίκτυα. Έτσι λοιπόν στις μέρες μας γίνεται λόγος για υπηρεσίες πραγματικού χρόνου όπως mobile TV, mobile gaming, mobile streaming κ.α. Ένα από τα σημαντικότερα βήματα των δικτύων κινητών επικοινωνιών προς την κατεύθυνση της παροχής νέων, προηγμένων πολυμεσικών υπηρεσιών είναι η εισαγωγή της υπηρεσίας Multimedia Broadcast / Multicast Service (MBMS). Η υπηρεσία MBMS έχει σαν κύριο σκοπό την υποστήριξη IP εφαρμογών πανεκπομπής (broadcact) και πολυεκπομπής (multicast), επιτρέποντας με αυτό τον τρόπο την παροχή υπηρεσιών υψηλού ρυθμού μετάδοσης σε πολλαπλούς χρήστες με οικονομικό τρόπο. Η multicast μετάδοση δεδομένων σε κινητά δίκτυα επικοινωνιών είναι μια σχετικά νέα λειτουργικότητα η οποία βρίσκεται ακόμη στο στάδιο των δοκιμών και της προτυποποίησης της. Ένας multicast μηχανισμός μεταδίδει τα δεδομένα μόνο μία φορά πάνω από κάθε ασύρματο σύνδεσμο που αποτελεί τμήμα των μονοπατιών προς τους προορισμούς-κινητούς χρήστες. Το κρισιμότερο σημείο που εντοπίζεται κατά τη multicast μετάδοση δεδομένων στα κινητά δίκτυα επικοινωνιών είναι ο αποτελεσματικός έλεγχος ισχύος. Οι σταθμοί βάσης των κυψελωτών αυτών δικτύων διαθέτουν περιορισμένους πόρους ισχύος, γεγονός που περιορίζει τη χωρητικότητα της κυψέλης (cell) και επιβάλλει τη χρήση μίας βέλτιστης στρατηγικής για την όσο το δυνατόν καλύτερη αξιοποίηση των διαθέσιμων πόρων ισχύος. Ο έλεγχος ισχύος στοχεύει στη μείωση της εκπεμπόμενης ισχύος, στην ελαχιστοποίηση του θορύβου στο κυψελωτό δίκτυο και κατά συνέπεια στη διασφάλιση μεγαλύτερης χωρητικότητας επιπλέον χρηστών. Ένα από τα βασικότερα στοιχεία του ελέγχου ισχύος στα δίκτυα κινητών επικοινωνιών επόμενης γενιάς κατά τη multicast μετάδοση πολυμεσικών δεδομένων αποτελεί η επιλογή του κατάλληλου καναλιού μεταφοράς για τη μετάδοση των δεδομένων στον κινητό χρήστη. Συγκεκριμένα, πρόκειται για ένα κρίσιμο ζήτημα το οποίο είναι ακόμα υπό εξέταση στο 3GPP. Προς την κατεύθυνση αυτή, στο MBMS πρότυπο έχουν αναπτυχθεί διάφοροι μηχανισμοί, με χαρακτηριστικό τον MBMS Counting Mechanism. Στόχος του μηχανισμού αυτού είναι η βελτιστοποίηση της ροής δεδομένων για την υπηρεσία MBMS, όταν αυτά διέρχονται από τις διεπαφές του UMTS/HSPA δικτύου. Ωστόσο, η υπάρχουσα μορφή του μηχανισμού αυτού, καθώς και των αρκετών άλλων μηχανισμών που έχουν προταθεί από το 3GPP, διακρίνεται από πολλές αδυναμίες που δεν επιτρέπουν την αποτελεσματική και μαζική μετάδοση πολυμεσικών δεδομένων. Τα σημαντικότερα προβλήματα των μηχανισμών αυτών είναι η απουσία ευρυζωνικών χαρακτηριστικών καθώς και η σπατάλη σημαντικού τμήματος των ούτως ή άλλως περιορισμένων πόρων ισχύος. Εν γένει, η επιλογή του κατάλληλου καναλιού μεταφοράς των πολυμεσικών δεδομένων στο ασύρματο μέσο είναι μια δύσκολη διαδικασία καθώς μια λανθασμένη επιλογή καναλιού μπορεί να οδηγήσει στην αστοχία μίας ολόκληρης κυψέλης. Γίνεται σαφές λοιπόν, ότι απαιτείται μία βελτιωμένη έκδοση των υπαρχόντων μηχανισμών για την αποτελεσματικότερη και οικονομικότερη μετάδοση πολυμεσικού περιεχομένου σε μεγάλο πλήθος χρηστών. Λαμβάνοντας υπόψη τα παραπάνω, στόχος της παρούσας διδακτορικής διατριβής είναι η μελέτη του ελέγχου ισχύος στα δίκτυα κινητών επικοινωνιών επόμενης γενιάς καθώς και η ανάπτυξη νέων μεθόδων/μηχανισμών για τη βελτιστοποίηση του. Ιδιαίτερο χαρακτηριστικό της διατριβής αυτής είναι η ενσωμάτωση και η «εκμετάλλευση» όλων των ιδιαίτερων χαρακτηριστικών της HSPA τεχνολογίας στην MBMS υπηρεσία. Προς αυτή την κατεύθυνση, στην παρούσα διδακτορική διατριβή αναλύονται και αξιολογούνται όλα τα υπάρχοντα κανάλια μεταφοράς του UMTS και της τεχνολογίας HSPA τα οποία μπορούν να χρησιμοποιηθούν για τη multicast μετάδοση MBMS υπηρεσιών. Η αξιολόγηση γίνεται με βάση την απαιτούμενη ισχύ που πρέπει να ανατεθεί από το σταθμό βάσης για καθένα από αυτά, και κατά συνέπεια με βάση το ρυθμό μετάδοσης τους, τον αριθμό των χρηστών που μπορούν να εξυπηρετήσουν, την ποιότητα υπηρεσιών για κάθε χρήστη, τη μέγιστη δυνατή κάλυψη της κυψέλης κ.α. Οι ιδιαίτερα αυξημένες απαιτήσεις των MBMS υπηρεσιών μας οδήγησαν στη συνέχεια στη διερεύνηση και αξιολόγηση ορισμένων τεχνικών μείωσης της εκπεμπόμενης ισχύος, με απώτερο σκοπό την αποδοτικότερη χρήση των πόρων του συστήματος κατά τη μετάδοση MBMS υπηρεσιών. Ενδεικτικά αναφέρουμε πως μία MBMS υπηρεσία με ρυθμό μετάδοσης 128 Kbps μπορεί να καταναλώσει έως και το 80% των πόρων ισχύος ενός σταθμού βάσης. Επομένως, γίνεται κατανοητό ότι η μετάδοση MBMS υπηρεσιών με τόσο υψηλούς ρυθμούς μετάδοσης καθίσταται δύσκολη έως και αδύνατη. Για την αντιμετώπιση αυτού του προβλήματος έχουν αναπτυχθεί τεχνικές, όπως η FACH Dynamic Power Setting, η Macro Diversity Combining και το Rate Splitting, ικανές να μειώσουν τα επίπεδα ισχύος κατά τη μετάδοση multicast δεδομένων στους MBMS χρήστες. Η διδακτορική αυτή διατριβή εξετάζει την αποδοτικότητα της χρήσης αυτών των τεχνικών εξοικονόμησης ισχύος και παρουσιάζει πειραματικά αποτελέσματα που αποκαλύπτουν το ποσό ισχύος που εξοικονομείται από κάθε μία τεχνική. Η αξιολόγηση τόσο των καναλιών μεταφοράς όσο και των τεχνικών μείωσης ισχύος θα οδηγήσει στην εύρεση ενός κατάλληλου σχήματος/μηχανισμού, ο οποίος θα εξασφαλίζει την αποδοτική εναλλαγή μεταξύ των διάφορων τύπων καναλιών κατά τη μετάδοση MBMS υπηρεσιών. Ο μηχανισμός αυτός, τον οποίο καλούμε MBMS Channel Assignment Mechanism (ή χάριν συντομίας «MCAM»), αναμένεται να εξασφαλίσει βελτιωμένη απόδοση σε σχέση με τους αντίστοιχους μηχανισμούς που έχουν προταθεί από το 3GPP, μείωση της καταναλισκόμενης ισχύος και κατά συνέπεια αύξηση της χωρητικότητας των κινητών δικτύων επόμενης γενιάς. Ωστόσο, το πιο αξιοπρόσεκτο πλεονέκτημα του προτεινόμενου μηχανισμού, που ουσιαστικά τον διαφοροποιεί από τις άλλες προσεγγίσεις, είναι ότι προσαρμόζεται στις αυξημένες απαιτήσεις των κινητών δικτύων επόμενης γενιάς για ταυτόχρονη παροχή πολλαπλών πολυμεσικών συνόδων. Το γεγονός αυτό μπορεί να επιτρέψει τη μαζική μετάδοση πολυμεσικών δεδομένων σε πληθώρα κινητών χρηστών, θέτοντας κατά τον τρόπο αυτό τον MCAM σαν έναν ισχυρό υποψήφιο για τα δίκτυα επόμενης γενιάς. / The rapid growth of mobile communications networks has involved an increasing demand for wireless, multimedia communication. The fast development of this area was mainly motivated by the requirements of modern market for a unified and functional system of mobile communications that, at the same time, may provide numerous broadband services to its users. More specifically, in the recent years, the usage of third generation (3G) - Universal Mobile Telecommunication System (UMTS) cellular networks has begun to rise in most European countries, as in Greece. 3G networks have replaced the second generation mobile networks and moreover, are in position of offering advanced services to mobile users. However, the need for higher (broadband) speeds led to the further development of 3G networks and to the adoption of new technologies, with main representative the High Speed Packet Access (HSPA) technology. HSPA constitutes the evolution of UMTS and is known as 3.5G or 3G+ in order to indicate the upgrade from UMTS. However, despite the fact that HSPA technology is expected to allow the provision of numerous broadband services, the 3rd Generation Partnership Project (3GPP), the authorized organization for the standardization of new mobile technologies, already examines new technologies that will prevail in the mobile communications industry over the next decades. This novel project is known as Long Term Evolution (LTE) and aims at achieving increased data rates and reduced latency compared to UMTS and HSPA networks. Therefore, the mobile communications industry progressively evolves to next generation networks, with main target the achievement of the so called “Mobile Broadband”. Simultaneously, multimedia content and service providers show an increased interest in supporting multicast data in order to effectively manage and re-use the available network resources. Additionally, more and more users require access to applications and services that until today could only be accessed by conventional wired networks. Thus, real time applications and services may face low penetration today; however, they are expected to gain high interest in future mobile networks. These applications actually reflect a modern, future way of communication among mobile users. For instance, mobile TV is expected to be a “killer” application for 3G’s. Such mobile TV services include streaming live TV (news, weather forecasts etc.) and streaming video (such as video clips). All the above constitute a series of indicative emerging applications that necessitate advanced transmission techniques. One of the most significant steps towards the provision of such demanding services is the introduction of Multimedia Broadcast/Multicast Service (MBMS). MBMS is a point-to-multipoint service in which data is transmitted from a single source entity to multiple destinations, allowing the networks resources to be shared. Actually, MBMS extends the existing UMTS infrastructure and efficiently uses network and radio resources, both in the core network and most importantly, in the air interface of UMTS, where the bottleneck is placed to a large group of users. Therefore, MBMS constitutes an efficient way to support the plethora of the emerging wireless multimedia applications and services such as IP video conferencing and video streaming. The main requirement during the provision of MBMS multicast services is to make an efficient overall usage of radio and network resources. This necessity mainly translates into improved power control strategies, since the base stations’ transmission power is the limiting factor of downlink capacity in UMTS networks. Under this prism, power control is one of the most critical aspects in MBMS due to the fact that downlink transmission power in UMTS networks is a limited resource and must be shared efficiently among all MBMS users in a cell. Moreover, power control aims at minimizing the transmitted power, eliminating in this way the intercell interference. However, when misused, the use of power control may lead to a high level of wasted power and worse performance results. In order to have efficient power control in MBMS, one of the most critical aspects is the selection of the transport channel for the transmission of MBMS multicast traffic. MBMS services can be provided in each cell by either multiple point-to-point (PTP) channels or by a single point-to-multipoint (PTM) channel. A wrong channel selection may result to a significant capacity decrease, thus, preventing the mass delivery of multimedia applications. It is worth mentioning that channel selection is still an open issue in today’s MBMS infrastructure mainly due to its catalytic role in MBMS performance. In the frame of MBMS power control and transport channel selection several approaches have been proposed, with main representative the 3GPP MBMS Counting Mechanism. However, none of these approaches performs optimal transport channel selection either due to the fact that some of them do not consider the power consumption as the selection criterion or because of the fact that they do not consider all the available transport channels (or combination of them) for the transmission of the MBMS data. All the above stress the need for an advanced version of these mechanisms that could deliver multimedia content to a large number of mobile users in a more efficient and economic way. After taking into account the above analysis, objective of this dissertation is the study of power control issues in next generation mobile communication networks and the development of new approaches/ mechanisms for its optimization. To this direction, this dissertation analyzes and evaluates all the available UMTS and HSPA transport channels that could be used for the transmission of MBMS multicast services. Moreover, this dissertation investigates and evaluates several power saving techniques that aim at the efficient usage of radio and network resources. Techniques, such as Dynamic Power Setting, Macro Diversity Combining and Rate Splitting are capable of decreasing the power consumption during the provision of MBMS services and may enable the mass market delivery of multimedia services to mobile users. The evaluation of the available transport channels and power saving techniques will lead to the development of a novel scheme/mechanism that will enable the efficient selection of transport channels for the transmission of MBMS services. The proposed mechanism, which we call MBMS Channel Assignment Mechanism (or «MCAM»), is expected to optimally utilize the available power resources of base stations to MBMS sessions running in the network, resulting in that way to an extensive increase on the system’s capacity. Therefore, MCAM may allow the mass provision of multimedia data to a large number of mobile users, which makes MCAM a strong candidate for next generation networks.

[pt] Este trabalho descreve uma ferramenta de simulação esenvolvida para analisar o gerenciamento dos recursos de rádio e parâmetros de QoS (Quality of Service) dos sistemas móveis celulares. Pela natureza de um sistema real de telefonia celular, é extremamente difícil que as variáveis de saída de um simulador sejam derivadas de um conjunto real de funções. Isso se deve à grande quantidade de parâmetros que devem ser considerados no comportamento da mobilidade, nas condições de tráfego, nas características geográficas e morfológicas da região, na modelagem complexa do canal rádio propagação móvel, entre outras. Visando a desenvolver uma ferramenta de simulação próxima da realidade, adotam-se modelos de propagação, de mobilidade e de tráfego que sejam satisfatoriamente adequados ao caso real. A contribuição deste trabalho é oferecer uma ferramenta de simulação flexível, aqui adequada ao sistema norte-americano TDMA (IS-136), que possibilite ao usuário, além de analisar a capacidade do sistema,também avaliar novos algoritmos de controle de potência, novas estratégias de handoff, novos esquemas de alocação de canal e modelos de propagação. A ferramenta será validada seguindo o processo de um projeto real de telefonia celular e ao final, será aplicada a um sistema celular com sobreposição macro-células/micro-células, analisando-se algumas estratégias de handoff dedicadas a esses sistemas. / [en] This work describes a simulation tool, which was developed to analyze the radio resources and QoS (Quality of Service) parameters in mobile systems. Because of the complex characteristics of an actual cellular network, it is extremely difficult having the outputs of the simulator being derived from a real set of functions, due to the large amount of parameters that have to be considered such as the mobility behavior, the traffic conditions, the geographic and morphologic characteristics of the region, the complex modeling of mobile radio propagation channel, and so on. In order to develop a simulation tool as near as possible to the reality, models that are satisfactorily adequate to the real case have been considered. So, propagation, mobility and traffic models were adapted from the IS-136 American system. The contribution of this work is to offer a flexible simulation tool that allows the user, in addition to analyzing the capacity of the system, to evaluate new algorithms of power control, handoff strategies, channel allocation schemes and propagation models. The tool will be validated following the process of a real project of cellular telephony and at the end, it will be applied to a cellular system with overlapped macro- cells/micro-cells, and some handoff strategies dedicated to those systems will be analyzed.

[pt] Com o crescimento da utilização das redes celulares para a transmissão de dados, as operadoras de telefonia móvel estão enfrentando um aumento dramático na utilização do recurso rádio para suprir esta nova necessidade. Com isto, estão sendo obrigadas a migrarem para novas tecnologias que propiciem uma alta eficiência espectral, permitindo assim uma melhor utilização do espectro disponível. Este trabalho descreve uma ferramenta de simulação desenvolvida para analisar o gerenciamento dos recursos de rádio, além de propor um novo algoritmo de alocação de canais de dados para sistemas móveis pessoais, permitindo a transmissão de voz e dados sobre a mesma interface aérea. É sabido que é extremamente difícil levar em conta todos os parâmetros que devem ser considerados em um sistema móvel real. Procurou-se então adotar os mais conhecidos modelos de propagação, de mobilidade e de tráfego de voz e de dados disponíveis na literatura, de forma a tentar aproximar a ferramenta de simulação o máximo possível do caso real. A contribuição deste trabalho é oferecer uma ferramenta de simulação para as redes GSM/HSCSD que permita a otimização da eficiência no uso do espectro disponível para transmissão. Esta ferramenta possibilita ao usuário, além de analisar a capacidade do sistema, o controle de potência e estratégias de handover, avaliar novos algoritmos de alocação de canal para o tráfego de voz e dados em conjunto. Ao final desta dissertação serão apresentados os resultados obtidos com a utilização de um novo algoritmo de alocação de canais para o tráfego de dados, além de realizar algumas outras simulações buscando maximizar a eficiência espectral do sistema utilizando deste novo algoritmo. / [en] Due to the increasing use of cellular networks for data transmission, mobile telephone operators are facing a dramatic raise in using radio resources to supply their demand. As a result, they are being forced to migrate to new technologies that provide high spectral efficiency, allowing an optimized use of available spectrum. This work describes the development of an advanced tool to analyze the operator management of radio transmission for personal mobile systems. The model was built considering well-known propagation, mobility, voice and data traffic for transmission assumptions, in order to approximate the developed tool to the real world mobile systems. The simulation tool is suited for GSM/HSCSD networks allowing engineers to optimize the efficient use of the available spectrum. It also permits the evaluation of system capacity as well as the analysis of power control and handover strategies. Another application exploited in this work is the investigation of resource allocation algorithms. A new algorithm for resource allocation in integrated voice and data environments was proposed and its performance was evaluated using the simulation tool.

Emotion research is an important research topic, thus making the measurement of emotion in the workplace crucial. In attempting to study, understand and measure the role of emotions in the human condition, various researchers have identified different theoretical models to manage the information they have gathered and the observations they have made. In order to study or scientifically investigate any human behaviour, it is essential that such behaviour can be measured, if not quantitatively, then at least qualitatively. However, what one finds with regard to emotion research and measurement are two–dimensional models. The existing affect has been described with a choice of two dimensions and structures, i.e. circumplex, positive and negative affect, tense and energetic arousal, and eight combinations of pleasantness and activation. These two dimensions and structures measure a person’s experiences and, thereafter, report them. The question is if these two–dimensional emotion models are sufficient to cover the broad and often complex dynamics of emotions. The start of multiple–emotion dimension models were reported by researchers, who identified a three–dimensional structure in the emotion domain that is suggestive of the Evaluation–Potency– Activation (EPA) dimensions in the connotative or affective meaning of words. However, in recent studies the sufficiency of two–dimension models to comprehensively investigate emotions was questioned. The three–dimensional emotion model was replicated in cross–cultural similarity sorting studies by other researchers. The similarity sorting studies also indicate the importance of studying emotions in specific cultural contexts. Studying emotion in different cultures is especially relevant in a country such as South Africa that has a variety of cultures and eleven official languages. Researchers followed an approach that studied the meaning of emotion in different cultural groups in the context of 144 emotion features using a componential emotion theory approach. Researchers argue in the groundbreaking research that was published in Psychological Science that emotion meaning has more than only two dimensions. The approach postulated by researchers was tested in a student population of three language groups, namely Dutch–, Englishand French–speaking students. According to researchers this is an empirical and theoretical method to study the meaning of emotions across cultures. However, apart from studying the meaning of emotions in specific cultural groups, research also attempts to determine the meaning of emotion in the natural contexts in which they occur. The relevant natural contexts for the field of Industrial Psychology are the work contexts. It is therefore also important to investigate the categories of emotion episodes in the work environment. The general goal of this study was therefore a) to investigate the emotion lexicon in the white Afrikaans–speaking working adult language group, b) to determine the cognitive emotion structure of this cultural group, c) to investigate the meaning of emotion as comprehensively as possible (multidimensional models of the meaning of emotion), and d) to determine the meaning and content of emotion episodes in the workplace. Research Article 1 The research was subsequently presented in two independent phases. Firstly, a free listing of emotion terms was compiled, and secondly the emotion terms were prototypically rated by Afrikaans–speaking people in South Africa. Both of these were then used as measuring instruments. A survey was designed to explore the research objectives utilising availability samples in two studies. The participants in the free–listing (N=70) and in the prototypicality (N=70) study consisted of native Afrikaans–speaking employees. The sample consisted of participants from the white ethnic group speaking Afrikaans within the Eastern Cape, Gauteng, Free State, Mpumalanga, North–West and KZN provinces and use was made of an availability sample. After conducting the research, the emotion terms with the highest frequency, as identified during the first study, the free listing task, were to be happy (gelukkig wees), be sad (hartseer wees), love (liefde), anger (kwaad) and hateful (haatlik). The emotion terms with the lowest scores as identified during the free listing were uncomfortable (ongemaklik), painful (seer), be hurt (seergemaak wees), sympathetic (simpatiek) and shout/yell (skreeu). Correspondingly, the five (5) prototypical terms with the highest scores in Afrikaans were nice (lekker), fed–up/had enough (gatvol/“genoeg gehad”), loveable (liefdevol), anger (kwaad) and to be scared (om bang te wees). The five (5) least prototypical terms from the list generated in the free listing task were: unstable (onvas), bashfulness (skugterheid), captivation (geboeidheid), envy (naywer) and delight (opgetoënheid). From the information obtained in this research it was revealed that the emotion terms nice (lekker), fed up/had enough (gatvol/“genoeg gehad”) and loveable (liefdevol) are at this stage unique to the white Afrikaans language group. These terms had not been reported in any previously conducted prototypical studies. The results of this study contribute to a cross–cultural understanding of the emotion concepts within the Afrikaans–speaking language groups in South Africa. Research Article 2 A survey design was used to achieve the research objectives utilising availability samples in a series of one study. The participants of the Similarity study (N=131) consisted of native Afrikaans–speaking employees. The sample consisted of participants from the white ethnicity group speaking Afrikaans within the Eastern Cape, Gauteng, Free State, Mpumalanga, North– West, KZN and Northern Cape provinces and use was made of an availability sample. Results of Multidimensional Scaling revealed a three–dimensional cognitive emotion structure. The first dimension was the evaluation–pleasantness dimension. This dimension evaluates the pleasantness versus the unpleasantness of an emotion. This dimension is characterised by intrinsic appraisals of pleasantness and goal conduciveness and action tendencies of approach versus avoidance. The second dimension that emerged was a power–control dimension. This dimension is characterised by appraisals of control, how powerful or weak a person feels when a particular emotion is experienced. This includes feelings of dominance or submission, the impulse to act or withdraw and changes in speech and parasymphatic symptoms. The third dimension which emerged was an activation–arousal dimension. According to other researchers this arousal dimension is characterised by sympathetic arousal, e.g. rapid heartbeat and readiness for action. This study produced a cognitive emotion structure in a white Afrikaans–speaking working adult population in South Africa. To add value to the field of Industrial Psychology, the threedimension structure (evaluation–pleasantness, power–control and activation–arousal dimension) that was found, is very important and valuable when studying the meaning of emotion and can consequently be used as a reference for other emotion research constructs. If it is accurate as stated in literature, there are three and not only two emotion dimension structures, and researchers are missing out on a bigger picture for not drawing on the experience of emotion sufficiently. Research Article 3 A survey design and an availability sample (N=120) in the Eastern Cape, Free State and Gauteng provinces in South Africa was utilised for this study. The Meaning Grid was translated and backtranslated and adapted for use in Afrikaans. The Cronbach's alpha coefficients were obtained for the emotion terms. According to the results of the Meaning Grid instrument, the following emotion terms were the highest: disgust (afkeur) 0,95; pleasure (plesier) 0,94; stress (stres) 0,92; happiness (blydskap) 0,91; joy (vreugde) 0,91; fear (bang) 0,91; anger (angstig) 0,91 and hate (haat) 0,90. The emotion terms that scored the lowest with the Meaning Grid instrument were compassion (medelye) 0,79; pride (trots) 0,79 and contempt (minagting) 0,74. Out of the 24 emotion terms of the Meaning Grid instrument, 8 terms were above 0,90 and 13 were between 0,80 and 0,89. Only 3 terms were between 0,74 and 0,79 [compassion (medelye), pride (trots) and contempt (minagting)]. A three–factor solution was found which represented four emotion dimensions (evaluation, arousal/unpredictability and power) that were universal to the emotion structures found in European samples. Factor scores of the 24 Meaning Grid emotions indicate a three–factor solution that explained 62,2 % of the total variance. The first factor was labelled evaluation and explained 43,0% of the variance, the second factor was labelled arousal/unpredictability as it was a combination of arousal and unpredictability and explained 11,0% of the variance, and the third factor was labelled power and explained 8,2% of the variance. This study followed an approach that investigated the meaning structure of emotion in the sample group in the context of 144 emotion features using a componential emotion theory approach. Different researchers argued that emotion meaning has more than only two dimensions. A three–dimensional emotion structure was found that was universal to the emotion structures of three language groups in a European sample. Therefore, the meaning of emotions for this sample group is far more complex than the two–dimensional emotion models that are found in literature. According to the componential emotion theory approach, the 144 emotion features are very important building blocks for Industrial Psychology when studying the meaning of emotion. Research Article 4 A survey design was used in this research study. The Episode Meaning Grid was administered and participants reported on the two intense emotion experiences at work (in total 358 episodes). Employees rated their emotion experiences on features based on the componential emotion theory and also described the emotion events in their own words. The participants in the emotion episodes (N=179) study consisted of native white Afrikaans–speaking working adults. The sample consisted of participants from the white ethnicity group speaking Afrikaans within the Eastern Cape, Free State and North–West provinces and use was made of an availability sample. The results indicated a three–dimensional structure (evaluation–pleasantness, activation–arousal and power–control dimension) was identified within a white Afrikaans–speaking working adult language group. The first dimension was an evaluation–pleasantness dimension. The second dimension was an activation–arousal dimension. The third dimension was a power–control dimension. Regarding the reporting of emotion episodes one hundred and ninety seven respondents reported 84 satisfying emotion episodes and 267 less satisfying emotion episodes that took place at work. Nine different categories of episodes for satisfying emotions experienced were mentioned. It consists of behaviour of work colleagues, acts of boss/superior/management, goal achievement, receiving recognition, workplace policy, task recognition, personal incidents, emotion involvement and subordinate behaviour. The three highest categories of satisfying emotions episodes were “Goal Achievement” (N=31), “Receiving Recognition” (N=20) and “Personal Incidents” (N=10). Goal achievement describes situations where job related targets or goals were met, and receiving recognition refers to positive feedback from managers, supervisors and work colleagues on meeting targets. Nineteen different categories of episodes for less satisfying emotion episodes were mentioned. It consists of behaviour of work colleagues, acts of boss/superior/management, lack of goal achievement, lack of receiving recognition, workplace policy, task requirement, personal incidents, emotional involvement, subordinate behaviour, workload, work mistakes, customer behaviour, external environment, lack of control, physical well–being, involvement in disciplinary action, workplace strikes, wellness of colleagues and unfairness in the workplace. In the categories of less satisfying emotions episodes, the three highest were “Behaviour of Work Colleagues” (N=58), “Acts of Boss/Superior/Management” (N=47) and “Task Requirement” (N=33). The first two categories are appraised less satisfying behaviour towards oneself or others by work colleagues, managers, supervisors and customers. In terms of the categories of satisfying and less satisfying emotions episodes, less satisfying emotion episodes outnumbered satisfying emotions episodes by three to one. By making use of a multi–componential emotion model, the results confirm that the four factors of pleasantness, power, arousal, and unpredictability, in that order of importance, are essential to satisfactorily determine the emotion experience and meaning of emotion terms. A threedimensional emotion structure (evaluation, arousal and power) was found after determining the meaning of emotion in the natural contexts in which they occur. The answer to the question if these two–dimensional emotion models, as stated in literature, are sufficient to cover the broad and often complex dynamics of emotion, is certainly no. Recommendations for the organisation and future research were made. / Thesis (Ph.D. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2012.

Emotion research is an important research topic, thus making the measurement of emotion in the workplace crucial. In attempting to study, understand and measure the role of emotions in the human condition, various researchers have identified different theoretical models to manage the information they have gathered and the observations they have made. In order to study or scientifically investigate any human behaviour, it is essential that such behaviour can be measured, if not quantitatively, then at least qualitatively. However, what one finds with regard to emotion research and measurement are two–dimensional models. The existing affect has been described with a choice of two dimensions and structures, i.e. circumplex, positive and negative affect, tense and energetic arousal, and eight combinations of pleasantness and activation. These two dimensions and structures measure a person’s experiences and, thereafter, report them. The question is if these two–dimensional emotion models are sufficient to cover the broad and often complex dynamics of emotions. The start of multiple–emotion dimension models were reported by researchers, who identified a three–dimensional structure in the emotion domain that is suggestive of the Evaluation–Potency– Activation (EPA) dimensions in the connotative or affective meaning of words. However, in recent studies the sufficiency of two–dimension models to comprehensively investigate emotions was questioned. The three–dimensional emotion model was replicated in cross–cultural similarity sorting studies by other researchers. The similarity sorting studies also indicate the importance of studying emotions in specific cultural contexts. Studying emotion in different cultures is especially relevant in a country such as South Africa that has a variety of cultures and eleven official languages. Researchers followed an approach that studied the meaning of emotion in different cultural groups in the context of 144 emotion features using a componential emotion theory approach. Researchers argue in the groundbreaking research that was published in Psychological Science that emotion meaning has more than only two dimensions. The approach postulated by researchers was tested in a student population of three language groups, namely Dutch–, Englishand French–speaking students. According to researchers this is an empirical and theoretical method to study the meaning of emotions across cultures. However, apart from studying the meaning of emotions in specific cultural groups, research also attempts to determine the meaning of emotion in the natural contexts in which they occur. The relevant natural contexts for the field of Industrial Psychology are the work contexts. It is therefore also important to investigate the categories of emotion episodes in the work environment. The general goal of this study was therefore a) to investigate the emotion lexicon in the white Afrikaans–speaking working adult language group, b) to determine the cognitive emotion structure of this cultural group, c) to investigate the meaning of emotion as comprehensively as possible (multidimensional models of the meaning of emotion), and d) to determine the meaning and content of emotion episodes in the workplace. Research Article 1 The research was subsequently presented in two independent phases. Firstly, a free listing of emotion terms was compiled, and secondly the emotion terms were prototypically rated by Afrikaans–speaking people in South Africa. Both of these were then used as measuring instruments. A survey was designed to explore the research objectives utilising availability samples in two studies. The participants in the free–listing (N=70) and in the prototypicality (N=70) study consisted of native Afrikaans–speaking employees. The sample consisted of participants from the white ethnic group speaking Afrikaans within the Eastern Cape, Gauteng, Free State, Mpumalanga, North–West and KZN provinces and use was made of an availability sample. After conducting the research, the emotion terms with the highest frequency, as identified during the first study, the free listing task, were to be happy (gelukkig wees), be sad (hartseer wees), love (liefde), anger (kwaad) and hateful (haatlik). The emotion terms with the lowest scores as identified during the free listing were uncomfortable (ongemaklik), painful (seer), be hurt (seergemaak wees), sympathetic (simpatiek) and shout/yell (skreeu). Correspondingly, the five (5) prototypical terms with the highest scores in Afrikaans were nice (lekker), fed–up/had enough (gatvol/“genoeg gehad”), loveable (liefdevol), anger (kwaad) and to be scared (om bang te wees). The five (5) least prototypical terms from the list generated in the free listing task were: unstable (onvas), bashfulness (skugterheid), captivation (geboeidheid), envy (naywer) and delight (opgetoënheid). From the information obtained in this research it was revealed that the emotion terms nice (lekker), fed up/had enough (gatvol/“genoeg gehad”) and loveable (liefdevol) are at this stage unique to the white Afrikaans language group. These terms had not been reported in any previously conducted prototypical studies. The results of this study contribute to a cross–cultural understanding of the emotion concepts within the Afrikaans–speaking language groups in South Africa. Research Article 2 A survey design was used to achieve the research objectives utilising availability samples in a series of one study. The participants of the Similarity study (N=131) consisted of native Afrikaans–speaking employees. The sample consisted of participants from the white ethnicity group speaking Afrikaans within the Eastern Cape, Gauteng, Free State, Mpumalanga, North– West, KZN and Northern Cape provinces and use was made of an availability sample. Results of Multidimensional Scaling revealed a three–dimensional cognitive emotion structure. The first dimension was the evaluation–pleasantness dimension. This dimension evaluates the pleasantness versus the unpleasantness of an emotion. This dimension is characterised by intrinsic appraisals of pleasantness and goal conduciveness and action tendencies of approach versus avoidance. The second dimension that emerged was a power–control dimension. This dimension is characterised by appraisals of control, how powerful or weak a person feels when a particular emotion is experienced. This includes feelings of dominance or submission, the impulse to act or withdraw and changes in speech and parasymphatic symptoms. The third dimension which emerged was an activation–arousal dimension. According to other researchers this arousal dimension is characterised by sympathetic arousal, e.g. rapid heartbeat and readiness for action. This study produced a cognitive emotion structure in a white Afrikaans–speaking working adult population in South Africa. To add value to the field of Industrial Psychology, the threedimension structure (evaluation–pleasantness, power–control and activation–arousal dimension) that was found, is very important and valuable when studying the meaning of emotion and can consequently be used as a reference for other emotion research constructs. If it is accurate as stated in literature, there are three and not only two emotion dimension structures, and researchers are missing out on a bigger picture for not drawing on the experience of emotion sufficiently. Research Article 3 A survey design and an availability sample (N=120) in the Eastern Cape, Free State and Gauteng provinces in South Africa was utilised for this study. The Meaning Grid was translated and backtranslated and adapted for use in Afrikaans. The Cronbach's alpha coefficients were obtained for the emotion terms. According to the results of the Meaning Grid instrument, the following emotion terms were the highest: disgust (afkeur) 0,95; pleasure (plesier) 0,94; stress (stres) 0,92; happiness (blydskap) 0,91; joy (vreugde) 0,91; fear (bang) 0,91; anger (angstig) 0,91 and hate (haat) 0,90. The emotion terms that scored the lowest with the Meaning Grid instrument were compassion (medelye) 0,79; pride (trots) 0,79 and contempt (minagting) 0,74. Out of the 24 emotion terms of the Meaning Grid instrument, 8 terms were above 0,90 and 13 were between 0,80 and 0,89. Only 3 terms were between 0,74 and 0,79 [compassion (medelye), pride (trots) and contempt (minagting)]. A three–factor solution was found which represented four emotion dimensions (evaluation, arousal/unpredictability and power) that were universal to the emotion structures found in European samples. Factor scores of the 24 Meaning Grid emotions indicate a three–factor solution that explained 62,2 % of the total variance. The first factor was labelled evaluation and explained 43,0% of the variance, the second factor was labelled arousal/unpredictability as it was a combination of arousal and unpredictability and explained 11,0% of the variance, and the third factor was labelled power and explained 8,2% of the variance. This study followed an approach that investigated the meaning structure of emotion in the sample group in the context of 144 emotion features using a componential emotion theory approach. Different researchers argued that emotion meaning has more than only two dimensions. A three–dimensional emotion structure was found that was universal to the emotion structures of three language groups in a European sample. Therefore, the meaning of emotions for this sample group is far more complex than the two–dimensional emotion models that are found in literature. According to the componential emotion theory approach, the 144 emotion features are very important building blocks for Industrial Psychology when studying the meaning of emotion. Research Article 4 A survey design was used in this research study. The Episode Meaning Grid was administered and participants reported on the two intense emotion experiences at work (in total 358 episodes). Employees rated their emotion experiences on features based on the componential emotion theory and also described the emotion events in their own words. The participants in the emotion episodes (N=179) study consisted of native white Afrikaans–speaking working adults. The sample consisted of participants from the white ethnicity group speaking Afrikaans within the Eastern Cape, Free State and North–West provinces and use was made of an availability sample. The results indicated a three–dimensional structure (evaluation–pleasantness, activation–arousal and power–control dimension) was identified within a white Afrikaans–speaking working adult language group. The first dimension was an evaluation–pleasantness dimension. The second dimension was an activation–arousal dimension. The third dimension was a power–control dimension. Regarding the reporting of emotion episodes one hundred and ninety seven respondents reported 84 satisfying emotion episodes and 267 less satisfying emotion episodes that took place at work. Nine different categories of episodes for satisfying emotions experienced were mentioned. It consists of behaviour of work colleagues, acts of boss/superior/management, goal achievement, receiving recognition, workplace policy, task recognition, personal incidents, emotion involvement and subordinate behaviour. The three highest categories of satisfying emotions episodes were “Goal Achievement” (N=31), “Receiving Recognition” (N=20) and “Personal Incidents” (N=10). Goal achievement describes situations where job related targets or goals were met, and receiving recognition refers to positive feedback from managers, supervisors and work colleagues on meeting targets. Nineteen different categories of episodes for less satisfying emotion episodes were mentioned. It consists of behaviour of work colleagues, acts of boss/superior/management, lack of goal achievement, lack of receiving recognition, workplace policy, task requirement, personal incidents, emotional involvement, subordinate behaviour, workload, work mistakes, customer behaviour, external environment, lack of control, physical well–being, involvement in disciplinary action, workplace strikes, wellness of colleagues and unfairness in the workplace. In the categories of less satisfying emotions episodes, the three highest were “Behaviour of Work Colleagues” (N=58), “Acts of Boss/Superior/Management” (N=47) and “Task Requirement” (N=33). The first two categories are appraised less satisfying behaviour towards oneself or others by work colleagues, managers, supervisors and customers. In terms of the categories of satisfying and less satisfying emotions episodes, less satisfying emotion episodes outnumbered satisfying emotions episodes by three to one. By making use of a multi–componential emotion model, the results confirm that the four factors of pleasantness, power, arousal, and unpredictability, in that order of importance, are essential to satisfactorily determine the emotion experience and meaning of emotion terms. A threedimensional emotion structure (evaluation, arousal and power) was found after determining the meaning of emotion in the natural contexts in which they occur. The answer to the question if these two–dimensional emotion models, as stated in literature, are sufficient to cover the broad and often complex dynamics of emotion, is certainly no. Recommendations for the organisation and future research were made. / Thesis (Ph.D. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2012.