Vehicular Ad-hoc Network (VANET) is considered to be a viable technology for inter- vehicle communications for the purpose of improving road safety and efficiency. The En- hanced Distribution Channel Access (EDCA) mechanism and multichannel operations are introduced to ensure the Quality of Service (QoS). Therefore, it is necessary to create an accurate vehicular network simulator that guarantees the vehicular communications will work as described in the protocols. A comprehensive vehicular network simulator should consider the interaction between mobility models and network protocols. In this dissertation, a novel vehicular network simulation environment, VANET Toolbox, designed using discrete-event system (DES) is presented. The APP layer DES Module of the proposed simulator integrates vehicular mo- bility operations with message generation functions. The MAC layer DES module supports single channel and multichannel EDCA operations. The PHY layer DES module supports bit-level processing. Compared with packet-based simulator such as NS-3, the proposed PHY layer is more realistic and accurate. The EDCA scheme is evaluated and compared with the traditional Carrier-Sensing Mul- tiple Access (CSMA) scheme, with the simulations proving that data with different priorities can coexist in the same channel. The multichannel operation for the EDCA scheme is also analyzed in this dissertation. The multichannel switching operation and coordination may cause packet dropping or increased latency to the communication. The simulations show that with heavy network traffic, multichannel communication performs better than single channel communication. From the perspective of safety-related messages, the multichannel operation is able to isolate the interference from the non-safety messages in order to achieve a better packet delivery rate and latency. On the other hand, the non-safety messages can achieve high throughput with reasonable latency from multichannel communication under heavy load traffic scenario.

Microfiche copy available in the Institute Archives and Barker Engineering Library. / Vita. / Thesis (Ph. D.)--Massachusetts Institute of Technology. Dept. of Engineering and Computer Science, 1977. / Includes bibliographical references. / by John Ippocratis Capetanakis. / Ph.D.

One of the most challenging issues facing vehicular networks lies in the design of an efficient MAC protocol due to mobile nature of nodes, delay constraints for safety applications and interference. In this thesis, I propose an efficient Multichannel QoS Cognitive MAC (MQOG). MQOG assesses the quality of channel prior to transmission employing dynamic channel allocation and negotiation algorithms to achieve significant increase in channel reliability, throughput and delay constraints while simultaneously addressing Quality of Service. The uniqueness of MQOG lies in making use of the free unlicensed bands. To consider fair effective sharing of resources I propose a Mobility Based Dynamic Transmit Opportunity (MoByToP) while modifying the 802.11e TXOP (Transmit Opportunity). The proposed protocols were implemented in OMNET++ 4.1, and extensive experiments demonstrated a faster and more efficient reception of safety messages compared to existing VANet MAC Protocols. Finally, improvements in delay, packet delivery ratios and throughput were noticed.

One of the most challenging issues facing vehicular networks lies in the design of an efficient MAC protocol due to mobile nature of nodes, delay constraints for safety applications and interference. In this thesis, I propose an efficient Multichannel QoS Cognitive MAC (MQOG). MQOG assesses the quality of channel prior to transmission employing dynamic channel allocation and negotiation algorithms to achieve significant increase in channel reliability, throughput and delay constraints while simultaneously addressing Quality of Service. The uniqueness of MQOG lies in making use of the free unlicensed bands. To consider fair effective sharing of resources I propose a Mobility Based Dynamic Transmit Opportunity (MoByToP) while modifying the 802.11e TXOP (Transmit Opportunity). The proposed protocols were implemented in OMNET++ 4.1, and extensive experiments demonstrated a faster and more efficient reception of safety messages compared to existing VANet MAC Protocols. Finally, improvements in delay, packet delivery ratios and throughput were noticed.

The purpose of this study is to learn more about the consumers' interaction with companies over different channels. It is conducted from a consumer's point of view, but the insights gained through this study will help companies to design and build better services. In this context, the concepts of User Experience, cross-channel and Customer Experience provide a theoretical framework. The new approach in this study is to combine the three concepts, their framing and their identified design elements. This conceptual framing contains a list of design elements with a positive influence on the service experience. However, the conceptual framing provides no answers on how to apply these design elements. In the methodology part, possible approaches are discussed. The heuristic evaluation used in the two case studies is a method that takes all three concepts from the theoretical framework into account. With the first heuristic, it is possible to analyze single touchpoints like User Experience demands. The following heuristics are used within a cross-channel context. Finally, the last heuristic is responsible for the holistic perspective from Customer Experience. The case studies are then conducted to verify the applicability of the design elements with the heuristic evaluation. The findings of the study were positive and suggest that the heuristic evaluation is a suitable method to analyze a company's service offerings. Additionally, the case studies lead to results which are useful for the two companies (Migros and Nestlé). The overall conclusion of this study is that the three concepts complement each other very well. User Experience is responsible for well designed touchpoints. Cross-channel expands the perspective on ecosystems and evaluates how the touchpoints operate together. Finally, Customer Experience analyzes the whole company and its touchpoints on a heuristic perspective.

One of the most challenging issues facing vehicular networks lies in the design of an efficient MAC protocol due to mobile nature of nodes, delay constraints for safety applications and interference. In this thesis, I propose an efficient Multichannel QoS Cognitive MAC (MQOG). MQOG assesses the quality of channel prior to transmission employing dynamic channel allocation and negotiation algorithms to achieve significant increase in channel reliability, throughput and delay constraints while simultaneously addressing Quality of Service. The uniqueness of MQOG lies in making use of the free unlicensed bands. To consider fair effective sharing of resources I propose a Mobility Based Dynamic Transmit Opportunity (MoByToP) while modifying the 802.11e TXOP (Transmit Opportunity). The proposed protocols were implemented in OMNET++ 4.1, and extensive experiments demonstrated a faster and more efficient reception of safety messages compared to existing VANet MAC Protocols. Finally, improvements in delay, packet delivery ratios and throughput were noticed.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 136-151). Also available in print.

This study’s aim is to examine how companies integrate their multiple CRM channels to enhance the relationships with the customers. A qualitative method was used and the collection of data was conducted from eleven interviews. The interviews were semi-structured with open-ended questions. The theory is written in three main themes; customer relationship management, channels of communication and multichannel integration. Empirical findings and the analysis also follows these themes. The study is ending with conclusions. What is affecting companies channel selection depends on what message companies want to send, but also whether if it is existing or new potential customers’ that are targeted. The geographical factor also influences the channel selection. Channel decision further depends on the size of the companies, if it is business to business or business to consumer and what kind of product the company is selling. More complex products require more personal interactions. How to successfully implement a multichannel integration strongly depends on the quality of data, an organizational common interpretation of customer relationship management, integration of information from all departments and that the company has an easy, yet powerful system for the accessible data. This study helps to give an understanding of how the multichannel integration is done in a business to business company with complex products. The study can be applied on other companies using a multichannel integration. It can help managers to understand the importance of the multichannel integration, how to succeed and other important factors for a successful multichannel integration. It also contributes to an understanding of the critical factors of the multichannel integration.  A framework with an alternative model of multichannel integration is presented. The study also presented that the process of multichannel integration is of great importance and emphasized by a leading company in the field of customer relationship management. This study therefore has succeeded in giving an easy, more powerful and greater picture of the multichannel integration, which is an important determined factor for building customer relationships. A figure (figure 10) is provided for other companies to use that are business to business with complex products. This study is a case study with a qualitative research approach, the studied company is a business to business company with complex products. The study is made from the company’s perspective. Future research can be conducted by studying multichannel integration from the customers’ perspective instead of the company’s perspective. The study could have been conducted on more than one company to compare the results, or on a business to consumer company instead of a business to business company. Studies on multichannel integration can also be interesting regarding companies that are selling less complicated products. Finally, studies can be conducted regarding the “information overflow” from social media.

Purpose - The purpose of this study was to deepen the understanding of how showrooming affect the exploited brick-and-mortar businesses. This was done by investigating an industry characterized by high levels of employee knowledge where the expertise of the personnel create showrooming incentives. Methodology - The study applied a qualitative case study where semi-structured interviews was held with employees of a firm representing the case of an exploited firm. Findings - The empirical findings suggest that showrooming may affect the exploited firm in the areas; profits, offerings, channels, and personnel. Profit-losses due to showrooming may force the exploited firm to reduce number of personnel and working hours, decrease store areas and close of unprofitable stores, change the product and services offered, change how products are displayed, and in what channels the products are available. Further it may give rise to internal channel conflicts, and affect personnel motivation and sales performance. Practical Implications - A perceived showroomer should be treated as a paying customer to avoid misjudgment of character and a loss in service level. Private labels and exclusive selling rights allow for higher profits while reducing showrooming opportunities. In addition to this, rewards for cross-channel retention, synchronized channel information, and price consistency across channels may reduce internal conflicts. Contribution - This study contributes to the young research area of showrooming by assessing the effects an exploited firm may encounter when faced with showroomers.

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