Repozitorij samostojnih visokošolskih in višješolskih izobraževalnih organizacij

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po


1 - 3 / 3
Na začetekNa prejšnjo stran1Na naslednjo stranNa konec
A novel approach to aviation data links and data exchange between aircraft modules : doctoral dissertation
Ilija Subotić, 2023, doktorska disertacija

Opis: Aviation industry is a key driver of global economic development with over a third of all trade by value sent by air. It represents a highly significant global market with estimated revenue over 840 billion USD in 2023, while the industry directly and indirectly supports an estimated $3.5 trillion (4.1%) of the world's gross domestic product (GDP) through the jobs and services of air industry suppliers, employee spending and serving industries such as tourism. Due to increasing global air passenger demand, the global aviation industry is projected to grow by approximately 25% from 2022 to 2027. However, in some cases the operation of aircraft may still be reliant on outdated technology that could be years or even decades old. Due to safety concerns, the global system of civil aviation is one of the most regulated industries, and every new procedure, technological advancement or device is required to be thoroughly checked by licensed institutions, numerous experts and aviation regulatory authorities. This reasonable approach inevitably leads to difficulties when dealing with noticed problems in any particular field – whether these are flight operations, aircraft maintenance, corporate affairs or general compliance. One of these problems are aircraft communications and data transfers between aircraft and all other groundbased stations. Namely, apart from classical radio links for voice communications, digital radio links for data transmissions have been used for a few decades now. These are ACARS (Aircraft Communications, Addressing and Reporting System) and CPDLC (Controller-Pilot Data Link Communications). These aeronautical communications data links use HF/VHF links and, alternatively, over areas with no or with poor signal coverage, commercial data satellites. However, there are several fundamental problems with data link systems implemented this way. The first problem is that the authenticity of the messages being exchanged cannot be verified. Potential attackers can, without much effort, falsify messages or even pose as a legitimate air traffic control unit or an aircraft crew. Another problem lies in the available bandwidth for VHF data links and the possible maximum transmission speeds reachable: the data transmission speed of VHF channels is very low - usually around 15 Kbit/s, and the best achievable results barely exceed 30 Kbit/s. In addition, the third major problem is message delivery, which is not guaranteed to succeed. There were indeed cases when the sent message did not reach the desired destination or arrived after a long delay of even several minutes. Aside from the mentioned problems, there are still issues related to specific aspects of the used HF/VHF data transmission links, such as signal stability, switching between individual ground radio stations, signal coverage issues etc. Therefore, in this dissertation, the main motive is to explore alternatives and find ways to solve at least some of these problems. The research in this dissertation is based on the usage of the Internet for the transmission of messages, instead of the previous radio data links. During the research it was concluded that the cellular Internet connection, even in today's technically inadequate state in the means of aeronautical needs, meets the conditions to be used as a medium for CPDLC and ACARS connections at flight altitudes up to 10,000 ft. Another goal of the research is to consider and develop the possibility of integrating the CPDLC and ACARS systems into one platform, codenamed IACARP (Integrated Aeronautical Communications, Addressing and Reporting Platform), which would provide the possibility to increase the number of functions and capabilities of both systems. The third intention of the dissertation is to propose and develop a dedicated communication protocol, which will be based on the Internet as a medium for data transmission, which will allow the IACARP platform to use a protocol that is adapted for use in aeronautical operations. In addition to the communications protocol, the dissertation also provides a possible solution for the authentication problem of messages sent within the system, in a way that does not require encryption of those messages. The proposed solution represents a new algorithm for generating a special short code based on which the authenticity of the messages is confirmed. The possibilities of automatically sending individual reports from certain vital aircraft systems to the air traffic control units are also being considered, through the proposed IACARP system. This way of integrating the components yielded another possibility which is thoroughly considered, and that is the remote control of the aircraft by ATC units in cases of emergency situations. Remote control of the aircraft in this way can most likely be achieved since there is a significant number of aircraft equipped with systems that can land them automatically, without much human intervention. Hence, it would be enough to just remotely reprogram the FMC (Flight Management Computer), enter a new flight route that would initiate landing at a suitable airport, as well as to remotely monitor and control the state of vital aircraft systems by giving the appropriate command through the IACARP platform. As the final part of the dissertation, the conclusions and the decision to accept or reject the hypotheses are presented, along with some perspectives and ideas for further research in this area.
Ključne besede: aeronautical data links, cellular networks, CPDLC, ACARS, air traffic control, message authentication, dedicated communications protocol
Objavljeno v ReVIS: 15.03.2024; Ogledov: 474; Prenosov: 12
.pdf Celotno besedilo (13,29 MB)

The role of transnational value chains in regional innovation. Analysis of Central and Eastern European regions engaged in automotive and electronics production networks : doctoral dissertation
Cristian Gangaliuc, 2022, doktorska disertacija

Opis: The thesis touches on important concepts of innovation and regional development. Their empirical relevance for economic and social growth is a subject of active debate. Studies revealed that interactions have a major impact, de facto, on the capacity to innovate. Diversifying knowledge sources, joint ventures and co-creational practices can explain much of the locational factors and innovation in a-spatial networks. With the rise of globalisation, scholars found that Multinational Corporations and their global production chains are integrating more and more into regions worldwide. They share practices and engage local stakeholders in their innovation projects. This research aims to explore the importance of locational and global factors in this process. The goal is to see how these two forces contribute to innovation separately and when intertwined regionally, closing the gap between regional and global innovation frameworks. The thesis contributes to science by developing a new synthesis model based on mainstream Innovation theories. It includes the endogenous and exogenous forces that create environmental pressures and opportunities, pushing economic agents to innovate. The central aspect of this model is the acknowledgement of the multiscalar nature of innovation. Local institutions, mindsets and influence from the production chains create conditions and pressures in the network, which motivates companies to innovate. Depending on the local competencies and the needs of production networks, it creates various environments for companies. It is up to enterprises to use created opportunities, which can be local, national or global. Data collected in eight (distinct) regions in Central and Eastern Europe (active in automotive and electronics industries) was used in qualitative and logical analysis to observe patterns in regional behaviour. The results revealed that endogenous and exogenous forces act circumstantially in each region, partially proving all the hypotheses on endogenous and exogenous factors and validating the model. Each region displays different rates of local and regional engagement and, thus, different patterns of innovation, determining their competitive potential. The research also revealed additional factors (e.g., the importance of trust, particularities of information diffusion, etc.) relevant to innovation in Central and Eastern Europe.
Ključne besede: innovation, regional development, transnational value chains, networks, institutions, cognitive mindset, regional-global co-operation
Objavljeno v ReVIS: 25.10.2022; Ogledov: 782; Prenosov: 74
.pdf Celotno besedilo (5,96 MB)

Social networks as factors for innovations : doktorska disertacija
Victor Cepoi, 2018, doktorska disertacija

Opis: In the new local-global interconnection, nation states are losing their influence and legitimacy, while economic and cultural transformations are reconfiguring spatial formations. Going in line with the global trends, regions grasp more importance in shaping the political, economic and social environments. As a result, the regional level has an important role in creating a proper socio-economic framework for innovation development, which is considered one the engines of development. Relying on the theory of Social fields, the research considers three social forces (networks, institutions, and cognitive frames) as an alternative explanation for innovation processes, by encompassing the aspects of different social fields on the regional level. Consequently, within this dissertation we approach regional innovation systems as an analytical unit for exploring innovation performance of a regional environment. As case studies, we selected seven regions with different levels of innovation performance. The analysis of the semi-structured interviews and the Qualitative Comparative Analysis emphasized the social forces are a special component for explaining innovation processes in the selected case studies. Nonetheless, the results offer insights for regional mechanisms within the innovation performance with the focus on an approach toward innovation that is beyond simple economics.
Ključne besede: Regional Systems of Innovations, Networks, Social Field, Social Forces, Qualitative Comparative analysis
Objavljeno v ReVIS: 17.02.2020; Ogledov: 2583; Prenosov: 93
.pdf Celotno besedilo (3,40 MB)

Iskanje izvedeno v 0.11 sek.
Na vrh