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- Nurhadi, Lisiana
(författare)
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An Approach to Business Modeling for Sustainable Personal Road Transport
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Between 1950 and 2013 the total amount of Swedish travelling has increased from about 20 billion to about 140 billion passenger kilometers. This included an increase in travelling with private cars from about 3 billion to about 105 billion passenger kilometers, and in bus travelling from about 2.5 billion to about 5 billion passenger kilometers. The European commission has indicated that public transportation (if powered by clean fuels) is a suitable way to reduce environmental and health problems. This thesis focuses on sustainable personal road transport, and aims to develop and test a new approach to examining the economic and socio-ecological sustainability effects of various road vehicles for private travelling and related business models. A special focus is set on comparing various bus systems for public transport and ways (business models) for private people to access cars. The main comparison parameters are the total cost of ownership and carbon dioxide emissions of different energy carriers for buses and cars. The Design Research Methodology is used to guide the research approach. The approach also builds on the Framework for Strategic Sustainable Development, which includes, for example, principles that define any sustainable future and a strategic planning process. The approach first employs Strategic Life Cycle Assessment to give a quick overview of sustainability challenges in each bus life cycle stage from raw materials to end of life. Several analysis tools such as Life Cycle Costing, Life Cycle Analysis, Product Service System, and Business Model Canvas mapping are then iteratively used to ”dig deeper” into identified prioritized challenges. Literature reviews, interviews, and simulations are used as supporting methods. The results from a first theoretical test of the new approach suggest that a shift from diesel buses to electric buses (powered by renewable energy) could significantly lower carbon dioxide emissions, while also significantly lowering the total cost of ownership. The theoretical calculations were followed up by testing of electric buses in real operation in eight Swedish municipalities. The tests verified the theoretical results, and showed that electric buses are better than diesel buses both from a sustainability point of view and a cost point of view, and also that electric bus operation is a practically viable alternative for public transport. The new approach was tested also by comparing a variety of business models for private car travelling. The results indicate, among other things, that only people who travel more than 13.500 kilometers per year would benefit from owning a car. In all, the thesis suggests a simultaneous shift from diesel buses to electric buses in public transport and, for the majority of the car drivers that drive less than 13.500 kilometers per year, switching from car ownership to car use services would be favourable for an affordable transition of the transport sector towards sustainability.
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| 2. |
- Villamil Velasquez, Denny Carolina, 1978-
(författare)
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Integration of Sustainability Aspects in Product Portfolio
- 2020
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Several environmental issues are incrementing systematically, and many of them are linked to manufacturing activities. To mitigate these issues, it is necessary to develop sustainability solutions in the early stages of the innovation process, where there is room for creativity and innovation. The integration of sustainability at the strategic level of the company, where the essential decisions, the strategic plan, and the portfolio are developed, might ensure the implementation of sustainability aspects in products and services. Many companies develop product portfolios to organize and offer services, products, technologies and operations following the company strategy and targets. The portfolio components are assessed and selected using evaluation criteria. The most common criteria include: cost, quality, risk, revenue, time and market position. Usually sustainability is not included in the portfolio evaluation criteria.The aim of this research is to obtain a better understanding of how sustainability can be integrated in the product portfolio development of manufacturing companies. The main research targets are to: 1) define sustainability product portfolio based on a comprehension of the academic and industry perspectives, 2) identify how companies currently implement sustainability in their portfolio, 3) determine which evaluation criteria and tools are used for portfolio development and 4) how the product portfolio is developed, implemented and managed.A systematic literature review was performed to understand the state of the art about sustainability product portfolio. The literature review results supported the development of semi-structure interviews with companies and field experts. The interviews outcome provided a better understanding of the industry perspective. Afterwards, a workshop helped to understand what aspects are more significant for the portfolio evaluation criteria. Finally, a strategic sustainability assessment tool SLCA 2.0 was used to assess a technology product portfolio of a specific industry case.The results from the studies created a foundation to: a) determine the state of art of the sustainability product portfolio field and its relevance for integration and implementation of sustainability in the early stages of the product innovation process, b) define the concept of sustainability product portfolio, c) have a better understanding of the setting and the application of the portfolio evaluation criteria and how to include sustainability in the evaluation, d) identify key factors to integrate and implement sustainability in the product portfolio, e) apply and test a tool for assessing a technology portfolio from a sustainability perspective and f) create a prototype of a model to develop the product portfolio with a strategic sustainability perspective.This research provides a knowledge foundation of how sustainability can be integrated in product portfolio. In future research a model will be developed to support companies of how to include a strategic sustainability perspective into their product portfolio to enhance development of more sustainable solutions.
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| 3. |
- Ludwig Barbosa, Vinícius, 1990-
(författare)
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Effects of Small-Scale Ionospheric Irregularities on GNSS Radio Occultation Signals : Evaluations Using Multiple Phase Screen Simulator
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Radio Occultation (RO) is a remote sensing technique which uses Global Navigation Satellite System (GNSS) signals tracked by a Low-Earth Orbit (LEO) satellite to sound the earth's atmosphere both in low (troposphere, stratosphere) and high (ionosphere) altitudes. GNSS-RO provides global coverage and SI traceable measurements of atmospheric data with high-vertical resolution. Refractivity, dry temperature, pressure and water vapour profiles retrieved from RO measurements have a relevant contribution in Numerical Weather Prediction (NWP) systems and in climate-monitoring.Due to the partial propagation through the ionosphere, a systematic bias is added to the lower atmospheric data product. Most of this contribution is removed by a linear combination of data for two frequencies. In climatology studies, one can apply a second-order correction - so called κ-correction - which relies on a priori information on the conditions in the ionosphere. However, both approaches do not remove high-order terms in the error due to horizontal gradient and earth's geomagnetic fields. The remaining residual ionospheric error (RIE) and its systematic bias in RO atmospheric data is a well-known issue and its mitigation is an open research topic.In this licentiate dissertation, the residual ionospheric error after the standard correction is evaluated with computational simulations using a wave optics propagator (WOP). Multiple Phase Screen (MPS) method is used to simulate occultation events in different ionospheric scenarios, e.g. quiet and disturbed conditions. Electron density profiles (EDP) assumed in simulations are either defined by analytical equations or measurements. The disturbed cases are modelled as small-scale irregularities within F-region in two different ways: as sinusoidal fluctuations; and by using a more complex approach, where the irregularities follow a single-slope power-law that yields moderate to strong scintillation in the signal amplitude. Possible errors in MPS simulations assuming long segment of orbit and ionosphere are also evaluated.The results obtained with the sinusoidal disturbances show minor influence in the RIE after the standard correction, with the major part of the error due to the F-region peak. The implementation of the single-slope power-law is validated and the fluctuations obtained in simulation show good agreement to the ones observed in RO measurements. Finally, an alternative to overcome limitations in MPS simulations considering occultations with long segment of orbit and ionosphere is introduced and validated.The small-scale irregularities modelled in F-region with the power-law can be added in simulations of a large dataset subjected to κ-correction, in order to evaluate the RIE bending angle and the consequences in atmospheric parameters, e.g. temperature.
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| 4. |
- Sievert, Thomas, 1988-
(författare)
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GNSS Radio Occultation Inversion Methods and Reflection Observations in the Lower Troposphere
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- GNSS Radio Occultation (GNSS-RO) is an opportunistic Earth sensing technique where GNSS signals passing through the atmosphere are received in low Earth orbit and processed to extract meteorological parameters. As signals are received along an orbit, the measured Doppler shift is transformed to a bending angle profile (commonly referred to as bending angle retrieval), which, in turn, is inverted to a refractivity profile. Thanks to its high vertical resolution and SI traceability, GNSS-RO is an important complement to other Earth sensing endeavors. In the lower troposphere, GNSS-RO measurements often get degraded and biased due to sharp refractive gradients and other complex structures. The main objective of this thesis is to explore contemporary retrieval methods such as phase matching and full spectrum inversion to improve their performance in these conditions. To avoid the bias caused by the standard inversion, we attempt to derive additional information from the amplitude output of the examined retrieval operators. While simulations indicate that such information could be found, it is not immediately straightforward how to achieve this with real measurements. The approach chosen is to examine reflected signal components and their effect on the amplitude output.
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