du.sePublications
Change search
Refine search result
349350351352353354355 17551 - 17600 of 18123
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • chicago-author-date
  • chicago-note-bibliography
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 17551. Zhang, Xingxing
    et al.
    Li, Guozhen
    Tang, Llewellyn
    Zhou, Tongyu
    A compact flat-plate heat pipe with ammonia water as working medium2017Patent (Other (popular science, discussion, etc.))
  • 17552.
    Zhang, Xingxing
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Lovati, Marco
    Vigna, Ilaria
    Widén, Joakim
    Han, Mengjie
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Gál, Csilla V
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Feng, Tao
    A review of urban energy systems at building cluster level incorporating renewable-energy-source (RES) envelope solutions2018In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 230, p. 1034-1056Article in journal (Refereed)
    Abstract [en]

    The emergence of renewable-energy-source (RES) envelope solutions, building retrofit requirements and advanced energy technologies brought about challenges to the existing paradigm of urban energy systems. It is envisioned that the building cluster approach—that can maximize the synergies of RES harvesting, building performance, and distributed energy management—will deliver the breakthrough to these challenges. Thus, this paper aims to critically review urban energy systems at the cluster level that incorporate building integrated RES solutions. We begin with defining cluster approach and the associated boundaries. Several factors influencing energy planning at cluster scale are identified, while the most important ones are discussed in detail. The closely reviewed factors include RES envelope solutions, solar energy potential, density of buildings, energy demand, integrated cluster-scale energy systems and energy hub. The examined categories of RES envelope solutions are (i) the solar power, (ii) the solar thermal and (iii) the energy-efficient ones, out of which solar energy is the most prevalent RES. As a result, methods assessing the solar energy potentials of building envelopes are reviewed in detail. Building density and the associated energy use are also identified as key factors since they affect the type and the energy harvesting potentials of RES envelopes. Modelling techniques for building energy demand at cluster level and their coupling with complex integrated energy systems or an energy hub are reviewed in a comprehensive way. In addition, the paper discusses control and operational methods as well as related optimization algorithms for the energy hub concept. Based on the findings of the review, we put forward a matrix of recommendations for cluster-level energy system simulations aiming to maximize the direct and indirect benefits of RES envelope solutions. By reviewing key factors and modelling approaches for characterizing RES-envelope-solutions-based urban energy systems at cluster level, this paper hopes to foster the transition towards more sustainable urban energy systems.

  • 17553.
    Zhang, Xingxing
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Pan, Song
    Wu, Jinshun
    Xia, Liang
    China leans balance to distributed solar-power projects: challenge and opportunities2017Conference paper (Refereed)
  • 17554.
    Zhang, Xingxing
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Pan, Song
    Wu, Jinshun
    Xia, Liang
    Recycling discarded shipping containers for reliable building envelopes: a design case for senior citizens in Solar Decathlon China 20172017Conference paper (Refereed)
  • 17555.
    Zhang, Xingxing
    et al.
    University of Nottingham.
    Shen, Jingchun
    Adkins, Deborah
    Yang, Tong
    Tang, Llewellyn
    Zhao, Xudong
    He, Wei
    Xu, Peng
    Liu, Chenchen
    Luo, Huizhong
    The early design stage for building renovation with a novel loop-heat-pipe based solar thermal facade (LHP-STF) heat pump water heating system: Techno-economic analysis in three European climates2015In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 106, p. 964-986Article in journal (Refereed)
    Abstract [en]

    Most of the building renovation plans are usually decided in the early design stage. This delicate phase contains the greatest opportunity to achieve the high energy performance buildings after refurbishment. It is therefore important to provide the pertinent energy performance information for the designers or decision-makers from multidisciplinary and comparative points of view. This paper investigates the renovation concept of a novel loop-heat-pipe based solar thermal facade (LHP-STF) installed on a reference residential building by technical evaluation and economic analysis in three typical European climates, including North Europe (represented by Stockholm), West Europe (represented by London) and South Europe (represented by Madrid). The aim of this paper is firstly to explore the LHP-STF’s sensitivity with regards to the overall building socio-energy performance and secondly to study the LHP-STF’s economic feasibility by developing a dedicated business model. The reference building model was derived from the U.S. Department of Energy (DOE) commercial buildings research, in which the energy data for the building models were from the ASHRAE codes and other standard practices. The financial data were collected from the European statistic institute and the cost of system was based on the manufactured prototype. Several critical financial indexes were applied to evaluate the investment feasibility of the LHP-STF system in building renovation, such as Payback Period (PP), Net Present Value (NPV), and the modified internal rate of return method (IRR). Four common investment options were considered in this business model, including buying outright (BO), buying by instalment (BI), energy efficiency funding (EEF) and power purchase agreement (PPA). The research results indicate that the LHP-STF could contribute to the hot water load throughout the year with substantially reduced heating load in winter, and yet a slight increased cooling load in summer. Among four investment options, the BO was considered as the best investment method with the highest NPV, IRR and the shortest payback period. With regards to relatively limited solar resources, London was found to be the best place for investment with the highest economical revenues and an attractive payback period of less than four years for all purchase options. Although Madrid has the richest solar resource, this system has the lowest economic profit and the longest payback period. This outcome confirms that the renewable energy incentives have a higher impact than solar resources on current solar thermal facade technologies under such pricing fundamentals. This multidisciplinary research is expected to be helpful for the strategic decisions at the early design stage for building renovation with the proposed system and further promote development of solar driven service system, leading to the savings in fossil fuel consumption and reduction in carbon emission.

  • 17556.
    Zhang, Xingxing
    et al.
    University of Hull; University of Nottingham.
    Shen, Jingchun
    He, Wei
    Xu, Peng
    Zhao, Xudong
    Tan, Junyi
    Comparative study of a novel liquid-vapour separator incorporated gravitational loop heat pipe against the conventional gravitational straight and loop heat pipes - Part I: Conceptual development and theoretical analyses2015In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 90, p. 409-426Article in journal (Refereed)
    Abstract [en]

    Aim of the paper is to investigate the thermal performance of a novel liquid–vapour separator incorporated gravity-assisted loop heat pipe (GALHP) (T1), against a conventional GALHP (T2) and a gravitational straight heat pipe (T3), from the conceptual and theoretical aspects. This involved a dedicated conceptual formation, thermo-fluid analyses, and computer modelling and results discussion. The innovative feature of the new GALHP lies in the integration of a dedicated liquid–vapour separator on top of its evaporator section, which removes the potential entrainment between the heat pipe liquid and vapour flows and meanwhile, resolves the inherent ‘dry-out’ problem exhibited in the conventional GALHP. Based on this recognised novelty, a dedicated steady-state thermal model covering the mass continuity, energy conservation and Darcy equations was established. The model was operated at different sets of conditions, thus generating the temperature/pressure contours of the vapour and liquid flows at the evaporator section, the overall thermal resistance, the effective thermal conductivity, and the flow resistances across entire loop. Comparison among these results led to determination of the optimum operational settings of the new GALHP and assessment of the heat-transfer enhancement rate of the new GALHP against the conventional heat pipes. It was suggested that the overall thermal resistance of the three heat pipes (T1, T2, and T3) were 0.10 °C/W, 0.49 °C/W and 0.22 °C/W, while their effective thermal conductivities were 31,365 W/°C m, 9,648 W/°C m and 5,042 W/°C m, respectively. This indicated that the novel heat pipe (T1) could achieve a significantly enhanced heat transport effect, relative to T2 and T3. Compared to a typical cooper rod, T1 has around 78 times higher effective thermal conductivity, indicating that T1 has the tremendous competence compared to other heat transfer components. It should be noted that this paper only reported the theoretical outcomes of the research and the second paper would report the follow-on experimental study and model validation. The research results could be directly used for design, optimisation and analyses of the new GALHP, thus promoting its wide applications in various situations to enable the enhanced thermal performance to be achieved.

  • 17557.
    Zhang, Xingxing
    et al.
    University of Nottingham; University of Hull.
    Shen, Jingchun
    He, Wei
    Xu, Peng
    Zhao, Xudong
    Tan, Junyi
    Comparative study of a novel liquid-vapour separator incorporated gravitational loop heat pipe against the conventional gravitational straight and loop heat pipes - Part II: Experimental testing and simulation model validation2015In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 93, p. 228-238Article in journal (Refereed)
    Abstract [en]

    Aim of the paper is to report the experimental study of a novel liquid–vapour separator incorporated gravity-assisted loop heat pipe (GALHP) (T1), against the conventional GALHP (T2) and a gravitational straight heat pipe (T3). Based on the results derived from the theoretical analyses and computer modelling, three prototype heat pipes, one for each type, were designed, constructed and tested to characterise their thermal performance under a series of operational conditions. By using the experimental data, the computer simulation model reported in the authors’ previous paper was examined and analysed, indicating that the model could achieve a reasonable accuracy in predicting the thermal performance of the three heat pipes. Under the specifically defined testing condition, T1 has more evenly distributed axial temperature profile than the other two heat pipes (T2 and T3). The start-up timings for T1, T2 and T3 were 410 s, 1400 s and 390 s respectively, indicating that the heat transfer within T2 was affected by the larger evaporator dry-out surface area and restricted evaporation area. The overall thermal resistance of T1 was 0.11 °C/W, which was around 20% and 50% that of T2 and T3. The tested effective thermal conductivity in T1 was 29,968 W/°C m, which was 296% and 648% that of T2 and T3, and 7492% that of a standard copper rod. It is therefore concluded that the novel heat pipe (T1) could achieve a significantly enhanced heat transport effect, relative to T2, T3 and standard cooper rod. The experimental results derived from this research enabled characterisation of the thermal performance of T1, relative to other heat pipes, and validation of the developed computer simulation model derived from the authors’ previous research. These two parts researches in combination will enable design, optimisation and analyse of such a new GALHP, thus promoting its wide application and achieving efficient thermal management.

  • 17558.
    Zhang, Xingxing
    et al.
    University of Hull.
    Shen, Jingchun
    Lu, Yan
    He, Wei
    Xu, Peng
    Zhao, Xudong
    Qiu, Zhongzhu
    Zhu, Zishang
    Zhou, Jinzhi
    Dong, Xiaoqiang
    Active Solar Thermal Facades (ASTFs): From concept, application to research questions2015In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 50, p. 32-63Article in journal (Refereed)
    Abstract [en]

    The aim of the paper is to report a comprehensive review into a recently emerging building integrated solar thermal technology, namely, Active Solar Thermal Facades (ASTFs), in terms of concept, classification, standard, performance evaluation, application, as well as research questions. This involves the combined effort of literature review, analysis, extraction, integration, critics, prediction and conclusion. It is indicated that the ASTFs are sort of building envelope elements incorporating the solar collecting devices, thus enabling the dual functions, e.g., space shielding and solar energy collection, to be performed. Based on the function of the building envelopes, the ASTF systems can be generally classified as wall-, window-, balcony-and roof-based types; while the ASTFs could also be classified by the thermal collection typologies, transparency, application, and heat-transfer medium. Currently, existing building and solar collector standards are brought together to evaluate the performance of the ASTFs. The research questions relating to the ASTFs are numerous, but the major points lie in: (1) whole structure and individual components layout, sizing and optimisation; (2) theoretical analysis; (3) experimental measurement; and (4) energy saving, economic and environmental performance assessment. Based on the analysis of the identified research questions, achievements made on each question, and outstanding problems remaining with the ASTFs, further development opportunities on this topic are suggested: (1) development of an integrated database/software enabling both architecture design and engineering performance simulation; (2) real-time measurement of the ASTFs integrated buildings on a long-term scheme; (3) economic and environmental performance assessment and social acceptance analysis; (4) dissemination, marketing and exploitation strategies study. This study helps in identifying the current status, potential problems in existence, future directions in research, development and practical application of the ASTFs technologies in buildings. It will also promote development of renewable energy technology and thus contribute to achieving the UK and international targets in energy saving, renewable energy utilization, and carbon emission reduction in building sector.

  • 17559.
    Zhang, Xingxing
    et al.
    University of Hull.
    Shen, Jingchun
    Xu, Peng
    Zhao, Xudong
    Xu, Ying
    Socio-economic performance of a novel solar photovoltaic/loop-heat-pipe heat pump water heating system in three different climatic regions2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 135, p. 20-34Article in journal (Refereed)
    Abstract [en]

    This paper aimed to study the socio-economic performance of a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump water heating system for application in three different climatic regions, namely, cold area represented by London, warm area represented by Shanghai, and hot (subtropical) area represented by Hong Kong. This study involved prediction of the annual fossil-fuel energy saving, investment return period and carbon emission reduction of the new system against the traditional gas-fired and electrical boilers based water heating systems. An established dynamic model developed by the authors was utilised to predict the system’s energy performance throughout a year in the three climatic regions. A life-cycle analytical model was further developed to analyse the economic and environmental benefits of the new system relative to the traditional systems. Analyses of the modelling results drew out several conclusive remarks: (1) the system could achieve the highest energy efficiency when operating at the hot (subtropical) climatic region (represented by Hong Kong), enabling the heat output of as high as 922 kW h/m2 yr and water temperature of above 45 °C, while the grid power input is only 59 kW h/m2 yr; (2) the system is worth for investment when operating at the high energy charging tariff area (represented by London), with the cost payback periods of 8 and 5 years relative to the traditional gas-fired and electrical boilers based systems, respectively; (3) the system could obtain the most promising environmental benefits when operating in Shanghai where the energy quality (embodied carbon volume of per kW h energy) is relatively poor, enabling reduction in life-cycle carbon emissions of around 4.08 tons/m2 and 17.87 tons/m2 respectively, relative to the gas-fired and electrical boilers. Answer to such a question on which area is most suitable for the system application is highly dependent upon the priority order among the three dominating factors: (1) energy efficiency, (2) economic revenue, and (3) environmental benefit, which may vary with the users, local concerns and policy influence, etc. The research results will be able to assist in decision making in implementation of the new PV/thermal technology and analyses of the associated economic and environmental benefits, thus contributing to realisation of the regional and global targets on fossil fuel energy saving and environmental sustainability.

  • 17560. Zhang, Xingxing
    et al.
    Shen, Jingchun
    Yang, Tong
    Tang, Llewellyn
    Experimental study of a solar photovoltaic/thermal (PV/T) system2015Conference paper (Refereed)
  • 17561.
    Zhang, Xingxing
    et al.
    University of Nottingham.
    Shen, Jingchun
    University of Nottingham, Ningbo.
    Yang, Tong
    Tang, Llewellyn
    Wang, Luying
    Liu, Yingqi
    Xu, Peng
    Smart meter and in-home display for energy savings in residential buildings: a pilot investigation in Shanghai, China2019In: Intelligent Buildings International, ISSN 1750-8975, E-ISSN 1756-6932, Vol. 11, no 1, p. 4-26Article in journal (Refereed)
    Abstract [en]

    Smart meters and in-home displays (IHDs) have been recently adopted to help give residential users more control over energy consumption, and meet environmental and supply security objectives. The article aims to identify the effectiveness and potential of smart meters and real-time IHDs in reducing Shanghai household energy consumption by affecting occupants? behaviour. A general landscape of the occupant behaviour in residential buildings was briefly painted. A pilot study in Shanghai with an effective sample of 131 respondents was arranged into two groups as IHD and non-IHD households. A dedicated statistical analysis model was developed based on the micro-level empirical data to investigate the characteristics and the regulations of electricity consumption in these two groups, such as check frequency, electricity consumption reduction and shifting, energy bill saving, and standby power. The research results demonstrate that IHDs could lead to around 9.1% reduction in monthly electricity consumption and about 11.0% cut off in monthly electricity bills. A general comparison of the electricity consumption reduction between this research and the average UK case was further made. Barriers at current stage and challenges for further work were finally discussed. The statistical model is expected to ?future proof? smart meter and real-time displays through macro-level designing in modularity and flexibility in China. The overall research initially proves the concept of the feasible impact of smart meter and display technologies in the Chinese context, which is further expected to contribute to the empirical evidence on how IHD feedback could influence household electricity consumption in the Chinese context.

  • 17562. Zhang, Xingxing
    et al.
    Shen, Jingchun
    Yang, Tong
    Tang, Llewellyn
    Wu, Yupeng
    An initial concept design of an innovative flat-plate solar thermal facade for building integration2015In: Sustainable Buildings and Structures / [ed] Stephen P. Wilkinson, Jun Xia, Bing Chen, Taylor & Francis, 2015, p. 103-110Chapter in book (Refereed)
  • 17563.
    Zhang, Xingxing
    et al.
    University of Nottingham.
    Shen, Jingchun
    Yang, Tong
    Tang, Llewellyn
    Wu, Yupeng
    Pan, Song
    Wu, Jinshun
    Xu, Peng
    Assessment of the effectiveness of investment strategy in solar photovoltaic (PV) energy sector: a case study2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, p. 2977-2982Article in journal (Refereed)
    Abstract [en]

    Solar photovoltaic (PV) energy is now promising to offer potential solutions for sustainable development, especially in China. A representative Chinese solar PV manufacturer - Shunfeng International Clean Energy Limited (SFCE) - is therefore assessed in this paper, including (1) investment strategies in China’s recent macroeconomic exposure; (2) the market exposure and vulnerability. The macroeconomic challenges in case of China’s continuous GDP growth would have significant implications for SFCE’s investment strategy. Although SFCE’s vulnerability is high, it has mediated its macro exposure and protect itself by advanced non-pricing competition, product/service differentiation, vertical and horizontal integration, and high-profit diversification etc. The research result is expected to offer useful indications for solar PV companies to adapt and succeed in the future energy industry and simultaneously help the world to mitigate climate change.

  • 17564. Zhang, Xingxing
    et al.
    Shen, Jingchun
    Zhao, Xudong
    Comparative investigation of solar photovoltaic (PV) and photovoltaic/thermal (PV/T) systems by both laboratory and field experiments2016In: Renewable Energy in the Service of Mankind Vol II: Selected Topics from the World Renewable Energy Congress WREC 2014 / [ed] Ali Sayigh, Springer, 2016Chapter in book (Refereed)
  • 17565. Zhang, Xingxing
    et al.
    Shen, Jingchun
    Zhao, Xudong
    Photovoltaic/Loop-Heat-Pipe Heat Pump Techno for Low-Carbon Buildings2014Book (Refereed)
  • 17566.
    Zhang, Xingxing
    et al.
    University of Hull.
    Shen, Jingchun
    Zhao, Xudong
    Xu, ing
    Investigation of a Pilot-scale Photovoltaic/thermal System and its Opportunities for Future Development2014In: Open Journal of Renewable Energy and Sustainable Development, ISSN 2374-5371, Vol. 1, no 2, p. 24-34Article in journal (Refereed)
  • 17567. Zhang, Xingxing
    et al.
    Shen, Jingchun
    Zhao, Xudong
    Xu, Ying
    Nibeler, Benno
    A Pilot-scale Demonstration of a Novel Solar Photovoltaic/thermal (PV/T) System and its Scenarios for Future Development2014Conference paper (Refereed)
  • 17568. Zhang, Xingxing
    et al.
    Shen, Jingchun
    Zhao, Xudong
    Xu, Ying
    Nibeler, Benno
    Comparative Investigation of Solar Photovoltaic (PV) and Photovoltaic/thermal (PV/T) Systems2014Conference paper (Refereed)
  • 17569. Zhang, Xingxing
    et al.
    Shen, Jingchun
    Zhao, Xudong
    Xu, Ying
    Nibeler, Benno
    Investigation of a novel thermal absorber for retrofit of commercial photovoltaic panels2014Conference paper (Refereed)
  • 17570.
    Zhang, Xingxing
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Wang, X.
    Zhao, Xiaoyun
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Solar System Design and Energy Performance Assessment Approaches2019In: Advanced Energy Efficiency Technologies for Solar Heating, Cooling and Power Generation, Springer, 2019, p. 417-451Chapter in book (Refereed)
    Abstract [en]

    Recently, solar system has gained a rapid development in many countries because it is clean and sustainable. Many solar systems including the solar photovoltaic/loop-heat-pipe (PV/LHP), solar loop-heat-pipe (LHP), solar photovoltaic/micro-channel heat pipe (PV/MCHP) system, and solar thermal facade system (STF) have been designed for energy saving. To assess these systems’ performance, there are many approaches such as energy and exergy assessment which is used in this chapter to analyze their performance. Besides the system design, the authors set up dedicated experimental models in combination with computer models to test the systems’ performance. Furthermore, some systems are compared with the conventional system, and the performance of these solar systems is better than the conventional system. In addition, these solar systems are applied in many real buildings and their performance is examined, the results show that the solar systems have more potential to boost the building energy efficiency and create the possibility of solar development in buildings. © 2019, Springer Nature Switzerland AG.

  • 17571.
    Zhang, Xingxing
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Wei, Y.
    He, W.
    Qiu, Z.
    Zhao, Xiaoyun
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Solar Systems’ Economic and Environmental Performance Assessment2019In: Advanced Energy Efficiency Technologies for Solar Heating, Cooling and Power Generation / [ed] Xudong Zhao, Xiaoli Ma, Springer, 2019, p. 453-486Chapter in book (Refereed)
    Abstract [en]

    The economic and environmental performance assessment of the solar system plays a critical role in building design, operation and retrofit. A dedicated economic model is necessary to assess the investment feasibility on a new technology, which allows investors to decide on a profitable investment, compare investment projects and know about the benefits of the best investment. An environmental model is adopted to predict carbon emission reduction in the solar system relative to the traditional heating and electronic systems. This chapter introduced three up-to-date solar system models and corresponding assessments related to their applications, including solar photovoltaic/loop heat pipe (PV/LHP) heat pump water heating system, loop heat pipe-based solar thermal facade (LHP-STF), heat pump water heating system as well as solar thermal facade (STF). The research results will be able to assist in decision-making in implementation of the proposed PV/T technology and analyses of the associated economic and environmental benefits, thus contributing to realization of regional and global targets on fossil fuel energy saving and environmental sustainability.

  • 17572.
    Zhang, Xingxing
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Wu, J.
    Pan, S.
    Han, Mengjie
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    An economic analysis of the solar photovoltaic/thermal (PV/T) technologies in Sweden: A case study2019In: IOP Conference Series: Materials Science and Engineering, 2019, Vol. 556, no 1, article id 012002Conference paper (Refereed)
  • 17573.
    Zhang, Xingxing
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Wu, J
    Zhang, Y
    Pan, S
    Wei, Y
    Xia, L
    Zhang, W
    Numerical study on thermal performance of a gravity assisted loop heat pipe2017Conference paper (Refereed)
    Abstract [en]

    This article carried out a parametric study of the thermal performance of a novel gravity assisted loop heat pipe (GALHP)with composite mesh-screen wick structure. A refined three-way structure with interior liquid-vapour separator wasdeveloped on top of the evaporator to enable a gravity-assisted operation, which not only simplified the correspondingwick structure but also eliminated the ‘dry-out’ potential in conventional GALHPs. A dedicated simulation model wasdeveloped on basis of the heat transfer and the flow characteristics derived from the governing equations of mass, energyand momentum. The essential impact parameters to the GALHP thermal performance were further discussed. It was foundthat the GALHP thermal performance, represented by the reciprocal of overall thermal resistance, varies directly withapplied heat load, evaporator diameter, and vapour-liquid separator diameter. The research results would be useful fordesign, optimisation and application of such GALHP in the gravity-assisted circumstance for thermal management.

  • 17574.
    Zhang, Xingxing
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Xiao, M.
    He, W.
    Qiu, Z.
    Zhao, Xiaoyun
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Heat Pump Technologies and Their Applications in Solar Systems2019In: Advanced Energy Efficiency Technologies for Solar Heating, Cooling and Power Generation / [ed] Xudong Zhao, Xiaoli Ma, Springer, 2019, p. 311-339Chapter in book (Refereed)
    Abstract [en]

    As the well known that global energy demand is on a trend of continuous growth, reducing energy demand and making good use of renewable energy are thought to be the major routes toward low carbon and sustainable future, in particular for the building sector. Compared to traditional gas-fired heating systems, heat pumps have been proved to be an energy-efficient heating technology which can save fossil fuel energy and consequently reduce CO2 emission. However, the most outstanding challenges for the application of heat pumps lie in their high demand for electrical power, and the insufficient heat transfer between the heat source and the refrigerant. To overcome these difficulties, a solar-assisted heat pump has been proposed to tackle these challenges. A solar-assisted heat pump combines a heat pump with a solar collector, enabling the use of solar energy to provide space heating and hot water for buildings. This chapter introduces heat pump technologies and their applications in solar systems. Two types of solar-assisted heat pump, direct and indirect expansion, are illustrated in details. This work has provided the fundamental research and experience for developing a solar heat pump system and contributing to a significant fossil fuel saving and carbon reduction in the global extent.

  • 17575. Zhang, Xingxing
    et al.
    Xu, Peng
    Shen, Jingchun
    Tang, Llewellyn
    Hu, Di
    Xiao, Manxuan
    Wu, Yupeng
    Parametric study of a novel gravity assisted loop heat pipe (GALHP) with composite mesh-screen wick structure2016Conference paper (Refereed)
  • 17576. Zhang, Xingxing
    et al.
    Xu, Ying
    Xu, Jihuan
    A novel modular solar thermal facade2014Patent (Other (popular science, discussion, etc.))
  • 17577. Zhang, Xingxing
    et al.
    Xu, Ying
    Xu, Jihuan
    A novel solar photovoltaic/thermal cogeneration system using the corrugated flat-plate thin-metal sheets2014Patent (Other (popular science, discussion, etc.))
  • 17578. Zhang, Xingxing
    et al.
    Xu, Ying
    Xu, Jihuan
    A novel solar photovoltaic/thermal cogeneration system using the corrugated flat-plate thin-metal sheets2015Patent (Other (popular science, discussion, etc.))
  • 17579. Zhang, Xingxing
    et al.
    Xu, Ying
    Xu, Jihuan
    A novel solar thermal absorber for integration of photovoltaic panels2014Patent (Other (popular science, discussion, etc.))
  • 17580. Zhang, Xingxing
    et al.
    Xu, Ying
    Xu, Jihuan
    A novel thin-conductive solar thermal absorber and flat-plate solar collector2014Patent (Other (popular science, discussion, etc.))
  • 17581.
    Zhang, Xingxing
    et al.
    De Montfort University.
    Zhao, X.
    Xu, J.
    Yu, X.
    Study of the heat transport capacity of a novel gravitational loop heat pipe2013In: International Journal of Low-Carbon Technologies, ISSN 1748-1317, E-ISSN 1748-1325, Vol. 8, no 3, p. 210-223Article in journal (Refereed)
    Abstract [en]

    This article presented a theoretical analysis of the heat transfer limits associated with a gravitational loop heat pipe (LHP), which involves the utilization of an innovative liquid feeding/distributing and vapour/liquid-separating structure. The mathematical equations governing the heat transport capacity were applied to simulate several commonly known heat transfer limits of the pipe, namely, viscous, sonic, entrainment, capillary, boiling and liquid filling mass limits. This will allow the determination of the actual figure of the limitation and analyses of the factors effecting the limits, including the loop operational temperature, wick type, evaporator diameter/length, evaporator inclination angle, vapour column diameter in the three-way fitting, liquid filling mass and evaporator-to-condenser height difference. During the study, the heat-transfer limits associated with the three-way fitting for liquid feeding/distribution and vapour/liquid separation were given particular attention. The results derived from the analytical model indicated that the compound screen mesh wick can achieve better thermal performance over the sintered powder and open rectangular groove wicks. It was also found that the heat transport capacity of such LHP operation is positively proportional to the operational temperature, evaporator diameter, evaporator inclination angle, vapour column diameter within the three-way fitting, liquid filling mass and evaporator-to-condenser height difference, and in a reciprocal order to the evaporator length. With the specified loop configuration and operational conditions, the LHP can achieve a high heat transport capacity of around 900 W. Overall, the work presented in this article provided an approach to determine the heat transfer limitations for such a specific LHP operation that will be of practical use for the associated system design and performance evaluation. 

  • 17582. Zhang, Xingxing
    et al.
    Zhao, Xudong
    Characterization of a Hybrid Photovoltaic/ Heat-Pump Water Heating System2012In: Proceeding 5th International Forum on Energy Saving and Environmental Protection Technologies for Air-Conditioning and Refrigeration, Beijing, China, 13th -14th June, 2012, 2012Conference paper (Refereed)
  • 17583. Zhang, Xingxing
    et al.
    Zhao, Xudong
    Shen, Jingchun
    Case study of a pilot-scale solar Photovoltaic/thermal (PV/T) system and its opportunities for future development2013In: Proceeding Portugal Sustainable Building 2013 (SB13) conference, Lisbon, Portugal, 30th Oct - 1st November, 2013, 2013Conference paper (Refereed)
  • 17584. Zhang, Xingxing
    et al.
    Zhao, Xudong
    Shen, Jingchun
    Feasibility Study of a Solar Photovoltaic/Loop-Heat-Pipe Heat Pump Water Heating System2013In: Proceeding 13th International Conference on Sustainable Energy Technologies, Hong Kong, 28th -30th August 2013, 2013Conference paper (Refereed)
  • 17585.
    Zhang, Xingxing
    et al.
    University of Hull.
    Zhao, Xudong
    Shen, Jingchun
    Hu, Xi
    Liu, Xuezhi
    Xu, Jihuan
    Design, fabrication and experimental study of a solar photovoltaic/loop-heat-pipe based heat pump system2013In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 97, p. 551-568Article in journal (Refereed)
    Abstract [en]

    In this paper, a novel solar photovoltaic/loop-heat-pipe (PV/LHP) module-based heat pump system was designed and fabricated for both electricity and hot water generation. A coated aluminium-alloy (Al-alloy) sheet was applied as the baseboard of PV cells for enhanced heat dissipation to the surroundings, which was characterised by a series of laboratory-controlled conditions over the conventional Tedlar–Polyester–Tedlar (TPT) baseboard. The whole prototype system was subsequently evaluated in outdoor weather conditions throughout a consecutive period for about one week. Impact of several external parameters to the PV panel with different baseboards was discussed and the results showed that weaker incident radiation, lower air temperature, higher wind speed, and ground mounting solution, were propitious to the PV electrical performance. Given the specific indoor testing conditions, temperature of the Al-alloy based PV cells was observed at about 62.4 °C, which was 5.2 °C lower than that of the TPT based PV cells, and its corresponding PV efficiency was about 9.18%, nearly 0.26% higher than the TPT based type. During the outdoor testing, the mean daily electrical, thermal and overall energetic and exergetic efficiencies of the PV/LHP module were measured at 9.13%, 39.25%, 48.37% and 15.02% respectively. The basic-thermal system performance coefficient (COPth) was found at 5.51 and the advanced system performance coefficient (COPPV/T) was nearly 8.71. A simple comparison was also conducted between the PV/LHP based heat-pump system and those conventional solar/air energy systems, which indicated that this advanced system harvests larger amount of solar energy and therefore enables enhanced solar efficiency and system performance. Basic analysis into the economic and environmental benefits of this prototype system further demonstrated such technology will be competitive in the future energy supply industry with a payback period of 16 (9) years and a life-cycle carbon reduction of 12.06 (2.94) tons in Shanghai (London).

  • 17586.
    Zhang, Xingxing
    et al.
    University of Hull.
    Zhao, Xudong
    Shen, Jingchun
    Xu, Jihuan
    Yu, Xiaotong
    Dynamic performance of a novel solar photovoltaic/loop-heat-pipe heat pump system2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 114, p. 335-352Article in journal (Refereed)
    Abstract [en]

    Objective of the paper is to present an investigation into the dynamic performance of a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for potential use in space heating or hot water generation. The methods used include theoretical computer simulation, experimental verification, analysis and comparison. The fundamental equations governing the transient processes of solar transmission, heat transfer, fluid flow and photovoltaic (PV) power generation were appropriately integrated to address the energy balances occurring in different parts of the system, e.g., glazing cover, PV cells, fin sheet, loop heat pipe, heat pump cycle and water tank. A dedicated computer model was developed to resolve the above grouping equations and consequently predict the system’s dynamic performance. An experimental rig was constructed and operated under the real weather conditions for over one week in Shanghai to evaluate the system living performance, which was undertaken by measurement of various operational parameters, e.g., solar radiation, photovoltaic power generation, temperatures and heat pump compressor consumption. On the basis of the first- (energetic) and second- (exergetic) thermodynamic laws, an overall evaluation approach was proposed and applied to conduct both quantitative and qualitative analysis of the PV/LHP module’s efficiency, which involved use of the basic thermal performance coefficient (COPth) and the advanced performance coefficient (COPPV/T) of such a system. Moreover, a simple comparison between the PV/LHP heat-pump system and conventional solar/air energy systems was conducted. The research results indicated that under the testing outdoor conditions, the mean daily electrical, thermal and overall energetic and exergetic efficiencies of the PV/LHP module were 9.13%, 39.25%, 48.37% and 15.02% respectively, and the average values of COPth and COPPV/T were 5.51 and 8.71. The PV/LHP module was found to achieve 3–5% higher solar exergetic efficiency than standard PV systems and about 7% higher overall solar energetic efficiency than the independent solar collector. Compared to the conventional solar/air heat pump systems, the PV/LHP heat pump system could achieve a COP figure that is around 1.5–4 times that for the conventional systems. It is concluded that the computer model is able to achieve a reasonable accuracy in predicting the system’s dynamic performance. The PV/LHP heat pump system is able to harvest significant amount of solar heat and electricity, thus enabling achieving enhanced solar thermal and electrical efficiencies. All these indicate a positive implication that the proposed system has potential to be developed into a high performance PV/T technology that can contribute to significant fossil fuel energy saving and carbon emission.

  • 17587.
    Zhang, Xingxing
    et al.
    De Montfort University.
    Zhao, Xudong
    Smith, Stefan
    Xu, Jihuan
    Yu, Xiaotong
    Review of R&D progress and practical application of the solar photovoltaic/thermal (PV/T) technologies2012In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 16, no 1, p. 599-617Article in journal (Refereed)
    Abstract [en]

    In this paper, the global market potential of solar thermal, photovoltaic (PV) and combined photovoltaic/thermal (PV/T) technologies in current time and near future was discussed. The concept of the PV/T and the theory behind the PV/T operation were briefly introduced, and standards for evaluating technical, economic and environmental performance of the PV/T systems were addressed. A comprehensive literature review into R&D works and practical application of the PV/T technology was illustrated and the review results were critically analysed in terms of PV/T type and research methodology used. The major features, current status, research focuses and existing difficulties/barriers related to the various types of PV/T were identified. The research methods, including theoretical analyses and computer simulation, experimental and combined experimental/theoretical investigation, demonstration and feasibility study, as well as economic and environmental analyses, applied into the PV/T technology were individually discussed, and the achievement and problems remaining in each research method category were described. Finally, opportunities for further work to carry on PV/T study were identified. The review research indicated that air/water-based PV/T systems are the commonly used technologies but their thermal removal effectiveness is lower. Refrigerant/heat-pipe-based PV/Ts, although still in research/laboratory stage, could achieve much higher solar conversion efficiencies over the air/water-based systems. However, these systems were found a few technical challenges in practice which require further resolutions. The review research suggested that further works could be undertaken to (1) develop new feasible, economic and energy efficient PV/T systems; (2) optimise the structural/geometrical configurations of the existing PV/T systems; (3) study long term dynamic performance of the PV/T systems; (4) demonstrate the PV/T systems in real buildings and conduct the feasibility study; and (5) carry on advanced economic and environmental analyses. This review research helps finding the questions remaining in PV/T technology, identify new research topics/directions to further improve the performance of the PV/T, remove the barriers in PV/T practical application, establish the standards/regulations related to PV/T design and installation, and promote its market penetration throughout the world.

  • 17588. Zhang, Xingxing
    et al.
    Zhao, Xudong
    Tan, Junyi
    Ma, Shige
    Development of low-temperature air-source heat pump technology in Europe2015In: Heating, Ventilating and Air Conditioning, ISSN 1002-8501, Vol. 7, p. 48-52Article in journal (Refereed)
  • 17589. Zhang, Xingxing
    et al.
    Zhao, Xudong
    Xu, Jihuan
    Investigation of a Novel Solar Driven Water Heating System with Enhanced Energy Yield for Buildings2012In: Proceeding International Conference for Enhanced Building Operations (ICEBO) 2012, Manchester, UK, 23rd - 26th October 2012, 2012Conference paper (Refereed)
  • 17590. Zhang, Xingxing
    et al.
    Zhao, Xudong
    Xu, Jihuan
    Yu, Xiaotong
    A novel gravitational loop heat pipe using for micro solar photovoltaic/thermal cogeneration system2013Patent (Other (popular science, discussion, etc.))
  • 17591.
    Zhang, Xingxing
    et al.
    De Montfort University.
    Zhao, Xudong
    Xu, Jihuan
    Yu, Xiaotong
    Characterization of a solar photovoltaic/loop-heat-pipe heat pump water heating system2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 102, p. 1229-1245Article in journal (Refereed)
    Abstract [en]

    This paper introduced the concept, potential application and benefits relating to a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for hot water generation. On this basis, the paper reported the process and results of characterizing the performance of such a system, which was undertaken through dedicated thermo-fluid and energy balance analyses, computer model development and operation, and experimental verification and modification. The fundamental heat transfer, fluid flow and photovoltaic governing equations were applied to characterize the energy conversion and transfer processes occurring in each part and whole system layout; while the energy balance approach was utilized to enable inter-connection and resolution of the grouped equations. As a result, a dedicated computer model was developed and used to calculate the operational parameters, optimise the geometrical configurations and sizes, and recommend the appropriate operational condition relating to the system. Further, an experimental rig was constructed and utilized to acquire the relevant measurement data that thus enabled the parallel comparison between the simulation and experiment. It is concluded that the testing and modelling results are in good agreement, indicating that the model has the reasonable accuracy in predicting the system’s performance. Under the given experimental conditions, the electrical, thermal and overall efficiency of the PV/LHP module were around 10%, 40% and 50% respectively; whilst the system’s overall performance coefficient (COPPV/T) was 8.7. Impact of the operational parameters (i.e. solar radiation, air temperature, air velocity, heat-pump’s evaporation temperature, glazing covers, and number of the absorbing heat pipes) to the performance of the system (in terms of efficiencies of the PV/LHP module and the system’s overall performance coefficient COPPV/T) was investigated individually. The results indicated that lower solar radiation, lower air temperature, higher air velocity and smaller cover number led to enhanced electrical efficiency but reduced thermal efficiency of the module; whereas lower heat-pump’s evaporation temperature and larger number of heat absorbing pipes gave rise to both thermal and electrical efficiencies of the module. The research results would assist in developing a high efficient solar (space or hot water) heating system and thus contribute to realisation of the energy saving and associated carbon emission targets set for buildings globally.

  • 17592.
    Zhang, Yanqing
    Dalarna University, School of Education and Humanities, Comparative Literature.
    Ch’ien Chung-shu’s Fortress Besieged and Post-colonialism2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
  • 17593.
    Zhang, Yanqing
    Dalarna University, School of Education and Humanities, Comparative Literature.
    Virginia Woolf’s The Waves: A Study on Modernism2006Independent thesis Basic level (degree of Bachelor)Student thesis
  • 17594.
    Zhao, Long
    et al.
    Dalarna University, School of Technology and Business Studies, Tourism Studies.
    Abukadirov, Kudratilla
    Dalarna University, School of Technology and Business Studies, Tourism Studies.
    Europe as Chinese Outbound Travel Market:: Analysing Travel Patterns of Chinese Tourists in Selecting EuropeanDestinations2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    While China has become one of the larger tourism destination regions in the recent years, allindications point to China establishing itself as the biggest tourist outbound market in the nearfuture. As such, numerous countries prepare to attract more Chinese travelers with a higherspending power in order to sustain or extend the current level of tourism related income. Forpotential European destinations, it is therefore essential to understand the travel motivations aswell as the obstacles Chinese travelers face when considering Europe as a travel destination.Therefore, the aim of this research is to contribute to the understanding of the Chinese outboundtourism market towards European destinations. This was achieved by analyzing the impacts oftravel obstacles and the push and pull factors of Chinese travelers. This analysis has been basedupon the development of the travel flows in the past 10 years, in terms of tourist numbers, and isexplained by economic, political and social factors (i.e. push and pull).The method used within this research consists of quantitative secondary data. The data isrecorded from the World Tourism Organization statistics and re-analyzed using the LocationQuotient.While in the past much of the outbound tourism was concentrated in several countries the resultsindicate that destination choices vary more and more while all countries in this study recorded anincrease in Chinese tourists. The analyzing-results also indicated that with the rise of the Chineseeconomy, the number of outbound tourists will relatively rise. Moreover, the findings indicatethat the flow of outbound tourists from China has risen, also owing to relaxation of major staterestrictions and change of intervening obstacles.After analysing the situation of tourism market [during the past decade] between Europe andChina, the authors are able to comment about the future trends. Furthermore, suggestions forfuture investigation are presented.

  • 17595.
    Zhao, Ping
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    A Contour-based Separation of Vertically Attached Traffic Signs2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    This report presents an algorithm for locating the cut points for and separating vertically attached traffic signs in Sweden. This algorithm provides several advanced digital image processing features: binary image which represents visual object and its complex rectangle background with number one and zero respectively, improved cross correlation which shows the similarity of 2D objects and filters traffic sign candidates, simplified shape decomposition which smoothes contour of visual object iteratively in order to reduce white noises, flipping point detection which locates black noises candidates, chasm filling algorithm which eliminates black noises, determines the final cut points and separates originally attached traffic signs into individual ones. At each step, the mediate results as well as the efficiency in practice would be presented to show the advantages and disadvantages of the developed algorithm. This report concentrates on contour-based recognition of Swedish traffic signs. The general shapes cover upward triangle, downward triangle, circle, rectangle and octagon. At last, a demonstration program would be presented to show how the algorithm works in real-time environment.

  • 17596.
    Zhao, Xiaoyun
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Government vs Market in Sustainable Residential Development?: Microdata analysis of car travel, CO2 emission and residence location2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Increasing car usage and travel demands between residential locations and destinations in order to fulfill the various needs of residents is a primary cause of CO2 emissions. To win the battle against climate change, a better understanding of the question relating to which urban residential form may most effectively mitigate the CO2 emissions is the key pathway.

    This dissertation is concerned with the above problem and it mainly considers three objectives in providing insights on answering the question. The first objective is to comprehensively and microscopically understand intra-urban car travel behavior. The second objective is to estimate the induced CO2 emissions from daily intra-urban car travel and to ex-ante evaluate residential plans. The third objective is to assess whether the governmental sustainable residential development objective is aligned with the objectives of the estate market actors. To explore the research questions related to the objectives, a microdata analysis process (data collection, data assessment and transformation, data storage, data analysis and decision-making) is applied and is found essential in gaining access to key variables in exploring the answer of a preferable urban form. The dissertation offers many new solutions to various technical aspects through a microdata analysis process.

    The primary contribution of this dissertation is that it outlines an operational model that comprehensively integrates the investors’ investment strategy, the residents’ choice behavior, and the governmental sustainability objective in the interest of making an ex-ante assessment of residential plans. This ex-ante assessment provides decision-support in sustainable residential development at foremost local level.

    The first finding from the implementation of the model on the case study is that the market actors’ objectives are, in general, aligned with the government’s sustainable residential development objective. The second finding indicates that re-shaping the urban form into a compact city is preferable in mitigating CO2 emissions, in spite of the fact that the case city is of a polycentric urban form. These findings provide support for those advocating the compact city as the ideal for sustainable residential development, and also provide foresight on settling the answer to the preferred re-shaping of urban forms in climate change.

  • 17597.
    Zhao, Xiaoyun
    Dalarna University, School of Technology and Business Studies, Statistics.
    On processing GPS tracking data of car-movements in Borlänge, Sweden2014Report (Other academic)
    Abstract [en]

    The advancement of GPS technology enables GPS devices not only to be used as orientation and navigation tools, but also to track travelled routes. GPS tracking data provides essential information for a broad range of urban planning applications such as transportation routing and planning, traffic management and environmental control. This paper describes on processing the data that was collected by tracking the cars of 316 volunteers over a seven-week period. The detailed information is extracted. The processed data is further connected to the underlying road network by means of maps. Geographical maps are applied to check how the car-movements match the road network. The maps capture the complexity of the car-movements in the urban area. The results show that 90% of the trips on the plane match the road network within a tolerance.

  • 17598.
    Zhao, Xiaoyun
    Dalarna University, School of Technology and Business Studies, Statistics.
    On processing GPS tracking data of spatiotemporal car movements: a case study2015Report (Other academic)
    Abstract [en]

    The advancement of GPS technology has made it possible to use GPS devices as orientation and navigation tools, but also as tools to track spatiotemporal information. GPS tracking data can be broadly applied in location-based services, such as spatial distribution of the economy, transportation routing and planning, traffic management and environmental control. Therefore, knowledge of how to process the data from a standard GPS device is crucial for further use. Previous studies have considered various issues of the data processing at the time. This paper, however, aims to outline a general procedure for processing GPS tracking data. The procedure is illustrated step-by-step by the processing of real-world GPS data of car movements in Borlänge in the centre of Sweden.

  • 17599.
    Zhao, Xiaoyun
    Dalarna University, School of Technology and Business Studies, Statistics.
    On processing GPS tracking data of spatio-temporal car movements: a case study2015In: Journal of Location Based Services, ISSN 1748-9725, Vol. 9, no 4, p. 235-253Article in journal (Refereed)
    Abstract [en]

    The advancement of GPS technology has made it possible to use GPS devices as orientation and navigation tools, but also as tools to track spatio-temporal information. GPS tracking data can be broadly applied in location-based services, such as spatial distribution of the economy, transportation routing and planning, traffic management and environmental control. Therefore, knowledge of how to process the data from a standard GPS device is crucial for further use. Previous studies have considered various issues of the data processing at the time. This paper, however, aims to outline a general procedure for processing GPS tracking data. The procedure is illustrated step by step by the processing of real-world GPS data of car movements in Borlänge in the centre of Sweden. 

  • 17600.
    Zhao, Xiaoyun
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Road network and GPS tracking with data processing and quality assessment2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    GPS technology has been embedded into portable, low-cost electronic devices nowadays to track the movements of mobile objects. This implication has greatly impacted the transportation field by creating a novel and rich source of traffic data on the road network. Although the promise offered by GPS devices to overcome problems like underreporting, respondent fatigue, inaccuracies and other human errors in data collection is significant; the technology is still relatively new that it raises many issues for potential users. These issues tend to revolve around the following areas: reliability, data processing and the related application.

    This thesis aims to study the GPS tracking form the methodological, technical and practical aspects. It first evaluates the reliability of GPS based traffic data based on data from an experiment containing three different traffic modes (car, bike and bus) traveling along the road network. It then outline the general procedure for processing GPS tracking data and discuss related issues that are uncovered by using real-world GPS tracking data of 316 cars. Thirdly, it investigates the influence of road network density in finding optimal location for enhancing travel efficiency and decreasing travel cost.

    The results show that the geographical positioning is reliable. Velocity is slightly underestimated, whereas altitude measurements are unreliable.Post processing techniques with auxiliary information is found necessary and important when solving the inaccuracy of GPS data. The densities of the road network influence the finding of optimal locations. The influence will stabilize at a certain level and do not deteriorate when the node density is higher.

349350351352353354355 17551 - 17600 of 18123
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • chicago-author-date
  • chicago-note-bibliography
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf