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Zhao, Xiaoyun, Ph.D.ORCID iD iconorcid.org/0000-0002-7512-5321
Publications (10 of 16) Show all publications
Wei, Y., Zhang, X., Shi, Y., Xia, L., Pan, S., Wu, J., . . . Zhao, X. (2018). A review of data-driven approaches for prediction and classification of building energy consumption. Renewable & sustainable energy reviews, 82(1), 1027-1047
Open this publication in new window or tab >>A review of data-driven approaches for prediction and classification of building energy consumption
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2018 (English)In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 82, no 1, p. 1027-1047Article in journal (Refereed) Published
Abstract [en]

A recent surge of interest in building energy consumption has generated a tremendous amount of energy data, which boosts the data-driven algorithms for broad application throughout the building industry. This article reviews the prevailing data-driven approaches used in building energy analysis under different archetypes and granularities, including those methods for prediction (artificial neural networks, support vector machines, statistical regression, decision tree and genetic algorithm) and those methods for classification (K-mean clustering, self-organizing map and hierarchy clustering). The review results demonstrate that the data-driven approaches have well addressed a large variety of building energy related applications, such as load forecasting and prediction, energy pattern profiling, regional energy-consumption mapping, benchmarking for building stocks, global retrofit strategies and guideline making etc. Significantly, this review refines a few key tasks for modification of the data-driven approaches in the context of application to building energy analysis. The conclusions drawn in this review could facilitate future micro-scale changes of energy use for a particular building through the appropriate retrofit and the inclusion of renewable energy technologies. It also paves an avenue to explore potential in macro-scale energy-reduction with consideration of customer demands. All these will be useful to establish a better long-term strategy for urban sustainability.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Data driven approach, Building, Energy consumption, Prediction, Classification
National Category
Energy Engineering
Research subject
Energy, Forests and Built Environments
Identifiers
urn:nbn:se:du-26385 (URN)10.1016/j.rser.2017.09.108 (DOI)2-s2.0-85030703701 (Scopus ID)
Available from: 2017-10-09 Created: 2017-10-09 Last updated: 2017-11-15Bibliographically approved
Eriksson, P. E., Swenberg, T., Zhao, X. & Eriksson, Y. (2018). How gaze time on screen impacts the efficacy of visual instructions. Heliyon, 4(6), Article ID e00660.
Open this publication in new window or tab >>How gaze time on screen impacts the efficacy of visual instructions
2018 (English)In: Heliyon, ISSN 2405-8440, Vol. 4, no 6, article id e00660Article in journal (Refereed) Published
Abstract [en]

This article explores whether GTS (gaze time on screen) can be useful as an engagement measure in the screen mediated learning context. Research that exemplifies ways of measuring engagement in the on-line education context usually does not address engagement metrics and engagement evaluation methods that are unique to the diverse contemporary instructional media landscape. Nevertheless, unambiguous construct definitions of engagement and standardized engagement evaluation methods are needed to leverage instructional media's efficacy. By analyzing the results from a mixed methods eye-tracking study of fifty-seven participants evaluating their visual and assembly performance levels in relation to three visual, procedural instructions that are versions of the same procedural instruction, we found that the mean GTS-values in each group were rather similar. However, the original GTS-values outputted from the ET-computer were not entirely correct and needed to be manually checked and cross validated. Thus, GTS appears not to be a reliable, universally applicable automatic engagement measure in screen-based instructional efforts. Still, we could establish that the overall performance of learners was somewhat negatively impacted by lower than mean GTS-scores, when checking the performance levels of the entire group (N = 57). When checking the stimuli groups individually (N = 17, 20, 20), the structural diagram group's assembly time durations were positively influenced by higher than mean GTS-scores.

Keywords
psychology, education, information science
National Category
Design Learning Arts Educational Sciences
Research subject
Intercultural Studies
Identifiers
urn:nbn:se:du-28050 (URN)10.1016/j.heliyon.2018.e00660 (DOI)30003156 (PubMedID)2-s2.0-85048981564 (Scopus ID)
Note

Open Access APC beslut 5/2018

Available from: 2018-06-29 Created: 2018-06-29 Last updated: 2018-11-23Bibliographically approved
Zhao, X., Carling, K. & Håkansson, J. (2017). An evaluation of the reliability of GPS-based transportation data. In: Proceedings of IAC in Vienna 2017: . Paper presented at IAC (International Academic Conference on Transport, Logistics, Tourism and Sport Science) in Vienna November 24-25 2017 (pp. 323-334). , Article ID IAC201711035.
Open this publication in new window or tab >>An evaluation of the reliability of GPS-based transportation data
2017 (English)In: Proceedings of IAC in Vienna 2017, 2017, p. 323-334, article id IAC201711035Conference paper, Published paper (Refereed)
Abstract [en]

GPS-based data are becoming a cornerstone for real-time transportation applications. Tracking data of vehicles from GPS receivers are however susceptible to measurement errors. The assessment of the reliability of data from GPS receiver is a neglected issue, especially in a real road network setting and in the phase after data transfer but before information identification. An evaluation method is outlined and carried out by conducting a randomized experiment. We assess the reliability of GPS-based transportation data on geographical position, speed, and elevation from three varied receivers GlobalSat BT-338X, Magellan SporTrak Pro and smart phone for three transportation modes: bicycle, car, and bus. The positional error ranging from 0158 meters, and 74% to 100% with an error within 5 meters depending on the transportation mode and route, there is also a non-negligible risk for aberrant positioning. Speed is slightly underestimated or overestimated with errors around 5km/h except for SporTrak Pro which had an error of -10 km/h. Elevation measurements are unreliable with errors bigger than 100 meters.

Keywords
Transportation, GPS tracking, Reliability, Road network
National Category
Transport Systems and Logistics Geosciences, Multidisciplinary
Research subject
Complex Systems – Microdata Analysis
Identifiers
urn:nbn:se:du-26981 (URN)978-80-88203-04-9 (ISBN)
Conference
IAC (International Academic Conference on Transport, Logistics, Tourism and Sport Science) in Vienna November 24-25 2017
Available from: 2018-01-26 Created: 2018-01-26 Last updated: 2018-01-26Bibliographically approved
Zhao, X. (2017). Government vs Market in Sustainable Residential Development?: Microdata analysis of car travel, CO2 emission and residence location. (Doctoral dissertation). Borlänge: Dalarna University
Open this publication in new window or tab >>Government vs Market in Sustainable Residential Development?: Microdata analysis of car travel, CO2 emission and residence location
2017 (English)Doctoral 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.

Place, publisher, year, edition, pages
Borlänge: Dalarna University, 2017. p. 140
Series
Dalarna Doctoral Dissertations ; 6
National Category
Social Sciences
Research subject
Complex Systems – Microdata Analysis, General Microdata Analysis - transports
Identifiers
urn:nbn:se:du-24685 (URN)978-91-85941-84-1 (ISBN)
Public defence
2017-04-28, Clas Ohlson, Studenternas Hus Tenoren, Röda vägen, Borlänge, 13:00 (English)
Opponent
Supervisors
Available from: 2017-04-05 Created: 2017-04-04 Last updated: 2018-12-12Bibliographically approved
Zhao, X., Carling, K. & Håkansson, J. (2017). On assessing governmental sustainable residential planning and its alignment with residents’ and estate investors’ objectives. Borlänge: Högskolan Dalarna
Open this publication in new window or tab >>On assessing governmental sustainable residential planning and its alignment with residents’ and estate investors’ objectives
2017 (English)Report (Other academic)
Abstract [en]

There are three key actors in forming the sustainable spatial distribution of residency in an area, (local) government, the estate investor and the resident, each with its own objective. Most urban planning studies have mainly focused on the ex-post evaluation of residential development by considering the objective of each actor separately. This paper outlines a conceptual model where the three key actors and their unique objectives are integrated with the aim of providing an ex-ante evaluation of residential development for government to make policies operational on a micro level. The methodology is implemented on a Swedish city, where sustainable residential development is in high need due to the influx of immigrants. The case study demonstrates that the model can integrate the macro and micro actors well. The model can provide noteworthy insights for the government on where the objectives of sustainability, livability and profit can be met. A sensitivity check of the parameter settings shows that the implementation of the model is robust for replication in other cities.

Place, publisher, year, edition, pages
Borlänge: Högskolan Dalarna, 2017. p. 20
Series
Working papers in transport, tourism, information technology and microdata analysis, ISSN 1650-5581 ; 2017:01
Keywords
Sustainable urban development; CO2 emissions; Multi-agent system model; Urban mobility
National Category
Social and Economic Geography
Research subject
Complex Systems – Microdata Analysis
Identifiers
urn:nbn:se:du-24514 (URN)
Available from: 2017-03-08 Created: 2017-03-08 Last updated: 2017-11-15Bibliographically approved
Zhao, X., Carling, K. & Håkansson, J. (2017). Residential planning, driver mobility and CO2 emission: a microscopic look at Borlänge in Sweden. European Planning Studies, 25(9), 1597-1614
Open this publication in new window or tab >>Residential planning, driver mobility and CO2 emission: a microscopic look at Borlänge in Sweden
2017 (English)In: European Planning Studies, ISSN 0965-4313, E-ISSN 1469-5944, Vol. 25, no 9, p. 1597-1614Article in journal (Refereed) Published
Abstract [en]

In a city there are hotspots that attract citizens, and most of the transportation arises when citizens move between their residence and primary destinations (i.e. hotspots). However, an ex ante evaluation of energy-efficient mobility and urban residential planning has seldom been conducted. Therefore, this paper proposes an ex ante evaluation method to quantify the impacts, in terms of CO2 emissions induced by intra-urban car mobility, of residential plans for various urban areas. The method is illustrated in a case study of a Swedish midsize city, which is presently preoccupied with urban planning of new residential areas in response to substantial population growth due to immigration. In general, CO2 emissions increase from the continued urban core area (CUCA), to the sub-polycentric area (SPA), to the edge urbanization area (EUA), where CO2 emission of EUA is twice that of the CUCA. The average travel distances also increase in the same pattern, though the relative increase is more than four times. Apartment buildings could be more effective in meeting residential needs and mitigating CO2 emissions than dispersed single-family houses. 

Keywords
Ex ante evaluation, GPS-tracking data, spatial distribution, urban form
National Category
Social and Economic Geography
Research subject
Complex Systems – Microdata Analysis
Identifiers
urn:nbn:se:du-24824 (URN)10.1080/09654313.2017.1317722 (DOI)000404932100007 ()2-s2.0-85017904082 (Scopus ID)
Available from: 2017-05-08 Created: 2017-05-08 Last updated: 2017-11-15Bibliographically approved
Zhao, X., Carling, K. & Håkansson, J. (2016). Residential planning, driver mobility and CO2 emission. Borlänge: Högskolan Dalarna
Open this publication in new window or tab >>Residential planning, driver mobility and CO2 emission
2016 (English)Report (Other academic)
Abstract [en]

In a city there are hotspots that attract the citizens and most of the transportation in the city arises when citizens move between their residence and the hotspots. However, the evaluation between energy-efficient mobility and urban residential planning has been found to be rather weak. In this paper, we propose an ex-ante evaluation method to quantify the impacts in terms of CO2 emissions induced by intra-urban car mobility due to different residential plans implemented at various urban areas. The method is illustrated by a Swedish midsize city which is presently preoccupied with urban planning of new residential areas in response to substantial population growth due to immigration. On average, the CO2 emissions increase from the continued urban core area (CUCA) to the suburban polycentric area (SPA) to the edge urbanization area (EUA), EUA is almost 3 times more than CUCA. The average travel distances also increase in the same sequence, the overall increase is more than 4 times. Apartment buildings could be more effective in meeting residential needs and mitigating CO2 emissions than dispersed single-family houses.

Place, publisher, year, edition, pages
Borlänge: Högskolan Dalarna, 2016. p. 29
Series
Working papers in transport, tourism, information technology and microdata analysis, ISSN 1650-5581 ; 2016:05
Keywords
Ex-ante evaluation; Spatial distribution; Urban form; Counterfactual; GPS-tracking data
National Category
Social and Economic Geography
Research subject
Complex Systems – Microdata Analysis, General Microdata Analysis - transports
Identifiers
urn:nbn:se:du-23954 (URN)
Available from: 2017-01-23 Created: 2017-01-23 Last updated: 2017-04-04Bibliographically approved
Zhao, X., Rebreyend, P. & Håkansson, J. (2015). Does road network density matter in optimally locating facilities?.
Open this publication in new window or tab >>Does road network density matter in optimally locating facilities?
2015 (English)Report (Other (popular science, discussion, etc.))
Abstract [en]

Optimal location on the transport infrastructure is the preferable requirement for many decision making processes. Most studies have focused on evaluating performances of optimally locate p facilities by minimizing their distances to a geographically distributed demand (n) when p and n vary. The optimal locations are also sensitive to geographical context such as road network, especially when they are asymmetrically distributed in the plane. The influence of alternating road network density is however not a very well-studied problem especially when it is applied in a real world context. This paper aims to investigate how the density level of the road network affects finding optimal location by solving the specific case of p-median location problem. A denser network is found needed when a higher number of facilities are to locate. The best solution will not always be obtained in the most detailed network but in a middle density level. The solutions do not further improve or improve insignificantly as the density exceeds 12,000 nodes, some solutions even deteriorate. The hierarchy of the different densities of network can be used according to location and transportation purposes and increase the efficiency of heuristic methods. The method in this study can be applied to other location-allocation problem in transportation analysis where the road network density can be differentiated. 

Publisher
p. 14
Series
Working papers in transport, tourism, information technology and microdata analysis, ISSN 1650-5581 ; 2015:10
Keywords
Road network; Density; p – median model; CPLEX; Heuristics
National Category
Computer and Information Sciences Human Geography
Research subject
Complex Systems – Microdata Analysis
Identifiers
urn:nbn:se:du-19079 (URN)
Available from: 2015-08-21 Created: 2015-08-21 Last updated: 2018-01-11Bibliographically approved
Zhao, X., Rebreyend, P. & Håkansson, J. (2015). How does the complexity of a road network affect optimal facility locations?. Borlänge: Högskolan Dalarna
Open this publication in new window or tab >>How does the complexity of a road network affect optimal facility locations?
2015 (English)Report (Other academic)
Abstract [en]

The road network is a necessary component in transportation. It facilitiesspatial movements of people and goods, and it also influences the optimal locations of facilities that usually serve as destinations of the movements. To fulfill the transportation needs and to adapt to the facility development, the road network is often organized hierarchically and asymmetrically with various road levels and spatial structures. The complexity of the road network increases along with the increase of road levels and spatial structures. However, location models locate facilities on a given road network, usually the most complex one, and the influence from the complexity of road network in finding optimal locations is not well-studied. This paper aims to investigate how the complexity of a road network affects the optimal facility locations by applying the widely-applied p-median model. The main result indicates that an increase in road network complexity, up to a certain level, can obviously improve the solution, and the complexity beyond that level does not always lead to better solutions. Furthermore, the result is not sensitive to the choice of algorithms. In a specific case study, a detailed sensitivity analysis of algorithm and facility number further provides insight into computation complexity and location problems from intra-urban to inter-urban.

Place, publisher, year, edition, pages
Borlänge: Högskolan Dalarna, 2015. p. 19
Series
Working papers in transport, tourism, information technology and microdata analysis, ISSN 1650-5581 ; 2015:10
Keywords
Transportation system; Spatial optimization; Location models; Heuristics
National Category
Social Sciences Computer Sciences
Research subject
Complex Systems – Microdata Analysis, General Microdata Analysis - transports
Identifiers
urn:nbn:se:du-24682 (URN)
Note

New updated version of paper.

Available from: 2017-04-04 Created: 2017-04-04 Last updated: 2018-01-13Bibliographically approved
Zhao, X. (2015). On processing GPS tracking data of spatiotemporal car movements: a case study.
Open this publication in new window or tab >>On processing GPS tracking data of spatiotemporal car movements: a case study
2015 (English)Report (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.

Publisher
p. 28
Series
Working papers in transport, tourism, information technology and microdata analysis, ISSN 1650-5581 ; 2014:11
Keywords
GPS tracking data, visualized map, road network, map-matching
National Category
Human Geography
Research subject
Complex Systems – Microdata Analysis; Complex Systems – Microdata Analysis, General Microdata Analysis - transports
Identifiers
urn:nbn:se:du-18729 (URN)
Available from: 2015-07-14 Created: 2015-07-14 Last updated: 2016-06-13Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7512-5321

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