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  • 17751.
    Zetterberg, Hans L.
    Stiftelsen Riksbankens jubileumsfond, Stockholm.
    Traditioner och möjligheter i nordisk sociologi2013In: Sociologisk forskning, ISSN 0038-0342, Vol. 50, no 3-4, p. 289-309Article in journal (Refereed)
  • 17752.
    Zetterberg, Jonna
    et al.
    Dalarna University, School of Health and Social Studies, Caring Science/Nursing.
    Strandberg, Hanna
    Dalarna University, School of Health and Social Studies, Caring Science/Nursing.
    Förlossningsupplevelse hos kvinnor med normal graviditet och graviditetsdiabetes2011Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [sv]

    Bakgrund: Forskning har visat att förlossningsupplevelsen har betydelse för kvinnans framtida inställning till barnafödande. Forskningsresultat har huvudsakligen presenterats för normala graviditeter eller där urvalet varit blandat (normala och komplicerade graviditeter). Begränsad forskning finns om hur komplicerad graviditet kan påverka förlossningsupplevelsen. Syfte: Att jämföra förlossningsupplevelse bland kvinnor som haft normal graviditet respektive graviditetsdiabetes samt studera sambandsfaktorer för förlossningsupplevelsen. Metod: Studien är en retrospektiv kohortstudie där data insamlats med hjälp av enkäter. Deltagarna (n=444) är slumpmässigt valda bland kvinnor i Sverige med normal graviditet och kvinnor med graviditetsdiabetes. Kvinnor som fött tvillingar och som inte angivit barnets födelsevikt exkluderades från fördjupningsstudien, vilket innebar att data för 429 kvinnor, 326 med normal graviditet och 103 med graviditetsdiabetes ingick. Parametriska och ickeparametriska analyser har genomförts för att analysera materialet. Resultat: Nästan två tredjedelar av kvinnorna (62,9%) hade en positiv förlossningsupplevelse. Kvinnor med graviditetsdiabetes hade oftare en negativ förlossningsupplevelse jämfört med kvinnor med normal graviditet. Nöjdhet med smärtlindringen visade ett signifikant samband med förlossningsupplevelsen, de som var nöjda med smärtlindringen var mer nöjda med sin förlossningsupplevelse. Slutsats: Gravida kvinnor med komplicerad graviditet i form av graviditetsdiabetes har signifikant sämre förlossningsupplevelse jämfört med kvinnor som haft en normal graviditet.

  • 17753.
    Zetterblom, Ulrika
    Dalarna University, School of Education, Health and Social Studies, Educational Work.
    Planering och genomförande avteknikundervisningen i grundskolan: En systematisk litteraturstudie om lärares förståelse avtekniken som ämne och hur deras undervisning relaterar tillläromedel, material och undervisningslokal2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att undersöka hur teknikundervisningen i grundskolan

    kan planeras och genomföras för att eleverna skall ges möjlighet att utveckla

    förmågorna inom teknikämnet. För besvarandet av detta syfte har en systematisk

    litteraturstudie genomförts där tidigare forskning har använts. Genom sökning i

    databaserna NorDiNa, Avhandlingar.se, Summon och ERIC (Ebsco) har relevant

    forskning valts ut som sedan kritiskt granskats, sammanställts och diskuterats.

    Forskning visar att lärarna har både en ämnesdidaktisk kunskapsbrist och en

    bristande förståelse för tekniken som ämne vilket påverkar deras förmåga att koppla

    teknikämnet till kursplanen. Detta påverkar även tiden de lägger på att planera sin

    undervisning samt hur de använder materialet i sin teknikundervisning, samtidigt

    visar forskningen att det finns för lite material tillgängligt inom

    teknikundervisningen. Forskningen visar att läromedel har ett begränsat språk med

    en inkonsekvent begreppshantering och att språket inte främjar problematiserande

    diskussioner samt att de tekniska systemen inte är synbara i läromedelstexterna.

    Forskningen indikerar även att en speciellt utformad tekniksal kan främja att en

    fördjupad lärsituation skapas i det praktiska arbetet.

  • 17754.
    Zetterlund, Oskar
    Dalarna University, School of Languages and Media Studies, Sound and Music Production.
    Efterklangens inverkan vid ADR: Hur efterklangspålägg upplevs av filmtittaren vid eftersynkad dialog i filmljudläggning2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete går ut på att undersöka huruvida filmtittares upplevelser påverkas av inadekvat efterklangspålägg inom eftersynkronisering av dialog till film. Hur efterklangspålägget passar till filmen anses bestämmas mycket utav hur bildens perspektiv och miljön runt omkring illustreras.

    En lyssningsundersökning utfördes med två olika videoexempel som undersökningsdeltagarna fick se och sedan svara på frågor relaterade till dessa. Målet var att få in motiveringar till svaren för att få en grundligare bild av deltagarnas upplevelse av efterklangen. Detta lyckades och dessa kommentarer gav underlag för diskussion.

    Av resultaten att döma upplevde deltagarna att efterklangen inte stämde vidare överens med bildens perspektiv och miljö. Detta hade mycket att göra med att efterklangen var aningen för torr i sin karaktär för att kännas naturlig.

  • 17755.
    Zetterström, Denise
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Revisionsberättelsen & bokslutsrapporten: Små bolags redovisningsalternativ efter avskaffande avrevisionsplikten2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The audit requirement for small companies in Sweden was abolished in year 2010. After thederegulation, the management of small companies had several alternative actions to still becredible fore stakeholders. The companies can voluntarily choose to hire an accountant, let anauthorized bookkeeper create a financial report or take care of the financial statements ontheir own.The study´s purpose is to create understanding and knowledge of financial reports and auditreports, if they by the lenders point of view can help to increase the creditworthiness, as wellas trust and legitimacy of companies financial reporting.The result shows that a clean audit report can help to increase companies’ creditworthinessmore than the financial report. Both the financial report and the audit report may help orstrengthen companies’ legitimacy. However, the auditor and the audit report are seen as amore established method. Creditors know how the auditor operates, what laws, rules,standards and norms the auditor follows in its scrutiny. The fact that the auditor standsindependent to the companies who gets audited makes the accounts more credible. The auditreport and the auditors are therefore the kind of accounting that contributes most to creditorsfinding confidence in companies.The study´s theoretical framework is used to interpret and understand the collected empiricaldata and the study´s purpose and problem. The theoretical framework consists of stakeholdertheory, principal – agent theory, legitimating theory and previous research that can touch thestudy´s subject. Empirical data were collected using qualitative semi-structured interviews.Four credit managers and four business advisors from various banks in Sweden participated asrespondents. With help of the theoretical framework and collected empirical material ananalysis was made which finally resulted in the study´s conclusions.

  • 17756.
    Zhang, Baoxin
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    How the different time steps weather data affect the simulation results of solar combisystems2009Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The hourly time step weather data are very common used in the field of evaluations and predictions of the performance of solar heating systems, especially in the computer simulation area. However, studies in [3] states that using the hourly weather data in simulation of solar systems may ignore the variations of solar radiation during one hour, it will cause a inaccurate simulation results. Using the smaller time step weather data instead can resolve this problem and make the simulation results very close to the fact. In this paper, the variations of solar radiation during hourly will be found through comparison of the same weather data based on different time steps (hourly and 6min). A whole weather data reference year based on 6min, 12min, 18min, 30min and 60min in Borlänge, Sweden will be built. Then the total radiation on a sloped surface, clearness index and solar utilizability based on these different time steps weather data will be calculated and compared with each other respectively. The results show that same weather data based on different time steps do not affect the calculation results of total radiation on a sloped surface (collector surface) but they may affect the beam and diffuse fractions and estimate of collector performance. After that all the weather based on different time steps will be used in the simulations of three different solar combisystems. As the result shows, using the hourly weather data leads to relative conservative estimate of solar heating systems compare with that based on shorter time step weather data, although the difference is very limited.

  • 17757.
    Zhang, Fan
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    A hybrid structured deep neural network with Word2Vec for construction accident causes classification2019In: International Journal of Construction Management, ISSN 1562-3599Article in journal (Refereed)
    Abstract [en]

    According to the latest fatal work injury rates reported by the Bureau of Labors Statistics, construction sites remain the most hazardous workplaces. In the construction sector, fatality investigation summary reports are available for past accidents and by investigating such reports, valuable insights can be gained. In this study, text mining algorithms are explored for automatic construction accident causes classification. To be more specific, Word2Vec skip-gram model is utilized to learn word embedding from a domain-specific corpus and a hybrid structured deep neural network is proposed by incorporating the learned word embedding for accident reports classification. Dataset from Occupational Safety and Health Administration (OSHA) is employed in the experiment to evaluate the performance of the proposed approach. Besides, five baseline models: support vector machine (SVM), linear regression (LR), K-nearest neighbor (KNN), decision tree (DT), Naive Bayes (NB) are employed to compare with the proposed approach. Experiment results show that the proposed model achieves the highest average weighted F1 score among all models considered in this study. The result also proves the effectiveness of applying Word2Vec skip-gram algorithm for semantic information augmentation. As a result, robustness of the model is improved when classifying cases of low support values.

  • 17758.
    Zhang, Fan
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    A Review of Single Artificial Neural Network Models for Electricity Spot Price Forecasting2019In: European Energy Market 2019, 2019Conference paper (Refereed)
    Abstract [en]

    Electricity price forecasting plays a crucial role in a liberalized electricity market. In terms of forecasting approaches, computational intelligence based models have been widely used with respect to electricity price forecasting and among all computation intelligence based models, artificial neural networks are most popular among researchers due to their flexibility and efficiency in handling complexity and non-linearity. However, a review of recent applications of neural networks for electricity price forecasting is not found in the literature. The motivation of this paper is to fill this research gap. In this study, existing approaches are analyzed and a summary of the strengths and weaknesses of each approach is presented. Besides, each neural network model is briefly summarized, followed by reviews of the corresponding studies of each neural network with respect to electricity forecasting from year 2010 onwards. Major contributions, datasets adopted as well as the corresponding experiment results are analyzed for each reviewed study. Apart from the review of existing studies, the advantages and disadvantages of each type of neural network model are discussed in details. Compared with neural networks based hybrid models, a single neural network model is easier to be implemented, less complex and more efficient. Scope of the review is the application of non-hybrid neural network models. It is found that most literature focuses on short term electricity price forecasting while medium and long term forecasting still remain relatively uncovered.

  • 17759.
    Zhang, Fan
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    A review on electricity price forecasting using neural network based models2018Report (Other (popular science, discussion, etc.))
  • 17760.
    Zhang, Fan
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Hybrid Artificial Neural Networks Based Models for Electricity Spot Price Forecasting - A Review2019In: 2019 16th European Energy Market Conference (EEM 19), 2019, article id 8916245Conference paper (Refereed)
    Abstract [en]

    Electricity price forecasting plays a crucial role in aliberalized electricity market. In terms of forecasting approaches,artificial neural networks are the most popular amongresearchers due to their flexibility and efficiency in handlingcomplexity and non-linearity. On the other hand, a single neuralnetwork presents certain limitations. Therefore, in recent years,hybrid models that combine multiple algorithms to balance outthe advantages of a single model have become a trend. However,a review of recent applications of hybrid neural networks basedmodels with respect to electricity price forecasting is not found inthe literature and hence, the motivation of this paper is to fill thisresearch gap. In this study, methodologies of existing forecastingapproaches are briefly summarized, followed by reviews of neuralnetwork based hybrid models concerning electricity forecastingfrom year 2015 onwards. Major contributions of each study,datasets adopted in experiments as well as the correspondingexperiment results are analyzed. Apart from the review ofexisting studies, the novelty and advantages of each type of hybridmodel are discussed in detail. Scope of the review is theapplication of hybrid neural network models. It is found that theforecast horizon of the reviewed literature is either hour ahead orday ahead. Medium and long term forecasting are notcomprehensively studied. In addition, though hybrid modelsrequire relatively large computational time, time measurementsare not reported in any of the reviewed literature.

  • 17761.
    Zhang, Fan
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Short Term Electricity Spot Price Forecasting Using CatBoost and Bidirectional Long Short Term Memory Neural Network2019In: 19th European Energy Market Conference (EEM 19), 2019Conference paper (Refereed)
    Abstract [en]

    Electricity price forecasting plays a crucial role in liberalized electricity markets. Generally speaking, short term electricity price forecasting is essential for electricity providers to adjust the schedule of production in order to balance consumers’ demands and electricity generation. Short term forecasting results are also utilized by market players to decide the timing of purchasing or selling to gain maximized profit. Among existing forecasting approaches, neural networks are regarded as the state of art method. However, deep neural networks are not studied comprehensively in this field, thus the motivation of this study is to fill this research gap. In this paper, a novel hybrid approach is proposed for short term electricity price forecasting. To be more specific, categorical boosting (Catboost) algorithm is used for feature selection and a bidirectional long short term memory neural network (BDLSTM) serves as the main forecasting engine. To evaluate the effectiveness of the proposed approach, two datasets from the Nord Pool market are employed in the experiment. Moreover, the performance of multi-layer perception (MLP) neural network, support vector regression (SVR) and ensemble tree models are evaluated and compared with the proposed model. Results show that the proposed approach outperforms the rest models in terms of mean absolute percentage error (MAPE).

  • 17762.
    Zhang, Fan
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Wang, X.
    Lu, M.
    Construction site accident analysis using text mining and natural language processing techniques2019In: Automation in Construction, ISSN 0926-5805, E-ISSN 1872-7891, Vol. 99, p. 238-248Article in journal (Refereed)
    Abstract [en]

    Workplace safety is a major concern in many countries. Among various industries, construction sector is identified as the most hazardous work place. Construction accidents not only cause human sufferings but also result in huge financial loss. To prevent reoccurrence of similar accidents in the future and make scientific risk control plans, analysis of accidents is essential. In construction industry, fatality and catastrophe investigation summary reports are available for the past accidents. In this study, text mining and natural language process (NLP) techniques are applied to analyze the construction accident reports. To be more specific, five baseline models, support vector machine (SVM), linear regression (LR), K-nearest neighbor (KNN), decision tree (DT), Naive Bayes (NB) and an ensemble model are proposed to classify the causes of the accidents. Besides, Sequential Quadratic Programming (SQP) algorithm is utilized to optimize weight of each classifier involved in the ensemble model. Experiment results show that the optimized ensemble model outperforms rest models considered in this study in terms of average weighted F1 score. The result also shows that the proposed approach is more robust to cases of low support. Moreover, an unsupervised chunking approach is proposed to extract common objects which cause the accidents based on grammar rules identified in the reports. As harmful objects are one of the major factors leading to construction accidents, identifying such objects is extremely helpful to mitigate potential risks. Certain limitations of the proposed methods are discussed and suggestions and future improvements are provided.

  • 17763.
    ZHANG, LEI
    et al.
    Dalarna University, School of Technology and Business Studies, Economics.
    YOU, XI
    Dalarna University, School of Technology and Business Studies, Economics.
    The Choice of STIGA Table Tennis Blades: Evidence from China2010Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    The purpose of this paper is to investigate how individuals with different characteristics make their choice-decisions when consuming STIGA table tennis blades, which are combinations of various attributes, such as price, control, attack, etc. It is expected that the general trend of choice behavior on this special commodity can be, at least to some extent, revealed. Data were collected using questionnaires sent to registered members of a table tennis club in China. The questionnaires included information and questions about individuals’ monthly income levels, ages, technique styles, etc. A multinomial logit model was then applied to analyze factors determining Chinese consumers’ choice behavior on STIGA table tennis blades. The results indicated that the main element influencing Chinese consumers’ choice of STIGA ping-pong blades was the technique style and other variables did not seem to influence the choice of table tennis blades. These results might be explained by the limited sample size as well as unmeasured and immeasurable factors. Thus, a more extensive research is needed to be conducted in the future.

  • 17764.
    Zhang, Liming
    et al.
    Dalarna University, School of Technology and Business Studies, Statistics.
    Han, Yang
    Dalarna University, School of Technology and Business Studies, Statistics.
    Detecting Major Genes Controlling Robustness of Chicken Body Weight Using Double Generalized Linear Models2010Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Detecting both the majors genes that control the phenotypic mean and those controlling phenotypic variance has been raised in quantitative trait loci analysis. In order to mapping both kinds of genes, we applied the idea of the classic Haley-Knott regression to double generalized linear models. We performed both kinds of quantitative trait loci detection for a Red Jungle Fowl x White Leghorn F2 intercross using double generalized linear models. It is shown that double generalized linear model is a proper and efficient approach for localizing variance-controlling genes. We compared two models with or without fixed sex effect and prefer including the sex effect in order to reduce the residual variances. We found that different genes might take effect on the body weight at different time as the chicken grows.

  • 17765. Zhang, Nan
    et al.
    Chen, Xiangjie
    Su, Yuehong
    Zheng, Hongfei
    Ramandan, Omar
    Zhang, Xingxing
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Chen, Hongbin
    Riffat, Saffa
    Numerical investigations and performance comparisons of a novel cross-flow hollow fiber integrated liquid desiccant dehumidification system2019In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 182, p. 1115-1131Article in journal (Refereed)
    Abstract [en]

    The heat and mass transfer process of a novel cross-flow hollow fiber integrated liquid desiccant dehumidification system is analysed numerically. Compared with other porous media or packing towers in dehumidification applications, hollow fibre membranes have significant advantages including low weight, corrosion resistant and no liquid droplet carryover. A novel air-KCOOH cross-flow dehumidification system was designed and manufactured, with 5500 hollow fibres formed into a circular module. The variations of the dehumidification effectiveness and moisture removal rates were studied numerically and validated against experimental results under the incoming air mass flow rates of 0.08-0.26kg/s and relative humidity from 55% to 75%. The dehumidification performance comparisons for the proposed system using CaCl2, LiCl and KCOOH as the desiccants have been conducted as well. The results demonstrated that under the same m*(ratio between solution mass flow rate to the air mass flow rate), the proposed system using 62% KCOOH could achieve approximately the same latent effectiveness compared with 40% CaCl2 and 32% LiCl, with the at least 3.1% sensible effectiveness increased by. Therefore, it could be concluded that the proposed system using KCOOH as desiccant could be more applicable for dehumidification purpose compared with other systems using conventional liquid desiccants.

  • 17766.
    Zhang, Ning
    Dalarna University, School of Languages and Media Studies, Science communication.
    Science is Primary - Children Thinking and Learning in the Chemistry Laboratory2005Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The goal of primary science education is to foster children’s interest, develop positive science attitudes and promote science process skills development. Learning by playing and discovering provides several opportunities for children to inquiry and understand science based on the first–hand experience. The current research was conducted in the children’s laboratory in Heureka, the Finnish science centre. Young children (aged 7 years) which came from 4 international schools did a set of chemistry experiments in the laboratory. From the results of the cognitive test, the pre-test, the post-test, supported by observation and interview, we could make the conclusion that children enjoyed studying in the laboratory. Chemistry science was interesting and fascinating for young children; no major gender differences were found between boys and girls learning in the science laboratory. Lab work not only encouraged children to explore and investigate science, but also stimulated children’s cognitive development.

  • 17767.
    Zhang, Pengcheng
    Dalarna University, School of Technology and Business Studies, Economics.
    Is there wage premium to computer use in Sweden2005Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    This paper examines the wage premium to computer use in Sweden in the early 1990’s. I use simple regression model and interaction terms in my paper to examine the effect of computer use at work. Although the data is only one-year cross-section data, my results clearly show a wage premium to computer use in Sweden. There are also interesting findings in my paper by using Swedish data. From the results, I find wage premium to be related to intensity of computer use at work.

  • 17768. Zhang, S.
    et al.
    Song, William Wei
    Dalarna University, School of Technology and Business Studies, Information Systems.
    Ding, M.
    Hu, P.
    A multi-semantic classification model of reviews based on directed weighted graph2016In: Web Information Systems Engineering – WISE 2016: 17th International Conference, Shanghai, China, November 8-10, 2016, Proceedings, Part II / [ed] Wojciech Cellary, Mohamed F. Mokbel, Jianmin Wang, Hua Wang, Rui Zhou, Yanchun Zhang, 2016, Vol. 10042, p. 424-435Conference paper (Refereed)
    Abstract [en]

    Semantic and sentimental analysis plays an important role in natural language processing, especially in textual analysis, and has a wide range of applications in web information processing and management. This paper intends to present a sentimental analysis framework based on the directed weighted graph method, which is used for semantic classification of the textual comments, i.e. user reviews, collected from the e-commerce websites. The directed weighted graph defines a formal semantics lexical as a semantic body, denoted to be a node in the graph. The directed links in the graph, representing the relationships between the nodes, are used to connect nodes to each other with their weights. Then a directed weighted graph is constructed with semantic nodes and their interrelationships relations. The experimental results show that the method proposed in the paper can classify the semantics into different classification based on the computation of the path lengths with a threshold. © Springer International Publishing AG 2016.

  • 17769. Zhang, Sheng
    et al.
    Huang, Pei
    City University of Hong Kong.
    Sun, Yongjun
    A multi-criterion renewable energy system design optimization for net zero energy buildings under uncertainties2016In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 94, p. 654-665Article in journal (Refereed)
    Abstract [en]

    Net zero energy buildings (NZEBs) are promising to mitigate the increasing energy and environmental problems. For NZEBs, annual energy balance between renewable energy generation and building energy consumption is an essential and fundamental requirement. Conventional RES (renewable energy system) design methods for NZEBs have not systematically considered uncertainties associated with building energy generation and consumption. As a result, either the annual energy balance cannot be achieved or the initial investment of RES is unnecessarily large. Meanwhile, the uncertainties also have significant impacts on NZEB power mismatch which can cause severe grid stress. In order to overcome the above challenges, this study proposes a multi-criterion RES design optimization method for NZEBs under uncertainties. Under the uncertainties, Monte Carlo simulations have been employed to estimate the annual energy balance and the grid stress caused by power mismatch. Three criteria, namely the annual energy balance reliability, the grid stress and the initial investment, are used to evaluate the overall RES design performance based on user-defined weighted factors. A case study has demonstrated the effectiveness of the proposed method in optimizing the size of RES under uncertainties.

  • 17770.
    Zhang, Sheng
    et al.
    Nanchang Hangkong Univ, Sch Informat Engn, Nanchang, Peoples R China.;Dalarna Univ, Business Intelligence & Informat, Borlange, Sweden..
    Liu, Xiaodong
    Nanchang Hangkong Univ, Sch Informat Engn, Nanchang, Peoples R China..
    Bao, Xiaoling
    Nanchang Hangkong Univ, Sch Informat Engn, Nanchang, Peoples R China..
    Song, William Wei
    Dalarna University, School of Technology and Business Studies, Information Systems.
    Multilayer and multi-agent data fusion in WSN2015In: Web Information Systems Engineering – WISE 2014 Workshops: 15th International Workshops IWCSN 2014, Org2 2014, PCS 2014, and QUAT 2014, Thessaloniki, Greece, October 12-14, 2014, Revised Selected Papers / [ed] Boualem Benatallah, Azer Bestavros, Barbara Catania, Armin Haller, Yannis Manolopoulos, Athena Vakali, Yanchun Zhang, 2015, Vol. 9051, p. 211-225Conference paper (Refereed)
    Abstract [en]

    In the wireless sensor networks, the hardware limitations of sensor nodes cause high transmission failure rate. We usually increase the density of nodes to improve the quality of information transmission. However, it is difficult for the limited energy supply, storage, and communication bandwidth to transfer large amount of redundant sensory data. So we use data fusion technology to remove the redundant data as much as possible before the data transmission. Data fusion becomes a research hotspot in recent years. In this paper we propose a multilayer and multi-agent data fusion mode, and analyze the proposed mode performance in three aspects: hops, energy consumption and network delay. The simulation experiments show that, if reasonably suitable parameters, such as the network scale, the number and size of agents, the data processing cost, are selected, the mobile agent mode is much better than the client/server mode.

  • 17771. Zhang, Sheng
    et al.
    Sun, Yongjun
    Cheng, Yong
    Huang, Pei
    City University of Hong Kong.
    Oladokun, Majeed Olaide
    Lin, Zhang
    Response-surface-model-based system sizing for Nearly/Net zero energy buildings under uncertainty2018In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 228, p. 1020-1031Article in journal (Refereed)
    Abstract [en]

    Properly treating uncertainty is critical for robust system sizing of nearly/net zero energy buildings (ZEBs). To treat uncertainty, the conventional method conducts Monte Carlo simulations for thousands of possible design options, which inevitably leads to computation load that is heavy or even impossible to handle. In order to reduce the number of Monte Carlo simulations, this study proposes a response-surface-model-based system sizing method. The response surface models of design criteria (i.e., the annual energy match ratio, self-consumption ratio and initial investment) are established based on Monte Carlo simulations for 29 specific design points which are determined by Box-Behnken design. With the response surface models, the overall performances (i.e., the weighted performance of the design criteria) of all design options (i.e., sizing combinations of photovoltaic, wind turbine and electric storage) are evaluated, and the design option with the maximal overall performance is finally selected. Cases studies with 1331 design options have validated the proposed method for 10,000 randomly produced decision scenarios (i.e., users’ preferences to the design criteria). The results show that the established response surface models reasonably predict the design criteria with errors no greater than 3.5% at a cumulative probability of 95%. The proposed method reduces the number of Monte Carlos simulations by 97.8%, and robustly sorts out top 1.1% design options in expectation. With the largely reduced Monte Carlo simulations and high overall performance of the selected design option, the proposed method provides a practical and efficient means for system sizing of nearly/net ZEBs under uncertainty.

  • 17772.
    Zhang, Sheng
    et al.
    Nanchang Hangkong Univ, Sch Informat Engn, Nanchang, Peoples R China..
    Wang, Xin
    Nanchang Hangkong Univ, Sch Informat Engn, Nanchang, Peoples R China..
    Yao, Minghui
    Nanchang Hangkong Univ, Sch Informat Engn, Nanchang, Peoples R China..
    Song, William Wei
    Dalarna University, School of Technology and Business Studies, Information Systems. Dalarna Univ, Business Intelligence & Informat, Borlange, Sweden..
    Community-based message transmission with energy efficient in opportunistic networks2016In: Web Information Systems Engineering – WISE 2016: 17th International Conference, Shanghai, China, November 8-10, 2016, Proceedings, Part II, 2016, Vol. 10042, p. 411-423Conference paper (Refereed)
    Abstract [en]

    An Opportunistic Networks is a wireless self-organized network, in which there is no need to build a fixed connectivity between source node and destination node, and the communication depends on the opportunity of node meeting. There are some classical message transmission algorithms, such as PRoPHET, MaxProp, and so on. In the Opportunity Networks with community characteristic, the different message transmission strategies can be sued in inter-community and intra-community. It improves the message successful delivery ratio significantly. The classical algorithms are CMTS and CMOT. We propose an energy efficient message forwarding algorithm (EEMF) for community-based Opportunistic Networks in this paper. When a message is transmitted, we consider not only the community characteristic, but also the residual energy of each node. The simulation results show that the EEMF algorithm can improve the message successful delivery ratio and reduce the network overhead obviously, in comparison with classical routing algorithms, such as PRoPHET, MaxProp, CMTS and CMOT. Meanwhile the EEMF algorithm can reduce the node's energy consumption and prolong the lifetime of network.

  • 17773.
    Zhang, Xiaoxue
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Sun, Qiao
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Performance Evaluation of a Grid-connected PV system in Falun2009Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The photovoltaic system of 150WP in Falun is on the sloped roof which is 14 degree with east and west orientations. A calibration of the radiation sensors has been done in order to correct the voltage drop caused by the extended cable length. The radiation sensors are calibrated by comparing the measured irradiance of the PV system with the reference irradiance which is measured by a portable data logger system. The annual performance of the system is evaluated over one year from April 08 to March 09 according to IEC 61724. Two other PV systems are compared with Falun system based on the annual performance of each system. The total system energy production of one year is about 96 MWh and the performance ratio PR is 0.817.

  • 17774. Zhang, Xingxing
    An Initial Concept Design of an Innovative Flat-Plate Solar Thermal Facade for Building Integration2015Conference paper (Refereed)
  • 17775.
    Zhang, Xingxing
    University of Nottingham.
    Investigation of a Cogeneration of Cooling/heating-electricity Supply Heat Pump System Based on PV/e Roof Module2010In: Building Energy & Environment, ISSN 1003-0344, Vol. 2, p. 56-58Article in journal (Refereed)
  • 17776. Zhang, Xingxing
    Smart Meter and In-home Display Technology towards Sustainable Residential Development: Case Study of a Pilot Investigation in Shanghai2015Conference paper (Refereed)
  • 17777.
    Zhang, Xingxing
    et al.
    University of Nottingham.
    Jingshun, Shen
    Zehui, Hong
    Luying, Wang
    Tong, Yang
    Llewellyn, Tang
    Yupeng, Wu
    Yong, Shi
    Liang, Xia
    Shengchung, Liu
    Building integrated solar thermal (BIST) technologies and their applications: A review of structural design and architectural integration2015In: Journal of Fundamentals of Renewable Energy and Applications, ISSN 2090-4533, E-ISSN 2090-4541, Vol. 5, no 5, p. 1-21Article in journal (Refereed)
    Abstract [en]

    Solar energy has enormous potential to meet the majority of present world energy demand by effective integration with local building components. One of the most promising technologies is building integrated solar thermal (BIST) technology. This paper presents a review of the available literature covering various types of BIST technologies and their applications in terms of structural design and architectural integration. The review covers detailed description of BIST systems using air, hydraulic (water/heat pipe/refrigerant) and phase changing materials (PCM) as the working medium. The fundamental structure of BIST and the various specific structures of available BIST in the literature are described. Design criteria and practical operation conditions of BIST systems are illustrated. The state of pilot projects is also fully depicted. Current barriers and future development opportunities are therefore concluded. Based on the thorough review, it is clear that BIST is very promising devices with considerable energy saving prospective and building integration feasibility. This review shall facilitate the development of solar driven service for buildings and help the corresponding saving in fossil fuel consumption and the reduction in carbon emission.

  • 17778. 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.))
  • 17779.
    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.

  • 17780.
    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)
  • 17781.
    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)
  • 17782.
    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.

  • 17783.
    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.

  • 17784.
    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.

  • 17785.
    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.

  • 17786.
    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.

  • 17787. Zhang, Xingxing
    et al.
    Shen, Jingchun
    Yang, Tong
    Tang, Llewellyn
    Experimental study of a solar photovoltaic/thermal (PV/T) system2015Conference paper (Refereed)
  • 17788.
    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.

  • 17789. 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)
  • 17790.
    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.

  • 17791. 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)
  • 17792. Zhang, Xingxing
    et al.
    Shen, Jingchun
    Zhao, Xudong
    Photovoltaic/Loop-Heat-Pipe Heat Pump Techno for Low-Carbon Buildings2014Book (Refereed)
  • 17793.
    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)
  • 17794. 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)
  • 17795. 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)
  • 17796. 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)
  • 17797.
    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.

  • 17798.
    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.

  • 17799.
    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)
  • 17800.
    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.

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