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  • 3051.
    Zhao, Ming
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production. Reliability Engineering Center, Guizhou University, Guiyang, China .
    Yang, Jianfeng
    Guizho University.
    A DCA-based method for software prognostics and health management2012In: Proceedings of IEEE 2012 Prognostics and System Health Management Conference, PHM-2012, 2012, p. 6228830-Conference paper (Refereed)
    Abstract [en]

    In recent years, the prognostics and health management (PHM) technique has greatly been developed especially for electronic devices and systems. Little work, however, has been done on PHM techniques for software systems. During their total lifecycle, the software systems, due to various reasons such as new requirements or changes in technology, have to experience changes that can lead to a degeneration of the system's architecture. Therefore, it is important and necessary to identify and predict the software health status in order to avoid serious degeneration or erosion of system's architecture. In this paper, a software PHM approach based on Discriminant Coordinates Analysis (DCA) is proposed, and the health status of software systems is suggested to be categorized into five groups: Healthy, Normal, Sub-healthy, Unhealthy and Deteriorated. The proposed model based on software design metrics can help managers and developers predict and identify the software health status. Numerical example based on simulation data is given to illustrate its application on the modeling process.

  • 3052.
    Zhao, Ming
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Zhang, Y. J.
    School of Mathematics and Physics, Anhui University of Technology, Maanshan, China.
    Yang, J. F.
    Faculty of Information Engineering, Guizhou Institute of Technology, Guiyang, China.
    Masked data analysis for storage reliability model with initial failures2018In: Safety and Reliability - Safe Societies in a Changing World - Proceedings of the 28th International European Safety and Reliability Conference, ESREL 2018 / [ed] Stein Haugen, Anne Barros, Coen van Gulijk, Trond Kongsvik, Jan Erik Vinnem, CRC Press/Balkema , 2018, p. 2565-2572Conference paper (Refereed)
    Abstract [en]

    Storage reliability is of importance for the products that largely stay in storage in their total life-cycle such as warning systems for harmful radiation detection, rescue systems, many kinds of defense systems, etc. The storage reliability of a product is commonly defined as the probability that the product can perform its specific function for a period of specific storage time under specific storage environment. Logically, the failures of the product in storage should be identified with the same criteria as in its operation process. However, the failure data in storage may be observed indirectly through the maintenance or inspection activities. Nevertheless, when the storage reliability is concerned in general, the reliability model should take into consideration the possibility that the operational reliability does not start at 100%, for example, the one-shot product may have only 96% operational reliability when they are newly produced. In this paper, the storage reliability model with possibly initial failures, which are usually neglected at the beginning of storage in most of storage models, is studied on the statistical analysis method when the masked data are observed. The parametric estimation procedure, based on the Least Squares method, is developed generally by applying an EM-like (Expectation and Maximization) algorithm for the storage data in which some information about which components have caused the system failures is not known, namely the failure data are masked. The estimates of the model parameters including the initial reliability are formalized. In the case of exponentially distributed storage lifetime and series system, a numerical example is provided to illustrate the method and procedure though the method is not limited to such case. The results should be useful for planning a storage environment, decision-making concerning the maximum length of storage, maintenance strategy optimization and identifying the production quality.

  • 3053.
    Zhao, Ming
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Zhang, Y
    Guizho University.
    Xu, F R
    Guizho University.
    ESS profiles with step stress level2011In: ICRMS'2011 - Safety First, Reliability Primary: Proceedings of 2011 9th International Conference on Reliability, Maintainability and Safety, 2011, p. 1156-1161Conference paper (Refereed)
    Abstract [en]

    Environmental Stress Screening (ESS) is usually referred to the process of exposing a product to environmental stresses for detecting and eliminating latent defects made in manufacturing process. The common ESS profiles are using thermal cycling, random vibration or their combinations as the screening stresses. Various guidelines and standards have been available for determining an ESS profile. Nevertheless, there are cases that the standard ESS profiles may not be efficient enough to detect the latent defects in some manufacturing process. This paper reports the results of one industrial project on the ESS profile design for circuits. In the project, a comparative study was carried out for the evaluation of the ESS strength under the ESS profiles with incremental step stresses (ISS). The ISS profile under the study is firstly to implement a step thermal cycling and then perform the test with two screening stimuli concurrently: ordinary thermal cycling and random vibration of step increasing intensity levels. For the purpose of the comparative study, the ESS test samples were consisted of two groups A and B that were made at two different levels of manufacturing: soldering by skilled and unskilled workers, respectively. The comparative study shows that the ISS profiles are effective for exposing the latent defects in sample group A and B. Based on the project results, an ESS profile is recommended in this paper.

  • 3054.
    Zhao, Xuhui
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Automatic analysis for continuous integration test failures2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    CI (Continuous Integration) is a software development practice which became more and more popular in last decade. Ericsson followed the trends and used CI several years. Because of the complexity of RBS (Radio Base Station) software few levels of CI have been implemented there. In RCS (RBS Control System) module CI there are many automatic JCAT (Java Common Auto Tester) test loops running every day and some of them failed. This thesis tries to find a way to classify these test failures automatically, so efficiency and lead time can be improved.

    Two methods are presented and investigated in this report, rule matching and machine learning. After analysis and comparisons rule matching approach is selected because it does not require huge effort in the initial phase and rule matched data can be used as labeled data for machine learning. This approach requires manual work to add new rules continuously but with correctly defined rules the accuracy is 100%, if the rule is general it can classify one type of issue including the ones which never happen before.

    One analysis system is designed and implemented, and only small update is required to the result report block of the CI flow. One matching example is showed and according to estimation this method could save many man hours every year.

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  • 3055.
    ZHAO, YANG
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    WU, LEI
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Driving Force and Challenge of Developing Low-Carbon Economy in China2010Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    With the growth of population and development of the global economy, the unrestrained use of natural and energy resources have seriously influenced environment and economy of world. Many people start to realize the serious environmental problems that come from the high energy utilizations, especially of high carbon dioxide (CO2) emissions. So Low-Carbon Economy has become focus of attention around the world; it also has become every country‟s strategic goals for future development under this global situation.As the biggest country of CO2 emissions in the world, China‟s development of Low-Carbon Economy is increasingly influencing the economy and environmental development in the world, and the country has faced more and more pressure after United Nations Climate Change Conference, 2009. Transition to Low-Carbon Economy is essential road for China, whether respond to the threat of climate change or balance domestic economic development with environmental sustainability. However, China also faces lots of challenges and pressure in the process of transition to Low-Carbon Economy.This thesis combines quantitative method with qualitative methods to do a research about driving force and challenges of developing Low-Carbon Economy in China. Firstly, it discusses the driving forces for China to develop Low-Caron Economy from two aspects-pressures and benefits. Secondly, it investigates challenges that China is likely to face in Low-Carbon Economy development from energy and economic aspect. Finally, it uses cause and effect diagram to explain the bottlenecks of Low-Carbon Economy development in China.Our conclusion is that China faces the bottleneck between challenges and driving force to develop Low-Carbon Economy. And this situation was caused by national actual situations and conditions in China. This explains also why China requested in Copenhagen Conference that “developing countries take appropriated measures to emission control and reduction in terms of receiving the funding and technology support from developed countries. Those emission reduction actions should be done according to the national actual situations and conditions.”

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  • 3056.
    Zhao, Yixiang
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Niu, Hao
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Measurement of dynamic parameters of Delta-Sigma ADC2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In present day, digital signal processing (DSP) is a popular technology and widely used in many fields. There have increasing number of applications that need high resolution converters. Therefore, analog-to-digital converters play a major role in DSP, and a well-performed ADC will enhance the performance of a certain system. Different types of ADCs are available for various functions. Delta-sigma  converters are famous for high resolution. Dynamic parameters can be used to judge the performance of an ADC, this paper will focus on the critical parameters of spectrum analysis, which contains Signal-to-Noise-and-Distortion Ratio (SINAD), Effective Number of Bits (ENOB) and Spurious-free Dynamic Range (SFDR). The theory and test method of these critical parameters are proposed in this paper using the Evaluation Module and Matlab. The results we acquired from the Evaluation Module are SINAD=86.15dB, SFDR=109.2dB, ENOB=14.177bits; and the results we calculated from MATLAB are: SINAD=86.14dB, SFDR=108.8dB, ENOB=14bits.

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    Measurement of dynamic parameters of Delta-Sigma ADC
  • 3057.
    zhao, zhiyang
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Characterize the ZGST test bed2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Nyquist Shannon theory states that sampling rate of ADC should be at least twice of signal bandwidth in order to avoid aliasing. According to this theory, extracting an accurate behavior model of power amplifier by digitizing its output signal is a difficult task for current general ADC in the market, due to the trade off among the sampling rate, resolution and reasonable cost. Because of nonlinear effect that a power amplifier presents, the signal bandwidth further spread in spectrum at output side, which results in shortage of sampling rate of ADC to sample such broadband signal. To solve this problem, a special designed system named ZGST is considered in this work.

     

    This works mainly considers characterizing ZGST measurement system which consists of a wide bandwidth down convertor and a high speed ADC. For down convertor, calibrations are carried on radio frequency, local oscillator and intermediate frequency. Thus a three port calibration is applied by using a vector network analyzer. Meanwhile, its dynamic performance is evaluated by measuring SFDR. For ADC, the amplitude response is characterized by using a signal analyzer.

     

    This thesis work also describes a smart sampling strategy which reduces the requirement on sampling rate for repetitive signal. This strategy is able to compact a broadband digital signal into a relative small Nyquist region without overlapping. Thus, in spite of analog digital convertor does not meet the Nyquit sampling constraint, it still can sample a wide bandwidth signal.

     

    Finally, a broadband output signal of a power amplifier is collected by ZGST measurement system, and it is reconstructed by removing the conversion loss in both amplitude and phase which is caused by system. 

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  • 3058.
    Zhe, Qian
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Xiangying, Kong
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Xing, Ma
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Production logistics and control: case study in Kerneos a Franch building materials company2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In a production cycling, the time spent on logistics activities is much longer than the actual time spent in the process. Therefore, the potential space of improving production logistics is very large in many aspects, such as the ability of researching production logistics, the time saving, and the labor saving in the company. By studying the function of the company's production logistics, we can deeply improve our understanding of it, and make the production logistics work efficiently during the whole process of the production cycling. As we know, there are two main modes of production, pull and push production. Choosing a right or better one is the most important in production logistics. The purpose of thesis is to make production logistics work efficiently by analyzing the current production mode in Kerneos (small subsidiaries in Guiyang City in China) as an example. Firstly, we want to make known what is production logistics and production mode, providing readers with production logistics functions and principles of choosing production mode. Then, we will analyze the current production mode of our case company. Finally, basing on our knowledge, we would like to share our opinions or ideas on how to choose a proper way to make our production logistics better in this article. The literature of thesis is focus on pull and push production, and how to choose an effective production type that suit for the enterprise situation. According to the research completed, we suggest using “push” in the enterprise which has large quantities, less variety, and the production cycle is plenty. In the small quantity, variety, and short-cycle, we suggest using “pull”. Otherwise, there come out a new production type named CONWIP(Constant work-in-process), through compared the different advantages and disadvantages between pull and push, our case company Kerneos is suggested to use this new production.

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    Production logistics and control: Case study in Kerneos, a Franch building materials company
  • 3059.
    Zhou, Yun
    et al.
    University of Gävle, Department of Technology and Built Environment.
    Ye, Yuhan
    University of Gävle, Department of Technology and Built Environment.
    Measuring and analyzing the continued innovation capability in Guizhou Huagong Tools Company  2009Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Just  as  the  innovation  is  one  of  the  key  elements  in  organization,  therefore  the continued  innovation capacity will derive organization successful. Whilst, measuring and analyzing CI capacity  in organization  is an  important activity. The primary goal of this paper is to audit and analyze the continued innovation (CI) capacity in Guizhou Huagong  Tools  Company  with  the  innovation  model  developed  by  Bessant&Tidd (2005).This  research  includes  literature  study  and  case  company  investigation,  both quality and quantity research is used in this thesis in order to obey the deductive logic. The finding of this thesis showed that Huagong Tools Company relying on a series of innovation mechanism has been  an  advance  innovation but not  the best  one,  this  is due  to  a  paucity  of  radical  innovation  and  capture  ability  from  innovation, furthermore,  an  ill-defined  innovation  strategy  has  been  incriminated  as  one  of  this circumstances,  depending  on  that,  authors  briefly  summarize  suggestions  for  the problems. At  last but not  least  the discussion about  innovation  theory  expounded  in the end.

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  • 3060.
    Zhouhong, Liu
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Development Direction of China's Railway Warehousing Industry2013Independent thesis Basic level (degree of Bachelor), 80 credits / 120 HE creditsStudent thesis
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    Development Direction of China's Railway Warehousing Industry
  • 3061.
    Zhu, Hongxu
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Harmonic matching network for an amplifier2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nowadays, ‘green’ communication is of great importance to save electric energy. In communication systems, power amplifiers (PAs) play an important role and consume large amount of power. As a consequence, the enhancement of amplifier efficiency is significantly important for saving energy.

     

    This thesis describes a method to enhance the amplifier efficiency. The goal for this thesis is to find the matching impedances of harmonics for optimum efficiency performance of an amplifier. The idea is to control and change the load impedances at 2nd and 3rd harmonics for maximum efficiency performance of an amplifier at fundamental frequency and finally to build a matching network according to the matching impedances at harmonics.

     

    The load pull technique is applied in this thesis to control the impedances with automatically controlled tuners. In this way, different impedances correspond to specific tuner positions. Then for different tuner positions, the corresponding load impedances of the harmonics are determined, the input, output as well as DC power of the amplifier are measured, and the corresponding efficiency is computed. Therefore, after appropriate efficiency sweep for specific tuner positions, the matching impedances with maximum efficiency performance can be found.

     

    The efficiency of the amplifier with harmonic matching (the method implemented in this thesis) can be improved 2.13 percent which proves the feasibility of the method investigated in this thesis.

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  • 3062.
    Zhu, Xuanlin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    A Feasibility Study of Using River Water in University Cooling System2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis is to study the feasibility of using river water from Gavleån in the cooling system of University of Gävle. The project is proposed by the campus service manager Akademiska Hus AB which intended to replace the current cooling production system with the water cooling system to reduce the electricity cost in cooling production. The river by direct distance is 600 meters from the university, the river water is to be extracted from the river via a pump house, flow through pipeline buried underground and delivered to the equipment house of Akademiska Hus.

     

    Most water source cooling prefer water body with decent depth which contain low temperature water to use as free cooling source, but the issue that limits the practice is, the decent depth is not a very common feature of most water body near or within urban area. Like Gavleån which has an average depth of not over five meters while the sufficient depth is over 50 meters for the least or 70 meters to 100 meters often. So study the potential of using rather high temperature water from shallow water body can be of high interest for most cooling consumers.

     

    The thesis progressed through the work in five parts. To introduce cooling in general starting with literature review, the concept, the mechanism, the device for end use and production, the demand of cooling and the reason behind it. Followed by case studies of water source cooling projects worldwide, which is mostly deep water source cooling, and another case of the local hospital cooling system that extract water from Gavleån, demonstrate the use of shallow water body in assisting cooling production, it gives some insights how the potential if similar system is to be implemented in the campus, which is mounted on the same river. Several tours to the hospital were taken to acquire data and understanding of the system.

     

    Then the water temperature measurement from Gavleån in 2014 summer is presented. The measurement was carried out at a small dock by the river side during July to September of 2014. The measurements show the temperature of river water has been increasing which limits free cooling throughout the year, additional refrigerator is required to produce chilled water. The river water, in the hot seasons is used as cooler for the refrigerator and in cold season can be used for free cooling directly. Simulation of IDA-ICE gives the cooling demand of modelled building blocks, the output of cooling production season (consistent with the hot seasons) matches the cooling consumption data from Akademiska Hus by an error of 1% (414743 kWh of simulated result to 415270 kWh in documentation of Akademiska Hus).

     

    To meet the demand of cooling and select more cost-effective refrigerator type, consumption and COP (COP: Coefficient of Performance) are calculated for compressor chiller and absorption chiller with basic cooling cycle for both. The results shown compressor chiller has much better performance but also higher consumption in electricity, while absorption chiller has rather low COP value in comparison but the need of energy input is much less given by its major consumption of energy is heat from hot water, already a purchased item by the university from district heating network. Cost-effectiveness wise speaking absorption chiller is a more optional choice. Reasonable values of assumption are largely employed in the calculation to select the better candidate and bring certain errors, which is then exam in sensitivity analysis to weigh the alternative parameter and the outcome from it.

     

    The last part is to estimate the cost of chillers and pipeline, for the concern of minimizing errors due to uncertainty the operation cost, labor cost and future energy price are not included. As the calculation turns out the payback year of the new system can range from 7 to 12 years by different refrigerator setup and pipeline routine design, which is considered within the life time of the chiller and pipeline, also lower than the current cooling cost of the university and therefore concluded as promising investment.

     

    Discussion and conclusion exam and finalize the whole thesis work. For the uncertainties of the calculation, the lack of information and data, which are improvements, can be done in future work. Also the improvements in other perspectives noted in terms of better load management for the cooling production units so the cost of equipment can be reduced, changes in building attachment and cooling device to reduce the demand of cooling, etc. But mostly draw the conclusion that with proper system configuration shallow water body can be helpful in reducing cooling consumption, and be a promising option for cities that have access to such water body. 

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    A Feasibility Study of Using River Water in University Cooling System
  • 3063.
    Zhu, Xuanlin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Exploring the possibility of applying seasonal thermal energy storage in south-west of China2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Buildings energy consumption is rising continuously with massive urbanization progress, which then results in high greenhouse gas emission. A standing example is the urbanization process going on in the south-west part of China. Much has been discussed for improving building energy performance. However, to take another point of view, renewable energy source for buildings is a solution worth considering, for instance STES, which gains thermal energy from the sun, delivers it to buildings for space heating and hot tap water, also restores the solar energy in hot seasons in the storage system for the need of cold season.The aim of this paper is to couple the technology of STES with practical situation, explore the possibility of applying STES in south-west of China. This thesis work takes an estimation approach to weigh the possibility. The building project studied in this thesis is a campus project in the city of Guiyang, one of four major cities in the region of south-west China.Case study involves existing STES projects in Munich Germany and Anneberg Sweden, the performance evaluation of the Anneberg project is later to serve as an example in system gain & losses proportion, to guide the estimation work of the campus project.The estimation conclusion is drawn based on a cross-sectional analysis method, take the technology of STES, the practiced STES project and building projects in China as three loops visually, and observe how much they overlap each other. Behind the visual illustration, the overlapping is assessed with several factors, for instance possibility of storage system at location, possible STES performance and solar irradiation condition at site location etc. If most of these factors are checked to be “Ok” or “Good”, then the overlapping area is considered “large” enough, and therefore suggests a decent chance to implement STES system in the south-west China.A solar gain and sunlight simulation from a new police station energy consumption report assists in calculating the possible solar gain for the campus project, as the very close distance between these two sites (30 km) promises them the very similar solar irradiation condition. While the energy consumption of the studied campus project offers the energy demand for space heating and hot tap water in the need of 19,000 students, which is to be evaluated as the task of the STES system in the estimation work. Both building project reports are filed by GARDI (Architecture design research institution of Guizhou).Some key factors have been calculated and estimated, the heat demand of the studied campus project in Guiyang is 5,558 MWh/year, and the possible solar gain of this campus complexity is 4,900 MWh/year based on the gain & losses proportion of the Anneberg project evaluation. Due to the very different climate condition of Guiyang and Anneberg, as well as other uncertain factors such as effective roof area, solar collector efficiency, a sensitivity analysis evaluated the result with different parameters in changes of percentage. Final results in the changes of effective roof area at 80% and 85 %, borehole losses at 50% and 45%, available solar gain at 38%, STES system is shown to be capable of providing sufficient heat to buildings. If the heating demand and hot tap water, in the case of the campus project alone are all covered by STES system, there will be a reduction in CO2 emission of 5,368 tons/year.Cross-sectional analysis concludes four out of eight factors checked as “Good” and two as “Ok”, other two as “Unsure”. Other three cities (Chengdu, Kunming, and Chongqing) are brought to comparison later regarding climate condition. Besides Guiyang, two out of three are evaluated to have potential of STES implementation according to their sun hours, annual average temperature etc. STES system is estimated to be possible for implementation in south-west of China as the conclusion.

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    Thesis Xuanlin Zhu
  • 3064.
    Zhu, Zhu
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Zhao, Jiangye
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Logistic Risk Management in the Chinese Non-metallicMineral Industry: --A Case Study of Shenzhen Rocky Mountain2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is a single qualitative case study. The purpose of this thesis is to find out useful approaches to manage logistics risks for Chinese non-metallic mineral industry. A representative case company has been chosen as the research object. The authors aim at seeking out the useful and suitable processes and approaches in general, and seeking for the target industry. There is a research gap in the target industry for logistics risk management--the target industry is lacked of researches on risk management in logistics area. Multiple resources from internet, literature review and interviews have been summarized. According to the literature, in the conclusion part, the authors put forward 12 basic processes to manage risks in logistics management and logistics outsourcing, they also found out three simple processes, which are the most important steps, at last the authors suggested that as it is difficult for Chinese non-metallic mineral industry to fulfill these 12 steps, it is better to add another process to help the industry to complete the risk management in logistics management and logistics outsourcing.

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  • 3065.
    Zhu, Zhu
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Zhao, Jiangye
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Risk investigation of logistics management and logistics method in the Chinese non-metallic mineral industry: A Case Study of The Shenzhen Rocky Mountain2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to investigate the risks in logistics management and logistics

    methods for the non-metallic mineral companies. The authors review the current situation of

    logistics management and logistics method from the non-metallic mineral companies and find

    out the problems or risks from these companies. The authors reviewed a few articles that

    evaluate the risks and problems in the non-metallic mineral companies. The authors also had

    several interviews through the Internet with the interviewee, who works as a regional

    manager in the case company. This thesis is a qualitative single case study, the authors search

    for usable information from the Internet, interviews and the authors also review many

    literatures and write about the current situation of the logistics methods, logistics management

    and logistics outsourcing in the non-metallic mineral companies. In the conclusion part, the

    authors give out the answers about the common risks in the literature for logistics

    management and logistics outsourcing, the characteristics of logistics in non-metallic mineral

    companies and the risks and problems of logistics management and logistics outsourcing in

    the non-metallic mineral companies during practice. This part also includes limitation in this

    thesis and it shows the further study, which the authors want to study in the future.

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    degree project
  • 3066.
    Zhuo, Yue
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Measuring inaccessible points in land surveying and analysis of their uncertainty2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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  • 3067.
    Ziakoulis, Antonio
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Ombyggnation, från sågverkslokal till restaurang. antonio ziakoulis2010Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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  • 3068.
    Zou, Fan
    University of Gävle, Department of Technology and Built Environment.
    Energy Saving Curtain: ENERGY INVENTORY AND CONSERVATION POSSIBILITIES2008Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    This paper presents the energy saving curtains, in order to make the

    consumers be more aware of the energy efficiency of the energy saving

    curtains, the paper gave related analysis and conclusions.

    The work was performed by using the Parasol Program, developed by Lunds University, Sweden. The Program is used for quantifying the influence of window size, glass type, textile type, wall thermal insulation and sun shading on annual energy use and indoor thermal comfort. The results which are obtained from the calculations are applicable to similar climatic and environment conditions. Calculations were performed to investigate the potential for using sunshade devices to reduce annual energy demand for cooling and heating. Different materials and dimensions of the energy saving

    curtain are used as variables in the analysis. The results indicated that for the current climatic conditions and other related factors, the total reduction rate of the annual energy consumption of office used buildings in Stockholm is estimated generally 20% -30% lower comparing to those buildings without energy saving curtain system. That means at least 20% of energy cost can be saved by the energy saving curtain system.

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    FULLTEXT01
  • 3069.
    ZUO, Tianchi
    et al.
    University of Gävle, Department of Technology and Built Environment.
    LI, Ying
    University of Gävle, Department of Technology and Built Environment.
     Environment-oriented Logistics System Design2009Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Environmental issues have been highly in focus for several years. With the development of EMS, many companies get environmental improvements through implementing EMS. Also, "green logistics" turns out to be a popular issue. But the combination of environment issues and logistics system is rarely found in the previous researches. Therefore, environment-oriented logistics system design becomes the topic described here.

    The purpose of the thesis is to see potential of integrating environment issues into logistic system by literature review and case study. With the help of our supervisors, two Swedish companies Sandvik SMT and FLB Logistik become case companies in the thesis. The analysis is based on literature review about logistics and environment, the information from both companies‟ websites as well as face-to-face interviews.

    In analysis part, how logistics systems and environmental issues interact with each other is illustrated firstly. A proposed model based on logistics system decision-making model is shown. SWOT analysis is used to explain the outcomes and challenges of implementing EMS in Sandvik SMT. At last, the conditions such as customer environmental requirement and the cost for using EMS are briefly described.

    Based on the research, further study should begin with the collection of quantitative data about environmental performance from manufacturing companies, suppliers, as well as retailers. More recommendations are given in the conclusion part.

    Download full text (pdf)
    FULLTEXT01
  • 3070.
    Zutautas, Vaidutis
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Charcoal Kiln Detection from LiDAR-derived Digital Elevation Models Combining Morphometric Classification and Image Processing Techniques2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This paper describes a unique method for the semi-automatic detection of historic charcoal production sites in LiDAR-derived digital elevation models. Intensified iron production in the early 17th century has remarkably influenced ways of how the land in Sweden was managed. Today, the abundance of charcoal kilns embedded in the landscape survives as cultural heritage monuments that testify about the scale forest management for charcoal production has contributed to the uprising iron manufacturing industry. An arbitrary selected study area (54 km2) south west of Gävle city served as an ideal testing ground, which is known to consist of already registered as well as unsurveyed charcoal kiln sites. The proposed approach encompasses combined morphometric classification methods being subjected to analytical image processing, where an image that represents refined terrain morphology was segmented and further followed by Hough Circle transfer function applied in seeking to detect circular shapes that represent charcoal kilns. Sites that have been identified manually and using the proposed method were only verified within an additionally established smaller validation area (6 km2). The resulting outcome accuracy was measured by calculating harmonic mean of precision and recall (F1-Score). Along with indication of previously undiscovered site locations, the proposed method showed relatively high score in recognising already registered sites after post-processing filtering. In spite of required continual fine-tuning, the described method can considerably facilitate mapping and overall management of cultural resources.

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    fulltext
  • 3071.
    Ädling, Anna
    University of Gävle, Department of Technology and Built Environment.
    Timmerhusets historia och framtid: En studie av timmerhusets energianvändning2008Student paper second term, 10 points / 15 hpStudent thesis
    Abstract [en]

    In a time where our environmental awareness and our use of energy gets more and more attention, grows the demand requirements on all the materials that we use. An area where the focus on etc the energy consumption has increased is the construction industry. With EU´s directive 2002/91/EG the demand energy efficient requirements gets even higher. Even the timberhouse that has traditions for over a 1000 years has to make the demand requirements that we have in the 21-century. Boverket has on the basis of the directive

    established new demands that say that houses located in the northern climate zone gets to have a maximum energy consumption of 130 kWh/year and 110 kWh/year in the southern climate zone.

    Only the 8” timberhouse located in the southern climate zone made the demand requirements on 110 kWh/year.

    The report analyses five different energy saving alternatives;

    • Use of rougher timber

    • Externally addition isolation

    • Internally addition isolation

    • Internally addition isolation of the northern wall and only on thoose walls where the timberwall neverhteless is gonna be visible:

    - Bathroom

    - Kitchen

    • Doubble timberwall with isolation inbetween

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    FULLTEXT01
  • 3072.
    Älvebrink, Johan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Konceptutveckling av artikelpaletter för effektivare rengöring av detaljer2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Atlas Copco in Tierp focus its production on hand-held tools, fixtured tools and assembly systems. Examples of tools that the company produces are wrenches, screwdrivers, grinders and drills. The production unit in Tierp is the largest production unit in the Industrial Technique business area. The company manufactures articles in many sizes and shapes. The articles are stored and transported in workshop palettes (load carriers). In order to ensure quality standards the articles are cleaned every so often in large industrial washing machines.The rinsing process is not efficient enough when cleaning the company's smaller articles. Palettes which articles are placed in contributes greatly to the lack of efficiency. To get the articles completely clean rinsing must sometimes be done twice.The goal was to develop a new palette concept that enable increased cleanliness after rinsing.Through trial and error method several alternative concepts have been developed and the best selected using Pugh matrix.The selected concept significantly increases the water flow and detail capacity compared to the original palette, but manufacturing costs are estimated to increase.Depending on the manufacturing method selected for making the new palettes, construction design can part. If the palettes are made through 3D-printing it may be advantageous to reduce the height (possibly remove the support pillars) and the mass of the palette to lessen manufacturing costs, while too complex design can increase the cost of machining.I recommended a prototype of the palette too be tested in production to reliably evaluate its properties and quality.

    Download full text (pdf)
    fulltext
  • 3073.
    Ängalid, Filip
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Utredning av behovsstyrd ventilation: En jämförelse mellan CAV och VAV2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport är ett examensarbete på C-nivå som görs i sammarbete med teknikkonsulten Ramböll. Det vanligaste sättet att ventilera en byggnad idag är med så kallad CAV-ventilation (Constant Air Volume). Denna metod bygger på att ett luftflöde bestäms för rummet och upprätthålls med konstant flöde. En annan metod är så kallad VAV (Variable Air Volume) som bygger på att flödet varierar efter behovet. Anledningen till varför man väljer VAV istället för CAV är att med CAV finns det ofta en stor risk att man överventilerar ett rum eller byggnad, just på grund av att flödet är konstant. Problemet med VAV är att det är en högre investeringskostnad än för CAV så metoden lämpar sig bara där energibesparingen är så stor så den täcker mellanskillnaden i pris. Denna utredning visar i vilka typer av rum som det kan löna sig att installera VAV istället för det traditionella CAV-systemet. För att undersöka detta sker simuleringar av fiktiva modeller i programmet IDA Indoor Climate & Energy (IDA). IDA är ett simuleringsverktyg som används till att simulera den termiska komforten i byggnader samt byggnadens energianvändning. De olika rumstyperna som simuleras är: klassrummet, kontoret och mötesrummet. De olika fallen är utformade så att de liknar så som de ser ut i verkligheten både till geometri och nyttjandegrad. Om något av fallen visade sig vara en bra kandidat för att förse med VAV fortsätter utredningen med att fastställa hur stort bör flödet vara för att energibesparingen ska bli så stor så att det täcker investeringskostnaden. Den ekonomiska kalkyleringen sker både med en livscykelkostnadsanalys och med en enklare återbetalningstidskalkyl. Resultatet för simuleringarna visade att den enda rumstypen i denna utredning som var lönsam var mötesrummet. Klassrummet och kontoret visade sig båda ge en förlust. Detta var eftersom nyttjandegraden för dessa rum var så pass hög så att ventilationen med VAV var igång nästan lika mycket som för CAV. För mötesrummet var nyttjandegraden betydligt lägre vilket innebar att energibesparingen blev så pass hög att den täckte den höga investeringskostnaden. För mötesrummet gjordes sedan en flödesanalys som visade att rummets luftflöde bör vara dimensionerat för mellan omkring 20 – 30 personer för att vara en lönsam investering. 

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    Utredning av behovsstyrd ventilation
  • 3074.
    Ängskog, Per
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH - Royal Institute of Technology.
    Avsiktliga elektromagnetiska störningar: Det osynliga hotet2014In: Electronic Environment, no 1, p. 16-17Article in journal (Other (popular science, discussion, etc.))
  • 3075.
    Ängskog, Per
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH - Royal Institute of Technology.
    EMP-symposium 8-9 maj 2014 i Oslo2014In: Electronic Environment, no 2, p. 22-23Article in journal (Other (popular science, discussion, etc.))
  • 3076.
    Ängskog, Per
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Measurement and Analysis of Radio Wave Coverage in Industrial Environments2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Several studies have characterized the path loss properties in industrial environments. However most of them have focused on one frequency, and some two or maximum three frequencies, usually cellular telephone frequencies or the unlicensed ISM bands that are commonly used in various industries. Few, if any, have characterized a larger part of the useable frequency range.This thesis is taking that challenge and investigates the path loss characteristics over a large frequency range, 300 MHz – 3 GHz, in industrial environments.

    First a measurement system suitable for the harsh environments found in industries is designed and verified. The measurement system is designed as two asynchronous stand-alone units that can be positioned at an arbitrary position to measure the path loss characteristics in any environment without interfering with the normal activities at the location.

    After that a measurement campaign involving three different types of environments is carried out. The environment types are: first, one highly absorbing – a paper warehouse at a paper mill; second, one highly reflective – a furnace building filled with metal objects and constructions and third, a mine tunnel – located 1 km below the surface of earth which is neither highly reflective nor absorbing but exhibits somewhat wave-guide like characteristics.

    The environments are shown to have very different behavior when it comes to propagation characteristics. Observations in the first environment reveal an environment that almost cancels out certain frequency bands and only line-of-sight communication is possible, hence no improvement will be achieved if installing systems that take multipath propagation into account, like MIMO. In the second environment reflections are legion; there are so many reflecting surfaces at different angles so any polarization of the signal is almost completely eliminated. Large fading variations were observed.The third environment is the underground mine where signals propagate inside the tunnels like in waveguides. It is shown that there are regions in the spectrum where the path loss dips and that these dips at least partly can be modeled with a simple two-beam propagation model normally used for outdoor propagation over infinite fields.

    The overall conclusion is that industrial environments are more heterogeneous regarding propagation characteristics than commonly assumed when selecting communication solutions. And that the only way to really know if a radio system will work at a certain location is to measure and characterize the environment.

    Download full text (pdf)
    Measurement_and_Analysis_of_Radio_Wave_Coverage_in_Industrial_Environments
  • 3077.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. Electromagnetic Engineering Lab, KTH - Royal Institute of Technology, Stockholm, Sweden.
    Backstrom, M.
    Electromagnetic Engineering Lab, KTH - Royal Institute of Technology, Stockholm, Sweden; SAAB Aeronautics, SAAB AB, Linköping, Sweden.
    Vallhagen, B.
    SAAB Aeronautics, SAAB AB, Linköping, Sweden.
    Samuelsson, C.
    SAAB Aeronautics, SAAB AB, Linköping, Sweden.
    Shielding effectiveness of energy saving windows and HPM effects on coated window panes: Measurements conducted 2014-2016 - Results and lessons learned2016In: IEEE International Symposium on Electromagnetic Compatibility, 2016, p. 461-466, article id 7739288Conference paper (Refereed)
    Abstract [en]

    The past few decades have shown a veritable explosion of new versions of energy-saving windows and coated window panes. In the wake of this, problems with radio communications into and from within buildings has arisen. However, this unexpected attenuation of radio signals may also be used to shield a facility from incoming intentional electromagnetic interference (IEMI). With the intention to investigate the shielding effectiveness (SE) of modern windows and window panes a two-year measurement campaign was launched mid-2014. Another, little investigated area is what happens to coated glass when irradiated by a high-power microwave (HPM) source. Shielding effectiveness has been measured for different types of energy saving windows and coated window panes both in a semi-anechoic chamber and in a reverberation chamber over the frequency range 1-18 GHz. The effects of HPM irradiation were studied by comparing SE measured before and after the pulsed 28 kV/m L-band irradiation. The main conclusion is that with the right choice of window the shielding effectiveness of a building can reach up 40-50 dB. In this paper we summarize these measurements and lessons learned from the measurement campaign.

  • 3078.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics. Department of Electromagnetic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Bäckström, Mats
    Department of Electromagnetic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Samuelsson, Carl
    Saab Aeronautics, Linköping, Sweden.
    Kangashaka Vallhagen, Bengt
    Saab Aeronautics, Linköping, Sweden.
    Shielding Effectiveness and HPM Vulnerability of Energy-Saving Windows and Window Panes2019In: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187X, Vol. 61, no 3, p. 870-877Article in journal (Refereed)
    Abstract [en]

    In this paper, we report results from shielding effectiveness measurements on energy-saving windows and individual, coated window panes of different generations, as well as results from high-power microwave irradiation on single panes. Shielding effectiveness was measured with two complementary methods: first, with near isotropic irradiation in nested reverberation chambers, and the other with irradiation at normal incidence in a semianechoic chamber. The measurements show that the construction of the energy conserving windows has a clear impact on how well they attenuate radio frequency signals. The more modern the window or pane, the higher is the shielding effectiveness. The high-power irradiation on coated panes showed that depending on the type of coating, hotspots can build up causing the coating to crack and, hence, deteriorate the shielding effectiveness. These results may serve as guidance when reviewing high-altitude electromagnetic pulse (EMP), high-power microwave, or intentional electromagnetic interference protection of critical infrastructures, and provide assistance in the work with reduction of compromising emanations.

  • 3079.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH - Royal Institute of Technology, Stockholm, Sweden.
    Bäckström, Mats
    KTH - Royal Institute of Technology, Stockholm, Sweden.
    Samuelsson, Carl
    Saab Aeronautics - SAAB AB.
    Vallhagen, Bengt
    Saab Aeronautics - SAAB AB.
    Shielding Effectiveness Studies of Energy Saving Windows and Coated Window Panes - a Summary2016In: Proceedings of the European Electromagnetics Symposium (EUROEM) 2016, London: Institution of Engineering and Technology, 2016, article id 7.a.2Conference paper (Refereed)
    Abstract [en]

    In recent decades, window panes and windows have undergone a virtual revolution with respect to energy saving. Along with this revolution a strong reduction of radio transmission capability through windows has followed. It has been observed that radio communication (e.g. mobile telephony) in newly built or renovated buildings has become increasingly difficult to accomplish due to the higher attenuation in these energy-saving windows. On the upside though, the increased attenuation can help in the protection against intentional electromagnetic interference (IEMI) and compromising emanations from activities inside the building.

    In this paper we summarize shielding effectiveness (SE) measurements conducted on window panes and window modules during 2014 and 2015 and give some conclusions drawn regarding do’s and don’ts when installing windows.

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    fulltext
  • 3080.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH, Elektroteknisk teori och konstruktion.
    Bäckström, Mats
    KTH, Elektroteknisk teori och konstruktion; SAAB Aeronautics, SAAB AB.
    Vallhagen, Bengt
    SAAB Aeronautics, SAAB AB.
    High Power Microwave Effects on Coated Window Panes2015In: Asia Electromagnetics Conference (ASIAEM) 2015, 2015Conference paper (Refereed)
    Abstract [en]

    Today window panes are usually coated with at least one metal or metal oxide layer to prevent heat energy of the light spectrum from propagating to the other side. This has given problems regarding radio propagation through windows, which might be utilized as a part of a buildings IEMI protection. This paper reports the results from measurements of the shielding effectiveness of a selection of modern window panes before and after irradiation with high power electromagnetic waves. The shielding effectiveness measurements are made in a nested reverberation chamber covering the range 1 – 18 GHz; both before and after high power irradiation at 1.3 GHz. The results show that the shielding effectiveness of window panes may be severely impaired due to thermal stress effects on the coatings during the irradiation, depending of the type of coating.

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    fulltext
  • 3081.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH, Elektroteknisk teori och konstruktion.
    Bäckström, Mats
    KTH, Elektroteknisk teori och konstruktion; SAAB Aeronautics, SAAB AB.
    Vallhagen, Bengt
    SAAB Aeronautics, SAAB AB.
    Measurement of Radio Signal Propagation through Window Panes and Energy Saving Windows2015In: 2015 IEEE International Symposium on Electromagnetic Compatibility (EMC), IEEE conference proceedings, 2015, p. 74-79Conference paper (Refereed)
    Abstract [en]

    Glass windows have undergone an energy saving evolution over the past three, four decades, from single panes till today’s ultralow-emission windows. While the earliest energy saving windows were constructed as a sandwich of clear glass panes using the vacuum-flask principle, modern low-emission windows includes panes with coatings of metal and/or metal oxides. This coating has caused radio propagation problems for communication systems; something that may be utilized to protect a building from intentional electromagnetic interference (IEMI) attacks and to help protecting against information leakage. In this paper measurements of the shielding performance of different generations of windows and qualities of window panes are presented. The intention is to include the results in a guide-line for IEMI protection of critical infrastructures. Measurements are made using two complementary methods; in a nested reverberation chamber and in a semi-anechoic chamber, both over the range 1 – 18 GHz. The results show a clear generation dependency where the energy saving windows largely do not attenuate RF signals at all and low-emission windows offer shielding effectiveness values between 10 and 45 dB with potentially as much as around 60 dB in the upper half of the spectrum.

    Download full text (pdf)
    fulltext
  • 3082.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH - Royal Institute of Tecknology.
    Bäckström, Mats
    KTH - Royal Institute of Technology; Saab Aeronautics - SAAB AB.
    Vallhagen, Bengt
    Saab Aeronautics - SAAB AB.
    Samuelsson, Carl
    Saab Aeronautics - SAAB AB.
    Skärmverkan och mikrovågseffekter på fönster och fönsterglas2016Conference paper (Refereed)
    Abstract [sv]

    Ett allt vanligare fenomen är att mobil telekommunikation inte fungerar i moderna/nybyggda hus. Detta kan härledas till de moderna energisparfönster som monteras in. Denna skärmverkan är inte bara ett problem utan kan också vändas till en fördel i de fall man vill skydda verksamhet från yttre elektromagnetiska störningar, till exempel avsiktlig elektromagnetisk störning (IEMI), samt i de fall då man vill undvika att röjande strålning (RÖS) från elektronisk utrustning läcker ut och kan avlyssnas.

    Här kommer vi presentera resultaten från mätningar av skärmverkan hos dels fönster av olika generation och dels enskilda fönsterglas med olika funktion som används för att bygga upp dessa fönster. Dessutom presenteras resultat från mätningar av hur skärmverkan påverkas vid bestrålning med högeffekts mikrovågsstrålning (HPM).

    Download full text (pdf)
    Skärmverkan och mikrovågseffekter på fönster och fönsterglas
  • 3083.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH - Royal Institute of Technology.
    Bäckström, Mats
    KTH - Royal Institute of Technology.
    Vallhagen, Bengt
    Saab Aeronautics - SAAB AB.
    Samuelsson, Carl
    Saab Aeronautics - SAAB AB.
    Skärmverkan och mikrovågseffekter på fönster och fönsterglas2016In: Electronic Environment, Vol. -, no 3, p. 26-29Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Ett allt vanligare fenomen är att mobil telekommunikation inte fungerar i moderna/nybyggda hus. Detta kan härledas till de moderna energisparfönster som monteras in. Denna skärmverkan är inte bara ett problem utan kan också vändas till en fördel i de fall man vill skydda verksamhet från yttre elektromagnetiska störningar, till exempel avsiktlig elektromagnetisk störning (IEMI), samt i de fall då man vill undvika att röjande strålning (RÖS) från elektronisk utrustning läcker ut och kan avlyssnas.

    Här kommer vi presentera resultaten från mätningar av skärmverkan hos dels fönster av olika generation och dels enskilda fönsterglas med olika funktion som används för att bygga upp dessa fönster. Dessutom presenteras resultat från mätningar av hur skärmverkan påverkas vid bestrålning med högeffekts mikrovågsstrålning (HPM).

  • 3084.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Chilo, José
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    WLAN IEEE 802.11 i industriella miljöer: en riskabel strategi2013Conference paper (Refereed)
    Abstract [sv]

    WLAN är förmodligen den vanligaste trådlösa installationen inom våra industrier idag. Vad få inser är att den lösning de valt i första hand är avsedd för an vändning i kontorsmiljö med helt andra krav på säkerhet och robusthet.

  • 3085.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Chilo, José
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    WLAN IEEE 802.11 i industriella miljöer: En riskabel strategi2012In: Electronic Environment, Vol. 3, p. 24-26Article in journal (Other academic)
  • 3086.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Chilo, José
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Stenumgaard, Peter
    FOI.
    Limitations of WLAN IEEE 802.11 in Industrial Environments2012Conference paper (Refereed)
  • 3087.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Karlsson, Carl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Ferrer Coll, Javier
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Chilo, José
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Stenumgaard, Peter
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Sources of Disturbances on Wireless Communication in Industrial and Factory Environments2010In: 2010 Asia-Pacific Symposium on Electromagnetic Compatibility, APEMC 2010, 2010, p. 281-284Conference paper (Refereed)
    Abstract [en]

    Electrical and mechanical machinery, highly reflective industrial facilities and co-existing communication systems are the major sources of disturbances in wireless industrial applications. Characterization of industrial environments is important for the development of standards, to assess current and future deployment of wireless technologies, and to provide systems integrators and end user with guidelines. In this paper some deductions from measurements carried out at three industrial environments using traditional electric field strength, amplitude probability distribution (APD) and multipath time dispersion measurements are presented. These measurements have given surprising and interesting results.

  • 3088.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics. Department of Electromagnetic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Näsman, Per
    Department of Real Estate and Construction Management, Building, and Real Estate Economics, Center for Safety Research, KTH Royal Institute of Technology, Stockholm, Sweden.
    Mattsson, Lars-Göran
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Resilience to intentional electromagnetic interference is required for connected autonomous vehicles2019In: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187X, Vol. 61, no 5, p. 1552-1559Article in journal (Refereed)
    Abstract [en]

    The connected autonomous vehicle (CAV) will never be completely autonomous; on the contrary, it will be heavily dependent on so-called vehicular ad hoc networks (VANETs) for its function. To deserve the trust of the general public, the vehicles as well as the intelligent transport system (ITS) infrastructure must be able to handle not only natural disturbances but also attacks of malicious nature. In this paper, we discuss the effects of antagonistic attacks using intentional electromagnetic interference (IEMI) and how the antagonistic nature of the threat renders probabilistic risk analysis inadequate for the defense of the vehicles and the infrastructure. Instead, we propose a shift toward resilience engineering and vulnerability analysis to manage antagonistic threats. Finally, we also give two examples of possible scenarios to illustrate the type of situations a CAV must be able to handle.

  • 3089.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH – Royal Institute of Technology, Stockholm, Sweden.
    Oakes, Ben
    KTH – Royal Institute of Technology, Stockholm, Sweden.
    Maintaining Functional Safety under an Intentional Electromagnetic Interference (IEMI) Attack2013Conference paper (Refereed)
    Abstract [en]

    The importance of protection against IEMI effects in civilian applications is growing rapidly as more and more societal infrastructure is equipped with electronic devices. This paper discusses methods to help maintaining functional safety in the event of an IEMI attack.

    Download full text (pdf)
    fulltext
  • 3090.
    Ängskog, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH, Elektroteknisk teori och konstruktion.
    Ödman, Torbjörn
    SAAB Electronic Defence Systems, SAAB AB.
    Bäckström, Mats
    KTH, Elektroteknisk teori och konstruktion; SAAB Aeronautics, SAAB AB.
    Vallhagen, Bengt
    SAAB Aeronautics, SAAB AB.
    Shielding Effectiveness Study of Two Fabrics with Microwave Properties Before and After High Power Irradiation2015In: Proceedings of the 2015 International Conference on Electromagnetics in Advanced Applications: ICEAA 2015, IEEE conference proceedings, 2015, p. 930-933Conference paper (Refereed)
    Abstract [en]

    Over the past decade several applications forfabrics with electromagnetic properties have emerged, most ofthem relating to garments, including jackets with built-inantennas and workwear with increased radar visibility. Besidethese have surfaced two protective applications, namely toprotect transports of confidential equipment from discoveryand identification; and to protect sensitive apparatus fromdamage by high power electromagnetic irradiation e.g. in fieldoperations. In this paper results are presented frommeasurement of shielding effectiveness before and after highpower radiation for two types of fabrics under considerationfor the latter applications. Shielding effectivenessmeasurements have been conducted between 1 and 18 GHzwhile the high power irradiation

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  • 3091.
    Åberg, Christer
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Österberg, Maya
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Den urbana parkens användning och potential för social interaktion: En studie av Stadsträdgården i Gävle2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Urban green-spaces are considered to be more important today than ever before. Parks arenot only beneficial for their positive effects on human health, but also for their social aspects. Parks are consequently considered to be the most suitable environment for encounters between people with different backgrounds and interests. Urban parks have developed from a place where the city-eliteexpressedtheir power to the public into a common place for all. Even though the parksareconsidered to be an open and welcoming place,users are considered to represent a homogenous group of people, which in turn, eliminates the potential of social interaction between different social groups.

    In this thesis a part of the urban park, Stadsträdgården, is investigated with the intention to study and map its use, its users and the existing supply. The methods used in this project are a questionnaire and observations. During the observations elements like counting, mapping, a qualitative experiment and an inventory of the park-attributes have been implemented. In the park, a broad composition of visitors consisting of varied age, gender and ethnicity, can be found. The focus area of this case study is divided into zones through the area of use and the users. In parks, time is an important dimension controlling whether different people will meet or not. Social interaction between strangers occurs in a small amount, and when it does, it depends on a third component, an event or a physical object that calls for a common interest. The parklacksnumerous qualities in the existing supply of the parkaccording to the users. However, it is uncertain towhat extent the public influencesthe planning of existing urban parks in Gävle, and thus if their considerations are ever involved in the planning process.

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  • 3092.
    Åberg, Curt
    Högskolan i Gävle-Sandviken.
    En vädur i bäcken: om metoder att lyfta och framleda vatten1990Report (Other academic)
  • 3093.
    Åberg, Curt
    Högskolan i Gävle-Sandviken.
    Vädurpumpen i Sverige: utvecklingen 1977-19911991Report (Other academic)
  • 3094.
    Åberg, Hannes
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Riskpunkter för översvämning inom avrinningsområdet för Järvstabäcken vid extremregn: Modellering med MIKE FLOOD2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Gävle municipality's plans to exploit the city to the south are under the general plan for the areas Järvsta and Ersbo, these areas are dewatered to Järvsta stream. This thesis is an investigation of the Järvsta stream regarding flood risk areas within the basin with consideration to the planned development areas. Investigation of the catchment area has been carried out through field visits, literature studies and modeling with MIKE FLOOD.

    The problem with Järvsta stream is that it is already heavily loaded. With increased development areas for housing and commercial areas in Hemlingby and Järvsta expected Järvsta stream to be even more loaded in case of extreme rainfall. Ersbo industrial area is also expected to affect surface water flows, hence higher proportion paved surface in combination with the planned landfill for snow in the industrial area expect to impact the flow frequencies. The landfill for snow in Ersbo affects the flow frequencies during the melt period.

    Risk Points of flooding is found in low points and passages under E4, Södra Kungsvägen, Upplandsleden and Bomhusvägen. These points should delay stormwater to increase control over flows and reduce the risk of flooding and cost of restoration of the buildings and infrastructure. Risk points adjacent to the existing residential areas and planned residential areas should be prioritized for investigation.

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  • 3095.
    Åberg, Simon
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Konstruktion av lyftanordning för slanka känsliga rör2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sandvik Materials Technology, SMT, Tube Mill 68 in Sandviken, manufactures steam generator tubes for the nuclear industry. These tubes are up to 30 meters long and have a diameter of about 20 mm. When lifted out of the tube rack, where they are temporarily stored, a scrupulous care is required. Not the slightest scratch may occur on the tubes and they shouldn’t experience any deformation. The lifting is currently made by hand which is not preferable for the operators from a working environment point of view. Therefore there is a need for a lifting device to replace this manual procedure. The tubes will bend during lifting, and one of the aims with this thesis was to find relations between bending, lifting force and material stress. By beam theory application, experiments and analysis made using the Finite Element Method, stress and reacting forces on the tubes have been mapped and identified.

    Within lifting heights up to 1000 mm, and the bending that comes of that, the stress in the tubes reaches a maximum of 157 MPa. That gives a safety factor of 1.8 against permanent deformation. Some relations between bending and stress have also been determined. For example, the relationship between lifting height and material stress is exponential, and the stress increases according to a square root function.

    Based on interviews with the operators and results from calculations - a conceptual lifting device has been developed. While lifting the tubes in one end and placing them on the rolls of the device, the device is moved in under the tubes, obtaining a wave effect that lifts the tubes to desired level. The result is an innovative solution that takes advantage of the tubes elasticity.

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  • 3096.
    Ågren, Ulrika
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Laserskanning som metod för byggnadsarkeologisk visualisering2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sigtuna är en av de äldsta städerna i landet. Kyrkan S:t Olof är en av flera medeltida kyrkor i staden. Under hösten 2005 utförde Leica Geosystems en demonstrationsmätning med en laserskanner i S:t Olofs ruin. Från museets håll ville man därefter att hela ruinen skulle mätas upp tredimensionellt för att på ett bättre sätt kunna analysera komplicerade kronologiska händelser och förändringar.

    Man har tidigare inom vetenskapsgrenen byggnadsarkeologi upplevt problem med att åstadkomma en fullständig bild av en byggnad genom tvådimensionella ritningar. I en tredimensionell avbildning synliggörs rummet på ett mer fullkomligt och verklighetstroget sätt. Idag har man då och då börjat använda geodetiska metoder och datavisualisering. Detta kommer med stor sannolikhet att ingå i utvecklingen i framtiden. Det finns därför ett behov av att utvärdera användandet av geodetisk mätningsteknik utifrån byggnadsarkeologens önskemål och avsikter samt att undersöka den tredimensionella modellens kapacitet för visualiseringssyften.

    Målsättningen med detta examensarbete är att göra själva inmätningen av S:t Olofs ruin och undersöka hur den tredimensionella modellen ska kunna användas för att visualisera resultatet av den byggnadsarkeologiska analysen.

    Inom ramen för examensarbetet har ruinen efter kyrkan S:t Olof mätts in med hjälp av en laserskanner av fabrikatet Leica HDS 3000. De inmätta punkterna har georefererats till Sigtuna kommuns koordinatsystem. Objekt i punktmolnet har vektoriserats och importerats till dokumentationssystemet Intrasis.

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  • 3097.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Uppsala University, Department of Information Technology, Sweden.
    Mapping of roof types in orthophotos using feature descriptors2018In: International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM: Proceedings of the International Multidisciplinary Scientific GeoConference SGEM, 2018, Vol. 18, p. 285-291Conference paper (Refereed)
    Abstract [en]

    In the context of urban planning, it is very important to estimate the nature of the roof of every building and, in particular, to make the difference between flat roofs and gable ones. This analysis is necessary in seismically active areas. Also in the assessment of renewable energy projects such solar energy, the shape of roofs must be accurately retrieved. In order to perform this task automatically on a large scale, aerial photos provide a useful solution. The goal of this research project is the development of algorithm for accurate mapping of two different roof types in digital aerial images. The algorithm proposed in this paper includes several components: pre-processing step to reduce illumination differences of individual roof surfaces, statistical moments calculation and color indexing. Roof models are created and saved as masks with feature specific descriptors. Masks are then used to mark areas that contain elements of the different roof types (e.g. gable and hip). The final orthophoto visualize an accurate position of each of the roof types. The result is evaluated using precision recall method.

  • 3098.
    Åhman, Matilda
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Luftburen värme med ett centralaggregat i flerbostadshus2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The fact that the global warming is a major probelm in today´s society is no news and the climate change continues to take place at a very high rate. In order to create a sustainable society change requires where the potential is on energy efficiency and increased use of renewable energy. Energy efficiency can be changes in behavior, additional insulation of buildings or switching to more energy efficient installations. From a thermal comfort- and energyperspective today there are diffrent oppinions about airborne heat if it is a good heating system.

    This thesis is made for Ramböll, a consultant firm which focuse on technology and construction of society. The purpose of the study is to investigate whether a radiator system in an appartent buildning can be replaced by an airborne heating system with a central unit to get a more cost efficient system.

    This study is based on calculations for transmissions, airflow and directed operative temperature for the current building. Based on these data the ventilationsystem has been constructed and dimensioned. Also a proposal for the regulation of the indoor temperature for the system has been produced and also a economic comparison between the airborne heating system and the radiator heating system has been made.

    The resaults of the study shows that for the apartment building the airborne heating system is a cheaper alternative compared to the radiator system, based on prices of materials and work. The study shows that the thermal comfort with a airborne heating system is not affected in a bad way by the directed operative temparature in the occupied zone. Also larger ducts will be needed with airborne hating, which will require bigger and more space consuming shaft. The regulation of the indoor temperature is going to be with VAV-throttle in every appartmen, which means that the regulation can be done in each appartment but not in every single room. 

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  • 3099.
    Åhr, Simon
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Framtagning av ett multiplexerat datainsamlingssystem för mätning av små elektriska strömmar2019Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
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  • 3100.
    Åkerström, Johan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Alsade, Noor
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Nudging för att minska köttkonsumtion: En studie för att förändra studenters beteende2019Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The purpose of the study is to investigate whether nudging is an effective method for changing behavior among students at Gävle University. The study will investigate whether two nudging methods (information campaign and nudge) can change the students' behavior, while comparing which method gives better effect to changing behavior and reducing meat consumption. First, a literature study will investigate wheater meat affects the climate and how much greenhouse gas emissions from meat can potentially be reduced by students at the Högskolan i Gävle using information campaigns and nudge. To further answer the purpose, two surveys and two nudging methods have been conducted at the Högskolan i Gävle. The first survey study was conducted to measure how much meat and the type of meat consumed by students, then two nudging methods have been used in order to change behavior and reduce or change the choice of meat among students. The second survey study was conducted to investigate whether the campaigns have changed behavior and reduced or changed the choice of meat among students. Results show that nudging has had an effect and behavior has changed. Nudge has reduced meat consumption and carbon dioxide emissions. The survey study contained 6 questions where only question 1 turned out to be significant and can be linked to nudge [KH1] in the interaction, information campaign is a contributing factor to this change.

     

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