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  • 1751. Zhang, Hongxia
    et al.
    Xu, Tianhua
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Optik.
    Jia, Dagong
    Jing, Wencai
    Liu, Kun
    Zhang, Yimo
    Effects of angular misalignment in interferometric detection of distributed polarization coupling2009Inngår i: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 20, nr 9, s. 095112-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    White light interferometry is used to measure the distributed polarization coupling (DPC) in polarization-maintaining fibers (PMFs). By using a scanning Michelson interferometer to compensate the optical path difference (OPD) induced by the modal birefringence of PMFs, both the coupling strength and positions of the coupling points can be acquired. In ideal DPC measurement, the two reflective mirrors on the fixed and scanning arms of the Michelson interferometer are normal to each other. But in practice, the movable reflective mirror cannot be aligned normally to the fixed mirror exactly, which leads to an angular misalignment. The angular misalignment causes a variation of the OPD, which will reduce the fringe visibility. The theoretical simulation is investigated correspondingly. Consequently, the angular error leads to the miscalculation of the polarization coupling intensity. Based on the experimental results, a revised coupling strength calculation equation is proposed to minimize the influence of angular misalignment.

  • 1752.
    Zhang, Hualei
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Lu, Song
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Punkkinen, Marko Patrick John
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Hu, Qing-Miao
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Johansson, Börje
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik.
    Vitos, Levente
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik.
    Static equation of state of bcc iron2010Inngår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 82, nr 13, s. 132409-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Body-centered-cubic (bcc) iron is one of the most investigated solid-state systems. Using four different density-functional methods, we show that there is a magnetic transition close to the ground-state volume of bcc Fe, which originates from the particular magnetic band structure. The common equation of state functions, used to determine the basic ground-state physical quantities from the calculated total energies, cannot capture the physics of this magnetic transition leading to serious underestimation of the Fe bulk modulus. Ignorance of the magnetic transition found here is reflected by large scatter of the published theoretical bulk moduli of ferromagnetic bcc Fe. Due to the low performance of the exchange-correlation functionals, most of the erroneous results are accidentally in good agreement with the experimental values. The present finding is of fundamental importance, especially taking into account that bcc Fe is frequently used as a test system in assessing the performance of exchange-correlation approximations or total-energy methods.

  • 1753.
    Zhang, Jianjun
    et al.
    Southeast Univ, Natl Mobile Commun Res Lab, Nanjing 210096, Jiangsu, Peoples R China..
    Huang, Yongming
    Southeast Univ, Natl Mobile Commun Res Lab, Nanjing 210096, Jiangsu, Peoples R China..
    Yu, Tianyuan
    Sichuan Univ, Sch Elect & Informat Engn, Chengdu 210096, Sichuan, Peoples R China..
    Wang, Jiaheng
    Southeast Univ, Natl Mobile Commun Res Lab, Nanjing 210096, Jiangsu, Peoples R China..
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES).
    Hybrid Precoding for Multi-Subarray Millimeter-Wave Communication Systems2018Inngår i: IEEE Wireless Communications Letters, ISSN 2162-2337, E-ISSN 2162-2345, Vol. 7, nr 3, s. 440-443Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This letter studies analog and digital hybrid precoding for millimeter wave communication systems with multiple subarray architecture. To reap the benefit of multiple subarrays with less number of RF chains, subarray selection needs to be jointly optimized, which leads to a mixed integer nonlinear problem and hard to solve. To find a good solution, we propose an efficient hybrid precoding algorithm by leveraging the constraint-introducing-and-penalty (CIP) approach. Simulation results show that the spectral efficiency achieved by the proposed algorithm is larger than that of existing hybrid precoding algorithms.

  • 1754.
    Zhang, Jinbao
    et al.
    Monash Univ, Dept Mat Sci & Engn, Clayton, Vic 3800, Australia..
    Daniel, Quentin
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Zhang, Tian
    Monash Univ, Dept Mat Sci & Engn, Clayton, Vic 3800, Australia..
    Wen, Xiaoming
    Swinburne Univ Technol, Ctr Microphoton, Melbourne, Vic 3122, Australia..
    Xu, Bo
    Uppsala Univ, Phys Chem, Dept Chem, Angstrom Lab, Box 523, S-75120 Uppsala, Sweden..
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi. Dalian Univ Technol, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116012, Peoples R China..
    Bach, Udo
    Monash Univ, Dept Chem Engn, Clayton, Vic 3800, Australia.;CSIRO Mfg, Clayton, Vic 3168, Australia.;Melbourne Ctr Nanofabricat, Clayton, Vic 3800, Australia..
    Cheng, Yi-Bing
    Monash Univ, Dept Mat Sci & Engn, Clayton, Vic 3800, Australia.;Wuhan Univ Technol, State Key Lab Silicate Mat Architectures, Wuhan 430070, Hubei, Peoples R China..
    Chemical Dopant Engineering in Hole Transport Layers for Efficient Perovskite Solar Cells: Insight into the Interfacial Recombination2018Inngår i: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, nr 10, s. 10452-10462Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Chemical doping of organic semiconductors has been recognized as an effective way to enhance the electrical conductivity. In perovskite solar cells (PSCs), various types of dopants have been developed for organic hole transport materials (HTMs); however, the knowledge of the basic requirements for being efficient dopants as well as the comprehensive roles of the dopants in PSCs has not been clearly revealed. Here, three copper-based complexes with controlled redox activities are applied as dopants in PSCs, and it is found that the oxidative reactivity of dopants presents substantial impacts on conductivity, charge dynamics, and solar cell performance. A significant improvement of open- circuit voltage (V-oc) by more than 100 mV and an increase of power conversion efficiency from 13.2 to 19.3% have been achieved by tuning the doping level of the HTM. The observed large variation of V-oc for three dopants reveals their different recombination kinetics at the perovskite/HTM interfaces and suggests a model of an interfacial recombination mechanism. We also suggest that the dopants in HTMs can also affect the charge recombination kinetics as well as the solar cell performance. Based on these findings, a strategy is proposed to physically passivate the electron- hole recombination by inserting an ultrathin Al2O3 insulating layer between the perovskite and the HTM. This strategy contributes a significant enhancement of the power conversion efficiency and environmental stability, indicating that dopant engineering is one crucial way to further improve the performance of PSCs.

  • 1755. Zhang, Jinbao
    et al.
    Xu, Bo
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Johansson, Malin B.
    Vlachopoulos, Nick
    Boschloo, Gerrit
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Johansson, Erik M. J.
    Hagfeldt, Anders
    Strategy to Boost the Efficiency of Mixed-Ion Perovskite Solar Cells: Changing Geometry of the Hole Transporting Material2016Inngår i: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 10, nr 7, s. 6816-6825Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The hole transporting material (HTM) is an essential component in perovskite solar cells (PSCs) for efficient extraction and collection of the photoinduced charges. Triphenylamine- and carbazole-based derivatives have extensively been explored as alternative and economical HTMs for PSCs. However, the improvement of their power conversion efficiency (PCE), as well as further investigation of the relationship between the chemical structure of the HTMs and the photovoltaic performance, is imperatively needed. In this respect, a simple carbazole-based HTM X25 was designed on the basis of a reference HTM, triphenylamine-based X2, by simply linking two neighboring phenyl groups in a triphenylamine unit through a carbon-carbon single bond. It was found that a lowered highest occupied molecular orbital (HOMO) energy level was obtained for X25 compared to that of X2. Besides, the carbazole moiety in X25 improved the molecular planarity as well as conductivity property in comparison with the triphenylamine unit in X2. Utilizing the HTM X25 in a solar cell with mixed-ion perovskite [HC(NH2)(2)](0.85)(CH3NH3)(0.15)Pb(I0.85Br0.15)(3), a highest reported PCE of 17.4% at 1 sun (18.9% under 0.46 sun) for carbazole-based HTM in PSCs was achieved, in comparison of a PCE of 14.7% for triphenylamine-based HTM X2. From the steady-state photoluminescence and transient photocurrent/photovoltage measurements, we conclude that (1) the lowered HOMO level for X25 compared to X2 favored a higher open-circuit voltage (V-oc) in PSCs; (2) a more uniform formation of X25 capping layer than X2 on the surface of perovskite resulted in more efficient hole transport and charge extraction in the devices. In addition, the long-term stability of PSCs with X25 is significantly enhanced compared to X2 due to its good uniformity of HTM layer and thus complete coverage on the perovskite. The results provide important information to further develop simple and efficient small molecular HTMs applied in solar cells.

  • 1756.
    Zhang, Xinhai
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Mohan, Naveen
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Törngren, Martin
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Axelsson, J.
    Chen, DeJiu
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Architecture exploration for distributed embedded systems: A gap analysis in automotive domain2017Inngår i: 2017 12th IEEE International Symposium on Industrial Embedded Systems, SIES 2017 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2017, artikkel-id 7993377Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A large body of work can be found in literature on Design Space Exploration (DSE) methods for distributed embedded system architecting (DESA). However, almost none of these methods is successfully adopted in automotive industry. To clarify the reasons, this paper 1) analyzes the current state of the art (SOTA) on DSE methods for DESA through a systematic literature study, focusing on the assumed architecting process and concerns; 2) investigates the state of practice (SOP) on DESA in the automotive industry through a literature study and interviews with experienced system architects from five different automotive manufacturers; and 3) analyzes the gap between SOTA and SOP, and thereby discusses potential improvements of DSE methods.

  • 1757. Zhang, Y.
    et al.
    Beskow, Jonas
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    Kjellström, Hedvig
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    Look but Don’t Stare: Mutual Gaze Interaction in Social Robots2017Inngår i: 9th International Conference on Social Robotics, ICSR 2017, Springer, 2017, Vol. 10652, s. 556-566Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Mutual gaze is a powerful cue for communicating social attention and intention. A plethora of studies have demonstrated the fundamental roles of mutual gaze in establishing communicative links between humans, and enabling non-verbal communication of social attention and intention. The amount of mutual gaze between two partners regulates human-human interaction and is a sign of social engagement. This paper investigates whether implementing mutual gaze in robotic systems can achieve social effects, thus to improve human robot interaction. Based on insights from existing human face-to-face interaction studies, we implemented an interactive mutual gaze model in an embodied agent, the social robot head Furhat. We evaluated the mutual gaze prototype with 24 participants in three applications. Our results show that our mutual gaze model improves social connectedness between robots and users.

  • 1758. Zhang, Y.
    et al.
    Liu, Sichao
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion. Northwestern Polytechnical University, Shaanxi, China.
    Liu, Y.
    Yang, H.
    Li, M.
    Huisingh, D.
    Wang, Lihui
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    The ‘Internet of Things’ enabled real-time scheduling for remanufacturing of automobile engines2018Inngår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 185, s. 562-575Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Typical challenges that managers of remanufacturing face are composed of the lack of timely, accurate, and consistent information of remanufacturing resources. Therefore, it is difficult to implement real-time production scheduling for the shop floor. To address this problem, the authors applied the concept of the ‘Internet of Things’ to the remanufacturing of automobile engines to form an Internet of Manufacturing Things environment. Under the Internet of Manufacturing Things, an identification technology for disassembled engine parts was designed, and the real-time status of the remanufacturable resources can be monitored. Based on the captured remanufacturing information, a real-time production scheduling method was developed, and a mathematical model was developed to achieve cost reduction, dynamic management of remanufacturable resources, and energy consumption decrease. To obtain an optimal solution, a Pareto-based optimization method was used. Finally, a case study was performed to analyze the effectivity of the proposed method. The results showed that the remanufacturing cost and energy consumption were reduced by 34% and 34% respectively, and the worker load rate was more balanced. These improvements can contribute to more sustainable development and greener production within the remanufacturing industry, especially for remanufacturing of automobile engines.

  • 1759.
    Zhang, Yongping
    et al.
    Beihang Univ, Sch Automat Sci & Elect Engn, Beijing 100191, Peoples R China..
    Cheng, Ying
    Beihang Univ, Sch Automat Sci & Elect Engn, Beijing 100191, Peoples R China..
    Wang, Xi Vincent
    KTH, Skolan för industriell teknik och management (ITM).
    Zhong, Ray Y.
    Univ Hong Kong, Dept Ind & Mfg Syst Engn, Hong Kong, Peoples R China..
    Zhang, Yingfeng
    Northwestern Polytech Univ, Key Lab Contemporary Design & Integrated Mfg Tech, Minist Educ, Xian 710072, Shaanxi, Peoples R China..
    Tao, Fei
    Beihang Univ, Sch Automat Sci & Elect Engn, Beijing 100191, Peoples R China..
    Data-driven smart production line and its common factors2019Inngår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 103, nr 1-4, s. 1211-1223Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Due to the wide usage of digital devices and easy access to the edge items in manufacturing industry, massive industrial data is generated and collected. A data-driven smart production line (SPL), which is a basic cell in a smart factory, is derived primarily. This paper studies the data-driven SPL and its common factors. Firstly, common factors such as integration, data-driven, service collaboration, and proactive service of SPL are investigated. Then, a data-driven method including data self-perception, data understanding, decision-making, and precise control for implementing SPL is proposed. As a reference, the research of the common factors and the data-driven method could offer a systematic standard for both academia and industry. Moreover, in order to validate this method, this paper presents an industrial case by taking an energy consumption forecast and fault diagnosis based on energy consumption data in a prototype of LED epoxy molding compound (EMC) production lines for example.

  • 1760.
    Zhang, Zhe
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Tiikoja, Heiki
    KTH.
    Peerlings, Luck
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Åbom, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Experimental Analysis on the 'Exact' Cremer Impedance in Rectangular Ducts2018Inngår i: SAE technical paper series, ISSN 0148-7191, Vol. 2018-June, nr JuneArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cremer impedance, first proposed by Cremer (Acustica 3, 1953) and then improved by Tester (JSV 28, 1973), refers to the locally reacting boundary condition that can maximize the attenuation of a certain acoustic mode in a uniform waveguide. One limitation in Tester's work is that it simplified the analysis on the effect of flow by only considering high frequencies or the 'well cut-on' modes. This approximation is reasonable for large duct applications, e.g., aero-engines, but not for many other cases of interest, with the vehicle intake and exhaust system included. A recent modification done by Kabral et al. (Acta Acustica united with Acustica 102, 2016) has removed this limitation and investigated the 'exact' solution of Cremer impedance for circular waveguides, which reveals an appreciable difference between the exact and classic solution in the low frequency range. Consequently, the exact solution can lead to a much higher low-frequency attenuation level. In addition, the exact solution is found to exhibit some special properties at very low frequencies, e.g., a negative resistance. In this paper, liners designed on the basis of the exact solution are tested and the difference between the exact and classic solution in the low frequency range (not low enough to go into the negative resistance region) is experimentally investigated.

  • 1761.
    Zhang, Zhengquan
    et al.
    Southwest Jiaotong Univ, Chengdu, Sichuan, Peoples R China..
    Yang, Guang
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Ma, Zheng
    Southwest Jiaotong Univ, Chengdu, Sichuan, Peoples R China.;Sch Informat Sci & Technol, Stockholm, Sweden..
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Ding, Zhiguo
    Univ Lancaster, Lancaster, Lancs, England..
    Fan, Pingzhi
    Southwest Jiaotong Univ, Inst mobile Commun, Chengdu, Sichuan, Peoples R China..
    Heterogeneous Ultradense Networks with NOMA System Architecture, Coordination Framework, and Performance Evaluation2018Inngår i: IEEE Vehicular Technology Magazine, ISSN 1556-6072, E-ISSN 1556-6080, Vol. 13, nr 2, s. 110-120Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Heterogeneous ultradense networks (H-UDNs) are one key enabler for fifth-generation (5G) wireless networks and beyond to satisfy the explosive growth of mobile data traffic, which exploits spatial reuse of scarce spectrum by deploying massive base stations (BSS) to boost network capacity and enhance network coverage. In this article, we present the system architecture for 5G H-UDNs, consisting of virtualized integrated ground-Air-space radio access networks (RANs) and core networks and study network coordination for virtualized H-UDN to efficiently manage computing resources and intercell interference. We look at a cloud-fog-computing coordination framework for efficient computing resource management by achieving reasonable computing task distribution and transfer; computing load balance for computing tasks among virtual computing resources to improve network performance and computing resource efficiency; and a macro-small cell coordination framework for virtualized H-UDN with nonorthogonal multiple access (NOMA) to efficiently manage intercell interference and improve network performance. The joint macro-small enhanced intercell interference coordination (eICIC) and small-small coordinated multipoint joint transmission (CoMP-JT) scheme can efficiently eliminate macro-small intercell interference and utilize small-small intercell interference.

  • 1762. Zhao, J.
    et al.
    Chen, X.
    Duan, X.
    Shen, Tong
    KTH, Skolan för elektro- och systemteknik (EES).
    Study on demand forecasting and allocation of expressway emergency vehicle resource2014Inngår i: Journal of Computational Information Systems, ISSN 1553-9105, Vol. 10, nr 10, s. 4205-4215Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Emergency vehicles are the key resources of expressway for the rescue mission to traffic accidents. For optimal emergency vehicle resources allocation, an improved Case-Based Reasoning (CBR) and an allocation model are established. First, the effecting factors of traffic safety on expressway are analyzed to establish an accident hazard indicator system. A difference coefficient is introduced to improve Case-Based Reasoning for predicting the demand of emergency vehicle resources. Then, the resource allocation model is established based on the objective constrained optimization method, which tries to find the minimum rescue time with constraints such as road hazard, rescue time, resource demand, and the configuration result is obtained by adopting Particle Swarm Optimization (PSO). Finally, according to the study of a bridge case, it shows that the prediction error of resource demands becomes smaller by using the improved case-based reasoning method and the resource allocation results are reasonable through the calculation of objective constrained optimization model.

  • 1763.
    Zhao, Yueming
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och geoinformatik.
    Key Technologies in Low-cost Integrated Vehicle Navigation Systems2013Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Vehicle navigation systems incorporate on-board sensors/signal receivers and provide necessary positioning and guidance information for land, marine, airborne and space vehicles. Among different navigation solutions, the Global Positioning System (GPS) and an Inertial Navigation System (INS) are two basic navigation systems. Due to their complementary characters in many aspects, a GPS/INS integrated navigation system has been a hot research topic in recent decades. Both advantages and disadvantages of each individual system and their combination are analysed in this thesis.

    The Micro Electrical Mechanical Sensors (MEMS) successfully solved the problems of price, size and weight with traditional INS, and hence are widely applied in GPS/INS integrated systems. The main problem of MEMS is the large sensor errors, which rapidly degrade the navigation performance in an exponential speed. By means of different methods, such as autoregressive model, Gauss-Markov process, Power Spectral Density and Allan Variance, we analyse the stochastic errors within the MEMS sensors. The test results show that different methods give similar estimates of stochastic error sources. An equivalent model of coloured noise components (random walk, bias instability and ramp noise) is given.

    Three levels of GPS/IMU integration structures, i.e. loose, tight and ultra-tight GPS/IMU navigation, are introduced with a brief analysis of each character. The loose integration principles are presented with detailed equations as well as the INS navigation principles. The Extended Kalman Filter (EKF) is introduced as the data fusion algorithm, which is the core of the whole navigation system. Based on the system model, we show the propagation of position standard errors with the tight integration structure under different scenarios. Even less than 4 observable GNSS satellites can contribute to the integrated system, especially for the orientation errors. A real test with loose integration is carried out, and the EKF performance is analysed in detail.

    Since the GPS receivers are normally working with a digital map, the map matching principle and its link-choosing problem are briefly introduced. This problem is proposed to be solved by the lane detection from real-time images. The procedures for the lane detection based on image processing are presented. The test on high ways, city streets and pathways are successfully carried out, and analyses with possible solutions are given for some special failure situations.

    To solve the large error drift of the IMU, we propose to support the IMU orientation with camera motion estimation from image pairs. First the estimation theory and computer vision principles are briefly introduced. Then both point and line matches algorithms are given. Finally the L1-norm estimator with balanced adjustment is proposed to deal with possible mismatches (outliers). Tests and comparisons with the RANSAC algorithm are also presented.

    For the latest trend of MEMS chip sensors, their industry and market are introduced. To evaluate the MEMS navigation performance, we augment the EKF with an equivalent coloured noise model, and the basic observability analysis is given. A realistic simulated navigation test is carried out with single and multiple MEMS sensors, and a sensor array of 5-10 sensors are recommended according to the test results and analysis. Finally some suggestions for future research are proposed.

  • 1764.
    Zhao, Yueming
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och geoinformatik.
    Horemuz, Milan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och geoinformatik.
    Sjöberg, Lars E.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och geoinformatik.
    Stochastic modelling and analysis of IMU sensor errors2011Inngår i: Archives of Photogrammetry, Cartography and Remote Sensing, ISSN 2083-2214, Vol. 22, s. 437-449Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The performance of a GPS/INS integration system is greatly determined by the ability of stand-alone INS system to determine position and attitude within GPS outage. The positional and attitude precision degrades rapidly during GPS outage due to INS sensor errors. With advantages of low price and volume, the Micro Electrical Mechanical Sensors (MEMS) have been wildly used in GPS/INS integration. Moreover, standalone MEMS can keep a reasonable positional precision only a few seconds due to systematic and random sensor errors. General stochastic error sources existing in inertial sensors can be modelled as (IEEE STD 647, 2006) Quantization Noise, Random Walk, Bias Instability, Rate Random Walk and Rate Ramp. Here we apply different methods to analyze the stochastic sensor errors, i.e. autoregressive modelling, Gauss-Markov process, Power Spectral Density and Allan Variance. Then the tests on a MEMS based inertial measurement unit were carried out with these methods. The results show that different methods give similar estimates of stochastic error model parameters. These values can be used further in the Kalman filter for better navigation accuracy and in the Doppler frequency estimate for faster acquisition after GPS signal outage.

  • 1765.
    Zheng, Miaomiao
    et al.
    KTH, Skolan för teknik och hälsa (STH), Medicinsk teknik.
    Härmark, Johan
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Strukturell bioteknik.
    Grishenkov, Dmitry
    KTH, Skolan för teknik och hälsa (STH), Medicinsk teknik.
    Janerot Sjöberg, Birgitta
    CLINTEC, Department of Medical Imaging and Technology, Karolinska Institute.
    Polymer-Shelled Ultrasound Contrast Agents with controlled size and polydispersity.2011Inngår i: Nanomedicine: Nanotechnology, Biology & Medicine, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Ultrasound imaging techniques can be greatly improved by the use of ultrasound contrast agents (UCAs). Gas bubbles encapsulated into biocompatible polymer shell are of particular interest of this work. Shell of the bubbles produced from Poly-Vinyl-Alcohol (PVA) offers considerable chemical versatility and stability. However, questions regarding the size and polydispersity of the microbubbles must be further investigated. The ideal UCAs should not obstruct the blood flow in pulmonary capillaries which diameter is less than 10 μm. From the technical perspective UCAs should modify the acoustic properties of a region of interest, by increasing backscattered efficiency. In order to enhance the ultrasound response UCAs should be engineered with narrow size distribution. In the present work PVA-shelled UCAs with controlled size and polydispersity is manufactured under varied parameters of the manufacturing protocol. It was observed that temperature of the surrounding atmosphere has major effect on the size of the UCAs, while polydispersity is regulated by geometry and speed of the disperser. Finally, the acoustic response of these microbubbles is tested using developed ultrasound test rig. The enhancement of the backscattered power of about 25 dB from a suspension of the microbubbles is observed at 5 MHz ultrasound frequency. Keeping in mind that in clinical practice ultrasound scatter from the blood is of about 30 dB weaker than scatter from surrounding tissue, introduction of novel PVA microbubbles will potentially improve diagnosis of the cardiovascular patients.

  • 1766.
    Zheng, Weisen
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    He, Shuang
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Wang, Jingya
    IMDEA Mat Inst, C Eric Kandel 2, Madrid, Spain..
    Mao, Huahai
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
    Thermodynamic Evaluation of the Co-Al-C System by Coupling Ab Initio Calculations and CALPHAD Approach2018Inngår i: JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION, ISSN 1547-7037, Vol. 39, nr 5, s. 538-548Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The ternary Co-Al-C system was thermodynamically assessed using the CALPHAD method based on the critical review of all experimental information in the system. The kappa-carbide was described with a three-sublattice model (Al,Co)(3)(Al,Co)(1)(C,Va)(1). To support the assessment, the enthalpies of formation of all end-members of the kappa-carbide were studied by ab initio calculations. The solubility ranges of the carbon in the kappa-carbide, the alpha Co and the AlCo (B2) phases were well reproduced. The equilibria involving the liquid phase were reasonably described using the present set of thermodynamic parameters.

  • 1767.
    Zhou, Hanyue
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Medieteknik och interaktionsdesign, MID.
    Fashion E-Commerce in the 3D Digital Era: A 3D Interactive Web User Interface for Online Products2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Fashion brands have always been avant-garde in embracing new technologies and new formats of retail business models. The rapid development in 3D digital technologies, including 3D scanning, 3D modelling and 3D web rendering, have brought many new opportunities to the fashion industry, especially in shaping the future fashion e-commerce. The traditional 2D user interface and 2D media content have limited ability of displaying every detail of a product in full 360 degree, and the color accuracy of products in pictures is also a common problem. This thesis focuses on how to use 3D technologies to enhance the brand identity and  to reduce return rate, by designing and implementing a web 3D user interface for fashion e-commerce. An interactive 3D product user interface were designed and used for test. The results presented the pros and cons of the designed 3D user interface, and evaluated to what extent can this approach help to solve the brand identity problem and the high return rate issue for fashion e-commerce. It turns out that indeed the 3D user interface is rich in detail storytelling and the product accuracy can be improved by using the Physically Based Rendering technology and dynamic virtual lighting environments. However, the results also indicate that there are still lots of technical constraints for developing the virtual showrooms and the 3D user interface.

  • 1768.
    Zhou, Jian
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Li, Shanghua
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Soliman, Hesham M. A.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Toprak, Muhammet S.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Muhammed, Mamoun
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Platzek, Dieter
    Müller, Eckhard
    Synthesis and Seebeck coefficient of nanostructured phosphorus-alloyed bismuth telluride thick films2008Inngår i: Physica Status Solidi. C, Current topics in solid state physics, ISSN 1610-1634, E-ISSN 1610-1642, Vol. 5, nr 11, s. 3453-3457Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Phosphorous-alloyed Bi2Te3 thick films have been prepared by electrochemical deposition. The average grain size of the films was calculated to be 14-26 nm based on Scherrer's equation. The effect of P on the Seebeck coefficient of thermoelectric P-alloyed Bi2Te3 thick film was investigated. The results show that P-alloyed thick film has n-type conductivity with the Seebeck coefficient of -35 mu V/K. The correlation between P site occupancy in the crystal and the Seebeck coefficient was discussed.

  • 1769.
    Zhou, Tao
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap. Univ Sci & Technol Beijing, China.
    Yu, Hao
    Wang, Shaoyang
    Effect of microstructural types on toughness and microstructural optimization of ultra-heavy steel plate: EBSD analysis and microscopic fracture mechanism2016Inngår i: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 658, s. 150-158Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The uniformity of toughness along thickness direction has long been the critical problem for producing ultra-heavy steel plate. To clarify the rule and mechanism of the influence of microstructures on toughness, different microstructures and their mixtures have been obtained through various heat treatment processes. The microstructures and substructures were characterized by means of optical microscope and transmission electron microscope. Furthermore, the correlations between misorientation, grain size, microscopic fracture propagation and toughness have been studied in detail using electron backscatter diffraction. Results suggest that after tempering, lath bainite can achieve better toughness property than martensite, whereas granular bainite is detrimental for toughness. Note that firstly generated lath bainite can effectively refine subsequent martensitic packets and blocks, and increase barriers for fracture propagation. Compared with single-phase martensite microstructure, the mixture of martensite+bainite obtains finer substructure and more percentage of large misorientation, which are favorable for hindering the propagation of microcrack, meanwhile it is an ideal microstructural type to achieve the optimal combination of toughness and strength. Besides, functional mechanism of packet boundaries and block boundaries for hindering crack propagation is different, as it is more difficult for crack propagation to bridge between different lattice planes than between different crystallographic orientations.

  • 1770.
    Zhou, Xiamo
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Mikro- och nanosystemteknik.
    Haraldsson, Tommy
    KTH, Skolan för elektro- och systemteknik (EES), Mikro- och nanosystemteknik.
    van der Wijngaart, Wouter
    KTH, Skolan för elektro- och systemteknik (EES), Mikro- och nanosystemteknik.
    ONE-STEP INJECTION MOLDING OF OSTE+ MICROFLUIDIC DEVICES WITH SCREW THREADED PORTS2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present a simplified method for molding internally threaded fluidic ports in microfluidic devices using a deformable mold and dual-cure OSTE+ polymer. We demonstrate a lab-on-a-chip device where monolithically integrated chip-to-world threaded interfaces, vias and microchannels are reaction injection molded in one single step. 

  • 1771. Zhou, Y.
    et al.
    Boem, F.
    Fischione, Carlo
    KTH, Skolan för elektro- och systemteknik (EES), Nätverk och systemteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Parisini, T.
    Distributed fault detection with sensor networks using pareto-optimal dynamic estimation method2017Inngår i: 2016 European Control Conference, ECC 2016, Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 728-733Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, a distributed method for fault detection using sensor networks is proposed. Each sensor communicates only with neighboring nodes to compute locally an estimate of the state of the system to monitor. A residual is defined and suitable stochastic thresholds are designed, allowing to set the parameters so to guarantee a maximum false alarms probability. The main novelty and challenge of the proposed approach consists in addressing the individual correlations between the state, the measurements, and the noise components, thus significantly generalising the estimation methodology compared to previous results. No assumptions on the probability distribution family are needed for the noise variables. Simulation results show the effectiveness of the proposed method, including an extensive sensitivity analysis with respect to fault magnitude and measurement noise.

  • 1772.
    Zhou, Yan
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Materialfysik, MF.
    Shin, Franklin G.
    Guan, Bo
    Åkerman, Johan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Materialfysik, MF.
    Capacitance Effect on Microwave Power Spectra of Spin-Torque Oscillator With Thermal Noise2009Inngår i: IEEE transactions on magnetics, ISSN 0018-9464, E-ISSN 1941-0069, Vol. 45, nr 6, s. 2773-2776Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A macro-spin simulation has been carried out to study the thermal stability of a spin-torque oscillator (STO) connected in parallel with a capacitance. To study the impact of realistic thermal fluctuation on an STO, a stochastic magnetic field vector is added into the Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation. From the numerical solution, it is found that the addition of capacitance positively influences the thermal stability of the system, and can improve the quality factor of the microwave power spectrum even in the presence of thermal fluctuation. The results of I-V phase shift under different conditions suggest that there may exist an optimum capacitance for which the thermal stability of the system can be most enhanced.

  • 1773.
    Zhou, Yan
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Materialfysik, MF.
    Zha, Chaolin
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Materialfysik, MF.
    Bonetti, Stefano
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Materialfysik, MF.
    Persson, Johan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Åkerman, Johan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Materialfysik, MF.
    Microwave generation of tilted-polarizer spin torque oscillator2009Inngår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 105, nr 7, s. 07D116-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Microwave frequency generation in a spin torque oscillator (STO) with a tilted fixed layer magnetization is studied using numerical simulation of the Landau-Lifshitz-Gilbert-Slonczewski equation. The dependence of the STO free layer precession frequency on drive current is determined as a function of fixed layer tilt angle. We find that zero-field STO operation is possible for almost all tilt angles, which allow for great freedom in choosing the detailed layer structure of the STO.

  • 1774. Zhou, Zude
    et al.
    Yao, Bitao
    Xu, Wenjun
    Wang, Lihui
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion, Produktionssystem.
    Condition monitoring towards energy-efficient manufacturing: a review2017Inngår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 91, nr 9-12, s. 3395-3415Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Recently, sustainable development has obtained increasing attentions from governments, industry, and academia owing to the limited natural resources. In the area of energy consumption, manufacturing accounts for a major portion of the total energy usage in industry. There is a clear necessity for energy-efficient manufacturing by optimizing manufacturing activities. Condition monitoring is the technology that provides runtime information for optimization. This paper aims to provide a better understanding of past achievements and future trends of condition monitoring towards energy-efficient manufacturing. Since there are a variety of sensors and technologies that can be used for condition monitoring towards energy-efficient manufacturing, this paper divides manufacturing activities into three levels, namely unit process level, shop-floor level, and supply chain level, and summarizes and discusses the sensors and technologies required to enable energy-efficient manufacturing on each level. With the advancement of technology, condition monitoring shows the characteristic of intelligence. Intelligent sensors that can be applied to condition monitoring in energy-efficient manufacturing are also reviewed. This paper can be helpful to manufacturers who are willing to improve energy efficiency in own manufacturing practice.

  • 1775.
    Zhu, Bin
    et al.
    KTH.
    Kürth-Landwehr, S.
    Corbi, Victor Guerrero
    KTH.
    YU: An artistic exploration of interface design for home healthcare2014Inngår i: TEI '14 Proceedings of the 8th International Conference on Tangible, Embedded and Embodied Interaction, 2014, s. 332-334Konferansepaper (Fagfellevurdert)
    Abstract [en]

    YU is an artistic home healthcare system including measuring, visualizing and displaying personal bio-data as well as biofeedback. It integrates with the home setting and aims for bringing aesthetic experience. Through the system YU, we explore possibilities of design health technologies with artistic interface into our home life. Instead of commonly used numeric or graphical interface, we use Chinese ink painting to visualize the pulse and HRV (Heart Rate Variability). We design an artistic interface with two display modes and three levels of interactivity involving in the home life.

  • 1776.
    zhu, yue
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Applying lean philosophy to the redesign of service delivery process: A case study in the telecommunication industry2012Independent thesis Advanced level (degree of Master (Two Years)), 80 poäng / 120 hpOppgave
    Abstract [en]

    Lean is an umbrella term for a powerful combination of techniques to maximize customer value by minimizing waste and achieving continuous flow through a sustainable culture of continuous improvement. The term ―lean is used in the U.S. for what was originally created as the "Toyota Production System" by the Japanese carmaker. It is so fashionable since it was born that it’s been widely used in the manufacturing industry during the past decades all over the world. No matter in the opinion of insiders or outsiders, this is a magical word stands for discovering and eliminating discreet wastes, reducing resources requirement and time demand for production, making the manufacturing process efficient and cost effective and eventually building the sustainable competitive advantage of the organization.

    There’s already a world of books discussing the implementations. But as for the service delivery process, especially within the telecom industry, there’s no qualitative research carried out to check the validation of lean tool yet. Most researchers still remain on the theoretical level, arguing and debating on the applicability. The objective of this research is to fill in this research niche, check the possibility of using lean tool, naming VSM, to study and redesign the service delivery process in a qualitative way. The research question comes to how to apply the tool in a qualitative way and exam the both sides of the coin.

    The author investigated on the service delivery process performance in the Business-As-Usual projects and the key performance indicators of the case company business unit to find out any inconsistencies. One of the powerful lean tools - VSM is used step by step, node by node to identify existing discreet wastes. Based on the lean philosophy and literature reviews, potential possible improvements are proposed to eliminate the wastes, afterwards an ideal new VSM is created, with which it is able to dramatically reduce the resources required to seize customer value, satisfy the same amount of customer demand, increase customer satisfaction, make the company focusing on continuous improvement, and in the end move the company to a higher position in the field with stronger competence to win more market share.

    This research work is conducted as a single case study under the lean philosophy by collecting and studying qualitative data using various semi-structured interviews and archival data analysis. Six applicable solutions to lead the organization lean is proposed, and based on which, a brand new Optimization Focus Matrix is introduced to have a broader applicability. Possible benefit, difficulties in implementation and potential risks are also presented. The thesis ends with conclusion, answer to the research questions and discussion on the thesis limitation & future research direction.

  • 1777.
    Álvarez Carranza, Ricardo
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Digging into Dirty Laundry: e-Standardization of Legal Services Procurement2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The purpose of this thesis is to propose a standardization model for the purchase process of legal professional services leveraging e-Procurement and to validate the benefits brought by the implementation of both, an e-Procurement tool and a new procurement process. The hypotheses of this thesis are applicable to the procurement of legal professional services of large companies with a central legal department in charge of managing the relations with different legal firms (legal services suppliers). The information presented was gathered in a large global manufacturing company with strong presence in Europe. The procurement of legal professional services throughout the entire organization was analyzed and validated by central legal department based in the headquarters. An innovative model for the procurement of the legal services has been proposed based on different findings in the current literature. Also, a model developed by Ronchi et al. was leveraged to quantitatively measure the benefits brought by the implementation of e-Procurement. The model was implemented in the organization with the help of central purchasing and legal departments. The results showed it is possible to standardize the operative procurement of legal professional services for end-users to perceive the same process as the one used for direct purchases of office supplies. In order to accomplish this, some roles and an important transformation within the organization must be carried out. A general model to implement a comprehensive procurement process leveraging e-Procurement is presented in this study. The conclusions are that the specialized procurement literature focuses very little on service procurement standardization and even less in legal professional services or process standardization through e-Procurement, and thus this study and the model introduced might work as a starting point for professional practitioners or academic researchers alike. Further research topics are suggested at the end of this study to continue research on this topic.

  • 1778.
    Ågren, Jonas
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    Sjöberg, Lars E.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    Errors in geoid and quasigeoid models as propagated from systematic uncertainties in the Digital Elevation Model2013Konferansepaper (Fagfellevurdert)
  • 1779.
    Ågren, Jonas
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering. Lantmäteriet, The Swedish Mapping, Cadastre and Registry Authority, Sweden .
    Sjöberg, Lars E.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    Investigation of gravity data requirements for a 5 mm-quasigeoid model over Sweden2014Inngår i: International Association of Geodesy Symposia, 2014, Vol. 141, s. 143-150Konferansepaper (Fagfellevurdert)
    Abstract [en]

    When GNSS height determination improves in the future, users will ask for increasingly better geoid models. It is not unlikely that a standard error of 5 mm will more or less be required in a couple of years. The main purpose of this paper is to investigate the gravity data requirements to compute a Swedish gravimetric quasigeoid model to that order. The propagation of errors in the terrestrial gravity observations and the Earth Gravitational Model (EGM) are studied using both variance-covariance analysis in the spectral domain and least squares collocation. These errors are also checked by computing a new gravimetric quasigeoid model and comparing it with GNSS/levelling height anomalies. It is concluded that it will be possible to compute a 5 mm model over Sweden in the case that the gravity data set is updated to fulfil the following requirements: the resolution should be at least 5 km and there should be no data gaps nearby. Finally, the standard errors of the uncorrelated and correlated gravity anomaly noises should be below 0.5 and 0.1 mGal, respectively.

  • 1780. Åhlund, J.
    et al.
    Nilson, K.
    Palmgren, Pål
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Göthelid, E.
    Schiessling, J.
    Göthelid, Mats
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Mårtensson, N.
    Puglia, C.
    STM investigation of FePc on InSb(001)c8x2Manuskript (Annet vitenskapelig)
  • 1781.
    Åkerlund, Elias
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Marbinah, Johan
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Undersökning av skillnader och likheter i användarvänlighetsproblem/styrkor för användargränssnitt av populära esporter inom populära genrer2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Det senaste decenniet har esporter växt förvånansvärt mycket i popularitet. Fenomenet esport har lett till utvecklingen av en hel uppsjö olika genrer, som alla har sina distinkta problem hos deras användarvänlighet i dess olika gränssnitt [22]. Den här studiens metod baseras på Nielsens tumregler för utvärdering av användarvänlighet i användargränssnitt, samt en kombination av både Turunen [5] och Quintans [2] uppsättning av frågor som även de är baserade på Nielsens tumregler, för att hitta vilka likheter och skillnader som finns i användarvänligheten hos tre olika spel som varje tillhör tre distinkta genrer, specifikt FPS (First Person Shooter), MOBA (Multiplayer Online Battle Arena) och RTS (Real-Time Strategy). De korresponderande spelen som undersöks är Counter Strike global offensive (CSGO), League of legends (LoL), respektive Starcraft II (SC2).

    Undersökningens resultat visar bland annat att SC2, spelet som representerar RTS, hade flest problem i användarvänligheten medan LoL och CSGO hade betydligt färre problem. HUD:en (Heads-Up Display) var gränssnittet som stod ut mest för SC2 eftersom det antog flest antal problem. Detta resultat kan anses som logiskt när man ser till spelets popularitet jämfört med de övriga två, då de andra är mycket populärare sett till antal visningstimmar. Dock är genrerna RTS och MOBA mycket lika i sin utformning och man hade därför kunnat förvänta sig att LoL och SC2 skulle haft ett flertal likheter, vilket de inte hade. Studien visar generellt sett på en mångfald i skillnader hos deras problem och även en mångfald i styrkor.

  • 1782. Åkerman, Jonas
    Potential för ny fordonsteknikoch förnybara drivmedel inomvägtransportsektorn2012Rapport (Annet (populærvitenskap, debatt, mm))
  • 1783.
    Åkerman, Jonas
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Höjer, Mattias
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Gunnarsson-Östling, Ulrika
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    En Stockholmsregion utan klimatpåverkan från transport- och bebyggelsesektorn 2050: framtidsbilder och strategier i närtid2018Rapport (Annet vitenskapelig)
  • 1784.
    ÖBERG, JENNY
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Industriell Management.
    STENLÖF, ELIN
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Industriell Management.
    What role to play in strategy implementation?: Constructive interplay between middle and frontline managers2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Purpose: The purpose of this research was to study the interplay between middle managers (MMs) and front-line managers (FLMs) in strategy implementation (SI). To successfully manage and run a complex technology corporation a well-performed strategy is essential. By comparing MMs’ and FLMs’ different views and responsibilities in the SI process, both theoretical and empirical. Methodology: Theoretical material regarding leadership, middle and front-line manager roles and responsibilities, as well the strategy implementation process, obstacles and success factors are compared in the study. Supplemented by a general pilot study and primary interviews covering their view of the SI-process, obstacles and leverages, leadership, and their roles description. In total, ten pilot interviews and 12 primary interviews have been conducted, with MMs and FLMs, equally represented. Findings: In large, the main findings regarding the creation of a dynamic interplay between MMs and FLMs were three identified key attributes. Firstly, success in the SI process and constructive dynamic require a clear distribution of tasks and responsibilities between MMs and FLMs or the key responsibilities in the process. Secondly, select key people for the SI process, picked from different levels in the organization with different viewpoint and expertise. Making sure that there are total transparency and knowledge sharing between all key members and organizational levels. This will enable a greater involvement and commitment in the SI-process. Finally, to create a successful SI-process and a dynamic interplay between MMs and FLMs, strategic work must be rewarded equally compared to operational excellence and product-development efforts.

  • 1785.
    Öhman, Oskar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    Creation of antimicrobial biomaterials by coupling spidersilk with enzymes using Sortase Amediated protein conjugation2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Förekomsten av antibiotikaresistentamikroorganismer ökar och har blivit ett av de största hoten mot global hälsa. På grund avdetta, så minskar effektivitet av antibiotika och därför har det blivit önskvärt att utveckla nyteknik för att kringgå eller minska användningen av antibiotika. Speciellt i operationer därimplantat och proteser inkorporeras i kroppen ärantibiotika viktigt för att förhindra infektioner. En alternativ strategi för att förhindraomfattande användning av antibiotika inom dettaområde är att skapa antimikrobiella ytor. I dennarapport skapades antimikrobiella ytor genom attkoppla antibakteriella och anti-biofilm enzymertill det rekombinanta spindelsilket 4RepCT. Deenzymer som kopplades var endolysinerna Sal-1och PlysS2, den katalytiska domänen hos Sal-1som kallas CHAP och Dispersin B. Kopplingenerhölls genom Sortase A-medieradproteinkonjugering och undersöktes med SDSPAGE-analys för kopplingsreaktion i lösningoch med Octet-analys för kopplingsreaktion med4RepCT i beläggningsformat. Vidareundersöktes den enzymatiska aktiviteten hos detenzymkopplade spindelsilket medturbiditetsreduktionsanalys (TRA), därminskningen i OD600 hos Staphylococcusaureus-bakterier mättes. För Sal-1 och DispersinB utfördes också aktivitetstest medsubstratadditionsanalys. Kopplingsreaktionen ilösning visade lyckad koppling för CHAP ochSal-1. Kopplingsreaktioner i lösning medDispersin B och PlySs2 indikerade inte tydligten lyckad koppling. Octet-analysen indikeradedock en lyckad koppling med alla enzymer.Enzymatisk aktivitet kunde demonstreras förSal-1-kopplad spindelsilke i TRA ochsubstratadditionsanalys med fluorescein-di-Dgalaktopyranosid(FDG). I TRA, visade sig Sal-1-kopplade spindelsilkbeläggningar, framställdagenom att använda 17,3 μM 4RepCT för attskapa beläggningen och 17,3 μM Sal-1 förkopplingsreaktionen (17,3 / 17,3-beläggning) attminska OD600 med 62% efter 100 minuter. FörSal-1-kopplade spindelsilkbeläggningar,framställda genom användning av 17,3 μM Sal-1och 4,3 μM 4RepCT (17,3 / 4,3-beläggning) varOD600-minskningen 48% efter 100 minuter.OD600-reduktionen av 17,3 / 17,3-beläggningaroch 17,3 / 4,3-beläggningar betraktades somjämförbara med 25 nM Sal-1 i lösningrespektive 12,5 nM Sal-1 i lösning.

  • 1786.
    Öhnander, Fred
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Fordonsdynamik.
    Höghastighetståg på rätt spår?: EN HISTORISK OCH TEKNISK ANALYS AV HÖGHASTIGHETSTÅG I VÄRLDEN2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Det finns en stor efterfrågan på ökad mobilitet och effektivitet för höghastighetståg i världen. Resenärer vill så snabbt och smidigt som möjligt anlända till sina destinationer. För att uppfylla dessa krav krävs en förbättring av restiderna mellan järnvägsstationer. Detta kan åtgärdas genom en ökning av hastigheter på höghastighetslinjer och mer specifikt behöver medelhastigheten mellan stationer ökas.

    Det är därför intressant att utforska hur denna utveckling av högre hastigheter har utvecklats ur ett historiskt perspektiv. Målsättningen är även att öka förståelsen för ett antal tekniska områden och innovationer som har inverkan på ett tågs medelhastighet. Rent konkret behandlas korglutning, aerodynamik och virvelströmsbroms, som alla har en viktig inverkan på medelhastigheten.

    Arbetet grundar sig främst på litteraturstudier av redan kända kunskaper ur ett teknikhänseende. Information om historisk utveckling i olika länder har erhållits främst från internetkällor och där förståelse för tekniska lösningar till höghastighetståg behövts har forskningsrapporter, artiklar och doktorsavhandlingar studerats.

    Användning av korglutningssystem är lämpligt för tåg som trafikerar äldre järnvägslinjer där många horisontalkurvor finns. Passiv korglutningsteknik fungerar effektivt vad gäller att reducera sidoaccelerationer. Dock försämras säkerheten eftersom tyngdpunkten för tåget förskjuts i sidled. Den aktiva korglutningstekniken kompenserar för sidoaccelerationen och tyngdpunkten förskjuts marginellt. En hastighetsökning på cirka 15% och en restidsvinst på cirka 10% erhålls för ett tåg med aktiv korglutningsteknik.

    Underliggande komponenter hos ett tåg har stor inverkan på det aerodynamiska motståndet om vagnskorgens motståndsarea är relativt stor. Tågets ytbeskaffenheter har stor inverkan på det aerodynamiska motståndet då vagnskorgens motståndsarea är relativt liten. Längden på en tågnos har liten inverkan på det aerodynamiska motståndet om ett längd/bredd-förhållande på minst 1,0 används. En lång och spetsig akter är optimal för att reducera motståndet.

    Virvelströmsbromsen är effektiv i höga hastigheter men bör kompletteras med andra bromssystem vid låg- och medelhöga hastigheter. Bromsen är slitagefri och oberoende av väderlek. På grund av stor värmeutveckling kan dock solkurvor uppkomma i spåren vid använding av bromsen.

  • 1787.
    Önsten, Anneli
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Materialfysik, MF.
    Surface Reactivity and Electronic Structure of Metal Oxides2011Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The foci of this thesis are the metal oxides Cu2O, ZnO and Fe3O4 and their interaction with water and sulfur dioxide (SO2). The intention is to study SO2-induced atmospheric corrosion on a molecular level. All studies are based on photoelectron spectroscopy (PES) and scanning tunneling microscopy (STM) measurements. The band structure of Cu2O in the Γ-M direction has been probed by angle-resolved PES (ARPES). It reveals a more detailed picture of the bulk band structure than earlier data and gives the first experimental evidence of a dispersive hybridized Cu 3d-Cu 4s state. The experimental data is compared to band structure calculations. The structure of clean metal oxide surfaces and impact of sample preparation have been studied. Oxygen vacancies can form a (√3x√3)R30° reconstruction on Cu2O(111). Oxygen atoms adjacent to copper vacancies, steps or kinks are shown to be adsorption sites for both water and SO2. Annealing temperature influences the defect density and hydrogen content in ZnO, which can have large impact on the surface properties of ZnO(0001). Water is shown to adsorb dissociatively on ZnO(0001) and partly dissociatively on Cu2O(111). The dissociation occurs at undercoordinated oxygen sites on both surfaces. Water stays adsorbed on ZnO(0001) at room temperature but on Cu2O(111), all water has desorbed at 210 K. SO2 interacts with one or two undercoordinated O-sites on all studied oxide surfaces forming SO3 or SO4 species respectively. SO4 on Fe3O4(100) follows the (√2x√2)R45° reconstruction. On Cu2O(111) and ZnO(0001), SO2 adsorbs on defect sites. An SO3 to SO4 transition is observed on Cu2O(111) when heating an SO3 adsorbate layer from 150 K to 280K. Coadsorption of water and SO2 on ZnO(0001) and Fe3O4(100) has been studied briefly. Water blocks SO2 adsorption sites on ZnO(0001). On Fe3O4(100) and on one type of reduced ZnO(0001) sample, SO2 dissociation to atomic sulfur or sulfide occurs to a higher extent on water exposed surfaces than on clean surfaces. Water thus appears to increase the charge density on some surfaces. Further studies are needed to reveal the cause of this unexpected effect.

  • 1788.
    Önsten, Anneli
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik.
    Månsson, Martin
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik.
    Claesson, Thomas
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik.
    Muro, Takayuki
    Japan Synchrotron Radiation Research Institute (JASRI).
    Matsushita, Tomohiro
    Japan Synchrotron Radiation Research Institute (JASRI).
    Nakamura, Tetsuya
    Japan Synchrotron Radiation Research Institute (JASRI).
    Kinoshita, Toyohiko
    Japan Synchrotron Radiation Research Institute (JASRI).
    Karlsson, Ulf O.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik.
    Tjernberg, Oscar
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik.
    Probing the valence band structure of Cu2O using high-energy angle-resolved photoelectron spectroscopy2007Inngår i: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 76, nr 11, s. 115127-1-115127-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present angle-resolved photoemission data along the M-Gamma-M direction from a Cu2O(111) single crystal, collected at high photon energies (h nu=619 and 891 eV) and T=100 K. Because of the high photon energies and effective background subtraction, our data give a clear picture of the bulk band structure. The results confirm the existence of a hybridized Cu 3d-Cu 4s state located between the two main Cu 3d and O 2p band regions. Several theoretical studies have predicted the existence of this band, but until now it has not been detected in any photoemission measurements. The experimentally derived band structure is compared to local density approximation calculations with and without the Hubbard potential U. The clear band dispersion in our experimental data has enabled us to extract a refined Hubbard U value, which makes it possible to achieve a better agreement between theoretically calculated bands and experimental data.

  • 1789.
    Örlü, Ramis
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Segalini, Antonio
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Klewicki, J.
    Alfredsson, P. Henrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    High-order generalisation of the diagnostic scaling for turbulent boundary layers2016Inngår i: Journal of turbulence, ISSN 1468-5248, E-ISSN 1468-5248, Vol. 17, nr 7, s. 664-677Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The diagnostic scaling concept, introduced for the streamwise turbulence intensity in wall-bounded turbulent flows (Alfredsson, Segalini and Örlü, Phys. Fluids 2011;23:041702), is here extended and generalised not only for the higher even-order central statistical moments, but also for the odd moments and thereby the probability density distribution of the streamwise velocity fluctuations. Turbulent boundary layer data up to a friction Reynolds number of 60,000 are employed and demonstrate the feasibility of the diagnostic scaling for the data throughout the logarithmic and wake regions. A comparison with the generalised logarithmic law for even-order moments by Meneveau and Marusic (J. Fluid Mech. 2013;719:R1) based on the attached-eddy hypothesis, is reported. The diagnostic plot provides an apparent Reynolds-number-independent scaling of the data, and is exploited to reveal the functional dependencies of the constants needed in the attached-eddy-based model. In particular, the invariance of the lowest order diagnostic scaling poses an intriguing incompatibility with the asymptotic constancy of the Townsend–Perry constant.

  • 1790. Östlund, Britt
    Granskningsrapport. En kartläggning om välfärdsteknik.2017Rapport (Annet vitenskapelig)
  • 1791.
    Östlund, Britt
    Lund Universitet.
    Hur kan teknik skapa möjligheter för äldre människor?2012Inngår i: E-hälsa. Innovationer, metoder, interventioner och perspektiv / [ed] Gard, Gunvor och mealnder Wikman Anita, Lund: Studentlitteratur AB, 2012, 1:1, s. 209-222Kapittel i bok, del av antologi (Fagfellevurdert)
  • 1792. Östlund, Britt
    et al.
    Karlsson, MariAnne
    Chalmers Institute of Technology.
    To follow the path of the user - discovering unintended consequences of everyday technology1999Rapport (Annet vitenskapelig)
  • 1793.
    Östlund, Stefan
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Vehicle performance and Technology1997Inngår i: Efficient Train Systems for Future Passenger Services / [ed] Bo Lennart Nelldal, KTH Royal Institute of Technology, 1997, s. 79-99Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 1794.
    Östlund, Stefan
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Lilliesköld, Joakim
    KTH, Skolan för elektro- och systemteknik (EES), Industriella informations- och styrsystem.
    Assessing project courses with several teachers involved2007Inngår i: Proceedings of the 3rd annual CDIO conference, 2007Konferansepaper (Fagfellevurdert)
  • 1795.
    Öun, Maria
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Affärsutveckling och Entreprenörskap.
    Pettersson, Ida
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Affärsutveckling och Entreprenörskap.
    Critical Factors for Successful Strategy Formation in Venture Capital Funded Companies: A study made for SEB Venture Capital2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
33343536 1751 - 1795 of 1795
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