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  • 101. Castillo, Patricia
    et al.
    San-Roman, Ebert
    Bengtsson, Olof
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    On the design of a planar, harmonic, triplex-filter for 3G, load-pull measurement applications2007Inngår i: RFMTC-07, 2007Konferansepaper (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    This paper describes the design of a planar harmonic triplex-filter for 3G load-pull measurement applications. The designs are based on planar 2D field simulations on individual and combined filters of different structures like stepped impedance, coupled lines and ring resonators. Triplex-filters of different combinations on Teflon substrate and mixed substrates for loss reduction were simulated, fabricated and evaluated in this work. It is found that using lithographic process on Teflon with SMA endlaunchers a filter with 0.44 dB f0 insertion loss, IL, and 50 dB isolation can be achieved. On the low loss substrate the mechanical design process limits the results to about 1.0 dB IL. Low loss launchers and substrate interconnects are suggested and 3D simulations performed for the mixed design.

  • 102.
    Cebollada Alvarez, Virginia
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap.
    Evaluation of the performance of optimizerbased PV systems under shading conditions2019Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [en]

    Total or partial shading conditions have a detrimental impact in the output energy ofphotovoltaic (PV) systems and in the semiconductor materials PV technologies are made of.Residential PV installations are very likely to be exposed to shade projected by nearbyobjects such as buildings or neighboring trees. The electrical configuration of PV systems iscrucial to mitigate the shading effect, as it is the use of power optimizers. This study assessesthe shading impact on two different types of residential PV systems to verify gains associatedwith SolarEdge optimizers and support product marketing. It aspires to help PV ownersselect power inverters that maximize the annual energy produced. Experiments have beenperformed simulating snow coverage and tree shading on a string-based system (Fronius)and an optimizer-based system (SolarEdge). Findings demonstrated the decrease in lossesfrom partial shading conditions with power optimizers. SolarEdge optimizers reduceshading power losses from 50% to 29% in comparison to a standard string system whensimulated snow coverage is applied. Results also showed that SolarEdge system decreasedtree shading losses from 17% to 13% in comparison to string-based system.

  • 103.
    Chang, Keke
    et al.
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Chen, Ruipeng
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Wang, Shun
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Li, Jianwei
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Hu, Xinran
    School of Human Nutrition and Dietetics, McGill University, Canada..
    Liang, Hao
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Cao, Baiqiong
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Sun, Xiaohui
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Ma, Liuzheng
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Zhu, Juanhua
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Jiang, Min
    College of life sciences, Henan Agricultural University, Zhengzhou, China.
    Hu, Jiandong
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China; State key laboratory of wheat and maize crop science, Zhengzhou, China.
    Considerations on Circuit Design and Data Acquisition of a Portable Surface Plasmon Resonance Biosensing System2015Inngår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 15, nr 8, s. 20511-20523Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this study was to develop a circuit for an inexpensive portable biosensing system based on surface plasmon resonance spectroscopy. This portable biosensing system designed for field use is characterized by a special structure which consists of a microfluidic cell incorporating a right angle prism functionalized with a biomolecular identification membrane, a laser line generator and a data acquisition circuit board. The data structure, data memory capacity and a line charge-coupled device (CCD) array with a driving circuit for collecting the photoelectric signals are intensively focused on and the high performance analog-to-digital (A/D) converter is comprehensively evaluated. The interface circuit and the photoelectric signal amplifier circuit are first studied to obtain the weak signals from the line CCD array in this experiment. Quantitative measurements for validating the sensitivity of the biosensing system were implemented using ethanol solutions of various concentrations indicated by volume fractions of 5%, 8%, 15%, 20%, 25%, and 30%, respectively, without a biomembrane immobilized on the surface of the SPR sensor. The experiments demonstrated that it is possible to detect a change in the refractive index of an ethanol solution with a sensitivity of 4.99838 × 10(5) ΔRU/RI in terms of the changes in delta response unit with refractive index using this SPR biosensing system, whereby the theoretical limit of detection of 3.3537 × 10(-5) refractive index unit (RIU) and a high linearity at the correlation coefficient of 0.98065. The results obtained from a series of tests confirmed the practicality of this cost-effective portable SPR biosensing system.

  • 104.
    Chani Cahuana, Jessica Adaid
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Pulse Modulated Transmitter Architectures: Carrier Bursting2012Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
  • 105. Chen, R.
    et al.
    Wang, M.
    Wang, S.
    Liang, Hao
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Hu, X.
    Sun, X.
    Zhu, J.
    Ma, L.
    Jiang, M.
    Hu, J.
    Li, J.
    A low cost surface plasmon resonance biosensor using a laser line generator2015Inngår i: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 349, s. 83-88Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Due to the instrument designed by using a common surface plasmon resonance biosensor is extremely expensive, we established a portable and cost-effective surface plasmon resonance biosensing system. It is mainly composed of laser line generator, P-polarizer, customized prism, microfluidic cell, and line Charge Coupled Device (CCD) array. Microprocessor PIC24FJ128GA006 with embedded A/D converter, communication interface circuit and photoelectric signal amplifier circuit are used to obtain the weak signals from the biosensing system. Moreover, the line CCD module is checked and optimized on the number of pixels, pixels dimension, output amplifier and the timing diagram. The micro-flow cell is made of stainless steel with a high thermal conductivity, and the microprocessor based Proportional-Integral-Derivative (PID) temperature-controlled algorithm was designed to keep the constant temperature (25 °C) of the sample solutions. Correspondingly, the data algorithms designed especially to this biosensing system including amplitude-limiting filtering algorithm, data normalization and curve plotting were programmed efficiently. To validate the performance of the biosensor, ethanol solution samples at the concentrations of 5%, 7.5%, 10%, 12.5% and 15% in volumetric fractions were used, respectively. The fitting equation ΔRU=-752987.265+570237.348×RI with the R-Square of 0.97344 was established by delta response units (ΔRUs) to refractive indexes (RI). The maximum relative standard deviation (RSD) of 4.8% was obtained. 

  • 106.
    Cheng, Yuelong
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Ma, Xiaoying
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Cyclic Redundancy Check for Zigbee-Based Meeting Attendance Registration System2012Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The research accomplished in this dissertation is focused on the design of effective solutions to the problem that error codes occur in the ZigBee-based meeting attendance registration system. In this work, several different check algorithms are compared, and the powerful error-detecting Cyclic Redundancy Check (CRC) algorithm is studied. In view of the features of the meeting attendance registration system, we implement the check module of CRC-8. This work also considers the data reliability. We assume use retransmission mechanism to ensure the validity and completeness of transmission data. Finally, the potential technical improvement and future work are presented.

  • 107.
    Chilo, José
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Feature Extraction for Low-Frequency Signal Classification2008Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The development of the International Monitoring System (IMS) for the verification of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has led to a rapid revival of interest in infrasound. Furthermore, the installation of low-frequency sensors at seismic sites has increased in recent years, providing researchers with large and heterogeneous data-sets in near real-time. New techniques are needed to better process all of this data and to extract meaningful information quickly for various applications. In particular, there is a need to find distinct features in the infrasonic signals that allow one to distinguish low level nuclear tests from seismic events.

    In this thesis three methods for feature extraction from infrasound and other types of low frequency signal data are discussed: (1) discrete wavelets transforms (DWTs); (2) time scale spectra (TSSs) using continuous wavelet transforms (CWTs); and (3) empirical mode decomposition (EMD). The dimensionality of the feature space can range from a few to thousands. For processing high-dimensional data we use multi-modal data space to find low-dimensional structures. The advantage of this space is that multiple metrics of similarity are converted into one single Euclidean space.

    The overall goal of our research is a system for automatic identification and classification of low-frequency signals in real-time that is easy to implement in hardware. In this thesis we present our design and implementation of the discrete wavelet transform (DWT) on FPGAs for processing a continuous flow of data to obtain optimal extraction of feature information. FPGA simulation and implementation has been realized by using the polyphase structure, the filter reuse method and techniques such as pipelining and basic operations on the QUARTUS II platform. VHDL has been used to describe the functionality of the discrete wavelet transform and ModelSim has been used for the functional verification.

    Advancements in electronics provide a vital new option for implementation of low-frequency smart sensors that can perform signal processing close to the sensors and transmit the data wirelessly. These smart sensors can improve the efficiency of an automatic classification system and reduce the cost of actual infrasound microphones. The design of a digital wireless data acquisition system using a QF4512 programmable signal converter from Quickfilter Technologies, a MSP430 microcontroller from Texas Instruments and a F2M03GLA Bluetooth module from Free2move for infrasonic records is also presented in this thesis. The digital wireless data acquisition system has passed extensive laboratory and field tests (e.g. with man-made explosions).

    A study of using a miniature 3-axis fluxgate magnetometer to get fingerprints from ferrous objects is also presented in this thesis. In this experiment, distinguishing features of iron samples of four different shapes were determined using wavelet methods. Systematic differences were observed between the signatures of the four shaped iron samples.

  • 108.
    Chilo, José
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Filtering extracting features from infrasound data2006Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

     

    The goal of the research presented in this thesis is to extract features, to filter and get fingerprints from signals detected by infrasound, seismic and magnetic sensors. If this can be achieved in a real time system, then signals from various events can be detected and identified in an otherwise torrent data.

    Several approaches have been analyzed. Wavelet transform methods are used together with ampligram and time scale spectrum to analyze infrasound, seismic and magnetic data. The energy distribution in the frequency domain may be seen in wavelet scalograms. A scalogram displays the wavelet coefficients as a function of the time scale and of the elapsed time. The ampligram is a useful method of presentation of the physical properties of the time series. The ampligram demonstrate the amplitude and phase of components of the signal corresponding to different spectral densities. The ampligram may be considered as an analogy to signal decomposition into Fourier components. In that case different components correspond to different frequencies. In the present case different components correspond to different wavelet coefficient magnitudes, being equivalent to spectral densities. The time scale spectrum is a forward wavelet transform of each row (wavelet coefficient magnitude) in the ampligram. The time scale spectrum reveals individual signal components and indicates the statistical properties of each component: deterministic or stochastic.

    Next step is to distinguish between different sources of infrasound on-line. This will require signal classification after detection is made. The implementation of wavelet – neural network in hardware may be a first choice. In this work the Independent Component Analysis is presented to improve the quality of the infrasonic signals by removing background noise before the hardware classification. The implementation of the discrete wavelet transform in a Field Programmable Gate Array (FPGA) is also included in this thesis using Xilinx System Generator and Simulink software.

    A study of using infrasound recordings together with a miniature 3-axis fluxgate magnetometer to find meteorites as soon as possible after hitting the earth is also presented in this work.

  • 109.
    Chilo, José
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Low-Frequency Signal Classification: Filtering and extracting features from infrasound data2008Bok (Annet vitenskapelig)
  • 110.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Horvath, György
    Lindblad, Thomas
    Olsson, Roland
    A Flexible Electronic Nose for Odor Discrimination Using Different Methods of Classification2009Inngår i: IEEE NPSS Real Time Conference 2009, New York: IEEE , 2009, s. 317-320Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Ovarian cancer is one of the leading causes of death front cancer in women. The lifetime risk is around 1.5%, which makes it the second most common gynecologic malignancy (the first one being breast cancer). To have a definitive diagnose, a surgical procedure is generally required and suspicious areas (samples) will be removed and sent for microscopic and other analysis. This paper describes the result of a pilot study in which an electronic nose is used to "smell" the aforementioned samples, analyze the multi-sensor signals and have a close to real-time answer on the detection of cancer. Besides being, fast. the detection method is inexpensive and simple. Experimental analysis using real ovarian carcinoma samples shows that the use of proper algorithms for analysis of the multi-sensor data front the electronic nose yielded surprisingly good results with more than 77% classification rate. The electronic nose used in this pilot study was originally developed to be used as a "bomb dog" and can distinguish between e.g. TNT. Dynamex. Prillit. However, it was constructed to be a flexible multi-sensor device and the individual (16) sensors call easily be replaced/exchanged. This is suggestive for further investigations to obtain even better results with new, specific sensors. In another pilot experiment, headspace of an ovarian carcinoma sample and a control sample were analyzed using gas chromatography-mass spectrometry. Significant differences in chemical composition and compound levels were recorded, which would explain the different response obtained with the electronic nose.

  • 111.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Horvath, György
    Department of Oncology, Sahlgrenska University Hosp. Gothenburg.
    Lindblad, Thomas
    Department of Physics, Royal Institute of Technology.
    Olsson, Roland
    Department of Computer Science, Ostfold University College, N-1757 Halden, Norway.
    Electronic Nose Ovarian Carcinoma Diagnosis Based on Machine Learning2009Inngår i: Advances in Data Mining: Applications and Theoretical Aspects, Berlin: Springer Berlin / Heidelberg , 2009, s. 13-23Kapittel i bok, del av antologi (Fagfellevurdert)
  • 112.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Jabor, Abbas
    Liszka, L.
    Eide, Å.J.
    Lindblad, T.
    Bergkvist, L.P.
    Stahlsten, T.
    Andersson, B.L.
    Karasalo, I.
    Cederholm, A.
    Filtering and extracting features from infrasound data2005Inngår i: Real Time Conference, 2005, 2005, s. 451-455Konferansepaper (Fagfellevurdert)
  • 113.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Jabor, Abbas
    Liszka, L.
    Ejde, Å.J.
    Lindblad, Th.
    Persson, L.
    Infrasonic and Seismic Signals from Earthquake and Explosions in Arequipa, Perú2006Inngår i: Western Pacific Geophysics Meeting., 2006Konferansepaper (Annet vitenskapelig)
  • 114.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Jabor, Abbas
    Royal Institute of Technology, Department of Physics, Stockholm, Sweden.
    Lizska, Ludwik
    Swedish Institute of Space Physics in Umeå, Sweden.
    Eide, Åge J.
    Ostfold University College, Halden, Norway.
    Lindblad, Thomas
    Royal Institute of Technology, Department of Physics, Stockholm, Sweden.
    Obtaining “images” from iron objects using a 3-axis fluxgate magnetometer2007Inngår i: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 580, nr 2, s. 1105-1109Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Magnetic objects can cause local variations in the Earth's magnetic field that can be measured with a magnetometer. Here we used tri-axial magnetometer measurements and an analysis method employing wavelet techniques to determine the "signature" or "fingerprint" of different iron objects. Clear distinctions among the iron samples were observed. The time-dependent changes in the frequency powers were extracted by use of the Morlet wavelet corresponding to frequency bands from 0.1 to 100 Hz.

  • 115.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Karlsson, Carl
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Ängskog, Per
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Elofsson, Carl
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Stenumgaard, Peter
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Characterizing electromagnetic interference in vicinity to a railway freight train2009Inngår i: Proc. IEEE Int. Symp. on EMC/EMECO, Saint-Petersburg, 2009, s. 23-26Konferansepaper (Fagfellevurdert)
  • 116.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Karlsson, Carl
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Ängskog, Per
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Stenumgaard, Peter
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    APD measurements for characterization and evaluation of radio interference in steel mill2009Inngår i: Proceedings IEEE nternational Symposiumon EMC, Kyoto, 2009, s. 625-628Konferansepaper (Fagfellevurdert)
  • 117.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Karlsson, Carl
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Ängskog, Per
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Stenumgaard, Peter
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    EMI disruptive effect on wireless industrial communication systems in a paper plant2009Inngår i: Proc. IEEE EMC Symp. Austin-Texas, 2009, s. 221-224Konferansepaper (Fagfellevurdert)
    Abstract [en]

    It is well known that industrial and factory environments present considerable challenges for wireless communications. Because every industrial environment is different, and may offer a unique set of obstacles to effective wireless communication, a site characterization is needed at first step in determining improvements of existent wireless technologies to increase the reliability. In this work electric field strength and APD measurements have been performed to characterize electromagnetic interference in an industrial paper plant. Common characteristics of the industrial environments affecting wireless communication were identified. Additionally, results show high interference levels at the frequencies for the DECT band 1880-1890 MHz. The interference level is correlated to the working mode of the electrical engines used in the process.

  • 118.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Karlsson, Carl
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Ängskog, Per
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Stenumgaard, Peter
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Impulsive noise measurement methodologies for APD determination in M2M environments2009Inngår i: Proc. IEEE EMC Symp. Austin-Texas, 2009, s. 151-154Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Wireless communications in industrial environments are maintained under persistent adverse conditions, such as noise, fading and many electromagnetic interference sources. These electromagnetic interferences exhibit usually impulsive characteristics and it can seriously degrade the performance of the current wireless systems. Over the last few years, the amplitude probability distribution (APD) had been formally written into CISPR16 as a measure of the emitted electromagnetic energy from electrical equipment. In this approach we present two APD measurement methods. The first method based on 12-bit A/D converter and the second one based on in-phase and quadrature components of the impulsive noise at frequencies between 20 and 3000 MHz. Electromagnetic interference measurements in three different industrial environments were performed using the developed methods with promising results.

  • 119.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Kinser, Jason
    Lindblad, Thomas
    Discrimination of Nuclear Explosions Sites by Seismic Signals using Intrinsic Mode Functions and Multi-Modal Data Space2008Inngår i: IEEE International Geoscience and Remote Sensing Symposium, 2008, s. 895-898Konferansepaper (Fagfellevurdert)
  • 120.
    Chilo, José
    et al.
    Royal Institute of Technology, Stockholm, Sweden.
    Lindblad, Thomas
    Royal Institute of Technology, Stockholm, Sweden.
    A Low Cost Digital Data Acquisition System for Infrasonic Records2007Inngår i: 4th IEEE Workshop on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications, Piscataway, NJ: IEEE , 2007, s. 35-37Konferansepaper (Annet (populærvitenskap, debatt, mm))
  • 121.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Lindblad, Thomas
    Data Acquisition and Digital Filtering for Infrasonic Records on Active Volcanoes2007Inngår i: Sensors & transducers, ISSN 1726-5479, Vol. 77, nr 3, s. 1058-1064Artikkel i tidsskrift (Fagfellevurdert)
  • 122.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Lindblad, Thomas
    Obtaining images from iron objects using a 3-axis fluxgate magnetometer2006Inngår i: International Conference on Imaging Techniques in Subatomic Physics, Astrophysics, Medicine, Biology and Industry, 2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Magnetic objects can cause local variations in the Earth's magnetic field that can be measured with a magnetometer. Here we used triaxial magnetometer measurements and an analysis method employing wavelet techniques to determine the "signature" or "fingerprint" of different iron objects. Clear distinctions among the iron samples were observed. The time-dependent changes in the frequency powers were extracted by use of the Morlet wavelet corresponding to frequency bands from 0.1 to 100 Hz. (c) 2007 Elsevier B.V. All rights reserved.

  • 123.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik. Royal Institute of Technology, Stockholm, Sweden.
    Lindblad, Thomas
    Royal Institute of Technology, Stockholm, Sweden.
    Real-Time Signal Processing of Infrasound Data Using 1D Wavelet Transform on FPGA Device2007Inngår i: 2007 15TH IEEE-NPSS REAL-TIME CONFERENCE, VOLS 1 AND 2, Piscataway, NJ: IEEE , 2007, s. 170-174Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Infrasound is a low frequency acoustic phenomenon typically in the frequency range 0.01 to 20 Hz. Data collected from infrasound microphones are presented online by the infrasound monitoring system operating in Northern Europe, Swedish-Finnish Infrasound Network (SFIN). Processing the continuous flow of data to extract optimal feature information is important. Using wavelet decomposition as a tool for removing noise from the real-time signals is an alternative. The purpose of this paper is to present the design and FPGA implementation of Discrete Wavelet Transform (DWT) for real-time infrasound data processing, in which only two FIR filters, a high-pass and a low-pass filter, are used. With the filter reuse method and techniques such as pipeline, basic operations, by the VHDL on the platform QUARTUS II, FPGA simulation and implementation are fulfilled. This implementation takes advantage from the low sampling rate used by the infrasound monitoring system that is only 18 Hz.

  • 124.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Lindblad, Thomas
    Wireless Data Acquisition System Using Bluetooth Technology for Infrasonic Records2008Inngår i: International Scientific Journal of Computing, ISSN 1727-6209, Vol. 7, nr 2, s. 18-21Artikkel i tidsskrift (Fagfellevurdert)
  • 125.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Lindblad, Thomas
    Olsson, Roland
    Hansen, Stig-Erland
    Comparison of three feature extraction techniques to distinguish between different infrasound signals2007Inngår i: Progress in pattern recognition, London: Springer , 2007, s. 75-82Kapittel i bok, del av antologi (Annet (populærvitenskap, debatt, mm))
  • 126.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Olsson, Roland
    Hansen, Stig-Erland
    Lindblad, Thomas
    Classification of Infrasound Events with Various Machine Learning Techniques2007Inngår i: CITSA 2007 / CCCT 2007: The 4th International Conference on Cybernetics and Information Technologies, Systems and Applications jointly with The 5th International Conference on Computing, Communications and Control Technologies, 2007, s. Vol. II, 191-195Konferansepaper (Fagfellevurdert)
  • 127.
    Chilo, José
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Pelegri-Sebastia, José
    Universitat Politècnica de València, Valencia, Spain.
    Cupane, Maria
    University of Palermo, Palermo, Italy.
    Sogorb, Tomas
    Universitat Politècnica de València, Valencia, Spain.
    E-nose application to food industry production2016Inngår i: IEEE Instrumentation & Measurement Magazine, ISSN 1094-6969, E-ISSN 1941-0123, Vol. 19, nr 1, s. 27-33Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Food companies worldwide must constantly engage in product development to stay competitive, cover existing markets, explore new markets, and meet key consumer requirements. This ongoing development places high demands on achieving quality at all levels, particularly in terms of food safety, integrity, quality, nutrition, and other health effects. Food product research is required to convert the initial product idea into a formulation for upscaling production with ensured significant results. Sensory evaluation is an effective component of the whole process. It is especially important in the last step in the development of new products to ensure product acceptance. In that stage, measurements of product aroma play an important role in ensuring that consumer expectations are satisfied. To this end, the electronic nose (e-nose) can be a useful tool to achieve this purpose. The e-nose is a combination of various sensors used to detect gases by generating signals for an analysis system. Our research group has investigated the scent factor in some foodstuff and attempted to develop e-noses based on low-cost technology and compact size. In this paper, we present a summary of our research to date on applications of the e-nose in the food industry.

  • 128.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Schluter, Andreas
    KTH.
    Lindblad, Thomas
    KTH.
    Development of a high-resolution wireless sensor network for monitoring volcanic activity2009Inngår i: Geoscience and Remote Sensing / [ed] Pei-Gee Peter Ho, InTech , 2009, s. 53-74Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 129.
    Chilo, José
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Stenumgaard, Peter
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Amplitude Probability Distribution Measurement in Industrial Environments2010Inngår i: IEEE International Symposium on Electromagnetic Compatibility: Workshop & Tutorial Notes, 2010, s. 642-645Konferansepaper (Annet vitenskapelig)
  • 130.
    Chilo, José
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Stenumgaard, Peter
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Vulnerability of Radio Technologies Used in Wireless Industry Automation2010Inngår i: Proceedings of Gigahertz 2010, Lund / [ed] Henrik Sjöland, 2010Konferansepaper (Fagfellevurdert)
  • 131.
    Chilo, José
    et al.
    Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Thomas, Lindblad
    Hardware implementation of 1D wavelet transform on an FPGA for infrasound signal classification2008Inngår i: IEEE Transactions on Nuclear Science, ISSN 0018-9499, E-ISSN 1558-1578, Vol. 55, nr 1, part 1, s. 9-13Artikkel i tidsskrift (Fagfellevurdert)
  • 132.
    Chistiakova, Tatiana
    et al.
    Uppsala university, Uppsala, Sweden.
    Mattsson, Per
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Carlsson, Bengt
    Uppsala university, Uppsala, Sweden.
    Wigren, Torbjörn
    Ericsson.
    Nonlinear system identification of the dissolved oxygen to effluent ammonia dynamics in an activated sludge process2017Inngår i: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, nr 1, s. 3917-3922Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aeration of biological reactors in wastewater treatment plants is important to obtain a high removal of soluble organic matter as well as for nitrification but requires a significant use of energy. It is hence of importance to control the aeration rate, for example, by ammonium feedback control. The goal of this paper is to model the dynamics from the set point of an existing dissolved oxygen controller to effluent ammonia using two types of system identification methods for a Hammerstein model, including a newly developed recursive variant. The models are estimated and evaluated using noise corrupted data from a complex mechanistic model (Activated Sludge Model no.1). The performance of the estimated nonlinear models are compared with an estimated linear model and it is shown that the nonlinear models give a significantly better fit to the data. The resulting models may be used for adaptive control (using the recursive Hammerstein variant), gain-scheduling control, L2 stability analysis, and model based fault detection.

  • 133.
    Choudhary, Vipin
    et al.
    Department of Electronics and Communication, ASET, Amity University Uttar Pradesh, Noida, India .
    Gupta, Aastha
    Department of Electronics and Communication, ASET, Amity University Uttar Pradesh, Noida, India .
    Tripathy, Malay Ranjan
    Department of Electronics and Communication, ASET, Amity University Uttar Pradesh, Noida, India .
    Rönnow, Daniel
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    A compact multi-band slotted circular patch MIMO antenna with defective ground surface for wireless application2017Inngår i: 2017 4th International Conference on Signal Processing and Integrated Networks (SPIN), IEEE conference proceedings, 2017, s. 33-37, artikkel-id 8049911Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A compact multi band slotted two elements MIMO antenna is designed on FR4 substrate with the dimensions 60×60×1.5 mm3 and an εr of 4.4. To achieve high isolation between the radiation elements, a Defected Ground Surface (DGS) technique is applied. The isolation between the elements and gain both increased considerably. In the simulated and measured return loss vs frequency results, multi bands are obtained. The maximum isolation is obtained as -36.32 dB at 8.8 GHz in the measured results.

  • 134.
    Choudhary, Vipin
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektroteknik, matematik och naturvetenskap, Elektronik. KTH.
    Rönnow, Daniel
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektroteknik, matematik och naturvetenskap, Elektronik.
    Jansson, Magnus
    KTH.
    A Singular Value Decomposition Based Approach for Classifying Concealed Objects in Short Range Polarimetric Radar Imaging2019Inngår i: 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring), 2019, s. 4109-4115, artikkel-id 9017334Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In current research one of the main challenges in short range synthetic aperture radar (SAR) is electrically small structures and objects, which tend to unclear reinforced or through the wall objects, object orientation angle, and obscure contribution to extract the position of concealed multiple small objects. In this paper, ultra-wide-band (UWB) polarimetric radar was used to study reinforced objects and for estimation of object angle at short range. Electrically small 1D periodic mesh, 2D periodic meshes and differently oriented small objects or meshes could not be distinguished in conventional SAR images. A radar system with transmit and receive antennae mounted on a two dimensional scanning grid was used. The aim is non-destructive testing of built structures, in concrete slab manufacturing and for use in the renovation process. UWB short range radar data and images corresponding to different polarization states were analysed by using singular value decomposition (SVD). To perform decomposition, the proposed approach applies SVD to image data matrices produced from the back projection algorithm (BPA) to classify the different objects and identify the object angle. Then, sets of singular-components of different polarization states are analysed to classify objects. Also, the BPA algorithm is performed to construct the object images from the polarimetric radar signals. The object reflection varied with the polarimetric state of the UWB radar, which contributes to different object signatures (i.e., object intensity) since the object signature depends on the orientation, the size, and the number of objects. Object orientation with respect to the radar system and object anisotropy could be determined from the ratio of the different polarimetric singular-components. This proposed complex data analysis method demonstrates the usefulness of the SVD using BPA in extracting more information about and for classifying an object.

  • 135.
    Christensen, Simon
    et al.
    Aalborg University, Aalborg, Denmark.
    Bai, Shaoping
    Aalborg University, Aalborg, Denmark.
    Rafique, Sajid
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektroteknik, matematik och naturvetenskap, Elektronik.
    Isaksson, Magnus
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektroteknik, matematik och naturvetenskap, Elektronik.
    O'Sullivan, Leonard
    University of Limrick, Limerick, Ireland.
    Power, Valerie
    University of Limrick, Limerick, Ireland.
    Virk, Gurvinder Singh
    Innovative Technology and Science Limited, Cambridge, United Kingdom.
    AXO-SUIT: A Modular Full-Body Exoskeleton for Physical Assistance2019Inngår i: Mechanism Design for Robotics: Proceedings of the 4th IFToMM Symposium on Mechanism Design for Robotics / [ed] Alessandro Gasparetto and Marco Ceccarelli, Cham: Springer Netherlands, 2019, Vol. 66, s. 443-450Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    This paper presents the design of a modular full-body assistive exoskeleton (FB-AXO) for older adults which was developed with funding under the AAL funded AXO-SUIT project. Processes used to formulate a prioritized set of functional and design requirements via close-end-user involvement are outlined and used in realizing the exoskeleton. Design of the resulting mechanics and electronics details for the lower and upper-body subsystems (LB-AXO and (UB-AXO)) are described. Innovative designs of shoulder and spine mechanisms are presented. TheFB-AXO system comprises 27 degrees of freedom, of which 17 are passive and 10 active. The exoskeleton assists full-body motions such as walking, standing, bending, as well as performing lifting and carrying tasks to assist older users performing tasks of daily living.

  • 136.
    Climent, Enric
    et al.
    Sensors and Magnetism Group, Institut de Recerca per a la Gestió Integrada de Zones Costaneres, Campus de Gandia, Universitat Politècnica de València, Grao de Gandia, Spain.
    Pelegri-Sebastia, Jose
    Sensors and Magnetism Group, Institut de Recerca per a la Gestió Integrada de Zones Costaneres, Campus de Gandia, Universitat Politècnica de València, Grao de Gandia, Spain.
    Sogorb, Tomas
    Sensors and Magnetism Group, Institut de Recerca per a la Gestió Integrada de Zones Costaneres, Campus de Gandia, Universitat Politècnica de València, Grao de Gandia, Spain.
    Talens, J. B.
    Sensors and Magnetism Group, Institut de Recerca per a la Gestió Integrada de Zones Costaneres, Campus de Gandia, Universitat Politècnica de València, Grao de Gandia, Spain.
    Chilo, Jose
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Development of the MOOSY4 eNose IoT for Sulphur-Based VOC Water Pollution Detection2017Inngår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 17, nr 8, artikkel-id E1917Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, we describe a new low-cost and portable electronic nose instrument, the Multisensory Odor Olfactory System MOOSY4. This prototype is based on only four metal oxide semiconductor (MOS) gas sensors suitable for IoT technology. The system architecture consists of four stages: data acquisition, data storage, data processing, and user interfacing. The designed eNose was tested with experiment for detection of volatile components in water pollution, as a dimethyl disulphide or dimethyl diselenide or sulphur. Therefore, the results provide evidence that odor information can be recognized with around 86% efficiency, detecting smells unwanted in the water and improving the quality control in bottled water factories.

  • 137.
    Condo Neira, Edith Graciela
    Högskolan i Gävle, Institutionen för teknik och byggd miljö.
    Multidimensional Measurements on RF Power Amplifiers2008Independent thesis Advanced level (degree of Magister), 20 poäng / 30 hpOppgave
    Abstract [en]

    Measurements are important to specify and verify properties for components, modules and systems. The specifications for a certain figure of merit are usually given in a numerical value or a two dimensional plot. However, there are some devices, like power amplifiers with certain figure of merits that depends on two or more working conditions, requiring a three dimensional plot.

    This thesis presents a measurement method including graphical user interface of three parameters gain, efficiency and distortion when two-tone or WCDMA signals are used as an input to the PA.

  • 138.
    Condori-Arapa, Cristina
    Högskolan i Gävle, Akademin för teknik och miljö. Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Antenna elements matching: time-domain analysis2010Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Time domain analysis in vector network analyzers (VNAs) is a method to represent the frequency response, stated by the S-parameters, in time domain with apparent high resolution. Among other utilities time domain option from Agilent allows to measure microwave devices into a specific frequency range and down till DC as well with the two time domain mode: band-pass and low-pass mode. A special feature named gating is of important as it allows representing a portion of the time domain representation in frequency domain.

     

    This thesis studies the time domain option 010 from Agilent; its uncertainties and sensitivity. The task is to find the best method to measure the antenna element matching taking care to reduce the influence of measurement errors on the results.

     

    The Agilent 8753ES is the instrument used in the thesis. A specific matching problem in the antenna electric down-tilt (AEDT) previously designed by Powerwave Technologies is the task to be solved. This is because it can not be measured directly with 2-port VNAs. It requires adapters, extra coaxial cables and N-connectors, all of which influences the accuracy. The AEDT connects to the array antenna through cable-board-connectors (CBCs). The AEDT and the CBCs were designed before being put into the antenna-system. Their S-parameters do not coincide with the ones measured after these devices were put in the antenna block.

     

    Time domain gating and de-embedding algorithms are two methods proposed in this thesis to measure the S-parameters of the desired antenna element while reducing the influence of measurement errors due to cables CBCs and other connectors. The aim is to find a method which causes less error and gives high confidence measurements.

     

    For the time domain analysis, reverse engineering of the time domain option used in the Agilent VNA 8753ES is implemented in a PC for full control of the process. The results using time-domain are not sufficiently reliable to be used due to the multiple approximations done in the design. The methodology that Agilent uses to compensate the gating effects is not reliable when the gate is not centered on the analyzed response. Big errors are considered due to truncation and masking effects in the frequency response.

     

    The de-embedding method using LRL is implemented in the AEDT measurements, taking away the influences of the CBCs, coaxial cables and N-connector. It is found to have sufficient performance, comparable to the mathematical model. Error analysis of both methods has been done to explaine the different in measurements and design.

  • 139.
    cui, qiaofeng
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Suppression of impulsive noise in wireless communication2014Independent thesis Advanced level (degree of Master (Two Years)), 80 poäng / 120 hpOppgave
    Abstract [en]

    This report intends to verify the possibility that the FastICA algorithm could be applied to the GPS system to eliminate the impulsive noise from the receiver end. As the impulsive noise is so unpredictable in its pattern and of great energy level to swallow the signal we need, traditional signal selection methods exhibit no much use in dealing with this problem. Blind Source Separation seems to be a good way to solve this, but most of the other BSS algorithms beside FastICA showed more or less degrees of dependency on the pattern of the noise. In this thesis, the basic mathematic modelling of this advanced algorithm, along with the principles of the commonly used fast independent component analysis (fastICA) based on fixed-point algorithm are discussed. To verify that this method is useful under industrial use environment to remove the impulsive noises from digital BPSK modulated signals, an observation signal mixed with additive impulsive noise is generated and separated by fastICA method. And in the last part of the thesis, the fastICA algorithm is applied to the GPS receiver modeled in the SoftGNSS project and verified to be effective in industrial applications. The results have been analyzed.

  • 140. Cupane, M.
    et al.
    Pelegrí Sebastiá, J.
    Guarrasi, V.
    Chilo, José
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Sogorb, T.
    Electronic nose to detect off-flavor of drinking water2014Inngår i: , 2014, s. 61-61Konferansepaper (Fagfellevurdert)
  • 141.
    Dahal, Robi
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Mercan, Demet
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Design and performance analysis of purely textile antenna for                                                   wireless applications2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis work is concerned with the design and performance analysis of purely textile antenna for wireless applications. The materials used for radiating element, ground plane and dielectric substrate are purely textile. Two types of antennas are studied, the microstrip patch antenna and RFID tag antenna. Each type of antenna is designed and fabricated using two different conductive textile materials as radiating element.

     The radiating element and ground plane of conventional printed antenna is manufactured with the metal plating on a solid dielectric substrate. The radiating element which is used in this thesis work has different characteristics as compared to printed antenna because it is made of conductive textile material which is less conductive than metal and elastic in nature. Each conductive textile material has different surface resistivity. The study has been made to analyze the effect on gain and radiation efficiency of the antenna when different conductive textile material is used as the radiating element. The measured results of the fabricated antennas present the full potential of conductive textile materials to be used as an antenna.

  • 142.
    Dahal, Robi
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Mercan, Demet
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Lukas, Vojtech
    Telecommunications Engineering, Czech Technical University in Prague.
    Marek, Neruda
    Telecommunications Engineering, Czech Technical University in Prague.
    Textile Antenna for 50 ohm Applications2012Inngår i: Advances in Electrical and Electronic Engineering, ISSN 1336-1376, E-ISSN 1804-3119, Vol. 10, nr 4, s. 229-234Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The new generation of textile materials have the capability to conduct electricity and at the same time be wearable. There are much more applications involved if an antenna is made from parts that are totally wearable. This new property of conductivity in textile materials is used to implement the wireless functions to clothing. In general, the antennas are made of highly conductive metal with is a solid structure, which results in stable output. The challenge with textile antenna is output stability which is given by pure textile material of the radiating element, dielectric material and also ground, which can be can be folded and twisted. The paper presents the design and fabricated output results of the textile antenna which is used for the 50 ohm system (as GPS or WLAN) at 2,45 GHz.

  • 143.
    del Cueto Belchi, Alejandro
    et al.
    UPV.
    Rodriguez, Daniel
    UPV.
    Rothpfeffer, Niklas
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Sebastia, José
    UPV.
    Chilo, José
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Multi-sensor olfactory system: Using temperature modulation2012Inngår i: 2012 IEEE I2MTC - International Instrumentation and Measurement Technology Conference, Proceedings, IEEE conference proceedings, 2012, s. 1139-1141Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In recent years, with the advent of new and cheaper sensors, the use of olfactory systems in home, industry and hospital has get a new start. Multi-sensor systems can improve the ability to distinguish between complex mixtures of volatile substances. In this approach, 32 metal oxide semiconductor (MOS) sensors operating at different temperatures have been used to develop a multi-sensor olfactory system. 

  • 144.
    del Cueto Belchi, Alex
    et al.
    Polytechnic University of Valencia, Spain, Department of Electronic Engineering.
    Rothpfeffer, Niklas
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Pelegrí-Sebastia, José
    Polytechnic University of Valencia, Spain, Department of Electronic Engineering.
    Chilo, José
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Garcia Rodriguez, Daniel
    Polytechnic University of Valencia, Spain, Department of Electronic Engineering.
    Sogorb, T.
    Polytechnic University of Valencia, Spain, Department of Electronic Engineering.
    Sensor characterization for multisensor odor-discrimination system2013Inngår i: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 191, s. 68-72Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In recent years, with the advent of new and cheaper sensors, the use of olfactory systems in homes, industries, and hospitals has a new start. Multisensor systems can improve the ability to distinguish between complex mixtures of volatile substances. To develop multisensor systems that are accurate and reliable, it is important to take into account the anomalies that may arise because of electronic instabilities, types of sensors, and air flow. In this approach, 32 metal oxide semiconductor sensors of 7 different types and operating at different temperatures have been used to develop a multisensor olfactory system. Each type of sensor has been characterized to select the most suitable temperature combinations. In addition, a prechamber has been designed to ensure a good air flow from the sample to the sensing area. The multisensor system has been tested with good results to perform multidimensional information detection of two fruits, based on obtaining sensor matrix data, extracting three features parameters from each sensor curve and using these parameters as the input to a pattern recognition system.

  • 145.
    Deng, Kai
    et al.
    Högskolan i Gävle. Högskolan i Gävle, Institutionen för teknik och byggd miljö. Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    Ma, Minjie
    Högskolan i Gävle. Högskolan i Gävle, Institutionen för teknik och byggd miljö. Högskolan i Gävle, Institutionen för teknik och byggd miljö, Ämnesavdelningen för elektronik.
    THE STUDY AND IMPLEMENTATION OF MEANDER-LINE ANTENNA FOR AN INTEGRATED TRANSCEIVER DESIGN2010Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    This thesis focuses on the design and evaluation of the meander-line antenna geometry. One standard meander-line antenna and other two non-standard meander antennas have been studied. These printed antennas are discussed with the goal of identifying which is suitable for use in a miniaturized wireless transceiver design and which is able to provide the better performance using minimal Printed Circuit Board (PCB) space. In a word, the main objective is to characterize tradeoffs and identify which antenna provides the best compromise among volume, bandwidth and efficiency.

    The performance of each antenna is evaluated based on return loss, operational bandwidth, and radiation pattern characteristics. During our measurement, return loss is measured by reading the S11-port reflection coefficient on Vector Network Analyzer (VNA). This coefficient can be used to characterize how well the antenna is able to be efficiently fed. Operational bandwidth is measured as the frequency range over which the antenna keeps the value of Voltage Standing Wave Ratio (VSWR) or equivalently has -10dB return loss. Ansoft High Frequency Structure Simulator (HFSS) is used to simulate expected characteristics which are resonant frequency, bandwidth, VSWR, and radiation pattern. HFSS is used to provide a good guide for the antenna design before the actual prototype is manufactured. Simulated results are compared with results of measurement to point out the differences and help demonstrate the practical effects on antenna performance. Radiation pattern are measured to illustrate the effects of antenna miniaturization. All the above measurements are done in the anechoic chamber.

  • 146.
    Didriksson, Mattias
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad.
    Blomkvist, Anders
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad.
    En precisionsstudie av förstärkt verklighet som positioneringsverktyg2015Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    This study investigates augmented reality using third person perspective and what precision can be achieved by using this method. There have been prior studies in regards to precision using augmented reality, however studies using third person perspective is scarce. This study presents a solution using a static camera capturing the user as well as the plane to augment from behind. This augmented image is then transferred to a handheld device that is held by the user. Using this method the user will be free to manipulate and work with the plane without removing the device that captures the scene, a common problem when using visual reference markers in augmented reality. The study successfully shows that this can be implemented without compromising user experience as well as achieving a precision below 13 millimeters. The AR-tool has been proven to reduce time consumption of the task by up to four times compared to the manual method using a folding ruler.

  • 147.
    Dolz, Jose
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Marzal, Silvia
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    A new Propagation Model for Industrial Environments2010Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis is a project carried out at the “Centre for RF measurements Technology“at the University of Gävle. The first aim was basically the characterization of different industrial indoor environments to get a model that describes dispersive features of each environment.

     

    The results of previous measurements campaign on three industrial environments as steel mill, storage paper and industrial process mill are used. Also new Power Delay Profile (PDP) on corridor and laboratory has been developed.

     

    Measurements for three frequency bands are done (183-683 MHz, 1640-2140MHz and 2200-2700MHz) and for line-of-sight (LOS) and non-line-of-sight (NLOS) industrial and laboratory scenaries cases are presented.

     

    All these models have been compared with other existing models as Saleh-Valenzuela Model, Two Cluster Model and Indoor Power Delay Profile Model (IPDP Model) and fit-line, typical deviation are shown.

     

    Finally we present a study of the different systems used in the industry and the best suited system to the conditions is chosen.

     

  • 148.
    Dong, X.
    et al.
    Zhongyuan Univ Technol China, Zhengzhou , Peoples R China.
    Liu, Z.
    Zhongyuan Univ Technol China, Zhengzhou , Peoples R China.
    Yang, Y.
    Zhongyuan Univ Technol China, Zhengzhou , Peoples R China.
    Zhou, You
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Study on household metering and temperature control in central air-conditioning2010Inngår i: Proceedings of the 2010 5th IEEE Conference on Industrial Electronics and Applications, ICIEA 2010: Vol. 2, 2010, s. 931-935Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper studies the Frequency Temperature Control mechanism and cold (heat) metering algorithm about central air-conditioning terminal installations. The temperature control and household metering management system for central air-conditioning terminal machine are developed. The system hardware, software design programs and key technologies are expatiated. The terminal machine is integrated with PIC microcontroller, user data acquisition, transmission and control. Delphi language is used in the accounting management system of the host computer. The results show that, the system is no need of new wire, the high performance-price ratio, easy assembly, stable operation and reasonable charge. It is of great significance to adopt the heat and cold metering for the energy conservation, environmental protection and property management. At the same time, it provides the property management with a new technology and channels for the modern intelligent building. © 2010 IEEE.

  • 149.
    Eissa, M. M.
    et al.
    Electrical Power and Machines Engineering, Helwan University, Egypt.
    Virk, Gurvinder S.
    Electrical Power and Machines Engineering, South Westphalia University, Germany.
    AbdelGhany, A. M.
    Electrical Power and Machines Engineering, Helwan University, Egypt.
    Ghith, E. S.
    Optimum Induction Motor Speed Control Technique Using Genetic Algorithm2013Inngår i: American Journal of Intelligent Systems, ISSN 2165-8978, E-ISSN 2165-8994, Vol. 3, nr 1, s. 1-12Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Industrial processes are subjected to variation in parameters and parameter perturbations, which when significant makes the system unstable. In order to overcome this problem of parameter variation the PI controllers are widely used in industrial plants because it is simple and robust. However there is a problem in tuning PI parameters. So the control engineers are on look for automatic tuning procedures. In recent years, many intelligence algorithms are proposed to tuning the PI parameters. Tuning PI parameters using different optimal algorithms such as the simulated annealing, genetic algorithm, and particle swarm optimization algorithm. In this paper a scheduling PI tuning parameters using genetic algorithm strategy for an induction motor speed control is proposed. The results of our work have showed a very low transient response and a non-oscillating steady state response with excellent stabilization. The simulation results presented in this paper show the effectiveness of the proposed method, with satisfied response for GA-PI controller.

  • 150.
    Eklöv, Christina
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    DESIGN AND PROTOTYPING OF A LOW-SIDE ACTIVE CLAMPFORWARD CONVERTER POWER SUPPLY: Comparison with an existing Fixed Frequency Resonant Power Supply2014Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    This thesis details the design, build and commissioning of an active clamp forward converter with synchronous rectification and comparison to an existing fixed frequency resonant switching converter power supply. The points of comparison are: noise and ripple, power efficiency, number of components, size of components and cost. The goal is to increase the efficiency by 10% and reduce the cost and component count by 33% as compared to the existing design. A partial implementation of the new design was completed in the project timeframe and a provisional comparison showed a promising efficiency and reduced component count for comparable cost. Design improvements are proposed and follow up work is discussed to prototype a complete unit and confirm these results.

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