| 1. |
- Adolfsson, Stefan, et al.
(författare)
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Automatic Detection of Burn-through in GMA Welding Using a Parametric Model
- 1996
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Ingår i: Mechanical Systems & Signal Processing. - London : Academic Press. - 0888-3270. ; 10:5, s. 633-651
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Tidskriftsartikel (refereegranskat)abstract
- This paper addresses the problem of automatic detection of burn-through in weld joints. Gas metal are (GMA) welding with pulsed current is used, and welding voltage and current are recorded. As short-circuitings are common between the welding electrode and the work piece during burn-through, a short-circuit detector is developed to detect these events. To detect another specific characteristic of burn-through-a broadband long-lasting voltage component-this detector is combined with a square-law detector. This second detector is based on a non-linear modification of an autoregressive model with extra input (ARX-model) of the welding process. The results obtained from this compound detector indicate that it is possible to detect burn-through in the welds automatically. The work also indicates that it is possible to design an on-line monitoring system for robotic GMA welding.
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| 2. |
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| 3. |
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| 4. |
- Dias,, Jacklyn, et al.
(författare)
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Improving the Performance Evaluation of ADSL systems by using a Modem Diagnosis Methodology
- 2006
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Ingår i: Simpósio Brasileiro de Microondas e Optoeletrônica – Congresso Brasileiro de Eletromagnetismo.
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Konferensbidrag (refereegranskat)abstract
- This paper presents test methodologies to measure and evaluate performance of ADSL modems which take into account loss of packet rate, bit rate, and latency in transporting ADSL service scenario. This evaluation method can be used by ADSL provider (CO - Central Office) to guarantee the system quality and avoid low performance of service. In order to present this evaluation method, this paper considers a traffic generator, modems under test, a telephony local loop carring ADSL service, and DSLAM as the lab setup to perform such tests.
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| 5. |
- Englund, Ulrica, et al.
(författare)
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The use of a recombinant lentiviral vector for ex vivo gene transfer into the rat CNS
- 2000
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Ingår i: NeuroReport. - : Lippincott Williams & Wilkins. - 0959-4965 .- 1473-558X. ; 11:18, s. 3973-3977
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Tidskriftsartikel (refereegranskat)abstract
- A major obstacle in ex vivo gene transfer has been the loss of transgene expression soon after implantation of the grafted transduced cells. Recently, a lentiviral vector system has been developed which has proven to express high levels of transgenes in vivo after direct injection into the tissue. In this study, we have investigated the use of such a vector for ex vivo gene transfer to the brain. A number of neural cell types were found to be permissive to transduction by the lentiviral vector in vitro and a majority of them expressed the transgene after transplantation to the rat brain. Transgene expression was detected up to 8 weeks post-grafting. These findings suggest that recombinant lentiviral vectors may be used for further development of ex vivo gene therapy protocols to the CNS.
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| 6. |
- Ericson, Cecilia, et al.
(författare)
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Ex vivo and in vitro studies of transgene expression in rat astrocytes transduced with lentiviral vectors.
- 2002
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Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 173:1, s. 22-30
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Tidskriftsartikel (refereegranskat)abstract
- Implantation of cells genetically modified to express therapeutic genes into the brain has been proposed as a potential treatment for neurodegenerative diseases. In the current study embryonic rat-derived astrocytes were cultured and transduced with a lentiviral vector expressing the reporter gene green fluorescent protein (GFP) and subsequently grafted into the adult rat brain. The proportion of GFP expressing cells was stable, albeit small (1%), at all survival times, up to 6 weeks, the longest time point studied. In parallel in vitro studies, the astrocytes were lentivirally transduced to express either one of the two isoforms of glutamate decarboxylase (GAD(65) or GAD(67)) or glial cell line-derived neurotrophic factor (GDNF). When transducing 293T cells with the two GAD vectors, released GABA could be measured using high-performance liquid chromatography. Further studies of rat astrocytes transduced with the same vectors resulted in a level of GAD activity about 10 times higher than the activity of an intact rat striatum. One hundred thousand astrocytes transduced with LV-GDNF released approximately 27 ng of GDNF per hour. Thus, taken together, our observations provide support for the use of rat astrocytes in ex vivo gene transfer of these proteins in animal models of CNS disorders, e.g., Parkinson's disease or epilepsy.
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| 7. |
- Ericson, Stefan, et al.
(författare)
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Information Fusion for Autonomous Robotic Weeding
- 2009
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Ingår i: INFORMATIK 2009. - : Köllen Druck + Verlag GmbH. - 9783885792482 ; , s. 2461-2473
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Konferensbidrag (refereegranskat)abstract
- Information fusion has a potential applicability to a multitude of differentapplications. Still, the JDL model is mostly used to describe defense applications.This paper describes the information fusion process for a robot removing weed ina field. We analyze the robotic system by relating it to the JDL model functions.The civilian application we consider here has some properties which differ from thetypical defense applications: (1) indifferent environment and (2) a predictable andstructured process to achieve its objectives. As a consequence, situation estimatestend to deal with internal properties of the robot and its mission progress (throughmission state transition) rather than external entities and their relations. Nevertheless, the JDL model appears useful for describing the fusion activities of the weeding robot system. We provide an example of how state transitions may be detected and exploited using information fusion and report on some initial results. An additional finding is that process refinement for this type of application can be expressed in terms of a finite state machine.
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| 8. |
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| 9. |
- Fertner, Antoni, et al.
(författare)
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Applications of Backscattering for the Study of Twisted Pair Transmission Lines
- 2018
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480. ; 66:12, s. 5230-5237
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Tidskriftsartikel (refereegranskat)abstract
- The phenomenon of backscattering in copper cables has been recently observed and initially explicated. It can provide promising techniques to address the problem of loop diagnostic and maintenance. The backscattering is analyzed both in frequency and time domains. To demonstrate the practical use of the phenomenon, we estimate certain properties of the loop using wideband, high-frequency $\selevenf(f)$ measurements performed in the laboratory on real cables. The results corroborate the usefulness and accuracy of the investigated method.
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| 10. |
- Fertner, Antoni, et al.
(författare)
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Backscattering in Twisted-Pair Nonhomogeneous Transmission Lines
- 2018
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480. ; 66:6, s. 2674-2682
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Tidskriftsartikel (refereegranskat)abstract
- The development of the communication networks tends gradually toward exploiting higher frequencies, sometimes even reaching the lowest microwave band (P-band). As the signal bandwidth used for transmission over twisted-pairs increases, as recommended by G.fast and other broadband systems, new phenomenon was observed, namely, backscattering. Motivated by the measurements of copper cables in frequency band up to 400 MHz, we propose a novel backscattering model. It may be productively applied to the problem of loop diagnostics. The methods to accurately and reliable determine the relevant transmission-line parameters are sine qua non condition to appropriately exploit the potential of short-to-medium range access lines. In this paper, a recursive formulation of the frequency-domain response of the backscattering is used for a space-time characterization. To confirm the practical use of the finding, we evaluate the properties of a loop using wideband, high-frequency S₁₁ measurements of the real cables. These laboratory results confirm the effectiveness and accuracy of the proposed method.
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