43 research outputs found

    Multi-object recognition and retrieval using Puma560 robot

    Full text link
    The objective of the research described here is to develop efficient algorithm and software tools for multiobject recognition and retrieval. This research project addresses two major issues: The first issue is the identification of features and efficient methods for feature extraction which can completely describe an object. These features can be acquired using visual and ultra-sonic sensors. The second issue is the development of efficient algorithms for the retrieval of multi-objects based on their features; The methods and algorithms developed in this research are verified on a Unimation PUMA 560 robot. Non contact sensors (a vision and a range sensor) are employed for feature detection. The information from both sensors will be combined for feature extraction and feature mapping (sensor fusion). The sensors and the robot have been integrated for this purpose with a Pentium 133 Mhz Personal Computer

    Equivalent circuit and calculation of unbalanced power in three-wire three-phase linear networks

    Full text link
    [EN] For analysis of three-wire three-phase linear systems, the transformations wye-delta and delta-wye from theorem of Kennelly are used. These transformations can be applied to balanced systems but not to unbalanced systems. This is due to the fact that zero-sequence voltages or zero-sequence currents are present in these types of connections. This modifies the value of the unbalance power in the load with respect to the generator. These zero-sequence voltages and currents that appear in generators and loads are not transferred over the network. The zero-sequence voltage in a delta-connected load and the zero-sequence current that is obtained using theorem of Kennelly in a star-connected load, or vice versa, cause different imbalance effects. Here, the equivalent circuit for any point of the system is developed. The impedances of the equivalent circuit in any node are calculated using line-to-line voltages and line currents. This equivalent circuit incorporates all energetic phenomena, including the unbalance of all downstream loads. For its verification, the phasor unbalance power is used.Montoya-Mira, R.; Diez-Aznar, J.; Blasco Espinosa, PA.; Montoya Villena, R. (2018). Equivalent circuit and calculation of unbalanced power in three-wire three-phase linear networks. IET Generation Transmission & Distribution. 12(7):1466-1473. https://doi.org/10.1049/iet-gtd.2017.0670S14661473127Emanuel, A. E. (1993). On the definition of power factor and apparent power in unbalanced polyphase circuits with sinusoidal voltage and currents. IEEE Transactions on Power Delivery, 8(3), 841-852. doi:10.1109/61.252612Jeon, S.-J. (2005). Definitions of Apparent Power and Power Factor in a Power System Having Transmission Lines With Unequal Resistances. IEEE Transactions on Power Delivery, 20(3), 1806-1811. doi:10.1109/tpwrd.2005.848658Czarnecki, L. S. (1994). Misinterpretations of some power properties of electric circuits. IEEE Transactions on Power Delivery, 9(4), 1760-1769. doi:10.1109/61.329509Willems, J. L. (2004). Reflections on Apparent Power and Power Factor in Nonsinusoidal and Polyphase Situations. IEEE Transactions on Power Delivery, 19(2), 835-840. doi:10.1109/tpwrd.2003.823182Emanuel, A. E. (1999). Apparent power definitions for three-phase systems. IEEE Transactions on Power Delivery, 14(3), 767-772. doi:10.1109/61.772313Jayatunga, U., Ciufo, P., Perera, S., & Agalgaonkar, A. P. (2015). Deterministic methodologies for the quantification of voltage unbalance propagation in radial and interconnected networks. IET Generation, Transmission & Distribution, 9(11), 1069-1076. doi:10.1049/iet-gtd.2014.0661Von Jouanne, A., & Banerjee, B. (2001). Assessment of voltage unbalance. IEEE Transactions on Power Delivery, 16(4), 782-790. doi:10.1109/61.956770Viswanadha Raju, G. K., & Bijwe, P. R. (2008). Efficient reconfiguration of balanced and unbalanced distribution systems for loss minimisation. IET Generation, Transmission & Distribution, 2(1), 7. doi:10.1049/iet-gtd:20070216Kersting, W. H. (2001). Causes and effects of unbalanced voltages serving an induction motor. IEEE Transactions on Industry Applications, 37(1), 165-170. doi:10.1109/28.903142Pillay, P., & Manyage, M. (2006). Loss of Life in Induction Machines Operating With Unbalanced Supplies. IEEE Transactions on Energy Conversion, 21(4), 813-822. doi:10.1109/tec.2005.853724Emanuel, A. E. (1998). The Buchholz-Goodhue apparent power definition: the practical approach for nonsinusoidal and unbalanced systems. IEEE Transactions on Power Delivery, 13(2), 344-350. doi:10.1109/61.660900Leon-Martinez, V., Montanana-Romeu, J., & Palazon-Garcia, J. M. (2011). Unbalance Compensator for Three-Phase Industrial Installations. IEEE Latin America Transactions, 9(5), 808-814. doi:10.1109/tla.2011.6030993Reginatto, R., & Ramos, R. A. (2014). On electrical power evaluation in dq coordinates under sinusoidal unbalanced conditions. IET Generation, Transmission & Distribution, 8(5), 976-982. doi:10.1049/iet-gtd.2013.0532Diez, J. M., Blasco, P. A., & Montoya, R. (2016). Formulation of phasor unbalance power: application to sinusoidal power systems. IET Generation, Transmission & Distribution, 10(16), 4178-4186. doi:10.1049/iet-gtd.2016.0730Marzband, M., Moghaddam, M. M., Akorede, M. F., & Khomeyrani, G. (2016). Adaptive load shedding scheme for frequency stability enhancement in microgrids. Electric Power Systems Research, 140, 78-86. doi:10.1016/j.epsr.2016.06.03

    A probabilistic method for the operation of three-phase unbalanced active distribution networks

    Get PDF
    YesThis paper proposes a probabilistic multi-objective optimization method for the operation of three-phase distribution networks incorporating active network management (ANM) schemes including coordinated voltage control and adaptive power factor control. The proposed probabilistic method incorporates detailed modelling of three-phase distribution network components and considers different operational objectives. The method simultaneously minimizes the total energy losses of the lines from the point of view of distribution network operators (DNOs) and maximizes the energy generated by photovoltaic (PV) cells considering ANM schemes and network constraints. Uncertainties related to intermittent generation of PVs and load demands are modelled by probability density functions (PDFs). Monte Carlo simulation method is employed to use the generated PDFs. The problem is solved using ɛ-constraint approach and fuzzy satisfying method is used to select the best solution from the Pareto optimal set. The effectiveness of the proposed probabilistic method is demonstrated with IEEE 13- and 34- bus test feeders

    Regional and experiential differences in surgeon preference for the treatment of cervical facet injuries: a case study survey with the AO Spine Cervical Classification Validation Group

    Get PDF
    Purpose: The management of cervical facet dislocation injuries remains controversial. The main purpose of this investigation was to identify whether a surgeon’s geographic location or years in practice influences their preferred management of traumatic cervical facet dislocation injuries. Methods: A survey was sent to 272 AO Spine members across all geographic regions and with a variety of practice experience. The survey included clinical case scenarios of cervical facet dislocation injuries and asked responders to select preferences among various diagnostic and management options. Results: A total of 189 complete responses were received. Over 50% of responding surgeons in each region elected to initiate management of cervical facet dislocation injuries with an MRI, with 6 case exceptions. Overall, there was considerable agreement between American and European responders regarding management of these injuries, with only 3 cases exhibiting a significant difference. Additionally, results also exhibited considerable management agreement between those with ≤ 10 and > 10 years of practice experience, with only 2 case exceptions noted. Conclusion: More than half of responders, regardless of geographical location or practice experience, identified MRI as a screening imaging modality when managing cervical facet dislocation injuries, regardless of the status of the spinal cord and prior to any additional intervention. Additionally, a majority of surgeons would elect an anterior approach for the surgical management of these injuries. The study found overall agreement in management preferences of cervical facet dislocation injuries around the globe

    Effect of surgical experience and spine subspecialty on the reliability of the {AO} Spine Upper Cervical Injury Classification System

    Get PDF
    OBJECTIVE The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5–10 years, 10–20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery). METHODS A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson’s chi-square or Fisher’s exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility. RESULTS The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5–10 years: 0.69 vs 10–20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5–10 years: 0.62 vs 10–20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5–10 years: 0.61 vs 10–20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36). CONCLUSIONS The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system

    Extragonadal endodermal sinus tumour of teilum report of two cases and review of literature

    No full text
    A 2-year perineal swelling of a 4-year-old girl and a 2-month swelling in the abdomen of a 1 year-old boy were found to be endodermal sinus tumours of Teilum. The gonads were normal in both. The histological appearance was typical with epithelial and stromal combinations and glomerulus-like structures called Schiller-Duval bodies. A brief review of the literature on the origin of these tumours is given. The girl is still alive but the boy died 2 days after laparotomy

    Robust Distribution Power Flow

    No full text

    Negative ion chemical ionization (Cl<SUP>-</SUP>) mass spectra of amino acids

    No full text
    Negative ion chemical ionization (Cl-) mass spectra of the commonly occurring amino acids are simple and give information regarding molecular weight by the presence of [M + Cl]- adduct in the case of simple amino acids and [M - H]- in the case of amino acids containing additional polar groups. tert-Butyloxycarbonyl (BOC)-protected di-, tri- and tetrapeptides also given abundant [M + Cl]- ions
    corecore