627 research outputs found
Load Modulation for Damping of Electro-Mechanical Oscillations
No full textToday it is feasible for utilities to control selected customer loads in a nondisturbing fashion. This is comparable to load shedding, but has a wider area of application. This paper focuses on direct load control or modulation for power system damping and is based on a field test of on-off control and modal analysis of differential-algebraic equation models of three test systems. Real power load controlled by bus frequency is found to be robust to changes in network topology. It is shown that on-off modulation is more effective than sinusoidal modulation for damping of large oscillations, but not for small oscillations. It proves difficult to give a general measure of the required amount of controlled load, since modulation of real power loads has an additive rather than multiplicative effect on power flows. Different structures of load control systems are listed. If the system is centralized, it is suggested that the distribution company owns and operates the system and that damping is sold as ancillary servic
Estimation of Electro-Mechanical Mode Parameters using Frequency Measurements
No full textOscillation frequency and damping of electro-mechanical modes in a power system have traditionally been determined from events caused by large disturbances such as line switchings or generator tripping. Recent papers have shown the possibility to extract this information during normal operation from measurements of power through, or angle difference across, a transmission line. In this paper these methods are applied to frequency measurements from a 230 V wall-outlet. If accurate frequency and phase estimates can be obtained, this can be used for load control to damp electro-mechanical oscillations. Doing this in the distribution system is easier than in the transmission system. Using frequency for this has the advantage that this signal is available everywhere. It would thus be convenient if the estimation of modes and damping could be done in the distribution system. The results show that it is much harder to detect electro-mechanical mode information from frequency than from angle difference or power. However, it is possible to find the frequency of two electromechanical modes whereas the damping has too large an uncertainty. Fundamental problems when using frequency for mode estimation are further discusse
Acetate<em>,</em> naturally
No full textThe Beatles author, Hans Olof Gottfridsson, reveals a newly-unearthed version of Why, a record subsequently cut by the band and Tony Sheridan.</p
Mapping functions in health-related quality of life: mapping from the Achilles Tendon Rupture Score to the EQ-5D
No full textPurpose: Health state utility values are derived from preference-based measurements and are useful in calculating quality-adjusted life years (QALYs), which is a metric commonly used in cost-effectiveness studies. The purpose of this study was to convert the Achilles Tendon Rupture Score (ATRS) to the preference-based European Quality of Life-5 Dimension Questionnaire (EQ-5D) by estimating the relationship between the two scores using mapping. Methods: Data were collected from a randomised controlled trial, where 100 patients were treated either surgically or non-surgically for Achilles tendon rupture. Forty-three and forty-four patients in surgical group and non-surgical group completed the ATRS and the EQ-5D alongside each other during follow-up at three time points. Different models of the relationship between the ATRS and the EQ-5D were developed and analysed based on direct mapping and cross-validation. The model with the lowest mean absolute error was observed as the one with the best fit. Results: Among the competing models, mapping based on using a combination of the ATRS items four, five, and six associated with limitation due to pain, during activities of daily living and when walking on uneven ground, produced the best predictor of the EQ-5D score. Conclusions: The present study provides a mapping algorithm to enable the derivation of utility values directly from the ATRS. This approach makes it feasible for researchers, as well as medical practitioners, to obtain preference-based values in clinical studies or settings where only the ATRS is being administered. The algorithm allows for the calculation of QALYs for use in cost-effectiveness analyses, making it valuable in the study of acute Achilles tendon ruptures. Level of evidence: II
Författaren i arbete. Biografens maskinrum som heterotopi i Eyvind Johnsons Romanen om Olof
No full textJohan Klingborg, Department of Culture and Aesthetics, Stockholm University The Author at Work: The Projection Room as Heterotopia in Eyvind Johnson’s The Novel about Olof (Författaren i arbete. Biografens maskinrum som heterotopi i Eyvind Johnsons Romanen om Olof) The sociological understanding of Swedish proletarian literature usually goes like this: in order to become a working class author the ‘proletarian’ writer paradoxically needs to abandon labor. While Eyvind Johnson’s four-part autobiographical Künstlerroman The Novel about Olof (1934–37) at first glance appears to follow that trajectory, this article shows how a particular line of work—namely, the work as a projectionist—in fact plays a fundamental role in the protagonist’s development towards writerly consciousness. The article takes as its point of departure the pivotal closing sequence of the third part, in which Olof, employed as a projectionist, starts to read an edition of the Odyssey during the screening of a film. Through a media-archaeological analysis of that scene, the article argues that Olof is reading in the projection room because historically it has functioned precisely as a space for reading. Not only was the projection room secluded and out of reach from the mechanisms of perception control in the auditorium; it also granted a livelihood without claiming all of the worker’s attention. In the words of Michel Foucault, the projection room can thus be regarded as a heterotopia—i.e. a space that simultaneously stands in relation to, and inverts, the power dynamics of all other spaces—both with regard to the cinema building and to capitalist society at large. The article shows how Olof ’s willingness and ability to read is indeed connected to his access to this heterotopian space for reading. Moreover, it argues that Olof is reading the Odyssey specifically because the Homeric epic is analogous to the tasks of the projectionist. The repetitive labor of the projectionist makes them a Penelope figure: the former is repeatedly winding and rewinding, while the latter is continually weaving and unweaving
Författaren i arbete. Biografens maskinrum som heterotopi i Eyvind Johnsons Romanen om Olof
No full textJohan Klingborg, Department of Culture and Aesthetics, Stockholm University The Author at Work: The Projection Room as Heterotopia in Eyvind Johnson’s The Novel about Olof (Författaren i arbete. Biografens maskinrum som heterotopi i Eyvind Johnsons Romanen om Olof) The sociological understanding of Swedish proletarian literature usually goes like this: in order to become a working class author the ‘proletarian’ writer paradoxically needs to abandon labor. While Eyvind Johnson’s four-part autobiographical Künstlerroman The Novel about Olof (1934–37) at first glance appears to follow that trajectory, this article shows how a particular line of work—namely, the work as a projectionist—in fact plays a fundamental role in the protagonist’s development towards writerly consciousness. The article takes as its point of departure the pivotal closing sequence of the third part, in which Olof, employed as a projectionist, starts to read an edition of the Odyssey during the screening of a film. Through a media-archaeological analysis of that scene, the article argues that Olof is reading in the projection room because historically it has functioned precisely as a space for reading. Not only was the projection room secluded and out of reach from the mechanisms of perception control in the auditorium; it also granted a livelihood without claiming all of the worker’s attention. In the words of Michel Foucault, the projection room can thus be regarded as a heterotopia—i.e. a space that simultaneously stands in relation to, and inverts, the power dynamics of all other spaces—both with regard to the cinema building and to capitalist society at large. The article shows how Olof ’s willingness and ability to read is indeed connected to his access to this heterotopian space for reading. Moreover, it argues that Olof is reading the Odyssey specifically because the Homeric epic is analogous to the tasks of the projectionist. The repetitive labor of the projectionist makes them a Penelope figure: the former is repeatedly winding and rewinding, while the latter is continually weaving and unweaving
Författaren i arbete. Biografens maskinrum som heterotopi i Eyvind Johnsons <em>Romanen om Olof</em> [Elektronisk resurs]
No full textJohan Klingborg, Department of Culture and Aesthetics, Stockholm University The Author at Work: The Projection Room as Heterotopia in Eyvind Johnson’s The Novel about Olof (Författaren i arbete. Biografens maskinrum som heterotopi i Eyvind Johnsons Romanen om Olof) The sociological understanding of Swedish proletarian literature usually goes like this: in order to become a working class author the ‘proletarian’ writer paradoxically needs to abandon labor. While Eyvind Johnson’s four-part autobiographical Künstlerroman The Novel about Olof (1934–37) at first glance appears to follow that trajectory, this article shows how a particular line of work—namely, the work as a projectionist—in fact plays a fundamental role in the protagonist’s development towards writerly consciousness. The article takes as its point of departure the pivotal closing sequence of the third part, in which Olof, employed as a projectionist, starts to read an edition of the Odyssey during the screening of a film. Through a media-archaeological analysis of that scene, the article argues that Olof is reading in the projection room because historically it has functioned precisely as a space for reading. Not only was the projection room secluded and out of reach from the mechanisms of perception control in the auditorium; it also granted a livelihood without claiming all of the worker’s attention. In the words of Michel Foucault, the projection room can thus be regarded as a heterotopia—i.e. a space that simultaneously stands in relation to, and inverts, the power dynamics of all other spaces—both with regard to the cinema building and to capitalist society at large. The article shows how Olof ’s willingness and ability to read is indeed connected to his access to this heterotopian space for reading. Moreover, it argues that Olof is reading the Odyssey specifically because the Homeric epic is analogous to the tasks of the projectionist. The repetitive labor of the projectionist makes them a Penelope figure: the former is repeatedly winding and rewinding, while the latter is continually weaving and unweaving.</p
Förnyade Strindberg versdramat? Versmått, poetisk ordföljd och ämnesbyten i Mäster Olof
No full textStaffan Hellberg, Department of Swedish Language and Multilingualism, Stockholm University Did Strindberg renew the verse drama? Metre, poetic word order, and changes of subject in Master Olof (Förnyade Strindberg versdramat? Versmått, poetisk ordföljd och ämnesbyten i Mäster Olof) Strindberg’s decision to write the third version of his drama Master Olof in verse may have been a concession to historical drama tradition. The question posed here is whether he renewed the Swedish verse drama. It is shown that, contrary to general belief, Strindberg was the first author in the 19th century to use doggerel verse. Concerning poetic word order, his renewal is less apparent, although he shows a special tendency to vary the degree and kind of poetic wordorder with the situation. Finally, the dialogue is examined with a conversation analysis method. It is shown that Strindberg’s characters, also in verse drama, change the subject of the conversation in a manner closer to observed natural talk than do those of his predecessors
Förnyade Strindberg versdramat? Versmått, poetisk ordföljd och ämnesbyten i <em>Mäster Olof</em> [Elektronisk resurs]
No full textStaffan Hellberg, Department of Swedish Language and Multilingualism, Stockholm UniversityDid Strindberg renew the verse drama? Metre, poetic word order, and changes of subject in Master Olof(Förnyade Strindberg versdramat? Versmått, poetisk ordföljd och ämnesbyten i Mäster Olof)Strindberg’s decision to write the third version of his drama Master Olof in verse may have been a concession to historical drama tradition. The question posed here is whether he renewed the Swedish verse drama. It is shown that, contrary to general belief, Strindberg was the first author in the 19th century to use doggerel verse. Concerning poetic word order, his renewal is less apparent, although he shows a special tendency to vary the degree and kind of poetic wordorder with the situation. Finally, the dialogue is examined with a conversation analysis method. It is shown that Strindberg’s characters, also in verse drama, change the subject of the conversation in a manner closer to observed natural talk than do those of his predecessors.</p
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