An alternative method for obtaining the optimal directional characteristic angle of directional overcurrent relays in transmission networks

2018 ◽  
Vol 11 (4) ◽  
pp. 149-164 ◽  
Author(s):  
Jose Jaramillo Serna ◽  
Jesus Maria Lopez-Lezama
Keyword(s):  
Directional Characteristic ◽  
Transmission Networks ◽  
Alternative Method ◽  
Overcurrent Relays ◽  
Characteristic Angle

scholarly journals Alternative Methodology to Calculate the Directional Characteristic Settings of Directional Overcurrent Relays in Transmission and Distribution Networks

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3779 ◽  
Author(s):  
Jaramillo Serna ◽  
López-Lezama
Keyword(s):  
Optimization Problem ◽  
Operating Characteristic ◽  
Short Circuit ◽  
Distribution Networks ◽  
Directional Characteristic ◽  
Overcurrent Relays ◽  
Alternative Methodology ◽  
Transmission And Distribution

When addressing the problem of calculating the settings for directional overcurrent elements, the focus is usually the determination of the pickup, time dial and operating characteristic, in order to ensure proper selectivity with adjacent protection elements, thus limiting the problem related to the settings calculation of the direction determination characteristic to the application of typical settings and general guidelines, which cannot provide a reliable measure of the suitability of such settings. The present article describes in detail an alternative methodology for determining these settings, based on a characterization of the power system where the directional protection is to be applied, through the performance of a detailed short-circuit sensitivity analysis. From this, an optimization problem is formulated and solved to obtain the main settings shaping the direction determination characteristic, and then, a series of variables are used to measure the performance of the obtained settings, and even to improve it. The obtained results show the advantages of the application of the proposed methodology over the traditional methodology, based on typical settings and general guidelines, pointing out the risks of using the later.

An Alternative Method for Identifying a Failed Engine in Twin-Engine Propeller Aircraft

2020 ◽  
Vol 10 (2) ◽  
pp. 103-111
Author(s):  
Andrey K. Babin ◽  
Andrew R. Dattel ◽  
Margaret F. Klemm
Keyword(s):  
Human Error ◽  
Flight Simulator ◽  
Traditional Group ◽  
Aircraft Accidents ◽  
Alternative Method ◽  
Indicator Group ◽  
Group A ◽  
The Dead ◽  
Engine Failure ◽  
And Performance

Abstract. Twin-engine propeller aircraft accidents occur due to mechanical reasons as well as human error, such as misidentifying a failed engine. This paper proposes a visual indicator as an alternative method to the dead leg–dead engine procedure to identify a failed engine. In total, 50 pilots without a multi-engine rating were randomly assigned to a traditional (dead leg–dead engine) or an alternative (visual indicator) group. Participants performed three takeoffs in a flight simulator with a simulated engine failure after rotation. Participants in the alternative group identified the failed engine faster than the traditional group. A visual indicator may improve pilot accuracy and performance during engine-out emergencies and is recommended as a possible alternative for twin-engine propeller aircraft.

Using the ARTIST approach for diagnosing power transmission networks

1994 ◽  
Vol 3 (3) ◽  
pp. 125 ◽  
Author(s):  
R. Leitch ◽  
H. Freitag ◽  
A. Stefanini ◽  
G. Tornielli
Keyword(s):  
Power Transmission ◽  
Transmission Networks ◽  
Power Transmission Networks

Determination of Myocardial FFA Elimination Rates by Functional Images of Uncorrected Half-Time Values

1984 ◽  
Vol 23 (06) ◽  
pp. 277-282 ◽  
Author(s):  
A. Van Lingen ◽  
G. Westera ◽  
M. van ◽  
W. Den Hollander ◽  
E. E. Van der Wall ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Regions Of Interest ◽  
Heptadecanoic Acid ◽  
Half Time ◽  
Alternative Method ◽  
Functional Images ◽  
Functional Image ◽  
Back Ground ◽  
Objective Determination

SummaryThis paper presents an alternative method of demarcating regions of in terest over the myocardium after ad ministration of 123I-heptadecanoic acid to patients with coronary artery disea se. In a matrix of 32 × 32 pixels the elimination rates of the radioactivity, which are not corrected for back ground activity, are visualized per pixel in a functional image. The func tional image showed areas in the myocardium with high values of uncorrected elimination rates. These areas corresponded with the tracer defects on the scintigram. Corrected elimination rates obtained from re gions of interest of functional images were comparable with those of scinti grams. Thus based on functional im ages of uncorrected elimination rates a reliable, objective determination of regions of interest over normal and abnormal myocardium can be made.

Evaluation of Sacroiliac Wedge Rotation to Increase Acetabular Ventroversion

1999 ◽  
Vol 12 (04) ◽  
pp. 173-177 ◽  
Author(s):  
R. L. Aper ◽  
M. D. Brown ◽  
M. G. Conzemius
Keyword(s):  
Hip Joint ◽  
Hip Dysplasia ◽  
Clinical Effect ◽  
Pelvic Osteotomy ◽  
Alternative Method ◽  
Angular Measurements ◽  
Si Joint ◽  
In Vivo Effects ◽  
Canine Hip Dysplasia

SummaryTreatment of canine hip dysplasia (CHD) via triple pelvic osteotomy (TPO) is widely accepted as the treatment that best preserves the existing hip joint. TPO, however, has several important disadvantages. In an effort to avoid some of the difficulties associated with TPO an alternative method of creating acetabular ventroversion (AW) was sought. The purpose of this study was to explore the effects of placement of a wedge in the sacroiliac (SI) joint on A W and to compare this to the effect of TPO on A W . On one hemipelvis a 30° pelvic osteotomy plate was used for TPO. The contralateral hemipelvis had a 28° SI wedge inserted into the SI joint. Pre- and postsurgical radiographs of each pelvis were taken and the angular measurements were recorded. On average, the 28° SI wedge resulted in 20.9° of A W, the 30° canine pelvic osteotomy plate resulted in 24.9° A W . Significant differences were not found (p >0.05) between the two techniques. Sacroiliac wedge rotation effectively creates A W and has several theoretical advantages when compared to TPO. The in vivo effects of sacroiliac wedge rotation should be studied in order to evaluate the clinical effect of the technique.Sacroiliac wedge rotation was tested as an alternative method to increase the angle of acetabular ventroversion. This technique effectively rotated the acetabulum and has several theoretical advantages when compared to triple pelvic osteotomy.

Bollywood and Postmodernism

2015 ◽  
Author(s):  
Neelam Sidhar Wright
Keyword(s):  
Film Studies ◽  
First Century ◽  
Indian Cinema ◽  
Alternative Method ◽  
Twenty First Century

‘New Bollywood’ has arrived, but its postmodern impulse often leaves film scholars reluctant to theorise its aesthetics. How do we define the style of a contemporary Bollywood film? Are Bollywood films just uninspired Hollywood rip-offs, or does their borrowing signal genuine innovation within the industry? Applying postmodern concepts and locating postmodern motifs in key commercial Hindi films, this book reveals how Indian cinema has changed in the twenty-first century. Equipping readers with an alternative method of reading contemporary Indian cinema, the book takes Indian film studies beyond the standard theme of diaspora, and exposes a new decade of aesthetic experimentation and textual appropriation in mainstream Bombay cinema. A bold celebration of contemporary Bollywood texts, this book radically redefines Indian film and persuasively argues for its seriousness as a field of cinematic studies.

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