scholarly journals Co-ordinated Follow-Up of Transiting Planet Candidates with Robotic Telescope Facilities

2008 ◽  
Vol 4 (S253) ◽  
pp. 412-415
Author(s):  
R. A. Street ◽  
T. A. Lister
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
False Positives ◽  
Light Curves ◽  
Robotic Telescope ◽  
High False Alarm Rate ◽  
Planetary Transits

AbstractThere are now several large photometric surveys scanning millions of stellar light-curves for signs of planetary transits. All produce large candidate lists with a high false alarm rate, so that further observations are required to confirm new detections. One such survey, SuperWASP, produced ~150 candidates during the 2007–2008 season. Here we describe our campaign to follow-up 86 of these candidates using the robotic facilities of Las Cumbres Observatory Global Telescope Network and the Tenagra-II robotic telescope in Arizona. The aim of these observations was to eliminate false positives as far as possible ahead of spectroscopic follow-up and to provide additional photometry to help characterise the surviving targets.

Effects of Practice and Instructional Set on the Measurement of Lingual Vibrotactile Thresholds

1983 ◽  
Vol 26 (2) ◽  
pp. 289-293
Author(s):  
Donald Fucci ◽  
Larry H. Small ◽  
Linda Petrosino
Keyword(s):  
Data Collection ◽  
False Alarm ◽  
False Alarm Rate ◽  
Normal Adult ◽  
Practice Condition ◽  
Instructional Set ◽  
Vibrotactile Thresholds ◽  
Threshold Data ◽  
The Subject ◽  
High False Alarm Rate

The effects on lingual vibrotactile thresholds of three different instructional sets and three different practice conditions were determined for 30 normal adult subjects. Results showed no measurable differences between thresholds obtained with the use of the three different instructional sets, but a high false alarm rate occurred for all conditions. When a subject was given practice at obtaining thresholds with a particular instructional set as a prerequisite to threshold data collection, false Mama responses disappeared. Lower (more sensitive) thresholds also were achieved when the practice condition used required the subject to provide three thresholds within 1µ of each other before commencing with actual testing.

Vertical Reversal and Lateral Reversal as Components of Inversion in Recognition Memory for Upside-down Faces

1987 ◽  
Vol 65 (2) ◽  
pp. 388-390
Author(s):  
Stuart J. McKelvie
Keyword(s):  
Recognition Memory ◽  
False Alarm ◽  
False Alarm Rate ◽  
High False Alarm Rate

Subjects viewed upright photographs of faces, then attempted to recognize them unchanged, vertically reversed or inverted. In two of four conditions, hit scores were lower for inverted than vertically reversed faces, suggesting that lateral reversal is a meaningful component of inversion. The effect was not sufficiently strong, however, to overcome a generally high false-alarm rate for upside-down faces.

scholarly journals Robotic Monitoring of Gravitationally Lensed Quasars

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Luis J. Goicoechea ◽  
Vyacheslav N. Shalyapin ◽  
Aurora Ullán
Keyword(s):  
Light Curves ◽  
Current Status ◽  
Second Phase ◽  
Scientific Results ◽  
Robotic Telescope

We report on the first observational phase of the Liverpool Quasar Lens Monitoring (LQLM) project. This mainly consisted of the optical follow-up of three lensed quasars using the 2 m Liverpool Robotic Telescope. The observational subprogram started in January 2005 and was completed in July 2007. We also describe our photometric approaches (including two pipelines to extract accurate and reliable fluxes of images of lensed quasars), the performance of the telescope when taking modest nightly exposures of lens systems, and the main scientific results from the observed light curves. The LQLM archive and the current status of the project (second phase) are also outlined.

Pandrol track fastener defect detection based on local convolutional neural networks

2020 ◽  
pp. 095965182095367
Author(s):  
Anqi Ma ◽  
Zhaomin Lv ◽  
Xingjie Chen ◽  
Liming Li ◽  
Yijin Qiu ◽  
...  
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
False Alarm ◽  
Convolutional Neural Network ◽  
False Alarm Rate ◽  
Defect Detection ◽  
Automatic Segmentation ◽  
The Other ◽  
Local Feature Extraction ◽  
High False Alarm Rate

The Pandrol track fastener image is composed of two parts: track fastener clip sub-graph and track fastener bolt sub-graph. However, the detection of track fastener clip defect can be realized by track fastener image and track fastener image cannot effectively detect whether the bolt is loose. When the convolutional neural network is used to extract whole picture features and detect, many bolt features unrelated to the clips will be obtained, thereby resulting in a high false alarm rate. To solve these problems, a method based on local convolutional neural network to detect the Pandrol track fastener defects is proposed. First, the algorithm for automatic segmentation of track fastener pictures was used to divide the picture of the Pandrol track fastener into two sub-pictures, one sub-picture is the track fastener bolt and the other sub-picture is the track fastener clip. Second, convolutional neural network was used to detect the track fastener clip pictures. The influence of bolt features unrelated to clips on clips detection can be avoided through image segmentation for local feature extraction, thereby reducing the false alarm rate. Finally, the validity of the proposed method is verified using real Pandrol track fastener images.

scholarly journals Volatility of Tornadogenesis: An Ensemble of Simulated Nontornadic and Tornadic Supercells in VORTEX2 Environments

2017 ◽  
Vol 145 (11) ◽  
pp. 4605-4625 ◽  
Author(s):  
Brice E. Coffer ◽  
Matthew D. Parker ◽  
Johannes M. L. Dahl ◽  
Louis J. Wicker ◽  
Adam J. Clark
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
Near Surface ◽  
Vertical Vorticity ◽  
Low Level ◽  
Tornado Warnings ◽  
Surface Buoyancy ◽  
Strong Dynamic ◽  
High False Alarm Rate

Despite an increased understanding of the environments that favor tornado formation, a high false-alarm rate for tornado warnings still exists, suggesting that tornado formation could be a volatile process that is largely internal to each storm. To assess this, an ensemble of 30 supercell simulations was constructed based on small variations to the nontornadic and tornadic environmental profiles composited from the second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2). All simulations produce distinct supercells despite occurring in similar environments. Both the tornadic and nontornadic ensemble members possess ample subtornadic surface vertical vorticity; the determinative factor is whether this vorticity can be converged and stretched by the low-level updraft. Each of the 15 members in the tornadic VORTEX2 ensemble produces a long-track, intense tornado. Although there are notable differences in the precipitation and near-surface buoyancy fields, each storm features strong dynamic lifting of surface air with vertical vorticity. This lifting is due to a steady low-level mesocyclone, which is linked to the ingestion of predominately streamwise environmental vorticity. In contrast, each nontornadic VORTEX2 simulation features a supercell with a disorganized low-level mesocyclone, due to crosswise vorticity in the lowest few hundred meters in the nontornadic environment. This generally leads to insufficient dynamic lifting and stretching to accomplish tornadogenesis. Even so, 40% of the nontornadic VORTEX2 ensemble members become weakly tornadic. This implies that chaotic within-storm details can still play a role and, occasionally, lead to marginally tornadic vortices in suboptimal storms.

scholarly journals Reducing the False Alarm Rate in Intrusion Detection System by Providing Authentication and Improving the Efficiency of Intrusion Detection System by using Filtered Clusterer Algorithm using Weka Tool

2021 ◽  
Vol 10 (4) ◽  
pp. 134-142
Author(s):  
Pratik Jain ◽  
Ravikant Kholwal ◽  
Tavneet Singh Khurana,
Keyword(s):  
Intrusion Detection ◽  
False Alarm ◽  
False Alarm Rate ◽  
False Positive ◽  
Intrusion Detection System ◽  
Detection System ◽  
False Positives ◽  
Cyber Safety ◽  
Authentication System ◽  
Similar Issue

An IDS supervises network traffic by searching for skeptical activities and previously determined threats and sends alerts when detected. In the current times, the splendors of Intrusion detection still prevail censorial in cyber safety, but maybe not as a lasting resolution. To study a plant, one must start with roots, so Cambridge dictionary defines an intrusion as "an occasion when someone goes into an area or situation where they're not wanted or expected to be". For understanding the article, we will characterize interruption as any network movement or unapproved framework identified with one or more PCs or networks. This is an interpretation of permissible use of a system attempting to strengthen his advantages to acquire more noteworthy access to the framework that he is at present endowed, or a similar client attempting to associate with an unapproved far-off port of a server. These are the interruptions which will cause from the surface world, a bothered ex-representative who was terminated recently, or from your reliable staff. In this proviso, the fair information is found as an attack when the case is a false positive. Here they are zeroing in on this issue with a representation and offering one answer for a similar issue. The KDD CUP 1999 informational index is utilized. Here we dropped the number of counts and considered the OTP authentication system. In the result of this test, it may be very well seen that on the off chance that a class has a higher number of checks, at that point this class is believed to be an anomaly class. In any case, it will be considered an oddity if the genuine individual is passing the edge esteem is considered an intruder. One arrangement is proposed to distinguish the genuine individual and to eliminate false positives.

The Effects of the Contrast Polarity of Dot-Pair Partners on the Detection of Bilateral Symmetry

Perception ◽  
1996 ◽  
Vol 25 (7) ◽  
pp. 757-771 ◽  
Author(s):  
Peter Wenderoth
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
Bilateral Symmetry ◽  
The Other ◽  
Symmetry Detection ◽  
Detection Mechanism ◽  
Point Matching ◽  
Independent Evidence ◽  
Very High ◽  
High False Alarm Rate

Detection of vertical bilateral symmetry has previously been studied in patterns composed of black or white dots on a grey background under four conditions: (a) same contrast (black or white) for all dots (called BB or WW, for ‘all black or all white’); (b) half of the dots black and half white with positive correspondence between symmetrical dot pairs (called MA for ‘matched’); (c) half of the dots black and half white with negative correspondence between symmetrical dot pairs (called OPP for ‘opposite’); and (d) black (white) dots on one side of the axis and white (black) dots on the other (called BW for ‘one side black the other white’). It was found that performance was ordered BB (or WW) = MA > OPP =BW, where > indicates better performance. That experiment was repeated here in experiment 1 with symmetry axes not only at vertical but also at horizontal and the two diagonals. It was found overall that BB = MA > OPP, BW. However, OPP > BW when random trials were included in the analysis but when they were excluded BW > OPP. This was due to a very high false-alarm rate in condition BW which could be accounted for if grouping by colour occurs prior to symmetry detection. In experiment 2 it was shown that vertical-symmetry salience over other orientations remained about the same as OPP patterns progressively changed into BB patterns by varying the percentage same polarity between 0% and 100% in 12%–13% steps. Thus, dot-pair polarity affects performance without affecting relative axis salience, as was also found recently when dot pattern outlines were masked. All of the data indicate that although opposite dot polarity does reduce performance slightly, the symmetry-detection mechanism is remarkably resilient to such perturbation. The high false-alarm rate in the BW condition of experiment 1 may be accounted for by extremely salient global grouping of dots by luminance which effectively creates an integral stimulus which is perceptually difficult to break down into its component dot pairs, prohibiting the required point-by-point matching necessary to reject symmetry detection. The small detrimental effect of nonmatched polarity might be due to the polarity differences masking the grouping of dots into ‘clumps’ on either side of the axis, a process for which there is a great deal of independent evidence.

scholarly journals Correlating data from different sensors to increase the positive predictive value of alarms: an empiric assessment

F1000Research ◽  
2012 ◽  
Vol 1 ◽  
pp. 45 ◽  
Author(s):  
Yuval Bitan ◽  
Michael F O’Connor
Keyword(s):  
Positive Predictive Value ◽  
False Alarm ◽  
False Alarm Rate ◽  
Predictive Value ◽  
Left Ventricular ◽  
False Alarms ◽  
Expert Clinician ◽  
Correlated Information ◽  
Sensitivity Specificity ◽  
High False Alarm Rate

Objectives: Alarm fatigue from high false alarm rate is a well described phenomenon in the intensive care unit (ICU). Progress to further reduce false alarms must employ a new strategy. Highly sensitive alarms invariably have a very high false alarm rate. Clinically useful alarms have a high Positive-Predictive Value. Our goal is to demonstrate one approach to suppressing false alarms using an algorithm that correlates information across sensors and replicates the ways that human evaluators discriminate artifact from real signal.Methods: After obtaining IRB approval and waiver of informed consent, a set of definitions, (hypovolemia, left ventricular shock, tamponade, hemodynamically significant ventricular tachycardia, and hemodynamically significant supraventricular tachycardia), were installed in the monitors in a 10 bed cardiothoracic ICU and evaluated over an 85 day study period. The logic of the algorithms was intended to replicate the logic of practitioners, and correlated information across sensors in a way similar to that used by practitioners. The performance of the alarms was evaluated via a daily interview with the ICU attending and review of the tracings recorded over the previous 24 hours in the monitor. True alarms and false alarms were identified by an expert clinician, and the performance of the algorithms evaluated using the standard definitions of sensitivity, specificity, positive predictive value, and negative predictive value.Results: Between 1 and 221 instances of defined events occurred over the duration of the study, and the positive predictive value of the definitions varied between 4.1% and 84%.Conclusions: Correlation of information across alarms can suppress artifact, increase the positive predictive value of alarms, and can employ more sophisticated definitions of alarm events than present single-sensor based systems.

scholarly journals A Pair of Warm Giant Planets near the 2:1 Mean Motion Resonance around the K-dwarf Star TOI-2202*

2021 ◽  
Vol 162 (6) ◽  
pp. 283
Author(s):  
Trifon Trifonov ◽  
Rafael Brahm ◽  
Nestor Espinoza ◽  
Thomas Henning ◽  
Andrés Jordán ◽  
...  
Keyword(s):  
Orbital Period ◽  
Dynamical Evolution ◽  
Giant Planets ◽  
Light Curves ◽  
Dynamical Analysis ◽  
Dwarf Star ◽  
Mean Motion ◽  
Robotic Telescope ◽  
Mean Motion Resonance

Abstract TOI-2202 b is a transiting warm Jovian-mass planet with an orbital period of P = 11.91 days identified from the Full Frame Images data of five different sectors of the TESS mission. Ten TESS transits of TOI-2202 b combined with three follow-up light curves obtained with the CHAT robotic telescope show strong transit timing variations (TTVs) with an amplitude of about 1.2 hr. Radial velocity follow-up with FEROS, HARPS, and PFS confirms the planetary nature of the transiting candidate (a b = 0.096 ± 0.001 au, m b = 0.98 ± 0.06 M Jup), and a dynamical analysis of RVs, transit data, and TTVs points to an outer Saturn-mass companion (a c = 0.155 ± 0.002 au, m c = 0.37 ± 0.10 M Jup) near the 2:1 mean motion resonance. Our stellar modeling indicates that TOI-2202 is an early K-type star with a mass of 0.82 M ⊙, a radius of 0.79 R ⊙, and solar-like metallicity. The TOI-2202 system is very interesting because of the two warm Jovian-mass planets near the 2:1 mean motion resonance, which is a rare configuration, and their formation and dynamical evolution are still not well understood.

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