Using a combined localization/detection model to simulate human localization performance near the masked detection threshold level

2002 ◽  
Vol 111 (5) ◽  
pp. 2467
Author(s):  
Jonas Braasch
Keyword(s):  
Detection Threshold ◽  
Threshold Level ◽  
Detection Model ◽  
Localization Performance ◽  
Masked Detection

scholarly journals An Efficient Robust Multiple Watermarking Algorithm for Vector Geographic Data

Information ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 296 ◽  
Author(s):  
Yingying Wang ◽  
Chengsong Yang ◽  
Changqing Zhu ◽  
Kaimeng Ding
Keyword(s):  
Detection Efficiency ◽  
Detection Threshold ◽  
Detection Algorithm ◽  
Multiple Watermarking ◽  
Detection Model ◽  
Detection Algorithms ◽  
Geographic Data ◽  
Multiple Watermarks ◽  
Watermark Algorithm ◽  
Made In

Vector geographic data play an important role in location information services. Digital watermarking has been widely used in protecting vector geographic data from being easily duplicated by digital forensics. Because the production and application of vector geographic data refer to many units and departments, the demand for multiple watermarking technology is increasing. However, multiple watermarking algorithm for vector geographic data draw less attention, and there are many urgent problems to be solved. Therefore, an efficient robust multiple watermark algorithm for vector geographic data is proposed in this paper. The coordinates in vector geographic data are first randomly divided into non-repetitive sets. The multiple watermarks are then embedded into the different sets. In watermark detection correlation, the Lindeberg theory is used to build a detection model and to confirm the detection threshold. Finally, experiments are made in order to demonstrate the detection algorithm, and to test its robustness against common attacks, especially against cropping attacks. The experimental results show that the proposed algorithm is robust against the deletion of vertices, addition of vertices, compression, and cropping attacks. Moreover, the proposed detection algorithm is compatible with single watermarking detection algorithms, and it has good performance in terms of detection efficiency.

scholarly journals Incoherent Integration Detection Method of Airborne Phased Array Radar in a Multipath Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yili Hu ◽  
Yongbo Zhao ◽  
Sheng Chen
Keyword(s):  
Phased Array ◽  
Detection Method ◽  
Detection Threshold ◽  
Constant False Alarm Rate ◽  
Detection Model ◽  
Cfar Detection ◽  
Phased Array Radar ◽  
Multipath Signal ◽  
Multipath Environment ◽  
Airborne Phased Array Radar

Airborne phased array radar (PAR) suffers from multipath problems when flying over a calm sea surface. The existence of a multipath phenomenon will cause the electromagnetic echo of the same target to be reflected back to the airborne PAR from two paths, namely, direct path (DP) and multipath. Compared with the ground-based radar, the target echo received by airborne PAR in the multipath environment has two important characteristics: one is that the DP signal and the multipath signal exist in different range bins, and the other is that the radar cross section (RCS) in the DP direction may be smaller than that in the multipath direction. Considering these two characteristics, this paper first proposes a target pairing algorithm for matching the DP range and multipath range of the same target in signal detection, and then, combined with the cell-averaging constant false alarm rate (CA-CFAR) detection model, an incoherent integration detection method for airborne PAR in the multipath environment is proposed. In the target pairing process, the geometric structure relationship of the airborne PAR model can be fully utilized. After a successful target pairing process, the energy of the multipath signal will be incoherently accumulated into the corresponding DP range bin, so as to improve the probability of DP range bin data passing the detection threshold. In essence, the proposed method makes full use of multipath energy to improve the detection capability of airborne PAR in the multipath environment. Finally, the detection probability of the proposed method is given, and the detection performance is analyzed.

scholarly journals UWB Localization System for Indoor Applications: Concept, Realization and Analysis

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Lukasz Zwirello ◽  
Tom Schipper ◽  
Marlene Harter ◽  
Thomas Zwick
Keyword(s):  
Detection Threshold ◽  
Threshold Level ◽  
Time Measurement ◽  
Error Sources ◽  
Localization Accuracy ◽  
Localization System ◽  
Average Accuracy ◽  
Measurement Results ◽  
Precise Analysis ◽  
Positioning Method

A complete impulse-based ultrawideband localization demonstrator for indoor applications is presented. The positioning method, along with the method of positioning error predicting, based on scenario geometry, is described. The hardware setup, including UWB transceiver and time measurement module, as well as the working principles is explained. The system simulation, used as a benchmark for the quality assessment of the performed measurements, is presented. Finally, the measurement results are discussed. The precise analysis of potential error sources in the system is conducted, based on both simulations and measurement. Furthermore, the methods, how to improve the average accuracy of 9 cm by including the influences of antennas and signal-detection threshold level, are made. The localization accuracy, resulting from those corrections, is 2.5 cm.

scholarly journals Coarse-to-Fine Adaptive People Detection for Video Sequences by Maximizing Mutual Information †

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 4
Author(s):  
Álvaro García-Martín ◽  
Juan SanMiguel ◽  
José Martínez
Keyword(s):  
Mutual Information ◽  
Detection Threshold ◽  
Ground Truth ◽  
Training Data ◽  
Training Dataset ◽  
People Detection ◽  
Detection Model ◽  
Unseen Data ◽  
Bounding Boxes ◽  
Coarse To Fine

Applying people detectors to unseen data is challenging since patterns distributions, such as viewpoints, motion, poses, backgrounds, occlusions and people sizes, may significantly differ from the ones of the training dataset. In this paper, we propose a coarse-to-fine framework to adapt frame by frame people detectors during runtime classification, without requiring any additional manually labeled ground truth apart from the offline training of the detection model. Such adaptation make use of multiple detectors mutual information, i.e., similarities and dissimilarities of detectors estimated and agreed by pair-wise correlating their outputs. Globally, the proposed adaptation discriminates between relevant instants in a video sequence, i.e., identifies the representative frames for an adaptation of the system. Locally, the proposed adaptation identifies the best configuration (i.e., detection threshold) of each detector under analysis, maximizing the mutual information to obtain the detection threshold of each detector. The proposed coarse-to-fine approach does not require training the detectors for each new scenario and uses standard people detector outputs, i.e., bounding boxes. The experimental results demonstrate that the proposed approach outperforms state-of-the-art detectors whose optimal threshold configurations are previously determined and fixed from offline training data.

Aging: Sensitivity vs Criterion in Taste Perception

1983 ◽  
Vol 6 (1) ◽  
pp. 105-115
Author(s):  
T. Kushnir ◽  
N. Shapira
Keyword(s):  
Strategic Behavior ◽  
Tap Water ◽  
Detection Threshold ◽  
Threshold Level ◽  
The Elderly ◽  
False Positives ◽  
Taste Perception ◽  
Elderly Subjects ◽  
Age Related ◽  
Young Subjects

The study employed the signal-detection paradigm as a model for investigating age related biological vs cognitive (decision) effects on perceptual behavior. Old and young subjects reported the presence or absence of sugar in threshold level solutions and tap water. It was found that the aged subjects displayed a higher detection threshold. They also obtained a higher (stricter) criterion of decision, fewer false-positives and a greater false-negatives-to-total-errors ratio. These findings were interpreted as strategic behavior motivated by the elderly subjects' greater need to perform well through reducing the error rate. A post-hoc interview found that most subjects equated the term 'error' with false-positives only. Therefore, the negative response bias found among the elderly subjects may represent a strategic attempt to reduce the rate of false-positive errors. It is also speculated that it may reflect a need to save energy, since negative responses imply an unwillingness to commit oneself to exert effort.

scholarly journals Evaluation of the psychophysical detection threshold level for vibrotactile and pressure stimulation of prosthetic limbs using bone anchorage or soft tissue support

2000 ◽  
Vol 24 (2) ◽  
pp. 133-142 ◽  
Author(s):  
R. Jacobs ◽  
R. Brånemark ◽  
K. Olmarker ◽  
B. Rydevik ◽  
D. van Steenberghe ◽  
...  
Keyword(s):  
Detection Threshold ◽  
Threshold Level ◽  
Contralateral Side ◽  
Vibratory Stimulation ◽  
Threshold Levels ◽  
Prosthetic Limb ◽  
Prosthetic Limbs ◽  
Amputation Stump ◽  
Significant Difference ◽  
Stimulation Of

In the present study the psychophysical detection threshold levels for mechanical stimulation of 32 prosthetic limbs were determined. Prosthetic limbs were anchored to the bone by means of an implant (n=17) or supported by a socket enclosing the amputation stump (n=15). Detection threshold levels were assessed for pressure and vibratory stimulation of the prosthesis and the limb at the contralateral side (control). Following vibratory stimulation, thresholds were increased on an avarage 20% for socket prostheses, but approached those of the control for boneanchored prostheses. For pressure stimulation, thresholds were increased up to 60% for socket prostheses and 40% for boneanchored prostheses compared to the control. While boneanchored prostheses yielded significantly lower threshold levels than socket prostheses, there was no significant difference between both treatments regarding pressure stimulation. Results were applicable to both upper and lower limb amputees. It could be concluded that detection thresholds for pressure and especially vibratory stimulation of prosthetic limbs were generally higher than for control limbs. The outcome was related to the prosthetic limb design with boneanchored prostheses yielding better perception than socket prostheses.

scholarly journals Transitional–turbulent spots and turbulent–turbulent spots in boundary layers

2017 ◽  
Vol 114 (27) ◽  
pp. E5292-E5299 ◽  
Author(s):  
Xiaohua Wu ◽  
Parviz Moin ◽  
James M. Wallace ◽  
Jinhie Skarda ◽  
Adrián Lozano-Durán ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Reynolds Shear Stress ◽  
Detection Threshold ◽  
Plate Boundary ◽  
Threshold Level ◽  
Viscous Sublayer ◽  
Small Scale ◽  
Bypass Transition ◽  
Turbulent Spot ◽  
Turbulent Spots

Two observations drawn from a thoroughly validated direct numerical simulation of the canonical spatially developing, zero-pressure gradient, smooth, flat-plate boundary layer are presented here. The first is that, for bypass transition in the narrow sense defined herein, we found that the transitional–turbulent spot inception mechanism is analogous to the secondary instability of boundary-layer natural transition, namely a spanwise vortex filament becomes aΛvortex and then, a hairpin packet. Long streak meandering does occur but usually when a streak is infected by a nearby existing transitional–turbulent spot. Streak waviness and breakdown are, therefore, not the mechanisms for the inception of transitional–turbulent spots found here. Rather, they only facilitate the growth and spreading of existing transitional–turbulent spots. The second observation is the discovery, in the inner layer of the developed turbulent boundary layer, of what we call turbulent–turbulent spots. These turbulent–turbulent spots are dense concentrations of small-scale vortices with high swirling strength originating from hairpin packets. Although structurally quite similar to the transitional–turbulent spots, these turbulent–turbulent spots are generated locally in the fully turbulent environment, and they are persistent with a systematic variation of detection threshold level. They exert indentation, segmentation, and termination on the viscous sublayer streaks, and they coincide with local concentrations of high levels of Reynolds shear stress, enstrophy, and temperature fluctuations. The sublayer streaks seem to be passive and are often simply the rims of the indentation pockets arising from the turbulent–turbulent spots.

scholarly journals Enhancing Multi-Camera People Detection by Online Automatic Parametrization Using Detection Transfer and Self-Correlation Maximization †

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4385
Author(s):  
Rafael Martín-Nieto ◽  
Álvaro García-Martín ◽  
José Martínez ◽  
Juan SanMiguel
Keyword(s):  
Critical Parameter ◽  
State Of The Art ◽  
Detection Threshold ◽  
Ground Truth ◽  
High Variability ◽  
Experimental Results ◽  
People Detection ◽  
Training Time ◽  
Detection Model ◽  
Complicated Task

Finding optimal parametrizations for people detectors is a complicated task due to the large number of parameters and the high variability of application scenarios. In this paper, we propose a framework to adapt and improve any detector automatically in multi-camera scenarios where people are observed from various viewpoints. By accurately transferring detector results between camera viewpoints and by self-correlating these transferred results, the best configuration (in this paper, the detection threshold) for each detector-viewpoint pair is identified online without requiring any additional manually-labeled ground truth apart from the offline training of the detection model. Such a configuration consists of establishing the confidence detection threshold present in every people detector, which is a critical parameter affecting detection performance. The experimental results demonstrate that the proposed framework improves the performance of four different state-of-the-art detectors (DPM , ACF, faster R-CNN, and YOLO9000) whose Optimal Fixed Thresholds (OFTs) have been determined and fixed during training time using standard datasets.

Maternal DDAVP-induced hyponatremia: Threshold level for fetal urinary diuresis

1998 ◽  
Vol 5 (1) ◽  
pp. 151A-151A
Author(s):  
M NIJLAND ◽  
T ROBERTS ◽  
M CURRAN ◽  
M ROSS
Keyword(s):  
Threshold Level

Role of pinnae and head movements in localizing pure tones 1The authors would like to thank Mr. Remi Humbert for implementing the experiment in Turbo Pascal and for his further assistance.

1999 ◽  
Vol 58 (3) ◽  
pp. 170-179 ◽  
Author(s):  
Barbara S. Muller ◽  
Pierre Bovet
Keyword(s):  
Sound Source ◽  
Head Movement ◽  
Movement Analysis ◽  
Head Movements ◽  
Sound Sources ◽  
Localization Accuracy ◽  
Sound Effects ◽  
Posterior Quadrant ◽  
Localization Performance ◽  
Pure Tones

Twelve blindfolded subjects localized two different pure tones, randomly played by eight sound sources in the horizontal plane. Either subjects could get information supplied by their pinnae (external ear) and their head movements or not. We found that pinnae, as well as head movements, had a marked influence on auditory localization performance with this type of sound. Effects of pinnae and head movements seemed to be additive; the absence of one or the other factor provoked the same loss of localization accuracy and even much the same error pattern. Head movement analysis showed that subjects turn their face towards the emitting sound source, except for sources exactly in the front or exactly in the rear, which are identified by turning the head to both sides. The head movement amplitude increased smoothly as the sound source moved from the anterior to the posterior quadrant.

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