2,344 research outputs found
On using gait to enhance frontal face extraction
Visual surveillance finds increasing deployment formonitoring urban environments. Operators need to be able to determine identity from surveillance images and often use face recognition for this purpose. In surveillance environments, it is necessary to handle pose variation of the human head, low frame rate, and low resolution input images. We describe the first use of gait to enable face acquisition and recognition, by analysis of 3-D head motion and gait trajectory, with super-resolution analysis. We use region- and distance-based refinement of head pose estimation. We develop a direct mapping to relate the 2-D image with a 3-D model. In gait trajectory analysis, we model the looming effect so as to obtain the correct face region. Based on head position and the gait trajectory, we can reconstruct high-quality frontal face images which are demonstrated to be suitable for face recognition. The contributions of this research include the construction of a 3-D model for pose estimation from planar imagery and the first use of gait information to enhance the face extraction process allowing for deployment in surveillance scenario
On Using Gait Biometrics to Enhance Face Pose Estimation
Many face biometrics systems use controlled environments where subjects are viewed directly facing the camera. This is less likely to occur in surveillance environments, so a process is required to handle the pose variation of the human head, change in illumination, and low frame rate of input image sequences. This has been achieved using scale invariant features and 3D models to determine the pose of the human subject. Then, a gait trajectory model is generated to obtain the correct the face region whilst handing the looming effect. In this way, we describe a new approach aimed to estimate accurate face pose. The contributions of this research include the construction of a 3D model for pose estimation from planar imagery and the first use of gait information to enhance the face pose estimation process
Oscillation death in coupled counter-rotating identical nonlinear oscillators
We study oscillatory and oscillation suppressed phases in coupled
counter-rotating nonlinear oscillators. We demonstrate the existence of limit
cycle, amplitude death, and oscillation death, and also clarify the Hopf,
pitchfork, and infinite period bifurcations between them. Especially, the
oscillation death is a new type of oscillation suppressions of which the
inhomogeneous steady states are neutrally stable. We discuss the robust neutral
stability of the oscillation death in non-conservative systems via the
anti-PT-symmetric phase transitions at exceptional points in terms of
non-Hermitian systems.Comment: 7 pages, 4 figure
Amplitude death in a ring of nonidentical nonlinear oscillators with unidirectional coupling
We study the collective behaviors in a ring of coupled nonidentical nonlinear
oscillators with unidirectional coupling, of which natural frequencies are
distributed in a random way. We find the amplitude death phenomena in the case
of unidirectional couplings and discuss the differences between the cases of
bidirectional and unidirectional couplings. There are three main differences;
there exists neither partial amplitude death nor local clustering behavior but
oblique line structure which represents directional signal flow on the
spatio-temporal patterns in the unidirectional coupling case. The
unidirectional coupling has the advantage of easily obtaining global amplitude
death in a ring of coupled oscillators with randomly distributed natural
frequency. Finally, we explain the results using the eigenvalue analysis of
Jacobian matrix at the origin and also discuss the transition of dynamical
behavior coming from connection structure as coupling strength increases.Comment: 14 pages, 11 figure
Audio-Visual Spatial Integration and Recursive Attention for Robust Sound Source Localization
The objective of the sound source localization task is to enable machines to
detect the location of sound-making objects within a visual scene. While the
audio modality provides spatial cues to locate the sound source, existing
approaches only use audio as an auxiliary role to compare spatial regions of
the visual modality. Humans, on the other hand, utilize both audio and visual
modalities as spatial cues to locate sound sources. In this paper, we propose
an audio-visual spatial integration network that integrates spatial cues from
both modalities to mimic human behavior when detecting sound-making objects.
Additionally, we introduce a recursive attention network to mimic human
behavior of iterative focusing on objects, resulting in more accurate attention
regions. To effectively encode spatial information from both modalities, we
propose audio-visual pair matching loss and spatial region alignment loss. By
utilizing the spatial cues of audio-visual modalities and recursively focusing
objects, our method can perform more robust sound source localization.
Comprehensive experimental results on the Flickr SoundNet and VGG-Sound Source
datasets demonstrate the superiority of our proposed method over existing
approaches. Our code is available at: https://github.com/VisualAIKHU/SIRA-SSLComment: Camera-Ready, ACM MM 202
China\u27s Strategic Choices Towards North Korea and Iran
This study tests two hypotheses. First, China cooperates with the United States only when it is able to obtain material rewards. Second, without material incentives from the United States, China straddles between the United States on one hand and Iran and North Korea on the other. My findings show that neither Structural Realism, which holds anti-hegemonism alliance, nor Constructivism, which holds positive assimilation of the nuclear nonproliferation norm explains Chinese international behavior comprehensively. My balance of interest model explains Chinese foreign policy on the noncompliant states better. The cases cover the Sino-North Korean and Sino-Iranian diplomatic histories from 1990 to 2013 vis-à-vis the United States. The study is both a within-case comparison—that is, changes of China’s stance across time—and a cross-case comparison in China’s position regarding Iran and North Korea.
My comparisons contribute to theoretical and empirical analyses in international relations literature. Theoretically, the research creates different options for the third party between the two antagonistic actors. China will have seven different types of reaction: balancing, bandwagoning, mediating, and abetting that foster strategic clarity versus hiding, delaying, and straddling which are symptomatic of strategic ambiguity. I argue that there is a gradation between pure balancing and pure supporting. Empirically, the test results show that Chinese leaders have tried to find a balance between its material interests and international reputation by engaging in straddling and delaying inconsistently.
There are two major findings. First, China’s foreign policy has been reactive. Whereas prior to 2006, balancing against the U.S. had been a dominant strategy, since 2006, China has shown strategic ambiguity. Second, Chinese leaders believe that the preservation of stability in the region outweighs denuclearization of the noncompliant states, because it is in China’s interest to maintain a manageable tension between the U.S. and the noncompliant states. The balance of interest model suggests that the best way to understand China’s preferences is to consider them as products of rough calculation of risks and rewards on both the U.S. and the noncompliant states
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