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Four levels of pattern recognition
Analytica Chimica Acta, 1978Abstract Problems of pattern recognition in chemistry and other subjects can be divided conveniently into four different types depending on the level of scope of the problem. (1) Classification into one of a number of defined classes. As an example blood samples taken from persons known to be either controls or welders are considered. The problem is
Christer Albano +6 more
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2014
This chapter is a brief description of the four levels in Chinese medicine, which chronicles the stages of symptoms as a pathogen penetrates levels of the body from the exterior to the interior. The first is the wei level, which corresponds to the taiyang stage, which describes the initial symptoms after a pathogenic invasion.
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This chapter is a brief description of the four levels in Chinese medicine, which chronicles the stages of symptoms as a pathogen penetrates levels of the body from the exterior to the interior. The first is the wei level, which corresponds to the taiyang stage, which describes the initial symptoms after a pathogenic invasion.
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Four-level ultrafast modulation spectroscopy
Optics Communications, 1998Abstract Based on the interference between two two-photon processes, we demonstrated a four-level ultrafast modulation spectroscopy in Na vapor, where 3S, 3P, 5S and 4D formed a four-level system. We obtained signal modulation with period of 25 fs, corresponding to the splitting between 5S and 4D.
Xin Mi +4 more
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Four-level video summary coding
2010 3rd International Congress on Image and Signal Processing, 2010In this paper, we describe the video content using the codebooks of four summary levels, which are from lower to higher. The four levels are the local feature point, consistent region, object and scene. The local feature point is viewpoint and scale-invariant, and is described using local descriptor; the consistent region is the region that the color ...
Zhenyong Fu +3 more
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2017
In Chap. 2, we discussed the interaction between a single two-level atom and an electromagnetic (EM) field.
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In Chap. 2, we discussed the interaction between a single two-level atom and an electromagnetic (EM) field.
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Four levels of self-interpretation
Philosophy & Social Criticism, 2004If we are to find the criteria for critical analyses of social arrangements and processes not in some abstract, universalist framework, but from the guiding ‘self-interpretations’ of the societies in question, as contemporary contextualist and ‘communitarian’ approaches to social philosophy suggest, the vexing question arises as to where these self ...
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Nonreciprocal Amplification with Four-Level Hot Atoms
Physical Review Letters, 2019Optical nonreciprocity is of paramount importance to optical signal processing and one-way optical communication. Here, we theoretically and experimentally demonstrate nonreciprocal amplification based on four-level hot atoms by exploiting atomic Doppler shifts. Our approach is simple and easy to implement.
Gongwei, Lin +5 more
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Optical bistability in four-level nonradiative dyes
Optics Communications, 1983Most saturably absorbing dyes show a large unstaturable loss which removes the possibility of purely absorptive bistability. However, nonradiative dyes such as those used for Q-switching have an intensity-dependent phase shift which may allow bistability.
Zhen Fu Zhu, E. Garmire
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Realization of Four-Level Qudits Using Biphotons
Physical Review Letters, 2006The novel experimental realization of four-level optical quantum systems (ququarts) is presented. We exploit the polarization properties of the frequency nondegenerate biphoton field to obtain such systems. A simple method that does not rely on am interferometer is used to generate and measure the sequence of states that can be used in quantum key ...
Moreva, E.V. +3 more
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Covariant cloning machines for four-level systems
Physical Review A, 2003The study of quantum cryptography and quantum entanglement has traditionally been based on two-level quantum systems (qubits) and more recently on three-level systems (qutrits). We investigate several classes of state-dependent quantum cloners for four-level systems (quartits). These results apply to symmetric as well as asymmetric cloners, so that the
Durt, Thomas, Nagler, Bob
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