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From fractional Fourier transformation to quantum mechanical fractional squeezing transformation 被引量:1
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作者 吕翠红 范洪义 李东韡 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第2期35-38,共4页
By converting the triangular functions in the integration kernel of the fractional Fourier transformation to the hyperbolic function,i.e.,tan α → tanh α,sin α →〉 sinh α,we find the quantum mechanical fractional... By converting the triangular functions in the integration kernel of the fractional Fourier transformation to the hyperbolic function,i.e.,tan α → tanh α,sin α →〉 sinh α,we find the quantum mechanical fractional squeezing transformation(FrST) which satisfies additivity.By virtue of the integration technique within the ordered product of operators(IWOP) we derive the unitary operator responsible for the FrST,which is composite and is made of e^iπa+a/2 and exp[iα/2(a^2 +a^+2).The FrST may be implemented in combinations of quadratic nonlinear crystals with different phase mismatches. 展开更多
关键词 fractional Fourier transformation fractional squeezing transformation unitary operator the IWOPtechnique
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Optical wavelet-fractional squeezing combinatorial transform
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作者 Cui-Hong Lv Ying Cai +1 位作者 Nan Jin Nan Huang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第2期209-216,共8页
By virtue of the method of integration within ordered product(IWOP)of operators we find the normally ordered form of the optical wavelet-fractional squeezing combinatorial transform(WFrST)operator.The way we successfu... By virtue of the method of integration within ordered product(IWOP)of operators we find the normally ordered form of the optical wavelet-fractional squeezing combinatorial transform(WFrST)operator.The way we successfully combine them to realize the integration transform kernel of WFr ST is making full use of the completeness relation of Dirac’s ket–bra representation.The WFr ST can play role in analyzing and recognizing quantum states,for instance,we apply this new transform to identify the vacuum state,the single-particle state,and their superposition state. 展开更多
关键词 wavelet transform fractional squeezing transform combinatorial transform IWOP technique
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Fractional squeezing-Hankel transform based on the induced entangled state representations
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作者 Cui-Hong Lv Su-Qing Zhang and Wen Xu 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第9期301-305,共5页
Based on the fact that the quantum mechanical version of Hankel transform kernel(the Bessel function) is just the transform between |q, r〉 and(s, r′|, two induced entangled state representations are given, and ... Based on the fact that the quantum mechanical version of Hankel transform kernel(the Bessel function) is just the transform between |q, r〉 and(s, r′|, two induced entangled state representations are given, and working with them we derive fractional squeezing-Hankel transform(FrSHT) caused by the operator e(-iα)(a1-a-2-+a-1a-2)e-(-iπa2-a2), which is an entangled fractional squeezing transform operator. The additive rule of the FrSHT can be explicitly proved. 展开更多
关键词 induced entangled state representation entangled fractional squeezing transform fractional squeezing-Hankel transform
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Coordinate-Dependent One- and Two-Mode Squeezing Transformation and the Corresponding Squeezed States
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作者 REN Gang SONG Tong-Qiang Department of Physics,Ningbo University,Ningbo 315211,China 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第12期1093-1098,共6页
We introduce the coordinate-dependent one-and two-mode squeezing transformations and discuss theproperties of the corresponding one-and two-mode squeezed states.We show that the coordinate-dependent one-and two-mode s... We introduce the coordinate-dependent one-and two-mode squeezing transformations and discuss theproperties of the corresponding one-and two-mode squeezed states.We show that the coordinate-dependent one-and two-mode squeezing transformations can be constructed by the combination of two transformations,a coordinate-dependentdisplacement followed by the standard squeezed transformation.Such a decomposition turns a nonlinear problem intoa linear one because all the calculations involving the nonlinear one- and two-mode squeezed transformation have beenshown to be able to reduce to those only concerning the standard one- and two-mode squeezed states. 展开更多
关键词 one-and two-mode squeezed states nonlinear Bogoliubov transformations
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Quantum Optical Squeezing Transform for Generalizing Fractional Fourier Transform
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作者 HU Li-Yun FAN Hong-Yi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第10期951-954,共4页
By establishing the relation between the optical scaled fractional Fourier transform (FFT) and quantum mechanical squeezing-rotating operator transform, we employ the bipartite entangled state representation of two-... By establishing the relation between the optical scaled fractional Fourier transform (FFT) and quantum mechanical squeezing-rotating operator transform, we employ the bipartite entangled state representation of two-mode squeezing operator to extend the scaled FFT to more general cases, such as scaled complex FFT and entangled scaled FFT. The additiyity and eigenmodes are presented in quantum version. The relation between the scaled FFT and squeezing-rotating Wigner operator is studied. 展开更多
关键词 squeezing transform scaled fractional Fourier transform IOWP technique
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Four-Particle Entangled State Representation and Its Squeezing Transformation
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作者 SONGTong-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第6期1107-1110,共4页
The four-particle EPR entangled state 【 p, X2,X3,X4 】 is constructed. Thecorresponding quantum mechanical operator with respect to the classical transformation p → e~(λ1)p, X2 → e~(λ2)X2, X3 → e~(λ3) X3, and ... The four-particle EPR entangled state 【 p, X2,X3,X4 】 is constructed. Thecorresponding quantum mechanical operator with respect to the classical transformation p → e~(λ1)p, X2 → e~(λ2)X2, X3 → e~(λ3) X3, and X4 → ee~(λ4) X4 in the state 【 p, X2, X3, X4 】 isinvestigated, and the four-mode realization of the S U(1, 1) Lie algebra as well as thecorresponding squeezing operators are presented. 展开更多
关键词 four-mode entangled state representation squeezing transformation four-modesqueezing operator
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Coordinate-Dependent Two-Mode Squeezing Transformations and the Corresponding Squeezed States
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作者 SONG Tong-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2期325-329,共5页
We introduce the coordinate-dependent two-mode squeezing transformations and discuss the properties of the corresponding two-mode squeezed states.
关键词 coordinate-dependent two-mode squeezing transformation two-mode squeezed states
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New Poisson Sum Formula Derived by Squeezing Transformation in Quantum Optics
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作者 范洪义 马善钧 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第4期637-639,共3页
Using squeezing transform in the context of quantum optics and based on the Fourier series expansion we rigorously derive a new Poisson sum formula. Application of this new formula to the representation transformation... Using squeezing transform in the context of quantum optics and based on the Fourier series expansion we rigorously derive a new Poisson sum formula. Application of this new formula to the representation transformation of kq-wave function for describing electrons in periodic lattice is demonstrated. In so doing, the transition matrix element of harmonic oscillator in kq representation is derived. 展开更多
关键词 new poisson sum formula squeezing transformation kq representation
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Coordinate-Dependent N-Mode Squeezing Transformations
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作者 REN Gang SONG Tong-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第4期1009-1012,共4页
We introduce the coordinate-dependent N-mode squeezing transformation and show that it cain be constructed by the combination of two unitary transformations, a coordinate-dependent displacement followed by the standar... We introduce the coordinate-dependent N-mode squeezing transformation and show that it cain be constructed by the combination of two unitary transformations, a coordinate-dependent displacement followed by the standard squeezed transformation. The properties of the corresponding N-mode squeezed states are also discussed. 展开更多
关键词 N-mode squeezing transformation N-mode nonlinear Bogoliubov transformation
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Squeezing Transformation of Three-Mode Entangled State
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作者 QIAN Xiao-Qing SONG Tong-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5X期911-916,共6页
We introduce the three-mode entangled state and set up an experiment to generate it. Then we discuss the three-mode squeezing operator squeezed |p, X2, X3〉→μ^-3/2|p/μ, X2/μ, X3/μ) and the optical implement to... We introduce the three-mode entangled state and set up an experiment to generate it. Then we discuss the three-mode squeezing operator squeezed |p, X2, X3〉→μ^-3/2|p/μ, X2/μ, X3/μ) and the optical implement to realize such a squeezed state. We also reveal that c-number .asymmetric shrink transform in the three-mode entangled state, i.e. |p, X2,X3)→μ^-1/2|p/μ, X2,X3), maps onto a kind of one-sided three-mode squeezing operator {iλ (∑i^3=1 Pi) (∑i^3=1 Qi) -λ/2}. Using the technique of integration within an ordered product (IWOP) of operators, we derive their normally ordered forms and construct the corresponding squeezed states. 展开更多
关键词 three-mode entangled state c-number asymmetric shrink transform one-sided three-mode squeezing operator
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Squeezing Properties of the Generalized Multimode Squeezed States
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作者 SONGTong-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第2期203-206,共4页
By means of the invariance of Weyl ordering under similar transformations we derive the explicit form of the generalized multimode squeezed states. Moreover, the completeness relation and the squeezing properties of t... By means of the invariance of Weyl ordering under similar transformations we derive the explicit form of the generalized multimode squeezed states. Moreover, the completeness relation and the squeezing properties of the generalized multimode squeezed states are discussed. 展开更多
关键词 generalized multimode squeezed state squeezing similar transformation
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New 3-mode bosonic operator realization of SU(2) Lie algebra:From the point of view of squeezing
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作者 笪诚 陈千帆 范洪义 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第9期62-64,共3页
We consider the quantum mechanical SU(2) transformation e^2λJzJ±e^-2λJz = e^±2λJ±as if the meaning of squeezing with e^±2λ being squeezing parameter. By studying SU(2) operators (J±,... We consider the quantum mechanical SU(2) transformation e^2λJzJ±e^-2λJz = e^±2λJ±as if the meaning of squeezing with e^±2λ being squeezing parameter. By studying SU(2) operators (J±, Jz) from the point of view of squeezing we find that (J±,Jz) can also be realized in terms of 3-mode bosonic operators. Employing this realization, we find the natural representation (the eigenvectors of J+ or J-) of the 3-mode squeezing operator e^2λJz. The idea of considering quantum SU(2) transformation as if squeezing is liable for us to obtain the new bosonic operator realization of SU(2) and new squeezing operators. 展开更多
关键词 quantum mechanical SU(2) transformation 3-mode squeezing operator new 3-mode bosonic op-erator realization of SU(2) Lie algebra
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基于同步挤压小波变换和Transformer的轴承故障诊断模型 被引量:4
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作者 张向宇 王衍学 《机电工程》 CAS 北大核心 2024年第6期1011-1019,共9页
针对采用神经网络对滚动轴承进行故障诊断时,故障信息利用不充分,特征提取困难的问题,提出了一种基于同步挤压小波变换(SST)-Transformer的滚动轴承智能故障诊断方法。首先,以同步挤压小波变换作为信号处理模块,将一维振动信号转为时频... 针对采用神经网络对滚动轴承进行故障诊断时,故障信息利用不充分,特征提取困难的问题,提出了一种基于同步挤压小波变换(SST)-Transformer的滚动轴承智能故障诊断方法。首先,以同步挤压小波变换作为信号处理模块,将一维振动信号转为时频图;接着,设计了一种最大程度保留故障信息的时频图分割方式,将时频图分割为一系列图像块序列;然后,将序列输入到具有强大的处理序列数据能力的Transformer模型中,进行了特征提取;最后,将特征数据输入分类器进行了分类,对比了不同的时频图分割方式的诊断效果,并将SST-Transformer模型与基准算法相比较。研究结果表明:相较于其他分割方式,基于SST-Transformer的滚动轴承智能故障诊断方法的诊断准确率提升了3.45%,并大幅提升了模型训练的收敛速度;相比于其他基准算法,该方法的平均准确率至少提升了1.05%。该方法有较高的诊断准确率和较好的稳定性。 展开更多
关键词 故障智能诊断 神经网络 故障特征提取 注意力机制 深度学习 同步挤压小波变换 transformer模型
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Coherent State Projection Operator Representation of Symplectic Transformations as a Loyal Representation of Symplectic Group
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作者 FAN Hong-Yi CHEN Jun-Hua 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第8期147-150,共4页
We find that the coherent state projection operator representation of symplectic transformation constitutesa loyal group representation of symplectic group. The result of successively applying squeezing operators on n... We find that the coherent state projection operator representation of symplectic transformation constitutesa loyal group representation of symplectic group. The result of successively applying squeezing operators on numberstate can be easily derived. 展开更多
关键词 COHERENT state PROJECTION operator SYMPLECTIC transformation squeezing OPERATOR
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A New Expression of the Fractional Fourier Transformation
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作者 YU Zu-Rong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第10期399-400,共2页
With the help of su(2) algebra technique, a new equivalent form of the fractional Fourier transformation is given. Two examples are illustrated for their physical application in quantum optics.
关键词 SU(2) algebra the FRACTIONAL FOURIER transformation squeezED state WIGNER operator
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Nonstandard Unitary Transformations of Quantum States
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作者 Gombojav O. Ariunbold 《Journal of Applied Mathematics and Physics》 2023年第9期2568-2575,共8页
In quantum optics, unitary transformations of arbitrary states are evaluated by using the Taylor series expansion. However, this traditional approach can become cumbersome for the transformations involving non-commuti... In quantum optics, unitary transformations of arbitrary states are evaluated by using the Taylor series expansion. However, this traditional approach can become cumbersome for the transformations involving non-commuting operators. Addressing this issue, a nonstandard unitary transformation technique is highlighted here with new perspective. In a spirit of “quantum” series expansions, the transition probabilities between initial and final states, such as displaced, squeezed and other nonlinearly transformed coherent states are obtained both numerically and analytically. This paper concludes that, although this technique is novel, its implementations for more extended systems are needed. 展开更多
关键词 Taylor Series Unitary transformation Temporal Evolution Displaced State Coherent State squeezed State Two-Mode squeezed State Holstein-Primakoff State
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基于多道同步挤压广义S变换的凌乱体属性断裂检测 被引量:1
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作者 文欢 王震 +4 位作者 丁立明 李杰 杜天玮 张奎 王群武 《地球物理学进展》 北大核心 2025年第3期992-1003,共12页
受限于传统时频分析算法分辨率的不足,导致地震数据从时间域转换至时频域后,时频谱能量发散,无法准确刻画地质信息.多道同步挤压广义S变换具有较高的时频聚焦能力,可以在地震数据从时间域转换至时频域时,尽可能的保留断裂信息,减少时频... 受限于传统时频分析算法分辨率的不足,导致地震数据从时间域转换至时频域后,时频谱能量发散,无法准确刻画地质信息.多道同步挤压广义S变换具有较高的时频聚焦能力,可以在地震数据从时间域转换至时频域时,尽可能的保留断裂信息,减少时频误差,进而开展时频域断裂识别.地震数据低频段对大中尺度断裂识别有利,地震数据高频段对微小断裂识别有利,因此基于时频域的断裂识别算法可以刻画不同尺度的断裂信息.地震凌乱体属性在断裂识别中具有很强的实用性,本文将凌乱体检测技术和多道同步挤压广义S变换结合开展地震数据断裂识别.通过理论模型及单道信号表明,多道同步挤压广义S变换算法具有高时频聚焦能力,融合凌乱体检测技术后,对大断裂具有更强的刻画能力,断层更连续,同时对微小断裂也能较好表征. 展开更多
关键词 时频分析 多道同步挤压广义S变换 时频分辨率 凌乱体属性
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基于振动监测数据的大跨斜拉桥实时索力识别 被引量:1
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作者 尚旭强 唐蕾 +1 位作者 黄天立 王亚飞 《铁道科学与工程学报》 北大核心 2025年第7期3303-3313,共11页
斜拉索实时索力识别是斜拉桥整体状态评估的关键步骤,然而现有的大多数索力识别方法通常只能计算一段时间内的平均索力。为实时监测斜拉桥索力变化,提出一种结合带通滤波器和同步压缩变换(synchrosqueezing transform,SST)的时变索力识... 斜拉索实时索力识别是斜拉桥整体状态评估的关键步骤,然而现有的大多数索力识别方法通常只能计算一段时间内的平均索力。为实时监测斜拉桥索力变化,提出一种结合带通滤波器和同步压缩变换(synchrosqueezing transform,SST)的时变索力识别新方法。首先,利用带通滤波器从斜拉索振动加速度响应中提取目标阶模态分量;然后使用SST识别提取的目标阶模态分量的瞬时频率;最后将识别的瞬时频率代入振动法公式中计算时变索力。通过斜拉索有限元数值案例,实验室斜拉索缩尺试验以及某双塔斜拉桥现场实测数据对该方法的时变索力识别精度及实用性进行验证。研究结果表明:在斜拉索有限元数值案例中,所提方法识别结果的平均误差为0.56%,最大误差为3.33%;在实验室斜拉索缩尺试验中,索力线性变化时,识别结果的平均误差为1.36%,最大误差为5.25%;索力正弦变化时,识别结果的平均误差为1.04%,最大误差为4.28%;在实际斜拉桥的时变索力识别中,所提方法的识别结果在合理范围内波动,验证了其实用性。针对不同的案例,所提方法均能实现从单个加速度传感器采集的数据中识别时变索力,且具有较高的识别精度。该方法识别过程简单高效,可用于现有斜拉桥的实时索力识别,从而为桥梁全生命周期内的高效管理和维护提供技术参考和理论支撑。 展开更多
关键词 大跨斜拉桥 时变索力 振动法 同步压缩变换 带通滤波器
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On the entangled fractional squeezing transformation 被引量:2
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作者 Hong-Yi Fan Jun-Hua Chen Peng-Fel Zhang 《Frontiers of physics》 SCIE CSCD 2015年第2期67-71,共5页
We propose an entangled fractional squeezing transformation (EFrST) generated by using two mu- tually conjugate entangled state representations with the following operator: e-iα(a1a2+a1a2)eiπa2a2; this transfo... We propose an entangled fractional squeezing transformation (EFrST) generated by using two mu- tually conjugate entangled state representations with the following operator: e-iα(a1a2+a1a2)eiπa2a2; this transformation sharply contrasts the complex fractional Fourier transformation produced by e-ia(a1a1+a2a2)eiπa2a2 (see Front. Phys. DOI 10.1007/s11467-014-0445-x). The EFrST is obtained by converting the triangular functions in the integration kernel of the usual fractional Fourier transformation into hyperbolic functions, i.e., tan α→ tanh α and sin α→ sinh α. The fractional property of the EFrST can be well described by virtue of the properties of the entangled state representations. 展开更多
关键词 entangled fractional squeezing transformation entangled state representation squeezingoperator core operator
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基于迭代压缩U型网络的煤颗粒分割与粒度分析方法 被引量:3
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作者 程德强 张瑞 +4 位作者 谢同喜 刘敬敬 郑丽娟 寇旗旗 江鹤 《煤炭学报》 北大核心 2025年第2期1362-1375,共14页
煤中甲烷气体传播与煤粒的粒度分布特征紧密相连,进而影响煤炭的安全开采和利用。随着数字图像处理技术的不断发展,基于数字图像分割的煤粒形态检测方法已成为获取煤颗粒粒度分布特征的主流方法。在数字图像分割过程中,全局信息和边缘... 煤中甲烷气体传播与煤粒的粒度分布特征紧密相连,进而影响煤炭的安全开采和利用。随着数字图像处理技术的不断发展,基于数字图像分割的煤粒形态检测方法已成为获取煤颗粒粒度分布特征的主流方法。在数字图像分割过程中,全局信息和边缘细节起着关键作用,直接影响分割结果的准确性。基于卷积神经网络架构的U型网络过于注重局部信息,忽视了全局信息的重要性,容易导致过分割现象。而基于Transformer的网络利用多头自注意力机制有效地建模了全局信息,但却没有充分利用边缘细节特征,导致煤颗粒漏分割问题。为了解决上述问题,本研究提出了迭代压缩U型网络(Iterative Squeeze UNet,ISUNet)用于煤颗粒粒度分析。ISUNet模型引入了压缩激励空洞空间金字塔池化模块和基于Transformer的多路迭代编码器。压缩激励空洞空间金字塔池化模块通过增强不同尺度特征的通道信息和全局上下文信息,解决了煤粒过分割问题。编码器中的多头自注意力模块将ResNet50的卷积特征作为其中一个输入,通过点乘自注意力机制不断强化重要的边缘细节特征,解决了煤粒漏分割问题。与5种经典图像分割模型和4种目前主流的分割模型相比,ISUNet表现出色。相较于经典的分割模型TransUNet来说,平均交并比提高了6.6%,准确率提高了0.3%,召回率提高了7.0%,相较于目前主流的图像分割大模型Segment Anything来说,平均交并比提高了4.6%,准确率提高了0.2%,召回率提高了4.9%。在煤粒粒度测量方面,准确率达到了97.49%。这些试验结果充分证实了ISUNet在煤粒粒度分析中的有效性和优越性。 展开更多
关键词 煤粒粒度分析 图像分割 基于transformer的多路迭代编码器 压缩激励空洞空间金字塔池化 U型网络
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