Metasurfaces provide a potent platform for the dynamic manipulation of electromagnetic waves.Cou⁃pled with phase-change materials,they facilitate the creation of versatile metadevices,showcasing various tun⁃able funct...Metasurfaces provide a potent platform for the dynamic manipulation of electromagnetic waves.Cou⁃pled with phase-change materials,they facilitate the creation of versatile metadevices,showcasing various tun⁃able functions based on the transition between amorphous and crystalline states.However,the inherent limitation in tunable states imposes constraints on the multiplexing channels of metadevices.Here,this paper introduces a novel approach-a multi-functional metadevice achieved through the two-level control of the encoding phasechange metaatoms.Utilizing the phase-change material Ge_(2)Sb_(2)Se_(4)Te1(GSST)and high refractive-index liquid di⁃iodomethane(CH_(2)I_(2)),this paper showcases precise control over electromagnetic wave manipulation.The GSST state governs the tunable function,switching it ON and OFF,while the presence of liquid in the hole dictates the deflection angle when the tunable function is active.Importantly,our tunable coding metasurface exhibits robust performance across a broad wavelength spectrum.The incorporation of high refractive-index liquid extends the regulatory dimension of the metadevice,enabling dynamic switching of encoding bit levels.This two-level tun⁃able metadevice,rooted in phase-change materials,presents a promising avenue for the dynamic control of func⁃tions.展开更多
In this paper, more efficient, low-complexity and reliable region of interest （ROI） image codec for compressing smooth low texture remote sensing images is proposed. We explore the efficiency of the modified RO! cod...In this paper, more efficient, low-complexity and reliable region of interest （ROI） image codec for compressing smooth low texture remote sensing images is proposed. We explore the efficiency of the modified RO! codec with respect to the selected set of convenient wavelet filters, which is a novel method. Such ROI coding experiment analysis representing low bit rate lossy to high quality lossless reconstruction with timing analysis is useful for improving remote sensing ground truth surveillance efficiency in terms of time and quality. The subjective [i.e. fair, five observer （HVS） evaluations using enhanced 3D picture view Hyper memory display technology] and the objective results revealed that for faster ground truth ROI coding applications, the Symlet-4 adaptation performs better than Biorthogonal 4.4 and Biorthogonal 6.8. However, the discrete Meyer wavelet adaptation is the best solution for delayed ROI image reconstructions.展开更多
Whether the breakdown structure and coding system of construction projects are reasonable or not determines to a large degree the performance level of the entire project management. We analyze in detail the similariti...Whether the breakdown structure and coding system of construction projects are reasonable or not determines to a large degree the performance level of the entire project management. We analyze in detail the similarities and differences of two kinds of decomposing methods classified by type of work and construction elements based on the discussion of international typical coding standards system designing. We then deduce the differential coefficient relation between project breakdown structure (PBS) and work breakdown structure (WBS). At the same time we constitute a comprehensive construction project breakdown system including element code and type of work code and make a further schematic presentation of the implementation of the system’s functions.展开更多
In this paper, STC with water-filling transmit power distribution in MISO system is proposed when the partial channel information feedback is possible, for example, at slow fading scenario. The performances of the wat...In this paper, STC with water-filling transmit power distribution in MISO system is proposed when the partial channel information feedback is possible, for example, at slow fading scenario. The performances of the water-filling STC including water-filling STTC and water-filling STBC are analyzed. Performance comparison of the Ungerboeck's 2/3 trellis coded 8PSK modulated 2-STBC and 2-STTCs with QPSK is given out in different channel correlation.展开更多
To obtain the radar High Range Resolution (HRR) profile of the slowly moving ground target in strong clutter background, the Phase-Coded Hopped-Frequency (PCHF) waveform is proposed. By multiple-bursts coherent proces...To obtain the radar High Range Resolution (HRR) profile of the slowly moving ground target in strong clutter background, the Phase-Coded Hopped-Frequency (PCHF) waveform is proposed. By multiple-bursts coherent processing, the HRR profile synthesis, target velocity compensation and clutter compression can be accomplished simultaneously. The new waveform is shown to have good ability to suppress ground clutter and good Electronic Counter-CounterMeasures (ECCM) ability as well. The clutter compression performance of the proposed method is verified by the numerical results.展开更多
ASTEC and ICARE / CATHARE are computer codes allowing analysing severe accidents in LWRs. The applicability of these codes to Russian reactors of VVER type is a clear common IRSN-GRS objective. The current work in col...ASTEC and ICARE / CATHARE are computer codes allowing analysing severe accidents in LWRs. The applicability of these codes to Russian reactors of VVER type is a clear common IRSN-GRS objective. The current work in collaboration between IRSN and RRC K1 （Russia） aims at reaching this objective. This paper is devoted to ASTEC and ICARE / CATHARE simulations of a severe accident scenario on a VVER-1000. A Large Break LOCA （850 mm） sequence accompanied with the station blackout was selected for analysis. ICARE / CATHARE V2.2 successfully predicted main events of the accident： heat-up of the core, core degradation and melt relocation to the lower part of the core. A simulation of a complete accidental sequence was performed with ASTEC V 1.3-rev3 code： core heat-up and melting, melt relocation, reactor vessel rupture, molten corium / concrete interaction, release and distribution of steam, H2, CO, CO2, fission products and aerosols in the RCS and the containment. It must be pointed out that, as concerns the thermalhydraulics front-end phase and the in-vessel degradation phase, the ASTEC simulation exhibited consistent results with respect to the best-estimate ICARE / CATHARE ones.展开更多
In the present paper, we focus on constructive spherical codes. By employing algebraic geometry codes, we give an explicit construction of spherical code sequences. By making use of the idea involved in the proof of t...In the present paper, we focus on constructive spherical codes. By employing algebraic geometry codes, we give an explicit construction of spherical code sequences. By making use of the idea involved in the proof of the Gilbert-Varshamov bound in coding theory, we construct a spherical code sequence in exponential time which meets the best-known asymptotic bound by Shamsiev and Wyner.展开更多
We consider a symbolic coding of bi-infinite non periodic geodesics on the L-shaped translation surface tiled by three squares. Each bi-infinite non periodic geodesic is associated with a cutting sequence correspondin...We consider a symbolic coding of bi-infinite non periodic geodesics on the L-shaped translation surface tiled by three squares. Each bi-infinite non periodic geodesic is associated with a cutting sequence corresponding to the sequence of labeled saddle connections hit. We prove that there is a relationship between the cutting sequences and the actions of some affine automorphisms of the translation surface. We also get an explicit formula to determine the direction of a bi-infinite non periodic geodesic by using the corresponding cutting sequence.展开更多
基金Supported by the Strategic Priority Research Program(B)of Chinese Academy of Sciences(XDB0580000,XDB43010200)National Natural Science Foundation of China(62222514,62350073,U2341226,61991440)+5 种基金National Key Research and Development Program of China(2023YFA1406900)Shanghai Science and Technology Committee(23ZR1482000,22JC1402900,22ZR1472700)Natural Science Foundation of Zheji‐ang Province(LR22F050004)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)Youth Innovation Promotion Association(Y2021070)and International Partnership Program(112GJHZ2022002FN)of Chinese Academy of SciencesShanghai Human Resources and Social Security Bureau(2022670),and China Postdoctoral Science Foundation(2023T160661,2022TQ0353 and 2022M713261).
文摘Metasurfaces provide a potent platform for the dynamic manipulation of electromagnetic waves.Cou⁃pled with phase-change materials,they facilitate the creation of versatile metadevices,showcasing various tun⁃able functions based on the transition between amorphous and crystalline states.However,the inherent limitation in tunable states imposes constraints on the multiplexing channels of metadevices.Here,this paper introduces a novel approach-a multi-functional metadevice achieved through the two-level control of the encoding phasechange metaatoms.Utilizing the phase-change material Ge_(2)Sb_(2)Se_(4)Te1(GSST)and high refractive-index liquid di⁃iodomethane(CH_(2)I_(2)),this paper showcases precise control over electromagnetic wave manipulation.The GSST state governs the tunable function,switching it ON and OFF,while the presence of liquid in the hole dictates the deflection angle when the tunable function is active.Importantly,our tunable coding metasurface exhibits robust performance across a broad wavelength spectrum.The incorporation of high refractive-index liquid extends the regulatory dimension of the metadevice,enabling dynamic switching of encoding bit levels.This two-level tun⁃able metadevice,rooted in phase-change materials,presents a promising avenue for the dynamic control of func⁃tions.
基金Project (No. 2004144013) supported by the Chinese Government Scholarship Council, China
文摘In this paper, more efficient, low-complexity and reliable region of interest （ROI） image codec for compressing smooth low texture remote sensing images is proposed. We explore the efficiency of the modified RO! codec with respect to the selected set of convenient wavelet filters, which is a novel method. Such ROI coding experiment analysis representing low bit rate lossy to high quality lossless reconstruction with timing analysis is useful for improving remote sensing ground truth surveillance efficiency in terms of time and quality. The subjective [i.e. fair, five observer （HVS） evaluations using enhanced 3D picture view Hyper memory display technology] and the objective results revealed that for faster ground truth ROI coding applications, the Symlet-4 adaptation performs better than Biorthogonal 4.4 and Biorthogonal 6.8. However, the discrete Meyer wavelet adaptation is the best solution for delayed ROI image reconstructions.
文摘Whether the breakdown structure and coding system of construction projects are reasonable or not determines to a large degree the performance level of the entire project management. We analyze in detail the similarities and differences of two kinds of decomposing methods classified by type of work and construction elements based on the discussion of international typical coding standards system designing. We then deduce the differential coefficient relation between project breakdown structure (PBS) and work breakdown structure (WBS). At the same time we constitute a comprehensive construction project breakdown system including element code and type of work code and make a further schematic presentation of the implementation of the system’s functions.
文摘In this paper, STC with water-filling transmit power distribution in MISO system is proposed when the partial channel information feedback is possible, for example, at slow fading scenario. The performances of the water-filling STC including water-filling STTC and water-filling STBC are analyzed. Performance comparison of the Ungerboeck's 2/3 trellis coded 8PSK modulated 2-STBC and 2-STTCs with QPSK is given out in different channel correlation.
基金Supported by the National Natural Science Foundation of China (No.60302009).
文摘To obtain the radar High Range Resolution (HRR) profile of the slowly moving ground target in strong clutter background, the Phase-Coded Hopped-Frequency (PCHF) waveform is proposed. By multiple-bursts coherent processing, the HRR profile synthesis, target velocity compensation and clutter compression can be accomplished simultaneously. The new waveform is shown to have good ability to suppress ground clutter and good Electronic Counter-CounterMeasures (ECCM) ability as well. The clutter compression performance of the proposed method is verified by the numerical results.
文摘ASTEC and ICARE / CATHARE are computer codes allowing analysing severe accidents in LWRs. The applicability of these codes to Russian reactors of VVER type is a clear common IRSN-GRS objective. The current work in collaboration between IRSN and RRC K1 （Russia） aims at reaching this objective. This paper is devoted to ASTEC and ICARE / CATHARE simulations of a severe accident scenario on a VVER-1000. A Large Break LOCA （850 mm） sequence accompanied with the station blackout was selected for analysis. ICARE / CATHARE V2.2 successfully predicted main events of the accident： heat-up of the core, core degradation and melt relocation to the lower part of the core. A simulation of a complete accidental sequence was performed with ASTEC V 1.3-rev3 code： core heat-up and melting, melt relocation, reactor vessel rupture, molten corium / concrete interaction, release and distribution of steam, H2, CO, CO2, fission products and aerosols in the RCS and the containment. It must be pointed out that, as concerns the thermalhydraulics front-end phase and the in-vessel degradation phase, the ASTEC simulation exhibited consistent results with respect to the best-estimate ICARE / CATHARE ones.
文摘In the present paper, we focus on constructive spherical codes. By employing algebraic geometry codes, we give an explicit construction of spherical code sequences. By making use of the idea involved in the proof of the Gilbert-Varshamov bound in coding theory, we construct a spherical code sequence in exponential time which meets the best-known asymptotic bound by Shamsiev and Wyner.
基金supported by National Natural Science Foundation of China(Grant No.11371035)
文摘We consider a symbolic coding of bi-infinite non periodic geodesics on the L-shaped translation surface tiled by three squares. Each bi-infinite non periodic geodesic is associated with a cutting sequence corresponding to the sequence of labeled saddle connections hit. We prove that there is a relationship between the cutting sequences and the actions of some affine automorphisms of the translation surface. We also get an explicit formula to determine the direction of a bi-infinite non periodic geodesic by using the corresponding cutting sequence.
