The organization of biological neuronal networks into functional modules has intrigued scientists and inspired engineers to develop artificial systems.These networks are characterized by two key properties.First,they ...The organization of biological neuronal networks into functional modules has intrigued scientists and inspired engineers to develop artificial systems.These networks are characterized by two key properties.First,they exhibit dense interconnectivity(Braitenburg and Schüz,1998;Campagnola et al.,2022).The strength and probability of connectivity depend on cell type,inter-neuronal distance,and species.Still,every cortical neuron receives input from thousands of other neurons while transmitting output to a similar number of neurons.Second,communication between neurons occurs primarily via chemical or electrical synapses.展开更多
To extract and display the significant information of combat systems,this paper introduces the methodology of functional cartography into combat networks and proposes an integrated framework named“functional cartogra...To extract and display the significant information of combat systems,this paper introduces the methodology of functional cartography into combat networks and proposes an integrated framework named“functional cartography of heterogeneous combat networks based on the operational chain”(FCBOC).In this framework,a functional module detection algorithm named operational chain-based label propagation algorithm(OCLPA),which considers the cooperation and interactions among combat entities and can thus naturally tackle network heterogeneity,is proposed to identify the functional modules of the network.Then,the nodes and their modules are classified into different roles according to their properties.A case study shows that FCBOC can provide a simplified description of disorderly information of combat networks and enable us to identify their functional and structural network characteristics.The results provide useful information to help commanders make precise and accurate decisions regarding the protection,disintegration or optimization of combat networks.Three algorithms are also compared with OCLPA to show that FCBOC can most effectively find functional modules with practical meaning.展开更多
A piezoelectric platform using function module actuator is presented to achieve nano-positioning and high frequency scanning in large working range. A function module actuator is designed to produce a pair of orthogon...A piezoelectric platform using function module actuator is presented to achieve nano-positioning and high frequency scanning in large working range. A function module actuator is designed to produce a pair of orthogonal bending deformations and a longitudinal deformation through partition exciting. The bending deformations are used to actuate the planar motion,while the longitudinal deformation is utilized to dynamically adjust the driving force and broaden the scanning frequency. The dynamic model of the platform system is developed. The open-loop performances of a prototype are first tested: a scan frequency of 308 Hz in a scanning range of 3.368 μm×3.396 μm is measured in direct actuation mode,and the displacement resolution is measured to be 16 nm;maximum speed is measured to be 3.38 mm s^-1 in the inertial actuation mode. Furthermore,the closedloop experiments are carried out and a switching strategy is proposed to obtain the switching of the inertial and direct actuation modes automatically;the platform achieves the scanning with frequency of 300 Hz at the set position.展开更多
In this paper, we firstly identify the functional modules enriched with differentially expressed genes （DEGs） and characterized by biological processes in specific cellular locations, based on gene ontology （GO） a...In this paper, we firstly identify the functional modules enriched with differentially expressed genes （DEGs） and characterized by biological processes in specific cellular locations, based on gene ontology （GO） and microarray data. Then, we further define and filter disease relevant signature modules according to the ranking of the disease discriminating abilities of the pre-selected functional modules. At last, we analyze the potential way by which they cooperate towards human disease. Application of the proposed method to the analysis of a liver cancer dataset shows that, using the same false discovery rate （ FDR ） threshold, we can find more biologically meaningful and detailed processes by using the cellular localization information. Some biological evidences support the relevancy of our biological modules to the disease mechanism.展开更多
AIM:To investigate how angles kappa and alpha affect postoperative visual quality in patients with multifocal intraocular lens(mIOLs)implantation.METHODS:Retrospective cases series.A total of 46 patients(46 eyes)who u...AIM:To investigate how angles kappa and alpha affect postoperative visual quality in patients with multifocal intraocular lens(mIOLs)implantation.METHODS:Retrospective cases series.A total of 46 patients(46 eyes)who underwent phacoemulsification were subsumed.The correlation between Preoperative angles kappa and alpha,wave-front aberrations and objective visual quality of cornea,internal,and total eye after surgery were analyzed using iTrace.RESULTS:The magnitude of angle kappa was negatively correlated with internal and total modulation transfer function(MTF)at 3 mm;the magnitude of angle kappa was positively correlated with astigmatism,trefoil,higher-order aberrations(HOAs)of both internal and total eye at 3 mm.The magnitude of angle alpha was negatively correlated with total MTF and total Strehl ratio at 3 mm.The magnitude of angle alpha was positively correlated with corneal coma at 5 mm,internal astigmatism at both 3 mm and 5 mm,and total spherical aberration(SA)at 3 mm.Multivariate linear regression analysis showed that,among candidate independent variables(kappa,alpha,astigmatism,SA,coma,trefoil,and HOAs),astigmatism is the only independent factor for altering corneal MTF at 3 mm and 5 mm;astigmatism and HOAs emerged as independent factors for altering internal MTF at 3 mm and 5 mm,and total MTF at 3 mm;astigmatism,SA and HOAs emerged as independent factors for altering total MTF at 5 mm.CONCLUSION:With greater preoperative angle kappa or angle alpha,patients who accept mIOL implantation tend to have larger internal astigmatism and HOAs,which resulting in poor visual quality,especially those with small pupil size.展开更多
Continuing advancement in astronomy,space exploration,and scientific detection,has increased demand for infrared multi-band detection systems.Traditional three-band optical systems,designed to simultaneously image at ...Continuing advancement in astronomy,space exploration,and scientific detection,has increased demand for infrared multi-band detection systems.Traditional three-band optical systems,designed to simultaneously image at infrared short-wave,mid-wave,and long-wave bands typically rely on dispersive elements,leading to bulky sizes,complex system architectures,low efficiency,and challenges in rapid assembly.To overcome these obstacles,in combination with the latest third-generation infrared detectors,we propose a design for a compact and lightweight three-band optical system,with infrared capabilities in all three required bands.The core of this approach is an integrated design philosophy that emphasizes the high steepness of mirror surfaces.This design achieves uniform correction and optimization of chromatic aberration and off-axis aberration across the spectral range.We introduce a novel integration of optical and mechanical elements to replace traditional assembly,reducing manufacturing and assembly errors,and degrees of freedom,associated with high-power optical elements.Confirming the effectiveness through a combination of simulations and experimental comparisons,the measured mid-wave full-field transfer function exceeds 0.405 at 17 lp/mm,satisfying the imaging requirements of the system.The optical system is lightweight and compact,with a total mass under 408 g and a compact volume of justΦ112 mm×117 mm.This serves as a valuable reference for the engineering application of high-performance,compact multi-band infrared composite detection systems for astronomy and space exploration.展开更多
AIM: To describe the characteristics of modulation transfer function (MTF) of anterior corneal surface, and obtain the the normal reference range of MTF at different spatial frequencies and optical zones of the anteri...AIM: To describe the characteristics of modulation transfer function (MTF) of anterior corneal surface, and obtain the the normal reference range of MTF at different spatial frequencies and optical zones of the anterior corneal surface in myopes. METHODS: Four hundred eyes from 200 patients were examined under SIRIUS corneal topography system. Phoenis analysis software was applied to simulate the MTF curves of anterior corneal surface at vertical and horizontal meridians at the 3, 4, 5, 6, 7mm optical zones of cornea. The MTF values at spatial frequencies of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60 cycles/degree (c/d) were selected. RESULTS: The MTF curve of anterior corneal surface decreased rapidly from low to intermediate frequency (0-15cpd) at various optical zones of cornea, the value decreased to 0 slowly at higher frequency (>15cpd). With the increase of the optical zones of cornea, MTF curve decreased gradually. 3) In the range of 3 mm- 6 mm optical zones of the cornea, the MTF values measured at horizontal meridian were greater than the corresponding values at horizontal meridian of each spatial frequency, the difference was statistically significant (P<0.05). At 7 mm optical zones of cornea, the MTF values measured at horizontal meridian were less than the corresponding values at vertical meridian at 10-60 spatial frequencies (cpd), and the difference was statistically significant in 25, 30, 35, 40, 45, 50 cpd(P<0.05). CONCLUSION: MTF can be used to describe the imaging quality of optical systems at anterior corneal surface objectively in detail.展开更多
The resolution characteristic can be obtained by the modulation transfer function （MTF） of a GaAs/GaA1As photocathode. After establishing the theoretical model of GaAs（100）-oriented atomic configuration and the fo...The resolution characteristic can be obtained by the modulation transfer function （MTF） of a GaAs/GaA1As photocathode. After establishing the theoretical model of GaAs（100）-oriented atomic configuration and the formula for the ionized impurity scattering of the non-equilibrium carriers, this paper calculates the trajectories of photoelectrons in a photocathode. Thus the distribution of photoelectron spots on the emit-face is obtained, which is namely the point spread function. The MTF is obtained by Fourier transfer of the line spread function obtained from the point spread function. The MTF obtained from these calculations is shown to depend heavily on the electron diffusion length, and enhanced considerably by decreasing the electron diffusion length and increasing the doping concentration. Furthermore, the resolution is enhanced considerably by increasing the active-layer thickness, especially at high spatial frequencies. The best spatial resolution is 860 lp/mm, for the GaAs photocathode of doping concentration 1 ×10^19 cm 3 electron diffusion length 3.6 μm and the active-layer thickness 2 μm, under the 633-nm light irradiated. This research will contribute to the future improvement of the cathode＇s resolution for preparing a high performance GaAs photocathode, and improve the resolution of a low light level image intensifier.展开更多
When imaging ocean surface waves by X-band marine radar, the radar backscatter from the sea surface is modulated by the long surface gravity waves. The modulation transfer function （MTF） comprises tilt, hydrodynamic...When imaging ocean surface waves by X-band marine radar, the radar backscatter from the sea surface is modulated by the long surface gravity waves. The modulation transfer function （MTF） comprises tilt, hydrodynamic, and shadowing modulations. A conventional linear MTF was derived using HH-polarized radar observations under conditions of deep water. In this study, we propose a new quadratic polynomial MTF based on W-polarized radar measurements taken from heterogeneous nearshore wave fields. This new MTF is obtained using a radar-observed image spectrum and in situ buoy-measured wave frequency spectrum. We validate the MTF by comparing peak and mean wave periods retrieved from X-band marine radar image sequences with those measured by the buoy. It is shown that the retrieval accuracies of peak and mean wave periods of the new MTF are better than the conventional MTF. The results also show that the bias and root mean square errors of the peak and mean wave periods of the new MTF are 0.05 and 0.88 s, and 0.32 and 0.53 s, respectively, while those of the conventional MTF are 0.61 and 0.98 s, and 1.39 and 1.48 s, respectively. Moreover, it is also shown that the retrieval results are insensitive to the coefficients in the proposed MTF.展开更多
An efficient unbiased estimation method is proposed for the direct identification of linear continuous-time system with noisy input and output measurements.Using the Gaussian modulating filters,by numerical integratio...An efficient unbiased estimation method is proposed for the direct identification of linear continuous-time system with noisy input and output measurements.Using the Gaussian modulating filters,by numerical integration,an equivalent discrete identification model which is parameterized with continuous-time model parameters is developed,and the parameters can be estimated by the least-squares (LS) algorithm.Even with white noises in input and output measurement data,the LS estimate is biased,and the bias is determined by the variances of noises.According to the asymptotic analysis,the relationship between bias and noise variances is derived.One equation relating to the measurement noise variances is derived through the analysis of the LS errors.Increasing the degree of denominator of the system transfer function by one,an extended model is constructed.By comparing the true value and LS estimates of the parameters between original and extended model,another equation with input and output noise variances is formulated.So,the noise variances are resolved by the set of equations,the LS bias is eliminated and the unbiased estimates of system parameters are obtained.A simulation example by comparing the standard LS with bias eliminating LS algorithm indicates that the proposed algorithm is an efficient method with noisy input and output measurements.展开更多
AIM:To analyze the retinal modulation transfer function between amblyopes whose visual acuity was corrected to 5.0 and normal subjects at the same age. METHODS: RM-800 used to detect contrast sensitivity was adopted t...AIM:To analyze the retinal modulation transfer function between amblyopes whose visual acuity was corrected to 5.0 and normal subjects at the same age. METHODS: RM-800 used to detect contrast sensitivity was adopted to measure MTF of 96 amblyopes (96 eyes) whose visual acuity was corrected to 5.0 and 80 normal controls (80 eyes) at the same age under six interference fringes (IVA=0.06, 0.1, 0.2, 0.4, 0.6, 0.8). RESULTS: The functional values of amblyopes were significantly lower than those of normal subjects in every fringe (P<0.01), especially in medium and high frequency. CONCLUSION: For amblyopes, MTF was still abnormal after stopping the treatments.展开更多
The atmospheric scattering optical transfer function （OTF） is solved by applying the multi-coupled single scattering （MCSS） method to the three-dimensional radiative transfer equation （RTE） under the periodic gr...The atmospheric scattering optical transfer function （OTF） is solved by applying the multi-coupled single scattering （MCSS） method to the three-dimensional radiative transfer equation （RTE） under the periodic ground condition. This approach is a direct hit to the atmospheric scattering OTF using the same original context of modulation transfer function （MTF） measurement, i.e., images of sinusoidal grating at different spatial frequencies. Both the amplitude and phase shift of the OTF at various zenith and azimuth angles can be obtained at an arbitrary spatial frequency.展开更多
The key difficulty of restoring a fuzzy image is to estimate its point spread function( PSF). In the paper,PSF is modelled based on modulation transfer function( MTF). The first step is calculating the image MTF. In t...The key difficulty of restoring a fuzzy image is to estimate its point spread function( PSF). In the paper,PSF is modelled based on modulation transfer function( MTF). The first step is calculating the image MTF. In the traditional slanted-edge method,a sub-block is always manually extracted from original image and its MTF will be viewed as the result of the whole image. However,handcraft extraction is inefficient and will lead to inaccurate results. Given this,an automatic MTF computation algorithm is proposed,which extracts and screens out all the effective sub-blocks and calculates their average MTF as the final result. Then,a two-dimensional MTF restoration model is constructed by multiplying the horizontal and vertical MTF,and it is combined with conventional image restoration methods to restore fuzzy image. Experimental results indicate the proposed method implementes a fast and accurate MTF computation and the MTF model improves the performance of conventional restoration methods significantly.展开更多
Deoxyribozyme(DNAzyme)and its substrate hybridization are crucial for achieving desirable detection performance in the DNAzyme coupling nanomaterial biosensor system.However,interfacial factors such as electrostatic r...Deoxyribozyme(DNAzyme)and its substrate hybridization are crucial for achieving desirable detection performance in the DNAzyme coupling nanomaterial biosensor system.However,interfacial factors such as electrostatic repulsion,steric hindrance,and nonspecific adsorption from gold nanoparticles make this hybridization process complicated and challenging.Moreover,the DNAzyme structure changes with different application purposes,which might affect the DNAzyme and substrate's connection.Few studies have focused on the interplay of DNAzyme and interfacial factors in the biosensor field.In this work,three types of DNAzyme variants were designed,and their biosensor performance rules were studied and summarized with the synergistic effect of interfacial factors.Additionally,corresponding biosensor applications,such as multiple modulation functions and mi RNA detections,were constructed based on the distinct principles of DNAzyme variants.展开更多
Linux-based Platform for Open Architecture Controller ( POAC ), a new open architecture controller and its modular developing method are discussed. POAC divides the application software of controller into the developi...Linux-based Platform for Open Architecture Controller ( POAC ), a new open architecture controller and its modular developing method are discussed. POAC divides the application software of controller into the developing system and the application system. In the developing system, PAOC abstracts a series of function modules with unified data interface and function interface. In the application system, POAC defines the model of the architecture module, realizing the interoperability and interchangeability between the architecture modules. The modular developing method entities the users to make up an application system with some architecture modules, which consist of a set of function modules. The modular developing method decreases the developing time from the standard of controller architecture to the product.展开更多
Considering research on multi-objective optimization for reliability and performance suffering cost constraints in digital circuits,an improved multi-objective optimization algorithm based on performance and reliabili...Considering research on multi-objective optimization for reliability and performance suffering cost constraints in digital circuits,an improved multi-objective optimization algorithm based on performance and reliability was proposed to solve the problem of discrete system resources configuration in this paper. This algorithm used the particle-swarm optimization( PSO) to evaluate the tradeoffs configuration of the system resources between reliability and performance and proved the feasibility through the simulation.Finally, the information of resources configuration from optimization algorithm was used to effectively guide the system design so as to mitigate soft errors caused by single event effect( SEE).展开更多
Coronary artery disease （CAD） is a complex human disease, involving multiple genes and their nonlinear interactions, which often act in a modular fashion. Genome-wide single nucleotide polymorphism （SNP） profiling...Coronary artery disease （CAD） is a complex human disease, involving multiple genes and their nonlinear interactions, which often act in a modular fashion. Genome-wide single nucleotide polymorphism （SNP） profiling provides an effective technique to unravel these underlying genetic interplays or their functional involvements for CAD. This study aimed to identify the susceptible pathways and modules for CAD based on SNP omics. First, the Wellcome Trust Case Control Consortium （WTCCC） SNP datasets of CAD and control samples were used to assess the joint effect of multiple genetic variants at the pathway level, using logistic kernel machine regression model. Then, an expanded genetic network was constructed by integrating statistical gene-gene interactions involved in these susceptible pathways with their protein protein interaction （PPI） knowledge. Finally, risk functional modules were identified by decomposition of the network. Of 276 KEGG pathways analyzed, 6 pathways were found to have a significant effect on CAD. Other than glycerolipid metabolism, glycosaminoglycan biosynthesis, and cardiac muscle contraction pathways, three pathways related to other diseases were also revealed, including Alzheimer＇s disease, non-alcoholic fatty liver disease, and Huntington＇s disease. A genetic epistatic network of 95 genes was further constructed using the abovementioned integrative approach. Of 10 functional modules derived from the network, 6 have been annotated to phospholipase C activity and cell adhesion molecule binding, which also have known functional involvement in Alzheimer＇s disease. These findings indicate an overlap of the underlying molecular mechanisms between CAD and Alzheimer＇s disease, thus providing new insights into the molecular basis for CAD and its molecular relationships with other diseases.展开更多
Selecting differentially expressed genes(DEGs) is one of the most important tasks in microarray applications for studying multi-factor diseases including cancers.However,the small samples typically used in current mic...Selecting differentially expressed genes(DEGs) is one of the most important tasks in microarray applications for studying multi-factor diseases including cancers.However,the small samples typically used in current microarray studies may only partially reflect the widely altered gene expressions in complex diseases,which would introduce low reproducibility of gene lists selected by statistical methods.Here,by analyzing seven cancer datasets,we showed that,in each cancer,a wide range of functional modules have altered gene expressions and thus have high disease classification abilities.The results also showed that seven modules are shared across diverse cancers,suggesting hints about the common mechanisms of cancers.Therefore,instead of relying on a few individual genes whose selection is hardly reproducible in current microarray experiments,we may use functional modules as functional signatures to study core mechanisms of cancers and build robust diagnostic classifiers.展开更多
An approach to identification of linear continuous-time system is studied with modulating functions. Based on wavelet analysis theory, the multi-resolution modulating functions are designed, and the corresponding filt...An approach to identification of linear continuous-time system is studied with modulating functions. Based on wavelet analysis theory, the multi-resolution modulating functions are designed, and the corresponding filters have been analyzed. Using linear modulating filters, we can obtain an identification model that is parameterized directly in continuous-time model parameters. By applying the results from discrete-time model identification to the obtained identification model, a continuous-time estimation method is developed. Considering the accuracy of parameter estimates, an instrumental variable (Ⅳ) method is proposed, and the design of modulating integral filter is discussed. The relationship between the accuracy of identification and the parameter of modulating filter is investigated, and some points about designing Gaussian wavelet modulating function are outlined. Finally, a simulation study is also included to verify the theoretical results.展开更多
Niche theory is one of the most important ecological theories. It is widely applied to analyzing such phenomena as competition among, and evolution of, urban ecosystem functional modules. This paper describes a study ...Niche theory is one of the most important ecological theories. It is widely applied to analyzing such phenomena as competition among, and evolution of, urban ecosystem functional modules. This paper describes a study concerning＇different functional modules of Kaifeng city urban ecosystem. Niche theory and techniques were used to analyze the changes of these functional modules in the period 1994-2003. The results showed that, in the period 1994-2003： （1） Niche value of the atmospheric environment and urban virescence modules increased, while niche value of the water environment and sound environment modules decreased; （2） niche value of the tertiary industry module increased, niche value of the secondary industry module decreased, while niche value of the primary industry module showed little change; and （3） niche value of the infrastructure, resource distribution, and production ＆ social security modules increased, while niche value of the population module decreased. This study may contribute to macroscopic planning of urban functional modules, economic development, and environmental protection.展开更多
基金supported in part by the Rosetrees Trust(#CF-2023-I-2_113)by the Israel Ministry of Innovation,Science,and Technology(#7393)(to ES).
文摘The organization of biological neuronal networks into functional modules has intrigued scientists and inspired engineers to develop artificial systems.These networks are characterized by two key properties.First,they exhibit dense interconnectivity(Braitenburg and Schüz,1998;Campagnola et al.,2022).The strength and probability of connectivity depend on cell type,inter-neuronal distance,and species.Still,every cortical neuron receives input from thousands of other neurons while transmitting output to a similar number of neurons.Second,communication between neurons occurs primarily via chemical or electrical synapses.
文摘To extract and display the significant information of combat systems,this paper introduces the methodology of functional cartography into combat networks and proposes an integrated framework named“functional cartography of heterogeneous combat networks based on the operational chain”(FCBOC).In this framework,a functional module detection algorithm named operational chain-based label propagation algorithm(OCLPA),which considers the cooperation and interactions among combat entities and can thus naturally tackle network heterogeneity,is proposed to identify the functional modules of the network.Then,the nodes and their modules are classified into different roles according to their properties.A case study shows that FCBOC can provide a simplified description of disorderly information of combat networks and enable us to identify their functional and structural network characteristics.The results provide useful information to help commanders make precise and accurate decisions regarding the protection,disintegration or optimization of combat networks.Three algorithms are also compared with OCLPA to show that FCBOC can most effectively find functional modules with practical meaning.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.U1913215&51975162)。
文摘A piezoelectric platform using function module actuator is presented to achieve nano-positioning and high frequency scanning in large working range. A function module actuator is designed to produce a pair of orthogonal bending deformations and a longitudinal deformation through partition exciting. The bending deformations are used to actuate the planar motion,while the longitudinal deformation is utilized to dynamically adjust the driving force and broaden the scanning frequency. The dynamic model of the platform system is developed. The open-loop performances of a prototype are first tested: a scan frequency of 308 Hz in a scanning range of 3.368 μm×3.396 μm is measured in direct actuation mode,and the displacement resolution is measured to be 16 nm;maximum speed is measured to be 3.38 mm s^-1 in the inertial actuation mode. Furthermore,the closedloop experiments are carried out and a switching strategy is proposed to obtain the switching of the inertial and direct actuation modes automatically;the platform achieves the scanning with frequency of 300 Hz at the set position.
基金the National High Technology Research and Development Programme of China(No.2003AA2Z20512002AA2Z2052)+1 种基金the National Natural Science Foundation of China(No.3017051530370388)
文摘In this paper, we firstly identify the functional modules enriched with differentially expressed genes （DEGs） and characterized by biological processes in specific cellular locations, based on gene ontology （GO） and microarray data. Then, we further define and filter disease relevant signature modules according to the ranking of the disease discriminating abilities of the pre-selected functional modules. At last, we analyze the potential way by which they cooperate towards human disease. Application of the proposed method to the analysis of a liver cancer dataset shows that, using the same false discovery rate （ FDR ） threshold, we can find more biologically meaningful and detailed processes by using the cellular localization information. Some biological evidences support the relevancy of our biological modules to the disease mechanism.
文摘AIM:To investigate how angles kappa and alpha affect postoperative visual quality in patients with multifocal intraocular lens(mIOLs)implantation.METHODS:Retrospective cases series.A total of 46 patients(46 eyes)who underwent phacoemulsification were subsumed.The correlation between Preoperative angles kappa and alpha,wave-front aberrations and objective visual quality of cornea,internal,and total eye after surgery were analyzed using iTrace.RESULTS:The magnitude of angle kappa was negatively correlated with internal and total modulation transfer function(MTF)at 3 mm;the magnitude of angle kappa was positively correlated with astigmatism,trefoil,higher-order aberrations(HOAs)of both internal and total eye at 3 mm.The magnitude of angle alpha was negatively correlated with total MTF and total Strehl ratio at 3 mm.The magnitude of angle alpha was positively correlated with corneal coma at 5 mm,internal astigmatism at both 3 mm and 5 mm,and total spherical aberration(SA)at 3 mm.Multivariate linear regression analysis showed that,among candidate independent variables(kappa,alpha,astigmatism,SA,coma,trefoil,and HOAs),astigmatism is the only independent factor for altering corneal MTF at 3 mm and 5 mm;astigmatism and HOAs emerged as independent factors for altering internal MTF at 3 mm and 5 mm,and total MTF at 3 mm;astigmatism,SA and HOAs emerged as independent factors for altering total MTF at 5 mm.CONCLUSION:With greater preoperative angle kappa or angle alpha,patients who accept mIOL implantation tend to have larger internal astigmatism and HOAs,which resulting in poor visual quality,especially those with small pupil size.
基金National Natural Science Foundation of China(12073028,12473084).
文摘Continuing advancement in astronomy,space exploration,and scientific detection,has increased demand for infrared multi-band detection systems.Traditional three-band optical systems,designed to simultaneously image at infrared short-wave,mid-wave,and long-wave bands typically rely on dispersive elements,leading to bulky sizes,complex system architectures,low efficiency,and challenges in rapid assembly.To overcome these obstacles,in combination with the latest third-generation infrared detectors,we propose a design for a compact and lightweight three-band optical system,with infrared capabilities in all three required bands.The core of this approach is an integrated design philosophy that emphasizes the high steepness of mirror surfaces.This design achieves uniform correction and optimization of chromatic aberration and off-axis aberration across the spectral range.We introduce a novel integration of optical and mechanical elements to replace traditional assembly,reducing manufacturing and assembly errors,and degrees of freedom,associated with high-power optical elements.Confirming the effectiveness through a combination of simulations and experimental comparisons,the measured mid-wave full-field transfer function exceeds 0.405 at 17 lp/mm,satisfying the imaging requirements of the system.The optical system is lightweight and compact,with a total mass under 408 g and a compact volume of justΦ112 mm×117 mm.This serves as a valuable reference for the engineering application of high-performance,compact multi-band infrared composite detection systems for astronomy and space exploration.
文摘AIM: To describe the characteristics of modulation transfer function (MTF) of anterior corneal surface, and obtain the the normal reference range of MTF at different spatial frequencies and optical zones of the anterior corneal surface in myopes. METHODS: Four hundred eyes from 200 patients were examined under SIRIUS corneal topography system. Phoenis analysis software was applied to simulate the MTF curves of anterior corneal surface at vertical and horizontal meridians at the 3, 4, 5, 6, 7mm optical zones of cornea. The MTF values at spatial frequencies of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60 cycles/degree (c/d) were selected. RESULTS: The MTF curve of anterior corneal surface decreased rapidly from low to intermediate frequency (0-15cpd) at various optical zones of cornea, the value decreased to 0 slowly at higher frequency (>15cpd). With the increase of the optical zones of cornea, MTF curve decreased gradually. 3) In the range of 3 mm- 6 mm optical zones of the cornea, the MTF values measured at horizontal meridian were greater than the corresponding values at horizontal meridian of each spatial frequency, the difference was statistically significant (P<0.05). At 7 mm optical zones of cornea, the MTF values measured at horizontal meridian were less than the corresponding values at vertical meridian at 10-60 spatial frequencies (cpd), and the difference was statistically significant in 25, 30, 35, 40, 45, 50 cpd(P<0.05). CONCLUSION: MTF can be used to describe the imaging quality of optical systems at anterior corneal surface objectively in detail.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60678043)the Research and Innovation Plan for Graduate Students of Jiangsu Higher Education Institutions,China (Grant No. CX09B 096Z)
文摘The resolution characteristic can be obtained by the modulation transfer function （MTF） of a GaAs/GaA1As photocathode. After establishing the theoretical model of GaAs（100）-oriented atomic configuration and the formula for the ionized impurity scattering of the non-equilibrium carriers, this paper calculates the trajectories of photoelectrons in a photocathode. Thus the distribution of photoelectron spots on the emit-face is obtained, which is namely the point spread function. The MTF is obtained by Fourier transfer of the line spread function obtained from the point spread function. The MTF obtained from these calculations is shown to depend heavily on the electron diffusion length, and enhanced considerably by decreasing the electron diffusion length and increasing the doping concentration. Furthermore, the resolution is enhanced considerably by increasing the active-layer thickness, especially at high spatial frequencies. The best spatial resolution is 860 lp/mm, for the GaAs photocathode of doping concentration 1 ×10^19 cm 3 electron diffusion length 3.6 μm and the active-layer thickness 2 μm, under the 633-nm light irradiated. This research will contribute to the future improvement of the cathode＇s resolution for preparing a high performance GaAs photocathode, and improve the resolution of a low light level image intensifier.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2013AA09A505)the National Natural Science Foundation of China(Nos.41076119,41176160,41476158)+4 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Natural Science Youth Foundation of Jiangsu Province(No.BK2012467)the Natural Science State Key Foundation of Jiangsu Province(No.BK2011008)the National Natural Science Youth Foundation of China(No.41206171)the Startup Foundation for Introducing Talent of Nanjing University of Information Science and Technology(No.S8113078001)
文摘When imaging ocean surface waves by X-band marine radar, the radar backscatter from the sea surface is modulated by the long surface gravity waves. The modulation transfer function （MTF） comprises tilt, hydrodynamic, and shadowing modulations. A conventional linear MTF was derived using HH-polarized radar observations under conditions of deep water. In this study, we propose a new quadratic polynomial MTF based on W-polarized radar measurements taken from heterogeneous nearshore wave fields. This new MTF is obtained using a radar-observed image spectrum and in situ buoy-measured wave frequency spectrum. We validate the MTF by comparing peak and mean wave periods retrieved from X-band marine radar image sequences with those measured by the buoy. It is shown that the retrieval accuracies of peak and mean wave periods of the new MTF are better than the conventional MTF. The results also show that the bias and root mean square errors of the peak and mean wave periods of the new MTF are 0.05 and 0.88 s, and 0.32 and 0.53 s, respectively, while those of the conventional MTF are 0.61 and 0.98 s, and 1.39 and 1.48 s, respectively. Moreover, it is also shown that the retrieval results are insensitive to the coefficients in the proposed MTF.
基金Project(50875028) supported by the National Natural Science Foundation of China
文摘An efficient unbiased estimation method is proposed for the direct identification of linear continuous-time system with noisy input and output measurements.Using the Gaussian modulating filters,by numerical integration,an equivalent discrete identification model which is parameterized with continuous-time model parameters is developed,and the parameters can be estimated by the least-squares (LS) algorithm.Even with white noises in input and output measurement data,the LS estimate is biased,and the bias is determined by the variances of noises.According to the asymptotic analysis,the relationship between bias and noise variances is derived.One equation relating to the measurement noise variances is derived through the analysis of the LS errors.Increasing the degree of denominator of the system transfer function by one,an extended model is constructed.By comparing the true value and LS estimates of the parameters between original and extended model,another equation with input and output noise variances is formulated.So,the noise variances are resolved by the set of equations,the LS bias is eliminated and the unbiased estimates of system parameters are obtained.A simulation example by comparing the standard LS with bias eliminating LS algorithm indicates that the proposed algorithm is an efficient method with noisy input and output measurements.
基金Supported by Wenzhou Science and Technology Commission in 2009, China (No.Y20090384)
文摘AIM:To analyze the retinal modulation transfer function between amblyopes whose visual acuity was corrected to 5.0 and normal subjects at the same age. METHODS: RM-800 used to detect contrast sensitivity was adopted to measure MTF of 96 amblyopes (96 eyes) whose visual acuity was corrected to 5.0 and 80 normal controls (80 eyes) at the same age under six interference fringes (IVA=0.06, 0.1, 0.2, 0.4, 0.6, 0.8). RESULTS: The functional values of amblyopes were significantly lower than those of normal subjects in every fringe (P<0.01), especially in medium and high frequency. CONCLUSION: For amblyopes, MTF was still abnormal after stopping the treatments.
基金supported by the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences(Grant No.KGFZD-125-13-006)
文摘The atmospheric scattering optical transfer function （OTF） is solved by applying the multi-coupled single scattering （MCSS） method to the three-dimensional radiative transfer equation （RTE） under the periodic ground condition. This approach is a direct hit to the atmospheric scattering OTF using the same original context of modulation transfer function （MTF） measurement, i.e., images of sinusoidal grating at different spatial frequencies. Both the amplitude and phase shift of the OTF at various zenith and azimuth angles can be obtained at an arbitrary spatial frequency.
基金Supported by the National High Technology Research and Development Programme of China(No.2012AA12A305)the National Key Technology R&D Program of the Ministry of Science and Technology(No.2013BAH03B01)+1 种基金Fundamental Research Funds for the Central Universities of China(No.2042015kf0059)China Postdoctoral Science Foundation(No.2015M582277)
文摘The key difficulty of restoring a fuzzy image is to estimate its point spread function( PSF). In the paper,PSF is modelled based on modulation transfer function( MTF). The first step is calculating the image MTF. In the traditional slanted-edge method,a sub-block is always manually extracted from original image and its MTF will be viewed as the result of the whole image. However,handcraft extraction is inefficient and will lead to inaccurate results. Given this,an automatic MTF computation algorithm is proposed,which extracts and screens out all the effective sub-blocks and calculates their average MTF as the final result. Then,a two-dimensional MTF restoration model is constructed by multiplying the horizontal and vertical MTF,and it is combined with conventional image restoration methods to restore fuzzy image. Experimental results indicate the proposed method implementes a fast and accurate MTF computation and the MTF model improves the performance of conventional restoration methods significantly.
基金financially supported by the National Natural Science Foundation of China(Nos.82172372 and 82302651)the Training Program of Innovation and Entrepreneurship for Undergraduates of Hubei Province(No.S202210487267)。
文摘Deoxyribozyme(DNAzyme)and its substrate hybridization are crucial for achieving desirable detection performance in the DNAzyme coupling nanomaterial biosensor system.However,interfacial factors such as electrostatic repulsion,steric hindrance,and nonspecific adsorption from gold nanoparticles make this hybridization process complicated and challenging.Moreover,the DNAzyme structure changes with different application purposes,which might affect the DNAzyme and substrate's connection.Few studies have focused on the interplay of DNAzyme and interfacial factors in the biosensor field.In this work,three types of DNAzyme variants were designed,and their biosensor performance rules were studied and summarized with the synergistic effect of interfacial factors.Additionally,corresponding biosensor applications,such as multiple modulation functions and mi RNA detections,were constructed based on the distinct principles of DNAzyme variants.
基金Shanghai Science and Technology Development Foundation (995107017)
文摘Linux-based Platform for Open Architecture Controller ( POAC ), a new open architecture controller and its modular developing method are discussed. POAC divides the application software of controller into the developing system and the application system. In the developing system, PAOC abstracts a series of function modules with unified data interface and function interface. In the application system, POAC defines the model of the architecture module, realizing the interoperability and interchangeability between the architecture modules. The modular developing method entities the users to make up an application system with some architecture modules, which consist of a set of function modules. The modular developing method decreases the developing time from the standard of controller architecture to the product.
文摘Considering research on multi-objective optimization for reliability and performance suffering cost constraints in digital circuits,an improved multi-objective optimization algorithm based on performance and reliability was proposed to solve the problem of discrete system resources configuration in this paper. This algorithm used the particle-swarm optimization( PSO) to evaluate the tradeoffs configuration of the system resources between reliability and performance and proved the feasibility through the simulation.Finally, the information of resources configuration from optimization algorithm was used to effectively guide the system design so as to mitigate soft errors caused by single event effect( SEE).
基金supported in part by the National Natural Science Foundation of China(Grant Nos.31071166 and 81373085)Natural Science Foundation of Guangdong Province,China(Grant No.8251008901000007)+2 种基金Science and Technology Planning Project of Guangdong Province(Grant No.2009A030301004)Dongguan Science and Technology Project,Guangdong,China(Grant No.2011108101015)the funds from Guangdong Medical College,China(Grant Nos.XG1001,JB1214,XZ1105,STIF201122,M2011024,and M2011010)
文摘Coronary artery disease （CAD） is a complex human disease, involving multiple genes and their nonlinear interactions, which often act in a modular fashion. Genome-wide single nucleotide polymorphism （SNP） profiling provides an effective technique to unravel these underlying genetic interplays or their functional involvements for CAD. This study aimed to identify the susceptible pathways and modules for CAD based on SNP omics. First, the Wellcome Trust Case Control Consortium （WTCCC） SNP datasets of CAD and control samples were used to assess the joint effect of multiple genetic variants at the pathway level, using logistic kernel machine regression model. Then, an expanded genetic network was constructed by integrating statistical gene-gene interactions involved in these susceptible pathways with their protein protein interaction （PPI） knowledge. Finally, risk functional modules were identified by decomposition of the network. Of 276 KEGG pathways analyzed, 6 pathways were found to have a significant effect on CAD. Other than glycerolipid metabolism, glycosaminoglycan biosynthesis, and cardiac muscle contraction pathways, three pathways related to other diseases were also revealed, including Alzheimer＇s disease, non-alcoholic fatty liver disease, and Huntington＇s disease. A genetic epistatic network of 95 genes was further constructed using the abovementioned integrative approach. Of 10 functional modules derived from the network, 6 have been annotated to phospholipase C activity and cell adhesion molecule binding, which also have known functional involvement in Alzheimer＇s disease. These findings indicate an overlap of the underlying molecular mechanisms between CAD and Alzheimer＇s disease, thus providing new insights into the molecular basis for CAD and its molecular relationships with other diseases.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30170515,30370388 and 30970668)
文摘Selecting differentially expressed genes(DEGs) is one of the most important tasks in microarray applications for studying multi-factor diseases including cancers.However,the small samples typically used in current microarray studies may only partially reflect the widely altered gene expressions in complex diseases,which would introduce low reproducibility of gene lists selected by statistical methods.Here,by analyzing seven cancer datasets,we showed that,in each cancer,a wide range of functional modules have altered gene expressions and thus have high disease classification abilities.The results also showed that seven modules are shared across diverse cancers,suggesting hints about the common mechanisms of cancers.Therefore,instead of relying on a few individual genes whose selection is hardly reproducible in current microarray experiments,we may use functional modules as functional signatures to study core mechanisms of cancers and build robust diagnostic classifiers.
基金This project was supported by China Postdoctoral Science Foundation (2003034466)Scientific Research Fund of Hunan Provincial Education Department (02B032).
文摘An approach to identification of linear continuous-time system is studied with modulating functions. Based on wavelet analysis theory, the multi-resolution modulating functions are designed, and the corresponding filters have been analyzed. Using linear modulating filters, we can obtain an identification model that is parameterized directly in continuous-time model parameters. By applying the results from discrete-time model identification to the obtained identification model, a continuous-time estimation method is developed. Considering the accuracy of parameter estimates, an instrumental variable (Ⅳ) method is proposed, and the design of modulating integral filter is discussed. The relationship between the accuracy of identification and the parameter of modulating filter is investigated, and some points about designing Gaussian wavelet modulating function are outlined. Finally, a simulation study is also included to verify the theoretical results.
基金National Natural Science Foundation of China, No.30570301 No.40671175
文摘Niche theory is one of the most important ecological theories. It is widely applied to analyzing such phenomena as competition among, and evolution of, urban ecosystem functional modules. This paper describes a study concerning＇different functional modules of Kaifeng city urban ecosystem. Niche theory and techniques were used to analyze the changes of these functional modules in the period 1994-2003. The results showed that, in the period 1994-2003： （1） Niche value of the atmospheric environment and urban virescence modules increased, while niche value of the water environment and sound environment modules decreased; （2） niche value of the tertiary industry module increased, niche value of the secondary industry module decreased, while niche value of the primary industry module showed little change; and （3） niche value of the infrastructure, resource distribution, and production ＆ social security modules increased, while niche value of the population module decreased. This study may contribute to macroscopic planning of urban functional modules, economic development, and environmental protection.
