[Objective] This study aimed to construct Myostatin （MSTN） gene targeting vector of mouse. [Method] Total RNA was extracted from hindlimb muscle tissues of mouse to synthesize cDNA as the template to clone the codin...[Objective] This study aimed to construct Myostatin （MSTN） gene targeting vector of mouse. [Method] Total RNA was extracted from hindlimb muscle tissues of mouse to synthesize cDNA as the template to clone the coding region of MSTN. The CDS of MSTN gene including 3 kb 5’ homologous arm and 1.4 kb 3’ homologous arm were inserted into vector pBluescript_SK ＋ to construct the targeting vector pLoxP-5N3T-M. The neo and HSV-tk gene were cloned into vector pBluescript_SK＋ as positive and negative selective gene. [Result] Restriction enzyme digestion and sequencing results showed that mouse MSTN gene was cloned into the targeting vector pLoxP-5N3T-M. [Conclusion] The mouse MSTN gene targeting vector pLoxP5N3T-M was successfully constructed.展开更多
In order to improve measurement accuracy of moving target signals, an automatic target recognition model of moving target signals was established based on empirical mode decomposition(EMD) and support vector machine(S...In order to improve measurement accuracy of moving target signals, an automatic target recognition model of moving target signals was established based on empirical mode decomposition(EMD) and support vector machine(SVM). Automatic target recognition process on the nonlinear and non-stationary of Doppler signals of military target by using automatic target recognition model can be expressed as follows. Firstly, the nonlinearity and non-stationary of Doppler signals were decomposed into a set of intrinsic mode functions(IMFs) using EMD. After the Hilbert transform of IMF, the energy ratio of each IMF to the total IMFs can be extracted as the features of military target. Then, the SVM was trained through using the energy ratio to classify the military targets, and genetic algorithm(GA) was used to optimize SVM parameters in the solution space. The experimental results show that this algorithm can achieve the recognition accuracies of 86.15%, 87.93%, and 82.28% for tank, vehicle and soldier, respectively.展开更多
A 23 amino acid, bifunctional integrin-targeted synthetic oligopeptide was evaluated for ex vivo gene delivery to rabbit bone marrow stromal cells （BMSCs）. Synthesis of the peptide （K）16GRGDSPC was performed on a ...A 23 amino acid, bifunctional integrin-targeted synthetic oligopeptide was evaluated for ex vivo gene delivery to rabbit bone marrow stromal cells （BMSCs）. Synthesis of the peptide （K）16GRGDSPC was performed on a solid-phase batch peptide synthesizer. BMSCs were transfected with plasmid DNA coding for luciferase by （K）j6GRGDSPC and the transfection efficiency was assayed. The influences of chloroquine and polyethyleneimine on the transfection efficiency were also examined. The target specificity of （K）16GRGDSPC to mediate exogenous gene into BMSCs was analyzed using cell attachment test and gene delivery inhibition test. The results showed that the transfection efficiency of the oligopeptide vector was lower than that of Lipofectamine. But in the presence of endosomal buffer chloroquine or endosomal disrupting agent polyethyleneimine, the transfection efficiency of the vector was greatly enhanced. In addition, RGD-containing peptides inhibited BMSCs＇ attachment to the 96-well plates pretreated with fibronectin or vitronecfin and significantly decreased the transfection efficiency of the oligopeptide vector. These studies demonstrated that oligopeptide （K）16GRGDSPC was an ideal novel targeted non-viral gene delivery vector, which was easy to be synthesized, high efficient and low cytotoxicity. The vector could effectively deliver exogenous gene into rat BMSCs.展开更多
Objective: To construct the EGFR targeted non-viral vector GE7 system and explore the in vitro effect of p21WAF-1/CIPI gene on growth of human glioma cells mediated by the GE7 system. Methods: The EGFR targeted non-vi...Objective: To construct the EGFR targeted non-viral vector GE7 system and explore the in vitro effect of p21WAF-1/CIPI gene on growth of human glioma cells mediated by the GE7 system. Methods: The EGFR targeted non-viral vector GE7 gene delivery system was constructed. The malignant human glioma cell line U251MG was transfected in vitro with β-galactosidase gene ( reporter gene) and p21WAF-1/CIPI gee (therapeutic gene) using the GE7 system. By means of X-gal staining, MTS and FACS, the transfection efficiency of exogenous gene and apoptosis rate of tumor cells were examined. The expression of p21WAF-1/ CIPI gene in transfected U251MG cell was examined by immunohistochemis-try staining. Results: The highest transfer rate of exogenous gene was 70% . After transfection with p21WAF-1/CIPI gene, the expression of WAF-1 increased remarkably and steadily; the growth of U251MG cells were inhibited evidently. FACS examination showed G1 arrest. The average apoptosis rate was 25.2%. Conclusion: GE7 system has the ability to transfer exogenous gene to targeted cells efficiently, and expression of p21WAF-1/CIPI gene can induce apoptosis of glioma cell and inhibit its growth.展开更多
The electromagnetic scattering computation has developed rapidly for many years; some computing problems for complex and coated targets cannot be solved by using the existing theory and computing models. A computing m...The electromagnetic scattering computation has developed rapidly for many years; some computing problems for complex and coated targets cannot be solved by using the existing theory and computing models. A computing model based on data is established for making up the insufficiency of theoretic models. Based on the ＂support vector regression method＂, which is formulated on the principle of minimizing a structural risk, a data model to predicate the unknown radar cross section of some appointed targets is given. Comparison between the actual data and the results of this predicting model based on support vector regression method proved that the support vector regression method is workable and with a comparative precision.展开更多
Objective: To construct and apply a replacement targeting vector for mouse coagulation factor IX(mFIX) gene in embryonic stem (ES) cells. Methods: Based on the cloning and structural analysis of the genomic DNA fragme...Objective: To construct and apply a replacement targeting vector for mouse coagulation factor IX(mFIX) gene in embryonic stem (ES) cells. Methods: Based on the cloning and structural analysis of the genomic DNA fragment of coagulation factor IX gene from 129Sv mouse genomic DNA A phage library, PMFIXDEL plasmid was designed with positive-negative-selection (PNS) strategy, and constructed with commonmolecular cloning techniques. Structure of PMFIXDEL was identified by PCR and restriction analysis. Afterelectroporation with the linearized PMFIXDEL DNA, transfected ES cells were cultured in G418/GANC drugselection medium. The recombination efficacy of this vector was tested. Results: The main components ofPMFIXDEL were two copies of negative selection gene (HSV-tk expression cassette), a positive selectiongene (Neo expression cassette), long and short homologous fragments and plasmid backbone. The introduction of negative selection gene (HSV-tk ) into the construct resulted in 24-fold increase of selection.Conclusion: An effective replacement vector for mFIX gene targeting was constructed and applied in ES cell.展开更多
Safe and effective gene therapy approaches require targeted tissue-specific transfer of a therapeutic transgene.Besides traditional approaches, such as transcriptional and transductional targeting, micro RNA-dependent...Safe and effective gene therapy approaches require targeted tissue-specific transfer of a therapeutic transgene.Besides traditional approaches, such as transcriptional and transductional targeting, micro RNA-dependent posttranscriptional suppression of transgene expression has been emerging as powerful new technology to increase the specificity of vector-mediated transgene expression. Micro RNAs are small non-coding RNAs and often expressed in a tissue-, lineage-, activation- or differentiation-specific pattern. They typically regulate gene expression by binding to imperfectly complementary sequences in the 3' untranslated region(UTR) of the m RNA. To control exogenous transgene expression, tandem repeats of artificial micro RNA target sites are usually incorporated into the 3' UTR of the transgene expression cassette, leading to subsequent degradation of transgene m RNA in cel s expressing the corresponding micro RNA. This targeting strategy, first shown for lentiviral vectors in antigen presenting cells, has now been used for tissue-specific expression of vector-encoded therapeutic transgenes, to reduce immune response against the transgene, to control virus tropism for oncolytic virotherapy, to increase safety of live attenuated virus vaccines and to identify and select cell subsets for pluripotent stem cell therapies, respectively. This review provides an introduction into the technical mechanism underlying micro RNA-regulation, highlights new developments in this field and gives an overview of applications of micro RNA-regulated viral vectors for cardiac, suicide gene cancer and hematopoietic stem cell therapy, as well as for treatment of neurological and eye diseases.展开更多
Objective： To compare the transferring efficiency and killing effects of one time and continuous mediation with GE7, a non-viral targeted delivery system, in transfection of thymidine kinase gene of herpes simplex vi...Objective： To compare the transferring efficiency and killing effects of one time and continuous mediation with GE7, a non-viral targeted delivery system, in transfection of thymidine kinase gene of herpes simplex virus （HSV-tk） into ovarian cancer cells. Methods： GE7 was used to prepare recombinants with β-galactosidase （β-gal） and HSVI-tk; the recombinants were then used to transfect human ovarian cancer line CaOV3 once and continuously. β-gal staining was used to compare the efficiencies of one time and continuous mediation with GE7 system. Ganciclovior （GCV） was introduced into HSVI-tk transfected ovarian cells. Through drawing the cell growth curve and flow cytometry, the killing effects of GCV on once and continuously GE7/HSVI-tk transfected cells were observed. Results： We found that the one time and continuous exogenous gene transfer efficiencies were about 80% and 85%, respectively. When 1 μg/mL GCV was used to treat ovarian cell transfected with HSVI-tk gene, growth inhibiting rates of ovarian cells of one time and continuous transferring were 82% and 90%, respectively; their apoptosis indices were 15 and 30, respectively. Under same GCV concentration, continuous mediation of GE7/pCMV-tk transfection into ovarian cancer cells had more significant inhibitory effect than one time mediation （P 〈 0.05）. Conclusion： Compared with one time mediation, continuous mediation of transfection with GE7 gene delivery system has higher efficiency. Continuous mediation of GE7/HSVI-tk/GCV therapeutic gene system has more powerful killing effect.展开更多
The different approaches used for target decomposition （TD） theory in radar polarimetry are reviewed and three main types of theorems are introduced： those based on Mueller matrix, those using an eigenvector analys...The different approaches used for target decomposition （TD） theory in radar polarimetry are reviewed and three main types of theorems are introduced： those based on Mueller matrix, those using an eigenvector analysis of the coherency matrix, and those employing coherent decomposition of the scattering matrix. Support vector machine （SVM）, as a novel approach in pattern recognition, has demonstrated success in many fields. A new algorithm of target classification, by combining target decomposition and the support vector machine, is proposed. To conduct the experiment, the polarimetric synthetic aperture radar （SAR） data are used. Experimental results show that it is feasible and efficient to target classification by applying target decomposition to extract scattering mechanisms, and the effects of kernel function and its parameters on the classification efficiency are significant.展开更多
Steering control of a capsule robot in curve environment by magnetic navigation is not yet solved completely.A petal-shaped capsule robot with less steering resistance based on multiple wedge effects is presented,and ...Steering control of a capsule robot in curve environment by magnetic navigation is not yet solved completely.A petal-shaped capsule robot with less steering resistance based on multiple wedge effects is presented,and an optimization method with two processes for determining the orientation of a pre-applied universal magnetic spin vector is proposed.To realize quick and non-contact steering swimming,a fuzzy comprehensive evaluation method for optimizing the steering driving angle is presented based on two evaluation indexes including the average steering speed and the average steering trajectory deviation,achieving the initial optimal orientation of a universal magnetic spin vector.To further reduce robotic magnetic vibration,a main target method for optimizing its final orientation,which is used for fine adjustment,is employed under the constrains of the magnetic moments.Swimming experimental results in curve pipe verified the effectiveness of the optimization method,which can be effectively used to realize non-contact steering swimming of the petal-shaped robot and reduce its vibration.展开更多
On the basis of scale invariant feature transform（SIFT） descriptors,a novel kind of local invariants based on SIFT sequence scale（SIFT-SS） is proposed and applied to target classification.First of all,the merits o...On the basis of scale invariant feature transform（SIFT） descriptors,a novel kind of local invariants based on SIFT sequence scale（SIFT-SS） is proposed and applied to target classification.First of all,the merits of using an SIFT algorithm for target classification are discussed.Secondly,the scales of SIFT descriptors are sorted by descending as SIFT-SS,which is sent to a support vector machine（SVM） with radial based function（RBF） kernel in order to train SVM classifier,which will be used for achieving target classification.Experimental results indicate that the SIFT-SS algorithm is efficient for target classification and can obtain a higher recognition rate than affine moment invariants（AMI） and multi-scale auto-convolution（MSA） in some complex situations,such as the situation with the existence of noises and occlusions.Moreover,the computational time of SIFT-SS is shorter than MSA and longer than AMI.展开更多
Current research on target detection and recognition from synthetic aperture radar （SAR） images is usually carried out separately. It is difficult to verify the ability of a target recognition algorithm for adapting...Current research on target detection and recognition from synthetic aperture radar （SAR） images is usually carried out separately. It is difficult to verify the ability of a target recognition algorithm for adapting to changes in the environment. To realize the whole process of SAR automatic target recognition （ATR）, es- pecially for the detection and recognition of vehicles, an algorithm based on kernel fisher discdminant analysis （KFDA） is proposed. First, in order to make a better description of the difference be- tween the background and the target, KFDA is extended to the detection part. Image samples are obtained with a dual-window approach and features of the inner and outer window samples are extracted by using KFDA. The difference between the features of inner and outer window samples is compared with a threshold to determine whether a vehicle exists. Second, for the target area, we propose an improved KFDA-IMED （image Euclidean distance） combined with a support vector machine （SVM） to recognize the vehicles. Experimental results validate the performance of our method. On the detection task, our proposed method obtains not only a high detection rate but also a low false alarm rate without using any prior information. For the recognition task, our method overcomes the SAR image aspect angle sensitivity, reduces the requirements for image preprocessing and improves the recogni- tion rate.展开更多
To accelerate the training of support vector domain description （SVDD）, confidence support vector domain description （CSVDD） is proposed based on the observation that the description boundary is determined by a sm...To accelerate the training of support vector domain description （SVDD）, confidence support vector domain description （CSVDD） is proposed based on the observation that the description boundary is determined by a small subset of training data called support vectors. Namely, the number of training samples in the userdefined sphere is calculated and taken as the confidence measure, according to which the training samples are ranked in ascending order. Those former ranked ones are selected as the boundary targets for the SVDD training. Simulations on UCI data demonstrate the effectiveness and superiority of CSVDD： the number of training targets and the training time are reduced without any loss of accuracy.展开更多
基金Supported by Project from Science and Technology Department of Guizhou Province ([2009]2173)~~
文摘[Objective] This study aimed to construct Myostatin （MSTN） gene targeting vector of mouse. [Method] Total RNA was extracted from hindlimb muscle tissues of mouse to synthesize cDNA as the template to clone the coding region of MSTN. The CDS of MSTN gene including 3 kb 5’ homologous arm and 1.4 kb 3’ homologous arm were inserted into vector pBluescript_SK ＋ to construct the targeting vector pLoxP-5N3T-M. The neo and HSV-tk gene were cloned into vector pBluescript_SK＋ as positive and negative selective gene. [Result] Restriction enzyme digestion and sequencing results showed that mouse MSTN gene was cloned into the targeting vector pLoxP-5N3T-M. [Conclusion] The mouse MSTN gene targeting vector pLoxP5N3T-M was successfully constructed.
基金Projects(61471370,61401479)supported by the National Natural Science Foundation of China
文摘In order to improve measurement accuracy of moving target signals, an automatic target recognition model of moving target signals was established based on empirical mode decomposition(EMD) and support vector machine(SVM). Automatic target recognition process on the nonlinear and non-stationary of Doppler signals of military target by using automatic target recognition model can be expressed as follows. Firstly, the nonlinearity and non-stationary of Doppler signals were decomposed into a set of intrinsic mode functions(IMFs) using EMD. After the Hilbert transform of IMF, the energy ratio of each IMF to the total IMFs can be extracted as the features of military target. Then, the SVM was trained through using the energy ratio to classify the military targets, and genetic algorithm(GA) was used to optimize SVM parameters in the solution space. The experimental results show that this algorithm can achieve the recognition accuracies of 86.15%, 87.93%, and 82.28% for tank, vehicle and soldier, respectively.
基金This project was supported by grants from National Natural Sciences Foundation of China (No. 30200063, 30470483).
文摘A 23 amino acid, bifunctional integrin-targeted synthetic oligopeptide was evaluated for ex vivo gene delivery to rabbit bone marrow stromal cells （BMSCs）. Synthesis of the peptide （K）16GRGDSPC was performed on a solid-phase batch peptide synthesizer. BMSCs were transfected with plasmid DNA coding for luciferase by （K）j6GRGDSPC and the transfection efficiency was assayed. The influences of chloroquine and polyethyleneimine on the transfection efficiency were also examined. The target specificity of （K）16GRGDSPC to mediate exogenous gene into BMSCs was analyzed using cell attachment test and gene delivery inhibition test. The results showed that the transfection efficiency of the oligopeptide vector was lower than that of Lipofectamine. But in the presence of endosomal buffer chloroquine or endosomal disrupting agent polyethyleneimine, the transfection efficiency of the vector was greatly enhanced. In addition, RGD-containing peptides inhibited BMSCs＇ attachment to the 96-well plates pretreated with fibronectin or vitronecfin and significantly decreased the transfection efficiency of the oligopeptide vector. These studies demonstrated that oligopeptide （K）16GRGDSPC was an ideal novel targeted non-viral gene delivery vector, which was easy to be synthesized, high efficient and low cytotoxicity. The vector could effectively deliver exogenous gene into rat BMSCs.
基金Supported by the National High Science and Technical Foundation of China(No. 102-12-02-05)
文摘Objective: To construct the EGFR targeted non-viral vector GE7 system and explore the in vitro effect of p21WAF-1/CIPI gene on growth of human glioma cells mediated by the GE7 system. Methods: The EGFR targeted non-viral vector GE7 gene delivery system was constructed. The malignant human glioma cell line U251MG was transfected in vitro with β-galactosidase gene ( reporter gene) and p21WAF-1/CIPI gee (therapeutic gene) using the GE7 system. By means of X-gal staining, MTS and FACS, the transfection efficiency of exogenous gene and apoptosis rate of tumor cells were examined. The expression of p21WAF-1/ CIPI gene in transfected U251MG cell was examined by immunohistochemis-try staining. Results: The highest transfer rate of exogenous gene was 70% . After transfection with p21WAF-1/CIPI gene, the expression of WAF-1 increased remarkably and steadily; the growth of U251MG cells were inhibited evidently. FACS examination showed G1 arrest. The average apoptosis rate was 25.2%. Conclusion: GE7 system has the ability to transfer exogenous gene to targeted cells efficiently, and expression of p21WAF-1/CIPI gene can induce apoptosis of glioma cell and inhibit its growth.
文摘The electromagnetic scattering computation has developed rapidly for many years; some computing problems for complex and coated targets cannot be solved by using the existing theory and computing models. A computing model based on data is established for making up the insufficiency of theoretic models. Based on the ＂support vector regression method＂, which is formulated on the principle of minimizing a structural risk, a data model to predicate the unknown radar cross section of some appointed targets is given. Comparison between the actual data and the results of this predicting model based on support vector regression method proved that the support vector regression method is workable and with a comparative precision.
文摘Objective: To construct and apply a replacement targeting vector for mouse coagulation factor IX(mFIX) gene in embryonic stem (ES) cells. Methods: Based on the cloning and structural analysis of the genomic DNA fragment of coagulation factor IX gene from 129Sv mouse genomic DNA A phage library, PMFIXDEL plasmid was designed with positive-negative-selection (PNS) strategy, and constructed with commonmolecular cloning techniques. Structure of PMFIXDEL was identified by PCR and restriction analysis. Afterelectroporation with the linearized PMFIXDEL DNA, transfected ES cells were cultured in G418/GANC drugselection medium. The recombination efficacy of this vector was tested. Results: The main components ofPMFIXDEL were two copies of negative selection gene (HSV-tk expression cassette), a positive selectiongene (Neo expression cassette), long and short homologous fragments and plasmid backbone. The introduction of negative selection gene (HSV-tk ) into the construct resulted in 24-fold increase of selection.Conclusion: An effective replacement vector for mFIX gene targeting was constructed and applied in ES cell.
基金Supported by The Deutsche Forschungsgemeinschaft,Nos.FE785/2-2 and FE785/4-1the Bundesministerium für Bildung und Entwicklung,No.031A331
文摘Safe and effective gene therapy approaches require targeted tissue-specific transfer of a therapeutic transgene.Besides traditional approaches, such as transcriptional and transductional targeting, micro RNA-dependent posttranscriptional suppression of transgene expression has been emerging as powerful new technology to increase the specificity of vector-mediated transgene expression. Micro RNAs are small non-coding RNAs and often expressed in a tissue-, lineage-, activation- or differentiation-specific pattern. They typically regulate gene expression by binding to imperfectly complementary sequences in the 3' untranslated region(UTR) of the m RNA. To control exogenous transgene expression, tandem repeats of artificial micro RNA target sites are usually incorporated into the 3' UTR of the transgene expression cassette, leading to subsequent degradation of transgene m RNA in cel s expressing the corresponding micro RNA. This targeting strategy, first shown for lentiviral vectors in antigen presenting cells, has now been used for tissue-specific expression of vector-encoded therapeutic transgenes, to reduce immune response against the transgene, to control virus tropism for oncolytic virotherapy, to increase safety of live attenuated virus vaccines and to identify and select cell subsets for pluripotent stem cell therapies, respectively. This review provides an introduction into the technical mechanism underlying micro RNA-regulation, highlights new developments in this field and gives an overview of applications of micro RNA-regulated viral vectors for cardiac, suicide gene cancer and hematopoietic stem cell therapy, as well as for treatment of neurological and eye diseases.
基金a grant from the National Natural Sciences Foundation of China (No 39800144)
文摘Objective： To compare the transferring efficiency and killing effects of one time and continuous mediation with GE7, a non-viral targeted delivery system, in transfection of thymidine kinase gene of herpes simplex virus （HSV-tk） into ovarian cancer cells. Methods： GE7 was used to prepare recombinants with β-galactosidase （β-gal） and HSVI-tk; the recombinants were then used to transfect human ovarian cancer line CaOV3 once and continuously. β-gal staining was used to compare the efficiencies of one time and continuous mediation with GE7 system. Ganciclovior （GCV） was introduced into HSVI-tk transfected ovarian cells. Through drawing the cell growth curve and flow cytometry, the killing effects of GCV on once and continuously GE7/HSVI-tk transfected cells were observed. Results： We found that the one time and continuous exogenous gene transfer efficiencies were about 80% and 85%, respectively. When 1 μg/mL GCV was used to treat ovarian cell transfected with HSVI-tk gene, growth inhibiting rates of ovarian cells of one time and continuous transferring were 82% and 90%, respectively; their apoptosis indices were 15 and 30, respectively. Under same GCV concentration, continuous mediation of GE7/pCMV-tk transfection into ovarian cancer cells had more significant inhibitory effect than one time mediation （P 〈 0.05）. Conclusion： Compared with one time mediation, continuous mediation of transfection with GE7 gene delivery system has higher efficiency. Continuous mediation of GE7/HSVI-tk/GCV therapeutic gene system has more powerful killing effect.
文摘The different approaches used for target decomposition （TD） theory in radar polarimetry are reviewed and three main types of theorems are introduced： those based on Mueller matrix, those using an eigenvector analysis of the coherency matrix, and those employing coherent decomposition of the scattering matrix. Support vector machine （SVM）, as a novel approach in pattern recognition, has demonstrated success in many fields. A new algorithm of target classification, by combining target decomposition and the support vector machine, is proposed. To conduct the experiment, the polarimetric synthetic aperture radar （SAR） data are used. Experimental results show that it is feasible and efficient to target classification by applying target decomposition to extract scattering mechanisms, and the effects of kernel function and its parameters on the classification efficiency are significant.
基金Supported by National Natural Science Foundation of China(Grant Nos.60875064,61175102,51277018)
文摘Steering control of a capsule robot in curve environment by magnetic navigation is not yet solved completely.A petal-shaped capsule robot with less steering resistance based on multiple wedge effects is presented,and an optimization method with two processes for determining the orientation of a pre-applied universal magnetic spin vector is proposed.To realize quick and non-contact steering swimming,a fuzzy comprehensive evaluation method for optimizing the steering driving angle is presented based on two evaluation indexes including the average steering speed and the average steering trajectory deviation,achieving the initial optimal orientation of a universal magnetic spin vector.To further reduce robotic magnetic vibration,a main target method for optimizing its final orientation,which is used for fine adjustment,is employed under the constrains of the magnetic moments.Swimming experimental results in curve pipe verified the effectiveness of the optimization method,which can be effectively used to realize non-contact steering swimming of the petal-shaped robot and reduce its vibration.
基金supported by the National High Technology Research and Development Program (863 Program) (2010AA7080302)
文摘On the basis of scale invariant feature transform（SIFT） descriptors,a novel kind of local invariants based on SIFT sequence scale（SIFT-SS） is proposed and applied to target classification.First of all,the merits of using an SIFT algorithm for target classification are discussed.Secondly,the scales of SIFT descriptors are sorted by descending as SIFT-SS,which is sent to a support vector machine（SVM） with radial based function（RBF） kernel in order to train SVM classifier,which will be used for achieving target classification.Experimental results indicate that the SIFT-SS algorithm is efficient for target classification and can obtain a higher recognition rate than affine moment invariants（AMI） and multi-scale auto-convolution（MSA） in some complex situations,such as the situation with the existence of noises and occlusions.Moreover,the computational time of SIFT-SS is shorter than MSA and longer than AMI.
基金supported by the National Natural Science Foundation of China(6107113961471019+5 种基金61171122)the Aeronautical Science Foundation of China(20142051022)the Foundation of ATR Key Lab(C80264)the National Natural Science Foundation of China(NNSFC)under the RSE-NNSFC Joint Project(2012-2014)(61211130210)with Beihang Universitythe RSE-NNSFC Joint Project(2012-2014)(61211130309)with Anhui Universitythe"Sino-UK Higher Education Research Partnership for Ph D Studies"Joint Project(2013-2015)
文摘Current research on target detection and recognition from synthetic aperture radar （SAR） images is usually carried out separately. It is difficult to verify the ability of a target recognition algorithm for adapting to changes in the environment. To realize the whole process of SAR automatic target recognition （ATR）, es- pecially for the detection and recognition of vehicles, an algorithm based on kernel fisher discdminant analysis （KFDA） is proposed. First, in order to make a better description of the difference be- tween the background and the target, KFDA is extended to the detection part. Image samples are obtained with a dual-window approach and features of the inner and outer window samples are extracted by using KFDA. The difference between the features of inner and outer window samples is compared with a threshold to determine whether a vehicle exists. Second, for the target area, we propose an improved KFDA-IMED （image Euclidean distance） combined with a support vector machine （SVM） to recognize the vehicles. Experimental results validate the performance of our method. On the detection task, our proposed method obtains not only a high detection rate but also a low false alarm rate without using any prior information. For the recognition task, our method overcomes the SAR image aspect angle sensitivity, reduces the requirements for image preprocessing and improves the recogni- tion rate.
基金supported by the National Natural Science Foundation of China(6057407560674108).
文摘To accelerate the training of support vector domain description （SVDD）, confidence support vector domain description （CSVDD） is proposed based on the observation that the description boundary is determined by a small subset of training data called support vectors. Namely, the number of training samples in the userdefined sphere is calculated and taken as the confidence measure, according to which the training samples are ranked in ascending order. Those former ranked ones are selected as the boundary targets for the SVDD training. Simulations on UCI data demonstrate the effectiveness and superiority of CSVDD： the number of training targets and the training time are reduced without any loss of accuracy.
