A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is proposed.In the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are compensated.The feedforward contr...A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is proposed.In the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are compensated.The feedforward controller is a novel input rate-dependent neural network hysteresis inverse model,while the feedback controller is a proportion integration differentiation(PID)controller.In the proposed inverse model,an input ratedependent auxiliary inverse operator(RAIO)and output of the hysteresis construct the expanded input space(EIS)of the inverse model which transforms the hysteresis inverse with multi-valued mapping into single-valued mapping,and the wiping-out,rate-dependent and continuous properties of the RAIO are analyzed in theories.Based on the EIS method,a hysteresis neural network inverse model,namely the dynamic back propagation neural network(DBPNN)model,is established.Moreover,a hybrid compensation scheme for the PEAs is designed to compensate for the hysteresis.Finally,the proposed method,the conventional PID controller and the hybrid controller with the modified input rate-dependent Prandtl-Ishlinskii(MRPI)model are all applied in the experimental platform.Experimental results show that the proposed method has obvious superiorities in the performance of the system.展开更多
A novel behavioral model using three-layer time-delay feed-forward neural networks (TDFFNN)is adopted to model radio frequency (RF)power amplifiers exhibiting memory nonlinearities. In order to extract the paramet...A novel behavioral model using three-layer time-delay feed-forward neural networks (TDFFNN)is adopted to model radio frequency (RF)power amplifiers exhibiting memory nonlinearities. In order to extract the parameters, the back- propagation algorithm is applied to train the proposed neural networks. The proposed model is verified by the typical odd- order-only memory polynomial model in simulation, and the performance is compared with different numbers of taped delay lines(TDLs) and perceptrons of the hidden layer. For validating the TDFFNN model by experiments, a digital test bench is set up to collect input and output data of power amplifiers at a 60 × 10^6 sample/s sampling rate. The 3.75 MHz 16-QAM signal generated in the vector signal generator(VSG) is chosen as the input signal, when measuring the dynamic AM/AM and AM/PM characteristics of power amplifiers. By comparisons and analyses, the presented model provides a good performance in convergence, accuracy and efficiency, which is approved by simulation results and experimental results in the time domain and frequency domain.展开更多
AIM: To assess the role of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels in regu- lating the excitability of vagal and spinal gut afferents. METHODS: The mechanosensory response of mese...AIM: To assess the role of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels in regu- lating the excitability of vagal and spinal gut afferents. METHODS: The mechanosensory response of mesen- teric afferent activity was measured in an ex vivo murine jejunum preparation. HCN channel activity was recorded through voltage and current clamp in acutely dissoci- ated dorsal root ganglia (DRG) and nodose ganglia (NG) neurons retrogradely labeled from the small intestine through injection of a fluorescent marker (DiI). The isoforms of HCN channels expressed in DRG and NG neurons were examined by immunohistochemistry. RESULTS: Ramp distension of the small intestine evok- ed biphasic increases in the afferent nerve activity, re- flecting the activation of low- and high-threshold fibers.HCN blocker CsCl (5 mmol/L) preferentially inhibited the responses of low-threshold fibers to distension and showed no significant effects on the high-threshold re- sponses. The effect of CsCI was mimicked by the more selective HCN blocker ZD7288 (10 ~mol/L). In 71.4% of DiI labeled DRG neurons (/7 = 20) and 90.9% of DiI labeled NG neurons (n = 10), an inward current (Ih current) was evoked by hyperpolarization pulses which was fully eliminated by extracellular CsCI. In neurons expressing Ih current, a typical "sag" was observed upon injection of hyperpolarizing current pulses in cur- rent-clamp recordings. CsCI abolished the sag entirely. In some DiI labeled DRG neurons, the Ih current was potentiated by 8-Br-cAMP, which had no effect on the Ih current of DiI labeled NG neurons. Immunohistochem- istry revealed differential expression of HCN isoforms in vagal and spinal afferents, and HCN2 and HCN3 seemed to be the dominant isoform in DRG and NG, respec- tively.CONCLUSION: HCNs differentially regulate the excit- ability of vagal and spinal afferent of murine small in- testine.展开更多
Many applications of principal component analysis (PCA) can be found in dimensionality reduction. But linear PCA method is not well suitable for nonlinear chemical processes. A new PCA method based on im-proved input ...Many applications of principal component analysis (PCA) can be found in dimensionality reduction. But linear PCA method is not well suitable for nonlinear chemical processes. A new PCA method based on im-proved input training neural network (IT-NN) is proposed for the nonlinear system modelling in this paper. Mo-mentum factor and adaptive learning rate are introduced into learning algorithm to improve the training speed of IT-NN. Contrasting to the auto-associative neural network (ANN), IT-NN has less hidden layers and higher training speed. The effectiveness is illustrated through a comparison of IT-NN with linear PCA and ANN with experiments. Moreover, the IT-NN is combined with RBF neural network (RBF-NN) to model the yields of ethylene and propyl-ene in the naphtha pyrolysis system. From the illustrative example and practical application, IT-NN combined with RBF-NN is an effective method of nonlinear chemical process modelling.展开更多
Several data mining techniques such as Hidden Markov Model (HMM), artificial neural network, statistical techniques and expert systems are used to model network packets in the field of intrusion detection. In this pap...Several data mining techniques such as Hidden Markov Model (HMM), artificial neural network, statistical techniques and expert systems are used to model network packets in the field of intrusion detection. In this paper a novel intrusion detection mode based on understandable Neural Network Tree (NNTree) is pre-sented. NNTree is a modular neural network with the overall structure being a Decision Tree (DT), and each non-terminal node being an Expert Neural Network (ENN). One crucial advantage of using NNTrees is that they keep the non-symbolic model ENN’s capability of learning in changing environments. Another potential advantage of using NNTrees is that they are actually “gray boxes” as they can be interpreted easily if the num-ber of inputs for each ENN is limited. We showed through experiments that the trained NNTree achieved a simple ENN at each non-terminal node as well as a satisfying recognition rate of the network packets dataset. We also compared the performance with that of a three-layer backpropagation neural network. Experimental results indicated that the NNTree based intrusion detection model achieved better performance than the neural network based intrusion detection model.展开更多
Objective: To retrospectively evaluate the feasibility and clinical value of video assisted endoscopic thyroidectomy by the breast approach. Methods: From December 2002 to May 2003, 28 patients with a mean age of 28 ...Objective: To retrospectively evaluate the feasibility and clinical value of video assisted endoscopic thyroidectomy by the breast approach. Methods: From December 2002 to May 2003, 28 patients with a mean age of 28 years (range from 20 to 45 years) were selected and given video assisted endoscopic thyroidectomy by the breast approach. The subcutaneous space in the breast area and the subplatysmal space in the neck were bluntly dissociated through a 10 mm incision between the nipples, and CO 2 was insufflated at 6 8 kban to create the operative space. Three trocars were inserted in the mammary regions, and dissection of the thyroid and division of the thyroid vessels and parenchyma were performed endoscopically using an ultrasonically activated scalpel. The recurrent laryngeal nerve, the superior laryngeal nerve, and the parathyroid glands were preserved properly. Results: Among the patients, 3 were mass resections, 17 subtotal lobectomies, 2 total lobectomies, and 6 subtotal lobectomies plus contralateral mass resections. The mean operative time was (87.1±26.0) min; the mean estimated blood loss was (47.9±19.6) ml; and the mean postoperative hospital stay was (3.4±0.7) d. The drainage tubes were pulled out at 36 60 h postoperatively. There were no conversions to open surgery or complications. No scars left in the neck, and the patients were satisfied with the postoperative appearance. Conclusion: Video assisted endoscopic thyroidectomy using a breast approach and low pressure subcutaneous CO 2 insufflation is a feasible and safe procedure, which results in satisfactory appearance. We believe that video assisted endoscopic thyroidectomy by such approach will play a role in the future.展开更多
OBJECTIVE To explore the clinical and therapeutic effects of cervical plexus reinnervation for infiltrated or injured unilateral recurrent laryngeal nerve (URLN). METHODS Functional neck dissection for removal of di...OBJECTIVE To explore the clinical and therapeutic effects of cervical plexus reinnervation for infiltrated or injured unilateral recurrent laryngeal nerve (URLN). METHODS Functional neck dissection for removal of differentiated thyroid carcinoma (DTC) in patients was performed, in which cervical plexus reinnervation was adopted for patients with stage I disease and URLN with injury or with tumor invasion. Outcomes of surgery were evaluated by examination under fibrolaryngoscope, and the patients' voices were evaluated before and after surgery. RESULTS All cases were followed up for 3 mon-2 years (average 8 mon). Abductory motion of the vocal cords of 15 patients was completely or partly restored, but 3 patients' vocal cords were immovable. The recovery rate of abductory motion of the paralyzed vocal cords was 83.33% (15/18). The function of phonation in the 16 patients was restored to normal or near normal limits, and their hoarseness was improved significantly. CONCLUSION Cervical plexus-URLN reinnervation should be considered when treating patients with unilateral vocal cord paralysis. Removing the tumor simultaneously with cervical plexus reinnervation during surgery for repair of unilateral recurrent laryngeal nerve injury was convenient and easy to perform with less functional damage compared with other methods of reinnervation. The abductory motion of vocal cord could be satisfactorily restored by this reinnervation. Surgical performance skills and application of neurotrophic drugs were important for the success of the surgery.展开更多
To explore the problems of monitoring chemical processes with large numbers of input parameters, a method based on Auto-associative Hierarchical Neural Network(AHNN) is proposed. AHNN focuses on dealing with datasets ...To explore the problems of monitoring chemical processes with large numbers of input parameters, a method based on Auto-associative Hierarchical Neural Network(AHNN) is proposed. AHNN focuses on dealing with datasets in high-dimension. AHNNs consist of two parts: groups of subnets based on well trained Autoassociative Neural Networks(AANNs) and a main net. The subnets play an important role on the performance of AHNN. A simple but effective method of designing the subnets is developed in this paper. In this method,the subnets are designed according to the classification of the data attributes. For getting the classification, an effective method called Extension Data Attributes Classification(EDAC) is adopted. Soft sensor using AHNN based on EDAC(EDAC-AHNN) is introduced. As a case study, the production data of Purified Terephthalic Acid(PTA) solvent system are selected to examine the proposed model. The results of the EDAC-AHNN model are compared with the experimental data extracted from the literature, which shows the efficiency of the proposed model.展开更多
Machine learning potentials are promising in atomistic simulations due to their comparable accuracy to first-principles theory but much lower computational cost.However,the reliability,speed,and transferability of ato...Machine learning potentials are promising in atomistic simulations due to their comparable accuracy to first-principles theory but much lower computational cost.However,the reliability,speed,and transferability of atomistic machine learning potentials depend strongly on the way atomic configurations are represented.A wise choice of descriptors used as input for the machine learning program is the key for a successful machine learning representation.Here we develop a simple and efficient strategy to automatically select an optimal set of linearly-independent atomic features out of a large pool of candidates,based on the correlations that are intrinsic to the training data.Through applications to the construction of embedded atom neural network potentials for several benchmark molecules with less redundant linearly-independent embedded density descriptors,we demonstrate the efficiency and accuracy of this new strategy.The proposed algorithm can greatly simplify the initial selection of atomic features and vastly improve the performance of the atomistic machine learning potentials.展开更多
An extended self-organizing map for supervised classification is proposed in this paper. Unlike other traditional SOMs, the model has an input layer, a Kohonen layer, and an output layer. The number of neurons in the ...An extended self-organizing map for supervised classification is proposed in this paper. Unlike other traditional SOMs, the model has an input layer, a Kohonen layer, and an output layer. The number of neurons in the input layer depends on the dimensionality of input patterns. The number of neurons in the output layer equals the number of the desired classes. The number of neurons in the Kohonen layer may be a few to several thousands, which depends on the complexity of classification problems and the classification precision. Each training sample is expressed by a pair of vectors : an input vector and a class codebook vector. When a training sample is input into the model, Kohonen's competitive learning rule is applied to selecting the winning neuron from the Kohouen layer and the weight coefficients connecting all the neurons in the input layer with both the winning neuron and its neighbors in the Kohonen layer are modified to be closer to the input vector, and those connecting all the neurons around the winning neuron within a certain diameter in the Kohonen layer with all the neurons in the output layer are adjusted to be closer to the class codebook vector. If the number of training sam- ples is sufficiently large and the learning epochs iterate enough times, the model will be able to serve as a supervised classifier. The model has been tentatively applied to the supervised classification of multispectral remotely sensed data. The author compared the performances of the extended SOM and BPN in remotely sensed data classification. The investigation manifests that the extended SOM is feasible for supervised classification.展开更多
We applied a primitive equation ocean model to simulate submesoscale activities and processes over the shelf of the northern South China Sea(NSCS) with a one-way nesting technology for downscaling.The temperature and ...We applied a primitive equation ocean model to simulate submesoscale activities and processes over the shelf of the northern South China Sea(NSCS) with a one-way nesting technology for downscaling.The temperature and density fields showed that submesoscale activities were ubiquitous in the NSCS shelf.The vertical velocity was considerably enhanced in submesoscale processes and could reach an average of 58 m per day in the subsurface.At this point,the mixed layer depth also was deepened along the front,and the surface kinetic energy also increased with the intense vertical movement induced by submesoscale activity.Thus,submesoscale stirring/mixing is important for tracers,such as temperature,salinity,nutrients,dissolved organic,and inorganic carbon.This result may have implication for climate and biogeochemical investigations.展开更多
This paper is a revised version of a seminal paper, written as early as 1986, that introduces the concept of contemplative psychology as a psychology that is an intrinsic part of the contemplative traditions of most w...This paper is a revised version of a seminal paper, written as early as 1986, that introduces the concept of contemplative psychology as a psychology that is an intrinsic part of the contemplative traditions of most world religions. It refers to the psychological insights and methods that are-often implicitly-present in the spiritual traditions themselves. The paper delineates this psychology as a psychology in its own right and in dialogue with the conventional view of psychology and science. Later research by the author has been published in two books entitled Contemplative Psychology and The Spiritual Path: An Introduction to the Psychology of the Spiritual Traditions.展开更多
This paper addresses the problem of three-dimensional trajectory tracking control for underactuated autonomous underwater vehicles in the presence of parametric uncertainties,environmental disturbances and input satur...This paper addresses the problem of three-dimensional trajectory tracking control for underactuated autonomous underwater vehicles in the presence of parametric uncertainties,environmental disturbances and input saturation.First,a virtual guidance control strategy is established on the basis of tracking error kinematics,which resolves the overall control system into two cascade subsystems.Then,a first-order sliding mode differentiator is introduced in the derivation to avoid tedious analytic calculation,and a Gaussian error function-based continuous differentiable symmetric saturation model is explored to tackle the issue of input saturation.Combined with backstepping design techniques,the neural network control method and an adaptive control approach are used to estimate composite items of the unknown uncertainty and approximation errors.Meanwhile,Lyapunov-based stability analysis guarantees that control error signals of the closed-loop system are uniformly ultimately bounded.Finally,simulation studies are conducted for the trajectory tracking of a moving target and a spiral line to validate the effectiveness of the proposed controller.展开更多
Using retroactive adjustment approach of history data published by the National Bureau of Statistics (NBS), this study has adjusted micro-level survey data of China Household Income Project Survey (CHIPS, 2007) an...Using retroactive adjustment approach of history data published by the National Bureau of Statistics (NBS), this study has adjusted micro-level survey data of China Household Income Project Survey (CHIPS, 2007) and conducted point estimation on household income Gini coefficient using the NBS method. On this basis, the standard error of the point estimation of China's Gini coefficient is estimated using bootstrap method, creating a confidence interval of Gini coefficient. Results indicate that among five continuous declines of Gini coefficient between 2008 and 2013, only three declines are statistically significant. It is thus too early to jump at the conclusion that the Gini coefficient of China's household income distribution has already entered into a downward channel and at least the argument that China's Gini coefficient has been on the decline for five consecutive years is questionable.展开更多
基金National Natural Science Foundation of China(Nos.62171285,61971120 and 62327807)。
文摘A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is proposed.In the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are compensated.The feedforward controller is a novel input rate-dependent neural network hysteresis inverse model,while the feedback controller is a proportion integration differentiation(PID)controller.In the proposed inverse model,an input ratedependent auxiliary inverse operator(RAIO)and output of the hysteresis construct the expanded input space(EIS)of the inverse model which transforms the hysteresis inverse with multi-valued mapping into single-valued mapping,and the wiping-out,rate-dependent and continuous properties of the RAIO are analyzed in theories.Based on the EIS method,a hysteresis neural network inverse model,namely the dynamic back propagation neural network(DBPNN)model,is established.Moreover,a hybrid compensation scheme for the PEAs is designed to compensate for the hysteresis.Finally,the proposed method,the conventional PID controller and the hybrid controller with the modified input rate-dependent Prandtl-Ishlinskii(MRPI)model are all applied in the experimental platform.Experimental results show that the proposed method has obvious superiorities in the performance of the system.
基金The National Natural Science Foundation of China(No.60621002)the National High Technology Research and Development Pro-gram of China(863 Program)(No.2007AA01Z2B4).
文摘A novel behavioral model using three-layer time-delay feed-forward neural networks (TDFFNN)is adopted to model radio frequency (RF)power amplifiers exhibiting memory nonlinearities. In order to extract the parameters, the back- propagation algorithm is applied to train the proposed neural networks. The proposed model is verified by the typical odd- order-only memory polynomial model in simulation, and the performance is compared with different numbers of taped delay lines(TDLs) and perceptrons of the hidden layer. For validating the TDFFNN model by experiments, a digital test bench is set up to collect input and output data of power amplifiers at a 60 × 10^6 sample/s sampling rate. The 3.75 MHz 16-QAM signal generated in the vector signal generator(VSG) is chosen as the input signal, when measuring the dynamic AM/AM and AM/PM characteristics of power amplifiers. By comparisons and analyses, the presented model provides a good performance in convergence, accuracy and efficiency, which is approved by simulation results and experimental results in the time domain and frequency domain.
基金Supported by Science and Technology Commission of Shanghai Municipality,No. 10ZR1417300Educational Commission of Shanghai Municipality,No. 10ZZ69
文摘AIM: To assess the role of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels in regu- lating the excitability of vagal and spinal gut afferents. METHODS: The mechanosensory response of mesen- teric afferent activity was measured in an ex vivo murine jejunum preparation. HCN channel activity was recorded through voltage and current clamp in acutely dissoci- ated dorsal root ganglia (DRG) and nodose ganglia (NG) neurons retrogradely labeled from the small intestine through injection of a fluorescent marker (DiI). The isoforms of HCN channels expressed in DRG and NG neurons were examined by immunohistochemistry. RESULTS: Ramp distension of the small intestine evok- ed biphasic increases in the afferent nerve activity, re- flecting the activation of low- and high-threshold fibers.HCN blocker CsCl (5 mmol/L) preferentially inhibited the responses of low-threshold fibers to distension and showed no significant effects on the high-threshold re- sponses. The effect of CsCI was mimicked by the more selective HCN blocker ZD7288 (10 ~mol/L). In 71.4% of DiI labeled DRG neurons (/7 = 20) and 90.9% of DiI labeled NG neurons (n = 10), an inward current (Ih current) was evoked by hyperpolarization pulses which was fully eliminated by extracellular CsCI. In neurons expressing Ih current, a typical "sag" was observed upon injection of hyperpolarizing current pulses in cur- rent-clamp recordings. CsCI abolished the sag entirely. In some DiI labeled DRG neurons, the Ih current was potentiated by 8-Br-cAMP, which had no effect on the Ih current of DiI labeled NG neurons. Immunohistochem- istry revealed differential expression of HCN isoforms in vagal and spinal afferents, and HCN2 and HCN3 seemed to be the dominant isoform in DRG and NG, respec- tively.CONCLUSION: HCNs differentially regulate the excit- ability of vagal and spinal afferent of murine small in- testine.
基金Supported by Beijing Municipal Education Commission (No.xk100100435) and the Key Research Project of Science andTechnology from Sinopec (No.E03007).
文摘Many applications of principal component analysis (PCA) can be found in dimensionality reduction. But linear PCA method is not well suitable for nonlinear chemical processes. A new PCA method based on im-proved input training neural network (IT-NN) is proposed for the nonlinear system modelling in this paper. Mo-mentum factor and adaptive learning rate are introduced into learning algorithm to improve the training speed of IT-NN. Contrasting to the auto-associative neural network (ANN), IT-NN has less hidden layers and higher training speed. The effectiveness is illustrated through a comparison of IT-NN with linear PCA and ANN with experiments. Moreover, the IT-NN is combined with RBF neural network (RBF-NN) to model the yields of ethylene and propyl-ene in the naphtha pyrolysis system. From the illustrative example and practical application, IT-NN combined with RBF-NN is an effective method of nonlinear chemical process modelling.
基金Supported in part by the National Natural Science Foundation of China (No.60272046, No.60102011), Na-tional High Technology Project of China (No.2002AA143010), Natural Science Foundation of Jiangsu Province (No.BK2001042), and the Foundation for Excellent Doctoral Dissertation of Southeast Univer-sity (No.YBJJ0412).
文摘Several data mining techniques such as Hidden Markov Model (HMM), artificial neural network, statistical techniques and expert systems are used to model network packets in the field of intrusion detection. In this paper a novel intrusion detection mode based on understandable Neural Network Tree (NNTree) is pre-sented. NNTree is a modular neural network with the overall structure being a Decision Tree (DT), and each non-terminal node being an Expert Neural Network (ENN). One crucial advantage of using NNTrees is that they keep the non-symbolic model ENN’s capability of learning in changing environments. Another potential advantage of using NNTrees is that they are actually “gray boxes” as they can be interpreted easily if the num-ber of inputs for each ENN is limited. We showed through experiments that the trained NNTree achieved a simple ENN at each non-terminal node as well as a satisfying recognition rate of the network packets dataset. We also compared the performance with that of a three-layer backpropagation neural network. Experimental results indicated that the NNTree based intrusion detection model achieved better performance than the neural network based intrusion detection model.
文摘Objective: To retrospectively evaluate the feasibility and clinical value of video assisted endoscopic thyroidectomy by the breast approach. Methods: From December 2002 to May 2003, 28 patients with a mean age of 28 years (range from 20 to 45 years) were selected and given video assisted endoscopic thyroidectomy by the breast approach. The subcutaneous space in the breast area and the subplatysmal space in the neck were bluntly dissociated through a 10 mm incision between the nipples, and CO 2 was insufflated at 6 8 kban to create the operative space. Three trocars were inserted in the mammary regions, and dissection of the thyroid and division of the thyroid vessels and parenchyma were performed endoscopically using an ultrasonically activated scalpel. The recurrent laryngeal nerve, the superior laryngeal nerve, and the parathyroid glands were preserved properly. Results: Among the patients, 3 were mass resections, 17 subtotal lobectomies, 2 total lobectomies, and 6 subtotal lobectomies plus contralateral mass resections. The mean operative time was (87.1±26.0) min; the mean estimated blood loss was (47.9±19.6) ml; and the mean postoperative hospital stay was (3.4±0.7) d. The drainage tubes were pulled out at 36 60 h postoperatively. There were no conversions to open surgery or complications. No scars left in the neck, and the patients were satisfied with the postoperative appearance. Conclusion: Video assisted endoscopic thyroidectomy using a breast approach and low pressure subcutaneous CO 2 insufflation is a feasible and safe procedure, which results in satisfactory appearance. We believe that video assisted endoscopic thyroidectomy by such approach will play a role in the future.
文摘OBJECTIVE To explore the clinical and therapeutic effects of cervical plexus reinnervation for infiltrated or injured unilateral recurrent laryngeal nerve (URLN). METHODS Functional neck dissection for removal of differentiated thyroid carcinoma (DTC) in patients was performed, in which cervical plexus reinnervation was adopted for patients with stage I disease and URLN with injury or with tumor invasion. Outcomes of surgery were evaluated by examination under fibrolaryngoscope, and the patients' voices were evaluated before and after surgery. RESULTS All cases were followed up for 3 mon-2 years (average 8 mon). Abductory motion of the vocal cords of 15 patients was completely or partly restored, but 3 patients' vocal cords were immovable. The recovery rate of abductory motion of the paralyzed vocal cords was 83.33% (15/18). The function of phonation in the 16 patients was restored to normal or near normal limits, and their hoarseness was improved significantly. CONCLUSION Cervical plexus-URLN reinnervation should be considered when treating patients with unilateral vocal cord paralysis. Removing the tumor simultaneously with cervical plexus reinnervation during surgery for repair of unilateral recurrent laryngeal nerve injury was convenient and easy to perform with less functional damage compared with other methods of reinnervation. The abductory motion of vocal cord could be satisfactorily restored by this reinnervation. Surgical performance skills and application of neurotrophic drugs were important for the success of the surgery.
基金Supported by the National Natural Science Foundation of China(61074153)
文摘To explore the problems of monitoring chemical processes with large numbers of input parameters, a method based on Auto-associative Hierarchical Neural Network(AHNN) is proposed. AHNN focuses on dealing with datasets in high-dimension. AHNNs consist of two parts: groups of subnets based on well trained Autoassociative Neural Networks(AANNs) and a main net. The subnets play an important role on the performance of AHNN. A simple but effective method of designing the subnets is developed in this paper. In this method,the subnets are designed according to the classification of the data attributes. For getting the classification, an effective method called Extension Data Attributes Classification(EDAC) is adopted. Soft sensor using AHNN based on EDAC(EDAC-AHNN) is introduced. As a case study, the production data of Purified Terephthalic Acid(PTA) solvent system are selected to examine the proposed model. The results of the EDAC-AHNN model are compared with the experimental data extracted from the literature, which shows the efficiency of the proposed model.
基金supported by CAS Project for Young Scientists in Basic Research(YSBR-005)the National Natural Science Foundation of China(No.22073089 and No.22033007)+1 种基金Anhui Initiative in Quantum Information Technologies(AHY090200)the Fundamental Research Funds for Central Universities(WK2060000017)。
文摘Machine learning potentials are promising in atomistic simulations due to their comparable accuracy to first-principles theory but much lower computational cost.However,the reliability,speed,and transferability of atomistic machine learning potentials depend strongly on the way atomic configurations are represented.A wise choice of descriptors used as input for the machine learning program is the key for a successful machine learning representation.Here we develop a simple and efficient strategy to automatically select an optimal set of linearly-independent atomic features out of a large pool of candidates,based on the correlations that are intrinsic to the training data.Through applications to the construction of embedded atom neural network potentials for several benchmark molecules with less redundant linearly-independent embedded density descriptors,we demonstrate the efficiency and accuracy of this new strategy.The proposed algorithm can greatly simplify the initial selection of atomic features and vastly improve the performance of the atomistic machine learning potentials.
基金Supported by National Natural Science Foundation of China (No. 40872193)
文摘An extended self-organizing map for supervised classification is proposed in this paper. Unlike other traditional SOMs, the model has an input layer, a Kohonen layer, and an output layer. The number of neurons in the input layer depends on the dimensionality of input patterns. The number of neurons in the output layer equals the number of the desired classes. The number of neurons in the Kohonen layer may be a few to several thousands, which depends on the complexity of classification problems and the classification precision. Each training sample is expressed by a pair of vectors : an input vector and a class codebook vector. When a training sample is input into the model, Kohonen's competitive learning rule is applied to selecting the winning neuron from the Kohouen layer and the weight coefficients connecting all the neurons in the input layer with both the winning neuron and its neighbors in the Kohonen layer are modified to be closer to the input vector, and those connecting all the neurons around the winning neuron within a certain diameter in the Kohonen layer with all the neurons in the output layer are adjusted to be closer to the class codebook vector. If the number of training sam- ples is sufficiently large and the learning epochs iterate enough times, the model will be able to serve as a supervised classifier. The model has been tentatively applied to the supervised classification of multispectral remotely sensed data. The author compared the performances of the extended SOM and BPN in remotely sensed data classification. The investigation manifests that the extended SOM is feasible for supervised classification.
基金Supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Nos.KZCX1-YW-12-04,KZCX2-YW-201)
文摘We applied a primitive equation ocean model to simulate submesoscale activities and processes over the shelf of the northern South China Sea(NSCS) with a one-way nesting technology for downscaling.The temperature and density fields showed that submesoscale activities were ubiquitous in the NSCS shelf.The vertical velocity was considerably enhanced in submesoscale processes and could reach an average of 58 m per day in the subsurface.At this point,the mixed layer depth also was deepened along the front,and the surface kinetic energy also increased with the intense vertical movement induced by submesoscale activity.Thus,submesoscale stirring/mixing is important for tracers,such as temperature,salinity,nutrients,dissolved organic,and inorganic carbon.This result may have implication for climate and biogeochemical investigations.
文摘This paper is a revised version of a seminal paper, written as early as 1986, that introduces the concept of contemplative psychology as a psychology that is an intrinsic part of the contemplative traditions of most world religions. It refers to the psychological insights and methods that are-often implicitly-present in the spiritual traditions themselves. The paper delineates this psychology as a psychology in its own right and in dialogue with the conventional view of psychology and science. Later research by the author has been published in two books entitled Contemplative Psychology and The Spiritual Path: An Introduction to the Psychology of the Spiritual Traditions.
基金Project(51979116)supported by the National Natural Science Foundation of ChinaProject(2018KFYYXJJ012,2018JYCXJJ045)supported by the Fundamental Research Funds for the Central Universities,China+1 种基金Project(YT19201702)supported by the Innovation Foundation of Maritime Defense Technologies Innovation Center,ChinaProject supported by the HUST Interdisciplinary Innovation Team Project,China。
文摘This paper addresses the problem of three-dimensional trajectory tracking control for underactuated autonomous underwater vehicles in the presence of parametric uncertainties,environmental disturbances and input saturation.First,a virtual guidance control strategy is established on the basis of tracking error kinematics,which resolves the overall control system into two cascade subsystems.Then,a first-order sliding mode differentiator is introduced in the derivation to avoid tedious analytic calculation,and a Gaussian error function-based continuous differentiable symmetric saturation model is explored to tackle the issue of input saturation.Combined with backstepping design techniques,the neural network control method and an adaptive control approach are used to estimate composite items of the unknown uncertainty and approximation errors.Meanwhile,Lyapunov-based stability analysis guarantees that control error signals of the closed-loop system are uniformly ultimately bounded.Finally,simulation studies are conducted for the trajectory tracking of a moving target and a spiral line to validate the effectiveness of the proposed controller.
文摘Using retroactive adjustment approach of history data published by the National Bureau of Statistics (NBS), this study has adjusted micro-level survey data of China Household Income Project Survey (CHIPS, 2007) and conducted point estimation on household income Gini coefficient using the NBS method. On this basis, the standard error of the point estimation of China's Gini coefficient is estimated using bootstrap method, creating a confidence interval of Gini coefficient. Results indicate that among five continuous declines of Gini coefficient between 2008 and 2013, only three declines are statistically significant. It is thus too early to jump at the conclusion that the Gini coefficient of China's household income distribution has already entered into a downward channel and at least the argument that China's Gini coefficient has been on the decline for five consecutive years is questionable.