Classification is always the key point in the field of remote sensing. Fuzzy c-Means is a traditional clustering algorithm that has been widely used in fuzzy clustering. However, this algorithm usually has some weakne...Classification is always the key point in the field of remote sensing. Fuzzy c-Means is a traditional clustering algorithm that has been widely used in fuzzy clustering. However, this algorithm usually has some weaknesses, such as the problems of falling into a local minimum, and it needs much time to accomplish the classification for a large number of data. In order to overcome these shortcomings and increase the classifi-cation accuracy, Gustafson-Kessel (GK) and Gath-Geva (GG) algorithms are proposed to improve the tradi-tional FCM algorithm which adopts Euclidean distance norm in this paper. The experimental result shows that these two methods are able to detect clusters of varying shapes, sizes and densities which FCM cannot do. Moreover, they can improve the classification accuracy of remote sensing images.展开更多
The Main Optical Telescope (MOT) is an important payload of the Space Solar Telescope (SST) with various instruments and observation modes. Its real-time data handling and management and control tasks are arduous. Bas...The Main Optical Telescope (MOT) is an important payload of the Space Solar Telescope (SST) with various instruments and observation modes. Its real-time data handling and management and control tasks are arduous. Based on the advanced techniques of foreign countries, an improved structure of onboard data handling systems feasible for SST, is proposed. This article concentrated on the development of a Central Management & Control Unit (MCU) based on FPGA and DSP. Through reconfigurating the FPGA and DSP programs, the prototype could perform different tasks. Thus the inheritability of the whole system is improved. The completed dual-channel prototype proves that the system meets all requirements of the MOT. Its high reliability and safety features also meet the requirements under harsh conditions such as mine detection.展开更多
For complex industrial processes with multiple operational conditions, it is important to develop effective monitoring algorithms to ensure the safety of production processes. This paper proposes a novel monitoring st...For complex industrial processes with multiple operational conditions, it is important to develop effective monitoring algorithms to ensure the safety of production processes. This paper proposes a novel monitoring strategy based on fuzzy C-means. The high dimensional historical data are transferred to a low dimensional subspace spanned by locality preserving projection. Then the scores in the novel subspace are classified into several overlapped clusters, each representing an operational mode. The distance statistics of each cluster are integrated though the membership values into a novel BID (Bayesian inference distance) monitoring index. The efficiency and effectiveness of the proposed method are validated though the Tennessee Eastman benchmark process.展开更多
AIM:To determine the effect of oral sumatriptan on gastric emptying using a continuous 13 C breath test(BreathID system).METHODS:Ten healthy male volunteers participated in this randomized,2-way crossover study.The su...AIM:To determine the effect of oral sumatriptan on gastric emptying using a continuous 13 C breath test(BreathID system).METHODS:Ten healthy male volunteers participated in this randomized,2-way crossover study.The subjects fasted overnight and were randomly assigned to receive a test meal(200 kcal/200 mL) 30 min after pre-medication with sumatriptan 50 mg(sumatriptan condition),or the test meal alone(control condition).Gastric emptying was monitored for 4 h after administration of the test meal by the 13 C-acetic acid breath test performed continually using the BreathID system.Then,using Oridion Research Software(β version),the time taken for emptying of 50% of the labeled meal(T 1/2) similar to the scintigraphy lag time for 10% emptying of the labeled meal(T lag),the gastric emptying coefficient(GEC),and the regression-estimated constants(β and κ) were calculated.The statistical significance of any differences in the parameters were analyzed using Wilcoxon's signed-rank test.RESULTS:In the sumatriptan condition,significant differences compared with the control condition were found in T 1/2 [median 131.84 min(range,103.13-168.70) vs 120.27 min(89.61-138.25);P = 0.0016],T lag [median 80.085 min(59.23-125.89) vs 61.11 min(39.86-87.05);P = 0.0125],and β [median 2.3374(1.6407-3.8209) vs 2.0847(1.4755-2.9269);P = 0.0284].There were no significant differences in the GEC or κ between the 2 conditions.CONCLUSION:This study showed that oral sumatriptan significantly delayed gastric emptying of a liquid meal.展开更多
The inner-formation gravity field measurement satellite （IFS） is a novel pure gravitational orbiter. It aims to measure the Earth＇s gravity field with unprecedented accuracy and spatial resolution by means of preci...The inner-formation gravity field measurement satellite （IFS） is a novel pure gravitational orbiter. It aims to measure the Earth＇s gravity field with unprecedented accuracy and spatial resolution by means of precise orbit determination （POD） and relative state measurement. One of the key factors determining the measurement level is the outer-satellite control used for keeping the inner-satellite flying in a pure gravitational orbit stably. In this paper the integrated orbit and attitude control of IFS during steady-state phase was investigated using only thrusters. A six degree-of-freedom translational and rotational dynamics model was constructed considering nonlinearity resulted from quaternion expression and coupling induced by community thrusters. A feasible quadratic optimization model was established for the integrated orbit and attitude control using con- strained nonlinear model predictive control （CNMPC） techniques. Simulation experiment demonstrated that the presented CNMPC aigorithm can achieve rapid calculation and overcome the non-convexity of partial constraints. The thruster layout is rational with low thrust consumption, and the mission requirements of IFS are fully satisfied.展开更多
基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry
文摘Classification is always the key point in the field of remote sensing. Fuzzy c-Means is a traditional clustering algorithm that has been widely used in fuzzy clustering. However, this algorithm usually has some weaknesses, such as the problems of falling into a local minimum, and it needs much time to accomplish the classification for a large number of data. In order to overcome these shortcomings and increase the classifi-cation accuracy, Gustafson-Kessel (GK) and Gath-Geva (GG) algorithms are proposed to improve the tradi-tional FCM algorithm which adopts Euclidean distance norm in this paper. The experimental result shows that these two methods are able to detect clusters of varying shapes, sizes and densities which FCM cannot do. Moreover, they can improve the classification accuracy of remote sensing images.
基金Project 863-2.5.2.25 supported by the National High Technology Research & Development (863) Program of China
文摘The Main Optical Telescope (MOT) is an important payload of the Space Solar Telescope (SST) with various instruments and observation modes. Its real-time data handling and management and control tasks are arduous. Based on the advanced techniques of foreign countries, an improved structure of onboard data handling systems feasible for SST, is proposed. This article concentrated on the development of a Central Management & Control Unit (MCU) based on FPGA and DSP. Through reconfigurating the FPGA and DSP programs, the prototype could perform different tasks. Thus the inheritability of the whole system is improved. The completed dual-channel prototype proves that the system meets all requirements of the MOT. Its high reliability and safety features also meet the requirements under harsh conditions such as mine detection.
基金Supported by the National Natural Science Foundation of China (61074079)Shanghai Leading Academic Discipline Project (B054)
文摘For complex industrial processes with multiple operational conditions, it is important to develop effective monitoring algorithms to ensure the safety of production processes. This paper proposes a novel monitoring strategy based on fuzzy C-means. The high dimensional historical data are transferred to a low dimensional subspace spanned by locality preserving projection. Then the scores in the novel subspace are classified into several overlapped clusters, each representing an operational mode. The distance statistics of each cluster are integrated though the membership values into a novel BID (Bayesian inference distance) monitoring index. The efficiency and effectiveness of the proposed method are validated though the Tennessee Eastman benchmark process.
文摘AIM:To determine the effect of oral sumatriptan on gastric emptying using a continuous 13 C breath test(BreathID system).METHODS:Ten healthy male volunteers participated in this randomized,2-way crossover study.The subjects fasted overnight and were randomly assigned to receive a test meal(200 kcal/200 mL) 30 min after pre-medication with sumatriptan 50 mg(sumatriptan condition),or the test meal alone(control condition).Gastric emptying was monitored for 4 h after administration of the test meal by the 13 C-acetic acid breath test performed continually using the BreathID system.Then,using Oridion Research Software(β version),the time taken for emptying of 50% of the labeled meal(T 1/2) similar to the scintigraphy lag time for 10% emptying of the labeled meal(T lag),the gastric emptying coefficient(GEC),and the regression-estimated constants(β and κ) were calculated.The statistical significance of any differences in the parameters were analyzed using Wilcoxon's signed-rank test.RESULTS:In the sumatriptan condition,significant differences compared with the control condition were found in T 1/2 [median 131.84 min(range,103.13-168.70) vs 120.27 min(89.61-138.25);P = 0.0016],T lag [median 80.085 min(59.23-125.89) vs 61.11 min(39.86-87.05);P = 0.0125],and β [median 2.3374(1.6407-3.8209) vs 2.0847(1.4755-2.9269);P = 0.0284].There were no significant differences in the GEC or κ between the 2 conditions.CONCLUSION:This study showed that oral sumatriptan significantly delayed gastric emptying of a liquid meal.
基金supported by the National Natural Science Foundation of China (Grant No. 11002076)the National Defense Pre-Research (Grant No.51320010201)
文摘The inner-formation gravity field measurement satellite （IFS） is a novel pure gravitational orbiter. It aims to measure the Earth＇s gravity field with unprecedented accuracy and spatial resolution by means of precise orbit determination （POD） and relative state measurement. One of the key factors determining the measurement level is the outer-satellite control used for keeping the inner-satellite flying in a pure gravitational orbit stably. In this paper the integrated orbit and attitude control of IFS during steady-state phase was investigated using only thrusters. A six degree-of-freedom translational and rotational dynamics model was constructed considering nonlinearity resulted from quaternion expression and coupling induced by community thrusters. A feasible quadratic optimization model was established for the integrated orbit and attitude control using con- strained nonlinear model predictive control （CNMPC） techniques. Simulation experiment demonstrated that the presented CNMPC aigorithm can achieve rapid calculation and overcome the non-convexity of partial constraints. The thruster layout is rational with low thrust consumption, and the mission requirements of IFS are fully satisfied.
