The observing failure and feedback instability might happen when the partial sensors of a satellite attitude control sys- tem （SACS） go wrong. A fault diagnosis and isolation （FDI） method based on a fault observer...The observing failure and feedback instability might happen when the partial sensors of a satellite attitude control sys- tem （SACS） go wrong. A fault diagnosis and isolation （FDI） method based on a fault observer is introduced to detect and isolate the fault sensor at first. Based on the FDI result, the object system state-space equation is transformed and divided into a correspon- sive triangular canonical form to decouple the normal subsystem from the fault subsystem. And then the KX fault-tolerant observers of the system in different modes are designed and embedded into online monitoring. The outputs of all KX fault-tolerant observers are selected by the control switch process. That can make sense that the SACS is part-observed and in stable when the partial sen- sors break down. Simulation results demonstrate the effectiveness and superiority of the proposed method.展开更多
Reentry attitude control for reusable launch vehicles （RLVs） is challenging due to the characters of fast nonlinear dy- namics and large flight envelop. A hierarchical structured attitude control system for an RLV i...Reentry attitude control for reusable launch vehicles （RLVs） is challenging due to the characters of fast nonlinear dy- namics and large flight envelop. A hierarchical structured attitude control system for an RLV is proposed and an unpowered RLV con- trol model is developed. Then, the hierarchical structured control frame consisting of attitude controller, compound control strategy and control allocation is presented. At the core of the design is a robust adaptive control （RAC） law based on dual loop time-scale separation. A radial basis function neural network （RBFNN） is implemented for compensation of uncertain model dynamics and external disturbances in the inner loop. And then the robust op- timization is applied in the outer loop to guarantee performance robustness. The overall control design frame retains the simplicity in design while simultaneously assuring the adaptive and robust performance. The hierarchical structured robust adaptive con- troller （HSRAC） incorporates flexibility into the design with regard to controller versatility to various reentry mission requirements. Simulation results show that the improved tracking performance is achieved by means of RAC.展开更多
Attiéké is fermented cassava semolina steamed and consumed with proteins and vegetables. From Ivorian traditional origin, its popularity is increasing in Africa and production networks are developing. Howeve...Attiéké is fermented cassava semolina steamed and consumed with proteins and vegetables. From Ivorian traditional origin, its popularity is increasing in Africa and production networks are developing. However, the growth of attiéké industry is still curbed by lack of technical skills of producers and irregular quality, depending on cassava variety, processing and inoculum. In the present study, a traditional inoculum and four cassava varieties (two improved local (IAC and Bonoua) and two improved sweet ones from Nigeria (Olekanga and TMS 4 (2) 1425)) were used for producing attiéké Ebrié. For the sensorial evaluation of prepared attiéké, qualitative sensory profiling was used. The sensory quality descriptors where quantitatively measured by a trained sensory panel. With this method the most important quality criteria of attiéké were judged. These quality criteria were selected with the aid of surveys on its production and consumption. The relationships between sensory attributes of the four attiéké prepared of the different cassava varieties and biochemical characteristics were studied. Sensory analysis revealed that the four attiéké were cream-colored products with sweet and/or sour tastes, made of cohesive and well-formed grains of different sizes, with an odor of fermentation specific to attiéké and showing a firm texture. The differences between sensory profiles of the four attiéké produced from four cassava varieties (12 months growth) concern only some descriptors of quality. Pearson correlation coefficients between physicochemical descriptors of quality showed that biochemical parameters may help predict organoleptic characteristics of attiéké Ebrié (pH-size of grains: r = 0.99;pH-acidity: r = ?0.92;acidity-rounded grains: r = ?0.98: starch-cohesion between grains: r = ?0.96;starch-sweet: r = ?0.95;starch-granulous: r = 0.97, total sugar-yellow color: r = 0.96;total sugar-aroma of attiéké: r = 0.96;reducing sugar-odor of attiéké: r = 0.95;cyanide-fibrous: r = 0.95).展开更多
Attiéké is an essentially flavour starchy food produced from fermented cassava root. The product is widely consumed in Burkina Faso. The objective of the present study was to investigate the biochemical and ...Attiéké is an essentially flavour starchy food produced from fermented cassava root. The product is widely consumed in Burkina Faso. The objective of the present study was to investigate the biochemical and the microbiological characteristics of attiéké from Burkina Faso. The samples (36) were collected from six (6) producers. Cassava dough which is used for attiéké production contains from 70.67% ± 0.25% to 86.02% ± 0.2% as starch. The undesirable organic elements rate is about 1.28% ± 0.14% to 26.46% ± 0.53%. The inorganic impurities rate is about 0 to 7 ± 0.1 mg/100g. Cassava dough acidity varies from 1.8 ± 0.2 to 12.4 ± 0.1;and its pH from 3.48 ± 0.01 to 4.20 ± 0.01. Lactic bacteria are the main microorganisms involved in cassava dough fermentation (5.17 to 9.30 log cfu/g). Yeasts and molds number is low (<6.53 log cfu/g). Attiéké moister is about 50.6% ± 0.00% to 55.12% ± 0.7% and its protein contents from 0.77 to 1.74 ± 0.13 g/100g. The content in lipid of attiéké shows an important variation and is about 0.15 to 3.28 ± 0.32 g/100g. Carbohydrates content varies from 36.6 ± 0.04 to 47.01 ± 0.1 g/100g and its ashes content is from 140 to 780 ± 20 mg/100g. Attiéké acidity and pH are less weak than cassava dough. They vary respectively from 0.92% ± 0.05% to 4.08% ± 0.57% and from 3.7 to 4.4 ± 0.01. As a main energizer food, attiéké energizing value is from 161.95 to 215.26 Kcal/100g. All the attiéké analyzed was exempt of aflatoxin (B1, B2, G1, G2) and ochratoxin A. The local attiéké has higher acidity, fermented bacteria load, protein and minerals salt than the imported one. The process mastery is the mainly factor that determines nutritional and sanitary quality of attiéké.展开更多
It is recognized by both teachers and researchers that affect has played an important role in learning second or foreign language.It can influence the rate and success of learning foreign or second language.It include...It is recognized by both teachers and researchers that affect has played an important role in learning second or foreign language.It can influence the rate and success of learning foreign or second language.It includes anxiety,motivation,attitude,inhibition,empathy,confidence,self-image etc.This paper analyzes the role of students’self-image,motivation,attitude in learning English as a foreign language.Students’affect towards English learning are relatively positive if those affective factors are controlled well.展开更多
基金supported by the National High Technology Research and Development Program (863 Program) (2007AA04Z438)
文摘The observing failure and feedback instability might happen when the partial sensors of a satellite attitude control sys- tem （SACS） go wrong. A fault diagnosis and isolation （FDI） method based on a fault observer is introduced to detect and isolate the fault sensor at first. Based on the FDI result, the object system state-space equation is transformed and divided into a correspon- sive triangular canonical form to decouple the normal subsystem from the fault subsystem. And then the KX fault-tolerant observers of the system in different modes are designed and embedded into online monitoring. The outputs of all KX fault-tolerant observers are selected by the control switch process. That can make sense that the SACS is part-observed and in stable when the partial sen- sors break down. Simulation results demonstrate the effectiveness and superiority of the proposed method.
基金supported by the National Natural Science Foundation of China(61174221)
文摘Reentry attitude control for reusable launch vehicles （RLVs） is challenging due to the characters of fast nonlinear dy- namics and large flight envelop. A hierarchical structured attitude control system for an RLV is proposed and an unpowered RLV con- trol model is developed. Then, the hierarchical structured control frame consisting of attitude controller, compound control strategy and control allocation is presented. At the core of the design is a robust adaptive control （RAC） law based on dual loop time-scale separation. A radial basis function neural network （RBFNN） is implemented for compensation of uncertain model dynamics and external disturbances in the inner loop. And then the robust op- timization is applied in the outer loop to guarantee performance robustness. The overall control design frame retains the simplicity in design while simultaneously assuring the adaptive and robust performance. The hierarchical structured robust adaptive con- troller （HSRAC） incorporates flexibility into the design with regard to controller versatility to various reentry mission requirements. Simulation results show that the improved tracking performance is achieved by means of RAC.
文摘Attiéké is fermented cassava semolina steamed and consumed with proteins and vegetables. From Ivorian traditional origin, its popularity is increasing in Africa and production networks are developing. However, the growth of attiéké industry is still curbed by lack of technical skills of producers and irregular quality, depending on cassava variety, processing and inoculum. In the present study, a traditional inoculum and four cassava varieties (two improved local (IAC and Bonoua) and two improved sweet ones from Nigeria (Olekanga and TMS 4 (2) 1425)) were used for producing attiéké Ebrié. For the sensorial evaluation of prepared attiéké, qualitative sensory profiling was used. The sensory quality descriptors where quantitatively measured by a trained sensory panel. With this method the most important quality criteria of attiéké were judged. These quality criteria were selected with the aid of surveys on its production and consumption. The relationships between sensory attributes of the four attiéké prepared of the different cassava varieties and biochemical characteristics were studied. Sensory analysis revealed that the four attiéké were cream-colored products with sweet and/or sour tastes, made of cohesive and well-formed grains of different sizes, with an odor of fermentation specific to attiéké and showing a firm texture. The differences between sensory profiles of the four attiéké produced from four cassava varieties (12 months growth) concern only some descriptors of quality. Pearson correlation coefficients between physicochemical descriptors of quality showed that biochemical parameters may help predict organoleptic characteristics of attiéké Ebrié (pH-size of grains: r = 0.99;pH-acidity: r = ?0.92;acidity-rounded grains: r = ?0.98: starch-cohesion between grains: r = ?0.96;starch-sweet: r = ?0.95;starch-granulous: r = 0.97, total sugar-yellow color: r = 0.96;total sugar-aroma of attiéké: r = 0.96;reducing sugar-odor of attiéké: r = 0.95;cyanide-fibrous: r = 0.95).
文摘Attiéké is an essentially flavour starchy food produced from fermented cassava root. The product is widely consumed in Burkina Faso. The objective of the present study was to investigate the biochemical and the microbiological characteristics of attiéké from Burkina Faso. The samples (36) were collected from six (6) producers. Cassava dough which is used for attiéké production contains from 70.67% ± 0.25% to 86.02% ± 0.2% as starch. The undesirable organic elements rate is about 1.28% ± 0.14% to 26.46% ± 0.53%. The inorganic impurities rate is about 0 to 7 ± 0.1 mg/100g. Cassava dough acidity varies from 1.8 ± 0.2 to 12.4 ± 0.1;and its pH from 3.48 ± 0.01 to 4.20 ± 0.01. Lactic bacteria are the main microorganisms involved in cassava dough fermentation (5.17 to 9.30 log cfu/g). Yeasts and molds number is low (<6.53 log cfu/g). Attiéké moister is about 50.6% ± 0.00% to 55.12% ± 0.7% and its protein contents from 0.77 to 1.74 ± 0.13 g/100g. The content in lipid of attiéké shows an important variation and is about 0.15 to 3.28 ± 0.32 g/100g. Carbohydrates content varies from 36.6 ± 0.04 to 47.01 ± 0.1 g/100g and its ashes content is from 140 to 780 ± 20 mg/100g. Attiéké acidity and pH are less weak than cassava dough. They vary respectively from 0.92% ± 0.05% to 4.08% ± 0.57% and from 3.7 to 4.4 ± 0.01. As a main energizer food, attiéké energizing value is from 161.95 to 215.26 Kcal/100g. All the attiéké analyzed was exempt of aflatoxin (B1, B2, G1, G2) and ochratoxin A. The local attiéké has higher acidity, fermented bacteria load, protein and minerals salt than the imported one. The process mastery is the mainly factor that determines nutritional and sanitary quality of attiéké.
文摘It is recognized by both teachers and researchers that affect has played an important role in learning second or foreign language.It can influence the rate and success of learning foreign or second language.It includes anxiety,motivation,attitude,inhibition,empathy,confidence,self-image etc.This paper analyzes the role of students’self-image,motivation,attitude in learning English as a foreign language.Students’affect towards English learning are relatively positive if those affective factors are controlled well.
