The necessary and sufficient condition of the stability of linear nonautonomous system under the frequently-acting perturbation has been given and proved on the basis of[1] and [2], and the theorem of the equivalence ...The necessary and sufficient condition of the stability of linear nonautonomous system under the frequently-acting perturbation has been given and proved on the basis of[1] and [2], and the theorem of the equivalence on the uniform and asymptotical stability in the sense of Liapunov ami the stability under the frequently-acting perturbation of linear nonautonomous system has been given in this paper. Besides, the analysis of the dynamic stabilitv of robot has been presented by applying the theorem in this paper, which is closer to reality展开更多
In this paper the stability of nonlinear nonautonomous systems under the frequently-acting perturbation is studied. This study is a forward development of the study of the stability in the Liapunov sense; furthermore,...In this paper the stability of nonlinear nonautonomous systems under the frequently-acting perturbation is studied. This study is a forward development of the study of the stability in the Liapunov sense; furthermore, it is of significance in practice since perturbations are often not single in the time domain. Malkin proved a general theorem about thesubject. To apply the theorem, however, the user has to construct a Liapunov function which satisfies specified conditions and it is difficult to find such a function for nonlinear nonautonomous systems. In the light of the principle of Liapunov's indirect method, which is an effective method to decide the stability of nonlinear systems in the Liapunov sense, the authors have achieved several important conclusions expressed in the form of theorems to determine the stability of nonlinear nonautonomous systems under the frequently-acting perturbation.展开更多
We find the necessary and sufficient conditions on a coproduct of connected acts over a semigroup to be strongly hopfian. From this, we deduce the conditions of the strong hopfness for unitary acts over groups. Moreov...We find the necessary and sufficient conditions on a coproduct of connected acts over a semigroup to be strongly hopfian. From this, we deduce the conditions of the strong hopfness for unitary acts over groups. Moreover, we prove that a finite coproduct of strongly hopfian acts over an arbitrary semigroup is strongly hopfian.展开更多
Flipped is a book written by American author Wendelin Van Draanen. It is a novel about young teenagers and was adapted into the famous film of the same name in 2010. The thesis employs speech acts, as pioneered by Joh...Flipped is a book written by American author Wendelin Van Draanen. It is a novel about young teenagers and was adapted into the famous film of the same name in 2010. The thesis employs speech acts, as pioneered by John Austin and further developed by John Searle, to investigate the influence of dialogues on characterization and plot development in Flipped. By exploring the theory of speech acts presented in dialogues between characters, the author deciphers the underlying intentions embodied in the dialogues and demonstrates the importance of the use of speech acts in dialogues in revealing the characters, driving the development of the plot and expressing the theme of the text.展开更多
Ba-constructions carry high level of transitivity,but a deviation towards low transitivity happens.It is found that mode provides axis of this transitivity deviation,especially in spoken dialogue.Under the influence o...Ba-constructions carry high level of transitivity,but a deviation towards low transitivity happens.It is found that mode provides axis of this transitivity deviation,especially in spoken dialogue.Under the influence of irrealis mode,parameters such as aspects,affectedness of O,individuation of O,and affirmation exhibit different degrees of transitivity deviation.Speech acts,which is closely related to mode,are the driving force in discourse of this phenomenon.The composition rules of speech acts of directive,declarative,commitment,and emotive,which account for the majority of speech acts in spoken dialogue,determine that they are all irrealis.Therefore,under the axis of irrealis mode,several transitivity parameters of ba-constructions in oral dialogue deviates towards low transitivity.The phenomenon of deviation of transitivity in ba-constructions verifies transitivity hypothesis.展开更多
BACKGROUND Direct acting antivirals have revolutionized hepatitis C virus(HCV)treatment.However,the high price of the brand forms is a barrier for their use in resource limited countries as Egypt.AIM To assess the saf...BACKGROUND Direct acting antivirals have revolutionized hepatitis C virus(HCV)treatment.However,the high price of the brand forms is a barrier for their use in resource limited countries as Egypt.AIM To assess the safety and efficacy of the generic sofosbuvir(SOF)/ledipasvir(LED)in Egyptian HCV-infected children and to compare the results with the brand form.METHODS This analytical retrospective study included HCV infected children and adolescents aged 12-18 years or weighing>35 kg.Collected data included:Age,sex,risk factors of HCV acquisition,comorbidities,liver functions,HCV viral load,degree of hepatic fibrosis,sustained virologic response(SVR)and frequency of treatment adverse effects.Patients who received the generic form of SOF/LED(Ledisbuvir)were compared to patients who received the brand form(Harvoni®)regarding SVR and frequency of adverse events.RESULTS The study included 43 patients who received Ledisbuvir and 73 who received Harvoni®.All patients achieved SVR.Treatment side effects were mild,transient and comparable in both groups.CONCLUSION The use of generic SOF/LED in HCV infected children is safe and effective.It is comparable to the brand form at a reduced price and represents an affordable and effective alternative.展开更多
文摘The necessary and sufficient condition of the stability of linear nonautonomous system under the frequently-acting perturbation has been given and proved on the basis of[1] and [2], and the theorem of the equivalence on the uniform and asymptotical stability in the sense of Liapunov ami the stability under the frequently-acting perturbation of linear nonautonomous system has been given in this paper. Besides, the analysis of the dynamic stabilitv of robot has been presented by applying the theorem in this paper, which is closer to reality
文摘In this paper the stability of nonlinear nonautonomous systems under the frequently-acting perturbation is studied. This study is a forward development of the study of the stability in the Liapunov sense; furthermore, it is of significance in practice since perturbations are often not single in the time domain. Malkin proved a general theorem about thesubject. To apply the theorem, however, the user has to construct a Liapunov function which satisfies specified conditions and it is difficult to find such a function for nonlinear nonautonomous systems. In the light of the principle of Liapunov's indirect method, which is an effective method to decide the stability of nonlinear systems in the Liapunov sense, the authors have achieved several important conclusions expressed in the form of theorems to determine the stability of nonlinear nonautonomous systems under the frequently-acting perturbation.
文摘We find the necessary and sufficient conditions on a coproduct of connected acts over a semigroup to be strongly hopfian. From this, we deduce the conditions of the strong hopfness for unitary acts over groups. Moreover, we prove that a finite coproduct of strongly hopfian acts over an arbitrary semigroup is strongly hopfian.
文摘Flipped is a book written by American author Wendelin Van Draanen. It is a novel about young teenagers and was adapted into the famous film of the same name in 2010. The thesis employs speech acts, as pioneered by John Austin and further developed by John Searle, to investigate the influence of dialogues on characterization and plot development in Flipped. By exploring the theory of speech acts presented in dialogues between characters, the author deciphers the underlying intentions embodied in the dialogues and demonstrates the importance of the use of speech acts in dialogues in revealing the characters, driving the development of the plot and expressing the theme of the text.
文摘Ba-constructions carry high level of transitivity,but a deviation towards low transitivity happens.It is found that mode provides axis of this transitivity deviation,especially in spoken dialogue.Under the influence of irrealis mode,parameters such as aspects,affectedness of O,individuation of O,and affirmation exhibit different degrees of transitivity deviation.Speech acts,which is closely related to mode,are the driving force in discourse of this phenomenon.The composition rules of speech acts of directive,declarative,commitment,and emotive,which account for the majority of speech acts in spoken dialogue,determine that they are all irrealis.Therefore,under the axis of irrealis mode,several transitivity parameters of ba-constructions in oral dialogue deviates towards low transitivity.The phenomenon of deviation of transitivity in ba-constructions verifies transitivity hypothesis.
文摘BACKGROUND Direct acting antivirals have revolutionized hepatitis C virus(HCV)treatment.However,the high price of the brand forms is a barrier for their use in resource limited countries as Egypt.AIM To assess the safety and efficacy of the generic sofosbuvir(SOF)/ledipasvir(LED)in Egyptian HCV-infected children and to compare the results with the brand form.METHODS This analytical retrospective study included HCV infected children and adolescents aged 12-18 years or weighing>35 kg.Collected data included:Age,sex,risk factors of HCV acquisition,comorbidities,liver functions,HCV viral load,degree of hepatic fibrosis,sustained virologic response(SVR)and frequency of treatment adverse effects.Patients who received the generic form of SOF/LED(Ledisbuvir)were compared to patients who received the brand form(Harvoni®)regarding SVR and frequency of adverse events.RESULTS The study included 43 patients who received Ledisbuvir and 73 who received Harvoni®.All patients achieved SVR.Treatment side effects were mild,transient and comparable in both groups.CONCLUSION The use of generic SOF/LED in HCV infected children is safe and effective.It is comparable to the brand form at a reduced price and represents an affordable and effective alternative.
