For the constrained generalized Hamiltonian system with dissipation, by introducing Lagrange multiplier and using projection technique, the Lie group integration method was presented, which can preserve the inherent s...For the constrained generalized Hamiltonian system with dissipation, by introducing Lagrange multiplier and using projection technique, the Lie group integration method was presented, which can preserve the inherent structure of dynamic system and the constraint-invariant. Firstly, the constrained generalized Hamiltonian system with dissipative was converted to the non-constraint generalized Hamiltonian system, then Lie group integration algorithm for the non-constraint generalized Hamiltonian system was discussed, finally the projection method for generalized Hamiltonian system with constraint was given. It is found that the constraint invariant is ensured by projection technique, and after introducing Lagrange multiplier the Lie group character of the dynamic system can't be destroyed while projecting to the constraint manifold. The discussion is restricted to the case of holonomic constraint. A presented numerical example shows the effectiveness of the method.展开更多
This paper reviewed the concepts of Project Evaluation Review Technique and<span style="font-family:Verdana;"> Critical Path Method in project management with practical examples. The methods and succes...This paper reviewed the concepts of Project Evaluation Review Technique and<span style="font-family:Verdana;"> Critical Path Method in project management with practical examples. The methods and success of quantitative decision-making approaches in project management through t</span><span style="font-family:Verdana;">he use of project evaluation review technique and the critical path method as regards project duration and critical activities of a project, were discussed. The review found that while both methods are effective in achieving success in project management, the relationship and connectivity of activities involved in a project life cycle are key aspects. The paper concludes that the project evaluation review technique is more effective when the duration of the project is uncertain, while the critical path method is effective when the project’s end time is certain. The paper, therefore, recommends that to achieve maximum operative efficiency in utilizing resources in project management, p</span><span style="font-family:Verdana;">rior to commencing the execution of a project, all required resources to cover every activity must be assembled and prioritized to eliminate interruptions that could bring delay and unnecessary cost implications. Again, policies focused on improving project execution should be implemented in developing nations to minimize the many cases of failed and delayed projects. Subsequently, stakeholders in projects must be given the right, under the law, to prosecute the government, its agencies and/or the executors of projects for failure to execute a project on schedule.</span>展开更多
BACKGROUND The data obtained on the anatomical knowledge of the tracheobronchial system can be used for diagnosis,treatment and interventional interventions in areas such as anesthesia,thoracic surgery,pulmonary physi...BACKGROUND The data obtained on the anatomical knowledge of the tracheobronchial system can be used for diagnosis,treatment and interventional interventions in areas such as anesthesia,thoracic surgery,pulmonary physiology.AIM To determine the tracheobronchial branching angles in pediatric and adult populations by using the multislice computed tomography(CT)and minimum intensity projection(MinIP)technique,which is a non-invasive method.METHODS Our study was carried out retrospectively.Patients who underwent contrast and non-contrast CT examination,whose anatomically and pathophysiologically good tracheobronchial system and lung parenchyma images were obtained,were included in the study.Measurements were made in the coronal plane of the lung parenchyma.In the coronal plane,right main bronchus-left main bronchus angle,right upper lobe bronchus-intermedius bronchus angle,right middle lobe bronchus-right lower lobe bronchus angle,left upper lobe bronchus-left lower lobe bronchus angle were measured.RESULTS The study population consisted of 1511 patients,753 pediatric(mean age:13.4±4.3;range:1-18 years)and 758 adults(mean age:54.3±17.3;range:19-94 years).In our study,tracheal bifurcation angle was found to be 73.3°±13.7°(59.6°-87°)in the whole population.In the pediatric group,the right-left main coronal level was found to be higher in boys compared to girls(74.6°±12.9°vs 71.2°±13.9°,P=0.001).In the adult group,the right-left main coronal level was found to be lower in males compared to females(71.9°±12.9°vs 75.8°±14.7°,P<0.001).CONCLUSIONS Our study,with the number of 1511 patients,is the first study in the literature with the largest number of patient populations including pediatric and adult demographic data,measuring the angle values of the tracheobronchial system using multislice CT and MinIP technique.Study data will not only be a guide during invasive procedures,but it can also guide studies to be done with imaging methods.展开更多
We present a non-Markovian master equation for a qubit interacting with a general reservoir, which is derived according to the Nakajima-Zwanzig and the time convolutionless projection operator technique. The non-Marko...We present a non-Markovian master equation for a qubit interacting with a general reservoir, which is derived according to the Nakajima-Zwanzig and the time convolutionless projection operator technique. The non-Markovian solutions and Markovian solution of dynamical decay of a qubit are compared. The results indicate the validity of non-Markovian approach in different coupling regimes and also show that the Markovian master equation may not precisely describe the dynamics of an open quantum system in some situation. The non-Markovian solutions may be effective for many qubits independently interacting with the heated reservoirs.展开更多
文摘For the constrained generalized Hamiltonian system with dissipation, by introducing Lagrange multiplier and using projection technique, the Lie group integration method was presented, which can preserve the inherent structure of dynamic system and the constraint-invariant. Firstly, the constrained generalized Hamiltonian system with dissipative was converted to the non-constraint generalized Hamiltonian system, then Lie group integration algorithm for the non-constraint generalized Hamiltonian system was discussed, finally the projection method for generalized Hamiltonian system with constraint was given. It is found that the constraint invariant is ensured by projection technique, and after introducing Lagrange multiplier the Lie group character of the dynamic system can't be destroyed while projecting to the constraint manifold. The discussion is restricted to the case of holonomic constraint. A presented numerical example shows the effectiveness of the method.
文摘This paper reviewed the concepts of Project Evaluation Review Technique and<span style="font-family:Verdana;"> Critical Path Method in project management with practical examples. The methods and success of quantitative decision-making approaches in project management through t</span><span style="font-family:Verdana;">he use of project evaluation review technique and the critical path method as regards project duration and critical activities of a project, were discussed. The review found that while both methods are effective in achieving success in project management, the relationship and connectivity of activities involved in a project life cycle are key aspects. The paper concludes that the project evaluation review technique is more effective when the duration of the project is uncertain, while the critical path method is effective when the project’s end time is certain. The paper, therefore, recommends that to achieve maximum operative efficiency in utilizing resources in project management, p</span><span style="font-family:Verdana;">rior to commencing the execution of a project, all required resources to cover every activity must be assembled and prioritized to eliminate interruptions that could bring delay and unnecessary cost implications. Again, policies focused on improving project execution should be implemented in developing nations to minimize the many cases of failed and delayed projects. Subsequently, stakeholders in projects must be given the right, under the law, to prosecute the government, its agencies and/or the executors of projects for failure to execute a project on schedule.</span>
文摘BACKGROUND The data obtained on the anatomical knowledge of the tracheobronchial system can be used for diagnosis,treatment and interventional interventions in areas such as anesthesia,thoracic surgery,pulmonary physiology.AIM To determine the tracheobronchial branching angles in pediatric and adult populations by using the multislice computed tomography(CT)and minimum intensity projection(MinIP)technique,which is a non-invasive method.METHODS Our study was carried out retrospectively.Patients who underwent contrast and non-contrast CT examination,whose anatomically and pathophysiologically good tracheobronchial system and lung parenchyma images were obtained,were included in the study.Measurements were made in the coronal plane of the lung parenchyma.In the coronal plane,right main bronchus-left main bronchus angle,right upper lobe bronchus-intermedius bronchus angle,right middle lobe bronchus-right lower lobe bronchus angle,left upper lobe bronchus-left lower lobe bronchus angle were measured.RESULTS The study population consisted of 1511 patients,753 pediatric(mean age:13.4±4.3;range:1-18 years)and 758 adults(mean age:54.3±17.3;range:19-94 years).In our study,tracheal bifurcation angle was found to be 73.3°±13.7°(59.6°-87°)in the whole population.In the pediatric group,the right-left main coronal level was found to be higher in boys compared to girls(74.6°±12.9°vs 71.2°±13.9°,P=0.001).In the adult group,the right-left main coronal level was found to be lower in males compared to females(71.9°±12.9°vs 75.8°±14.7°,P<0.001).CONCLUSIONS Our study,with the number of 1511 patients,is the first study in the literature with the largest number of patient populations including pediatric and adult demographic data,measuring the angle values of the tracheobronchial system using multislice CT and MinIP technique.Study data will not only be a guide during invasive procedures,but it can also guide studies to be done with imaging methods.
基金Project supported by the Natural Science Foundation of Hunan Province of China (Grant No. 09JJ6011)the Natural Science Foundation of the Education Department of Hunan Province of China (Grant Nos. 06C652 and 07C528)
文摘We present a non-Markovian master equation for a qubit interacting with a general reservoir, which is derived according to the Nakajima-Zwanzig and the time convolutionless projection operator technique. The non-Markovian solutions and Markovian solution of dynamical decay of a qubit are compared. The results indicate the validity of non-Markovian approach in different coupling regimes and also show that the Markovian master equation may not precisely describe the dynamics of an open quantum system in some situation. The non-Markovian solutions may be effective for many qubits independently interacting with the heated reservoirs.