The ant colony algorithm is a new class of population basic algorithm. The path planning is realized by the use of ant colony algorithm when the plane executes the low altitude penetration, which provides a new method...The ant colony algorithm is a new class of population basic algorithm. The path planning is realized by the use of ant colony algorithm when the plane executes the low altitude penetration, which provides a new method for the path planning. In the paper the traditional ant colony algorithm is improved, and measures of keeping optimization, adaptively selecting and adaptively adjusting are applied, by which better path at higher convergence speed can be found. Finally the algorithm is implemented with computer simulation and preferable results are obtained.展开更多
The principle of direct method used in optimal control problem is introduced. Details of applying this method to flight trajectory generation are presented including calculation of velocity and controls histories. And...The principle of direct method used in optimal control problem is introduced. Details of applying this method to flight trajectory generation are presented including calculation of velocity and controls histories. And capabilities of flight and propulsion systems are considered also. Combined with digital terrain map technique, the direct method is applied to the three dimensional trajectory optimization for low altitude penetration, and simplex algorithm is used to solve the parameters in optimization. For the small number of parameters, the trajectory can be optimized in real time on board.展开更多
The development of colorectal cancer(CRC)can be influenced by genetic factors in both familial cases and sporadic cases.Familial CRC has been associated with genetic changes in high-,moderate-and low-penetrance suscep...The development of colorectal cancer(CRC)can be influenced by genetic factors in both familial cases and sporadic cases.Familial CRC has been associated with genetic changes in high-,moderate-and low-penetrance susceptibility genes.However,despite the availability of current gene-identification techniques,the genetic causes of a considerable proportion of hereditary cases remain unknown.Genome-wide association studies of CRC have identified a number of common lowpenetrance alleles associated with a slightly increased or decreased risk of CRC.The accumulation of low-risk variants may partly explain the familial risk of CRC,and some of these variants may modify the risk of cancer in patients with mutations in high-penetrance genes.Understanding the predisposition to develop CRC will require investigators to address the following challenges:the identification of genes that cause uncharacterized hereditary cases of CRC such as familial CRC type X and serrated polyposis;the classification of variants of unknown significance in known CRC-predisposing genes;and the identification of additional cancer risk modifiers that can be used to perform risk assessments for individual mutation carriers.We performed a comprehensive review of the genetically characterized and uncharacterized hereditary CRC syndromes and of lowand moderate-penetrance loci and variants identified through genome-wide association studies and candidate-gene approaches.Current challenges and future perspectives in the field of CRC predisposition are also discussed.展开更多
文摘The ant colony algorithm is a new class of population basic algorithm. The path planning is realized by the use of ant colony algorithm when the plane executes the low altitude penetration, which provides a new method for the path planning. In the paper the traditional ant colony algorithm is improved, and measures of keeping optimization, adaptively selecting and adaptively adjusting are applied, by which better path at higher convergence speed can be found. Finally the algorithm is implemented with computer simulation and preferable results are obtained.
文摘The principle of direct method used in optimal control problem is introduced. Details of applying this method to flight trajectory generation are presented including calculation of velocity and controls histories. And capabilities of flight and propulsion systems are considered also. Combined with digital terrain map technique, the direct method is applied to the three dimensional trajectory optimization for low altitude penetration, and simplex algorithm is used to solve the parameters in optimization. For the small number of parameters, the trajectory can be optimized in real time on board.
基金The Spanish Ministry of the Economy(State Secretariat for Research,Development and Innovation),grant SAF2012-38885Ramon y Cajal contract+1 种基金L’Oreal-UNESCO"For Women in Science"and the Scientific Foundation Asociacion Espanola Contra el Cancer
文摘The development of colorectal cancer(CRC)can be influenced by genetic factors in both familial cases and sporadic cases.Familial CRC has been associated with genetic changes in high-,moderate-and low-penetrance susceptibility genes.However,despite the availability of current gene-identification techniques,the genetic causes of a considerable proportion of hereditary cases remain unknown.Genome-wide association studies of CRC have identified a number of common lowpenetrance alleles associated with a slightly increased or decreased risk of CRC.The accumulation of low-risk variants may partly explain the familial risk of CRC,and some of these variants may modify the risk of cancer in patients with mutations in high-penetrance genes.Understanding the predisposition to develop CRC will require investigators to address the following challenges:the identification of genes that cause uncharacterized hereditary cases of CRC such as familial CRC type X and serrated polyposis;the classification of variants of unknown significance in known CRC-predisposing genes;and the identification of additional cancer risk modifiers that can be used to perform risk assessments for individual mutation carriers.We performed a comprehensive review of the genetically characterized and uncharacterized hereditary CRC syndromes and of lowand moderate-penetrance loci and variants identified through genome-wide association studies and candidate-gene approaches.Current challenges and future perspectives in the field of CRC predisposition are also discussed.
