This paper discusses the two-block large-scale nonconvex optimization problem with general linear constraints.Based on the ideas of splitting and sequential quadratic optimization(SQO),a new feasible descent method fo...This paper discusses the two-block large-scale nonconvex optimization problem with general linear constraints.Based on the ideas of splitting and sequential quadratic optimization(SQO),a new feasible descent method for the discussed problem is proposed.First,we consider the problem of quadratic optimal(QO)approximation associated with the current feasible iteration point,and we split the QO into two small-scale QOs which can be solved in parallel.Second,a feasible descent direction for the problem is obtained and a new SQO-type method is proposed,namely,splitting feasible SQO(SF-SQO)method.Moreover,under suitable conditions,we analyse the global convergence,strong convergence and rate of superlinear convergence of the SF-SQO method.Finally,preliminary numerical experiments regarding the economic dispatch of a power system are carried out,and these show that the SF-SQO method is promising.展开更多
Minimizing transportation time and getting optimal solutions are always considered as important factors while solving transportation problem. This paper shows a new approach for finding initial basic solution for tran...Minimizing transportation time and getting optimal solutions are always considered as important factors while solving transportation problem. This paper shows a new approach for finding initial basic solution for transportation problem which reduces cost of transportation more than any transportation method such as LCM, northwest, Vogel’s approximation and so on. This method has been illustrated by taking an example;afterwards, it compares basic initial feasible solution with other methods IBF and optimal dictate solutions such as MODI and Steppingstone method.展开更多
Multidisciplinary feasible method (MDF) is conventional method to multidisciplinary optimization (MDO) and well-understood by users. It reduces the dimensions of the multidisciplinary optimization problem by using the...Multidisciplinary feasible method (MDF) is conventional method to multidisciplinary optimization (MDO) and well-understood by users. It reduces the dimensions of the multidisciplinary optimization problem by using the design variables as independent optimization variables. However, at each iteration of the conventional optimization procedure, multidisciplinary analysis (MDA) is numerously performed that results in extreme expense and low optimization efficiency. The intrinsic weakness of MDF is due to the times that it loop fixed-point iterations in MDA, which drive us to improve MDF by building inexpensive approximations as surrogates for expensive MDA. An simple example is presented to demonstrate the usefulness of the improved MDF. Results show that a significant reduction in the number of multidisciplinary analysis required for optimization is obtained as compared with original MDF and the efficiency of optimization is increased.展开更多
In this paper, we propose a homotopy continuous method (HCM) for solving a weak efficient solution of multiobjective optimization problem (MOP) with feasible set unbounded condition, which is arising in Economical Dis...In this paper, we propose a homotopy continuous method (HCM) for solving a weak efficient solution of multiobjective optimization problem (MOP) with feasible set unbounded condition, which is arising in Economical Distributions, Engineering Decisions, Resource Allocations and other field of mathematical economics and engineering problems. Under the suitable assumption, it is proved to globally converge to a weak efficient solution of (MOP), if its x-branch has no weak infinite solution.展开更多
Transportation of products from sources to destinations with minimal total cost plays an important role in logistics and supply chain management. In this article, a new and effective algorithm is introduced for findin...Transportation of products from sources to destinations with minimal total cost plays an important role in logistics and supply chain management. In this article, a new and effective algorithm is introduced for finding an initial basic feasible solution of a balanced transportation problem. Number of numerical illustration is introduced and optimality of the result is also checked. Comparison of findings obtained by the new heuristic and the existing heuristics show that the method presented herein gives a better result.展开更多
Transportation Problems (TP), as is known, are a basic network problem which can be formulated as a Linear Programming Problem (LPP). Transportation networks are built up in order to save transportation cost. In the s...Transportation Problems (TP), as is known, are a basic network problem which can be formulated as a Linear Programming Problem (LPP). Transportation networks are built up in order to save transportation cost. In the solution procedure of a TP, finding an Initial Basic Feasible Solution (IBFS) is necessary to obtain the optimal solution. Optimality gives us the optimal route that prompts either most extreme benefit or least aggregate cost whichever is required. In this research paper, a new method named Least Cost Mean Method is proposed to obtain a better IBFS where row penalty and column penalty is brought out by the mean of lowest and next lowest cost of each row and each column of the cost matrix. The method is illustrated with numerical examples. To verify the performance of the proposed method, a comparative study is also carried out and observed that it is computationally easier and yielding comparatively better solution.展开更多
A detailed study is carried out on the nonconvex feasible region of heat exchanger net-works with uncertain stream parameters.The new property of nonconvex feasible region——infeasiblehole property is revealed.By the...A detailed study is carried out on the nonconvex feasible region of heat exchanger net-works with uncertain stream parameters.The new property of nonconvex feasible region——infeasiblehole property is revealed.By theoretical analysis to infeasible hole property,and combining with amethod of mathematical programming,the problem of flexibility analysis for the heat exchanger net-work with nonconvex feasible region can be solved more reasonably.展开更多
To determine the reasonable resource dependent relations between activities for the purpose of exactly computing the total floats and the free floats of activities, correctly identifying critical activities and critic...To determine the reasonable resource dependent relations between activities for the purpose of exactly computing the total floats and the free floats of activities, correctly identifying critical activities and critical sequences in a project schedule with variable resource constraints, the concept of the minimal feasible set (MFS) is proposed and the properties of MFS are discussed. The methods to identify optimal MFSs and resource links are then studied. Furthermore, MFS is generalized to the situation that the preconditions of MFS are not satisfied. Contrastive results show that in establishing resource links and resolving floats, MFS is at least not inferior to other methods in all cases and is superior in most situations.展开更多
Given a complete graph with vertex set X and subsets X_1, X_2,..., X_n, the problem of finding a subgraph G with minimum number of edges such that for every i = 1, 2,..., n G contains a spanning tree on X_i, arises in...Given a complete graph with vertex set X and subsets X_1, X_2,..., X_n, the problem of finding a subgraph G with minimum number of edges such that for every i = 1, 2,..., n G contains a spanning tree on X_i, arises in the design of vaccum systems. In general, this problem is NP-complete and it is proved that for n = 2 and 3 this problem is polynomial-time solvable. In this paper, we prove that for n = 4, the problem is also polynomial-time solvable and give a method to construct the corresponding graph.展开更多
Feasible sets play an important role in model predictive control(MPC) optimal control problems(OCPs). This paper proposes a multi-parametric programming-based algorithm to compute the feasible set for OCP derived from...Feasible sets play an important role in model predictive control(MPC) optimal control problems(OCPs). This paper proposes a multi-parametric programming-based algorithm to compute the feasible set for OCP derived from MPC-based algorithms involving both spectrahedron(represented by linear matrix inequalities) and polyhedral(represented by a set of inequalities) constraints. According to the geometrical meaning of the inner product of vectors, the maximum length of the projection vector from the feasible set to a unit spherical coordinates vector is computed and the optimal solution has been proved to be one of the vertices of the feasible set. After computing the vertices,the convex hull of these vertices is determined which equals the feasible set. The simulation results show that the proposed method is especially efficient for low dimensional feasible set computation and avoids the non-unicity problem of optimizers as well as the memory consumption problem that encountered by projection algorithms.展开更多
This paper introduced problems in the current construction of "new urbanization" from four perspectives, namely making new countryside planning, but not eliminating countryside, protecting architectural cult...This paper introduced problems in the current construction of "new urbanization" from four perspectives, namely making new countryside planning, but not eliminating countryside, protecting architectural cultures, avoiding pursuit of grandiose western-style projects. In addition, solutions to the problems were proposed, the necessity and urgency of promoting new urbanization scientifi cally and reasonably was stressed, the feasible approach for the construction of new urbanization was explored.展开更多
The primary function of the peripheral nerves is to transmit signals from the spinal cord to the rest of the body,or to convey sensory information from the rest of the body to the spinal cord.In case of injury or a he...The primary function of the peripheral nerves is to transmit signals from the spinal cord to the rest of the body,or to convey sensory information from the rest of the body to the spinal cord.In case of injury or a health disorder,this pathway can be partially or totally disrupted,resulting in pain,loss of sensation,reduced muscular strength,poor coordination,or complete paralysis.展开更多
Minimization of transportation time is a great concern of the transportation problems like the cost minimizing transportation problems. In this writing, a transportation algorithm is developed and applied to obtain an...Minimization of transportation time is a great concern of the transportation problems like the cost minimizing transportation problems. In this writing, a transportation algorithm is developed and applied to obtain an Initial Basic Feasible Solution (IBFS) of transportation problems in minimizing transportation time. The developed method has also been illustrated numerically to test the efficiency of the method where it is observed that the proposed method yields a better result.展开更多
A new SQP type feasible method for inequality constrained optimization is presented,it is a combination of a master algorithm and an auxiliary algorithm which is taken only in finite iterations.The directions of the m...A new SQP type feasible method for inequality constrained optimization is presented,it is a combination of a master algorithm and an auxiliary algorithm which is taken only in finite iterations.The directions of the master algorithm are generated by only one quadratic programming, and its step\|size is always one, the directions of the auxiliary algorithm are new “second\|order” feasible descent. Under suitable assumptions,the algorithm is proved to possess global and strong convergence, superlinear and quadratic convergence.展开更多
It is expected that a total of 5 billion US dollars will be invested in Nanhai Petrochemical Project,the largest Chinese-foreign equity joint venture(JV)in petrochemical industry of south part of China,which includes ...It is expected that a total of 5 billion US dollars will be invested in Nanhai Petrochemical Project,the largest Chinese-foreign equity joint venture(JV)in petrochemical industry of south part of China,which includes 50%from Shell a and 50%from Chinese party.The investment of the Chinese party is comprised of 20%from CNOOC,10%separately from Sinopech,Guangdong pro-vince,Bureau of Business Promotion.展开更多
After China entries WTO, China's ‘ textile · garment'industry will confront the difficulties of growth and development. From the view of supply and demand interaction which is common in the social econom...After China entries WTO, China's ‘ textile · garment'industry will confront the difficulties of growth and development. From the view of supply and demand interaction which is common in the social economy, this article analyzes the economic construction and character of China's ‘ textile · garment' industry, represented by Shanghai,Research shows that industrial construction backwardness hinders China's ‘ textile· garment' industry development, which features four bottlenecks in supply and demand interaction in ‘ textile· garment' industry.The key of optimizing the construction and quality of supply and denand interaction in ‘textile· garment'industry is to adjust industrial construction, break the bottlenecks, establish Shanghai as international fashion center, open middle and small size textile processing area with several levels, attach importance to scientific and technology creation and development combined with production, learning and research, and take part in domestic and international maket competition by high added value product, technology and marketing network.展开更多
To provide guidance for photovoltaic(PV)system integration in net-zero distribution systems(DSs),this paper proposes an analytical method for delineating the feasible region for PV integration capacities(PVICs),where ...To provide guidance for photovoltaic(PV)system integration in net-zero distribution systems(DSs),this paper proposes an analytical method for delineating the feasible region for PV integration capacities(PVICs),where the impact of battery energy storage system(BESS)flexibility is considered.First,we introduce distributionally robust chance constraints on network security and energy/carbon net-zero requirements,which form the upper and lower bounds of the feasible region.Then,the formulation and solution of the feasible region is proposed.The resulting analytical expression is a set of linear inequalities,illustrating that the feasible region is a polyhedron in a high-dimensional space.A procedure is designed to verify and adjust the feasible region,ensuring that it satisfies network loss constraints under alternating current(AC)power flow.Case studies on the 4-bus system,the IEEE 33-bus system,and the IEEE 123-bus system verify the effectiveness of the proposed method.It is demonstrated that the proposed method fully captures the spatio-temporal coupling relationship among PVs,loads,and BESSs,while also quantifying the impact of this relationship on the boundaries of the feasible region.展开更多
Optimal power flow(OPF) is the fundamental mathematical model to optimize power system operations.Based on conic relaxation, Taylor series expansion and McCormick envelope, we propose three convex OPF models to improv...Optimal power flow(OPF) is the fundamental mathematical model to optimize power system operations.Based on conic relaxation, Taylor series expansion and McCormick envelope, we propose three convex OPF models to improve the performance of the second-order cone alternating current OPF(SOC-ACOPF) model. The underlying idea of the proposed SOC-ACOPF models is to drop assumptions of the original SOC-ACOPF model by convex relaxation and approximation methods.A heuristic algorithm to recover feasible ACOPF solution from the relaxed solution of the proposed SOC-ACOPF models is developed. The proposed SOC-ACOPF models are examined through IEEE case studies under various load scenarios and power network congestions. The quality of solutions from the proposed SOC-ACOPF models is evaluated using MATPOWER(local optimality) and LINDOGLOBAL(global optimality). We also compare numerically the proposed SOC-ACOPF models with other two convex ACOPF models in the literature.The numerical results show robust performance of the proposed SOCACOPF models and the feasible solution recovery algorithm.展开更多
This paper concerns the solution of the NP-hard max-bisection problems. NCP functions are employed to convert max-bisection problems into continuous nonlinear programming problems. Solving the resulting continuous non...This paper concerns the solution of the NP-hard max-bisection problems. NCP functions are employed to convert max-bisection problems into continuous nonlinear programming problems. Solving the resulting continuous nonlinear programming problem generates a solution that gives an upper bound on the optimal value of the max-bisection problem. From the solution, the greedy strategy is used to generate a satisfactory approximate solution of the max-bisection problem. A feasible direction method without line searches is proposed to solve the resulting continuous nonlinear programming, and the convergence of the algorithm to KKT point of the resulting problem is proved. Numerical experiments and comparisons on well-known test problems, and on randomly generated test problems show that the proposed method is robust, and very efficient.展开更多
Esophageal cancer(EC)is a common cancer and is histopathologically classified into esophageal squamous cell carcinoma and esophageal adenocarcinoma.EC is a worldwide public health issue because of late diagnosis and l...Esophageal cancer(EC)is a common cancer and is histopathologically classified into esophageal squamous cell carcinoma and esophageal adenocarcinoma.EC is a worldwide public health issue because of late diagnosis and lack of effective therapy.In contrast to standard tumor biopsies,liquid biopsies are emerging as a tool which is minimally invasive that can complement or even substitute more classical approaches.Specifically,cell-free DNA(cfDNA)has shown promise in cancer-related clinical applications.Indeed,cfDNA has been shown to be an effective circulating biomarker for non-invasive cancer diagnosis and monitoring of cancer patients.Although the clinical application of cfDNA has been reported on other cancers,few studies have evaluated its use in EC.Here,we review this relevant literature and discuss limitations and advantages of its application in the diagnosis and monitoring of EC.展开更多
基金supported by the National Natural Science Foundation of China(12171106)the Natural Science Foundation of Guangxi Province(2020GXNSFDA238017 and 2018GXNSFFA281007)the Shanghai Sailing Program(21YF1430300)。
文摘This paper discusses the two-block large-scale nonconvex optimization problem with general linear constraints.Based on the ideas of splitting and sequential quadratic optimization(SQO),a new feasible descent method for the discussed problem is proposed.First,we consider the problem of quadratic optimal(QO)approximation associated with the current feasible iteration point,and we split the QO into two small-scale QOs which can be solved in parallel.Second,a feasible descent direction for the problem is obtained and a new SQO-type method is proposed,namely,splitting feasible SQO(SF-SQO)method.Moreover,under suitable conditions,we analyse the global convergence,strong convergence and rate of superlinear convergence of the SF-SQO method.Finally,preliminary numerical experiments regarding the economic dispatch of a power system are carried out,and these show that the SF-SQO method is promising.
文摘Minimizing transportation time and getting optimal solutions are always considered as important factors while solving transportation problem. This paper shows a new approach for finding initial basic solution for transportation problem which reduces cost of transportation more than any transportation method such as LCM, northwest, Vogel’s approximation and so on. This method has been illustrated by taking an example;afterwards, it compares basic initial feasible solution with other methods IBF and optimal dictate solutions such as MODI and Steppingstone method.
文摘Multidisciplinary feasible method (MDF) is conventional method to multidisciplinary optimization (MDO) and well-understood by users. It reduces the dimensions of the multidisciplinary optimization problem by using the design variables as independent optimization variables. However, at each iteration of the conventional optimization procedure, multidisciplinary analysis (MDA) is numerously performed that results in extreme expense and low optimization efficiency. The intrinsic weakness of MDF is due to the times that it loop fixed-point iterations in MDA, which drive us to improve MDF by building inexpensive approximations as surrogates for expensive MDA. An simple example is presented to demonstrate the usefulness of the improved MDF. Results show that a significant reduction in the number of multidisciplinary analysis required for optimization is obtained as compared with original MDF and the efficiency of optimization is increased.
文摘In this paper, we propose a homotopy continuous method (HCM) for solving a weak efficient solution of multiobjective optimization problem (MOP) with feasible set unbounded condition, which is arising in Economical Distributions, Engineering Decisions, Resource Allocations and other field of mathematical economics and engineering problems. Under the suitable assumption, it is proved to globally converge to a weak efficient solution of (MOP), if its x-branch has no weak infinite solution.
文摘Transportation of products from sources to destinations with minimal total cost plays an important role in logistics and supply chain management. In this article, a new and effective algorithm is introduced for finding an initial basic feasible solution of a balanced transportation problem. Number of numerical illustration is introduced and optimality of the result is also checked. Comparison of findings obtained by the new heuristic and the existing heuristics show that the method presented herein gives a better result.
文摘Transportation Problems (TP), as is known, are a basic network problem which can be formulated as a Linear Programming Problem (LPP). Transportation networks are built up in order to save transportation cost. In the solution procedure of a TP, finding an Initial Basic Feasible Solution (IBFS) is necessary to obtain the optimal solution. Optimality gives us the optimal route that prompts either most extreme benefit or least aggregate cost whichever is required. In this research paper, a new method named Least Cost Mean Method is proposed to obtain a better IBFS where row penalty and column penalty is brought out by the mean of lowest and next lowest cost of each row and each column of the cost matrix. The method is illustrated with numerical examples. To verify the performance of the proposed method, a comparative study is also carried out and observed that it is computationally easier and yielding comparatively better solution.
文摘A detailed study is carried out on the nonconvex feasible region of heat exchanger net-works with uncertain stream parameters.The new property of nonconvex feasible region——infeasiblehole property is revealed.By theoretical analysis to infeasible hole property,and combining with amethod of mathematical programming,the problem of flexibility analysis for the heat exchanger net-work with nonconvex feasible region can be solved more reasonably.
基金supported partly by the Postdoctoral Science Foundation of China(2007042-0922)the Program of Educational Commission of Guangxi Zhuang Minority Autonomous Region(200712LX128)the Scientific Research Foundation of Guangxi University for Nationalities for Talent Introduction(200702YZ01).
文摘To determine the reasonable resource dependent relations between activities for the purpose of exactly computing the total floats and the free floats of activities, correctly identifying critical activities and critical sequences in a project schedule with variable resource constraints, the concept of the minimal feasible set (MFS) is proposed and the properties of MFS are discussed. The methods to identify optimal MFSs and resource links are then studied. Furthermore, MFS is generalized to the situation that the preconditions of MFS are not satisfied. Contrastive results show that in establishing resource links and resolving floats, MFS is at least not inferior to other methods in all cases and is superior in most situations.
文摘Given a complete graph with vertex set X and subsets X_1, X_2,..., X_n, the problem of finding a subgraph G with minimum number of edges such that for every i = 1, 2,..., n G contains a spanning tree on X_i, arises in the design of vaccum systems. In general, this problem is NP-complete and it is proved that for n = 2 and 3 this problem is polynomial-time solvable. In this paper, we prove that for n = 4, the problem is also polynomial-time solvable and give a method to construct the corresponding graph.
基金supported by the Natural Science Foundation of Zhejiang Province(LR17F030002)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(61621002)
文摘Feasible sets play an important role in model predictive control(MPC) optimal control problems(OCPs). This paper proposes a multi-parametric programming-based algorithm to compute the feasible set for OCP derived from MPC-based algorithms involving both spectrahedron(represented by linear matrix inequalities) and polyhedral(represented by a set of inequalities) constraints. According to the geometrical meaning of the inner product of vectors, the maximum length of the projection vector from the feasible set to a unit spherical coordinates vector is computed and the optimal solution has been proved to be one of the vertices of the feasible set. After computing the vertices,the convex hull of these vertices is determined which equals the feasible set. The simulation results show that the proposed method is especially efficient for low dimensional feasible set computation and avoids the non-unicity problem of optimizers as well as the memory consumption problem that encountered by projection algorithms.
文摘This paper introduced problems in the current construction of "new urbanization" from four perspectives, namely making new countryside planning, but not eliminating countryside, protecting architectural cultures, avoiding pursuit of grandiose western-style projects. In addition, solutions to the problems were proposed, the necessity and urgency of promoting new urbanization scientifi cally and reasonably was stressed, the feasible approach for the construction of new urbanization was explored.
文摘The primary function of the peripheral nerves is to transmit signals from the spinal cord to the rest of the body,or to convey sensory information from the rest of the body to the spinal cord.In case of injury or a health disorder,this pathway can be partially or totally disrupted,resulting in pain,loss of sensation,reduced muscular strength,poor coordination,or complete paralysis.
文摘Minimization of transportation time is a great concern of the transportation problems like the cost minimizing transportation problems. In this writing, a transportation algorithm is developed and applied to obtain an Initial Basic Feasible Solution (IBFS) of transportation problems in minimizing transportation time. The developed method has also been illustrated numerically to test the efficiency of the method where it is observed that the proposed method yields a better result.
基金Supported by the National Natural Science Foundation of China(1 980 1 0 0 9) and by the Natural Sci-ence Foundation of Guangxi
文摘A new SQP type feasible method for inequality constrained optimization is presented,it is a combination of a master algorithm and an auxiliary algorithm which is taken only in finite iterations.The directions of the master algorithm are generated by only one quadratic programming, and its step\|size is always one, the directions of the auxiliary algorithm are new “second\|order” feasible descent. Under suitable assumptions,the algorithm is proved to possess global and strong convergence, superlinear and quadratic convergence.
文摘It is expected that a total of 5 billion US dollars will be invested in Nanhai Petrochemical Project,the largest Chinese-foreign equity joint venture(JV)in petrochemical industry of south part of China,which includes 50%from Shell a and 50%from Chinese party.The investment of the Chinese party is comprised of 20%from CNOOC,10%separately from Sinopech,Guangdong pro-vince,Bureau of Business Promotion.
文摘After China entries WTO, China's ‘ textile · garment'industry will confront the difficulties of growth and development. From the view of supply and demand interaction which is common in the social economy, this article analyzes the economic construction and character of China's ‘ textile · garment' industry, represented by Shanghai,Research shows that industrial construction backwardness hinders China's ‘ textile· garment' industry development, which features four bottlenecks in supply and demand interaction in ‘ textile· garment' industry.The key of optimizing the construction and quality of supply and denand interaction in ‘textile· garment'industry is to adjust industrial construction, break the bottlenecks, establish Shanghai as international fashion center, open middle and small size textile processing area with several levels, attach importance to scientific and technology creation and development combined with production, learning and research, and take part in domestic and international maket competition by high added value product, technology and marketing network.
基金supported by the Natural Science Foundation of Tianjin(No.22JCZDJC00820)。
文摘To provide guidance for photovoltaic(PV)system integration in net-zero distribution systems(DSs),this paper proposes an analytical method for delineating the feasible region for PV integration capacities(PVICs),where the impact of battery energy storage system(BESS)flexibility is considered.First,we introduce distributionally robust chance constraints on network security and energy/carbon net-zero requirements,which form the upper and lower bounds of the feasible region.Then,the formulation and solution of the feasible region is proposed.The resulting analytical expression is a set of linear inequalities,illustrating that the feasible region is a polyhedron in a high-dimensional space.A procedure is designed to verify and adjust the feasible region,ensuring that it satisfies network loss constraints under alternating current(AC)power flow.Case studies on the 4-bus system,the IEEE 33-bus system,and the IEEE 123-bus system verify the effectiveness of the proposed method.It is demonstrated that the proposed method fully captures the spatio-temporal coupling relationship among PVs,loads,and BESSs,while also quantifying the impact of this relationship on the boundaries of the feasible region.
文摘Optimal power flow(OPF) is the fundamental mathematical model to optimize power system operations.Based on conic relaxation, Taylor series expansion and McCormick envelope, we propose three convex OPF models to improve the performance of the second-order cone alternating current OPF(SOC-ACOPF) model. The underlying idea of the proposed SOC-ACOPF models is to drop assumptions of the original SOC-ACOPF model by convex relaxation and approximation methods.A heuristic algorithm to recover feasible ACOPF solution from the relaxed solution of the proposed SOC-ACOPF models is developed. The proposed SOC-ACOPF models are examined through IEEE case studies under various load scenarios and power network congestions. The quality of solutions from the proposed SOC-ACOPF models is evaluated using MATPOWER(local optimality) and LINDOGLOBAL(global optimality). We also compare numerically the proposed SOC-ACOPF models with other two convex ACOPF models in the literature.The numerical results show robust performance of the proposed SOCACOPF models and the feasible solution recovery algorithm.
文摘This paper concerns the solution of the NP-hard max-bisection problems. NCP functions are employed to convert max-bisection problems into continuous nonlinear programming problems. Solving the resulting continuous nonlinear programming problem generates a solution that gives an upper bound on the optimal value of the max-bisection problem. From the solution, the greedy strategy is used to generate a satisfactory approximate solution of the max-bisection problem. A feasible direction method without line searches is proposed to solve the resulting continuous nonlinear programming, and the convergence of the algorithm to KKT point of the resulting problem is proved. Numerical experiments and comparisons on well-known test problems, and on randomly generated test problems show that the proposed method is robust, and very efficient.
文摘Esophageal cancer(EC)is a common cancer and is histopathologically classified into esophageal squamous cell carcinoma and esophageal adenocarcinoma.EC is a worldwide public health issue because of late diagnosis and lack of effective therapy.In contrast to standard tumor biopsies,liquid biopsies are emerging as a tool which is minimally invasive that can complement or even substitute more classical approaches.Specifically,cell-free DNA(cfDNA)has shown promise in cancer-related clinical applications.Indeed,cfDNA has been shown to be an effective circulating biomarker for non-invasive cancer diagnosis and monitoring of cancer patients.Although the clinical application of cfDNA has been reported on other cancers,few studies have evaluated its use in EC.Here,we review this relevant literature and discuss limitations and advantages of its application in the diagnosis and monitoring of EC.