This paper proposes a multilevel placer targeted at hierarchical FPGA（Field Programmable Gate Array） devices.The placer is based on multilevel optimization method which combines the multilevel bottom-up clustering p...This paper proposes a multilevel placer targeted at hierarchical FPGA（Field Programmable Gate Array） devices.The placer is based on multilevel optimization method which combines the multilevel bottom-up clustering process and top-down placement process into a V-cycle.It provides superior wirelength results over a known heuristic high-quality placement tool on a set of large circuits,when restricted to a short run time.For example,it can generate a placement result for a circuit with 5000 4-LUTs（4-Input Look Up Tables） in 70 seconds,almost 30%decrease of wirelength compared with than the heuristic implementation that takes over 500 seconds.We have verified our algorithm yields good quality-time tradeoff results as a low-temperature simulated annealing refinement process can only improve the result by an average of 1.11%at the cost of over 25-fold runtime.展开更多
The concrete-steel platform structure is rather complicated because it involves such materials as concrete, reinforcing bars, steel, and so on. If the traditional dimension optimization method is employed, the optimal...The concrete-steel platform structure is rather complicated because it involves such materials as concrete, reinforcing bars, steel, and so on. If the traditional dimension optimization method is employed, the optimal design of the platform will meet many handicaps, even it cannot be implemented at all. The multilevel optimal design approach is an efficient tool for the solution of large-scale engineering structures. In this paper, this approach is applied to the optimal design of a concrete-steel platform, which is formulated as a system level optimal design problem and a set of uncoupled substructure level optimal design problems. The process of optimization is a process of iteration between system level and substructure level until the objective function converges. An illustrative example indicates that this method is effective in the optimal design of concrete-steel platforms.展开更多
For digital channelized frequency division multiple access based satellite communication(SATCOM) systems,it is a challenging but critical issue to improve the transponder power and spectrum efficiency simultaneously u...For digital channelized frequency division multiple access based satellite communication(SATCOM) systems,it is a challenging but critical issue to improve the transponder power and spectrum efficiency simultaneously under limited and non-linear high-power amplifier conditions.In this paper,different from the traditional link supportability designs aiming at minimizing the total transponder output power,a maximal sum Shannon capacity optimization objective is firstly raised subject to link supportability constraints.Furthermore,an efficient multilevel optimization(MO) algorithm is proposed to solve the considered optimization problem in the case of single link for each terminal.Moreover,in the case of multiple links for one terminal,an improved MO algorithm involving Golden section and discrete gradient searching procedures is proposed to optimize power allocation over all links.Finally,several numerical results are provided to demonstrate the effectiveness of our proposals.Comparison results show that,by the MO algorithm,not only all links' supportability can be guaranteed but also a larger sum capacity can be achieved with lower complexity.展开更多
Decisions in supply chains are hierarchically organized. Strategic decisions involve the long-term planning of the structure of the supply chain network.Tactical decisions are mid-term plans to allocate the production...Decisions in supply chains are hierarchically organized. Strategic decisions involve the long-term planning of the structure of the supply chain network.Tactical decisions are mid-term plans to allocate the production and distribution of materials, while operational decisions are related to the daily planning of the execution of manufacturing operations. These planning processes are conducted independently with minimal exchange of information between them. Achieving a better coordination between these processes allows companies to capture benefits that are currently out of their reach and improve the communication among their functional areas. We propose a network representation for the multilevel decision structure and analyze the components that are involved in finding integrated solutions that maximize the sum of the benefits of all nodes of the decision network.Although such task is very challenging, significant research progress has been made in each component of this structure. An overview of strategic models, mid-term planning models, and scheduling models is presented to address the solution of each node in the decision network.Coordination mechanisms for converging the integrated solutions are also analyzed, including solving large-scale models, multiobjective optimization, bi-level programming, and decomposition. We conclude by summarizing the challenges that hinder the full integration of multilevel decision making in supply chain management.展开更多
Nanoprodrugs that are directly assembled by prodrugs attract considerable attention with high anticancer potentials.However,their stability and efficiency of tumor-targeted delivery remain a major challenge in practic...Nanoprodrugs that are directly assembled by prodrugs attract considerable attention with high anticancer potentials.However,their stability and efficiency of tumor-targeted delivery remain a major challenge in practical biomedical applications.Here,we report a new deep tumor-penetrating nano-delivery strategy to achieve enhanced anti-cancer performance by systematic optimization of a porphyrin-doxorubicin-based nanoprodrug using various PEGylations/crosslinks and co-administration of targeting peptide iRGD.Polyethylene glycols(PEGs)with different molecular weights and grafts are employed to crosslink the nanoprodrug and optimize size,charge,tumor accumulation and penetration,and anti-cancer efficiency,etc.The tumor penetration was validated in syngeneic oral cancer mouse models,patient-derived xenograft(PDX)models,and oral cancer tissue from patients.The optimized nanoprodrug co-administrated with iRGD remarkably enhances the accumulation and penetration both in tumor vascular and PDX tumor tissue.It is effective and safe to improve in vivo therapeutic efficacy via the passive tumor targeting dependent and independent mode.Our tumor-penetrating nano-delivery strategy is promising to strengthen the nanoprodrugs in clinical implementation.展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos.60876026 and 60833004.
文摘This paper proposes a multilevel placer targeted at hierarchical FPGA（Field Programmable Gate Array） devices.The placer is based on multilevel optimization method which combines the multilevel bottom-up clustering process and top-down placement process into a V-cycle.It provides superior wirelength results over a known heuristic high-quality placement tool on a set of large circuits,when restricted to a short run time.For example,it can generate a placement result for a circuit with 5000 4-LUTs（4-Input Look Up Tables） in 70 seconds,almost 30%decrease of wirelength compared with than the heuristic implementation that takes over 500 seconds.We have verified our algorithm yields good quality-time tradeoff results as a low-temperature simulated annealing refinement process can only improve the result by an average of 1.11%at the cost of over 25-fold runtime.
基金This work was financially supported by the Natural Science Foundation of China(Grant No.59895410)
文摘The concrete-steel platform structure is rather complicated because it involves such materials as concrete, reinforcing bars, steel, and so on. If the traditional dimension optimization method is employed, the optimal design of the platform will meet many handicaps, even it cannot be implemented at all. The multilevel optimal design approach is an efficient tool for the solution of large-scale engineering structures. In this paper, this approach is applied to the optimal design of a concrete-steel platform, which is formulated as a system level optimal design problem and a set of uncoupled substructure level optimal design problems. The process of optimization is a process of iteration between system level and substructure level until the objective function converges. An illustrative example indicates that this method is effective in the optimal design of concrete-steel platforms.
基金supportedin part by Natural Science Foundation under grant No.91338108,91438206Co-innovation Laboratory of Aerospace Broadband Network Technology
文摘For digital channelized frequency division multiple access based satellite communication(SATCOM) systems,it is a challenging but critical issue to improve the transponder power and spectrum efficiency simultaneously under limited and non-linear high-power amplifier conditions.In this paper,different from the traditional link supportability designs aiming at minimizing the total transponder output power,a maximal sum Shannon capacity optimization objective is firstly raised subject to link supportability constraints.Furthermore,an efficient multilevel optimization(MO) algorithm is proposed to solve the considered optimization problem in the case of single link for each terminal.Moreover,in the case of multiple links for one terminal,an improved MO algorithm involving Golden section and discrete gradient searching procedures is proposed to optimize power allocation over all links.Finally,several numerical results are provided to demonstrate the effectiveness of our proposals.Comparison results show that,by the MO algorithm,not only all links' supportability can be guaranteed but also a larger sum capacity can be achieved with lower complexity.
文摘Decisions in supply chains are hierarchically organized. Strategic decisions involve the long-term planning of the structure of the supply chain network.Tactical decisions are mid-term plans to allocate the production and distribution of materials, while operational decisions are related to the daily planning of the execution of manufacturing operations. These planning processes are conducted independently with minimal exchange of information between them. Achieving a better coordination between these processes allows companies to capture benefits that are currently out of their reach and improve the communication among their functional areas. We propose a network representation for the multilevel decision structure and analyze the components that are involved in finding integrated solutions that maximize the sum of the benefits of all nodes of the decision network.Although such task is very challenging, significant research progress has been made in each component of this structure. An overview of strategic models, mid-term planning models, and scheduling models is presented to address the solution of each node in the decision network.Coordination mechanisms for converging the integrated solutions are also analyzed, including solving large-scale models, multiobjective optimization, bi-level programming, and decomposition. We conclude by summarizing the challenges that hinder the full integration of multilevel decision making in supply chain management.
基金supported by National Institutes of Health/National Cancer Institute(Nos.R01CA199668 and R01CA232845)National Institutes of Health/National Institute of Dental and Craniofacial Research(No.1R01DE029237)+1 种基金National Institutes of Health/National Institute of Biomedical Imaging and Bioengineering(No.9R01EB033677-06A1)UC Davis Comprehensive Cancer Center Support Grant(CCSG)awarded by the National Cancer Institute(No.NCI P30CA093373).
文摘Nanoprodrugs that are directly assembled by prodrugs attract considerable attention with high anticancer potentials.However,their stability and efficiency of tumor-targeted delivery remain a major challenge in practical biomedical applications.Here,we report a new deep tumor-penetrating nano-delivery strategy to achieve enhanced anti-cancer performance by systematic optimization of a porphyrin-doxorubicin-based nanoprodrug using various PEGylations/crosslinks and co-administration of targeting peptide iRGD.Polyethylene glycols(PEGs)with different molecular weights and grafts are employed to crosslink the nanoprodrug and optimize size,charge,tumor accumulation and penetration,and anti-cancer efficiency,etc.The tumor penetration was validated in syngeneic oral cancer mouse models,patient-derived xenograft(PDX)models,and oral cancer tissue from patients.The optimized nanoprodrug co-administrated with iRGD remarkably enhances the accumulation and penetration both in tumor vascular and PDX tumor tissue.It is effective and safe to improve in vivo therapeutic efficacy via the passive tumor targeting dependent and independent mode.Our tumor-penetrating nano-delivery strategy is promising to strengthen the nanoprodrugs in clinical implementation.
