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22.
This paper addresses the multi-objective optimization problem arising in the operation of heat integrated batch plants, where makespan and utility consumption are the two conflicting objectives. A new continuous-time MILP formulation with general precedence variables is proposed to simultaneously handle decisions related to timing, product sequencing, heat exchanger matches (selected from a two-stage superstructure) and their heat loads. It features a complex set of timing constraints to synchronize heating and cooling tasks, derived from Generalized Disjunctive Programming. Through the solution of an industrial case study from a vegetable oil refinery, we show that major savings in utilities can be achieved while generating the set of Pareto optimal solutions through the ɛ-constraint method. 相似文献
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24.
In this paper, we study scheduling games under mixed coordination mechanisms on hierarchical machines. The two scheduling policies involved are ‐ and ‐, where ‐ (resp., ‐) policy sequences jobs in nondecreasing order of their hierarchies, and jobs of the same hierarchy in nonincreasing (resp., nondecreasing) order of their processing times. We first show the existence of a Nash equilibrium. Then we present the price of anarchy and the price of stability for the games with social costs of minimizing the makespan and maximizing the minimum machine load. All the bounds given in this paper are tight. 相似文献
25.
Considering autonomous mobile robots with a variety of specific functions as a kind of service, when there are many types and quantities of services and the density of regional services is large, proposing an algorithm of Circular Area Search (CAS) because of the problem of multi-robot service scheduling in various areas. Firstly, Django is used as the web framework to build the Service-Oriented Architecture (SOA) multi-robot service cloud platform, which is the basic platform for multi-service combination. Then, the service type, the latitude and longitude and the scoring parameters of the service are selected as the service search metrics to design the CAS algorithm that based on the existing service information registered in MySQL and the Gaode Map for screening optimal service, and then providing the service applicant with the best service. Finally, the service applicant applies for the self-driving tour service as an example to perform performance simulation test on the proposed CAS algorithm. The results show that the CAS algorithm of the multi-robot service cloud platform proposed in this paper is practical compared to the global search. And compared with the Greedy Algorithm experiment, the service search time is reduced about 58% compared with the Greedy Algorithm, which verifies the efficiency of CAS algorithm. 相似文献
26.
Based on the current spin density functional theory, a theoretical model of three vertically aligned semiconductor quantum dots is proposed and numerically studied. This quantum dot molecule (QDM) model is treated with realistic hard-wall confinement potential and external magnetic field in three-dimensional setting. Using the effective-mass approximation with band nonparabolicity, the many-body Hamiltonian results in a cubic eigenvalue problem from a finite difference discretization. A self-consistent algorithm for solving the Schrödinger-Poisson system by using the Jacobi-Davidson method and GMRES is given to illustrate the Kohn-Sham orbitals and energies of six electrons in the molecule with some magnetic fields. It is shown that the six electrons residing in the central dot at zero magnetic field can be changed to such that each dot contains two electrons with some feasible magnetic field. The Förster-Dexter resonant energy transfer may therefore be generated by two individual QDMs. This may motivate a new paradigm of Fermionic qubits for quantum computing in solid-state systems. 相似文献
27.
Paul Feautrier 《International journal of parallel programming》2006,34(5):459-487
Scheduling a program (i.e. constructing a timetable for the execution of its operations) is one of the most powerful methods
for automatic parallelization. A schedule gives a blueprint for constructing a synchronous program, suitable for an ASIC or
VLIW processor. However, constructing a schedule entails solving a large linear program. Even if one accepts the (experimental)
fact that the Simplex is almost always polynomial, the scheduling time is of the order of a large power of the program size.
Hence, the method does not scale well. The present paper proposes two methods for improving the situation. First, a large
program can be divided into smaller units (processes), which can be scheduled separately. This is structured scheduling. Second, one can use projection methods for solving linear programs incrementally. This is specially efficient if the dependence
graph is sparse. 相似文献
28.
文章介绍了新一代IP骨干网上的IP QoS实现技术,论述了集成业务(IntServ)与差分业务(DiffServ)解决方案的特点,详细介绍了相关的队列管理与排队机制。并结合多协议标签交换(MPLS)技术的最新发展,阐述了综合多协议标签交换流量工程与DiffServ技术体系端到端IP QoS的实现。 相似文献
29.
嵌入式RTOS中任务优先级反转问题研究 总被引:1,自引:0,他引:1
针对嵌入式实时系统任务调度策略的特点,任务在运行的时候可能被更高优先级的任务中断。分析了嵌入式RTOS中的最高就绪任务的查找算法,指出该调度算法存在的不同优先级的反转问题,并且针对这一问题进行研究,给出了相应的优先级继承方案。较好地解决了RTOS中任务调度中的优先级的反转问题。 相似文献
30.
东海盆地油气勘探焦点问题探讨 总被引:3,自引:0,他引:3
东海盆地自西向东可分为 3个带 ,即西部断陷带、中部隆起带和东部断坳带 ,其构造格局各具特色 ,并且均有自身的烃源岩。西部断陷带由多个以古新世为发育高峰期的半地堑组成 ,主要烃源岩为下古新统湖相泥岩 ,该带有利的勘探区是丽水、椒江凹陷 ,围绕下古新统主力烃源岩寻找油气是丽水、椒江凹陷油气勘探的焦点 ;中部隆起带是中生界残留盆地的叠置区 ,主要烃源岩为侏罗系湖相泥岩 ,福州凹陷是该带较有利的勘探区 ,烃源岩的规模、潜力以及圈闭保存条件是福州凹陷油气勘探的焦点 ;东部断坳带是厚度逾万米的新生代沉积断坳区 ,主要烃源岩为始新世煤系地层 ,该带有利的勘探区是西湖凹陷 ,烃源岩和盖层条件是西湖凹陷油气勘探的关键。目前 ,东海盆地比较现实和最具勘探前景的地区是西湖凹陷及丽水、椒江凹陷 相似文献