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81.
针对跨数据中心的资源调度问题,提出了一种基于组合双向拍卖(PCDA)的资源调度方案。首先,将云资源拍卖分为三个部分:云用户代理报价、云资源提供商要价、拍卖代理组织拍卖;其次,在定义用户的优先级及任务紧迫度的基础上,在拍卖过程中估算每一个工作发生的服务等级协议(SLA)违规并以此计算云提供商的收益,同时每轮竞拍允许成交多项交易;最终达到根据用户等级合理分配云资源调度的效果。仿真实验结果表明该算法保证了竞拍成功率,与传统一次拍卖成交一项的组合双向拍卖方案相比,PCDA在竞拍时间段产生的能耗降低了35.00%,拍卖云提供商的利润提高了约38.84%。 相似文献
82.
《International Journal of Hydrogen Energy》2021,46(62):31816-31827
This study investigates an appropriate combined cycle as the electric propulsion system in a large container ship. A gas turbine combined cycle and molten carbonate fuel cell-steam turbine cycle are considered; the gas turbine uses LNG or hythane fuels. Because it is difficult to choose an appropriate propulsion system from only one perspective, comprehensive and unbiased analyses refer to the system performance, eco-efficiency, and economic feasibility for three configurations. An LNG-fueled COGES (combined gas turbine and steam integrated electric drive system) seems to be a promising alternative with regards to economic feasibility as well as a greenhouse gas regulation. The following alternative is the molten carbonate fuel cell-steam turbine cycle. A hythane-fueled COGES has a relatively low economic feasibility but will be the sole propulsion system if the regulation of greenhouse gas emission from shipping is stringent. On the other hand, the carbon taxation and implementation of an incentive for hydrogen fuel may facilitate a greener shipping environment; the additional eco-friendly policy for the shipping industry needs to be provided, shortly soon. 相似文献
83.
基于合成氨厂洗氨塔的换热设备碳钢水箱换热效果不理想的问题,提出了在洗氨塔内采用5454铝水箱替代碳钢水箱的解决方案,以增强水箱的换热效果,改善了塔内作业状况,提高了产气量,节约冷却用水量,同时又延长了水箱的使用寿命,减少水箱的清洗、更换次数,有良好的经济效益。通过相关的测量及计算数据,分析了此方案的可行性。 相似文献
84.
Zusammenfassung Gegenstand des Beitrags ist die Entwicklung eines Tabu Search-Verfahrens (TSV) für Containerbeladeprobleme mit schwach heterogenem Kistenvorrat. Das TSV basiert auf einem zweistufigen Verfahrensansatz. Ein integrierter Greedy-Algorithmus dient unmittelbar der Erzeugung von Stauplänen. Vermittelt über eine geeignete Repräsentation zulässiger Problemlösungen wird in einer zweiten Verfahrensstufe eine Tabu-Suche durchgeführt. Das TSV berücksichtigt einige praxisrelevante Restriktionen. Die Performance des TSV wird anhand von Benchmarkproblemen aus der Literatur demonstriert, wobei Containerbeladeverfahren verschiedener Autoren zu Vergleichszwecken herangezogen werden. 相似文献
85.
86.
Tülin Yılmaz Nayır 《分离科学与技术》2018,53(10):1592-1603
Treatment of container washing wastewater (CWW) by using combined electrocoagulation (EC)–electrooxidation (EO) process was studied. CWW contains many organic compounds such as surfactants used in cleaning agents. Wastewater was first treated by EC with iron (Fe) and aluminum (Al) electrodes. The process performance was measured according to the removal efficiencies of soluble chemical oxygen demand (sCOD) and color. Maximum sCOD removal efficiency was found 82% and color removal efficiencies were 95%, 95% and 98% at 436, 525 and 620 nm, respectively, with Fe electrodes under 25 mA/cm2 current density, initial pH of 5 and 120-min operation time. Because of the low sCOD removal efficiency, EO was used as post-treatment process by using boron doped diamond electrode (BDD). sCOD removal efficiency was increased to 89% and color removal efficiencies decreased to 72%, 64%, 71% at 436, 525 and 620 nm, respectively, under 25 mA/cm2 current density, initial pH of 3 and 300-min operation time. This study showed that electrochemical processes caused new complex molecules formation in the CWW, which caused deterioration of water color and limited the process efficiency. 相似文献
87.
论述集装箱用方矩形管研制的全过程,包括产品技术要求,机组设备造型和改进,轧辊孔型设计,生产工艺参数,质量控制和检验,用户使用情况及经济效益等。 相似文献
88.
随着高压变频器产品技术的不断成熟和广泛应用,各应用企业越来越多的开始注重产品在应用场地受限条件下的适应性和恶劣环境下的稳定性。户外集装箱式高压变频器作为行内针对其应用的解决方案之一,设备是否可以长久、稳定、可靠的运行尤为重要,因此在进行户外集装箱式高压变频器设计时需要谨慎对待。本文主要对户外集装箱式高压变频器的基本结构和特点进行了介绍,并对其在设计过程中所需注意的问题进行了研究和分析,明确了其在恶劣环境、散热、质量和尺寸、运输震动等方面的设计要求,这对户外集装箱式高压变频器的设计具有很好的指导意义。 相似文献
89.
In order to enhance the efficiency of port operations, the scheduling problem of the quay cranes and yard trucks is crucial. Conventional port operation mode lacks optimization research on efficiency of port handling operation, yard truck scheduling, and container storage location. To make quay crane operations and horizontal transportation more efficient, this study uses a dual-cycle strategy to focus on a quay crane and yard truck scheduling problem in conjunction with a mixed storage strategy. A dispatching plan for yard trucks is considered, as well as the storage location of inbound containers. Based on the above factors, a mixed-integer programming model is formulated to minimize vessels’ berth time for completing all tasks. The proposed model is solved using a particle swarm optimization-based algorithm. Validation of the proposed model and algorithm is conducted through numerical experiments. Additionally, some managerial implications which may be potentially useful for port operators are obtained. 相似文献
90.
《Advanced Engineering Informatics》2015,29(3):339-354
With the emerging of free trade zones (FTZs) in the world, the service level of container supply chain plays an important role in the efficiency, quality and cost of the world trade. The performance of container supply chain network directly impacts its service level. Therefore, it is imperative to seek an appropriate method to optimize the container supply chain network architecture. This paper deals with the modeling and optimization problem of multi-echelon container supply chain network (MCSCN). The problem is formulated as a mixed integer programming model (MIP), where the objective is subject to the minimization of the total supply chain service cost. Since the problem is well known to be NP-hard, a novel simulation-based heuristic method is proposed to solving it, where the heuristic is used for searching near-optimal solutions, and the simulation is used for evaluating solutions and repairing unfeasible solutions. The heuristic algorithm integrates genetic algorithm (GA) and particle swarm optimization (PSO) algorithm, where the GA is used for global search and the PSO is used for local search. Finally, computational experiments are conducted to validate the performance of the proposed method and give some managerial implications. 相似文献