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Summary A simple and specific HPLC method with coulometric detection was developed for the determination of 2′-acetyl erythromycin
and erythromycin in human plasma. Methyl tert-butyl ether was used as the extraction solvent after alkalization of plasma
samples. The plasma extracts were chromatographed on a reverse phase column using 4-component mobile phase. The manual sample
preparation procedure was modified so that it could also be applied to the robotic system (Zymate™ Laboratory Automation System). The linear range was 0.25–7.0 μg/ml. The quantitation limit for 2′-acetyl erythromycin and
erythromycin was 0.05 μg/ml. Equivalent manual and robotic sample preparation methods were used to analyze a large number
of plasma samples. 相似文献
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A general framework for modeling and solving cyclic scheduling problems is presented. The objective is to minimize the cycle time. The model covers different cyclic versions of the job-shop problem found in the literature, robotic cell problems, the single hoist scheduling problem and tool transportation between the machines.It is shown that all these problems can be formulated as mixed integer linear programs which have a common structure. Small instances are solved with CPLEX. For larger instances tabu search procedures have been developed. The main ideas of these methods are indicated. 相似文献
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Jacques Carlier Mohamed Haouari Mohamed Kharbeche Aziz Moukrim 《European Journal of Operational Research》2010,202(3):859
This study investigates an optimization-based heuristic for the robotic cell problem. This problem arises in automated cells and is a complex flow shop problem with a single transportation robot and a blocking constraint. We propose an approximate decomposition algorithm. The proposed approach breaks the problem into two scheduling problems that are solved sequentially: a flow shop problem with additional constraints (blocking and transportation times) and a single machine problem with precedence constraints, time lags, and setup times. For each of these problems, we propose an exact branch-and-bound algorithm. Also, we describe a genetic algorithm that includes, as a mutation operator, a local search procedure. We report the results of a computational study that provides evidence that the proposed optimization-based approach delivers high-quality solutions and consistently outperforms the genetic algorithm. However, the genetic algorithm delivers reasonably good solutions while requiring significantly shorter CPU times. 相似文献
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Using three-dimensional computer simulations, we probe biomimetic free swimming of an internally actuated flexible plate in the regime near the first natural frequency. The plate is driven by an oscillating internal moment approx-imating the actuation mechanism of a piezoelectric macro fiber composite (MFC) bimorph. We show in our simulations that the addition of a passive attachment increases both swim-ming velocity and efficiency. Specifically, if the active and passive sections are of similar size, the overall performance is the best. We determine that this optimum is a result of two competing factors. If the passive section is too large, then the actuated portion is unable to generate substantial deflection to create sufficient thrust. On the other hand, a large actu-ated section leads to a bending pattern that is inefficient at generating thrust especially at higher frequencies. 相似文献
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The present work describes the development of a novel robotic vane shear test tool for characterization of soil parameters with high precision and accuracy. The tool automates industrial standards for testing procedures. The proposed system is capable of performing high resolution torque measurements, which are then used to estimate the shear strength of the soil. The design of the instrument and its advantages over traditional manual instruments are discussed, after which error sources, calibration, and test procedures are described. The developed tool was successfully validated against high-end commercial equipment. The built unit was employed for characterizing mine waste in a laboratory setting and also deployed in the field on board an Unmanned Ground Vehicle for remote soil characterization. 相似文献
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OBJECTIVES/HYPOTHESIS: We hypothesize that bimanual, three-dimensional robotic surgery will prove valuable for glottic microsurgical procedures. STUDY DESIGN: To test this hypothesis, we developed and optimized a canine model for glottic microsurgery using a commercially available surgical robot. Methods Using a da Vinci Surgical Robot (Intuitive Surgical, Inc., Sunnyvale, CA), glottic microsurgery was performed with a hydrodissection technique in a canine model. The experiments were performed on two orotracheal intubated mongrel dogs under general anesthesia in the supine position on a standard operating room table. A videoscope and two, 360-degree rotating, 5- and 8-mm, wrested-end effector instruments were introduced transorally with three robotic arms. The surgeon performed the actual procedures while positioned at a robotic system console that was located across the operating room suite. The procedure was performed in duplicate and was documented with still and video photography. RESULTS: Glottic microsurgery was successfully performed using the da Vinci Surgical Robot, with both 5- and 8-mm instrumentation. The smaller, 5-mm instruments afforded greater visualization of the operative site and increased maneuverability, which resulted in reduced operative time. The robotic system provided excellent visualization as well as controlled and delicate microdissection at the vocal cord level. CONCLUSIONS: Robotic laryngeal microsurgery is technically feasible in the canine model and warrants consideration for evaluation in controlled human trials. 相似文献
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本文对移动机器人履行系统中货架调度任务的履行过程进行分析,根据机器人在货架装载、搬运、拣选、卸载四个过程的作业特点建立闭排队网络模型。采用近似平均值分析算法求解,实现系统绩效的迅速评估。通过与仿真计算实验的对比证明,模型对系统绩效的评估误差不超过5%。利用闭排队网络模型评估拣选台、机器人利用率和调度任务履行能力,实现对系统设施配置的讨论和优化。研究表明,拣选台均匀分布于仓库较长的两侧能提高系统履行绩效;系统存在最优机器人投放数量使系统整体利用率较高。 相似文献
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