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991.
Equipment has dual nature: physical objects existing in nature, and artificial objects designed by human. The decision on the configuration and structural parameters of equipment is made by engineers based on technical-physical effects which control the behavioral parameters of the equipment. Sensors are mounted on the equipment to monitor the equipment state. Current methods for state monitoring and diagnosis mostly use mathematics and artificial intelligence technology to construct evaluation methods. This paper presents an integrated design and state maintenance method, in which graph and dual graph are used for recording design data and sensor arrangement and for mapping method from signals to substructures and connection pairs. An example of state maintenance of hydro power generating equipment is illustrated.  相似文献   
992.
993.
[Objectives]In order to give full play to role of "operational concepts" in the engineering process of military equipment development, it is necessary to understand and form standardized operational concept documents (OCD), and study the modeling design of OCD in order to implement the transformation of the system engineering process from document-centric to model-centric. [Methods]This study analyzes the US military's definition of operational concepts and introduces its hierarchical operational concepts, especially the bottom level ConOps or OpsCon, usually as a part of equipment acquisition and requirement engineering. Lessons are then drawn from the relevant theories and standards such as IEEE 29148:2018 and ANSI/AIAA G-043B-2018 of the operational concepts document outline in order to design the specifications of the OCD. Finally, key technologies are studied, including SysML-based OpsCon modeling, UML Profile-based OpsCon framework design and MSDL/C-BML-based operational scenario development.[Result]The results indicate the effectiveness of implementing the modeling design of OCDs. [Conclusions]In the process of equipment requirement engineering, the results of this study can help to improve the efficiency of equipment requirement demonstration through an ambiguous operational concept model and an engineering environment for all stakeholders of the system. © 2022 Journal of Clinical Hepatology. All rights reserved.  相似文献   
994.
基于STCA模型和公交优先权的概念,结合直线式公交停靠站附近的交通流运行特性,在优化车辆跟驰规则和换道规则的基础上,建立三车道元胞自动机车辆换道模型。运用建立的模型,分别对设置完全式公交专用道(DBL)和间歇式公交专用道(IBL)的道路交通运行情况进行局部仿真。考虑车辆换道率和公交发车频率,从基本图、时空图、平均速度和速度稳定性方面对比分析,进一步探究IBL策略的适用条件。结果表明,当车辆密度大于20 veh/km且公交车辆发车频率小于200 veh/h时,IBL策略较DBL策略效果更好。此时允许部分社会车辆进出公交专用道,虽然车辆换道率更高,但并不会对路段交通流造成负面影响,反而能提升车辆通行效率和道路资源利用率,减轻交通拥堵。  相似文献   
995.
Directionality of image plays a very important role in human visual system and it is important prior information of image. In this paper we propose a weighted directional total variation model to reconstruct image from its finite number of noisy compressive samples. A novel self-adaption, texture preservation method is designed to select the weight. Inspired by majorization-minimization scheme, we develop an efficient algorithm to seek the optimal solution of the proposed model by minimizing a sequence of quadratic surrogate penalties. The numerical examples are performed to compare its performance with four state-of-the-art algorithms. Experimental results clearly show that our method has better reconstruction accuracy on texture images than the existing scheme.  相似文献   
996.
It is possible for a twin-screw ship that one screw failure occurs during navigation, and the maneuverability in this case should be noticed by ship designers and operators. It is of great significance to evaluate the related risk. Firstly, a mathematical model for the twin-screw ship maneuvering motion with one failed screw is developed based on the maneuvering model group (MMG) equations, and verified by the model test results. Secondly, the maneuvering motions of a twin-screw liquefied natural gas (LNG) ship with one free rotating failure screw or with one locked failure screw are simulated and compared by using the mathematical model. It is shown that the numerical modeling results are in agreement with the model test results. Compared with those of normal navigation, the port turning ability of the ship with one failed port screw is better, but the starboard turning ability and yaw checking ability become worse. The maneuverability of the ship with locked failure screw is better than that with free failure screw, although the ship speed drops obviously.  相似文献   
997.
An experimental investigation is performed to assess the relation of interference performance on the total resistance of a pentamaran model advancing in calm water. For this motivation, the total drag of the ship is performed for several values of asymmetric outrigger configuration and hull separation, altering the Froude number in the range 0.3–0.9. Our results indicate that remarkable changes in resistance require notable changes in transverse distance values (hull separation) when wave interference may occur. In addition, there is no single configuration that consistently outperforms the other configurations across the entire speed range and the optimum interference factor ?0.2 appears at a Froude number of 0.45 in S/L=0.33 with the outrigger outer position: asymmetric outboard for A3 configuration.  相似文献   
998.
A novel high-voltage electrostatics corona ions pre-charger apparatus and methods were invented earlier by Hamade related to treat various types of receptors such as but not limited to electret polymer, air filters, particulates, catalytic converters, bioaerosols, fluids, pollutants, virus, and bacteria. It is shown in this article that his work led to the construction of various prototype chargers, customized differently for each type of a receptor. In particular his recent development of biological matter corona charger (BMCC) prototype related to expose, treat, sanitize, and disinfect bioaerosols, virus, bacteria, and contaminated fluids and blood such as human immunodeficiency virus (HIV) - acquired immune deficiency syndrome (AIDS). It is shown in this paper that each previous investigated research contemplated ionized corona charger attendant to a charging process and the corona, imparts and provides enough treatment charges to receptors including the aforementioned receptors. Researchers often relied on adopting prior corona charger methods that do not necessarily and effectively solve the problems associated with them or utilize them for optimum treatment effect. The inventor exhaustively studied the characteristics of corona discharge, and has found that the greatest difficulty in corona discharge has to do with the maintenance of the corona, particularly when the receptor is being charged. This is due to variations in either the dielectric value between the corona electrode and a grounded base or flaws in the design as the receptor passes there between suppressing or hindering corona and its effectiveness. What is needed in-the-art is an apparatus and method to achieve maximum possible charge on a receptor, a charge order of magnitude greater than that used by other investigators. This often requires customizing each apparatus and method and does not just merely use one type of a charger to satisfy all applications. To satisfy this need, we build a low cost prototype BMCC that generates self-sustaining charge corona, eliminates many previous design flaws such as spark over, and make it ready for testing remotely or with apparatus.  相似文献   
999.
A controller which is locally optimal near the origin and globally inverse optimal for the nonlinear system is proposed for path following of over actuated marine crafts with actuator dynamics. The motivation is the existence of undesired signals sent to the actuators, which can result in bad behavior in path following. To attenuate the oscillation of the control signal and obtain smooth thrust outputs, the actuator dynamics are added into the ship maneuvering model. Instead of modifying the Line-of-Sight (LOS) guidance law, this proposed controller can easily adjust the vessel speed to minimize the large cross-track error caused by the high vessel speed when it is turning. Numerical simulations demonstrate the validity of this proposed controller.  相似文献   
1000.
基于国内已建成的现代有轨电车车辆基地,大多是在引进国外有轨电车车辆基地设计的基础上完成,不完全适合国内的的维修方式和体制的现状。通过分析现代有轨电车的自身技术特点,针对设计中重停放、轻维护的现象,以及建设过程中发现的重点和难点,提出了在工程设计中应注意的问题及建议,主要包括:运用库设计,检修周期,物业开发,总平面设计,主要检修设备选择,充电装置设置等。  相似文献   
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