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In condition monitoring systems, condition indicators(CIs) are usually used to describe health state of equipment. Usually, detailed fault isolation is conducted by various diagnoses model, threshold alarming is used to detect exceptions. However, how to set threshold that performs best become a problem. Based on ROC analysis, a condition indicator threshold optimization method is proposed in this...
In order to comprehensively and quantitatively evaluate the cooling performance of the refrigerator, a model for evaluating refrigerator cooling performance was designed. The model selected several key parameters of the refrigerator cooling process as the evaluation index, and assigned its set value, base deviation and weight coefficient, calculated the deviation proportion of each evaluation index,...
Condition indicators are significant elements in condition monitoring systems. A condition indicator (CI) performance assessment method would help users to select effective CIs and improve fault diagnosis performance of condition monitoring system (CMS). Investigating of measurement influence factors shows that CIs obey normal distribution. Taking advantage of signal detection theory, a CI assessment...
A surface-flashover trigger vacuum switch (TVS) was developed to satisfy the stability and high temperature (above 120 degrees) working environment requirements for the discharge switch. Compared with the self-breakdown gas switch, TVS can greatly improve the working life and stability of the whole device. In this paper, TVS was designed with multi-rod electrode system to improve the ability of current...
A fault implantable signal model could be helpful for researchers to develop fault diagnosis methods of planetary gearboxes. Considering meshing regularity between given planet gear tooth and ring gear, as well as AM effect caused by rotating of carrier, fault implantable signal model is established. The theoretical derivations are validated through spectrum analysis of simulation signal. Furthermore,...
Some research of Internet of Things in online garment recommendation concentrates on collecting information of customer and garment without enough quantitative analysis on how comfortable people feel, which would make little contributions to personalized decisions about the size selection. In order to recommend the best garment size and help the producers to improve the design and production according...
Executing task in the complex environment, the traditional RRT algorithm is easy to make the tree fall into local minimum area which resulted in poor efficiency. In order to solve the problem, this paper proposes an adaptive RRT algorithm based on dynamic step for path planning and uses the cubic polynomial BSpline curve fitting to smooth the plannned path. The simulation results show that the number...
Vehicular technologies have been recently introduced to highway safety applications and caught much attention of governments and management authorities. The vehicular ad hoc network (VANET) uses cars as mobile nodes to form a mobile network. VANET offers potential and promising technical solutions to vehicular safety. Multi-hop broadcasting schemes are particularly preferred methods to transmit time-sensitive...
The ground surface daily reflected solar radiation (DRSR) reflects the interaction between solar radiation and ground surface, thus plays a significant role on the energy exchange between surface and atmosphere. In the paper, empirical models and Landsat-7 ETM+ data are used to estimate surface daily reflected solar radiation (DRSR) in Chengdu, China. Firstly, empirical models are used to calculate...
This paper presents two adaptive two-stage fuzzy controllers for traffic signals at isolated intersections. Firstly, a two-stage combination fuzzy controller is designed. For traffic status variables in two-stage controller leading to the inefficiency of traffic states weakening under low traffic flow, the controller introduces 0–1 combination and determines the combination of traffic status variables...
In the light of more traffic status variables are considered under low traffic flow in traffic intensity-based two-stage fuzzy control for urban traffic signals, thus leading to the inefficiency of traffic states weakening at isolated intersections. This paper introduces a two-stage combination fuzzy optimal controller for traffic signals at urban isolated intersections: the proposed controller adopts...
Responding to the problem of tag ambiguity and lack of tag semantics, we propose a new recommendation algorithm based on SCOT tag ontology. The algorithm utilizes rich semantics provided by SCOT ontology to expand tag co-occurrence and eliminate tag disambiguation based on tag semantic similarity for candidate tag sets, aiming to eliminate ambiguity tags and recommend semantic related tags, thereby...
The design of automatic test system based on VC++ implemented the communications between the spectrum analyzer and PC. USB-GPIB Interface board is used, USB with its unique advantages of strong anti-interference?high speed and easy to use make the application of automated test system based on GPIB more extensive and flexible. This paper describes the working principle of the test system and the design...
Background error covariance (B) plays an important role in any meteorological variational data assimilation system, which determines how information of observations is spread in model space. In this paper, based on the WRF model and it's 3D-Var system, an algorithm using orthogonal wavelet to model B-matrix is developed. Because each wavelet function contains both information on position and scale,...
In this paper, genetic algorithm is used to optimize the bus dispatching problem, which coordinates with the arrival of the passengers and improves service level by reducing the average passenger waiting time. The arrival distribution of the transfer passenger associates with the former transport modes in hub, and the discrete stochastic arrival distribution can be depicted by simulation. Firstly,...
A novel memetic algorithm (MA) for the design of vector quantizers (VQs) is presented in this paper. The algorithm uses steady-state genetic algorithm (GA) for the global search and C-means algorithm for the local improvement. As compared with the usual MA using the generational GA for global search, the proposed MA effectively reduces the computational time for VQ training. In addition, it attains...
MATSim-T (Multi-Agent Traffic Simulation Toolkit) is a simulation platform for large-scale agent-based traffic. Each agent plans its day and performs its activities based on that plan. Then it chooses appropriate routes to reach its destinations. The queue based micro-simulation of MATSim-T ignores the conflicts in intersections. To avoid conflicts in intersections, signal control is added into MATSim-T...
The received signal by acoustic Doppler velocity log (DVL) is the seabed reverberation signal, in accordance with the seabed scattering model for modeling and signal processing. In this paper, ellipse scattering model is proposed, which can carry on the signal-level simulation for DVLpsilas echo. And based on simulated signals, the Monte Carlo statistics of the pulse-pair method is carried on. Statistical...
Due to the short history of researches for wireless sensor network which has been emerging prominently since the early 1990s, the systemic assessment indicators and efficient evaluating methods of wireless sensor networks is still under exploring. Hereupon, the designing of systemic indicators and assessment methods inspired by the rough set theory are described in this paper to enrich the methodologies...
Based on designing a set of indicators to assess the main features of wireless sensor networks, the conceptual frame of Markov chain is incorporated as the evaluating approach and the improved approaches are given as well. Hereafter, two testing examples of optimizing strategies are described through which original condition and improved conditions are listed and compared. Thus, both evaluation results...
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