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Solutions to mitigate the impact of measurement noise on the air pollution source strength estimation in a multi-zone building

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建筑模拟（英文版） 2020年第6期13卷 1329-1337页

作者： Fei Li Xiaoran Liu Jinxiang Liu Hao Cai Haidong Wang Kai Zhang Chunxiang Dai College of Urban Construction Nanjing Tech University Nanjing 210009 China School of Environment and Architecture University of Shanghai for Science and Technology Shanghai 200093 China School of Energy and Mechanical Engineering Nanjing Normal University Nanjing 210046 China

Indoor contaminants jeopardize people's health and may even cause serious consequences under extreme conditions. Therefore, the prompt and accurate identification of indoor airborne contaminant characteristics is significant for indoor health and safety. In this paper, we used an inverse Markov chain model, combined with the regularization proposed in our previous research, to identify periodic source strength under steady airflow in a multi-zone building. The impact of different measurement noise (0.05％, 0.1％, 0.2％) on the inverse results was investigated. The results showed that the greater the noise, the greater the oscillation of the inverse result. Furthermore, we also investigated the effect of adjusting the calculation time step (5 s, 10 s, 20 s, 30 s) and adding digital filters (Sliding window filter and Butterworth low pass filter) on the inverse source release rate. The results showed that properly increasing the calculation time step can reduce the impact of measurement noise. The root mean square error (RMSE) of the inverse source strength with 0.1％ noise decreased from 22.89 under a 5-s time step to 0.9793 under a 30-s time step. It was also found that adding digital filters could reduce the oscillation of the inverse source results, and the performance of the filters also depends on the calculation time steps.

关键词： source identification measurement noise inverse modeling CONTAM Markov chain filtering algorithm

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Optimal state estimation for singular system with stochastic uncertain parameter

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OPTIMAL CONTROL APPLICATIONS & METHODS 2020年第4期41卷 1001-1015页

作者： Yu, Xingkai Li, Jianxun Shanghai Jiao Tong Univ Sch Elect Informat & Elect Engn 800 Dongchuan Rd Shanghai 200240 Peoples R China Tsinghua Univ Dept Precis Instrument Beijing 100084 Peoples R China

This article studies singular systems with uncertain parameters by using a direct method which is called the first restricted equivalent transformation (FRET). The stochastic uncertain parameters we studied in the article, which are more general and challenging, are different from the two existing types: time-invariant parameters and time-varying parameters. We propose an optimal filtering algorithm to filter out artifacts, such as noise, from the uncertain parameter by using the projection theorem and the FRET. The proposed algorithm guarantees optimum in the sense of linear minimum mean-square error. Simulation results verify the proposed algorithm.

关键词： equivalent transformation filtering algorithm projection theorem singular system stochastic uncertain parameter

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Predictive deviation filter for deadbeat control

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IET ELECTRIC POWER APPLICATIONS 2020年第6期14卷 1041-1049页

作者： Wang, Zitan Chai, Jianyun Sun, Xudong Lu, Haifeng Tsinghua Univ Dept Elect Engn Beijing Peoples R China

Deadbeat control calculates excitation by a differential equation model that takes measurements of state variables as initial values and instructions as terminal values. Ideally, this excitation can force state variables to track instructions in the succeeding control interval. However, in a practical system, noises in measured signals can mislead the control system and degrade its performance with increased ripples and harmonics. Therefore, some filters are often used in measurements, but their inherent delay can lead to inaccurate initial values and cause severe overshoots in dynamic cases. In this study, a new type filtering algorithm called predictive deviation filter is proposed for deadbeat control, which filters only the predicted deviation obtained by removing the expected values from measured ones, and then the real values of state variables are recovered. With this method, the influence of the filter delay can be limited only on the deviation which is a small part of the signal, significantly improving the accuracy of the initial values. Furthermore, a comprehensive frequency-domain analysis of the predictive deviation filter is provided. Finally, the new filtering algorithm is applied to drive control of permanent magnet synchronous motor. The simulation and experimental results verify the effectiveness and performance of this approach.

关键词： machine control frequency-domain analysis permanent magnet motors differential equations filtering theory synchronous motor drives predictive deviation filter deadbeat control differential equation model state variables terminal values control system filtering algorithm predicted deviation filter delay drive control permanent magnet synchronous motor comprehensive frequency-domain analysis

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Data assimilation for flow forecasting in urban drainage systems by updating a hydrodynamic model of Damhusaen Catchment, Copenhagen

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URBAN WATER JOURNAL 2020年第10期17卷 847-859页

作者： Babel, Mukand Tansar, Husnain Mark, Ole Weesakul, Sutat Madsen, Henrik Asian Inst Technol Water Engn & Management Pathum Thani Thailand DHI AS Horsholm Denmark Hydro Informat Inst Krung Thep Maha Nakhon Thailand

Accurate model-based forecasts (discharge and water level) are considered significant for efficient planning and management of urban drainage systems. These model-based predictions can be improved by assimilating system measurements in physically based, distributed, 1D hydrodynamic urban drainage models. In the present research, a combined filtering and error forecast method was applied for the data assimilation to update the states of the urban drainage model. The developed data assimilation set-up in combination with the 1D hydrodynamic model was applied at the Damhusaen Catchment, Copenhagen. Discharge assimilation represented significant potential to update model forecast, and maximum volume error was reduced by 22% and 6% at two verification locations. The assimilation of water levels had a minor impact on the update of the system states. The updated forecast skill using error forecast models was enhanced up to 1-2 hours and 6-7 hours lead time at upstream assimilation and downstream verification locations, respectively.

关键词： filtering algorithm auto-regressive model data assimilation 1D hydrodynamic model updating

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A filtering algorithm for Constrained Clustering with Within-Cluster Sum of Dissimilarities Criterion

A Filtering Algorithm for Constrained Clustering with Within...

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25th IEEE International Conference on Tools with Artificial Intelligence (ICTAI)

作者： Thi-Bich-Hanh Dao Duong, Khanh-Chuong Vrain, Christel Univ Orleans ENSI Bourges LIFO EA 4022 F-45067 Orleans France

ISBN: (纸本)9781479929719

Constrained clustering is an important task in Data Mining. In the last ten years, many works have been done to extend classical clustering algorithms to handle user-defined constraints, but restricted to handle one kind of user-constraints. In a previous work 1], we have proposed a declarative and generic framework, based on Constraint Programming, which enables to design a clustering task by specifying an optimization criterion and different kinds of user-constraints. One of the criteria is the within-cluster sum of dissimilarities, which is represented by a sum constraint and reified equality constraints V = Sigma(<= i <= j <= n)(G[i] = = G[j])a(ij). A direct implementation using predefined constraints is not effective as the propagation of theses constraints is weak. In this paper, we consider this criterion as a global constraint and develop a filtering algorithm for it. This filtering helps to improve significantly the model performance. Experiments on classical databases show the interest of our approach.

关键词： Constrained clustering modeling filtering algorithm

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Restoration of Information in On-Board Information and Controlling Complexes of Movable Objects in Emergency Situations 2

Restoration of Information in On-Board Information and Contr...

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2nd International Workshop on Modern Machine Learning Technologies and Data Science (MoMLeT+DS)

作者： Mashkov, Oleg Kosenko, Viktoriya State Ecol Acad Postgrad Educ & Management St Metropolitan Vasily Lipkivsky 35 UA-03035 Kiev Ukraine

The technology of estimation of efficiency of methods of information recovery in on-board information-control complexes of moving objects in emergency situations caused by failures of hardware and software parts of on-board information-control complexes is offered. The proposed approach is considered as one of the steps of ensuring the functional stability of complex dynamic objects. Functional stability is considered as a property of a dynamic system, which is the ability to perform at least a set volume of its functions when failures in the information, computing, energy parts of the system, as well as external influences that are not foreseen by the operating conditions. It is proposed to provide functional stability in real time by performing the following actions: control of the state of functioning of a complex management system and detection of the fact of disturbances of its functioning (formation of the team "Accident");identification of the cause of the fact of malfunctions in real time (localization of the place of damage of functioning and / or detection of unauthorized disturbances);shutting down the damaged parts or compensating for the effects of unauthorized disturbances on the general real-time control system;redistribution of system resources (information, computing, power) to ensure the functioning of the management system (possibly with impaired performance) in real time. It is determined that the implementation of functional stability can be achieved by the introduction into the complex dynamic system of various forms of redundancy (structural, functional, information, etc.) and the readiness of the operator of the dynamic object to control movement during a sudden reconfiguration of the complex. A mathematical model is proposed that allows you to build functional stability when using an automated control system for a complex dynamic object. The peculiarities of the application of the method of optimal filtration in emergencies caused by the evo

关键词： filtering algorithm On-Board Information-Control Complex Failures Information Recovery Dynamic System Identification Markov Chain Emergency Situation Optimal Filtration Functional Stability

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An Experiment for Outdoor GPS Localization Enhancement using Kalman Filter with Multiantenna Consumer-Grade Sensors

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INTERNATIONAL JOURNAL OF ADVANCED COMPUTER SCIENCE AND APPLICATIONS 2021年第4期12卷 382-388页

作者： Singkhamfu, Phudinan Suwansrikham, Parinya Chiang Mai Univ Coll Arts Media & Technol Chiang Mai Thailand

Consumer-Grade global positioning system (GPS) is widely used in many domains. The obvious issue of this consumer-grade device is low accuracy and reading fluctuation results. In terms of using an application that requires a more precise location, the output could be difficult. In this study, the authors deploy various methods to reduce the global positioning system data fluctuation and present field test results. Two main types of the device worked together to collect data from global positioning systems, such as Microcontroller for algorithm processing and presenting data and global positioning system receivers for receiving data from a satellite. We combine three global positioning system modules to received signals in a single device and test calculated data compared with the Kalman filtering methods in many cases, including moving and static devices. Implementing the Standard Kalman Filter to multiple global positioning system Modules has improved the constancy of cheap global positioning system equipment. The experiment algorithm is presented significant improvement to overcome the retrieved data fluctuation problem. This study's contribution will enable creating a cheap global positioning system locator device for various applications that require more accuracy than the standard consumer-grade receiver.

关键词： Global positioning systems accuracy kalman multi global positioning systems global positioning systems pointer global positioning systems enhance filtering algorithm

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Dual Adaptive Factors-Based Integrated Navigation Performance Improvement for Airborne POS

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IEEE SENSORS JOURNAL 2019年第20期19卷 9479-9485页

作者： Wang, Bo Liu, Yanhong Ye, Wen Beijing Univ Aeronaut & Astronaut Sch Instrumentat & Optoelect Engn Beijing 100191 Peoples R China Natl Inst Metrol Inst Mech & Acoust Metrol Beijing 102200 Peoples R China

Airborne position and orientation system (POS) can provide high accuracy motion parameters for multiple aerial mission loads and has become a vital equipment in aerial remote sensing system. However, the airborne POS often suffers from the systematic kinematic model and observation model inaccuracy, which further affects the accuracy of motion parameters, and the conventional innovation-based adaptive method only deals with the observation model inaccuracy and results in the limited performance improvement. In this paper, a dual adaptive factors filtering algorithm is adopted to deal with the kinematic model and observation model inaccuracy together, which has been validated by the real flight experiment and the results show that the performance improvement has achieved.

关键词： Dual adaptive factors filtering algorithm airborne position and orientation system SINS/GPS integrated navigation system real-time performance

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Low-Loss Optical Nyquist Pulse Train Generation Using Nonauxiliary Wavelength Selective Switch in Communication Band

IEEE PHOTONICS JOURNAL

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IEEE PHOTONICS JOURNAL 2019年第2期11卷 1-9页

作者： Takahashi, Koji Yamasaki, Yu Inoue, Takashi Konish, Tsuyoshi Osaka Univ Grad Sch Engn Suita Osaka 5650871 Japan Hamamatsu Photon KK Cent Res Lab Shizuoka 4348601 Japan

We report low-loss optical Nyquist pulse train generation using a non-auxiliary wavelength selective switch (WSS). The typical approach for optical Nyquist pulse train generation involves two procedures. The first is conversion from a laser output Gaussian pulse to a Nyquist pulse via spectral filtering with a WSS. The second is multiplexing to generate a Nyquist pulse train with an optical circuit. To generate a high optical signal-tonoise ratio (OSNR) Nyquist pulse train, the first procedure was improved by developing a high-power laser and improving the filtering process by using nonlinear effects in a highly nonlinear fiber. The second procedure also has the potential to further improve the OSNR, because an optical circuit typically causes an optical loss of 9 dB in the case of eight-multiplexing. In this study, we demonstrate optical loss reduction for multiplexing using a nonauxiliary WSS approach without an auxiliary optical circuit. The experimental results show that the optical loss for the Nyquist eight-pulse train is successfully reduced to 2.8 dB.

关键词： Nyquist pulse wavelength selective switch pulse shaping filtering algorithm

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Modified tropical algebra based median filter for removing salt and pepper noise in digital image

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IET IMAGE PROCESSING 2019年第14期13卷 2790-2795页

作者： Abdurrazzaq, Achmad Mohd, Ismail Junoh, Ahmad Kadri Yahya, Zainab Univ Malaysia Perlis Inst Engn Math Kampus Pauh Putra Arau 02600 Perlis Malaysia Univ Putra Malaysia Lab Computat Stat & Operat Res Inst Math Res Upm Serdang 43400 Selangor Malaysia

Noise is the information damage that may occur in the image due to the changes in information during the transmission process. In order to overcome these problems, it is necessary to do filtering process on the image. Until now many filtering algorithms have been proposed to remove noise. Most existing methods only work for low level noise. In this study, the authors proposed an efficient and easy-to-understand filtering algorithm using the concept of tropical algebra and singular value decomposition (SVD). The SVD will be used to detect noise in 3 x 3 templates. Furthermore, if noise is detected then new pixels will be obtained by using the concept of tropical operations. The results of this study show that the proposed method provides better results from the existing methods in terms of quantitative and visual.

关键词： singular value decomposition filtering theory image denoising median filters algebra digital image information damage transmission process filtering process filtering algorithm low level noise singular value decomposition SVD tropical operations modified tropical algebra median filter salt pepper noise

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