Source Coordinates Research Articles

Radio sources location determination by the difference-range measuring method based on swarm intelligence

The solution of the location determining problem by the difference-range measuring method in most cases boils down to finding the extremums of functions using various modifications of the gradient optimization method, which has a number of disadvantages, including the need to specify the first approximation of the coordinates of the source, the dependence of the solution of the system of equations on this approximation, as well as the potential possibility of finding a local extremum, instead of a global one. Because of this, there is a need to use global optimization methods that do not have these disadvantages. One of such methods is a heuristic method based on the intelligence of a swarm of particles. The article presents the results of research on the possibility of using swarm intelligence to solve the problem of determining the location of radio sources by the difference-rangefinder method. An analytical description of the method of global optimization of functions based on the intelligence of a "swarm" of particles is presented. The objective function of coordinates of radio emission sources is formed in relation to the difference-rangefinder method of location determination using the Mahalanobis metric. The results of solving the problem of determining the coordinates of radio emission sources based on the search for the minimum of the formed objective function by the "swarm" of particles are presented. The obtained results can be used in the development of mathematical models and software and hardware complexes for determining the location of radio sources by the difference-rangefinder method.

Optimal Coordination of Transportable Power Sources and Repair Crews for Service Restoration of Distribution Networks Considering Uncertainty of Traffic Congestion

Optimal Coordination of Transportable Power Sources and Repair Crews for Service Restoration of Distribution Networks Considering Uncertainty of Traffic Congestion

Аналитический метод решения задачи определения местоположения источника радиоизлучения в трёхмерном пространстве

For the location system of time difference of arrival consisting of two arbitrary pairs of receiving stations, an analytical method for solving the problem of estimating the coordinates of a radio emission source in three-dimensional space is proposed, assuming that the height of this source is known or specified.

Formalization of Natural-Technical System Characteristics for System Approach to Assess its Ecological State

The increased attention of the State to the problem of environmental safety is associated with the growth of anthropogenic and man-made impacts on the environment. Reducing this impact is the goal of implementing federal-level policy documents. The achievement of program goals in the sphere of environmental is associated with the development, planning and implementation of a set of environmental measures at various levels. It is obvious that the effectiveness of these measures is largely determined by the completeness and reliability of current and forecast information on the state of the environment in areas subject to negative impacts (primarily pollution) from industrial enterprises, economic and other activities. In order to obtain such information, environmental monitoring of the territory is carried out. The aspects of the impact of a man-made object on the environment within the framework of a unified natural and technical system are considered. Two main approaches to the organization of the monitoring system for the state of the environment in the zone of technogenic influence are identified. The purpose of the first one is to monitor the implementation of the negative environmental impact standards established for the given facility. The second approach is aimed at identifying and assessing negative changes in the natural environment itself at an early stage of their occurring. At the same time, environmental monitoring acts as a feedback channel. The following main parameters characterizing the interaction of a technogenic object with the environment are described: types of negative impact; coordinates of sources of negative impact; lists of pollutants; intensity of exposure; type of natural environment; coordinates of monitoring points (sampling points); list of controlled indicators; current values of controlled indicators; name of ecosystems; coordinates of biomonitoring sites. Based on the selected parameters, an ER-model of environmental monitoring of the territory of the natural-technical system is developed. It is noted that the built-in ER-model can be the basis for creating an effective system for storing and analyzing monitoring information, including an assessment of the ecological state of the territory of the natural-technical system and a forecast of its changes.

Economic, energy and environmental analysis and evaluation of hybrid CCHP system considering different buildings: A two-level optimization model

Combined cooling, heating and power (CCHP) integrated energy systems can realize the gradient utilization of energy and the coordination and complementarity of multiple energy sources, which is the primary choice for solving the energy crisis and alleviating the environmental pressure. However, most current design and operational optimizations for CCHP are performed under rule-based operational strategies. This paper constructs a two-level alternating optimization framework for the planning-operation of the CCHP system with an embedded scheduling strategy. The upper-level solves for the optimal capacity configuration of the system to optimize energy, economic and environmental performance, and the lower-level solves for the operating capacity of the equipment system to optimize the operation and maintenance cost. In order to obtain the optimal configuration scheme and scheduling strategy for the system, a novel multi-objective weIghted meaN oF vectOrs (MOINFO)-mixed integer linear programming (MILP) method is proposed. The optimization results suggest that the hybrid CCHP for three buildings (market, office, and restaurant) under the two-level optimization model can achieve better economic, energy, and environmental performance than the rule-based single-level optimization model. Generally, for the market, office and restaurant, the two-Level model achieves maximum economic, energy and environmental performance improvements of 29.12%, 29.88%, and 42.13%; 38.32%, 19.56%, and 34.68%; and 47.37%, 30.93%, and 45.47%, respectively.

Design of the Light Source Layout Optimization Strategy Based on Region Partition and Pre-Bias Compensation for Indoor Visible Light Communication Systems

Optimization of the light source layout is an important issue for indoor visible light communication systems, as it affects the received optical power distribution and user perception. In this paper, we propose a local optimization strategy for the light source layout that balances optimization effectiveness with optimization efficiency. First, we divide the optimization region into multiple sub-regions with different sizes and optimization priorities, where the sizes and optimization priorities of the individual sub-regions are determined based on the effect minimization principle among the sub-regions. We then calculate the pre-bias factor based on the equivalent mapping, which can compensate for the effect of the light sources in the latter optimized sub-region on the source layout optimization in the current sub-region. Finally, we search for the coordinate of a single light source for each sub-region using the variance of the squared distance between the projection of the light source on the receiving plane and the received point as a fitness function. Simulation results show that the proposed optimization strategy performs well when the vertical distance between the ceiling and the receiving plane is not less than 2.85 m.

Визначення двовимірних нестаціонарних температурних полів у плитах та панелях з плоскопаралельними межами за наявності джерел тепла

Non-stationary two-dimensional problems of thermal conductivity for plates and panels with plane-parallel boundaries in the presence of volume-distributed non-stationary heat sources are formulated. A method of constructing a solution to the formulated heat conduction problems for the considered bodies is proposed. The technique uses the approximation of the temperature distribution in both elements by the thickness variable by a cubic polynomial. The coefficients of the approximation polynomial are given through the integral over the thickness variable temperature characteristics and the conditions for the boundary values of the temperature on the outer surfaces of the plate and panel. As a result, the initial two-dimensional initial boundary value problems for the temperature for the plate and panel are reduced to one-dimensional initial boundary value problems for the integral temperature characteristics. To construct the solution of the initial-boundary value problem for the integral characteristics of the temperature in the case of a plate infinite in longitudinal and transverse coordinates, the integral Laplace transform in time and the integral Fourier transform in the longitudinal coordinate were used. The solution of the problem on the integral temperature characteristics in the case of the panel is found using the integral Laplace transform in time and the finite integral transform in the transverse coordinate. Expressions of integral temperature characteristics for the plate and panel are obtained in the form of convolutions of functions corresponding to homogeneous solutions of initial-boundary value problems for integral temperature characteristics and functions describing the available non-stationary heat sources in these bodies and given surface temperature values. The general solutions of the two-dimensional initial boundary value problems of thermal conductivity for slabs and panels are recorded for the presence of arbitrarily variable spatial coordinates of non-stationary heat sources and the conditions of convective heat exchange with the external environment on the surfaces of the considered bodies.

Influence of convective amplification on aeroacoustics oscillations in main gas pipeline

Influence of convective amplification on aeroacoustics oscillations in main gas pipeline

Multiscale spatial-temporal evolution of energy carbon footprint in the Yellow River Basin of China based on DMSP/OLS and NPP/VIIRS integrated data.

Increased CO2 emissions from urban energy consumption pose a significant challenge to regional carbon mitigation policies. In this paper, we integrated two nighttime light (NTL) data: the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) and the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (NPP) composite data to estimate the energy carbon emissions from 2000 to 2019. Then the spatiotemporal dynamics of carbon footprint and deficit in the Yellow River Basin were analyzed at the provincial, municipal, and county scales combined with NPP data. The study shows that (1) the total amount of energy consumption CO2 emissions in the Yellow River Basin had increased from 1332 Mt in 2000 to 6469 Mt in 2019, but the average annual growth rate slowed down after 2010 from 11.5 to 5.61%. (2) From 2000 to 2018, the provinces with the highest carbon footprint and carbon deficit were concentrated in Inner Mongolia and Shanxi. In 2018, Inner Mongolia's carbon footprint was 1366.91 × 104 km2, accounting for 22.8% of the total. Cities with high carbon footprint were mainly economic centers and energy-intensive areas of various provinces. High-carbon deficit counties were mainly distributed in the western region. In 2018, 954 counties exhibited carbon deficits. (3) The carbon footprint in the Yellow River Basin at the municipal and county scales have a significant spatial correlation. The H-H clusters of the carbon footprint on the municipal scale were distributed in the middle reaches of the Yellow River Basin. At the county scale, the L-L clusters were mainly in Sichuan and eastern Henan regions. Through the analysis of the spatial and temporal evolution of carbon footprint and carbon deficit in the Yellow River Basin, it is significant to measure the degree of comprehensive coordination of carbon sources and sinks in the basin, to grasp the differences in the level of regional carbon emissions, and to promote synergistic regional governance, assist in the formulation of more precise carbon emission reduction policies, and to promote green and high-quality development.

Computer model of the transponder for the analysis of phase distortions of the signal

The article discusses issues related to the development of a computer model of an on-board relay complex with linear signal retransmission for the analysis of phase distortion of the signal. It is very important to know the phase distortion (foray) when determining the coordinates of the radio source by the phase method using a virtual antenna array in satellite communication systems. The literature review given in the article showed that it was not possible to conduct these studies on existing computer models. Based on the classical version of the block diagram of the on-board relay complex, a computer model was developed in the MATLAB R 2016b (Simulink) environment. The model includes a receiving device, an input and output multiplexer and power amplifiers. Mathematical models of Saleh and Gorbanni amplifiers implemented on traveling wave lamps and solid-state amplifiers, respectively, were taken as nonlinear amplifiers. Multiplexers are implemented in the form of bandpass filters connected in parallel. The hybrid divider and ferrite circulators were not included in the model. In the model, it is possible to investigate the dependence of the phase distortion of the signal on the characteristics of the structural blocks of the on-board relay complex. The computer model also provides for the possibility of studying the effect of noise on phase distortion.

Planning shared energy storage systems for the spatio-temporal coordination of multi-site renewable energy sources on the power generation side

The application prospects of shared energy storage services have gained widespread recognition due to the increasing use of renewable energy sources. However, the decision-making process for connecting different renewable energy generators and determining the appropriate size of the shared energy storage capacity becomes a complex and interrelated problem when considering the multi-site spatio-temporal characteristics. This paper presents an optimal planning and operation architecture for multi-site renewable energy generators that share an energy storage system on the generation side. Furthermore, an economic-environmental model is proposed to minimize the costs associated with the energy system infrastructure while maintaining a high penetration rate of renewable energy. The centralized multi-objective model allows renewable energy generators to make cost-optimal planning decisions for connecting to the shared energy storage station, while also optimizing the size of the storage capacity to maximize renewable energy generation and minimize costs. The Non-dominated Sorting Genetic Algorithm-II is employed in a centralized manner to solve the multi-objective nonlinear model. Numerical experiments are conducted to demonstrate the economic and environmental benefits of the proposed system. Therefore, this method is highly recommended for implementation on the generation side.

Evaluation of the first three years of Vgos 24 h sessions using a Kalman filter with C5++

We analyzed the first three years of VGOS 24 h sessions, and evaluated the performance in terms of Earth orientation parameters (EOP) and station positions. We estimated radio source coordinates which might be of particular importance in VGOS due to the different observing frequencies compared to legacy S/X VLBI. We investigated the impact of this procedure in the determination of the celestial reference, and detected possible increased crosstalk between radio source positions and nutation. We, thus, created an updated source coordinate catalogue that contains information from the VGOS observations and utilized that as our a priori for further analysis. We found that this procedure significantly attenuates mean biases in the estimated EOP time series. We then utilized a kalman filter with an empirically tuned stochastic modelling for nutation and polar motion and estimated repeatabilities on the 60–80 mu as level for nutation, and 100–130 mu as level for polar motion. The station position repeatabilities were evaluated to be 1.80 and 2.12 mm for the east and north components and 3.98 mm for the vertical, while the baseline length repeatabilities were estimated to be 4.22 mm at 6000 km. These results are promising with respect to the expected future VGOS performance, while increased attention should be paid to the celestial frame determination in the VGOS observing bands.Graphical

Intelligent Energy Management for Distributed Power Plants and Battery Storage

A smart energy management controller is required for effective source coordination and load demand management. This work proposes a novel instantaneous current reference technique for use in power management of hybrid power systems (HPS), both autonomous and interconnected with the grid. A grid integrated hybrid power system (GI-HPS) includes both the AC grid and additional sources used in industrial and commercial environments. Solar photovoltaic (SPV) panels, wind turbine generators, proton exchange membrane fuel cells, and batteries are all part of the test system. The suggested energy management system (SEMS) manages power from the hybrid power source and the energy storage components to meet the load needs. The recommended SEMS can transit between 12 different modes of operation to fulfil the load demand requirements. The SEMS employs a scaling factor N to accelerate the rate at which the measured current approaches the reference current. The proposed scaling factor significantly improves the SEMS’s dynamic performance since it can quickly respond to the changes in the source and load characteristics. The dependability of an HPS powered by a variety of renewable energy sources can also be improved.

Online optimization of energy management strategy for FCV control parameters considering dual power source lifespan decay synergy

The decay process of fuel cell (FC) and battery is highly inconsistent. The existing research focuses on the energy management strategy (EMS) aiming at minimizing the lifespan loss of a single power source. However, this EMS cannot guarantee the optimal overall durability of dual power source systems. Based on this, this paper proposes an EMS for lifespan decay coordination of dual power sources for fuel cell vehicle (FCV). Firstly, a continuous characterization model for FC lifespan decay was developed. Secondly, the influence of control parameters such as FC response speed, filtering order, equivalent consumption minimum strategy (ECMS) equivalent factor on dual power source decay rate is analyzed. Then, the proposed energy management strategy (PEMS) is based on the cooperative control of lifespan decay of two power sources based on the condition identification. Finally, the advantages of PEMS are verified by hardware in-loop simulation. The results show that: under the working conditions of CWC1 and CWC2, compared with ECMS, PEMS reduces the difference of lifespan decay rate of dual power source by 25.62 times and 32.25 times, respectively, and the lifespan decay of fuel cell and power battery tends to be consistent. It is proved that PEMS can realize the decay cooperation of dual power source of FCV under different characteristic working conditions, and significantly improve the overall durability of dual power source system.

Evaluation of the noise immunity of the navigation equipment of consumers of the global navigation satellite system with spatial adaptation based on the algorithm of maintaining the level of the useful signal

Problem statement. The use of spatial filtering of signals in adaptive antenna arrays (AAR) of consumer navigation equipment (NAP) of the global navigation satellite system (GNSS) in conditions of intentional interference is an effective means of ensuring stability and continuity of positioning of mobile objects. The specifics of solving this problem is the low level of navigation signals received from the upper hemisphere of space against the background of powerful concentrated interference, significantly exceeding noise. Most compact L-band AARs consist of 4-8 elements, and the algorithms used optimize compensation indicators without the presence of a priori information about the position of useful and interfering signals. At the same time, the formed dips on the sources of interference in width can lead to a loss of the availability of spacecraft signals for subsequent processing. This circumstance determines the relevance and practical orientation of the task of evaluating the effectiveness of the diagram formation algorithm, taking into account the integration of interference attenuation indicators and maintaining the level of the useful signal. Purpose. Investigation of the characteristics of the spatial interference compensation algorithm with a linear restriction on the direction of reception of the useful signal, as well as an assessment of its impact on the performance of the equipment of consumers of the global navigation satellite system. Results. The level of compensation of spatially distributed interference sources is analyzed using a processing algorithm that minimizes the average power of the adaptive antenna array with the exception of the direction of reception of the useful signal to the zenith. The influence of the spatial compensator on the availability of spacecraft signals for subsequent processing, depending on the number, level and angular coordinates of interference sources, is investigated. Practical significance. A model is proposed for evaluating an algorithm that maintains constant gain at the zenith and minima in the interference directions for a four-element L-band antenna array. The given values of interference attenuation depending on the number, level, angle of location and azimuth of the impact make it possible to clarify the indicators of noise immunity of the equipment of consumers of a global navigation satellite system equipped with a spatial compensator.

XRBcats: Galactic low-mass X-ray binary catalogue

We present a new catalogue of low-mass X-ray binaries (LMXBs) in the Galaxy. The catalogue contains source names, coordinates, source types, fluxes, distances, system parameters, and other characteristic properties of 349 LMXBs, including systems that have been newly discovered or reclassified since the most recently reported LMXB catalogues. The aim of this catalogue is to provide a list of all currently known Galactic objects identified as LMXBs with some basic information on each system (including X-ray and optical/IR properties where possible). Literature published before May 2023 has been taken into account where possible when compiling this information. References for all reported properties as well as object-finding charts in several energy bands are provided as part of the catalogue. We plan to update the catalogue regularly, in particular to reflect new objects discovered in the ongoing large-scale surveys such as Gaia and eROSITA.

A Sound Source Localization Method Based on Frequency Divider and Time Difference of Arrival

In recent years, sound source localization, as a passive localization technique with higher safety and convenience compared with other localization techniques such as active emission of electromagnetic waves, has received more and more attention in academia. This paper researches and improves the far-field sound source localization algorithm based on the generalized cross-correlation method (GCC) Time Difference of Arrival (TDOA) estimation algorithm and completes the design and implementation of the microphone array sound source localization system. This paper adds a frequency divider to the traditional generalized correlation time delay estimation algorithm for pre-processing, sampling, and localization of sound source acoustic waves and adopts a low-cost microphone array deployment scheme as far as possible to improve the flexibility and practicality of the localization system; at the same time, the “Minimum Sphere Method” is used at the back end of the algorithm to classify the localization coordinates at different frequencies and, finally, output reasonable sound source coordinates. In the back-end of the algorithm, the “Minimum Sphere Method” is used to classify the localization coordinates at different frequencies and, finally, output the reasonable sound source coordinates. The experimental results show that the sound source localization system designed in this paper has good performance in terms of localization accuracy and cost-effectiveness and overcomes the failure of the generalized mutual correlation algorithm in the original application of high noise environment and multi-source environment localization.

Harris Hawks optimization for ambulance vehicle routing in smart cities

The ambulance routing problem is one of the capacitated ambulance routing problem forms. It deals with injuries and their requests for saving. Therefore, the main aim of the ambulance routing problem is to determine the minimum (i.e., optimum) required distances of between: 1) accident places and the ambulance station; 2) the location of the nearest hospital and the accident places. Although of the efforts proposed in the literature, determining the optimum route is crucial. Therefore, this article seeks to tackle ambulance vehicle routing in smart cities using Harris Hawks Optimization (HHO) algorithm. It attempts to take the victims as quickly as possible and confidently. Several engineering optimization problems confirm that HHO outperforms many well-known Swarm intelligence approaches. In our system, let’s use the node approach to produce a city map. Initially, the control station receives accident site information and sends it to the hospital and the ambulance. The HHO vehicle routing algorithm receives data from the driver; the data includes the location of the accident and the node position of the ambulance vehicle. Then, the driver’s shortest route to the accident scene by the HHO. The locations of the accident and hospital are updated by the driver once the car reaches the accident site. The fastest route (which results in the least travel time) to the hospital is then determined. The HHO can provide offline information for a potential combination of the coordinates of destination and source. Extensive simulation experiments demonstrated that the HHO can provide optimal solutions. Furthermore, performance evaluation experiments demonstrated the superiority of the HHO algorithm over its counterparts (SAODV, TVR, and TBM methods). Furthermore, for ten malicious nodes, the PDF of the algorithm was 0.91, which is higher than the counterparts

Control strategy of vibration zone avoidance based on a hydropower-battery hybrid unit

As a growing number of renewable energy sources (RESs) are integrated into the power system, how to reduce the wear and tear on units while enhancing the regulating capability becomes one of the most pressing concerns for hydropower plants (HPPs). A hydropower flexibility enhancement innovation technology is studied in this paper, which can provide a real-time control ability to avoid the vibration zones for hydropower units (HUs) by the ‘power sources coordination’ between the HU and the unit-side battery. Firstly, the hydropower-battery hybrid unit (HBHU) model and the zone division of HU and battery are introduced. Secondly, the general principles of hydropower-battery coordinated control are proposed. Based on the state of charge (SOC) management and fast response ability of the battery, a control strategy of vibration zone avoidance for HU is suggested, of which feasibility is verified by the simulation in four typical scenarios. The results show that the coordination of the battery not only helps the HU avoid the vibration zones effectively but also improves the regulation performance, as well as reduces the wear and tear of the unit.

Automatic Interpretation of Potential Field Data Based on Euler Deconvolution with Linear Background

Euler deconvolution is a popular technique used for analyzing potential field data because it requires little prior information. However, the reliability of Euler solutions can be impacted by interference from adjacent field sources, or background fields. In this manuscript, we present an effective Euler deconvolution algorithm that accounts for linear background fields. Our algorithm, called improved finite-difference Euler deconvolution, builds upon the finite-difference method and is less susceptible to interference from nearby sources. We use this algorithm to achieve a joint estimation of the coefficients of the source coordinates, the structure index, and the linear background trend. Compared to Euler deconvolution methods based on differential similarity transformations, which also account for linear background fields, our method is easier to understand and implement programmatically and is faster. We tested our method using both 2D and 3D synthetic data, and the results indicate that our algorithm has better computational accuracy than the finite-difference algorithm and is comparable to the Euler deconvolution algorithm based on differential similarity transformations. In addition, our method was shown to be effective when tested on real data.