Two-dimensional Coordinate System Research Articles

Target location estimation for vehicle dual radar based on unscented Kalman filter

In the research of unmanned vehicle, the state estimation of target detected by sensors is one of the key issues in environmental sensing technology. In this paper, an algorithm based on unscented Kalman filter is proposed to predict and update the position of the target based on the obtained radar data, which is used to estimate the target position of the unmanned vehicle dual radar system. The vehicle radar system in this paper is composed of four lines laser and millimeter wave radar. The calibrated vehicle coordinate system is a two-dimensional coordinate system parallel to the ground. On the basis of the system and coordinate system, the real radar data are collected and simulated in the experimental site. Experiments show that compared with single sensor, the measurement error of radar combination model is effectively reduced, and the accuracy of fusion data is improved. Compared with the most commonly used extended Kalman filtering algorithm, the mean square error of the moving direction of vehicle descends from 6.15 per thousand to 4.83 per thousand. The mean square error value of the average position decreases from 4.24 per thousand to 2.99 per thousand in the direction parallel to the front axle, which indicates that the estimation of the target position of this algorithm is more accurate and closer to the real value. In addition, in the same operating environment, the average time of processing 500 groups of radar data is reduced from 5.9 ms to 2.1 ms, proving that the algorithm has a higher algorithm efficiency.

Experiment and Simulation Study on the Breakdown Current, Velocity, and E-Field in Air Gap Discharge

The breakdown current, current impulse velocity, and E-field in air gap discharge are of interest among researchers on high-voltage engineering and lightning study. It is the breakdown current and current impulse velocity that govern the radiated E-field property. The current impulse velocity, however, is not well addressed in the literature. In this paper, we use a self-developed high-speed observation system, a Rogowski coil, and a transient E-field sensor to measure the current impulse propagation velocity, breakdown current, and vertical E-field in the rod-to-plane discharge after the air gap breakdown under dc voltage. From the time difference of arrival of light signals in different receiving channels, the resultant current impulse propagation velocity is measured as 6.81 ± 0.57 × 106 m/s. Meanwhile, the breakdown current at the bottom of the grounded rod electrode has a peak value of approximately 1.3 kA and 10%–90% rise time of 40 ns, and the transient vertical E-field at ground level has an amplitude of approximately 15 kV/m and 10%–90% rise time of 64 ns. In addition, according to the measured breakdown current and resultant current impulse velocity, the vertical E-field is computed by using the finite-difference time-domain method in the two-dimensional cylindrical coordinate system. The computed vertical E-field agrees well with the measured E-field, validating our measured current impulse velocity. Besides, the computed horizontal E-field and azimuthal H-field are also analyzed. Finally, the influence of current impulse velocity on the vertical and horizontal E-field and azimuthal H-field is discussed.

Target Detection Coverage Algorithm Based on 3D-Voronoi Partition for Three-Dimensional Wireless Sensor Networks

The detection of target events is an important research area in the field of wireless sensor networks (WSNs). In recent years, many researchers have discussed the problem of WSN target coverage in a two-dimensional (2D) coordinate system. However, the target detection problem in a 3D coordinate system has not been investigated extensively, and it is difficult to improve the network coverage ratio while ensuring reliable performance of WSN. In addition, sensor nodes that are initially deployed randomly cannot achieve accurate target coverage in practice. Moreover, it is necessary to consider the energy consumption factor owing to the limited energy of the sensor node itself. Hence, with the objective of addressing the target event coverage problem of WSNs in 3D space applications, this paper proposes a target detection coverage algorithm based on 3D-Voronoi partitioning for WSNs (3D-VPCA) in order to ensure reliable performance of the entire network. First, we extend Voronoi division based on the 2D plane, which allows 3D-Voronoi partitioning of sensor nodes in 3D regions. Then, it is optimized according to the 3D-Voronoi neighbouring node partitioning characteristics and combined with the improved algorithm. Next, we set the priority coverage mechanism and introduce the correlation force between the target point and the sensor node in the algorithm, so that the sensor node can move to the target position for accurate coverage. Finally, we carry out related simulation experiments to evaluate the performance and accuracy of the proposed algorithm. The results show that the proposed algorithm can effectively improve the coverage performance of the network while ensuring a high overall coverage ratio.

Effect of Inclined Magnetic Field on Peristaltic Flow of Carreau Fluid through Porous Medium in an Inclined Tapered Asymmetric Channel

During this article, we have a tendency to show the peristaltic activity of magnetohydrodynamics flow of carreau fluid with heat transfer influence in an inclined tapered asymmetric channel through porous medium by exploitation the influence of non-slip boundary conditions. The tapered asymmetric channel is often created because of the intrauterine fluid flow induced by myometrial contraction and it had been simulated by asymmetric peristaltic fluid flow in an exceedingly two dimensional infinite non uniform channel, this fluid is known as hereby carreau fluid, conjointly we are able to say that one amongst carreau's applications is that the blood flow within the body of human. Industrial field, silicon oil is an example of carreau fluid. By exploitation, the perturbation technique for little values of weissenberg number, the nonlinear governing equations in the two-dimensional Cartesian coordinate system is resolved under the assumptions of long wavelength and low Reynolds number. The expressions of stream function, temperature distribution, the coefficient of heat transfer, frictional forces at the walls of the channel, pressure gradient are calculated. The effectiveness of interesting parameters on the inflow has been colluded and studied.

Finite difference method based analysis of bio-heat transfer in human breast cyst

Bio-heat transfer is a branch of bio-medical engineering which has its foundation linked to engineering disciplines of heat transfer. The thermal properties and behaviour of various malfunctioning tissues in human body varies as compared with normal tissues. Among various cancer tissues one which is commonly diagnosed in women is breast cyst (cancer causing fluid). The aim of present work is to develop one, two and three-dimensional computational models to study bio-heat transfer problems using finite difference method. First of all, a numerical model based on finite difference method is developed to solve Pennes’s bio-heat transfer equation in one-dimension to get temperature profiles normal to skin surface and validated with existing analytical solutions. Secondly, the numerical model is extended to study the thermal behaviour of human breast section embedded with cyst using two-dimensional cylindrical coordinate systems and validated with previous researcher’s results. The effect of size, location and presence of multiple cysts on surface temperature is studied. Lastly, the work is extended for the case of three-dimensional breast section with cyst located at the centre. The numerical results obtained using one, two and three-dimensional computational models will be highly helpful in the early detection of breast cancer tissues and also the location of it inside the body.

Understanding the Abrupt Climate Change in the Mid-1970s from a Phase-Space Transform Perspective

AbstractAbrupt climate change may cause heat, drought, and flood disasters. In this study, we find that many climate factors [e.g., the East Asian summer monsoon (EASM), the Arctic Oscillation (AO) and the Pacific decadal oscillation (PDO)] show a decadal-scale abrupt change in the 1970s. To analyze this phenomenon thoroughly, a new method of pedigree clustering combined with phase-space analysis (PCPSA) is used to establish two-dimensional phase-space coordinate systems of EASM–AO, EASM–PDO, and AO–PDO and the three-dimensional phase-space coordinate system of EASM–AO–PDO. By using the PCPSA method, it is found that all of the phase-space coordinate systems have a significant abrupt change in the mid-1970s, with a transition period, and the fit to the abrupt change of the phase-space coordinate system is better than 80%, which indicates excellent fit. By analyzing the correlation of EASM, AO, and PDO with sea level pressure (SLP) and sea surface temperature (SST), it is found that SLP has an obvious weakening trend in the high latitudes and an increasing trend in the tropics while SST has an increasing trend in most of the Southern Hemisphere waters and a minor weakening trend in the North Pacific Ocean waters between 30° and 40°N. Therefore, the abrupt climate change of the 1970s may well be a global abrupt change of the climatic system.

Is metatarsus primus elevatus truly observed in hallux rigidus? Radiographic study using mapping methods

BackgroundHallux rigidus and metatarsus primus elevatus (MPE) are associated, but their causal relationship remains unknown. Several surgical approaches for treating hallux rigidus are available. We evaluated morphological characteristics of hallux rigidus with different grades to determine the optimal surgical approach. The amount of degenerative change in the metatarsophalangeal joint on the preoperative roentgenograms was graded on a scale of 1–3. We analyzed the morphology of hallux rigidus using X-ray image mapping developed by our team. MethodsThis study involved weight-bearing, dorsoplantar, and lateral foot X-rays of 36 feet from 26 patients underwent surgery for hallux rigidus (Group R) at our institution, and 26 normal feet (Group N). A two-dimensional coordinate system was used to analyze the sharps of these feet by converting each dot on the radiographs into X and Y coordinates. Diagrams of the feet from each group were drawn for comparison. Feet with grades 2 (Group R2) and 3 (Group R3) hallux rigidus and normal feet were compared by Kruskal–Wallis test. ResultsMapping revealed that the tip of distal phalanges of the second, and third toes in Group R medially shifted (P < 0.05) in dorsoplantar image of the feet, and that the medial point, a part of the talus, navicular, cuneiform, and first metatarsal bone in Group R, shifted lower (P < 0.05) in lateral feet images of the feet. Multiple comparisons revealed a significant navicular bone depression in grade 3 hallux rigidus compared with normal feet. A significant difference was observed between Group N and R3 but not between Group R2 and N or R3. ConclusionsX-ray morphological analysis of the foot revealed MPE in Group R. Elevation gradually increased as hallux rigidus grade worsened. Therefore, osteotomy combined with cheilectomy, whereby the first metatarsal bone can be tilted toward the plantar side, are useful for treating a higher-grade hallux rigidus. Level of evidenceLevel III, comparative study.

Formulaic Language in the Magnifying Glass. Setting Parameters on the Analyzability of Linguistic Structure

Adopting the model of Cognitive Grammar as proposed and developed by Ronald Langacker (1987, 1991, 2008), the article applies three basic cognitive parameters on the continuum of linguistic structure: analyzability, compositionality, and institutionalization, to an analysis of proverbs and especially to new proverbial modifications. The aim of the study is twofold: first, by proposing a two-dimensional coordinate system, we seek to establish a correlation between analyzability and compositionality. Second, by adding a third parameter on linguistic structure, namely institutionalization, we develop a three-dimensional system which, we believe, can offer a fuller account of the grammar-lexicon continuum.

Analytical study on wave power extraction from a hybrid wave energy converter

In this paper, a hybrid wave energy converter (WEC) is proposed, consisting of a fixed inverted flume with long length and a bottom hole, and a long floating cube hinged with the flume. The inverted flume and the long floating cube works as an oscillating water column (OWC) and a rotational float, respectively, to capture power from incident waves. To study the performance of this hybrid WEC, analytical solution of the wave diffraction/radiation problems, considering the hydrodynamic interaction between the OWC and the float, is derived based on linear potential flow theory and eigen-function expansion matching method in the two-dimensional Cartesian coordinate systems. The corresponding hydrodynamic coefficients, such as wave excitation forces, added mass and wave radiation damping, are also obtained, which can be further used in evaluation of the maximum theoretical power absorption of the hybrid WEC. Results are compared with a parallel study of an isolated OWC and an isolated float. Additionally, analytical study on power capture capability of the device for various geometrical parameters is then carried out.

RESEARCH ON COORDINATE TRANSFORMATION METHOD OF GB-SAR IMAGE SUPPORTED BY 3D LASER SCANNING TECHNOLOGY

Abstract. In the image plane of GB-SAR, identification of deformation distribution is usually carried out by artificial interpretation. This method requires analysts to have adequate experience of radar imaging and target recognition, otherwise it can easily cause false recognition of deformation target or region. Therefore, it is very meaningful to connect two-dimensional (2D) plane coordinate system with the common three-dimensional (3D) terrain coordinate system. To improve the global accuracy and reliability of the transformation from 2D coordinates of GB-SAR images to local 3D coordinates, and overcome the limitation of traditional similarity transformation parameter estimation method, 3D laser scanning data is used to assist the transformation of GB-SAR image coordinates. A straight line fitting method for calculating horizontal angle was proposed in this paper. After projection into a consistent imaging plane, we can calculate horizontal rotation angle by using the linear characteristics of the structure in radar image and the 3D coordinate system. Aided by external elevation information by 3D laser scanning technology, we completed the matching of point clouds and pixels on the projection plane according to the geometric projection principle of GB-SAR imaging realizing the transformation calculation of GB-SAR image coordinates to local 3D coordinates. Finally, the effectiveness of the method is verified by the GB-SAR deformation monitoring experiment on the high slope of Geheyan dam.

Developing a safety heatmap of uncontrolled intersections using both conflict probability and severity

This paper presents a method to assess the safety of uncontrolled intersections considering two major properties of traffic conflicts—conflict probability and severity. This method assesses both the safety level of the entire intersection in addition to the distribution of safety within it. Intersections are modeled by a two-dimensional Cartesian coordinate system and the internal space of intersections is divided into cells. First, the vehicle movement characteristics of an uncontrolled intersection are modeled. Second, the conflict probability of each cell within the intersection is estimated considering the approaching probability and lateral migration probability of vehicles. The quantification of conflict severity is based on kinetic energy loss of potential crashes. Cluster analysis is used to combine conflict probability and severity to model the safety assessment of each cell. Third, the application of the method is discussed, and an overall safety index of intersections is proposed which considers weighted safety level and relative value of areas of different safety levels. Finally, a case study, which includes three different designs, is presented along with safety heatmaps to demonstrate the results. The results not only demonstrate the validity of the model, but also indicate that the proposed method can be applied to: i) safety evaluation of build-up intersections; ii) dangerous position management within an intersection; iii) safety assessment of designed intersections, and iv) safety level comparison among different intersections or various designs for a single intersection. Using this method, engineers and planners can better evaluate and improve the safety of existing or future uncontrolled intersections.

Testing with Values: the Refugee Problem and Political Prospects of the “Alternative for Germany”

The article analyses the reasons for the electoral success of the &ldquo;Alternative for Germany&rdquo; party at the federal and state levels in 2016-2017. Looking at the ideological spectrum of German political parties through the research lens of a two-dimensional coordinate system that, alongside the traditional ideological dimension includes the value axis, the author points out the fact that the problem of the refugees, which appeals to the values of the nation, perplexed German parties, as the choice of a particular strategy in regard to the refugees involved high risks of losing a significant number of votes. As a result, those parties, which managed to clearly articulate their system of values, above all the &ldquo;Alternative&rdquo;, benefited from this situation. The author states that the rise of the &ldquo;Alternative&rdquo; was caused by the &ldquo;value vacuum&rdquo; in the party life in Germany stemming from the progressive &ldquo;open-door&rdquo; refugee policy introduced by Chancellor Merkel in order to resolve the European refugee crisis. Much consideration is given to the reasons that led the CDU to adopt such an unusual strategy for a predominantly centrist party. In conclusion the author suggests that, in spite of its electoral success, political influence of the &ldquo;Alternative&rdquo; will be seriously limited by the unwillingness on the part of other parties to establish contacts and build inter-party ties with an inexperienced political player, which is prone to neglect the achievements of German democracy and does not fit into the framework of modern political mainstream. From the other hand, the tightening of the immigration policy weakens the protest potential of German voters.

Modelling of Newtonian blood flow through a bifurcated artery with the presence of an overlapping stenosis

Mathematical modelling of blood flow is developed by treating the blood as a Newtonian fluid. In this study, stenosis has been accounted as an overlapping shaped in two-dimensional Cartesian coordinate system. Blood are assumed as steady laminar flow, fully developed and incompressible which flowing through an arterial bifurcation where the wall considered rigid with no-slip condition. Galerkin weighted residual method is performed and a Matlab code is developed to solve the problem. To validate the code, comparison has been made with the results obtained by COMSOL Multiphysics. Results on the velocity profiles and the streamlines pattern are observed and discussed in details.

QUANTITATIVE CALCULATION OF THE QUALITY OF TEACHING AS A PROJECT MANAGEMENT FACTOR OF THE INTERNATIONAL CONTRACT

One of the most problematic places in the implementation of international contracts is inefficient project management. The choice of inappropriate methodology for managing the educational project, irrational allocation of resources, untimely monitoring quality of the provided services can lead not only to the loss of an existing contract, but also to the reduction of the university's reputation in the international arena in conditions of competitive struggle in the educational services market. In turn, this minimizes the probability of concluding of new contracts. An innovative methodology for managing projects for the provision of educational services to a foreign customer has been developed. A general calculation of the quantitative assessment of a quality of the provision of an educational service is applied in this methodology. In order to significantly reduce the calculation time was created a universal computational program that allows processing of large data blocks with visualization of results in a two-dimensional coordinate system. The methodology was implemented in the NUOS workflow. The obtained results make possible to control the quality of rendering educational services to a foreign customer with minimum expenses of human resources and make adjustments to the educational process quickly if it necessary.

Solid-supported synergistic twain probes with aggregation-induced emission: A sensing platform for fingerprinting volatile amines

Two solid emitters DMA and HBA were synthetized, showing aggregation-induced emission (AIE) phenomenon. Incorporation of electron donor-acceptor (D-A) pairs endows the solid emitters with both charge transfer (CT) state emission and distinct solvatochromic effect. The compounds undergo a rapid interaction with amines followed by the resulting weakened electron withdrawing ability to yield florescent products with either hypochromatic shift or decrease in the emission intensity. DFT calculations on HOMO and LUMO electronic cloud distribution and energy levels have demonstrated that the transition from CT state to locally excited (LE) state is mainly responsible for the spectral changes. The AIE compounds were thus developed into solid-supported amine sensor and show nice linear relationship. The detection limits of DMA- and HBA-based sensing film to ammonia gas are 2.61Pa and 2.63Pa, respectively. Time-dependent emission spectra upon treating with a variety of amines exhibited differential responses, in which two factors were defined accordingly, including maximum emission wavelength and quenching efficiency. Two-dimensional coordinate system was then built on the basis of the two factors, creating a fingerprint data base for the involved amines. The fingerprint map shows a clear differentiation of the tested amines, making DMA and HBA synergistic twain probes for identification of diverse amines.

INNOVATIVE PROJECT MANAGEMENT METHODOLOGY FOR GLOBAL EDUCATIONAL MARKET

Innovative project management methodology for the provision of educational services to the foreign customer was developed. In this methodology is applied the general calculation of a quantitative assessment of the quality of teaching. To significantly reduce the time for calculations, the universal computing program has been created, which allows to process extensive data blocks with the visualization of the results in the two-dimensional coordinate system. This methodology was implemented to working process of Admiral Makarov National University of Shipbuilding. The results made it possible to quickly make adjustments in the educational process in order to improve the quality of educational services for the international customer.

A novel approach to phase space reconstruction of single lead ECG for QRS complex detection

Abstract Two-dimensional reconstructed phase space (RPS) of single lead Electrocardiogram (ECG) is usually implemented by plotting the ECG amplitude x(t + τ) versus x(t) into the two-dimensional coordinate system, where the value of time delay τ determined the morphology of the reconstructed trajectory. However, the value of τ is very difficult to select because different theories derived different τ. In this paper, a novel approach to phase space reconstruction of single lead ECG without using τ is proposed. The first two coordinates (x, y) from (x, y, t) were projected into the x-y coordinate system, where x is the amplitude of the ECG and y is the first order difference of x. Besides, time t is corresponding to the sampling time moment. As QRS complex is usually the most striking waveform that dominant with the highest amplitude or the highest slope, the largest semi-circle in the RPS is usually derived from QRS complex. The location of QRS complex in the original ECG is determined by the time coordinate t that corresponds to the largest semi-circle in the x-y coordinate system. The algorithm was developed at the MIT-BIH Arrhythmia Database (109494 beats within 24 h in total) and was tested on the Long-term ST Database (8897780 beats within 1991.8 h in total). The accuracy (ACC), the sensitivity (SEN) and the positive predictivity value (PPV) for the MIT-BIH Arrhythmia Database were 99.81%, 99.87% and 99.93%, respectively; while the corresponding values for the Long-term ST Database were 99.87%, 99.96% and 99.91%, respectively. Meanwhile, the consuming time was only 6.73 ms for processing 6 s’ ECG data. Furthermore, the anti-noise ability of the proposed method was tested on the MIT-BIH Noise Stress Test Database (4265 beats in total at each noise level for one lead ECG). Both ACC and PPV were higher than 85% and the SEN was higher than 99% even when the signal-to-noise ratio (SNR) was as low as 0 dB. In conclusion, the proposed algorithm achieves better performance on QRS complex detection when in comparison with the state-of-the-art methods, and it is suited for the detection of QRS complex in the ECG associated with poor signal quality and severe arrhythmia.

Finding Propagation Constants of Leaky and Degenerate Modes Using Simultaneous Transcendental Equations of Holey Optical Fibers

This paper presents a simple solution to simultaneous transcendental equations of propagation constants for leaky and degenerate modes. Using a block version of the Sakurai–Sugiura method (SSM) and a criterion for distinguishing physical solutions from spurious ones, we solved a nonlinear matrix equation formulated by the multipole method in a two-dimensional cylindrical coordinate system. Numerical examples showed that we can obtain accurate propagation constants and extract field distributions of leaky and degenerate modes of holey fibers without imposing symmetry. In addition, the condition numbers of the eigenvalues are efficient criteria for distinguishing solutions computed by the block version of the SSM.

Hydrodynamics of a self-propelled flexible fin near the ground

Many animals in nature experience hydrodynamic benefits by swimming near the ground. Inspired by near-ground swimmers, a flexible fin flapping near the ground was modeled in a two-dimensional Cartesian coordinate system. The transverse heaving motion was prescribed at the leading edge and the posterior part of the fin fluttered passively under the fin–fluid interaction. The fin freely moved horizontally in a quiescent flow, which dynamically determined the swimming speed. The fluid–flexible fin interaction was considered by using an immersed boundary method. The fin could swim up to 14% faster near the ground than in the bulk fluid, and the vortices in the wake moved away from the ground. The body kinematics was passively altered by flapping near the ground, and the trailing edge amplitude decreased as the ground proximity increased. The benefits or penalties in the thrust and the power input by swimming near the ground were not only the direct results of the hydrodynamic changes, but also the indirect results of the altered body kinematics. The thrust was enhanced by approximately 37% and the power input increased by about 17% at the ground proximity of 1.5, which were the pure results of the hydrodynamic changes near the ground. The flexible fin could generate more thrust near the ground with a smaller penalty in the power input, leading to the enhancement of the Froude propulsive efficiency by about 17%.

Evaluation of the quality of teaching as an element of management of joint international educational project

Project management of educational services in international market is impossible without evaluation of the quality of teaching. In innovative project management methodology for the provision of educational services is applied the general calculation of a quantitative assessment of the quality of teaching. To significantly reduce the time for calculations, the universal computing program has been created, which allows to process extensive data blocks with the visualization of the results in the two-dimensional coordinate system