Objects In Two-dimensional Space Research Articles

Single-Source SIE for 2-D Arbitrarily Connected Penetrable and PEC Objects With Nonconformal Meshes

We proposed a simple and efficient modular single-source surface integral equation (SS-SIE) formulation for electromagnetic analysis of arbitrarily connected penetrable and perfectly electrical conductor (PEC) objects in two-dimensional space. In this formulation, a modular equivalent model for each penetrable object consisting of the composite structure is first independently constructed through replacing it by the background medium, no matter whether it is surrounded by the background medium, other media, or partially connected objects, and enforcing an equivalent electric current density on the boundary to remain fields in the exterior region unchanged. Then, by combining all the modular models and any possible PEC objects together, an equivalent model for the composite structure can be derived. The troublesome junction handling techniques are not needed and non-conformal meshes are intrinsically supported. The proposed SS-SIE formulation is simple to implement, efficient, and flexible, which shows significant performance improvement in terms of CPU time compared with the original SS-SIE formulation and the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) formulation. Several numerical examples including the coated dielectric cuboid, the large lossy objects, the planar layered dielectric structure, and the partially connected dielectric and PEC structure are carried out to validate its accuracy, efficiency and robustness.

On the Classification of Fractal and Non-Fractal Objects in Two-Dimensional Space

The method of numerical Fourier analysis is used to investigate the fractal properties of 2D objects with micrometer–centimeter sizes. This numerical method simulates the small-angle light scattering experiment. Different geometric 2D-regular fractals, such as the Sierpinski carpet, Sierpinski triangle, Koch snowflake, and Vishek snowflake, are studied. We can divide 2D fractals, by analogy with 3D fractals, into “plane” and “boundary” fractals with fractal dimensions lying in the intervals from 1 to 2 and from 2 to 3, respectively. For an object with a smooth boundary, i.e., a circle, the model small-angle scattering curve decreases according to the power law q–3, where q is the momentum transferred.

Measuring Technical Drawing Capability through Online Learning as a Basic Competency for Vocational Students

The ability to read projection systems and describe projections of real objects in two-dimensional space are two important things that can lead potential engineering personnel to become professional vocational personnel in mechanical engineering. Therefore, this research is conducted to measure these abilities based on online learning activities in mechanical engineering drawing. There are two research variables used, namely reading and drawing on projection material. The quantitative descriptive method is used to process data on learning outcomes from these two variables collected from the online survey through structured assignments given to students. It can be concluded that the students could understand basic competency learning activities of projection images and complete drawing work which is distributed online properly. They could also complete the assignments according to the specified time given. Thus, drawing technique practices in the era of reality and virtual integration does not always require direct guidance from the supervisor. The online vocational education model can be developed for technology fields that require engineering technology skills in collaboration with the industry.

High-Resolution Muography Using a Prototype Portable Muon Telescope

We report on our continued development of a portable muon telescope with excellent angular resolution capable of imaging large archaeological structures in detail. The first prototype (Phase I) consists of four trays of scintillator bars, Winston cones, silicon photomultipliers (SiPMs), readout electronics, and a network of Arduinos to handle data acquisition. Finally, we developed a reconstruction algorithm to create the final image. The cosmic muons produce scintillation photons as they pass through the scintillator bars; these photons are transported by the Winston cones to the SiPMs where they are converted into electrical signals. The electrical signals are then digitized and transmitted to an offline computer for reconstruction. The entire system is mounted on a wheeled cart and can be pointed to target different objects of interest. With Phase I, we are able to reconstruct large objects in two-dimensional space with an angular resolution of 20 mrad with an operating efficiency of 89%.

The research about radiometric technology of two-dimensional rotary table based on image gray level

It is difficult to measure infrared radiation quantitatively for fast dynamic targets such as aircraft and missile. At present, there are many problems such as low measurement accuracy, feedback delay, and complex measurement system. In this paper, a radiation measurement scheme based on image grayscale is proposed. The scheme adopts a two-dimensional turntable structure, which can measure the radiation quantity rapidly and accurately. Based on the image method, this method is used to calibrate the gray value of the target point and compare it with that of the absolute standard radiator, so as to obtain the radiation value of the target indirectly. The key of this method is to establish an accurate radiation measurement model. The proposed model based on dynamic calibration is about 50% more accurate than the traditional model. The final measurement accuracy of this model is 75%. Through the infrared radiation measurement of specific dynamic objects in two-dimensional space, it is found that the dynamic calibration model based on this measurement method has higher measurement precision.

Clustering of objects with poorly formalizable features based on a neural network in the form of Kohonen layers

Analysis of profiles of minors in social networks shows that teenagers indicate in them information that increases the level of their social desirability. Such information often does not correspond to the real behavior of the teenager. For a full analysis of the level of deviance of a minor need tools covering the full range of indicators. In contrast to the usual approach to clustering objects based on their Association in groups by the criterion of the minimum distance in multidimensional space when clustering features it is advisable to take into account their proximity to the methods of obtaining information and methods of processing of this information by the inspector for minors. In the first phase of the study is the clustering of signs of deviation, the second the determination of the weighting factors of indicator of the degree of deviance within each group of signs, the third uses the method of cluster-hierarchical approach to forming integral indicator of assessment of deviant behavior of minors. The indicator has a considerable flexibility of the correlation between groups of symptoms and partial characteristics through the introduction of appropriate sets of weighting coefficients. The conclusion is made about the preference of methods based on clustering of objects in the two-dimensional space of targets or accounts of the principal components method, as well as the need for additional analysis of the graphical picture of the relative location of objects. From the comparison of different approaches: 1) clustering on the basis of the generalized indicator of quality and the sign of reverse deviance, 2) clustering on two accounts of the principal components method; 3) clustering on all signs of examination, the following conclusions can be drawn. All methods properly allocate the objects to clusters. However, when you save the main totals (highlighting the best and worst features), the results are slightly different. This is due to the different volume and forms of presentation of the source information. The program assigns numbers of active neurons (clusters) arbitrarily, so in order to arrange the cluster numbers by some feature (for example, the quality of objects), you need to use additional graphical information. From a practical point of view, the first two methods are preferred, based on clustering objects in two-dimensional space, the method of principal components and the analysis of the graphical picture of the mutual location of objects.

Implementation of Fuzzy Aided Kalman Filter for Tracking a Moving Object in Two-Dimensional Space

Implementation of Fuzzy Aided Kalman Filter for Tracking a Moving Object in Two-Dimensional Space

Visualization of Linear Ordering Results for Ordinal Data with Application of Multidimensional Scaling

A two-step procedure was proposed to visualization of linear ordering results for ordinal data. In the first step as a result of the application of multidimensional scaling (see Borg, Groenen, 2005; Mair et al., 2016) is to visualize objects in two-dimensional space. In the next step, a linear ordering is carried out with the use of the Euclidean distance from the pattern (ideal) object. The proposed approach expanded the possibilities of interpretation of the results of the linear ordering of set of objects. The article uses the concept of isoquant and path of development (the shortest way connecting ideal and anti-ideal object) proposed by Hellwig (1981). The proposed approach is illustrated by an empirical example with application of script of R environment.

A 27-Intersection Model for Representing Detailed Topological Relations between Spatial Objects in Two-Dimensional Space

Determining the spatial relations between objects is a primary function of a geographic information system (GIS). One important aspect of spatial relations is topological relations, which remain constant under topological transformations. Describing the geometry of a spatial object using the OpenGIS Simple Features Specification requires only simple features: the interior, boundary and exterior of a spatial object are defined. This paper proposes a comprehensive model, the 27-intersection model (27IM), which considers both the dimensions and the number of intersections. Some propositions are presented to exclude relations that the 27IM cannot implement. The 27IM describes six groups of topological relations: point/point, point/line, point/region, line/line, line/region and region/region. The formalism of the 27IM and the corresponding geometric interpretations between spatial objects are illustrated and then compared to the topological relations represented by the existing models, the nine-intersection model (9IM), the dimensionally-extended nine-intersection matrix (DE-9IM) and the separation number extended nine-intersection matrix (SNE-9IM). The results show that (1) the 27IM can represent the topological relations between two-dimensional spatial objects, (2) the 27IM can distinguish more topological relations than can the 9IM, DE-9IM or the SNE-9IM and that (3) the interoperability of the 27IM with the 9IM, DE-9IM and SNE-9IM is good.

ELABORATION OF THE METHOD OF ASSESSMENT OF THE SEVERITY DEGREE OF COMPANIES CRISIS

The analysis of scientific literature allowed us to establish the absence of unified approach to the assessment of severity of the company crisis. The definition of the term “crisis severity degree” was specified and its five-level gradation was offered, namely: absence of the crisis, its light, middle, hard and critical severity degree. From our point of view, this gradation is intuitively comprehensive for all groups of stakeholders, involved in the process of anti-crisis management and most fully characterizes the condition of the company in the aspect of possible anti-crisis arrangements. The three-level hierarchic structure of the types of crisis of the company was offered. The use of hierarchic structure favors the better understanding of the causes of crisis, its results and possible ways out of crisis. The aforesaid is attained by separation of the different types of crisis then the components of these types of crisis are separated and so on. At the same time at each step it is necessary to concentrate attention on understanding of the current element, temporarily abstracting from all other components. At such analysis the whole complexity and severity of the company crisis can be understood. The methodology of determination of the severity degree of the company crisis was elaborated for each level of hierarchy. The diagnostics of the severity degree of the company crisis of the higher level of hierarchy must be realized using the matrix of pair comparison and the severity degrees of crisis must be integrated for each its component based on the laws of economic logic. The matrix of comparison of the severity degrees of the company crisis is recommended to be formed by comparison of two parameters of assessment of the crisis of the low level of hierarchy that allows range the comparable objects in two-dimensional space. The severity degree of financial crisis of the company is offered to be determined taking into account the probability of its bankruptcy and of economic, social and ecological one – by the comparison of the current values of assessment parameters with their base values. The values of pre-crisis period are recommended to be used as the base ones. The approbation of offered methodology of assessment of the severity degree of the company crisis was realized.

The model for echolocation of insects by using bat-like sounds

Bats use frequency-modulated echolocation to identify and capture flying insects in real three dimensional space. Experimental evidence indicates that bats are capable of locating static objects with a range accuracy of less than 1 μs. A previously introduced model could localize objects in two-dimensional space by accurately estimating the object’s range at each timepoint by extracting temporal changes from the time-frequency pattern and interaural range differences while echoes were measured at two receiving points by intermittently emitting LFM sounds. In addition, this model was shown to localize moving objects in two-dimensional space by accurately estimating the object’s range under the influences of the Doppler shift, which was dependent on the movements. However, it was not evaluated whether this model could detect and localize small sized objects, e.g., small moths, whose echoes were weak. In this presentation, the echoes were measured from two kinds of moth, Spodoptera litura and Helicoverpa armigera. The accuracies of estimated range and direction were examined while echoes were measured from flying moths by intermittently emitting bat-like sounds.

Effective and efficient trajectory outlier detection based on time-dependent popular route

With the rapid proliferation of GPS-equipped devices, a myriad of trajectory data representing the mobility of various moving objects in two-dimensional space have been generated. This paper aims t...

Visualization of linear ordering results for metric data with the application of multidimensional scaling / Wizualizacja wyników porządkowania liniowego dla danych metrycznych z wykorzystaniem skalowania wielowymiarowego

The article discusses the two-step research procedure allowing the visualization of linear ordering results for metric data. In the first step, as a result of the application of multidimensional scaling (see [Borg, Groenen 2005; Mair et al. 2016]) the visualization of objects in two-dimensional space is obtained. In the next step, the linear ordering of a set of objects is carried out based on the Euclidean distance from the pattern (ideal) object. The suggested approach expanded the possibilities for the interpretation of the linear ordering results of a set of objects. The article applies the concept of isoquants and the path of development (the shortest way connecting a pattern and an anti-pattern object) proposed by [Hellwig 1981]. The graphical presentation of the linear ordering results based on this concept was possible for two variables only. The application of multidimensional scaling expanded the applicability of the results of linear ordering visualization for m variables. The suggested approach is illustrated by an empirical example with the application of R environment script.

Localization and tracking of moving objects in two-dimensional space by echolocation

Bats use frequency-modulated echolocation to identify and capture moving objects in real three-dimensional space. Experimental evidence indicates that bats are capable of locating static objects with a range accuracy of less than 1 μs. A previously introduced model estimates ranges of multiple, static objects using linear frequency modulation (LFM) sound and Gaussian chirplets with a carrier frequency compatible with bat emission sweep rates. The delay time for a single object was estimated with an accuracy of about 1.3 μs by measuring the echo at a low signal-to-noise ratio (SNR). The range accuracy was dependent not only on the SNR but also the Doppler shift, which was dependent on the movements. However, it was unclear whether this model could estimate the moving object range at each timepoint. In this study, echoes were measured from the rotating pole at two receiving points by intermittently emitting LFM sounds. The model was shown to localize moving objects in two-dimensional space by accurately estimating the object's range at each timepoint.

Echolocation of static and moving objects in two-dimensional space using bat-like frequency-modulation sound

Bats use frequency-modulated echolocation to identify and capture moving objects in real three-dimensional space. The big brown bat, Eptesicus fuscus, emits linear period modulation sound, and is capable of locating static objects with a range accuracy of less than 1 μs. A previously introduced model can estimate ranges of multiple, static objects using linear frequency modulation (LFM) sound and Gaussian chirplets with a carrier frequency compatible with bat emission sweep rates. The delay time for a single object was estimated with an accuracy of about 1.3 μs by measuring the echo at a low signal-to-noise ratio. This model could estimate the location of each moving object in two-dimensional space. In this study, the linear period modulation sounds, mimicking the emitting pulse of big brown bats, were introduced as the emitted signals. Echoes were measured from moving objects at two receiving points by intermittently emitting these sounds. It was clarified that this model could localize moving objects in two-dimensional space by accurately estimating the object ranges.

Quantum Hall transitions: An exact theory based on conformal restriction

We revisit the problem of the plateau transition in the integer quantum Hall effect. Here we develop an analytical approach for this transition, and for other two-dimensional disordered systems, based on the theory of ``conformal restriction.'' This is a mathematical theory that was recently developed within the context of the Schramm-Loewner evolution which describes the ``stochastic geometry'' of fractal curves and other stochastic geometrical fractal objects in two-dimensional space. Observables elucidating the connection with the plateau transition include the so-called point-contact conductances (PCCs) between points on the boundary of the sample, described within the language of the Chalker-Coddington network model for the transition. We show that the disorder-averaged PCCs are characterized by a classical probability distribution for certain geometric objects in the plane (which we call pictures), occurring with positive statistical weights, that satisfy the crucial so-called restriction property with respect to changes in the shape of the sample with absorbing boundaries; physically, these are boundaries connected to ideal leads. At the transition point, these geometrical objects (pictures) become fractals. Upon combining this restriction property with the expected conformal invariance at the transition point, we employ the mathematical theory of ``conformal restriction measures'' to relate the disorder-averaged PCCs to correlation functions of (Virasoro) primary operators in a conformal field theory (of central charge $c=0$). We show how this can be used to calculate these functions in a number of geometries with various boundary conditions. Since our results employ only the conformal restriction property, they are equally applicable to a number of other critical disordered electronic systems in two spatial dimensions, including for example the spin quantum Hall effect, the thermal metal phase in symmetry class D, and classical diffusion in two dimensions in a perpendicular magnetic field. For most of these systems, we also predict exact values of critical exponents related to the spatial behavior of various disorder-averaged PCCs.

A diagram of the minimum necessary internal force required to resist external forces on two-point-grasped objects in two-dimensional space

SUMMARYThis paper considers the magnitude of the gripping power, i.e., the internal force that depends on the grasping posture or object orientation in a two-dimensional grasp by two contact points with friction. Expressing the effect of variations in the object posture as the direction of an external force, we propose an “internal force diagram.” The internal force necessary to create a statically stable grasp is depicted in the object coordinate frame. Then, a polar coordinate system is introduced in which the orientation represents the direction of the external force, while the distance from the origin represents the minimum necessary internal force. We demonstrate a method based on friction cone configurations to manually draw the internal force diagram, using only a ruler and a compass. The validity of this drawing method is confirmed by a comparison with computer-generated plots. Finally, the characteristics of the internal force diagram are discussed.

Novel tracking function of moving target using chaotic dynamics in a recurrent neural network model

Chaotic dynamics introduced in a recurrent neural network model is applied to controlling an object to track a moving target in two-dimensional space, which is set as an ill-posed problem. The motion increments of the object are determined by a group of motion functions calculated in real time with firing states of the neurons in the network. Several cyclic memory attractors that correspond to several simple motions of the object in two-dimensional space are embedded. Chaotic dynamics introduced in the network causes corresponding complex motions of the object in two-dimensional space. Adaptively real-time switching of control parameter results in constrained chaos (chaotic itinerancy) in the state space of the network and enables the object to track a moving target along a certain trajectory successfully. The performance of tracking is evaluated by calculating the success rate over 100 trials with respect to nine kinds of trajectories along which the target moves respectively. Computer experiments show that chaotic dynamics is useful to track a moving target. To understand the relations between these cases and chaotic dynamics, dynamical structure of chaotic dynamics is investigated from dynamical viewpoint.

Calculation of the local electric field for an infinite array of conducting nanosized objects

The electric field for an infinite array of conducting nanosized objects in two-dimensional space has been calculated. The mirror symmetry for this physical problem has been introduced. By taking into account this symmetry, we transform the original problem into an infinite two-dimensional array of nanosized objects with the same solution. The electric field equation of the model has been successfully constructed using a single-layer potential of the periodic Green function. The electric field operator has been introduced. This mathematical approach yields a solution for determining the optimum structure of nanosized electronic devices such as carbon nanotube-based field emitters.

Symmetrical Form and Common-Practice Tonality

This article is a study of symmetry, briefly as applied to objects in two-dimensional space and pitch-class space, then more extensively to musical form. Despite the limited presence of complete symmetry in tonal music, the concept-along with the related one of symmetrybreaking-is helpful for understanding this music's formal properties. Special attention is given to a rare kind of antecedentconsequent period in which symmetry-in some cases retrograde, but more commonly transpositonal-is rigorously preserved. Its evolution is traced in compositions by Haydn, Beethoven, Schumann, Chopin, and Scriabin. This content downloaded from 157.55.39.37 on Thu, 28 Apr 2016 05:44:05 UTC All use subject to http://about.jstor.org/terms