Previous Issue

Table of Contents

Symmetry, Volume 11, Issue 2 (February 2019)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
Cover Story (view full-size image) "Is it possible to model the many features of the brain activity by using simple differential [...] Read more.
View options order results:
result details:
Displaying articles 1-119
Export citation of selected articles as:
Open AccessArticle The Indirect-Utility Criterion for Ranking Opportunity Sets over Time
Symmetry 2019, 11(2), 241; https://doi.org/10.3390/sym11020241 (registering DOI)
Received: 31 January 2019 / Revised: 12 February 2019 / Accepted: 13 February 2019 / Published: 15 February 2019
PDF Full-text (233 KB)
Abstract
A preference defined on a set of alternatives can be extended to a preference on the subsets of alternatives (named opportunity sets) in different ways. We specifically consider the application of the indirect-utility (IU) criterion in various stages, when both the alternatives and [...] Read more.
A preference defined on a set of alternatives can be extended to a preference on the subsets of alternatives (named opportunity sets) in different ways. We specifically consider the application of the indirect-utility (IU) criterion in various stages, when both the alternatives and the preferences can change over time. In other words, we maintain the symmetry over time as far as criteria are concerned, but neither in the preferences, nor in the alternatives. We characterize this criterion by three testable axioms. Our study bears comparison with Krause (Economic Theory, 2008) for the two-period model. Full article
Open AccessArticle Time Series ARIMA Model for Prediction of Daily and Monthly Average Global Solar Radiation: The Case Study of Seoul, South Korea
Symmetry 2019, 11(2), 240; https://doi.org/10.3390/sym11020240 (registering DOI)
Received: 15 January 2019 / Revised: 5 February 2019 / Accepted: 12 February 2019 / Published: 15 February 2019
PDF Full-text (2080 KB) | HTML Full-text | XML Full-text
Abstract
Forecasting solar radiation has recently become the focus of numerous researchers due to the growing interest in green energy. This study aims to develop a seasonal auto-regressive integrated moving average (SARIMA) model to predict the daily and monthly solar radiation in Seoul, South [...] Read more.
Forecasting solar radiation has recently become the focus of numerous researchers due to the growing interest in green energy. This study aims to develop a seasonal auto-regressive integrated moving average (SARIMA) model to predict the daily and monthly solar radiation in Seoul, South Korea based on the hourly solar radiation data obtained from the Korean Meteorological Administration over 37 years (1981–2017). The goodness of fit of the model was tested against standardized residuals, the autocorrelation function, and the partial autocorrelation function for residuals. Then, model performance was compared with Monte Carlo simulations by using root mean square errors and coefficient of determination (R2) for evaluation. In addition, forecasting was conducted by using the best models with historical data on average monthly and daily solar radiation. The contributions of this study can be summarized as follows: (i) a time series SARIMA model is implemented to forecast the daily and monthly solar radiation of Seoul, South Korea in consideration of the accuracy, suitability, adequacy, and timeliness of the collected data; (ii) the reliability, accuracy, suitability, and performance of the model are investigated relative to those of established tests, standardized residual, autocorrelation function (ACF), and partial autocorrelation function (PACF), and the results are compared with those forecasted by the Monte Carlo method; and (iii) the trend of monthly solar radiation in Seoul for the coming years is analyzed and compared on the basis of the solar radiation data obtained from KMS over 37 years. The results indicate that (1,1,2) the ARIMA model can be used to represent daily solar radiation, while the seasonal ARIMA (4,1,1) of 12 lags for both auto-regressive and moving average parts can be used to represent monthly solar radiation. According to the findings, the expected average monthly solar radiation ranges from 176 to 377 Wh/m2. Full article
Figures

Figure 1

Open AccessArticle Some Real-Life Applications of a Newly Constructed Derivative Free Iterative Scheme
Symmetry 2019, 11(2), 239; https://doi.org/10.3390/sym11020239 (registering DOI)
Received: 1 January 2019 / Revised: 24 January 2019 / Accepted: 28 January 2019 / Published: 15 February 2019
PDF Full-text (4917 KB) | HTML Full-text | XML Full-text
Abstract
In this study, we present a new higher-order scheme without memory for simple zeros which has two major advantages. The first one is that each member of our scheme is derivative free and the second one is that the present scheme is capable [...] Read more.
In this study, we present a new higher-order scheme without memory for simple zeros which has two major advantages. The first one is that each member of our scheme is derivative free and the second one is that the present scheme is capable of producing many new optimal family of eighth-order methods from every 4-order optimal derivative free scheme (available in the literature) whose first substep employs a Steffensen or a Steffensen-like method. In addition, the theoretical and computational properties of the present scheme are fully investigated along with the main theorem, which demonstrates the convergence order and asymptotic error constant. Moreover, the effectiveness of our scheme is tested on several real-life problems like Van der Waal’s, fractional transformation in a chemical reactor, chemical engineering, adiabatic flame temperature, etc. In comparison with the existing robust techniques, the iterative methods in the new family perform better in the considered test examples. The study of dynamics on the proposed iterative methods also confirms this fact via basins of attraction applied to a number of test functions. Full article
(This article belongs to the Special Issue Symmetry with Operator Theory and Equations)
Figures

Figure 1

Open AccessArticle An Intelligent and Interactive Interface to Support Symmetrical Collaborative Educational Writing among Visually Impaired and Sighted Users
Symmetry 2019, 11(2), 238; https://doi.org/10.3390/sym11020238 (registering DOI)
Received: 11 December 2018 / Revised: 13 February 2019 / Accepted: 13 February 2019 / Published: 15 February 2019
PDF Full-text (563 KB) | HTML Full-text | XML Full-text
Abstract
It is often uncomfortable for disabled individuals, especially those with vision impairment, to conduct educational activities in collaboration with people that have perfect vision. This can be because of the former’s lack of confidence, vision capability, and acceptance. Information and communications technology (ICT) [...] Read more.
It is often uncomfortable for disabled individuals, especially those with vision impairment, to conduct educational activities in collaboration with people that have perfect vision. This can be because of the former’s lack of confidence, vision capability, and acceptance. Information and communications technology (ICT) has played a vital role in giving support to people with visual impairments so that they can overcome their issues. This study proposes innovative solutions that address the challenges faced by partially or completely visually impaired people. It provides an interactive and intelligent interface, which they may use to perform educational activities, such as editing, writing, or reviewing documents, in collaboration with people without visual impairments. The system provides high-quality awareness features by sending them instant voice notifications about the actions and events occurring in the shared environment. A speech-recognition engine has been integrated into the system to allow users to interact with the application through voice commands. The system is evaluated through experiments, where people with visual impairment and people without visual impairment were engaged in collaborative writing. The obtained results are encouraging. The users showed curiosity in the system and were able to focus on the productive task instead of their disability. Full article
Figures

Figure 1

Open AccessArticle A Decomposition Approach for Stochastic Shortest-Path Network Interdiction with Goal Threshold
Symmetry 2019, 11(2), 237; https://doi.org/10.3390/sym11020237 (registering DOI)
Received: 11 January 2019 / Revised: 6 February 2019 / Accepted: 12 February 2019 / Published: 15 February 2019
PDF Full-text (742 KB)
Abstract
Shortest-path network interdiction, where a defender strategically allocates interdiction resource on the arcs or nodes in a network and an attacker traverses the capacitated network along a shortest s-t path from a source to a terminus, is an important research problem [...] Read more.
Shortest-path network interdiction, where a defender strategically allocates interdiction resource on the arcs or nodes in a network and an attacker traverses the capacitated network along a shortest s-t path from a source to a terminus, is an important research problem with potential real-world impact. In this paper, based on game-theoretic methodologies, we consider a novel stochastic extension of the shortest-path network interdiction problem with goal threshold, abbreviated as SSPIT. The attacker attempts to minimize the length of the shortest path, while the defender attempts to force it to exceed a specific threshold with the least resource consumption. In our model, threshold constraint is introduced as a trade-off between utility maximization and resource consumption, and stochastic cases with some known probability p of successful interdiction are considered. Existing algorithms do not perform well when dealing with threshold and stochastic constraints. To address the NP-hard problem, SSPIT-D, a decomposition approach based on Benders decomposition, was adopted. To optimize the master problem and subproblem iteration, an efficient dual subgraph interdiction algorithm SSPIT-S and a local research based better-response algorithm SSPIT-DL were designed, adding to the SSPIT-D. Numerical experiments on networks of different sizes and attributes were used to illustrate and validate the decomposition approach. The results showed that the dual subgraph and better-response procedure can significantly improve the efficiency and scalability of the decomposition algorithm. In addition, the improved enhancement algorithms are less sensitive and robust to parameters. Furthermore, the application in a real-world road network demonstrates the scalability of our decomposition approach. Full article
Figures

Graphical abstract

Open AccessArticle Dynamics Models of Synchronized Piecewise Linear Discrete Chaotic Systems of High Order
Symmetry 2019, 11(2), 236; https://doi.org/10.3390/sym11020236 (registering DOI)
Received: 17 January 2019 / Revised: 30 January 2019 / Accepted: 11 February 2019 / Published: 15 February 2019
PDF Full-text (2000 KB) | HTML Full-text | XML Full-text
Abstract
This paper deals with the methods for investigating the nonlinear dynamics of discrete chaotic systems (DCS) applied to piecewise linear systems of the third order. The paper proposes an approach to the analysis of the systems under research and their improvement. Thus, effective [...] Read more.
This paper deals with the methods for investigating the nonlinear dynamics of discrete chaotic systems (DCS) applied to piecewise linear systems of the third order. The paper proposes an approach to the analysis of the systems under research and their improvement. Thus, effective and mathematically sound methods for the analysis of nonlinear motions in the models under consideration are proposed. It makes it possible to obtain simple calculated relations for determining the basic dynamic characteristics of systems. Based on these methods, the authors developed algorithms for calculating the dynamic characteristics of discrete systems, i.e. areas of the existence of steady-state motion, areas of stability, capture band, and parameters of transients. By virtue of the developed methods and algorithms, the dynamic modes of several models of discrete phase synchronization systems can be analyzed. They are as follows: Pulsed and digital different orders, dual-ring systems of various types, including combined ones, and systems with cyclic interruption of auto-tuning. The efficiency of various devices for information processing, generation and stabilization could be increased by using the mentioned discrete synchronization systems on the grounds of the results of the analysis. We are now developing original software for analyzing the dynamic characteristics of various classes of discrete phase synchronization systems, based on the developed methods and algorithms. Full article
(This article belongs to the Special Issue Discrete Mathematics and Symmetry)
Figures

Figure 1

Open AccessArticle Continuous Wavelet Transform of Schwartz Tempered Distributions in S′ ( R n )
Symmetry 2019, 11(2), 235; https://doi.org/10.3390/sym11020235 (registering DOI)
Received: 11 January 2019 / Revised: 2 February 2019 / Accepted: 12 February 2019 / Published: 15 February 2019
PDF Full-text (257 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, we define a continuous wavelet transform of a Schwartz tempered distribution fS(Rn) with wavelet kernel ψS(Rn) and derive the corresponding wavelet inversion formula interpreting convergence in the [...] Read more.
In this paper, we define a continuous wavelet transform of a Schwartz tempered distribution f S ( R n ) with wavelet kernel ψ S ( R n ) and derive the corresponding wavelet inversion formula interpreting convergence in the weak topology of S ( R n ) . It turns out that the wavelet transform of a constant distribution is zero and our wavelet inversion formula is not true for constant distribution, but it is true for a non-constant distribution which is not equal to the sum of a non-constant distribution with a non-zero constant distribution. Full article
(This article belongs to the Special Issue Integral Transforms and Operational Calculus)
Open AccessArticle A Programming-Based Algorithm for Probabilistic Uncertain Linguistic Intuitionistic Fuzzy Group Decision-Making
Symmetry 2019, 11(2), 234; https://doi.org/10.3390/sym11020234 (registering DOI)
Received: 7 January 2019 / Revised: 8 February 2019 / Accepted: 11 February 2019 / Published: 15 February 2019
PDF Full-text (438 KB)
Abstract
As an effective tool to express the subjective preferences of decision makers, the linguistic term sets (LTS) have been widely used in group decision-making (GDM) problems, such as hesitant fuzzy LTS, linguistic hesitant fuzzy sets, probabilistic LTS, etc. However, due to the increasing [...] Read more.
As an effective tool to express the subjective preferences of decision makers, the linguistic term sets (LTS) have been widely used in group decision-making (GDM) problems, such as hesitant fuzzy LTS, linguistic hesitant fuzzy sets, probabilistic LTS, etc. However, due to the increasing complexity of practical decision-making (DM) problems, LTS still has a lot of room to expand in fuzzy theory. Qualitative uncertainty information in the application of GDM is yet to be improved. Therefore, in order to improve the applicability of linguistic terms in DM problems, a probabilistic uncertain linguistic intuitionistic fuzzy set (PULIFS) that can fully express the decision-maker’s (DM’s) evaluation information is first proposed. To improve the rationality of DM results, we give a method for determining individual weights in the probabilistic uncertain linguistic intuitionistic fuzzy preference relation (PULIFPR) environment. In addition, we present two consistency definitions of PULIFPR to reflect both the assessment information and risk attitudes of decision makers. Subsequently, a series of goal programming models (GPMs) are established, which effectively avoid the consistency check and correction process of existing methods. Finally, the developed method is applied to an empirical example concerning the selection of a virtual reality (VR) project. The advantages of the proposed method are demonstrated by comparative analysis. Full article
(This article belongs to the Special Issue Fuzzy Techniques for Decision Making 2018)
Open AccessArticle Relationship between Motor Laterality and Aggressive Behavior in Sheepdogs
Symmetry 2019, 11(2), 233; https://doi.org/10.3390/sym11020233 (registering DOI)
Received: 10 January 2019 / Revised: 7 February 2019 / Accepted: 11 February 2019 / Published: 15 February 2019
PDF Full-text (875 KB) | HTML Full-text | XML Full-text
Abstract
Sheepdogs’ visuospatial abilities, their control of prey-driven behavior and their motor functions are essential characteristics for success in sheepdog trials. We investigated the influence of laterality on 15 sheepdogs’ (Canis familiaris) spontaneous turning motor pattern around a herd and on their [...] Read more.
Sheepdogs’ visuospatial abilities, their control of prey-driven behavior and their motor functions are essential characteristics for success in sheepdog trials. We investigated the influence of laterality on 15 sheepdogs’ (Canis familiaris) spontaneous turning motor pattern around a herd and on their behavior during the first encounter with sheep in a training session. The most relevant finding of this research was that the dogs displayed significantly more aggressive behavior toward the sheep when turning in a counterclockwise direction around the herd. Considering that in counterclockwise turns the sheep were in the dogs’ left visual hemifield, the high frequency of aggressions registered during counterclockwise turns suggests right hemisphere main activation. Overall, our results revealed the existence of a relationship between motor lateralization and aggressive behavior in dogs during sheepdog training and have practical implications for sheepdog training. Full article
(This article belongs to the Special Issue Left Versus Right Asymmetries of Brain and Behaviour)
Figures

Figure 1

Open AccessFeature PaperArticle A Dunkl–Type Generalization of Szász–Kantorovich Operators via Post–Quantum Calculus
Symmetry 2019, 11(2), 232; https://doi.org/10.3390/sym11020232 (registering DOI)
Received: 24 December 2018 / Revised: 7 February 2019 / Accepted: 11 February 2019 / Published: 15 February 2019
PDF Full-text (268 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, we define the (p,q)-variant of Szász–Kantorovich operators via Dunkl-type generalization generated by an exponential function and study the Korovkin-type results. We also obtain the convergence of our operators in weighted space by the modulus of [...] Read more.
In this paper, we define the ( p , q ) -variant of Szász–Kantorovich operators via Dunkl-type generalization generated by an exponential function and study the Korovkin-type results. We also obtain the convergence of our operators in weighted space by the modulus of continuity, Lipschitz class, and Peetre’s K-functionals. The extra parameter p provides more flexibility in approximation and plays an important role in symmetrizing these newly-defined operators. Full article
(This article belongs to the Special Issue Integral Transforms and Operational Calculus)
Open AccessArticle β–Hyers–Ulam–Rassias Stability of Semilinear Nonautonomous Impulsive System
Symmetry 2019, 11(2), 231; https://doi.org/10.3390/sym11020231 (registering DOI)
Received: 5 January 2019 / Revised: 7 February 2019 / Accepted: 9 February 2019 / Published: 15 February 2019
PDF Full-text (283 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, we study a system governed by impulsive semilinear nonautonomous differential equations. We present the β–Ulam stability, β–Hyers–Ulam stability and β–Hyers–Ulam–Rassias stability for the said system on a compact interval and then extended it to an unbounded interval. [...] Read more.
In this paper, we study a system governed by impulsive semilinear nonautonomous differential equations. We present the β –Ulam stability, β –Hyers–Ulam stability and β –Hyers–Ulam–Rassias stability for the said system on a compact interval and then extended it to an unbounded interval. We use Grönwall type inequality and evolution family as a basic tool for our results. We present an example to demonstrate the application of the main result. Full article
(This article belongs to the Special Issue Nonlinear, Convex, Nonsmooth, Functional Analysis in Symmetry)
Open AccessArticle Grey Regulatory Focus Theory Weighting Method for the Multi-Criteria Decision-Making Problem in Evaluating University Reputation
Symmetry 2019, 11(2), 230; https://doi.org/10.3390/sym11020230
Received: 26 December 2018 / Revised: 6 February 2019 / Accepted: 8 February 2019 / Published: 14 February 2019
Viewed by 104 | PDF Full-text (522 KB)
Abstract
Evaluating the reputation of higher institutions is important as a benchmark for the continuous development of universities. In multi-criteria decision-making (MCDM), the estimation of the criteria weight is significant in improving the accuracy of the evaluation results. However, criteria weights assigned by decision [...] Read more.
Evaluating the reputation of higher institutions is important as a benchmark for the continuous development of universities. In multi-criteria decision-making (MCDM), the estimation of the criteria weight is significant in improving the accuracy of the evaluation results. However, criteria weights assigned by decision makers (DMs) can be inaccurate when not measured from the orientations from which the DMs pursue their decision goals. This paper combines the grey system theory (GST) and regulatory focus theory (RFT) in estimating the weights of criteria by measuring the promotional and prevention focus orientations of the DMs and representing it as grey numbers. In this paper, we showed not all weight measurements from the DMs are symmetrical. In essence, to improve the accuracy of the MCDM weights, the grey regulatory focus theory (GRFT) weighting method is proposed to estimate the weights of an MCDM problem as well as aggregating the weights of the group DMs, thereby overcoming the limitation of a single orientation measurement. Furthermore, the GRFT weighting method is applied in ranking four universities in Xi’an city of China from a sample data from 1,200 students. The most reputable university is consistent with the other ranking indexes in the literature. Full article
(This article belongs to the Special Issue Multi-Criteria Decision Aid methods in fuzzy decision problems)
Figures

Graphical abstract

Open AccessArticle The Role of Strontium Enriched Hydroxyapatite and Tricalcium Phosphate Biomaterials in Osteoporotic Bone Regeneration
Symmetry 2019, 11(2), 229; https://doi.org/10.3390/sym11020229
Received: 30 December 2018 / Revised: 1 February 2019 / Accepted: 11 February 2019 / Published: 14 February 2019
Viewed by 94 | PDF Full-text (1878 KB)
Abstract
Background: Strontium (Sr) enriched biomaterials have been used to improve bone regeneration in vivo. However, most studies provide only two experimental groups. The aim of our study was to compare eleven different bone sample groups from osteoporotic and healthy rabbits’ femoral neck, as [...] Read more.
Background: Strontium (Sr) enriched biomaterials have been used to improve bone regeneration in vivo. However, most studies provide only two experimental groups. The aim of our study was to compare eleven different bone sample groups from osteoporotic and healthy rabbits’ femoral neck, as it is the most frequent osteoporotic fracture in humans. Methods: Osteoporotic bone defects were filled with hydroxyapatite 30% (HA) and tricalcium phosphate 70% (TCP), 5% Sr-enriched HA30/TCP70, HA70/TCP30, or Sr-HA70/TCP30 granules and were compared with intact leg, sham surgery and healthy non-operated bone. Expression of osteoprotegerin (OPG), nuclear factor kappa beta 105 (NFkB-105), osteocalcin (OC), bone morphogenetic protein 2/4 (BMP-2/4), collagen I (Col-1α), matrix metalloproteinase 2 (MMP-2), tissue inhibitor of matrix metalloproteinase 2 (TIMP-2), interleukin 1 (IL-1) and interleukin 10 (IL-10) was analyzed by histomorphometry and immunohistochemistry. Results: Our study showed that Sr-HA70/TCP30 induced higher expression of all above-mentioned factors compared to intact leg and even higher expression of OC, MMP-2 and NFkB-105 compared to Sr-HA30/TCP70. HA70/TCP30 induced higher level of NFkB-105 and IL-1 compared to HA30/TCP70. Conclusion: Sr-enriched biomaterials improved bone regeneration at molecular level in severe osteoporosis and induced activity of the factors was higher than after pure ceramic, sham or even healthy rabbits. Full article
(This article belongs to the Special Issue Biomaterials and Symmetry)
Open AccessArticle Parametric Fault Diagnosis of Analog Circuits Based on a Semi-Supervised Algorithm
Symmetry 2019, 11(2), 228; https://doi.org/10.3390/sym11020228
Received: 10 January 2019 / Revised: 6 February 2019 / Accepted: 12 February 2019 / Published: 14 February 2019
Viewed by 105 | PDF Full-text (2483 KB) | HTML Full-text | XML Full-text
Abstract
The parametric fault diagnosis of analog circuits is very crucial for condition-based maintenance (CBM) in prognosis and health management. In order to improve the diagnostic rate of parametric faults in engineering applications, a semi-supervised machine learning algorithm was used to classify the parametric [...] Read more.
The parametric fault diagnosis of analog circuits is very crucial for condition-based maintenance (CBM) in prognosis and health management. In order to improve the diagnostic rate of parametric faults in engineering applications, a semi-supervised machine learning algorithm was used to classify the parametric fault. A lifting wavelet transform was used to extract fault features, a local preserving mapping algorithm was adopted to optimize the Fisher linear discriminant analysis, and a semi-supervised cooperative training algorithm was utilized for fault classification. In the proposed method, the fault values were randomly selected as training samples in a range of parametric fault intervals, for both optimizing the generalization of the model and improving the fault diagnosis rate. Furthermore, after semi-supervised dimensionality reduction and semi-supervised classification were applied, the diagnosis rate was slightly higher than the existing training model by fixing the value of the analyzed component. Full article
(This article belongs to the Special Issue Symmetry in Engineering Sciences)
Figures

Figure 1

Open AccessArticle Estimating Efforts and Success of Symmetry-Seeing Machines by Use of Synthetic Data
Symmetry 2019, 11(2), 227; https://doi.org/10.3390/sym11020227
Received: 29 December 2018 / Revised: 4 February 2019 / Accepted: 11 February 2019 / Published: 14 February 2019
Viewed by 103 | PDF Full-text (623 KB)
Abstract
Representative input data are a necessary requirement for the assessment of machine-vision systems. For symmetry-seeing machines in particular, such imagery should provide symmetries as well as asymmetric clutter. Moreover, there must be reliable ground truth with the data. It should be possible to [...] Read more.
Representative input data are a necessary requirement for the assessment of machine-vision systems. For symmetry-seeing machines in particular, such imagery should provide symmetries as well as asymmetric clutter. Moreover, there must be reliable ground truth with the data. It should be possible to estimate the recognition performance and the computational efforts by providing different grades of difficulty and complexity. Recent competitions used real imagery labeled by human subjects with appropriate ground truth. The paper at hand proposes to use synthetic data instead. Such data contain symmetry, clutter, and nothing else. This is preferable because interference with other perceptive capabilities, such as object recognition, or prior knowledge, can be avoided. The data are given sparsely, i.e., as sets of primitive objects. However, images can be generated from them, so that the same data can also be fed into machines requiring dense input, such as multilayered perceptrons. Sparse representations are preferred, because the author’s own system requires such data, and in this way, any influence of the primitive extraction method is excluded. The presented format allows hierarchies of symmetries. This is important because hierarchy constitutes a natural and dominant part in symmetry-seeing. The paper reports some experiments using the author’s Gestalt algebra system as symmetry-seeing machine. Additionally included is a comparative test run with the state-of-the-art symmetry-seeing deep learning convolutional perceptron of the PSU. The computational efforts and recognition performance are assessed. Full article
(This article belongs to the Special Issue Visual Symmetry 2018)
Figures

Graphical abstract

Open AccessArticle Polynomial Decay Rate for Kirchhoff Type in Viscoelasticity with Logarithmic Nonlinearity and Not Necessarily Decreasing Kernel
Symmetry 2019, 11(2), 226; https://doi.org/10.3390/sym11020226
Received: 14 January 2019 / Revised: 25 January 2019 / Accepted: 12 February 2019 / Published: 14 February 2019
Viewed by 105 | PDF Full-text (317 KB) | HTML Full-text | XML Full-text
Abstract
This paper describes a polynomial decay rate of the solution of the Kirchhoff type in viscoelasticity with logarithmic nonlinearity, where an asymptotically-stable result of the global solution is obtained taking into account that the kernel is not necessarily decreasing. Full article
Open AccessArticle Bilateral Symmetry Strengthens the Perceptual Salience of Figure against Ground
Symmetry 2019, 11(2), 225; https://doi.org/10.3390/sym11020225
Received: 27 December 2018 / Revised: 5 February 2019 / Accepted: 12 February 2019 / Published: 14 February 2019
Viewed by 88 | PDF Full-text (1995 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Although symmetry has been discussed in terms of a major law of perceptual organization since the early conceptual efforts of the Gestalt school (Wertheimer, Metzger, Koffka and others), the first quantitative measurements testing for effects of symmetry on processes of Gestalt formation have [...] Read more.
Although symmetry has been discussed in terms of a major law of perceptual organization since the early conceptual efforts of the Gestalt school (Wertheimer, Metzger, Koffka and others), the first quantitative measurements testing for effects of symmetry on processes of Gestalt formation have seen the day only recently. In this study, a psychophysical rating study and a “foreground”-“background” choice response time experiment were run with human observers to test for effects of bilateral symmetry on the perceived strength of figure-ground in triangular Kanizsa configurations. Displays with and without bilateral symmetry, identical physically-specified-to-total contour ratio, and constant local contrast intensity within and across conditions, but variable local contrast polarity and variable orientation in the plane, were presented in a random order to human observers. Configurations with bilateral symmetry produced significantly stronger figure-ground percepts reflected by greater subjective magnitudes and consistently higher percentages of “foreground” judgments accompanied by significantly shorter response times. These effects of symmetry depend neither on the orientation of the axis of symmetry, nor on the contrast polarity of the physical inducers. It is concluded that bilateral symmetry, irrespective of orientation, significantly contributes to the, largely sign-invariant, visual mechanisms of figure-ground segregation that determine the salience of figure-ground in perceptually ambiguous configurations. Full article
(This article belongs to the Special Issue Visual Symmetry 2018)
Figures

Figure 1

Open AccessArticle Framework for a Symmetric Integration Approach
Symmetry 2019, 11(2), 224; https://doi.org/10.3390/sym11020224
Received: 26 December 2018 / Revised: 2 February 2019 / Accepted: 5 February 2019 / Published: 14 February 2019
Viewed by 67 | PDF Full-text (3609 KB) | HTML Full-text | XML Full-text
Abstract
An Application-to-Application integration framework in the cloud environment is proposed. The methodological demarche is developed using a data symmetry approach. Implementation aspects of integration considered the Open Data Protocol (OData) service as an integrator. An important issue in the cloud environment is to [...] Read more.
An Application-to-Application integration framework in the cloud environment is proposed. The methodological demarche is developed using a data symmetry approach. Implementation aspects of integration considered the Open Data Protocol (OData) service as an integrator. An important issue in the cloud environment is to integrate and ensure the quality of transferred and processed data. An efficient way of ensuring the completeness and integrity of data transferred between different applications and systems is the symmetry of data integration. With these considerations, the integration of SAP Hybris Cloud for Customer with S/4 HANA Cloud was implemented. Full article
Figures

Figure 1

Open AccessArticle The Non-Relativistic Limit of the DKP Equation in Non-Commutative Phase-Space
Symmetry 2019, 11(2), 223; https://doi.org/10.3390/sym11020223
Received: 11 December 2018 / Revised: 23 January 2019 / Accepted: 31 January 2019 / Published: 14 February 2019
Viewed by 91 | PDF Full-text (283 KB) | HTML Full-text | XML Full-text
Abstract
The non-relativistic limit of the relativistic DKP equation for both of zero and unity spin particles is studied through the canonical transformation known as the Foldy–Wouthuysen transformation, similar to that of the case of the Dirac equation for spin-1/2 particles. By considering only [...] Read more.
The non-relativistic limit of the relativistic DKP equation for both of zero and unity spin particles is studied through the canonical transformation known as the Foldy–Wouthuysen transformation, similar to that of the case of the Dirac equation for spin-1/2 particles. By considering only the non-commutativity in phases with a non-interacting fields case leads to the non-commutative Schrödinger equation; thereafter, considering the non-commutativity in phase and space with an external electromagnetic field thus leads to extract a phase-space non-commutative Schrödinger–Pauli equation; there, we examined the effect of the non-commutativity in phase-space on the non-relativistic limit of the DKP equation. However, with both Bopp–Shift linear transformation through the Heisenberg-like commutation relations, and the Moyal–Weyl product, we introduced the non-commutativity in phase and space. Full article
(This article belongs to the Special Issue Mathematical Physics and Symmetry)
Open AccessArticle EasyStego: Robust Steganography Based on Quick-Response Barcodes for Crossing Domains
Symmetry 2019, 11(2), 222; https://doi.org/10.3390/sym11020222
Received: 22 January 2019 / Revised: 4 February 2019 / Accepted: 12 February 2019 / Published: 14 February 2019
Viewed by 94 | PDF Full-text (1307 KB) | HTML Full-text | XML Full-text
Abstract
Despite greater attention being paid to sensitive-information leakage in the cyberdomain, the sensitive-information problem of the physical domain remains neglected. Anonymous users can easily access the sensitive information of other users, such as transaction information, health status, and addresses, without any advanced technologies. [...] Read more.
Despite greater attention being paid to sensitive-information leakage in the cyberdomain, the sensitive-information problem of the physical domain remains neglected. Anonymous users can easily access the sensitive information of other users, such as transaction information, health status, and addresses, without any advanced technologies. Ideally, secret messages should be protected not only in the cyberdomain but also in the complex physical domain. However, popular steganography schemes only work in the traditional cyberdomain and are useless when physical distortions of messages are unavoidable. This paper first defines the concept of cross-domain steganography, and then proposes EasyStego, a novel cross-domain steganography scheme. EasyStego is based on the use of QR barcodes as carriers; therefore, it is robust to physical distortions in the complex physical domain. Moreover, EasyStego has a large capacity for embeddable secrets and strong scalability in various scenarios. EasyStego uses an AES encryption algorithm to control the permissions of secret messages, which is more effective in reducing the possibility of sensitive-information leakage. Experiments show that EasyStego has perfect robustness and good efficiency. Compared with the best current steganography scheme based on barcodes, EasyStego has greater steganographic capacity and less impact on barcode data. In robustness tests, EasyStego successfully extracts secret messages at different angles and distances. In the case of adding natural textures and importing quantitative error bits, other related steganography techniques fail, whereas EasyStego can extract secret messages with a success rate of nearly 100%. Full article
(This article belongs to the Special Issue Information Technology and Its Applications 2018)
Figures

Figure 1

Open AccessArticle SAGBI Bases in G-Algebras
Symmetry 2019, 11(2), 221; https://doi.org/10.3390/sym11020221
Received: 10 January 2019 / Revised: 6 February 2019 / Accepted: 8 February 2019 / Published: 13 February 2019
Viewed by 106 | PDF Full-text (268 KB)
Abstract
In this article, we develop the theory of SAGBI bases in G-algebras and create a criterion through which we can check if a set of polynomials in a G-algebra is a SAGBI basis or not. Moreover, we will construct an algorithm [...] Read more.
In this article, we develop the theory of SAGBI bases in G-algebras and create a criterion through which we can check if a set of polynomials in a G-algebra is a SAGBI basis or not. Moreover, we will construct an algorithm to compute SAGBI bases from a subset of polynomials contained in a subalgebra of a G-algebra. Full article
(This article belongs to the Special Issue Mirror Symmetry and Algebraic Geometry)
Open AccessArticle The Second-Order Correction to the Energy and Momentum in Plane Symmetric Gravitational Waves Like Spacetimes
Symmetry 2019, 11(2), 220; https://doi.org/10.3390/sym11020220
Received: 5 December 2018 / Revised: 18 January 2019 / Accepted: 22 January 2019 / Published: 13 February 2019
Viewed by 109 | PDF Full-text (246 KB) | HTML Full-text | XML Full-text
Abstract
This research provides second-order approximate Noether symmetries of geodetic Lagrangian of time-conformal plane symmetric spacetime. A time-conformal factor is of the form eϵf(t) which perturbs the plane symmetric static spacetime, where ϵ is small a positive parameter that [...] Read more.
This research provides second-order approximate Noether symmetries of geodetic Lagrangian of time-conformal plane symmetric spacetime. A time-conformal factor is of the form e ϵ f ( t ) which perturbs the plane symmetric static spacetime, where ϵ is small a positive parameter that produces perturbation in the spacetime. By considering the perturbation up to second-order in ϵ in plane symmetric spacetime, we find the second order approximate Noether symmetries for the corresponding Lagrangian. Using Noether theorem, the corresponding second order approximate conservation laws are investigated for plane symmetric gravitational waves like spacetimes. This technique tells about the energy content of the gravitational waves. Full article
Open AccessFeature PaperArticle Starlike Functions Related to the Bell Numbers
Symmetry 2019, 11(2), 219; https://doi.org/10.3390/sym11020219
Received: 19 January 2019 / Revised: 8 February 2019 / Accepted: 12 February 2019 / Published: 13 February 2019
Viewed by 119 | PDF Full-text (315 KB) | HTML Full-text | XML Full-text
Abstract
The present paper aims to establish the first order differential subordination relations between functions with a positive real part and starlike functions related to the Bell numbers. In addition, several sharp radii estimates for functions in the class of starlike functions associated with [...] Read more.
The present paper aims to establish the first order differential subordination relations between functions with a positive real part and starlike functions related to the Bell numbers. In addition, several sharp radii estimates for functions in the class of starlike functions associated with the Bell numbers are determined. Full article
(This article belongs to the Special Issue Integral Transforms and Operational Calculus)
Open AccessFeature PaperArticle Normalized Weighted Bonferroni Harmonic Mean-Based Intuitionistic Fuzzy Operators and Their Application to the Sustainable Selection of Search and Rescue Robots
Symmetry 2019, 11(2), 218; https://doi.org/10.3390/sym11020218
Received: 11 January 2019 / Revised: 2 February 2019 / Accepted: 3 February 2019 / Published: 13 February 2019
Viewed by 109 | PDF Full-text (483 KB)
Abstract
In this paper, Normalized Weighted Bonferroni Mean (NWBM) and Normalized Weighted Bonferroni Harmonic Mean (NWBHM) aggregation operators are proposed. Besides, we check the properties thereof, which include idempotency, monotonicity, commutativity, and boundedness. As the intuitionistic fuzzy numbers are used as a basis for [...] Read more.
In this paper, Normalized Weighted Bonferroni Mean (NWBM) and Normalized Weighted Bonferroni Harmonic Mean (NWBHM) aggregation operators are proposed. Besides, we check the properties thereof, which include idempotency, monotonicity, commutativity, and boundedness. As the intuitionistic fuzzy numbers are used as a basis for the decision making to effectively handle the real-life uncertainty, we extend the NWBM and NWBHM operators into the intuitionistic fuzzy environment. By further modifying the NWBHM, we propose additional aggregation operators, namely the Intuitionistic Fuzzy Normalized Weighted Bonferroni Harmonic Mean (IFNWBHM) and the Intuitionistic Fuzzy Ordered Normalized Weighted Bonferroni Harmonic Mean (IFNONWBHM). The paper winds up with an empirical example of multi-attribute group decision making (MAGDM) based on triangular intuitionistic fuzzy numbers. To serve this end, we apply the IFNWBHM aggregation operator. Full article
Open AccessArticle 4D, N = 1 Matter Gravitino Genomics
Symmetry 2019, 11(2), 217; https://doi.org/10.3390/sym11020217
Received: 21 December 2018 / Revised: 21 January 2019 / Accepted: 6 February 2019 / Published: 13 February 2019
Viewed by 141 | PDF Full-text (605 KB)
Abstract
Adinkras are graphs that encode a supersymmetric representation’s transformation laws that have been reduced to one dimension, that of time. A goal of the supersymmetry “genomics” project is to classify all 4D, N=1 off-shell supermultiplets in terms of their adinkras. In [...] Read more.
Adinkras are graphs that encode a supersymmetric representation’s transformation laws that have been reduced to one dimension, that of time. A goal of the supersymmetry “genomics” project is to classify all 4D, N = 1 off-shell supermultiplets in terms of their adinkras. In previous works, the genomics project uncovered two fundamental isomer adinkras, the cis- and trans-adinkras, into which all multiplets investigated to date can be decomposed. The number of cis- and trans-adinkras describing a given multiplet define the isomer-equivalence class to which the multiplet belongs. A further refining classification is that of a supersymmetric multiplet’s holoraumy: the commutator of the supercharges acting on the representation. The one-dimensionally reduced, matrix representation of a multiplet’s holoraumy defines the multiplet’s holoraumy-equivalence class. Together, a multiplet’s isomer-equivalence and holoraumy-equivalence classes are two of the main characteristics used to distinguish the adinkras associated with different supersymmetry multiplets in higher dimensions. This paper focuses on two matter gravitino formulations, each with 20 bosonic and 20 fermionic off-shell degrees of freedom, analyzes them in terms of their isomer- and holoraumy-equivalence classes, and compares with non-minimal supergravity which is also a 20 × 20 multiplet. This analysis fills a missing piece in the supersymmetry genomics project, as now the isomer-equivalence and holoraumy-equivalence for representations up to spin two in component fields have been analyzed for 4D, N = 1 supersymmetry. To handle the calculations of this research effort, we have used the Mathematica software package called Adinkra.m. This package is open-source and available for download at a GitHub Repository. Data files associated with this paper are also published open-source at a Data Repository also on GitHub. Full article
(This article belongs to the Special Issue Supersymmetric Field Theory 2018)
Open AccessArticle A Novel Computational Technique for Impulsive Fractional Differential Equations
Symmetry 2019, 11(2), 216; https://doi.org/10.3390/sym11020216
Received: 24 December 2018 / Revised: 23 January 2019 / Accepted: 25 January 2019 / Published: 13 February 2019
Viewed by 109 | PDF Full-text (924 KB) | HTML Full-text | XML Full-text
Abstract
A computational technique for impulsive fractional differential equations is proposed in this paper. Adomian decomposition method plays an efficient role for approximate analytical solutions for ordinary or fractional calculus. Semi-analytical method is proposed by use of the Adomian polynomials. The method successively updates [...] Read more.
A computational technique for impulsive fractional differential equations is proposed in this paper. Adomian decomposition method plays an efficient role for approximate analytical solutions for ordinary or fractional calculus. Semi-analytical method is proposed by use of the Adomian polynomials. The method successively updates the initial values and gives the numerical solutions on different impulsive intervals. As one of the numerical examples, an impulsive fractional logistic differential equation is given to illustrate the method. Full article
(This article belongs to the Special Issue Symmetry and Complexity 2019)
Figures

Figure 1

Open AccessArticle MAIAD: A Multistage Asymmetric Information Attack and Defense Model Based on Evolutionary Game Theory
Symmetry 2019, 11(2), 215; https://doi.org/10.3390/sym11020215
Received: 30 November 2018 / Revised: 20 January 2019 / Accepted: 29 January 2019 / Published: 13 February 2019
Viewed by 98 | PDF Full-text (2030 KB) | HTML Full-text | XML Full-text
Abstract
With the rapid development and widespread applications of Internet of Things (IoT) systems, the corresponding security issues are getting more and more serious. This paper proposes a multistage asymmetric information attack and defense model (MAIAD) for IoT systems. Under the premise of asymmetric [...] Read more.
With the rapid development and widespread applications of Internet of Things (IoT) systems, the corresponding security issues are getting more and more serious. This paper proposes a multistage asymmetric information attack and defense model (MAIAD) for IoT systems. Under the premise of asymmetric information, MAIAD extends the single-stage game model with dynamic and evolutionary game theory. By quantifying the benefits for both the attack and defense, MAIAD can determine the optimal defense strategy for IoT systems. Simulation results show that the model can select the optimal security defense strategy for various IoT systems. Full article
(This article belongs to the Special Issue Symmetry in Computing Theory and Application)
Figures

Figure 1

Open AccessEditorial Brain Asymmetry of Structure and/or Function
Symmetry 2019, 11(2), 214; https://doi.org/10.3390/sym11020214
Received: 31 January 2019 / Accepted: 31 January 2019 / Published: 13 February 2019
Viewed by 94 | PDF Full-text (133 KB) | HTML Full-text | XML Full-text
Abstract
This book contains submissions to a Special Issue of Symmetry on the topic of brain asymmetry in humans (4 papers) and non-humans (7 papers) [...] Full article
(This article belongs to the Special Issue Brain Asymmetry of Structure and/or Function) Printed Edition available
Open AccessEditorial Emerging Approaches and Advances in Big Data
Symmetry 2019, 11(2), 213; https://doi.org/10.3390/sym11020213
Received: 31 January 2019 / Accepted: 31 January 2019 / Published: 13 February 2019
Viewed by 122 | PDF Full-text (128 KB) | HTML Full-text | XML Full-text
Abstract
This special issue of Symmetry entitled “Emerging Approaches and Advances in Big Data” consists of 17 papers [...] Full article
(This article belongs to the Special Issue Emerging Approaches and Advances in Big Data)
Open AccessReview Empirical Study of Software Defect Prediction: A Systematic Mapping
Symmetry 2019, 11(2), 212; https://doi.org/10.3390/sym11020212
Received: 3 January 2019 / Revised: 24 January 2019 / Accepted: 2 February 2019 / Published: 13 February 2019
Viewed by 89 | PDF Full-text (2433 KB) | HTML Full-text | XML Full-text
Abstract
Software defect prediction has been one of the key areas of exploration in the domain of software quality. In this paper, we perform a systematic mapping to analyze all the software defect prediction literature available from 1995 to 2018 using a multi-stage process. [...] Read more.
Software defect prediction has been one of the key areas of exploration in the domain of software quality. In this paper, we perform a systematic mapping to analyze all the software defect prediction literature available from 1995 to 2018 using a multi-stage process. A total of 156 studies are selected in the first step, and the final mapping is conducted based on these studies. The ability of a model to learn from data that does not come from the same project or organization will help organizations that do not have sufficient training data or are going to start work on new projects. The findings of this research are useful not only to the software engineering domain, but also to the empirical studies, which mainly focus on symmetry as they provide steps-by-steps solutions for questions raised in the article. Full article
Figures

Figure 1

Symmetry EISSN 2073-8994 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top