Symmetry2015, 7(2), 383-394; doi:10.3390/sym7020383 - published 17 April 2015 Show/Hide Abstract
Abstract: Internet Communication Technologies (ICTs) are making progress day by day, driven by the relentless need to utilize them for everything from leisure to business. This inevitable trend has dramatically changed contemporary digital behavior in all aspects. Undoubtedly, digital fingerprints will be at some point unwarily left on crime scenes creating digital information security incidents. On the other hand, corporates in the private sector or governments are on the edge of being exploited in terms of confidential digital information leakages. Some digital fingerprinting is volatile by its nature. Alternatively, once the power of computing devices is no longer sustainable, these digital traces could disappear forever. Due to the pervasive usage of Google Calendar and Safari browser among network communities, digital fingerprinting could be disclosed if forensics is carried out in a sound manner, which could be admitted in a court of law as probative evidences concerning certain cybercrime incidents.
Symmetry2015, 7(2), 376-382; doi:10.3390/sym7020376 - published 16 April 2015 Show/Hide Abstract
Abstract: In order to prevent drug abuse or misuse cases and avoid over-prescriptions, it is necessary for medicine taker to be provided with detailed information about the medicine. In this paper, we propose a drug information system and develop an application to provide information through drug image recognition using a smartphone. We designed a contents-based drug image search algorithm using the color, shape and imprint of drug. Our convenient application can provide users with detailed information about drugs and prevent drug misuse.
Symmetry2015, 7(2), 365-375; doi:10.3390/sym7020365 - published 13 April 2015 Show/Hide Abstract
Abstract: A link diagram is said to be (orientedly) everywhere equivalent if all the diagramsobtained by switching one crossing represent the same (oriented) link. We classify suchdiagrams of two components.
Symmetry2015, 7(2), 354-364; doi:10.3390/sym7020354 - published 9 April 2015 Show/Hide Abstract
Abstract: Fractal symmetry is symmetry across scale. If one looks at a branch of a tree its branching pattern is reminiscent of the tree as a whole. Plants exhibit a number of different symmetries, including bilateral, rotational, translational, and fractal; deviations from each of these types has been associated with organisms developing in stressful environments. Here, we explore the utilization and meaning of fractal analysis on annual growth ring production in woody plants. Early detection of stress in plants is difficult and the compounding effects of multiple or severe stressors can lead to irreversible damage or death. Annual wood production was used to produce a time series for individuals from stands classified as either high vigor or low vigor (a general measure of health). As a measure of symmetry over time, the fractal dimension of each time series was determined and compared among vigor classes. We found that individuals obtained from low vigor sites had a significantly lower fractal dimension than those from high vigor sites. These results agree with patterns found in a variety of other organisms, and we argue that the reduced fractal dimension is related to a loss in system complexity of stressed individuals.
Symmetry2015, 7(2), 336-353; doi:10.3390/sym7020336 - published 3 April 2015 Show/Hide Abstract
Abstract: The visual system is sensitive to symmetries in the frontoparallel plane, and bilateral symmetry about a vertical axis has a particular salience. However, these symmetries represent only a subset of the symmetries realizable in three-dimensional space. The retinal image symmetries formed when viewing natural objects are typically the projections of three-dimensional objects—animals, for example—that have a symmetry in depth. To characterize human sensitivity to depth symmetry, experiments measured observers’ ability to discriminate stereo displays that were symmetrically distributed in depth and those that were asymmetrically distributed. Disparity values were distributed about one of four planes passing through the z-axis and differing in frontoparallel orientation. Asymmetrical patterns were generated by perturbing one of these disparities. Symmetrical-asymmetrical discrimination thresholds were lowest for symmetry about the vertical plane and highest for the horizontal plane. Thresholds for discriminating repetitions and non-repetitions of depth values did not differ across the four planes, whereas discriminations for depth gradients differed from both the symmetry and repetition cases. The heightened sensitivity to symmetry in depth about the vertical plane is a 3-D analog of 2-D mirror-image symmetry performance and could be its source.
Symmetry2015, 7(2), 327-335; doi:10.3390/sym7020327 - published 1 April 2015 Show/Hide Abstract
Abstract: Two principal methods are commonly employed for the estimation of developmental instability at the population level. Some studies use variances of morphological traits (σ2p), while others use fluctuating asymmetry (FA). In both cases, differences in the degree of developmental instability can be tested with an F-test, which is the most common way to compare variances. However, the variance is expected to scale proportionally to the square of the mean as there is a tendency in biological data for σ2p to scale proportionally to the square of the mean ( ): σ2p = Zξ, where ξ is the scaling exponent, which is expected to be two for pure statistical reasons, is the mean of the trait and Z is a measure of individual-level variability. Because of this scaling effect, the fluctuating asymmetry will be affected, FA is estimated as the variance between the right and the left sides of a trait (σ2r − l = σ2r + σ2l − 2rσrσl), where σ2r and σ2l are the variances of the right and the left trait values, respectively. In this paper, we propose a novel method that allows an exact correction of the scaling effect, which will enable a proper comparison of the degree of fluctuating asymmetry for a trait. The problem of the scaling of the FA with the trait size is quite crucial if FA is to be considered an indicator of fitness or an indicator of environmental or genetic stress, as different stresses or fitness levels are typically accompanied by a change of the traits’ .