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On the stability of solitary wave solutions for a generalized fractional Benjamin–Bona–Mahony equation
No full textIn this paper we establish a rigorous spectral stability analysis for solitary waves associated to a generalized fractional Benjamin-Bona-Mahony type equation. Besides the well known smooth and positive solitary wave with large wave speed, we present the existence of smooth negative solitary waves having small wave speed. The spectral stability is then determined by analysing the behaviour of the associated linearized operator around the wave restricted to the orthogonal of the tangent space related to the momentum at the solitary wave. Since the analytical solution is not known, we generate the negative solitary waves numerically by using Petviashvili method. We also present some numerical experiments to observe the stability properties of solitary waves for various values of the order of nonlinearity and fractional derivative. Some remarks concerning the orbital stability are also celebrated.TÜBİTA
NTIRE 2022 challenge on night photography rendering
No full textThis paper reviews the NTIRE 2022 challenge on night photography rendering. The challenge solicited solutions that processed RAW camera images captured in night scenes to produce a photo-finished output image encoded in the standard RGB (sRGB) space. Given the subjective nature of this task, the proposed solutions were evaluated based on the mean opinions of viewers asked to judge the visual appearance of the results. Michael Freeman, a world-renowned photographer, further ranked the solutions with the highest mean opinion scores. A total of 13 teams competed in the final phase of the challenge. The proposed methods provided by the participating teams represent state-of-the-art performance in nighttime photography.Croatian Science Foundation ; Huawei Technologies ; Reality Labs ; Bending Spoons ; MediaTe
Discrete phase analysis of self heating particles over an immersion liquid cooled high power blue light-emitting diode with suspended phosphor particles
No full textIn recent years, the interaction of unrestricted particles with dispersed multiphase flows has been linked to a number of important engineering applications. Among these applications, the novel idea of immersion-cooled phosphor particles, which has the potential of significantly increasing the thermal limits of phosphor converted white light-emitting diode (LEDs) (Pc-WLEDs), has yet to be thoroughly investigated. With this objective, this research utilizes the discrete phase modeling (DPM) technique for the characterization of phosphor location and movements within a buoyancy-driven flow, which is the determining factor in the optical behavior of the newly proposed Pc-WLED configuration. Two-phase flow analysis is conducted to characterize particle movement. Heat transfer, flow, and energy paths of self-heating phosphor particles are extracted, and the influence of particle sizes is analyzed in detail. The results show that with immersion liquid cooling, the highest phosphor particle temperature is recorded to be under 420 K, while larger size particles introduce higher heat transfer rates to the Pc-WLED package for the same number of particles. Moreover, depending on the particle size and position, individual phosphor particles can follow a different trajectory that can affect the probability of obtaining white light emission.TÜBİTA
Summary of an effective formulation of the multi-criteria test suite minimization problem
No full textThis is an extended abstract of the article: Okan Orsan Ozener and Hasan Sozer, 'An Effective Formulation of the Multi-Criteria Test Suite Minimization Problem', published in the Journal of Systems and Software, Vol. 168, pp. 110632, 2020. https://doi.org/10.1016/j.jss.2020.110632
Modifications on the properties of (2317) as four-quark state in thermal medium
No full textThe low mass of Ds∗0(2317) presents problems for the conventional quark model, leading to consideration of other options regarding a multi-quark system. Here, we investigate the scalar open-charm state Ds∗0(2317) and its bottom partner by the Thermal QCD Sum Rules (TQCDSR) method using the two-point correlation function with contributions of the nonperturbative condensates up to dimension six. Our calculations indicate that the variations in mass and decay constant values are stable through temperatures up to T ∼= 100 MeV and fall after this point. At the critical temperature, the values of mass and decay constant change up to 94%, 71% of their values in vacuum in the molecular scenario, and 94%, 75% in the diquark–antidiquark scenario. Besides, we find more dramatic changes in mass and decay constant above Tc, and hence we interpret it as the hadrons starting to disappear. Also, the detailed search for hot medium effects on the hadronic parameters of open-charm meson Ds∗0(2317) and the bottom partner may have implications for the QCD phase diagram derived from heavy-ion collision experiments. Finally, these results may help distinguish conventional quark model mesons from exotic states.Publisher versio
Indulgence and risk-taking behavior of firms: Direct and interactive influences
No full textThis study examines the impact of Hofstede's indulgence vs restraint national culture dimension (IVR) on firms' risk-taking behavior. We argue that firms in more indulgent societies will show greater risk-taking behavior given their tendencies to be less rigid and their greater inclination for discounting risk-taking losses. We further argue that the buffers that slack resources provide against risk-taking losses and the positive expectations of potential gains from risk-taking provided by growth opportunities will further increase firms' risk-taking behavior when interacting with indulgence mechanisms. Our findings from a 37-country study support these arguments. They show that high indulgence does increase firms' risk-taking behavior and slack resources and growth opportunities intensify this causal effect. Tests of three-way interactions further reveal that the positive impact of indulgence on firms' risk-taking behavior is strongest when both slack resources are abundant and the growth opportunities are high. We extend current knowledge about culture's effect on firm behavior
A pilot project for power quality improvements in distribution system by a Li-ion battery
No full textPower quality (PQ) metrics deterioration occurs in the distribution system by increasing the distributed generation plants, the existence of non-linear and harmonic loads. As a distribution system operator running under the Turkishelectricity regulation, a battery investment was made to improve PQ metrics to provide quality electricity service to customers by focusing on Volt/VAr optimization to obtain voltage stability parameters. The reverse power flow caused by the distributed generation can be eliminated and the power factor would be improved with the reactive support with this investment. This study includes the reasons for the battery pilot project, the engineering methodology, and post-solution improvements
Design and analysis of a continuous optoelectronic pulse wave velocity blood pressure sensor with multiple-subject controlled experiments
No full textGoal: The main purpose of this study is to perform the pulse wave velocity (PWV) measurements with a new noninvasive optoelectronic continuous-time wearable sensor design and to analyze the quantitative relation between the reference blood pressure (BP) measurement. Methods: PWV was measured at baseline 32 normotensive volunteers, including 15 females and 17 males aged between 23 and 41 years old. The day before the measurements, the volunteers were not allowed to drink alcohol, stay up late or use any medicine that would affect BP. Repeated BP measurements were performed with an average follow-up system at certain times of the day. Results: Equivalent constituents were established after questioning age, height, weight, physical activity levels in daily life, genetic predisposition for blood pressure and diabetic from all volunteers participating in the measurements. Systolic BP (SBP), diastolic BP (DBP), heart rate (HR), pulse pressure (PP), mean arterial pressure (MAP), distance between brachial to radial artery (D), pulse transit time between brachial to radial artery (brPTT) and PWV measurements were all collected to correlate results with the introduced sensor's readings. Following the experimental results, a linear link was found between SBP and PWV when the two groups separated by gender related were examined and the correlation coefficients between them were r: 0.9915 in females and r: 0.9845 in males Conclusion: Measurements taken with the new non-invasive low-power continuous-time sensor design show that the PWV may in the near future be used as a screening tool to identify continuous SBP values in clinical practice. Significance: The new non-invasive design suggests that SBP has the strongest correlation with PWV among a variety of BP parameters.Mert Karaca of Microelectronics La
Lower uncertainty bounds of diffraction-based nanoparticle sizes
No full textA self-consistent analysis is reported of traditional diffraction-based particle size determination techniques applied to synthetic diffraction profiles generated with the Patterson approach. The results show that dimensions obtained from traditional techniques utilizing peak fitting or Fourier analysis for single-crystal nanoparticles have best-case error bounds of around 5%. For arbitrarily shaped particles, lower error magnitudes are possible only if the zeroes of the thickness fringes are used. The errors for sizes obtained by integral-breadth-And Fourier-decomposition-based techniques depend on the shape of the diffracting domains. In the case of integral-breadth analysis, crystal shapes which scatter more intensity into the central peak of the rocking curve have lower size errors. For Fourier-decomposition analysis, crystals which have non-uniform distributions of chord lengths exhibit nonlinearities in the initial ranges of the normalized Fourier cosine coefficient versus column length (|A L | versus L) plots, even when the entire rocking curve is used in the decomposition. It is recommended that, in routine analysis, all domain size determination techniques should be applied to all reflections in a diffraction pattern. If there is significant divergence among these results, the 'average particle size(s)' obtained might not be reliable.TÜBİTAKPublisher versio
Distributed decision trees
No full textIn a budding tree, every node is part internal node and part leaf. This allows representing the tree in a continuous parameter space and training it with backpropagation, like a neural network. Unlike a traditional tree whose construction is composed of two distinct stages of growing and pruning, “bud” nodes grow into subtrees or are pruned back dynamically during learning. In this work, we extend the budding tree and propose the distributed tree where the children use different and independent splits; hence, multiple paths in a tree can be traversed at the same time. In a traditional tree, the learned representations are local, that is, activation makes a soft selection among all the root-to-leaf paths in a tree, but the ability to combine multiple paths of the distributed tree gives it the power of a distributed representation, as in a traditional perceptron layer. Our experimental results show that distributed trees perform comparably or better than budding and traditional hard trees