Nonlinear supratransmission in multicomponent systems

A method is proposed to solve the challenging problem of determining the supratransmission threshold (onset of instability of harmonic boundary driving inside a band gap) in multicomponent nonintegrable nonlinear systems. It is successfully applied to the degenerate three-wave resonant interaction in a birefringent quadratic medium where the process generates spatial gap solitons. No analytic expression is known for this model showing the broad applicability of the method to nonlinear systems.Comment: 4 pages, 3 figure

Cross-Racial Misidentification: A Call to Action in Washington State and Beyond

Research indicates eyewitness identifications are incorrect approximately one-third of the time in criminal investigations. For years, this phenomenon has significantly contributed to wrongful convictions all over the country, including in Washington State. But jurors, attorneys, and police remain unaware of the nature and extent of the problem and continue to give undue weight to eyewitness evidence. Experts have estimated that approximately 5,000–10,000 felony convictions in the United States each year are wrongful, and research suggests that approximately 75% of wrongful convictions involve eyewitness misidentification. The phenomenon of eyewitness misidentification is also amplified and most troublesome in the context of cross-racial identification—when a witness identifies someone of another race. Experimental research suggests that an eyewitness trying to identify a stranger is over 50% more likely to make a misidentification when the stranger and eyewitness are of different races. Consistent with this finding, approximately one-third of wrongful convictions uncovered by DNA analysis nationwide have involved whites misidentifying blacks. For these reasons, this Article focuses on cross-racial misidentification, and discusses the nature and extent of the problem and potential tools for addressing it; however, this Article’s reasoning applies in large part to eyewitness misidentification in general. The Washington State Supreme Court had two recent opportunities to address the issue of cross-racial misidentification in State v. Cheatam and State v. Allen. These cases establish that Washington State trial courts have broad discretion to permit expert testimony and jury instruction on cross-racial misidentification when relevant. In light of this precedent, this Article proposes that Washington State trial courts begin exercising their broad discretion regularly to admit such testimony and instruction whenever relevant as an initial step toward preventing wrongful convictions and improving our criminal justice system. Going forward, additional education and reform efforts will be needed to solve this ongoing problem

Localized Faraday patterns under heterogeneous parametric excitation

Faraday waves are a classic example of a system in which an extended pattern emerges under spatially uniform forcing. Motivated by systems in which uniform excitation is not plausible, we study both experimentally and theoretically the effect of heterogeneous forcing on Faraday waves. Our experiments show that vibrations restricted to finite regions lead to the formation of localized subharmonic wave patterns and change the onset of the instability. The prototype model used for the theoretical calculations is the parametrically driven and damped nonlinear Schr\"odinger equation, which is known to describe well Faraday-instability regimes. For an energy injection with a Gaussian spatial profile, we show that the evolution of the envelope of the wave pattern can be reduced to a Weber-equation eigenvalue problem. Our theoretical results provide very good predictions of our experimental observations provided that the decay length scale of the Gaussian profile is much larger than the pattern wavelength.Comment: 10 pages, 9 figures, Accepte

Implementation of the Integrated TOD Spatial Model for Jakarta Metropolitan Region

Jakarta Metropolitan Region (JMR) is the biggest megacity urban areas in Indonesia. However,theexistingpublictransportfacilitiesarenotadequatelyfulfillingthedemand ofitsinhabitant.Therefore,itisimportantforovercomingthoseissueswithshedlighton the integration of spatial and transportation by applying Transit Oriented Development (TOD) model. The method of this paper using the spatial and transportation approach by differentiates TOD each railway stations based on the typology. The results were that the TOD spatial model is focusing on solving public transport issues related to urban planning. Therefore, certain policy from stakeholders for this region greatly encourages transport planning in a more sustainable manner

Simplex-Coded BOTDA Sensor Over 120 km SMF with 1 m Spatial Resolution Assisted by Optimized Bidirectional Raman Amplification

Bidirectional low-noise Raman amplification and simplex coding based on the return-to-zero modulation format are optimized through numerical simulations for long-range Brillouin optical time-domain analysis sensing. Experimental results are reported on sensing capabilities along 120-km distance with 1-m spatial resolution, and worst-case temperature and strain resolution values of 1.3 °C and 26 με, respectively

New Seiberg Dualities from N=2 Dualities

We propose a number of new Seiberg dualities of N=1 quiver gauge theories. The new Seiberg dualities originate in new S-dualities of N=2 superconformal field theories recently proposed by Gaiotto. N=2 S-dual theories deformed by suitable mass terms flow to our N=1 Seiberg dual theories. We show that the number of exactly marginal operators is universal for these Seiberg dual theories and the 't Hooft anomaly matching holds for these theories. These provide strong evidence for the new Seiberg dualities. Furthermore, we study in detail the Klebanov-Witten type theory and its dual as a concrete example. We show that chiral operators and their non-linear relations match between these theories. These arguments also give non-trivial consistency checks for our proposal.Comment: 31 pages, 7 figures. v2:version to appear in JHE

Optical fiber systems are convectively unstable

We theoretically and experimentally evidence that fiber systems are convective systems since their nonlocal inherent properties, such as the dispersion and Raman effects, break the reflection symmetry. Theoretical analysis and numerical simulations carried out for a fiber ring cavity demonstrate that the third-order dispersion term leads to the appearance of convective and absolute instabilities. Their signature is an asymmetry in the output power spectrum. Using this criterion, experimental evidence of convective instabilities is given in a fiber cavity pumped by a pulsed laser

Macdonald operators and homological invariants of the colored Hopf link

Using a power sum (boson) realization for the Macdonald operators, we investigate the Gukov, Iqbal, Kozcaz and Vafa (GIKV) proposal for the homological invariants of the colored Hopf link, which include Khovanov-Rozansky homology as a special case. We prove the polynomiality of the invariants obtained by GIKV's proposal for arbitrary representations. We derive a closed formula of the invariants of the colored Hopf link for antisymmetric representations. We argue that a little amendment of GIKV's proposal is required to make all the coefficients of the polynomial non-negative integers.Comment: 31 pages. Published version with an additional appendi