Numerical periodic normalization for codim 2 bifurcations of limit cycles : computational formulas, numerical implementation, and examples

Explicit computational formulas for the coefficients of the periodic normal forms for codimension 2 (codim 2) bifurcations of limit cycles in generic autonomous ODEs are derived. All cases (except the weak resonances) with no more than three Floquet multipliers on the unit circle are covered. The resulting formulas are independent of the dimension of the phase space and involve solutions of certain boundary-value problems on the interval [0, T], where T is the period of the critical cycle, as well as multilinear functions from the Taylor expansion of the ODE right-hand side near the cycle. The formulas allow one to distinguish between various bifurcation scenarios near codim 2 bifurcations of limit cycles. Our formulation makes it possible to use robust numerical boundary-value algorithms based on orthogonal collocation, rather than shooting techniques, which greatly expands its applicability. The implementation is described in detail with numerical examples, where numerous codim 2 bifurcations of limit cycles are analyzed for the first time

Estimasi Value-at-Risk Dengan Pendekatan Extreme Value Theory-Generalized Pareto Distribution (STUDI KASUS IHSG 1997-2004)

Dalam paper ini, akan diperkenalkan suatu metode dalam perhitungan VaR yaitu VaR-GPD. Kelebihan metode ini adalah pendekatannya bahwa data mengikuti distribusi GPD (Generalized Pareto Distribution) yang mengakomodasi bentuk distribusi empiris data yang cenderung memiliki ekor gemuk (heavy tail). Kata kunci: Extreme value theory, Generalized Pareto distribution, Value at ris

Grand narratives then and now: can we still conceptualise history?

Reading the Communist Manifesto today, it is impossible not to be struck by the confidence with which it conceptualises history. The positive energy of this bold grand narrative stands in such stark contrast to the negative and jaded mentality of our times, which conceives of grand narratives only to tell us that there can be none. Such talk as there is of history today is more likely to be of "the end of history". There are three senses in which references to the end of history feature in contemporary debates: apocalyptic prediction, postmodernist pronouncement and capitalist triumphalism. This paper addresses the crisis of historicity in our time in relation to these positions and asks what is it about our age that produces them. It explores the widespread rejection of grand narratives, as well as grand narratives, which nevertheless persist, implicit and explicit, right and left. It looks at the position of marxism in the 1990s, counterposing it to postmarxism and postmodernism in particular on the question of grand narratives. It calls for resistance to the detotalising pressures of the age and revival of a totalising (as opposed to totalised) philosophy of history

Chandra Observation of the Edge-on Spiral NGC 5775: Probing the Hot Galactic Disk/Halo Connection

We study the edge-on galaxy NGC 5775, utilizing a 58.2 ks {\sl Chandra} ACIS-S observation together with complementary {\sl HST} ACS, {\sl Spitzer} IRAC and other multi-wavelength data sets. This edge-on galaxy, with its disk-wide active star formation, is particularly well-suited for studying the disk/halo interaction on sub-galactic scales. We detect 27 discrete X-ray sources within the $D_{25}$ region of the galaxy, including an ultra-luminous source with a 0.3-7 keV luminosity of $\sim7\times10^{40}\rm ergs s^{-1}$. The source-removed diffuse X-ray emission shows several prominent extraplanar features, including a $\sim10\rm kpc$ diameter ``shell-like'' feature and a ``blob'' reaching a projected distance of $\sim25\rm kpc$ from the galactic disk. The bulk of the X-ray emission in the halo has a scale height of $\sim$1.5 kpc and can be characterized by a two-temperature optically thin thermal plasma with temperatures of $\sim$ 0.2 and 0.6 keV and a total 0.3-2 keV luminosity of $\sim3.5\times10^{39}\rm ergs s^{-1}$. The high-resolution, multi-wavelength data reveal the presence of several extraplanar features around the disk, which appear to be associated with the in-disk star formation. We suggest that hot gas produced with different levels of mass loading can have different temperatures, which may explain the characteristic temperatures of hot gas in the halo. We have obtained a sub-galactic scale X-ray-intensity-star formation relation, which is consistent with the integrated version in other star forming galaxies.Comment: 25 pages, 10 figures, 4 tables, accepted for publication in MNRA

Multi-sensor analysis of extreme events in North-Eastern Italy

International audienceThe North-eastern part of Italy is known to be one of the most rainy regions in Europe. In this paper three extreme events are analysed, using a multi-sensor observing system including a weather radar and a dense telemetric network of surface stations, recording precipitation, wind, temperature and relative humidity. The cases examined comprise two long lasting rainfall events impacting two distinct areas, and a vigorous hail-producing thunderstorm event over the plains. In all cases, inter-comparison between remotely sensed and surface observations, including estimates and measures of precipitation and wind, helps to better understand the behaviour of the atmosphere, thus supporting operational fore- and now-casting. In the case of widespread precipitation, a relation is suggested between the wind speed and direction at medium/low levels with the location of the maximum precipitation relative to the mountains. This reflects the dynamical interaction between the mountain barrier and the atmospheric flux impinging upon it. This flux can be estimated by the automatic weather station of Mt. Cesen, a focal point for a now-casting of the rain in the Veneto Region. Analysis of strong thunderstorm activity makes extensive use of radar data. In the examined case the interaction of a sea breeze-like circulation with a mesoscale trough gave rise to a distinct convergence line that triggered a severe and long-lived hail-producing multi-cell thunderstorm. The hail was successfully detected by the radar's hail detection algorithm

Pengaruh Orientasi Pasar, Orientasi Kewirausahaan terhadap Keunggulan Bersaing dan Kinerja Pemasaran pada Warung Kucingan/angkringan di Kota Semarang

Penelitian ini bertujuan untuk mengetahui pengaruh orientasi pasar, orientasi kewirausahaan terhadap keunggulan bersaing dan kinerja pemasaran pada warung kucingan (angkringan) di kota Semarang.Tipe penelitian yang digunakan adalah explanatory research. Sampel dalam penelitian ini adalah 100 orang responden yang menjadi pemilik warung kucingan/angkringan yang diambil secara inccidental sampling. Pengumpulan datanya dilakukan dengan menggunakan kuesioner. Analisis yang digunakan adalah analisis regresi linier berganda, dimana X1 menunjuk pada variable orientasi pasar, X2 pada orientasi kewirausahaan, Y1 pada keunggulan bersaing, dan Y2 pada kinerja pemasaran.Berdasarkan hasil penelitian disimpulkan bahwa orientasi pasar dan orientasi kewirausahaan berpengaruh positif dan signifikan terhadap keunggulan bersaing dan kinerja pemasaran. Orientasi pasar dan orientasi kewirausahaan yang lebih baik akan meningkatkan keunggulan bersaing dan kinerja pemasaran. Keunggulan bersaing berpengaruh positif dan signifikan terhadap kinerja pemasaran

New development of a Radiation-Hard Polycrystalline CdTe Detector for LHC Luminosity Monitoring

Detectors presently considered for monitoring and control of the LHC luminosity will sample the hadronic/electromagnetic showers produced by neutrons and photons in copper absorbers designed to protect the superconducting magnets from quenching. At this location the detectors will have to withstand extreme radiation levels and their long term operation will have to be assured without requiring human intervention. For this application we have successfully tested thick polycrystalline-CdTe detectors. The paper summarizes the results obtained on rise-times, sensitivity and resistance to neutron irradiation up to a dose of 10 ^15/cm 2

Imaging Fabry-Perot Spectroscopy of NGC 5775: Kinematics of the Diffuse Ionized Gas Halo

We present imaging Fabry-Perot observations of Halpha emission in the nearly edge-on spiral galaxy NGC 5775. We have derived a rotation curve and a radial density profile along the major axis by examining position-velocity (PV) diagrams from the Fabry-Perot data cube as well as a CO 2-1 data cube from the literature. PV diagrams constructed parallel to the major axis are used to examine changes in azimuthal velocity as a function of height above the midplane. The results of this analysis reveal the presence of a vertical gradient in azimuthal velocity. The magnitude of this gradient is approximately 1 km/s/arcsec, or about 8 km/s/kpc, though a higher value of the gradient may be appropriate in localized regions of the halo. The evidence for an azimuthal velocity gradient is much stronger for the approaching half of the galaxy, although earlier slit spectra are consistent with a gradient on both sides. There is evidence for an outward radial redistribution of gas in the halo. The form of the rotation curve may also change with height, but this is not certain. We compare these results with those of an entirely ballistic model of a disk-halo flow. The model predicts a vertical gradient in azimuthal velocity which is shallower than the observed gradient, indicating that an additional mechanism is required to further slow the rotation speeds in the halo.Comment: 18 pages, 18 figures. Uses emulateapj.cls. Accepted for publication in Ap

Comment on "water-Soluble Fluorescent Probe with Dual Mitochondria/Lysosome Targetability for Selective Superoxide Detection in Live Cells and in Zebrafish Embryos"

Recently, a new water-soluble, fluorescein-based probe for the detection of superoxide radical anion in aqueous media was developed by Lu et al. (ACS Sens. 2018, 3, 59-64). The probe was proven to be selective for superoxide and was used successfully also in cells and zebrafish embryos. To characterize the response of the probe to superoxide, Lu et al. used KO2 dissolved in deionized water as a surrogate. In testing this probe in different applications, we repeated some of these experiments and came to realize that the fluorescence signal observed by the Authors in their experiments with KO2 was incorrectly attributed to the reaction of the probe with superoxide and is due instead to its reactions with HO- and HO2-. We show that indeed under the conditions used in these assays KO2 undergoes very fast reaction with water to form HO- and HO2-. On the other hand, by using a proper surrogate, namely, KO2 dissolved in DMSO, and spin trapping experiments, we confirmed the ability of the probe to detect superoxide