9,615 research outputs found
Envelope Expansion with Core Collapse. III. Similarity Isothermal Shocks in a Magnetofluid
We explore MHD solutions for envelope expansions with core collapse (EECC)
with isothermal MHD shocks in a quasi-spherical symmetry and outline potential
astrophysical applications of such magnetized shock flows. MHD shock solutions
are classified into three classes according to the downstream characteristics
near the core. Class I solutions are those characterized by free-fall collapses
towards the core downstream of an MHD shock, while Class II solutions are those
characterized by Larson-Penston (LP) type near the core downstream of an MHD
shock. Class III solutions are novel, sharing both features of Class I and II
solutions with the presence of a sufficiently strong magnetic field as a
prerequisite. Various MHD processes may occur within the regime of these
isothermal MHD shock similarity solutions, such as sub-magnetosonic
oscillations, free-fall core collapses, radial contractions and expansions. We
can also construct families of twin MHD shock solutions as well as an
`isothermal MHD shock' separating two magnetofluid regions of two different yet
constant temperatures. The versatile behaviours of such MHD shock solutions may
be utilized to model a wide range of astrophysical problems, including star
formation in magnetized molecular clouds, MHD link between the asymptotic giant
branch phase to the proto-planetary nebula phase with a hot central magnetized
white dwarf, relativistic MHD pulsar winds in supernova remnants, radio
afterglows of soft gamma-ray repeaters and so forth.Comment: 21 pages, 33 figures, accepted by MNRA
“PEMBUATAN ANIMASI NON-HUMAN CHARCTER PADA GAME MENGUNAKAN TEKNIK ANIMASI FRAME BY FRAME”
Game merupakan salah satu media hiburan yang paling banyak digemari pada saat ini. Game dapat
dimainkan oleh siapa saja baik anak-anak maupun orang dewasa, tergantung dari jenis game yang dipilih. Game
yang mempunyai game world yang baik akan mempengaruhi minat dari pemain untuk memainkan game tersebut.
Tugas Akhir ini berfokus pada pembuatan animasi non-human character pada game Cookurubukan meliputi
animasi yang 2D look. Animasi pada game Cookurubukan dibuat dengan menggunakan pinsip-prinsip animasi.
Tugas Akhir ini dibuat dengan menggunakan metodologi Pra Produksi, Produksi dan Post Produksi.
Hasil akhir dari penelitian ini adalah animasi pada game cookurubukan berupa gambar 2D look. Animasi
nantinya akan digunakan dalam pembuatan game Cookurubukan. Pada saat ini penelitian ini sudah mencapai tahap
perancangan.
Kata kunci: Animasi Non-Human Character, frame by frame.animasi berbentuk computer
Retrieval of phase memory in two independent atomic ensembles by Raman process
In spontaneous Raman process in atomic cell at high gain, both the Stokes
field and the accompanying collective atomic excitation (atomic spin wave) are
coherent. We find that, due to the spontaneous nature of the process, the
phases of the Stokes field and the atomic spin wave change randomly from one
realization to another but are anti-correlated. The phases of the atomic
ensembles are read out via another Raman process at a later time, thus
realizing phase memory in atoms. The observation of phase correlation between
the Stokes field and the collective atomic excitations is an important step
towards macroscopic EPR-type entanglement of continuous variables between light
and atoms
Benchmarking explanatory models for inertia forecasting using public data of the nordic area
This paper investigates the performance of a day-ahead explanatory model for inertia forecasting based on field data in the Nordic system, which achieves a 43% reduction in mean absolute percentage error (MAPE) against a state-of-the-art time-series forecast model. The generalizability of the explanatory model is verified by its consistent performance on Nordic and Great Britain datasets. Also, it appears that a long duration of training data is not required to obtain accurate results with this model, but taking a more spatially granular approach reduces the MAPE by 3.6%. Finally, two further model enhancements are studied considering the specific features in Nordic system: (i) a monthly interaction variable applied to the day-ahead national demand forecast feature, reducing the MAPE by up to 18%; and (ii) a feature based on the inertia from hydropower, although this has a negligible impact. The field dataset used for benchmarking is also made publicly available
Fick's law and Fokker-Planck Equation in inhomogeneous environments
In inhomogeneous environments, the correct expression of the diffusive flux
is often not given by the Fick's law . The most general
hydrodynamic equation modelling diffusion is indeed the Fokker-Planck Equation
(FPE). The microscopic dynamics of each specific system may affect the form of
the FPE, either establishing connections between the diffusion and the
convection term, as well as providing supplementary terms. In particular, the
Fick's form for the Diffusion Equation may arise only in consequence of a
specific kind of microscopic dynamics. It is also shown how, in the presence of
sharp inhomogeneities, even the hydrodynamic FPE limit may becomes inaccurate
and mask some features of the true solution, as computed from the Master
Equation.Comment: V2: English amended. V3: final version accepted by Physics Letters
Reconsideration of Second Harmonic Generation from neat Air/Water Interface: Broken of Kleinman Symmetry from Dipolar Contribution
It has been generally accepted that there are significant quadrupolar and
bulk contributions to the second harmonic generation (SHG) reflected from the
neat air/water interface, as well as common liquid interfaces. Because there
has been no general methodology to determine the quadrupolar and bulk
contributions to the SHG signal from a liquid interface, this conclusion was
reached based on the following two experimental phenomena. Namely, the broken
of the macroscopic Kleinman symmetry, and the significant temperature
dependence of the SHG signal from the neat air/water interface. However,
because sum frequency generation vibrational spectroscopy (SFG-VS) measurement
of the neat air/water interface observed no apparent temperature dependence,
the temperature dependence in the SHG measurement has been reexamined and
proven to be an experimental artifact. Here we present a complete microscopic
analysis of the susceptibility tensors of the air/water interface, and show
that dipolar contribution alone can be used to address the issue of broken of
the macroscopic Kleinman symmetry at the neat air/water interface. Using this
analysis, the orientation of the water molecules at the interface can be
obtained, and it is consistent with the measurement from SFG-VS. Therefore, the
key rationales to conclude significantly quadrupolar and bulk contributions to
the SHG signal of the neat air/water interface can no longer be considered as
valid as before. This new understanding of the air/water interface can shed
light on our understanding of the nonlinear optical responses from other
molecular interfaces as well
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