8,237,380 research outputs found
Harness processes and harmonic crystals
In the Hammersley harness processes the real-valued height at each site i in
Z^d is updated at rate 1 to an average of the neighboring heights plus a
centered random variable (the noise). We construct the process "a la Harris"
simultaneously for all times and boxes contained in Z^d. With this
representation we compute covariances and show L^2 and almost sure time and
space convergence of the process. In particular, the process started from the
flat configuration and viewed from the height at the origin converges to an
invariant measure. In dimension three and higher, the process itself converges
to an invariant measure in L^2 at speed t^{1-d/2} (this extends the convergence
established by Hsiao). When the noise is Gaussian the limiting measures are
Gaussian fields (harmonic crystals) and are also reversible for the process.Comment: 21 pages. Revised version with minor changes. Version almost
identical to the one to be published in SP
Statistical physics of power fluctuations in mode locked lasers
We present an analysis of the power fluctuations in the statistical steady
state of a passively mode locked laser. We use statistical light-mode theory to
map this problem to that of fluctuations in a reference equilibrium statistical
physics problem, and in this way study the fluctuations non-perturbatively. The
power fluctuations, being non-critical, are Gaussian and proportional in
amplitude to the inverse square root of the number of degrees of freedom. We
calculate explicit analytic expressions for the covariance matrix of the
overall, pulse and cw power variables, providing complete information on the
single-time power distribution in the laser, and derive a set of
fluctuation-dissipation relations between them and the susceptibilities of the
steady-state quantities.Comment: 7 pages, 1 figure, RevTe
Peningkatan Hasil Belajar Fisika Tentang Momentum Dan Impuls Melalui Model Pembelajaran Awarenes Training Siswa Kelas X T OI A SMK Negeri 1 Jenangan
Tujuan dari penelitian ini adalah untuk mengetahui peningkatan hasil belajar Memahami Konsep Impuls dan Hukum Kekekalan Momentum melalui strategi pembelajaran Awarenes Training pada siswa Kelas X T OI A, SMK Negeri 1 Jenangan Semester I Tahun Pelajaran 2017/2018. Berdasarkan kenyataan yang ada, tingkat keterampilan siswa Kelas X dalam hal menguasai materi Memahami Konsep Impuls dan Hukum Kekekalan Momentum dalam kategori kurang. Hal ini didukung adanya mean skor kelas hanya mencapai 56,25. Sedangkan siswa yang telah mencapai KKM 50,00% atau 16 siswa saja dari KKM yang telah ditetapkan 75. Penelitian ini merupakan penelitian tindakan kelas yang dilaksanakan dalam 3 siklus, terdiri atas 6 pertemuan. Tiap pertemuan terdiri atas 2 x 40 menit. Tiap siklus meliputi kegiatan perencanaan, pelaksanaan, observasi dan refleksi. Data diambil dengan menggunakan instrument tes, wawancara, angket dan jurnal. Peranan model pembelajaran Awarenes Training dalam meningkatkan hasil belajar Fisika ini ditandai adanya peningkatan nilai rerata (Mean Score), yakni : siklus I 71,88; siklus II 75,63; dan siklus III 81,56. Selain itu juga ditandai adanya peningkatan persentase ketuntasan belajar, yaitu pada siklus I 68,75%, siklus II 75,00%, siklus III terjadi peningkatan mencapai 100%
Does It Pay to Treat Patients With Coronavirus Disease 2019? Social Perception of Physicians Treating Patients With Coronavirus Disease 2019
During the coronavirus disease 2019 (COVID-19) pandemic, the public has often expressed great appreciation toward medical personnel who were often shown in the media expressing strong emotions about the situation. To examine whether the perception of people on a physician is in fact influenced by whether the physician treats patients with COVID-19 and the emotions they expressed in response to the situation, 454 participants were recruited in May 2020. Participants saw facial expressions of anger, sadness, happiness, and neutrality which supposedly were shown by physicians who were presented as working either in COVID-19 wards or in an internal medicine ward. Participants rated how competent, empathetic, caring, and likable each physician was, to what degree they would wish to be treated by each physician, and what salary each physician deserved. Physicians treating patients with COVID-19 were seen more positively and as deserving higher pay; they appeared more competent, caring, likable, and were more likely to be chosen as a caregiver compared to physicians not treating patients with COVID-19. The expressed emotions of physicians had a strong impact on how they were perceived, yet this effect was largely unrelated to whether they treated patients with COVID-19 or not such that happy physicians seemed more empathetic, caring, and likable than the physicians who showed negative emotions. Positive regard toward physicians treating patients with COVID-19 was associated with the fact that they were seen as saving lives and not due to the risk imposed by their work.Peer Reviewe
The greedy basis equals the theta basis
We prove the equality of two canonical bases of a rank 2 cluster algebra, the
greedy basis of Lee-Li-Zelevinsky and the theta basis of
Gross-Hacking-Keel-Kontsevich.Comment: 17 page
PENGARUH STRUKTUR ASET, STRUKTUR MODAL DAN KEPEMILIKAN MANAJERIAL TERHADAP KEBIJAKAN HUTANG
Penelitian ini bertujuan untuk menguji pengaruh struktur aset, struktur modal, dan kepemilikan manajerial, terhadap kebijakan hutang. Data yang digunakan adalah data sekunder. Populasi pada penelitian ini yaitu perusahaan jasa subsektor hotel, restoran, dan pariwisata yang terdaftar di Bursa Efek Indonesia. Teknik pengambilan sampel dilakukan dengan metode purposive sampling dengan jumlah sampel sebanyak 30 data. Menggunakan 10 perusahaan selama 3 tahun penelitian mulai dari tahun 2018 sampai tahun 2020. Pengujian hipotesis menggunakan analisis regresi data panel menggunakan software Eviews9. Hasil penelitian menunjukkan bahwa struktur aset dan kepemilikan manajerial berpengaruh negatif terhadap kebijakan hutang. Sementara pada struktur modal berpengaruh positif terhadap kebijakan hutang
On Border Basis and Groebner Basis Schemes
Hilbert schemes of zero-dimensional ideals in a polynomial ring can be
covered with suitable affine open subschemes whose construction is achieved
using border bases. Moreover, border bases have proved to be an excellent tool
for describing zero-dimensional ideals when the coefficients are inexact. And
in this situation they show a clear advantage with respect to Groebner bases
which, nevertheless, can also be used in the study of Hilbert schemes, since
they provide tools for constructing suitable stratifications.
In this paper we compare Groebner basis schemes with border basis schemes. It
is shown that Groebner basis schemes and their associated universal families
can be viewed as weighted projective schemes. A first consequence of our
approach is the proof that all the ideals which define a Groebner basis scheme
and are obtained using Buchberger's Algorithm, are equal. Another result is
that if the origin (i.e. the point corresponding to the unique monomial ideal)
in the Groebner basis scheme is smooth, then the scheme itself is isomorphic to
an affine space. This fact represents a remarkable difference between border
basis and Groebner basis schemes. Since it is natural to look for situations
where a Groebner basis scheme and the corresponding border basis scheme are
equal, we address the issue, provide an answer, and exhibit some consequences.
Open problems are discussed at the end of the paper.Comment: Some typos fixed, some small corrections done. The final version of
the paper will be published on "Collectanea Mathematica
Di gliklekhe sovetishe yugnt = Laimīga Padomju jaunatne
https://www.ester.ee/record=b5454163*es
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