5,206 research outputs found
Pendekatan Sistem Pembelajaran Bahasa Arab di Madrasah Mu'allimin Muhammadiyah YOGYAKARTA
Penelitian ini membahas tentang pengembangan dan pembelajaran bahasa Arab di Madrasah Mu'allimin Muhammadiyah Yogyakarta. enelitian ini mencoba mendiagnosa komponen atau sub-sub system dalam pembelajaran bahasa Arab yang meliputi siswa, guru, tujuan pembelajaran, metode, dan buku ajar bahasa Arab.Hal ini dimaksudkan untuk mendeskripsikan proses pembelajaran bahasa Arab dalam perspektif pendekatan system. Penelitian ini merupakan jenis penelitian kombinasi (mix research) antara kualitatif dan kuantitatif. Secara umum, interaksi antar sub system seperti siswa, kondisi guru, tujuan, metode, dan buku ajar saling kolaboratif dan sinergis. Meskipun masih banyak ditemukan beberapa masalah di masing-masing sub system tersebut. Interaksi antar sub system tersebut dapat berjalan dengan baik dalam proses pembelajaran dengan melaksanakan prinsipi interdependensi, sinergitas, dan dinamis. Disamping itu, perlu melakukan upaya-upaya edukatif untuk meningkatkan kompetensi guru dan kualitas siswa dengan pendidikan dan pelatihan, workshop, seminar, penulisan buku ajar, studi banding (comparative study), dan praktek langsung (direct practice). Dengan begitu, proses pembelajaran bahasa arab dapat menemukan format ideal dan langkah-langkah solutif-edukatif dalam mendesain pembelajaran bahasa Arab yang aktif, kondusif, kreatif, inovatif dan menyenangkan
Minimal-memory realization of pearl-necklace encoders of general quantum convolutional codes
Quantum convolutional codes, like their classical counterparts, promise to
offer higher error correction performance than block codes of equivalent
encoding complexity, and are expected to find important applications in
reliable quantum communication where a continuous stream of qubits is
transmitted. Grassl and Roetteler devised an algorithm to encode a quantum
convolutional code with a "pearl-necklace encoder." Despite their theoretical
significance as a neat way of representing quantum convolutional codes, they
are not well-suited to practical realization. In fact, there is no
straightforward way to implement any given pearl-necklace structure. This paper
closes the gap between theoretical representation and practical implementation.
In our previous work, we presented an efficient algorithm for finding a
minimal-memory realization of a pearl-necklace encoder for
Calderbank-Shor-Steane (CSS) convolutional codes. This work extends our
previous work and presents an algorithm for turning a pearl-necklace encoder
for a general (non-CSS) quantum convolutional code into a realizable quantum
convolutional encoder. We show that a minimal-memory realization depends on the
commutativity relations between the gate strings in the pearl-necklace encoder.
We find a realization by means of a weighted graph which details the
non-commutative paths through the pearl-necklace. The weight of the longest
path in this graph is equal to the minimal amount of memory needed to implement
the encoder. The algorithm has a polynomial-time complexity in the number of
gate strings in the pearl-necklace encoder.Comment: 16 pages, 5 figures; extends paper arXiv:1004.5179v
Encoding One Logical Qubit Into Six Physical Qubits
We discuss two methods to encode one qubit into six physical qubits. Each of
our two examples corrects an arbitrary single-qubit error. Our first example is
a degenerate six-qubit quantum error-correcting code. We explicitly provide the
stabilizer generators, encoding circuit, codewords, logical Pauli operators,
and logical CNOT operator for this code. We also show how to convert this code
into a non-trivial subsystem code that saturates the subsystem Singleton bound.
We then prove that a six-qubit code without entanglement assistance cannot
simultaneously possess a Calderbank-Shor-Steane (CSS) stabilizer and correct an
arbitrary single-qubit error. A corollary of this result is that the Steane
seven-qubit code is the smallest single-error correcting CSS code. Our second
example is the construction of a non-degenerate six-qubit CSS
entanglement-assisted code. This code uses one bit of entanglement (an ebit)
shared between the sender and the receiver and corrects an arbitrary
single-qubit error. The code we obtain is globally equivalent to the Steane
seven-qubit code and thus corrects an arbitrary error on the receiver's half of
the ebit as well. We prove that this code is the smallest code with a CSS
structure that uses only one ebit and corrects an arbitrary single-qubit error
on the sender's side. We discuss the advantages and disadvantages for each of
the two codes.Comment: 13 pages, 3 figures, 4 table
Force-Free Models of Magnetically Linked Star-Disk Systems
Disk accretion onto a magnetized star occurs in a variety of astrophysical
contexts, from young stars to X-ray pulsars. The magnetohydrodynamic
interaction between the stellar field and the accreting matter can have a
strong effect on the disk structure, the transfer of mass and angular momentum
between the disk and the star, and the production of bipolar outflows, e.g.,
plasma jets. We study a key element of this interaction - the time evolution of
the magnetic field configuration brought about by the relative rotation between
the disk and the star - using simplified, largely semianalytic, models. We
first discuss the rapid inflation and opening up of the magnetic field lines in
the corona above the accretion disk, which is caused by the differential
rotation twisting. Then we consider additional physical effects that tend to
limit this expansion, such as the effect of plasma inertia and the possibility
of reconnection in the disk's corona, the latter possibly leading to repeated
cycles in the evolution. We also derive the condition for the existence of a
steady state for a resistive disk and conclude that a steady state
configuration is not realistically possible. Finally, we generalize our
analysis of the opening of magnetic field lines by using a non-self-similar
numerical model that applies to an arbitrarily rotating (e.g. keplerian) disk.Comment: 75 pages, 22 figures, 2 tables. Submitted to Astrophysical Journa
"Propeller" Regime of Disk Accretion to Rapidly Rotating Stars
We present results of axisymmetic magnetohydrodynamic simulations of the
interaction of a rapidly-rotating, magnetized star with an accretion disk. The
disk is considered to have a finite viscosity and magnetic diffusivity. The
main parameters of the system are the star's angular velocity and magnetic
moment, and the disk's viscosity, diffusivity. We focus on the "propeller"
regime where the inner radius of the disk is larger than the corotation radius.
Two types of magnetohydrodynamic flows have been found as a result of
simulations: "weak" and "strong" propellers. The strong propeller is
characterized by a powerful disk wind and a collimated magnetically dominated
outflow or jet from the star. The weak propeller have only weak outflows. We
investigated the time-averaged characteristics of the interaction between the
main elements of the system, the star, the disk, the wind from the disk, and
the jet. Rates of exchange of mass and angular momentum between the elements of
the system are derived as a function of the main parameters. The propeller
mechanism may be responsible for the fast spinning-down of the classical T
Tauri stars in the initial stages of their evolution, and for the spinning-down
of accreting millisecond pulsars.Comment: 18 pages, 16 figures, ApJ (accepted), added references, corrected
typos; see animation at
http://astrosun2.astro.cornell.edu/us-rus/disk_prop.ht
Visceral adipose tissue-derived serine protease inhibitor (VASPIN) as a prognostic marker in systemic hypertension
Background: Visceral adipose tissue-derived serine protease inhibitor (VASPIN) is an adipocytokine that exerts anti-migratory and anti-inflammatory roles through certain anti-oxidative effects in the peripheral vascular wall. Objective: In this study, we studied the relevance of plasma VASPIN levels in patients with hypertension, correlating VASPIN level assay to absence or occurrence of hypertension and its related complications. Patient and Methods: This was a cross-sectional observational study. A total of 87 subjects were included, divided into 21 age- and sex- matched control (patients’ healthy relatives of some of the study- patients) and 66 hypertensive patients. Of the 66 patients with hypertension, thirty-two were newly diagnosed with uncomplicated essential hypertension and thirty four hypertensive patients with macro- and/or microvascular/ complications. Patients with any other chronic diseases like diabetes, chronic renal disease, liver disease, any rheumatological disease and malignancy were excluded. Plasma VASPIN levels and clinical parameters were assessed at baseline for all studied groups. Results: Comparing VASPIN levels among hypertensive patients showed a negative correlation between serum VASPIN levels and hypertension. Serum VASPIN levels were found lower in the newly diagnosed uncomplicated hypertensive patients group than in control group, and much lower in those with macrovascular and/or microvascular complications group compared to both uncomplicated hypertensive and control groups. Conclusions: Plasma VASPIN may be used as an independent predictive biomarker for early detection of macrovascular and/or microvascular hypertensive complications
Recommended from our members
Management factors associated with bovine respiratory disease in preweaned calves on California dairies: The BRD 100 study.
The objective of this cross-sectional study was to determine how management practices on California dairies may be associated with bovine respiratory disease (BRD) in preweaned calves. A convenience sample of 100 dairies throughout California, providing a study population of 4,636 calves, were visited between May 2014 and April 2016. During each farm visit, in-person interviews with the herd manager or calf caretaker were conducted to collect information about herd demographics, maternity pen, colostrum and calf management, herd vaccinations, and dust abatement. A random sample of preweaned calves was identified and evaluated for the presence of BRD using a standardized tool. A survey-adjusted generalized linear mixed model with a logit link function was fitted with calf as the unit of analysis and dairy as the random effect. Mean study herd size (±SE) was 1,718 (±189.9) cows. Survey-adjusted estimates of breed types in the sample were 81.6% (±0.6) Holstein, 13.1% (±0.4) Jersey, and 5.3% (±0.5) crossbred or other purebred breeds, and calf sex proportions were 73.8% (±1.0) female and 26.2% (±1.0) male. Overall survey-adjusted BRD prevalence in the study herds was 6.91% (±0.69). Housing factors positively associated with BRD were metal hutches compared with wood hutches [odds ratio (OR) = 11.19; 95% confidence interval (CI) = 2.80-44.78], calf-to-calf contact in calves >75 d of age (OR = 9.95, 95% CI = 1.50-65.86), feeding Holstein calves <2.84 L of milk or replacer per day (OR = 7.16, 95% CI = 1.23-41.68), and lagoon water used for flushing manure under hutches compared with no flush (OR = 12.06, 95% CI = 1.93-75.47). Providing extra shade over hutches (OR = 0.08; 95% CI = 0.02-0.37), feeding calves at least 90% saleable milk (OR = 0.27, 95% CI = 0.13-0.54) or pasteurized milk (OR = 0.10; 95% CI = 0.03-0.36), and feeding >5.68 L of milk or replacer per day to Jersey calves (OR = 0.04; 95% CI = 0.01-0.28) were negatively associated with BRD. Our study identified management practices on California dairies with variability and that may contribute to differences in BRD prevalence, which will be incorporated into a risk-assessment tool to control and prevent BRD in preweaned dairy calves
Torque bistability in the interaction between a neutron star magnetosphere and a thin accretion disc
We present a time-dependent model of the interaction between a neutron star
magnetosphere and a thin (Shakura-Sunyaev) accretion disc, where the extent of
the magnetosphere is determined by balancing outward diffusion and inward
advection of the stellar magnetic field at the inner edge of the disc. The
nature of the equilibria available to the system is governed by the magnetic
Prandtl number Pm and the ratio \xi of the corotation radius to the Alfven
radius. For \xi > Pm^0.3, the system can occupy one of two stable states, where
the torques are of opposite signs. If the star is spinning up initially, in the
absence of extraneous perturbations, \xi decreases until the spin-up
equilibrium vanishes, the star subsequently spins down, and the torque
asymptotes to zero. Vortex-in-cell simulations of the Kelvin-Helmholtz
instability suggest that the transport speed across the mixing layer between
the disc and magnetosphere is less than the shear speed when the layer is thin,
unlike in previous models.Comment: 11 pages, 10 figure
- …