431 research outputs found
Residual Momentum
Conventional momentum strategies exhibit substantial time-varying exposures to the Fama and French factors. We show that these exposures can be reduced by ranking stocks on residual stock returns instead of total returns. As a consequence, residual momentum earns risk-adjusted profits that are about twice as large as those associated with total return momentum; is more consistent over time; and less concentrated in the extremes of the cross-section of stocks. Our results are inconsistent with the notion that the momentum phenomenon can be attributed to a priced risk factor or market microstructure effects
PENANAMAN SIKAP KEWARGANEGARAAN MELALUI KEGIATAN ORGANISASI SISWA INTRA SEKOLAH (OSIS)Â DIÂ SMK NEGERI 1 CERME GRESIK
Abstrak
Penelitian ini bertujuan untuk mendeskripsikan penanaman sikap kewarganegaraan (sikap disiplin dan sikap tanggung jawab) dalam kegiatan OSIS di SMK Negeri 1 Cerme Gresik. Penelitian ini menggunakan pendekatan kualitatif deskriptif, penelitian dilaksanakan di di SMK Negeri 1 Cerme Gresik. Teknik pengumpulan data melalui wawancara mendalam dengan sembilan informan yang memenuhi kriteria informan, yakni pembina OSIS, ketua OSIS, dan koordinator seksi bidang, observasi, dan dokumentasi, kemudian dianalisis dengan reduksi data, penyajian data, dan penarikan kesimpulan. Berdasarkan hasil analisis data dapat disimpulkan proses penanaman sikap kewarganegaraan (sikap disiplin) terdapat tujuh proses penanamannya, yakni kesepakatan peraturan melalui pemberian hukuman, latihan terus menerus, keteladanan pembina, disiplin dan teratur dalam merencanakan kegiatan dengan adanya dateline dan proposal kegiatan, disiplin dalam pelaksanaan rapat kegiatan, proses penamaman sikap disiplin sangat tergantung saat pelaksanaan kegiatan, proses penanaman sikap disiplin pada pengurus OSIS tetap tercermin setelah kegiatan tersebut dilaksanakan. Proses penanaman sikap kewarganegaraan (sikap tanggung jawab) terdapat tiga proses penanamannya, yakni dalam perencanaan kegiatan tentunya dilakukan pembagian kepanitiaan dan tugas yang dilakukan oleh pengurus OSIS, proses penanaman sikap tanggung jawab juga dilakukan ketika pelaksaan kegiatan, tanggung jawab seorang pengurus OSIS dibutuhkan ketika berakhirnya kegiatan.
Kata Kunci: Penanaman Sikap Kewarganegaraan, Sikap Disiplin, Sikap Tanggung Jawab
Modeling the Subsurface Structure of Sunspots
While sunspots are easily observed at the solar surface, determining their
subsurface structure is not trivial. There are two main hypotheses for the
subsurface structure of sunspots: the monolithic model and the cluster model.
Local helioseismology is the only means by which we can investigate
subphotospheric structure. However, as current linear inversion techniques do
not yet allow helioseismology to probe the internal structure with sufficient
confidence to distinguish between the monolith and cluster models, the
development of physically realistic sunspot models are a priority for
helioseismologists. This is because they are not only important indicators of
the variety of physical effects that may influence helioseismic inferences in
active regions, but they also enable detailed assessments of the validity of
helioseismic interpretations through numerical forward modeling. In this paper,
we provide a critical review of the existing sunspot models and an overview of
numerical methods employed to model wave propagation through model sunspots. We
then carry out an helioseismic analysis of the sunspot in Active Region 9787
and address the serious inconsistencies uncovered by
\citeauthor{gizonetal2009}~(\citeyear{gizonetal2009,gizonetal2009a}). We find
that this sunspot is most probably associated with a shallow, positive
wave-speed perturbation (unlike the traditional two-layer model) and that
travel-time measurements are consistent with a horizontal outflow in the
surrounding moat.Comment: 73 pages, 19 figures, accepted by Solar Physic
Electric current circuits in astrophysics
Cosmic magnetic structures have in common that they are anchored
in a dynamo, that an external driver converts kinetic energy into internal
magnetic energy, that this magnetic energy is transported as Poynting fl ux across the magnetically dominated structure, and that the magnetic energy
is released in the form of particle acceleration, heating, bulk motion,
MHD waves, and radiation. The investigation of the electric current system is
particularly illuminating as to the course of events and the physics involved.
We demonstrate this for the radio pulsar wind, the solar flare, and terrestrial
magnetic storms
Recent Advances in Understanding Particle Acceleration Processes in Solar Flares
We review basic theoretical concepts in particle acceleration, with
particular emphasis on processes likely to occur in regions of magnetic
reconnection. Several new developments are discussed, including detailed
studies of reconnection in three-dimensional magnetic field configurations
(e.g., current sheets, collapsing traps, separatrix regions) and stochastic
acceleration in a turbulent environment. Fluid, test-particle, and
particle-in-cell approaches are used and results compared. While these studies
show considerable promise in accounting for the various observational
manifestations of solar flares, they are limited by a number of factors, mostly
relating to available computational power. Not the least of these issues is the
need to explicitly incorporate the electrodynamic feedback of the accelerated
particles themselves on the environment in which they are accelerated. A brief
prognosis for future advancement is offered.Comment: This is a chapter in a monograph on the physics of solar flares,
inspired by RHESSI observations. The individual articles are to appear in
Space Science Reviews (2011
Physics of Solar Prominences: II - Magnetic Structure and Dynamics
Observations and models of solar prominences are reviewed. We focus on
non-eruptive prominences, and describe recent progress in four areas of
prominence research: (1) magnetic structure deduced from observations and
models, (2) the dynamics of prominence plasmas (formation and flows), (3)
Magneto-hydrodynamic (MHD) waves in prominences and (4) the formation and
large-scale patterns of the filament channels in which prominences are located.
Finally, several outstanding issues in prominence research are discussed, along
with observations and models required to resolve them.Comment: 75 pages, 31 pictures, review pape
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