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) DI 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