Large Amplitude Longitudinal Oscillations in a Solar Filament

We have developed the first self-consistent model for the observed large-amplitude oscillations along filament axes that explains the restoring force and damping mechanism. We have investigated the oscillations of multiple threads formed in long, dipped flux tubes through the thermal nonequilibrium process, and found that the oscillation properties predicted by our simulations agree with the observed behavior. We then constructed a model for the large-amplitude longitudinal oscillations that demonstrates that the restoring force is the projected gravity in the tube where the threads oscillate. Although the period is independent of the tube length and the constantly growing mass, the motions are strongly damped by the steady accretion of mass onto the threads by thermal nonequilibrium. The observations and our model suggest that a nearby impulsive event drives the existing prominence threads along their supporting tubes, away from the heating deposition site, without destroying them. The subsequent oscillations occur because the displaced threads reside in magnetic concavities with large radii of curvature. Our model yields a powerful seismological method for constraining the coronal magnetic field and radius of curvature of dips. Furthermore, these results indicate that the magnetic structure is most consistent with the sheared-arcade model for filament channels.Comment: ApJ in pres

Competition versus cooperation: German federalism in need of constitutional amendments

Article by Professor Dr Jur Ulrich Karpen (Hamburg) published in Amicus Curiae - Journal of the Society for Advanced Legal Studies. The Journal is produced by the Society for Advanced Legal Studies at the Institute of Advanced Legal Studies, University of London

The Role of Helicity in Magnetic Reconnection: 3D Numerical Simulations

We demonstrate that conservation of global helicity plays only a minor role in determining the nature and consequences of magnetic reconnection in the solar atmosphere. First, we show that observations of the solar coronal magnetic field are in direct conflict with Taylor's theory. Next, we present results from three-dimensional MHD simulations of the shearing of bipolar and multi-polar coronal magnetic fields by photospheric footpoint motions, and discuss the implications of these results for Taylor's theory and for models of solar activity. The key conclusion of this work is that significant magnetic reconnection occurs only at very specific locations and, hence, the Sun's magnetic field cannot relax completely down to the minimum energy state predicted by conservation of global helicity.Comment: AGU LaTeX manuscript, 17 pages, 2 b-w figures, 4 color plate

Formation of Solar Filaments by Steady and Nonsteady Chromospheric Heating

It has been established that cold plasma condensations can form in a magnetic loop subject to localized heating of the footpoints. In this paper, we use grid-adaptive numerical simulations of the radiative hydrodynamic equations to parametrically investigate the filament formation process in a pre-shaped loop with both steady and finite-time chromospheric heating. Compared to previous works, we consider low-lying loops with shallow dips, and use a more realistic description for the radiative losses. We demonstrate for the first time that the onset of thermal instability satisfies the linear instability criterion. The onset time of the condensation is roughly \sim 2 hr or more after the localized heating at the footpoint is effective, and the growth rate of the thread length varies from 800 km hr-1 to 4000 km hr-1, depending on the amplitude and the decay length scale characterizing this localized chromospheric heating. We show how single or multiple condensation segments may form in the coronal portion. In the asymmetric heating case, when two segments form, they approach and coalesce, and the coalesced condensation later drains down into the chromosphere. With a steady heating, this process repeats with a periodicity of several hours. While our parametric survey confirms and augments earlier findings, we also point out that steady heating is not necessary to sustain the condensation. Once the condensation is formed, it can keep growing also when the localized heating ceases. Finally, we show that the condensation can survive continuous buffeting by perturbations resulting from the photospheric p-mode waves.Comment: 43 pages, 18 figure

Diagnosa Penyakit Kulit Wajah Menggunakan Metode Decession Tree Dan Algoritma C4.5

Today's face is something that is very much considered by both women and men. Women and men do facial treatments so often because the face is the first thing to see when meeting someone. However, there are those that often interfere with the face, one of which is a skin disease that is very diverse ranging from acne, dullness, blackheads to cancer. In fact, to overcome this, many people always consult with doctors, especially face problems. One thing that can be done is to diagnose facial skin diseases using the decession tree method and the c 4.5 algorithm. The existence of this system is expected to be a solution in conducting consultations for women and men for facial problems. By using the decession tree method and the c 4.5 algorithm and by using a number of data mining, it will give results that can be used as guidelines in treating facial skin diseases. In addition, the existence of this system will also be very helpful in the field of services to consumers, both women and men, especially for facial care to avoid facial skin diseases, which has been a problem so far

Signatures of impulsive localized heating in the temperature distribution of multi-stranded coronal loops

We study the signatures of different coronal heating regimes on the differential emission measure (DEM) of multi-stranded coronal loops by means of hydrodynamic simulations. We consider heating either uniformly distributed along the loops or localized close to the chromospheric footpoints, in both steady and impulsive conditions. Our simulations show that condensation at the top of the loop forms when the localized heating is impulsive with a pulse cadence time shorter than the plasma cooling time, and the pulse energy is below a certain threshold. A condensation does not produce observable signatures in the global DEM structure. Conversely, the DEM coronal peak is found sensitive to the pulse cadence time. Our simulations can also give an explanation of the warm overdense and hot underdense loops observed by TRACE, SOHO and Yohkoh. However, they are unable to reproduce both the transition region and the coronal DEM structure with a unique set of parameters, which outlines the need for a more realistic description of the transition region.Comment: 31 pages, 7 figure

IMPLEMENTASI METODE CUSTOMER SATISFACTION INDEX (CSI) UNTUK MENGANALISA KEPUASAN PELANGGAN PADA FAMILY SWALAYAN

Family Swalayan merupakan salah satu tempat berbelanja yang cukup diminati oleh konsumen dan  mempunyai lokasi yang strategis di Kota Dumai. Adanya persaingan yang terjadi antara para penjual produk atau ritel, menimbulkan sebuah kompetisi strategi yang tepat untuk meraih pangsa pasar terbesar. Pihak manajemen family swalayanharus memperhatikan hal-hal yang dapat mempengaruhi minat beli konsumen. Hal ini patut diperhatikan karena konsumen tidak hanya berpedoman pada harga  yang  murah  saja,  tetapi  juga  pada kualitas pelayanan, lokasi usaha, kualitas produk yang ditawarkan, serta kerapian tata letak produk yang. Faktor-faktor inilah yang dapat menyebabkan konsumen dapat beralih ke tempat-tempat perbelanjaan lain yang mempunyai daya tarik lebih dibandingkan. Tujuan penelitian untuk mengetahui kepuasan pelanggan family swalayan menggunakan metode customer satisfaction index (CSI) berdasarkan kualitas pelayanan, fasilitas, dan harga produk. Metode CSI digunakan untuk mengetahui tingkat kepuasan konsumen secara menyeluruh dengan melihat tingkat kepentingan atribut – atribut produk / jasa. Berdasarkan penelitian yang dilakukan, diperoleh hasil pencarian CSI untuk kepuasan pelanggan berada pada tingkat Puas sebesar 0.7

IMPLEMENTASI METODE CUSTOMER SATISFACTION INDEX (CSI) UNTUK MENGANALISA KEPUASAN PELANGGAN PADA FAMILY SWALAYAN

Family Swalayan merupakan salah satu tempat berbelanja yang cukup diminati oleh konsumen dan  mempunyai lokasi yang strategis di Kota Dumai. Adanya persaingan yang terjadi antara para penjual produk atau ritel, menimbulkan sebuah kompetisi strategi yang tepat untuk meraih pangsa pasar terbesar. Pihak manajemen family swalayanharus memperhatikan hal-hal yang dapat mempengaruhi minat beli konsumen. Hal ini patut diperhatikan karena konsumen tidak hanya berpedoman pada harga  yang  murah  saja,  tetapi  juga  pada kualitas pelayanan, lokasi usaha, kualitas produk yang ditawarkan, serta kerapian tata letak produk yang. Faktor-faktor inilah yang dapat menyebabkan konsumen dapat beralih ke tempat-tempat perbelanjaan lain yang mempunyai daya tarik lebih dibandingkan. Tujuan penelitian untuk mengetahui kepuasan pelanggan family swalayan menggunakan metode customer satisfaction index (CSI) berdasarkan kualitas pelayanan, fasilitas, dan harga produk. Metode CSI digunakan untuk mengetahui tingkat kepuasan konsumen secara menyeluruh dengan melihat tingkat kepentingan atribut – atribut produk / jasa. Berdasarkan penelitian yang dilakukan, diperoleh hasil pencarian CSI untuk kepuasan pelanggan berada pada tingkat Puas sebesar 0.7

Can Thermal Nonequilibrium Explain Coronal Loops?

Any successful model of coronal loops must explain a number of observed properties. For warm (~ 1 MK) loops, these include: 1. excess density, 2. flat temperature profile, 3. super-hydrostatic scale height, 4. unstructured intensity profile, and 5. 1000--5000 s lifetime. We examine whether thermal nonequilibrium can reproduce the observations by performing hydrodynamic simulations based on steady coronal heating that decreases exponentially with height. We consider both monolithic and multi-stranded loops. The simulations successfully reproduce certain aspects of the observations, including the excess density, but each of them fails in at least one critical way. Monolithic models have far too much intensity structure, while multi-strand models are either too structured or too long-lived. Our results appear to rule out the widespread existence of heating that is both highly concentrated low in the corona and steady or quasi-steady (slowly varying or impulsive with a rapid cadence). Active regions would have a very different appearance if the dominant heating mechanism had these properties. Thermal nonequilibrium may nonetheless play an important role in prominences and catastrophic cooling events (e.g., coronal rain) that occupy a small fraction of the coronal volume. However, apparent inconsistencies between the models and observations of cooling events have yet to be understood.Comment: 40 pages, 10 figures, accepted by the Astrophysical Journal (vol. 714