High-energy Emission from Pulsar Outer Magnetospheres

We investigate a stationary pair production cascade in the outer magnetosphere of an isolated, spinning neutron star. The charge depletion due to global flows of charged particles, causes a large electric field along the magnetic field lines. Migratory electrons and/or positrons are accelerated by this field to radiate gamma-rays via curvature and inverse-Compton processes. Some of such gamma-rays collide with the X-rays to materialize as pairs in the gap. The replenished charges partially screen the electric field, which is self-consistently solved together with the energy distribution of particles and gamma-rays at each point along the field lines. By solving the set of Maxwell and Boltzmann equations, we demonstrate that an external injection of charged particles at nearly Goldreich-Julian rate does not quench the gap but shifts its position and that the particle energy distribution cannot be described by a power-law. The injected particles are accelerated in the gap and escape from it with large Lorentz factors. We show that such escaping particles migrating outside of the gap contribute significantly to the gamma-ray luminosity for young pulsars and that the soft gamma-ray spectrum between 100 MeV and 3 GeV observed for the Vela pulsar can be explained by this component. We also discuss that the luminosity of the gamma-rays emitted by the escaping particles is naturally proportional to the square root of the spin-down luminosity.Comment: 24 pages, 11 figures; to appear in the inaugural (Sep) issue of Progress in Astrophysics Researches (a new book series

Wedge-Local Quantum Fields on a Nonconstant Noncommutative Spacetime

Within the framework of warped convolutions we deform the massless free scalar field. The deformation is performed by using the generators of the special conformal transformations. The investigation shows that the deformed field turns out to be wedge-local. Furthermore, it is shown that the spacetime induced by the deformation with the special conformal operators is nonconstant noncommutative. The noncommutativity is obtained by calculating the deformed commutator of the coordinates

Penentuan Lot Size Pemesanan Bahan Baku Furniture Menggunakan Metode Dynamic Lot Sizing

PT. Wirasindo Santakarya (Wisanka) an Indonesia manufacturer and worldwide exporter of indoor and outdoor furniture. The importance of the raw materials inventory supervision for production process and must be able to maintain the avaibility of raw materials inventory to ensure the good flow of production process and to fulfill the customer demands precisely. The problems that exist in the company, especially is calculate a company’s optimal order quantity of raw materials. All this time the order quantity has been only to meet the needs for a certain periode that it doesn’t consider total transaction cost. The main objective of this study is inventory control policies determine of raw materials requirements for the coming period by consider total transaction cost. Lot sizing calculations using Silver Meal Algorithm and Wagner Within Algorithm. Study result is using Silver Meal Algorithm method produces a efficiencies cost of 4,5% for wh klabang while for rotan semi poles of 3,2% and 4,2% for leles the lowest compared to company’s method

Recent results from COMPTEL observations of Cygnus X‐1

The COMPTEL experiment on the Compton Gamma‐Ray Observatory (CGRO) has now observed Cyg X‐1 on four separate occasions during phase 1 and phase 2 of its orbital mission (April, 1991 to August, 1993). Here we report on the results of the latest analysis of these data, which provide a spectrum extending to energies greater than 2 MeV. A spectral analysis of these data, in the context of a classical Comptonization model, indicates an electron temperature much higher than previous hard X‐ray measurements would suggest (200 keV vs 60–80 keV). This implies either some limitations in the standard Comptonization model and/or the need to incorporate a reflected component in the hard X‐ray spectrum. Although significant variability near 1 MeV has been observed, there is no evidence for any ‘MeV excess.

Gamma-Ray Spectra & Variability of the Crab Nebula Emission Observed by BATSE

We report ~ 600 days of BATSE earth-occultation observations of the total gamma-ray (30 keV to 1.7 MeV) emission from the Crab nebula, between 1991 May 24 (TJD 8400) and 1994 October 2 (TJD 9627). Lightcurves from 35-100, 100-200, 200-300, 300-400, 400-700, and 700-1000 keV, show that positive fluxes were detected by BATSE in each of these six energy bands at significances of approximately 31, 20, 9.2, 4.5, 2.6, and 1.3 sigma respectively per day. We also observed significant flux and spectral variations in the 35-300 keV energy region, with time scales of days to weeks. The spectra below 300 keV, averaged over typical CGRO viewing periods of 6-13 days, can be well described by a broken power law with average indices of ~ 2.1 and ~ 2.4 varying around a spectral break at ~ 100 keV. Above 300 keV, the long-term averaged spectra, averaged over three 400 d periods (TJD 8400-8800, 8800-9200, and 9200-9628, respectively) are well represented by the same power law with index of ~ 2.34 up to ~ 670 keV, plus a hard spectral component extending from ~ 670 keV to ~ 1.7 MeV, with a spectral index of ~ 1.75. The latter component could be related to a complex structure observed by COMPTEL in the 0.7-3 MeV range. Above 3 MeV, the extrapolation of the power-law continuum determined by the low-energy BATSE spectrum is consistent with fluxes measured by COMPTEL in the 3-25 MeV range, and by EGRET from 30-50 MeV. We interpret these results as synchrotron emission produced by the interaction of particles ejected from the pulsar with the field in different dynamical regions of the nebula system, as observed recently by HST, XMM-Newton, and Chandra.Comment: To be published in the November 20, 2003, Vol 598 issue of the Astrophysical Journa

Twitter sebagai Media Pertunjukan Diri Figur Publik melalui Tweet dengan Tema Isu Pemilihan Presiden 2014 (Analisis Semiotika Akun Twitter @AHMADDHANIPRAST dan @GlennFredly)

Twitter merupakan media sosial yang berfungsi sebagai media komunikasi dan informasi. Kemudahan yang diberikan Twitter membuat fungsi Twitter digunakan sebagai ajang pertunjukan diri dari para penggunanya untuk menginformasikan hal-hal yang bersifat umum hingga pribadi. Figur publik atau selebritis adalah tokoh yang paling banyak memiliki followers atau pengikut dalam akun Twitter. Hal ini memberi kesempatan pada para figur publik untuk menunjukkan diri mereka. Pada tahun 2014, banyak dari beberapa figur publik yang berusaha menunjukkan diri sebagai orang yang peduli dengan masalah politik dengan memposting tweet bertema isu pemilihan presiden (Pilpres) 2014. Beberapa dari mereka adalah musisi Ahmad Dhani (@AHMADDHANIPRAST) dan Glenn Freedly (@GlennFredly). Penelitian ini bertujuan untuk mengungkapkan pertunjukan diri pemilik akun Twitter @GlennFredly dan @AHMADDHANIPRAST melalui isu-isu politik tentang pemilihan presiden 2014 yang mereka posting. Peneliti menggunakan paradigma konstruktivistis dan tradisi semiotika untuk mengkaji dan mendeskripsikan teks tweet bertema isu Pilpres 2014 dari akun Twitter @AHMADDHANIPRAST dan @GlennFredly. Teori yang digunakan dalam penelitian ini adalah Teori Interaksi Sosial, Teori Dramaturgi, Teori Stratifikasi Sosial.Hasil penelitian ini menunjukkan bahwa akun Twitter @AHMADDHANIPRAST dan @GlennFredly melakukan pertunjukan diri di Twitter sebagai orang yang peduli dengan isu Pilpres 2014 yang sedang berkembang. Dhani menunjukkan diri sebagai orang yang mendukung pasangan Prabowo-Hatta dengan memposting tweet isu Pilpres 2014 seperti pelanggaran HAM yang melibatkan Prabowo, Jokowi yang dinilai sebagai capres boneka, hingga ketegasan sebagai kriteria pemimpin yang baik. Sedangkan @GlennFredly menunjukkan diri sebagai orang yang mendukung pasangan Jokowi-JK dengan memposting tweet isu Pilpres 2014 seperti kekuasaan ditahun 1998, rapor merah kepemimpian SBY dengan latar belakang militer yang mempunyai sifat tegas, hingga seragam Nazi yang dipakai Ahmad Dhani dalam video klip dukungan untuk Prabowo-Hatta

Analisis Isi Twitter Politikus Indonesia Menjelang Pemilu 2014

Twitter adalah salah satu media sosial yang banyak digunakan saat inidengan angka pengguna yang terus meningkat dari tahun ke tahun, termasuk diIndonesia. Twitter dipercaya telah membawa bentuk baru dalam duniakomunikasi, termasuk komunikasi politik. Di Indonesia dan beberapa negaralainnya, penggunaan Twitter oleh politikus telah menjadi hal yang lumrah.Politikus mulai mengadopsi dan menggunakan Twitter sebagai cara baru dalamberinteraksi dengan audiens, terutama menjelang dan semasa kampanye pemilihanumum. Penelitian ini bertujuan untuk mengetahui pola politikus Indonesia dalammenggunakan Twitter dan topik apa yang mereka bicarakan di dunia Twittersebelum masa kampanye berlangsung.Penelitian ini mengacu pada konsep penggunaan Twitter oleh politikusdari Tamara Small dan Graham et al. Analisis isi dilakukan terhadap 2.174 tweetyang dikeluarkan oleh politikus Indonesia selama 3 bulan menjelang pemilihanumum di tahun 2014, yaitu September, Oktober, dan November 2013. Ujireliabilitas data dilakukan dengan uji korelasi di antara tiga coder.Hasil penelitian menunjukkan pola politikus Indonesia dalammenggunakan twitter sebagai media berkomunikasi dengan audiens sebelum masakampanye. Politikus Indonesia telah intensif menggunakan Twitter sebelum masakampanye berlangsung. Dimana rata-rata tweet yang dikeluarkan oleh politikusadalah berkisar dari angka 15 - 441 tweet tiap bulannya. Twitter digunakan untukmenjalin hubungan atau berinteraksi dengan audiens melalui fitur Retweet danReply yang telah disediakan. 50% tweet yang dikeluarkan oleh politikusberbentuk Retweet. Politikus Indonesia pun lebih banyak mengeluarkan tweetyang memberikan gambaran mengenai pandangan dan ide politikus terhadapsuatu isu tertentu (position taking) sebanyak 48% tweet. Disamping itu, politikusjuga menginformasikn hal personal seperti berita mengenai keluarga mereka dankegiatan politikus itu sendiri (updating) sebanyak 35%. Mengenai topik yangterkait dengan isu politik dan kampanye hanya sedikit dibicarakan oleh politikusIndonesia di twitter. Topik berupa Sapaan dikeluarkan oleh politikus Indonesiasebanyak 22%. Hal tersebut tampaknya dipengaruhi oleh masa kampanye yangmasih jauh dan belum berlangsung di tahun 2014. Twitter dalam hal ini digunakanoleh politikus Indonesia sebagai sarana menjalin hubungan serta berinteraksi,menyampaikan pendapat, menginformasikan kegiatan dan hal personal kepadaaudiens

Resepsi Khalayak Pembaca Berita Tragedi Anak (Aqj) Pada Media Online

This research based on the rampant of news about children tragedy in mass media. Childrenare exploited and reported in news excessively, and the news ignore children's right to beprotected from publicity. Online media is one of the public choice that reprimanded by presscouncil in reporting AQJ accident, because a lot of media showed the face and wrote hisidentity clearly and didn't place him as vict im of the systemThis research aims to understand audiences' reception of the purpose of online mediain AQJ accident news. The type of this research is qualitative research used receptionanalysis to discover the reception of the audiences with different experience and background.This research show three types of audience position on AQJ news. The majority of audiences are in negotiated and interpret AQJ accident news as important news because it harms to others, detailed information often expected but they thought that underage children need to be protected from publicity, related to their identity and another aspect that could bother their psychological. Audience who are in dominant reading, interpret the news as natural news that gives positive benefit and important to note audiences widely, and have to be reported in detail. While another audience who are in oppositional reading interpret that news about children tragedy didn't need to be published, according to the audience news about children tragedy will violate children's psychology who are still developing and the news about AQJ accident on online media as unobjective and excessive news