Coupled Vlasov and two-fluid codes on GPUs

We present a way to combine Vlasov and two-fluid codes for the simulation of a collisionless plasma in large domains while keeping full information of the velocity distribution in localized areas of interest. This is made possible by solving the full Vlasov equation in one region while the remaining area is treated by a 5-moment two-fluid code. In such a treatment, the main challenge of coupling kinetic and fluid descriptions is the interchange of physically correct boundary conditions between the different plasma models. In contrast to other treatments, we do not rely on any specific form of the distribution function, e.g. a Maxwellian type. Instead, we combine an extrapolation of the distribution function and a correction of the moments based on the fluid data. Thus, throughout the simulation both codes provide the necessary boundary conditions for each other. A speed-up factor of around 20 is achieved by using GPUs for the computationally expensive solution of the Vlasov equation and an overall factor of at least 60 using the coupling strategy combined with the GPU computation. The coupled codes were then tested on the GEM reconnection challenge

Molecular Hydrogen and Paschen-alpha Emission in Cooling Flow Galaxies

We present near-infrared spectra obtained to search for Pa-alpha and molecular hydrogen lines in edge-darkened (FR I-type) radio galaxies with bright Halpha emission in the redshift range 0.0535<z<0.15. We find that all three galaxies in our sample (PKS 0745-191, PKS 1346+26, & PKS2322-12) which are associated with strong cooling flows also have strong Pa-alpha and H_2 (1-0) S(1) through S(5) emission, while other radio galaxies do not. Together with earlier observations this confirms claims that cooling flow galaxies are copious emitters of molecular hydrogen with large H_2 (1-0) S(3)/Pa-alpha ratios in the range 0.5 to 2. The emission is centrally concentrated within the inner few kiloparsec and could come from warm (T ~ 1000-1500 K) molecular material which is being deposited by the cooling flow. We speculate that the H_2 emission could be related to the interaction between the jets and this molecular gas.Comment: ApJ Letters, in press, AAS LaTex, preprint also available at http://www.astro.umd.edu/~hfalcke/publications.html#nirga

Penerapan Good Corporate Governance dan Earning Management terhadap Biaya Hutang pada Perusahaan BUMN Listing CGPI 2010 – 2012

The company's efforts in increasing the high trust of creditors will be low risk, so the company can improve the effectiveness of motoring action that is in company like Good Corporate Governance. Investors tend to see the level of GCG implementation as an indicator of the company's risk level before making a funding decision. While the decision of investors in investing in a company based on various considerations, one of which is profit. As an organization, BUMN functioning as a development agent but also carrying out government policies and programs, while on the other hand it is required to become a healthy business unit. The results of this study indicate that the GCG index has no significant effect on the cost of debt and accrual income management has a significant effect on the cost of debt. It means that earnings management is done by management to influence investor perception, especially to influence buying decision of company stock and influence company value

Concurrent Segmentation and Localization for Tracking of Surgical Instruments

Real-time instrument tracking is a crucial requirement for various computer-assisted interventions. In order to overcome problems such as specular reflections and motion blur, we propose a novel method that takes advantage of the interdependency between localization and segmentation of the surgical tool. In particular, we reformulate the 2D instrument pose estimation as heatmap regression and thereby enable a concurrent, robust and near real-time regression of both tasks via deep learning. As demonstrated by our experimental results, this modeling leads to a significantly improved performance than directly regressing the tool position and allows our method to outperform the state of the art on a Retinal Microsurgery benchmark and the MICCAI EndoVis Challenge 2015.Comment: I. Laina and N. Rieke contributed equally to this work. Accepted to MICCAI 201

Analisis Strategi Bersaing pada Distributor Gula di Indonesia

Penelitian ini dilakukan dengan tujuan untuk mengetahui strategi bersaing yang dapat digunakan dalam menghadapi persaingan di sektor perdagangan industri distributor gula. Seperti yang kita ketahui bahwa produksi gula di Indonesia, sampai saat ini masih belum dapat memenuhi permintaan masyarakat Indonesia. Oleh karena itu pemerintah tidak punya pilihan lain selain mengimport gula dari luar negeri untuk dapat memenuhi permintaan gula di pasar. Hal ini menyebabkan banyak pembisnis yang berkecimpung dalam bisnis ini, hal ini menjadi sangat menarik untuk diteliti bagi penulis mengenai bagaimana strategi yang dapat digunakan Perusahaan distributor gula untuk dapat bersaing dengan Perusahaan pesaing yang ada. Pengumpulan data dilakukan oleh penulis dengan cara wawancara dan observasi secara langsung di lapangan. Setelah mendapatkan data, penulis memastikan keabsahan data dengan metode Trianggulasi. Cara yang dilakukan dalam penelitian ini adalah dengan membadingkan data hasil pengamatan dengan data hasil wawancara, dan membandingkannya kembali dengan data – data tertulis yang dimiliki oleh Perusahaan . Hasil penelitian ini menunjukan, bahwa strategi yang digunakan oleh Perusahaan adalah pengembangan pasar, dan strategi ini masih relevan untuk digunakan. Perusahaan hanya perlu menambahkan strategi baru yaitu penetrasi pasar untuk dapat memaksimalkan omset penjualan

Real-time 3D Tracking of Articulated Tools for Robotic Surgery

In robotic surgery, tool tracking is important for providing safe tool-tissue interaction and facilitating surgical skills assessment. Despite recent advances in tool tracking, existing approaches are faced with major difficulties in real-time tracking of articulated tools. Most algorithms are tailored for offline processing with pre-recorded videos. In this paper, we propose a real-time 3D tracking method for articulated tools in robotic surgery. The proposed method is based on the CAD model of the tools as well as robot kinematics to generate online part-based templates for efficient 2D matching and 3D pose estimation. A robust verification approach is incorporated to reject outliers in 2D detections, which is then followed by fusing inliers with robot kinematic readings for 3D pose estimation of the tool. The proposed method has been validated with phantom data, as well as ex vivo and in vivo experiments. The results derived clearly demonstrate the performance advantage of the proposed method when compared to the state-of-the-art.Comment: This paper was presented in MICCAI 2016 conference, and a DOI was linked to the publisher's versio

Pengembangan Modul Luas dan Keliling Bangun Datar yang Valid dengan Pendekatan Kontekstual Berbasis Keunggulan Lokal di Sekolah Dasar

Penelitian ini bertujuan untuk menghasilkan modul luas dan keliling bangun datar yang valid di sekolah dasar. Jenis penelitian ini adalah penelitian pengembangan dengan menggunakan model 4D (define, design, develop, dan desseminate). Tahap desseminate tidak dilakukan. Penelitian ini untuk mengetahui apakah modul yang dirancang sudah valid, kemudian divalidasi oleh pakar mengenai materi, penyajian, bahasa dan keterbacaan. Hasil penelitian menunjukkan bahwa modul luas dan keliling bangun datar sudah valid oleh pakar. Oleh sebab itu, disimpulkan bahwa modul luas dan keliling bangun datar di sekolah dasar telah valid