Towards the Formal Reliability Analysis of Oil and Gas Pipelines

It is customary to assess the reliability of underground oil and gas pipelines in the presence of excessive loading and corrosion effects to ensure a leak-free transport of hazardous materials. The main idea behind this reliability analysis is to model the given pipeline system as a Reliability Block Diagram (RBD) of segments such that the reliability of an individual pipeline segment can be represented by a random variable. Traditionally, computer simulation is used to perform this reliability analysis but it provides approximate results and requires an enormous amount of CPU time for attaining reasonable estimates. Due to its approximate nature, simulation is not very suitable for analyzing safety-critical systems like oil and gas pipelines, where even minor analysis flaws may result in catastrophic consequences. As an accurate alternative, we propose to use a higher-order-logic theorem prover (HOL) for the reliability analysis of pipelines. As a first step towards this idea, this paper provides a higher-order-logic formalization of reliability and the series RBD using the HOL theorem prover. For illustration, we present the formal analysis of a simple pipeline that can be modeled as a series RBD of segments with exponentially distributed failure times.Comment: 15 page

Ballisticity of nanotube FETs: Role of phonon energy and gate bias

We investigate the role of electron-phonon scattering and gate bias in degrading the drive current of nanotube MOSFETs. Our central results are: (i) Optical phonon scattering significantly decreases the drive current only when gate voltage is higher than a well-defined threshold. It means that elastic scattering mechanisms are most detrimental to nanotube MOSFETs. (ii) For comparable mean free paths, a lower phonon energy leads to a larger degradation of drive current. Thus for semiconducting nanowire FETs, the drive current will be more sensitive than carbon nanotube FETs because of the smaller phonon energies in semiconductors. (iii) Radial breathing mode phonons cause an appreciable reduction in drive current.Comment: 16 pages, 1 table, 4 figure

Multicriterial ranking approach for evaluating bank branch performance

14 ranking methods based on multiple criteria are suggested for evaluating the performance of the bank branches. The methods are explained via an illustrative example, and some of them are applied to a real-life data for 23 retail bank branches in a large-scale private Turkish commercial bank

A Novel Real-Time Non-invasive Hemoglobin Level Detection Using Video Images from Smartphone Camera

Hemoglobin level detection is necessary for evaluating health condition in the human. In the laboratory setting, it is detected by shining light through a small volume of blood and using a colorimetric electronic particle counting algorithm. This invasive process requires time, blood specimens, laboratory equipment, and facilities. There are also many studies on non-invasive hemoglobin level detection. Existing solutions are expensive and require buying additional devices. In this paper, we present a smartphone-based non-invasive hemoglobin detection method. It uses the video images collected from the fingertip of a person. We hypothesized that there is a significant relation between the fingertip mini-video images and the hemoglobin level by laboratory gold standard. We also discussed other non-invasive methods and compared with our model. Finally, we described our findings and discussed future works

Pemodelan Dan Simulasi Penyebaran Penyakit Demam Berdarah Dengue (DBD) Dengan Menggunakan Model Cellular Automata

Demam Berdarah Dengue (DBD) merupakan salah satu masalah kesehatan masyarakat di Indonesia. Penyakit demam berdarah sering terjadi di daerah tropis dikarenakan nyamuk pembawa virus terdapat hampir di seluruh pelosok Indonesia khususnya daerah yang beriklim tropis. Kota Manado merupakan salah satu daerah yang endemik untuk kasus demam berdarah, jumlah kasus DBD di kota Manado hampir setiap tahunnya meningkat. Melihat realita kasus DBD yang terjadi, maka perlu adanya kerja sama dari semua elemen baik dari masyarakat umum, pelayanan kesehatan, dunia pendidikan dan pemerintah untuk bersama-sama mencegah terjadinya wabah demam berdarah dilingkungan sekitar tempat tinggal. Penelitian ini akan membahas tentang perkembangan penyakit DBD i kota Manado pada tahun 2011 – 2014, sehingga dari hasil penelitian tersebut menghasilkan sebuah aplikasi yang dapat menjalankan simulasi penyebaran penyakit DBD pada tahun 2011 – 2014 di kota Manado. Aplikasi tersebut bermanfaat untuk memberikan informasi tentang perkembangan kasus DBD tahun 2011 – 2014 pada 9 kecamatan yang ada di kota Manado

Photoemission of Bi2_2Se3_3 with Circularly Polarized Light: Probe of Spin Polarization or Means for Spin Manipulation?

Topological insulators are characterized by Dirac cone surface states with electron spins aligned in the surface plane and perpendicular to their momenta. Recent theoretical and experimental work implied that this specific spin texture should enable control of photoelectron spins by circularly polarized light. However, these reports questioned the so far accepted interpretation of spin-resolved photoelectron spectroscopy. We solve this puzzle and show that vacuum ultraviolet photons (50-70 eV) with linear or circular polarization probe indeed the initial state spin texture of Bi$_2$Se$_3$ while circularly polarized 6 eV low energy photons flip the electron spins out of plane and reverse their spin polarization. Our photoemission calculations, considering the interplay between the varying probing depth, dipole selection rules and spin-dependent scattering effects involving initial and final states explain these findings, and reveal proper conditions for light-induced spin manipulation. This paves the way for future applications of topological insulators in opto-spintronic devices.Comment: Submitted for publication (2013

Analisis Pengelolaan Penangkapan Ikan Kembung Lelaki (Rastrelliger Kanagurta) secara Berkelanjutan di Perairan Selat Lombok

Penelitian ini bertujuan untuk menganalisis beberapa parameter aspek biologi reproduksi ikan kembung, menentukan status keberlanjutan pengelolaan ikan kembung berdasarkan dimensi ekologi, ekonomi, sosial, teknologi, dan etika serta menentukan strategi pengelolaan ikan kembung.Waktu penelitan mulai dari bulan Januari sampai Maret 2016, dilakukan melalui metode pendekatan survey. Pengambilan sampel ikan dilakukan secara random sampling. sedangkan penentuan respoden nelayan dilakukan secara purposive sampling. Hasil penelitian menujukkan Pola pertumbuhan ikan kembung lelaki baik yang jantan maupun betina bersifat allometrik negatif. Nisbah kelamin menunjukkan kondisi seimbang dengan perbandingan 1:1.Tingkat kematangan gonadnya yang dominan ditemukan TKG 4 sebanyak 31,66%, TKG III sebanyak 30%, ini diduga bahwa ikan kembung pada bulan tersebut sedang dalam proes pemijahan. Status keberlanjutan pengelolaan ikan kembung hasil MDS- RAPFISH sebesar 52 dengan status cukup berkelanjutan pada skala sustainabilitas 0-100. Nilai indeks keberlanjutan menunjukkan bahwa apabila pegelolaan dan pemanfaatan tetap seperti saat ini maka kegiatan penangkapan ikan kembung akan tetap berkelanjutan.Strategi pengelolaan diantaranya mengatur pembuangan limbah atau sampah pencemaran, mengatur daerah penangkapan, membatasi upaya penangkapan, meningkatkan pendidikan dan pegetahuan nelayan terhadap kelestarian lingkungan, revitalisasi aturan pengelolaan berdasarkan kearifan lokal, dan meningkatkan peranan penyuluhan perikanan