Polarization Beam Splitter Based on Self-Collimation of a Hybrid Photonic Crystal

A photonic crystal polarization beam splitter based on photonic band gap and self-collimation effects is designed for optical communication wavelengths. The photonic crystal structure consists of a polarization-insensitive self-collimation region and a splitting region. TM- and TE-polarized waves propagate without diffraction in the self-collimation region, whereas they split by 90 degrees in the splitting region. Efficiency of more than 75% for TM- and TE-polarized light is obtained for a polarization beam splitter size of only 17 μm x 17 μm in a wavelength interval of 60 nm including 1.55 μm

Signatures of Resonant Super-Partner Production with Charged-Current Decays

Hadron collider signatures of new physics are investigated in which a primary resonance is produced that decays to a secondary resonance by emitting a W-boson, with the secondary resonance decaying to two jets. This topology can arise in supersymmetric theories with R-parity violation where the lightest supersymmetric particles are either a pair of squarks, or a slepton - sneutrino pair. The resulting signal can have a cross section consistent with the Wjj observation reported by the CDF collaboration, while remaining consistent with earlier constraints. Other observables that can be used to confirm this scenario include a significant charge asymmetry in the same channel at the LHC. With strongly interacting resonances such as squarks, pair production topologies additionally give rise to 4 jet and WW + 4 jet signatures, each with two equal-mass dijet resonances within the 4 jets.Comment: Note added for recent developments concerning the Wjj final state. Version to appear in PRD. 21 pages, 12 figure

Automatic categorization of Ottoman poems

Cataloged from PDF version of article.This work is partially supported by the Scientific and Technical Research Council of Turkey (TÜBİTAK) under the grant number 109E006.Authorship attribution and identifying time period of literary works are fundamental problems in quantitative analysis of languages. We investigate two fundamentally different machine learning text categorization methods, Support Vector Machines (SVM) and Naïve Bayes (NB), and several style markers in the categorization of Ottoman poems according to their poets and time periods. We use the collected works (divans) of ten different Ottoman poets: two poets from each of the five different hundred-year periods ranging from the 15th to 19 th century. Our experimental evaluation and statistical assessments show that it is possible to obtain highly accurate and reliable classifications and to distinguish the methods and style markers in terms of their effectiveness

Partial evaluation of queries for bit-sliced signature files

Cataloged from PDF version of article.Our research extends the bit-sliced signature organization by introducing a partial evaluation approach for queries. The partial evaluation approach minimizes the response time by using a subset of the on-bits of the query signature. A new signature file optimization method, Partially evaluated Bit-Sliced Signature File (P-BSSF), for multi-term query environments using the partial evaluation approach is introduced. The analysis shows that, with 14% increase in space overhead, P-BSSF provides a query processing time improvement of more than 85% for multi-term query environments with respect to the best performance of the bit-sliced signature file (BSSF) method. Under the sequentiality assumption of disk blocks, P-BSSF provides a desirable response time of 1 second for a database size of one million records with a 28% space overhead, Due to partial evaluation, the desirable response time is guaranteed for queries with several terms

Experimental detection of quantum coherent evolution through the violation of Leggett-Garg-type inequalities

We discuss the use of inequalities of the Leggett-Garg type (LGtI) to witness quantum coherence and present the first experimental violation of this type of inequalities using a light-matter interfaced system. By separately benchmarking the Markovian character of the evolution and the translational invariance of the conditional probabilities, the observed violation of a LGtI is attributed to the quantum coherent character of the process. These results provide a general method to benchmark `quantumness' when the absence of memory effects can be independently certified and confirm the persistence of quantum coherent features within systems of increasing complexity.Comment: published version, including supplementary materia

Vertical framing of superimposed signature files using partial evaluation of queries

Cataloged from PDF version of article.A new signature file method, Multi-Frame Signature File (MFSF), is introduced by extending the bit-sliced signature file method. In MFSF a signature file is divided into variable sized vertical frames with different on-bit densities to optimize the response time using a partial query evaluation methodology. In query evaluation the on-bits of the lower on-bit density frames are used first. As the number of query terms increases, the number of query signature on-bits in the lower on-bit density frames increases and the query stopping condition is reached in fewer evaluation steps. Therefore, in MFSF, the query evaluation time decreases for increasing numbers of query terms. Under the sequentiality assumption of disk blocks, in a PC environment with 30 ms average disk seek time, MFSF provides a projected worst-case response time of 3.54 seconds for a database size of one million records in a uniform distribution multi-term query environment with 1-5 terms per query. Due to partial evaluation, this desired response time is guaranteed for queries with several terms. The comparison of MFSF with the inverted file approach shows that MFSF provides promising research opportunities. (C) 1997 Elsevier Science Ltd

Kabarcık Dinamiği için Birinci Mertebe Gaz Basıncı Yasası

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Akustik bir basınç işaretiyle tetiklenen sıvı içindeki bir gaz kabarcığının ısıl davranışı, düzgün basınç dağılımı varsayılarak kabarcık içindeki gaz basıncı ve sıcaklık dağılımını belirleyen sıvı ile gaz kabarcığı arasındaki enerji bilançosu denklemleriyle yinelemeli bir yöntem kullanılarak incelenmektedir. Birinci yinelemeli çözümün, gaz basıncının kabarcık cidar sıcaklığı ve kabarcık yarıçapının politropik üssü olduğu gösterilmekte, politropik üs de gazın izentropik üssünün bir fonksiyonu olarak belirlenmektedir. Elde edilen birinci mertebe gaz basıncı yasasının, uygun limit durumlarında klasik eşsıcaklık ve adyabatik yasalara indirgendiği görülmektedir. Birinci mertebe gaz basıncı yasası, Rayleigh-Plesset kabarcık dinamiği denklemi çözülerek akustik olarak tetiklenen kavitasyon kabarcığına uygulanmaktadır. Elde edilen sonuçlar, büzülmenin son aşamasında kabarcık cidar sıcaklığının sıvı sıcaklığının bir kaç mertebe üstüne çıktığını göstermektedir.The thermal behaviour of a spherical gas bubble in a liquid driven by an acoustic pressure is investigated in the uniform pressure approximation by employing an iterative method to solve the energy balance equations between the gas bubble and the surrounding liquid for the temperature distribution and the gas pressure inside the bubble. It is shown that the first iterative solution leads to the first order law of the gas pressure as a polytropic power law of the bubble wall temperature and of the bubble radius, with the polytropic index given as an explicit function of the isentropic exponent of the gas. The resulting first order law of the gas pressure reduces to the classical isothermal and adiabatic laws in the appropriate limits. The first order gas pressure law is then applied to an acoustically driven cavitation bubble by solving the Rayleigh-Plesset equation. Results obtained show that the bubble wall temperature pulsations during the late stage of collapse can become a few orders of magnitude higher than the bulk liquid temperature