• 제목/요약/키워드: DE based

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LAGUERRE EXPANSIONS AND PRODUCTS OF DISTRIBUTIONS

  • Catuogno, Pedro;Martinez, Federico;Molina, Sandra
    • 대한수학회논문집
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    • 제23권2호
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    • pp.201-209
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    • 2008
  • In this paper we introduce two products of tempered distributions with positive support. These products are based in the Laguerre representation of distributions. We calculate some products as, $[{\delta}]x^{\lambda}_+={\delta}[x^{\lambda}_+]=0\;and\;[x^{\lambda}_+]x^{\mu}_+=x^{{\lambda}+{\mu}}_+$ for appropriate ${\lambda}$ and ${\mu}$.

생태 기반 하이브리드 차등 진화 (Ecological Based Hybrid Differential Evolution)

  • 신성윤;조광현;조승표
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2022년도 추계학술대회
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    • pp.416-417
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    • 2022
  • 본 논문에서는 SparkHDE-EM이라는 생태학적 모델 알고리즘에 기반한 하이브리드 DE를 제안한다. 이 모델은 Spark에 기반한 섬 모델을 도입하여 다양한 DE 변형의 병렬화를 구현하고 Monod 모델을 활용하여 자원 간의 균형을 유지한다.

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Corrosion in Oil well Stimulation Processes Caused by Different Chelating Agents Based on EDTA Compounds

  • Calderon, J.A.;Vasquez, F.A.;Arbelaez, L.;Carreno, J.A.
    • Corrosion Science and Technology
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    • 제16권2호
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    • pp.59-63
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    • 2017
  • Chelating solutions can be damaged by strong acids during oil production. To design effective corrosion inhibitors and other alternatives for corrosion control, it is important to understand not only the behavior of the system under operating condition but also the kinetics of electrochemical reactions during the corrosion process. In this study, the electrochemical behaviors of P-110 steel in aqueous fluids based on ethylenediaminetetraacetic acid (EDTA) compounds under various temperatures and hydrodynamic regime conditions were assessed. Electrochemical measurements were conducted using rotating disc electrodes manufactured. Electrolytes were prepared using aqueous compounds of EDTA like diammonium salt, disodium salt, and tetrasodium salt. Potentiodynamic polarization, electrochemical impedance, and mass loss tests were performed in order to assess the corrosion kinetic in electrolytes. Hydrodynamic effects were observed only in the cathodic polarization curve. This proves that hydrodynamic regime plays an important role in the corrosion of steel mainly in disodium and diammonium EDTA solutions. Two cathodic reactions controlled the corrosion process. However, oxygen level and pH of the electrolyte played the most important role in metal corrosion. Corrosion rates in those fluids were decreased drastically when oxygen concentration was reduced.

Design and Implementation of an FPGA-based Real-time Simulator for a Dual Three-Phase Induction Motor Drive

  • Gregor, Raul;Valenzano, Guido;Rodas, Jorge;Rodriguez-Pineiro, Jose;Gregor, Derlis
    • Journal of Power Electronics
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    • 제16권2호
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    • pp.553-563
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    • 2016
  • This paper presents a digital hardware implementation of a real-time simulator for a multiphase drive using a field-programmable gate array (FPGA) device. The simulator was developed with a modular and hierarchical design using very high-speed integrated circuit hardware description language (VHDL). Hence, this simulator is flexible and portable. A state-space representation model suitable for FPGA implementations was proposed for a dual three-phase induction machine (DTPIM). The simulator also models a two-level 12-pulse insulated-gate bipolar transistor (IGBT)-based voltage-source converter (VSC), a pulse-width modulation scheme, and a measurement system. Real-time simulation outputs (stator currents and rotor speed) were validated under steady-state and transient conditions using as reference an experimental test bench based on a DTPIM with 15 kW-rated power. The accuracy of the proposed digital hardware implementation was evaluated according to the simulation and experimental results. Finally, statistical performance parameters were provided to analyze the efficiency of the proposed DTPIM hardware implementation method.

Sensorless Passivity Based Control of a DC Motor via a Solar Powered Sepic Converter-Full Bridge Combination

  • Linares-Flores, Jesus;Sira-Ramirez, Hebertt;Cuevas-Lopez, Edel F.;Contreras-Ordaz, Marco A.
    • Journal of Power Electronics
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    • 제11권5호
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    • pp.743-750
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    • 2011
  • This article deals with the sensor-less control of a DC Motor via a SEPIC Converter-Full Bridge combination powered through solar panels. We simultaneously regulate, both, the output voltage of the SEPIC-converter to a value larger than the solar panel output voltage, and the shaft angular velocity, in any of the turning senses, so that it tracks a pre-specified constant reference. The main result of our proposed control scheme is an efficient linear controller obtained via Lyapunov. This controller is based on measurements of the converter currents and voltages, and the DC motor armature current. The control law is derived using an exact stabilization error dynamics model, from which a static linear passive feedback control law is derived. All values of the constant references are parameterized in terms of the equilibrium point of the multivariable system: the SEPIC converter desired output voltage, the solar panel output voltage at its Maximun Power Point (MPP), and the DC motor desired constant angular velocity. The switched control realization of the designed average continuous feedback control law is accomplished by means of a, discrete-valued, Pulse Width Modulation (PWM). Experimental results are presented demonstrating the viability of our proposal.

연속적 차분 확장 기반 가역 DNA 워터마킹 (Consecutive Difference Expansion Based Reversible DNA Watermarking)

  • 이석환;권기룡
    • 전자공학회논문지
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    • 제52권7호
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    • pp.51-62
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    • 2015
  • 대용량의 DNA 정보 저장, DNA 서열 저작권 보호를 위한 DNA 워터마킹, 및 비밀 통신을 위한 DNA 스테가노그라픽에 대한 관심이 증대되면서, 원본 DNA 서열의 기능 유지와 복원이 가능한 가역성 DNA 워터마킹이 필요하다. 본 논문에서는 비부호영역 DNA 서열을 이용한 DE(Difference expansion) 기반 가역 DNA 워터마킹 기법을 제안한다. 가역 DNA 워터마킹에서는 생물학적 기능 변경이 없고, 문자 형태의 서열 내에 대용량의 데이터를 은닉하여야 하며, 원본 DNA 서열이 복원되어야 한다. 제안한 방법에서는 문자 서열을 십진수 형태의 수치계수로 변환한 다음, 인접 수치 계수 쌍의 DE 기반 다중비트 은닉 방법(DE-MBE, DE based multiple bits embedding)과 이전 은닉 수치계수를 예측으로 한 연속 DE 기반 다중비트 은닉 방법들(C-DE-MBE, consecutive DE based multiple bits embedding)에 의하여 워터마크가 은닉된다. 은닉 과정에서는 워터마크된 서열에 의하여 부호영역을 나타내는 허위 시작코돈 발생을 방지하기 위하여 비교 탐색을 수행한다. 실험 결과로부터 제안한 방법이 기존 방법에 비하여 높은 은닉 용량을 가지며, 허위 시작코돈이 발생되지 않으며, 기준 서열없이 원본 DNA 서열이 복원됨을 확인하였다.

Inelastic displacement-based design approach of R/C building structures in seismic regions

  • Rubinstein, Marcelo;Moller, Oscar;Giuliano, Alejandro
    • Structural Engineering and Mechanics
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    • 제12권6호
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    • pp.573-594
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    • 2001
  • A two-level displacement-based design procedure is developed. To obtain the displacement demands, elastic spectra for occasional earthquakes and inelastic spectra for rare earthquakes are used. Minimum global stiffness and strength to be supplied to the structure are based on specified maximum permissible drift limits and on the condition that the structure responds within the elastic range for occasional earthquakes. The performance of the structure may be assessed by an inelastic push-over analysis to the required displacement and the evaluation of damage indices. The approach is applied to the design of a five-story reinforced concrete coupled wall structure located in the most hazardous seismic region of Argentina. The inelastic dynamic response of the structure subjected to real and artificially generated acceleration time histories is also analyzed. Finally, advantages and limitations of the proposed procedure from the conceptual point of view and practical application are discussed.

Muscular and collagenous cerebellar choristoma in a dog

  • Ripplinger, Angel;de Melo, Stella Maris Pereira;Ferrarin, Denis Antonio;Schwab, Marcelo Luis;Wrzesinski, Mathias Reginatto;Rauber, Julia da Silva;Flores, Mariana Martins;Kommers, Glaucia Denise;Mazzanti, Alexandre
    • Journal of Veterinary Science
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    • 제23권2호
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    • pp.30.1-30.6
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    • 2022
  • This report aims to describe the first case of muscular and collagenous choristoma in a dog. A 10-yr-old female mixed-breed dog presented with lateral recumbence, vocalization, positional vertical nystagmus, divergent strabismus, anisocoria, and status epilepticus. The clinical condition evolved to stupor and ultimately, death. Necropsy revealed a white mass causing an irregular increase in the volume of the cerebellar vermis. In histological analysis, a well circumscribed, unencapsulated mass was observed in the cerebellum, consisting of fibers of striated skeletal muscle and collagen fibers, mostly mineralized. Based on the histopathological and histochemical findings, a diagnosis of muscular and collagenous cerebellar choristoma was made.