• Title/Summary/Keyword: Network Synthesis

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Synthesis of Filtering Structures for Microstrip Active Antennas Using Orlov's Formula

  • Urbani, Fabio;Bilotti, Filiberto;Vegni, Lucio
    • ETRI Journal
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    • v.27 no.2
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    • pp.166-171
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    • 2005
  • In this paper, a synthesis technique for nonuniform filtering structures to be employed in active integrated antenna layouts is presented. The idea is to suppress the higher harmonic contribution due to the presence of nonlinear components through a nonuniform transmission line properly designed via Orlov's synthesis formula. The theory presented is applied here to synthesize an amplifier-based active antenna layout for wireless local area network (WLAN) purposes working at 2.4 GHz. The numerical results presented show the capabilities of the proposed approach.

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Pervaporation Separation of Water/Ethanol Mixtures through PBMA/anionic PAA IPN Membrane

  • Jin, Young-Sub;Kim, Sung-Chul
    • Proceedings of the Membrane Society of Korea Conference
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    • 1996.10a
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    • pp.86-87
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    • 1996
  • IPN (Interpenetrating Polymer Network) is a mixture of two or more crosslinked polymers with physically interlocked network structures between the component polymers. IPN can be classified as an alloy of thermosets and has the characteristics of thermosets such as the thermal resistance and chemical resistance and also has the characteristics of polymer alloys with enhanced impact resistance and amphoteric properties. The physical interlocking during the synthesis restricts the phase separation of the component polymer with chemical pinning process, thus the control of morphology is possible through variations of the reaction temperature and pressure, catalyst concentration and crosslinking agent concentration. Finely dispersed domain structure can be obtained through IPN synthesis of polymer components with gross immiscibility. In membrane applications, particularly for the separation of liquid mixtures, crosslinked polymer component with specific affinity to the permeate is needed. With the presence of the permeant-inert polymer component, the mechanical strength and the selectivity of the membranes are enhanced by restricting the swelling of the transporting polymer component networks.

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Design Models for Electric Coupling Probe in Combline Resonators Using Neural Network (신경망을 이용한 Combline 공진기 내의 전계결합 프로브 설계 모델)

  • 김병욱;김영수
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2002.11a
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    • pp.366-369
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    • 2002
  • Two artificial neural networks (ANN) are used to model the electric coupling probe in the combline resonators. One is used to analyze and synthesize the electric probe, and the other is used to correct errors between the results of the analysis and the synthesis ANNs and the fabrication results. The ANNs for the analysis and the synthesis of the electric probe are trained using the physical dimensions of the electric probe and the corresponding coupling bandwidth which is obtained using the finite element method. The ANNs for the error correction are trained using a very small set of the measurement results. Once trained, the ANN models provide the correct result approaching the accuracy of the measurement. The results from the ANN models show fairly good agreement with those of the measurement and they can be used as good initial design values.

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Modeling for the Automation of Start-up Operation in Boiler Plant (보일러 플랜트의 Start-Up 운전자동화를 위한 모델링)

  • 윤영진;황규석
    • Journal of the Korean Society of Safety
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    • v.12 no.1
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    • pp.60-70
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    • 1997
  • Since, human error is a major factor contributing to disaster during start-up of operation in Boiler plant. it is necessary to develop an automation system which prevent mode of operation that are known to be dangerous and to bring a loss of energy. The aim of this study is to suggest a model for the computer-aided synthesis of operation sequence as a part of automation system for start-up operation. Synthesis is accomplished by the formation of a hierarchical network of goals which decide sequence of operations. Hierarchical Network is formed by using method which upper goals ( i.e. upper operation al situation) are classified by the function of themselves into lower goals (i.e. lower operational situation). Knowledge for deciding operation sequence is generated by putting In order the knowledge of hazard operation and energy management.

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Design of Multivariable PID Controllers: A Comparative Study

  • Memon, Shabeena;Kalhoro, Arbab Nighat
    • International Journal of Computer Science & Network Security
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    • v.21 no.8
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    • pp.212-218
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    • 2021
  • The Proportional Integral Derivative (PID) controller is the most popular industrial controller and more than 90% process industries use this controller. During the past 50 years, numerous good tuning methods have been proposed for Single Input Single Output Systems. However, design of PI/PID controllers for multivariable processes is a challenge for the researchers. A comparative study of three PID controllers design methods has been carried-out. These methods include the DS (Direct Synthesis) method, IMC (Internal model Control) method and ETF (Effective Transfer Function) method. MIMO PID controllers are designed for a number of 2×2, 3×3 and 4×4 process models with multiple delays. The performance of the three methods has been evaluated through simulation studies in Matlab/Simulink environment. After extensive simulation studies, it is found that the Effective Transfer Function (ETF) Method produces better output responses among two methods. In this work, only decentralized methods of PID controllers have been studied and investigated.

Design of Multivariable PID Controllers: A Comparative Study

  • Memon, Shabeena;Kalhoro, Arbab Nighat
    • International Journal of Computer Science & Network Security
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    • v.21 no.9
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    • pp.11-18
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    • 2021
  • The Proportional Integral Derivative (PID) controller is the most popular industrial controller and more than 90% process industries use this controller. During the past 50 years, numerous good tuning methods have been proposed for Single Input Single Output Systems. However, design of PI/PID controllers for multivariable processes is a challenge for the researchers. A comparative study of three PID controllers design methods has been carried-out. These methods include the DS (Direct Synthesis) method, IMC (Internal model Control) method and ETF (Effective Transfer Function) method. MIMO PID controllers are designed for a number of 2×2, 3×3 and 4×4 process models with multiple delays. The performance of the three methods has been evaluated through simulation studies in Matlab/Simulink environment. After extensive simulation studies, it is found that the Effective Transfer Function (ETF) Method produces better output responses among two methods. In this work, only decentralized methods of PID controllers have been studied and investigated.

The First Multi-Frequency Synthesis Space-VLBI Observations of 0059+581 with Radioastron

  • Alexey Rudnitskiy;Mikhail Shchurov;Taehyun Jung;Marcello Giroletti
    • Journal of The Korean Astronomical Society
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    • v.56 no.1
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    • pp.91-96
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    • 2023
  • In this paper, we describe the first multi-frequency synthesis observations of blazar 0059+581 made with the Radioastron space-ground interferometer in conjunction with the Korean VLBI Network (KVN), Medicina and Torun ground telescopes. We conducted these observations to assess the spaceground interferometer multi-frequency mode capability for the first time.

Solution Structure and Backbone Dynamics of the Biotinylation Domain of Helicobacter pylori Biotin-carboxyl Carrier Protein

  • Jung, Jin-Won;Lee, Chul-Jin;Jeon, Young-Ho;Cheong, Chae-Joon;Lee, Weon-Tae
    • Bulletin of the Korean Chemical Society
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    • v.29 no.2
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    • pp.347-351
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    • 2008
  • Acetyl-CoA carboxylase (ACC) is an excellent candidate for antibiotics drug target, which mediates malonyl-CoA synthesis from acetyl-CoA through acetylation process. It is also involved in the committed step of fatty acid synthesis which is essential for living organisms. We have determined the three dimensional structure of C terminal domain of HP0371, biotin-carboxyl carrier protein of H. pyroli, in solution state using heteronuclear multi-dimensional NMR spectroscopy. The structure of HP0371 shows a flatten b-sheet fold which is similar with that of E. coli. However, the sequence and structure of protruding thumb are different with that of E. coli and the thumb shows different basis of structural rigidity based on backbone dynamics data.

5D Light Field Synthesis from a Monocular Video (단안 비디오로부터의 5차원 라이트필드 비디오 합성)

  • Bae, Kyuho;Ivan, Andre;Park, In Kyu
    • Journal of Broadcast Engineering
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    • v.24 no.5
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    • pp.755-764
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    • 2019
  • Currently commercially available light field cameras are difficult to acquire 5D light field video since it can only acquire the still images or high price of the device. In order to solve these problems, we propose a deep learning based method for synthesizing the light field video from monocular video. To solve the problem of obtaining the light field video training data, we use UnrealCV to acquire synthetic light field data by realistic rendering of 3D graphic scene and use it for training. The proposed deep running framework synthesizes the light field video with each sub-aperture image (SAI) of $9{\times}9$ from the input monocular video. The proposed network consists of a network for predicting the appearance flow from the input image converted to the luminance image, and a network for predicting the optical flow between the adjacent light field video frames obtained from the appearance flow.

Atomic structure and crystallography of joints in SnO2 nanowire networks

  • Hrkac, Viktor;Wolff, Niklas;Duppel, Viola;Paulowicz, Ingo;Adelung, Rainer;Mishra, Yogendra Kumar;Kienle, Lorenz
    • Applied Microscopy
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    • v.49
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    • pp.1.1-1.10
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    • 2019
  • Joints of three-dimensional (3D) rutile-type (r) tin dioxide ($SnO_2$) nanowire networks, produced by the flame transport synthesis (FTS), are formed by coherent twin boundaries at $(101)^r$ serving for the interpenetration of the nanowires. Transmission electron microscopy (TEM) methods, i.e. high resolution and (precession) electron diffraction (PED), were utilized to collect information of the atomic interface structure along the edge-on zone axes $[010]^r$, $[111]^r$ and superposition directions $[001]^r$, $[101]^r$. A model of the twin boundary is generated by a supercell approach, serving as base for simulations of all given real and reciprocal space data as for the elaboration of three-dimensional, i.e. relrod and higher order Laue zones (HOLZ), contributions to the intensity distribution of PED patterns. Confirmed by the comparison of simulated and experimental findings, details of the structural distortion at the twin boundary can be demonstrated.