• Title/Summary/Keyword: pattern modulation

검색결과 230건 처리시간 0.038초

Ensemble Modulation Pattern based Paddy Crop Assist for Atmospheric Data

  • Sampath Kumar, S.;Manjunatha Reddy, B.N.;Nataraju, M.
    • International Journal of Computer Science & Network Security
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    • 제22권9호
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    • pp.403-413
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    • 2022
  • Classification and analysis are improved factors for the realtime automation system. In the field of agriculture, the cultivation of different paddy crop depends on the atmosphere and the soil nature. We need to analyze the moisture level in the area to predict the type of paddy that can be cultivated. For this process, Ensemble Modulation Pattern system and Block Probability Neural Network based classification models are used to analyze the moisture and temperature of land area. The dataset consists of the collections of moisture and temperature at various data samples for a land. The Ensemble Modulation Pattern based feature analysis method, the extract of the moisture and temperature in various day patterns are analyzed and framed as the pattern for given dataset. Then from that, an improved neural network architecture based on the block probability analysis are used to classify the data pattern to predict the class of paddy crop according to the features of dataset. From that classification result, the measurement of data represents the type of paddy according to the weather condition and other features. This type of classification model assists where to plant the crop and also prevents the damage to crop due to the excess of water or excess of temperature. The result analysis presents the comparison result of proposed work with the other state-of-art methods of data classification.

Three-Dimensional Phase-Only Holographic Correlation

  • Kim, Tae-Geun
    • Journal of the Optical Society of Korea
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    • 제5권3호
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    • pp.99-109
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    • 2001
  • This paper presents a phase-only modulation scheme for a three-dimensional (3-D) image matching system to improve optical efficiency of the system. The 3-D image matching system is based on the two mask heterodyne scanning. A hologram of the 3-D reference object is first created and then the phase of the hologram is extracted. The phase of the hologram is represented as one mask with the other mask being a plane wave. The superposition of each beam modulated by the two masks generated a scanning beam pattern. This beam pattern scans the 3-D target object to be recognized. The output of the scanning system gives out the correlation of the phase-only hologram of the reference object and the complex hologram of the target object. Since a hologram contains 3-D information of an object as a form of fringe pattern, the correlation of holograms matches whole 3-D aspect of the objects. Computer simulations are performed with additive gaussian noise and without noise for the complex hologram modulation scheme and the phase-only hologram modulation scheme. The computer simulation results show that the phase-only hologram modulation scheme improves the optical efficiency. Thus the system with the phase-only hologram modulation scheme is more robust than the system with the complex hologram modulation scheme.

3상 매트릭스 컨버터의 고효율 변조방법 설계 및 시뮬레이션 (Design and Simulation of High Efficiency PWM Modulation Method for Three-phase Matrix Converter)

  • 임현주;차한주
    • 전력전자학회논문지
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    • 제17권4호
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    • pp.337-344
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    • 2012
  • A matrix converter is used for converting AC/AC power directly. In order to generate sinusoidal input/output waveform in matrix converter, it uses nine bidirectional switches and PWM modulation. This paper presents an analytical averaged loss model of matrix converter with DDPWM(direct duty ratio PWM) and proposes a new switching method for reducing switching losses. A Mathematical loss models with average magnitude of voltage/current are classed as conduction and switching loss. The proposed switching pattern is improved with existing DDPWM. To prove improved efficiency with proposed DDPWM, this paper compares losses between suggested switching pattern and conventional switching pattern using mathematical and simulation method. Each loss types are influenced by environmental factors such as temperature, switching frequency, output current and modulation method.

변형 공간벡터방식을 사용한 Z-Source 인버터의 해석 및 제어 (Analysis and Control of Z-Source Inverter using Modified Space Vector Methods)

  • 전태원;황빈트랜;김흥근;노의철
    • 전력전자학회논문지
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    • 제12권4호
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    • pp.332-338
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    • 2007
  • 본 논문은 ZSI에서 shoot-through 시간을 효율적으로 제어하기 위한 변형 공간전압 변조방식으로 3종류를 제시하였다. 3개의 변형 공간전압 변조방식에 대한 스위칭 패턴과 shoot-through 시간변화에 대한 변조신호의 변화를 분석한다. Shoot-through 시간 제어 범위와 함께 스위칭 패턴 및 변조신호의 평형성 등을 고려하여 최적의 변형 공간전압 변조방식을 선정하였으며, 32비트 DSP를 사용한 실험을 통하여 그 타당성을 확인한다.

격자 간섭계에서 탈봇 패턴의 섬광체 스크린 투과 시 전달 특성에 대한 시뮬레이션 연구 (A Simulation Study on the Transfer Characteristics of the Talbot Pattern Through Scintillation Screens in the Grating Interferometer)

  • 김대승;김영주;이세호;이승욱
    • 대한방사선기술학회지:방사선기술과학
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    • 제42권1호
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    • pp.67-75
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    • 2019
  • Grating interferometry based imaging technology is a kind of radiation imaging system, which can acquire not only absorption image but also phase difference and dark field image using the Talbot pattern. However, because of the technological difficulties and high cost of fabricating the gratings that make up the system, much efforts are being made to look for ways to replace them. The is a preliminary study to see how the Talbot pattern transfer through various kinds of scintillators and if the optical grating can be a way to replace the conventional absorption gratings. The geometry of the interferometer, the scintillator model, and the scintillator thickness are the main inputs for our simulation. We have used the concept of modulation for quantitative analysis of the contrast ratio of the Talbot pattern. This research is expected to provide very useful information on the design of optical gratings, which is an alternative way to analyze the Talbot pattern, which we have filed a patent on.

One Idea on a Three Dimensional Measuring System Using Light Intensity Modulation

  • Fujimoto Ikumatsu;Cho In-Ho;Pak Jeong-Hyeon;Pyoun Young-Sik
    • International Journal of Control, Automation, and Systems
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    • 제3권1호
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    • pp.130-136
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    • 2005
  • A new optical digitizing system for determining the position of a cursor in three dimensions(3D) and an experimental device for its measurement are presented. A semi-passive system using light intensity modulation, a technology that is well known in radar ranging, is employed in order to overcome precision limitations imposed by background light. This system consists of a charge-coupled device camera placed before a rotating mirror and a light-emitting diode whose intensity is modulated. Using a Fresnel pattern for light modulation, it is verified that a substantial improvement of the signal to noise ratio is realized for the background noise and that a resolution of less than a single pixel can be achieved. This opens the doorway to the realization of high precision 3D digitized measurement. We further propose that a 3D position measurement with a monocular optical system can be realized by a numerical experiment if a linear-period modulated waveform is adopted as the light-modulating one.

혼합형 감각조절장애 아동에 대한 단기집중 감각통합치료 프로그램의 효과-사례보고 (The Effect of Short-Term Intensive Sensory Integration Therapy Program on a Child with Sensory Modulation Disorder(Mixed Pattern) : Case Study)

  • 김은영;지석연
    • 대한감각통합치료학회지
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    • 제4권1호
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    • pp.37-46
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    • 2006
  • Objective : This single-subject study explored the effect of short-term intensive sensory integration therapy program which was provided in a 2006 sensory integration treatment course on adaptive response of a four-year-girl with sensory modulation disorder(mixed pattern). Method : Based on results of the assessment to the child, her therapist offers an organized sensory integration program during four days. Results : Improvement of child's movement quality and variety in physical environment in therapy rooms and interaction with her therapist were observed. Conclusions : This report of the case will be helpful for occupational therapists who plan to intervent with a short-term intensive sensory integration therapy program. In addition, the need for consideration of consultation with the child's parents is discussed.

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영구자석 직선형 리니어 동기전동기의 오프셋 전압에 의한 공간벡터 PWM의 구현 (Realization of Space Vector PWM using Offset Voltage for PMLSM)

  • 장석명;박지훈;장원범;유대준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 B
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    • pp.1088-1090
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    • 2004
  • This paper presents control pattern of air-cored slotless permanent magnet linear synchronous motor using voltage modulation method which is used space vector voltage modulation and offset voltage modulation.

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홀로그래픽 데이터 저장장치에서 트렐리스 인코딩을 이용한 4-레벨 4/6 변조부호 (4-Level 4/6 Modulation Code with Trellis Encoding on Holographic Data Storage)

  • 정성권;이재진
    • 전자공학회논문지
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    • 제54권6호
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    • pp.11-16
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    • 2017
  • 멀티레벨 홀로그래픽 데이터 저장장치는 성능을 저하시키는 요소인 2차원 인접 심볼간 간섭을 피하기 위해 변조부호가 요구된다. 변조부호는 주변의 가장 큰 심볼과 가장 작은 심볼에 의해 발생되는 심각한 ISI 패턴을 제거할 수 있다. 본 논문에서는 4-레벨 홀로그래픽 데이터 저장장치를 위한 4/6 변조부호를 제안하며 또한 트렐리스 인코딩 방식을 이용하여 오류정정능력을 갖는 변조부호를 제안한다. 제안하는 4/6 변조부호는 가장 작은 심볼인 '0'과 가장 큰 심볼인 '3'이 어느 방향에서도 인접하지 않도록 한다. 또한 4-레벨 홀로그래픽 데이터 저장장치에서 같은 코드율을 갖는 변조부호들과 성능 비교를 한다.

수신된 전파신호의 자동 변조 인식을 위한 딥러닝 방법론 (A deep learning method for the automatic modulation recognition of received radio signals)

  • 김한진;김혁진;제준호;김경섭
    • 한국정보통신학회논문지
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    • 제23권10호
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    • pp.1275-1281
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    • 2019
  • 무선 신호의 자동 변조 인식은 지능형 수신기의 주요한 작업으로 다양한 민간 및 군대 응용분야가 있다. 본 논문에서는 딥 뉴럴 네트워크 모델을 기반한 무선통신에서 전파신호의 변조 방식을 식별하는 방법을 제안한다. 순차적인 데이터에 대해 장기적인 패턴을 잡아내는데 용이한 LSTM 모델을 통과하여 얻은 연속적인 신호의 특징값을 딥 뉴럴 네트워크의 입력 데이터로 사용하여 신호의 변조 패턴을 분류한다. 변조된 신호의 진폭 및 위상, 동상(In-phase) 반송파, 직각 위상(Quadrature-phase) 반송파의 값을 LSTM 모델의 입력 데이터로 사용하여 분류한다. 제안된 학습 방법의 성능을 검증하기 위해, 다양한 신호 대 잡음비로 10 가지 유형의 변조 신호를 포함하는 대형 데이터 세트를 사용하여 학습하고 테스트한다. 본 논문의 변조 인식 프로그램은 신호의 사전 정보가 없는 환경에서 변조방식을 예측하는데 적용될 수 있다.