• 한국통신학회논문지
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• 제15권1호
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• pp.58-70
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• 1990

본 논문에서는 저 전송률 비디오 코덱의 영상 데이터 압축을 위한 실시간 이차원 이상여현변환기 구현에 대해 기술한다. 제안된 구조는 벡터 내적 연산의 병렬 처리에 효율적인 분산연산을 이용하였으며 동시성을 최대로 활용하고 있어 CCITT에서 제안하는 완전 CSIF 30 프레임/초의 처리성능을 만족한다. 또한 제안된 구조를 비트 수준으로 모의시험을 수행하여 CCITT에서 제안하는 IDCT 정확도 사양을 만족함을 보였다. 실제로 효율적인 VLSI 실현을 위해 설계방법론을 연구하고 SUN3/150C를 중심으로 모듈발생기 지향적 설계환경을 구축하였다. 구축된 설계환경을 이용하여 제안된 구조의 핵심모듈을 이중 금속선 2m CMOS 기술로써 구현하였으며 설계된 이차원 DCT 칩의 크기는 약 3.9mmx4.8mm이다.

• 센서학회지
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• 제26권1호
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• pp.66-72
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• 2017

The three dimensional ultrasonic anemometer was constructed to reduce the disadvantages of the two-dimensional anemometer and to be free from the use environment. Three pairs of transmitting and receiving ultrasonic sensors were designed to face each other at an angle of $45^{\circ}$ to the upper and lower surfaces at intervals of $120^{\circ}$. 200 kHz ultrasonic sensor Oscillation, transmission and reception, level detection, power supply circuit were designed and U, V, W wind speed vector components were obtained by measuring the time of first received ultrasonic pulse by transmitting pulse ultrasound. It is implemented as firmware in ARM Coretex-M3 processor so that horizontal and vertical wind direction and wind speed can be converted into digital signal by vector calculation. In this study, The three-dimensional ultrasonic anemometer can complement the disadvantages of the two-dimensional anemometer (mechanical and ultrasonic), and it is expected to gradually replace the two-dimensional anemometer due to its high utilization rate by collecting additional information such as vertical wind.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권3호
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• pp.154-161
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• 2005

This paper proposes a speed-sensorless induction motor control system using a rotor speed compensation. To explain the proposed system, this paper describes an induction motor model in the synchronous reference frame for the vector control. The rotor flux is estimated by the rotor flux observer using the reduced-dimensional state estimator technique. The estimated rotor speed is directly obtained from the electrical frequency, the slip frequency, and the rotor speed compensation with the estimated q-axis rotor flux. The error of the rotor time constant is indirectly reflected in the rotor speed compensation using the compensation of the flux error angle. To precisely estimate the rotor flux, the actual value of the stator resistance, whose actual variation is reflected, is derived. An implementation of pulse-width modulation (PWM) pulses using an effective space vector modulation (SVM) is briefly mentioned. For fast calculation and improved performance of the proposed algorithm, all control functions are implemented in software using a digital signal processor (DSP) with its environmental circuits. Also, it is shown through experimental results that the proposed system gives good performance for the speed-sensorless induction motor control.

• ETRI Journal
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• 제20권2호
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• pp.133-148
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• 1998

The objective of this paper is to present an adaptive algorithm for computing the weight vector which provides a beam pattern having its maximum gain along the direction of the mobile target signal source in the presence of interfering signals within a cell. The conjugate gradient method (CGM) is modified in such a way that the suboptimal weight vector is produced with the computational load of O(16N), which has been found to be small enough for the real-time processing of signals in most land mobile communications with the digital signal processor (DSP) off the shelf, where N denotes the number of antenna elements of the array. The adaptive procedure proposed in this paper is applied to code division multiple access (CDMA) mobile communication system to show its excellent performance in terms of signal to interference plus noise ratio (SINR), bit error rate (BER), and capacity, which are enhanced by about 7 dB, ${\frac{1}{100}}$ times, and 7 times, respectively, when the number of antenna elements is 6 and the processing gain is 20 dB.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.268-270
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• 1995

In crane drives, DC motor has been most widely used due to simple control characteristic and favorable transient behavior. Nowadays, however, the squirrel cage induction motor is known as an attractive candidate due to elimination of all sliding electrical contacts, resulting in an exceedingly simple and rugged construction. Especially, in hoist application, the smooth torque control and four quadrant operation are essential. In this paper, an operation of dual inverters with common DC bus fed by vector controlled induction motor is described. Single DSP is employed as a main processor to control dual inverters and communicates each input/output signal with PLC. As well as giving a detailed expression, full simulation and experimental results are presented.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.308-312
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• 2002

In this paper, EPLD(Erasable Programmable Logic Device) based induction motor drives with a SRP-PWM(Separatley Randomized Pulse Position PWM) is proposed. In the proposed RPWM (Random PWM), each of three phase pulses is located randomly in each switching interval. Based on the space vector modulation technique, the duty ratio of the pulses is calculated. To verify the validity of the proposed RPWM, the experimental study was tried. Along with the randomization of PWM pulses, the space vector modulation is also executed in the TMS320C31 DSP(Digital Signal Processor). The experimental results show that the voltage and switching noise harmonics are spread to a wide band area. Also, the performance of the proposed SRP-PWM and the conventional SVM-PWM are nearly the same from the viewpoing of the v/f constant control.

• Journal of Power Electronics
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• 제16권6호
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• pp.2109-2118
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• 2016

Based on the space vector pulse width modulation (SVPWM) theory, this paper realizes an easier SVPWM strategy, which is equivalently implemented by CBSPWM with zero-sequence voltage injection. The traditional SVPWM strategy has no effect on controlling the neutral-point voltage balance. In order to solve the neutral-point voltage unbalance problem for neutral-point-clamped (NPC) three-level inverters, this paper proposes a neutral-point voltage balance controller. The proposed controller realizes controlling the neutral-point voltage balance by dynamically calculating the offset superimposed to the three-phase modulation waves of an equivalent SVPWM strategy. Compared with the traditional SVPWM strategy, the proposed neutral-point voltage balance controller has a strong ability to balance the neutral-point voltage, has good steady-state performance, improves the output waveforms quality and is easy for digital implementation. An experiment has been carried out on a NPC three-level inverter prototype based on a digital signal processor-complex programmable logic device (DSP-CPLD). The obtained experimental results verify the effectiveness of the proposed neutral-point voltage balance controller.

• 한국컴퓨터그래픽스학회논문지
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• 제16권4호
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• pp.11-16
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• 2010

본 논문에서는 그래픽스 하드웨어를 이용한 스윕 곡면의 효율적인 렌더링 알고리즘을 제안한다. 스윕 곡면은 스플라인 모션을 따라 움직이는 단면 곡선으로 표현된다. 이러한 표현은 행렬과 벡터의 곱으로 계산되며, 이는 프로그래밍이 가능한 그래픽스 하드웨어에 쉽게 적용될 수 있다. 스플라인 모션과 단면 곡선의 정보는 텍스쳐 메모리에 저장된다. 그래픽스 하드웨어의 정점 프로세서는 두 개의 곡면 매개변수를 2차원 정점으로 입력받아 한 번의 행렬 곱셈으로 스윕 곡면의 정점 좌표와 법선 벡터를 계산한다. 제안한 GPU 기반 스윕 곡면의 렌더링은 CPU 기반 렌더링에 비해 10배에서 40배 정도의 속도 향상을 보였다.

• 센서학회지
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• 제22권4호
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• pp.292-296
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• 2013

The ultrasonic wind sensor that pass through the air, beating the delivery of ultrasonic wind speed increases or decreases by the physical characteristics of the wind speed and the direction of the sensor, the transmission and reception of ultrasonic time difference measured by a two-axis vector wind and wind speed measured by calculating a device that converts the digital signal is Anemometer and wind direction meteorological facilities management, management of the ship sail used for various purposes, including, but used the existing 3-cup (mechanical) anemometer wind rotor caused by mechanical wear parts replacement due to the short-term, the reliability of the product is low, parts replacement, and according to the characteristics caused the car, there is a problem in high maintenance costs. In addition, because the bearings use of the marine environment and the cryogenic environment was constrained. In this study, the excellent long-term reliability, using ultrasonic-type environment that is not constrained to produce wind anemometer located $90^{\circ}$ conformal road using four piezoelectric sensors were fabricated structures, the piezoelectric oscillator circuit produces a rash and receiving transmit and receive speeds the car through the two-axis vector calculation to measure wind velocity processor firmware programming, and its characteristics were tested.

• 수산해양기술연구
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• 제31권4호
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• pp.393-401
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• 1995

본 논문에서는 전압형제어에 의한 유도전동기의 토크 속응제어법의 메카니즘이 기술되어 졌다. 특히 본 논문에서는 펄스전압 인가에 의한 과도토크 소거원리를 전류레벨에서 해석함과 동시에 직관적 이해를 돕기 위해 벡터표현을 이용하여 제안 방식의 이론적 타당성을 입증하였다. 이상의 검토에서 얻어진 결과를 요약하면 다음과 같다. (1) 전압형제어에 있어서는 임펄스를 인가함으로써 스텝응답을 실현할 수 있다. (2) 유한 미소정정시간 $\Delta$를 매개로 정식화를 행함으로써, 토크의 스텝응답을 실현할 수 있는 이론적인 전압해 및 현실적으로 실현 가능한 전압해를 동시에 구할 수 있다. (3) 토크 속응제어를 $\Delta$이후의 과도전류가 0으로 되는 전압지령에 의해 실현하므로 펄스전압인가에 의한 스파이크 전류는 발생하지 않는다. (4) 전동기 정수가 불변 또는 실시간으로 동정된다면, 제안방식은 제어지령을 결정함에 있어서 전류정보에 직접 의존하지 않고도 피드포워드적으로 전압지령의 연산이 가능하다. 따라서 제어 시스템 구성의 간략화와 동시에 제어정도가 전류정보에 전적으로 의존하지 않는 제어계의 구축이 가능하다