• 대한전자공학회논문지SD
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• 제37권12호
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• pp.79-90
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• 2000

본 논문에서는 고성능 수퍼스칼라 마이크로프로세서에 적합하고, IEEE 754 표준을 준수하는 고성능 부동 소수점 유닛의 구조를 설계한다. 부동 소수점 AU에서는 비정규화 수 처리를 모두 하드웨어적으로 지원하면서 추가적인 지연 시간이 생기지 않도록 점진적 언더플로우 예측 기법을 제안 구현한다. 부동 소수점 제산/제곱근기는 기존의 고정적인 길이의 몫을 구하는 방식과 달리 매 사이클마다 가변적인 길이의 몫을 구하는 구조를 채택하여 성능과 설계 복잡도 면에서 SRT 알고리즘에 의한 구현 보다 우수하도록 설계한다. 또한, 수퍼스칼라 마이크로프로세서에 이식이 용이하도록 익셉션 예측 기법을 세분화하여 적용하며, 제산 연산에서의 익셉션 예측에 필요한 스톨사이클을 제거하도록 한다. 설계된 부동 소수점 AU와 제산/제곱근기는 부동 소수점 유닛의 구성요소인 명령어 디코더, 레지스터 파일, 메모리 모델, 승산기 등과 통합되어 기능과 성능을 검증하였다.

• 한국한의학연구원논문집
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• 제14권2호
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• pp.113-119
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• 2008

In pulse diagnosis, floating pulse and sinking pulse are frequently used for diagnosis about where disease is located and how much severe they are. However, in what mechanism floating pulse and sinking pulse arise is not known well. There are two point of views on substantial of floating pulse and sinking pulse. The first one is the floating and sinking degrees is the expression on the depth of pulsation. And, the second one is floating and sinking pulse is based on the response of pulsation to the indent pressure on radial artery. In this paper, we discussed these two opinions in the view point of tonometric measurement. The process for diagnosis on floating pulse and sinking pulse is similar to the tonometric measurement for non invasive blood pressure or intraocular pressure. We modelled the degrees of depth of pulsation with different indent pressures for initial pulsation feeling and different slopes of indent pressure lines. From this modelling, we can confirm the effect of pulsation depth on P-H curve, that is, in the model where lower pulsation is assumed, the shift of optimal indent pressure to the right was observed. The response of pulse pressure to the indent pressure was tried to be modelled with the degrees of mean blood pressure. Consequently, we tried to model the phenomenon of floating and sinking pulse for the first. And, from this modelling, we can get abundant understanding on how floating and sinking pulse can be caused. In the further study, we want to prove the suitability of this tonometric measurement based modelling with various studies including ultrasound measurement for the depth of pulsation in different EMI subjects.

• The Journal of the Acoustical Society of Korea
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• 제16권1E호
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• pp.41-48
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• 1997

The very purpose of subband codec is the attainment of data rate compression through the use of quantizer and optimum bit allocation for each decimated signal. Yet the question of floating-point quantization effects in subband codec has received scant attention. There has been no direct focus on the analysis of quantization errors, nor on design with quantization errors embedded explicitly in the criterion. This paper provides a rigorous theory for the modelling, analysis and optimum design of the general M-band subband codec in the presence of the floating-point quantization noise. The floating-point quantizers are embedded into the codec structure by its equivalent multiplicative noise model. We then decompose the analysis and synthesis subband filter banks of the codec into the polyphase form and construct an equivalent time-invariant structure to compute exact expression for the mean square quantization error in the reconstructed an equivalent time-invariant structure to compute exact expression for the mean square quantization error in the reconstructed output. The optimum design criteria of the subband codec is given to the design of the analysis/synthesis filter bank and the floating-point quantizer to minimize the output mean square error. Specific optimum design examples are developed with two types of filter of filter banks-orthonormal and biorthogonal filter bank, along with their perpormance analysis.

• 한국해양공학회지
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• 제12권2호통권28호
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• pp.121-129
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• 1998

A quantitative non-contact multi-point measurement system is proposed to the measurement of three-dimensional movement of floating vessels by using digital image processing. The instantaneous three-dimensional movement of a floating structure which is floating in a small water tank is measured by this system and its three-dimensional movement is reconstructed by the measurement results. The validity of this system is verified by position identification for spatially distributed known positional values of basic landmarks set for the camera calibration. It is expected that this system is applicable to the non-contact measurement for an unsteady physical phenomenon especially for the measurement of three-dimensional movement of floating vessels in the laboratory model test.

• Journal of the Optical Society of Korea
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• 제18권6호
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• pp.706-713
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• 2014

An enhanced 360-degree integral-floating three-dimensional display system using a hexagonal lens array and a hidden point removal operator is proposed. Only the visible points of the chosen three-dimensional point cloud model are detected by the hidden point removal operator for each rotating step of the anamorphic optics system, and elemental image arrays are generated for the detected visible points from the corresponding viewpoint. Each elemental image of the elemental image array is generated by a hexagonal grid, due to being captured through a hexagonal lens array. The hidden point removal operator eliminates the overlap problem of points in front and behind, and the hexagonal lens array captures the elemental image arrays with more accurate approximation, so in the end the quality of the displayed image is improved. In an experiment, an anamorphic-optics-system-based 360-degree integral-floating display with improved image quality is demonstrated.

• Journal of Power Electronics
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• 제17권3호
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• pp.653-663
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• 2017

Multilevel active neutral-point-clamped (ANPC) converter combines the advantages of three-level ANPC converter and multilevel flying capacitor (FC) converter. However, multilevel ANPC converter often suffers from capacitor voltage balancing problems. In order to solve the capacitor voltage balancing problems for five-level ANPC converter, phase-shifted pulse width modulation (PS-PWM) is used, which generally provides natural voltage balancing ability. However, the natural voltage balancing ability depends on the load conditions and converter parameters. In order to eliminate voltage deviations under steady-state and dynamic conditions, the active voltage-balancing control (AVBC) methods of floating capacitors and dc-link capacitors based on PS-PWM are proposed. First, the neutral-point current is regulated to balance the neutral-point voltage by injecting zero-sequence voltage. After that, the duty cycles of the redundant switch combinations are adjusted to balance the floating-capacitor voltages by introducing moderating variables for each of the phases. Finally, the effectiveness of the proposed AVBC methods is verified by experimental results.

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1137-1143
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• 2009

This paper presents the FPGA implementation of efficient algorithms for approximating exponential function based on floating point format data. The Taylor-Maclaurin expansion as a conventional approximation method becomes inefficient since high order expansion is required for the large number to satisfy the approximation error. A format converter is designed to convert fixed data format to floating data format, and then the real number is separated into two fields, an integer field and an exponent field to separately perform mathematic operations. A new assembly command is designed and added to previously developed command set to refer the math table. To test the proposed algorithm, assembly program has been developed. The program is downloaded into the Altera DSP KIT W/STRATIX II EP2S180N Board. Performances of the proposed method are compared with those of the Taylor-Maclaurin expansion.

• 대한한의학회지
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• 제29권5호
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• pp.104-110
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• 2008

Objectives : The purpose of this study is to develop the method of selecting representative pulse wave. Methods : The pulse waves were acquired at the right and the left Guan point(關部) with 1420 people who were apparently healthy. The shape agreement of right and left pulse wave and the floating-sinking ratio were compared with three cases, which were the pulse height based method, the pulse area based method, and the pulse time based method. Results : In the point of the shape accordance, the pulse time based method was the best, and the pulse area based method was the worst. In the point of the floating-sinking ratio, the pulse height based method was the worst, and the pulse time based method was the best. Conclusions : So, the pulse time based method was recommended for selecting the representative pulse wave. This study compared the selection methods of representative pulse using the physiological characteristics of pulse wave. Further studies are required, because the representative pulse wave is the main factor of determining the shape and the floating-sinking characteristic of the pulse wave.

• 대한전자공학회논문지
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• 제20권4호
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• pp.24-29
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• 1983

본 논문에서는 32bit 부동 소수점 처리장치를 IEEE 표준에 따른 데이터 양식에 맞도록 설계하여 TTLIC로서 구성하였고 이 시스템과 Z-80 마이크로프로세서와 부동 소수점 4칙 연산에 관한 실행시간을 비교해 본 결과 10배 이상의 시간단축을 보았다. 제어회로 설계에는 AHPL(A Hardware Programming Language)을 사용하였고 TTL IC로 구성하였으나 연산장치와 제어장치를 1칩으로 만들 수 있는 기초를 이룩하였다. 이것을 조금 더 복원하면 32bit 컴퓨터의 연산장치로써 사용될 수 있음을 확신하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.98-100
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• 2005

DSPs used at motor control are usually fixed point processor. They need scaling because they cannot excute floating point calculation. Scaling for floating point calculation makes the DSP's speed down, complex coding and etc. Therefore the IQ math is adopted. IQ math makes the fixed point processor possible to calculate the floating point math. In addition, IQ math can reduce memory usage and be more faster than that without IQ math. It seems that IQ math is appropriate in motor position control. In comparison of the position calculation between the IQ math, math function and the sine table, the method using IQ math is superior than other methods.