• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.665-671
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• 2010

This paper propose the DDEGST(divergent-direction-emphasis generalized symmetry transform) which emphasis the symmetry of divergent intensity orientation for effective target extraction in FLIR(forward looking infra-red) images. In the proposed method, we use the exponential function instead of cosine function as a phase weight function in the generalized symmetry transform for effective target extraction in FLIR images which contain a target with higher intensity than a background intensity. To evaluate the performance of the proposed method, we compare the proposed mehtod with conventional GST method in experiments. We prove that the proposed method have better performance in IR images.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.2
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• pp.99-106
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• 2006

In this paper, the new method that estimates a sensing ability of smart sensor will be proposed. A study is estimation method that evaluates sensing ability about smart sensor respectively. According to acceleration(g) and displacement changing, we estimated sensing ability of smart sensor using SAI(Sensing Ability Index) method respectively. Smart sensors was made fer experiment. The types of smart sensor are two types(hard and soft smart sensor). Smart sensors developed for recognition of material. Experiment and analysis are executed for estimate the SAI method. In develop a smart sensor, the SAI method will be useful for finding optical design condition of smart sensor that can sense a material. And then dynamic characteristics of smart sensors(frequency changing, acceleration changing, critical point, etc.) are evaluated respectively through new method(SAI) that use the power spectrum density. Dynamic characteristic of sensor is evaluated with SAI method relatively. We can use the SAI for finding critical point of smart sensor, too.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.3
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• pp.311-319
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• 1992

In this paper, a direct adaptive pole placement controller for an unknown linear time-invariant single-input single-output nonminimum phase plant is proposed. To design this direct adaptive pole placement controller, the auxiliary signals are introduced. Consequently, a linear equation error model is formulated for estimating both the controller parameters and the additional auxiliary parameters. To estimate the controller parameters and the additional auxiliary parameters, the exponentially weighted least-squares algorithm is implemented, and a method of selecting the characteristic polynomials of the sensitivity function filters is proposed. In this method, all the past measurement data are weighted exponentially. A series of simulations for a nonminimum phase plant is presented to illustrate some features of both the parameter estimation and the output response of this adaptive pole placement controller.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.43-46
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• 1990

A general scheme for a discrete adaptive observer having exponetial weighting properties is presented for a single-input single-output linear system. In this scheme, all the past measurement data are weighted esponetially both with the weighting factor and the stable matrix F. This observer is then implemented in the design of an indirect adaptive pole placement contoller. To increase nemerical stability in getting the controller parameter, a recusive algorithm is introduced. It is shown that the overall control scheme is globally stable with the persistent excition

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.648-648
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• 2015

이 연구는 수자원 환경을 전반적으로 객관화, 계량화하는 새로운 방법이 성공적임을 소개한다. 기존의 계량법이 일강수량, 월 강수량, 년 강수량 등등, 단순한 수학적 합계에 치중한 결과 가중 중요한 강수의 시간 분포를 간과하였다. 이 단점을 해결하여, 1) 구체적으로 매 시간, 매일 남아 있다고 추정되는 물의 양 만을 합산하는 방법을 택했다. 시간적 감소함수를 이용하여, 강수 후 유출과 증발 등으로 사라지는 물의 양을 고려한 것이다. 2) 합산기간을 객관화하였다. 기본 합산 기간을 365일로 하고, 물 부족 또는 물 과잉이 지속될 경우는 지속되는 기간만큼, 합산기간을 늘이는 방법을 택했다. 따라서 다른 지수들이 임의로 3개월 또는 12개월 등등으로 기간을 결정하는 단점을 해결했다. 이렇게 계산되는 4차원 강수지수(4-Dimensional Rain Index, 4RI)는 1) 일별유효강수지수 (AWRI), 2) 일별가뭄지수(EDI), 3) 일별 홍수지수(FI), 4) 시간별 장기 물지수(LWI), 5) 시간별 단기 물지수(SWI) 등 5개가 기본지수이다. AWRI는 매일 남아 있는 물의 양이다. 이로 인해, 전 지구의 수자원과 재해위험의 시공간적 분포의 정량화 분석이 정밀해졌다. 지구상에서 물 집중이 가장 강한 곳은 캄보디아 내의 한 지점이며 시기는 7월 말이고, 가장 약한 곳은 사하라 사막의 한 지역임이 확인되었다. 또 한국에서 발생하는 갈수기와 풍수기가 정의되었고, 이들의 각 지역별 특성과 차이가 정량적으로 드러났다. 시간적 분포 또한 명확하게 드러나, 각종 저수지의 물 관리나 농?임산물의 생산관리에 획기적 전환점이 마련되었다. 각 국가별로, 각 지역별로 이런 분석은 향후도 무수히 시도되어야 할 것이다. EDI는 매일의 AWRI를 그 날짜의 평균치와 비교한 값이다. 장기가뭄 및 단기가뭄의 강도를 모두 가장 정밀하게 표현한다. FI는 일별로 홍수, 산사태, 침수, 토사 (이하 홍수 등이라 칭함)의 위험을, LWI는 장기 누적된 강수량에 의한 돌발적 홍수 등의 위험을, SWI는 단기 누적된 강수량에 의한 돌발적 홍수 등의 위험을 잘 반영한다. 이들은 모두 시간적으로 산발적인 호우에 의한 홍수 등의 위험을 한 개의 지수로 표현해 주는 장점이 있다. 강수 후 홍수가 발생하기 까지는 시간차이가 있기 때문에, 특히 호우 경보에는 SWI가, 홍수 경보에는 LWI가 아주 효과적이다. 결론적으로 5개의 4차원 강수지수는 물환경의 시공간적 분포진단과 예측, 그리고 조기경보에 혁명적 진화를 초래함이 확인되었다. 따라서 추후 모든 강수기후와 연관된 연구는 연강수량 등의 단순 합산보다, 4차원 강수지수를 먼저 사용하는 것이 바람직 할 것임이 제안되었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.330-335
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• 2000

This paper deals with sensing ability of smart sensor that has a sensing ability of distinguish materials. We have developed new signal processing method that have distinguish different materials. We made the two type of smart sensors for experiment. The first type of smart sensor is H2 type. The second type of smart sensor is HH type. The smart sensor was developed for recognition of material. And then we developed estimation method of sensing ability of smart sensors. The first method(Sensing Ability Index) is developed for H2 smart sensor. The second method($R_{SAI}$ Index) is developed for HH smart sensor. We estimated sensing ability of smart sensor with new SAI and $R_{SAI}$ method. This paper describes our primary study for a new method of estimate sensing ability of smart sensor, which is need for precision work system. This is a study of dynamic characteristics of smart sensor according to frequency and displacement changing with new SAI and $R_{SAI}$ method. Experiment and analysis are executed for proper dynamic sensing condition. First, we developed advanced smart sensors. Second, we develop new SAI and $R_{SAI}$ methods that have a sensing ability of distinguish materials. Dynamic characteristics of smart sensor are evaluated through new SAI and $R_{SAI}$ method relatively. We can use the new SAI and $R_{SAI}$ method for finding materials. Applications of this method are finding abnormal condition of object(auto-manufacturing), feeling of object(medical product), robotics, safety diagnosis of structure, etc.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.1-9
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• 2009

A simplified model of seat-human body is presented to analyze vibrations of human body on a seat of vehicle. The theoretical model having seven degrees-of-freedom is composed of the inter-connected masses, springs and dampers. Until now, evaluation of ride comfort has been usually performed only through vehicle tests. This study aims to complement shortcomings of conventional vehicle tests in evaluation of ride comfort by using the theoretical model. The acceleration values of the human body are obtained from frequency response functions of the theoretical model. Thereafter, Ride and SEAT indexes are acquired by considering response characteristics of the human body for the 12 axes that are presented in BS 6841. A vehicle test is carried out to measure the acceleration values for the three parts of the human body such as upper body, hip and foot. Ride and SEAT indexes of the vehicle test are also obtained by considering the response characteristics of the human body, of which results are compared with the values from the theoretical model. It is found that the theoretical results are in good agreement with the experimental results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.3
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• pp.288-296
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• 1992

This paper describes an improved 2D QPS(quadrature polar separable) filter design and its applications to texture processing. The filter kernel pair consists of the product of a radial weighting function based on the finite PSS (prolate spheroidal sequences) and an exponential at tenuation function for the orientational angle. It is quadrature and polar separable in the frequency domain. It is near optimal in the energy loss because we let the orientational angle function approximate the radial weighting function. The filter frequency characteristics is easy to control as it depends only upon the design specifications such as the bandwidth, the directional angle, the attenuation constant, and the shift constant of the central frequency. Some applications of the filter in texture processing, such as the generation of the texture image, the estimation of orientation angles, and the segmentations for the synthetic texture image, are considered. The result shows that the filter with the wide bandwidth can be used for the generation of discrimination of the strong orientational textures and the segmentation results are good.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11C
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• pp.1098-1110
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• 2003

In this paper, we propose a homomorphic wavelet-based MMSE filter with edge detection to restore images degraded by speckle noise. In the proposed method, a noisy image is first transformed into logarithmic domain. Each pixel in the transformed image is then classified into flat and edge regions by applying DIP operator to the image restored by homomorphic directional MMSE filter. Each pixel in flat region is restored by homomorphic wavelet-based MMSE filter. Each pixel in edge region is restored by the weighted sum of the output of homomorphic wavelet-based MMSE filtering and that of homomorphic directional MMSE filtering. The restored image in spatial domain is finally obtained by applying the exponential function to the restored image in logarithmic domain. Experimental results show that the restored images by the proposed method have ISNR improvement of 3.3-4.0 ㏈ and ${\beta}$, a measurement parameter on edge preservation, improvement of 0.0103-0.0126 and superior subjective image quality over those by conventional methods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.26-38
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• 2020

Mixture design of self-compacting concrete is a typical multi-criteria decision making problem and conventional mixture designs are based on the low level engineering method like trials and errors through iteration method to satisfy the various requirements. This study concerns with performing the straightforward multiobjective design optimization of economic SCC mixture considering relative importances of the various requirements and cost-effectives of SCC. Total five requirements of 28day compressive strength, filling ability, segregation stability, material cost and mass were taken into consideration to prepare the objective function to be formulated in form of the weighted-multiobjective mixture design optimization problem. Economic SCC mixture computational design can be given in a rational way which considering material costs and the relative importances of the requiremets and from the result of this study it is expected that the development of SCC mixtue computational design and the consequent univeral concrete material design optimization methodology can be advanced.