• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1276-1279
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• 2006

This article on environmental noise qualify is concerned with the relationships between the annoyance and perception and sound quality metrics according to exposition time for traffic noise. For invested the characteristics of noise quality, we conducted to the subjective experiments of the annoyance response using the absolute 100 scaling method for the traffic noise sources. The traffic noise sources are composed to varieties exposition time from 15sec to 1200sec. As the results, the first there are decreased the perception loud level for the increase of exposition time with logarithm scale, but increased the annoyance. Second, evaluation index of annoyance is correlated to the loudness(sones), tonality and logarithm scale time with R2=0.83. Also, the composition ratio of traffic noise according to exposition time has the change of range as the logarithm scale ($30{\sim}50%$), tonality($27{\sim}37%$) and loudness($34{\sim}20%$).

• 한국멀티미디어학회논문지
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• 제11권5호
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• pp.641-650
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• 2008

휴대 기기의 보급 확대에 따라 작은 배터리의 사용 시간 연장을 위해 배터리의 전력 관리 기법이 필요하다. 기존의 전력 관리 기법들은 전압 변경에 따른 오버헤드를 고려하지 않거나 부분적으로 고려하였다. 따라서 전압 변경 오버헤드는 개인용 멀티미디어 시스템의 실시간 태스크의 스케줄을 보장 못하는 경우가 발생할 수 있다. 본 논문은 전압 변경 오버헤드를 고려하면서 시스템의 이용률 정보를 바탕으로 사용 가능한 주파수의 개수와 연속된 주파수 사이의 간격을 조절하여 소비 전력을 줄이는 전력 관리 알고리즘을 제안한다. 본 알고리즘은 주파수 변경 회수를 줄여 기존의 CC RT-DVS 방법과 smoothing 방법에 비해 10에서 25%정도 소비 전력을 절감할 수 있다.

• 한국음향학회지
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• 제31권7호
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• pp.427-434
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• 2012

WSOLA 방식은 음성 신호의 시간축 변환을 위한 고음질의 효율적인 알고리즘으로 알려져 있다. WSOLA의 계산량은 두 신호 파형 사이의 유사도를 평가하는 반복적인 정규상호상관도 계산에 집중되어 있다. 본 논문은 WSOLA 계산량 감축을 위해 고속의 정규상호상관도 계산 방법을 제안하며, 제안된 방법에서는 미리 계산된 합 테이블을 통해 인접한 구간에서의 반복적인 정규상호상관도 계산의 중복성을 제거한다. 정규상호상관도의 분모 부분은 시간축 변환 비율에 관계없이 높은 중복성을 가지는데 반해, 분자 부분은 보다 낮은 중복성을 가지며 중복 정도가 시간축 변환 비율과 최적 이동값에 의해 영향을 받기 때문에 고속 계산을 위해 보다 복잡한 알고리즘이 요구된다. 시뮬레이션 결과, 제안된 방법이 기존의 WSOLA와 완전히 동일한 음질을 유지하면서도 시간축 압축의 경우 약 40%, 그리고 1/2배속 및 1/3배속으로의 시간축 신장의 경우 각각 약 47% 및 52%의 실행시간을 감소시킴을 보인다.

• Journal of information and communication convergence engineering
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• 제12권2호
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• pp.128-134
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• 2014

In this paper, we present a graphics processing unit (GPU)-based matching technique for the purpose of fast feature matching between different images. The scale invariant feature transform algorithm developed by Lowe for various feature matching applications, such as stereo vision and object recognition, is computationally intensive. To address this problem, we propose a matching technique optimized for GPUs to perform computations in less time. We optimize GPUs for fast computation of keypoints to make our system quick and efficient. The proposed method uses a self-organizing map feature matching technique to perform efficient matching between the different images. The experiments are performed on various image sets to examine the performance of the system under varying conditions, such as image rotation, scaling, and blurring. The experimental results show that the proposed algorithm outperforms the existing feature matching methods, resulting in fast feature matching due to the optimization of the GPU.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.592-595
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• 1999

In this paper, we propose a unified method to solve the various robust filtering problem for a class of uncertain discrete time systems. Generally, to solve the robust filtering problem, we must convert the convex optimization problem with uncertainty blocks to the uncertainty free convex optimization problem. To do this, we derive the robust matrix inequality problem. This technique involves using constant scaling parameter which can be optimized by solving a linear matrix inequality problem. Therefore, the robust matrix inequality problem does not conservative. The robust filter can be designed by using this robust matrix inequality problem and by considering its solvability conditions.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.177-184
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• 2005

Even in moderate to low seismic regions like Korean peninsular where wind loading usually governs the structural design of a tall building, the probable structural impact of the design basis earthquake or the maximum credible earthquake on the selected structural system should be considered at least in finalizing the design. In this study, by using response spectrum analysis and time history analysis method, seismic performance evaluation was conducted for wind-designed concentrically braced steel highrise buildings. Input ensemble was normalized to be compatible with expected peak ground acceleration. The analysis results showed that wind-designed concentrically braced steel highrise buildings possess significantly increased elastic seismic capacity due to the system overstrength resulting from the wind-serviceability criterion and the width-to-thickness ratio limits on steel members. The time history analysis tended to significantly underestimated the seismic response as compared to response spectrum analysis. Further detailed studies regarding selection and scaling scheme of input ground motions is needed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.262-266
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• 2014

Military vehicle equipped with an antenna and a shelter for operating radar has a vibration exposure during driving time. This vibration would have influence on structure of military vehicle critically. In this paper, driving stability of the military vehicle is obtained through the vibration response analysis. And, vibration level of the military vehicle satisfied the military vibration specification through analysis and comparing the MIL-STD-810G. PSD and Grms data obtained by road test can be used for vibration test specification of cabinets and electronic equipment in shelter.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.707-710
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• 2004

This paper reported the results of mock-up test on mass concrete for transfer girder using setting time difference of super retarding agent(SRA). According to test results, two mock-up structures were made. Plain concrete without placing layer reached maximum temperature after 24hours since placement and caused surface hydration cracks at top section. However, concrete with placing layer reached maximum temperature after 72hours and surface temperature was higher than center temperature, which did not cause surface crack. After form removing, no crack was observed at side surface of plain concrete, while concrete using SRA at mid section had surface scaling and settling crack. According to coring results, concrete with placing layer had a penetration crack from top section to bottom section. Therefore, the setting time difference method to reduce hydration heat will have difficulty in applying the mass concrete for transfer girder.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.221-226
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• 1999

A data assimilation system for a 1-dimensional mixed layer model has been constructed using the adjoint method. The classical adjoint method does not work well for the mixed layer variabilities due to the occurrence of spikes in the gradient of the cost function. To solve this problem, the two techniques of scaling the cost function and optimization in the frequency space are used. As a result, the heat flux can be reliably estimated with an accuracy of 8Wm$^{-2}$ rms error in the identical twin experiments. We then applied this system to the tropical Pacific TOGA-TAO buoy data. The air-sea heat flux as well as the mixed layer variability were estimated in close approximation to the buoy data, particularly on time scales longer than the seasonal one.

• 제어로봇시스템학회논문지
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• 제8권4호
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• pp.327-332
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• 2002

The main problems of computational complexity in object tracking are definition of objects, segmentations and identifications in non-structured environments with erratic movements and collisions of objects. The object's information as a region that corresponds to objects without discriminating among objects are considered. This paper describes the algorithm that, automatically and efficiently, recognizes and keeps tracks of interest-regions selected by users in video or camera image sequences. The block-based feature matching method is used for the region tracking. This matching process considers only dominant feature points such as corners and curved-edges without requiring a pre-defined model of objects. Experimental results show that the proposed method provides above 96% precision for correct region matching and real-time process even when the objects undergo scaling and 3-dimen-sional movements In successive image sequences.