• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 한국에너지공학회 2003년도 추계 학술발표회 논문집
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• pp.131-135
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• 2003

• Journal of the Institute of Electronics Engineers of Korea CI
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• 제46권5호
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• pp.1-13
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• 2009

Filter cache has been introduced as one solution of reducing cache power consumption. More than 50% of the power reduction results from the filter cache, whereas more than 20% of the performance is compromised. To minimize the performance degradation of the filter cache, the predictive filter cache has been proposed. In this paper, we review the previous filter cache predictors and analyze the problems of the solutions. As a result, we found main problems that cause prediction misses in previous filter cache schemes and, to resolve the problems, this paper proposes a new prediction policy. In our scheme, some reference bit entries, called MSBs, are inserted into filter cache and BTB, to adaptively control the filter cache access. In simulation parts, we use a modified SimpleScalar simulator with MiBench benchmark programs to verify the proposed filter cache. The simulation result shows in average 5% performance improvement, compared to previous ones.

• Journal of Broadcast Engineering
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• 제1권2호
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• pp.118-132
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• 1996

This paper proposes a wavelet transform- based image compression method using the energy distribution. The proposed method Involves two steps. First, we use a wavelet transform for the subband decomposition. The original image Is decomposed into one low resolution subimage and three high frequency subimages. Each high frequency subimages have horizontal, vertical, and diagonal directional edges. The wavelet transform is luther applied to these high frequency subimages. Resultant transformed subimages have different energy distributions corresponding to different orientation of the high pass filter. Second, for higer compression ratio and computational effciency, we discard some subimages with small energy. The remaining subimages are encoded using either DPCM or quantization followed by entropy coding. Experimental results show that the proposed coding scheme has better performance in the peak signal to noise ratio(PSNR) and higher compression ratio than conventional image coding method using the wavelet transform followed by the straightforward vector quantization.

• Journal of KIISE:Databases
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• 제32권4호
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• pp.372-382
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• 2005

Aggregation such as computing an average value of data measured in each sensor commonly occurs in many applications of sensor networks. Since sensor networks consist of low-cost nodes with limited battery power, reducing energy consumption must be considered in order to achieve a long network lifetime. Reducing the amount of messages exchanged is the most important for saving energy. Earlier work has demonstrated the effectiveness of in-network data aggregation and data filtering for minimizing the amount of messages in sensor networks. In this paper, we propose an adaptive error adjustment scheme that is simpler, more effective and efficient than previous work. The proposed scheme is based on self-adjustment in each sensor node. We show through various experiments that our scheme reduces the network traffic significantly, and performs better than existing methods.

• Journal of Energy Engineering
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• 제24권2호
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• pp.144-153
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• 2015

At low temperature, Wax build-up and settling can affect adversely the cold weather performance of the diesel vehicle. In this study, we test the cold properties of diesel by blending ratio of biodiesel, kerosene and WAFI. Also, we test the cold weather performance for diesel vehicle by fuel cold properties. Cold properties of diesel are improved by adding the WAFI, kerosene and get worse by adding the biodiesel. WAFI is effective to improve a cold filter plugging point(CFPP) and Kerosene is effective to improve a cloud point(CP). CFPP and pour point(PP) are related to cold weather performance of diesel vehicle but CP is unrelated. CFPP indicate a limit temperature of vehicle driving possibility.

• The Journal of the Acoustical Society of Korea
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• 제20권2호
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• pp.58-65
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• 2001

Recently, a 5-degrees-of-freedom (DOF) reverberation model was proposed as a method of representing subjective perception of reverberation as objective measures[1]. This model approximates sound energy decay curve by five objective measures, widely used in which have been concert hall acoustics. However, it is note worthy that there can be infinite number of impulse responses which correspond to a selected 5-DOF reverberation model. There may exist some filters making very unnatural and unrealistic sound. In this paper, the limitation of the 5-DOF reverberation model when it is used as a filter design criteria is investigated. When a 5-DOF reverberation model is given, additional constraints to get natural reverberation are suggested. This is based on the listening tests for several quite different source sounds.

• The Journal of the Acoustical Society of Korea
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• 제25권8호
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• pp.370-374
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• 2006

Mel-frequency cepstral coefficients are widely used as the feature for speech recognition. In FMCC extraction process. the spectrum. obtained by Fourier transform of input speech signal is divided by met-frequency bands, and each band energy is extracted for the each frequency band. The coefficients are extracted by the discrete cosine transform of the obtained band energy. In this Paper. we calculate the output energy for each bandpass filter by taking the weighting function when applying met-frequency scaled bandpass filter. The weighting function is Gaussian distributed function whose center is at the formant frequency In the experiments, we can see the comparative performance with the standard MFCC in clean condition. and the better Performance in worse condition by the method proposed here.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.642-645
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• 2012

본 논문에서는 자외선 및 적외선 필터를 기반으로 불이 연소하면서 에너지를 빛과 열의 형태로 방출하는 산화 과정으로 여러 가지의 연소반응에 의해 표출 형태가 열, 전기, 연소가스, 복사 등으로 나타날 때, 이중 열복사로 빛이 방출되는 화염의 온도에 따라 각각 특성이 다른 파장을 활용한 적외선과 자외선(IR/UV) 필터를 활용한 불꽃영상 감지시스템 설계방안을 제안한다.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.83-83
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• 2010

산업이 고도화되는 과정에서 에너지의 고효율화를 위하여 고온, 고압 등의 극한환경 하의 공정이 불가결하며, 이에 따라 초미세분진인 나노 입자가 증가되고 있다. 이에 따라 해당 나노의 입자 처리를 위하여 다양한 용도에서의 고온 필터가 산업적으로 요구되고 있다. 본 연구에서는 디젤엔진 매연저감 후처리 장치, 소각로, 발전소 등의 미세 분진 포집 필터로서의 응용을 위해, 카본 파이버에 SiC 휘스커를 증착하는 실험을 진행하였다. 휘스커 증착 공정은 촉매없이 SiC 휘스커를 카본 파이버 위에 화학증착하였다. 휘스커 성장 시 증착 조건의 변화를 통하여 다양한 휘스커의 증착 형태 및 미세구조를 관찰하였다. 또한 높은 포집 효율 및 기체투과도를 갖추기 위해, 휘스커가 증착된 시편의 포집효율 및 기체투과도 향상을 위한 실험을 진행하였다. 해당 실험의 결과로, 증착된 필터는 70% 이상의 포집효율을 보이면서도 기체 투과도는 현재 상용화되어 있는 코디얼라이트보다 5배 이상 높았다. 또한 필터에 추가적인 SiC 침윤공정을 통하여 시편의 내산화성, 내마모성, 내열성 등의 특성이 향상됨을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• 제37권4호
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• pp.56-64
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• 2000

The design of filters for pattern recognition that have optimal trade-off for the criteria of noise robustness, peak sharpness and Homer efficiency, when input scene noise is spatially disjoint (nonoverlapping) with the target, are presented Three different criteria, ie, signal-to-noise ratio, peak-to-output energy ratio and light efficiency are used to design the filter. Computer simulation is made for the various types of noise and parameters to illustrate filter performance for optical pattern recognition. When we compare the new trade-off filter with the original optimal trade-off filter, the performance of trade-off filter for nonoverlapping background is better than that of trade-off filter for overlapping background.