• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.393-396
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• 2008

센서 네트워크에서 병합 질의를 효율적으로 처리하기 위한 다양한 인-네트워크 질의 처리 기법이 제안되었다. 스카이라인 질의는 일반적인 병합 질의와 달리 다차원 데이터에 대한 비교를 요구하므로 인-네트워크 처리가 쉽지 않다. 스카이라인 질의를 에너지 효율적으로 처리하기 위해서 불필요한 데이터의 전송을 제거하는 것이 중요하다. 기존에 제안된 스카이라인 처리 기법은 전체 네트워크에 필터를 배포함으로써 불필요한 데이터 전송을 차단한다. 하지만 많은 False Positive 발생에 따른 불필요한 데이터 전송과 필터 배포시 발생하는 에너지 소모로 인해 네트워크의 수명이 단축된다. 본 논문에서는 필터 배포에 따른 에너지 소모를 줄이기 위한 방법으로 상향식 필터 설정을 통한 스카이라인 질의 처리 기법과 필터링 성능을 향상시키는 기법을 제안한다. 제안하는 기법은 데이터를 수집하는 과정에서 스카이라인 필터테이블(SFT)설정하는 상향식 필터링을 수행한다. 그리고 선-필터링(Pre-filtering) 기법을 통해 필터효과를 증가시킨다. 제안하는 알고리즘의 우수성을 보이기 위해 시뮬레이션을 통해 기존에 제안된 MFTAC기법과 비교하였으며, 그 결과 평균 False Positive가 평균 84.44% 감소하였고, 네트워크 수명이 약 75.99% 증가하였다.

• Science of Emotion and Sensibility
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• v.25 no.1
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• pp.67-78
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• 2022

Interest in bio-signal monitoring of wearable devices is increasing significantly as the next generation needs to develop new devices to dominate the global market of the information and communication technology industry. Accordingly, this research developed a resistive textile strain sensor through a wetting process in a single-wall carbon nanotube dispersion solution using an E-Band with low hysteresis. To measure the resistance signal in the E-Band to which electrical conductivity is applied, a universal material tester, an Arduino, and LCR meters that are microcontroller units were used to measure the resistance change according to the tensile change. To effectively handle various noises generated due to the characteristics of the fabric textile strain sensor, the filter performance of the sensor was evaluated using the moving average filter, Savitsky-Golay filter, and intermediate filters of signal processing. As a result, the reliability of the filtering result of the moving average filter was at least 89.82% with a maximum of 97.87%, and moving average filtering was suitable as the noise filtering method of the textile strain sensor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12A
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• pp.1781-1786
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• 2000

본 논문에서는, 적응 간섭 제거기(AIC : adaptive interference canceller)에 사용되는 적응 알고리즘 중 계산량이 적고, 하드웨어적 복잡성이 낮은 최소 평균 자승(LMS)알고리즘의 적응화 상수(constant step size)를 여러 개 사용하여 빠른 수렴 속도와 낮은 평균 자승 에러를 가지는 방법을 제안한다. 최소 평균 자승 알고리즘에서 적응화 상수는 수렴속도와 평균 자승 에러를 제거하는데, 적응화 상수가 증가할수록 수렴속도가 빨라지는 반면, 평균 자승 에러는 증가하게 된다. 이 논문에서는 수렴속도를 증가하는 동시에 평균 자승 에러를 줄이기 위해, 최소 평균 자승 알고리즘에서 세 개의 적응화 상수를 가지는 새로운 검출기를 제안한다. 이 구조에서, 매 반복횟수에 따른 각 그룹 출력 값들을 가지고, 선택(selection)부분에서 평균 자승 에러들을 비교하며, 가장 작은 평균 자승 에러를 나타내는 그룹의 에러 값과 필터 계수 값들이 선택되어져 여러 적응화 상수 최소 평균 자승 알고리즘(several step size LMS algorithm)부분에서 각 그룹의 필터 계수를 갱신하는데 필요한 정보로 이용된다.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.4
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• pp.65-73
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• 2007

This study devotes to compare the accuracy of Top-N recommendations of items transacted on the web site for customers with the accuracy of rank conformity of the real ratings with estimated ratings for customers preference about items generated from two types of collaborative filtering algorithms. One is Neighborhood Based Collaborative Filtering Algorithm(NBCFA) and the other is Correspondence Mean Algorithm(CMA). The result of this study shows the accuracy of Top-N recommendations and the rank conformity of real ratings with estimated ratings generated by CMA are better than that of NBCFA. It would be expected that the customer's satisfaction in Recommender System is more improved by using the prediction result from CMA than NBCFA, and then Using CMA in collaborative filtering recommender system is more efficient than using NBCFA.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.201-202
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• 2021

본 논문에서는 다중 엑세스 포인트 환경에서 전송전력, 수신필터, 엑세스 포인트 선정 최적화 알고리즘을 제안한다. 최종목적은 신호대간섭비를 유지하면서, 전송전력의 총합을 최소화하는 것이다. 증명을 통해서 제안하는 알고리즘은 최소전력에 수렴함을 보인다. 제안하는 알고리즘이 기존에 제안되었던 두 개의 알고리즘인 1)전송전력과 최소제곱평균오차(MMSE) 수신필터 최적화 알고리즘, 2) 전송전력 최적화 알고리즘보다 전송전력 소모량에서 성능이 우수함을 실험을 통해서 확인하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.986-991
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• 2014

The PPG signal used in mobile-healthcare and telemedicine system is including the various motion artifact that is signal generated from patient's movements. Recently, although the various methods to remove motion artifacts have been suggested, the performances of these methods are still not satisfactory. Therefore, this s study suggested the novel method based on the Kalman filter and adaptive filter to remove motion artifacts, and we used various motion artifacts to analyze the performance of the proposed method. In the results of experiments, the signal-to-noise ratio of proposed method showed good performace that was 4.8 times of moving average filter.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.914-919
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• 1998

This study was conducted to evaluate the purification efficacy by filter and ultra violet (UV) irradiation against inlet and outlet seawater of the land based fish farm. Purification efficacies for inlet seawater (50$\ell$/min) has been examined with filter of 60$\mu$m pore size and UV irradiation at an average dose 0.5 mWS/$cm^2$ for 5 months. For outlet seawater filter of 90 $\mu$m pore size only was used. Temperature, salinity, pH, $NO_3-N,\;NO_2-N,\;NH_4-N,\;PO_4-P$, DO and COD of inlet and outlet seawater in the system were not influenced. However, the removing rate of suspended solid and turbidity of inlet seawater were appeared to be $48.7\~65.6\%$ (average $51.9\%$) and $33/3\~42/5\%$ (average $34.8\%$) after passing through screen filter respectively. Also, germicidal efficiency to the total bacteris and Vibrio species were $16.7\~20.2\%$ (average $19.2\%$) $20.0\~21.9\%$ (average $20.9\%$) respectively after passing through UV irradiation. After passing through drum filter of 90$\mu$m pore size, suspended solid and turbidity of outlet seawater were appeared to be $42.7\~52.6\%$ (average $46.9\%$), $27.7\~29.9\%$ (average $28.3\%$), respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.959-962
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• 2012

In the process of image acquisition, transmission and storage, image degradation occurs due to various reason, the mainly reason is noise. To restore basic methods used images of impulse noise pollution by SM, AF, CWMF. In this paper, using the modified filter to remove impulse noise. The method consists of detection and noise filtering of the noise signal. For a non-noise signal is intact, the noise signal is filtered according to the algorithm. And then through the simulation is compared with known basic methods, with PSNR as judged by reference.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.78-81
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• 2004

As a society has Progressed rapidly toward a highly advanced digital information age, a multimedia communication service for acquisition, transmission and storage of image data as well as voice has being commercialized externally and internally. However, in the process of digitalization or transmission of data, noise is generated by several causes, and researches for eliminating those noises have been continued until now. The mean filter is useful method to remove AWGN (additive white gaussian noise) from degraded image and has excellent low-frequency properties. However, it brings about degradation of high-frequency properties in image. So in this paper we removed noise with mean filters added directional information and minimized degradation of high-frequency properties.

• Journal of The Korean Radiological Technologist Association
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• v.28 no.1
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• pp.241-241
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• 2002

영상 데이타는 전송, 검출 및 처리과정에서 여러 잡음에 의해 훼손될 수 있다. 적응성 가중 메디안 필터라는 공간변화 필터를 사용하여 X-선 산란 잡음을 제거하였다. 제안된 필터는 처리 윈도우 내 각 픽셀의 국소 통계치의 변화에 따라 필터의 성능이 변화하여 에너지를 최대한 보존하면서 잡음만을 제거하고자 이러한 국소 통계값에 근거한 적응성 가중 메디안 필터(AWMF)를 제시한다. AWMF를 구현함에 있어 두 가지 방법으로 나뉘는데, 우선 국소 통계의 특성에