• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.491-492
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• 2012

• ETRI Journal
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• 제36권3호
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• pp.460-468
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• 2014

This paper addresses the problem of joint time of arrival (TOA) and direction of arrival (DOA) estimation in impulse radio ultra-wideband systems with a two-antenna receiver and links the joint estimation of TOA and DOA to the sparse representation framework. Exploiting this link, an orthogonal matching pursuit algorithm is used for TOA estimation in the two antennas, and then the DOA parameters are estimated via the difference in the TOAs between the two antennas. The proposed algorithm can work well with a single measurement vector and can pair TOA and DOA parameters. Furthermore, it has better parameter-estimation performance than traditional propagator methods, such as, estimation of signal parameters via rotational invariance techniques algorithms matrix pencil algorithms, and other new joint-estimation schemes, with one single snapshot. The simulation results verify the usefulness of the proposed algorithm.

• 방송공학회논문지
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• 제7권4호
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• pp.317-326
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• 2002

기존 비디오 압축 기술에 비해 높은 부호화 효율 덴 추가적으로 오류내성, 네트워크 친화성 등의 특성을 지닌 H.264 표준안 부호화 기술 가운데, 복수개 참조 영상을 이용하여 다양한 블록 크기로 움직임 보상하는 기법은 높은 부호화 효율을 갖게 하는 주 요인임과 동시에 높은 복잡도를 갖게 하는 원인으로 작용한다. 이러한 움직임 보상의 복잡도를 줄이기 위해 본 논문에서는 다양한 블록 크기에 대한 선택적 움직임 추정 알고리즘을 제안하고자 한다. 제안된 기법에서는 먼저 다이아몬드 탐색 기법을 이용해 초기 위치 지점에 대해 SAD(Sum of Absolute Difference)를 구하고 이를 기반으로 움직임 추정을 추가적으로 수행할 것인가를 각 블록 크기 단위로 결정하게 된다. 실험 결과, 움직임 탐색 영역을 $\pm$32로 하였을 경우 제안 기법은 기존의 전역 탐색(Full Search)에 비해 약 5배 정도 속도 향상을 보였다.

• 한국음향학회지
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• 제23권7호
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• pp.514-520
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• 2004

수중에서 음원의 위치 추정을 위해 적용되어지는 기법으로써 시간지연차 (TDOA : Time Difference Of Arrival) 추정, 빔 형성 기법, 고 분해능 기법 등이 있다. 본 논문에서는 상대적으로 적은 수의 센서를 사용하여 주파수 영역에서 시간 지연차 추정에 사용되는 MCPSP (Modified Cross Power Spectrum Phase) 함수를 이용하였다. 그러나 MCPSP 함수에 기반한 방법은 CW (Continuous Wate) 신호를 대상으로 할 경우 추정 성능이 크게 떨어진다. 이에 본 논문에서는 Pulsed CW신호를 사용하는 수중 음원의 위치를 추정하기 위해 단 구간 (short-time) 에너지 검출을 이용하여 핑(ping)의 경계 영역을 포함하는 세그먼트를 구성하고 이로부터 MCPSP 함수를 구하는 방법을 제안하였다. 제안된 방법의 성능에 대한 이론적인 접근과 함께 다양한 환경 하에서 분석이 이루어졌다.

• 한국산림과학회지
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• 제99권3호
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• pp.304-311
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• 2010

본 연구는 2006년부터 시작된 국가산림자원조사부터 표본점 설계방법과 적용 단목재적식을 변경하여 적용함으로써 과거와는 다른 임목축적 추정치의 경향을 보이고 있어 그 원인을 구명하기 위해 수행하였다. 이를 위해 본 연구에서는 20개 집락의 80개 표본점을 대상으로 제4차 및 제5차 국가산림자원조사의 표본점 설계방법에 따라 자료를 수집한 후, 현재 사용하고 있는 수종별 단목재적식과 과거에 사용하였던 단목재적식을 적용하여 임목축적을 추정한 후 표본점 설계 방법 및 적용 단목재적식의 변경에 따른 임목축적 추정치의 차이가 있는지를 평가하였다. 임목축적 차이의 원인을 구명하기 위해 t-검정을 실시한 결과 표본점 설계방법의 변경에 따른 임목축적의 차이는 인정되지 않았으며, 사용된 단목재적식의 변경에 의해서 통계적으로 인정할 수 있는 임목축적의 차이가 발생하는 것으로 분석되었다. 결과적으로 제5차 국가산림자원조사를 통해 얻어지는 임목축적은 적용 단목재적식의 변경에 의해 차이가 발생하기 때문에, 국제기구에 보고하기 위해서는 재계산을 통해 2006년 이전의 임목축적 추정치의 보정이 필요할 것으로 평가되었다.

• Journal of Biosystems Engineering
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• 제34권4호
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• pp.269-277
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• 2009

In this research, the vegetation growth and rice taste of the liquid fertilizer applied fields (LF) were compared with those of chemical fertilizer applied fields(CF) in order to confirm the possibility of methane fermentation digested sludge as liquid fertilizer using precision agriculture and remote sensing technology. In panicle initiation stage, the vegetation growth at LF was 60%~80% of it at CF and there were significant difference of nitrogen contents between CF and LF. The estimation model of nitrogen contents was established by GNDVI (R=0.607, RMSE=$1.04\;g/m^2$, n=36, p<0.01). In heading stage, vegetation growth at LF went close to it at CF as ratio of 80%~95%. The nitrogen content estimation model was also established (R=0.650, RMSE=$1.73\;g/m^2$, n=35, p<0.01) and there were significant difference of spatial variability between LF and CF. There were not significant difference of rice taste and it's elements, when three samples, which were more than twice of standard deviation, were excepted. The protein contents estimation model using GNDVI of before harvesting (R=0.700, RMSE=0.470%, n=29, p<0.01) were more suitable to predict the protein contents at harvesting comparing with it of heading stage(R=0.610, RMSE=0.521%, n=29, p<0.01).

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.283-286
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• 2003

In order to examine effects of sampling frequency during rainfall-runoff process from paddy field on the estimation of pollution load, EMCs of several water sampling frequencies were examined. It was found that the difference of EMCs between one time sampling and two hours consecutive sampling during storm event showed $34.1{\sim}-19.1%$ for T-N, $55.4{\sim}-27.3%$ for T-P, $68.5{\sim}-41.0%$ for the SS, respectively. Five times sampling reduced difference of EMCs compared to those two hours interval sampling to $15.2{\sim}-15.2%$ for T-N, $20.0{\sim}-26.2%$ for T-P, $28.6{\sim}-35.7%$ for the SS, respectively.

• 한국인터넷방송통신학회논문지
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• 제13권5호
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• pp.85-91
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• 2013

실내에서의 위치기반 서비스 및 상황인식 서비스를 위해서는 실내에서의 정밀한 위치인식 기술이 필수적이다. 신호원과 여러 개의 신호 수신기와의 거리 차이를 이용하여 신호원의 상대위치를 추정하는 TDOA(Time Difference of Arrival) 기술이 사용되고 있는데, 거리 차이 측정의 오차에 따른 위치 추정 오차가 발생하므로 이를 최소화하기 위한 연구가 많이 진행되어 왔다. 본 논문에서는 신호원과의 거리 차이값을 이용하여 계산된 여러 근중에서 실제의 근을 선별하고 이를 평균내어 신호원의 위치를 추정하는 알고리즘이 제안되었으며, 기존의 방법에 비해 오차가 개선되었다.

• 초등상담연구
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• 제4권1호
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• pp.215-236
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• 2005

The Purpose of this study is that self-growth program searches effect self-concept and peer-relationship with elementary school student, and advance following assumption to achieve this purpose and achieved study. First, self-concept point of experiment group students who execute self-growth program will be improved is meaning than self-concept point of control group students. Second, peer-relationship point of experiment group students who execute self-growth program will be improved is meaning than peer-relationship point of control group students. Third, effect that self-growth program gets to self-concept may be meaning difference according to sex. Fourth, difference that impact that self-growth program gets in peer- relationship is meaning according to sex may join. Chose fifth-year student 2 class 68 people (experiment group n=34, control group n=34) in I primary school locating to Jeonrabuk-do Iksan-si to verify above construction for study target. Disposal about experiment group executed over 10th for 60-80 minute 2 times in a week because investigator uses reconstructing self-growth program with virtue research paper such as learning program for own growth of Lee-Hyeong-Deuk (1998). In order to verify the effect after experiment, 1 collected materials for estimation by providing the subject children with questionaires about self-concept and peer-relationship before and after the experiment, and then analyzed the average differences in number of marks between the experiment group and the control group before and after the experiment through and by using One-Way ANOVA, and SPSS 11.0 program. The following is the result what I obtained from the above study. First, there was significant difference is between average difference before and after of experiment group and control group which execute self-growth program in self-concept elevation ($F_{(1,66)} =28.734$, p <.001). From the sub-variable, there was significant difference in academic self ($F_{(1,66)}=6.423$, p<.05), Social Self ($F_{(1,66)}=48.331$, p<.001), Physical Self ($F_{(1,66)}=11.074$, p <.01), sentimental self ($F_{(1,66)}=9.402$, p <.01) Second, there was significant difference is average difference before and after of experiment group and control group which execute self-growth program in peer-relationship promotion ($F_{(1,66)}=24.109$, p <.001). From the sub-variable there W3S Significant difference in trust ($F_{(1,66)}=14.507$, p<.001), respect ($F_{(1,66)}=15.271$, p <.001). Third, there was expose that significant difference does not exist in average self-concept before and after by sex of experiment group which executes self-growth program, and was not shown significant difference in sub-vairable. Fourth, there was expose that significant difference of whole peer- relationship and in respect of sub-variable in average peer-relationship before-after by sex of experiment group which execute self-growth program, but significant difference did not appear in trust. Could get conclusion that self-growth program is effect in elementary school student self-concept elevation and peer-relationship promotion according to these study finding, and confirmed possibility that self-growth program may contribute to change emotional special quality of children positively in education spot.

• 설비공학논문집
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• 제23권1호
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• pp.32-37
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• 2011

The present study has been conducted to propose an algorithm regarding real-time load estimation of a gas engine-driven heat pump. In the study, thermal load of an indoor unit is estimated in terms of air-side and refrigerant-side. The air-side estimation is based on a typical heat exchanger model and is found to be in good agreement with experimental data. When it comes to the refrigerant-side load, a pressure difference across a valve must be estimated. For the estimation, it is assumed to be proportional to a bigger pressure difference that is available either by measurement or by estimation. Relative good agreement between the air- and refrigerant-sides suggests that the assumption may be plausible for the load estimation. The summed flow rate of all of indoor units is in good agreement with the throughput of the compressor which are calculated from the manufacturer's software. Accordingly, estimated thermal loads are also in good agreement. The proposed algorithm may be further developed for improved control algorithm and fault diagnosis.