• Proceedings of the Korea Society for Industrial Systems Conference
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• 1998.03a
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• pp.305-311
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• 1998

본 논문에서는 회전과 크리에 무관한 상관결과를 얻기 위하여 WCHF-fSDF(wavelet circular harmonic function-filter modulation synthetic discriminant function)필터를 제안하였다. WCHF-fSDF 필터는 기준영상에 대하여 크기변화된 영상들을 웨이브릿 변환한 후, 이들로부터 추출한 단일 원형고조함수를 학습영상으로 사용하여 합성한다. 웨이브릿 변환은 입력영상과 웨이브릿 함수와의 상관으로 정의되므로 웨이브릿 변환을 이용한 패턴인식을 하기 위해서는 두 개의 4f 광 상관 시스템이 필요하다. 여기서 입력영상에 필요한 웨이브릿 함수를 제안된 필터의 설계과정에 포함시켜 전체 광 상관 시스템을 하나의 4f 광상관시스템을 대체시켰다.

• Journal of Korea Multimedia Society
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• v.7 no.3
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• pp.349-356
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• 2004

In this paper, a practical image security system using SA algorithm and 4-f optical correlator system is proposed. The encrypted image and key image with binary phase components are generated using an iterative SA algorithm. a decrypted image is found through the correlation of the encrypted and key images using 4-f optical correlator system. The encrypted and key images are consisted of binary phase components. So, it is easy to implement the optical security system using the proposed technique. And if we fix the encrypted image in the optical security system and change the key images, we get different images, so it is possible to apply to the distinguished authorization system using different key images. Computer simulations show that despite the binary phase components of the two images(encrypted and key image), decrypted images are generated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.173-181
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• 1997

To estimate the leaf area index(LAI) of rice plant by non-destructive method, spectral reflectance from rice plant canopy was measured by using the spectroradiometer (LI-1800, LICOR Inc.) with one week interval during the rice growing season at Suwon paddy field in 1993. LAI of two medium late maturing varieties, Daechungbyeo and Ilpumbyeo, and one early maturing variety, Jinbubyeo, were observed and compared with those estimated by vegetation index. The reflectance(R) of visible wavelength remained less than 0.1 over entire growing season, but that of near infrared wavelength remained from 0.1 to 0.5 with the significant positive correlation with LAI. Vegetation index determined by the reflectance of visible against near infrared wavelength showed high correlation with LAI of rice canopy. Vegetation index derived from wide band ratio, NIR(720~1, 100nm) /Blue(400~500nm), showed the highest correlation coefficient with LAI. Vegetation index derived from narrow band(10nm interval) ratio, R910/R460, from transplanting to heading stage corresponded well to measured values (Y=0.16799X-0.79776 ; $R^2$=0.94). But another vegetation index, NIR(720~1, 100nm) /Red (600~700nm), showed higher correlation with LAI than NIR /Blue did from heading stage to maturity.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.2
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• pp.383-388
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• 2024

This paper is a study to derive the predicted value of power generation based on the photovoltaic power generation data measured in Jeollanam-do, South Korea. Multivariate variables such as direct current, alternating current, and environmental data were measured in the inverter to measure the amount of power generation, and pre-processing was performed to ensure the stability and reliability of the measured values. Correlation analysis used only data with high correlation with power generation in time series data for prediction using partial autocorrelation function (PACF). Deep learning models were used to measure the amount of power generation to predict the amount of photovoltaic power generation, and the results of correlation analysis of each multivariate variable were used to increase the prediction accuracy. Learning using refined data was more stable than when existing data were used as it was, and the solar power generation prediction algorithm was improved by using only highly correlated variables among multivariate variables by reflecting the correlation analysis results.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.101-101
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• 2016

하천원격탐사는 원격탐사의 하위 개념으로서 계측하고자 하는 대상인 하천이나 호소 수체에서 발생하는 빛의 반사, 복사 또는 방출되는 양을 획득하고 분석하여 수리량, 지형 등 하천 조사에 활용하는 기법이다. 일반적으로 원격탐사는 주로 위성영상 자료를 활용하여 수행되어 자료취득비용이 고가이고 해외 위성자료에 의존하여 시공간적인 해상도가 매우 낮아 유역에 비해 공간적인 규모가 작고 변동 시간이 짧은 하천에 적용하는 데 한계가 있어 왔다. 또한, 단순한 사진촬영으로 도출할 수 있는 정보에 한계가 있고 자료를 저장 및 분석할 수 있는 기법도 부족하여 하천조사에 원격탐사를 활용한 사례가 드물었다. 그러나, 최근 드론과 같은 운반체 기술이 획기적으로 개선되고 있고 다양한 영상촬영장비의 개발과 IT기술의 발전으로 인해 위성영상에 비해 시공간적 해상도가 매우 정밀한 자료를 저렴한 비용으로 획득 가능해졌다. 또한, 매우 조밀한 파장대로 세분된 빛의 세기를 측정할 수 있는 초분광 영상을 이용한 원격탐사기법도 하천과 같은 좁은 영역에 적용이 가능해졌다. 초분광영상은 가시광선 외에 자외선과 적외선 영역에 해당하는 반사광을 200개 이상의 조밀한 파장대로 나누어 측정할 수 있어 수리량, 하상, 식생 등 하천 수체와 관련된 정보를 조사할 가능성이 증가하였다. 본 연구에서는 하천 수체에서 취득한 초분광 영상을 이용하여 하천특성과의 상관관계를 규명하고 이를 통해 초분광 영상 기반의 하천특성 계측 기법을 개발하고자 하였다. 드론과 같은 항공영상에 적용하기 전에, 우선 지상에서 측정된 초분광 영상과 하상재료 및 수심과의 상관관계를 규명하여 초분광 영상의 하천조사로의 사용 가능성을 점검해 보았다. 폭 10m, 수심 1m의 저수심의 소하천에 적용한 결과, 초분광 영상의 표준화 및 패턴 분석을 통해 수중에 위치한 하상재료를 구분할 수 있었고 주성분분석 등을 통해 수심과 상관성도 일부 도출되어 하천조사에 초분광영상이 활용될 수 있음을 확인하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.704-706
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• 2022

In this study, we analyzed the correlation between the amount of photovoltaic power generation and the factors of meteorological changes. A total of 52,561 data were used in the correlation analysis from January 2018 to January 2020, and the variables used in the correlation analysis were time, horizontal plane scattering solar radiation, direct solar radiation, wind velocity, and relative humidity. The temperature was used. Based on this data, we used the Google Colab platform to analyze the correlation, and the analysis revealed whether there was a correlation between solar power and meteorological change factors.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.11
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• pp.111-118
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• 1990

In this paper, pSDF-based referance image is realized. Using BJTC (binary joint transform correlator) as the spatial plane correlator, optical pattern recognition for interclass identification and interclass discrimination is performed. Computer simulation shows that the correlation performance of BJTC is superior to that of JTC. Experimental results using BJTC reveal that correlation peak intensity is constant within the error rang from $4.1{\%}\to\9.6{\%}$ in interclass identification and correlation peak intensity of one class is two times higher than that of the other class in interclass discrimination, which indicates its superiority in discrimination sensitivity.

• Ecology and Resilient Infrastructure
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• v.6 no.3
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• pp.171-177
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• 2019

The hyperspectral images can be analyzed in more detail compared to the conventional multispectral images so they can be used for analyzing surface properties which are difficult to detect. Therefore, the purpose of this study is to obtain information on river environment by using actual depth data and drone-based images. For this purpose, this study acquired the image values for 100 points of 1 survey line using drone-based hyperspectral sensors and analyzed the correlation in comparison with the actual depth information obtained through ADCP. The ADCP measurements showed that the depth tended to get deeper toward the center and that the average water depth was 0.81 m. As a result of analyzing the hyperspectral images, the value of maximum intensity was 645 and the value of minimum intensity was 278, and the correlation between the actual depth and the results of analyzing the hyperspectral images showed that the depth increased as the value of maximum intensity decreased.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1995.06a
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• pp.758-763
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• 1995

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.56-60
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• 2002

Since the transmittance of solar radiation directly affected by the structural frames of greenhouse can be changed according to the ratio of diffuse to direct radiations, it is necessary to investigate the transmittance of greenhouse at the different weather conditions. We can easily get the data of total solar radiation from the Meteorological Administration, but we have to personally measure the photosynthetic photon flux (PPF). If the relationship between total solar radiation and PPF is established, the PPF can be simply acquired from the relationship. Sol it is required to develop the equation to calculate PPF depending on weather condition. This study was conducted to determine the transmittance of PPF at canopy level in glasshouse and the correlation between total solar radiation and PPF at clear and cloudy days. The variation phase of greenhouse transmittance at clear day was very different from that at cloudy day. It was concluded that the proper transmittance, depending on the weather condition, should be adopted to calculate the accurate total solar radiation and PPF in greenhouse. The transmittance of solar radiation was the same as that of PPF in greenhouse. It was confirmed that the ratio of PPF to total radiation increased as the amount of cloud increased. The correlation between the hourly total solar radiation and PPF was derived.