• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.715-722
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• 2019

This paper introduces the implementation of an user-aware system using a visible light communication and its operations. The user-aware system using a visible light communication consists of the transmitter based on the Android system and the receiver based on an open-source controller. In the transmitter, user's personal information data is encoded and converted to visible light signals by the Android camera interface. In the receiver, the photodiode module receives the incoming visible light signals and converts to electrical signals and the open-source controller, that is arduino processes the received data. The processing module finds the start bit of 0111 to determine the user information data from the packet for the burst-mode communication. According to the experimental results, the proposed system successfully transmits and receives visible light data with the manchester encoding.

• Korean Journal of Optics and Photonics
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• v.23 no.4
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• pp.143-146
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• 2012

All-optical data extraction, one of the key technologies for all-optical computing and optical communication to perform add-drop, packet switching, and data reset, etc., is experimentally demonstrated by using cross-gain modulation (XGM) of semiconductor optical amplifiers (SOAs). Also, all-optical data extraction based on numerical simulation is performed by using the VPI simulation tool. In this paper, the suggested optical system based on SOAs shows the potential for high speed, and highly integrable and low power optical data computing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.514-517
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• 2017

In solar photovoltaic systems, power generation is greatly affected by the weather conditions, so it is essential to predict solar energy for stable load operation. Therefore, data on weather conditions are needed as inputs to machine learning algorithms for solar energy prediction. In this paper, we use 15 kinds of weather data such as the precipitation accumulated during the 3 hours of the surface, upward and downward longwave radiation average, upward and downward shortwave radiation average, the temperature during the past 3 hours at 2 m above from the ground and temperature from the ground surface as input data to the algorithm. We analyzed the statistical characteristics and correlations of weather data and extracted the downward and upward shortwave radiation averages as a major elements of a feature vector with high correlation of 70% or more with solar energy.

• 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 Contents Association Conference
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• 2011.05a
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• pp.83-84
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• 2011

초분광 영상은 기존의 다중분광 영상보다 많은 밴드를 통해 넓은 범위의 파장 영역에 대한 반사율을 담고 있는 고차원 데이터이다. 이와 같은 고차원 데이터를 기존의 R-Tree, X-Tree와 같은 다차원 색인 방법을 사용하게 되면 차원의 저주(Course of Dimensionality)라는 문제가 발생한다. 본 논문에서는 차원의 저주 문제를 해결하기 위해 피라미드 기법을 사용하여 초분광 영상 라이브러리의 색인을 구축하였다. 파라미드 기법은 D차원의 데이터를 2D차원의 피라미드에 사상하고, B+-트리를 이용하여 1차원적으로 색인하는 방법이다. 실험 결과 스펙트럼 매칭을 위한 영역질의 방법이 후보자 추출 시간, 데이터 접근 빈도 측면에서 순차적 접근 방법보다 좋은 성능을 나타냈다.

• The Journal of the Acoustical Society of Korea
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• v.3 no.2
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• pp.30-34
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• 1984

본 논문에서는 인코히어런트광 매트릭스-벡터곱셈기를 이용하여 입력 데이터를 광학적으로 DFT 할 수 있는 방법을 연구하였다. DFT의 웨이팅함수를 매트릭스로 나타내어 본 논문에서 제시한 2 개의 성분 분할 방법을 이용하여 마스크상에 부호화하고 광매트릭스-벡터곱셈기내에 고정시켜서 입력 데이터와 광학적으로 곱하도록 하였다.

• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.68-74
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• 2006

We have extracted an optical clock signal from a return-to-zero(RZ) pseudorandom bit sequence(PRBS) and non-return-to-zero(NRZ) PRBS data in a pulsation multi-section laser diode with DFB reflector. The ms timing jitter achieved less than 1 ps for the input 11.727 Gbit/s RZ PRBS and NRZ PRBS data. The PRE data wasconverted from the NRZ data using an NRZ to pseudo-return to zero(PRZ) converter module. The optical clock was extracted from the PRZ data which contains the clock components. Although the input PRZ data gives a timing jitter of 2 ps, the extracted clock has timing jitter of ${\~}$1 ps.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.549-550
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• 2021

사용자에게 맞춘 개인화된 제품과 서비스를 제공하는 기술의 발전으로 개인화의 수요는 점점 늘어날 것으로 전망하고 있다. 또한 개인 맞춤형으로 전문 스포츠 선수화, 족부 장애우를 위한 정형 제화 등 전문적인 기능 중심의 개인화나 패션을 위한 스타일 중심의 개인화 등 개인 맞춤 제작 신발을 제작할 때 기존의 아날로그적인 방식으로 발 변인을 측정했을 때 각 변인에 대해 기준점이 명확하지 않아서 재현성이 떨어진다. 따라서 본 논문에서는 자를 이용해 간단히 측정 가능한 기본적인 발 변인 이용하여 다른 변인들을 학습하고 딥러닝을 이용해 추정하는 방법에 대해 서술한다. 이를 위해 20개의 발 변인을 휙득 하였고 그 중 6개의 기본적인 발 변인을 이용해 14개 변인을적합 방지를 위해 Dorpout을 적용해 학습하고 학습한 데이터를 이용해 학습하지 않은 데이터를 테스트해 각 변인별 결과를 보여준다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.738-740
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• 2017

Visible light communication is a communication method using light, and it has advantage of ensuring security in a single space as compared with RF communication. However, in the area outside the visible line of the light, communication disconnection occurs. Therefore, this paper proposes a relay module to overcome the coverage extension and communication disconnection phenomenon of visible light communication. The proposed relay module transmits and receives data of visible light communication by sequentially transmitting data packets including target ID through adjacent visible light module. Through experimentation of data transmission, we confirmed the extension of the transmission range and the data reception in the area outside the line of sight.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.41-46
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• 2012

Visible light communication(VLC) system based on LED devices has some specific advantages compared with RF system. First, visible light is harmless to human and there is no limit to using frequency band. Also, VLC system has good security performance, and it can use the very wide frequency band for data transmission. However, for simultaneously using the illumination and data transmission in VLC systems, degradation of code rate is occurred. So, in this paper, we proposed the novel line coding scheme for flicker free and efficient dimming control in VLC systems. From the simulation results, it is confirmed that proposed scheme has good flicker, dimming, and transmission performance compared to conventional variable pulse position modulation(VPPM) scheme.