CGI 기능의 확장에 의한 분산 WWW 정보검색 시스템

홍영진(Young-Jin Hong),김영실(Young-Sil Kim),백두권(Doo-Kwon Baik) 한국정보과학회 1995 한국정보과학회 학술발표논문집 Vol.22 No.2A

본 논문은 최근 들어 각광 받고 있는 WWW 정보검색 시스템의 CGI 기능을 확장하여 기존에 독립(standalone)형의 정보검색 시스템을 분산된 형태의 정보검색이 가능하도록 하는데 주안점을 두고 있다. 이렇게 확장된 CGI 는 각 DB 호스트가 가지고 있는 정보에 대한 참조 자료로 주검색 서버용으로는 UQMDIL 를, DB 호스트용으로는 LQMD 를 각 DB 호스트의 DBMS 스키마 정보를 이용해 구성하여 사용한다.

무선 통신과 스마트폰을 이용한 LED 색온도 제어 조명 시스템에 관한 연구

홍영진(Young-Jin Hong),임순자(Soon-Ja Lim),이완범(Wan-Bum Lee) 한국산학기술학회 2017 한국산학기술학회논문지 Vol.18 No.11

현대 사회에서 조명은 인간 중심적인 자연 조명의 변화를 연출하고 에너지 소비 절감과 효율적인 관리를 위하여 IT 기술과 LED를 결합한 형태로 개발 되고 있다. 따라서 본 논문에서는 Arduino Due와 Bluetooth 및 Zigbee 무선통신 기술을 이용하여 3000K Warm LED와 6000K Cool LED로 구성된 LED 조명의 색온도 및 밝기를 제어할 수 있는 LED 조명 제어시스템을 제안하였다. Arduino Due는 Duty rate을 조절하여 조명의 색온도를 여러 단계로 조절 할 수 있도록 하였고, 1:N 다중통신이 가능한 Zigbee 통신을 이용하여 많은 조명을 제어할 수 있도록 하였다. 그리고 Bluetooth 통신을 이용하여 스마트 폰 어플리케이션으로 LED 조명을 손쉽게 제어할 수 있도록 하여 사용자의 편리성을 증대시켰다. 본 논문에서 구현한 무선통신 기반의 LED 조명제어 시스템은 3067K∼5960K의 다양한 색온도 제어와 조도 제어를 통하여 인간 중심적인 조명을 연출할 수 있을 뿐만 아니라 소비전력을 줄일 수 있어 자연 친화적인 조명 시스템으로 활용될 수 있을 것으로 사료된다. Lighting systems in modern society has been developed using a combination of IT technology and LED lighting for the purpose of bringing aboutchanges in human-centered natural lighting and to take advantage of the efficient management and energy saving of LED lighting. In this paper, we propose an LED lighting control system that can control the color temperature and brightness of LED lighting composed of 3000K Warm LEDs and 6000K Cool LEDs by using an Arduino Due and wireless communication technology such as Bluetooth and Zigbee. The Arduino Due allows the color temperature of the lighting to be adjustedin several steps by controlling the duty rate and enables many lights to be controlledusing Zigbee communication capable of 1: N multiple communication. By using Bluetooth communication, it is possible to easily control the LED lighting by means of a smartphone application, thereby enhancing the convenience for the user. The wireless communication based LED lighting control system implemented in this studycannot only provide human-centered lighting through its color temperature control from 3067K to 5960K and illumination control, but can also reduce the power consumption and be used as a natural-friendly lighting system.

DMFT 수치와 법랑질 강도 간 상관관계

홍영진 ( Young Jin Hong ) 국군의무사령부 2018 대한군진의학학술지 Vol.49 No.1

Objectives; This Study was performed in order to find out about corelation between DMFT(Decay, Missing, Filling Tooth) index and tooth enamel density. Previously, difference in caries evolving rate between each individual was explained by the difference of saliva formation rate or the mineral construction of saliva. However the goal of this study is to find out whether there is a significant difference in tooth enamel density between each individual and whether that difference in density affects caries evolving rate. Methods; To find the corelation between DMFT index and tooth enamel density, 18 to 23 year old male who wanted their third molar extracted were selected as subject of this study. After examining DMFT index of each subject, 3rd molars were extracted in general method. Tooth enamel portion from extracted 3rd molar was collected and prepared into cube shaped specimen and embedded into epoxy resin mold. Microload system (Universal Testing System; R&B Inc.) was used to examine the density of every specimen. After the data was collected, t-test was perform to find out about the correlation between DMFT index and tooth enamel density. Results; According to the study, DMFT index of total 20 individuals differed from 0/28 to 18/28 and maximum stress value of tooth enamel specimen varied from 39.8 to 102.8 MPa and the mean value of maximum stress was 68 MPa. By conducting t-test between DMFT index and tooth enamel density value, the result showed no statistically significant correlation between DMFT index and tooth enamel density. Conclusions; Although the result of this study showed no statistically significant correlation between DMFT index and tooth enamel density, there were limitations in the study and a few things to modify. Also, if there were a way to quantitatively analyze XRD(X-ray diffraction) result, it would better clarify whether there is a correlation between tooth caries evolving rate and calcification of each individual's enamel. However, according to this study, it would be better to provide more personalized treatment opportunity to each one serving in the military than providing preventive services such as fluoride care.

와이파이AP 용 FFT 전단 스마트안테나의 성능 개선

홍영진(Hong, Young-Jin) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.5

Wi-Fi AP(Access Point)의 기반구조인 OFDM(Orthogonal Frequency Division Multiplexing)의 동일채널 간섭 신호에 대한 취약성과 그 대책의 하나인 OFDM과 스마트안테나의 결합구조가 설명되었다. 높은 효율을 보장하지만 복잡성을 수반하는 FFT(Fast Fourier Transform) 후단 구조 대신 저렴한 구축비용이 장점인 수신신호 분산행렬 기반의 FFT 전단 스마트안테나의 수학적 모델이 전개되었다. 그 BER(Bit Error Rate) 특성을 높이기 위하여 제안된 채널행렬 출력 분산행렬을 기반으로 한 FFT 전단 구조 스마트안테나의 성능 측정을 위한 컴퓨터 모의실험이 수행되었다. 수신 신호 분산행렬에 의해 생성된 가중치벡터에 비해 채널행렬 출력에 의한 가중치벡터가 다양한 페이딩 환경 변화에서 우월한 성능을 보임이 증명되었다. OFDM Wi-Fi AP is susceptible to the co-channel interference. As a countermeasure, the insertion of a smart has been addressed. Despite of the guaranteed efficiency, the complexity of the post-FFT algorithm often keeps itself from being selected as the countermeasure. Instead, simply constructed pre-FFT smart antenna of which the algorithm is based on the received signal covariance matrix is commonly used and the mathematical modeling of it has been deployed. Computer simulations evaluating the improved BER characteristics of the proposed pre-FFT using the covariance matrix of channel estimator output have been carried out. It has been demonstrated that channel matrix output based smart antenna is superior to that using received signal covariance matrix.

M-ary OSTBC MIMO 시스템의 성능 연구

홍영진(Hong, Young-Jin) 한국산학기술학회 2015 한국산학기술학회논문지 Vol.16 No.9

Alamouti 알고리즘에 기반한 M-ary 2×N OSTBC(Orthogonal Space Time Block Coded) MIMO(Multi Input Multi Output) 시스템의 성능을 두개의 파라미터, 즉 constellation 숫자(M)와 수신안테나 숫자(N)를 변화시키며 컴퓨터 모의실험에 의하여 알아보았다. 2×N MIMO 시스템의 성능과 단일 송신안테나 시스템의 성능비교를 위하여 MRC(Maximum Ratio Combining) 다이버시티 안테나 시스템의 성능 역시 컴퓨터 모의실험을 통하여 수행하였다. 10 dB EbNo QPSK 시스템의 경우 Alamouti 2×1 MIMO가 단수안테나 시스템에 비해 4.2 dB의 BER을 향상시켰으며 2×2 MIMO는 1×2 MRC 대비 7.4 dB의 BER을 향상시켰다. Performance of the Alamouti algorithm based M-ary 2×N OSTBC(Orthogonal Space Time Block Coded) MIMO(Multi Input Multi Output) system has been simulated varying two main parameters – the number of constellation(M), and the number of receiving antennas(N). Computer simulation has also been carried out using Matlab software for performance comparison between 2×N MIMO and MRC(Maximal Ratio Combining) diversity antenna system to evaluate the degree of enhancement achieved through the use of Alamouti 2×N MIMO. Under 10 dB EbNo QPSK scenario, 2×1 MIMO brought 4.2 dB BER improvement over single antenna system and 2×2 MIMO resulted in 7.4 dB BER improvement over 1×2 MRC.

농촌유역의 질소 오염원과 기여도 해석을 위한 δ ¹⁵N 분석

홍영진 ( Hong Young Jin ),권순국 ( Kwun Soon Kuk ) 한국농공학회 2000 한국농공학회 학술대회초록집 Vol.2000 No.-

It has been acknowledged that fertilizer, natural soil nitrogen and animal waste, municipal waste have different mass ratio of nitrogen which is presented as a symbol of δ ¹⁵N. and that the values of δ ¹⁵N for fertilizer and natural soil nitrogen and animal waste are placed less than +5‰ and higher than +10‰, respectively. thus, Nitrogen pollution sources and contribution can be interpreted in watershed through δ ¹⁵N analysis and then, analysis is performed with Kjeldhl-Dumas method. In this study, The values of δ ¹⁵N are between +1.46‰ and +8.97‰, and the nitrate concentration is placed less than 3.31mg/L and higher than 0.19mg/L, respectively. Thus, this watershed is noncontamination area at the present time. But as a result of δ ¹⁵N, contribution of natural soil nitrogen be discovered in this watershed, presently.

농촌하천 유역의 주 오염원 추적을 위한 안정성 동위원소 질량비 분석

홍영진 ( Hong Young Jin ),김철성 ( Kim Chul Sung ),권순국 ( Kwun Soon Kuk ) 한국농공학회 1999 한국농공학회 학술대회초록집 Vol.1999 No.-

It has been acknowledged that fertilizer and animal waste have different ratio of ¹⁵N/¹⁴N which is presented as a symbol of δ ¹⁵N, and that the values of δ ¹⁵N for fertilizer and animal waste are placed less than +8%₀ and higher than +10%₀, respectively. By this reason, the demarcation range for the source nitrogen mass ratio is between +8 %₀ and + 10 %₀. In this study, we would suggest a possible method to trace the major pollution basis using 'the nitrogen isotope analysis method for management of water quality.

다중경로페이딩이 DDLMS 기반 스마트안테나의 성능에 미치는 영향

홍영진(Young-Jin Hong) 한국통신학회 2009 韓國通信學會論文誌 Vol.34 No.9

레일리 페이딩 내구성을 개선시키는 OFDM 스마트안테나의 성능 분석

홍영진(Young Jin Hong) 大韓電子工學會 2011 電子工學會論文誌-TC (Telecommunications) Vol.48 No.4

OFDM(Orthogonal Frequency Division Multiplexing) 시스템의 Rayleigh fading 에 대한 내구성을 증대시키기 위하여 채용되는 2 종류의 스마트안테나 즉 귀납적인 고유공간법에 기반한 FFT(Fast Fourier Transform) 전단 스마트안테나와 Wiener 해법에 기반한 FFT 후단 스마트안테나의 가중치벡터 갱신의 수학적 모델을 정의한 후 컴퓨터 모의실험에 의거, 그 성능들을 비교 분석하였다. 장치의 복잡성의 대가로 FFT 후단 스마트안테나의 성능이 훨씬 우수함이 보여졌고 특히 다중경로의 시간지연이 OFDM 가드타임을 벗어날 경우와 강한 동일채널 간섭신호가 존재할 경우의 FFT 후단 스마트안테나 성능의 우월성이 입증되었다. FFT 후단 스마트안테나의 복잡성을 줄이기 위하여 제안된 부채널 군집형 가중치벡터 갱신 안테나와 부채널 전력기반의 MRC(Maximum Ratio Combining) 다이버시티 안테나 기법의 성능이 전형적인 Wiener 해법에 기반한 FFT 후단 스마트안테나와 비교되었다. In order to augment the robustness of OFDM system to Rayleigh multipath fading, there exist two smart antenna algorithms, namely, Pre-FFT smart antenna and Post-FFT smart antenna. After the mathematical modeling of both smart antenna algorithms, computer simulations have been carried to compare and analyze the performance of generalized eigen problem based Pre-FFT algorithm and the performance of Wiener solution based Post-FFT algorithm. It has been shown that the Post-FFT smart antenna far outperforms the Pre-FFT smart antenna due to the computational complexities. Especially it is so when the multipath signal arrives at beyond the guard interval and a rich co-channel interferer is introduced. Performance of a subcarrier clustering method proposed to lessen the computing load has been compared to that of a typical Wiener solution based Post-FFT smart antenna. Performance comparison between MRC(Maximum Ratio Combining) diversity based Post-FFT algorithm and typical Post-FFT algorithm has also been carried.

안정 동위원소비를 이용한 농촌하천유역 질산성 질소의 오염원 추정

홍영진 ( Hong Young Jin ),권순국 ( Kwun Soon Kuk ),홍성구 ( Hong Seong Gu ) 한국농공학회 2001 韓國農工學會誌 : 전원과 자원 Vol.43 No.4

Pollution sources and their environmental contributions were investigated to select the best management practices for the effective control of water quality. The nitrogen isotope mass ratio was determined to estimate the nitrate sources and their contribution Sampling sites were chosen by calculating effluent loads at each watershed. Two liters each of the surface water samples were collected from four sites at Bokha river and two sites at Gwanri river. They were sequentially prepared through distillation method and analyzed using an isotope ratio mass spectrometer(IsoPrime EA). As revealed by the experimental values obtained, the mass ratio values(□ ¹⁵N) of watersheds with a large amount of nonpoint sources were less than +5%, an indication that the samples were influenced by chemical fertilizers. However, watersheds with large amount of point sources were influenced not only by chemical fertilizers but also by animal and municipal wastes. The mass ratio values of samples generally decreased during rainy days. But, during dry days, the mass ratio values well-reflected the nitrate sources the condition of watersheds. Through this study, the nitrogen isotope mass ratio has been found to be useful for estimating nitrate sources and their contribution to the rural watersheds