이동통신 기지국용 광대역 이중편파 다이폴 안테나 설계

백경훈(Kyung-hoon Baek),이용창(Yong-chang Lee),손태호(Tae-ho Son) 한국정보기술학회 2019 한국정보기술학회논문지 Vol.17 No.6

This paper is to design the base station antenna for the mobile communication system. It designed and fabricated the broadband array antenna for mobile communication base station that is commonly available for seven 3G frequency band and two 4G frequency band, totally nine mobile communication network. We used HFSS v.13 3D tool for the design and simulation of the designed antenna. Antenna was designed as orthogonally crossed printed dipole using teflon material, and the feeding part of antenna was designed as balun. The feeding array was designed using Dolph-Tschebyscheff array method equally spaced to 0.7 wavelength. It set up the reflection plate under substrate and fabricated the designed antenna on basis of simulation result, and measured its performances. The fabricated antenna has good performances as follows; VSWR and isolation of the fabricated antenna were measured under 2:1 and under -20dB respectively over desire frequency band. The result of performance measurement is good for the broadband moblie communication base station. The result of this study shows that the number of antennas for mobile communication base stations can be greatly reduced.

수평방향의 3차 스플라인 보간과 ELA을 이용한 개선된 디인터레이싱 연구

백경훈(Kyung-Hoon Baek) 한국산학기술학회 2017 한국산학기술학회논문지 Vol.18 No.1

본 논문에서는 하나의 필드 만을 사용하여 비월 주사 영상을 순차 주사 영상으로 변환하는 개선된 디인터레이싱 방법을 제안한다. 우선, 구하고자 하는 화소의 위와 아래 각각 4개 화소를 이용하여 화소 사이의 3개 점을 3차 스플라인 보간을 적용하여 구한다. 알려진 위와 아래 화소값과 3차 스플라인 보간으로 구한 위와 아래 화소 사이의 보간값으로 부터 구하고자 하는 화소를 중심으로 9방향으로 세분화하여 각각의 상관 관계를 구한다. 구하고자 하는 화소에서 위 · 아래 상관 관계가 가장 최소가 되는 방향으로 에지의 방향성을 예측하고 화소 사이의 상대적인 값이 최소가 되는 방향으로 화소의 방향성을 결정한다. 결정된 방향의 위 · 아래 화소값의 평균으로 화소값을 계산한다. 모의실험 결과 기존의 디인터레이싱 방법에 비해 약간의 소요 시간이 걸리는 문제점은 있으나 CPU의 개선으로 시간적 제약은 없다고 판단된다. 기존의 연구된 여러 디인터레이싱 방법들과의 비교를 통하여 본 논문에서 제시된 방법이 주관적 화질에 있어서 개선이 있었으며 객관적 화질에 있어서도 정량적으로 PSNR이 0.1~0.5dB 향상됨을 보이고 있다. This paper proposes an improved de-interlacing method that converts interlaced images into progressive images from one field. First, it calculates inter-pixel values applying third-order spline interpolation for the horizontal direction from four upper · lower pixel values of missing pixels. From inter-pixel values obtained from spline interpolation and upper · lower pixels with value, the proposed method makes an accurate estimate of the direction by applying the correlation between upper and lower pixels. The correlation between upper and lower pixels is calculated in nine directions of a missing pixel by using values obtained from spline interpolation and pixels with value. The direction of an edge is determined as the direction in which the correlation between upper and lower pixels is at its minimum. Thus, a missing pixel is calculated by taking the average of upper · lower pixels obtained from the predicted direction of an edge. From the simulation results, there are problems in that it takes a bit more time for processing, but it is expected that the time problem will be improved by increasing CPU processing speed. As for image quality, it is shown that the proposed method improves both subjective and objective image quality and quantitatively improves picture signal-to-noise ratio (PSNR) in the range between 0.1 dB to 0.5 dB, as compared with previously presented de-interlacing methods.

세분화된 평균값 필터 및 개선된 ELA를 이용한 디인터레이싱 연구

백경훈(Kyung-Hoon Baek),이상운(Sang-Un Lee) 한국정보기술학회 2014 한국정보기술학회논문지 Vol.12 No.5

This paper proposes an improved de-interlacing method that converts the interlaced images into the progressive images by one field. In the first, it calculates inter-pixel value applying Newtons interpolation of horizontal direction from upper·lower 5 pixel values of missing pixel. The subdivided corelation between upper and lower pixels is calculated at the edge direction of missing pixel by using values obtained from interpolation of horizontal direction and known pixels. The edge direction is estimated as the direction that the corelation value is minimum. If edge direction is incorrectly estimated, we newly determine edge direction as applying the subdivided pixels obtained by horizontal direction interpolation to MELA(Modified edge-based line average) and calculate the missing pixel from median value filter. From simulation results, it is shown that the proposed method improves both subjective and objective image quality and improves quantitatively as compared with previous de-interlacing methods.

스크립트에 기반한 시공간 상황들을 표현하기 위한 멀티미디어 시뮬레이터의 개발

백경훈(Kyung-Hoon Baek),박종희(Jong-Hee Park),김남철(Nam-Chul Kim) 한국방송·미디어공학회 1996 한국방송공학회 학술발표대회 논문집 Vol.1996 No.-

신속한 적조 예찰이 가능한 형광 측정시스템 개발

백경훈 ( Kyung-hoon Baek ),오영지 ( Yeongji Oh ),조현서 ( Hyeonseo Cho ),강윤자 ( Yoonja Kang ),이준석 ( Joon-seok Lee ) 한국센서학회 2024 센서학회지 Vol.33 No.1

The occurrence of harmful algae on the coast of Korea has been a cause of damage to the aquaculture industry and deterioration of the coastal ecosystem environment. A method is required to predict their outbreak in real-time at the site. Therefore, this study attempted to develop a small hybrid optical sensor and real-time monitoring system based on LiDAR that can be used in the field and laboratory and can be applied to various platforms. FMS-L specifically suggested the amount of Chlorophyll a (Chl a) in the sample by measuring and analyzing the fluorescence emitted by the irradiating light. The accuracy of FMS-L was verified by measuring the concentrations of standard Chlorophyll a substances and Margalfidinium polykirkoids. In addition, the precision was verified by comparing the measurement results of FMS-L using commercial equipment Phyto-PAM-II. This equipment is compact and easy to move. Therefore, it can be easily applied to field surveys, allows short time measurements (10 s), and can be applied at a distance of 10 m from the measurement site.

동적 ID 할당 기법을 이용한 CAN 통신에서의 전송지연 개선

백경훈(Kyoung hoon Baek),이원석(Won Seok Lee),하경남(Kyoung Nam Ha),Byoung Jum Son,이석(Suk Lee),이경창(Kyung Chang Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

CAN(controller area network) is widely used as the network protocol for the real-time distributed control system. Given ID with the priority to message, CAN avoid the collision of message on the bus. But with the increase of bus traffic, it has a characteristic that transmission delay of message is on the increase. So some message with the low priorities can't guarantee the maximum allowable transmission delay. On this paper we suggest the enhanced ID algorithm which gives a dynamic ID allocation for guaranteeing the transmission delay according to the bus traffic. The feasibility of the suggested algorithm is evaluated experimentally on a test bed.

저지방 고품질 돈육 생산을 위한 돼지 복강 및 피하지방 항체 개발

최창원,백경훈,최창본,오영균,홍성구,Choi, Chang-Weon,Baek, Kyung-Hoon,Choi, Chang-Bon,Oh, Young-Kyoon,Hong, Seong-Koo 한국축산식품학회 2010 한국축산식품학회지 Vol.30 No.1

The aim of the present study was to develop polyclonal antibodies to regional inedible adipocytes of pigs and investigate the effect of these antibodies on adipocytes in vitro. As antigens, abdominal and subcutaneous adipocyte PMPs from pigs were injected into sheep 3 times per 3 wk intervals for passive immunization, and non-immunized serum, antisera against abodominal (AAb) or subcutaneous adipocyte PMPs (SAb) were collected before and after the injections. Titers of the antisera obtained from sheep and their cross-reactivities with the heart, kidney, liver, lung, muscle, and spleen of pig were determined by ELISA. Isolation and culture of abdominal and subcutaneous adipocytes from pigs were performed to analyze LDH concentration. At a 1:1,000 dilution, little antibody reactivity was observed for non-immunized serum whereas both AAb and SAb had relatively strong reactivity up to a dilution of 1:16,000. These findings may indicate that strong antibodies against adipocyte PMPs can be developed using an immunological approach. Extremely low reactivity of AAb and SAb was detected with the PMPs of the organs. Both antisera most strongly reacted with each adipocyte PMPs and showed statistically (p<0.05) higher cross-reactivities compared with the non-immunized serum. In conclusion, these results may indicate that the present polyclonal antibodies against regional inedible adipocyte PMPs are well developed and are safe against cross-reactivities with the organs of pigs. Further studies on the in vivo nutritional safety and fat reduction of these antibodies in pigs will be required fat-reduced high quality pork production.

중간값 필터를 이용한 적응적 디인터레이싱 알고리듬

이상운,백경훈,Lee, Sang-Un,Baek, Kyung-Hoon 한국인터넷방송통신학회 2011 한국인터넷방송통신학회 논문지 Vol.11 No.6

In this paper, we propose a new deinterlacing method that converts the interlaced images into the progressive images using a field. Firsr of all, it estimates the direction of edge. If it makes an accurate estimate of the direction, then it interpolates a pixel using ELA(Edge-based Line Average). Otherwise, it estimates the new direction of edge, and then,, it interpolates a pixel using a proposed median filter. From simulation results, it is shown that the proposed method improves both subjective and objective image quality as compared with previous deinterlacing methods. 본 논문에서는 하나의 필드만을 사용하여 비월 주사 영상을 순차 주사 영상으로 변환하는 디인터레이싱 방법을 제안한다. 먼저, ELA 기법을 이용하여 에지의 방향성을 예측한다. 에지의 방향성을 정확히 예측하였을 경우에는 ELA(Edge-based Line Average) 기법에 의한 화소를 보간하고 에지의 방향을 잘못 예측하였을 경우에는 다시 새로운 에지의 방향을 결정한다. 결정된 방향에 대하여 화소를 본 논문에서 제안한 중간값 필터(median filter)를 이용하여 보간한다. 모의실험 결과 기존의 비인터레이싱 방법에 비해 주관적 및 객관적 화질이 개선됨을 보인다.

동계 낙동강 하류 물금수역에서의 수질악화 원인구명

송미경(Mi Kyung Song),박청길(Chung Kil Park),이석모(Suk Mo Lee),백경훈(Kyung Hoon Baek),신성교(Sung Kyo Shin),송교욱(Kyo Ook Song) 한국물환경학회 2000 한국물환경학회지 Vol.16 No.3

The study was performed to find the cause of high concentration of BOD and algal bloom during winter season at Mulgum in the downstream of Nakdong River since 1995. There was high correlationship between BOD concentration and Chl. a contents which shows that algal bloom makes Autochthonous BOD. The dominant algae during of winter blooming season was Stephanodiscus sp.. This algae maintained the blooming under the condition of low water temperature, long retention time with decrease of flow rate, and abundant nutrient concentration. To reduce the amount of Stephanodiscus sp. biomass, it is important to decrease the loading of TP and TN from the upstream, because of the possible approach to control.

낙동강 중 , 하류수역에서 클로로필 α 최대농도 출현지역 평가

신성교(Sung Kyo Shin),백경훈(Kyung Hoon Baek),송미경(Mi Koung Song) 한국하천호수학회 2002 생태와 환경 Vol.35 No.1

The frequent occurrence of excessive phytoplankton populations in the downstream Nakdong River has been an important water quality problem in recent years. The limnological survey of the Nakdong River was conducted from January 1997 to December 1999 on once or twice per month. A typical phenomenon of eutrophication appears with the persistent algal bloom due to high nutrients in the mid-lower part of the river. This study showed that the point at which Chl. a concentration reaches maximum was affected by the water temperature and the flow rate. For example, Chl. a concentration reached maximum after around 380, 240 and 120 hours which were estimated from the time of flow at low(≤10℃), mean(10∼20℃) and high(≥20℃) water temperature conditions, respectively. It was estimated that increase coefficients of phytoplankton (Chl. a) on the water temperature are 0.201, 0.254 and 0.289 day^-1, on the contrary, decrease coefficients are -0.012, -0.128 and -0.193 day^-1 in low, mean and high water temperature. therefore, to prevent formation of Chl. a maximum concentration in the specific water resource, it is necessary to increase the discharge of dam as well as to decrease.