광대역 평면형 모노폴 안테나의 설계

이윤경,윤현보,Lee Yun-Kyung,Yoon Hyun-Bo 한국전자파학회 2005 한국전자파학회논문지 Vol.16 No.4

This paper designed a very low profle, light and broadband internal antenna for operating at PCS, IMT-2000 and Wibro bands. The proposed antenna can be reduced the size by using shorting-pin and a broadband characteristic is obtained by using slit. It is optimized by using the CST Microwave Studio commercial software based on the FIA(Finite Integration Algorithm) and PBA(Perfect Boundary Approximation) and then fabricated and measured. As a result of measurement, the bandwidth(VSWR<2.5) is $40.8\;\%$ at $1.934\;\cal{GHz}$ and the size of antenna is 3$30\;\cal{mm}\times10\;\cal{mm}\times0.2\;\cal{mm}$.

미세 유체 칩 기반의 히알루론산 미세 실의 제작

이윤경,이광호,Lee, Yun-Kyung,Lee, Kwang-Ho 대한의용생체공학회 2017 의공학회지 Vol.38 No.1

The successful synthesis of hyaluronic acid micro-threads is very promising approach for the broad application in tissue engineering such as dermal fillers. Because hyaluronic acid has the excellent biocompatibility and ability to maintain the moisture of up to several hundred times its own weight. In order to generate the hyaluronic acid micro-threads in microfluidic system, we employed two-phase flow microfluidic chip to make a rapid synthesis of the hyaluronic acid hydrogel. Hyaluronic acid was mixed with 0.02N NaOH solution and 1, 4-Butanediol diglycidyl ether (BDDE) solution and then injected into core channel. The ethanol was used for the 3-dimensional micro-thread formation in sheath channel. We manipulated the diameter of HA micro-threads using controlling of flow rates in microfluidic chip, and showed the feasibility of immobilization in HA micro-threads with florescent substances. Also, the generated HA micro-threads were evaluated and showed the suitable properties with tensile strength, bending property, and swelling profiles for dermal fillers. As a result, we suggested an innovative method for microfluidic chip-based HA micro-threads which could safely be applied as dermal filler in tissue engineering.

CASA 기반 음성분리 성능 향상을 위한 형태 분석 기술의 응용

이윤경,권오욱,Lee, Yun-Kyung,Kwon, Oh-Wook 대한음성학회 2008 말소리 Vol.65 No.-

We propose a new method to apply shape analysis techniques to a computational auditory scene analysis (CASA)-based speech separation system. The conventional CASA-based speech separation system extracts speech signals from a mixture of speech and noise signals. In the proposed method, we complement the missing speech signals by applying the shape analysis techniques such as labelling and distance function. In the speech separation experiment, the proposed method improves signal-to-noise ratio by 6.6 dB. When the proposed method is used as a front-end of speech recognizers, it improves recognition accuracy by 22% for the speech-shaped stationary noise condition and 7.2% for the two-talker noise condition at the target-to-masker ratio than or equal to -3 dB.

두부 제조시 발생되는 순물의 이화학적 특성 및 기능성 물질의 함량 분석

이윤경,황인경 ( Yun Kyung Lee,In Kyeong Hwang ) 한국식품조리과학회 1997 한국식품조리과학회지 Vol.13 No.2

To evaluate the quality of commercial anchovy sauces, 8 varieties (2 products from the Fishery Cooperation, 2 from small companies, and 4 well-known brands) were chosen and their physicochemical and sensory properties were examined. The salinity of anchovy sauces ranged from 19.8% to 26%, where product E was the saltiest and followed by F > H > B > E > A > C = G > D. Product D with the least salinity was turbid, rancid, and high in ammonia content, suggesting that it is difficult to control the quality of anchovy source with a low salt content. Protein content of anchovy sauces ranged from 2.51% to 2.64%. The unit price of anchovy source A was the highest, whereas B was the lowest. Sensory evaluation scores of anchovy sauces were in the order of B > G > A > F > E > C > H > D for color, B > G = C > H > E = F > G > D for odor, E > C > F > G > H > D > B > A for saltiness, and B > A > C > H > E = F > G > D for overall acceptability. Above results suggest that product B was the best in quality as well as the cheapest among all. Based on the above results, kimchies were prepared with product A, B, C with a high sensory quality and product H with a high market occupancy, and sensory evaluation was performed. The kimchi with product C got the highest sensory score in appearance and the one with product A and H in odor. Although the kimchi with product A generally had high scores throughout the fermentation period, there were no significant differences in texture, salty taste, and overall acceptability among kimchies with different varieties of anchovy sauces.

위상 모델 기반의 소프트 마스크를 이용한 단일 채널 음성분리

이윤경,권오욱,Lee, Yun-Kyung,Kwon, Oh-Wook 한국음향학회 2010 韓國音響學會誌 Vol.29 No.2

본 논문은 혼합 음성 신호로부터 크기와 위상 정보를 모두 고려하여 목표 음성 신호를 추출하고 향상하는 음성 분리 알고리듬을 제안한다.기존 연구에서는 혼합된 음성 신호의 로그 전력 스펙트럼 값이 시간-주파수 영역에서 서로 독립이라고 가정한 통계적 모델을 적용하기 때문에 음성 분리 결과 파형에 불연속을 야기한다. 본 논문에서는 이러한 불연속을 감소시키기 위하여 시간-주파수 영역에서의 스무딩 필터를 적용한다. 음성 분리 성능을 더욱 향상시키기 위하여 음성 신호의 크기와 함께 위상 정보를 고려하는 통계적 모델을 제안한다. 실혐 결과, 제안된 알고리즘이 기존의 크기 정보만을 사용한 알고리즘에 비하여 1.5 dB의 화자대간섭비 (SIR)를 개선하는 것으로 나타난다. In this paper, we propose a new speech separation algorithm to extract and enhance the target speech signals from mixed speech signals by utilizing both magnitude and phase information. Since the previous statistical modeling algorithms assume that the log power spectrum values of the mixed speech signals are independent in the temporal and frequency domain, discontinuities occur in the resultant separated speech signals. To reduce the discontinuities, we apply a smoothing filter in the time-frequency domain. To further improve speech separation performance, we propose a statistical model based on both magnitude and phase information of speech signals. Experimental results show that the proposed algorithm improve signal-to-interference ratio (SIR) by 1.5 dB compared with the previous magnitude-only algorithms.

급식규모에 따른 산업체 급식소의 운영실태 조사

이윤경,백재은,주나미,전희정 ( Yun Kyung Lee,Jae Eun Paik,Na Mi Joo,Hui Jung Chun ) 대한가정학회 1995 Human Ecology Research(HER) Vol.33 No.2

시간-주파수 스무딩이 적용된 소프트 마스크 필터를 이용한 단일 채널 음성 분리

이윤경,권오욱,Lee, Yun-Kyung,Kwon, Oh-Wook 대한음성학회 2008 말소리 Vol.67 No.-

This paper addresses the problem of single-channel speech separation to extract the speech signal uttered by the speaker of interest from a mixture of speech signals. We propose to apply time-frequency smoothing to the existing statistical single-channel speech separation algorithms: The soft mask and the minimum-mean-square-error (MMSE) algorithms. In the proposed method, we use the two smoothing later. One is the uniform mask filter whose filter length is uniform at the time-Sequency domain, and the other is the met-scale filter whose filter length is met-scaled at the time domain. In our speech separation experiments, the uniform mask filter improves speaker-to-interference ratio (SIR) by 2.1dB and 1dB for the soft mask algorithm and the MMSE algorithm, respectively, whereas the mel-scale filter achieves 1.1dB and 0.8dB for the same algorithms.

MANET에서 Interrupt message를 이용한 AODV 라우팅 프로토콜의 성능 개선

이윤경(Yun-kyung Lee),김주균(Ju-gyun Kim) 한국통신학회 2013 한국통신학회논문지 Vol.38 No.10(네트워크)

MANET 환경에서 AODV는 요구기반 방식으로써의 장점을 갖지만 다른 라우팅 프로토콜들에 비해 제어패킷 오버헤드가 크다는 단점도 가지고 있다. 본 논문은 로컬 연결의 탐지와 이웃 목록을 유지하기 위해 주기적으로 브로드캐스트하는 Hello message로 인한 문제점을 개선한다. 주기적인 Hello message는 패킷 전달률과 제한된 대역폭의 효율성을 감소시키고, 제어 패킷 오버헤드를 증가시켜 잔존 에너지량과 네트워크 수명을 감소시킨다. 또한 AODV에서의 주기적인 Hello message는 “Reactive”하지 않은 방식이기 때문에 많은 논쟁의 근원이었다. 이러한 문제점을 개선하기 위해 본 연구에서는 인터럽트 방식을 이용하여 주기적인 Hello message를 제거함으로써 제어패킷 오버헤드를 줄여 성능을 개선하였다. 기존의 AODV와 제안된 mod_AODV의 성능은 QualNet 5.0을 이용하여 실험 분석하였고, 실험 결과는 시뮬레이션 파라메터들의 변화에 대한 모든 성능 매트릭들에서 mod_AODV가 전반적으로 우수한 성능을 보였다. In MANET, AODV(Ad hoc On-demand Distance Vector) has its advantages as on-demand approach but it also has a disadvantage that the control packet overhead is high compared to other routing protocols. This paper improves the problem caused by Hello messages that are broadcasted periodically to detect the local connectivity and maintain neighbor list. Periodic hello messages reduce the Packet delivery ratio and the efficiency in the limited bandwidth. And its increased Control packet overhead leads to decrease the Residual battery capacity and the Network lifetime. Further, non-reactive nature of periodic hello messages in AODV has also been the source of numerous controversies. In order to solve these problems, this paper improves the performance by using the interrupt driven approach which removes periodic hello messages and decreases the Control packet overhead. Performance comparisons between the traditional AODV and proposed mod_AODV done with network simulator QualNet 5.0 show that the mod_AODV performs better in most performance metrics under scenarios with various values of simulation parameters.

노인의 낙상과 연관된 위험요소와 균형 측정 방법

이윤경 ( Yun Kyung Lee ),배성수 ( Sung Soo Bae ) 대한물리의학회 2007 대한물리의학회지 Vol.2 No.1

우리나라 흡연경험이 있는 청소년의 흡연유형 관련요인

이윤경(Yun-Kyung Lee),류소연(So-Yeon Ryu) 한국산학기술학회 2018 한국산학기술학회논문지 Vol.19 No.2

본 연구의 목적은 ‘제11차(2015년) 청소년건강행태온라인조사’를 이용하여 흡연을 경험한 청소년의 흡연특성과 흡연유형에 따른 특성을 파악하여 복합흡연에 관련된 요인을 알아보고자 하였다. ‘제11차(2015년) 청소년건강행태온라인조사’에 응답한 68,043명 중 일반담배 및 전자담배 흡연 경험이 있는 중․고등학생 5,347명을 대상으로 분석하였다. 사용된 데이터는 가중치가 적용된 복합표본분석을 이용하여 빈도분석, 카이제곱 검정, 로지스틱 회귀분석으로 분석하였다. 전체 흡연 청소년의 20%가 복합흡연자였으며 전자담배 이용자 85.6%가 니코틴을 사용하였다. 다중 로지스틱 회귀분석 결과 남학생인 경우 (OR 1.63,; 95% CI 1.15-2.31), 대도시에 거주하는 경우(OR 1.76; 95% CI 1.32-2.33), 하루에 패스트푸드를 1-2회 먹는 경우 (OR 2.48; 95% CI 1.33-4.64), 최초흡연 경험 시기가 고등학교인 경우(OR 0.76; 95% CI 0.58-0.98), 간접흡연 경험이 있는 경우(OR 1.24; 95% CI 1.07-1.44), 음주경험이 있는 경우(OR 2.03; 95% CI 1.65-2.48), 일주일간 용돈수준이 높을수록 복합흡연의 위험이 높았다. 본 연구는 청소년의 전자담배와 복합흡연에 대한 기초자료를 제공하고 금연 프로그램 및 정책 개발에 도움이 되리라 판단된다. This study was conducted to investigate the factors related to smoking and smoking differences among adolescents who have experienced smoking using data from the 11th (2015) Korean Youth Risk Behavior Web-based Survey. The data used in this study were from 5,347 middle and high school students who had cigarette smoking and electronic cigarette smoking experience among 68,043 respondents to the 11th (2015) Korean Youth Risk Behavior Web-based Survey. The data were evaluated by frequency analysis, the χ² test and logistic regression analysis using weighted composite sample analysis. Overall 20% of the total smoking adolescents were dual users and 85.6% of the users of electronic cigarettes used nicotine. The results from multinomial regressions show that: male students (OR 1.63; 95% CI 1.15-2.31), living in the metropolitan area (OR 1.76; 95% CI 1.32-2.33), an average consumption of fast food of once or twice a day (OR 2.48; 95% CI 1.33-4.64), first started smoking during high school (OR 0.76; 95% CI 0.58-0.98), having experience with passive smoking (OR 1.24; 95% CI 1.07-1.44), experience drinking alcohol (OR 2.03; 95% CI 1.65-2.48) and those with higher weekly allowances were more likely to be at risk than dual users. This study provides basic data regarding the dual use of electronic cigarettes and cigarettes by adolescents. The results presented herein will facilitate development of a smoking cessation program and policy.