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$30\;\cal{mm}\times10\;\cal{mm}\times0.2\;\cal{mm}$.

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.

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.

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.

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

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.

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.

UVA이 조사된 인간진피섬유아세포에서 멜라닌 세포 자극 호르몬 α-MSH에 의한 발현변화 분석

이윤경 ( Yun Kyung Lee ),최수기 ( Su Ki Choi ),김영주 ( Young Joo Kim ),차화준 ( Hwa Jun Cha ),안성관 ( Sungkwan An ) 한국미용학회 2012 한국미용학회지 Vol.18 No.1

Photo-aging of skin is caused by chronic irradiation of Ultraviolet A (UVA). It has been known that chronic irradiation of UVA induces loss of dermal extracellular matrix due to loss of fibroblast cells and their versatile functions. Melanogenesis induced by alpha-melanocyte stimulating hormone (α-MSH) is a representative mechanism to protect skin against UV. However, there are few studies on another effect of α-MSH on protection of UVA. To demonstrate another function of α-MSH in fibroblasts, in this report, we present the alteration of transcription patterns by α-MSH in UVA-irradiated human dermal fibroblasts (HDFs). Eleven genes with known functions for proliferation and hormone secretion were significantly up-regulated and 31 transcripts for apoptosis were down-regulated by α-MSH. Especially, bax, one of well studied apoptosis related genes, was down-regulated by α- MSH in UVA-irradiated HDFs. Moreover, viability decreased by UVA was recovered by α-MSH. These results demonstrate that α-MSH is a critical repressor of UVA-dependent growth inhibition and apoptosis by regulating the expression of transcripts in HDFs.

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.

국내 의류제품 고객은 가격할인을 기다리며 구매를 늦추는가?

이윤경(Lee Yun Kyung),황선진(Sun Jin Hwang) 한국마케팅과학회 2005 마케팅과학연구 Vol.15 No.1

이 연구는 빈번한 가격할인을 하고 있는 국내 의류시장에서, 소비자들이 가격이 떨어질 것을 기대하여 제품의 구입을 늦추는 '가격기대효과'가 실제로 존재하는지 실증적으로 분석하고자 하는데 그 목적이 있다. 특히, 지금까지의 가격연구에서는 규범적, 행태적, 서술적 연구 등 각 분야의 영역을 접목시킨 통합적 접근이 미진하여 소비자의 심리적 요인을 가격책정에 반영한 시도가 드물었고 시간의 흐름에 따라 변화하는 가격과 판매량의 관계를 살피는 동태적 연구가 부족하기 때문에, 규범적 연구와 행태적 연구를 접목시켜 의류제품의 가격기대효과를 밝혀내고자 하였다. 이를 위해 기존의 의류제품에 적합한 동태적인 가격기대효과 모델을 수립하였으며 모델을 검증하기 위하여 국내 백화점의 여성복 판매 데이터를 이용 하였다. 분석결과 국내 의류제품을 구매하는 소비자들에게 가격기대효과가 존재한다는 사실을 이론적, 실증적으로 밝혀내었다. 이러한 결과는 패션제품의 가격변화에 따른 소비자들의 독특한 구매행동을 반영한 것으로 기존의 동태적 가격연구의 범위를 넓혔다는데 의의가 있다. This study intends to examine whether consumers, especially buying apparel product postpone purchase in the beliefs of price break in the near future. For this research objectives, the dynamic price expectation effect model for apparel product is proposed and is applied to weekly sales data and price information of 43 women's apparel brands from a department store over the spring season. The main results are summarized as follows. 1. Dynamic price expectation effect model is developed and the model is more robust to apparel product than Gutenberg model, which is not considered these conditions. 2. By applying the model to empirical data, we find out the price expectation effect in the apparel product; concretely there are 23 brands out of 43 brands. This study confirms the price expectation effects in the apparel product theoretically and extends the research boundary of price expectation effects.