계층적 MPSK 신호에 대한 일반화된 BER 성능

이재윤,윤동원,현광민,박상규,Lee Jae-Yoon,Yoon Dong-Weon,Hyun Kwang-Min,Park Sang-Kyu 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.9C

본 논문에서는 수신기에서 I/Q 위상 및 진폭 불균형을 갖는 계층적 MPSK(Hierarchical M-ary Phase Shift Keying) 신호에 대해 수치 적분이 필요 없는 정확하고 일반화된 closed-form 형태의 비트 오류 확률(Bit Error Probability) 표현을 유도한다. 새롭게 유도된 비트 오류 확률 표현은 간결한 형태의 일반화된 식으로 되어 있어 다양한 환경으로의 적용이 용이하다. 뿐만 아니라, 계층적 MPSK를 적용하는 많은 디지털 통신 시스템에서 복조시 발생할 수 있는 I/Q 불균형들에 의한 시스템 성능 변화에 대하여 정확한 이론적 성능 기준을 제공할 것으로 기대된다. In this paper, we present an exact and general expression involving two-dimensional Gaussian Q-functions for the bit error rate (BER) of hierarchical MPSK with I/Q phase and amplitude imbalances over an additive white Gaussian noise (AWGN) channel. First we derive a BER expression for the k-th bit of hierarchical 4, 8, 16-PSK signal constellations when Gray code bit mapping is employed. Then, from the derived k-th bit BER expression, we present the exact and general average BER expression for hierarchical MPSK with I/Q phase and amplitude imbalances. This result can readily be applied to numerical evaluation for various cases of practical interest in an I/Q unbalanced hierarchical MPSK system, because the one- and two-dimensional Gaussian Q-functions can be easily and directly computed usinB commonly available mathematical software tools.

I/Q 위상 불균형을 고려한 Uniform M-PSK의 일반화된 BER 성능 분석

이재윤,윤동원,현광민,박상규,Lee Jae-Yoon,Yoon Dong-Weon,Hyun Kwang-Min,Park Sang-Kyu 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.3C

본 논문에서는 2차원 결합 가우시안 Q-함수(Two-dimensional joint Gaussian Q-function)를 이용하여 AWGN(Additive White Gaussian Noise) 환경에서 M-PSK(M-ary Phase Shift Keying) 신호의 I/Q 위상 불균형(Phase unbalance) 존재 시 수치 적분이 필요 없는 정확하고 일반화된 closed-form 형태의 비트 오류율(Bit Error Rate) 표현을 유도한다. 새롭게 유도된 표현은 평균 BER 뿐만 아니라 k-번째 비트의 BER에 대하여도 일반화된 식으로 되어 있어 다양한 환경으로의 적용이 용이하여 M-PSK를 적용하는 많은 디지털 통신 시스템에서 복조 시 발생할 수 있는 I/Q 위상 불균형에 의한 시스템 성능 변화에 대하여 정확한 이론적 성능 기준을 제공할 것으로 기대된다. I/Q phase unbalance caused by non-ideal circuit components is inevitable physical phenomenons and leads to performance degradation when we implement a practical coherent M-ary phase shift keying(M-PSK) demodulator. In this paper, we present an exact and general expression involving two-dimensional Gaussian Q-functions for the bit error rate(BER) of uniform M-PSK with I/Q phase unbalance over an additive white Gaussian noise(AWGN) channel. First we derive a BER expression for the k-th bit of 8, 16-PSK signal constellations when Gray code bit mapping is employed. Then, from the derived k-th bit BER expression, we present the exact and general average BER expression for M-PSK with I/Q phase unbalance. This result can readily be applied to numerical evaluation for various cases of practical interest in an I/Q unbalanced M-PSK system, because the one- and two-dimensional Gaussian Q-functions can be easily and directly computed using commonly available mathematical software tools.

부산에서 분리된 황색포도상구균의 항생제 내성 양상

이재윤,박정희,문경호,Lee, Jae-Yoon,Park, Jung-Hee,Moon, Kyung-Ho 대한약학회 2007 약학회지 Vol.51 No.3

Antibiotic resistance patterns of 21 antibiotics were studied for 50 strains of Staphylococcus aureus isolated from a hospital in Busan from July 2005 to December 2006. All strains showed antibiotic resistance to more than one antibiotic and 3 strains showed resistance to 17 different antibiotics. The strains isolated between 2005 and 2006 had lower resistance rate to 12 antibiotics (other than vancomycin and ampicilin) than the strains isolated between 1989 and 1990. In particular, no chlorarmphenicol resistant strain was found in this study which is contrasted with 34.8% resistant rate obtained in the study conducted between 1989 and 1990. In respect of vancomycin, no resistant strain was found in this study which is the same result obtained in the 1989 to 1990 study; All strains investigated in this study showed 100% resistance rate to ampicillin compared to 69.6% in the previous study.

비선형 채널에서 임의의 2차원 변조 신호의 SER 분석

이재윤,윤동원,조경국,Lee, Jae-Yoon,Yoon, Dong-Weon,Cho, Kyong-Kuk 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.7a

본 논문에서는 비선형 특성을 갖는 고출력 증폭기(high power amplifier : HPA) 및 I/Q 진폭/위상 불균형과 위상 오류를 갖는 비이상적인 수신기가 고려된 APSK 뿐만 아니라 임의의 2차원 신호를 갖는 변조방식에 대한 오류 확률 표현을 유도하고, 그 표현의 수치적 결과로부터 비선형 특성 및 비 이상적인 특성이 오류 확률에 미치는 영향을 분석한다. HPA의 모델로는 가장 많이 사용되는 Saleh 모델을 적용하며, 한 신호점에서의 오류 확률 분석을 2차원 결합 가우시안 Q함수(2-dimensional joint Gaussian Q-function)의 표현으로 간편히 할 수 있는 방법을 통하여 정확한 오류 확률의 유도 및 분석을 수행한다. The non-linearity of HPA(high power amplifier) which is an important component in modern communications systems introduces AM/AM and AM/PM distortion so that the transmitted signal is deteriorated. And, the I/Q unbalances and phase error which are generated by non-ideal components are inevitable physical phenomena and lead to performance degradation when we implement a practical two-dimensional (2-D) modulation system. In this paper, we provide an exact and general expression involving the 2-D Gaussian Q-function for the error probabilities of arbitrary 2-D signaling with I/Q amplitude and phase unbalances in nonlinear additive white Gaussian noise (AWGN) channels by using the coordinate rotation and shifting technique.

한국 운항승무원의 전문성이 장거리 비행 피로에 미치는 효과

이재윤,신용환,손영우,Lee, Jae Yoon,Shin, Yong Hwan,Sohn, Young Woo 한국항공운항학회 2021 한국항공운항학회지 Vol.29 No.2

Factors that cause fatigue, such as circadian rhythm abnormalities, have adverse effects on long-haul flights. Among many elements, the present study focused on the flight crew's expertise as a crucial factor that could influence their fatigue. The purpose of the study was to demonstrate whether long-haul flights cause fatigue and to examine whether this symptom differed between low- and high-experienced flight crews. A total of 62 Korean flight crews were informed to perform a five-minute psychomotor vigilance task twice each before and after the flight to measure objective fatigue level. Also, they were asked to indicate current flight experience to identify their expertise. Results revealed that fatigue was significantly increased after the flight compared to before the flight but this increase was significant for flight crews with low expertise not for flight crews with high expertise. Implications of our findings and limitations of the present study were discussed.

전투 및 비전투 상황에서의 효율적 리더십에 대한 비교 연구

이재윤,Lee, Jae-Yoon 대전대학교 군사연구원 2007 군사학연구 Vol.5 No.-

The current problems with the changing nature of the battlefield of the future point up the serious need for more and better research on the nature of effective military leadership. The purpose of this study was to examine effective leadership traits and behaviors of junior officers in combat situation. During times of peace, leader study battles and imagine themselves in all sorts of combat situations while at the same time, they must cope with numerous challenges and fill a variety of roles that they perceive are not battle related. This illustrates one of the fundamental paradoxes of the peacetime environment. Early studies, showing that combat leadership and noncombat leadership needed different talents, produced some clusters of traits which good combat leader were said to possess. Good combat leaders, for example, were described as possessing courage(e.g., bravery, fearlessness, daring, prowess, gallantry, guts, intrepidity, undaunted courage, fighting spirit, aggressive action), personal integrity(e.g., sincerity, flair, calmness, modesty), adaptability(e.g., flexibility, rapidity in action, speedy decision-making, clarity of thought) and so on. Behaviors found to be important in both combat and noncombat situations bore some relation to role requirements common to both situations. Behaviors important in one situation but not the other could be explained in terms of situational differences in role requirements for effective leadership. In order to achieve this purpose, a number of literature reviews were analysed. These results, though obtained in a somewhat rough and ready fashion, were useful not because they pointed to different leaders in war and in peace, but because they showed leaders the different things that were expected of them in different situations. It was also worth knowing how develop combat leadership. While these findings clearly suggest combat and noncombat differences, they do not necessarily confirm the complete study on effective leadership in combat situation. In conclusion, this study would be useful basis for further improvement on effective combat leadership and some further researches were recommended.

전체염기서열 결정에 의한 황색포도상구균의 내성 플라스미드 동정

이재윤,박정희,문경호,Lee, Jae-Yoon,Park, Jung-Hee,Moon, Kyung-Ho 대한약학회 2008 약학회지 Vol.52 No.2

Previously, we reported on the antibiotic resistance patterns of 50 strains of Staphylococcus aureus which were isolated from a hospital in Busan, Korea from July 2005 to December 2006. We have isolated small plasmids and classified plasmid types by agarose gel electrophoresis. We have selected 5 plasmids and determined complete nucleotide sequences of those plasmids. The aim of this paper is to report on the characteristics of cadmium, erythromycin, lincomycin resistance plasmids and a cryptic plasmid based on the sequence analysis obtained by using the BLAST program.

강원도 지역의 조경식물의 식재현황 분석

이재윤,박준석,김혜란,김동엽,노희선,이기의,Lee, Jae-Yoon,Park, Jun-Seok,Kim, Hea-Ran,Kim, Dong-Yeob,Noh, Hee-Sun,Lee, Ki-Eui 한국조경학회 2011 韓國造景學會誌 Vol.39 No.2

강원도내 초 중 고 총 632개교의 교화와 교목을 조사한 결과, 교목의 종수는 45종이었으며, 이 중 자생종이 35종이고, 외래종이 10종이었다. 영서지방에서 가장 많이 이용되고 있는 교목은 향나무, 잣나무, 소나무, 전나무, 은행나무, 느티나무, 주목 순이었다. 영동지방에서도 향나무, 소나무, 전나무, 주목, 은행나무, 해송의 순이었다. 교화는 총 43종이었으며, 이 중 자생종이 22종이고, 외래종이 21 종이었다. 영서지방에서 많이 지정하고 있는 교화는 장미, 개나리, 철쭉, 목련, 진달래의 순이었으며, 영동지역에서는 개나리, 장미, 목련, 백일홍, 철쭉, 국화, 해당화의 순이었다. 강원도 시 군에서 지정한 꽃과 나무는 총 19종으로 꽃은 12종이고, 나무는 7종이었다. 종별로는 은행나무가 7개 시 군에서, 도화인 철쭉이 5개 시 군에서, 도목인 잣나무가 5개 시 군에서, 주목은 3개 시 군에서 지정되었고, 개나리, 함박꽃나무, 살구나무 등이 각각 2개 시 군에서 지정되었다. 강원도 영서지역에 식재된 수목은 87종에 약 619,835주였으며, 많은 시 군에서 선호하는 수종으로는 소나무, 왕벚나무, 산벚나무, 산수유, 돌배나무, 산철쭉, 단풍나무, 잣나무, 주목, 무궁화, 개나리, 느티나무, 복자기 등이었다. 단일종으로 가장 많이 심겨진 수종은 개나리, 무궁화, 산철쭉, 자작나무, 자산홍, 쥐똥나무 등의 순이었다. 전체 87종 중에서 자생종이 56종이고, 외래종이 31종이었다. 영동지방에 심겨진 목본류는 총 77종에 914,668주였으며, 이 중 52종이 자생종이고, 외래종이 25종이었다. 시 군에서 선호하는 주요 수종은 곰솔, 영산홍, 철쭉, 무궁화, 왕벚나무, 소나무, 수수꽃다리, 산철쭉, 해당화, 산벚나무, 장미, 향나무, 사철나무, 개나리, 이팝나무, 단풍나무, 모과나무 등이었다. 단일종으로 가장 많이 심겨진 수종으로는 해당화, 무궁화, 영산홍, 개나리, 산철쭉, 벚나무, 사철나무 등의 순이었다. This study was carried out to improve planting and use of landscape plants in Gangwon-do. The designated plants by schools and cities in Gangwon-do were surveyed and then compared with the planted trees on streets, public parks, schools, etc. in 2009. There were 45 tree species and 43 flower species designated as school trees and school flowers at 632 schools in Gangwon-do. The majority of school tree species were Juniperus chinensis, Pinus densiflora, Abies holophylla, Ginkgo biloba, Pinus koraiensis, Taxus cuspidata, Zelkova serrata, and Pinus thunbergii. The ratio of native species to exotic was 35:10. The majority of school flower species Rosa centifolia, Forsythia koreana, Zinnia elegans, Rhododendron mucronulatum, Chrysanthemum morifolium, and Rosa rugosa. The ratio of native species to the exotic was 22:21. There were 12 flower species and 7 tree species designated as city trees and city flowers in 18 cities and guns. The high frequency flower species were Rhododendron schlippenbachii, Forsythia koreana, Magnolia sieboldii, and Prunus armeniaca var. ansu. The high frequency tree species were Ginkgo biloba, Pinus koraiensis, and Taxus cuspidata. There were 87 woody landscape tree species planted, and a total of 619,835 landscape plants were planted in Youngseo region (western part of Gangwon-do) in 2009. The ratio of native species to exotic species was 56:31. The majority of landscape trees planted were Pinus densiflora, Prunus yedoensis, Prunus sargentii, Comus officinalis, Pyrus pyrifolia, Rhododendron yedoense var. poukhanense, Pinus koraiensis, Taxus cuspidata, Hibiscus syriacus, Forsythia koreana, Zellkova serrata, Acer triflorum, Rhododendron obutusum, and Ligustrum obtusifolium A in 2009. The ratio of native species to the exotic was 64:36. There were 77 woody landscape tree species planted, and a total of 914,668 landscape plants were planted in Youngdong region (eastern part of Gangwon-do) in 2009. The ratio of native species to exotic was 52:25. The major landscape trees planted were Pinus thunbergii, Rhododendron lateritium, Rhododendron schlippenenbachii, Hibiscus syriacus, Prunus yedoensis, Pinus densiflora, Syringa dilatata, Rhododendron yedoense var. poukhanense, Rosa rugosa, Prunus sargentii, Rosa centifolia, Juniperus chinensis, Euonymus japonica, Forsythia koreana, Chionanthus retusus, Acer palmatum, and Chaenomeles sinensis. The results indicate that landscape plants need to be diverse in species in each region of Gangwon-do. Selection of suitable plants for each region and the use of native species need to be emphasized.

초임계 이산화탄소 사이클을 이용한 연료 재순환 MCFC의 폐열회수

이재윤,안지호,김동섭,Lee, Jae Yoon,Ahn, Ji Ho,Kim, Tong Seop 한국플랜트학회 2019 플랜트 저널 Vol.15 No.2

용융탄산염 연료전지는 폐열의 온도가 높아 하부 사이클을 구성하여 효율을 높일 수 있다. 이러한 목적으로 연료를 재순환하는 용융탄산염 연료전지에 하부 사이클로 증기 터빈 사이클을 적용한 선행 연구가 있었다. 본 연구는 하부 사이클을 증기 터빈 사이클에서 초임계 이산화탄소 사이클로 대체하는 것을 고려하였다. 그리고 출력을 비교하여 하부 사이클을 대체하는 것에 대한 검토를 하였다. 그 결과 현재 개발 단계의 초임계 이산화탄소 사이클의 출력은 증기 터빈 사이클보다 낮지만, 이론적으로 증기 터빈 사이클보다 출력이 더 커질 수 있음을 확인하였다. 만약 초임계 이산화탄소 사이클이 터빈의 등엔트로피 효율을 89%, 압축기의 등엔트로피 효율을 83%, 복열기의 유용도를 0.9의 수준으로 향상 시킨다면 증기 터빈 사이클과 동등한 출력을 낼 수 있다. The molten carbonate fuel cell has a high temperature of waste heat and can constitute a bottoming cycle to increase the efficiency. Previous study used a bottoming cycle as steam turbine cycle. In this study, we are going to replace the bottoming cycle with a supercritical carbon dioxide power cycle. The system power was compared to consider replacing the bottoming cycle. As a result, the power of the supercritical carbon dioxide power cycle at the present development stage is lower than that of the steam turbine cycle, but theoretically, the power can be larger than the steam turbine cycle. If the supercritical carbon dioxide power cycle improves the isentropic efficiency of the turbine by 89%, the isentropic efficiency of the compressor by 83%, and the effectiveness of the recuperator by 0.9, the power can be same to the steam turbine cycle.

구역전기사업자 전기설비 유지관리·비상대응 기술분석 및 지침개발에 관한 연구

이재윤(Jae-Yoon Lee),남기범(Gi-Beom Nam),권오규(Oh-Kyu Kwon),유연태(Yeon-Tae Yu),김진형(Jin-Hyung Kim),이일무(Ill-Moo Lee) 대한전기학회 2018 대한전기학회 학술대회 논문집 Vol.2018 No.10