특이값 제거 기법을 적용한 수중 이동체의 음향 거리 추정

이경원,오단비,김기만,김태형,이희창,Kyung-won Lee,Dan-bi Ou,Ki-man Kim,Tae Hyeong Kim,Heechang Lee 한국음향학회 2024 韓國音響學會誌 Vol.43 No.4

수중 이동체의 방사소음을 측정하는 경우 이동체와 수신기 사이의 거리 정보가 중요한 요소이지만 수중에서는 Global Positioning System(GPS)를 사용할 수 없기 때문에 대체 수단이 필요하다. 대체 수단으로써 별도의 음향신호를 이용하여 도달 시간, 도달 시간 차 및 도달 주파수 차 등을 추정하여 거리를 측정한다. 하지만 채널 환경에 의해 오류가 발생하며, 이러한 특이값들은 연속적으로 거리를 측정함에 있어서 장애 요인이 된다. 본 논문에서는 거리 정보를 측정하는 과정에서 발생한 특이값들을 제거하기 위하여 사후 처리로써 V-곡선 형태의 함수로 곡선 적합하여 오류를 감소시키는 방법을 제안한다. 제안한 방법의 성능검증을 위해 모의, 호수 및 해상실험을 수행하였다. 호수실험 결과에서는 Root Mean Square Error(RMSE) 관점에서 약 85 % 정도로 거리 추정 오차가 감소하였다. When measuring the radiated noise of an underwater vehicle, the range information between the vehicle and the receiver is an important factor, but since Global Positioning System (GPS) is not available in underwater, an alternative method is needed. As an alternative, the range is measured by estimating the arrival time, arrival time difference, and arrival frequency difference using a separate acoustic signal. However, errors occur due to the channel environment, and these outliers become obstacles in continuously measuring range. In this paper, we propose a method to reduce errors by curve fitting with a function in the form of a V-curve as a post-processing to remove outliers that occurred in the process of measuring range information. Simulation, lake and sea trials were conducted to verify the performance of the proposed method. In the results of the lake trial, the range estimation error was reduced by about 85 % from the Root Mean Square Error (RMSE) point of view.

범주형 환경변수를 고려한 부대성과평가 방법에 관한 연구 - DEA와 CCCA의 결합을 중심으로 -

이경원,박명섭,임재풍,Lee, Kyung-Won,Park, Myung-Seop,Im, Jae-Poong 한국국방경영분석학회 2006 한국국방경영분석학회지 Vol.32 No.1

There are many occasions that the performance of a corps is influenced not only by its own efforts but by the commander of the next higher unit in a vertical organizational structure. When the direction of the commander in the next higher organization is different from that of the actual evaluation agency, the unit under evaluation may get rated lower than what it should deserve. This study suggests an alternative method to evaluate the performance of military units in the situation that there exist critical environmental factors which affect the performance. This method employes DEA, a non parametric method, and Constrained Canonical Correlation Analysis(CCCA), a parametric method which is used to estimate a efficient frontier with multiple dependent variables and constraints. This article also exploits a set of categorical environmental variables in the CCCA to improve the fairness of performance evaluation. It is shown that the introduction of the categorical variables helps evaluating the true performance of individual units such as battalions subordinated to different next higher commanders. 계층구조로 이루어진 군부대에서 예하부대의 성과는 피평가부대의 개별적인 노력뿐만 아니라, 그 부대가 속해있는 지휘라인의 1차 상급지휘관의 부대지휘방향에 따라 상당한 영향을 받는 경우가 많다 평가를 담당하는 기관인 2차 상급조직에서 제시하는 평가요소에 대한 중요도가 1차 상급지휘관의 부대지휘방향과 상이하다면, 해당부대는 1차 상급지휘관의 의도를 충실히 구현하였음에도 불구하고 다른 지휘라인의 부대들보다 낮은 평가를 받을 수 있다. 본 연구는 계층적 구조하에서 성과방향의 차이를 야기하는 지휘라인별 특성을 집단외생변수로 취급하여 평가의 공정성을 기하기 위한 연구이다. 비모수적 기법인 DEA와 모수적 기법으로서 다수의 종속변수가 존재하고 모수의 제약을 반영할 수 있는 제약정준상관분석(CCCA: Constrained Canonical Correlation Analysis)의 결합모형을 이용하였으며, 이 과정에서 성과에 영향을 미치는 집단환경변수를 범주화하여 대대급 부대의 성과평가를 수행하였다.

액와접근법을 이용한 무기하 내시경 갑상선 절제술 후 국소 부위 통증 조절 장치(On-Q^Ⓡ PainBuster^Ⓡ)와 자가 통증 조절 장치의 무작위 대조 연구에 대한 예비 자료

이경원,박찬흔,박용래,현기훈,윤지섭,Kyung-Won Lee,Chan-Heun Park,Yong-Lai Park,Ki-Hun Hyun,Ji-Sup Yoon 대한갑상선-내분비외과학회 2013 The Koreran journal of Endocrine Surgery Vol.13 No.4

Purpose: Gasless transaxillary approach to endoscopic thyroidectomy is a widely performed procedure for benign or malignant thyroid neoplasms. However, it requires wide dissection for approaching the target area. The intravenous patient-controlled analgesia (IV PCA) is an effective method for postoperative pain control and patients can use it according to their requirement. However, patients suffer from nausea, vomiting, sleep disturbance, etc. due to opioids. Pain pump ON-Q^Ⓡ PainBuster^Ⓡ (pain buster) has been used widely in various surgeries for control of postoperative localizing and wide area pain without side effects of opioid analgesia because it consists of Ropivacaine. Methods: From Aug. 2008 to Jan. 2013, Gasless transaxillary endoscopic thyroidectomy was performed in 90 patients in a single institution, who were divided into three groups, including the IV PCA, pain buster, and null groups. We compared postoperative outcomes, pain severity between groups. We recorded scores immediately, 6, 12, 24, and 48 hours after surgery following visual analog pain score (VAS), and investigated hospital stay and occurrence of events of nausea, vomiting, and complications. Results: In the IV PCA group, it was discontinued due to nausea in 36.7% of patients. No significant difference in pain severity following VAS score was observed among the three groups. However, smaller numbers of analgesia injections were required in the Pain buster group than in the other groups, and fewer patients suffered from constipation, compared with the PCA group. Conclusion: Pain buster showed even effects compared to IV PCA, with few side effects and less discomfort of patients, compared with the other groups. Therefore, pain buster was thought to be the proper method for pain control after dissection of the anterior chest wall, cervical area in order to secure an operative view for transaxillary endoscopic thyroi-dectomy.

실험적 안구천공상에서 일차적 공막돌륭술의 효과

이경원,이석준,이종혁,Kyung-won Lee,M,D,Seok-joon Lee,M,D,Jong-hyuck Lee,M,D 대한안과학회 2005 대한안과학회지 Vol.46 No.1

Purpose: Scleral buckles are frequently performed as an additional procedure in perforated ocular injury surgery, but little is known about their independent effect after ocular trauma. The authors made a posterior penetrating ocular injury model in rabbits to evaluate the isolated role of primary scleral buckle placement. Methods: Twenty eyes underwent surgery. The penetrating injury consisted of two 5 mm circumferential incisions placed five clock hours apart and 7 mm behind the limbus. A segmental scleral buckle was placed over a randomly chosen penetrating injury site after wound closure. The degree of the fibrous proliferation, traction, and the presence of retinal detachment were evaluated on follow-up examination. After enucleation and fixation, tissue sectioning was performed including injury sites. The greatest dimension of the fibrous proliferation at both wound sites was measured. Results: Two eyes were excluded from the study due to unsuccessful buckling. Four eyes developed a retinal detachment. The remaining 14 eyes showed varying degrees of proliferation and traction on the retina. The greatest dimension of the fibrous proliferation at the buckle site (1.69±0.29 mm) was significantly different from that at the non-buckle site (2.07±0.37 mm, P<0.05). Conclusion: Primary scleral buckle placement at the time of surgical repair reduces vitreous traction and decreases the degree of fibrous proliferation.

수정된 설계 방정식을 이용한 허니컴 구조의 차폐 효과 예측

이경원,정영철,홍익표,육종관,Lee Kyung-Won,Cheong Yeong-Chul,Hong Ic-Pyo,Yook Jong-Gwan 한국전자파학회 2005 한국전자파학회논문지 Vol.16 No.9

In this paper, the modified design equation of shielding effectiveness was presented to predict more accurately the shielding effectiveness of honeycomb structure with hexagonal waveguide. The design equation of shielding effectiveness in honeycomb was represented from adding shielding effectiveness of single lattice to shielding effectiveness of infinite array of single lattice. This paper proposed the generalized design equation of shielding effectiveness by analyzing basis lattice of hexagonal waveguide which composes honeycomb structure and infinite array structure of basis lattice. To provide the validity of the modified design equation of shielding effectiveness in this paper, comparison with other available date using 3D EM commercial software is made. 본 논문에서는 전자기 차폐 구조로 널리 알려진 육각형 도파관 구조를 갖는 허니컴 구조의 차폐 효과를 정확하게 예측하기 위하여 기존의 차폐 효과 설계식을 수정하여 새로운 차폐 효과 설계식을 제안하였다. 허니컴의 차폐 효과 설계 방정식은 단일 격자의 차폐 효과와 무수히 많은 격자 구조의 차폐 효과의 합으로 표현되는데, 본 논문에서는 허니컴 구조를 이루고 있는 육각형 기본 격자를 해석하고, 기본격자가 다수의 배열로 이루어진 해석을 통해 일반화 된 차폐 효과 설계 방정식을 제안하였다. 제안한 차폐 효과 설계 방정식의 유효함을 입증하기 위하여 상용 소프트웨어의 3D EM 시뮬레이션과 비교하였다. 또한, 측정 결과와 비교하여 본 논문에서 제안한 수정된 차폐 효과 설계 방정식이 기존의 설계 방정식보다 더 정확하다는 것을 보여주었다.

동학과 유교의 관련성에 대한 검토

이경원(Lee, Kyung-Won) 역사학연구소 2014 역사연구 Vol.- No.27

This writing examines previous studies on connections between Donghak and Confucianism through three different topics: Donghak’s doctrine, propagation, and Donghak Peasant Army’s consciousness. Previous studies on connections between Donghak and Confucianism predominantly regards Donghak doctrine as deviation from Confucianism. These studies either regard Donghak doctrine as a mixture of different religions including Confucianism or as something inheriting Confucianism while embracing equality by overcoming discrimination based on class. Few studies on connections between propagation of Donghak and Confucianism point out Choi Si-Hyung added elements of Confucian practical ethics such as loyalty and filial piety in propagation to receive official recognition from the government. This view in part made simplified interpretation on why leaders of Donghak adopted Confucianism during propagation due to their view which regards Confucianism as an ideology of a conqueror. Various study methods have been implemented on study on connections between Donghak and Confucianism. Another view argues that Choi Je-Woo and Choi Si-Hyung amended Confucian ethics and codes of province as a method of practice of Donghak in response to various problems occurred during propagation. Also scholars examined for meaning behind Confucian practical ethics as argued by followers of Donghak during the period of the movement vindicating the innocence of the founder of Donghak. Studies on connections between consciousness of Donghak Peasant Army and Confucianism are rejuvenated as criticisms poured down upon previous studies on Donghak Peasant War. Previous studies focused on the War’s influence in the process of modernization. Studies based on this view sought for modern ideologies such as equality and political system in consciousness of Donghak Peasant Army. Since then, a question over whether Donghak Peasant Army truly intended for modernization and a new view which defines people as an entity with autonomy and unique culture surfaced. Based on this view, there has been a sudden spark of interest in connections between consciousness of Donghak Peasant Army and Confucianism. First, there had been studies which argue Donghak Peasant Army desired ruling system based on Min-Bon ideology and Royalism by a benevolent king as well as Confucian utopia based on “all people under one king(一君萬民)”. Also some argue that ideological and structural foundation of the Confucian scholars participating in Donghak Peasant Army influenced consciousness and activities of the people involved. Lastly, there had been studies claiming Donghak Peasant Army acquired legitimacy by arguing Confucian practical ethics and this initiated members of rural community societies to participate in Donghak.

탈식민주의의 ‘뿌리’

이경원(Kyung-Won Lee) 한국비평이론학회 2009 비평과이론 Vol.14 No.2

This paper purports to trace back the roots of postcolonialism under the assumption that postcolonialism began with the inseparble history of black diaspora, anti-slavery, and decolonization. The foremost precursors were eighteenth-century African American writers who described their experiences of slavery in the mode of autobiography or reminiscence, exploring the genre of the slave narrative elabrated later by Frederick Douglass. These ex-slaves have given not only a dramatic story of captivity and liberation but also a Christian confession that depicts their physical deliverance as an allegory of spiritual salvation. But the later half of the nineteenth century has witnessed the emergence of a more radical and subversive discourse of black self-representation. Most noteworthy among them are Martin R. Delany, Alexander Crummell, and Edward W. Blyden. Reconstructing the pejorative concepts of the 'Negro"and Africa, these early black nationalists attempted to undermine and debunk the dominant ideology of white supremacy and Eurocentric mode of thought. Their argumentations for the necessity and possibility to 'uplift' the Negro and 'civilize' Africa were intellectually invigorating and politically provocative as well. Yet they disclosed a variety of struggles and contradictions, say, between idealism and materialism, between separatism and assimilationism, or between universal civilizationism and ethnocentric racialism. Moreover, they displayed flamboyant and chauvinistic slogans like 'Back ot Africa' and 'Africa for Africans,' but showed little readiness to divorce themselves from the institutional support of white abolitionists and philanthropists. So their nationalist and Afrocentric undertakings were embedded in the yearning to venerate Christian ethics and imitate Anglo-Saxon civilization. Their dream of a renascent Africa as well as a reconstructed black America always implied making blacks more like whites. Despite these theoretical and ideological contradictions, however, the early black nationalists cannot be reduced to 'white men's niggers' or 'fools of history' incapable of articulating their thoughts. Rather, by engaging with the taken-for-granted notions of black inferiority and barbarity, they have laid the cornerstone of anticolonial movements and national liberations in the next century. As the progenitor of Pan-Africanism and Negritude, these early black nationalists can be legitimately called the roots of postcolonialism today.

지역사회 노인의 치매지식, 치매불안감 및 치매예방행위와의 관계

이경원(Lee, Kyung-Won),김애리(Kim, Aee-Lee) 한국웰니스학회 2018 한국웰니스학회지 Vol.13 No.4

본 연구는 지역사회의 노인들을 대상으로 치매지식, 치매불안감 및 치매예방행위 관계를 파악하여 치매예방을 위한 기초자료를 제공하기 위해 시도되었다. 2017년 3월2일부터 5월10일 까지 서울시에 거주하는 60세 이상 노인 150명을 대상으로 하는 서술적 조사연구로 SPSS 23.0 프로그램으로 상관계수와 단계적 회귀분석을 하였다. 분석결과 대상자의 치매예방행위와 치매지식은 정적상관관계가 있었으며, 치매예방행위와 치매불안감은 부적상관관계가 있는 것으로 나타났다. 또한 대상자의 치매예방행위에 중요한 영향을 미치는 것은 300만원 이상의 소득과 치매불안감임을 학인하였다. 따라서 본 연구에서 도출된 결과를 반영하여 저소득층이거나 치매불안이 높은 노인을 대상으로 치매예방행위를 독려하고 증진시켜야하며, 효율적인 치매교육 및 체계화된 치매관리 프로그램의 개발을 통하여 치매예방 및 조기발견에 도움이 되어야할 것이다. The purpose of this research is to provide basic data about preventing dementia to elderly via investigating the relationships between dementia knowledge, dementia anxiety, and its preventive behavior. The subjects of this study were 150 elderlies with age over 60 residing in Seoul. Analysing with SPSS 23.0 program, dementia preventive behavior and dementia knowledge showed positive correlation whereas, dementia preventive behavior and dementia anxiety had negative correlation. The level of income of three million won and dementia anxiety was notable factors effecting dementia preventive measures. Therefore, the need to focus more on the elderly with lower income and dementia anxiety are emphasized through the research. Hence, it is necessary to investigate and develop effective dementia education and structured management programs reflecting the results of the research, encouraging the promotion of elderly"s dementia prevention behavior.

Type 3 복합소재 압력용기의 파열압 분석

이경원(Kyung-won Lee),조성민(Sung-Min Cho),이선규(Sun-Kyu Lee),이승국(Seong-Kuk Lee),이연재(Yeon-Jae Lee) 한국가스학회 2016 한국가스학회 학술대회논문집 Vol.2016 No.11

Al metal 패키지 구조에 따른 UV-C LED 광특성 비교

이경원(Kyung-Won Lee),김완호(Wan-Ho Kim),구대형(Dai-Hyoucg Koo),김재필(Jae-Pil Kim),여인선(In-Seon Yeo) 대한전기학회 2014 대한전기학회 학술대회 논문집 Vol.2014 No.7