고체산화물 연료전지용 (Ca,Sr)도핑된 LaCrO₃계 세라믹 연결재 코팅층의 특성 연구

이길용,백동현,송락현,Lee, Gil-Yong,Peck, Dong-Hyun,Song, Rak-Hyun 한국전기화학회 2005 한국전기화학회지 Vol.8 No.4

본 연구는 Pechini법을 이용하여 Ca과 Sr이 도핑된 $LaCrO_3$계의 $La_{0.6}Ca_{0.41}CrO_3$ (LCC41), $La_{0.8}Sr_{0.05}Ca_{0.15}CrO_3$, (LSCC), $La_{0.75}Ca_{0.27}CrO_3$ (LCC27) 분말들을 제조하여, 분말의 소결 특성 및 코팅층의 특성을 조사하였다. 제조된 LCC41, LSCC, LCC27 분말은 각각 0.6, 0.9, $1.5{\mu}m$의 평균 입자크기를 가졌으며, LCC41의 경우 $1400^{\circ}C$에서 98% 이상의 소결 밀도를 나타내었다. 연료극 지지체상의 LSCC 코팅은 LCC41층에 있는 Ca의 이동을 어느 정도 억제하는 역할을 하는 것으로 나타났다. 대기 용사 코팅된 LCC27은 치밀한 코팅막을 형성하였으며, 이 코팅층 위에 LCC41을 습식 코팅할 경우 더욱 치밀하고 높은 전기전도도를 갖는 코팅막을 얻을 수 있었다. 용사코팅된 LCC27, 습식 코팅된 LCC41는 높은 전기전도도를 나타내었으나, LSCC의 경우 낮은 소결성으로 인해 전기전도도가 작게 나타났다. Using Pechini method, we synthesized the $La_{0.6}Ca_{0.41}CrO_3$ (LCC41) and $La_{0.8}Sr_{0.05}Ca_{0.15}CrO_3$ (LSCC) powders for slurry dip coating, and $La_{0.75}Ca_{0.27}CrO_3$ (LCC27) powder for air plasma spray coating. The sintering property of the powders and their coating properties were investigated. The average particle sizes of the LCC41, LSCC, LCC27 were 0.6, 0.9, $1.5{\mu}m$, respectively. The relative density of LCC41 bulk was to be found about 98%. The LSCC coating on anode support prevented Ca migration of the coated LCC41 on the anode some or less, which was confirmed from EDS result. The air plasma spray-coated LCC27 with the dip-coated LCC41 were more dense and showed better electrical conductivity than those of the air plasma spray-coated LCC27 and the dip-coated LSCC and LSCC41. The LCC41 and LCC27 showed good electrical conductivities, but the LSCC had a poor electrical conductivity probably due to low sinterability

수질 TMS 설치.운영사례 소개 및 발전방향

이길용,Lee, Gil-Yong 환경보전협회 2008 환경정보 Vol.30 No.373

나노입자집속 프린팅을 이용한 고감도 센서의 직접 인쇄 및 응용

이길용(Gil-Yong Lee),안성훈(Sung-Hoon Ahn) 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.11

특발성 후복막강섬유증 1예 보고

이길용(Gil Yong Lee),류병윤(Byoung Yoon Ryu),이해완(Hae Wan Lee),김홍기(Hong Ki Kim),최창식(Chang Sig Choi) 대한외과학회 1995 Annals of Surgical Treatment and Research Vol.49 No.5

급성 충수돌기염의 음성개복률에 영향을 미치는 인자들

이길용(Gil Yong Lee),이해완(Hae Wan Lee),류병윤(Byoung Yoon Ryu),김홍기(Hong Ki Kim),석홍(Hong Suk) 대한외과학회 1996 Annals of Surgical Treatment and Research Vol.51 No.4

Development of proper generalized decomposition-based harmonic balance method for nonlinear frequency response analysis

Gil Yong Lee(이길용),Phill-Seung Lee(이필승),Yong-Hwa Park(박용화) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11

In structural dynamics, the harmonic balance method (HBM) has been widely applied to obtain the frequency response of many mechanical systems in the presence of nonlinearities. It approximates the periodic solution utilizing a truncated Fourier series, resulting in a set of nonlinear algebraic equations in the frequency domain. However, one still difficulty in the HBM is that dimension of the nonlinear equations is the product of number of degrees of freedoms and harmonics , so the computational cost of the continuation over the frequency range can be easily burdensome . In this work , we present the proper generalized decomposition -based harmonic balance method (PGD-HBM) for the efficient numerical continuation of the nonlinear frequency response. The PGD-HBM utilizes the low-dimensional subspace of the HBM, constructing the HBM response as a separated representation of the spatial and temporal components . The updated progressive Galerkin scheme is adopted to obtain a set of components . During the continuation , the spatial modes obtained at the previous computation are used as a reduced basis. Through numerical studies, it is demonstrated that the PGD-HBM not only provides significant computational savings compared to the HBM, but also maintains accuracy.

종설(綜說) : 경락학설(經絡學說)의 기원(起源)에 대한 소고(小考)

이길용 ( Gil Yong Lee ),이준연 ( Jun Yeon Lee ),이은주 ( Eun Joo Lee ),양재하 ( Chae Ha Yang ),이봉효 ( Bong Hyo Lee ),김희영 ( Hee Young Kim ) 대구한의대학교 제한동의학술원 2011 東西醫學 Vol.36 No.4

Object : To investigate how meridian theory has been formed and changed, we reviewed several papers and literatures concerning meridian theory and Oriental medical history. Method : Previous publications including translations of Mawangdui medical book meridian theories of Han Dynasty and recent papers were reviewed and summarized. Result : Bassed on previous publications, (1) the meridian had been formed from long-time experience of old traditional doctors, (2) the meridians were functional lines to treat specific diseases rather than the anatomical structure of body, (3) it is guessed that the old anatomists and doctors found specific line with similar effects (now called as the meridian) on specific disorders and named after moxibustion-specific Qi channels. They also considered that these channels were the important basis in th vital activity of the human body and sensitive to pathological changes, and thus it could be used for diagnosis and treatment of th disease. Conclusion : Meridians and their names have been formed from experience of many traditinal doctors and changed over long periods of time.

터널 단면적 변화를 고려한 각부보강 영향성 평가

이길용(Gil-Yong Lee),오현문(Hyeon-Mun Oh),조계환(Kye-Hwan Cho),오정호(Jeong-Ho Oh),김종주(Jong-Ju Kim),김용성(Yong-Seong Kim) 한국지반신소재학회 2018 한국지반신소재학회 논문집 Vol.17 No.1

단층 등 취약지반 조건에서의 터널굴착 시 터널천단 및 측벽변위의 억제를 목적으로 하는 각부보강공이 일반적으로 적용되고 있으며, 터널 단면증가 변화율에 따른 각부보강공 설치각도 및 길이를 고려한 지보안전성 확인을 위한 주요 인자로서 내공변위 · 천단침하 · 각부침하 · 각부축력 등의 여러 응력변위 특성 변수들이 있다. 이러한 굴착중 안전성확인을 위한 변수들에 대한 검토 결과, 우각부 침하영향성이 단면증가율 보다 더 큰 변위경향을 보이는 가장 중요한 중점관리 지배요소로 분석되었으며, 터널단면 증가변화율에 대한 각 보강공 길이별 축력의 변화관점에서는 큰 연관성을 보여주지 못하는 터널단면 증가율 대비 작은 증가율을 나타냈다. 또한, 각부 보강공 축력의 발생경향은 터널 단면증가율보다 보강공 마찰지지 개념 메커니즘에 따른 거동 영향성을 보여주는 것으로 분석되었다. 본 연구결과, 일정한 길이의 각부 보강공이 선정될 경우 지반불량 구간에서의 터널 단면이 다소 대단면화하여도 무리하게 각부보강공의 길이를 연장시키지 않는 것이 시공성 및 경제성을 고려한 보다 더 합리적인 방법으로 판단된다. In case of excavation of the tunnel under weak ground conditions, such as fault zone, leg pile reinforcement with the purpose of suppressing tunnel crown settlement and side wall displacement is commonly applied. There are convergence, crown settlement, leg settlement, and the axial force of leg as a main factor for confirming the safety of support considering the installation angle and length of leg pile reinforcement according to the increase in rate of change of tunnel cross-section. In particular, the influence of right corner settlement, among variables for safety confirmation during excavation, has been analyzed as the dominant factor in the most important priority management showing larger displacement tendency than the increase in rate of the cross-section. And, it was analyzed that the occurrence tendency of axial force on leg pile reinforcement showed the influence of behavior according to the friction support concept mechanism of the pile reinforcement rather than the increase in rate of tunnel cross-section, as it showed a small increase compared to the increase rate of the tunnel cross-section which did not show a great correlation from the viewpoint of the change of the axial force by the length of each leg pile reinforcement with regards to the change in rate of increase in tunnel cross-section. If a certain length of the leg pile reinforcement is selected based on the above grounds, even if the cross-section of the tunnel in poor ground condition is somewhat larger, it has been proved to be a more reasonable method considering the workability and economical efficiency by not extending the length of the leg pile reinforcement by force.

사이프러스 에센셜 오일의 흡입이 전임상 실험동물의 손상된 학습능력과 기억력에 미치는 영향

이길용 ( Gil-yong Lee ),이찬 ( Chan Lee ),백정인 ( Jeong-in Baek ),배근영 ( Keunyoung Bae ),박찬익 ( Chan-ik Park ),장정희 ( Jung-hee Jang ) 대한본초학회 2020 大韓本草學會誌 Vol.35 No.5

Objectives : Increasing evidence supports the biological and pharmacological activities of essential oils on the central nervous system such as pain, anxiety, attention, arousal, relaxation, sedation and learning and memory. The purpose of present work is to investigate the protective effect and molecular mechanism of cypress essential oil (CEO) against scopolamine (SCO)-induced cognitive impairments in C57BL/6 mice. Methods : A series of behavior tests such as Morris water maze, passive avoidance, and fear conditioning tests were conducted to monitor learning and memory functions. Immunoblotting and RT-PCR were also performed in the hippocampal tissue to determine the underlying mechanism of CEO. Results : SCO induced cognitive impairments as assessed by decreased step-through latency in passive avoidance test, relatively low freezing time in fear conditioning test, and increased time spent to find the hidden platform in Morris water maze test. Conversely, CEO inhalation significantly reversed the SCO-induced cognitive impairments in C57BL/6 mice comparable to control levels. To elucidate the molecular mechanisms of memory enhancing effect of CEO we have examined the expression of brain-derived neurotrophic factor (BDNF) in the hippocampus. CEO effectively elevated the protein as well as mRNA expression of BDNF via activation of cAMP response element binding protein (CREB). Conclusions : Our findings suggest that CEO inhalation effectively restored the SCO-impaired cognitive functions in C56BL/6 mice. This learning and memory enhancing effect of CEO was partly mediated by up-regulation of BDNF via activation of CREB.

위치인식 불가의 극한상황에서 성범죄 예방 상황인지 서비스를 위한 스마트 전자발찌 시스템

이길용(Gil-Yong Lee),박수현(Soo-Hyun Park) 대한전자공학회 2012 전자공학회논문지 Vol.49 No.11

기존 전자발찌 시스템은 GPS 위성 및 휴대폰 기지국 통신을 통해 성범죄자의 위치를 추적하고 재범을 방지하는 장치이다. 하지만 GPS 위성통신 방식은 위성 신호 수신이 어려운 도심 건물의 실내나 지하철에서는 제대로 작동하지 않는다. 이러한 경우 휴대폰 기지국 통신을 통해 위치추적을 할 수 있다. 그러나 휴대폰 기지국은 설치범위가 수백 미터 간격으로 넓기 때문에, 위치추적을 할 경우 오차범위가 최대 2 ㎞일 만큼 정확도가 떨어진다. 만약 도심의 5층 건물에서 유치원이 2층에 위치해 있고 커피숍과 성범죄자가 3층에 위치해 있다면, 기존 전자발찌는 건물 내부로 인해 GPS 위성통신으로 위치추적이 안되고 휴대폰 기지국 통신으로도 정확한 층에 대한 위치인식이 안 된다. 전자발찌는 위치인식 기반의 시스템으로 이러한 현상은 커다란 문제가 된다. 따라서 본 논문은 이런 위치인식 불가의 극한환경에서 USN을 이용하여 성범죄자들을 감시할 수 있는 스마트 전자발찌 시스템을 제안한다. The existing electronic tagging system traces the location of a sex offender through communicating with GPS satellites and mobile phone base stations in order to prevent repeated crimes. However, the GPS satellite communication method does not work well in the interiors of downtown buildings or on the subways where it is difficult to receive satellite signals. In such cases, the location can be traced through communication with mobile phone base stations. But the distance between mobile phone base stations is several hundred meters, and as a result the margin of error for location tracing can be maximum of 2㎞ in accuracy reduction. Take for example, if a kindergarten is located on the 2nd floor and a coffee shop and the sex offender are located on the 3rd floor in a 5-story building that is downtown, the existing electronic tagging system cannot trace the location of the sex offender as the GPS satellite communication does not work in the interior of the building and the exact floor that the sex offender is located on cannot be recognized through communication with mobile phone base stations. This occurrence is a big problem for the existing electronic tagging system, which is based on position recognition. Therefore, this study suggests a smart electronic tagging system that can monitor sex offenders by using a Ubiquitous Sensor Network in such extreme situations where position recognition is not possible.