역세권 개발압축도가 지하철 수요에 미치는 영향

이영락 서울대학교 환경대학원 2015 環境論叢 Vol.56 No.-

개폐식 대공간 구조물의 효율적인 지진응답제어를 위한 TMD의 최적 설치 위치 분석

이영락,김현수,강주원,Lee, Young-Rak,Kim, Hyun-Su,Kang, Joo-Won 한국공간구조학회 2018 한국공간구조학회지 Vol.18 No.2

In this study, TMD(Tuned Mass Damper) is installed in a retractable-roof spatial structure in order to investigate dynamic response characteristics according to mass ratio and installed position of TMD on large spatial structures. The example analytical model is generated based on the Singapore sports hub stadium. Twenty eight analytical models are used to investigate optimal installation position of TMD for the example retractable-roof spatial structure using 4 to 16 TMDs. The mass of one TMD is set up 1% of total mass at the example analytical model. Displacement response ratio of model with TMD is compared with that of base model without TMD. It has been found from numerical simulation that it is more effective to install TMD at the edge of the spatial structure rather than to concentrate the TMD at the center of the spatial structure.

TMD의 질량 변화에 따른 개폐식 대공간 구조물의 지진응답 제어성능 분석

이영락,노호성,김현수,강주원,Lee, Young-Rak,Ro, Ho-Sung,Kim, Hyun-Su,Kang, Joo-Won 한국공간구조학회 2019 한국공간구조학회지 Vol.19 No.1

In the precedent study, the retractable-roof spatial structure was selected as the analytical model and a tuned mass damper (TMD) was installed to control the dynamic response for the earthquake loads. Also, it is analyzed that the installation location of TMD in the analytical model and the optimal number of installations. A single TMD mass installed in the analytical model was set up 1% of the mass of the whole structure, and the optimum installation location was derived according to the number of change. As a result, it was verified that most effective to install eight TMDs regardless of opening or closing. Thus, in this study, eight TMDs were installed in the retractable-roof spatial structure and the optimum mass ratio was inquired while reducing a single TMD. In addition, the optimum mass distribution ratio was identified by redistributing the TMD masses differently depending on the installation position, using the mass ratio of vibration control being the most effective for seismic load. From the analysis results, as it is possible to confirm the optimum mass distribution ratio according to the optimum mass ratio and installation location of the TMD in the the retractable-roof spatial structure, it can be used as a reference in the TMD design for large space structure.

개폐식 대공간 건축물의 지붕구조에 따른 특성분석

이영락,김현수,강주원,Lee, Young-Rak,Kim, Hyun-Su,Kang, Joo-Wo 한국공간구조학회 2016 한국공간구조학회지 Vol.16 No.4

개에서 발정유도가 인공수정효율에 미치는 영향

이영락,강태영,최상용 韓國受精卵移植學會 2003 한국동물생명공학회지 Vol.18 No.1

본 실험은 개의 인공수정에 사용할 신선정액, 그리고 동결정액을 이용한 자연교미와 발정유도된 실험견에 인공수정시 임신율과 산자수를 검증하여 그 효율성을 조사하였다. 1. 개의 인공수정시에 자연발정, clomifene, bromocriptine 단독 투여 그리고 GnRH + bromocriptine/GnRH 혼합 투여에 따른 발정유도방법은 임신율과 산자수에 영향을 미치지 않는 것으로 나타났으며, 신선정액을 이용한 인공 수정방법은 자연교미방법과 유사한 임신율 Considerable attention has been focused on the cryopreservation of semen and estrus induction in dog, as consequence of poor productivity caused by long anestrus period, in order to enhance the productivity of youngs and to preserve the breeds. The objectives of this study were to improve reproductive efficiency of artificial insemination with fresh- and frozen-semen following estrus induction in dog. Fifty infertilie dogs (age 2~3 years) were selected fur the study and divided into three different estrus induction treatment groups. Group 1 : dogs (n=15) were given clomifene (0.1 mg/kg) orally f3r five days at 12 hr intervals. Croup 2: dogs (n=15) were given bromocriptine (50 g/kg) orally for five days at 12 hr intervals, followed by single injection intravenously of 500 IU GnRH (Croup 3, n=20) when pro-estrus occurred. After being treated, the dogs were evaluated fur the rates of estrus induction and time interval lapses from treatment to beginning of the pro-estrus. The rates of pregnancy in estrus inducted dogs mated naturally compared to those inseminated artificially with ejaculated fresh semen and frozen-thawed semen. Estrus detection was performed using the method of vaginal smear and confirmed by the plasma progesterone assay. Pregnancy was confirmed by ultrasonograpy on day 25, 35 and 55 post insemination. The ejaculated semen was exposed to a mixture of Tris extender with cryoprotectant (Trisma, 81 mM; TES, 209 mM; citric acid, 6 mM; glucose, 5 mM; glycerol, 8%) and cryopreserved gradually by slow-cooling at 17 co above the surface of liquid nitrogen (L) for 23 min. The use of fresh semen, the pregnancy rates were observed 66.6, 66.6, 75.0 and 83.3% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. The use of frozen-thawed semen, the pregnancy rates were observed 66.6, 33.3, 50.0 and 60.0% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. No difference was observed in the number of offspring produced among natural estrus and treated groups inseminated with fresh or frozen-thawed semen. In conclusion, there was no significant differences in the pregnancy rate of dogs between group treated with a combination of GnRH and bromocriptine and group treated clomifene or bromocriptine only. However, frozen-thawed semen can be used successfully fur artificial insemination in dog.

상부 돔구조와 하부구조간의 고유진동수비에 따른 동적응답특성

이영락,김광일,강주원,Lee, Young-Rak,Kim, Kwang-Il,Kang, Joo-Won 한국공간구조학회 2015 한국공간구조학회지 Vol.15 No.2

This study investigate the dynamic response changes of rib dome structure according to property changes of Substructure. Eigenvalue analysis is conducted in first natural frequency of rib dome versus substructure and searched in the dominant mode of horizontal and vertical direction. Resonance frequency by each first natural frequency of the rib dome structure, substructure and total structure is applied for a seismic wave. That is analyzed about maximum displacement response ratio and maximum acceleration response ratio.

TMD 설치 질량 변화에 따른 대공간 구조물과 고층건물의 변위 응답 특성

이영락,김현수,강주원,Lee, Young-Rak,Kim, Hyun-Su,Kang, Joo-Won 한국공간구조학회 2020 한국공간구조학회지 Vol.20 No.3

In this paper, the displacement response to seismic loads was analyzed after installing TMD in spatial structures and high-rise buildings. In the case of a spatial structures, since it exhibits complex dynamic behavior under the influence of various vibration modes, it is not possible to effectively control the seismic response by installing only one TMD, unlike ordinary structures. Therefore, after installing eight TMDs in the structure, the correlation between displacement response and mass ratio was examined while changing the mass. The TMD must be designed to have the same frequency as the structure frequency so that the maximum response reduction effect can be exhibited. It can be confirmed that the most important variable is to select the optimal TMD mass in order to install the TMD on the structure and secure excellent control performance against the earthquake load. As a result of analyzing the TMD mass ratio, in the case of high-rise buildings, a mass ratio of 0.4% to 0.6% is preferable. In spatial structures, it is desirable to select a mass ratio of 0.1% to 0.2%. Because this study is based on the theoretical study based on numerical analysis, in order to design a TMD for a real structure, it is necessary to select within a range that does not affect the safety of the structure.

개 정자의 동결융해 후 생존성 및 첨체의 변화

이영락,이성림,강태영,최상용 韓國受精卵移植學會 2003 한국동물생명공학회지 Vol.18 No.1

본 실험은 개의 인공수정에 사용할 정자의 보존에 있어서, 개 정액 동결시 동결속도와 응해온도에 따른 정자의 생존율, 운동성 그리고 intact acrosome의 비율을 조사하였던 바 결과는 다음과 같다. 1. 본 실험에서 실험견의 사출된 평균 신선정액의 농도는 3.44 /ml로 정상범위에 들었으며, 정자의 형태학적 판정에서 정상적인 정자의 농도는 평균 59.453.45%로 상대적인 기형율은 약 30~40% 정도 나타났으며, 이는 정상적인 상태의 개 정액 This study was carried out to evaluate the effect of different freezing and thawing rates on the viability, motility and acrosomal changes of frozen canine spermatozoa. The ejaculated semen was extended with Tris-egg yolk buffer containing 8% glycerol and equilibrated for 60 min after cooled to 4 for 58 min. The straws were cryopreserved gradually by slow-cooling at different distance(6, 10 and 17 cm, respectively) from the liquid nitrogen (L) to achieve temperature rate of 3, 8.9 and 19 /min. Thawing of the straws was performed in a water bath fur 2 min at 37 and 55 , respectively. The motility of frozen-thawed spermatozoa was assessed by phase-contrast microscopy. To assess their viability and acrosome content, spermatozoa were stained with a vital stain and Fluorescence conjugated lectin Pisum Savitum Agglutinin (FITC/PAS), respectively. Concentration of the ejaculated fresh semen was normal range of 3.44 10 /ml. Freezing temperature were reduced to -110, -70 and -35, as higher distance from liquid nitrogen, 6, 10 and 17 cm, respectively. Freezing at 3/min in distance of 17 cm from liquid nitrogen yielded better motility, viability and rate of intact acrosome than 8.9 or 19/min and the optimal thawing was 37 for 2 min.

Dichromated Gelatin 홀로그램의 편광 특성과 편광분리 소자 응용

이영락,임용석,곽종훈,최옥식,박진원,이윤우 한국광학회 1997 한국광학회지 Vol.8 No.4

DCG(dichromated gelatin : 7.mu.m 두께) 필름을 이용하여 홀로그래픽 편광분리(Holographic Polarization Separation : HPS)소자를 설계 제작하였다. 제작한 HPS소자의 편광특성을 노출시간, 입사각, 편광각 등의 몇가지 물리적 변수들을 이용하여 조사하였다. 실험결과가 Kogelnik의 결합 파동이론에 기초한 이론적 결과와 잘 일치함을 알 수 있었다. 제작한 HPS소자는 633 nm 파장에서 편광 회절 강도비가 500:1(S편광:P편광)이상이였다. 또한 HPS소자의 광 스위치 및 자유공간 광 연결소자로서의 응용 가능성을 제시하였다. Holographic optical elements for polarization separation (HPS) are fabricated in a dichromated gelatin(DCG) thin film of 7${\mu}{\textrm}{m}$ thickness. The polarization properties of HPS is characterized by measuring diffraction efficiency with several physical parameters like exposure time, incident angle and read-out polarization angles. The experimental data are compared with theoretical results based on Kogelnik's coupled wave theory, which shows good agreement. It is also found that the HPS element has a very high extinction ratio of polarization over 500:1 for S and P polarizations, respectively, with He-Ne laser wavelength. We also propose an optical switch optical interconnects by using HPS elements.

Ti : PPLN 도파로 소자를 이용한 전광 신호처리

이영락,Lee, Yeong-Rak 한국광학회 2005 광학과 기술 Vol.9 No.4