다단계 온도프리스트레싱기법을 활용한 HEAT 가설교량

이승재,이상우,장지훈,Lee, Seung-Jae,Lee, Sang-U,Jang, Ji-Hun 한국건설관리학회 2007 한국건설관리학회 논문집 Vol.8 No.6

건설안전실무: 건설현장 추락재해 방지

이승재,Lee, Seung-Jae 대한산업안전협회 2010 안전기술 Vol.156 No.-

Failed recanalization mediates the association of women with poor outcomes after thrombectomy: a single-center experience

이승재,Lee Tae-Kyeong,Moon Ji Eun 대한신경집중치료학회 2022 대한신경집중치료학회지 Vol.15 No.2

Background: Whether thrombectomy benefits differ according to sex remains debatable. We aimed to investigate whether there was a difference in stroke outcomes between men and women treated with thrombectomy.Methods: We studied 173 patients with anterior circulation strokes. Failed recanalization was defined as thrombolysis in cerebral infarction grade 0-2a. Scores >2 on the modified Rankin Scale at 3 months were regarded as poor outcomes. To prove that failed recanalization mediated the association between sex differences and functional outcome, the four steps of the reasoning process adapted from Baron and Kenny’s causal-steps approach were tested. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. Results: This study included 76 women and 97 men. Women were older and presented with atrial fibrillation more frequently than men. Female sex was independently associated with failed recanalization (aOR, 2.729; 95% CI, 1.334–5.582), which was an independent predictor of poor outcomes (aOR, 4.630; 95% CI, 1.882–11.389). Women were associated with poor outcomes in the analysis adjusted for confounders, except for failed recanalization (aOR, 2.285; 95% CI, 1.064–4.906). However, the association became insignificant in the additional analysis adjusted for failed recanalization (aOR, 1.670; 95% CI, 0.738–3.784). The indirect effect between female sex and poor outcomes via failed recanalization was statistically significant (aOR, 1.038; 95% CI, 1.010–1.127). Conclusion: Our study showed that failed recanalization mediated the association between women and poor outcomes after thrombectomy. Nonetheless, this might be explained by chance given our limited study population.

Conjugate Gradient 기법을 이용한 관측교통량 기반 통행수요 추정

이승재,이헌주(Hum Ju Lee) 대한교통학회 2003 대한교통학회 학술대회지 Vol.44 No.-

관측교통량으로 OD행렬을 추정하는 일반적인 형태는 엔트로피 최대화 방법(Entropy Maximizing), 일반화 최소자승법(Generalized Least Squares), 베이지안 추론기법(Bayesian Inference) 등이 있다. 이러한 기법들을 이용한 모형들은 일반적으로 2단계(bi-level)형태를 이루고 있다.

백색 발광다이오드용 M-Si(Al)-O-N (M: Sr, Ca) 형광체의 합성 및 발광 특성

이승재,이준성,김영진,Lee, Seung-Jae,Lee, Jun-Seong,Kim, Young-Jin 한국마이크로전자및패키징학회 2012 마이크로전자 및 패키징학회지 Vol.19 No.2

백색 LED용 산질화물계 녹색발광 형광체를 합성하고, 광특성을 분석하였다. $SrSi_2O_{2-{\delta}}N_{2+2/3{\delta}}:Eu^{2+}$의 조성을 갖는 $SrSi_2O_2N_2:Eu^{2+}$ 경우 합성조건에 따라서 N/O비 ($\delta$)가 변하고 있었다. 수소 분위기로 $1700^{\circ}C $에서 합성된 시편이 Eu의 농도가 5 mol%일 때 $Eu^{2+}$의 $5d{\rightarrow}4f$ 전이에 의한 545 nm 근처에서의 가장 높은 녹색 발광강도를 얻을 수 있었다. $Ca_{0.5m-0.005}Yb_{0.005}Si_{12-(m+n)}Al_{m+n}O_nN_{16-n}$의 조성을 갖는 $Ca-{\alpha}-SiAlON:Yb^{2+}$는 m = 3 (n = 0.15)에서 잘 발달된 결정성과 균일한 크기를 갖는 입자를 얻을 수 있었고, 이 것이 550 nm 근처에서 가장 높은 녹색 발광을 하고 있었다. Oxynitride green phosphors for white light emitting diodes (LEDs) were synthesized and their optical properties were evaluated. The N/O ratio ($\delta$) of $SrSi_2O_{2-{\delta}}N_{2+2/3{\delta}}:Eu^{2+}$ closely depended on the synthesizing conditions. The most excellent green emission (545 nm), which was assigned to the $5d{\rightarrow}4f$ transition of $Eu^{2+}$ ions, was achieved at the conditions of $1700^{\circ}C$, 5 mol% $Eu^{2+}$, and $H_2$ atmosphere. The well-developed $Ca-{\alpha}-SiAlON:Yb^{2+}$ particles with homogeneous size were obtained at m = 3 (n = 0.15) for the compound of $Ca_{0.5m-0.005}Yb_{0.005}Si_{12-(m+n)}Al_{m+n}O_nN_{16-n}$, resulting in the strong green emission at around 550 nm.

한국 산업인력구조의 변화와 주조산업계 대응방안

이승재,조인성,Lee, Seung-Jae,Cho, In-Sung 한국주조공학회 2018 한국주조공학회지 Vol.38 No.2

The lack of industrial manpower that Korean companies have been suffering in 21st century is largely responsible for the low-fertility phenomenon. This research suggests an alternative solution with a program for fostering foreign laborers with technical skills in casting industry. Industrial manpower growth is feasible through accepting migrants who have had official education on the fundamental industrial technologies provided by Korean government. These technically trained migrants who can keep economical self-perpetuating ability are can help to effectively address the problem of the declining working-age population and the decreasing potential growth rate in Korea.

가을 환절기 농장관리 포인트 - 환절기 산란계 사양관리 포인트

이승재,Lee, Seung-Jae 대한양계협회 2018 월간 양계 Vol.50 No.9

초대형 막구조물 지붕용 ETFE 필름 막재의 인장특성

이승재,이소라,Lee, Seung-Jae,Lee, So-Ra 한국공간구조학회 2010 한국공간구조학회지 Vol.10 No.1

ETFE is the abbreviation of Ethylen Tetra Fluoro Etylene, a sort of colorless and transparent granules. The advantage ETFE film has daylight transmission and chemical the resistance and The thickness of ETFE film is used to from $50{\mu}m$ to $300{\mu}m$ and tensile strength of ETFE film changes from 40MPa to 60MPa and the tensile strain at break can get to about 300-400%. In this paper, ETFE film carried out the tensile proprieties, such as the tensile strain at break, the tensile strength are examined. ETFE 필름 막재는 Ethylen Tetra Fluoro Etylene의 약자로, 무색의 투명한 막재료이다. ETFE 필름 막재는 내화학성이 있고 매우 가벼운 장점이 있는 것으로 알려져 있다. ETFE 필름 막재는 $50{\mu}m$에서 $300{\mu}m$의 두께가 주로 사용되며, 인장강도는 40MPa에서 60MPa 300%에서 400%정도이다. 본 연구에서는 최근 해외에서 초대형 박구조물의 박재료로 시용되는 ETFE 필름 막재에 대한 기초적 역학적 특성을 조사하기 위하여 인장시험을 수행하였다. 인장시험으로부터 인장강도, 인장연신율, 영계수(Young's Modulus) 등 건축 설계 시 필요한 기초적 자료를 제공하고자 한다.

강박증 이환기간과 임상 양상

이승재,유소영,강도형,권준수,Lee, Seung-Jae,Yoo, So-Young,Kang, Do-Hyung,Kwon, Jun-Soo 대한불안의학회 2006 대한불안의학회지 Vol.2 No.1

Objectives : There is a paucity of data on the long-term course of obsessive-compulsive disorder (OCD) and chronological relationship between OC symptoms and their related symptoms such as anxiety and depression. The purpose of this study was to investigate the longitudinal course of OC symptoms as well as anxiety and depression which are believed to be associated with OC symptoms. Methods : Data for 155 patients with OCD who completed general evaluation for OCD were used. Forty four were excluded to minimize the effect of the different age of onset on the clinical course. One hundred eleven patients finally participated in the analysis. Cross-sectional correlations between each symptom as well as between such symptoms and the duration of illness were analyzed. Further correlation analysis was done within two groups that were divided by 7 years of the duration of illness. Results : There were significant correlations not only between the severity of OC symptoms and anxiety but also between anxiety and depressive symptom, regardless of the duration of illness. These correlations between such symptoms were also found within patients with the duration of illness below 7 years, whereas these were not within the group with the duration of illness above 8 years. Conclusion : Patients with OCD in this study shows the moderate to severe level of OC symptoms irrespective of the duration of illness. Our finding also suggests that the OC symptoms, especially obsessions are closely related to anxiety and depressive symptoms and these relationships might be pronounced in relatively early phase of the OCD after onset.

단기 창업교육이 예비창업자의 심리적 특성 변화 영향에 대한 탐색적 연구

이승재,황보윤,Lee, Seung-Jae,HwangBo, Yun 한국벤처창업학회 2010 벤처창업연구 Vol.5 No.1

This study intend to analyze effect on a change mental feature of founder received entrepreneurship short-term education called the successful foundation package. In other words, what kind of change the mental feature of founder before and after entrepreneurship education. The founder of the psychological characteristics include the locus of control, risk-taking propensity, need for achievement, ambiguity tolerance and specially new psychological trait, that is, creativity. The result of paired T-test and ANCOVA on pre-founders who received Entrepreneurship short-term education which called successful business start-up package is that need for achievement, ambiguity tolerance and creativity among pre-founders' psychological characteristics are enhanced by Entrepreneurship short-term education. However ANCOVA shows that there are no psychological characteristics changes according to age, education, the number of Entrepreneurship education.