거시모델을 이용한 벽 구조 해석 방법의 개발 및 적용

학위논문 (석사)-- 서울대학교 대학원 : 건축학과, 2012. 2. 박홍근.본 연구는 우리나라 전체 주택의 대부분을 차지하는 벽식 RC 공동주택을 대상으로 복잡한 비선형 해석의 정확하고 간편한 거시 모델의 개발 및 적용을 위한 것이다. 기존에 제시된 거시모델의 단점을 보완하고 상대적으로 간단하면서 정확한 벽식 구조의 비선형 해석을 위한 거시모델을 개발하고 이를 이용하여 벽식 구조의 정적 비탄성 및 시간이력해석을 수행한다. 이 때 해석모델은 10층 벽식 RC 공동주택 1:5 축소 모형으로써 실제 진동대 실험 결과와의 비교를 통해 벽식 구조의 거시 모델 적용에 따른 해석 결과의 타당성을 검토한다. 해석은 Opensees를 사용하여 철근과 콘크리트의 재료모델을 정의한 후 벽체는 LDLEM모델을 이용하고 슬래브는 강막(Diaphragm)과 쉘요소로 각각 해석을 수행하였으며, 이 때 벽체의 면외 휨강성과 슬래브의 강성을 산정하여 해석에 적용하였다. 또한 실제 크기의 벽식 공동주택의 해석을 수행함으로써 강막인 경우와 슬래브 강성을 고려한 경우의 구조물 전체의 철근 배근량을 바탕으로 경제성을 검토하였다.This study is for the development and application.of an accurate and easy macro model for complicated nonlinear analysis of reinforced concrete wall systems. A simple and accurate nonlinear analysis of reinforced concrete wall systems is proposed, which is to overcome the shortcomings of a previously proposed macro model. And by using them, a nonlinear static and time history analysis of reinforced concrete wall systems is performed. This paper is to check the reliability of nonlinear analysis program Opensees, by comparing the analysis results with those of shaking table test performed on 1:5 scale 10-story reinforced concrete wall building model. The Wall is using a LDLEM model and the slab is defined as a diaphragm or shell element. And an analysis is applied to out-of-plane bending stiffness of the wall and stiffness of the slab. Also, in each case, an apartment, which is reinforced concrete wall systems of the actual size, is performed to check the amount of reinforcement of an Entire structure.Maste

일반화된 캐츠-무디 수퍼대수의 정의식

Thesis (master`s)--서울대학교 대학원 :수학과,1998.Maste

Comparison of the Microbiological Efficacy of Disinfection Using Ultraviolet and Hydrogen Peroxide System for Carbapenemase-producing Enterobacteriaceae in a Healthcare Setting

Background: This study aimed to compare the efficacy of microbiological disinfection between the ultraviolet-C (UV-C) device and aerosolized hydrogen peroxide (aHP) system in a healthcare setting. Methods: Four rooms were installed with two UV-C devices and two aHP systems. Thirty formica sheets contaminated with carbapenemase-producing Enterobacteriaceae (CPE) were placed in each room. After intervention, the median log10 reduction and modified decontamination rates were compared between the two methods using Rodac plates. Eight sink drains in the rooms previously occupied by a patient with CPE were sampled separately before and after the interventions. Results: The median log10 reduction was 5.52 and 5.37 after the UV-C (n=60) and aHP (n=60) interventions, respectively (P=0.86), whereas the modified decontamination rate was 50% and 45%, respectively (P=0.71). At the UV-direct sites, UV-C showed higher median log10 reduction (5.91 vs. 5.61, P=0.002) and modified decontamination rate (83% vs. 53%, P=0.03) than those of aHP. Conversely, at UV-indirect sites, aHP showed higher median log10 reduction (4.63 vs. 5.07%, P=0.02) and modified decontamination rate (17% vs. 37%, P=0.01) than those of UV-C. After the intervention, carbapenemase-resistant Gram-negative bacilli decreased further in five of the seven sink drains disinfected by sodium. Conclusion: Both UV-C and aHP reduced the bacterial contamination in the rooms. The aHP was significantly more effective than UV-C at the UV-indirect sites, and the converse was true for the UV-direct sites. Application of the intervention to disinfect the sink drains resulted in additional bacterial decontamination. Considering the features of the machines and the results of this study, healthcare facilities can choose either UV-C or aHP for decontamination

Adverse Reactions Following the First Dose of ChAdOx1 nCoV-19 Vaccine and BNT162b2 Vaccine for Healthcare Workers in South Korea

Background: We performed a prospective survey on the adverse reactions following the first dose of two types of vaccines against coronavirus disease 2019 (COVID-19) in healthcare workers (HCWs) in South Korea. Methods: HCWs at a tertiary referral hospital in Seoul, South Korea, received a chimpanzee adenovirus-vectored vaccine (ChAdOx1 nCoV-19) or an mRNA-based vaccine (BNT162b2) between March 5 and March 26, 2021. The HCWs were asked to report adverse reactions through a mobile self-report questionnaire for three days after vaccination. Results: A total of 7,625 HCWs received the first dose of ChAdOx1 or BNT162b2 vaccine during the study period. Of them, 5,866 (76.9%) HCWs (ChAdOx1, n = 5,589 [95.3%]; BNT162b2, n = 277 [4.7%]) participated at least once in the survey, of whom 77% were female and 86% were younger than 50 years. The overall adverse reaction rate was 93% in the ChAdOx1 group and 80% in the BNT162b2 group (P < 0.001). Both local and systemic reactions were more commonly reported in the ChAdOx1 group, and the difference was larger in systemic reactions such as fever and fatigue. In the ChAdOx1 group, the incidence of adverse reactions was significantly higher in females and those in the younger age groups, while the BNT162b2 group showed such difference according to age. Conclusion: In our prospective survey, vaccine-associated adverse reactions were more commonly reported in the ChAdOx1 group than in the BNT162b2 group. Females and younger age groups experienced vaccine-associated adverse reactions more frequently

Management and development of Knowledge Clinic Center for SME

funder : 미래창조과학부funder : KAagency : 한국과학기술정보연구원agency : Korea Institute of Science and Technology Information○ 주요 연구결과 - 지식클리닉 유망프로그램 10선 도출 ․협력형 전문클니닉, 한국형 크라우드소싱 플랫폼 구축, 지역특화형 유망기술 매칭 프로그램, 중소기업 애로기술 수준별 진단 및 중개프로그램, 한국형 유어앙코르 시스템 개발, 지식멘토링서비스 대상기업 선정지표 개발, 상생형 기술사업화 활성화 프로그램, 창업부터 강소기업까지 육성 길라잡이, 지역맞춤형 슈퍼컴퓨팅 인력양성 및 중소기업지원, KISTI 수탁사업 기술시장분석보고서 외부서비스 - 지식클리닉 프로그램 시범운영 및 검증 ․현대코퍼레이션(특허회피설계), 창림이엔지(시장분석, 기술이전), 웨스텍(전문가 탐색, 제품검증), 에나인더스트리(시장분석, 기술협력), 리지스(공정개선, 전문가탐색), 뉴테크(기술분석, 타당성 검증), 삼익SDT(시장분석, 타당성 검증)IV. Result of the Study ○ Collective Special Clinic ○ Construction of a Korean Crowdsourcing Platform ○ Regional promising technology matching program ○ Diagnosis & Brokerage Program for SME's ○ Development of a Korean YourEncore System ○ Development of indicators for selecting companies for the knowledge mentoring service ○ Benefit sharing Technology commercialization program ○ Guide from the foundation to becoming a small giant ○ Regional Supercomputing man power promotion and supporting SME's ○ KISTI's technology and market analysis report servic

Frequent Occurrence of SARS-CoV-2 Transmission among Non-close Contacts Exposed to COVID-19 Patients

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission among non-close contacts is not infrequent. We evaluated the proportion and circumstances of individuals to whom SARS-CoV-2 was transmitted without close contact with the index patient in a nosocomial outbreak in a tertiary care hospital in Korea. From March 2020 to March 2021, there were 36 secondary cases from 14 SARS-CoV-2 infected individuals. Of the 36 secondary cases, 26 (72%) had been classified as close contact and the remaining 10 (28%) were classified as non-close contact. Of the 10 non-close contact, 4 had short conversations with both individuals masked, 4 shared a space without any conversation with both masked, and the remaining 2 entered the space after the index had left. At least one quarter of SARS-CoV-2 transmissions occurred among non-close contacts. The definition of close contact for SARS-CoV-2 exposure based on the mode of droplet transmission should be revised to reflect the airborne nature of SARS-CoV-2 transmission

Nosocomial Outbreak of COVID-19 in a Hematologic Ward

Background Coronavirus disease 2019 (COVID-19) outbreaks occur in hospitals in many parts of the world. In hospital settings, the possibility of airborne transmission needs to be investigated thoroughly. Materials and Methods There was a nosocomial outbreak of COVID-19 in a hematologic ward in a tertiary hospital, Seoul, Korea. We found 11 patients and guardians with COVID-19 through vigorous contact tracing and closed-circuit television monitoring. We found one patient who probably had acquired COVID-19 through airborne-transmission. We performed airflow investigation with simulation software, whole-genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Results Of the nine individuals with COVID-19 who had been in the hematologic ward, six stayed in one multi-patient room (Room 36), and other three stayed in different rooms (Room 1, 34, 35). Guardian in room 35 was close contact to cases in room 36, and patient in room 34 used the shared bathroom for teeth brushing 40 minutes after index used. Airflow simulation revealed that air was spread from the bathroom to the adjacent room 1 while patient in room 1 did not used the shared bathroom. Airflow was associated with poor ventilation in shared bathroom due to dysfunctioning air-exhaust, grill on the door of shared bathroom and the unintended negative pressure of adjacent room. Conclusion Transmission of SARS-CoV-2 in the hematologic ward occurred rapidly in the multi-patient room and shared bathroom settings. In addition, there was a case of possible airborne transmission due to unexpected airflow