• 제목/요약/키워드: Response Period

검색결과 2,781건 처리시간 0.04초

Seismic Behavior of the Spacial Structure with Seismic Isolation (면진장치를 적용한 대공간구조물의 지진응답 분석)

  • Kim, Gee-Cheol;Ju, Dong-Hyem
    • Journal of Korean Association for Spatial Structures
    • /
    • 제8권6호
    • /
    • pp.49-57
    • /
    • 2008
  • The seismic isolation systems could be used to reduce the seismic response of a structure. The natural period of a structure with seismic isolation system got be long to avoid the prominent seismic period. The purpose of this study is to analyzed the seismic behavior of the truss arch that is supported to column with LRB. Truss arch structures subjected to horizontal seismic have large horizontal and vertical response unlike seismic behavior of normal rahmen structures. When seismic load is applied to the truss arch with isolation systems, the horizontal acceleration response of the truss arch is reduced and the vertical seismic response is remarkably reduced. Also, the seismic behaviors of the truss arch with strengthen column as like lattice column are very similar to that of the truss arch supported to directly foundation. The Seismic Isolation system can be applied to reduce efficiently the seismic response of the spacial structure with not strong column.

  • PDF

Collateral damage of emergency medical services due to COVID-19 (COVID-19에 의한 EMS 동반손상)

  • Lee, Nam-Jin;Yang, Jin-Cheol;Moon, Jun-dong
    • The Korean Journal of Emergency Medical Services
    • /
    • 제25권3호
    • /
    • pp.189-200
    • /
    • 2021
  • Purpose: We aimed to provide effective emergency medical services (EMS) response strategies for coping with high acuity patients during the pandemic by analyzing the influence of the COVID-19 and social distancing on EMS. Methods: In this retrospective observational study, we analyzed the distribution of high acuity patients transported by Daejeon 1-1-9 EMS during the COVID-19 pandemic period, between February 1, 2020 and October 31, 2020 and the same period in 2019, as well as the level 3 social distancing enforced period, between July 27, 2020 and October 31, 2020. Results: The EMS dispatches decreased by 17% during the observed COVID-19 pandemic period compared to the same period in 2019. The number of cases with cardiac arrest and positive prehospital stroke scale rose by (p<.001). Patients with cardiac arrest, trauma, and positive prehospital stroke scale increased by during the level 3 social distancing period. Conclusion: Unlike the decreased EMS call volume and patient transports during the COVID-19 pandemic, cardiac arrest cases and the severity of high acuity patients tended to increase. We suggest that EMS systems should contrive a response strategy considering the collateral effect of major epidemics on the incidence rate of high acuity patients.

Developing Prevention System of Overseas Infectious Disease Based on MERS and Zika Virus Outbreak (중동호흡기증후군과 지카바이러스의 대응사례분석을 통한 해외유입 신종감염병 예방시스템 구축 방안)

  • Kim, Ja Young;Bang, Joon Seok
    • Korean Journal of Clinical Pharmacy
    • /
    • 제26권4호
    • /
    • pp.330-340
    • /
    • 2016
  • Objective: The outbreak of Middle East Respiratory Syndrome (MERS) started in South Korea in May 2015 and the end of crisis was declared in December 2015 by Korea Centers of Disease Control and Prevention (KCDC). However, Zika virus emerged in less than 2 months following MERS and showed higher mortality than other countries. This study is to assess the current prevention system of overseas infectious diseases, based on MERS and Zika virus outbreak and to suggest effective response system for the future. Methods: We conducted two surveys on medical specialists working at tertiary general hospitals regarding the effectiveness of responding system by KCDC against MERS and Zika virus and education in individual medical institutions using 5-Likert points. Response system was examined in three different periods as initial period, spreading period, and post disease period. Results: Although medical specialists received the notifications in initial period, no practical prevention was proven to be placed in responding stage by medical facilities (averagely 3.5/5 points in total and sub-analyses). During spreading period, there were several academic seminars conducted, which were evaluated as helpful. In post disease period, all answered that there were changes on patient treatment in all medical facilities, with mainly report system and the treatment regulations in case of suspicious patients for infection. Only 49% respondents answered positive on the possibility of initial responses. For questionnaire items regarding Zika virus, all answered that there were notifications prior to the first outbreak of the infected patient. Eighty% of respondents were aware of 'the Guideline system for traveling to dangerous areas', and answered that the system was moderately effective (averagely 3.8/5 points in total). For the effectiveness of prevention measures for foreign novel disease by KCDC, the average point was 3.0 in both of total and sub-analyses. Conclusion: There is not enough response system to prevent infectious disease in medical institutional and governmental levels in Korea. It would warrant the modification of overall medical system to improve preventive measures for initial spread of such diseases.

Daily Mean Sea Level and Atmospheric Pressure Along the Coasts of the Northwestern Pacific Ocean

  • Oh, Im-Sang;Moon, Il-Ju;Youn, Yong-Hoon
    • Journal of the korean society of oceanography
    • /
    • 제32권4호
    • /
    • pp.171-180
    • /
    • 1997
  • Daily mean sea level variability and its response to atmospheric pressure along the coasts of the northwestern Pacific Ocean are investigated. Daily values of sea level and atmospheric pressure covering the period 1976-1986 from 72 stations are analyzed. The sea level and the air pressure in all the data set have a definite seasonal signal, and higher frequency oscillations at time scales of several days to several weeks are also observed. Among the short-period oscillations of sea level with periods shorter than six months, the period of around 3 or 4 months is dominant in most study stations. According to the statistical analysis of sea level and air pressure, the length scale of sea level variability is smaller than that of air pressure for the present study area. The overall variability of sea level is found to be the smallest around Hokkaido, Japan and the largest in the China coasts. Large short-period (< 6 months) sea level variability is found in the southern coasts of China and Hokkaido, and large long-period (> 6 months) variability in the southern coasts of Japan and Korea along Tsushima Current and Kuroshio. The patterns of air pressure are very similar to those of sea level. The air pressure field is found to account for 31% of the overall sea level variability in the study area. Conside.ins the fact that the results (40%) of Pang and Oh (1995) were obtained through monthly sea level, the present result implies that the short-period sea level variability is less affected by air pressure. Generally the sea level response to air pressure are found to be isostatic, but significantly nonisostatic for the periods around 4 months and for those of 2 to 4 days. In particular, nonisostatic response for higher frequencies seem to be due to the restrictions to water transport necessary for barometric responsein the Korea Strait.

  • PDF

Development of Site Classification System and Modification of Design Response Spectra considering Geotechnical Site Characteristics in Korea (I) - Problem Statements of the Current Seismic Design Code (국내 지반특성에 적합한 지반분류 방법 및 설계응답스펙트럼 개선에 대한 연구 (I) - 국내 내진설계기준의 문제점 분석)

  • Yoon, Jong-Ku;Kim, Dong-Soo;Bang, Eun-Seok
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • 제10권2호
    • /
    • pp.39-50
    • /
    • 2006
  • Site response analyses were peformed based on equivalent linear technique using the shear wave velocity profiles of 162 sites collected around the Korean Peninsula. The she characteristics, particularly the shear wave velocities and the depth to bedrock, are compared to those in the western United States. The site coefficients of short period $(F_a)$ and the long period $(F_v)$ obtained from this study were significantly different compared to 1997 Uniform Building Code (1997 UBC). $F_a$ underestimated the motion in shot period ranges and $F_v$ overestimated the motion in mid period ranges in Korean seismic guideline. It is found that the existing Korean seismic design code were is required to be modified considering geological site conditions in Korea for the reliable estimation of sue amplification. Problems of the current seismic design code were dicussed in this paper and the development of site classification method and modification of desing response spectra were discussed in the companion papers(II-Development of Site Classification System and III-Modification of Dosing Response Specra).

Acceleration Variation of Surrounding Ground according to distance from Strip-Type Crushed Stone Foundation (쇄석 띠기초와의 거리에 따른 주변지반의 가속도 변화)

  • Son, Su-Won;Son, Tae-Ik;Kim, Soo-Bong;Kim, Jin-Man
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • 제20권1호
    • /
    • pp.217-223
    • /
    • 2019
  • In this study, the acceleration changes of the surrounding ground when crushed stones were installed in a strip-type were analyzed using the 1-G shaking table test. The ground was constructed from clay, and the foundation was installed using crushed stone of strip-type form. The response acceleration and response spectrum for various input seismic motions were analyzed. The change in acceleration was examined according to the adjacent distance to the strip-type crushed stone foundation. In the Hachinohe seismic motion results, there was no significant decrease in acceleration, but the maximum response acceleration for the two seismic motions was inversely proportional to the distance from the crushed stone foundation. As a result of the response spectrum analysis, the attenuation period in the long period and the short period input wave were different from each other, and the change in response spectrum affected the maximum acceleration value. As the distance from the crushed stone foundation was increased, the attenuation was larger in the period between 0.08 and 0.5 sec in the Hachinohe seismic motion, the attenuation was larger in the period of less than 0.2 seconds in the Northridge seismic motion.

Effects of long double-stranded RNAs on the resistance of rock bream Oplegnathus fasciatus fingerling against rock bream iridovirus (RBIV) challenge

  • Kosuke, Zenke;Kim, Ki-Hong
    • Journal of fish pathology
    • /
    • 제23권3호
    • /
    • pp.273-280
    • /
    • 2010
  • To determine whether rock bream Oplegnathus fasciatus can be protected from rock bream iridovirus (RBIV) infection by intramuscular injection of long double-stranded RNAs (dsRNAs), we compared protective effect of virus-specific dsRNAs corresponding to major capsid protein (MCP), ORF 084, ORF 086 genes, and virus non-specific green fluorescent protein (GFP) gene. Furthermore, to determine whether the non-specific type I interferon (IFN) response was associated with protective effect, we estimated the activation of type I IFN response in fish using expression level of IFN inducible Mx gene as a marker. As a result, mortality of fish injected with dsRNAs and challenged with RBIV was delayed for a few days when comparing with PBS injected control group. However, virus-specific dsRNA injected groups exhibited no significant differences in survival period when compared to the GFP dsRNA injected group. Semi-quantitative analysis indicated that the degree of antiviral response via type I IFN response is supposedly equal among dsRNA injected fish. These results suggest that type I IFN response rather than sequence-specific RNA interference might involve in the lengthened survival period of fish injected with virus-specific dsRNAs.

An equivalent linear SDOF system for prediction of nonlinear displacement demands of non-ductile reinforced concrete buildings with shear walls

  • Saman Yaghmaei-Sabegh;Shabnam Neekmanesh;Nelson Lam;Anita Amirsardari;Nasser Taghizadieh
    • Structural Engineering and Mechanics
    • /
    • 제85권5호
    • /
    • pp.655-664
    • /
    • 2023
  • Reinforced concrete (RC) shear wall structures are one of the most widely used structural systems to resist seismic loading all around the world. Although there have been several efforts to provide conceptually simple procedures to reasonably assess the seismic demands of structures over recent decades, it seems that lesser effort has been put on a number of structural forms such as RC shear wall structures. Therefore, this study aims to represent a simple linear response spectrum-based method which can acceptably predict the nonlinear displacements of a non-ductile RC shear wall structure subjected to an individual ground motion record. An effective period and an equivalent damping ratio are introduced as the dynamic characteristics of an equivalent linear SDOF system relevant to the main structure. By applying the fundamental mode participation factor of the original MDOF structure to the linear spectral response of the equivalent SDOF system, an acceptable estimation of the nonlinear displacement response is obtained. Subsequently, the accuracy of the proposed method is evaluated by comparison with another approximate method which is based on linear response spectrum. Results show that the proposed method has better estimations for maximum nonlinear responses and is more utilizable and applicable than the other one.

Fast Response Driving of TFT LCD for Motion Picture

  • Choi, Yu-Jin;Mo, Soon-Hee;Bae, Young-Min;Lim, Young-Jin
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
    • /
    • pp.449-451
    • /
    • 2002
  • We reported the algorithm of driving scheme that enhances moving picture property by improving gray-to-gray response time. Here, we report result of simulation for estimation of driving voltage to reduce response time, and experimental result. We investigated optimization of algorithm so that minimum size of LUT can support to reducing the gray-to-gray response time within 1 frame period, and with single algorithm it is possible to apply the algorithm to various kinds of LC material. So in our system there is no external EEPROM.

  • PDF

Tests for the Structure Change and Asymmetry of Price Volatility in Farming Olive Flounder (양식 넙치가격 변동성의 구조변화와 비대칭성 검증)

  • Kang, Seok-Kyu
    • The Journal of Fisheries Business Administration
    • /
    • 제45권2호
    • /
    • pp.29-38
    • /
    • 2014
  • This study is to analyse the timing of the structural change of price volatility and the asymmetry of price volatility during the period before and after the timing of the structural change of price volatility using Jeju Farming Olive Flounder's production area market price data from January 1, 2007 to June 30, 2013. The analysis methods of Quandt-Andrews break point test and Threshold GARCH model are employed. The empirical results of this study are summarized as follows: First, the result of Quandt-Andrews break point test shows that a single structural change in price volatility occurred on May 4, 2010 over the sample period. Second, during the period before structural change, daily price change rate has averagely positive value which means price increase, but during the period after structural change daily price change rate has averagely negative value which means price decrease. Also, daily volatility of price change rate during the period before structural change is higher than during the period after structural change. This indicates that price volatility decreases after structural change. Third, the estimation results of Threshold GARCH Model show that the volatility response against price increase is larger during the period after structural change than during the period before structural change. Also the result shows the volatility response against price decrease is larger during the period after structural change than during the period before structural change. And, irrespective of the timing of structural change, price increase has an larger effect on volatility than price decrease. This means volatility is asymmetric at price increase.