• Earthquakes and Structures
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• v.15 no.5
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• pp.513-528
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• 2018

A typical viable technique to decrease the seismic response of liquid storage tanks is to isolate them at the base. Base-isolation systems are an efficient and feasible solution to reduce the vulnerability of structures in high seismic risk zones. Nevertheless, when liquid storage tanks are under long-period shaking, the base-isolation systems could have different impacts. These kinds of earthquakes can damage the tanks readily. Hence, the seismic behaviour and vibration of cylindrical liquid storage tanks, subjected to earthquakes, is of paramount importance, and it is investigated in this paper. The Finite Element Method is used to evaluate seismic response in addition to the reduction of excessive liquid sloshing in the tank when subjected to the long-period ground motion. The non-linear stress-strain behaviour pertaining to polymers and rubbers is implemented while non-linear contact elements are employed to describe the 3-D surface-to-surface contact. Therefore, Nonlinear Procedures are used to investigate the fluid-structure interactions (FSI) between liquid and the tank wall while there is incompressible liquid. Part I, examines the effect of the flexibility of the isolation system and the tank aspect ratio (height to radius) on the tank wall radial displacements of the tank wall and the liquid sloshing heights. Maximum stress and base shear force for various aspect ratios and different base-isolators, which are subjected to three seismic conditions, will be discussed in Part II. It is shown that the composite-base isolator is much more effective than other isolators due to its high flexibility and strength combined. Moreover, the base isolators may decrease the maximum level pertaining to radial displacement.

• Smart Structures and Systems
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• v.23 no.1
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• pp.91-106
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• 2019

Adopting sloped rolling-type isolation devices underneath a raised floor system has been proved as one of the most effective approaches to mitigate seismic responses of the protected equipment installed above. However, pounding against surrounding walls or other obstructions may occur if such a base-isolated raised floor system is subjected to long-period excitation, leading to adverse effects or even more severe damage. In this study, real-time hybrid simulation (RTHS) is adopted to assess the control performance of a smart base-isolated raised floor system as it is an efficient and cost-effective experimental method. It is composed of multiple sloped rolling-type isolation devices, a rigid steel platen, four magnetorheological (MR) dampers, and protected high-tech equipment. One of the MR dampers is physically tested in the laboratory while the remainders are numerically simulated. In order to consider the effect of input excitation characteristics on the isolation performance, the smart base-isolated raised floor system is assumed to be located at the roof of a building and the ground level. Four control algorithms are designed for the MR dampers including passive-on, switching, modified switching, and fuzzy logic control. Six artificial spectrum-compatible input excitations and three slope angles of the isolation devices are considered in the RTHS. Experimental results demonstrate that the incorporation of semi-active control into a base-isolated raised floor system is effective and feasible in practice for high-tech industry.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.700-703
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• 2004

The purpose of this study is to present the design methodology of base isolated buildings. To achieve the goal of this study, time-history analysis was performed with seismic performance level and recorded seismic data. From the analysis results of MDOF system, the maximum. displacement and base shear were evaluated as 25 cm and $4\%$ by the input level which is maximum velocity of 50 kine. By introducing hybrid isolation system, seismic energy can be concentrated consequently high seismic capacity of the total building is secured.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.652-654
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• 2004

클라이언트와 서비스 제공자간의 서비스 수준 계약인 SLA(Service Level Agreement)를 만족시키기 위해서는 클라이언트 요청을 우선순위 클래스로 구분하여, 낮은 수준의 서비스를 요청하는 클라이언트보다는 고수준의 서비스를 요구하는 클라이언트에게 우선적으로 서비스를 제공할 수 있는 기술이 필요하다. 본 논문에서는 서비스 제공자의 웹 서버 노드를 우선 순위에 따라 정적.동적으로 분할하는 방법을 연구하였으며, 시뮬레이션을 통해 SLA를 고려할 수 있는 응답시간 성능을 분석하였다.

• 한국약용작물학회:학술대회논문집
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• 2007.11a
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• pp.319.1-319.1
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• 2007

• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.107.2-107.2
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• 2006

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.280-292
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• 2016

This descriptive survey assessed knowledge of intensive care unit (ICU) nurses regarding compliance with infection control for six kinds of multi-drug resistant organisms to assist in development of effective intervention strategies. Participants included 210 nurses working in the ICUs of general hospitals who completed a structured questionnaire. The results showed that the nurses' knowledge level and infection control compliance was 10.54 and 3.39 for MRSA; 11.25 and 3.69 for VRE; and 9.60 and 3.49 for CRGNB, respectively[ED highlight - consider providing additional information to describe what these values indicate.]. Knowledge regarding MRSA infection control differed significantly based on age, clinical experience, and experience as a trainee, while compliance with MRSA infection control differed based on age. Knowledge regarding VRE infection control was significantly different based on academic qualification level, experience as a trainee, and whether guidelines existed, while compliance with VRE infection control differed based on academic qualification level and the presence of an isolation environment. Knowledge regarding CRGNB infection control differed significantly based on academic qualification level and experience as a trainee, while compliance with CRGNB infection control differed based on the presence of an isolation environment. Thus, intervention strategies should include education programs for enhancing ICU nurse' knowledge regarding strategies for creating isolation environments.

• The Journal of Korean Society of Virology
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• v.29 no.2
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• pp.65-74
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• 1999

Reovirus was found to inhabit both the respiratory and the enteric tract of human and animals. The genome of reovirus comprises 10 segments of double-stranded RNA, total size 24 kbp. Nine strains of reovirus were isolated from human and field mice in Korea. Aseptically collected sera from human and lung tissues from field mice were used for virus isolation. For serotype determination, hemagglutination inhibition test was used, and three strains were confirmed to type 2 and six strains to type 3. To determine the genomic diversity and molecular phylogeny of reoviruses isolated in Korea, part of S4 genomic segment of reovirus was enzymatically amplified and directly sequenced. In nucleotide level, Apo98-35 strain showed 15.4%, 19.3%, and 14.4% differences compared to type 1 (T1L, Lang), type 2 (T2J), and type 3 reference strains, respectively. In amino acid level, Apo98-35 strain showed 10.5%, 13.7%, and 9.5% differences compared to type 1, type 2, and type 3 reference strains, respectively. Using the maximum parsimony method based on 285 bp spaning region of the S4 genomic segment, phylogenetic analysis indicated that Apo98-35 from Korea formed different phylogenetic branch. Our data obtained by sequence and phylogenetic analyses of reoviruses are consistent with the distinct geographically dependent evolution of reoviruses in Korea.

• Journal of fish pathology
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• v.22 no.3
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• pp.229-237
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• 2009

The causative agent for the tunic softness syndrome of the cultured ascidian Halocynthia roretzi from Jan 1999 to Feb 2009 was identified using virus isolation and polymerase chain reaction (PCR). The pathogenicity of the isolated virus MABV UR-1 strain was determined by experimental infection trials. The cytopathic effects was observed in CHSE-214 cell line at a level 5.1% (4/78) in normal ascidian and 1.8% in abnormal ascidian showing tunic softness syndrome signs. MABV gene was detected in 16.8% (18/107) of normal and 13.1% (5/38) of abnormal organisms by PCR. The ratio of MABV isolation and gene detection was similar level in normal and soft tunic diseased ascidian. Based on the VP2/NS junction region sequences, eight strains of virus isolated from ascidian, were included in the same genogroup with MABV which is originally isolated in wide ranges of marine fish and shellfish species. The UR-1 strain caused 60% mortality (36.5% mortality in control group) by immersion infection and 37% mortality (same mortality in control group) in injection infection indicating no significant differences in infected and control groups. These results suggest that ascidian can act as reservoir of the MABV, and this virus is not directly related with the ascidian mortality.

• Korean Journal of Optics and Photonics
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• v.8 no.6
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• pp.476-481
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• 1997

Optimum operating conditions of the 0.98 $\mu\textrm{m}$-pumped broadband erbium-doped fiber sources, where the mean wavelength variation is minimized, have been experimentally investigated. The optimum conditions for the mean wavelength stabilization were found to be different between the case of the isolated source and the case of the presence of feedback. In case of feedback, the proper pump power that yields zero slope of mean wavelength variation was found to be lower than that of the isolated case, and the mean wavelength was found nearly unchanged over the wide range of pump power. Howerer, the feedback resulted in lower output power and the mean wavelength was found to be sensitive to the variation of feedback level. In the respect of mean wavelength stability, the better performance could be obtained with some feedback, provided that the feedback level is kept constant. Thus we could also enhance the mean wavelength stability by allowing appropriate constant feedback into the source.