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A response spectrum method for seismic response analysis of structures under multi-support excitations

  • Li, Jian-Hua;Li, Jie
    • Structural Engineering and Mechanics
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    • 제21권3호
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    • pp.255-273
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    • 2005
  • Based on the random vibration theory, a response spectrum method is developed for seismic response analysis of linear, multi-degree-of-freedom structures under multi-support excitations is developed. Various response quantities, including the mean and variance of the peak response, the response mean frequency, are obtained from proposed combination rules in terms of the mean response spectrum. This method makes it possible to apply the response spectrum to the seismic reliability analysis of structures subjected to multi-support excitations. Considering that the tedious numerical integration is required to compute the spectral parameters and correlation coefficients in above combination rules, this paper further offers simplified procedures for their computation, which enhance dramatically the computational efficiency of the suggested method. The proposed procedure is demonstrated for tow numerical examples: (1) two-span continuous beam; (2) two-tower cabled-stayed bridge by using Monte Carlo simulation (MC). For this purpose, this paper also presents an approach to simulation of ground motions, which can take into account both mean and variation properties of response spectrum. Computed results based on the response spectrum method are in good agreement with Monte Carlo simulation results. And compared with the MSRS method, a well-developed multi-support response spectrum method, the proposed method has an incomparable computational efficiency.

Solution verification procedures for modeling and simulation of fully coupled porous media: static and dynamic behavior

  • Tasiopoulou, Panagiota;Taiebat, Mahdi;Tafazzoli, Nima;Jeremic, Boris
    • Coupled systems mechanics
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    • 제4권1호
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    • pp.67-98
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    • 2015
  • Numerical prediction of dynamic behavior of fully coupled saturated porous media is of great importance in many engineering problems. Specifically, static and dynamic response of soils - porous media with pores filled with fluid, such as air, water, etc. - can only be modeled properly using fully coupled approaches. Modeling and simulation of static and dynamic behavior of soils require significant Verification and Validation (V&V) procedures in order to build credibility and increase confidence in numerical results. By definition, Verification is essentially a mathematics issue and it provides evidence that the model is solved correctly, while Validation, being a physics issue, provides evidence that the right model is solved. This paper focuses on Verification procedure for fully coupled modeling and simulation of porous media. Therefore, a complete Solution Verification suite has been developed consisting of analytical solutions for both static and dynamic problems of porous media, in time domain. Verification for fully coupled modeling and simulation of porous media has been performed through comparison of the numerical solutions with the analytical ones. Modeling and simulation is based on the so called, u-p-U formulation. Of particular interest are numerical dispersion effects which determine the level of numerical accuracy. These effects are investigated in detail, in an effort to suggest a compromise between numerical error and computational cost.

Simultaneous Determination of the Novel Neuroprotective Agent KR-31378 and its Metabolite KR-31612 Using High Performance Liquid Chromatography with Tandem Mass Spectrometry in Human Plasma

  • Kim, John;Ji, Hye-Young;Yoo, Sung-Eun;Kim, Sun-Ok;Lee, Dong-Ha;Lim, Hong;Lee, Hye-Suk
    • Archives of Pharmacal Research
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    • 제25권5호
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    • pp.647-651
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    • 2002
  • An LC/MS/MS method for the simultaneous determination of a neuroprotective agent for ischemia-reperfusion damage, KR-31378 and its N-acetyl metabolite KR-31612 in human plasma was developed. KR-31378, KR-31612 and the internal standard. KR-31543 were extracted from human plasma by liquid-liquid extraction. A reverse-phase HPLC separation was performed on Luna phenylhexyl column with the mixture of acetonitrile-5 mM ammonium formate (55:45, v/v) as mobile phase. The detection of analytes was performed using an electrospray ionization tandem mass spectrometry in the multiple reaction monitoring mode. The lower limits of quantification for KR-31378 and KR-31612 were 2.0 ng/ml. The method showed a satisfactory sensitivity, precision, accuracy, recovery and selectivity.

Metabolism of a New Neuroprotective Agent for Ischemia-Reperfusion Damage, KR-31543 in the Rats using Liquid Chromatography/Electrospray Mass Spectrometry

  • Kim, John;Ji, Hye-Young;Lee, Seung-Seok;Yoo, Sung-Eun;Kim, Sun-Ok;Lee, Dong-Ha;Lim, Hong;Lee, Hye-Suk
    • Archives of Pharmacal Research
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    • 제25권5호
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    • pp.664-668
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    • 2002
  • KR-31543,(2S,3R,4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amino]-3,4-dihydro-2-dimethoxymethyl-3-hydroxy-2-methyl-2H-1-benzopyran is a new neuroprotetive agent for ischemia-reperfusion damage. The in vitro and in vivo metabolism of KR-31543 in rats has been studied by LC-electrospray mass spectrometry. Rat liver microsomal incubation of KR-31543 in the presence of NADPH resulted in the formation of a metabolite M1. M1 was identified as N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amine on the basis of LC-MS/MS analysis with the synthesized authentic standard. Rat CYP3A1 and 3A2 are the major CYP isozymes involved in the formation of M1.

Sapstain and Mold Control on Radiata Pine Lumber: Laboratory and Field Tests of Selected Fungicides

  • Kim, Jae-Jin;Ra, Jong-Bum;Kim, Hyung-Jun;Kim, Gyu-Hyeok
    • Mycobiology
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    • 제30권1호
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    • pp.37-40
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    • 2002
  • The susceptibility of radiata pine sapwood to fungal attack and the ability of selected fungicides to control colonization of sapstain and mold fungi on green radiata pine sapwood were evaluated. Radiata pine sapwood was highly susceptible to fungal staining, suggesting that prompt application of fungicides after sawing is essential for preventing fungal colonization. The ability of commercial fungicides to prevent fungal discoloration on radiata pine sapwood was assessed using an accelerated 6-week test on small samples in the laboratory, and in field tests using bulk-piled boards exposed outdoors for 6 weeks during summer rainy season. In laboratory tests, Hylite extra provided excellent protection against fungal discoloration even at the lowest concentrations. Hylite clear, Britewood S, and NP-1 Plus provided good short-term protection(2 to 4 weeks), but higher chemical loadings were, required for long-term protection(6 weeks). Woodguard produced little or no protection over the test periods. In field tests, Kathon 893 provided markedly superior protection at the concentration of 0.5 percent or higher. NP-1 Plus provided relatively good protection at all concentrations evaluated. Hylite extra was effective only for short-term protection(2 to 4 weeks) at all concentrations tested, but higher solution strengths were needed for longterm protection.

Localization of the SALMFamide neuropeptides in the starfish $Marthasterias$ $glacialis$

  • Yun, Sang-Seon;Thorndyke, Michael
    • Animal cells and systems
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    • 제16권2호
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    • pp.114-120
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    • 2012
  • In echinoderms, the SALMFamide neuropeptides sharing the SxL/FxFamide motif seem widespread throughout the phylum and may be important signalling molecules that mediate various physiological functions. Recent identification of S1 and its analogues, MagS3 and MagS4, along with the S2 analogue, MagS2 from the starfish $Marthasterias$ $glacialis$, indicated that SALMFamides in the class Asteroidea are more diverse than previously thought. Further, isolation of the neuropeptides from the radial nerve cord and studies on pharmacological actions of the neuropeptides on the cardiac stomach warrant studies on the tissue distributions of these peptides in both the nervous and digestive systems. In the present study, antisera raised against an S1 analogue, KYSALMFamide, and an S2 analogue, KYSGLTFamide, were used to localize the distribution patterns of the S1- and S2-like immunoreactivities (S1-IR/S2-IR) in the nervous and digestive systems of the starfish. In the nervous system, cell bodies in the ectoneural part were immunostained for both S1 and S2 peptides, while in the digestive system, the basiepithelial plexus and mucosal cell bodies were immunoreactive. These immunocytochemical data support the notion that the SALMFamides may play a neuroendocrine role in mediating feeding behaviour of the starfish. Further studies including identification of peptide binding sites and differential expression pattern of mRNAs encoding the peptides are required to elucidate their physiological functions.

Development and Distribution of Dungeness Crab Larvae in Glacier Bay and Neighboring Straits in Southeastern Alaska: Implications for Larval Advection and Retention

  • Park, Won-Gyu;Shirley, Thomas C.
    • Animal cells and systems
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    • 제12권4호
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    • pp.279-286
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    • 2008
  • Development and distribution of larval Dungeness crab, Cancer magister Dana, 1852 were investigated in southeastern Alaska from late May to mid-September in 2004. Larvae were collected during daylight hours at three inner and two outer Glacier Bay stations at the two different depths in the water column, above and below the thermocline. Larval density decreased dramatically for three larval stages, zoeae I(ZI), zoeae IV, and zoeae V(ZV), but relatively little for zoeae II and zoeae III. ZI predominated at all stations in late May and were collected until late July. Larval stages progressed seasonally from ZI to ZV and density decreased from ZI through ZV. The densities of each zoeal stage at the inner and outer bay stations and at the shallow and deep depths were similar. The density of each larval stage above(shallow) and below(deep) the thermocline and between inner and outer bay stations were not significantly different. The occurrence of larval Dungeness crab is dramatically later than in other parts of the species range, in that larvae appear in abundance beginning in late May. The pattern of spatial distribution of larval stages for the inland waters of Alaska was also markedly different than the patterns reported for Dungeness crab larvae from other parts of the species range, in that the early and intermediate stages occurred within inland waters; from British Columbia to California these larval stages increase in abundance with distance offshore.

3차원 그래픽의 활용이 온라인 쇼핑몰 소비자 정보처리 과정에 미치는 영향 (The Effect of 3 Dimensional Graphics on Consumer Information Processing in Online Shopping Malls)

  • 이영은;서길수
    • Asia pacific journal of information systems
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    • 제13권3호
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    • pp.151-172
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    • 2003
  • The purpose of this research is, first, to assess empirically web3D impacts on consumer information processing. Second, this research aimed to reveal the circumstances under which web3D impact can be maximized. To achieve the second goal, products were classified into physical dominant and information dominant products, and web3D impact was assessed on these two product categories. The laboratory experiment was adopted to compare the web3D impacts on the physical dominant products with that on the information dominant products. The result of this experiment showed that overall, web3D positively influenced consumer comprehension, memory, and attitude toward the products. In detail, for the physical dominant products, subjects significantly comprehended and memorized information better and performed positive attitude toward the products. For the information dominant products, subjects significantly comprehended and memorized better but did not perform the positive attitude toward the products. This paper explains theses results by suggesting that, overall, web3D impact is large and can be maximized when the characteristics of web3D such as interactivity, realistic display of objects support the characteristics of products that web3D represents.

Enamel matrix derivative for replanted teeth in animal models: a systematic review and meta-analysis

  • Kim, Sahng G.;Ryu, Steven I.
    • Restorative Dentistry and Endodontics
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    • 제38권4호
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    • pp.194-203
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    • 2013
  • Objectives: To investigate the effect of enamel matrix derivative (EMD) on periodontal healing of replanted teeth in animal models. Materials and Methods: The authors searched MEDLINE, PubMed, EMBASE, Cochrane Library, Web of Knowledge and Scopus for articles published up to Oct 2012. Animal studies in which EMD was applied in transplanted or replanted teeth with adequate controls and histological data were considered. Normal periodontal healing or root resorption determined by histology after EMD was applied in replanted teeth with adequate controls was used as outcome measures. The following search strategy was used: ('Emdogain' OR 'enamel matrix proteins' OR 'enamel matrix derivative') AND ('avulsion' OR 'transplantion' OR 'autotransplantation' OR 'replantation'). Results: Six animal studies were included in the final review. There was great heterogeneity in study design among included studies. Two studies with similar study designs were identified and analyzed by a meta-analysis. The pooled estimates showed a significantly higher normal healing and surface resorption and significantly less inflammatory and replacement resorption in EMD-treated groups compared with non-EMD-treated groups. Conclusions: With the limitations of this systematic review, the use of EMD led to greater normal periodontal healing and surface root resorption and less inflammatory and replacement root resorption in the presence of periodontal ligaments. However, no definite conclusion could be drawn with regard to the effect of EMD on periodontal healing and root resorption when no periodontal ligaments exist.

휘발성(揮發性) Warmed-Over Flavor의 연구(硏究)를 위한 변형(變形)된 Direct Sampling GLC법(法) (Modified Direct-Sampling GLC Method to Study Warmed-Over Flavor Related Volatiles)

  • 신승이;이종욱
    • 한국식품과학회지
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    • 제22권5호
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    • pp.562-568
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    • 1990
  • 조리(調理) 육류(肉類)의 WOF와 관련(關聯)된 휘발성(揮發性) 성분(成分)을 분석(分析)하기 위하여 변형(變形)된 Direct GLC 방법(方法)을 이용(利用)하였다. 이 변형(變形)된 방법(方法)은 기존(旣存)의 다른 방법(方法)과는 달리 수분함량(水分含量)이 많은 시료(試料)로부터 휘발성(揮發性) 성분(成分)을 분리(分離)하는데 유용(有用)하였으며, 특히 저분자량(低分子量)의 포화(飽和) $aldehyde\;(C_c-C_{15})$류(類), 불포화(不飽和)$aldehyde(C_5{\sim}C_9)$류(類)의 연구(硏究)에 적절한 것으로 판명(判明)되었다.

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