• Structural Engineering and Mechanics
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• v.84 no.5
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• pp.591-604
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• 2022

A gravity wall combined with an anchoring lattice frame (a combined retaining structure) is adopted at a typical engineering site at Dali-Ruili Railway Line China. Where, the combined retaining structure supports a soil deposit covering on different inclined rock slopes. With an aim to investigate and compare the effects of inclined rock slopes on the response of combined retaining structure under seismic excitation, three groups of shaking table tests are conducted. The rock slopes are shaped as planar surfaces inclined at angles of 20°, 30°, and 40° with the horizontal, respectively. The shaking table tests are supplemented by dynamic numerical simulations. The results regarding the horizontal acceleration response, vertical acceleration response, permanent displacement mode, and axial anchor force are comparatively examined. The acceleration response is more susceptible to outer structural profile of combined retaining structure than to inclined angle of rock slope. The permanent displacement decreases when the inclined angle of the rock slope increases within a range of 20°-40°. A critical inclined angle of rock slope exists within a range of 20°-40°, and induces the largest axial anchor force in the combined retaining structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.75-80
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• 2000

Evaluation method of seismic performance has mainly used elastic spectrum analysis. This method has simplicity of analysis but deficiency of accuracy. And evaluation method of seismic performance using inelastic dynamic analysis reflects accurately inelasticity of material but hardly reflects site effects. This study suggested evaluation scheme of seismic performance for bridge structure using capacity spectrum method applied inelastic static analysis and standard design response spectrum of Korea Standard Specification for Highway Bridge. Two results, capacity spectrum method and inelastic dynamic analysis method, are very similar. As a result, this study appropriately supply both simplicity of analysis and accuracy of result.

• Toxicological Research
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• v.6 no.2
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• pp.205-213
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• 1990

The regulation of neurotoxicants has usually been based upon setting reference doses by dividing a no observed adverse effect level (NOAEL) by uncertainty factors that theoretically account for interspecies and intraspecies extraploation of experimental results in animals to humans. Recently, we have proposed a four-step alternative procedure which provides quantitative estimates of risk as a function of dose. The first step is to establish a mathematical relationship between a biological effect or biomarker and the dose of chemical administered. The second step is to determine the distribution (variability) of individual measurements of biological effects or their biomarkers about the dose response curve. The third step is to define an adverse or abnormal level of a biological effect or biomarker in an untreated population. The fourth and final step is to combine the information from the first three steps to estimate the risk (proportion of individuals exceeding on adverse or abnormal level of a biological effect or biomarker) as a function of dose. The primary purpose of this report is to enhance the certainty of the first step of this procedure by improving our understanding of the relationship between a biomarker and dose of administered chemical. Several factors which need to be considered include: 1) the pharmacokinetics of the parent chemical, 2) the target tissue concentrations of the parent chemical or its bioactivated proximate toxicant, 3) the uptake kinetics of the parent chemical or metabolite into the target cell(s) and/or membrane interactions, and 4) the interaction of the chemical or metabolite with presumed receptor site(s). Because these theoretical factors each contain a saturable step due to definitive amounts of required enzyme, reuptake or receptor site(s), a nonlinear, saturable dose-response curve would be predicted. In order to exemplify this process, effects of the neurotoxicant, methlenedioxymethamphetamine (MDMA), were reviewed and analyzed. Our results and those of others indicate that: 1) peak concentrations of MDMA and metabolites are ochieved in rat brain by 30 min and are negligible by 24 hr, 2) a metabolite of MDMA is probably responsible for its neurotoxic effects, and 3) pretreatment with monoamine uptake blockers prevents MDMA neurotoxicity. When data generated from rats administerde MDMA were plotted as bilolgical effect (decreases in hippocampal serotonin concentrations) versus dose, a saturation curve best described the observed relationship. These results support the hypothesis that at least one saturable step is involved in MDMA neurotoxicity. We conclude that the mathematical relationship between biological effect and dose of MDMA, the first step of our quantitative neurotoxicity risk assessment procedure, should reflect this biological model information generated from the whole of the dose-response curve.

• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.39-48
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• 2012

Risk Assessment to list possible safety disasters and their probability and severity is the starting point for effective safety management on construction project site. However, the safety managers in owners, construction supervisors, contractors, and sub-contractors still have difficulties in judging the priorities of safety activities and preparing responses to each potential safety disasters. Therefore, this study aimed to suggest a systematic method in assessing safety risk prior to commencement with the agreement of stakeholders. FMECA(failure mode effects and criticality analysis) was selected as a main assessment tool and it was modified according to the characteristics of construction projects and trades. Each risk is, firstly, evaluated with occurrence probability, possible loss and impacts to projects, and detections, and then risk priority number(RPN) is calculated. Subsequently, the managers of each stakeholder discuss the types, timing, and responsibilities of responses as a group decision-making process.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.178-185
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• 1999

Minimum life-cycle cost helps to evaluate cost effectiveness of base-isolated bridges under specific condition. Life-cycle cost mainly consists of the initial construction cost and the expected damage cost. Damage cost estimation needs proper model of input ground motion failure probability evaluation method and limit states definition. We model the input ground motion as spectral density function compatible with the response spectra defined at each seismicity and site condition. Spectrum analysis and crossing theory is suitable for reseating calculation of failure probabilities in the process of cost minimization. Limit states of base-isolated bridges re defined for superstructure isolator and pier respectively The method is applied to both base-isolated bridges and conventional bridges under the same conditions to investigate cost effectiveness of base isolation in low and moderate seismic region. the results show that base-isolation of bridges are more effective in low and moderate seismic region and that the site effects on the economical efficiency may not be negligible in such a region.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.893-897
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• 2006

Structures with additional frictional damping system have strong nonlinearity that the dynamic behavior is highly affected. by the relative magnitude between frictional force and excitation load. In this study, normalized response spectra of the structures with non-dimensional friction force are obtained through nonlinear time history analyses of the mass-normalized single degree of freedom systems using 20 ground motion data recorded on rock site. The variation of the control performance of frictional damping system is investigated in terms of the dynamic load and the structural natural period, of which effects were not considered in the previous studies. Least square curve fitting equations are presented for describing those normalized response spectrum and optimal non-dimensional friction forces are obtained for controlling the peak displacement and absolute acceleration of the structure based on the derivative of the curve fitted design spectrum.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.343-348
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• 2002

Carbon monoxide (CO) are produced by heme oxygenase (HO), and HO was detected in hypothalamus. However, the roles of CO produced in hypothalamus was not fully elucidated. So, we tested the effects of CO on body temperature because preoptic-anterior hypothalamus was known as the presumptive primary fever-producing site. CO-saturated aCSF ($4{\;}{\mu}l$, i.c.v.) and hemin ($10{\;}{\mu}g$, i.c.v.) elicited marked febrile response. Pretreatment with indomethacin completely inhibited CO- and hemin-induced fever. Zinc protoporphyrin-IX ($10{\;}{\mu}g$, i.c.v.) or ODQ ($50{\;}{\mu}g$, i.c.v.) partially reduced hemin-induced febrile response. Dibutyryl-cGMP ($100{\;}{\mu}g$, i.c.v.) produced profound febrile response and this febrile response was attenuated by indomethacin. These results indicate that endogenous CO may have a role as a pyrogenic mediator in CNS and CO-mediated pyresis is dependent on prostaglandin production and partially on activation of soluble guanylate cyclase.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.57-62
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• 2005

The potentiometric responses for various anions are investigated with membrane electrode (membrane 1) based on 1,3-diethyl-1,3-dihydroxy-1,3-bis(2-dimethylaminomethyl ferrocenyl) disiloxane. The nitrate ion-selective electrode based on compound 1 gave a good Nernstian response of 58.18 mV per decade for nitrate with the detection limit of −e5.66 of log [NO3−e]. Compound 1 has all those functional groups and the other two compounds have less functional group of ferrocenyl or ferrocenyl and hydroxide, respectively. Even though, potentiometric response to anions was excellent at pH 5, the selectivity pattern for all three membrane electrode based on series of disiloxane is almost like Hofmeister sequence at pH 5. However, the membrane electrode 1-3 exhibited very different response to anions at pH 7. In this pH, NH2 is not protonated and ionophore may act as neutral carrier. Hydrogen bond may enhance the responsibility to hydrogen acceptors and intramolecular electro-active site may increase the permeability of analyte to ionophore in membrane.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.1 s.118
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• pp.88-94
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• 2007

Structures with additional frictional damping system have strong nonlinearity that the dynamic behavior is highly affected by the relative magnitude between frictional force and excitation load. In this study, normalized response spectra of the structures with non-dimensional friction force are obtained through nonlinear time history analyses of the mass-normalized single degree of freedom systems using 20 ground motion data recorded on rock site. The variation of the control performance of frictional damping system is investigated in terms of the dynamic load and the structural natural period, of which effects were not considered in the previous studies. Least square curve fitting equations are presented for describing those normalized response spectrum and optimal non-dimensional friction forces are obtained for controlling the peak displacement and absolute acceleration of the structure based on the derivative of the curve-fitted design spectrum.

• Journal of Ginseng Research
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• v.43 no.3
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• pp.335-341
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• 2019

Background: Inflammation is a host-defensive innate immune response to protect the body from pathogenic agents and danger signals induced by cellular changes. Although inflammation is a host-defense mechanism, chronic inflammation is considered a major risk factor for the development of a variety of inflammatory autoimmune diseases, such as rheumatic diseases. Rheumatic diseases are systemic inflammatory and degenerative diseases that primarily affect connective tissues and are characterized by severe chronic inflammation and degeneration of connective tissues. Ginseng and its bioactive ingredients, genocides, have been demonstrated to have antiinflammatory activity and pharmacological effects on various rheumatic diseases by inhibiting the expression and production of inflammatory mediators. Methods: Literature in this review was searched in a PubMed site of National Center for Biotechnology Information. Results: The studies reporting the preventive and therapeutic effects of ginseng and ginsenosides on the pathogenesis of rheumatic diseases were discussed and summarized. Conclusion: Ginseng and ginsenosides play an ameliorative role on rheumatic diseases, and this review provides new insights into ginseng and ginsenosides as promising agents to prevent and treat rheumatic diseases.