• Korean Journal of Construction Engineering and Management
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• 제23권6호
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• pp.3-14
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• 2022

Quantitative analysis of the number of construction workers and construction period can present a new standard for appropriate personnel. This study presents a Queueing model that predicts the execution time of work procedures, the most important factor among work efficiency indicators. During the working cycle of apartment frame construction the same process tends to be repeated the volume of contruction. Based on these characteristics, this study used a Queueing Model and analyzed reference layer cycle of the delayed frame construction. After adjusting the number of people and the construction period, the performance of the model was analyzed and suggested. This study aims to support the decision making of personnel distribution according to the volume of construction by performing a performance analysis of the Queueing Model.

• Analytical Science and Technology
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• 제19권1호
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• pp.50-57
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• 2006

Well known environmental wastes from dye industry were separated by the micellar electrokinetic capillary chromatography(MECC). These wastes include H-acid modifier and 2-naphthylamine-1,5-disulfonic acid, and are known to be the diazo components of the azo dye. The results of the separation were compared with the result obtained by the HPLC using ion-pairing mechnism. MECC method was also applied to separate a few direct dyes including Direct Blue 2, Direct Blue 6 and Direct Blue 15, and reactive dye such as Reactive Orange 4. Informations about the diazo components of any azo dye could be obtained by comparison of electropherogram of the reduction solution of given dye with those obtained from standard materials such as H-acid, J-acid, ${\gamma}$-acid, orthanilic acid, sulfanilic acid and 2-naphthylamine-1,5-disulfonic acid which are used as diazo components of the typical azo dyes. It has been concluded that MECC and HPLC with ion-pairing mechanism could be successfully applied for the analysis of unknown dyes and their diazo components.

• The Korea Journal of Herbology
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• 제25권4호
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• pp.17-21
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• 2010

Objectives : The aim of this study was to evaluate the differential mechnism of vasodilation of alcohol steamed Rhei Tangutici Radix et Rhizoma. (ART) and Rhei Tangutici Radix et Rhizoma. (RT) in rat thoracic aorta. Methods : Rat aortic ring preparations were mounted in organ baths with oxygenated (95% $O_2$-5% $CO_2$) Krebs-Ringer bicarbonate solutions at $37{\pm}0.5^{\circ}C$ and subjected to contractions or relaxations. Results : ART exerted vasorelaxation on phenylephrine(PE)-induced contraction in a dose dependent manner. Vasorelaxation effects of ART and RT were endothelium-independent. In the $Ca^{2+}$-free high KCl (60 mM) baths, the contraction of aortic rings induced by accumulative addition of $Ca^{2+}$ (0.3-10.0 mM) was significantly reduced by pre-treatment with both ART and RT for 10 min. The magnitude of vasodilatation was biggerin ART. Moreover, verapamil ($0.001{\mu}M$) and diltiazem ($10{\mu}M$), voltage operative $Ca^{2+}$channel blockers, attenuated the relaxation effect of ART but not that of RT. In the absence of extracellular $Ca^{2+}$, pre-incubation of the aortic rings with RT ($1.0mg/m{\ell}$) significantly reduced the contraction caused by PE but not that of ART. $K^+$ channel inhibitors such as glibenclamide (Gli, $10^{-5}M$), tetraethylammonium (TEA, 1 mM) and 4-aminopyridine (4-AP, 0.2 mM) significantly reduced the ART's vasorelaxation efficacy, but not that of RT. However, the relaxation effects of ART and RT were not inhibited by pre-treatment with indomethacin ($10^{-5}M$), and atropine ($10^{-6}M$). Conclusions : These results suggest that the endothelium-independent relaxation is due to inhibition of $Ca^{2+}$ influx via the suppression of $Ca^{2+}$ release from intracelluar store in RT but via both voltage operative $Ca^{2+}$channel blockage and $K^+$ channel activation in ART.

• Geophysics and Geophysical Exploration
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• 제6권2호
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• pp.87-94
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• 2003

ULF geomagnetic field anomalies related to earthquakes have been reported and a mechnism that magnetic field variations could be generated by the induced telluric current due to the high frequency fluctuation of conductivity in a fault Bone have been proposed. In this study, we calculated electromagnetic anomalies using a simple fault model and investigated the possibility of significant perturbation. Since low frequency electromagnetic fields are modulated by the high frequency oscillation of conductivity and the modulated fields are concentrated in a narrow ULF band, the electromagnetic fields in ULF band could be perturbed significantly. The amplitude of electromagnetic field anomaly depends on various factors: the geometry and conductivity of fault zone, the magnitude and frequency of conductivity fluctuation, the resistivity structure of crust or mantle, the frequency bandwidth of observational data and so on. Therefore, it is strongly required to reveal the deep resistivity structure of crust a.: well ah the structure of fault zone and to ,select the optimal observation frequency band for the observation of electromagnetic activities related with earthquakes.

• Journal of Korean Tunnelling and Underground Space Association
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• 제14권6호
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• pp.653-666
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• 2012

This study made progress about Demage Mechanism of Transition Section in Cut and Cover Tunnel. For this study, Inspection and test was carried out about Transition Section. After this process, Numerical Analysis was accomplished by 2D, 3D. A result of inspection and test, It couldn't find the reason why the upper slab Demage was detected. So 2D Numerical Analysis was conducted. It was analyzed that the Safety Factor(1.0) was satisfied in 2D. But, the result of 3D Numerical Analysis, The reason was found that the Demage on upper slab was caused by moment change. The Moment was changed by column interval transition. For Retrofitting, Column was added under slab in tunnel. It was found that the addition column decreased upper slab deformation. After this study, It could be find that are important 3D Numerical Analysis as well as 2D Numerical Analysis in case of Transition Section. This Study can help developing construction and maintenance about Tunnel. Finally, It's going to study Retrofitting plans which have minimum influence of Transition Section in Cut and Cover Tunnel.

• The Journal of Internal Korean Medicine
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• 제27권2호
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• pp.394-406
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• 2006

Backgrounds and Objectives: Asthma is considered to be an inflammatory disease characterized by airway hyperresponsiveness and Pulmonary eosinophilia. And it is known the structure and function of IL-5, its receptor and the mechnism IL-5 triggered eosinophil accumulation and inflammaion of the airways. At this point of view, we assume which oriental materia medics can the splenocyte inhibit from secreting the IL-S in vitro. Material and Methosds: We used the splenocyte of mouse 8 weeks after its birth, and then cnltivated those into the 2 experimental groups and control group for 48 hours. The culture medium of experimental groups were made of $1{\mu}g/ml,\;10{\mu}g/ml$, oriental materia medics, representative. And the culture media of control group was given no oriental materia medica. Then, we assayed the quantity of cytokine-expression by the Sandwich ELISA. The quantifies of cytokine-expression of the experimental groups were compared with that of the control group which was standardized These method were used for the all of oriental materia medica treated. Results: In this study, we demonstrated that 12 oriental materia medica that inhibit the splenocyte from secreting the IL-5 in both $1{\mu}g/ml,\;and\;10{\mu}g/ml$ culture media. Those were Equiseti Herbs, Sophorae Subprostratae Radix, Moutan Radicis Cortex. Trichosanthis Radix, Buddleiae Flos. Cyperi Rhizoma. Benincasae Semen, Armeniacae Semen. Zedoariae Rhizoma, Astragali Semen, Dolichoris Semen. Lilii Bulbus, Asparagi Radix, Atractylodes Rhizoma White, Polygonati Officinallis Rhizoma. Conculusions: These findinga indicate that some oriental materia medica, specially Antipyretics, Herbs for Resolving Phlegm, Relieving Cough and Calming Wheezing and Herbs for Tonifring and Invigorating effects inhibit the splenocyte from secreting the IL-5. And further study experimented in vivo is needed for treating IL-5-driven inflammatory disease including asthma.

• Applied Chemistry for Engineering
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• 제2권2호
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• pp.165-174
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• 1991

The kinetics and the mechanism for the selective oxidation of ethylene on the supported monolithic silver catalyst were experimentally investigated in a fixed bed tubular reactor. The formation rates of ethylene oxide and carbon dioxide were measured at the atmospheric pressure with various combinations of partial pressures of ethylene and oxygen at temperature range of $225-300^{\circ}C$, conversion with 1.2-7.5 %, and then the mechanism of the selective oxidation of ethylene was verified. Their formation rates fitted with the Langmuir-Hinshelwood mechnism. The ethylene oxide and carbon dioxide are produced by reation of adsorbed ethylene with monoatomic oxygen adsorbed on the active sites of Ag-surface, and their formation rate equation are expressed as : $R_{EO}={\frac{k_1K_0{^{1/2}}K_EK_SP_{02}{^{3/2}}P_E}{(1+{\sqrt{K_0P_{02}}}+K_EP_E+K_PP_P)^2(1+{\sqrt{K_SP_{02}})^2}}$ $R_C={\frac{k_2K_0{^3}K_EK_S{^{7/2}}P_{02}{^{13/2}}P_E}{(1+{\sqrt{K_0P_{02}}}+K_EP_E+K_PP_P)^7(1+{\sqrt{K_SP_{02}})^7}}$ The activation energies of ethylene oxide and dioxide and carbon dioxide formations can be estimated to be 12.25 and 17.85 Kcal/mol, respectively.

• Journal of Korean Philosophical Society
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• 제129권
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• pp.267-290
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• 2014

The slippery slope argument means that if we accept a type of action A, we are committed to accepting B, C and eventually N. Then, N is situation which we must not accept morally. It works causal mechnism that B because A is raised, C because B is raised. But in the logic textbooks and treatises, the slippery slope argument is classified as fallacy. The reason is that the argument is not a causal argument. Actually, it is a probable. Also it is argued that the argument is wrong because it fears about the future extremely. But We can not say all slippery slope argument is fallacy even though a slippery slope argument is sometimes fallacy. I think it is persuasive argument in a significant place. Therefore I argue that the argument is not simple logic as a form of thinking, but practical reasoning applied the context of dialogue. So in order to find it to be practical reasoning we demand the new understanding to fallacy theory. In traditionally, fallacy is defined to wrong reasoning logically, but according to Walton, fallacy means a verbal tactic or deceptive trick that can be used to cause someone to fall down in argument. That is to say, whether or not the argument is successful depends on how it uses as argument tactic in a given context of dialogue. Therefore I argue that whether or not the argument is successful, because of it is practical problem used in a context of dialogue, is to be approached to pragma and dialectical method, not semantic.