• Textile Coloration and Finishing
• /
• v.2 no.2
• /
• pp.33-38
• /
• 1990

Nitrocellulose [NC]-Poly(vinylamine) [PVAm] blended membranes with the change of amino group contents were prepared. The sorption and permeation of a mono-sulfonic acid dye, Orange II, in the membranes were investigated by the steady-state permeation method at $50^{\circ}C$ and pH 2.2. The results were discussed in the framework of dual sorption and diffusion theory. It was found that thesorption isotherms comprise a partition and two Langmuir type adsorption having similar binding constants. One of the latter sorption modes is due to unknown adsorption sites in NC and the other is due to the amino groups in PVAm. Apparent diffusion coefficients for collective P and L dye species, $D_P\; and D_L$, were obtained. Interpretation of $D_P$ values leads to two modes of partitions; one is such that dye is immobilized in NC and the other is the dissolution of the dye into the internal water phase.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.9
• /
• pp.981-985
• /
• 1997

13C, 15N, and 29Si NMR chemical shifts have been computed for selected X-substituted silatranes (X=Cl, F, H, CH3) using Gauge-Including Atomic Orbitals (GIAO) at the Hartree-Fock level of theory. The isotropic 13C chemical shifts are largely insensitive to substituent-induced structural changes. In this study, the isotropic 13C chemical shifts between 1-methyl- and 1-hydrogensilatranes by GIAO-SCF calculation at the HF/6-31G level are very similar. But the results of 1-chloro- and 1-fluorosilatranes are about 4 ppm different from the experimental values. In contrast, the isotropic 15N and 29Si chemical shifts and the chemical shielding tensors are quite sensitive to substituent-induced structural changes. These trends are consistent with those of the experiment. The isotropic 15N chemical shift demonstrates a very clear correlation with Si-N distance. But in case of 29Si the correlations are not as clean as for the 15N chemical shift; the calculated variation in the 29Si chemical shift is much larger.

• Proceedings of the KSR Conference
• /
• 2009.05b
• /
• pp.465-470
• /
• 2009

This paper discusses the numerical study on the dynamics of the high-speed EMU by developing the 34 degrees-of-freedom (DOF) lumped parameter model including the effect of the creepage. In order to reflect the creepage, the Kalker's wheel-rail contact theory is introduced in the proposed model. The dynamic analysis using $Matlab^{(R)}$ software is conducted, and its results are compared with those from ADAMS/Rail to investigate the validity of the proposed 34-DOF lumped parameter model. It is demonstrated that the results from the numerical study are similar to those from ADAMS/Rail. In addition, the critical design parameters of high-speed EMU are examined, and the design guidelines for reducing vibration and enhancing ride quality are proposed.

• Journal of Aerospace System Engineering
• /
• v.9 no.3
• /
• pp.17-22
• /
• 2015

The UAV industry grows rapidly and the civil UAV market which preparing the commercial services is expected to accelerate the growth. The new opportunities from the technological progress and deregulation show two kinds of organizational structure in the UAV industry. The companies from the traditional aircraft industry and the other sectors like IT industry have different organizational structures of the value chains, supply chains and the regulatory policies which related with them. And from the isomorphism theory it is predicted that those structures will change and converge to certain similar homogeneous features as the UAV industry matures. The matured form will be resulted by the new regulatory policies about the airspace, certifications and the operation rules about the UAV and the future market size and growth speed are also affected by them.

• Journal of the Korean Mathematical Society
• /
• v.58 no.3
• /
• pp.609-631
• /
• 2021

Let C[0, T] denote a generalized analogue of Wiener space, the space of real-valued continuous functions on the interval [0, T]. Define $Z_{\vec{e},n}$ : C[0, T] → ℝⁿ⁺¹ by $$Z_{\vec{e},n}(x)=\(x(0),\;{\int}_0^T\;e_1(t)dx(t),{\cdots},\;{\int}_0^T\;e_n(t)dx(t)\)$$, where e₁,…, e_n are of bounded variations on [0, T]. In this paper we derive a simple evaluation formula for Radon-Nikodym derivatives similar to the conditional expectations of functions on C[0, T] with the conditioning function $Z_{\vec{e},n}$ which has an initial weight and a kind of drift. As applications of the formula, we evaluate the Radon-Nikodym derivatives of various functions on C[0, T] which are of interested in Feynman integration theory and quantum mechanics. This work generalizes and simplifies the existing results, that is, the simple formulas with the conditioning functions related to the partitions of time interval [0, T].

• Journal of architectural history
• /
• v.28 no.5
• /
• pp.71-82
• /
• 2019

The purpose of this study is to establish the relationship between Durand's architectural theory which provided reasonable architectural logic in the early 19th century, and architectural logic of the Modern Movement of Architecture led by avant-garde architects in the 1920's. The system of thought in architecture proposed by Durand which clarified a architectural design method(composition) is very similar to the one of the International Style(Book), which summarizes commonalities in the flow of modern architecture. This approach has something in common from the perspective of the systems of thought, despite differences in external forms and time gaps. Therefore, this study intends to examine the systems of thought in three ways. It is to examine how the two systems of thought define architecture, what is the logic of building production, and finally the value of architecture (including aesthetic values) while eliminating classical aesthetics.

• Korean Chemical Engineering Research
• /
• v.57 no.5
• /
• pp.723-729
• /
• 2019

A theoretical analysis was conducted of convective instability driven by buoyancy forces under transient temperature fields in an annular porous medium bounded by coaxial vertical cylinders. Darcy's law and Boussinesq approximation are used to explain the characteristics of fluid motion and linear stability theory is employed to predict the onset of buoyancy-driven motion. The linear stability equations are derived in a global domain, and then cast into in a self-similar domain. Using a spectral expansion method, the stability equations are reformed as a system of ordinary differential equations and solved analytically and numerically. The critical Darcy-Rayleigh number is founded as a function of the radius ratio. Also, the onset time and corresponding wavelength are obtained for the various cases. The critical time becomes smaller with increasing the Darcy-Rayleigh number and follows the asymptotic relation derived in the infinite horizontal porous layer.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.23 no.4
• /
• pp.522-528
• /
• 1986

Based on the modified effective index method, analysis of dielectric rectangular waveguides and directional couplers are presented. Aside from the effective index concept of channel region, the equivalent index concept of cladding region is proposed. The error problem of eigenvalues, which has been experienced when the effective index method is used, is improved. Our approxiamtions give similar accuracy when compared with the results of other regorous approxiamtion techiniques. The advantage of the modified effective index methods is utilized by replacing the directional coupler with the equivalent slab guides, and the coupling constant is calculated by the coupled mode theory. The effectiveness of the equivalent index concept is positively confirmed.

• International conference on construction engineering and project management
• /
• 2015.10a
• /
• pp.357-360
• /
• 2015

For the last 40 years, the Korean government has built and supplied diverse public facilities. The Korean government, which has supplied diverse public facilities for the last 40 years, has maintained these public facilities as breakdown maintenance under limited budget. Because of increase of aging of public facilities and insufficient budget, it needs the total public facility maintenance. Especially, as Japan has also experienced similar issues and solved these, they are the introduction of P-FM theory and see successful examples. In this study, by comparison Analysis on the Merits and Demerits for Public Facility management (P-FM) between domestic and abroad, it would find a future direction to public facility management P-FM is to go.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.05a
• /
• pp.23-24
• /
• 2023

In this study, an easily recyclable separable glued-laminated timber (GLT)-steel beam was developed, and a structural design method was presented. The GLT and steel were mechanically composited using self-tapping screws. The GLT-steel beam was designed to fail in the compression of GLT. The bending moment and load-carrying capacity of the GLT-steel beam were predicted based on composite beam theory and compared with experimental test data. As a result, the GLT-steel beam exhibited ductile behavior, and compression failure of GLT was observed. The screw connection showed no damage while the steel plate was extended. The load-carrying capacity of GLT after failure was similar to the load resistance predicted by the compressive strength of GLT and the tensile strength of steel. This indicates that the ductile behavior of the GLT-steel beam can be safely designed by the tensile strength (yield) of steel.