• Geotechnical Engineering
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• v.2 no.1
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• pp.7-14
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• 1986

The structure of the collapsible soils, such as decomposed granite soil and loess, were examined by the odeometer test, SEM & XES analysis and static & cyclic triaxial test, and hove this structure have influences upon the collapsible behaviour under static and cyclic load was investigated. The study results obtained are as follows; 1. The macropores space of decomposed granite soil (rd=1.50g/cm3) and loess (rd=1.43g/cm3) used in this test were well developed, and showed the behaviour of collapsible soil. 2. Collapsible soil has high resistance on the strain under natural moisture content, however, the resistance on the strain was sharply decreased by the absorption and increasing load since its special structure was destructed. 3. Under the static load, the strain of collapsible soil was high by the viscous flow of the cyclic bonds with time lapse, but Infer the cyclic load, the strain of collapsible soil was low since the tinge needed to destruct the bonding force of clay was not enough. 4. The understanding about the cyclic behaviour of collapsible soil may be helpful to predict the elastic & residual strain of the foundations by the earthquake together with the damage by the additional failure.

• Bulletin of the Korean Mathematical Society
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• v.53 no.2
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• pp.479-486
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• 2016

The norm N(G) of a group G is the intersection of the normalizers of all the subgroups of G. In this paper, the structure of finite groups with a cyclic norm quotient is determined. As an application of the result, an interesting characteristic of cyclic groups is given, which asserts that a finite group G is cyclic if and only if Aut(G)/P(G) is cyclic, where P(G) is the power automorphism group of G.

• Journal of KSNVE
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• v.8 no.6
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• pp.1150-1157
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• 1998

In this Paper, we present an efficient method for finite element vibration analysis of constantly rotating structures with cyclic symmetry, which are deformed to some considerable extent by centrifugal force, Coriolis force and operating load, and vibrate due to several types of exciting forces. A structure with cyclic symmetry is composed of circumferentially repeated substructures with the same geometry. Being only one substructure modeled. the dynamic characteristics of the structure can be analyzed systematically. rapidly and exactly using discrete Fourier transform by means of a computer with small memory.

• Journal of the Korean Society for Heat Treatment
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• v.3 no.2
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• pp.37-44
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• 1990

The effect of the microstructural change on the near threshold fatigue crack growth rate in SM40C steel has been studied using the ${\Delta}K$ decreasing method. Below the total strain amplitude of 0.56%, cyclic softening occured, whereas above this value cyclic hardening occurred in the pearlitic lamellar structure. However, in the spherodized structure the cyclic hardening solely occurred. The crack growth rate in the near-threshold region was decreased with increasing prior austenite grain size and this was due to surface roughness. The crack growth rate of the spherodized structure was lower than that of the pearlite lamellar structure and the ${\Delta}K_{th}$ of the former was higher than that of the latter. It was understood that the crack propagates preferentially through the ferrite phase. The intergranular facets in the near-threshold region appeared in the spherodized structure.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.6 s.324
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• pp.9-15
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• 2004

In MIMO-OFDM systems, conventional channel estimation techniques using comb type training symbols give relatively large mean squared errors(MSEs) at the edge subcarriers. To reduce the MSEs at these subcarriers, a cyclic comb type training structure is proposed. In the proposed cyclic training structure, all types of training symbols are transmitted cyclically at each antenna. At the receiver, the channel frequency responses that are estimated using each training symbol are averaged with weights obtained from the corresponding MSEs. Computer simulations showed that the proposed cyclic training structure gives more SNR gain than the conventional training structure.

• Bulletin of the Korean Mathematical Society
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• v.53 no.6
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• pp.1617-1628
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• 2016

In this paper, we extend the results given in [3] to a nonchain ring $R_p={\mathbb{F}}_p+v{\mathbb{F}}_p+{\cdots}+v^{p-1}{\mathbb{F}}_p$, where $v^p=v$ and p is a prime. We determine the structure of the cyclic codes of arbitrary length over the ring $R_p$ and study the structure of their duals. We classify cyclic codes containing their duals over $R_p$ by giving necessary and sufficient conditions. Further, by taking advantage of the Gray map ${\pi}$ defined in [4], we give the parameters of the quantum codes of length pn over ${\mathbb{F}}_p$ which are obtained from cyclic codes over $R_p$. Finally, we illustrate the results by giving some examples.

• Geomechanics and Engineering
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• v.35 no.6
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• pp.627-636
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• 2023

The essence of subgrade mud pumping under train load is the migration of fine particles in subgrade soil. The migration of fine particles will change the pore structure of overlying ballast, thus affecting the mechanical properties and hydraulic properties of ballast layer. It is of great theoretical significance and engineering value to study the effect of fine particle migration on the pore structure of ballast layer under cyclic loading. In this paper, a tailor-made subgrade mud pumping test model and an X-ray computed tomography (CT) scanning equipment were used to study the influence of migration of fine particles in subgrade soil on the pore parameters (plane porosity, volume porosity, pore distribution and pore connectivity) of overlying ballast under cyclic loading. The results show that the compression of ballast pores and the blockage of migrated fine particles make the porosity of ballast layer decreases gradually. And the percentage of small pores in ballast layer increases, while the percentage of large pores decreases; the connectivity of pores also gradually decreases. Based on the test results, an empirical model of ballast porosity evolution under cyclic loading is established and verified.

• Proceedings of the Korea Concrete Institute Conference
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• 1990.04a
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• pp.66-71
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• 1990

The prediction and estimation of R/C structure behavior subjected to earthquake type loading is partly based on the experimental results of the monotonically increased cyclic loading, rather than that of the irregularly increased cyclic loading. However, actual earthquake is typical random vibration. In this respect, comparing and analysing experimental test results of R/C specimens subjected to monotonically increased cyclic loading and irregularly increased cyclic loading, this study proposes the research direction of irregularly increased cyclic loading during earthquake.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2467-2470
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• 2009

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.777-779
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• 2003

Density functional calculations and ab initio calculations have been carried out to study the lowest energy structure of the water ($H_2O)_{11}$. Among five structures suggested by four different groups, the lowest energy structure is found to have the skeletal structure of Prism56 (Pr56-24) that a cyclic pentamer and a cyclic hexamer are fused into a prism-shape with 16 hydrogen-bonds (HBs).