• Earthquakes and Structures
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• v.1 no.2
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• pp.215-230
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• 2010

The main objectives of this work were to investigate the effects of the nonlinear behavior of the isolation pads on the seismic response of bridges with rubber bearings, and to identify when base isolation improved their seismic performance. To achieve these objectives a parametric study was conducted designing a set of bridges for three different soil types and varying the number of spans, span lengths, and pier heights. The seismic responses (accelerations, displacements and pier seismic forces) were evaluated for three different structural models subjected to three earthquakes with different dynamic characteristics. The first represented bridges without base isolation; the second corresponded to the same bridges including now rubber bearings as an isolation system, with linear elastic behavior that shifted the natural period of the bridge by a factor of 2 to 4. In the third model the seismic response of bridges supported on lead-Rubber bearings was studied accounting for the nonlinear behavior of the lead. The results show clearly the importance of the nonlinear behavior on the seismic performance of the bridges.

• Journal of information and communication convergence engineering
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• v.12 no.2
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• pp.75-82
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• 2014

Dispersion management (DM), optical phase conjugation (OPC), and the combination of DM and OPC are promising techniques to compensate for optical signal distortion due to group velocity dispersion and nonlinear Kerr effects. The system performance improvement in DM links combined with OPC has been reported; however, the fixed residual dispersion per span (RDPS) usually used in these links restricts the flexibility of link configuration. Thus, in this paper, a flexible optical link configuration with artificially distributed single-mode fiber (SMF) lengths and RDPS in the combination of DM and OPC is proposed. Simulation results show that the best artificial distribution pattern is the gradually descending distribution of SMF lengths and the gradually ascending distribution of RDPS, as the number of fiber spans is increased, regardless of the average RDPS, the optimal net residual dispersion, and the dispersion coefficient of the dispersion compensating fiber.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.865-870
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• 2001

An effective live load model for analyzing probable maximum live load effects in longitudinal direction such as moment and shear was developed. The main procedure of this live load model is composed of two parts. Firstly, determination of the appropriate influence lines, and secondly, application of the characteristics of vehicles and traffic patterns. Through this procedure, probabilistic distributions of maximum probable load effects are deduced in the form of probability density function (PDF) or cumulative density function (CDF). The proposed live load model is not limited by bridge types(number of spans or girders) and can consider local or global deterioration of bridges in the analysis. Besides, load effects can be determined at any section without restrictions.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1389-1396
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• 2014

The entire nucleotide sequence of the TKL1 gene encoding transketolase (TKL) in an erythritol-producing yeast of Candida magnoliae was determined by degenerate polymerase chain reaction and genome walking. Sequence analysis revealed an open reading frame of C. magnoliae TKL1 (CmTKL1) that spans 2,088 bp and encodes 696 amino acids, sharing 61.7% amino acid identity to Kluyveromyces lactis TKL. Functional analysis showed that CmTKL1 complemented a Saccharomyces cerevisiae tkl1 tkl2 double mutant for growth in the absence of aromatic amino acids and restored transketolase activity in this mutant. An enzyme activity assay and RT-PCR revealed that the expression of CmTKL1 is induced by fructose, $H_2O_2$, and KCl. The GenBank accession number for C. magnoliae TKL1 is KF751756.

• Journal of information and communication convergence engineering
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• v.15 no.4
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• pp.205-211
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• 2017

Combining dispersion-managed optical links with midway optical phase conjugation (OPC) is a possible method of compensating for optical signal distortion due to group velocity dispersion and nonlinear Kerr effects. Although an improvement in the performance of these optical links has been reported, the fixed residual dispersion per span (RDPS) that is typically used restricts the flexibility of link configurations. Thus, in this paper, a flexible dispersion-managed link configuration, comprising artificial distributions of linearly/nonlinearly incremented RDPS, is proposed. Simulations show that a descending distribution of RDPS before the midway OPC, and an ascending distribution of RDPS after the midway OPC, gives the best artificial distribution pattern as the number of fiber spans is increased, regardless of the RDPS incrementation method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.1
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• pp.111-118
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• 2002

Currently, the inspection of bridges is conduced for the parts or elements of a bridges and the results of inspection are depicted for those local elements. Therefore, the representative rating of a bridge as a whole bridge system is not presented. The purpose of the present study is to purpose a reasonable method which can yield realistic representative rating for an actual bridge. The purpose method consists of two steps, i.e, visual inspection step and safety assessment step. The importance of members is considered by introducing the weighting factors and the number of spans is also considered to obtain the representative rating of a whole bridge system. The purpose method may be efficiently used to calculate the realistic representative rating bridge structures.

• Journal of the Korean Mathematical Society
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• v.56 no.2
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• pp.507-521
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• 2019

For any $m{\times}n$ nonbinary Boolean matrix A, its spanning column rank is the minimum number of the columns of A that spans its column space. We have a characterization of spanning column rank-1 nonbinary Boolean matrices. We investigate the linear operators that preserve the spanning column ranks of matrices over the nonbinary Boolean algebra. That is, for a linear operator T on $m{\times}n$ nonbinary Boolean matrices, it preserves all spanning column ranks if and only if there exist an invertible nonbinary Boolean matrix P of order m and a permutation matrix Q of order n such that T(A) = PAQ for all $m{\times}n$ nonbinary Boolean matrix A. We also obtain other characterizations of the (spanning) column rank preserver.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.363-366
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• 2003

Concrete structures are becoming larger, higher, longer and more specialized. Currently, one of the biggest problems of concrete structures is the occurrence of cracks. Cracks are a serious structural problem that decreases durability and causes external damage leading to corrosion. The specimen without steel fiber fractured between 60-70% of the static ultimate strength (the fatigue strength to one million cycles on the number of cycles from the S-N curve was 73.7% and the fatigue strength to two million cycles was approximately 67.2%). The specimen with steel fiber fractured at 65-80% of the static ultimate strength, concluding fatigue strength to one million cycles around 74.6% and to two million cycles around 75%.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.176-184
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• 1999

Dynamic characteristics of pantograph-catenary system that supplies electrical power to high-speed trains are investigated. A simple catenary is composed of the contact and messenger wires connected by hamgers possessing bi-directional stiffness properties. The influences of parameters that determine the contact properties of pantograph-catenary system are investigated through numerical simulations. For the catenary, a finite difference model composed of 10 spans is constructed. The contact and messenger wires are modeled as strings with respective tension and damping ratio values. The pantograph is modeled as a linear 3-degree-of-freedom system. It is found that the tension, number of hangers and damping ratios as well as the speed of the train significantly influence the contact forces and contact separation rate

• Steel and Composite Structures
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• v.30 no.3
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• pp.253-269
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• 2019

This paper investigates the effects of the tensile catenary action on dynamic increase factor (DIF) in the nonlinear static analysis for progressive collapse of steel-frame buildings. Numerical analyses were performed to verify the accuracy of the empirical and analytical expressions proposed in the literature in cases where the catenary action is activated. For this purpose, nonlinear static and dynamic analyses of a series of steel moment frame buildings with a different number of spans and stories were carried out following the alternate path method. Different column removal scenarios were considered as separate load cases. The dynamic increase factor that approximately compensates for the dynamic effects in the nonlinear static analysis was selected so to match results from the nonlinear dynamic analysis. The study results showed that the many expressions in literature may not work in cases where the catenary stage is fully developed.