• Journal of KSNVE
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• v.6 no.1
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• pp.57-64
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• 1996

The objectiv of this paper is to offer the method of the optimum structural modification by fixing the stiffener on the structure. The vibrational characteristics of a open box type structure are analyzed by the sub-structure synthesis method and sensitivies of each sub-structure are calculated by sensitivity analysis method. The positions to modify are found and the quantities to change are obtained by optimization techniques. As the result, it was found that; (1) The sensitivites of the natural frequency could easily be calculated by the sensitivity analysis method and the optimum position to fix stiffeners could be found. (2) The exact size of stiffeners could be calculated by the optimum structural modification method and the natural frequency could be easily shifted to the objective value. (3) It could be confirmed that the stiffener is a effective tool for accomplishing structural modification.

• Interaction and multiscale mechanics
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• v.5 no.2
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• pp.145-155
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• 2012

The thin-plate structure and the box-beam structure are two typical welded structures in railway vehicles. Because of their structure complexity, bigger size and multi-seams, welding residual distortion which occur in welding process bring unfavorable effect on the quality of welding products manufacturing and service. As a result, welding distortion forecasting and control become an important and urgent research topic in railway vehicles. In this paper, three different numerical methods are presented corresponding to three typical types of welded structures of railway vehicles and welding deformation are simulated. Consistence of numerical results and experimental data proves the correctness of models and feasibility of simulation methods.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.319-322
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• 2002

In this paper, an experimental study is carried out to find out structural behavior of upper slab in concrete box girder bridges. The major variables in the tests are the cross-section of upper slab including haunch dimensions. The strains of concrete and steel bars and the deflections of slabs are measured automatically during the tests. The test results indicate that the size of haunches has much influence on the structural behavior of box girders. The appropriate haunch dimensions are suggested from the present study.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.3
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• pp.19-24
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• 1991

본 고에서는 자동차 안전대책중에서 One-box car의 전면충돌 안전대책에 대하여 개략적으로 소개하고자 한다. 1. 충돌기본식 1/2M$V^{2}$=F.S에서 에너지 흡수율이 frame의 변형 평균 하중과 차체 변형량에 좌우된다. 2. frame 형상은 굽힘형보다 압축형이 동일한 변형구간에서 월등한 충돌에너지를 흡수한다. 3. 압축형 frame의 에너지 흡수효과는 main-frame의 버팀강도가 e.a-frame의 변형 하중보다 강해야만 그 효과를 충분히 얻을 수 있다.

• Journal of Plant Biology
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• v.38 no.3
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• pp.259-266
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• 1995

To investigate how the dyad symmetry region (DSR) and the distance between vir box and -35 sequence of the virE promoter plays a role in virE gene expression, two mutants were constructed by base substitution and insertional mutagenesis. The base substitutional mutation, a AAlongrightarrowCG substitution at positions -39 and -40 on the DSR, showed the level of $\beta$-galactosidase activity approximately 91% of the wild type virE promoter activity. Therefore, the native structure of the DSR seems to be not essential for virE expression. The insertional mutation, constructed by inserting 8 bp ClaI linker between -49 and -50, displayed the $\beta$-galactosidase activity at 12% of the native virE promoter activity. However, this striking reduction appears to be not caused by destruction of the native DSR structure, but by shifting the vir box far from putative -35 sequence.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.3
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• pp.435-444
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• 1997

Many of the problems which are faced to the edentulous patients are related to a minimal amount of available mandibular bone volume and height. Most of the patients with mild atrophy of the mandible are treated using endosseous implant prosthodontics. TMI(Trans-mandibular Implant) can be used in case of severe mandibular atrophy, poor bone quality, atrophy of the mandible with exposed of inferior alveolar nerve, osteoporosis and the fracture of the atrophic mandible. Also it can eliminate the need for bone grafting and vestibuloplasty. The TMI is a rigid box frame structure which controls and distribute the masticatory force over the severely resorbed mandible. The box frame structure consist of a superstructure, baseplate, 4 transosseous posts, and 5 cortical screws. This is a case report that also describes about the transmandibular implant reconstruction system.

• Journal of Aerospace System Engineering
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• v.15 no.2
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• pp.1-9
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• 2021

In this paper, a thickness compensation function is introduced to consider the shear deformation and warping effect resulting from increased thickness in the composite multi-cell wing box. The thickness compensation function is used to perform the structure optimization of the multi-cell. It is determined by minimizing the error of an analytical formula using solid mechanics and the Ritz method. It is used to define a structural performance prediction expression due to the increase in thickness. The parameter is defined by the number of spars and analyzed by the critical buckling load and the limited failure index as a response. Constraints in structural optimization are composed of displacements, torsional angles, the critical buckling load, and the failure index. The objective function is the mass, and its optimization is performed using a genetic algorithm.

• Bulletin of the Korean Mathematical Society
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• v.60 no.5
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• pp.1281-1293
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• 2023

The purpose of this paper is to study the relationship between the structure of a factor ring R/P and the behavior of some derivations of R. More precisely, we establish a connection between the commutativity of R/P and derivations of R satisfying specific identities involving the prime ideal P. Moreover, we provide an example to show that our results cannot be extended to semi-prime ideals.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.625-630
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• 2002

PSC box girder is widely used in a domestic bridge and overpass, etc., therefore, the design and construction technique for the PSC box girder is developing day by day. Even if it were so, however, the design for anchorage zone in PSC box girder has depended on common sense and empirical results. And it is the current situation that the designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of anchorage zone. Besides, the design based on Leonhardt's method is being done in general, but the design may be various even for the same structure because of the difference in a way of applying. In this paper, therefore, anchorage zone in PSC box girder bridge is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice, and this study presents that strut-tie model can be a rational and an economical design than current design methods.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.672-677
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• 2005

The standard reference collection of strains for E. coli, the ECOR collection, was analyzed by a genome-based typing method. Seventy-one ECOR strains were subjected to repetitive extragenic palindromic PCR genome fingerprinting with BOX primers (BOX-PCR). Using a similarity value of 0.8 or more after cluster analysis of BOX-PCR fingerprinting patterns to define the same genotypes, we identified 28 genotypes in the ECOR collection. Shannon's entropy-based diversity index was 3.07, and the incident-based coverage estimator indicated potentially 420 genotypes among E. coli populations. Chi-square test of goodness-of-fit showed statistically significant association between the genotypes defined by BOX-PCR fingerprinting and the groups previously defined by multi-locus enzyme electrophoresis. This study suggests that the diversification of E. coli strains in natural populations is actively ongoing, and rep-PCR fingerprinting is a convenient and reliable method to type E. coli strains for the purposes ranging from ecology to quarantine.ine.