• 한국언론정보학보
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• 제43권
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• pp.314-358
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• 2008

신문에서는 사회의 커다란 갈등이 생겼을 시 '국론분열'이라는 표현을 사용한다. 하지만 이 말은 매체 속에서 사회적으로 특정한 의미를 구성하고 있는 사회맥락적인 언어이다. 본 논문에서는 우리 사회에서 '국론 분열'이라는 표현이 함축하고 있는 의미는 무엇이며 이것이 우리 사회에서 맡고 있는 역할은 무엇인지를 살펴보았다. 특히 이 단어가 특정한 상황을 명명하고 있으며, 그중에서도 특히 사회 내의 최고 위계를 갖는 사회적 단어인 승부수 언어라는 점에서 '국론 분열'의 쓰임을 분석하였다. 연구대상으로는 세계, 중앙, 문화, 동아, 서울, 국민, 한국, 경향, 조선, 한겨레 등 총 10개의 주요 일간지를 선정하였다. 그리고 각 신문에서 나타나는 '국론 분열'이라는 단어의 텍스트적 의미를 밝히기 위해 은유와 등치된 단어들의 빈도를 살펴보았다. 그리고 사회적 맥락속에서 구성되는 의미를 알아보기 위해 각 신문에서 지칭한 '국론 분열'적 사건과 '국론분열'의 주체를 찾아 빈도를 측정하였다. 결과는 다음과 같다. 첫째 '국론 분열'은 병, 재앙, 비용의 은유로 주로 표현되고 있었으며, 이에 대한 태도나 제시하는 대처행동은 부정적이면서 수동적이었다. 둘째 '국론 분열'은 국정, 국가적 손실, 사회문제, 이념 등과 같은 단어들과 같은 위계를 가지고 있었다. 셋째 '국론 분열'적 사건과 '국론 분열'의 주체는 각 신문사마다 각기 다르게 지칭되어 신문사에 따라 승부수 언어를 다르게 의미 구성하고 있음을 알 수 있었다. 그리고 이러한 승부수 언어는 참여자들과 기존 행위자간의 권력 불균형을 만들고 일부 개인이나 집단을 배제시킨다는 점에서 수사적 힘을 갖게 된다는 논의 또한 이뤄졌다.

• 한국안전학회지
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• 제10권4호
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• pp.3-8
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• 1995

Anchors find their use in providing tie-back resistance for submerged footings, transmission towers, tunnels and ocean structures. Laboratory model teats were performed for the short-term net ultimate uplift capacity of a circular anchors with respect to various embedment depths and moisture content in saturated bentonite. The tests have been conducted with the anchor at two different moisture contents. Based an the model test results, empirical relationships between the net load, rate of strain, and time have been developed. Test results are as follows. 1) In creep tests for load versus ultimate uplift capacity, the displacement of plate anchors rapidly increases during the primary stage but thereafter becomes constant over a period of time. 2) Displacement increased with the increase of the sustain load and embedded ratio in soil. 3) If the load is less than or equal to 75% of the short-term ultimate uplift capacity, a complete pullout does not occur due to creep.

• Advances in concrete construction
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• 제9권3호
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• pp.289-299
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• 2020

To investigate the long-term behavior of eccentrically loaded RC columns, which are more realistic in practice than concentrically loaded RC columns, long-term eccentric loading tests were conducted for 10 RC columns. Test parameters included concrete compressive strength, reinforcement ratio, bar yield strength, eccentricity ratio, slenderness ratio, and loading pattern. Test results showed that the strain and curvature of the columns increased with time, and concrete forces were gradually transferred to longitudinal bars due to the creep and shrinkage of concrete. The long-term behavior of the columns varied with the test parameters, and long-term effects were more pronounced in the case of using the lower strength concrete, lower strength steel, lower bar ratio, fewer loading-step, higher eccentricity ratio, and higher slenderness ratio. However, in all the columns, no longitudinal bars were yielded under service loads at the final measuring day. Meanwhile, the numerical analysis modeling using the ultimate creep coefficient and ultimate shrinkage strain measured from cylinder tests gave quite good predictions for the behavior of the columns.

• Structural Engineering and Mechanics
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• 제15권3호
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• pp.345-365
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• 2003

The adoption of fibre reinforced polymer (FRP) rebars (whose behaviour is elastic-brittle) in reinforced concrete (RC) cross sections requires the assessment of the influence of time-dependent behaviour of concrete on the load-carrying capacity of these sections. This paper presents a method of computing the load-carrying capacity of sections that are at first submitted to a constant long-term service load and then overloaded up to ultimate load. The method solves first a non-linear visco-elastic problem, and then a non-linear instantaneous analysis up to ultimate load that takes into account the self-equilibrated stress distribution previously computed. This method is then adopted to perform a parametric analysis that shows that creep and shrinkage of concrete increase the load-carrying capacity of the cross section reinforced with FRP and allows for the suggestion of simple design rules.

• Steel and Composite Structures
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• 제39권1호
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• pp.21-33
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• 2021

This paper aims to improve the current state-of-the-art in long-term deflection prediction in steel-concrete composite beams. The efficiency of a time-dependent finite element model based on linear creep theory is verified with available experimental data. A parametric numerical study is then carried out, which focuses on the effects of concrete creep and/or shrinkage, ultimate shrinkage strain and reinforcing bars in the slab. The study shows that the long-term deformations in composite beams are dominated by concrete shrinkage and that a higher area of reinforcing bars leads to lower long-term deformations and steel stresses. The AISC model appears to overestimate the shrinkage-induced deflection. A modified ACI equation is proposed to quantify time-dependent deflections in composite beams. In particular, a modified reduction factor reflecting the influence of reinforcing bars and a coefficient reflecting the influence of ultimate shrinkage are introduced in the proposed equation. The long-term deflections predicted by this equation and the results of extensive numerical analyses are found to be in good agreement.

• Clinical and Experimental Pediatrics
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• 제51권11호
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• pp.1133-1135
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• 2008

The ultimate goal of the term alteration to pediatrics is that not only infants and children but also adlescents are subjet to pediatrics. At 27, June, 2007 the term pediatrics was altered to pediatrics (children and aoldescent medicine). From now on the roles of pediatricians for adolescents are needed and adolescent medicine should be reorganized in Korea. Although the numbers of children are decreased in the times of low birth rate, the efforts of pediatricians try to enlarge the range of treatment for adolescents are need.

• Structural Engineering and Mechanics
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• 제20권6호
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• pp.673-693
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• 2005

A general step-by-step simulation for the time-dependent analysis of segmentally-erected prestressed concrete box-girder bridges is presented. A three dimensional finite-element model for the balanced-cantilever construction of segmental bridges, including effects of the load history, material nonlinearity, creep, shrinkage, and aging of concrete and the relaxation of prestressing steel was developed using ABAQUS software. The models included three-dimensional shell elements to model the box-girder walls and Rebar elements representing the prestressing tendons. The step-by-step procedure allows simulating the construction stages, effects of time-dependent deformations of materials and changes in the structural system of the bridges. The structural responses during construction and throughout the service life were traced. A comparison of the developed computer simulation with available experimental results was conducted and good agreement was found. Deflection of the bridge deck, changes in stresses and strains and the redistribution of internal forces were calculated for different examples of bridges, built by the balanced-cantilever method, over thirty-year duration. Significant time-dependent effects on the bridge deflections and redistribution of internal forces and stresses were observed. The ultimate load carrying capacities of the bridges and the behavior before collapse were also determined. It was observed that the ultimate load carrying capacity of such bridges decreases with time as a result of time-dependent effects.

• 한국안전학회지
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• 제15권2호
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• pp.97-102
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• 2000

This paper presents the design, construction and performance of ground treatment to support road embankment on refuse landfill. Long-term settlement of refuse landfill is analysised by Sower and Yen/scanlon. As a results of site test, predicting settlement excess the allowable settlement and ultimate bearing capacity is not satisfied. The effectiveness of DDR(Deep Dynamic Replacement) is monitered by field tests (SPT, PBT, PMT) before, during and after construction of the stone columns. The ultimate bearing capacity for reinforced landfill by stone columns obtained from the in-situ test results has been compared with the existing theories. In municipal wastes landfill, settlement after treatment using stone column is satisfied to allowable residual settlement. Therefore, long-term stability can be gain in these cases.

• International Journal of Concrete Structures and Materials
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• 제8권2호
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• pp.99-116
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• 2014

The American Concrete Institute (ACI) 318-11 permits the use of the moment magnifier method for computing the design ultimate strength of slender reinforced concrete columns that are part of braced frames. This computed strength is influenced by the column effective length factor K, the equivalent uniform bending moment diagram factor $C_m$ and the effective flexural stiffness EI among other factors. For this study, 2,960 simple braced frames subjected to short-term loads were simulated to investigate the effect of using different methods of calculating the effective length factor K when computing the strength of columns in these frames. The theoretically computed column ultimate strengths were compared to the ultimate strengths of the same columns computed from the ACI moment magnifier method using different combinations of equations for K and EI. This study shows that for computing the column ultimate strength, the current practice of using the Jackson-Moreland Alignment Chart is the most accurate method for determining the effective length factor. The study also shows that for computing the column ultimate strength, the accuracy of the moment magnifier method can be further improved by replacing the current ACI equation for EI with a nonlinear equation for EI that includes variables affecting the column stiffness and proposed in an earlier investigation.

• 열처리공학회지
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• 제34권6호
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• pp.294-301
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• 2021

In the present study, we investigate the effects of long-term heat treatment at elevated temperatures on the mechanical softening of the Mn-Mo-Ni low-alloy steel. The influence of long-term heat treatment on microstructure and mechanical strength was evaluated. To simulate the long-term material degradation, heat treatment test was interrupted at several stages up to 10,000 hours in an electric furnace. The Mn-Mo-Ni low-alloy steel shows a typical bainitic phase, which consists of a well-developed lath substructure with fine precipitates along the lath boundaries. However, these fine precipitates were redissolved into the matrix with long-term heat treatment, and then the lath substructures were recovered. Consequently, ultimate tensile strength and yield strength decreased during long-term heat treatment showing a mechanical softening phenomenon.