• Journal of Korean Society of Steel Construction
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• v.9 no.1 s.30
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• pp.51-63
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• 1997

Highly curved steel-box bridges are usually constructed as ramp structures for the highway interchange and metropolitan elevated highway junction, but a number of these bridges are deteriorated and damaged to a significant degree due to heavy traffic. The main objective of the study is to develop a practical reliability-based assessment of safety and residual load carrying-capacity of existing curved steel-box ramp bridges. In the paper, for the realistic assessment of safety and residual load carrying-capacity of deteriorated and/or damaged curved steel-box bridges, an interactive non-linear limit state model is formulated based on the von Mises's combined stress yield criterion. It is demonstrated that the proposed model is effective for the assessment of reliability-based safety and the evaluation of residual load carrying-capacity of curved steel-box bridges. In addition, this study comparatively shows the applicability of various reliability analysis methods, and suggests a practical and effective one to be used in practice.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.6
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• pp.705-719
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• 2017

Progressive Collapse Method (PCM) has been broadly applied to predict moment-carrying capacity of a hull girder, however accuracy of PCM has not been much studied. Accuracy of PCM is known to be dependent on how Load-Shortening and -Elongation (LSE) curve of a structural units are well predicted. This paper presents a new procedure to determine LSE datum based on box girder Finite Element Analyses (FEAs) instead of using finite element model of stiffened panels. To verify reliability of FEA results, the simple box girder collapse test results are compared with FEA results of same box girders. It reveals one frame-based box girder model is sufficiently accurate in terms of ultimate strengths of the box girders. After extracting LSE data from the box girders, PCM-based moment-carrying capacities are compared with those from FEAs of the box girders. PCM results are found to be equivalent to FEAs in terms of moment-carrying capacity if accurate LSE data are secured. The new procedure is applied to well-known 1/3 scaled frigate full section. Very excellent moment-carrying capacity of frigate hull section is obtained from PCM with LSE data from box girder FEAs.

• Steel and Composite Structures
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• v.37 no.5
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• pp.503-516
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• 2020

A novel spiral confined angle-steel reinforced concrete (SCARC) column was developed in this study. A total of 16 specimens were prepared and tested (eight of them were tested under axial loading, the other eight were tested under eccentric loading). The failure processes and load-displacement relationships of specimens under axial and eccentric loads were examined, respectively. The load-carrying capacity and ductility were evaluated by parametric analysis. A calculation approach was developed to predict the axial and eccentric load-carrying capacity of these novel columns. Results showed that the spiral reinforcement provided enough confinement in SCARC columns under axial and low eccentric loads, but was not effective in that under high eccentric loads. The axial load-carrying capacity and ductility of SCARC columns were improved significantly due to the satisfactory confinement from spirals. The outer reinforcement and other construction measures were necessary for SCARC columns to prevent premature spalling of the concrete cover. The proposed calculation approach provided a reliable prediction of the load-carrying capacity of SCARC columns.

• Journal of Environmental Impact Assessment
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• v.18 no.1
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• pp.1-9
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• 2009

Even though the center of Cheongju city needs redevelopment because of a doughnut phenomenon, it has to be permitted within the environmental carrying capacity like a target water quality proposed on the Total maximum daily loads(TMDL) of Musim and Miho river watersheds. The aim of in this study is to identify the limit of redeveloping Cheongju downtown after analyzing its environmental carrying capacity using QUAL2E model. As a result of modeling various scenarios, the water quality of Musin river was shown that $BOD_5$ is 2.3mg/L which is the target water quality in the double of existing development plan of the Cheongju downtown. The water quality of Miho river was $BOD_5$ 3.97mg/L which is less than the target water quality of Miho B watershed in the same condition. Therefore, this means that the limit of redevelopment within the environmental carrying capacity of cheongju downtown was estimated to be the double of existing development plan.

• School Mathematics
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• v.11 no.4
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• pp.607-623
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• 2009

This study aims to investigate a child's informal knowledge of carrying and borrowing in additive calculations. The additive word problems including three types of calculations are posed a child that is the first grader and has no lessons about carrying and borrowing. By analysing his answers, his informal knowledge, that is his methods and strategies for calculating the additive problems are revealed. As a result, conceptual aspects and procedural aspects of his informal knowledge are recognized, and the didactical implications are induced for connecting his informal knowledge and the formal knowledge about carrying and borrowing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.669-675
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• 2003

To increase fishery resources in coastal waters, juvenile fish and bivalves are artificially released every year in Korea. This study provides a methodology to estimate an optimal release quantity based on the carrying capacity of the receiving basins. Carrying capacity was defined by E.p. Odum's theory of ecosystem development as the upper limit of biomass, where total system respiration equals total primary production. The Ecopath trophic ecological model was used to determine carrying capacity in the surfzone ecosystem of Bangjukpo on the southern coast of Korea. Using a top-down control method, various biomasses of fish groups were given to the simulation, with primary production constant and no catch. The results showed that biomass of selected fish groups increased by two orders of magnitude, yielding a five-fold increase in overall consumer biomass. The resultant values are 10 times higher than those estimated in open seas. This can be explained by higher primary production in the Bangjukpo surfzone ecosystem. This method can be used for strategic releases and ecosystem management, particularly when based on an ecological background.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.3
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• pp.115-122
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• 2001

Bridge load rating calculations provide a basis for determining the load carrying capacity of bridges. Load rating requires engineering judgement in determining a rating value that is applicable to maintaining the safe use of the bridge and arriving at posting and permit decisions. Load testing is an effective means in calculating the rating value of bridge. In Korea, load carrying capacity of bridge is modified by response modification factor that is determined from comparisons of measured values and analysis results. This paper presents the development of a method for determining the response the modification factor, using traffic loads. The proposed method is based on the results of computer simulations of traffic action effects. The simulation program generates random traffic actions for defined traffic conditions and determines the frequency distribution of maximum traffic action effects. A comparison between the proposed method and the present method shows good agreement in estimating the modified load carrying capacity of bridges.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.2032-2037
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• 2009

The load carrying capacity of bridge structures in public use is generally evaluated without considering their actual behavioral characteristics. This study examined common errors taking place in the evaluation of load carrying capacity of bridge structures. In order to account for their current behavioral characteristics such as the boundary condition, we evaluated the load carrying capacity of a bridge in terms of axial force, which was calculated by applying deflection to the buckling equation for members with initial imperfections, and in terms of bending moment obtained from deflection.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.4
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• pp.209-216
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• 2003

Load carrying capacity evaluation is very important element in maintenance of bridge. There are several reasons about differences in deflection caused by loading test and structural analysis. Especially when we do modeling uniformly without considering real structural characteristics of support, this problem can be more deepened. This computes modification factor high so we may evaluate the load carrying capacity more than fact. In this study, we do structural analysis nearing real structure with negative bending moment of support that computes considering structural characteristics of support, and then evaluate load carrying capacity.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.3
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• pp.1840-1848
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• 2019

Background : There is lack of studies on the effects of the bag-carrying style on the shoulder muscles and body alignment in adults with rounded shoulder posture (RSP). Objective: The purpose of this study was to investigate the effects of various bag-carrying styles on muscle tone, muscle stiffness and spinal alignment in 20 adults with RSP as they were walking on a treadmill. Design : Crossover Study Design. Methods: A subject performed treadmill walking for 15 minutes at a speed of 4 ㎞/ｈ while carrying three different types of bags: a backpack, a cross bag, and a shoulder bag. Results : The results showed that the main effect of timing was observed in the muscle tone for all the variables and in muscle stiffness only for the upper and lower trapezius muscles. As for the main effect of timing, the muscle tone of the upper trapezius and the pectoralis major significantly increased in all conditions, while the muscle tone of the lower trapezius significantly decreased in all conditions. The muscle stiffness of the upper trapezius significantly increased in all conditions, while the muscle stiffness of the lower trapezius significantly decreased in all conditions. As for the spinal alignment, the dimple distance data values significantly decreased for the cross-bag style. Conclusions : This study demonstrated that walking with a heavy bag, regardless of the bag-carrying style, increased muscle stiffness around the shoulders in adults with rounded shoulder posture, and walking with a cross-bag also induced changes in spinal alignment.