• Steel and Composite Structures
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• v.26 no.6
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• pp.693-703
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• 2018

To better understand the influence of hollow ratio on the hollow concrete-filled circular steel tubular (H-CFT) stub columns under axial compression and to propose the design formula of ultimate bearing capacity for H-CFT stub columns, 3D finite element analysis and laboratory experiments were completed to obtain the load-deformation curves and the failure modes of H-CFT stub columns. The changes of the confinement effect between core concrete and steel tube with different hollow ratios were discussed based on the finite element results. The result shows that the axial stress of concrete and hoop stress of steel tube in H-CFT stub columns are decreased with the increase of hollow ratio. AfteGr the yield of steel, the reduction rate of longitudinal stress and the increase rate of circumferential stress for the steel tube slowed down. The confinement effect from steel tube on concrete also weakened slowly with the increase of hollow ratio. Based on the limit equilibrium method, a simplified formula of ultimate bearing capacity for the axially loaded H-CFT stub columns was proposed. The predicted results showed satisfactory agreement with the experimental and numerical results.

• Journal of Korean Society for Quality Management
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• v.21 no.2
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• pp.215-223
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• 1993

A paired comparison which is a method of comparative judgements is widely used to increase the amount of information transmitted to human sense organ. In this study, a paired comparison method is proposed for the discrimination capacity and preference analysis of non-skilled sensory inspectors. We consider on order effect, that is, difference of evaluation occurred as a result of sample presentation by random order. The purpose of this paper is to determine a sample with the highest preference degrees by analyzing a discrimination capacity and evaluating preference degrees of sensory inspectors. An analysis of a discrimination capacity is bared on the capacity index obtained by an eigen-vector method and an evaluation of preference degrees is performed by a significance test.

• Structural Engineering and Mechanics
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• v.15 no.3
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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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.317-319
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• 2002

In this paper, a new method to get the optimum channel capacity of a Multiple-Input Multiple-Output (MIMO) system is presented. The proposed method exploits the diagonal structure o f channel matrix in order to maximize the channel capacity. The diagonal format of the channel matrix is formed by multiplying the transmitted signal with the precompensated channel (PCC) matrix. Numerical simulations show that the proposed method exploiting the diagonal structure of channel matrix could significantly increase the system capacity compared with the system without applying the diagonal structure of channel matrix.

• Geomechanics and Engineering
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• v.18 no.4
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• pp.391-406
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• 2019

The aim of this paper was to study the influence of the footing shape and the effect of the roughness of the foundation base on the bearing capacity of shallow foundations on rock masses. For this purpose the finite difference method was used to analyze the bearing capacity of various types and states of rock masses under the assumption of Hoek-Brown failure criterion, for both plane strain and axisymmetric model, and considering smooth and rough interface. The results were analyzed based on a sensitivity study of four varying parameters: foundation width, rock material constant (mo), uniaxial compressive strength and geological strength index. Knowing how each parameter influences the bearing capacity depending on the footing shape (circular vs strip footing) and the footing base interface roughness (smooth vs rough), two correlation factors were developed to estimate the percentage increase of the ultimate bearing capacity as a function of the footing shape and the roughness of the footing base interface.

• Journal of the Korean Geotechnical Society
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• v.23 no.12
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• pp.5-11
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• 2007

Among soft ground improvement methods by using granular material, the sand compaction pile method has been widely utilized in Korea, but, as a result of shortage and increase of unit price of sand, a necessity of an alternative method has been required. In this study, a series of in-situ static load tests for crushed-stone compaction piles were performed. Pile diameter was fixed to 700mm and areas of loading plates were changed. The static load tests were performed for area replacement ratios of 20, 30 and 40% respectively. Based on the test results, bearing capacity of single crushed-stone compaction pile was estimated. It showed that the settlement decreases as the replacement ratio increases. Also, a yielding capacity equation of the crushed-stone compaction pile considering replacement ratio was suggested.

• Journal of the Korean Geotechnical Society
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• v.27 no.2
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• pp.17-26
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• 2011

To solve the problem of saturated dredged soil dumping area, it is possible to extend the life span of dredged soil dumping area by accelerating consolidation of dredged soil and making alluvial soil layer consolidated additionally by using dewatering method and PDF method without construction of new dumping area which entails great expense. Self-weight consolidation tests on samples from Busan and Incheon with the column of 400 mm in diameter were conducted to estimate those methods applicability to domestic dredged soil. As a result of tests, it was proved that dewatering method and PDF method were highly effective in increasing reclamation capacity of dredged soil by reduction of self-weight consolidation completion time and increase of self-weight consolidation settlement.

• Communications for Statistical Applications and Methods
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• v.13 no.3
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• pp.577-585
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• 2006

This paper presents a method for reliability evaluation of a telecommunication network with variable link-capacities when the simple paths of the network are known. The LP-EM, suggested by Lee and Park (2001), identifies a composite path as a subnetwork and adds only a minimal set of links at each step which gives maximal increase on the maximum capacity flow of the subnetwork. Thereby the LP-EM reduces the possible occurrence of redundant composite paths significantly over other existing methods. Based on the LP-EM, our method further reduces the possible redundancy by identifying such simple paths that could give no increase of maximum capacity flow on the current subnetwork and excluding those simple paths from consideration in the process of constructing composite paths.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.4
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• pp.11-18
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• 2021

Purpose : The purpose of this study was to investigate the effect on lung capacity of healthy men and women in their twenties by performing an intervention using the chest extension exercise and the bridge exercise, which are respiratory muscle strengthening exercises. Methods : Thirty adult men and women in their 20s participated in this study. All subjects participated in the study after hearing the explanation of the purpose and method of the study, filling out a consent form. All subjects were randomly assigned to the chest extension exercise (CEE) group and the bridge exercise (BE) group of fifteen each. Each exercise was performed twice a week for 4 weeks. Lung capacity was measured by forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁) using spirometry. Lung capacity was measured before and after exercise. The measured data were compared through the dependent t-test and the independent t-test. The statistical significance level was set at .05. Results : After the intervention, the CEE group showed a significant increase in FVC and FEV₁ compared to before the intervention (p<.05). After the intervention, the BE group also had a significant increase in FVC and FEV₁ compared to before the intervention (p<.05). However, there was no difference in FVC and FEV₁ between groups before and after the intervention (p>.05). Conclusion : There was no difference between groups in lung capacity after exercise. However, both the chest extension exercise and the bridge exercise increased FVC and FEV1, which was thought to be because both exercise methods were effective in increasing lung capacity. Therefore, both chest extension exercises and bridge exercises can be effectively applied as a way to increase lung capacity.

• Journal of Navigation and Port Research
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• v.33 no.5
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• pp.353-359
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• 2009

Most domestic container terminals are lack of container storage capacity compared to the throughput of container. The main reason is the difference between the theoretical capacity applied to the development of terminals and the real capacity of a berth Another reason seems to be the increase of the container crane in number per berth to match the need for the getting larger vessel, which is resulted from the increase of the berth capacity from the start. This study, therefore, aims to suggest the economic size of container yard by comparing the existing one. For this the berth capacity was recalculated, the required yard size derived considering up to 10,000TEU vessel and then cost comparison done.