• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.3
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• pp.79-88
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• 2011

In the context of sustainability which is understood as equilibrium among three elements; human, space and time, the imbalance within the Seoul metropolitan area hinders its own area or the nation from development. Claims for the balanced development in the area are set up on the premise that there is a locational order of priority among the zones named 'overpopulation suppression', 'growth management' and 'conservation'. Based on the systematic consideration of competitiveness this study adopts the premise as a research hypothesis. Factor scales derived from the factor analysis, a kind of multivariate dependence analysis play an important role in this research process since they are measured by interval-ratio level and can be used for dependent variables in the statistical analysis. The hypothesis test carried out by means of the analysis of variance(ANOVA) concludes that the hypothesis assuming no difference in the competitiveness is rejected but the alternative hypothesis of the locational order mentioned above should be adjusted. Eigenvalues derived from the factor analysis could be used as weights for aggregate factor scales and the scales show that the priority is in the order of growth management - overpopulation suppression - conservation zones. This finding has also a significant implication that the countermeasures to cope with the lowering of the competitiveness resulted from the continuous and absolute restraints should be provided. And strategic approaches which are composed of key factors for each zone are deducted from in-depth review. (1) overpopulation suppression zone; health-welfare, educational base, public service factors, focusing on health-welfare one, (2) growth management zone; public service factor and (3) conservation zone; health-welfare, educational base factors, also focusing on health-welfare one.

• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.71-79
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• 2011

Due to the self-equilibrium status of the cable system, the loss of the tensioning in the cable system results in other cables carrying larger tension forces than those initially calculated by structural engineers. Also, turn-buckle systems, which have been widely used to pre-tension and/or re-tension the cables, are limited to use for small cables and to provide a rough estimation for tension forces. In this study, the re-tensioning cable connection systems were developed to overcome the problems mentioned above. The main objective of the proposed system is to re-tension large cables and measure the exact amount of tension forces of the cable systems. This connection system is also combined with the wireless signal monitoring module so that engineers are able to measure the tension forces any place where the internet is available. This paper presents the development of the re-tensioning cable connection systems and experiment using the real-scale cable systems to verify the fe-tensioning and signal monitoring systems.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.588-594
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• 2005

We have investigated Y zeolite and activated carbon for an adsorptive desulfurization of diesel. In batch experiments, cation ($Cu^{2+}$, $Ni^{2+}$) exchanged Y zeolites showed high equilibrium adsorption capacity for sulfur compounds in model diesel, which contained BT, DBT and 4,6-DMDBT of each 50 ppmw in n-octane. But the cation exchanged Y zeolites lost its capacity in commercial diesel (186 ppmw). On the other hand, activated carbon showed reasonable adsorption capacity for sulfur compounds in both model and commercial diesel. The adsorption capacity of sulfur on Ni-Y zeolite was decreased with the increase of benzene concentration in model diesel but the sorption capacity on activated carbon was insensitive to aromatic concentration. In breakthrough test, activated carbon of 1 g could treat 15 ml of commercial diesel with 186 ppmw sulfur. Toluene showed good solvent for regenerating activated carbon among several solvents.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.279-288
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• 2016

The present study simplified the moment-curvature relationship to straightforwardly determine the flexural behavior of reinforced concrete (RC) columns. For the idealized column section, moments and neutral axis depths at different stages(first flexural crack, yielding of tensile reinforcing bar, maximum strength, and 80% of the maximum strength at the descending branch) were derived on the basis of the equilibrium condition of forces and compatibility condition. Concrete strains at the extreme compression fiber beyond the maximum strength were determined using the stress-strain relationship of confined concrete, proposed by Kim et al. The lateral load-displacement curves converted from the simplified moment-curvature relationship of columns are well consistent with test results obtained from column specimens under various parameters. The moments and the corresponding neutral axis depth at different stages were formulated as a function of longitudinal reinforcement and transverse reinforcement indices and/or applied axial load index. Overall, curvature ductility of columns was significantly affected by the axial load level as well as concrete compressive strength and the amount of longitudinal and transverse reinforcing bars.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.39-49
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• 1993

In order to present the geometrically nonlinear F.E. formulation of space frames, two beam/column elements including the effects of transverse shear deformation and bending stretching coupling are developed. In the case of the first element (Finite segment method), the tangent stiffness matrices are derived by directly integrating the equilibrium equations, whereas in the case of the second element (Finite element method) elastic and geometric stiffness matrices are calculated by using the hermitian polynomials including shear deformation effect as the shape function. Both elements possess the usual twelve degrees of freedom. Also, the bowing function including shear deformation effects is obtained in order to account for the effect of shortening of member chord length due to the bending and torsional behavior. Numerical results are presented for the selected test problems which demonstrate that both elements represent reliable and highly accurate tools.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1299-1306
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• 2011

In this study, crack-growth model parameters subjected to variable amplitude loading are estimated in the form of a probability distribution using the method of Bayesian parameter estimation. Huang's model is employed to describe the retardation and acceleration of the crack growth during the loadings. The Markov Chain Monte Carlo (MCMC) method is used to obtain samples of the parameters following the probability distribution. As the conventional MCMC method often fails to converge to the equilibrium distribution because of the increased complexity of the model under variable amplitude loading, an improved MCMC method is introduced to overcome this shortcoming, in which a marginal (PDF) is employed as a proposal density function. The model parameters are estimated on the basis of the data from several test specimens subjected to constant amplitude loading. The prediction is then made under variable amplitude loading for the same specimen, and validated by the ground-truth data using the estimated parameters.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.3
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• pp.175-181
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• 2013

This paper presents a simulation for passenger ship evacuation considering the inclination of a ship. In order to describe a passenger's behavior in an evacuation situation, a passenger is modeled as a rigid body which translates in the horizontal plane and rotates along the vertical axis. The position and rotation angle of a passenger are calculated by solving the dynamic equations of motions at each time step. To calculate inclined angle of damaged ship, static equilibrium equations of damaged ship are derived using "added weight method". Using these equations, physical external forces due to the inclination of a ship act on the body of each passenger. The crowd behavior of the passenger is considered as the flock behavior, a form of collective behavior of a large number of interacting passengers with a common group objective. Passengers can also avoid an obstacle due to penalty forces acting on their body. With the passenger model and forces acting on its body, the test problems in International Maritime Organization, Maritime Safety Committee/Circulation 1238(IMO MSC/Circ.1238) are implemented and the effects of ship's inclination on the evacuation time are confirmed.

• Journal of Plant Biology
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• v.24 no.4
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• pp.181-190
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• 1981

Rye in Paldang was investigated with regard to the occurrence of B-chromosomes from 1963 through 1977, and frequencies of B-chromosomes were as follows; 2% (1963), 8% (1964), 8% (1965), 15% (1966), 11.5% (1968), 11.7% (1969), 20% (1975), 19.6% (1976), and 12.8% (1977). The result of the chi-square test showed statistically no significant difference between the frequency of B-chromosomes each year. The analysis revealed that distribution of B-chromosomes seemed to be relatively uniform in the rye field. With regard to the sample size 50 plants were quite enough to estimate the frequency of B-chromosomes in rye population. Quadrivalent due to translocation heterozygote were observed in the population of Paldang rye from 1966 through 1977, their frequencies being 1 to 7%. Numerical increase of B-chromosomes in rye due to non-disjunction process in the pollen as well as in the ovules was well-known phenomenon, whereas B-chromosomes tended to be eliminated in meiosis and seed fertility of rye was reduced in the individuals with B-chromosomes. The mechanism of gain or loss for B-chromosomes might support the equilibrium of B-chromosomes in Paldang rye population.

• Physical Therapy Korea
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• v.9 no.3
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• pp.77-91
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• 2002

Asymmetrical stance posture, balance, and gait disturbance are common problems in hemiplegic patients. Posterior leaf springs (PLS) are frequently prescribed to correct these problems. Recently, anterior leaf springs (ALS) have also been prescribed, but only limited studies have been performed to investigate the effects of ALS. The purpose of this study was to compare the effects of three conditions, i.e., wearing an ALS, wearing a PLS, and not wearing an AFO (ankle foot orthosis),: on 1) the distribution of weight bearing on the affected side, 2) standing balance, and 3) the gait patterns of hemiplegic patients. Eleven hemiplegic patients (10 men and 1 woman) participated in this study. The data were analyzed by the Friedman test. The results were as follows: 1) More weight bearing on the affected leg was observed in the ALS and PLS conditions than in the condition without an AFO. No significant difference between the ALS and PLS conditions was found. 2) There were statistically significant differences in the composite equilibrium scores (CES) among the three conditions. The CES in the PLS condition was significantly higher than in the ALS condition or the condition without an AFO. 3) Gait patterns improved significantly in the ALS and PLS conditions. No statistically significant difference between the ALS and PLS conditions was found. These results suggest that both ALS and PLS effectively improve the distribution of weight bearing on the affected side, standing balance, and gait patterns of hemiplegic patients. Further study using three-dimensional kinematic analysis and dynamic electromyography is needed to support these findings.

• Journal of the Korea Concrete Institute
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• v.25 no.6
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• pp.641-648
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• 2013

Current design codes regulate the minimum torsional reinforcement requirement for reinforced concrete members to prevent their brittle failure. The minimum torsional reinforcement ratio specified in the current national code and ACI318-11, however, have problems in the minimum longitudinal reinforcement ratio for torsion, the equilibrium condition in space truss model, and a marginal strength, etc. Thus, in order to overcome such shortcomings, this study presents a rational equation for minimum torsional reinforcement ratio that can provide a sufficient margin of safety in design. The minimum torsional reinforcement ratio proposed in this study was compared to the test results available in literature, and it was confirmed that it gave a proper margin of safety for all specimens studied in this paper.