• Journal of the Korean Geographical Society
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• v.44 no.6
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• pp.761-778
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• 2009

This study investigates and proves the historical facts about the confidential land survey on Korean peninsula made by Japanese intelligence officers at the end of Chosun Dynasty. Under the command of general staff office of Japanese army, the military officers produced several maps through road map measurements and visual measurements. Although previous literature indicated road map measurements on Korea were originally implemented from 1885, this study confirms that road map measurements were initiated in 1882 by a lieutenant Isobayashi. Reflecting secret map making procedures, the individual military intelligence officers had specialized roles for swift information collection and map production.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.7
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• pp.1044-1049
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• 1993

In this paper, it is shown that B-CDMA systems inherently reduce the effects of Multi Path fading phenomena which causes to degrade the performance of mobile communication systems. B-COMA systems use PN codes of high chip rates ( > 10 Mbps) and evaluate autocorrelation with the same code in the receiver. Therefore, it is possible that multipath signals, whose delay time is longer than one chip duration compared to the first signal, are removed. We model the wideband fading channel as a suitable linear filter, and perform computer simulation of signal transmission and reception. Graphic comparison of eye diagrams between the narrowband and wideband systems is shown.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.1
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• pp.180-187
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• 1997

A formula for estimating the elastic stiffness of TW-HDS with a uniformly tapered width from w$_{0}$ to w$_{1}$ over the length, has been analytically derived based on Euler beam theory and Castigliano's theorem. Elastic stiffnesses of the TW-HDSs designed in the same dimensional design spaces as the KOFA HDSs have been estimated from the derived formula, in addition, a sensitivity study on the elastic stiffness of the TW-HDSs has been carried out. Analysis results show that elastic stiffnesses of the TW-HDSs have been by far higher than those of the KOFA HDSs, and that, as the effects of axial and shear force on the elastic stiffness have been 0.15-0.21%, most of the elastic stiffness is attributed to the bending moment. As a result of sensitivity analysis, the elastic stiffness sensitivity at each design variable is quantified and design variables having remarkable sensitivity are identified. Among the design variables, leaf thickness is identified as that of having the most remarkable sensitivity of the elastic stiffness.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.3 s.73
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• pp.233-238
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• 2006

In this paper, mixed mode magneto-rheological(MR) damper, which is applicable for vibration control of a small scale multi-story structure, is devised. First, the schematic configurations of the shear, flow, and mixed mode MR dampers are described with design constraints and then the analytical models to predict the field-dependent damping forces are derived for each type. Second, an appropriate size of the mixed mode MR damper is manufactured and its field-dependent damping characteristics are evaluated in time domain. Finally, the performance of the manufactured MR damper which is semi-actively applied to a small scale building excited by earthquake load, is numerically evaluated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.7
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• pp.873-881
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• 1997

A numerical simulation has been carried out for three-dimensional turbulent flows around an Ahmed body. The Reynolds-averaged Navier-Stokes equation is solved with the SIMPLE method in general curvilinear coordinates system. Several k-.epsilon. turbulence models with two convective difference schemes are evaluated for the performance such as drag coefficient, velocity and pressure fields. The drag coefficient, the velocity and pressure fields are found to be changed considerably with the adopted k-.epsilon. turbulence models as well as the finite difference schemes. The results of simulation prove that the RNG k-.epsilon. model with the QUICK scheme predicts fairly well the tendency of velocity and pressure fields and gives more reliable drag coefficient. It is also demonstrated that the large difference between simulations and experiment in the drag coefficient is due to relatively high predicted values of pressure drag from vertical rear end base.

• Archives of design research
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• v.20 no.3 s.71
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• pp.39-48
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• 2007

This study explored the Eye Movement, the horizontal and vertical flow of vision, and genetic, cultural and empirical schema, and the differentiation of the visual system of the cerebrum through the engineering psychological or the cognitive neuroscientific experiments measuring Eye Movement to maximize the efficiency of the Public Sign System in the urban environment. Accordingly, the study derived an algorithm that can bring out the most efficient visual design measurement by using EMR test and bitmap counting method. The scientific test data in this study will show the existence of the momentum of differentiation and visual sampling by the Schema and Sensory Qualia of the human.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.3
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• pp.193-200
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• 2009

Purpose：In this study is to verify the effects postural control training based on Bobath approach for body schema and visual perception on Middle Cerebral Artery(MCA) Infarcts. Methods：The subject was a 46 years old man with MCA infaction, lives in B city. An AB design for a single-subject research was used for this study. The procedures consisted of 1 time of baseline phase(A), 20 times of treatment phase(B). We applied the Bobath approach at the subject. Treatments included to facilitate trunk alignment and stability, and to train weight bearing and shifting, to facilitate pelvis movement, and to train walk especially stance phase and assist up-down stairs locomotion in environment similar to actual daily life. Results：With this treatment, the majority of body schema and visual perception and postural control was improved in treatment phase compared with in baseline phase. Therefore, this study supported the effectiveness of postural control training based on Bobath approach for body sechma and visual perception of hemiplegia. Conculusion：This study is integrated postural control training with Bobath approach that are widespread for hemiplegia and measured outcomes based on individualized therapy goals. Consequently the study is suggested the meaning of quality effectiveness of Bobath approach.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.8
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• pp.1276-1290
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• 1997

The previous elastic stiffness formulas of leaf type holddown spring assemblies(HDSs) have been corrected and extended to be able to consider the point of taper runout for the TT-HDS and all the strain energies for both the TT-HDS and the TW-HDS based on Euler beam theory and Castigliano'stheorem. The elastic stiffness sensitivity of the leaf type holddown spring assemblies was analyzed using the derived elastic stiffness formulas and their gradient vectors obtained from the mid-point formula. As a result of the sensitivity analysis, the elastic stiffness sensitivity at each design variable is quantified and design variables having remarkable sensitivity are identified. Among the design variables, leaf thickness is identified as that of having the most remarkable sensitivity of the elastic stiffness. In addition, it was found that the sensitivity of the leaf type HDS's elastic stiffness is exponentially correlated to the leaf thickness.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1285-1293
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• 1992

The fracture behavior of glass/epoxy plain woven composite plates containing circular holes is experimentally investigated to examine the effects of hole size and specimen width on notched tensile strength. It is shown in this paper that the characteristic length according to the point stress criterion depends on the hole size and specimen width. For predicting the notched tensile strength, a modified failure criterion is developed. An excellent agreement is found between the experimental results and the analytical prediction of modified failure criterion. The notched strength and the characteristic length have an increase and decrease relations. When the unstable fracture occured, the critical crack length equivalent for the damage zone size at the edge of hole is about twice the characteristic length. The critical energy release rate G$_{c}$ is independent of hole size(0.03 .leq. 2R/W .leq. 0.5) under the same specimen width. However G$_{c}$ increases with an increase in specimen width which can be explained by stress relaxation due to the notch insensitivity.ity.

• Journal of Educational Research in Mathematics
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• v.23 no.2
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• pp.237-252
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• 2013

The philosophy of science of Bachelard is introduced mainly with epistemological obstacles in the discussions within mathematics education. In his philosophy, epistemological obstacles are connected with the dialectical developments of science. Science progresses through generalization of concepts and theories by negating things which were recognized as obvious. These processes start with ruptures against the existing knowledge. Epistemological obstacles are failure in keeping distance with the existing knowledge when reorganization is needed. This concept means that there are the inherent difficulties in the processes of concept formation. Finally I compare the view of Bachelard on the developments of science and the 'interiorization-condensation-objectification' scheme of reflexive abstraction in mathematics education and discuss the inherent difficulties in the learning mathematics.