• Korean Journal of Remote Sensing
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• v.7 no.1
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• pp.69-86
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• 1991

An unsupervised region based image segmentation algorithm implemented with a pyramid structure has been developed. Rather than depending on thraditional local splitting and merging of regions with a similarity test of region statistics, the algorithm identifies the homogenous and boundary regions at each level of pyramid, then the global parameters of esch class are estimated and updated with values of the homogenous regions represented at the level of the pyramid using the mixture distribution estimation. The image is then classified through the pyramid structure. Classification results obtained for both simulated and SPOT imagery are presented.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.367-367
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• 2012

We investigate Landau level spectra of twisted bilayer graphene under a perpendicular magnetic field, showing that the layers provide rich electronic structure depending on misoriented angle. New types of excitations with Landau level sequences due to the reflection of interlayer coupling level are matter of interest in the present work. We calculate the electronic structure of bilayer systems with a relative small angle rotation of the two graphene layers. Calculated Landau level spectra for twisted bilayer graphene using a continuum formulation are in good agreement with existing experimental and theoretical studies. Twist angle dependent numerical simulations provide significant insights for the nature of the Landau level spectra in bilayer graphene, combining signals from both massive and massless Dirac fermions. We finally discuss the influence of the graphene layers in the experimental sample that related to the magneto-transport measurements including quantum Hall conductance.

• The Mathematical Education
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• v.39 no.2
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• pp.151-166
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• 2000

The purpose of this study is to understand what two models of SOLO taxonomy and van Hiele theory suggest and find out what relation there is between the category system of the SOLO taxonomy and the thinking level of the van Hiele theory. The van Hiele theory describes in line of ranking level so that it may increase the teaching effects by putting together a class, which takes into consideration the students thoughts. The SOLO taxonomy focused on the response mode of the students rather than the thinking level or the developmental stage of them to pursuit the method that can describe the students understanding in depth quality-wise. Although the SOLO taxonomy and the van Hiele model seem to have different form and character from outside in terms of their goals, a closer examination reveals that the two stances have much in common and that the models are complementary. Although the van Hiele placed more focus on the thoughts, because the conclusion was based on the students responses, the van Hiele theory can be interpreted within the structure identified in the SOLO model. In this study, we have tried to understand how the response structure form the SOLO taxonomy and the thinking level of the van Hiele theory are related, based on the studies of Pegg and Davery1998). If you briefly look at them, there are following corresponding relation between the SOLO taxonomy and the van Hiele theory. a) The relational level(R) in iconic moe is van Hiele level 1. b) The multisturctural level(M$_2$) in the second cycle of concrete-symbolic mode is van Hiel level 2. c) The relation level(R$_2$) in the second cycle of concrete-symbolic mode is van Hiele level 3. d) The unistructural level(U$_2$) in the second cycle of formal mode is van Hiele level 4. e) The postformal mode is van Hiele levle 5. Though it would be difficult to conclude that these correspondences were perfectly done, if you look at their relation, you can see that the learning process of the students were not carried out uniformly. Therefore, by studying the students response structure, using the SOLO taxonomy, and identifying the learning cycle and understand the geometrical concept more in depth.

• Ocean Systems Engineering
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• v.6 no.4
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• pp.345-362
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• 2016

This study aims to develop the numerical method to estimate level ice impact load and investigate the dynamic interaction between an arctic Spar with sloped surface and drifting level ice. When the level ice approaches the downward sloped structure, the interaction can be decomposed into three sequential phases: the breaking phase, when ice contacts the structure and is bent by bending moment; the rotating phase, when the broken ice is submerged and rotated underneath the structure; and the sliding phase, when the submerged broken ice becomes parallel to the sloping surface causing buoyancy-induced fictional forces. In each phase, the analytical formulas are constructed to account for the relevant physics and the results are compared to other existing methods or standards. The time-dependent ice load is coupled with hull-riser-mooring coupled dynamic analysis program. Then, the fully coupled program is applied to a moored arctic Spar with sloped surface with drifting level ice. The occurrence of dynamic resonance between ice load and spar motion causing large mooring tension is demonstrated.

• Journal of Navigation and Port Research
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• v.29 no.4
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• pp.327-333
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• 2005

Sea level (MSL, MHWL, or MLWL) change has been main concern to scientists and engineers and it can be primarily due to both change of climate and vertical movement of land. This paper reports the intensive analysis of the sea level changes and broad discussion of the future at the southwestern coast of Korean peninsula. Regression analysis was conducted to investigate general tendency and periodicity of the sea levels at the six different study sites such as Gunsan-I(inner port), Gunsan-O(outer port), Mokpo, Yeosu, Heuksan and Jeju and the results were compared with global values. Besides the changes of sea levels due to global warming, the influence of the man-made structure such as seadike and seawall was attempted to quantify using the minimization of the Root Mean Square(RMS) error. The results show that it is a general tendency that the values of mean sea level rise at the southwestern coast of Korean Peninsula, especially at Gunsan-I and Jeju, are somewhat larger compared to global average values. There is also some evidence that tidal amplifications are found just after construction of man-made structure at Gunsan-I and Mokpo. However, both sites show different mechanism in relation to tidal choking, tidal flat and river discharge. The impact due to construction of man-made structure is considerably larger at Mokpo site, while the impacts due to man-made structure and the effect of sea level rise are relatively identical at Gunsan-I site. This study is expected to provide some intuition to future design.

• Korean Journal of Remote Sensing
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• v.35 no.3
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• pp.389-400
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• 2019

Level meters are non-invasively capable of measuring the level of the medium, and a growing variety of level meters are being used in the industry in connection with safety and maintenance. The level meter can be measured according to various kinds of medium such as solid medium such as coal, flour, rice and liquid medium such as water and petroleum. In order to reduce the error depending on the medium, the measurement using the Doppler Effect can compensate the measurement error, However, the number of signal processing steps is increased, the operation speed is further increased, the hardware complexity increases, and a high cost structure is required. In this paper, we propose a method to improve the signal processing operation structure of the remote measurement level meter to reduce the amount of computation and the resource usage of the required FPGA.

• Journal of Korean Academy of Nursing
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• v.43 no.3
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• pp.321-330
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• 2013

Purpose: This cross-sectional study was done to compare factors influencing young adolescents' aggression according to family structure. Methods: Participants were 680 young adolescents aged 11 to 15 years (113 in single father families, 136 in single mother families, 49 in grandparent families, and 382 in both-parent families). All measures were self-administered. Data were analyzed using SPSS 18.0 program and factors affecting young adolescents' aggression were analyzed by stepwise multiple regression. Results: Levels of young adolescents' aggression and all variables were significantly different among the four family structure groups. Factors influencing young adolescents' aggression were also different according to these 4 groups. For single father families, depression-anxiety and family hardiness significantly predicted the level of young adolescents' aggression (adjusted R square=.37, p<.001). For single mother families, depression-anxiety, gender, and friends' support significantly predicted the level of young adolescents' aggression (adjusted R square=.58, p<.001). For grandparent families, depression-anxiety and family support significantly predicted the level of young adolescents' aggression (adjusted R square=.58, p<.001). For both-parent families, depression-anxiety, family hardiness, and friends' support significantly predicted the level of young adolescents' aggression (adjusted R square=.48, p<.001). Conclusion: Nurses working with young adolescents should consider family structure-specific factors influencing aggression in this population.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.368-376
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• 2011

This study has undertaken for the analysis of the level of recognition on the Transfer Income Tax. The statistical analysis through the questionnaire is made to find out the issues on the equitableness of Transfer Income Tax first with the level of equitableness of the Transfer Income Tax structure and appropriateness of the degree of different tax rate applied under the Transfer Income Tax, level of equitableness of the Transfer Income Tax structure and intent for avoidance of payment under the present tax policies, level of recognition for administrative disposition on those avoiding diligent payment of taxes, and it analyzed the relationship between the levels of understanding of the structure of the Transfer Income Tax and the level of complexity of the structure of the Transfer Income Tax in order to analyze if it has negative impact on the level of understanding for the structure of the Transfer Income Tax. On the basis of the above analysis result, as the improvement plan on the Transfer Income Tax system, following has been presented; enhancement of equitableness of tax rate structure under the Transfer Income Tax for improving the equitableness of tax burden, establishment of regulations to strengthen the appropriate tax investigation for prevention of diligent tax payment avoidance, relaxation of complication of the structure under the Transfer Income Tax.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.17-22
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• 2008

Construction project have extremely high risk in the process of construction owing to unexpected event, like as design amendment. As a result, owner have to endure enormous extra-cost to control the risk and continue to the project having more higher uncertainty. Also, if the structure is completed, it is needed that the structure is protected and maintained continuously during life cycle time to satisfying original aim of structure itself. LCC analysis to calculate cost of structure alternatives divides into two stage, one is design_LCC and the other is maintenace_LCC. But two stages all is needed in the transition deterioration model to calculate more reasonable LCC analysis. This paper developed the model using analysis of FMS contents and survey from professional about Prestressed concrete beam girder bridge(PC Beam bridge)in railway. The model is focused in project level of PC beam because any condition state information for element level analysis can not get up. This paper is intended to use the developed model in LCC analysis of PC Beam bridge in railway and constitute the foundation to perform more deep study in the near future.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.68-75
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• 2008

Space radiation environments depend on satellite mission orbit, period, and date, and it can be predicted by simulation. Total Ionizing Dose(TID) can be predicted by Dose-depth Curve which only inform the dose level depending on the shielding thickness. So detail effective shielding analysis considering real structure is necessary to predict part level TID. For this purpose, program is developed to calculate shielding thickness distribution by structure modeling and ray trace from certain point in the structure. Finally TID at certain point in the 3-dimensional structure can be calculated by integration of shielding distribution result and dose-depth curve data. Using this program, TID is analyzed at part level certain point by modeling of equipment box structure in the satellite.