• Journal of Digital Contents Society
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• v.8 no.3
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• pp.263-267
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• 2007

From our analysis of pedestrian walking behavior at the Daegeon underground shopping center, we think that the following changes might be necessary to improve sign placement and use. First, the discrepancy between the location of information signs and their rate of use should be reduced. Second, differences in information given by the signs that arise from problems with sign height and placement should be reduced. Third, signs should be distributed in such a way that they provide co-ordinated information about points and places. Fourth, the arrangement and placement of the signs should be considered from the view point of pedestrian walking behavior. Because there is difference in the number of installed signs and the rate of use of these signs, to increase the rate of information use it may be necessary to adjust the content and placement of the signs. Furthermore, analysis of subject walking paths shows that it is necessary for information to be offered about connections between spaces.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.1 s.9
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• pp.71-80
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• 1997

This paper suggests a Map Accuracy Standards by analyzing U.S. National Map Accuracy Standards, by considering korean terrain feature and statistical error theory for paper and digital maps on the scale of 1:50,000. Map accuracy standards require horizontal accuracy to be reported as a circular error with 90% confidence level through Linear Error Probable(LEP) theory and Circular Error Probable(CEP) theory. In order to verify the proposed methodology for positioning accuracy testing, several kinds of test point were selected and tested. These test points were extracted at the centers of roads and bridges, the comers of the independent building, the edges of geographical botany, and the tops of mountains. The positioning accuracy assessment was peformed by comparing the positions of test points in digital maps generated three different sources with those acquired by high accurate GPS surveying. The digital maps were produced from aerial photographs and SPOT satellite image using analytical plotter and 1:50,000 paper map.

• Journal of the Korean Society for Railway
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• v.14 no.1
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• pp.11-18
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• 2011

This paper proposed a new 2-D multi-body dynamic modeling technique to analyze overriding behaviors taking place during train collision. This dynamic model is composed of nonlinear springs, dampers and masses by considering the deformable characteristics of carbodies as well as energy absorbing structures and components. By solving this dynamic model for rollingstock, energy absorbing capacities of collision elements, accelerations of passenger sections, impact forces applied to interconnecting devices, and overriding displacements can be well estimated. For a case study, we chose KHST (Korean High Speed Train), obtained crush characteristic data of each carbody section from 3-D finite element analysis, and established a 2-D multi-body dynamic model. This 2-D dynamic model was simulated under the train-to-train collision scenarios, and evaluated with 3-D virtual testing model. It was founded from the simulation results that this 2-D dynamic model could well predict overriding behaviors, and the modeling technique of carbody deformation was very important in overriding estimation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.51-56
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• 2020

Measurement accuracy and required time is important to make ATE(Automatic test equipment) system in Ka band, and SCPI commands of power meter which is a representative RF test equipment are studied in this paper. Comparison data between FETCH and MEASURE which are SCPI commands are measured in 30 G ~ 31 GHz and -70 ~ +20 dBm using two power sensor. The data show that FETCH which is the fastest SCPI is able to get reliable data in linear interval above noise level. MEASURE which is the best accurate command takes longer time than FETCH, and the longest time is 13.2 seconds. These results offer that measurement accuracy and required time of the two SCPI for power meter and would be used as a guideline for efficient ATE system in Ka band.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1845-1850
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• 2014

Railway operators have given a lot of efforts to determine the railway route of the minimum cost. In order to determine the optimal alignment, the alignment should be allocated satisfying the design criteria on various geographical condition with the minimum earth works. The determination of the optimal railway alignment is a kind of combination optimization because that must consider various design elements. This study developed a numerical model to determine the optimal railway alignment with the minimum construction cost. The problem was analyzed by the genetic algorithm, and the concept of the optimal alignment was established with the results from the analyses. The methodology was applied to a fictitious rail construction section and the result was evaluated. This methodology is meaningful considering the fact that the cost for energy is greater than that of the construction.

• Journal of the Korean Institute of Intelligent Systems
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• v.6 no.4
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• pp.71-80
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• 1996

This paper presents stabilization and position control of the Inverted-Pendulum system with cart by using Evolution Strategies that is one of the Evolutionary Computation and is effective in searching real number. The control input of the Inverted-Pendulum is the element of chromosome corresponding to the divided space of Inverted-Pendulum state variable x, x, 0, 0 . In general, the larger the length of the chromosome is, the longer the time of evolution to search optimal solution is. So in this paper, we propose a scheme that reduce the state space by half by taking the method, that is, converting only the sign of the control input without obtaining separately for the symmetrical sections of the Inverted-Pendulum to improve the speed of Evolution, and improved the efficiency of the entire system in addition to the improvement of the chromosome's evolution time by carrying out the chromosome's evolutional process by two steps one of which is that cart is positioned near the control point and the other cart is positioned far from that point. We propose another method that is Neural Network-Evolution StrategiedNN-ES) Controller. We verify the effectiveness of the proposed control scheme by computer simulations.

• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.705-710
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• 2018

An electrochemical glucose sensor with enzyme-free was fabricated using Pt nanoparticles (Pt NPs) decorated CuO nanoflowers (CuO NFs). 3-D CuO nanoflowers film was directly synthesized on Cu foil by a simple hydrothermal method and Pt NPs were dispersed on the petal surface of CuO NFs through electrochemical deposition. This prepared sample was noted to Pt NPs-CuO NF. Morphology of the Pt NPs-CuO NFs layer was analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The electrochemical properties and sensing performances were investigated using cyclic voltammetry (CV) and chronoamperometry (CA) under alkaline condition. The sensor exhibited a high sensitivity, wide liner range and fast response time. Its excellent sensing performance was attributed to the synergistic effect of the Pt NPs and CuO nanostructure.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.5
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• pp.582-589
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• 2003

This paper presents the robust stability analysis and design methodology of the fuzzy feedback linearization control systems. Uncertainty and disturbances with known bounds are assumed to be included Un the Takagi-Sugeno (TS) fuzzy models representing the nonlinear plants. $L_2$ robust stability of the closed system is analyzed by casting the systems into the diagonal norm bounded linear differential inclusions (DNLDI) formulation. Based on the linear matrix inequality (LMI) optimization programming, a numerical method for finding the maximum stable ranges of the fuzzy feedback linearization control gains is also proposed. To verify the effectiveness of the proposed scheme, the robust stability analysis and control design examples are given.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.3
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• pp.1-9
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• 1998

The exhaustion of fossil fuels and serious environmental pollution put the concern about non-po llution energy into the world. On the developments of technology, wind energy has been spotlighted as a non-pollution energy in many countries. This study has carried out the aerodynamic and structural design procedure of the lightweight composite rotor blades with an appropriate aerodynamic performance and structural strength for the 500㎾ medium class wind turbine system. The previous design, which is shell-spar structure, is redesigned to shell-spar- sandwich structure for light weight. Large deformation problem from light weight is examined by non-linear analysis. Local buckling occurred under lower stress than failure stress. The buckling analysis is accomplished to confirm the safety of the composite blade. The stress analysis around pin hole joint part at hub is carried out and it is confirmed that the pin hole is not failed. The results show that the resonance of redesigned blade does not happen in operation range.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.6
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• pp.31-38
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• 2009

To improve the image quality and lower the power consumption of the mobile applications, it is the one of the best candidate to control the backlight unit of the LCD module with ambient light. Ambient light sensor and readout circuit were integrated in LCD panel for the mobile applications, and we designed them with LTPS TFT. We proposed noble start-up correction in order to correct the variation of the photo sensors in each panel. We used time-to-digital method for converting photo current to digital data. To effectively merge time-to-digital method with start-up correction, we proposed noble dual slope correction method. The entire readout circuit was designed and estimated with LTPS TFT process. The readout circuit has very simple and stable structure and timing, so it is suitable for LTPS TFT process. The readout circuit can correct the variation of the photo sensors without an additional equipment, and it outputs the 4-levels digital data per decade for input luminance that has a dynamic range of 60dB. The readout rate is 100 times/sec, and the linearity error for digital conversion is less than 18%.