• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.211-222
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• 2000

The design values of rock socketed pile related with properties of rock mass are not clearly established. However, the drilled shafts socketed in rock are widely used as the foundation of large scaled structure. In this study, the characteristics of behavior of rock socketed pile is researched, and the properties of interface between pile and rock considering soil-structure interaction are evaluated for numerical modeling of rock socketed pile based on the previous researches. Based on the properties of interface and rock mass, the behaviors of rock socketed piles are numerically modeled and compared with field measurement. To verify the numerical analysis, a micro pile socketed in rock is modeled and the results of numerical analysis are compared with field measurement. The numerical results show a good agreement with field measured data, especially in terms of load transfer characteristics.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.304-311
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• 2012

So far, the importance for an accurate load model has been constantly raised and its necessity would be further more emphasized. Currently used load model for analysis of power system in Korea was developed 10 years ago, which is aggregated by applying the statistically estimated load compositions to load models based on individual appliances. As modern appliances have diversified and rapidly changed, the existing load model is no longer compatible with current loads in the Korean power system. Therefore, a measurement based load model is more suitable for modern power system analysis because it can accurately include the load characteristics by directly measuring target load. This paper proposes a ZIP model employing a Kalman-filter as the estimation algorithm for the model parameters. The Kamlan-filter based parameter identification offers an advantage of fast parameter determination by removing iterative calculation. To verify the proposed load model, the four-second-interval real data from the Korea Energy Management System (K-EMS) is used.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.3
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• pp.331-336
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• 2013

In this paper, plasma modeling is achieved using fluid dynamics, thereby electron density is derived. The way proposes the key to overcoming the limitations of conventional researches which adopt simplified plasma model. The result is coupled with Maxwell-Boltzmann system in order to calculate scattering waves in various incident angle. The first part is dedicated to perform plasma modeling in dielectric barrier discharge(DBD) structure. Suzen-Huang model is adopted among various models due to the fact that it uses time independent variables to calculated potential and electron distribution in static system. The second part deals with finite difference time domain(FDTD) scheme which computes the scattered waves when the modulated Gaussian pulse is incident. Founded on it, radar cross section(RCS) is observed. Consequently, RCS is decreased by 1~2 dB with DBD plasma. The result is analogous to the RCS measurement in other researches.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.977-982
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• 2007

There have been many efforts in automatic object recognition using computing technologies. Especially in the development of automated construction equipment, automatic object recognition is very important issue for the proper equipment maneuvering. 3D laser scanning, which uses (time-of-flight) method to construct the 3-dimensional information, is applied to the civil earth work environment for its high accuracy, quick data collection, and object recognition capability that will be developed by the authors in the future. The 3D earth model is also used as a fundamental information for intelligent earth work task planning. This paper presents the analysis of the 3D laser scanner market and selection of the most optimum 3D scanner for the intelligent earth work planning. As well as the hardware configuration for the automated 3D earth modeling is developed but also the software structure and detailed user interface are designed in this research. In addition, it is presented in this paper that the accuracy comparison test between TotalStation(R) which is a traditional survey tool and ScanStation(R). The accuracy test is done by relative distance measurement using known targets.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.3
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• pp.21-27
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• 2010

When the capacity of underground caverns' structures is measured, a general surveying is difficult to decide an accurate section of irregular shape and a photographic surveying has problems on picture acquisition due to underground dusts, noise and lighting conditions, etc. The laser scanner system is being much used for 3-dimensional modeling such as topography, planimetric features and structures, etc. without a target by measuring arriving time of a laser pulse reflected after scanning the laser pulse and calculating space coordinates of the reflection position. Accordingly, the present research carried out section and earthwork volume measurement of a tunnel by using a laser scanner in underground anchorage excavation work that a bridge construction is being executed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.8
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• pp.783-789
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• 2017

In terms of 3D orientation estimation based on nine-axis IMMU(inertial and magnetic measurement unit), there are two disturbance components decreasing estimation accuracy: one is external acceleration disturbing accelerometer's signals and the other is magnetic disturbance related to magnetometer's signals. In order to minimize effects by these two disturbances, two approaches including switching approach and model-based approach have been suggested and further research comparing these two has also been conducted. Nevertheless, effect of disturbance modeling differences on orientation estimation accuracy in model-based approach has not been studied before. This paper compares the recently reported two orientation estimation algorithms that have difference in disturbance models, in order to investigate the effect of disturbance models on accuracy of IMMU-based orientation estimation under various operating conditions. This research shows that the difference in disturbance models leads to difference in process noise covariance matrix. Consequently, this affected the orientation estimation, i.e., the estimation differences between the algorithms were root mean square errors of $1.35^{\circ}$ in average and $3.63^{\circ}$ in yaw estimation.

• Journal of Korea Multimedia Society
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• v.12 no.4
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• pp.521-529
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• 2009

In this paper, we present a vision-based human primitive motion recognition method. It models the reference motion patterns, recognizes a user's motion, and measures the similarity between the reference action and the user's one. In order to recognize a motion, we provide a pattern modeling method based on the Hidden Markov Models. In addition, we provide a similarity measurement method between the reference motion and the user's one using the editing distance algorithm. Experimental results show that the recognition rate of ours is above 93%. Our method can be used in the motion recognizable games, the motion recognizable postures, and the rehabilitation training systems.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.621-627
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• 2017

In this study, GPS (Global Positioning System) is applied to rollers for quality control problems caused by empirical judgment of compaction construction. In addition, database and 3D modeling of location information can eliminate unnecessary compaction or excessive compaction, thereby improving quality and shortening the time. This paper presents a methodology of ICMV (Intelligent Compaction Measurement Values) analysis by designing a intelligent compaction method using an accelerometer. Detailed method of ICMV analysis includes CMV (Compaction Meter Value) analysis which can quickly and conveniently evaluate the compaction of the compacted ground.

• Journal of Korean Elementary Science Education
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• v.32 no.2
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• pp.139-158
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• 2013

This study investigated elementary students' (grade 4~6) learning progressions for water cycling drawn from iterative assessments using ordered multiple-choice (OMC) items. An assessment system, which consisted of construct map, item design, outcome space, and measurement model, was employed in this study to examine children's learning progressions. At the first stage of the assessment system, a construct map was designed on which children's conceptual understandings from naive to most sophisticated were represented. At the item design stage, 8 OMC items were drawn from the construct map. Each item option of the OMC items was scored from 0 to 3 according to its level of understanding at the stage of outcome space. As a measurement model, Rasch model, a branch of item response theory, was applied to interpreting the outcomes of the OMC items. This cycle of assessment system was furtherly implemented iteratively in order to elaborate on the first version of water cycling learning progression. In conclusion, children's understanding of water cycling could be described in two aspects: water distribution and water movement. We identified children's conjectural developmental pathways about water cycling existed from superficial and naive accounts to more complex and abstract accounts.

• Journal of Energy Engineering
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• v.22 no.4
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• pp.338-346
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• 2013

The conventional lead acid battery is optimized for cranking performance of engine. Recently electric devices and fuel economy technologies of battery have influenced more deep cycle of dynamic behavior of battery. I also causes to reduce battery life-time. This study proposed that aging battery model is focused for increasing of battery durability. The stress factors of battery aging consist of discharge rate, charging time, full charging time and temperature. This paper considers the electrochemical kinetics, the ionic species conservation, and electrode porosity. For prediction of battery life cycle we consider battery model containing strong impacts, corrosion of positive grid and shedding. Finally, we validated that modeling results were compared with the accelerated thermal measurement data.