• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.6
• /
• pp.1441-1455
• /
• 2017

In order to build a secure electric vehicle charging infrastructure, security research is required because various data including charging and payment data are transmitted in the electric vehicle charging infrastructure. However, previous researches have focused on smart grid related security research such as power system infrastructure rather than charging infrastructure for electric vehicle charging. In addition, research on charging infrastructure is still lacking, and research using a systematic methodology such as threat modeling is not yet under way. Therefore, it is necessary to apply threat modeling to identify security threats and systematically analyze security requirements to build a secure electric vehicle charging infrastructure. In this paper, we analyze the electric vehicle charging infrastructure by accurately identifying possible threats and deriving objective security requirements using threat modeling including Data Flow Diagram, STRIDE, and Attack Tree.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.411-416
• /
• 2020

Field investigations of forests are carried out by writing measured data by hand, and it is a hassle to reorganize the results after a field survey. In this study, a method using object modeling and augmented reality (AR) was applied in a test forest to increase the efficiency of a field investigations. Using a 3D laser scanner, data on were acquired 387 trees within an area of 1 ha at the study site. The coordinates, height, and diameter were calculated through object extraction and modeling of a tree. The proposed can reduce the time required to acquire data in the field and can be used as basic data for building related systems. In addition, the modeling results of trees and a survey using GNSS and AR techniques can be used check coordinates, labor, and attribute information, such as the chest height diameter of the trees being surveyed in the field. The shortcomings of the survey method could be improved. In the future, the method could greatly improve the efficiency of tree surveys and monitoring by reducing the manpower and time required for field surveys.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1101-1106
• /
• 2005

The purpose of this study was to develop a process management system to manage ingot fabrication and the quality of the ingot. The ingot is the first manufactured material of wafers. Operating data (trace parameters) were collected on-line but quality data (measurement parameters) were measured by sampling inspection. The quality parameters were applied to evaluate the quality. Thus, preprocessing was necessary to extract useful information from the quality data. First, statistical methods were employed for data generation, and then modeling was accomplished, using the generated data, to improve the performance of the models. The function of the models is to predict the quality corresponding to the control parameters. The dynamic polynomial neural network (DPNN) was used for data modeling that used the ingot fabrication data.

• Journal of the Korea Safety Management & Science
• /
• v.14 no.2
• /
• pp.185-192
• /
• 2012

It has been a huge amount of capacity of 10GB data base in a decade ago so far. Nowadays, however, 10TB is the common data base and even bigger capacities are available. So, new generation of Very Large Data Base (VLDB) has begun. Moving in to the new generation of VLDB has been caused major problems like backing up, restoring, and managing especially performance. It is very hard to export necessary data rapidly now due to the huge amount of data base. In the past, such kind of problems was out of the questions because of less data. As time goes on, however, optimization of performance became a big issue when the VLDB is common. Therefore, new professional technics are urgently required to maintain and optimize the data base that has become a VLDB or one that is in the progress of becoming one.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.28 no.2
• /
• pp.139-155
• /
• 2003

The aim of this study is to identify the data traffic capacity of 3G mobile communication networks, especially of cdma2000-1X networks. Three-layered ON/OFF traffic model is used to describe the dynamics of data traffics and the process of data transmission such as packet scheduling. We construct a simulator fully incorporating packet handling process of cdma2000-lX data network as well as three-layered ON/OFF traffic model describing the behavior of source data traffics. To get influence of traffic parameters on performance measures, the extensive simulations were performed for several data sets which are obtained from real trace data or previous studies. The experimental results show that the engineered throughput satisfying QoS criteria is approximately 25% of total capacity. Finally, some proposals to improve the system capacity are followed.

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.10
• /
• pp.1043-1049
• /
• 2012

The FEM analysis of machine tools is the general analysis process to evaluate machine performance in the industry for a long time. Despite advances in FEM software, because of difficult simplicity of CAD drawing, little experience of joints stiffness modeling and troublesome manual contact area divide for bindings, the industry designers think the FEM analysis is still an area of FEM analysis expert. In this paper, the automation of modeling process with simplicity of drawing, modeling of joints and contact area divide is aimed at easy FEM analysis to enlarge utilization of a virtual machine tools. In order to verify the effects of modeling automation, a slant bed type model with tilting table is analyzed. The results show FEM modeling automation method only needed 45 minutes to complete the whole modeling process, while manual modeling method requires almost one month with 8200 calculations for coordinate transformations and stiffness data input.

• Korean Journal of Construction Engineering and Management
• /
• v.5 no.5 s.21
• /
• pp.163-171
• /
• 2004

This research investigates a Modeling Spell Checker that, similarly to Word Spell Checker for word processing software, would conform as-built 3D models to standard construction rules. The work is focused on the study of pipe-spools. Specifically pipe diameters and coplanarity are checked and corrected by the Modeling Spell Checker, and elbows are deduced and modeled to complete models. Experiments have been conducted by scanning scenes of increasing levels of complexity regarding the number of pipes, the types of elbows and the number of planes constituting pipe-spools. For building models of pipes from sensed data, a modeling method, developed at the University of Texas at Austin, that is based on the acquisition of sparse point clouds and the human ability to recognize geometric shapes has been used Results show that primitive-based models obtained after scanning construction sites can be corrected and even improved automatically, and, since such models are expected to be used as feedback control models for equipment operators, the higher modeling accuracy achieved with the Modeling Spell Checker could potentially increase the level of safety in construction. Result also show that some improvements are still needed especially regarding the co-planarity of pipes. In addition, results show that the modeling accuracy significantly depends on the primitive modeling method, and improvement of that method would positively impact the modeling spell checker.

• Geophysics and Geophysical Exploration
• /
• v.11 no.1
• /
• pp.26-33
• /
• 2008

The analysis of wide-angle seismic reflection and refraction data plays an important role in lithospheric-scale crustal structure study. However, it is extremely difficult to develop an appropriate velocity structure model directly from the observed data, and we have to improve the structure model step by step, because the crustal structure analysis is an intrinsically non-linear problem. There are several subjective processes in wide-angle crustal structure modelling, such as phase identification and trial-and-error forward modelling. Because these subjective processes in wide-angle data analysis reduce the uniqueness and credibility of the resultant models, it is important to reduce subjectivity in the analysis procedure. From this point of view, we describe two software tools, PASTEUP and MODELING, to be used for developing crustal structure models. PASTEUP is an interactive application that facilitates the plotting of record sections, analysis of wide-angle seismic data, and picking of phases. PASTEUP is equipped with various filters and analysis functions to enhance signal-to-noise ratio and to help phase identification. MODELING is an interactive application for editing velocity models, and ray-tracing. Synthetic traveltimes computed by the MODELING application can be directly compared with the observed waveforms in the PASTEUP application. This reduces subjectivity in crustal structure modelling because traveltime picking, which is one of the most subjective process in the crustal structure analysis, is not required. MODELING can convert an editable layered structure model into two-way traveltimes which can be compared with time-sections of Multi Channel Seismic (MCS) reflection data. Direct comparison between the structure model of wide-angle data with the reflection data will give the model more credibility. In addition, both PASTEUP and MODELING are efficient tools for handling a large dataset. These software tools help us develop more plausible lithospheric-scale structure models using wide-angle seismic data.

• Journal of the Korean School Mathematics Society
• /
• v.20 no.2
• /
• pp.187-210
• /
• 2017

The animated discussion about mathematical modeling that had studied consistently in Korea since 1990s has flourished, because mathematical modeling was involved in the teaching-learning method to improve problem solving competency on 2015 reformed mathematics curriculum. In an attempt to re-examine the educational value and necessity of application to school education field, this study was to review the literature of mathematical modeling in mathematical competencies perspective. As a result, mathematical modeling could not only be involved the components of problem solving competency, but also support other competencies; reasoning, creativity-amalgamation, data-processing, communication, and attitude -practice. In this regard, This paper suggested the necessity of the discussion about the position of mathematical modeling in mathematical competencies and the active use of mathematical modeling tasks in mathematics textbook or school classes.

• Geophysics and Geophysical Exploration
• /
• v.18 no.4
• /
• pp.216-222
• /
• 2015

Airborne transient electromagnetic (ATEM) surveying was introduced several decades ago in the mining industry to detect shallow conductive targets. However, conventional ATEM systems have limited depth of investigation because of weak signal strength. Recently, the grounded electrical source airborne transient electromagnetic (GREATEM) system was proposed to increase the depth of investigation. The GREATEM is a semi-airborne transient electromagnetic system because a long grounded wire is used as the transmitter. Traditionally, ATEM sounding data have been interpreted with 1D earth models to save the computing time because modern ATEM systems generally collect large data sets. However, the GREATEM 1D modeling requires numerical integration along the wire, so it takes much more time than the 1D modeling of conventional ATEM. In this study, the adaptive Born forward mapping (ABFM) was applied to the ATEM 1D modeling because the ABFM is incommensurably faster than the ordinary GREATEM 1D modeling. Comparing the results from ordinary and ABFM 1D modeling, it was confirmed that the ABFM can be applied to the 1D modeling of GEATEM.