• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.338-341
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• 2018

Wireless Power Transfer(WPT) of array antenna applied to beam-forming techniques enables highly efficient WPT when transmitters and receivers are not contacting and even when they are separated. However, this WPT method is possible to use only when human safety restriction by distance between the transmitters and the receivers is satisfied. In the paper, a $4{\times}8$ array antenna for 2.4 GHz is modeled by simulation, then electric field intensity and 10 gram average head SAR(Specific Absorption Rate) by distance away from the array antenna inputted 1 W of 2.4 GHz sinusoidal wave at each single antenna of the array antenna for 2.4 GHz were obtained. And they were compared with human safety restriction of draft of 2018 ICNIRP(International Commission on Non-Ionizing Radiation Protection) guidelines. As the result, power density of far field derived from the electric field intensity was $33.257W/m^2$, which satisfied with occupational human safety restriction but exceeded public's. In addition, the 10 gram average head SAR exceeded the human safety restriction.

• Journal of the Korean Society for Library and Information Science
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• v.51 no.3
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• pp.163-188
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• 2017

This study aims to propose disaster safety information service model based on LOD for effective management and dissemination of the information. To achieve the aim of this study, current state of disaster safety information was analyzed through online search and face-to-face interviews, and then the information was divided into 6 types. Finally, this study proposed specific process of building disaster safety information LOD service with considerations reflecting the information characteristics. The process for building LOD was based on Guidelines for Building Linked Data written by National Information Society Agency. Especially, ontology concept model was defined by using standard lexical resources and modeling tools based on 6 types of disaster safety information, and classes and properties were proposed. The results of this study will make disaster safety information more useful for common people.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.6 s.312
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• pp.16-26
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• 2006

In this paper, we propose a 3D shape restoration system which measures height and surface shape of transparent ITO glass and delivers errors in focal length and incident angle of laser beam to femto-second laser micromachining. The proposed system is composed of a line scan laser, a high resolution camera, a linear motion guide synchronized to image capturing, and a control station. Also, we define the sensitivity indices that represent a relation between measurement error and a position of a camera and scan laser, and utilize it for optimum design. The results of the proposed system are compared with results of SPM(Scanning Probe Microscope) and prove the usefulness of the system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5357-5365
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• 2013

In this paper, we propose that a model based design for a electric tractor system by using ASM(Automotive Simulation Models). Before developing a realistic electric tractor, it is essential that defining the capacities of power sources and optimizing the parameters of electric tractor. In additionally, because the electric tractor must have not only driving function but also working function, two PMSM are used at electric tractor. ASM which is based on simulink and Carsim were used to design a electric system and powertrain of electric tractor. For verifying the electric tractor system, we compared the design parameters such as max power, state of charge, drive distance, velocity which were carried out by the simulation and experimental method. The predicted results by the development model were in good agreement with the simulation results. According to simulation of tractor, it is possible to arrange the advanced research of dynamical characteristic of tractor and present the guidelines for the electrical driving system.

• Journal of the Korea Institute of Building Construction
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• v.19 no.1
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• pp.77-86
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• 2019

Due to the increasing demand for and complexity of plant construction projects, unpredictable risk factors are on the consequent increase. For that reason, the quantitative risk analysis is being called for, in order for the development of a risk assessment model using risk indicators for the plant construction projects. This study used the claim payout data collected at a global insurance company to reflect the actual financial losses in plant construction projects as dependent variables in the risk assessment model. In terms of independent variables, the geographic information, i. e., landform, and the construction information including test-run, schedule rate, total cost and duration are adopted. In addition, this study suggests that the regression model containing such independent variables that are statistically significant can be applied to as a foundational guideline for the plant construction project risk analysis during the phase of construction and commissioning.

• Journal of the Korea Society of Computer and Information
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• v.27 no.1
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• pp.23-32
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• 2022

Image production using three-dimensional (3D) programs undergoes a process called rendering to visualize 3D data. Because this process is time-consuming and costly, the reduction of rendering cost has emerged as an important problem that requires resolution. This work aims to overcome the limitations of the current 3D image production pipeline and propose a method for reducing the production time by adopting a game engine for real-time rendering. In the experiment conducted in this study, rendering using Maya (a 3D production program) and Unity were compared and analyzed. The analysis results indicate that Unity enables rendering in real time; consequently, the rendering cost is reduced. Moreover, the quality of the rendered image is similar to that produced by Maya. The proposed technique involves reducing the render time and providing guidance through access to a real-time rendering engine.

• Spatial Information Research
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• v.23 no.1
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• pp.1-8
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• 2015

The purpose of this study is to develope BIM Template according to major building material for efficiently and quantitatively evaluating greenhouse gas emission at the design stage. Template users consider various environmental impacts without connecting simulation tools for analyzing environmental impact and Template users who have no prior knowledge can Life Cycle Assessment by using The green template. For this study, Database which was reflected in template was constructed considering environmental performance. and 6 kinds of environmental impact categories and PPS standard construction codes were analyzed by major building material derived from literature. Based on this analyzed data, The major Material Family according to the main building material was developed. When users conduct modeling by utilizing Family established, evaluating result can be confirmed in the Revit BIM Modeling program by using the schedule function of the Revit. Users through the modeling, the decision-making environment performance possible. In addition, we propose to create a guideline for the steps required to build an additional established family.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.1
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• pp.51-61
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• 2014

It is necessary to perform a dynamic analysis to numerically evaluate the effect of blasting on nearby facilities. The blast load time history, which cannot be directly measured, is most often determined from empirical equation. The load has to be adjusted to account for various factors influencing the load and the frequency, but there is not a clear guideline on how to adjust the load. In this study, a series of 2D dynamic numerical analyses that simulates a closely monitored test blasting is performed, from which the blast load that matches the measured vibrations are derived. In the analyses, it is assumed that the hole generated by the blasting is in the form of a circle, and the load was applied normally to the wall of the opening. Special attention was given in selecting the damping ratio for the ground, since it has important influence on the wave propagation and attenuation characteristics of the blast induce waves. The damping ratio was selected such that it matches favorably with the attenuation curve of the measurement. The analyses demonstrate that the empirical blast load widely used in practice highly overstimates the vibration since it does not account for the energy loss due to rock fragmentation. If the empirical load is used without proper adjustment, the numerical analysis may seriously overstimate the predicted vibration, and thus has to be reduced in the analysis.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1155-1160
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• 1999

The screening methodology modeling, dispersion modeling procedures for continuous and instantaneous releases of the gas phase flow from the storage tank and pressure relief valve were considered. This study was performed to develop the screening methodology for prediction and control of hazardous/toxic gas releases by estimating the 1-hr average maximum ground-level concentration of $Cl_2$ gas vs. downwind distance by incorporating source term model including the general/physical properties of released material and release mode of the $Cl_2$ storage tank of the chemical plant facilities, dispersion model, and meteorological/topographical data into the TSCREEN model. As the results of the study, it was found that dispersion modes of the dense gas were affected by the state of the released material, the released conditions, physical-chemical properties of released material, and the released modes (continuous and instantaneous releases), and especially largely affected by initial (depressurized) density of the released material and release emission rate as well as the wind velocity. Especially, this study was considered to release hazardous material as meteorological data. It was thought that this screening methodology can be useful as a preliminary guideline for application of the refined analysis model by developing the generic sliding scale methodology for various senarios selected.

• Smart Media Journal
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• v.9 no.4
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• pp.176-186
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• 2020

The size and shape of crops are diverse, and the growing environment is also different. Therefore, when one uses a drone to spray pesticides, the characteristics of each crop must be considered, and flight conditions such as the flight height and forwarding velocity of the drone should be changed. The droplet flow of pesticides is affected by various flight conditions, and a large change occurs in the sprayed area. As a result, an uneven distribution of liquid may be formed at the wake, and the transport efficiency will be decreased as well as there would be a risk of toxic scatter. Therefore, this paper analyzes the degree of distribution of pesticides to the crops through numerical analysis when pesticide is sprayed onto the selected three crops with different characteristics by using agricultural drones with different flight conditions. On the purpose of establishing a guideline for spraying pesticides using a drone in accordance with the characteristics of crops, this paper compares the amount of pesticides distributed in the crops at the wake of nozzle flow using the figure of merit, and the sum of transported liquid rate divided by the root mean square of the probability density function.