• The Journal of Engineering Geology
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• v.11 no.2
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• pp.131-139
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• 2001

Until recently, limestone yield production is mainly depend on geological investigation and boring. In the study seismic and electrical method are applied to calculate the basic data of limestone yield production. the result of geophysical prospecting, the depth of bed rock is approximately 17m. And there is a slightly difference between the limestone layer boundary which is drawn by electrical prospecting method and that of geological investigation.

• Journal of Sensor Science and Technology
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• v.13 no.1
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• pp.72-77
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• 2004

In this paper, we fabricated an apparatus of the electro-chemical discharge drilling for boring narrow through-hole into a glass. In the electrolyte, electro-chemical discharge creates high temperature condition by the electro-discharge energy. Therefore, glass are removed by the accelerated chemical reaction with glasses and chemicals in the high temperature condition. For optimization of the electro-chemical discharge drilling, the process condition was studied experimentally as a function of the electrolyte concentration, supply voltage and process time. The optimum condition was from DC25V to DC30V of applied voltage, 35 wt% NaOH solution.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.59-62
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• 2008

Scour vulnerability evaluation for shallow foundations was performed to assure bridge safety against scour in the national capital region. The case studies for 26 shallow foundations consisted of site investigation including boring test, bridge scour analysis for the design flood, bearing capacity evaluation of the bridge foundation before and after scour, and comprehensive evaluation of bridge scour vulnerability. Bridge scour vulnerability was determined based on the interdisciplinary concept considering predicted scour depth for the design floods and bearing capacity of foundation as well as dimensions of foundation. Nine of 26 shallow foundations showed the potential future vulnerability to scour with significant decrease in the bearing capacity of foundations due to scour and the remaining 17 were expected to maintain their stability against scour.

• Tunnel and Underground Space
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• v.4 no.2
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• pp.144-155
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• 1994

This research is designed to assess current achievement levels for mechanized excavation systems in Korea adn suggest the model predictive of TBM performance using statistical approaches. A test section in the TBM construction sites is selected to measure and analyze TBM performance. The field records including operating data, time allocation into downtime catagories, and machine design are analyzed on a shift basis. There are a total of 240 shifts, with most days operating two shifts per day. Examples of the probability density functions produced from the test section are presented and discussed. Relationships between TBM penetration rate and rock physical properties are investigated and the empirical equations for TBM performance prediction are also assessed with the field data.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.599-606
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• 2019

In this study, it was aimed to find the optimal cutting conditions by measuring and analyzing the dimensional accuracy of SNCM 616 alloy steel, which is commonly used in industry, by precision hole machining using Ø25 mm and 8-blade reamer in CNC-HBM to be. As a result of the roundness and dimensional accuracy, it was found that the spindle speed had a significant effect on the dimensional tolerance value. Optimum cutting conditions are spindle speed 25 rpm and feed rate 20 mm / min.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.607-613
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• 2019

In this study, we investigate the effect of SNCM616 alloy steel, which is commonly used in industry, such as rotors and crank-shafts, on the surface roughness of CNC HBM with Ø25 mm, 8-blade reamer to objective is to analyze and present optimal cutting conditions. The higher the feedrate for the spindle speed, the rougher the surface roughness. The surface roughness was found to be better when the feed rate was lower. The resultant value of the most accurate surface roughness is Ra 0.756 ㎛, and the optimal cutting conditions are 25 rpm at spindle speed and 20 mm/min at transfer speed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.7 no.2
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• pp.21-26
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• 1989

This module to input Korean Level Data has 4 capacities of inputing, deleting, referencing and saving. Data file of level line consists of sorted list of node on the basis of “ABSTRACT”. For easy work, interactive method was employed. As the result of removing the boring routine by applying the characteristics of level data, working efficiency was increased. This program was written in C-language and runs on a minimum hardware configuration of IBM PC/XT with 640KB memory, In the future, these unit modules combine to form Generalized Level Information System.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.5
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• pp.48-52
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• 2019

A coolant pump is the device that cools processed articles and tools when using cutting, boring, and grinding machine tools and provides cutting oil for distributing or cleansing the cut chip to the worktable, processing position, etc. In particular, it consumes a large proportion of energy in machine tools, so it plays an important role in terms of energy efficiency. The purpose of this research is to optimize the shape of impeller, which directly affects performance improvements, to determine the capacity of the coolant pump. To do so, we carried out a parametric analysis with the geometric shape of the impeller as the input variable.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.106-112
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• 2023

This study proposes learner participatory activities for learner-centered college liberal arts classes. In addition, it analyzes learners' perceptions of and satisfaction with learner-centered classes and identifies the issues that must be considered when planning learner-centered activities for college liberal arts classes. The study used a learner-centered participatory activity in which participants created a 4-cut cartoon addressing a specific theme. An open-ended questionnaire was administered to identify learners' attitudes about and satisfaction with the learner-centered classes. It showed that most learners (87.5%) were highly satisfied with the 4-cut cartoon creation activities in the learner-centered participatory class. Learners identified the burden- free nature of the class activities, the fact that they improved their understanding of class content, and that they were fun (not boring) as the main reasons they found the class activities satisfying. In liberal arts English classes, more diverse participatory class activities should be developed to arouse interest and motivation of learners and encourage learners' participation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.526-528
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• 2022

In this study, through the capstone design project, an IoT based piano training system was developed after identifying problems in piano learning. The piano training system recognizes sheet music through image processing technology and checks whether the correct keyboard is struck through FFT transformation during piano practicing. By providing a visual effect and score display function using a rhythm game, it was possible to arouse interest in boring piano practice and increase the effect of piano learning.