• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.401-402
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• 2017

본 논문에서는 아두이노와 스마트 폰 어플리케이션을 이용한 수중탐사로봇을 구현하였다. 구현된 시스템은 스마트폰으로 간편하게 조종을 할 수 있으며, 한눈에 알아보기 쉽게 수중의 영상 및 온도와 ph값, 수질 오염도를 체크할 수 있다. 양식업 사업에서 실시간으로 체크해 빠른 대처와 조치를 취할 수 있어 효율적으로 양식업을 관리 할 수 있다는 점에서 기대효과를 볼 수 있다. 또한 해양사고 발생 시 수중탐사로봇이 먼저 투입하여 인명구조를 하는 인력과 제 2의 피해자가 최소화 될 수 있고 더 이상 인명피해가 나지 않도록 안전적인 측면에서도 기대할 수 있다.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.588-601
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• 2013

In geophysics and geophysical exploration fields, we can use information about inclination and azimuth in various ways. These include borehole deviation logging for inversion process, real-time data acquisition system, geophysical monitoring system, and so on. This type of information is also necessarily used in the directional drilling of shale gas fields. We thus need to develop a subminiature, low-powered, multi-functional inclination and azimuth measurement system for geophysical exploration fields. In this paper, to develop real-time measurement system, we adopt the high performance low power Micro Control Unit (made with state-of-the-art Complementary Metal Oxide Semiconductor technology) and newly released Micro Electro Mechanical Systems Attitude Heading Reference System sensors. We present test results on the development of a multifunctional real-time inclination and azimuth measurement system. The developed system has an ultra-slim body so as to be installed in 42mm sonde. Also, this system allows us to acquire data in real-time and to easily expand its application by synchronizing with a depth encoder or Differential Global Positioning System.

• Geophysics and Geophysical Exploration
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• v.5 no.4
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• pp.309-315
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• 2002

Conventional electromagnetic (EM) method using small loops as a source and receiver has been used in detection of conductive buried objects like a metal detector or in qualitative estimation of the subsurface conductivity variation. Recently, however, since detection of buried objects and imaging of the subsurface conductivity distribution in a relatively conductive area are in a high demand for environmental and engineering purposes, the quantitative interpretation technique of EM data is actively studied. In this regard, we introduce a brief principle of EM survey and show an example of the detection of buried conductive material and imaging of the subsurface conductivity distribution based on data measured at a test survey area. Through this study, we show that multi-frequency EM surveys using small loops may be a good solution to give quick and detail information of subsurface in a conductive survey area.

• Geophysics and Geophysical Exploration
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• v.20 no.4
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• pp.241-267
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• 2017

Since the liberation in 1945, Korean specialists in the field of geological science and mineral resources engineering have developed two disciplines through the cooperation and competition with each other. Specialists both in the geophysics and in the geophysical exploration, who share much, have developed their own fields deeper and broader. Since the late 1990s, specialists in both fields felt the need for an independent society to deal with their fields and discussed the establishment of such a society. In 1997, they discussed to establish a unified society which integrates both fields instead of separated societies. However, in 1998, the Korean Geophysical Society and the Korean Society of Exploration Geophysicists were separately established due to some practical problems. During 7 ~ 8 years since the establishment of the two societies, many members of the two societies intended that the two societies should integrate into a single comprehensive society based on the facts that many fields of each society are overlapped and naturally many members of one society are the members of the other society. The leaders of the two societies accepted these opinions also and began to discuss thoroughly the integration from 2005. Eventually, in 2007, the two societies successfully integrated and established the Korean Society of Earth and Exploration Geophysicists. The Korean Society of Earth and Exploration Geophysicists continues to cooperate and compete with other societies of geological science and mineral resources engineering in Korea and in circumpacific area including Asia, Oceania and Americas, contributing to the development of geophysics and geophysical exploration.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.6
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• pp.479-486
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• 2018

In order to ensure reliable navigation performance of a lunar exploration rover, navigation algorithms using additional sensors such as inertial measurement units and cameras are essential on lunar surface in the absence of a global navigation satellite system. Unprecedentedly, Visual Odometry (VO) using a stereo camera has been successfully implemented at the US Mars rovers. In this paper, we estimate the 6-DOF pose of the lunar exploration rover from gray images of a lunar-like terrains. The proposed algorithm estimates relative pose of consecutive images by sparse image alignment based semi-direct VO. In order to overcome vulnerability to non-linearity of direct VO, we add adaptive motion prior weights calculated from a linear function of the previous pose to the optimization cost function. The proposed algorithm is verified in lunar-like terrain dataset recorded by Toronto University reflecting the characteristics of the actual lunar environment.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.281-286
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• 2005

This paper presents sensitivity analysis of generalized rapid relaxation inversion (GRRI) algorithm for inverting controlled-source audio-frequency magnetotelluric (CSAMT) data. The algorithm was originally developed by modifying the RRI algorithm to recover a two-dimensional (2-D) conductivity structure of the Earth from MT data, but can be extended to include CSAMT data if it is combined with 2.5-D forward modeling. These GRRI approximate sensitivities are validated by comparison with exact 1-D and 2.5-D sensitivities. The comparison shows that the GRRI sensitivity is a good approximation to the exact sensitivity and has about half magnitude of the RRI sensitivity. Although the magnitude of the GRRI sensitivity is still slightly larger than that of the 2.5-D sensitivity, both sensitivities are broadly similar in shape when source-receiver offsets are greater than one skin depth on the Earth.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.08a
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• pp.3-7
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• 2004

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.93.2-93
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• 1998

• Structural Engineering and Mechanics
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• v.52 no.3
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• pp.445-468
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• 2014

In this paper a new particle swarm ray optimization algorithm is proposed for truss shape and size optimization with natural frequency constraints. These problems are believed to represent nonlinear and non-convex search spaces with several local optima and therefore are suitable for examining the capabilities of new algorithms. The proposed algorithm can be viewed as a hybridization of Particle Swarm Optimization (PSO) and the recently proposed Ray Optimization (RO) algorithms. In fact the exploration capabilities of the PSO are tried to be promoted using some concepts of the RO. Five numerical examples are examined in order to inspect the viability of the proposed algorithm. The results are compared with those of the PSO and some other existing algorithms. It is shown that the proposed algorithm obtains lighter structures in comparison to other methods most of the time. As will be discussed, the algorithm's performance can be attributed to its appropriate exploration/exploitation balance.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.850-851
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• 2007

This paper presents an efficient approach for solving the economic dispatch (ED) problems with prohibited operating zones using an improved particle swarm optimization (PSO). Although the PSO-based approaches have several advantages suitable to the heavily constrained nonconvex optimization problems, they still have the drawbacks such as local optimal trapping due to the premature convergence (i.e., exploration problem) and insufficient capability to find nearly-by extreme points (i.e., exploitation problem). This paper proposes an improved PSO framework adopting a crossover operation scheme to increase both exploration and exploitation capability of the PSO. The proposed method is applied to ED problem with prohibited operating zones. Also, the results are compared with those of the state-of-the-art methods.