• The Journal of Korea Robotics Society
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• v.9 no.4
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• pp.197-205
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• 2014

As computer vision algorithms are developed on a continuous basis, the visual information from vision sensors has been widely used in the context of simultaneous localization and mapping (SLAM), called visual SLAM, which utilizes relative motion information between images. This research addresses a visual SLAM framework for online localization and mapping in an unstructured seabed environment that can be applied to a low-cost unmanned underwater vehicle equipped with a single monocular camera as a major measurement sensor. Typically, an image motion model with a predefined dimensionality can be corrupted by errors due to the violation of the model assumptions, which may lead to performance degradation of the visual SLAM estimation. To deal with the erroneous image motion model, this study employs a local bundle optimization (LBO) scheme when a closed loop is detected. The results of comparison between visual SLAM estimation with LBO and the other case are presented to validate the effectiveness of the proposed methodology.

• KIEAE Journal
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• v.10 no.4
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• pp.3-8
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• 2010

Recently, various daylight evaluation methods for visual environment have been developed; simulation analysis methods, numerical calculation, and data monitoring methods. However, it is impossible for simulation analysis to make real scenes and visualize real images exactly. Also, a numerical calculation is considered as an out of date and time-consuming mean. Therefore, for acquisition of accurate results, many studies often use the monitoring data methods. Especially, most studies regarding discomfort glare are evaluated by measuring the physical quantity of luminance through traditional measuring Minolta Luminance meters as an instrument. But, this method has a difficulty in measuring several points at the same time because of the limitation of spaces and time when mapping. So, this study focused on the potential usefulness of High Dynamic Range photography technique as a luminance mapping tool. In order to evaluate the accuracy of proposed programs such as webHDR, Photomatix and PHOTOLUX, this paper has conducted an experiment by using Canon EOS 5D and NICON Coolpix8400 digital camera.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1513-1518
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• 1996

A force reflecting hand controller can be used to provide more realistic information to the operator of a teleoperation system such as kinesthetic feedback from a slave robot. In this paper, a new design concept of a force reflecting 6-DOF hand controller utilizing the kinematic structure of a Stewart Platform is presented. Based on the optimal design technique of a Stewart Platform, a force reflecting hand controller has been designed and constructed to verify the technical feasibility of proposed design concept. In order to provide an operator with kinesthetic feedback information, a force mapping algorithm based on a reciprocal product of screws has been introduced. Finally, the technical feasibility of the design concept has been demonstrated through some of experimental results of the device under virtual environment on a real-time graphic system.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.101.1-101
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• 2001

This paper describes a grid mapping for a vision based mobile robot in uncertain indoor environment. The map building is a prerequisite for navigation of a mobile robot and the problem of feature correspondence across two images is well known to be of crucial Importance for vision-based mapping We use a stereo matching algorithm obtained by singular value decomposition of an appropriate correspondence strength matrix. This new correspondence strength means a correlation weight for some local measurements to quantify similarity between features. The visual range data from the reconstructed disparity image form an occupancy grid representation. The occupancy map is a grid-based map in which each cell has some value indicating the probability at that location ...

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.258-261
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• 2000

Geophysical surveys (electrical resistivity, self-potential, and magnetic methods) and streamwater sample analysis have been carried out at a site of tailings of waste deposits in an abandoned mine, Jangpoong, which is situated in Kowesan-Gun, Chungbuk-Do. The research was aimed at investigating the suitability of the various geophysical methods for detection of AMD (acid mine drainage) paths, and ultimately mapping of preferred AMD flow channels by incorporating the water sample analysis. Electrical resistivity section from the dipole-dipole line represents the low-resistivity zone trending northwest toward the stream nearby. The positions of the resistivity anomalies for AMD channels are well correlated to the ones from the various geophysical surveys. In addition they correspond to the sites of the higher peaks for the pH, EC, heavy metal content for the water sample data.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.304-307
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• 2005

A numerical modelling method using a backward-in-time advection dispersion equation is introduced in assessing the vulnerability of groundwater to contaminants as an alternative to classical vulnerability mapping methods. The flux and resident concentration measurements are normalized by the total contaminants mass released to the system to provide the travel time probability density function and the location probability function. With the results one can predict the expected travel time of a contaminant from up stream location to a well and also the relative concentration of the contaminant at a well. More specific groundwater vulnerability can be mapped by these predicted measurements.

• Journal of the Korean Society of Marine Environment & Safety
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• v.1 no.2
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• pp.39-52
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• 1995

There are numerous mapping, charting, geodetic systems and electronic digital products defined in various local geodetic datum. It becomes a straight forward requirement to simplify the complexity by referencing all the products to a common reference globally. WGS-84 is well known as a state-of-the-art global reference system based on the use of data, techniques and technology available within American Defence Mapping Agency(DMA). Its parameters can be translated into more accurate maps, charts and geodetic positioning compared to others previously. Since Global Positioning System(GPS/NAVSTAR), which is asssociated with World Geodetic System(WGS-84)in reference frame, has been widely used, the unified geodetic system has been required for GPS users in many fields.

• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.249-253
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• 2007

The Research on the ICT(Information & Communication Technology) is proposed the category to IT839 strategy by Government. Government is driving to researching on technology about IT839 Strategy. By transforming this category and research information into Semantic Web environment, it is possible to search function utilizing knowledge base and information object by use of TBox and ABox. In this regard, this study proposes technology for generation of Semantic Web Document about ICT Research Information. The ontology is constructed by using category to IT839 Strategy. The features of framework proposed in this study is to have used a skill to directly map Ontology instance and in case of inability of direct mapping, proposed a skill to establish reliable Semantic Web Document by suggesting indirect mapping skill using mechanical study. In addition, it is possible to establish low cost/high quality Semantic Web Document about ICT research information.

• The Journal of Korea Robotics Society
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• v.16 no.2
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• pp.122-129
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• 2021

For the Simultaneous Localization and Mapping (SLAM) problem, a different path results in different SLAM results. Usually, SLAM follows a trail of input data. Active SLAM, which determines where to sense for the next step, can suggest a better path for a better SLAM result during the data acquisition step. In this paper, we will use reinforcement learning to find where to perceive. By assigning entire target area coverage to a goal and uncertainty as a negative reward, the reinforcement learning network finds an optimal path to minimize trajectory uncertainty and maximize map coverage. However, most active SLAM researches are performed in indoor or aerial environments where robots can move in every direction. In the urban environment, vehicles only can move following road structure and traffic rules. Graph structure can efficiently express road environment, considering crossroads and streets as nodes and edges, respectively. In this paper, we propose a novel method to find optimal SLAM path using graph structure and reinforcement learning technique.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_2
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• pp.625-633
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• 2007

Recently human beings are enforcing marine investigations to extend their living environment from land to the sea. Therefore, this study grasped objects in the bottom of the sea and its topographical undulation and acquired topographic map with a sound detector. In result, This study acquired their images with a sound detector and can draw up a Drawing of Sea Mapping and a three-dimensional modeling map.