• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.155-161
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• 2009

This paper proposes a high capacity data hiding method using modulus function of pixel-value differencing (PVD) and least significant bit (LSB) replacement method. Many novel data hiding methods based on LSB and PVD methods were presented to enlarge hiding capacity and provide an imperceptible quality. A small difference value for two consecutive pixels is belonged to a smooth area and a large difference one is located on an edge area. In our proposed method, the secret data are hidden on the smooth area by the LSB substitution method and PVD method on the edge area. From the experimental results, the proposed method sustains a higher capacity and still a good quality compared with other LSB and modified PVD methods.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.387-388
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• 2010

There is no generalized and systematic method yet to data pre-processing for point cloud data classification even if there have been lots of previous studies such as local maxima filter, morphology filter, slope based filter and so on. Main focus of this study is to present classification method for bare ground information from LiDAR data for the mountainous area.

• The Journal of Industrial Distribution & Business
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• v.8 no.6
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• pp.61-73
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• 2017

Purpose - Aviation control, navigation, and aircraft control in the air transportation area are very specialized. Each part is in progress for safety, efficiency, automation, and further. On the other hand co-work among each part including knowledge sharing has been inattentive for many reasons. The purpose of this research is to show how practicians and professionals in the air transportation area perceive the issue of knowledge sharing and to recall the necessity of knowledge sharing in the area. And we try to find ways to activate the knowledge sharing in the area. Research design, data, methodology - For the research, we inquired into whether practicians and professionals think knowledge sharing can effect safe aviation positively or not and what steps are necessary to activate knowledge sharing in the area. We adopted survey method using questionnaires for current practicians and interview for specialists. The survey and interview results were analyzed using regression analysis and AHP method. The interview for specialists and analyzing the results using AHP was to investigate what are the precedence factors to activate the knowledge sharing. Results - First, practicians perceive that knowledge sharing will affect aviation safe positively. Second objective knowledges such as, tower air traffic control procedure of aviation control area, flight principle and structure of aircraft control area, instrument landing system of navigation area, for knowledge sharing of each area were identified. Also the precedence factors such as, knowledge absorbability of personal factor, personal expectation of result of expectation factor, leadership of management of Structure factor, method of knowledge spread of application factor for knowledge sharing were found. Conclusions - Knowledge sharing for practicians and professionals in the aviation area is very important especially from the perspective of safety. However, for various many reasons including the environment of each special area that focusing on their own area, knowledge sharing has not been emphasized. We found that practicians in the area feel that knowledge sharing is necessary and helpful. For it, each practician's active participation is the most important and many ways such as chatting room to share knowledge are to be developed. And the organization culture should be changed to encourage knowledge sharing.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.58-64
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• 2000

This paper proposes a method for determining optimal EDM parameters based on discharge area from the physical model of a tool electrode. Main parameters, which affect the EDM performance, are peak value of currents, pulse-on time, and pulse-off time. Such parameters are closely dependent on the discharge area in EDM process. In this paper the discharge area is estimated from the CMM scanning data to the tool electrode. The method is very useful when any geometric information to the tool electrode is not provided from tool modeler or producer. The method consists of following four steps. First a triangulation mesh is constructed from the CMM data. Secondly, the z-map is modeled from the triangulated mesh. Thirdly, the discharge area is estimated from intersection between the z-map model and a z-height plane. Finally, the machining parameters are easily calculated by some known EDM equations to the discharge area. An example is introduced to show that the machining parameters are calculated from the CMM data to a tool electrode.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.1
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• pp.64-72
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• 2016

The coverage area of a GNSS regional ionospheric delay model is mainly determined by the distribution of GNSS ground monitoring stations. Extrapolation of the ionospheric model data can extend the coverage area. An extrapolation algorithm, which combines observed ionospheric delay with the environmental parameters, is proposed. Neural network and least square regression algorithms are developed to utilize the combined input data. The bi-harmonic spline method is also tested for comparison. The IGS ionosphere map data is used to simulate the delays and to compute the extrapolation error statistics. The neural network method outperforms the other methods and demonstrates a high extrapolation accuracy. In order to determine the directional characteristics, the estimation error is classified into four direction components. The South extrapolation area yields the largest estimation error followed by North area, which yields the second-largest error.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.131-134
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• 2009

The red-eye effect in photography occurs when using a photographic flash very close to the camera lens, in ambient low light due to in experience. Once occurred, the photographer needs to remove it with image tool that requires time consuming, skillful process. In this paper, we propose a new method to extract and remove such red-eye area automatically. Our method starts with transforming ROB space to YCbCr and HSI space and it extracts the face area by using skin color information. The target red-eye area is then extracted by applying 8-direction contour tracking algorithm and removed. The experiment shows our method's effectiveness.

• Journal of KSNVE
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• v.9 no.5
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• pp.943-948
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• 1999

This paper proposes a feasible and effective method for measuring the mechanical-acoustic transfer function by the application of equivalent area and velocity transfer function, a manifestation of the vibro-acoustical reciprocity principle. On the contrary to the volume velocity used in traditional method, the equivalent area is a peculiar raidation characteristics of sound sources and not influenced by any input signal for driving sound source. This invariant property of equivalent area can get rid of boresome works to measure the volume velocity of a sound source every time the driving signal is changed. Moreover, this method has a remarkable advantage to use a general loudspeaker as an accoustic exciter without the assumption of point source and can be applied to all kinds of sound sources even if they are not omni-directional sources.

• ETRI Journal
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• v.23 no.3
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• pp.129-137
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• 2001

A random sampling or systematic sampling method is commonly used to assess the accuracy of classification results. In remote sensing, with these sampling methods, much time and tedious work are required to acquire sufficient ground truth data. So, a more effective sampling method that can represent the characteristics of the population is required. In this study, fractal analysis is adopted as an index for reference sampling. The fractal dimensions of the whole study area and the sub-regions are calculated to select sub-regions that have the most similar dimensionality to that of the whole area. Then the whole area's classification accuracy is compared with those of sub-regions, and it is verified that the accuracies of selected sub-regions are similar to that of whole area. A new kind of reference sampling method using the above procedure is proposed. The results show that it is possible to reduce sampling area and sample size, while keeping the same level of accuracy as the existing methods.

• Journal of Korea Multimedia Society
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• v.17 no.10
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• pp.1150-1159
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• 2014

This paper proposes a method for extracting tissue cells from an organism image by an electron microscope and getting the whole cell number and the area from the cell. In general, the difference between the cell color and the background is used to extract tissue cell. However, there may be a problem when overlapped cells are seen as a single cell. To solve the problem, we split them by using cell size and curvature. This method has a 99% accuracy rate. To measure the cell area, we compute two areas, the inside and boundary of the cell. The inside is simply calculated by the number of pixels. The cell boundary is obtained by applying super sampling, linear interpolation, and cubic spline interpolation. It improves the error rate, 18%, 19%, and 120% respectively, in comparison to the counting method that counts a pixel area as 1.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.648-649
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• 2022

Glass is a common object in living environments, but even humans are sometimes unable to identify it. This study proposes a method for detecting glass area by learning edge information from images. The network structure of Transformer is used to accept the base features extracted by backbone and extract the boundary information of RGB images, and both features are used to learn the features of glass area and determine the glass area based on these boundary features. The experimental results show that our proposed method can detect glass area in images.