• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.4103-4117
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• 2014

Image processing and computer vision algorithms are gaining larger concern in a variety of application areas such as robotics and man-machine interaction. Vision allows the development of flexible, intelligent, and less intrusive approaches than most of the other sensor systems. In this work, we determine the location and orientation of a mobile robot which is crucial for performing its tasks. In order to be able to operate in real time there is a need to speed up different vision routines. Therefore, we present and evaluate a method for introducing parallelism into the multiple non-overlapping camera pose estimation algorithm proposed in [1]. In this algorithm the problem has been solved in real time using multiple non-overlapping cameras and the Extended Kalman Filter (EKF). Four cameras arranged in two back-to-back pairs are put on the platform of a moving robot. An important benefit of using multiple cameras for robot pose estimation is the capability of resolving vision uncertainties such as the bas-relief ambiguity. The proposed method is based on algorithmic skeletons for low, medium and high levels of parallelization. The analysis shows that the use of a multiprocessor system enhances the system performance by about 87%. In addition, the proposed design is scalable, which is necaccery in this application where the number of features changes repeatedly.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4072-4079
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• 2021

This article presents a study on the state-of-the-art methods for automated radioactive material detection and identification, using gamma-ray spectra and modern machine learning methods. The recent developments inspired this in deep learning algorithms, and the proposed method provided better performance than the current state-of-the-art models. Machine learning models such as: fully connected, recurrent, convolutional, and gradient boosted decision trees, are applied under a wide variety of testing conditions, and their advantage and disadvantage are discussed. Furthermore, a hybrid model is developed by combining the fully-connected and convolutional neural network, which shows the best performance among the different machine learning models. These improvements are represented by the model's test performance metric (i.e., F1 score) of 93.33% with an improvement of 2%-12% than the state-of-the-art model at various conditions. The experimental results show that fusion of classical neural networks and modern deep learning architecture is a suitable choice for interpreting gamma spectra data where real-time and remote detection is necessary.

• The Journal of Korea Robotics Society
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• v.15 no.4
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• pp.392-397
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• 2020

Unmanned robots are very useful for autonomous security systems. These robots navigate autonomously move in a large area for surveillance. It is very important for robots that cover such a wide area to communicate with a control systems. Therefore, the control system needs various communication methods to check the status of the robot and send/receive messages. In addition, it is necessary to provide an easy interface for the user to send security mission commands to the robot. In this paper, we propose a control system based on a variety of communication techniques to perform security by safely communicating with a number of robots in a wide area space. The proposed system designed for considering user UI, data storage and management, and shows usability by constructing it in a real environment.

• Journal of Communications and Networks
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• v.8 no.2
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• pp.144-150
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• 2006

A serious problem with traditional 'command & control' spectrum management techniques is that they do not easily accommodate new technologies and new services. This paper describes the necessary principles of flexible-use spectrum rights which may allow a wide variety of spectrum uses in a single general-purpose band. Based on the electrospace description of the radio spectrum, these principles allow general aggregation or division of licensed electrospace regions via secondary markets, providing rules for how regulatory limits change under aggregation or division. These flexible-use principles limit transmitter behaviors that tend to create a more difficult operating environment for receivers, while making receivers responsible for handling any remaining interference. The author shows how flexible-use principles could provide a basis for real-world flexible-use frequency bands.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.329-332
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• 2006

$Conform^{TM}$, a continuous extrusion forming process can produce a variety of very long extruded products such as aluminum alloyed wires, strips and profiles, hollow sectioned tubes, coated wires used in the current forming industry. This process has some advantages like as superiority of pre-heating free, availability of high extrusion ratio and continuous forming without stroke limit. But it is still difficult to analyze the realistic model of the process. In this study the analysis using two-dimensional model of $Conform^{TM}$ process together with several parametric investigations on the heat transfer are carried out by FEA code DEFORM $^{TM}2D$. In spite of simple model the results of analysis shows a good guidance to design the real process.

• Applied Microscopy
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• v.45 no.2
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• pp.52-57
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• 2015

Bulk metallic glass (BMG) shows higth strength, high elastic limit, corrosion resistance and good wear resistance and soft magnetic properties and has been considering as a candidate for new structural materials. But they show limited macroscopic plasticity and lack of tensile ductility due to highly localized shear deformation, which should be solved for real structural application. In this paper researches on the enhancement of plasticity of BMG were reviewed briefly. Introducing heterogeneous structure in glass is effective to induce more shear transformation zones (STZs) active for multiple shear band initiation and also to block the propagating shear band. Several methods such as BMG alloy design for high Poisson's ratio, addition of alloying element having positive heat of mixing, pre-straining BMG and variety of BMG composites have been developed for homogenous distribution of locally weak region, where local strain can be initiated. Therefore enhancement of plasticity of BMG is normally accompanied with some penalty of strength loss.

• Communications for Statistical Applications and Methods
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• v.22 no.2
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• pp.121-135
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• 2015

We consider testing equality of mean functions from two samples of functional data. A novel test based on the adaptive Neyman methodology applied to the Hotelling's T-squared statistic is proposed. Under the enlarged null hypothesis that the distributions of the two populations are the same, randomization methods are proposed to find a null distribution which gives accurate significance levels. An extensive simulation study is presented which shows that the proposed test works very well in comparison with several other methods under a variety of alternatives and is one of the best methods for all alternatives, whereas the other methods all show weak power at some alternatives. An application to a real-world data set demonstrates the applicability of the method.

• Korean journal of communication and information
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• v.46
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• pp.485-510
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• 2009

Since the inception of Internet Protocol TV's real-time service on January, 2009, technological challenges and lack of content diversity of IPTV have been cited as problem areas. While past researches focused on IPTV's technological, industrial and policy facets, this research surveyed the viewers' viewing and usage patterns, and the level of service satisfaction among actual audiences of MegaTV, SKBroadband, and LGTV since January. The results show that subscription fee and content types were the two dominant determinants in audience's choice of a particular IPTV company. The high users of IPTV were on average aged between 30-39, and women tended to be heavier users than men. The surveyed audience also regarded IPTV to be more similar to the Internet than any other medium such as Cable TV and Satellite TV. IPTV audience cited 'lifestyle service' and 'additional service' offerings to be highly relevant to their usage and satisfaction; interactive service and educational service also showed high correlation to usage and satisfaction. The most watched contents on IPTV were domestic TV series, followed by foreign movies and variety shows. 'Fees for additional features,' 'lack of real-time terrestrial TV service', and 'lack of content variety' were the major areas of concern for IPTV viewers. They answered that the monthly fee was the most important factor in the selection of IPTV. Use of pay-per-view contents and add-on interactive service fees were also seen as problematic. With regards to future usage, the IPTV audience revealed that they were very sensitive and reluctant to pay for additional services. While existing researches concentrated on IPTV's technological problems and lack of content diversity, this study illuminated the more pragmatical side of the viewers, namely, the importance of price in audience's selection of an IPTV service provider. From these results, it is recommended that, before doing anything else, the service providers try to meet the audience's expected price points in order to garner the full potential of IPTV and the attendant mass audience.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.461-471
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• 2010

Recently, Augmented Reality(AR) technologies have been emerged, which shows the types of digital contents integrating real and virtual worlds. To maximize the effect of AR technology, tangible user interface, which enables users to interact with the contents in the same way in which they manipulate objects in real world, is applied. In particular, we expect that the technologies are able to enhance learners' interests and degree of immersion, and produce new learning contents in order to maximize the effect of learning. In this paper, we propose a learning system for scientific experiments with multi-touch screen and tangible user interface. The system consists of an experiment table equipped with a large multi-touch screen and a realistic learning device that can detect the user's simple gestures. In real world, some scientific experiments involve high cost, long time or dangerous objects, but this system will overcome such hindrance and provide learners with a variety of experiment experience in realistic ways.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.823-826
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• 2007

In the construction project, the efforts to use IT for efficient management and improvement of productivity is gradually increasing. For instance, the cite management model with 3D CAD and RFID shows one of efforts this model define and systematize a variety of data occurred each work unit(design, material and process management information, etc). However, so far, there has been the problem monitoring the site due to the an inaccurate data and low-practice which people should input in manual. In this paper, we would like to establish the data for real time monitoring system with data inputting automatically from RTPM system and the site, and analyze the relationship between tables consist of similar data through RED Diagram.