• Journal of IKEEE
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• v.23 no.1
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• pp.44-52
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• 2019

We implement an educational indoor autonomous mobile robot system that integrates LiDAR sensing information with RGB-D camera image information and exploits the integrated information. This system uses the existing sensing method employing a LiDAR with a small number of scan channels to acquire LiDAR sensing information. To remedy the weakness of the existing LiDAR sensing method, we propose the 3D structure recognition technique using depth images from a RGB-D camera and the deep learning based object recognition algorithm and apply the proposed technique to the system.

• Journal of Drive and Control
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• v.19 no.4
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• pp.97-103
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• 2022

Low fertility rates and increased life expectancy further exacerbate the process of an aging society. This is also reflected in the gradual increase in the proportion of vulnerable groups in the social population. The demand for improved mobility among vulnerable groups such as the elderly or the disabled has greatly driven the growth of the electric-assisted mobility device market. However, such mobile devices generally require a certain operating capability, which limits the range of vulnerable groups who can use the device and increases the cost of learning. Therefore, autonomous driving technology needs to be introduced to make mobility easier for a wider range of vulnerable groups to meet their needs of work and leisure in different environments. This study uses mini PC Odyssey, Velodyne Lidar VLP-16, electronic device and Linux-based ROS program to realize the functions of working environment recognition, simultaneous localization, map generation and navigation of electric powered mobile devices for vulnerable groups. This autonomous driving mobility device is expected to be of great help to the vulnerable who lack the immediate response in dangerous situations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.589-590
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• 2010

Recently, as various smart phones released smart phones are becoming popular.Accordingly, the growing interest in mobile information service or advertising serviece, and attention has been concentrated in the mobile environment. These servieces should be carried out smoothly in the all situation (cannot access mobile Wi-Fi networks and 3G services), and should have the uniqueness that is fit for purpose. In this papaer, module for a particular purpose of the foundation of specialized location-based map services was implemented using a Packing R-tree by using a GIS engine based on Microsoft Window Mobile and Android operating system without communication device like 3G or Wi-Fi.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.3
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• pp.391-398
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• 2022

The use rate of M-pass(transportation card for foreigners),developed and sold to provide convenience to foreign tourists, was only 0.0051 % of visitors to Seoul over the past five years. Even this poor sales fell to the 0.024 % level in 2020 due to COVID-19. The cause of the sluggish performance was that the Ministry of land, Transport and Maritime Affairs and the card issuer excluded transportation operating organizations, and problems such as poor public relation, irrationality in pricing, and limitied number of sales locations appeared. In order to solve this problem, the research result showed that business strategies such as the establishment of a digital marketing system, realistic pricing, and the establishment of a mobile sales system that fit the trend, as well as the development of new product that reflect the participation and opinions of all related organizations are necessary. It is expected that this study will not only provide convenience to foreign Seoul tourist in the age of Post Corona, but also help improve the management of subway operating organizations.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.79-82
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• 2017

A new and effective Doppler effects compensation scheme for orthogonal frequency division multiplex(OFDM) system based on constellation estimation is presented with analytical descriptions which quantitatively clarify the mechanism of inter-carrier interference(ICI). The proposed compensation techniques, applicable both frequency and time domain with remarkable accuracy, are crucial to the future OFDM system operating on ultra high speed mobile vehicles.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5745-5758
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• 2017

In this paper, we develop a simple but very effective 4 by 4 Multiple-Input Multiple-Output (MIMO) antenna system for mobile phones consisting of different types of antennas to achieve low correlation property at the frequency ranges of 1710 to 2170 MHz, which covers wide LTE service bands, from band 1 to band 4. The proposed antenna system consists of two pair of antennas. Each pair consists of a planar inverted-F antenna (PIFA) and a coupling antenna which has the property of the loop. The use of two different antenna types of IFA and a coupling achieves high isolation. Proposed antenna system occupies relatively small area and positions at the four corners of a printed circuit board. The gap between the two antennas is 4 mm, in order to realize the good isolation performance. To evaluate the performance of our proposed antenna system, we perform various experiments. The proposed antenna shows a wide operating bandwidth greater than 460 MHz with isolation between the feeding ports higher than 17.5-dB. It also shows that the proposed antenna has low Envelop Correlation Coefficient (ECC) values smaller than 0.08 over the all desired frequency tuning ranges.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.6
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• pp.523-529
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• 2008

In this paper, we proposed mobile LCD module test device on embedded based, when operating the existing LCD, divide flicker clearly in full frame, and configuration so as to support between other CPU interface, MDDI, SPI, 24Bit RGB interface, etc. that is based on a high-speed CPU. In addition, when demand to test about each pixel of LCD, it is possible to change IP design of H/W, FPGA, but proposed system is application possible without other design changing. Proposed system is made smaller and equipped with battery, so secure with mobility for effective test the LCD/OLED module and it is able to test the pattern by the client program, for example exiting picture, mpeg, simple pattern test and test per pixel, scale, rotation, Odd/Even pixel per video, etc. From now on, if integrating with independent test system and it is configured that is able to mutual communication and test, it is expected to reduce consumption of human resources and improve productivity for LCD module test.

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.305-313
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• 2018

With the explosive growth of smart phones and efficiency, the Android of an open mobile operating system is gradually increasing in the use and the availability. Android systems has proven its availability and stability in the mobile devices, the home appliances's operating systems, the IoT products, and the mechatronics. However, as the usability increases, the malicious code based on Android also increases exponentially. Unlike ordinary PCs, if malicious codes are infiltrated into mobile products, mobile devices can not be used as a lock and can be leaked a large number of personal contacts, and can be lead to unnecessary billing, and can be cause a huge loss of financial services. Therefore, we proposed a method to detect and delete malicious files in real time in order to solve this problem. In this paper, we also designed a method to detect and delete malicious codes in a more effective manner through the process of installing Android-based applications and signature-based malicious code detection method. The method we proposed and designed can effectively detect malicious code in a limited resource environment, such as mobile environments.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.1
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• pp.62-70
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• 2002

The purpose of this paper in that users can use mobile device applications more easily and efficiently through MoDAM (Mobile Device Application Management) system. MoDAM automates the process of web retrieval for obtaining mobile device applications and the process of installing or updating it on mobile devices and then supply users with these automated services in a step form by combining two separated processes. We implement a web agent conforming to OSD (Open Software Description) specification for automating software retrieval and downloading and also a mobile device based software management module conforming to SyncML (Synchronization Markup Language) specification for synchronizing common data between server and client. The method of automated software retrieval and management for mobile devices using these standard specifications minimizes users' interrupts and also can be applied to traditional several different mobile devices, operating systems or downloading web sites without platform dependent considerations.

• Journal of the Korea Society of Computer and Information
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• v.9 no.1
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• pp.55-62
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• 2004

The computer security is considered important due to the side effect generated from the expansion of computer network and rapid increase of the use of internet. Therefore, Intrusion detection system has been an active research area to reduce the risk from intruders. A number of advantages of using mobile agent computing paradigms have been Proposed. These advantages include : overcoming network latency, reducing network load, executing asynchronously and autonomously, adapting dynamically, and operating in heterogeneous environments. Many information security models have been proposed to mitigate agent-to-agent. agent-to-platform, and platform-to-agent element risks . In these paper, We have an object which is that through intrusion detection system development, the mobile agent is managed and through the analysis of performance data. the best environment is served.