• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.833-838
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• 2011

X-ray device used in the diagnosis has made possible to have more effective and accurate diagnosis, powered by the development of various devices. Based on this, X-ray device has become the most basic and essential diagnostic equipment in clinical medicine. At present, in the image acquisition field using X-ray, the use of Digital radiography which is useful in the acquisition time reduction and transfer of images and is possible to have the dose reduction has expanded. With the structure using one detector, this DR device has disadvantages in that it needs structural changes unlike existing X-ray and the detector should be moved to the desired position depending on the shooting location. Therefore, in this study, using BLDC(Brushless direct current) motor and PID(Proportional integral differential) control method, the automatic control system of 3-axis which is upward and downward, left and right and rotation of detector where having the most movement in DR was designed and produced and its performance was evaluated.

• Journal of Korean Library and Information Science Society
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• v.45 no.1
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• pp.249-270
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• 2014

The purpose of this study is to discover the mobile-based information behaviors of the older adults with comparison of the college students and then to provide some fundamental ideas of the bridging digital devide for them. For this aims, data were collected from seniors and college students living in Daegu and Kyung-buk province via a self-designed questionnaire, and the data of 375 seniors and 323 college students were analysed with $x^2$ and t-test using SPSS. It revealed that the economic condition did not influence in the possession of mobile devices, and for leisure was most favorite activity in both groups. However, the college student group suggested the supply of free or low price mobile device; whereas the older adults group suggested the spread of education of mobile device usage would be the most important matter for bridging the digital devide. Various results of the study were presented with tables and figures in this paper.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.5
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• pp.454-462
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• 2016

portable white space device(WSD) obeying the Korean regulations of TV white space(TVWS) can cause harmful interference to a digital TV receiver residing at the same pixel around the edge of the digital TV service coverage for the case with a changed propagation environment. In order to solve this problem, we propose a method to allocate the resource of a hybrid WSD based on TVWS geo-location DB with spectrum sensing. Using the received power of digital TV signal through the spectrum sensing, a hybrid WSD can calculate the maximum permitted EIRP based on location probability. Based on the accurate allocation method proposed in this paper, it is possible to satisfy the Korean TVWS regulations and to eliminate the harmful interference to TV receivers nearby the hybrid WSD.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.1-7
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• 2008

In this paper, we developed digital TV commerce system using mobile device for multimedia service. This system combines TV and mobile device, and enables a TV viewer to purchase and download the multimedia contents such as songs and video programs onto the mobile devices instantly when the viewer watches the contents. Our system is different from the conventional TV commerce system in the sense that it combines digital TV and mobile device for better service, and the contents such as songs, videos and games are downloaded directly to the devices. Furthermore, our system's data flow is designed for utilizing cheaper network to save costs. We implemented this new service system, and in this paper, we describe the service in detail, comparing with conventional TV commerce system, and we present the architecture and preliminary implementation of the proposed system.

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.351-359
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• 2012

This paper deals with the design and development of the remote control and measurement systems using CDMA(Code Division Multiple Access) data modem. We propose a bi-directional data communication link without the public IP address in CDMA modem device by the TCP/IP packet and SMS(Short Message Service) communication. The remote control and measurement systems are implemented by a Telit WM-800 modem as DCE(Data Communication Equipment), and Atmel AT89C51 microcontroller as DTE(Data Terminal Equipment). The user application software for the control and measurement system user, and the firmware software of device drivers for peripherals such as a digital input/output device, AD/DAC(Analog to Digital/Digital to Analog Converter), LCD, and temperature/humidity sensor are written in Microsoft C and Keil C language respectively for further various applications. The experimental result of the proposed control and measurement systems implemented in this paper is evaluated via real-time experiments, which works well as designed.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.96-104
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• 2006

In this study, data transmission ratio and power consumption issues of Zigbee based sensor module and personal digital assistant(PDA) were addressed to develop ECG telemetry device. PDA processes the data transmitted through serial port using non-blocking method. The transmission rate was dependent on the packet structure. It was 300 ECG samples/sec, when each packet was composed of 2 ECG data and 3-axial acceleration vector. Using two AAA batteries in series, operating time of the wireless sensor module was above 28 hours in average. Power consumption of PDA was dependent on screen ON/OFF condition and serial port usage. In this application, operating time of PDA was 5 hours in average. In conclusion, there was no problem in the power consumption of wireless sensor module and transmission rate, when the developed device was used as 24 hour Holter device. But, PDA has the problem of power consumption, which should be solved.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.6
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• pp.582-589
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• 2002

This paper presents 12.2 GHz ~ 12.7 GHz frequency band reflection type 5-bit digital phase shifter with constant insertion loss property that was fabricated with relatively low cost's InGaAs HEMT for amplifier. The unavoidable large insertion loss difference between on and off states of HEMT, when it is designed by conventional design theory based on ideal switching device, is removed by transforming the HEMT impedances at on and off states to other proper values connecting a certain length transmission line to HEMT and then applying the conventional design theory. The fabricated 5-bit digital phase shifter shows very good insertion loss properties of less than 1.5 dB insertion loss difference and -4.5 dB ~ -6 dB insertion loss in 35 phase steps at 12.2 GHz ~ 12.7 GHz. These results verify the design method presented in this paper, which is useful to design phase shifter of constant insertion loss with non-ideal switching device.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.6
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• pp.1425-1435
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• 2019

The expanded application of digital controls has raised the issue of cyber security for nuclear facilities. To cope with this, the cyber security technical standard RS-015 for Korean nuclear facilities requires nuclear system developers to apply security functions, analyze known vulnerabilities, and test and evaluate security functions. This requires the development of procedures and methods for testing the suitability of security functions in accordance with the nuclear cyber security technical standards. This study derived the security requirements required at the device level by classifying the details of the technical, operational and administrative security controls of RS-015 and developed procedures and methods to test whether the security functions implemented in the device meet the security requirements. This paper describes the process for developing security function compliance test procedures and methods and presents the developed test cases.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.6
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• pp.839-849
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• 2017

Recently, the role of the kitchen has evolved from the space for previous survival to the space that shows the present life and culture. Along with these changes, the use of IoT technology is spreading. As a result, the development and diffusion of new smart devices in the kitchen is being achieved. The user experience for using these smart devices is also becoming important. For a natural interaction between a user and a computer, better interactions can be expected based on context awareness. This paper examines the Natural User Interface (NUI) that does not touch the device based on the user interface (UI) of the smart device used in the kitchen. In this method, we use the image processing technology to recognize the user's hand gesture using the camera attached to the device and apply the recognized hand shape to the interface. The gestures used in this study are proposed to gesture according to the user's context and situation, and 5 kinds of gestures are classified and used in the interface.

• Convergence Security Journal
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• v.24 no.3
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• pp.3-11
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• 2024

Information security is crucial not only for protecting against external cyber-attacks but also for identifying and blocking internal data leakage risks in advance. To this end, many companies and institutions implement digital rights management(DRM) document security solutions, which encrypt files to prevent content access if leaked, and data loss prevention(DLP) solutions, which control devices such as USB ports on computing equipment to prevent data leaks. At a time when efforts to prevent internal data leaks are crucial, there is a growing need for control policies such as device control and the identification of information assets in standalone network environments, which could otherwise fall into unmanaged domains. In this study, we propose a Generation-Distribution-Application model for device control policies that are uniquely applied to standalone information assets that are not connected to internal networks. To achieve this, we developed an authentication technique linked with the asset management system, where information assets are automatically registered upon acquisition. This system allows for precise identification of information assets and enables flexible device control, and we have designed and implemented a system based on these principles.