• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.10
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• pp.28-33
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• 2009

In this paper, we propose the receiver algorithms suitable for the VHF (Very High Frequency) digital link mode-2(VDL Mode-2) system. Unlike conventional digital communication systems using the root raised cosine filter as a transmit and receive filter, raised cosine filter is used as a transmit filter in the VDL Mode-2 system. Hence, it is crucial to design and implement the optimum lowpass receive filter by considering inter-symbol interference and noise performance. On the other hand, due to the short preamble pattern, it is crucial to develop an efficient packet detection algorithm for reliable communication link for the VDL Mode-2 system. Also, frequency offset due to the carrier frequency difference between transmitter and receiver and doppler frequency shift must be estimated and compensated for reliable communication. In this paper, the optimum receive filter, packet detection and frequency offset compensation algorithms are proposed and the performance of the VDL system employing the proposed algorithms are evaluated.

• The KIPS Transactions:PartB
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• v.14B no.5
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• pp.329-336
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• 2007

In this paper we propose both the construction of image DB including information on the shooting location and direction of the captured outdoor images and the efficient retrieval method from the DB. Furthermore, for the automatic extraction of the location and direction information, we suggest to have the Digital Camera equipped with an expandable GPS modulo which has a function to calculate the location and direction and also to utilize GPS IFD tags in the EXIF. Then that will make it possible for us to retrieve quickly and precisely the target image with its geography and other objects on the ground included. In the previous retrieval method based only on the location, we eel some extra useless images due to the fact that all the images in the ROI(Region Of Interest) are searched on one condition, radius. However, with the proposed method in this paper, we can not only retrieve all the images selectively within the ROI but also achieve nearly 100% of precision when we search for the target images within DOI(Direction Of Interest) with another condition, direction, added. Applying this method to an image retrieval system, we can classify or retrieve natural images based on the location and direction information, which, in turn, will be vitally useful to diverse industrial fields such as disaster alarm system, fire and disaster prevention system, traffic information system, and so forth.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.463-467
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• 2015

When unforeseen accidents occur in a ship, it is important to save passengers safely and remove them from the accident area quickly. To solve such a situation, site information of passengers on board always must be identified. This paper implemented a site monitoring of crews and passengers based on the BLE and PLM combination, to prepare for unexpected accidents of the ships. This system was composed of BLE tag for crews, passengers and each room, PLM networks, data server, and monitoring PC. In this system, site information derived from the tag attached to the bodies and cabins of crews and passengers are transmitted through a power line network, and monitored on the screen of a monitoring PC. The proposed system guides them into the only authorized area considering the ship security and passengers' safety, and even has a special alarm call to warn them after entering an unauthorized area. This system enables the BLE-embedded tag battery to use for a long time because the BLE consumes low electric power, and can gain an economic advantage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.271-276
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• 2009

An local area weather condition monitoring system to minimize many disasters from the sudden change of weather condition in local and mountain area is proposed. Firstly, the comparison of present state of the related monitoring systems and the possibility of realization with some merits are investigated. Moreover, this paper present direction of local area weather condition monitoring system based on integration of wireless sensor network and CDMA network following some case study. Through the efficient integration of both networks, the measured weather condition data from sensors can be transmitted to the server or mobile to monitor with high reliability. The proposed monitoring system will guide new type of project in wireless sensor network and support alarm service of the sudden change of weather condition to mobile user from central official regulations.

• Journal of the Society of Disaster Information
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• v.15 no.3
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• pp.339-346
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• 2019

Purpose: In fact, to manage response and recovery successfully, although mitigation and preparedness should be accomplished naturally and automatically through thorough analysis and assessment, response, recovery, mitigation, and preparedness have not done in the way of virtuous cycles and continued broken disaster management repeatedly. Method: By Analysis through the critical methods, to enhance the community disaster resilience centered by social disaster management system in Korea, Result: (1) public training & education preparing for emergency or disaster (2) supplying public with disaster, or hazards information, and sharing at real time (3) networking emergency and disaster informational communication system & alarm system (4) analysis and assessment of risk(or disaster) in community (5) inter-governmental cooperative relationship and agreements (6) adopting and implementing disaster or hazards mitigation plan Conclusion: These will be able to be fully melt down into and specifically focused in the disaster policies in Korea for the better disaster management.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.4
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• pp.283-290
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• 2022

In this study, an IoT inspection system that can be linked with a server was developed using a gas timer and ESP-01 Wi-Fi module installed on a gas valve in the home. The server environment of the gas leak IoT inspection system was installed with APM (Apache, PHP, MySQL) to collect gas pressure data by generation so that leakage checks could be performed. In order to control the gas leak IoT inspection system, the app inventory was used to manage the gas leak check value in real time. In addition, user convenience has been enhanced so that membership management, WiFi settings, and leakage check values can be checked through mobile apps. In order to manage subscribers by region, the user list was checked by logging in in in the administrator mode so that the information on whether or not the leak test was conducted and the results could be provided. In addition, when the user presses the gas leak check button, the pressure is automatically checked, and the measured value is stored in the server, and when a gas leak occurs, the leakage check is performed after alarm and repair so that it can be used if normal. In addition, in order to prevent overlapping membership, membership management can be performed based on MAC addresses.

• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.455-466
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• 2006

This study was an attempt to control and monitor Computerized Numerical Controller (CNC) machines anywhere and anytime for the development of a ubiquitous machine (u-machine). With a Personal Digital Assistant (PDA) phone, the machine status and machining data of CNC machines can be monitored in wired and wireless environments, including the environments of IMT2000 and Wireless LAN. Moreover, CNC machines can be controlled anywhere and anytime. The concept of the anywhere-anytime controlling and monitoring of a manufacturing system was implemented in this study for the purpose of u-manufacturing and u-machines. In this concept, the communication between the CNC controller and the PDA phone was successfully performed anywhere and anytime for the real-time monitoring and control of CNC machines. In addition, the interface between the CNC controller and the developed application module was implemented by Object linking and embedding for Process Control (OPC) and shared CNC memory. For communication, the design of a server contents module within the target CNC was based on a TCP/IP. Furthermore, the client contents module within the PDA phone was designed with the aid of embedded c++ programming for mobile communication. For the interface, the monitoring data, such as the machine status, the machine running state, the name of the Numerical Control (NC) program, the alarm and the position of the stage axes, were acquired in real time from real machines with the aid of the OPC method and by sharing the CNC memory. The control data, such as the start, hold, emergency stop, reserved start and reserved stop, were also applied to the CNC domain of the real machine. CNC machines can therefore be controlled and monitored in real time, anywhere and anytime. Moreover, prompt notification from CNC machines to mobile phones, including cellular phones and PDA phones, can be automatically realized in emergencies.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.541-546
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• 2008

The purpose of this study was to evaluate ecosystem health effect in the physiological levels, based on ethoxyresorufin-O-deethylase (EROD) and total oxyradical scavenging capacity (TOSC) assays using sentinel fish species. We collected fish samples of Zacco platypus in May 2008 from 3 sampling sites including upstream, midstream, and downstream of the Gap Stream. EROD activity was averaged 4.54 in the downstream, 2.7 fold higher than upstream and indicated that stream condition was degraded along with longitudinal gradient from up to downstream. Downstream, especially was significantly increased (p < 0.01) so that indicated various pollutants including nutrient enrichment and toxicant exposure from the point sources, wastewater treatment plant and industrial complex may impact to the stream condition. In the mean time, TOSC assays showed higher in the midstream than other sites, but the values were not significant, compared to the previous report on oxidative stress. Overall results indicated that our approaches applying two biomarkers can be effectively used for diagnosis of the physiological levels in an integrative stream health assessments and can be applied as useful pre-warning techniques as a biochemical alarm system of organic pollutions.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.421-426
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• 2016

This study suggests a board fence design with a convergence-style mural. The basic structure contains pictorial factors with mural paintings on the fence. It is also equipped with electricity facilities inside the fence itself, so it has not only the unique function of the fence but also the complexity and expandability in order to be used as a garden lighting and security alarm system. All the components meet the standard so they can be manufactured in a factory. Through this design proposal, this study tries to suggest a fence which encourages personal or social communication one another as well as the basic function of the fence. As a result, the fence realizes a broad convergence function of its usefulness for social functioning such as the crime prevention as well as an esthetic function.

• Journal of the Korean Society for Library and Information Science
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• v.48 no.2
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• pp.25-44
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• 2014

This research evaluates the accessibility of the mobile applications for the South Korean libraries based on the accessibility guideline from the Ministry of Security and Public Administration. In order to enhance the credibility of the evaluation, this current research covers both the accessibility for the visually impaired and the accessibility for the people without disabilities. The research found four main results. First, we found that only 21 libraries (31%) provide alternative texts. Out of the 21 libraries, only one provide alternative texts across all sections of the mobile applications, including the main page, data search, information assistance, etc. Second, most of the mobile applications provide contents in texts, and the subtitles, sign language, blinking and background music provided as required or recommended standard by the guideline lack correlation. Third, alternative texts, focus movement, accessibility of operating system, button motion control, spacing between control and alarm functions must follow the standard guideline for the people with disabilities to use the mobile applications. Fourth, follow-up research on the development of accessibility standard for library mobile application is necessary in order to enable people with disabilities to freely use the library mobile applications.