• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4B
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• pp.311-322
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• 2006

Peer-to-peer (P2P) systems have become a popular medium through which to share huge amounts of data. On the basis of network topology, P2P systems are divided into three types: centralized, structured distribution, unstructured distribution. Unstructured P2P systems such as Gnutella are novel in the sense that they are extensible and reliable. However, as the number of nodes increases, unstructured P2P systems would suffer from the high complexity of search operations that have to scan the network to find the required data items. Efficient replication of data items can reduce the complexity, but it introduces another problem of maintaining consistency among replicated data items when each data item could be updated. In this paper, we propose a new update propagation algorithm that propagates an updated data item to all of its replica. The proposed algorithm can reduce the message transfer overhead by adopting the notion of timestamp and hybrid push/pull messaging.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.218-226
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• 2017

In this paper, optical transport network in real time monitoring system using smart phone. The existing housing using monitoring was a smart phone of optical transport network access switch about an event with new installation of cognitive system in real time. This paper can this problem to be solved of the invention in real time maintenance using smart phone application and optical cable closure switch. If you want to find optical cable closure fault location, this smart phone web is very useful. Cable tie is isolation of fiber spare board from fiber switch tie occur push message. Housing and access, and an external failures otdr the measurement of the global positioning to be able to easily using the This paper can find event of optical cable closure unauthorized work and fault using smart phone OTDR function. the optical cable fault time reduction and network transport quality by managing real time optical cable section by using the smart phone can be maintained efficiently.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.187-192
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• 2020

It is very useful because we can measure precise exercise volume at indoor and outdoor space, and receive push message and retrieve for exercise information by smart-phone at any-time and any-place if a fitness healthcare system base on IoT is utilized. This system is interlocked with IoT module including sensing device in sports equipment, IoT gateway, smart-phone, smart-band and server by internet. In this paper, when this, "a fitness healthcare system base on IoT", software is developed, a proper analysis and design method for practical affairs try to be presented due to showing software development analysis method and design method such as flowchart and UI design.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.369-376
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• 2018

This paper presents an android-based implementation of real-time remote monitoring system for industrial gas turbines. The use of remote monitoring techniques can be beneficial in terms of not only the reduction of monitoring cost but also the earlier detection of abnormal status. In order to achieve the ability of protecting sensitive information from unauthorized persons, the proposed system supports secure transmissions using the RSA(Rivest Shamir Adleman) algorithm. In the event of abnormal situation on the gas turbine, the remote monitoring system generates an alarm to attract the user's attention by exploiting a push-message technique. The proposed system has been verified through a series of experiments with an experimental setup including a virtual data generator.

• Journal of Internet Computing and Services
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• v.5 no.1
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• pp.85-97
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• 2004

Distributed Denial-of-Service(DDoS) attack prevent users from accessing services on the target network by spoofing its origin source address with a large volume of traffic. The objective of IP Traceback is to determine the real attack sources, as well as the full path taken by the attack packets. Existing IP Traceback methods can be categorized as proactive or reactive tracing. Proactive tracing(such as packet marking and messaging) prepares information for tracing when packets are in transit. Reactive tracing starts tracing after an attack is detected. In this paper, we propose a "advanced ICMP Traceback" mechanism. which is based on the modified push back system. Proposed mechanism can detect and control DDoS traffic on router and can generate ICMP Traceback message for reconstructing origin attack source.ck source.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.3
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• pp.9-15
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• 2008

This paper, in the field of home automation with increased security, is to develop a function of storing and inquiring images, which are taken by the camera of a videophone connected to DVR devices. Particularly, as soon as visitors push a bell button, the images of them are stored automatically and let us check the information of them Besides, we can monitor the status of an empty house with varieties of sensors. Information of these can be checked out through internet in real-time by home automation and web-based systems. Finally, we developed home security system that sends a homeowner a text message about the status of the house in case of strange things happening at the empty house.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.744-747
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• 2017

The Internet of things (IoT) needs to be an event-driven approach for efficient real time response and processing. An IoT gateway is sometimes employed to provide the connection and translation between devices and the cloud. Storing data in the local database, and then forwarding it on the cloud is a task to be relegated to a gateway device In this paper, we propose the design of the IoT gateway with Fog computing for storing data from sensors into a local database. In the procedure of designing storing tasks, we propose to use the interfacing software known as Ardulink MQTT bridge. MQTT is a protocol for sensors to publish data to the clients. When it comes to needing historical data, MQTT connector can push MQTT data into SQL database. We write an MQTT client and based on the message topic insert the values into a SQL Database The design of IoT gateway with Fog computing adds value because it provides processing of the data across multiple devices before it sends to the cloud.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.981-986
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• 2020

The Internet of Things refers to a space-of-things connection network configured to allow things with built-in sensors and communication functions to interact with people and other things, regardless of the restriction of place or time.IoT is a network developed for the purpose of services for human convenience, but the scope of its use is expanding across industries such as power transmission, energy management, and factory automation. However, the communication protocol of IoT, MQTT, is a lightweight message transmission protocol based on the push technology and has a security vulnerability, and this suggests that there are risks such as personal information infringement or industrial information leakage. To solve this problem, we designed a synchronous MQTT security channel that creates a secure channel by using the characteristic that different chaotic dynamical systems are synchronized with arbitrary values in the lightweight message transmission MQTT protocol. The communication channel we designed is a method of transmitting information to the noise channel by using characteristics such as random number similarity of chaotic signals, sensitivity to initial value, and reproducibility of signals. The encryption method synchronized with the proposed key value is a method optimized for the lightweight message transmission protocol, and if applied to the MQTT of IoT, it is believed to be effective in creating a secure channel.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.7-16
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• 2020

The mobile electronic notification service delivers notifications through mobile phone text or app-based message push to solve various problems of the paper-based mail service. And it is a service that an electronic document relay company proves to prove delivery. In order for public and administrative agencies to provide mobile electronic notification service, the user's identification information of the mobile phone number or the subscribed app is required. To overcome these limitations, ICT-regulated sandbox system was used to allow collective conversion of users' resident registration numbers into connecting information (CI). Therefore, in this paper, we propose a technical method for safe management of user CI in mobile electronic notice service, identity verification of electronic notice readers, and prevention of forgery and forgery of electronic notices. Through the proposed method, it is confirmed that the service can be activated by minimizing the adverse function of the mobile electronic notification service by securing the user's convenience and technical safety for the CI.

• Journal of Broadcast Engineering
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• v.24 no.6
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• pp.928-938
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• 2019

Republic of Korea has established 'Transmission and Reception for Terrestrial UHDTV Broadcasting Service' standard based on ATSC 3.0, the next-generation broadcasting standard in North America and is now providing commercial services. Republic of Korea has been studying terrestrial UHDTV based disaster broadcasting service using the ATSC 3.0 AEA system's technology since 2018. ATSC 3.0 has established a standard for expanding disaster broadcasting services, which were used to be simple push-type text message broadcasting, by introducing bidirectional and rich-media transporting mechanisms. However, the disaster information is still focused on the general public, and disaster broadcasting service including detailed information for the vulnerable are still insufficient. In this paper, we proposed the optimized disaster broadcasting service for vulnerable populations based on ATSC 3.0 after defined the disaster vulnerable populations as the target of the service. And we defined the extension element of disaster broadcasting message for service provision. The proposed service can be an effective means to increase the possibility of disaster information reception and evacuation to vulnerable populations. In addition, it is expected to be used as a basic research for development of diverse and effective advanced services for vulnerable populations through linkage with existing disaster alerting and countermeasures studies.