• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.239-243
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• 2011

In wireless ad-hoc network, the detection of link breakage and re-establishing the route path causes lots of network overhead and results in communication delay. In the LBN method, the node causing a link breakage actively sends a message to neighbors so that they can instantly start re-establishing process of new path. In this paper we describe the result of network simulation we performed using NS2 to show the effectiveness of LBN method.

• Journal of Korean language education
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• v.25 no.1
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• pp.203-234
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• 2014

This paper demonstrates how to incorporate the teaching of communication strategies into a large class of English-speaking learners of the Korean language. The method proposed here was developed to overcome the difficulty of conducting language activities involving communicative interactions amongst students and also between teacher and students in a large classroom. As a way of compensating the minimal opportunities for interactions in the classroom, students are given the task of expressing in Korean the English translations of authentic Korean comics via Twitter, which was later replaced with the feedback feature on Moodle, and then their Korean expressions are collected and projected onto a big screen. These collected expressions by students naturally differ from one another, helping students to realize that it is possible for them to express the same message or meaning in many different ways. The results of two separately conducted questionnaires show that this method is an effective way of providing students with significantly increased chances of producing 'comprehensible output' that requires them to think of how to communicate with their limited knowledge of the Korean language. Many students also commented that the teachers' feedback on errors provides them with the opportunity to learn about common errors as well as their own errors.

• Annual Conference of KIPS
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• 2012.11a
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• pp.87-90
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• 2012

원자력발전소에 사용되는 모든 시스템은 IEEE에서 최고 수준의 안전도인 CLASS 1E로 분류된다. 그중에서 안전계통은 원자력발전소 안전에 관련한 모든 분야를 관리하는 계통이다. 산업이 발전함에 따라 안전계통 또한 그 규모와 복잡성이 높아지고 있고, 이에 적용되는 요구사항 또한 엄격해지고 있다. 따라서 발전소에 적용되는 안전 동작에 대한 기준을 결정하기 위해서 철저한 오류 예측분석이 수행 되어야 한다. 그 중에서도 NUREG-0492로 규정되어 있는 결함수목분석(Fault Tree Analysis)은 연역적 오류 예측 분석방법으로 원자력 발전소, 우주 산업 등에 관련된 분야는 본 방법을 통하여 오류 예측 분석이 이루어 져야한다. 본 논문에서 원전안전계통을 관리하는 구현 모델인 원전안전등급제어기기(Safety Programmable Logic Controller)에 대하여 결함수목분석을 통한 오류 예측 분석을 하였다. 또한, 위의 구조에 대하여 MSC(Message Sequence Chart)를 통한 모델링을 수행하여, 결함수목분석을 적용하는 과정에서 신뢰도 향상을 더하였다.

• IEMEK Journal of Embedded Systems and Applications
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• v.16 no.6
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• pp.299-305
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• 2021

Dissolved oxygen, pH, and temperature are the most important factors for fish farming because they affect fish growth and mass mortality of the fish. Therefore, fish farm workers must always check all pools on the farm, but this is very difficult in reality. That's why we developed a control system for smart fish farms. This system includes a gateway, sensor gatherers, and a PC program using LabVIEW. One sensor gatherer can cover up to four pools. The sensor gatherers are connected to the gateway in the form of a bus. For the gateway, the ATmega2560 is used as the main processor for communication and the STM32F429 is used as a sub-processor for displaying LCD. For the sensor gatherer, ATmega2560 is used as the main processor for communication. MQTT (Message Queuing Telemetry Transport), RS-485, and Zigbee are used as the communication protocols in the control system. The users can control the temperature and the dissolved oxygen using the PC program. The commands are transferred from the PC program to the gateway through the MQTT protocol. When the gateway gets the commands, it transfers the commands to the appropriate sensor gatherer through RS-485 and Zigbee.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.157-162
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• 2018

This study uses sensors and Raspberry Pi to measure the values of current and voltage and transmits the measured sampled values to a network, carrying them in the frame of IEC 61850-9-2. A laboratory model was composed to send the sampled values, using the frame of IEC 61850-9-2. This study conducted a protocol analysis, using Wireshark for the accurate verification of the occurrence of the frame of IEC 61850-9-2. A visual analysis was conducted by displaying the received sampled values of current and voltage on the monitor in graphs. In addition, this study tested if the sampled values of IEC 61850-9-2 sent and received through the network equipment would meet the performance requirements of the message types of IEC 61850.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.1-8
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• 2019

Internet of Things (IoT) is proliferating to provide more intelligent services by interconnecting various Internet devices, and TCP based MQTT is being used as a standard communication protocol of the IoT. Although it is recommended to use TLS/SSL security protocol for TCP with MQTT-based IoT devices, encryption and decryption performance degenerates when applied to low-specification / low-capacity IoT devices. In this paper, we propose an end-to-end message security protocol using elliptic curve cryptosystem, a lightweight encryption algorithm, which improves performance on both sides of the client and server, based on the simulation of TLS/SSL and the proposed protocol.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.4
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• pp.11-18
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• 2014

Recently, ICT technology has been evolving towards an M2M (Machine to Machine) environment that allows communication between machine and machine from the communication between person and person, and now the IoT (Internet of Things) technology that connects all things without human intervention is receiving great attention. In such a network environment, the communication network between object and object as well as between person and person, and person and object is available which leads to the sharing of information between all objects, which is the essential technical element for us to move forward to the information service society of the era of future ubiquitous computing. On this paper, the protocol related to DTMNs in a Sparse M2M environment was applied and the improved routing protocol was applied by using the azimuth and density of the moving node in order to support a more efficient network environment to deliver the message between nodes in an M2M environment. This paper intends to verify the continuity of the study related to efficient routing protocols to provide an efficient network environment in the IoT and IoE (Internet of Everything) environment which is as of recently in the spotlight.

• Journal of Information Processing Systems
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• v.19 no.3
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• pp.394-406
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• 2023

In this study, a real-time surveillance system using Internet of Things technology is proposed for vaccine cold chains. This system fully visualizes vaccine transport and storage. It comprises a 4G gateway module, lowpower and low-cost wireless temperature and humidity collection module (WTHCM), cloud service software platform, and phone app. The WTHCM is installed in freezers or truck-mounted cold chain cabinets to collect the temperature and humidity information of the vaccine storage environment. It then transmits the collected data to a gateway module in the radiofrequency_physical layer (RF_PHY). The RF_PHY is an interface for calling the bottom 2.4-GHz transceiver, which can realize a more flexible communication mode. The gateway module can simultaneously receive data from multiple acquisition terminals, process the received data depending on the protocol, and transmit the collated data to the cloud server platform via 4G or Wi-Fi. The cloud server platform primarily provides data storage, chart views, short-message warnings, and other functions. The phone app is designed to help users view and print temperature and humidity data concerning the transportation and storage of vaccines anytime and anywhere. Thus, this system provides a new vaccine management model for ensuring the safety and reliability of vaccines to a greater extent.

• Archives of design research
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• v.15 no.2
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• pp.91-100
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• 2002

Unlike a study related in language alone, rhetorical study of current time, composed with multi-culture, medias, communication, presents its own field that covers from the form of discourse(persuasive) to another form of discourse(not persuasive). If there was a study of making beautiful sentences for story and finding simple method of speech in Greek and roman period of an ancient time, it now a study in which one finds the essence of literary style or terminology in the expression of sentence. The taller case is especially important, given that the importance of what to express visually is on-going active procedure of this stuffy as itself an activity of communication. When a visual object persuades viewers, the activity of communication derives them to react and to understand the intention of an artist. The matter of how to speak is the matter of how to shape message persuasively. This persuasive method or technique is study of rhetoric. The three aspects (figurative, accentuating, mutating) of rhetorical expression of an illustration, the visual image can give fresh feelings to be in intimate relations with public. These rhetorical expressions also vitalize the story that is expressed on illustration with crisp image. It helps to attain expected effects while discovering essential meaning through the corresponding linguistic interpretation of an image. The study aims at the most effective way to communicate by figuring the most strong and direct illustrative message out. One of the method is to patternize illustrative expressions that are established from all kinds of shapes of Rhetoric. Therefore ,an operation of significance and an implication can shape an ultimate goal of this study from acknowledging the mechanism that modern illustration embraces.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.1 s.343
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• pp.79-88
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• 2006

In this paper, we designed and implemented ubiquitous u-Health system using RFE and ZigBee. We made a wireless protocol Kit which combines RFE Tag recognition and ZigBee data communication capability. The software is designed and developed on the TinyOS. Wireless communication technologies which hold multi-protocol stacks with RFID and result in the wireless ubiquitous world could be Bluetooth, ZigBee, 802.11x WLAN and so on. The environments that the suggested u-Health system may be used is un-manned nursing, which would be utilized in dense sensor networks such as a hospital. The the size of devices with RFID and ZigBee will be so smaller and smaller as a bracelet, a wrist watch and a ring. The combined wireless RFID-ZigBee system could be applied to applications which requires some actions corresponding to the collected (or sensed) information in WBAN(Wireless Body Area Network) and/or WPAN(Wireless Person Area Network). The proposed ubiquitous u-Health system displays some text-type alert message on LCD which is attached to the system or gives voice alert message to the adequate node users. RFE will be used as various combinations with other wireless technologies for some application-specific purposes.