• Journal of Broadcast Engineering
• /
• v.25 no.3
• /
• pp.399-404
• /
• 2020

The Disaster text service is a text-based service for public alert. But, foreigners who are not familiar with korean can not understand exactly the disaster text messages provided. Using multimedia information such as images is expected to solve this problem. However, the current disaster message service method is not suitable for multimedia information delivery. This study proposes a firmware-based disaster character service method for displaying disaster image in a terminal. A device using this method should store images corresponding to the type of disaster and use special characters to inform the presentation of image in a terminal. This approach can be implemented in the new firmware installed device and it can be work with the existing device.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.39 no.4
• /
• pp.10-18
• /
• 2002

Network topology design is a multiobjective problem with various design components. The components such as cost, message delay and reliability are important to gain the best performance. Recently, Genetic Algorithms(GAs) have been widely used as an optimization method for real-world problems such as combinatorial optimization, network topology design, and so on. This paper proposed a method of Multi-objective GA for Design of the network topology which is to minimize connection cost and message delay time. A common difficulty in multiobjective optimization is the existence of an objective conflict. We used the prufer number and cluster string for encoding, parato elimination method and niche-formation method for the fitness sharing method, and reformation elitism for the prevention of pre-convergence. From the simulation, the proposed method shows that the better candidates of network architecture can be found.

• Convergence Security Journal
• /
• v.13 no.3
• /
• pp.47-54
• /
• 2013

Ad-hoc network is composed of mobile nodes and has a vulnerability of attack like on conventional wire networks. So, many studies have been conducted to apply the traceback mechanism on wire network to Ad-hoc network. In this paper, a new mechanism that can trace back to IP source of spoofing DDoS packet using iTrace message on Ad-hoc network is proposed. The proposed mechanism implements ICMP Traceback message and the traceback path between agents allocated in local network and a server located in management network. Also the proposed mechanism can trace the position of attacker even after an attack is over and has extendability through standardization by using a mechanism that IETF proposed. Result of performance evaluation shows a great improvement in terms of load, integrity, safety, traceback function as compared with conventional mechanisms.

• Journal of Advanced Navigation Technology
• /
• v.23 no.6
• /
• pp.548-553
• /
• 2019

Along with advanced vehicle to vehicle (V2V) communication technologies, platooning is regarded as one of the most promising form of autonomous driving solutions in order to increase road capacity. In this paper, we propose a novel V2V transmission scheme for safety message dissemination in platooning. The proposed scheme enhances the efficiency of channel access and multi-vehicle orthogonal frequency division multiple access (OFDMA) transmission by taking advantage of triggered uplink access technique and null data packet feedback report protocol introduced in the sixth generation WLAN standard, IEEE 802.11ax. The simulation results prove that the proposed scheme outperforms the conventional IEEE 802.11 transmission scheme throughout all measured vehicle density range.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.8
• /
• pp.1477-1484
• /
• 2015

In this paper, a novel reversible data hiding by using Reed-Solomon (RS) code is proposed for efficient transmission in encryption image. To increase the recovery of data from encrypted image, RS codes are used to encode messages, and then the codewords can be embedded into encrypted image according to encryption key. After receiving encrypted image which embeds the codewords, the receiver firstly decryptes the encrypted image using the encryption key and get metric about codewords containing messages. According to recovery capability of RS codes, better estimation of message is done in data hiding system. Simulation results about two images and two RS codes show that the performances of the proposed schemes are better than ones of the reference scheme.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.5
• /
• pp.581-591
• /
• 2016

RFID(Radio Frequency IDentification) is a key technology in ubiquitous computing and is expected to be employed in more fields in the near future. Nevertheless, the RFID system is vulnerable to attacks by eavesdropping or altering of the messages transmitted in wireless channels. In 2013, Oh et al. proposed a mutual authentication protocol between a tag and a reader in RFID systems. Their protocol is designed to resist location tracking for privacy protection. However, all tags and readers use only one network-wide key in their protocol and tags are usually vulnerable to physical attacks. We found that their protocol is still vulnerable to tag/reader impersonation attacks and location tracking if an attacker obtains the network-wide key from a tag. In this paper, we propose a security improved authentication protocol for privacy protection in RFID systems. In addition, we demonstrate that the proposed scheme is efficient in terms of computation and communication costs.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.5
• /
• pp.486-496
• /
• 2013

Time synchronization in underwater environment is challenging due to high propagation delay and mobility of sensor nodes. Previous researches do not consider practical issues affecting on the accuracy of time synchronization such as high-channel access delay and relative position between sensor nodes. Also, those protocols using bidirectional message exchange shorten the network lifetime and decrease the network throughput because numerous transmission, reception and unnecessary overhearing can be occurred. Therefore, in our research, we suggest enhanced time synchronization based on features of underwater environment. It controls the instant of transmission by exploiting the feature of an oceanic movement and node deployment. Moreover, the protocol uses more accurate time information by removing channel access delay from the timestamp. The proposed scheme is also practical on the underwater sensor network requiring low-power consumption because the scheme conducts time-synchronization with smaller transmission and reception compared with previous works. Finally, simulation results show that the proposed protocol deceases time error by 2.5ms and 0.56ms compared with TSHL and MU-Sync respectively, reducing energy consumption by 68.4%.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.2 s.46
• /
• pp.141-150
• /
• 2007

This paper proposes how to reduce the amount of data transmitted in each sensor and cluster head in order to lengthen the lifetime of sensor network. The most important factor of reducing the sensor's energy dissipation is to reduce the amount of messages transmitted. This paper proposed is to classify the node's cluster state into 6 categories in order to reduce both the number and amount of data transmission: Initial, Cluster Head, Cluster Member, Non-transmission Cluster Head, Non-transmission Cluster Member, and Sleep. This should increase the efficiency of filtering and decrease the inaccuracy of the data compared to the methods which enlarge the filter width to do more filtering. This method is much more efficient and effective than the previous work. We show through various experiments that our scheme reduces the network traffic significantly and increases the network's lifetime than existing methods.

• Science of Emotion and Sensibility
• /
• v.12 no.1
• /
• pp.33-44
• /
• 2009

This study investigates differential impacts of the positive and negative content and the interaction with pacing, as a structural feature, on information processing while watching televised video clips with moderately intensive emotional tone. College participants watched six positive messages and six negative video clips lasting approximately 60 seconds. Heart rate was used to index attention and skin conductance was used to measure arousal. After all of the stimuli were shown, the participants performed the free recall questionnaire. The result demonstrates, first, positivity superiority on attention in which participants' heart rates were slower during positive content compared to during negative content. Secondly, negativity superiority was shown on free recall memory as participants remembered positive content better than did negative content. The result also manifests the interaction of emotional valence and pacing as the effects of pacing were less for the negatively emotional content compared to those for the positively emotional content. It is suggested that future studies should examine further about the differential and independent functions of positive and negative contents on information processing and the potential interaction with formal features.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.4B
• /
• pp.165-173
• /
• 2008

In this paper, we propose a new reliable broadcast protocol referred to as timer-based reliable broadcast (TRB) for wireless sensor networks (WSNs). The proposed TRB scheme exploits (1) bitmap based explicit ACK to effectively reduce the unnecessary error control messages and (2) randomized timer for ACK transmission to substantially reduce the possibility of contentions. Although it has been argued that 100% reliability is not necessary in WSNs, there should be messages (such as mission-critical message, task assignment, software updates, etc.) that need to be reliably delivered to the entire sensor field. We propose to use the TRB algorithm for such cases. Performance evaluation shows that the TRB scheme achieves 100 % reliability significantly better than other schemes with expense of slightly increased energy consumption.