• Journal of Information Technology Services
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• v.13 no.4
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• pp.289-308
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• 2014

Mobile instant messaging (MIM) has been widely used in modern society due to its portability, speed and ease of use. In addition to simple text-based messaging, mobile instant message has now expanded to include graphics, images, and video. Many instant message service providers attempt to differentiate their service by providing an unique emoticon. Therefore, understanding the factors that affecting the continuous usage of emoticon is essential to capture users' interest. There is relatively little study on emoticon in information systems field. Hence, this study attempts to explore the continuous usage of emoticon through exploring the property of emoticon and usage motivation of emoticon. Based on the results, this study attempts to demonstrate practical implication of marketing on understanding user interest to mobile instant messenger service provider.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.757-766
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• 2005

A speed of a train is controlled by Automatic Train Control system and the continuous transmission system provide the speed related information in the Korean High Speed Line. The primary objective of this paper is to measure the level of continuous signal and to calculate the message of that signal. A measuring equipment is introduced and the equipment provide the base line of the level of current and the correction information of the message.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.351-355
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• 2009

There are two types of controller between railway and train. those are the Continuous Message Controller and the Intermittent Message Controller using for KHSR. The conventional Intermittent Message Controller board used a variable resister for setting the phase, but the variable resister affected some environmental facts, such as temperature, humidity, and vibration, etc. And It is requirement of reduction message processing time for speed-up operation in Next-Generation High-Speed Rail. This study suggests how to solve the problem described above. Using FPGA is quite profitable. It's easy to use and maintain, flexible with the New algorithm to fix up the problem.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.89-99
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• 2018

The number of traffic accidents in Korea has been increasing since 2014. In most school zones, safety signs are installed to prevent children's traffic accidents. However, it has been known that the effects of those signs are not significant. A variable message sign(VMS), one of the components of Intelligent Transport System(ITS), has emerged as an alternative method. Therefore, this study examines relative effects of two different VMS messages(Timely vs. Continuous) on vehicle speed. Experiments were conducted in two school zones. 6,676 vehicles were measured for speed limit compliance. A counterbalanced multiple baseline design was adopted. The results showed that both types of message are effective in reducing the speed of vehicle. Specifically, A timely message was more effective in slowing down vehicle speed and improving speed limit compliance than a continuous message. The present study suggested that a VMS with human factors can be effective.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1180-1184
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• 2004

There are two types of controller between railway and train. those are the Continuous Message Controller and the Intermittent Message Controller using for KHSR. The conventional Intermittent Message Controller board used a variable resister for setting the phase, but the variable resister affected some environmental facts, such as temperature, humidity, and vibration, etc. This study suggests how to solve the environmental problem described above. Using FPGA is quite profitable. It's easy to use and maintain, flexible with the New algorithm to fix up the problem.

• Journal of information and communication convergence engineering
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• v.19 no.1
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• pp.16-21
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• 2021

In this paper, to prevent accidents of school vehicles used by students, which have emerged as a continuous social problem, a boarding and leaving notification system using Bluetooth beacons is proposed. The platform structure uses Bluetooth, a smartphone, and an application, and provides real-time message reception between parents and teachers. It is not simply a system with Bluetooth capability alone, but also an IcT technology that is closely related to real life using two-way communication. The purpose is to provide user-friendly ICT technology as an integrated system for more practical effects. Two-way exchange of information between parents and teachers using cloud servers is made possible. By using this Bluetooth beacon notification system, safety accidents in student vehicles are reduced, which brings confidence from traffic accidents to schoolchildren of parents and teachers. Therefore, it is expected that parents and teachers are expected to improve their mental stability and quality of life from traffic accidents.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.625-631
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• 2010

In this paper, robustness performance of SNUR message is compared with those of existing ones, RTCM(Radio Technical Commission for Maritime Services) v2 MT(Message Type) 18/19 and MT 20/21 under a poor broadcast condition such as temporary data loss or disconnection We defined the temp oral data loss as 2 second delay and reconnection after disconnection as 7 second latency, and then evaluated its robustness for each latency case by double differentiating the observables. Our result shows that SNUR protocol method can reduce the latency error of the existing RTCM messages by 30~60%. Moreover, a rover using SNUR message, whose latency error is bounded within 1/4 L1 wave length, can figure out its own fixed position continuously in spite of 7 second disconnection, while the other using RTCM message, whose error is larger than half wave length, cannot keep its previous fixed solution.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.10
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• pp.1194-1205
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• 1999

인과적 메시지 로깅은 정상수행시 낙관적 메시지 로깅의 장점을 가지고, 회복시 비관적 메시지 로깅의 장점을 가지고 있다. 본 논문에서는 회복 프로세스들간의 비동기성을 향상시키기 위한 인과적 메시지 로깅에 기반한 새로운 회복 알고리즘을 제안하고자 한다. 기존의 인과적 메시지 로깅 기반 회복 알고리즘들은 살아있는 프로세스들의 수행을 대기시키거나, 회복 프로세스들간의 높은 동기성을 요구한다. 본 논문에서 제안하는 회복 알고리즘은 각 회복 프로세스가 자신의 회복만을 책임지게 함으로써, 여러 개의 프로세스들이 동시적으로 고장이 발생하더라도 회복시 살아있는 프로세스들의 수행을 대기시키지 않고, 회복 프로세스들 중 하나의 회복 프로세스에게만 과부하가 발생하지 않도록 한다. 또한, 제안하는 알고리즘은 각 회복 프로세스의 회복 과정이 다른 회복 프로세스의 연속적인 고장들에 의해 지연되지 않도록 한다. 본 논문에서는 제안하는 회복 알고리즘의 정당성을 증명하고, 시뮬레이션을 통해서 제안하는 회복 알고리즘이 기존 회복 알고리즘에 비해 고장난 프로세스의 평균회복시간을 단축시킨다는 것을 보여준다.Abstract Causal message logging has the advantages of optimistic message logging during failure-free execution and pessimistic message logging during recovery. In this paper, we present a new recovery algorithm based on causal message logging for improving asynchrony among recovering processes. Existing recovery algorithms based on causal message logging block the execution of live processes or require high synchronization among recovering processes. As each recovering process is responsible for only its recovery in our algorithm, the algorithm avoids blocking the execution of live processes during recovery even in concurrently multiple failures and overloading only one among recovering processes. Moreover, it allows the recovery of each recovering process not to be delayed by the continuous failures of other recovering processes. We prove the correctness of our recovery algorithm, and our simulation results show that our algorithm reduces the average recovery time of a failed process compared with the existing recovery algorithms.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.73-76
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• 2000

In the basic continuous ARQ schemes (Go-Back-N or Selective Repeat ARQ), each block is continuously transmitted without interruptions. Only when the transmitter receives NAK from the receiver side, the transmitter stops sending current data block and retransmit the erroneous block (Naked block). When channel error rate increases and become sufficiently high, there exists a point at which each block of message is transmitted, on average, more than once. Under such conditions, it will be more efficient to send continuously two or more copies(generally $\ell$ copies) of each block from the first transmission over noisy channel. A request for repeat will be made again only when none of $\ell$ duplicates are received correctly. By this way, the proposed scheme yields a better throughput efficiency and holds nearly constant throughput as compared to others continuous A.R.Q schemes under wide error rate variations (0 < P < 0.3).

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.661-671
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• 2018

The avoidance tendency of voice call in younger generation facilitates the growth of mobile O2O service that utilizes Messaging. This study adopted and elaborated original concepts of telephone apprehension to apply phone anxiety to O2O. We examined previous researches related to the ubiquity of service quality, communication ability and anxiety, and then conducted a survey to understand the consciousness of mobile O2O service users. The results show that users with high message intimacy and users with poor logicality are afraid of voice calls. The mobile O2O service is considered useful as a means to replace an unstable situation. In this study, we considered individual characteristics of acceptance factor of O2O mobile service technology, and it was a new attempt to expand telephone apprehension characteristic reflecting current situation. In addition, the different results of this research from prior studies that examined the relationships among apprehension, usefulness, and continuous use intentions might be helpful to expand and sophisticate the research area.