• Journal of Advanced Navigation Technology
• /
• v.14 no.5
• /
• pp.625-631
• /
• 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 the Korea Institute of Information and Communication Engineering
• /
• v.22 no.1
• /
• pp.140-146
• /
• 2018

Recently, VLC(Visible Light Communication) fusing with LED(Light Emitting Diode) used in indoor lighting and wireless communication technology has attracted attention. However, the VLC can communicate only within the coverage to measure the optical signal and the communication disconnection phenomenon is occur in the NLoS(Non-Line-of-Sight) area. In this paper, we propose VLC relay module to extend the coverage of VLC and improve the communication disconnection phenomenon in NLoS area. The proposed VLC relay module transmits the packet received from the transmitter to the VLC relay module and receiver. The experiment was carried out by installing one VLC transmitter and three VLC relay modules, communication coverage expansion and the improvement of communication disconnection phenomenon in the NLoS were confirmed by the increase of the VLC relay module. Also, we confirmed that the optical signal measurement performance is improved 2.4 times by using the dual sampling method.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.10
• /
• pp.121-128
• /
• 2013

Existing sensor network studies have only emphasized energy aspects that sensors themselves had. But when an actual sensor network is established, biased use of a specific sensor may cause a partial disconnection of the sensor network. It becomes an disadvantage to fail efficient operation of the sensor network for a long time and energy efficiency of specific sensor energy causes to drop the efficiency of the sensor network. When a sensor network is composed of many clusters or made up of a large network, sensor network's disconnection cannot be avoided because they emphasize sensor's energy efficiency. Therefore, it was tried to lengthen the lifespan of the sensor network by making sensors in the sensor network avoid disconnection through even use of all the sensors composing of the sensor network. This article proposes a protocol to maintain a sensor network for a long time by preventing a sensor networks' disconnection through efficient management of sensor network energy composed of the protocols composing of the sensor network in ubiquitous environments.

• KIPS Transactions on Computer and Communication Systems
• /
• v.8 no.3
• /
• pp.73-78
• /
• 2019

Due to frequent topology changes in wireless networks, inter-node link disconnection and path re-establishment occur, causing problems such as overloading control messages in the network. In this paper, to solve the problems such as link disconnection and control message overload, we perform path setup in three steps of the neighbor node discovery process, the route discovery process, and the route management process in the wireless network environment. The link stability value is calculated using the information of the routing table. Then, when the zone master monitors the calculated link value and becomes less than the threshold value, it predicts the link disconnection and performs the path reset to the corresponding transmitting and receiving node. The proposed scheme shows a performance improvement over the existing OLSR protocol in terms of data throughput, average path setup time, and data throughput depending on the speed of the mobile node as the number of mobile nodes changes.

• Korean Journal of Childcare and Education
• /
• v.13 no.3
• /
• pp.1-17
• /
• 2017

Objective: The purpose of this study was to analyze the effects of preschoolers' negative emotionality on their peer play behaviors, focusing on the mediation of behavioral problems. Methods: The study sample included 287 preschoolers aged 3 to 5 attending child care centers located in Seoul, Korea. The instruments used in this study were the Child Behavior Questionnaires (CBQ), Child Behavior Checklist (CBCL), and Penn Interactive Peer Play Scale (PIPPS). Results: The main results of this study are as follows: First, boys and girls' negative emotionality exerted positive effects on their behavioral problems. Second, boys and girls' negative emotionality had a positive influence on their play interaction, play disruption, and play disconnection. Further, the effect of boys' negative emotionality on their play disruption and play disconnection was totally mediated by their behavioral problems, and girls' negative emotionality on their play interaction and play disconnection was totally mediated by their behavioral problems. Conclusion/Implications: These findings provide preliminary evidence that the relationships between preschoolers' negative emotionality and peer play behaviors may be mediated by their behavioral problems.

• Journal of Korea Society of Industrial Information Systems
• /
• v.18 no.6
• /
• pp.61-70
• /
• 2013

This paper proposes a design of SARPE(Speed and Azimuth based Routing Protocol for Emergency) system which transfers an emergency message rapidly and accurately by minimizing path disconnection with a vehicle's speed and azimuth in case of accidents. The SARPE system accomplishes the path search based on an azimuth in order to minimize unnecessary messages and workload. It also selects the paths with the lowest probability that the path disconnection will happen by using the difference between the speed(maximum, minimum) of intermediate nodes and the average speed of a source node and destination node. Therefore, this paper minimizes the path resetting work happening due to path disconnection and transfers an emergency message rapidly and accurately.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.10
• /
• pp.1448-1453
• /
• 2015

In this paper, we propose an alternative method of communication to improve the reliability of in-vehicle networks by jointly using wireless communication networks. Wired Communication networks have been used in vehicles for the monitoring and the control of vehicle motion, however, the disconnection of wires or hardware fault of networks may cause a critical problem in vehicles. If the network manager detects a disconnection or faults in wired in-vehicle network like the Controller Area Network(CAN), it can redirect the communication path from the wired to the wireless communication like the Zigbee network. To show the validity and the effectiveness of the proposed in-vehicle network architecture, we implement the Electronic Stability Control(ESC) system as ECU-In-the-Loop Simulation(EILS) and verify that the control performance can be kept well even if some hardware faults like disconnection of wires occur.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.3
• /
• pp.165-172
• /
• 2024

This study illuminates the relationship between childhood abuse experiences and early maladaptive schemas, and compares the moderating effects of expressive suppression and cognitive reappraisal within this relationship. Conducting a self-report survey among 220 graduate students in Daejeon and Chungcheong regions, data from 210 participants were analyzed. The results notably revealed that the interaction effect of suppression, but not cognitive reappraisal, significantly moderates the relationship between childhood abuse experiences and disconnection/rejection schemas. Specifically, high levels of expressive suppression were associated with a decrease in the negative impact of childhood abuse on disconnection/rejection schemas, whereas low levels of suppression increased this negative impact. This suggests that for individuals with long-standing early maladaptive schemas, which have solidified over time akin to personality traits, cognitive reappraisal strategies may be less effective in inducing change. Conversely, expressive suppression strategies may more effectively reduce the intensity of disconnection/rejection schemas, among other early maladaptive schemas. These findings provide important implications for understanding the long-term effects of childhood abuse and developing intervention strategies to mitigate its resultant maladaptive schemas. Based on the outcomes of this study, suggestions for future research are discussed, along with the potential applicability and limitations of suppression and reappraisal strategies in psychological interventions.

• Proceedings of the Korean Information Science Society Conference
• /
• 1999.10b
• /
• pp.128-130
• /
• 1999

본 논문에서는 사용자 호스트와이 단절된 상태를 고려한 이동 에이전트 시스템 구현에 대해 논한다. 기존의 이동 에이전트 시스템에서는 사용자의 호스트와 단절 혹은 연결된 상태에서 부여된 태스크의 수행 결과를 사용자에게 전달하는데 있어서 비용이 상당히 많거나 불가능하며, 또한 일방적인 통보 형식이므로 전달한 결과에 대해 동적으로 사용자와 상호 작용할 수 없다. 본 논문에서 제안하는 시스템은 사용자 호스트와의 연결 상태에 상관없이 사용자에게 결과를 전달하고 전달한 결과에 대해 사용자와 동적으로 상호 작용하도록 구현하였다. 시스템은 IBM의 이동 에이전트 시스템인 AWB(Aglets Workbench)를 확장하였으며, 자바 메일 패키지(Java Mail Package)를 이용하여 작업 수행 결과를 사용자의 호스트나 개인 휴대 통신 기기 등을 통해 사용자에게 전다하고 사용자의 호스트가 수행 결과를 사용자의 호스트나 개인 휴대 통신 기기 등을 통해 사용자에게 전달하고 사용자의 호스트가 이동 에이전트 시스템에 재접속하면 결과에 대해 상호 작용할 수 있도록 구현하였다. 이러한 시스템은 단절(disconnection) 상태에서도 수행이 가능한 이동 에이전트의 장점을 보다 더 증가시킨다.

• Journal of Internet Computing and Services
• /
• v.6 no.5
• /
• pp.177-185
• /
• 2005

Caching in mobile computing environments Is an important technique that will reduce the effects such as limitation of bandwidth, restriction of resources and frequent disconnection. To reduce limitation and disconnection problems in mobile computing, a new form of caching system have been proposed based on a broadcast approach. This paper proposes a broadcast based cache protocol and examines the behaviors of the proposed scheme and well known schemes such as multiversion based scheme and Certification Reports. By a detailed simulation, we show some characteristics of different approaches to detect and resolve conflicts. We also show proposed scheme out performs other schemes with a low space and operation overhead.