• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.40.1-40
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• 2001

In this paper, control theoretic approaches are proposed to guarantee QoS (Quality of Series) such as packet delay and packet loss of real-time traffic in high-speed communication network. Characteristics of variable rate real-time traÆc in communication networks are described. The mathematical model describing networks including source and destination nodes are suggested. By a traffic control mechanism, it is shown that worst-case end-to-end transfer delay of traffic can be controlled and packet loss can be prevented. The simulation shows results of delay control and buer level control to raise QoS in realtime traffic.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.165-168
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• 2002

This paper has been studied about the real time monitoring system development using TCP/IP ethernet and RS-422 serial communication link in general communication methods that rocket fire control agents could be monitoring about real time Rocket fire event procedures and be managing total rocket fire courses. Also, this paper has been studied the HMI(Human Machine Interface) control program and algorithm that guarantee confidential control for the Fire Display System.

• Educational Technology International
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• v.8 no.2
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• pp.113-140
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• 2007

This study purports to contribute in deepening our understanding of ISD (instructional systems design/development) from Edward Hall's concept of intercultural communication. Renowned anthropologist Edward Hall introduced three concepts of cultural differences: time, space, and context. This paper explores how theses cultural dimensions - time, space and context- are reflected in ISD and compares the cultural differences between the east and the west that emerge in the process of applying ISD.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.11
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• pp.1124-1129
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• 2008

Recently, two-port time-domain passivity approach was modified for time-varying communication delay. The newly proposed approach could achieve stable teleoperation even under the serious time-varying delay and packet loss communication condition. However, after some operation hour, the accumulated energy difference between the input energy from one port and the output energy at the other port caused unstable behavior until the passivity controller is activated. Resetting scheme is introduced for solving this problem, and stable bilateral teleoperation can be guaranteed without worrying about the accumulated energy difference.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.4
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• pp.82-88
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• 1998

The purposes of this study was : 1) to describe the theoretical background of Clean-up Time Movement managing visitors' depreciative behavior ; 2) to test the effectiveness of a mass communication program, Clean-up Time Movement in National Park. This study employed a field experimental design (Multiple time-series design) in Naejangsan National Park. This study evaluated the differential effectiveness of the self-developed Clean-up Time Movement Program to reduce littering behavior between Control groups (Those who not received Clean-up Time Program) and Treatment groups (Those who received Clean-up Time Program) by weighting trash gathered in a litter box and scattered around picnic ground. The results showed that the Clean-up Time Movement Program was more effective to reduce the total trash and the trash degree per a person in Treatment groups than Control groups. It seemed to effective in managing depreciative behavior through the mass communication program in National Park.

• Journal of the Korean Society of Systems Engineering
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• v.13 no.2
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• pp.9-17
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• 2017

Concept development of a real-time Field Programmable Gate Array (FPGA)-based switched Ethernet data communication network for the Man-Machine Interface System (MMIS) is presented in this paper. The proposed design discussed in this research is based on the systems engineering (SE) approach. The design methodology is effectively developed by defining the concept development stage of the life-cycle model consisting of three successive phases, which are developed and discussed: needs analysis; concept exploration; and concept definition. This life-cycle model is used to develop an FPGA-based time-triggered Ethernet (TTE) switched data communication network for the non-safety division of MMIS system to provide real-time data transfer from the safety control systems to the non-safety division of MMIS and between the non-safety systems including control, monitoring, and information display systems. The original IEEE standard 802.3 Ethernet networks were not typically designed or implemented for providing real-time data transmission, however implementing a network that provides both real-time and on-demand data transmission is achievable using the real-time Ethernet technology. To develop the design effectively, context diagrams are implied. Conformance to the stakeholders needs, system requirements, and relevant codes and standards together with utilizing the TTE technology are used to analyze, synthesize, and develop the MMIS non-safety data communication network of the APR1400 nuclear power plant.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.4
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• pp.365-372
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• 2016

Recently, UWAC(: UnderWater Acoustic Communication) has been studied by many scholars and researchers. There are several method to estimate the time-difference between the two signals such estimating as the arrival time of the first non-background segment in both signals and calculate the temporal difference, calculating the cross-correlation between the two signal to infer the time-lagged, and estimating the phase delay to infer the time difference. In this paper, we present estimating method by the phase delay to infer the time difference in two signals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.3
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• pp.1301-1312
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• 2020

Using decode-and-forward relaying in the cognitive radio networks, the spectrum efficiency can improve furthermore. The optimization algorithm of the spectrum sensing estimation time is presented for the cognitive relay networks in this paper. The longer sensing time will bring two aspects of the consequences. On the one hand, the channel parameters are estimated more accurate so as to reduce the interferences to the authorized users and to improve the throughput of the cognitive users. On the other hand, it shortens the transmission time so as to decease the system throughput. In this time, it exists an optimal sensing time to maximize the throughput. The channel state information of the sub-bands is considered as the exponentially distributed, so a stochastic programming method is proposed to optimize the sensing time for the cognitive relay networks. The computer simulation results using the Matlab software show that the algorithm is effective, which has a certain engineering application value.

• ETRI Journal
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• v.42 no.5
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• pp.700-711
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• 2020

Because of the rapid increase of mobile traffic, flexible broadband supportive unmanned aerial vehicle (UAV)-based 6G mobile networks using free space optical (FSO) links have been recently proposed. Considering the advancements made in UAVs, big data processing, and artificial intelligence precision control technologies, the formation of an additional wireless network based on UAV aerial platforms to assist the existing fixed base stations of the mobile radio access network is considered a highly viable option in the near future. In this paper, a combined time bound optimization scheme is proposed that can adaptively satisfy the control and communication time constraints as well as the processing time constraints in FSO-based 6G UAV aerial networks. The proposed scheme controls the relation between the number of data flows, input data rate, number of worker nodes considering the time bounds, and the errors that occur during communication and data processing. The simulation results show that the proposed scheme is very effective in satisfying the time constraints for UAV control and radio access network services, even when errors in communication and data processing may occur.

• Journal of the Korean Home Economics Association
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• v.27 no.3
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• pp.147-159
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• 1989

The purpose of this study is to find out significant factors which have effects on the communition styles and adolescents' satisfaction in communication through the investigation of the communication styles between adolescents and mothers and the degree of adolescents' satisfaction in communication. The subjects of this study were 44 high school students in Seoul Statistical methods emploid to analyze the data were percentage, frequency, mean, X2-test, F-test and multiple regression. The results were as follows; 1) The communication styles between adolescents and mothers were divided into 4 grpups, and the proportion of these 4 groups were mutual open style 40.3% mutual closed style 34.5%, adolescent closed-mother open style 13.1% and adolescent open-mother closed style 12.2%. 2) Factors influencing the communication styles were sex (p<.001), communication time (p<.001) and atomosphere of families(p<.001). 3) The degree of adolescents' satisfaction in communication were significantly different depending on the communication style (p<.001), sex (p<.001), communication time (p<.001) educational level of father (p<.05), employment status of mother (p<.05), atomosphere of famlies (p<.001) and economic condition of families (p<.001). 4) The most significant variables influencing the degree of adolescents' satisfaction were communication styles and the atomosphere of families. The groups using open communication styles were more satisfied with their communication that the groups using closed communication styles. The female adolescents were more sensitively influenced than male adolescents with these two variables.