• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.177.2-177
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• 2001

The asynchronous gyro outputs in the 3-axis navigation system are defined as each of gyros has its own output frequency. In this case, the navigation system has gyro outputs concurrently with the sensor mechanical frequency instead of the attitude frequency. So, there is an asynchronous error between gyro outputs and attitude calculation. In this paper, we analyze the gyro output error caused by the asynchronous gyro and present the high speed sampling technique and the extrapolation and interpolation of gyro outputs for synchronizing the gyro outputs.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.10a
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• pp.73-73
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• 2011

In fact, asynchronous motors are used widely. Asynchronous motors which have large power (compared to the source supplies) is needed to start them in various methods. The theory of application reduced voltage to motor's stator or variable resistor fed rotor for the purpose of altering the motor's torque and power consumption characteristics is an idea that has existed for many years. These concepts have flourished mainly due to the need to limit torque and limited generator/power distribution capabilities. However, how can know exactly the time of switching steps with different types of motors as well as load characteristics is very difficult. This paper focuses on the design and development mathematical models of motor[1][2], load, ACB, asynchronous machine and then is implemented in SIMULINK in order to calculate this time, special on ships where power generation station is limited. The simulation results are both compared and discussed in detail so that it can apply to conclude the most suitable and applicable starting time for new system with various motors and load.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.2
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• pp.53-61
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• 2021

Purpose : The purpose of this study is to explore the effectiveness of online blended learning(asynchronous online learning class 1+synchronous online learning class 2) method and discuss the applicability of online blended learning. In this study, we will analyze the differences in class satisfaction and academic achievement between asynchronous online learning and online blended learning classes, and discuss the strengths, weaknesses, and satisfactions of online blended learning. Methods : The subjects of this study were 39 of the occupational therapy students who took the 'child development' course. Asynchronous online learning class was applied for 1-6 weeks and online blended learning was applied for 9~14 weeks. The online blended learning class consisted of 1 hours synchronous online learning and 2 hours asynchronous online learning. For the asynchronous online learning, the screen recording program of OBS Studio was used, and for the synchronous online learning, the Zoom program was used. The results of course evaluation and academic achievement of students according to the type of lecture were compared, and a survey was conducted on the satisfaction of online blended learning. Results : The results of this study are as follows. First, satisfaction(A class: t=-4.19, p=.001, B class: t=-7.94, p=.00) with online blended learning classes was significantly higher than asynchronous online learning. Second, when applying online blended learning class, academic achievement(t=-10.58, p=.00) was significantly higher. Third, the online blended learning class showed the highest satisfaction in improving the interest in the subject, and it was found to be helpful in online class management, professor-student interaction, and class content understanding. Conclusion : We have found that online blended learning can compensate for the shortcomings of online lectures and increase the quality of the lectures and the satisfaction of students. The application of online blended learning should be supplemented according to the characteristics of each class, and I hope that blended online teaching methods can be developed based on new ideas in the future.

• Korean Journal of Child Studies
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• v.29 no.1
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• pp.33-48
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• 2008

This study analyzed social development and self-efficacy in use of internet in adolescents. Subjects were 510 7th, 8th, 10th, and 11th grade students in Daegu. Instruments were the modified Activities Questionnaire for Students (Heitner & Erica, 2(02), the Personality Inventory for Youth (Heitner & Erica, 2002) and the Self-Efficacy Scale (Song, 1998). Findings were that (1) male students use more synchronous (multi-game) but female students use more asynchronous (e-mail) and asocial (web-surfing) internet activity. (2) Synchronous social internet (multi-game) users were more social and more efficient than asynchronous (e-mail) and asocial (web-surfing) internet users.

• Journal of Arbitration Studies
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• v.19 no.2
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• pp.155-178
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• 2009

The ODR can be categorized into four distinctive types. First type is the asynchronous non-demeanour method. Second type is the asynchronous demeanour method. Third type is the synchronous demeanour method. Fourth type is the synchronous demeanour method. A typical example of the asynchronous and non-demeanour method is e-mail. The example of the synchronous and non-demeanour method is tele conference. The example of the asynchronous demeanour method is video recordings. The example of synchronous and demeanour method is video conference. The primary benefit of e-mail is to avoid the physical violence. But the costs of email is the lack of emotional aspects of disputants. The benefits of tele conference is ease of use, and reduces the negative aspects of face to face communication. but the costs are limitation of the exchange of written information. The benefits of video conference is the approximation of face to face communication by providing oral as well as visual communication. but it is insufficient to represent eye contact. The common limitations of ODR are as follows. First is the lack of human face. Second is the neutrality of arbitrators and mediators. Third is the authenticity of electronic document. Fourth is the digital divide across South and North and generations. Fifth is the cross-cultural communication. The development strategy of ODR is the training and education of arbitrators and mediators in the area of writing skill. Furthermore, it is necessary to supplement the weakness of email via diverse kinds of expressions to show emotions. Finally, it is necessary to train neutrals in the area of cross-cultural communication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.950-956
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• 2015

In this paper, a WiMedia Distributed-MAC (D-MAC) protocol is adopted for development of a seamless N-screen wireless service in Indoor and Ship Area Networks. Furthermore, to provide the OSMU (One Source Multi Use) N-screen service through P2P streaming in the seamless D-MAC protocol, a ATMT (Asynchronous Traffic Multi-hop Transmission) technology is proposed and analyzed. In this system, a WiMedia ATMT D-MAC bridge transmits control and managing information to various sensors and instruments, from a central integrated ship area network station. For this technology, a time slot allocation scheme for WiMedia asynchronous traffic and a multi-hop resource reservation scheme are combined to evaluate the performance of each scheme. From simulation results, the proposed ATMT scheme enhances performances in viewpoints of N-screen asynchronous data latency and throughput, compared to the conventional WiMedia D-MAC system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9B
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• pp.1057-1065
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• 2011

In order to achieve the ease of development and to facilitate the maintenance of codes for complex Ajax (Asynchronous Java Script and XML)-based web clients, this paper proposes a CVC (Communicator-View-Controller) architecture pattern by modifying the well-known MVC (Model-View-Controller) framework. By composing the Communicator of codes for asynchronous data retrieval, which is common to Ajax-based clients, the proposed architecture pattern is able to cut out the graphic design related codes to constitute the View layer. Based on such declarative generalization of complex web-client codes, Ajax-related codes can be easily modularized and efficiently reused in development and maintenance stages, and graphics design can be done separately regardless of the other business logic related codes development, resulting in highly efficient development and maintenance of complex Ajax-based web clients.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.1
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• pp.1196-1204
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• 2001

In this paper, a new architecture of operating software associated with the component-based method is proposed. The proposed architecture comprises 문 execution module and a decision-making module. In order to make effective development and maintenance, the execution module is divided into three components. The components are referred to as Symbol, Gateway, and Control, respectively: The symbol component is for the GUI environments and the standard interfaces; the gateway component is for the network communication and the structure of asynchronous processes; the control component is for the asynchronous processing and machine setting or operations. In order to verify the proposed architecture, and off-line version of operating software is made, and its steps are as follows; I) Make virtual execution modules for the manufacturing devices such as dual-arm robot, handling robot, CNC, and sensor; ii) Make decision-making module; iii) Integrate the modules and GUI using a well-known development tools such as Microsofts Visual Basic; iv) Execute the overall operating software to validate the proposed architecture. The proposed software architecture in this paper has the advantages such as independent development of each module, easy development of network communication, and distributed processing of resources, and so on.

• Journal of the Korean Society of Safety
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• v.12 no.3
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• pp.67-75
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• 1997

This paper presents a study on the application of Asynchronous Team(A-Team) theory for QVC(Reactive power control) and security assessment in a power system. Reactive power control problem is the one of optimally establishing voltage level given reactive power sources, which is very important problem to supply the demand without interruption and needs methods to alleviate a bus voltage limit violation more quickly. It can be formulated as a mixed-integer linear programming(MILP) problem without deteriorating of solution accuracy to a certain extent. The security assessment is to estimate the relative robustness of the system and deterministic approach based on AC load flow calculations is adopted to assess it, especially voltage security. A distance measure, as a measurement for voltage security, is introduced. In order to analyze the above two problem, reactive power control and static security assessment, In an integrated fashion, a new organizational structure, called an A-team, is adopted. An A-team is well-suited to the development of computer-based, multi-agent systems for operation of large-scaled power systems. In order to verify the usefulness of the suggested scheme herein, modified IEEE 30 bus system is employed as a sample system. The results of a case study are also presented.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.7
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• pp.501-508
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• 2004

In this paper, a coordinated scheduling algorithm is proposed to reduce end-to-end delay in distributed control of systems. For the algorithm, the analysis of practical end-to-end delay in the worst case is performed priory with considering implementation of the systems. The end-to-end delay is composed of the delay caused by multi-task scheduling of operating systems, the delay caused by network communications, and the delay caused by asynchronous timing between operating systems and network communications. Through some simulation tests based on CAN(Controller Area Network), the proposed worst case end-to-end delay analysis is validated. Through the simulation tests, it is also shown that a real-time distributed control system designed to existing worst case delay cannot guarantee end-to-end time constraints. With the analysis, a coordinated scheduling algorithm is proposed here. The coordinated scheduling algorithm is focused on the reduction of the delay caused by asynchronous timing between operating systems and network communications. Online deadline assignment strategy is proposed for the scheduling. The performance enhancement of the distributed control systems by the scheduling algorithm is shown through simulation tests.