• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8A
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• pp.613-619
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• 2003

Bluetooth is a communication technology enabling short-range devices to be wirelessly connected. A master and one or more slave devices are connected to form a piconet, and piconets are joined to form a scatternet. The units participating in two or more piconets in a scatternet, is called bridge or gateway nodes. In order to operate the scatternet efficiently, both piconet scheduling for the master and slaves of a piconet, and scatternet scheduling for the bridge nodes are playing important roles. In this paper, we propose a traffic-adaptive dynamic scatternet scheduling algorithm based on rendezvous points and rendezvous windows. The performance of the proposed algorithm is compared and analyzed with that of a static scheduling algorithm via simulations. Simulation results show that our algorithm can distribute wireless resources efficiently to bridge nodes depending on the traffic characteristics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.761-764
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• 2010

Interest in vehicle infotainment system, that provides both entertainment of driving and information for safe and convenient driving, has been recently increased. MOST is defined as the network transmitting high-bandwidth infortainment data to vehicle, and it has been standardized as MOST150. In this research, dynamic behavior method that deals with roles and functions of each devices connected to MOST150 Network, and Power Management Method was studied. MOST Network consists of a master device, including function block 'NetworkMaster', and all other devices called slave devices. The purpose of this study is to apply the analysis of the methods of operating and power management based on condition of master device and slave devices on MOST150 network to the future development of MOST150 devices.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.392-399
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• 2019

In this paper, we have studied wireless time division duplex(TDD) time synchronization technique considering the propagation delay between mobile vehicles. The existing IEEE 1588 precision time protocol(IEEE 1588 PTP) algorithm was applied and the time synchronization between the two nodes was achieved through the propagation delay and clock offset time correction calculated between master slave nodes during wireless TDD communication. The time synchronization process and procedure of IEEE 1588 PTP algorithm were optimized, thereby reducing the propagation delay error sensitivity for real-time moving vehicles. The sync flag signal generated through the time correction has a time synchronization accuracy of max +252.5 ns within 1-symbol(1.74 M symbol/sec, ${\pm}287.35ns$) through test and measurement, and it was confirmed that the time synchronization between master slave nodes can be achieved through sync flag signal generated during GPS disturbance.

• Journal of Korea Game Society
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• v.9 no.3
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• pp.129-138
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• 2009

In this research, a new tabletop system is developed to provide a high resolution display by using multiple displays and computers connected through networks, based on a master/slave architecture. This distributed tabletop system is built to be scalable by just adding slave computers and monitors without modifying any software. Moreover, a EBITA (Environment for Building Interactive Tangible Applications) framework is developed to support constructing interactive games running on this scalable tabletop platforms. EBITA framework consists of the tangible interface module based on the infrared camera tracking system, and the modules that allow easy development of the graphical programs on a distributed environment. This paper describes the tangible interface based on the camera tracking system and EBITA framework. It also introduces a game built with the EBITA framework.

• Journal of Biomedical Engineering Research
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• v.24 no.4
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• pp.309-318
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• 2003

In this paper a 6 degree-of-freedom robot was studied for medical purpose. In the past the robot used for industry field was utilized for medical robot but in these days the robot used for rehabilitation. welfare, and service. This system was Proposed for a stroke patient or a patient who can not use one arm. A master-slave system was constructed to exercise either paralysis or abnormal arm using normal arms movement. Study on the human body motion result was applied to calculate a movement range of humans elbow and shoulder. In addition, a force-torque sensor is applied to estimate the rehabilitation extent of the patient in the slave robot. Therefore, the stability of the rehabilitation robot could be improved. By using the rehabilitation robot, the Patient could exercise by himself without any assistance In conclusion. the proposed system and control algorithm were verified by computer simulation and system experiment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.8
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• pp.573-581
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• 2022

This paper deals with the development of CanSat system, which ejects two maple seed-type autorotating science payloads and collects weather information. The CanSat consists of two autorotating science payloads and a container. The container is equipped with devices for launching science payloads and communication with the ground station, and launches science payloads one by one at different designated altitudes. The science payload consists of a space for loading and a large wing, and rotates to generate lift for slowing down the fall speed. Specifically, after being ejected, it descends at a speed of 20 m/s or less, measures the rotation rate, atmospheric pressure, and temperature, and transmits the measured value to the container at a rate of once per second. The communication system is a master-slave structure, and the science payload transmits all data to the master container, which aggregates both the received data and its own data, and transmits it to the ground station. All telemetry can be checked in real time using the ground station software developed in-house. A simulation was performed in the simulation environment, and the performance of the CanSat system that satisfies the mission requirements was confirmed.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.12
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• pp.1055-1063
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• 2015

In this paper, a new master arm was developed as an input device of the remote control system for easy control of the industrial robot arm; it has a structure similar to the robot arm and is easy to wear. For control of the slave arm, related equations were derived about the joints between the master and slave arm; and thereby using them, the master arm control system was developed. Furthermore, a control simulator was developed for the convenient and accurate control of the slave arm. Experiments, about controlling the slave arm in applying the master arm, were performed to validate the developed simulator and the derived related equations.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.457-458
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• 2011

본 논문에서는 2KW급 LLC 컨버터를 적용한 전원장치의 병렬운전 및 Load Sharing 기법을 제안한다. 각 모듈의 제어기로는 TI사의 TMS320F28035를 사용하였으며 모듈 각각의 독립적인 전압제어를 담당한다. 그리고 Load Share 모드에서는 CAN통신을 사용하여 각 전원장치의 전류제어 및 전압제어를 수행한다. 각 모듈에 전체전류의 1/N의 균일한 전류를 흐르게 하여 각 모듈에 임피던스 불균형으로 인한 스트레스를 줄일 수 있다. 기존방식은 마스터(Master) 모듈의 지령치에 따라 슬레이브(Slave)모듈에서 부한 분담을 수행하는 반면, 제안된 Load Share 알고리즘은 멀티 마스터(Multi-Master: MM) 방식으로써 각 모듈의 평균전류를 레퍼런스로 갖는 구조로 정확한 부하분담을 수행한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2261-2266
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• 2012

The general bus system architecture consists of masters, slaves, arbiter, decoder and so on in shared bus. As several masters can't use a bus concurrently, arbiter plays an role in bus arbitration. In compliance with the selection of arbitration method, The efficiency of bus usage can be determined. Fixed Priority, Round-Robin, TDMA, Lottery arbitration are studied in conventional arbitration method. In this paper, we draw the performance analysis of Fixed Priority, Round Robin, TDMA and Lottery bus arbitration policies due to the data traffic concentration and propose the methods of performance improvement.

• Journal of the Korea Computer Industry Society
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• v.3 no.2
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• pp.185-190
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• 2002

As the TSP(Traveling Salesman Problem) belongs to the class of NP-complete problems, various techniques are required for finding optimum or near optimum solution to the TSP. This paper designs a distributed genetic algorithm in order to reduce the execution time and obtain more near optimal using multi-slave model for the TSP. Especially, distributed genetic algorithms with multiple populations are difficult to configure because they are controlled by many parameters that affect their efficiency and accuracy. Among other things, one must decide the number and the size of the populations (demes), the rate of migration, the frequency of migrations, and the destination of the migrants. In this paper, I develop random dynamic migration rate that controls the size and the frequency of migrations. In addition to this, I design new migration policy that selects the destination of the migrants among the slaves