• Journal of the Society of Naval Architects of Korea
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• v.43 no.3 s.147
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• pp.392-398
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• 2006

A prototype of MES(Manufacturing Execution System) applied to panel assembly shop is implemented by using PDA(Personal Digital Assistant) and wireless database web server. The system is developed based on the Dot Net framework. The prototype can exchange the manufacturing execution data between production managers in the control room and workers in the factory through wireless internet communication. Manufacturing model of the panel shop is designed by using IDEF0 and UML method to understand the characteristics of the information and the data entities from the PPR-S view. Several issues in the shop were revealed from the manufacturing model analysis. The most typical problem was the lack of information sharing between the managing workers and the assembly workers. The problem prevents the workers and labors from sharing the process information and continuous workpiece flow In interactive way. To increase the information and data flow, a wireless internet based system is implemented and PDAs are linked together to exchange the process planning data and in-process data between the workers. It is anticipated that PDA and the implemented system can enable the process control at each process stages to obtain the well-organized operation.

• Journal of Satellite, Information and Communications
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• v.11 no.4
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• pp.48-51
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• 2016

Many studies have been carried out in order to develop a frequency efficient communication system than the current communication system for satisfying the increasing demands of wireless data services in mobile communication systems. Service providers must maintain a lot of base station equipments to meet the increasing demands of wireless data service. Therefore service provider needs a system or method to reduce maintenance costs. The amount of wireless data service are changed according to the time of day, geographical location and so on. Power consumption can be reduced if the supplied power of communication systems is controlled by the amount of wireless data traffics. In this paper, power management system of base station's equipment for mobile communication is designed and implemented. The proposed power management system controls the power supplied to the mobile communication infrastructures depending on the service amount of wireless data. Field test result of the implemented system shows the proposed system saves 26% of the power consumption in the base stations.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.307-312
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• 2007

Wireless Sensor Network(WSN) is considered as a core technology necessary for Ubiquitous computing, with its numerous possible applications in many practical areas, is being researched and studied actively by many around the world. WSN utilizes wireless sensors spatially placed to gather information regarding temperature, light condition, motion and change in speed of the objects within their surrounding environment. This paper implements an environmental information monitoring and indexing system based on spatial indexing technique by constructing a WSN system. This Multi-Query Indexing Technique coupled with wireless sensors provides an output based on the pre-defined built-in data index and new input from the sensors. If environment data is occured, system have to perform a proper action after collecting and analyzing this data. This is the purpose of implementing environment data monitoring system. We constructed environmental application using TinyOS and built tested with MICAz sensor bords. We designed and implemented a monitoring system which detects and multi-indexing process environmental data from distributed sensors.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.81-86
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• 2014

Content Centric Network (CCN) is one of candidate technologies for the future Information Centric Networks. Recently, adopting CCN concept to wireless networks has extensively been studied. One of the well-known studies is Enhanced-Content-centric multiHop wireless NETwork (E-CHANET), which proposes efficient methods to deliver contents adopting CCN concept over wireless environment. In E-CHANET, in order for a provider to send a data packet, one interest packet from a consumer is required. In this paper, efficiency of data-interest handshaking in E-CHANET has been investigated. It is compared with a method using only one interest packet for all data packets through simulations. As results, while the handshaking provides transmission reliability, it increses content down load time too much.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.921-928
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• 2017

Unlike wired networks, broadcasting in wireless networks can transmit data to several nodes at a time in a single transmission. The omnidirectional broadcasting of node in wireless networks simultaneously reaches all neighboring nodes. In this paper, we propose a greedy algorithm to solve the minimum power broadcasting problem that minimizes the total transmission power when broadcasting in wireless networks. The proposed algorithm uses a neighborhood list which is a set of nodes that can transmit messages within the maximum transmission range of each node, and among the transmitting nodes that have received the data, the node having the largest number of the neighboring nodes firstly transmits the data to neighboring node. The performance of the proposed algorithm was evaluated by computer simulation, and was compared with existing algorithms in terms of total transmission power and broadcasting frequency for broadcasting to all nodes. Experiment results show that the proposed algorithm outperforms the conventional algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7B
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• pp.649-658
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• 2009

Due to limited size and limited battery lifetime of sensor node, one has to address the power saving issue in wireless sensor network. The existing power saving algorithm based on data reuse was proposed for the cluster structured wireless sensor network. We state the problem of existing power saving algorithm and propose new power saving algorithm for tree structured wireless sensor network. The proposed algorithm reduces power consumption by buffering the sensed data at the selected relay node for its data lifetime. The optimum buffering node is selected so that the power saving gain is maximized and at the same time, power consumption among sensor nodes are equally distributed in the network. With computer simulations, it is shown that the proposed algorithm outperforms the conventional algorithm in terms of power saving gain.

• Journal of Advanced Navigation Technology
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• v.26 no.1
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• pp.1-8
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• 2022

Telemetry system is a system that measures and transmits status information in the aircraft to the ground. The data received from the ground is information for monitoring the state of the aircraft, and can be checked and analyzed in real time through the test program. Data processing test system for telemetry currently in operation is built to transmit data using wired communication and perform test. As smart devices become popular due to the continuous development of information and communication technology, wireless communication networks are becoming important, and technologies for improving performance are steadily being developed. In this paper, we suggests and builds data processing ground test system for telemetry using wireless communication(Wi-Fi) that can be checked through smart devices such as tablets, in order to break away from the existing method and apply future-oriented technology. Finally, the suggested test system performance was proved by testing in various environments by linking test equipment and test program.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.6
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• pp.1152-1168
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• 2010

Recently, due to the prevalence of various mobile devices and wireless broadband networks, there has been a significant increase in interest and demand for multimedia streaming services such as the mobile IPTV. In such a wireless broadband network, transmitting a continuous stream of multimedia data is difficult to achieve due to mobile stations (MSs) movement. Providing Quality of Service (QoS) for multimedia video streaming applications requires the server and/or client to be network-aware and adaptive. Therefore, in order to deploy a mobile IPTV service in wireless broadband networks, offering users efficient wireless resource utilization and seamlessly offering user perceived QoS are important issues. In this paper, we propose a new adaptive streaming scheme, called MARC (Mobile-aware Adaptive Rate Control), which adjusts the quality of bit-stream and transmission rate of video streaming based on the wireless channel status and network status. The proposed scheme can control the rate of multimedia streaming to be suitable for the wireless channel status by using awareness information of the wireless channel quality and the mobile station location. The proposed scheme can provide a seamless multimedia playback service in wireless broadband networks in addition to improving the QoS of multimedia streaming services. The proposed MARC scheme alleviates the discontinuity of multimedia playback and allocates a suitable client buffer to the wireless broadband network. The simulation results demonstrate the effectiveness of our proposed scheme.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.8
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• pp.1004-1010
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• 2019

In the EH-WSN (Energy harvesting wireless sensor network), a MAC (medium access control) protocol is required to select a relay node considering the power status of a node. Existing EH-WSN studies emphasize the power aspect, so it does not consider the QoS like the urgency of the sensed data. The required power and transmission delay must be changed according to the urgency so that the medium access control according to the data QoS can be performed. In case of relay node, relaying data without consideration of data urgency and node power may cause delay due to power shortage in case of urgent data. In this paper, we designed a MAC protocol that minimizes the power shortage that can occur during emergency data generation. For this, relay node requirements are set differently according to the urgency of data. The performance was analyzed through simulation. Simulation results show the reduced latency and improved reliability of urgent data transmission.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.432-434
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• 2004

Bluetooth is a promising wireless personal area network technology and is on the verge of being ubiquitously deployed over wide range of devices. This paper aims to implement a wireless network for image transmission using Bluetooth technology. The characteristics of Bluetooth are small size, low band width and low power consumption, However, there are some difficulties in implementing a wireless radio network using Bluetooth since a lot of repeaters may needed when Bluetooth depends a role of host on personal computer for data transmission. In this paper, a method to implement a wireless radio network is proposed and applied for image transmission using a small size microprocessor for each Bluetooth.