• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.224-230
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• 2009

In the latest date, medical body area networks (MBANs) are emerging as a new technology for diagnosis the human body. MBANs in the health care fields are based on short-range and low-power (e.g. ubiquitous computing) among small-sized devices, and have been used by means of medical services. In this paper, we proposed an emergency message transmission protocol using carrier sense multiple access/time division multiple access in MBANs. This scheme focuses on dependability and power-efficiency. In order to increase the reliability of the transmission, this scheme modified a MCTA slot of IEEE 802.15.3 standard to a SR-MCTA slot. SR-MCTA slot is assigned by MBAN coordinator according to requesting terminal nodes. The method, having the priority of transmission, occurs a collision packet randomly. Results from this proposed solution revel that reservation-based TDMA medical body area network(MBAN) protocol for transmitting emergency message was improved in terms of transmission delay.

• Journal of the Economic Geographical Society of Korea
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• v.7 no.1
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• pp.29-43
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• 2004

In this paper, we tries to investigate whether there are some differences of the characteristics between venture business in the metropolitan area and in the local area. We set up some hypotheses on the regional characteristics of venture business and test those using the raw data of Small and Medium Business Administration (SMBA) survey on the management of venture business. Our main findings are as follows: First, we analyze the industrial composition of ventures by region and find that in the metropolitan area high-technology venture business which is belong to software, or information, or communication industries is given much weight. But in the provinces, ventures belong to traditional manufacturing industries is given much weight. Second, we compared the characteristics of business network by region and find that the ventures in the metropolitan area are active in technical cooperation among companies and want strategic tie-ups in marketing field, whereas the ventures in the provinces are active in technical cooperation with university and want strategic tie-ups in technical development field. Third, ventures in the metropolitan area are more excellent in technical development and management than ventures in the provinces.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1547-1568
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• 2013

Wireless body area network (WBAN) is an emerging short-range wireless communication network with sensor nodes located on, in or around the human body for healthcare, entertainment and ubiquitous computing. In WBANs, energy is severely constrained which is the prime consideration in the medium access control (MAC) protocol design. In this paper, we propose a novel MAC protocol named Energy-efficient Relay MAC with dynamic Power Control (ERPC-MAC) to save energy consumption. Without relying on the additional devices, ERPC-MAC employs relaying nodes to provide relay service for nodes which consume energy fast. Accordingly the superframe adjustment is performed and then the network topology can be smoothly switched from single-hop to multi-hop. Moreover, for further energy saving and reliability improvement, the dynamic power control is introduced to adjust the power level whenever a node transmits its packets to the coordinator or the relaying node. To the best of the authors' knowledge, this is the first effort to integrate relay, topology adjustment and power control to improve the network performance in a WBAN. Comprehensive simulations are conducted to evaluate the performance. The results show that the ERPC-MAC is more superior to the existing standard and significantly prolongs the network lifetime.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.73-81
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• 2011

The WBAN(Wireless Body Area Network) technology is a short distance wireless network which provides each device's interactive communication by connecting devices inside and outside of body located within 3 meters. Standardization on the physical layer, data link layer, network layer and application layer is in progress by IEEE 802.15.6 TG BAN. The The WBAN servides consists of both medical and non-medical applications. The medical application service uses the sensor that transfer the periodic traffic and have different data rates. It uses GTS method to guarantee QoS. In this paper, a new method is proposed, which are suitable design for MAC Protocol. Firstly, MAC frame structure and a primitive based on the WBAN are proposed. Secondly, we proposed the GTS algorithm improved the channel utilization based on the WFQ(Weighted Fair Queuing). The proposed scheduling method is improved channel utilization compared with i-Game(Round Robin scheduling method).

• Journal of Digital Convergence
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• v.17 no.12
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• pp.197-202
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• 2019

In line with the era of the 4th Industrial Revolution, 5G technology has become common technology, and 5G technology is evaluated as a technology that minimizes the speed and response speed compared to 4G using technologies such as network slicing and ultra-multiple access. 5G NR stands for 5G mobile communication standard, and network slicing cuts the network into parallel connections to optimize the network. In addition, the risk of hacking is increasing as data is processed in the base station unit. In addition, since the number of accessible devices per unit area increases exponentially, there is a possibility of base station attack after hacking a large number of devices in the unit area. To solve this problem, this study proposes the introduction of quantum cryptography and 5G security standardization.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.63-68
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• 2008

The ubiquitous technology is capable of innovating various area to constructing intelligent and network to all objects. This technology can construct network infrastructure to facilities for applying legacy industry and need to develop intelligent service that analyze context-aware through network. This paper derive and propose the introduction range of ubiquitous technology, which should be testified and analyzed network, and studied the detection and analysis of information for managing gas facilities. We investigate the current status of gas facilities and automatic reading system, testing and analyzing wireless personal area network and mobile communication by scalability, self-configuration, connection in underground. Furthermore, we propose modelization method for intelligent service and derive the introduction range for applying ubiquitous technologies for managing gas facilities.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.359-366
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• 2018

Social infrastructure facilities that have been under construction since the country's high-growth period are undergoing rapid aging, and safety assessments of large structures such as bridge tunnels, which can be directly linked to large-scale casualties in the event of an accident, are necessary. Wireless smart sensor networks that improve SHM(Structural Health Monitoring) based on existing wire sensors are difficult to construct economical and efficient system due to short signal reach. The LPWAN, Low Power Wide Area Network, is becoming popular with the Internet of Things and it is possible to construct economical and efficient SHM by applying it to structural health monitoring. This study examines the applicability of LoRa LPWAN to structural health monitoring and proposes a channel usage pre-planning based LoRa network operation method that can efficiently utilize bandwidth while resolving conflicts between channels caused by using license - exempt communication band.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.341-341
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• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.425-425
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• 2006

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2002.05a
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• pp.205-208
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• 2002

The vericut is one of the best CAM application for manufacturing data verification system. It is much applied in most manufacturing company for checking the manufacturing work. Using it a off-line manufacturing system is connected for on-line working on local area network. First, we choose the serial communication to chain an off-line manufacturing system and a personal computer which link with the server running the vericut.