• Journal of the Korean Magnetics Society
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• v.24 no.6
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• pp.179-185
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• 2014

The existing USB connection type of the clip-type pulsmeter equipped with a Hall sensor and a permanent magnet does not have any error or malfunction to measure the pulse wave. The property of the wireless networking system communicating the pulse wave data through the wireless LAN communication by combination USB with Ethernet and Ethernet to Wi-Fi converting system instead of existing USB connection method was investigated. There are exited that the patient needs to stay at close site of the desktop PC without USB connector and the wireless transfer and receiver networking system has pulse wave measurement SW to receive the pulse wave data. Thus it is expected that the study becomes helpful to measure and transfer the exact pulse wave of the patient in a comfortable pose at close range.

• Journal of Information Processing Systems
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• v.1 no.1 s.1
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• pp.49-54
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• 2005

With the recent advances in Micro Electro Mechanical System (MEMS) technology, low cost and low power consumption wireless micro sensor nodes have become available. However, energy-efficient routing is one of the most important key technologies in wireless sensor networks as sensor nodes are highly energy-constrained. Therefore, many researchers have proposed routing protocols for sensor networks, especially cluster-based routing protocols, which have many advantages such as reduced control messages, bandwidth re-usability, and improved power control. Some protocols use information on the locations of sensor nodes to construct clusters efficiently. However, it is rare that all sensor nodes know their positions. In this article, we propose another cluster-based routing protocol for sensor networks. This protocol does not use information concerning the locations of sensor nodes, but uses the remaining energy of sensor networks and the desirable number of cluster heads according to the circumstances of the sensor networks. From performance simulation, we found that the proposed protocol shows better performance than the low-energy adaptive clustering hierarchy (LEACH).

• Tunnel and Underground Space
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• v.29 no.6
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• pp.367-378
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• 2019

As the development of IT technology, the way to manage the underground construction site in real time using wireless network communication is being considered. Underground space is limited area compared to the ground site due to the enclosed communication environment and spatial characteristics. BMN (Bluetooth Mesh Networking) technology is a recently introduced wireless communication technology that bluetooth device acts as a repeater to form a networking mesh and monitor individual devices. This article examines the areas to be considered for analyzing the applicability of BMN technology to underground spaces, and the cases studies of wireless communication monitoring systems currently being developed. And the BMN technology which is being developed for the underground application is also introduced.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.1
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• pp.74-90
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• 2014

Routing in mobile wireless sensor networks (MWSNs) is an extremely challenging issue due to the features of MWSNs. In this paper, we present a novel bio-inspired trusted routing protocol (B-iTRP) based on artificial immune system (AIS), ant colony optimization (ACO) and Physarum optimization (PO). For trust mechanism, B-iTRP monitors neighbors' behavior in real time and then assesses neighbors' trusts based on AIS. For routing strategy, each node proactively finds routes to the Sink based on ACO. When a backward ant is on the way to return source, it senses the energy residual and trust value of each node on the discovered route, and calculates the link trust and link energy of the route. Moreover, B-iTRP also assesses the availability of route based on PO to maintain the route table. Simulation results show how B-iTRP can achieve the effective performance compared to existing state-of-the-art algorithms.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.91-94
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• 2006

In this paper, we deployed the tunnel inspection and monitoring system by wireless sensor network. It is shown that the wireless sensor network which is composed of sensor, wireless communication module, and gateway system can be applied to tunnel monitoring system. Sensors included herein are acceleration transducers, fire-alarm sensors, water-level sensors, and magnetic contact sensors. It is also found that the wireless sensor network can deliver sensing data reliably by ad-hoc networking technology. The gateway system that can send the sensing data to server by CDMA (code division multiple access) is developed. Finally, monitoring system is constructed by web service technology, and it is observed that this system can monitor the present state of tunnel without difficulties. Furthermore, the above system provides an alternative to inspect and monitor the tunnel efficiently where the conventional wired system cannot be applied.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.1
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• pp.195-215
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• 2021

Multipath Transport Control Protocol (MPTCP) is a transport layer protocol that enables multiple TCP connections across various paths. Due to path heterogeneity, it incurs more energy in a multipath wireless network. Recent work presents a set of approaches described in the literature to support systems for energy consumption in terms of their performance, objectives and address issues based on their design goals. The existing solutions mainly focused on the primary system model but did not discourse the overall system performance. Therefore, this paper capitalized a novel stochastically multipath scheduling scheme for data and path capacity variations. The scheduling problem formulated over MPTCP as a stochastic optimization, whose objective is to maximize the average throughput, avoid network congestion, and makes the system more stable with greater energy efficiency. To design an online algorithm that solves the formulated problem over the time slots by considering its mindrift-plus penalty form. The proposed solution was examined under extensive simulations to evaluate the anticipated stochastic optimized MPTCP (so-MPTCP) outcome and compared it with the base MPTCP and the energy-efficient MPTCP (eMPTCP) protocols. Simulation results justify the proposed algorithm's credibility by achieving remarkable improvements, higher throughput, reduced energy costs, and lower-end to end delay.

• Journal of Communications and Networks
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• v.4 no.4
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• pp.336-343
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• 2002

A major challenge for next generation mobile communication is capturing the system architecture’s complexity with all its internal and external dependencies. Seamless integration of heterogeneous environments in all system parts is a key requirement. Moreover, future systems have to consider the different evolution cycles of individual system parts. Among those, services are expected to change the fastest. With respect to these considerations, we propose an overall architecture for next generation mobile communication systems. It covers all system parts from wireless transmission to applications including network and middleware platform. Our approach focuses on adaptability in terms of recon- figurability and programmability to support unanticipated system evolution. Therefore, we consider abstraction layers which consist of adaptable cooperating components grouped by open platforms rather than rigid system layers. In addition to that, we introduce cross-layer cooperation allowing an efficient use of the available resources. Specific scenarios illustrate the feasibility of our approach.

• Journal of the Korean Society of Industry Convergence
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• v.4 no.4
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• pp.441-450
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• 2001

This dissertation deal with over-all wireless communication technology. And introduce wireless communication technology analytically that it use for Home-LAN communication technology (HomeRF, Bluetooth, IEEE 802.11, HIPERLAN, etc). Home-LAN communications issue by the terminal field of the latest high-speed network construction. This technologies possesses characteristics and significances as the representative technology using in Home-LAN communication technology. Also, the method of application is conditional on individually. Wireless LAN put Home-LAN communications to practical use. Bluetooth have practical use for an individual mobile communications with internet. HomeRF have a vision that the construction of wireless system in house purely. Therefore, this dissertation investigates merits and demerits between those technologies. And then leads the most compatible technology for application of Home-LAN. Finally, this thesis have a view of the development course hereafter.

• Journal of Communications and Networks
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• v.14 no.6
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• pp.629-639
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• 2012

A challenge faced by smart grid systems is providing highly reliable transmissions to better serve different types of electrical applications and improve the energy efficiency of the system. Although wireless networking technologies can provide high-speed and cost-effective solutions, their performance may be impaired by various factors that affect the reliability of smart grid networks. Here, we first suggest the use of IEEE 802.11s-based wireless LAN mesh networks as high-speed wireless backbone networks for smart grid infrastructure to provide high scalability and flexibility while ensuring low installation and management costs. Thereafter, we analyze some vital problems of the IEEE 802.11s default routing protocol (named hybrid wireless mesh protocol; HWMP) from the perspective of transfer reliability, and propose appropriate solutions with a new routing method called HWMP-reliability enhancement to improve the routing reliability of 802.11s-based smart grid mesh networking. A simulation study using ns-3 was conducted to demonstrate the superiority of the proposed schemes.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.3
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• pp.15-22
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• 2007

An automatic measurement system which collects experimental data at an unmanned station where the networking to the internet could not be accessed was developed. With a Robo-rail accessing to the unmanned station, wireless local networking between server PC at the Rob-rail and client PC at the unmanned station is possible within 30 m from an access point equipment located at the unmanned station. An algorithm for transferring the data file which is saved in the client PC at the unmanned station to the server PC in the Robo-rail was proposed. IEEE-1394 camera was used to collect the data at the client PC. An extracting program from the IEEE-1394 captured images to character data and number data was developed using image processing technique, which drastically reduces the size of data file comparing to that of the raw image file.