• Journal of Communications and Networks
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• v.16 no.4
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• pp.465-474
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• 2014

Wireless sensor network (WSN) is considered to be one of the most important research fields for ubiquitous healthcare (u-healthcare) applications. Healthcare systems combined with WSNs have only been introduced by several pioneering researchers. However, most researchers collect physiological data from medical nodes located at static locations and transmit them within a limited communication range between a base station and the medical nodes. In these healthcare systems, the network link can be easily broken owing to the movement of the object nodes. To overcome this issue, in this study, the fast link exchange minimum cost forwarding (FLE-MCF) routing protocol is proposed. This protocol allows real-time multi-hop communication in a healthcare system based on WSN. The protocol is designed for a multi-hop sensor network to rapidly restore the network link when it is broken. The performance of the proposed FLE-MCF protocol is compared with that of a modified minimum cost forwarding (MMCF) protocol. The FLE-MCF protocol shows a good packet delivery rate from/to a fast moving object in a WSN. The designed wearable platform utilizes an adaptive linear prediction filter to reduce the motion artifacts in the original electrocardiogram (ECG) signal. Two filter algorithms used for baseline drift removal are evaluated to check whether real-time execution is possible on our wearable platform. The experiment results shows that the ECG signal filtered by adaptive linear prediction filter recovers from the distorted ECG signal efficiently.

• Journal of Sensor Science and Technology
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• v.24 no.2
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• pp.124-130
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• 2015

This paper presents a high performance HIGHT processor that can be applicable for CCM mode. In fact, HIGHT algorithm is a 64-bit block cipher. However, the proposed HIGHT extends the basic block length to 128-bit. The proposed HIGHT is operated as 128-bit block cipher and it can treat 128-bit block at once. Thus, it can be applicable for the various WSN applications that need fast and ultralight 128-bit block cipher, in particular, to be operated in CCM mode. In addition, the proposed HIGHT processor shares the common logics such as 128-bit key scheduler and control logics during encryption and decryption to reduce the area overhead caused by the extension of data block length. From the simulation results, the circuit area and power consumption of the proposed HIGHT are increases as 40% and 64% compared to the conventional 64-bit counterpart. However, the throughput of the proposed HIGHT can be up to two times as fast. Consequently, the proposed HIGHT is useful for USN and handheld devices based on battery as well as RFID tag the size of circuit is less than 5,000 gates.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.579-586
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• 2023

A wireless sensor network (WSN) has limited battery power because it is used wirelessly using low-cost small sensors. Since the battery cannot be replaced, the lifespan of the sensor node is directly related to the lifespan of the battery, so power must be used efficiently to maximize the lifespan of the network. In this study, based on PEGASIS, a representative energy-efficient routing protocol, we propose a protocol that classifies layers according to the distance from the sink node and configures multiple chains rather than one chain. The proposed protocol can increase network lifespan by reducing the transmission distance between nodes to prevent unnecessary energy consumption.

• Journal of Digital Convergence
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• v.12 no.1
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• pp.333-338
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• 2014

Zigbee is a wireless communication technology optimized for WSN (Wireless Sensor Network) environment. A WSN gateway is used for node control and data transmission. However, a fixed-type gateway can restrict the flexibility of the WSN environment. A smartphone-mounted high-performance processor and Android OS can be easily used in a mobile WSN gateway. In this paper, we proposed a mobile WSN gateway based on Android smartphones. In the proposed system, a Zigbee sensor module is connected with a smartphone via USB (Universal Serial Bus) port. We also implemented an Android application for the mobile WSN gateway.

• The Journal of Information Technology
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• v.12 no.3
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• pp.1-6
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• 2009

This paper has focused on the development of an educational sensor network (ESN) based on wireless sensor networks(WSN) and pervasive monitoring systems for students' activity during scientific experiments. A number of WSN systems have been proposed with integrated wireless transmission, mounted sensor boards and local processing. However, there is no trail to employ WSN on the educational field. In this paper, to facilitate research and development using wireless sensor network and multi-sensor data fusion, the educational sensor network (ESN) hardware development platform is presented. The ESN project is conducted over one semester time period (Spring Semesters). It involves approximately twenty middle school students who enrolled a gifted program in Kongju National University. Though under prepared, these students are in general highly motivated to learning specially when presented with the ESN project. An ESN project such as this is expected to provide an excellent means for teaching and learning scientific and mathematical principles.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.360-374
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• 2016

Since WSNs (Wireless Sensor Networks) applied to their application areas such as smart home, smart factory, environment monitoring, etc., depend on sensor data, the sensor data is the most important among WSN components. The resources of each node consisting of WSN are extremely limited in energy, hardware and so on. Due to these limitation, communication failure probabilities become much higher and the communication failure causes data loss to occur. For this reason, this paper proposes 2MC (Maximum/Minimum Compression) that is a method to compress sensor data by selecting circular queue-based maximum/minimum sensor data values. Our proposed method reduces sensor data losses and value errors when they are recovered. Experimental results of 2MC method show the maximum/minimum 35% reduction efficiency in average sensor data accumulation error rate after the 3 times compression, comparing with CQP (Circular Queue Compression based on Period) after the compressed data recovering.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.277-278
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• 2008

Localization system is an important problem for Wireless Sensor Networks(WSN). Since the sensor nodes are limited, the range-based that uses the special device for localization is unsuitable in WSN. DV-Hop is one of the range-free localization algorithm using hop-distance and number of hop count. But Its disadvantage is that it spend large communication cost in scalable sensor nodes. We propose a simple algorithm to reduce the communication cost, using the smallest number of hop count.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.1
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• pp.11-14
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• 2015

WSN (Wireless Sensor Network) based on low-power is one of the core technologies in the ubiquitous society. In this paper, we present a border surveillance and control system in WSN environment. The system consists of static sensor node, mobile sensor node, static gateway, mobile gateway, server and mobile application. Mobile applications are divided into user mode and manager mode. So users monitor border surveillance through mobile phone and get information of border network environment without time and space constraints. In manager mode, for the flexible operation of nodes, manager can update to the software remotely and adjust the position of the mobile node. And also we implement a suitable multi-hop routing protocol for scalable low-power sensor nodes and confirm that the system operates well in WSN environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.731-734
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• 2011

This paper proposed the Low power configuration of Single hop WSN(Wireless Sensor Network) system. When the RF communication is done each tag node during the WSN systems operating, power consumption is greatest. There for, if you configure the Network with the RF communication module turn on/off periodically, power consumption less then operating the module all the time without it toggles. However, some data omissions may occur in which transmission and receipt is done. So this paper proposed the algorithm for low power system without data omissions.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.292-305
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• 2013

EPCglobal has proposed the EPC Sensor Network to efficiently integrate and interoperate the RFID and WSN technologies based on the international standard EPCglobal Network. However, it can not deal with the sensor data without EPS. Also, it does not provide enough management function for the sensor data only. This study proposes USN management system that can deal with these weaknesses of EPC Sensor Network. Not only that, it is suitable for the medical environment properly. In the medical environment, it is important for the medical information to be integrated and interconnected via the standard for medical data. This proposed USN management system is based on SIP-HL 7 and can send RFID and WSN data based on SIP(Session Initiation Protocol). It can be interconnected with the existing hospital information system and exchange the information. Also it can design and materialize SIP Interface based on HL7 that allows the medical information to be exchanged and sent.