• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.35-40
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• 2013

In WBAN environment, it is very important to achieve energy efficiency of master and nodes, At the same time, a master also plays an important role in collecting data from nodes and controlling the nodes. By maintaining a master properly, any kinds of situation can be handled. Therefore, low power MAC protocol between a master and a node is highly required appropriately. We propose an improved MAC protocol by simply changing the frame structure of WBAN system. The simulation results show that the proposed scheme attains a lot of saving of energy consumption of master and each node compared with IEEE 802.15.6 and conventional schemes.

• Aerospace Engineering and Technology
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• v.13 no.2
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• pp.54-59
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• 2014

This paper cites about a test & analysis support set to support a testing and analysis of CFDP(CCSDS File Delivery Protocol) that processes commands and data as a series of file for reliable deep space communication. And this paper includes a basic description of CFDP and an objective and functions of CFDP-TASS(CFDP - Test Analysis & Support Set). CFDP-TASS is an equipment to examine OBC(On-Board Computer) CFDP in normal and abnormal cases, gather all packets in test, and support to analyze effectively the result of tests.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.797-803
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• 2012

Recently demands in construction of the stand-alone networks and interconnection between convergence devices have led an increase in research on and much attention has been paid to the application of MANET as a Ubiquitous network which is growing fast. With performance both as hosts and routers, easy network configuration, and fast response, mobile nodes participating in MANET are suitable for Embedded computing, but have vulnerable points, such as lack of network scalability and dynamic network topology due to mobility, passive attacks, active attacks, which make continuous security service impossible. In this study, hashed AODV routing is used to protect from counterfeiting messages by malicious nodes in the course of path finding and setting, and disguising misrouted messages as different mobile nodes and inputting them into the network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1059-1067
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• 1999

In this paper characteristics of ATM-PON is described and a TC layer controller for ATM-PON OLT is designed. This paper proposes an algorithm of economically controlling the grant information written by CPU to dynamically allocate the upstream bandwidth on the PON among the ONUs in a fair way and of encrypting the downstream data using a lower standard of encryption, termed data churning, which is used to distinguish it from existing transmission system scramblers and higher layer encryption methods. This paper also proposes a method of allocating churning-related message into the PLOAM cell in order to synchronously change the churning key between the OLT and the ONU.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.3
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• pp.1-11
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• 2018

This paper explores the reliability issue especially associated with the time-division synchronous communication when a networking stack is implemented using software timers provided by embedded operating systems. Especially, we explore the reliability of beacon synchronization of IEEE 802.15.4. Our experiments based on its practical implementation clearly show that processing delays or losses of hardware timer interrupts used for software timers lead to occasional failures in beacon synchronization. To avoid such failures, we suggest a reception time compensation scheme that turns on the receiver earlier than expected.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1266-1271
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• 2010

In this paper, we implemented a heartbeat-signal monitoring system that can measure and check the heartbeat of a human body in any time and anywhere. The implemented prototype is composed of heartbeat measurement terminal, gateway, and server that collect and process data. The terminal compose sensor network using ZigBee protocol. And server acquire heartbeat signal through differentiating collected data two times, and store above data to database and manage it. We can understand the status of examinee's heart without restriction and self-awareness. Through experiment, we confirmed the possibility of ubiquitous healthcare system based on sonsor network using the ZigBee.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.186-194
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• 2008

This paper has implemented a ubiquitous healthcare system that can measure and check the electrocardiogram of a human body in anytime and anywhere. The implemented prototype is composed of electrocardiogram measurement terminal, data gathering base node, and medical information server. The implemented node constructs a sensor network using the Zigbee protocol and the TinyOS is installed on each node. The data gathering base node is linux-based node that can transfer sensed medial data through wireless LAN. And, the medical information server stores the processed medical data and can promptly notify the urgent status to the connected medical team. Through experiment, we confirmed the possibility of ubiquitous healthcare system based on sensor network using the Zigbee.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.401-405
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• 2007

In sensor network, cluster based routing protocol about efficient energy usage method has researched variously. But existing cluster based routing protocol have problems. one of the problem is sensor nodes's imbalance energy consumption problem at cluster reconstruction. anther is non- connection problem between header node and spc node when they are far from each other, not properly connected. We propose cluster re-division and header node of multihop transmission method in this paper. The cluster re-division method is the method that re-divides existing routing protocol with the small-scale cluster and multihop transmission method is the method regarding the relay transmission between the header nodes. Through the simulation, the proposed routing mechanism shows more excellent than exiting routing protocol in balance energy consumption and energy efficiency.

• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.709-716
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• 2012

Recently, smartgrid has interested in enable to existing electrical grid to supplying stably and efficient energy management. Smartgrid environment using PLC is transmit PLC module collected electricity consumption information in each house from PLC module to server. This communication process can occurred security threats such as personal information leak of consumer, electrical grid paralysis. In this paper, we propose efficient electricity consumption information transmission protocol with ID-based key distribution method for respond to security threats.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.201-206
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• 2007

Development of Information and Communication technology coming to activity of internet banking and electronic business, and smart card of medium is generalized prevailing for user authentication of electronic signature certificate management center with cyber cash, traffic card, exit and entrance card. In field that using public network, security of smart cart and privacy of card possessor's is very important. Point of smart card security is use safety for smart card by user authentication. Anonymous establishment for privacy protection and denial of service attack for availability is need to provision. In this paper, after analyze for Hwang-Li, Sun's, L-H-Y scheme, password identify element is a change of safety using one time password hash function. We proposed an efficient new smart card authentication protocol against anonymity and denial of service.