• Journal of Communications and Networks
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• v.13 no.2
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• pp.167-174
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• 2011

In this paper, we propose and simulate an efficient interference cancellation scheme with an optimal ordering successive interference cancellation (SIC) algorithm for ultra wideband (UWB)/multiple-input-multiple-output (MIMO) systems in a wireless body area network (WBAN). When there are several wireless communication devices on a human body, multiple access interference (MAI) usually occurs. To mitigate the effect of MAI and achieve additional diversity gain, we utilize SIC with an optimal ordering algorithm. A zero correlation duration (ZCD) code with robust MAI capability is employed as a spread code for UWB systems in a multi-device WBAN environment. The performance of the proposed scheme is evaluated in terms of the bit error rate (BER). Simulation results confirm that the BER performance can be improved significantly if the proposed interference cancellation scheme and the ZCD code are jointly employed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.867-875
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• 2009

The reliability of wireless body area networks is an important research issue since it may jeopardize the vital human life, unless managed properly. In this article, a new modeling and analysis of node misbehaviors in wireless body area networks is presented, in the presence of multi-type failures. First, the nodes are classified into types in accordance with routing capability. Then, the node behavior in the presence of failures such as energy exhaustion and/or malicious attacks has been modeled using a novel Semi-Markov process. The proposed model is very useful in analyzing reliability of WBANs in the presence of multi-type failures.

• Journal of Biomedical Engineering Research
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• v.26 no.5
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• pp.331-335
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• 2005

The fusion technology of small sensor and wireless communication was followed by various application examples of the embedded system, where the social infrastructural facilities and ecological environment were wirelessly monitored. In addition, this technology represents the primary application area being extended into the healthcare field. In this study, a body area network for ubiquitous healthcare is presented. More specifically this represents a wireless biomedical signal acquisition device characterized by small size, low power consumption, pre-processing and archiving capability. Using this device, a new method for monitoring vital signs and activity is created. A PDA-based wireless sensor network enables patients to be monitored during their daily living, without any constraints. Therefore, the proposed method can be used to develop Activities of Daily Living (ADL) monitoring devices for the elderly or movement impaired people. A medical center would be able to remotely monitor the current state of elderly people and support first-aid in emergency cases. In addition, this method will reduce medical costs in society, where the average life expectancy is increasing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9B
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• pp.1305-1313
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• 2010

Last few years, wireless personal area network (WPAN) has been widely researched for various healthcare applications. Due to restriction of device hardware (e.g., energy and memory), we need to design a highly-versatile MAC layer protocol for WBAN (Wireless Body Area Network). In addition, when an emergency occurs to a patient, a priority mechanism is necessitated for a urgent message to get through to the final destination. This paper presents a priority mechanism referred to as hybrid priority MAC for WBAN. Through extensive simulation, we show the proposed MAC protocol can minimize the average packet latency for urgent data. Thus, when patients have an emergency situation, our MAC allows adequate assistance time and medical treatment for patients. The simulation based on NS-2 shows that our Hybrid Priority MAC has the good performance and usability.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.1
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• pp.87-93
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• 2012

Due to the development of information and communication, there is a rising interest on WBAN(Wireless Body Area Network) that maintain and check the human being health. According to the application of different quality of service and a special mechanism for transferring medical data are required in WBAN environment. In this paper, we proposed the new formed superframe that has CSMA/CA based TDMA scheduling and CSMA/CA used IEEE 802.15.4 in order to process emergency data and on-demand data in WBAN environment. We estimated performance of the proposed MAC protocol by compared performance of other MAC protocols that are IEEE 802.15.4 MAC protocl and Z-MAC protocol has contention access period based TDMA scheduling.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.133-138
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• 2009

In this paper, we propose a ZCD (Zero Correlation Duration) code based Ultra Wide Band(UWB) MODEM(modulation and demodulation) technique for WBAN as a hunman body wireless communication operating in WBAN (Wireless Body Area Network) environment. We certified ZCD code based UWB schemes are available for hunman body wireless communications by various simulation and performance analysis using WBAN transmission channels. Furthermore, we suggested some possibility of RFIC implementation related to human body based UWB communication module by presenting some related examples.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.104-109
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• 2008

MBAN(Medical Wireless Body Area Network)은 인체 내부에 이식한 장비를 인체 외부에서 모니터링하는 인체 이식형 의료 분야와 인체 표면이나 $3{\sim}5$미터내 인체의 주변에서 일어나는 신체 부착형 의료분야로 정의할 수 있다. 본 고에서는 기존 MBAN으로 사용하고 있던 무선장비들에 대한 각국의 기술 개발 동향을 분석하였으며, 인체 내부와 외부에서의 가장 큰 특성인 인체 전파 특성에 대해서도 분석해 보았다. 그리고 IEEE에서 표준화 작업중인 WBAN(Wireless Body Area Network)의 개념과 추진 상황과 더불어 현재 검토 중인 주파수 대역에 대해서 분석하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.5
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• pp.791-796
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• 2013

Advent of the brain wave health care system is considered as an important issues in the industrial and research area in these days. It is necessary to detect EEG signals in real-time in order to support the medical emergency service for the epileptic or brain infarct patients. Since the efficient network support is an essential factor for the system, several topologies using sensor node based wireless body area network is suggested and simulated in this paper. Finally the Opnet simulation result is evaluated for the efficient topology of the body area network.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.62-69
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• 2014

In this paper, WBAN(Wireless Body Area Network) On-body system using the surface-oriented antenna about the impact of human internal organs were analyzed through experiments. The received signal strength is measured for effect of human using the human model and the phantom of torso. Experiments are performed in anechoic chamber without moving and measured by Vector Network Analyzer. This paper confirms the effect of human body by comparing the human model and the phantom of torso. And also know the human internal organs effect on the antennas loss of received signal strength by measured data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1036-1057
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• 2013

Wireless body area network (WBAN) is a promising candidate for future health monitoring system. Nevertheless, the path to mature solutions is still facing a lot of challenges that need to be overcome. Energy efficient scheduling is one of these challenges given the scarcity of available energy of biosensors and the lack of portability. Therefore, researchers from academia, industry and health sectors are working together to realize practical solutions for these challenges. The main difficulty in WBAN is the uncertainty in the state of the monitored system. Intelligent learning approaches such as a Markov Decision Process (MDP) were proposed to tackle this issue. A Markov Decision Process (MDP) is a form of Markov Chain in which the transition matrix depends on the action taken by the decision maker (agent) at each time step. The agent receives a reward, which depends on the action and the state. The goal is to find a function, called a policy, which specifies which action to take in each state, so as to maximize some utility functions (e.g., the mean or expected discounted sum) of the sequence of rewards. A partially Observable Markov Decision Processes (POMDP) is a generalization of Markov decision processes that allows for the incomplete information regarding the state of the system. In this case, the state is not visible to the agent. This has many applications in operations research and artificial intelligence. Due to incomplete knowledge of the system, this uncertainty makes formulating and solving POMDP models mathematically complex and computationally expensive. Limited progress has been made in terms of applying POMPD to real applications. In this paper, we surveyed the existing methods and algorithms for solving POMDP in the general domain and in particular in Wireless body area network (WBAN). In addition, the papers discussed recent real implementation of POMDP on practical problems of WBAN. We believe that this work will provide valuable insights for the newcomers who would like to pursue related research in the domain of WBAN.