• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.3
• /
• pp.446-452
• /
• 2006

In this paper, I evaluated the throughput of various multimedia traffic by using computer simulation over wireless LAN environment based on 802.11e MAC protocol. The number of mobile terminals which generate various traffic and have different Internet QoS varies to improve the reliability of performance evaluation by simulation. Therefore, we investigate throughput of traffic that each mobile terminal generates. I expect that the result of study will be utilized as a fundamental data to control priorities of various types of traffic in case of formulating a scheduling policy supporting a variety of Internet QoS over wired and wireless networks.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.6
• /
• pp.873-878
• /
• 2002

Stator current spectrum by the fast Fourier transform (FFT) of current signals has been widely used for fault detection in induction motors. In this paper, we propose efficient rotor fault detection of Induction motors using stator current spectrum monitoring. The proposed method utilizes the mean absolute difference (MAD) between a Predetermined reference vector and a feature vector extracted from the stator current spectrum. Our proposed approach requires a smaller amount of computations when compared to fault detection algorithms based on neural networks, since it uses simple MAD criterion to detect rotor faults related broken rotor bars. Experimental results show that our proposed method can successively detect the rotor fault of the induction motor.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.5
• /
• pp.832-842
• /
• 2006

Wireless Personal Area Networks(WAPANs) are designed for short-range ad hoc connectivity among portable devices. They have gained much attention in the industry recently. One of them, High-rate WPAN, is designed to support multimedia traffic that requires high data rates. But, High-rate WPAN standards don't specify the time slot assignment scheduling method of CAT(Channel Time Allocation). So, there has been many studies regarding time slot assignment scheduling of CAT. However, present studies involve demerits about not applying various types of errors in air interlace or having a starvation of a specific DEV(data device). In this paper, we propose algorithms about supplying the intermediate channel assignment in order to avoid these demerits. This method will help other methods that use time slot assignment scheduling of CTA.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.5
• /
• pp.956-961
• /
• 2006

Keystroke time intervals can be a discriminating feature in the verification and identification of computer users. This paper presents a comparison result obtained using several classification methods including k-NN (k-Nearest Neighbor), back-propagation neural networks, and Bayesian classification for keystroke identification. Performance of k-NN classification was best with small data samples available per user, while Bayesian classification was the most superior to others with large data samples per user. Thus, for web-based on-line identification of users, it seems to be appropriate to selectively use either k-NN or Bayesian method according to the number of keystroke samples accumulated by each user.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.5
• /
• pp.970-974
• /
• 2006

In his paper, a remote screen control system by mobile networks on embedded system is implemented. For this system a server program is ported on the embedded system connected to the internet. And on the side of a mobile phone, a client program is ported using general virtual machine. The embedded system can display the image from the mobile phone on its LCD. In the implemented embedded system, the image data from GVM emulator is sent to the system for display on its LCD. The realization of the proposed embedded system can display the image from a working mobile phone.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.5
• /
• pp.931-940
• /
• 2001

In this paper, I propose Fuzzy Policing Mechanism(FPM) over ATM networks for the control of traffic which is unpredictable and bursty source. The FPM is consist of counter, subtracter and Fuzzy Logic Controller(FLC). The FLC is divided to fuzzifier, inference engine and defuzzifer The output of FLC inputs to the subtractor and it controls the counter. The counter works as a switch in transmission of cells. In simulation, I compared the FPM with the Leaky Bucket algorithm(LBM) in cell loss probability and performance characteristics. As a result, FPM gives lower cell loss probability than that of LBM and has good response behavior The FPM efficiently controls the transmission of packets which are variable traffic source and, it also has good selectivity.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.6
• /
• pp.1077-1082
• /
• 2009

Wireless Mesh Network(WMN) is wireless backbone networks technique which has ease of network configuration and cost of advantage. Recently, WNM released a new product, but most of existing research and technology analysis the performance through the simulation. This paper build the wireless mesh network testbed for actual situation. Testbed supports multi-channel multi-interface using bridge, the Wireless Distribution System and dynamic location-based routing protocol. This routing protocol strongly design against wireless interference using metric for link channel change and real distance. Then, the address of mesh clients assigned by the centralized address management server. Mesh clients is designed and implemented to manage network through Simple Network Management Protocol.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.6
• /
• pp.1215-1221
• /
• 2009

A novel approach for electrocardiogram (ECG) analysis within a functional sensor node has been developed and evaluated. The main aim is to reduce data collision, traffic overload and power consumption in healthcare applications of wireless sensor networks(WSN). The sensor node attached on the patient's body surface around the heart can perform ECG analysis based on a QRS detection algorithm to detect abnormal condition of the patient. Data transfer is activated only after detected abnormality in the ECG. This system can reduce packet loss during transmission by reducing traffic overload. In addition, it saves power supply energy leading to more reliable, cheap and user-friendly operation in the WSN for ubiquitous health monitoring.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.66-69
• /
• 2008

As a mobility support for IP have studied, Internet Engineering Task Force(ITEF) standardized the mobile IPv6 protocol. When a mobile node moves between networks, MIPv6 maintains connectivity to network and supports seamless communication, and these processes are called a Handover. IEEE 802.21 standardized MIH(Media Independent Handover) for seamless Handover. MIH used three services for Handover between low layer and upper layer. In this paper, we designed two modes on existing MIH for seamless Handover. We implemented a dual-interface mobile host(MH) model in network simulation2 (ns2) to evaluate how it performs in comparison with single-interface MH.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.4
• /
• pp.818-824
• /
• 2014

The solution of brachistochrone problem turned out the form of a cycloid but correct angle values of bead can be obtained from the table form of inverse relations for the complicated nonlinear equations. To enhance the accuracy, this paper employs the neural network to represent the inverse relation of the complicated nonlinear equations. The accurate minimum-time control is possible with the interpolation property of the neural network. For various final target points, we have found that the proposed method is superior to the conventional ones through the computer simulations.