• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.5
• /
• pp.937-942
• /
• 2000

This paper describes for applications of neural networks in the field of arc welding. Conventional, automated process generally involves sophisticated sensing and control techniques applied to various processing parameters. Welding parameters affecting quality include the arc voltage, the welding current and the torch travel speed. The relationship between the welding parameters and weld quality is not a direct one, and in addition, the effect of the weld parameter variables are not independent of the each other - changing the welding current will affect the arc voltage, and so on. Finally, a suitable proposal to improve the construction of the model has also been presented in the paper.

• Journal of information and communication convergence engineering
• /
• v.10 no.4
• /
• pp.329-336
• /
• 2012

For designing broadcast protocols in mobile ad hoc networks (MANETs), one of the important goals is to reduce the rebroadcast packets redundancy while reaching all the nodes in network. In this paper, we propose a probabilistic broadcasting mechanism based on selfishness and additional coverage in MANETs. Our approach dynamically adjusts the rebroadcast probability according to the extra covered area and number of neighbor nodes. By these two factors, mobile hosts can be classified into three groups: normal, low selfishness, and high selfishness groups. The nodes in the normal group forward packets for other nodes with high probability, whereas the nodes in the low selfishness group rebroadcast packets with low probability and the nodes in the high selfishness group do not rebroadcast packets. We compared our approach with simple flooding and the fixed probabilistic approach. The simulation results show that the proposed schemes can significantly reduce the number of retransmissions by up to 40% compared simple flooding and fixed probabilistic scheme without significant reduction in the network reachability and end-to-end packet delay.

• Journal of information and communication convergence engineering
• /
• v.10 no.4
• /
• pp.384-389
• /
• 2012

In this paper, we examine the problems of the low energy adaptive clustering hierarchy (LEACH) protocol and present ideas for improvement by selecting the cluster head node. The main problem with LEACH lies in the random selection of cluster heads. There exists a probability that the formed cluster heads are unbalanced and may remain in one part of the network, which makes some part of the network unreachable. In this paper, we present a new version of the LEACH protocol called the improved LEACH (ILEACH) protocol, which a cluster head is selected based on its ratio between the current energy level and an initial energy level, and multiplies by the root square of its number of neighbor nodes. The simulation results show that the proposed ILEACH increases the energy efficiency and network lifetime.

• Journal of information and communication convergence engineering
• /
• v.9 no.2
• /
• pp.155-160
• /
• 2011

In distributed source localization where sensors transmit measurements to a fusion node, we address the sensor selection problem where the goal is to find the best set of sensors that maximizes localization accuracy when quantization of sensor measurements is taken into account. Since sensor selection depends heavily upon rate assigned to each sensor, joint optimization of rate allocation and sensor selection is required to achieve the best solution. We show that this task could be accomplished by solving the problem of allocating rates to each sensor so as to minimize the error in estimating the position of a source. Then we solve this rate allocation problem by using the generalized BFOS algorithm. Our experiments demonstrate that the best set of sensors obtained from the proposed sensor selection algorithm leads to significant improvements in localization performance with respect to the set of sensors determined from a sensor selection process based on unquantized measurements.

• Journal of information and communication convergence engineering
• /
• v.6 no.2
• /
• pp.213-217
• /
• 2008

This paper proposes a novel method for the recognition of passports based on the CDM(Conditional Dilation Morphology) masking and the ART2-based RBF neural networks. For the extraction of individual codes for recognizing, this paper targets code sequence blocks including individual codes by applying Sobel masking, horizontal smearing and a contour tracking algorithm on the passport image. Individual codes are recovered and extracted from the binarized areas by applying CDM masking and vertical smearing. This paper also proposes an ART2-based hybrid network that adapts the ART2 network for the middle layer. This network is applied to the recognition of individual codes. The experiment results showed that the proposed method has superior in performance in the recognition of passport.

• Proceedings of the Korea Contents Association Conference
• /
• 2009.05a
• /
• pp.677-681
• /
• 2009

The Smoothly Coupled Integration (SCI) proposed in this paper takes only the strength of loosely coupled integration and tightly coupled integration. Furthermore, 3G network and WiBro network, which are coupled with SCI, have independent architecture which supports mobility and seamless services by fast handoff. Computer simulation with the use of OPNET marked excellence in performance of smoothly coupled integration.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.11
• /
• pp.2361-2366
• /
• 2009

Usually, it is possible for human administrator to control the facilities manually or automatically using sensors in order to manage the fixed electricity facilities. However, it is difficult to collect the status data of those facilities in the central management system. In this paper, we propose the electricity facility management system to collect the status of facilities using the Zigbee networks. the proposed system exploits the various types of sensors, such as motion, heat, optical, etc, to measure the states of the facilities.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.9
• /
• pp.2150-2156
• /
• 2010

We focus on the network itself and its ability to enable efficient and effective information flow. All networks are complex to a greater degree, including military command and control systems operating in a network-centric environment. It requires to understand the nature of complexity, what its effects are, and how to quantify them. In this paper, we present the beneficial effects of information accessibility and network-based redundancy into a single metric.

• Journal of information and communication convergence engineering
• /
• v.12 no.1
• /
• pp.1-7
• /
• 2014

A novel design of a simple circular ring with open-ended monopole antenna for wireless local area network (WLAN) applications is proposed in this article. The proposed antenna consists of an open-ended circular ring and $50-{\Omega}$ microstrip feed-line. The proposed antenna is capable of generating two separate resonant modes with good impedance-matching conditions. A prototype of the proposed antenna is designed, fabricated, and measured. Acceptable agreement between the measurement and simulation results is achieved. Experimental results show that the proposed antenna has operating bandwidths of 1.99-3.04 GHz and 5.08-6.1 GHz with a return loss of less than -10 dB, covering the required bandwidths of the 2.4/5.2/5.8-GHz WLAN standards. This is a microstrip antenna for IEEE 802.11a/b wireless local area networks applications. Meanwhile, the two-dimensional (2D) radiation patterns and three-dimensional (3D) gain performance of the antenna are also observed and discussed.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.6
• /
• pp.1318-1323
• /
• 2013

We consider the design of opportunistic spectrum access schemes where secondary users can opportunistically access unused spectrum in non-slotted primary systems. Two non-slotted spectrum sensing and access schemes for secondary users are considered. We present experimental results that demonstrate the performance of the considered schemes.