• Journal of Korea Multimedia Society
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• v.11 no.5
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• pp.641-650
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• 2008

As portable devices are used widely, power management algorithm is essential to extend battery use time on small-sized battery power. Although many methods have been proposed, they assumed the voltage transition overhead was negligible or was considered partially. However, the voltage transition overhead might not guarantee to schedule real-time tasks in portable multimedia systems. This paper proposes the adaptive power-aware algorithm to minimize the power consumption by considering the voltage transition overhead. It selects only a few discrete frequencies from the whole frequencies of a system and adjusts the interval between two consecutive frequencies based on the system utilization to reduce the number of frequency change. This algorithm saves the power consumption about 10 to 25 percent compared to a CC RT-DVS method and a frequency-smoothing method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.12
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• pp.2595-2600
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• 2012

In this study, we propose the new interface system for the disabled and old people who do not well using electronic equipment that is used physical switch interface system. The proposed new interface system is consisted of speech and motion recognition system. Speech recognition system is mike in the headset, and motion recognition system is 3-axis accelerometer in the headset. In order to verify the usefulness of the proposed system, we make an experiment on new interface.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.588-592
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• 2008

In this study the flow characteristics around the cutter head which makes the dredging soil suspended were measured to evaluate the environmental affect of the dredging action. The PIV was used for measuring the flow characteristics around the cutter head for suction and non-suction cases. As the results, the mean velocity was decreased from the cutter head to outward. The mean velocity decreasing rate of the non-suction case was larger than that of the suction case, but the turbulence intensity decreasing rate of the non-suction case was smaller than that of the suction case because of the suction energy which makes the z-direction flow.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1138-1145
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• 2003

The Bluetooth wireless technology is the new short-range RF transmission standard for low-power, low-cost, short-range radio links between mobile devices and electric product. The technology can eliminate the confusion of cables, connectors and protocols confounding communications between devices. Mobile phones, pagers, laptops, PDAs, digital cameras and more, all now have a common structure for communicating across their product platforms. In this paper, we present the Bluetooth protocol stack and headset profiles for the communication between mobile phone and headset. And then, we construct application software which is embedded in the device that operates an application over the Bluetooth protocol stack Next we implement wireless headset using MSP430, not real time operating system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.527-530
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• 2010

WSN is composed of a lot of small sensors with the limited hardware resources. In WSN, at the initial stage, sensor nodes are randomly deployed over the region of interest, and self-configure the clustered networks by grouping a bunch of sensor nodes and selecting a cluster header among them. Specially, in WSN environment, in which the administrator's intervention is restricted, the self-configuration capability is essential to establish a power-conservative WSN which provides broad sensing coverage and communication coverage. In this paper, we propose a communication coverage-aware cluster head election algorithm for Herearchical WSNs which consists of communication coverage-aware of the Base station is the cluster head node is elected and a clustering.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.25-30
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• 2010

Wireless sensor networks is composed of many similar sensor nodes with limited resources. They are randomly scattered over a specific area and self-organize the network. For guarantee of network life time, load balancing and scalability in sensor networks, sensor networks needs the clustering algorithm which distribute the networks to a local cluster. In existing clustering algorithms, the cluster head selection method has two problems. One is additional communication cost for finding location and energy of nodes. Another is unequal clustering. To solve them, this paper proposes a novel cluster head selection algorithm revised previous clustering algorithm, LEACH. The simulation results show that the energy compared with the previous clustering method is reduced.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.57-62
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• 2011

In this paper an efficient LT decoding scheme using GE triangularization is proposed. The proposed algorithm has the desirable performance in terms of both overhead and computational complexity. Belief propagation algorithm is a fast and simple decoding scheme for LT codes. However, for a small code block length k, it requires a large overhead to decode, and OFG which has a small overhead has a large computational complexity. Simulation results show that the proposed algorithm noticeably reduces the computational complexity by more than 1/5 with respect to that of OFG and also its overhead has a small value about 1~5%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.6
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• pp.1188-1193
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• 2009

Todays, many young people suffer from noise-induced hearing loss by using wearable hearing devices, such as Bluetooth headset. This paper present hearing loss reduction and more natural volumn control algorithms considering individual hearing characteristics and threshold of feeling for Bluetooth headset. Experimental results using CSR Bluetooth headset example design board(DEV-PC-1645) show that individuals maybe able to perceive without the inconvenience at the less sound intensity and the more sensitive frequency bands. As a result, we may prevent hearing loss to reduce excessive sound energy in each frequency bands.

• Archives of design research
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• v.21
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• pp.77-86
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• 1997

Modern society has created the age of mass media image. Advertising media strongly stimulate and influence the image contact and the frequency of receivers by visual communication media in everyday life. Until today no consciousness concerning the necessity of typographic visual image and it's selection for newspaper advertising has been developed. The necessity of headline typography visual image in newspaper advertising and it's selection should be considered a problem that must be solved by a more reasonable and logical approach, like it is done in the case of advertising copy, in order to increase the efficiency of advertising for the consumer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.3089-3095
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• 2013

The headliner was made of polyurethane(PU) and glass fiber(GF) composite materials are widely used as a sound insulation material. A large amount of waste materials occurs as a by-product in the headliner manufacturing process. In order to efficiently reuse the headliner waste materials, separation process of the components are very necessary. According to the results of thermal analysis, weight loss showed increase in the order polyurethane foam> non-foaming polyurethane> non-woven fabric> 1st layer> glass fiber in the range of up to $400^{\circ}C$. Analysis of the DSC characteristics, HDPE, LLDPE, PP, and Master Batch by adding additives the wasted scrap. As a result, except for the PP, there was no exothermic transition due to the crystallization.