• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.87-93
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• 2006

This is paper, with the development of computer and network communications technology, the technology of digital computer and modern communications has integrated into the field of intelligent home appliances, making them intelligentize with the function of a network information terminal. The paper introduces the Bluetooth SIG(Special Interesting Group) and the development of the standard of the Bluetooth. Researches the application model and the practical application of the Bluetooth technology, and the component elements of the Bluetooth. Finally deals with the outlook for the development of the Bluetooth technology.

• Culinary science and hospitality research
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• v.23 no.3
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• pp.166-173
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• 2017

This study was performed to compare the vitamin A, E, ${\beta}-carotene$, polyphenol content, and DPPH radical scavenging activity of carrot, apple, and blueberry juices as affected by extraction methods using slow juicer (HJ), no vacuum blending (NVJ) and vacuum blending (VJ). Juice yields of carrot, apple, and blueberry were 100% in NVJ and VJ groups. Vitamin A content of all juices was the highest in VJ group. Vitamin E content in carrot and apple juices increased most in the HJ group, followed by the NVJ and VJ group; Vitamin E content in blueberry juice was higher in the NVJ group than VJ or HJ group. ${\beta}-carotene$ and polyphenol content in all juices were highest in the VJ group. In addition, the differences between vacuum blending and non-vacuum blending were only shown on apple and blueberry juices. Polyphenol content in carrot and blueberry juices increased most in the HJ group, followed by the NVJ, and VJ groups, and in apple juice, polyphenol content was higher in the VJ group than the HJ or NVJ group. DPPH radical scavenging activity in the VJ group was significantly higher than the NVJ group. The results of this study showed the vacuum blending method had outstanding antioxidative nutrients compared to other juicing methods.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.163-170
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• 2012

This thesis suggests the application to the people who are using smart phone which is based on the Android operation system that makes it available to check their call and sms by a repeater and display in the limited places such as at the swimming pool or spa. This application is designed to save user's basic information. And when the user gets a call or a sms, it can make the sender number and fundamental information a data by PhonStateListener and SmsReceiver. The data is uploaded by bluetooth of a repeater. The smart phone user can use the repeater to check the received information by display.

• Journal of Advanced Navigation Technology
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• v.14 no.2
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• pp.253-259
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• 2010

Wireless mesh network is flexible network like Ad hoc network or bluetooth together based on base station. But, wireless mesh network shows high packet loss and when TCP was created, however as it was design based on wired link, wireless link made more transmission error than wired link. It is existent problem of TCP congestion control algorithm that TCP unfairness and congestion collapse over wireless mesh network. When TCP operation occurs with the packet loss where is not the congestion loss, it brings the performance degradation which is serious. In this paper, in order to improve efficient TCP congestion control algorithm in wireless mesh network, we proposed that TCP can adaptively regulate the congestion window in wireless link.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.578-580
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• 2013

Recently, personal mobile devices increased according to the rise of smart devices. Thus the all smart devices load with a bluetooth of standard specifications. However, it is deficiency to service using multiple connection of bluetooth device connection limit. Also bluetooth have other problem. bluetooth can't data communication until all device connection. In this paper, we proposed multi-connect algorithm based on TDM using AT command to overcome the problems above. As a result, it is confirmed that the real-time connectivity and data transmission between multiple devices is possible.

• The KIPS Transactions:PartC
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• v.11C no.1
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• pp.135-140
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• 2004

WLAH and WPAN technique are proposed as a home networking protocol in order to solve the problem of wireless communications and the bandwith extension. but, it is difficult to embed those technique to the home appliance devices because of economical efficiency and difficulty of standardization like a Bluetooth technique. In this paper, we suggEest a low-speed wireless protocol for wireless MODEM to control multiple devices. And we assure that this protocol not only maintain a accuracy and a characteristic of control information, but it is also suitable to a processor having low-processing ability and a processor embedded In the home appliance device through implementation of robot system and stable performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4A
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• pp.309-315
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• 2009

Wireless Ad-hoc networks are dynamic networks that consist of mobile nodes. Nodes in Ad-hoc networks are usually laptops, PDAs or mobile phones. These devices feature Bluetooth and/or IEEE 802.11 (WiFi) network interfaces and communicate in a decentralized manner. Due to characteristics of Ad-hoc networks, Mobility is a key feature of routing protocol design. In this paper, we present an enhanced routing maintenance scheme that cope with topology changes pre-actively. The key feature of the proposed scheme is to switch next-hop node to alternative neighbor node before link breakage for preventing route failure. From extensive experiments by using NS2, the performance of the proposed scheme has been improved by comparison to AODV protocol.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.3
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• pp.266-270
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• 2008

Bluetooth technology provides a way to connect and exchange information between personal devices over a secure and short-range radio frequency without any authentication infrastructures. For this infrastructure-less feature, Bluetooth has several problems which could not occur in other network, and among them location tracking attacks is essential problem which should be solved. In this paper, we introduce the location tracking attack and propose an anonymous connection protocol against it. We also perform security analysis based on possible scenarios of this attack, and estimate both execution time and memory spaces of our scheme and existing methods.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.12
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• pp.132-138
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• 2008

Recently, mastering processes for high density optical disc such as Blu-ray disc rely on electron beams, which are operable in only vacuum. In the mastering process, one of the most important tasks is to design precision stages for providing precise positioning of the works with respect to the source in a high vacuum environment. In this paper, we have developed a precision rotation table usable in the electron beam mastering. The rotation table adopted air bearings for a high positioning repeatability and velocity stability. The air leakage from the air bearings has been minimized by employing the differential exhaust scheme using three steps of air drain. The design parameters such as diameters of exhaust lines, seal lengths, and pumping speeds were decided according to the optimization method using genetic algorithm. The performance on the vacuum level of the rotation table was evaluated experimentally and theoretically. The results indicate that a vacuum level of $10^{-4}$ Pa is achieved with operation of air bearings in a vacuum chamber, which is sufficient for the electron beam mastering.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.467-471
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• 2005

In this paper, experimental methods about the flow behavior of thin polymer film by various edge patterns in the spin coating process for stable cover layer coating of a blu-ray disc is described. The blu-ray disc, a next-generation optical disc format over 25GB, consists of a 1.1m thick substrate and a 0.1mm tick cover layer. Generally, cover layer on the blu-ray disc is made by the polymer spin coating process. However, it is hard to secure sufficient coating uniformity around the rim on the cover layer. In order to get the uniform thickness deviation and to minimize the bead around the rim, the edge of the disc substrate can be modified into various patterns, such as normal plain, trench, step and chamfer pattern, etc, around the rim on the disc and experimented with various parameters, such as surface tension, viscosity, coating time, temperature and rotation speed, etc. And the optimal shape of the rim was tried to get by 3 dimensional computer simulation of the polymer expulsion process.