• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.5
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• pp.9-20
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• 2005

In this paper, we propose ubiTrack, a system which tracks users' location in indoor environments by employing infrared-based proximity method. Most of recently developed systems have focussed on performance and accuracy. For this reason, they adopted the idea of centralized management, which gathers all information in a main system to monitor users' location. However, these systems raise privacy concerns in ubiquitous computing environments where tons of sensors are seamlessly embedded into environments. In addition, centralized systems also need high computational power to support multiple users. The proposed ubiTrack is designed as a passive mobile architecture to relax privacy problems. Moreover, ubiTrack utilizes appropriate area as a unit to efficiently track users. To achieve this, ubiTrack overlaps each sensing area by utilizing the TDM (Time-Division Multiplexing) method. Additionally, ubiTrack exploits various filtering methods at each receiver and utilization module. The filtering methods minimize unexpected noise effect caused by external shock or intensity weakness of ID signal at the boundary of sensing area. ubiTrack can be applied not only to location-based applications but also to context-aware applications because of its associated module. This module is a part of middleware to support communication between heterogeneous applications or sensors in ubiquitous computing environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.833-835
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• 2014

On this study, we have developed respiratory training system to improve stability of respiration, one of the most important factors of Respiratory Gated Radiation Therapy, RGRT. Respiratory training system that we developed was applied to personal respiratory cycle so that it could provide comfortable respiratory triggering to patients. To give sufficient time for practice, we used modular portable device to practice easily and to be undetered by time and place. We have intended to improve efficiency and accuracy by providing it to patients. We are now planning to conduct experiment of 10 peoples to find out stability, degree of durability betterment and regularity of respiration when patients are using respiratory training system. There are three kinds of breathing style. First is free breathing that Individual patients can breathe freely. Second is guide breathing that patients apply to personal respiration cycle through the guiding sight and hearing program. Third is prediction breathing that patients breathe after respiratory training without guiding sight and hearing program. By using these 3 data of respiration method, we have evaluated usability of respiratory training system by quantitatively analyzing respiration period, amplitude and area's variation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.443-446
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• 2003

This paper implement Remote Meter Reading System which is used Bluetooth and SMS in CDMA. This System propose system which tan detect a total amount of gas, electricity or water without a meterman, at home BlueTooth is a close range wireless communication technology which uses a wireless frequency 2.4GHz and has a high trust and self error correction technology according to a low power consumption quality and a high-speed frequency hopping. This makes get a high trust concerning a data transmission than an existing modem. In addition, though wireless modem is restricted by a minimal of a wireless terminal, it will be possible to coincide with the function of the portable with the low power consumption quality by using Bluetooth. And as the system on a chip of module progresses, the possibility of the small size is present. Nowadays, SMS Protocol in CDMA for have a network function based on PPP in CDMA Phone. The proposed Remote Meter Reading System to get more nobility, efficiency, and have good function. SMS Protocol in CDMA have profits which is low power, low cost, and low microwave output.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.1
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• pp.63-72
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• 2010

RFID is one of useful identification technology in ubiquitous environments which can be a replacement of bar code. RFID is basically consisted of tag, reader, which is for perception of the tag, and back-end-database for saving the information of tags. Although the usage of mobile readers in cellular phone or PDA increases, related studies are not enough to be secure for practical environments. There are many factors for using mobile leaders, instead of static leaders. In mobile reader environments, before constructing the secure protocol, we must consider these problems: 1) easy to lose the mobile reader 2) hard to keep the connection with back-end-database because of communication obstacle, the limitation of communication range, and so on. To find the solution against those problems, Han et al. suggest RFID mutual authentication protocol without back-end-database environment. However Han et al.'s protocol is able to be traced tag location by using eavesdropping, spoofing, and replay attack. Passive tag based on low cost is required lots of communication unsuitably. Hence, we analyze some vulnerabilities of Han et al.'s protocol and suggest RFID mutual authentication protocol without online back-end-database in aspect of efficiency and security.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.278-283
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• 2000

As information communication technology developed we could check our blood pressure, pulsation electrocardiogram, SpO2 and blood test easily at home. To check our health at ordinary times is able though interlocking the house medical instrument with the wireless public data network This service will help the inconvenience to visit the hospital everytime and will save the individual's time and cost. In each house an organism data which is detected from the human body will be transmitted to the distance hospital and will be essentially applied through wireless public data network The medical information transmit system is utilized by wireless close range network It would transmit the obtained organism signal wirelessly from the personal device to the main center system in the hospital. Remote telemetry system is embodied by utilizing wireless media access protocol. The protocol is embodied by grafting CSMA/CA(Carrier Sense Multiple Access with Collision Avoidance) protocol falling mode which is standards from IEEE 802.11. Among the house care telemetry system which could measure blood pressure, pulsation, electrocardiogram, SpO2 the study embodies the ECC(electrocardiograph) measure part. It within the ECC function into the movable device and add 900㎒ band wireless public data interface. Then the aged, the patients even anyone in the house could obtain ECG and keep, record the data. It would be essential to control those who had a health-examination heart diseases or more complicated heart diseases and to observe the latent heart disease patient continuously. To embody the medical information transmit system which is based on wireless network. It would transmit the ECG data among the organism signal data which would be utilized by wireless network modem and NCL(Native Control Language) protocol to contact through wireless network Through the SCR(Standard Context Routing) protocol in the network it will be connected to the wired host computer. The computer will check the recorded individual information and the obtained ECC data then send the correspond examination to the movable device. The study suggests the medical transmit system model utilized by the wireless public data network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.702-708
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• 2017

The heat generation rate in a telecommunications cabinet keeps increasing due to the increased usage of mobile devices. Insufficient removal of the heat increases the cabinet temperature, which results in the malfunction of the electronic devices. In this study, tests were conducted on aluminum and plastic heat exchangers for cooling a telecommunications cabinet, and the results were compared with theoretical predictions. The aluminum heat exchanger comprised counter flow parallel channels with 4.5-mm pitch, and the plastic heat exchangers comprised cross or cross-counter flow triangular channels with 2.0-mm pitch. The volume of the cross flow heat exchanger was the same as that of the aluminum heat exchanger, and the volume of the cross-counter heat exchanger was 33% larger than that of the aluminum heat exchanger. The results show that the heat transfer rate is the highest for the cross-counter heat exchanger and lowest for the aluminum one. The temperature efficiency of the cross-counter heat exchanger was 56% higher than that of the aluminum one and 20% higher than that of the cross flow heat exchanger. The pressure drop of the cross-counter heat exchanger was approximately the same as that of the aluminum one. The heat exchange efficiency was the highest for the cross-counter heat exchanger and lowest for the cross flow heat exchanger. The theoretical analysis somewhat overestimated or underestimated the data.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.7
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• pp.315-324
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• 2023

A simple and accurate whole body rehabilitation interaction technology using immersive digital content is needed for elderly patients with steadily increasing age-related diseases. In this study, we introduce whole-body interaction technology using HoloLens and Kinect for this purpose. To achieve this, we propose three coordinate transformation methods: mesh feature point-based transformation, AR marker-based transformation, and body recognition-based transformation. The mesh feature point-based transformation aligns the coordinate system by designating three feature points on the spatial mesh and using a transform matrix. This method requires manual work and has lower usability, but has relatively high accuracy of 8.5mm. The AR marker-based method uses AR and QR markers recognized by HoloLens and Kinect simultaneously to achieve a compliant accuracy of 11.2mm. The body recognition-based transformation aligns the coordinate system by using the position of the head or HMD recognized by both devices and the position of both hands or controllers. This method has lower accuracy, but does not require additional tools or manual work, making it more user-friendly. Additionally, we reduced the error by more than 10% using RANSAC as a post-processing technique. These three methods can be selectively applied depending on the usability and accuracy required for the content. In this study, we validated this technology by applying it to the "Thunder Punch" and rehabilitation therapy content.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2793-2800
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• 2011

The purpose of this research is to develop and optimize a lane departure warning application based on a smartphone which can be applicable as a new platform for various mobile information applications. Recently, a lane detection warning system which is a representative application among safe driving assistant solutions is being commercialized. Due to the necessity of powerful embedded hardware platform and its price, its market is still not growing. In this research, it is proposed to develop and optimize a lane departure warning application on iPhone 3GS. OpenCV is used for efficient image processing, and for lane detection a heuristic algorithm based on Hough Transform is proposed. The application was developed under Macintosh PC platform with Xcode 3.2.4 development tools, downloaded to the iPhone and has been tested on the real paved road. The experimental result has shown that the detection ratio of the straight lane was over 90% and the processing speed was 1.52fps. For the enhancement of the speed, a few optimization methods were introduced and the fastest speed was 3.84fps. Through the improvement of lane detection algorithm, additional optimization works and the adoption of a new powerful platform, it will be successfully commercialized on smartphone application market.

• The Journal of Society for e-Business Studies
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• v.17 no.3
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• pp.129-147
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• 2012

In this paper, we research on the personal information protection system in smart-phone based on mobile environment. This paper proposes the enhanced personal location privacy mechanism in location-based service environment of a smart phone operating system(iOS, Android) for the relevant regulations on location-based protection and utilization. Also, the result verified that possibility on a self-control mechanism of the personal information protection system's subject in the window platform throughout the experiment. Therefore, this study have drew a method that user positively can cope with a protection of personal location information by having a user's self-control method in the system under development or done by illegal location-based service providers and illegal application developer.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.10
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• pp.1154-1160
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• 2010

In this paper, a novel printed meander monopole antenna is proposed for wireless USB dongle applications. Dual-wideband resonance is obtained by utilizing a printed meander monopole radiator. The proposed antenna was fabricated on a thin FR-4 substrate with a thickness of 1 mm and a dielectric constant of 4.6. The antenna is fed by a $50{\Omega}$ coaxial cable. This novel USB dongle antenna measures only $10{\times}50mm^2$. The measured results demonstrates that the antenna supports WiBro, Bluetooth/ISM, WLAN, S-DMB, and WiMAX service bands.