• Journal of Digital Contents Society
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• v.7 no.2
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• pp.103-108
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• 2006

Short-range wireless communication and networking technologies are becoming increasingly important in enabling useful mobile applications. for example, ZigBee technology is expected to provide low cost and low power connectivity for equipment that needs battery life as long as several months to several years. In addition, ZigBee can be implemented in mesh networks larger than is possible with Bluetooth. The main features of this ZigBee standard are network flexibility, low cost, very low power consumption, and low data rate in an adhoc self-organizing network among fixed, portable and moving devices. Home network/Home automation is one of the key market areas for Zigbee, with an example of a simple network This paper investigates the effect of short range wireless channel on the performance of Zigbee system and DSSS-BPSK signal transmission in AWGN, interference and Rician fading environments. And we investigate performance degradation due to interference and fading effects in short range wireless channel. In particular, the impacts of the fading and interference level on the bit error probability is shown in BER performance figures.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.10
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• pp.40-45
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• 2009

In this paper, we introduce a mobile-type tiny sensor device that can classify the activities of daily living based on the state-dependent motion analysis using a 3-axial accelerometer in real-time. The device consists of an accelerometer, GPS module, 32bit micro-controller for sensor data processing and activity classification, and a bluetooth module for wireless data communication. The size of device is 50*47*14(mm) and lasts about 10 hours in operation-mode and 160 hours in stand-by mode. Up to now, the device can recognize three user activities ("Upright", "Running", "Walking") based on the decision tree. This tree is constructed by the pre-learning process to activities of subjects. The accuracy rate of recognizing activities is over 90% for various subjects.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.103-109
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• 2017

In order to apply the patient monitoring system to the hospital field, it is necessary to be able to measure and analysis data the major bio-signals that are basically covered by the existing patient monitoring system. We have implemented a wearable device and the patient monitoring system for measuring ECG and oxygen saturation. The implemented system transmits the measured bio-signal to the server on the nursing station via Bluetooth. It is represented by graph waveforms and numerical values that can be checked by the medical staff in the patient monitoring system. The validity of this system is verified by comparing the data collected through the designed system with the data obtained from the conventional equipment.

• Journal of IKEEE
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• v.19 no.1
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• pp.18-26
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• 2015

In this paper, we proposed and evaluated the performance of an internal MIMO (Multiple Input Multiple Output) antenna for multiband operations including LTE (Long Term Evolution) 700/2300/2500. And to enhance the isolation characteristic, a parasitic element is designed and applied. The proposed single antenna has a volume of $60mm(W){\times}38mm(L)$, and the ground plane is $60mm(W){\times}100mm(L)$. The parasitic element used for enhancing the isolation of the antenna was designed with a copper on FR4 sized $60mm(W){\times}20mm(L){\times}1.6mm(H)$, and the pattern size is $60mm(W){\times}15mm(L)$. Simulated and measured results showed that LTE 700/2300/2500, DCS (Digital Cellular Service: 1710-1880MHz), K-PCS (Korea-Personal Communication Service: 1750-1870MHz), US-PCS (US-Personal Communication Service: 1850-1990MHz), WCDMA (Wideband Code Division Multiple Access: 1920-2170MHz), Wibro (2300-2390MHz), Bluetooth (2400-2483MHz), WLAN (Wireless Local Area Network: 2400-2483.5MHz), US-WiMAX (US-World interoperability for Microwave Access: 2400-2590MHz) frequency bands were covered with $S_{11}$ values less than -6dB (VSWR < 3). Simulated and measured results on $S_{21}$ at 730MHz for the firstly designed MIMO antenna showed -5.50dB and -5.65dB, respectively. When with the parasitic element at the separated ground plane to enhance the isolation performance, -10.33dB and -12.90dB are obtained for the simulation and measurement, so the enhanced isolation performance at lower frequency band (617-867MHz) is confirmed.

• Journal of IKEEE
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• v.18 no.4
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• pp.572-580
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• 2014

This study deals with reconfigurable modular robot with respect to the compact and capability of representing the various actions for promoting creativity through education and play. Generally modular robot can be designed as a suitable robot that is transformed to various structure by reconstructing each cells, However, there are only few research on the education and play using those robots in the world and still nothing domestically. Unlike the existing modular robots only having a repeating motion, the proposed modular works by individual module such as sound is produced by sound module, wheel is driven by wheel module, LED module controls the visual expression, power is supplied by battery module, bluetooth module for communication, and dynamic motion realization is possible by using joint module. By manipulating the abilities endowed by individual modules, diversity of creative activities is possible and thus made an easy access for children. This study deals with the design of modular robotic by using the variety of different modules to endowed the learning and playing ability. And the study showed the utility of the operating behavior over the actual production and testing.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.473-480
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• 2018

In 2012, a new energy capturing method called TENG was suggested for energy harvesting applications. The TENG which captures electric energy in forms of friction or vibration has been researched as a new energy harvesting generation device. However, TENG works on rather high voltage and yields relatively low current, and this requires additional energy conversion and saving methods with either in semiconductive elements or circuitry for its application. Irregular generation from vibration sources rattle under 5Hz especially requires empirical studies. In this article, we suggest a electricity generation platform with energy storage methods. The platform is mounted on large sized animals, and the generation is actively monitored and controlled via Bluetooth-Low Energy to verify the platform.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1845-1852
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• 2015

From bar code systems and radio frequency identification (RFID) to beacons utilizing low power bluetooth technology, the fusion of information technology and health and medical treatment is spreading through advances such as automated treatment and examination stages and the use of treatment information connected to smart devices. In this paper, designed and implemented a mobile health care system for the safe management of blood transfusions to prevent accidental problems that can occur during patient blood transfusions. It makes safe and effective blood transfusion possible by using smart devices to read information saved on patient bracelets, blood-collecting containers, blood transfusion bags, and medical personnel identification cards so that they match patient information. By applying the blood transfusion management mobile health care system presented and implemented in this paper to blood transfusion processes in hospitals, it was verified that it allows for safe and effective blood transfusion, preventing accidents which may occur in blood transfusion processes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.673-676
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• 2008

In wireless communications such as Bluetooth, Baseband should be able to minimize the DC bias of the data which passed the modem interface of either transmitter or receiver for the reliability of the circuit and the integrity of the data. The transmitter scrambles the data to send randomly to the error correction block and the receiver recovers the randomly spread data as they have been. To design the whitening block, it is important to select the prime polynomial for the filtering. In this paper, we designed a optimal whitening block using the prime polynomial $g(D)=D^7+D^4+1$ for hardware and area efficiency. The proposed hardware whitening block was described and verified using Verilog HDL and later to be automatically synthesized. The synthesized whitening block operated at 40Mhz normal clock speed of the target baseband microcontroller.

• Journal of Internet of Things and Convergence
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• v.2 no.1
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• pp.7-15
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• 2016

Bicycle users were surpassed a million recently as bicycle riding will be a key element of daily life. As users increase, we can expect that the user is more exposed to the risk of an unexpected accident. Therefore, we need to establish several preventive measures for a safe riding environment. In this paper, we developed mobile application by using the acquired GPS-based location information that provide safety services for the bike riding as a LBS service. In detail, we have been able to provide a bicycle safety navigation service by using the bluetooth transmission and reception method between Android and Arduino-based devices. As a future work, the safety could be improved if we expand various forms of Arduino sensors. As a result, a service developed in this study will be able to converge ahead to connect into several personalized mobile IoT services.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.533-539
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• 2013

Recently, Ionic Polymer Metal Composite (IPMC) systems receive great attention in the fields of the medical and biomedical Engineering because of several merits in terms of new actuators and sensors and fuel cell materials. When the voltage is excited to IPMC system, it moves. Conversely, if there are any movement on the IPMC, the IPMC has charge voltage by the internal properties. Therefore the IPMC can be used as a motion sensor or force sensor. In this paper, we identify characteristics of the IPMC and control its movements from remote locations by the smart-phone system based on visual information for monitoring. Additionally, control of movements of the IPMC is realized by transmit motion commands using the smart-phone system with the blue-tooth communication. Unfortunately, there are some deficiencies to perfectly attain physical properties of the IPMC systems from our experiments in this paper. However, in its utilization point of view, we demonstrate that the IPMC has some potentials as new sensors, actuators, and fuel cells.