• Journal of Korea Society of Digital Industry and Information Management
• /
• v.11 no.1
• /
• pp.19-25
• /
• 2015

In this time, as an industrial society developed to a welfare society, more and more people want their quality of lives upgraded and specially customized service by mass production/mass consumption. And it leads to an increase of requiring service. There're active developments and studies on various IT equipment as the requirement made IT devices used in service. In this paper, we try to design and realize radio paging DID by using smart device to be used as a receiver of a radio pager which is broadly used at face to face service. Firstly, we used MCU to design and implement Wireless Calling Gateway which change radio calling signal of ISM band to smart device. A receiver of wireless caller used original receiver module. Also it used bluetooth module to communicate with smart device. It was possible to have satisfactory communication since radio paging signal converter and smart device were linked in 3M. Secondly, to indicate various paging information delivered from a radio pager, we realized DID application program by using Smart PAD. As a result, we could indicate various information compared to an original receiver which only could indicate letters or numeric data. Secondly, we implemented the DID app for wireless calls that can display a variety of information sent from a wireless pager. Was implemented using the Smart Pad. As a result, it is shown that can display a variety of information than the existing receiver.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.3
• /
• pp.1337-1362
• /
• 2020

Advances in localization-based technologies and the increase in ubiquitous computing have led to a growing interest in location-based applications and services. High accuracy of the position of a wireless device is still a crucial requirement to be satisfied. Firstly, the rapid development of wireless communication technologies has affected the location accuracy of radio monitoring systems employed locally and globally. Secondly, the location is determined using standard complex computing methods and needs a relatively long execution time. In this paper, two geolocalization techniques, based on trigonometric and CORDIC computing processes, are proposed and implemented for Bluetooth-based indoor monitoring applications. Theoretical analysis and simulation results are investigated in terms of accuracy, scalability, and responsiveness. They show that the proposed techniques can locate a target wireless device accurately and are well suited for timing estimation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.5
• /
• pp.284-288
• /
• 2016

Among the various physiological information that could be obtained from human body, heartbeat rate is a commonly used vital sign in the clinical milieu. Photoplethysography (PPG) sensor is incorporated into many wearable healthcare devices because of its advantages such as simplicity of hardware structure and low-cost. However, healthcare device employing PPG sensor has been issued in susceptibility of light and motion artifact. In this paper, to develop the real-time heart rate measurement device that is less sensitive to the external noises, we have fabricated an ultra-small wireless LC resonant pressure sensor by MEMS process. After performance evaluation in linearity and repeatability of the MEMS pressure sensor, heartbeat waveform and rate on radial artery were obtained by using resonant frequency-pressure conversion method. The measured data using the proposed heartbeat rate measurement system was validated by comparing it with the data of an commercialized heart rate measurement device. Result of the proposed device was agreed well to that of the commercialized device. The obtained real time heartbeat wave and rate were displayed on personal mobile system by bluetooth communication.

• Journal of the Korean Society of Safety
• /
• v.30 no.6
• /
• pp.117-121
• /
• 2015

$O_2$-deficiency related accidents occur every year and the most effective way to prevent them is to measure $O_2$ concentration in air with a properly-calibrated $O_2$ monitoring device before entering low-$O_2$ areas. An electro-chemical sensor, Texas Instrument gas platform, and iPhone are used to construct a smartphone-based $O_2$ monitoring device. The smartphone based $O_2$ measuring approach offers advantages of small size, accessibility, internet-connectivity, and programmability in comparison to conventional $O_2$ measuring devices. Multiple gas sensors can be conveniently interfaced to single smartphone, allowing for creating a network of gas sensors distributed across workplaces and remote monitoring via existing mobile communication network. To check proper function of the $O_2$ monitoring device the sensor was exposed to shallow and deep human breaths. The readings decreased immediately after being exposed to exhalation and recovered during inhalation to a calibrated level of 20.9%. When readings decreased below a preset warning value of 19.5%, a low $O_2$ warning was successfully activated on the smartphone.

• Journal of Korea Multimedia Society
• /
• v.17 no.12
• /
• pp.1461-1472
• /
• 2014

Recently, smart devices has been spreaded and the definition of RFID/USN(Radio Frequency Identification/Ubiquitous Sensor Network) technology has also extended. So, originally, human is an agent of communications but now, 'the things' are also an agent of communication. That is, Internet of Things(IoT). IoT is very big IT infra technology that is based on wire-wireless network technologies such as Bluetooth and Wi-Fi. However, in reality, IoT service that can provide various meaning and integrate smoothly is not appear yet. To solve these problems of IoT, we implemented Publish/Subscribe system, which operate in Zigbee based wireless sensor network by using MQTT-SN protocol. Moreover, this system can operate with combining MQTT system that is already existed in external Internet network so, extensibility and flexibility aspect is excellent. We show that possibility of IoT services that is combined between different heterogeneous network through the MQTT-SN.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2016.10a
• /
• pp.501-502
• /
• 2016

최근 스마트기기 사용량이 증가함에 따라 NFC나 Bluetooth 등 다양한 근거리 통신 서비스가 제공되고있다. 그러나 이들 통신방식은 별도의 통신 모듈을 필요로 하는 단점이 있다. 이러한 단점을 해결하기 위해 비가청주파수 대역을 이용한 통신이 연구되고 있다. 비가청주파수 대역은 18kHz~22kHz 사이의 사람에게 들리지 않는 주파수 대역으로 마이크와 스피커만 있으면 비가청주파수 통신이 가능하다. 기존 연구는 특정 사용자를 식별하여 데이터를 보안상 안전하게 전송하는 방식이 없다. 본 논문에서는 통신에 사용되는 두 기기가 본 논문에서 제안한 공유키를 활용하여 3단계의 과정을 거쳐 사용자를 식별하는 방법을 제안한다. 또한 식별 과정에서 만들어진 값은 메시지를 암호화하는데 사용되어 보안을 강화한다. 이 식별 방법은 비가청주파수 통신을 IoT 등 다양한 분야에 활용하는데 사용할 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.9
• /
• pp.2064-2071
• /
• 2012

The generalization trend of smart phones have brought many smartphone games into daily lives. These games are mainly dependent on the interactions on the display of the phone using finger touches. On the other hand, functions for detecting the positions and actions of the phones such as gyro-sensors have been rapidly developed over the former orientation sensors and acceleration sensors. Though it has become technologically possible to detect the users' motion via the smartphone devices and to use the phone device directly as the game device, it is hard to find the actualized cases. This paper proposes a new paradigm including basic frameworks and algorithm for the games combining the motion recognitions and mutual communications on the smartphones and finally presents the details of its implementation and results.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.1
• /
• pp.145-152
• /
• 2016

The usage of LED(Light Emitting Diode) has been rapidly increased and energy efficient management of LED light system is regarded as an important technology to enhance the energy efficiency. In this paper, we design and implementation of LED lighting controller which can control the LED lighting by using the wire and wireless communication technology based on the LAN(Local Area Network) and PAN(Personal Area Network). The implemented system can reduce the cost of LED lighting installing and avoids complicated wiring problem. And it is possible to minimize power consumption through automatic or manual LED control that they wished. In experimental results, the implemented LED lighting controller was satisfactory for all of the desired functions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.386-389
• /
• 2016

The number of cyclists is on the steady growing for leisure, sports and transportation with the increasing interest in health and environment. However, the number of cycling accidents is also increasing steadily due to the lack of safety awareness and regulations. Focusing on these issues, we propose and develop the smart LED cycling helmet in order to reduce a risk of cycling accident. To provide the motion information of the bicycle for others, we attach the LEDs on the helmet and control the LED lights using Arduino. The motion information is displayed on the LED helmet by using sensors of the smartphone. Communication between Arduino and the smartphone is performed through Bluetooth.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.12 no.1
• /
• pp.35-41
• /
• 2017

We propose a face recognition and notification system that can transform visual face information into tactile signals in order to help visually impaired people. The proposed system consists of a glasses type camera, a mobile computer and an electronic cane. The glasses type camera captures the frontal view of the user, and sends this image to mobile computer. The mobile computer starts to search for human's face in the image when obstacles are detected by ultrasonic sensors. In a case that human's face is detected, the mobile computer identifies detected face. At this time, Adaboost and compressive sensing are used as a detector and a classifier, respectively. After the identification procedures of the detected face, the identified face information is sent to controller attached to a cane using a Bluetooth communication. The controller generates motor control signals using Pulse Width Modulation (PWM) according to the recognized face labels. The vibration motor generates vibration patterns to inform the visually impaired person of the face recognition result. The experimental results of face recognition and notification system show that proposed system is helpful for visually impaired people by providing person identification results in front of him/her.