• Journal of Digital Convergence
• /
• v.15 no.3
• /
• pp.287-294
• /
• 2017

This study attempted to develop a beacon scanner based ward monitoring service in order to respond to the new paradigm of medical environment which is trying to introduce ICT technology as medical service to track and manage the spread path of large infectious diseases such as MERS. The study also included beacon hardware development, firmware development for the beacon low-power bluetooth 4.0, and server and web-based dashboard UI development. Using these, we have developed a customized monitoring system that provides functions such as locating patients by location based service and monitoring based on web UI. It is possible to maximize the efficiency of offline hospital services and to value active infection control and patient safety by integrating online technology into the area where online technologies such as beacons are not properly integrated.

• KIPS Transactions on Computer and Communication Systems
• /
• v.5 no.9
• /
• pp.211-216
• /
• 2016

Worldwide casualties caused by earthquakes, floods, fire or other disaster has been increasing. So many researchers are being actively done technical studies to ensure golden-time. In this paper if a disaster occurs, use the IoT technologies in order to secure golden-time and transmits the message after to find the user of the accident area first. When the previous job is finished, gradually finds a user of the surrounding area and transmits the message. For national emergency information, OPEN API of Korea Meteorological Administration was used. To collect detailed information on a relevant area in real time, this study established the system that connects and integrates Crowd Sensing technology with BLE (Bluetooth Low Energy) Beacon technology. Up to now, the CBS based on base station has been applied. However, this study designed and mapped DB in the integration of Beacon based user positioning and national administrative address system in order to estimate local users. In this experiment, the accuracy and speed of information dif6fusion algorithm were measured with a rise in the number of users. The experiments were conducted in a manner that increases the number of users by one thousand and was measured the accuracy and speed of the message spread transfer algorithm. Finally, became operational in less than one second in 20,000 users, it was confirmed that the notification message is sent.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.6
• /
• pp.1123-1128
• /
• 2016

Recently BLE beacon has been widely used as a method for measuring the indoor location in the IoT Technique. But it requires a filtering technique for the measurement of the correct position. It is used the most fixed beacon. It is not accurate that calculates the position information through the identification of the beacon signal. Therefore, filtering is important. So it takes a lot of time, position measurement and filtering. Thus, we is to measure the exact position at the indoor using a mobile beacon. The measured beacon signal is composed of an ontology for reuse in the same pattern. RSSI is measured the receiver is the distance of the beacon. And this value configure the location ontology to be normalized by the relationship analysis between the values. The ontology is a method for calculating the position information of the moving beacon. It can detect fast and accurate indoor position information and provide the service.

• IEIE Transactions on Smart Processing and Computing
• /
• v.4 no.5
• /
• pp.371-378
• /
• 2015

In this paper, a different type of pulse width modulation (PWM) control scheme for a buck converter is introduced. The proposed buck converter uses PWM with frequency hopping and a low quiescent.current low dropout (LDO) voltage regulator with a power supply rejection ratio enhancer to reduce high spurs, harmonics and output voltage ripples. The low quiescent.current LDO voltage regulator is not described in this paper. A three-bit binary-to-thermometer decoder scheme and voltage ripple controller (VRC) is implemented to achieve low voltage ripple less than 3mV to increase the efficiency of the buck converter. An internal clock that is synchronized to the internal switching frequency is used to set the hopping rate. A center frequency of 2.5MHz was chosen because of the bluetooth low energy (BLE) application. This proposed DC-DC buck converter is available for low-current noise-sensitive loads such as BLE and radio frequency loads in portable communications devices. Thus, a high-efficiency and low-voltage ripple is required. This results in a less than 2% drop in the regulator's efficiency, and a less than 3mV voltage ripple, with -26 dBm peak spur reduction operating in the buck converter.

• Transactions on Semiconductor Engineering
• /
• v.2 no.3
• /
• pp.1-5
• /
• 2024

This paper presents a crystal-less reference clock recovery (CR) frequency synthesizer with compensation designed for Bluetooth Low Energy (BLE) Smart-tag applications, operating at frequencies of 32, 72, and 80MHz. In contrast to conventional frequency synthesizers, the proposed design eliminates the need for external components. Using a single-ended antenna to receive a minimal input power of -36dBm at a 2.4GHz signal, the CR synthesizes frequencies by processing the RF signal received through a Low Noise Amplifier ( L N A ) . This approach allows the system to generate a reference clock without relying on a crystal. The received signal is amplified by the LNA and then input to a 16-bit ACC (Automatic Clock Compensation) circuit. The ACC compares the frequency of the received signal with the oscillator output signal, using the synthesis of a 32MHz reference clock through a frequency compensation method. The oscillator is constructed using a Ring Oscillator (RO) with a Frequency Divider, offering three different frequencies (32/72/80MHz) for various system components. The proposed frequency synthesizer is implemented using a 55-nm CMOS process.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.1
• /
• pp.777-785
• /
• 2021

Many utility lines are buried underground to provide various functions of the city. Because historical records are not managed systematically, damage has occurred during excavation. In addition, the demand for an underground facility management system is increasing as the aerial underground project is progressing. By attaching an electronic recognition sensor to an underground facility, such as pipelines, the management history and site conditions can be carefully managed. Therefore, in this study, electronic recognition sensors, such as BLE Beacon, UHF RFID, geomagnetic sensor, and commercial marker, were tested to analyze the strengths, weaknesses, and field applicability through a pilot project. According to the limited research results collected through two pilot projects, the installation depth is most important to demonstrate the performance of the electronic reader. In addition, because it should be used in urban areas, the influence of environmental interference should be minimized, and there should be no performance degradation over time. In the case of the geomagnetic recognizer, the effect of environmental interference was large, and performance degradation occurred over time using the BLE Beacon. In the field situation, where the installation depth can be controlled to less than 40cm, the utility of the battery-free UHF RFID was the best.

• Journal of Integrative Natural Science
• /
• v.11 no.1
• /
• pp.44-50
• /
• 2018

In this paper, we propose a context-aware power management (CPM) scheme using beacons to reduce the power consumption of personal computers (PCs). In the proposed CPM scheme, the PC, smartphone, control server, and Internet of Things (IoT) device are necessary. PC users first log in the control server using their smartphones and select PCs to turn on. Then, the selected PCs automatically go into three different modes, i.e., sleep, shutdown, and standby power off modes, in order when the PC users leave the PCs without turning off them. Further, we develop a testbed with the proposed CPM scheme using the Arduino with Bluetooth low energy (BLE) and relay modules. Finally, it is shown that the proposed CPM scheme outperforms the conventional scheme in terms of the power consumption.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.12
• /
• pp.17-23
• /
• 2020

As the number of households with companion animals increases, the demand to monitor the health of companion animals in remote locations far away is increasing. We are going to put a wearable device on a companion animal so that it can monitor the heart beat signal from a remote location. However, the monitoring method using Bluetooth has some disadvantages. it can be accessed only in a short distances. In case of WiFi, large power consumption is the problem. To overcome these issues, we propose a system to reduce power consumption by indirectly receiving a user's request using Bluetooth at a time when the user does not need it, and sending sensor data through WiFi when the user makes a monitoring request.

• Review of KIISC
• /
• v.26 no.3
• /
• pp.50-57
• /
• 2016

최근 사물인터넷(IoT) 시장의 급격한 성장과 함께 적용 서비스 분야도 급격하게 늘어나고 있다. 다양한 객체와 인터넷의 연결로 무수히 많은 서비스가 제공되고 있으며 기업 및 공공기관은 이를 활용하여 다양한 콘텐츠를 개발하고 있다. 하지만 IoT인프라의 급격한 범위 확장 및 활용 표준화가 이루어지지 않았고, 이에 따라 인프라 프로세스의 혼란을 야기할 수 있다. 이는 내 외부적인 위협의 증가로 이어진다. 따라서 사물인터넷 기술이 현재 시장보다 활성화 되고 실 서비스 적용 분야가 증가할수록 제도적, 물리적, 기술적인 취약점이 원인이 되어 공격자는 사물인터넷 단말기 내부에 악성코드를 심어 원격 통제를 하거나, 일정 무선 주파수를 동기화 하여 스니핑이나 스푸핑 등의 공격으로 데이터 변조의 위협이 존재한다. 본 연구를 통해 콘텐츠 정보제공의 주 목적으로 활용되는 미들웨어장비인 Bluetooth 4.0 기반의 저전력 비콘(Beacon)의 기능을 활용한 서비스에서 발생될 수 있는 내재적 위협으로부터 정책적, 기술적, 물리적 통제 및 대응 방안을 제안하였다.

• Journal of Positioning, Navigation, and Timing
• /
• v.9 no.3
• /
• pp.169-173
• /
• 2020

Location-based services are used as core services in various fields. In particular, in the field of public services such as emergency rescue, accurate location estimation technology is very important. Recently, the technology of tracking the location of self-isolation subjects for COVID-19 has become a major issue. Therefore, location estimation technology using personal smart devices is being studied in various ways, and the most widely used method is to use GPS. Other representative methods are using Wi-Fi, Pedestrian Dead Reckoning (PDR), Bluetooth Low Energy (BLE) beacons, and LTE signals. In this paper, we introduced a positioning technology using deep learning based on LTE Channel State Information-Reference Signal (CSI-RS) data, and confirmed the possibility through an outdoor location estimation experiment using a commercial LTE signal.