• Proceedings of the Korea Contents Association Conference
• /
• 2016.05a
• /
• pp.247-248
• /
• 2016

To investigate activities in the evacuated situation of people, the measurement system is newly constructed, that composed of a wearable sensor device of heart beats rates and mobile devices like an Android smartphone with a bluetooth low energy (BLE) connection. Smartphone not only displays the heart beats variation (HBR) and the current location of evacuation person by Global Positioning System (GPS), but also exports the CSV formatted file that would be used for further analyzing the activity of person in detail. As an example of the application of this system, we show the case of evacuation routes for elderly person in Hizen-Hamashuku Area, Saga Prefecture. Using the proposed measuring system, the activities of evacuates can be clearly shown on the map of Geospatial Information System (GIS).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.4
• /
• pp.889-891
• /
• 2017

Visible light communication technology, which is a communication using LED lighting, is defined by IEEE 802.15.7 WG and active research is under way. Visible light communication is advantageous not only to avoid interference with existing RF communication but also to provide location based service through accurate positioning by utilizing LOS (Line of Sight) characteristic. Therefore, it is very easy and efficient to locate and track the user's location. In this paper, we implemented a visible light communication transceiver using USB interface for easy application to portable devices. It supports the mobility of mobile devices through internet protocol and showed BER performance of less than $10^{-3}dBm$ at over 1m, which is the height of lighting and smart device during walking.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.1
• /
• pp.97-108
• /
• 2013

Recently, mobile devices were increased and there was a sharp rise in demand. To exploit the location information of each device, many researcher was studying locating systems. The favorite locating or positioning systems were a GPS using satellites and a RTLS using wireless communication between devices. If some obstacle existed nearby the target device, The system have difference of performance. The obstacles near targets were caused signal disconnection and reflection because of NLOS condition. As the result, the NLOS condition degrade the locating performance. In this paper, we propose a locating system which is cooperated two systems using information reliability estimates from LOS/NLOS condition. We developed proposed system. In addition, we performed fields test and simulation tests at various environment for performance evaluation. As the result, the test showed 97% success rate to estimate NLOS condition. Furthermore, the simulation result of our locating system was increased to 89% compared with a single system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.2
• /
• pp.239-247
• /
• 2007

In this paper, we propose a system that the Linux is ported in embedded system with peripheral devices of CIS(CMOS Image Sensor) and GPS module. The system acquires GGA sentence from GPS module by recognizing camera and GPS is used module in Linux kernel. And then the received location information is used to include still image acquired through CIS According to this paper, We compose hardware for embedded system, attach board (including camera), port Linux BootLoader and Kernel. And. then we realize that it insert kernel in CIS control device driver and GPS module device driver.

• Journal of Korean Society for Geospatial Information Science
• /
• v.22 no.3
• /
• pp.57-69
• /
• 2014

As of 2013, Korean population density is 505 persons per $1km^2$ and is ranked 3rd place in the most densely populated countries exception of city-states. It shows clearly the population is concentrated in the city area. To fulfil this urban concentration population demand, the enlargement and complexation of buildings, subway and other underground spaces connection tendency has been intensified, and it is need to construct the indoor spatial information DB as well as the accurate indoor surveying DB to promote people's safety and social welfare. In this study, Sadang station and Incheon National Airport were aimed for the construction of Wi-Fi AP location DB and RadioMap DB by collecting the indoor AP raw datas by using mobile device and those collected results were ran through the process of verification, supplementation, and analyzation. To evaluate the performance of constructed DB, 10 points in Incheon Airport- 3rd flr in block A, and 9 points in Sadang station-B1 were selected and calculated the estimated points and ran evaluation experiment using survey positioning error, which is distance between real position and the estimated position. The result shows that Incheon international airport's average and standard deviation was separately 17.81m, 17.79m and Sadang station's average and standard deviation was separately 22.64m, 23.74m. In Sadang station's case, the areas near the exit has low performance of surveying position due to fewer visible AP points than other areas. As total datas were examined except those position, it was verified that the user's location was mapping close position in surveying positioning by using constructed DB. It means that constructed DB contains correct Wi-Fi AP locations and radio wave patterns in object region, so it is considered that the indoor spatial information service based on constructed DB would be available.

• Journal of the Korea Society for Simulation
• /
• v.31 no.3
• /
• pp.55-61
• /
• 2022

Currently police and fire departments use a Network/Wifi/GPS based emergency location positioning system established by mobile carriers to directly link with the device of the people who request the rescue to accurately position the expected location in the call area. However in the case of mountain rescue it is difficult to rescue the victim in golden time because the location of the search area cannot be limited when the victim is located in a radio shadow area of the mountain or the device power is off and this situation become worse if victim fail to report 911 by himself due to the injury. In this paper, we are expected to solve the previous problem by propose the mobile telecommunication forensic simulator consist of time series of cell information, human mobility model which include some general and specific features (age, gender, behavioral characteristics of victim, etc.) and intelligent infer system. The results of analysis appear in heatmap of polygons on the map based on the probability of the expected location information of the victim. With this technology we are expected to contribute to rapid and accurate lifesaving by reducing the search area of rescue team.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.331-335
• /
• 2016

When a boating accident, such as a January number three, the customer's risk management issues emerged. Ships and accident risk in confined spaces such as risk management to locate the customer and dangers of probation is available. In this paper, aboard after consent to obtain information for customers to wrist to customers, webbing or portable device embedded in devices and Wireless sensor information Input was attached, disposable consumer information. Customer on board the ship setting for location analysis and positioning according to information communication protocol, ships, each customer's real-time location information on the screen, 3 the foundation of d customers on the floor Can be designed to inform. Threshold designed to reduce the error of the information to analyze the position in current position and errors. Also, to system attacks would control the situation of accident and emergency jaenanguk server with real-time information transmission of information outside the emergency during a disaster, search and Disaster relief to be possible.

• Journal of Positioning, Navigation, and Timing
• /
• v.10 no.3
• /
• pp.179-187
• /
• 2021

To estimate the location of the train, we consider an integrated navigation system that combines Inertial Navigation System (INS) and Global Navigation Satellite System (GNSS). This system provides accurate navigation results in open sky by combining only the advantages of both systems. However, since measurement update cannot be performed in GNSS signal blocked areas such as tunnels, mountain, and urban areas, pure INS is used. The error of navigation information increases in this area. In order to reduce this problem, the train's Non-Holonomic Constraints (NHC) information can be used. Therefore, we deal with the INS/GNSS/NHC integrated navigation system in this paper. However, in the process of installing the navigation system on the train, a Mounting Misalignment Error of the IMU (MMEI) inevitably occurs. In this case, if the NHC is used without correcting the error, the navigation error becomes even larger. To solve this problem, a method of easily estimating the MMEI without an external device is introduced. The navigation filter is designed using the Extended Kalman Filter (EKF) by considering the MMEI. It is assumed that there is no vertical misalignment error, so only the horizontal misalignment error is considered. The performance of the integrated navigation system according to the presence or absence of the MMEI and the estimation performance of the MMEI according to the method of using NHC information are analyzed based on simulation. As a result, it is confirmed that the MMEI is accurately estimated by using the NHC information together with the GNSS information, and the performance and reliability of the integrated navigation system are improved.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.3
• /
• pp.770-776
• /
• 2021

Positioning systems have been actively researched and developed over the past few years and have been used in many applications. This paper presents a method to determine a location in a large space using a sensor system consisting of an accelerometer and a single-axis gyroscope. In particular, to consider usability, a sensor device was loosely worn on the waist so that the experimental data could be used in practical applications. Based on the experimental results of circular tracks with radiuses of 1m and 3m, in this paper, an algorithm using the threshold of rotation angle was proposed and applied to the experimental results. A tracking experiment was performed on the grid-pattern track model. For raw sensor data, the average deviation between the final tracking point and the target point was approximately 15.2 m, which could be reduced to approximately 4.0 m using an algorithm applying the rotation angle threshold.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.3
• /
• pp.487-498
• /
• 2013

A variety of location-based services applications, such as missing children search, emergency rescue requests and so on that requiring high-precision location information are increasing. Precision of GPS that can be used in most systems, however, is still low. In this paper, we design and propose a low cost differential global positioning system(DGPS) based on Web services using object-oriented modeling technique which can offer useable location service, variety device and safe service in wireless environment. The proposed system is designed with UML based on object-oriented modeling to maximize system recyclability and system scalability. In addition, we would like to improve the precision of the GPS in accordance with mobile station location when build low cost mobile station, location differential framework and server. We implement a communication interface based on web-service which is available in the form of a variety of services and can offer stable according to mobile environments. Finally, as performance evaluation results, we can obtain precision location within 1 ~ 2m through proposed system and 88.5% probability of less than 2m.