• IEIE Transactions on Smart Processing and Computing
• /
• v.4 no.3
• /
• pp.173-182
• /
• 2015

A real-time, Indoor navigation systems utilize ultra-wide band (UWB), radio-frequency identification (RFID) and received signal strength (RSS) techniques that encompass WiFi, FM, mobile communications, and other similar technologies. These systems typically require surplus infrastructure for their implementation, which results in significantly increased costs and complexity. Therefore, as a solution to reduce the level of cost and complexity, an inertial measurement unit (IMU) and quick response (QR) codes are utilized in this paper to facilitate navigation with the assistance of a smartphone. The QR code helps to compensate for errors caused by the pedestrian dead reckoning (PDR) algorithm, thereby providing more accurate localization. The proposed algorithm having IMU in conjunction with QR code shows an accuracy of 0.64 m which is higher than existing indoor navigation techniques.

• Journal of the Korea Safety Management & Science
• /
• v.15 no.1
• /
• pp.141-150
• /
• 2013

In this paper, the learnability of haptic icons was tested as a way of conveying turn-by-turn directions to users involved in navigation interactions with commercial smartphones. To do this, six most distinctive haptic icons were identified from those having different duration of each pulse, interval between pulses, and rhythm. Associations between the selected haptic icons and 3 pairs of navigation directions were analyzed using data gathered from 30 subjects by 7 point Likert scale. The haptic icons were then assigned to proper directions based on the results from that stereotype analysis. The results showed that the commercial smartphone with one linear motor at a fixed location is not capable of making hapticons to have clear directional stereotypes. The hapticons with poor stereotypes has no advantage in learnability compared to those of random assignment.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.5
• /
• pp.1194-1200
• /
• 2014

One of problems in car navigation systems is that a number of inputs are required for a directions search. This may even causes a car accident due to poor concentration while driving. In order to solve the issue we design and implement a safe and easy-to-use car navigation system which allows a driver to look up directions with just a single tap. Our smartphone app creates an NFC tag by deriving location information from a text, voice, GPS, and so on. The driver can then get the directions by just tapping a phone or card with the Tag on the navigation system. We show the feasibility and effectiveness of our system by comparing our implementation with the existing car navigation systems.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.9 no.1
• /
• pp.189-202
• /
• 2013

Recently, Smartphone is not only used as a communication medium, but also provide mobile service tool enabling game, internet surfing, DMB, navigation services, and so on. A lot of smartphone's applications are using for our daily lives. The purpose of this study was analyze affecting factors such as innovativeness, Self-Efficacy and Social-Influence on adoption behavior of smartphone application. This survey was carried out with university students. Data were obtained from 293 students who have smartphone. To Find difference among variables, exploratory factor analysis, t-test and multiple regression was carried out with collected data. Result shows that the distinction of sex is significantly difference in innovativeness and self-efficacy. And self-efficacy and social influence are significantly affect to smartpjone adoption. Therefore, self-efficacy and social influence are import consider factors to reconsider marketing strategy for smartphone business.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.37 no.5
• /
• pp.331-341
• /
• 2019

With the popularity of sensor-rich environments, smartphones have become one of the major platforms for obtaining and sharing information. Since it is difficult to utilize GNSS (Global Navigation Satellite System) inside the area with many buildings, the localization of smartphone in this case is considered as a challenging task. To resolve problem of localization using smartphone a four step image-based localization method and procedure is proposed. To improve the localization accuracy of smartphone datasets, MMS (Mobile Mapping System) and Google Street View were utilized. In our approach first, the searching for candidate matching image is performed by the query image of smartphone's using GNSS observation. Second, the SURF (Speed-Up Robust Features) image matching between the smartphone image and reference dataset is done and the wrong matching points are eliminated. Third, the geometric transformation is performed using the matching points with 2D affine transformation. Finally, the smartphone location and attitude estimation are done by PnP (Perspective-n-Point) algorithm. The location of smartphone GNSS observation is improved from the original 10.204m to a mean error of 3.575m. The attitude estimation is lower than 25 degrees from the 92.4% of the adjsuted images with an average of 5.1973 degrees.

• Journal of Positioning, Navigation, and Timing
• /
• v.12 no.4
• /
• pp.399-408
• /
• 2023

In this paper, we propose a solution that enables continuous indoor/outdoor positioning of smartphone users through the integration of Pedestrian Dead Reckoning (PDR) and GPS/WiFi signals. Considering that accurate step detection affects the accuracy of PDR, we propose a Deep Neural Network (DNN)-based technology to distinguish between walking and non-walking signals such as walking in place. Furthermore, in order to integrate PDR with GPS and WiFi signals, a technique is used to select a proper measurement by distinguishing between indoor/outdoor environments based on GPS Dilution of Precision (DOP) information. In addition, we propose a technology to adaptively change the measurement error covariance matrix by detecting measurement outliers that mainly occur in the indoor/outdoor transition section through a residual-based χ² test. It is verified through experiments on a testbed that these technologies significantly improve the performance of PDR and PDR/GPS/WiFi fingerprinting-based integrated pedestrian navigation.

• KIPS Transactions on Software and Data Engineering
• /
• v.4 no.10
• /
• pp.455-464
• /
• 2015

As the number of overseas travelers with smartphones increases, there is a growing interest in smartphone applications, which can assist traveling. Typically, travelers need applications to obtain basic information, such as weather, map, currency, etc. However, existing smartphone applications are not suitable to do so because they require network connection that is expensive and unstable in overseas. For example, one of the most frequently used smartphone map application requires a network connection, and much battery to download images. Since travelers spend most of their time outside, there is no chance to charge the battery. In this paper, we propose a study on implementation of a smartphone application for overseas travelers, called Travel Manager, which aims to reduce usages of network connection and battery. Travel Manager first checks whether smartphone is connected to the network, and then synchronizes the travel information. It also automatically calculates traveling expenses by considering currency rate. That is, the proposed smartphone application can be used regardless of the network connection and minimizes the battery usage.

• Journal of Positioning, Navigation, and Timing
• /
• v.7 no.4
• /
• pp.217-226
• /
• 2018

According to the Korea Coast Guard's maritime disaster statistics (Korea Coast Guard 2017, Korean Statistical information Service 2018), an average of 2,140 marine accidents occurred every year for the past 6 years and the number of accidents is increasing every year. Among them, maritime accidents of fishing vessels are the most frequent, and recently accidents involving fishing boat and leisure vessels are rapidly increasing as well. In particular, the number of accidents involving leisure vessels increased to about one-third of the accidents of fishing vessels, and emergency rescue requests are increasing every year accordingly. However, the number of crash accidents involving users of small vessels and marine leisure activities are increasing because of the difficulties of installing navigation equipment and electronic navigation charts. Recently, the demand for precise positioning using mobile devices is increasing in the fields of maritime safety, piloting support, and coastal survey. Although various applications of smart devices provide location-based services for users, the measurement results are discontinuous when using the position coordinates of the National Marine Electronics Association (NMEA) calculated by smartphone. Recently, Google announced that they will provide GPS raw data to developers from Android 7.0 Nougat. As a result, developers have an opportunity to receive precise carrier phase and code measurements to make more accurate positioning according to the performance of Android devices. This study analyzed GPS positioning performance using Android devices, and compared and analyzed the positioning performance at sea with high-performance GPS receivers.

• Asia pacific journal of information systems
• /
• v.31 no.1
• /
• pp.43-75
• /
• 2021

Clearly, the smartphone is increasingly playing a greater role in everyday life, thus providing opportunities to evaluate how well the use of the smartphone meets the requirements of undergraduate students in independent learning outside of a classroom setting. This study used the task-technology fit (TTF) model to explore the effectiveness of smartphone usage to interact with learning materials in independent learning outside of classrooms, the need for smartphone support, and the fit of devices to tasks as well as performance. First, the study used interviews, observation, and survey data to identify what are the most important constructs of smartphones that stimulate students to interact with learning materials in independent learning outside of classrooms. Based on the findings from the exploratory study and Task Technology Fit theory, we postulated the Navigation design, Ergonomic design, Content support, and Capacity as the essential dimension of the smartphone construct. Then, we proposed a research model and empirically tested hypotheses with the structural model analysis. The results reveal a significant positive impact of task and technology on TTF for smartphone usage to interact with learning materials in independent learning outside of classrooms; it also confirmed the TTF and performance have a direct effect on actual use.

• Journal of Positioning, Navigation, and Timing
• /
• v.13 no.3
• /
• pp.331-339
• /
• 2024

Reliable and precise indoor localization is crucial for personal navigation, emergency rescue, and monitoring workers indoors. To use this technology in different applications, it is important to make it less dependent on infrastructure and to keep the error as small as possible. Fingerprinting stands out as a popular choice for indoor positioning because it leverages existing infrastructure and works with just a smartphone. However, its accuracy heavily relies on the quality of that infrastructure. For instance, having too few access points or beacons can greatly reduce its effectiveness. To reduce dependence on RF infrastructure, we have developed surface correlation (SC) using accumulated Received Signal Strength Indicator (RSSI) signals This approach constructs a user mask for radio map comparisons using an accumulated RSSI vector and the trajectory of the user, which is estimated through PDR. The location with the highest correlation is considered as the user's position after comparison. Through a simulation, the performance of short RSSI vector-based technology and SC is analyzed, and future directions for the development of SC are discussed.