Sangjoon Park

Dr. Sangjoon Park


Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 October 2017 in Sensors
Verified
Journal Article
Open access
PDF file
FPFrancesco Potortì
Francesco Potortì
SPSangjoon Park
Sangjoon Park
ARAntonio Ramon Jimenez Ruiz
Antonio Ramon Jimenez Ruiz
Paolo BarsocchiPaolo Barsocchi
Paolo Barsocchi
Michele GirolamiMichele Girolami
Michele Girolami
JMJavier Macias-Guarasa
Javier Macias-Guarasa
In recent years, indoor localization systems have been the object of significant research activity and of growing interest for their great expected social impact and their impressive business potential. Application areas include tracking and navigation, activity monitoring, personalized advertising, Active and Assisted Living (AAL), traceability, Internet of Things (IoT) networks, and Home-land Security. In spite of the numerous research advances and the great industrial interest, no canned solutions have yet been defined. The diversity and heterogeneity of applications, scenarios, sensor and user requirements, make it difficult to create uniform solutions. From that diverse reality, a main problem is derived that consists in the lack of a consensus both in terms of the metrics and the procedures used to measure the performance of the different indoor localization and navigation proposals. This paper introduces the general lines of the EvAAL benchmarking framework, which is aimed at a fair comparison of indoor positioning systems through a challenging competition under complex, realistic conditions. To evaluate the framework capabilities, we show how it was used in the 2016 Indoor Positioning and Indoor Navigation (IPIN) Competition. The 2016 IPIN competition considered three different scenario dimensions, with a variety of use cases: (1) pedestrian versus robotic navigation, (2) smartphones versus custom hardware usage and (3) real-time positioning versus off-line post-processing. A total of four competition tracks were evaluated under the same EvAAL benchmark framework in order to validate its potential to become a standard for evaluating indoor localization solutions. The experience gained during the competition and feedback from track organizers and competitors showed that the EvAAL framework is flexible enough to successfully fit the very different tracks and appears adequate to compare indoor positioning systems.

26 May 2011 in Wireless Networks
Verified
Journal Article
Closed access
PDF file
WJWoo-Sung Jung
Woo-Sung Jung
KLKeun-Woo Lim
Keun-Woo Lim
Young-Bae KoYoung-Bae Ko
Young-Bae Ko
SPSangjoon Park
Sangjoon Park

24 December 2019 in Sensors
Verified
Journal Article
Open access
PDF file
Imran AshrafImran Ashraf
Imran Ashraf
Soojung HurSoojung Hur
Soojung Hur
SPSangjoon Park
Sangjoon Park
Yongwan ParkYongwan Park
Yongwan Park
A quickly growing location-based services area has led to increased demand for indoor positioning and localization. Undoubtedly, Wi-Fi fingerprint-based localization is one of the promising indoor localization techniques, yet the variation of received signal strength is a major problem for accurate localization. Magnetic field-based localization has emerged as a new player and proved a potential indoor localization technology. However, one of its major limitations is degradation in localization accuracy when various smartphones are used. The localization performance is different from various smartphones even with the same localization technique. This research leverages the use of a deep neural network-based ensemble classifier to perform indoor localization with heterogeneous devices. The chief aim is to devise an approach that can achieve a similar localization accuracy using various smartphones. Features extracted from magnetic data of Galaxy S8 are fed into neural networks (NNs) for training. The experiments are performed with Galaxy S8, LG G6, LG G7, and Galaxy A8 smartphones to investigate the impact of device dependence on localization accuracy. Results demonstrate that NNs can play a significant role in mitigating the impact of device heterogeneity and increasing indoor localization accuracy. The proposed approach is able to achieve a localization accuracy of 2.64 m at 50% on four different devices. The mean error is 2.23 m, 2.52 m, 2.59 m, and 2.78 m for Galaxy S8, LG G6, LG G7, and Galaxy A8, respectively. Experiments on a publicly available magnetic dataset of Sony Xperia M2 using the proposed approach show a mean error of 2.84 m with a standard deviation of 2.24 m, while the error at 50% is 2.33 m. Furthermore, the impact of devices on various attitudes on the localization accuracy is investigated.

29 September 2009 in Wireless Networks
Verified
Journal Article
Closed access
PDF file
SHSangjin Han
Sangjin Han
SLSungjin Lee
Sungjin Lee
SLSanghoon Lee
Sanghoon Lee
JPJongjun Park
Jongjun Park
SPSangjoon Park
Sangjoon Park

18 January 2024 in IEEE Journal of Indoor and Seamless Positioning and Navigation
Verified
Journal Article
Open access
FPFrancesco Potortì
Francesco Potortì
ACAntonino Crivello
Antonino Crivello
SLSoyeon Lee
Soyeon Lee
BVBlagovest Vladimirov
Blagovest Vladimirov
SPSangjoon Park
Sangjoon Park
Joaquín Torres-SospedraJoaquín Torres-Sospedra
Joaquín Torres-Sospedra
Indoor positioning is a thriving research area which is slowly gaining market momentum. Its applications are mostly customised, ad hoc installations; ubiquitous applications analogous to GNSS for outdoors are not available because of the lack of generic platforms, widely accepted standards and interoperability protocols. In this context, the Indoor Positioning and Indoor Navigation (IPIN) competition is the only long-term, technically sound initiative to monitor the state of the art of real systems by measuring their performance in a realistic environment. Most competing systems are pedestrian-oriented and based on the use of smartphones, but several competing Tracks were set up, enabling comparison of an array of technologies. The two IPIN competitions described here include only off-site Tracks. In contrast with on-site Tracks where competitors bring their systems on site - which were impossible to organise during 2021 and 2022 - in off-site Tracks competitors download pre-recorded data from multiple sensors and process them using the EvaalAPI, a real-time, web-based emulation interface. As usual with IPIN competitions, Tracks were compliant with the EvAAL framework, ensuring consistency of the measurement procedure and reliability of results. The main contribution of this work is to show a compilation of possible indoor positioning scenarios and different indoor positioning solutions to the same problem.

1 February 2008 in The 9th International Conference on Advanced Communication Technology
Verified
Conference Paper
Closed access
YMYoungBag Moon
YoungBag Moon
JLJongYoung Lee
JongYoung Lee
SPSangjoon Park
Sangjoon Park
The configuration of the u-sensor network is comprised of sink node, and the sensor node and gateway so that the USN (ubiquitous sensor network) application service can be provided. The middleware function need for a sink and sensor node for the sensor network management In the middleware function, it is required of the network topology management, the sensing data processing, a failure and power management, and etc. And it is designed in order to perform the network management through the u- sensor network overall. In this paper, it described about the design about the topology, event data, failure, power management for a sink and sensor node management and implementation issue. The topology configuration and all kinds of management data of sensor network nodes were shown through an implementation in the PAN network management GUI (graphical user interface).