• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.1
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• pp.31-38
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• 2012

The geo-referencing accuracy of the images acquired by a UAV based multi-sensor system is affected by the accuracy of the mounting parameters involving the relationship between a camera and a GPS/INS system as well as the performance of a GPS/INS system. Therefore, the estimation of the accurate mounting parameters of a multi-sensor system is important. Currently, we are developing a low altitude multi-sensor system based on a UAV, which can monitor target areas in real time for rapid responses for emergency situations such as natural disasters and accidents. In this study, we suggest a system calibration method for the estimation of the mounting parameters of a multi-sensor system like our system. We also generate simulation data with the sensor specifications of our system, and derive an effective flight configuration and the number of ground control points for accurate and efficient system calibration by applying the proposed method to the simulated data. The experimental results indicate that the proposed method can estimate accurate mounting parameters using over five ground control points and flight configuration composed of six strips. In the near future, we plan to estimate mounting parameters of our system using the proposed method and evaluate the geo-referencing accuracy of the acquired sensory data.

• The KIPS Transactions:PartA
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• v.13A no.5 s.102
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• pp.435-444
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• 2006

Recently, various applications of location trigger service have been required and developed as users of location-based services are increasing. The location trigger is detecting event of entering in, existing in or leaving from pre-specified area, and then alerting by short message service, an e-mall or servicing other pre-defined action to mobile subscribers. The conventional methodology of supporting location trigger is detecting location trigger events as periodical requesting location of mobile communication terminal to location gateway server in mobile communication network. But these conventional methods cause mobile communication interruption when the location trigger services are overloaded; thereby inducing performance of core server to be fell off. So in this paper, we have studied a new location trigger technology, named multilevel location trigger, to reduce mobile core network sewer triggering bottleneck and power consumption caused embedded GPS device of mobile phone. Actually, as design and evaluating the performance of location trigger after building test-bed environment, we contribute toward improving echnology of location trigger.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.428-435
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• 2016

Hundreds of millions of new posts and information are being uploaded and propagated everyday on Online Social Networks(OSN) like Twitter, Facebook, or Instagram. This paper proposes and implements a GPS-location based SNS data mapping, analysis, and visualization system, called Smart SNS Map, which collects SNS data from Twitter and Instagram using hundreds of PlanetLab nodes distributed across the globe. Like no other previous systems, our system uniquely supports a variety of functions, including GPS-location based mapping of collected tweets and Instagram photos, keyword-based tweet or photo searching, real-time heat-map visualization of tweets and instagram photos, sentiment analysis, word cloud visualization, etc. Overall, a system like this, admittedly still in a prototype phase though, is expected to serve a role as a sort of social weather station sooner or later, which will help people understand what are happening around the SNS users, systems, society, and how they feel about them, as well as how they change over time and/or space.

• Journal of Korea Spatial Information System Society
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• v.6 no.1 s.11
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• pp.51-58
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• 2004

Mobile Mapping System is an effective wav to obtain position and image using vehicle equipped with GPS(Global Positioning System), IMU(Inertial Measurement Unit), and CCD camera. It have been used various fields of load facility management, map upgrade and etc. It is difficult to upgrade Mobile Mopping System which is developed from abroad and add other sensors because we don't know the way to integrate and synchronize multi-sensors. In this paper, we present the effective way of the integration and synchronization method for multi sensors we designed and manufactured Synchronization equipment by considering sensors of laser, odometer and etc.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.625-628
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• 2004

Even though the tower crane is a major equipment in a construction of high rise buildings, there are lack of studies of it. This study is presenting a framework of developing a intelligent tower crane applied with the technology of machine-vision, RFID(Radio Frequency Identification), or GPS(Global positioning System) and proposing the prototype of machine-vision module, sub module of this Framework. Through monitoring form CCTV(Closed Circuit Television) and LCD(Liquid Crystal Display) in machine-module the real time communication between in-site workers and crane operator is possible. this will improve the productivity and safety of the tower crane.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.1
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• pp.41-49
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• 2000

This study was performed to establish PC-based Urban Infrastructure Information System(UIIS) using GPS and TotalStation as an alternative to UNIX-based UIIS. After carryig out this study, the following conclusions were derived: PC-based UIIS costs less time and money than UNIX-based UIIS. The coordinates of the control point of the site were obtained using DGPS, then based on this point, locational data were obtained using RTK GPS and TotalStation in the site with realtime data capture to enhance the accuracy of locational data. And image data were also entered into database together with the text data. So, the multimedia database is possible in UIIS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.4
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• pp.327-334
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• 2004

In this paper, a triplexer for Advanced Mobile Phone Service(AMPS), United States-Personal Communication Services(US-PCS), and Global Positioning System(CPS) is designed using L and C lumped elements. The triplexer shows the insertion loss of 0.6 ㏈, 1.1 ㏈, and 1.6 ㏈ for AMPS, US-PCS, and GPS bands, respectively. Also, it shows the attenuation characteristic of less than 18 ㏈, and the VSWR of less than 2.0 through the all pass-band.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.523-525
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• 2022

본 논문에서는 시각장애인을 위한 교통시설 앱 서비스를 제안한다. 이 서비스는 시각장애인이 편리하게 사용하고 안전하게 교통수단을 이용할 수 있는 음성지원 경로 알림이 탑재되어 있는 내비게이션 앱이다. 스마트 디바이스 기기만 있으면 쉽게 설치가 가능하며, 이를 통해 시각장애인에게 경로 이탈에 대한 두려움을 줄이고 음성지원 경로 알림 서비스를 제공해 안전하게 교통수단을 이용할 수 있다. 50개국 이상 언어지원 블록체인을 이용한 구조 A-GPS, T MAP, 음성을 사용 본 논문에서는 시뮬레이션을 통하여 문제점 해소와 더 나아가 시각장애인의 독립적인 이동 문화 형성을 제공한다.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.386-395
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• 2016

In trajectory-based navigation systems, a huge amount of trajectory data is needed for efficient route explorations. However, it would be very hard to collect trajectories from all the possible start and destination combinations. To provide a practical solution to this problem, we suggest a method combining collected GPS trajectories data into additional generated trajectories with new start and destination combinations without road information. We present a trajectory combination algorithm and its implementation with Scala programming language on Spark platform for big data processing. The experimental results proved that the proposed method can effectively populate the collected trajectories into valid trajectory paths more than three hundred times.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.87-88
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• 2011

본 논문에서는 멀티 센서 기반의 사용자 이동 상태 인식 서비스에 대해 제안 한다. 이 서비스는 스마트폰 단말의 가속도 센서, 방향센서, GPS 모듈의 정보를 퍼지 규칙 기반 알고리즘을 이용하여 각각의 클라이언트들의 현재 위치 및 이동 상황을 인식 하게 된다. 사용자 이동 상태 인식 알고리즘은 가속도 센서와 방향 센서를 이용하여 신체의 운동량과 방향을 측정 한다. 측정된 정보는 GPS모듈을 통하여 얻은 실제 이동속도를 계산하여 규칙 기반 퍼지 추론을 통하여 사용자의 이동 상태를 인식 하였다. 이동상태 인식 서비스의 신뢰도를 측정하기 위해 동일 구간에서 차량, 도보(걷기, 뛰기, 느리게 걷기 등)를 이용하여 신뢰도를 측정 하였다.