• International Journal of Advanced Culture Technology
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• 제9권4호
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• pp.302-306
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• 2021

Indoor localization is one of the basic elements of Location-Based Service, such as indoor navigation, location-based precision marketing, spatial recognition of robotics, augmented reality, and mixed reality. We propose a Voxel Labeling-based visual positioning system using object simultaneous localization and mapping (SLAM). Our method is a method of determining a location through single image 3D cuboid object detection and object SLAM for indoor navigation, then mapping to create an indoor map, addressing it with voxels, and matching with a defined space. First, high-quality cuboids are created from sampling 2D bounding boxes and vanishing points for single image object detection. And after jointly optimizing the poses of cameras, objects, and points, it is a Visual Positioning System (VPS) through matching with the pose information of the object in the voxel database. Our method provided the spatial information needed to the user with improved location accuracy and direction estimation.

• 한국초전도ㆍ저온공학회논문지
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• 제14권1호
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• pp.14-19
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• 2012

Shimming, active and/or passive, is indispensable for most MR (magnetic resonance) magnets where homogeneous magnetic fields are required within target spaces. Generally, shimming consists of two steps, field mapping and correcting of fields, and they are recursively repeated until the target field homogeneity is reached. Thus, accuracy of the field mapping is crucial for fast and efficient shimming of MR magnets. For an accurate shimming, a "magnetic" center, which is a mathematical origin for harmonic analysis, must be carefully defined, Although the magnetic center is in general identical to the physical center of a magnet, it is not rare that both centers are different particularly in HTS (high temperature superconducting) magnets of which harmonic field errors, especially high orders, are significantly dependent on a location of the magnetic center. This paper presents a new algorithm, based on a field mapping theory with harmonic analysis, to define the best magnetic center of an MR magnet in terms of minimization of pre-shimming field errors. And the proposed algorithm is tested with simulation under gaussian noise environment.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2005년도 하계학술대회
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• pp.10-15
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• 2005

In the area of mobile communication, Location Based Services (LBS) using the location of mobile terminal to provide their services are rapidly spreading as communication network and terminal evolves. Despite the LBS are highly demanded in high speed internet area, the services are very rare due to the difficulty locating terminals. In this paper, we propose the method to locate terminals in real time and describe its implementation system. The proposed system is designed to collect the information in real time for more than a terminal connecting internet. And, the system shows high performancecollecting and generating location information through simulation tests.

• ETRI Journal
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• 제42권1호
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• pp.108-117
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• 2020

This study proposes a robust range-only beacon mapping method for registering the locations of range-only beacons automatically. The proposed method deals with the multipath propagation of signals from range-only beacons using the range-only measurement association (RoMA) and an unscented Kalman filter (UKF). The RoMA initially predicts the candidate positions of a range-only beacon. The location of the range-only beacon is then updated using the UKF. With the proposed method, the locations of range-only beacons are accurately estimated in a multipath environment. The proposed method also provides the location uncertainty of each range-only beacon. Simulation results using the model for multipath propagation and experimental results in a real indoor environment verify the performance of the proposed method.

• 한국멀티미디어학회논문지
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• 제19권2호
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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.

• 센서학회지
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• 제16권4호
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• pp.270-276
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• 2007

A location-aware system, which is capable to detect a user's whereabout in a region and provide real-time location information in outdoor environment is designed and fabricated, specifically using the GPS (global positioning system) as key technology in view of its stability and high precision in outdoor environment. Experiment is conducted to test this application in campus-based environment. Once GPS receiver detects specific location which is tagged with GPS coordinates, the system provides information relevant to that context and user can operate and react accordingly. Besides, this location-aware system is able to provide user with the route in order to get to a desired place by detecting the direction that the user is moving towards from his/her initial location. The mapping data is transferred via wireless LAN to PDA carried by the user as well as to the back-end system on real-time basis. The test result is analyzed and discussed to validate the effectiveness of using GPS in implementing this system and indicates future works that could be made to improve this prototype to be implemented in other applications, such as theme park, tourist attraction spot or recreational park.

• 한국전자통신학회논문지
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• 제7권2호
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• pp.391-399
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• 2012

본 논문에서는 파티클 필터 방법을 이용한 이동로봇의 SLAM(Simultaneous Localization and Mapping) 방법을 제안한다. 이동로봇의 SLAM은 지도가 주어지지 않는 환경에서 로봇 스스로 자신의 위치를 파악하는 것과 동시에 지도를 만드는 것이다. 제안된 방법은 로봇의 위치를 추정함과 동시에 특징점인 외부 비이컨들의 위치를 추정하는 방법을 다루고 있다. 특히 파티클 필터 방법을 적용하여 이동로봇과 특징점 위치를 파티클의 분포에 의해 확률적으로 표현한다. 제안된 SLAM방법은 이동로봇의 동작 뿐 아니라 특징점 위치의 불확실성을 고려한다. 따라서 매 샘플링 시각에 특징점의 위치 정보도 불확실성을 고려하여 예측되어진다. 제안된 방법의 성능을 시뮬레이션과 실험을 통하여 평가하였다. 제안된 방법은 비이컨으로 부터의 거리 정보에 불규칙한 잡음이 있는 환경에서도 실질적으로 사용가능한 지도 정보를 제공하였다. 또한 통상의 최소자승법이나 데드레크닝 방법에 비해서 보다 정확하고 강건하게 로봇의 위치를 추정하였다.

• 한국철도학회논문집
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• 제20권5호
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• pp.703-712
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• 2017

철도는 인터페이스 산업으로 철도차량 선로 관제 등이 유기적으로 맞물려야 움직일 수 있다. 이를 정상적으로 운영하기 위해서는 많은 유지보수 활동이 필요한데 이러한 활동과정에서 발생하는 데이터들은 각 분야별로 관리하고 있어 업무특성에 따라 위치, 시간 등 기준 데이터가 각각 상이하여 시 공간 기반의 통합 분석을 할 수 없는 실정이다. 각 분야별로 상이한 데이터를 통합 분석하기 위해서는 데이터마이닝 기법을 통해 유의미한 정보를 추출하여 분석하는데, 이러한 분석을 위해서는 데이터 유형의 상호관련성을 인지하기 위한 기준정보의 추출과 매핑이 반드시 필요하다. 본 연구는 서로 다른 분야에서 발생하는 안전과 관련된 데이터에 대한 매핑 툴 선정과 결과에 대하여 검증을 수행하고자 한다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.47-48
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• 2022

The positioning technology that measures the position of a person or object is a key technology to deal with the location of the real coordinate system or converge the real and virtual worlds, such as digital twins, augmented reality, virtual reality, and autonomous driving. In estimating the location of a person or object at an indoor construction site, there are restrictions that it is impossible to receive location information from the outside, the communication infrastructure is insufficient, and it is difficult to install additional devices. Therefore, this study tested the direct sparse odometry algorithm, one of the visual Simultaneous Localization and Mapping (vSLAM) that estimate the current location and surrounding map using only image information, at an indoor construction site and analyzed its applicability as an indoor positioning technology. As a result, it was found that it is possible to properly estimate the surrounding map and the current location even in the indoor construction site, which has relatively few feature points. The results of this study can be used as reference data for researchers related to indoor positioning technology for construction sites in the future.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.163-164
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• 2020

When measuring fine dust at a large-scale site such as complex construction, the change in the value of fine dust measurement is large due to the influence of the time, location, wind speed, wind direction, and humidity. This study aims to find out the results of measuring fine dust in an actual construction site and inferring the changes.