• 제어로봇시스템학회논문지
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• 제16권5호
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• pp.420-427
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• 2010

This paper describes a localization method based on Monte Carlo Localization approach for a mobile robot. The method uses range data which are measured from ultrasound transmitting beacons whose locations are given a priori. The ultrasound receiver on-board a robot detects the range from the beacons. The method requires several beacons, theoretically over three. The method proposes a sensor model for the range sensing based on statistical analysis of the sensor output. The experiment uses commercialized beacons and detector which are used for trilateration localization. The performance of the proposed method is verified through real implementation. Especially, it is shown that the performance of the localization degrades as the sensor update rate decreases compared with the MCL algorithm update rate. Though the method requires exact location of the beacons, it doesn't require geometrical map information of the environment. Also, it is applicable to estimation of the location of both the beacons and robot simultaneously.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.243-245
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• 2021

기존 비콘은 비대면 서비스 제공에 적합한 기술이지만 환경에 따라 신호 세기의 편차가 커지기 때문에 정확한 실내 측위가 어렵다는 단점이 있다. 일반적으로 삼변측량기법을 사용하면 편차를 줄일 수 있으나 비콘 간 거리가 상당히 불규칙해지면 알고리즘 적용이 어려워진다. 이에 본 논문에서는 비콘 간 신호 세기 측정 오차를 줄일 방법에 대해 연구하였다. 먼저 TX값이 같다는 가정하에 RSSI를 이용한 거리 측정 공식을 변형하였다. 그리고 안드로이드로 구현한 비콘 스캐너 어플로 비콘 기기를 검색하여 기존 비콘과의 측정 오차를 비교하였다. 그 결과, 일정 거리가 멀어지면 측정값이 변동되지 않는 비콘보다 좀 더 먼 거리를 정확하게 측정하는 것을 확인할 수 있었다. 이를 통해 다양한 장애 상황에서도 정확한 실내 측위가 가능할 것이다. 또한 비콘을 비대면 서비스와 접목시킨 서비스 구축 사례도 늘어날 것으로 기대된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권10호
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• pp.4908-4922
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• 2019

The popularization of smartphones in recent years has created a rich ground for online-to-offline (O2O) services based on location information. In the process of finding user locations in O2O services, BLE (Bluetooth Low Energy) beacons are widely used because the beacons are economical in many ways. The current BLE method does not specify the direction of user movement, but adding that information could enrich the user experience for various O2O services. This paper proposes a method that identifies the user movement direction through data analysis on data sets generated by a pair of BLE beacons. Also we demonstrate its implementation with examples of services that need the direction information of users in order to show the feasibility of the method proposed.

• 한국멀티미디어학회논문지
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• 제20권8호
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• pp.1330-1337
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• 2017

In off-line phase of the preliminary Cut-off indoor positioning scheme, which is one of the indoor positioning scheme using the fingerprint, relative ranks of peak RSSIs received from beacons at each reference point are stored in the fingerprint map. In some reference points, signals of multiple beacons may be received. In this case, the relative ranks may be different when constructing fingerprint and when receiving signals in real-time. To solve this problem, we propose a method to utilize only up to five beacons with high ranking when constructing a fingerprint and when receiving signals in real-time and comparing them with stored information of a fingerprint. Experiments were conducted on the estimation probabilities and the average error when using this method. Those are compared with the previous methods. Experimental results show that the estimation probabilities and the average error are improved by removing only the remaining five beacons at each reference point of the fingerprint.

• KSBB Journal
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• 제31권1호
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• pp.33-39
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• 2016

Developing the method for the selection of animal cell line producing therapeutic monoclonal antibody (mAb) is invaluable as its market is rapidly growing. Although the quality of produced mAb is as important as quantity, however there is no method developed for the selective screening of cell lines on the basis of both quantity and quality. From recent reports, the ratio of light and heavy chain mRNAs of mAb in the cell is a key parameter for the indication of product quality. Therefore, it is obvious that developing the novel method that can detect both light and heavy chain mRNAs in single live cell will provide unprecedented opportunities in bio-industry. Here, we have constructed oligonucleotide probes, molecular beacons for the detection of light or heavy chain mRNAs, respectively, in the live cells producing mAbs. Both beacons showed increased fluorescent intensity after transient transfection of plasmid expressing mAbs analyzed by fluorometer. Flow cytometric analysis clearly demonstrated that both molecular beacons can simultaneously detect the expression of light and heavy chain mRNAs of mAb in the same cell. The technique described in the thesis provides the new direction and concept for developing the method for the smart selection of cell lines producing recombinant proteins including therapeutic mAbs.

• 한국자원공학회지
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• 제55권6호
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• pp.604-613
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• 2018

본 연구에서는 블루투스 비콘이 송신하는 저전력 블루투스 신호의 세기와 전파 방향성에 따른 수신 강도(Received Signal Strength Index, RSSI) 변화를 분석하였다. 자수정 지하광산에서 스마트폰을 이용하여 저전력 블루투스 신호의 RSSI 변화를 조사한 결과, 무지향성 비콘의 경우 비콘과 스마트폰 사이의 거리가 감소할수록 신호 세기가 증가할수록 RSSI 평균이 점차 증가하였다. 지향성 비콘의 RSSI 평균은 비콘과 스마트폰이 마주 보는 각도와는 연관성 없이 변화하였다. 본 연구의 결과는 블루투스 비콘 기반의 지하광산 근접경고시스템 개발을 위한 기초자료로 활용될 수 있을 것이다.

• 한국정보통신학회논문지
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• 제25권11호
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• pp.1457-1462
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• 2021

코로나 팬데믹 이후 비대면 주문 결제가 뉴 노멀로 자리잡고 있다. BLE 비콘은 블루투스 페어링 없이 70m이내의 범위에서 저전력 무선 통신을 지원하는 기술로, 실내측위에 특화되어 있다. 따라서 B2C(Business to Consumeri), B2B(Business to Business)서비스를 넘어 O2O(Online to Offline)서비스를 구축하고 제공하는데에 적합하다. 그러나 비콘은 장거리 무선 통신을 지원하는 wifi에 비해 구축된 플랫폼이 적어서 이용률이 낮은 편이다. 이에 본 논문에서는 BLE 비콘을 활용한 O2O 서비스 플랫폼을 설계 및 제안함으로써 이전보다 편리한 비대면 관련 서비스 제공을 목적으로 한다. 비콘을 스캐닝할 때, 단순히 비콘이 가진 광고 데이터를 수신하는 것만이 아니라 사용자 단말기와 비콘간 실제거리가 정확히 산출되도록 한다. 해당 O2O 서비스 플랫폼은 정확한 위치 파악을 통해 쿠폰이나 할인혜택 같은 상점정보, 박물관 전시물 정보, 교통정보 등을 적시적소에 사용자에게 제공할 수 있게 될 것이다. 비콘 거리 측정실험은 비콘 측위의 특징인 실내 공간을 가정하고 수행되었다.

• 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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.570-574
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• 1993

This paper proposes a new method of estimating the position and heading angle of a mobile robot moving on a flat surface. The proposed localization method utilizes two passive beacons and a single rotating ultrasonic sensor. The passive beacons consist of two cylinders with different diameters and reflect the ultrasonic pulses coming from the sonar sensor mounted on the mobile robot. The geometric parameter set of beacon is acquired from the sonar scan data obtained at a single mobile robot location using a new data processing algorithm. Form this parameter set, the position and heading angle of the mobile robot is determined directly. The performance and validity of the proposed method are evaluated using two beacons and a single sonar sensor attached at the pan-tilt device mounted on a mobile robot, named LCAR, in our laboratory.

• 한국멀티미디어학회논문지
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• 제22권1호
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• pp.62-69
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• 2019

In this paper, we propose iZone system for safe walking of children. The proposed system recognizes the state that a child is down a roadway as a dangerous situation. And then it informs the surrounding adults and guardians of the child in the event of a dangerous situation. The iZone system consists of the iZone device that attaches to a child's bag or clothing, the iZone app for children, the iZone server, and external beacons. The proposed system uses the ultrasonic sensor of the iZone device and the GPS coordinates and external beacons information by the children's smartphone to determine the dangerous situation. The proposed system uses external beacons to calibrate the GPS coordinates. Moreover, it determines whether the child is down the roadway in sidewalk by measuring the height difference between the roadway and the sidewalk using ultrasonic sensor.