Performance Evaluation of Location Estimation System Using a Non Fixed Single Receiver

Enkhzaya Myagmar,Soon-Ryang Kwon 한국콘텐츠학회(IJOC) 2014 International Journal of Contents Vol.10 No.4

General location aware systems are only applied to indoor and outdoor environments using more than three transmitters to estimate a fixed object location. Those kinds of systems have environmental restrictions that require an already established infrastructure. To solve this problem, an Object Location Estimation (OLE) algorithm based on PTP (Point To Point) communication has been proposed. However, the problem with this method is that deduction of performance parameters is not enough and location estimation is very difficult because of unknown restriction conditions. From experimental tests in this research, we determined that the performance parameters for restriction conditions are a maximum transmission distance of CSS communication and an optimum moving distance interval between personal locations. In this paper, a system applied OLE algorithm based on PTP communication is implemented using a CSS (Chirp Spread Spectrum) communication module. A maximum transmission distance for CSS communication and an optimum moving distance interval between personal locations are then deducted and studied to estimate a fixed object location for generalization.

Performance Evaluation of Location Estimation System Using a Non Fixed Single Receiver

Myagmar, Enkhzaya,Kwon, Soon-Ryang The Korea Contents Association 2014 International Journal of Contents Vol.10 No.4

General location aware systems are only applied to indoor and outdoor environments using more than three transmitters to estimate a fixed object location. Those kinds of systems have environmental restrictions that require an already established infrastructure. To solve this problem, an Object Location Estimation (OLE) algorithm based on PTP (Point To Point) communication has been proposed. However, the problem with this method is that deduction of performance parameters is not enough and location estimation is very difficult because of unknown restriction conditions. From experimental tests in this research, we determined that the performance parameters for restriction conditions are a maximum transmission distance of CSS communication and an optimum moving distance interval between personal locations. In this paper, a system applied OLE algorithm based on PTP communication is implemented using a CSS (Chirp Spread Spectrum) communication module. A maximum transmission distance for CSS communication and an optimum moving distance interval between personal locations are then deducted and studied to estimate a fixed object location for generalization.

WiFi 신호를 이용한 기점기반 위치 추정 연구

김선필,김남기 한국정보기술학회 2012 한국정보기술학회논문지 Vol. No.

본 논문은 WiFi 신호를 이용한 기점기반 위치 추정을 위한 모델을 제안한다. 실내 박물관이나 전시관과 같은 공간에서는 물체를 중심으로 위치기반서비스를 제공할 수 있기 때문에 사용자가 정확이 어떤 위치에 있는가 보다 어떤 물체에 가까이 있는지가 중요한 정보가 된다. 본 모델은 이러한 실내 공간을 고려하여 기점기반으로 영역을 정의하고 사용자의 위치를 상대적으로 추정한다. 이를 통해 기점기반 위치 추정은 기존의 좌표기반 위치 추정 보다 유연한 인프라 구축이 가능하고 사전 공간 정보가 필요 없는 장점을 가진다. 따라서 본 논문에서는 기점기반 위치 추정을 위한 알고리즘을 제안하고 실제 환경에서 이를 성능평가 한다. 그리고 실험 결과를 통해 본 논문에서 제안하는 기점기반 위치 추정이 효과적으로 사용자의 위치를 추정함을 확인할 수 있었다. In this paper, we propose a point-based location estimation model using WiFi signal. Because the indoor location-based service can be provided based on the objects, in indoor area such as museums or galleries, the information which object is close to a user is more important than the information where a user is. For such indoor environment, the proposed model defines the point-based area and relatively estimates the user location. Through this mechanism, the proposed model has advantages; proposed mechanism is flexible infrastructure and can not require pre-spatial information in comparison to axis-based location estimation. Therefore, in this paper, we design the algorithm for point-based location estimation model and measures performance evaluation in the real environment. Through experimental results, we knew that our point-based algorithm could efficiently estimate the user location.

BLE기반 비콘을 이용한 실내 환경에서의 사용자 위치추정

임수종,성민관,윤상석,Lim, Su-Jong,Sung, Min-Gwan,Yun, Sang-Seok 대한임베디드공학회 2021 대한임베디드공학회논문지 Vol.16 No.5

In this paper, we propose a method for a mobile robot to estimate a specific location of a service provision target using a beacon-tag for the purpose of providing location-based services (LBS) to users in an indoor environment. To estimate the location, the irregular characteristics and error factors of the received signal strength indicator (RSSI) generated from the beacon are analyzed, and the distance conversion function is derived from the RSSI data extracted by applying a Gaussian filter. Then, the distance data converted from the plurality of beacons estimates an indoor location through a triangulation technique. After that, the improvement in the location estimation is analyzed by applying the temporal confidence reasoning technique. The possibility of providing a LBS of a mobile robot was confirmed through a location estimation experiment for a plurality of designated locations in an indoor environment.

Influence of Camera Location on the Accuracy of Visual Estimation of Body Segment

Yan Qu,Jaejin Hwang,Kyung-Sun Lee,Jongseon Kwag,Myung-Chul Jung 대한인간공학회 2011 대한인간공학회 학술대회논문집 Vol.2011 No.5

Objective: The aim of this study is to investigate the influence of camera location on the accuracy of visual estimation (VE) of body segments. Background: Various ergonomic methods have been used to investigate the work-related musculoskeletal disorder factors. The VE method is regard as valid and reliable comparing to the self-report and direct method. The previous VE study is limited by choosing the observational direction. Method: Eight body segments at fullrange of motion (ROM) were presented by a volunteer, the ROMs at each 10º were measured by goniometer and captured from 5 camera locations. Thirty observers visually estimated the segment angles displayed on the digital images. The average absolute error respect to the goniometric measurement was calculated to assess the VE accuracy. Results: For the whole body, the camera location significantly (P<0.0001) affected the VE accuracy, the 135 and 90 degree camera location exposed the lowest error. Hand estimation and foot estimation showed the highest (14.0±11.7º) and lowest (9.0±8.0º) estimation error. Conclusion: The 135 degree camera location is the optimal direction to capture and visually estimate body postures in the laboratory. Application: This study would contribute to the direction determination when applying VE in the field, furthermore to provide the correlated data to assess the bias in epidemiological studies.

Real-time and Precise Indoor Localization System in Multi-Floor Buildings for Pedestrian using Cloud Platform

Taehun Kim,Beomju Shin,Chung G. Kang,Jung Ho Lee,Changsoo Yu,Hankyeol Kyung,Donghyun Shin,Taikjin Lee 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

Pedestrians use their smartphones to determine their location. Accordingly, there is a growing demand for seamless localization that can estimate the location regardless of indoor and outdoor space. However, the Global Navigation Satellite System used for outdoor location estimation has poor reception in the indoor environment, making it difficult to use in indoor space. Therefore, we propose the indoor localization technology based on Surface Correlation (SC). This indoor localization technology can estimate the location of pedestrians on only one floor. In this study, floor detection was performed using only RF signal without using other sensors such as barometric pressure sensor in the multi-floor building. The most important thing in floor detection is the reliability of the current floor and floor change detection. We can estimate the coarse floor using the unique ID of the RF source installed on each floor. Then, the virtual trajectory is generated using only RF signal, and the degree of similarity with the floor is determined by identifying the fine floor of the coarse floor estimated by applying the existing SC-based localization. Once the fine floor of pedestrians is identified, the final absolute location of pedestrians in the multi-floor building can be estimated by calculating the indoor location of the estimated floor using conventional SC-based localization. To verify the performance of the proposed algorithm in real-time, the algorithm was implemented in Google Cloud Platform. Pedestrians can check the indoor location results through real-time connection with the smartphone. In the actual multi-floor building, the similarity between the floor estimated by the proposed algorithm and the floor estimated using the barometric pressure sensor is about 95.0%. And the RMSE of the indoor localization results of the proposed system is about 3.662m.

C-ITS 및 Location Intelligence 데이터 융합을 통한 음영구간 교통량 추정 연구

손지언,김종형,이태헌 한국도로학회 2024 한국도로학회논문집 Vol.26 No.4

PURPOSES : This study aims to investigate the reliability of the real-time estimation of intersection traffic volumes based on the integration of location intelligence data and smart intersection data. METHODS : Location intelligence data (LID) and smart intersection data were obtained at eight intersections in Inju-daero, Incheon. The two datasets were then integrated to estimate traffic volumes for intersections in the shadow section, where traffic information was not expected to be obtained. The traffic estimation accuracy was evaluated using the total traffic, approach traffic, and turning movement volumes at the intersections. The estimated traffic was compared with the actual traffic volumes in the smart intersection data to validate the reliability of traffic estimation. RESULTS : The average traffic estimation error for the total intersection volume was approximately 4.5% for the five intersections in the shadow section. The estimation errors for the approach volumes (less than 5%) were also consistently low, except from 12 pm to 1 pm. CONCLUSIONS : The findings of this study suggest that location intelligence data can be combined with smart intersection data to estimate real-time traffic for shadow sections on roadways. This could enable a cost-effective cooperative intelligent transport system (C-ITS) when the municipal budget is limited, ultimately leading to the sustainable operation of C-ITS.

시설물 입지에 있어 인구 중심점 개념을 이용한 수요 규모 추정 방법 연구

주성아 ( Sung A Joo ),김영훈 ( Young Hoon Kim ) 한국지리정보학회 2007 한국지리정보학회지 Vol.10 No.2

This paper is to discuss analytical techniques to estimate demand sizes and volumes that determine optimal locations for multiple facilities for a given services. While demand size estimation is a core part of location modeling to enhance solution quality and practical applicability, the estimation method has been used in limited and restrict parts such as a single population centroid in a given larger census boundary area or small theoretical application experiments(e.s. census track and enumeration district). Therefore, this paper strives to develop an analytical estimation method of demand size that converts area based demand data to point based population weighted centroids. This method is free to spatial boundary units and more robust to estimate accurate demand volumes regardless of geographic boundaries. To improve the estimation accuracy, this paper uses house weighted value to the population centroid calculation process. Then the population weighted centroids are converted to individual demand points on a grid formated surface area. In turn, the population weighted centroids, demand points and network distance measures are operated into location-allocation models to examine their roles to enhance solution quality and applicability of GIS location models. Finally, this paper demonstrates the robustness of the weighted estimation method with the application of location-allocation models.

A multitype sensor placement method for the modal estimation of structure

Pei, Xue-Yang,Yi, Ting-Hua,Li, Hong-Nan Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.4

In structural health monitoring, it is meaningful to comprehensively utilize accelerometers and strain gauges to obtain the modal information of a structure. In this paper, a modal estimation theory is proposed, in which the displacement modes of the locations without accelerometers can be estimated by the strain modes of selected strain gauge measurements. A two-stage sensor placement method, in which strain gauges are placed together with triaxial accelerometers to obtain more structural displacement mode information, is proposed. In stage one, the initial accelerometer locations are determined through the combined use of the modal assurance criterion and the redundancy information. Due to various practical factors, however, accelerometers cannot be placed at some of the initial accelerometer locations; the displacement mode information of these locations are still in need and the locations without accelerometers are defined as estimated locations. In stage two, the displacement modes of the estimated locations are estimated based on the strain modes of the strain gauge locations, and the quality of the estimation is seen as a criterion to guide the selection of the strain gauge locations. Instead of simply placing a strain gauge at the midpoint of each beam element, the influence of different candidate strain gauge positions on the estimation of displacement modes is also studied. Finally, the modal assurance criterion is utilized to evaluate the performance of the obtained multitype sensor placement. A bridge benchmark structure is used for a numerical investigation to demonstrate the effectiveness of the proposed multitype sensor placement method.

RSSI기반 지능형 위치 추정 시스템 설계 및 구현

임창균 ( Chang Gyoon Lim ),강오성 ( O Seong Andrew Kang ),이창영 ( Chang Young Lee ),김강철 ( Kang Chul Kim ) 한국인터넷정보학회 2013 인터넷정보학회논문지 Vol.14 No.6

본 논문에서는 모바일 로봇이 주어진 환경에서 물건 객체를 찾기 위해 RFID(Radio Frequency IDentification) 태그의 위치를 추정할 수 있는 지능형 시스템을 설계하고 구현하였다. 개발된 지능형 시스템은 인공 신경망 시스템으로 RSSI(Received Signal Strength Indication)값을 입력으로 하고 절대 위치 좌표 값을 목표 값으로 하는 학습 시스템이다. 위치 추정을 위하여 수동형 RFID를 사용하였으며 능동형으로의 확장도 고려하였다. 실내에서 위치 추정을 위한 환경을 구축하여 사용될 수 있도록 시스템을 설계하였다. 또한 설계된 시스템을 소프트웨어 개발을 하였고, 실험을 통해 테스트베드 상에서 시스템 학습과 관련된 결과를 보여준다. 실제 현장과 유사한 환경에서 학습데이터 생성에서부터 실시간 위치 추정과 관련된 다양한 실험 결과를 보여준다. 실험 결과를 통해 모바일 로봇이 실내에서 원하는 객체를 쉽게 찾을 수 있음을 확인하였다. In this paper, we design and implement an intelligent system for finding objects with RFID(Radio Frequency IDentification) tag in which an mobile robot can do. The system we developed is a learning system of artificial neural network that uses RSSI(Received Signal Strength Indicator) value as input and absolute coordination value as target. Although a passive RFID is used for location estimation, we consider an active RFID for expansion of recognition distance. We design the proposed system and construct the environment for indoor location estimation. The designed system is implemented with software and the result related learning is shown at test bed. We show various experiment results with similar environment of real one from earning data generation to real time location estimation. The accuracy of location estimation is verified by simulating the proposed method with allowable error. We prepare local test bed for indoor experiments and build a mobile robot that can find the objects user want.