• Title/Summary/Keyword: localization characteristics

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A Selection Method of Reference Access Points to Improve the Localization Accuracy in Indoor Environments (실내 환경에서 측위 정확도 향상을 위한 기준 AP 선택 기법)

  • Lim, Yu-Jin;Park, Jae-Sung
    • Journal of KIISE:Information Networking
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    • v.37 no.6
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    • pp.489-493
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    • 2010
  • In an indoor localization method taking the lateration-based approach, the distance between a target and an AP (Anchor Point) is estimated using RSS (Received Signal Strength) measurements. Since the characteristics of a radio signal randomly vary in time and space, errors are unavoidable in distance estimation with measured RSS. Since the accuracy of distance estimation affects the localization accuracy of a lateration-based method, additional APs hearing a target have been used for localization in the literature. However, lots of experimental results show that the accuracy of a lateration-based method is improved by using carefully selected APs measuring the high quality RSSs which the distances estimated is close to the actual distances between nodes as reference APs, not using merely more APs. In this paper, we focus on selection method of reference AP and distance estimation method reflecting on environmental dynamics. We validate our method by implementing an indoor localization system and evaluating the accuracy of our method in the various experimental environments.

Market Entry Strategy of LINE in Japan

  • Jung, Woo-Bum;Jung, Chang-Moon;Choi, Hyun-Young;Kim, Byoung-Goo
    • East Asian Journal of Business Economics (EAJBE)
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    • v.4 no.1
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    • pp.16-21
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    • 2016
  • This study analyzed the successful case of Naver LINE's entry into the Japanese market. LINE pursued a strategy of establishing its dominance early on and implemented localization for Japan and thereby achieved success in the Japanese market. The various strategies adopted by LINE allowed it to win over 80% of the market share in Japan and function as a nationally ubiquitous mobile messenger. The conclusions to be drawn from our LINE analysis is that LINE must implement localization strategies suited to the characteristics of each country, as it had done successfully in Japan. In the Asian region, it should retain the platform that provides various contents while pursuing a localization strategy to secure competitive edge, by offering emoticons suitable for each country, such as Ramadan emoticons in Islamic regions.

A Three Dimensional Object Localization Scheme using A Smartphone (스마트폰을 이용한 물체의 3차원 위치 추정 기법)

  • Kwon, Oh-Heum;Joung, Myoung-Hwan;Song, Ha-Joo
    • Journal of Korea Multimedia Society
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    • v.20 no.8
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    • pp.1200-1207
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    • 2017
  • Sensors in a smartphone can be used to measure various physical quantities. In this paper, we propose an object localization scheme in a three dimenstional using a smart phone. The proposed scheme estimates the location of an object by observing it from several different points. The direction to the target object and the locations of the observation points are collected at each observation point using the location sensor and the orientation sensor in the smartphone. Based on these observations, the proposed scheme derives three dimensional line of sight vectors and estimates the location of the target object that minimizes the estimation error. We implemented the proposed scheme on an Android smartphone and tested its performance by estimating the height of a building and characteristics of the proposed approach.

An Exploratory Study on the Experts' Perception of Science Curriculum Localization Policy: Focus on the Revision of the Arrangement and Implementation Guideline and the Achievement Standard of Curriculum (과학과 교육과정 지역화 정책에 대한 전문가 인식 탐색 -교육과정 편성·운영 지침 및 성취기준 개정을 중심으로-)

  • Chun, Joo-young;Lee, Gyeong-geon;Hong, Hun-gi
    • Journal of The Korean Association For Science Education
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    • v.41 no.6
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    • pp.483-499
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    • 2021
  • The curriculum localization policy is closely related to the decentralization and autonomy policy, which is a direction of the 2022 revised curriculum. In particular, considering the continuously expanding and changing environment and contents in science education, the localization of the science curriculum has the advantage of advancing to expertise through diversity. In this paper, through experts' perception of the science curriculum localization policy, the implications of the curriculum revision were confirmed, focusing on 'MPOE(Metropolitan and Provincial Offices of Education) curriculum arrangement and implementation guidelines(hereinafter referred to as 'guidelines')' and the achievement standards revision of science curriculum. In conclusion, study participants considered that the possibility of expanding the localization of the curriculum was high due to the unique characteristics of science practices. And they recognized the level of localization at the 'district office of education or village'-level between MPOE-level and school-level. When localization reaches the school-level in the future, it was considered necessary to discuss linkage with teacher policies such as teacher's competency, noting that the level of teachers could become the level of localization. In addition, there was a common perception that in order for the science 'guidelines' to be localized, 17 MPOE must be given the authority to autonomously organize some achievement standards in parallel. It was considered that 'restructuring or slimming of achievement standards' should precede localization of achievement standards in connection with this. On the other hand, it was predicted that the curriculum localization policy would enhance the aspect of diversification and autonomy of the science curriculum, and the establishment of achievement standards was directly related to evaluation, so it recognized the need to refine policies such as new description for evaluation clause in future science 'guidelines'. Finally, considering science and characteristics, it was mentioned that it is necessary to specify regional intensive science education policies in the 'guidelines' themselves beyond the localization of teaching materials.

Efficient Placement of Artificial Landmarks for Low-cost Localization of a Mobile Robot (이동로봇의 저비용 위치추정을 위한 효율적인 인공표식 배치기법)

  • Kim, Jiwoong;Chung, Woojin
    • Journal of IKEEE
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    • v.17 no.4
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    • pp.434-439
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    • 2013
  • Artificial landmarks have been widely used for reducing the uncertainty in localization of a mobile robot. In addition, research for efficient placement of artificial landmarks has been considered as one of the fundamental issues since the cost of localization is increased with the number of used landmarks. Therefore, this paper proposes a method in which landmarks are efficiently placed by considering the uncertainty characteristics of the motion model and the sensor model. Because two models have different uncertainty distributions, the final uncertainty can be considerably reduced through their efficient combination. The usefulness of the proposed method is demonstrated by simulation results.

Driving Control of an Omniwheel a Polishing Robot Using Beacon System and Encoder (Beacon System과 Encoder를 이용한 Omniwheel 연마 로봇의 주행 제어)

  • Song, Jun-Woo;Choi, Byeong-Chan;Kim, Tae-Eon;Sreenivasan, Sreejith Manalipadam;Lee, Jang-Myung
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.4
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    • pp.213-221
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    • 2017
  • Utilizing the existing polishing robot prevents unrestricted change of direction, driving, and identification of driving pathway. To overcome this barrier, driving mechaism has been designed with Omniwheels with encoders and RSSI method of beacon system has been utilized to identify the driving path by position recognition. Due to the wheel characteristics, the Omniwheel mobile robot generates greater slip than the conventional mobile robot, which reduces its driving accuracy. Therefore, to improve the driving accuracy, the localization is conducted through the fusion of encoder and RSSI of beacon data to compensate for the errors caused by Dead Reckoning and inaccuracy of sensors. Finally, the localization accuracies of the proposed and conventional indoor localization method are compared to show effectiveness of the proposed driving control for a polishing robot.

A Real-time and Off-line Localization Algorithm for an Inpipe Robot by Detecting Elbows (엘보 인식에 의한 배관로봇의 실시간 위치 추정 및 후처리 위치 측정 알고리즘)

  • Lee, Chae Hyeuk;Kim, Gwang Ho;Kim, Jae Jun;Kim, Byung Soo;Lee, Soon Geul
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.10
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    • pp.1044-1050
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    • 2014
  • Robots used for pipe inspection have been studied for a long time and many mobile mechanisms have been proposed to achieve inspection tasks within pipelines. Localization is an important factor for an inpipe robot to perform successful autonomous operation. However, sensors such as GPS and beacons cannot be used because of the unique characteristics of inpipe conditions. In this paper, an inpipe localization algorithm based on elbow detection is presented. By processing the projected marker images of laser pointers and the attitude and heading data from an IMU, the odometer module of the robot determines whether the robot is within a straight pipe or an elbow and minimizes the integration error in the orientation. In addition, an off-line positioning algorithm has been performed with forward and backward estimation and Procrustes analysis. The experimental environment has consisted of several straight pipes and elbows, and a map of the pipeline has been constructed as the result.

Pre/post-processing Operator Selection for Accurate Program Bug Localization (정확한 프로그램 결함 위치 추적을 위한 전-후처리 방법론)

  • Kim, Dongsun
    • Journal of Broadcast Engineering
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    • v.27 no.2
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    • pp.240-243
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    • 2022
  • Tracking the location of program defects is an essential task for software maintenance and repair. When a bug report is submitted, bug localization is a costly task because of the developer's manual effort. Many researchers have tried to automate the task, but according to the reported results, the performance is still insufficient in practice. Therefore, in this study, we analyzed a large amount of bug report data and the latest research and found that the existing studies used only one preprocessing without considering the characteristics of the bug report. In this paper, to solve the problems mentioned earlier, we propose a pre/post-processing operator selection approach for bug localization.

A Study on the Location Correction Algorithm considering effects of obstacles on location estimation system (장애물이 위치 추정 시스템에 미치는 영향을 고려한 위치 보정 알고리즘에 관한 연구)

  • Kang, Dong-Jo;Lee, Jeong-Joo;Park, Hyun-Ju
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.7
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    • pp.1524-1532
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    • 2012
  • The calibration method using the existing environmental characteristics is to correct taking advantage of the data that is followed Judgement on the environment. If a decision is not made on the environmental judgement, the use of traditional methods may increase rather than errors. In this paper, UWB-based localization system is utilized. We propose Location Correction Algorithm which is available on if you can not make a judgment about any circumstances for location estimation system. Reference Points was selected to observe the characteristics of the localization system. This paper searched the characteristics of the localization system in LOS environment and NLOS environment, and used data correcting the location information of the moving object by combining the two environmental characteristics. The Location Correction Algorithm is applied to the location measured from the location estimation system. This algorithm corrects for the location information of the object. As a result, the location accuracy improvement were observed.

Investigation of noise source localization on High speed train (고속철도 소음원의 위치규명에 관한 고찰)

  • Koh, Hyo-In;You, Won-Hee;Lee, Jun-Seok
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1590-1597
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    • 2007
  • This paper deals with the noise source localization of the Korean High Speed Train (KTX) at the speed of 300 km/h. Using Microfonarray system and beamforming technology typical pass-by noise sources and their frequency characteristics are investigated. It is primarily aimed at investigating the location and characteristics of the high speed train emission. The results from the microphone array tests are also analyzed in relation to the remarks from analytic studies and experimental investigations on the high speed train that have been done with the intention of understanding the interior noise mechanism. The acoustical image shows the low frequency noise sources mainly at the position of the under part of the train at high speeds and the related source mechanism are discussed.

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