• 제목/요약/키워드: Positioning Algorithm

검색결과 815건 처리시간 0.032초

A Position Revision Method by Path-Loss Factor in GIS based Wireless Sensor Node Deployments (GIS기반 무선 센서노드 배치에서 경로손실을 고려한 위치 보정 방법)

  • Bae, Myung-Nam;Kwon, Hyuk-Jong;Kang, Jin-A;Lee, In-Hwan
    • Spatial Information Research
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    • 제19권6호
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    • pp.111-121
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    • 2011
  • In this paper, we proposes a sensor node positioning algorithm that utilizes the geo-spatial elements and considers the factors to represent the propagation loss generated by the various obstacles in the urban wireless environments. First, we measures the propagation loss about the radio frequencies in major road of the urban, and defines the correlation between the measured loss and the environment information for the road and its surrounding get from Urban GIS. Secondly, through the utilization of the loss-environment correlation, we describes the detailed instruction for requiring the radio coverage decision and deploy system implementation for the wireless sensor node in urban. By the consideration of interference factor by the building and the linear structure of road, we can evaluate the path loss below 5dB RMS error. And, we proposes the way to revise the sensor node deployment based on the corelation and the measured path loss.

Critical Care Medicine (호흡기내과 의사를 위한 Respiratory Review of 2010)

  • Park, Jie-Hae;Chae, Jin-Nyeong;Choi, Won-Il
    • Tuberculosis and Respiratory Diseases
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    • 제69권2호
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    • pp.75-80
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    • 2010
  • The year of 2009~2010 brought a number of concepts and new ideas were evaluated with promising results. However, some studies that challenged many beliefs. In acute respiratory distress syndrome (ARDS), recent clinical studies took into consideration of pathophysiologic changes of respiratory system compliance. Meta-analysis of positive end-expiratory pressure trials showed survival benefit of high positive end-expiratory pressure in ARDS. Until now, prone positioning did not show survival benefit in patients with ARDS. Extracorporeal membrane oxygenation (ECMO) based management improved survival in patients with severe ARDS. ECMO can be a management option in severe ARDS. Sedation is a standard practice in critically ill patients needing mechanical ventilation. However, Danish group reported less sedation of critically ill patients receiving mechanical ventilation was associated with an increase in days without ventilation. Although this single center study has some limitations, the overall results are promising. Use of maximal sterile barrier precautions (mask, sterile gown, sterile gloves, and large sterile drapes) with chlorhexidine-impregnated dressing reduced central venous catheter related infection. Selective oropharyngeal decontamination (application of topical antibiotics in the oropharynx) reduced the mortality rate of an intensive care unit (ICU) population. Normoglycemia in Intensive Care Evaluation and Survival Using Glucose Algorithm Regulation (NICE-SUGAR) trial reported intensive glucose control increased mortality among adults in the ICU. Some of the results of above papers are promising. However, some ideas may need for more frequent individual assessment and increase the workload of ICU staffs. Before implementation of new practice in ICU, we should take into consideration of individual hospital situation including human and material resources.

A Study on Spotlight SAR Image Formation by using Motion Measurement Results of CDGPS (CDGPS의 요동 측정 결과를 이용한 Spotlight SAR 영상 형성에 관한 연구)

  • Hwang, Jeonghun;Ko, Young-Chang;Kim, So-Yeon;Kwon, Kyoung-Il;Yoon, Sang-Ho;Kim, Hyung-Suk;Shin, Hyun-Ik
    • Journal of the Korea Institute of Military Science and Technology
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    • 제21권2호
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    • pp.166-172
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    • 2018
  • To develop and evaluate the real-time SAR(Synthetic Aperture Radar) motion measurement system, true antenna phase center(APC) positions during SAT(Synthetic Aperture Time) are needed. In this paper, CDGPS(Carrier phase Differential Global Positioning System) post processing method is proposed to get the true APC position for spotlight SAR image formation. The CDGPS position is smoothed to remove high frequency noise which exists inherently in the carrier phase measurement. This paper shows smoothed CDGPS data is enough to provide the true APC for high-quality SAR image formation through motion measurement result, phase error estimation and IRF(Impulse Response Function) analysis.

A UE Position Tracking Method for Optical Beamforming Transmission in Visible Light Communications (가시광 통신 시스템에서 광 빔포밍 전송을 위한 유저 단말 추적 방법)

  • Hwang, Yu Min;Kim, Kyung Ho;Song, Yu Chan;Lee, Sang Woon;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • 제9권2호
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    • pp.85-90
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    • 2014
  • In this paper, we propose a novel UE(User Equipment) position tracking algorithm of visible light signals, and analyze BER performance when optical beamforming scheme is applied in VLC(Visible Light Communications) system. The optical beamforming scheme as an interference mitigation method provides good optical channel conditions between UE(Rx) and LED light(Tx), and lead to better BER performance because UE is able to get a better RSSI(Received Signal strength indication) value. For the system BER, the proposed UE position tracking method for optical beamforming transmission demonstrates the performance enhancement compared to a system not applied the optical beamforming transmission scheme, and up to about 5~6dB SNR performance gain is achieved. The results of the paper can be applied to design of various VLC and LBS applications for ubiquitous home network systems.

Discovery of Frequent Sequence Pattern in Moving Object Databases (이동 객체 데이터베이스에서 빈발 시퀀스 패턴 탐색)

  • Vu, Thi Hong Nhan;Lee, Bum-Ju;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • 제15D권2호
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    • pp.179-186
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    • 2008
  • The converge of location-aware devices, GIS functionalities and the increasing accuracy and availability of positioning technologies pave the way to a range of new types of location-based services. The field of spatiotemporal data mining where relationships are defined by spatial and temporal aspect of data is encountering big challenges since the increased search space of knowledge. Therefore, we aim to propose algorithms for mining spatiotemporal patterns in mobile environment in this paper. Moving patterns are generated utilizing two algorithms called All_MOP and Max_MOP. The first one mines all frequent patterns and the other discovers only maximal frequent patterns. Our proposed approach is able to reduce consuming time through comparison with DFS_MINE algorithm. In addition, our approach is applicable to location-based services such as tourist service, traffic service, and so on.

Application of Social Big Data Analysis for CosMedical Cosmetics Marketing : H Company Case Study (기능성 화장품 마케팅의 소셜 빅데이터 분석 활용 : H사 사례를 중심으로)

  • Hwang, Sin-Hae;Ku, Dong-Young;Kim, Jeoung-Kun
    • Journal of Digital Convergence
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    • 제17권7호
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    • pp.35-41
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    • 2019
  • This study aims to analyze the cosmedical cosmetics market and the nature of customer through the social big data analysis. More than 80,000 posts were analyzed using R program. After data cleansing, keyword frequency analysis and association analysis were performed to understand customer needs and competitor positioning, formulated several implications for marketing strategy sophistication and implementation. Analysis results show that "prevention" is a new and essential attribute for appealing target customers. The expansion of the product line for the gift market is also suggested. It has been shown that there is a high correlation with products that can be complementary to each other. In addition to the traditional marketing technique, the social big data analysis based on evidence was useful in deriving the characteristics of the customers and the market that had not been identified before. Word2vec algorithm will be beneficial to find additional.

Position Tracking Method in Construction field using IT Technology (IT기술을 이용한 건설현장 내 위치관제 기법)

  • Kim, Hyun-soo;Do, Seoung-bok;Choi, Hyun-young;Jang, Young-gu;Jeon, Heung-su
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 한국정보통신학회 2014년도 춘계학술대회
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    • pp.475-478
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    • 2014
  • This paper proposed the position tracking and recognition method of workers and cars in construction field. The reason why the position of workers and cars has to be tracked is to prevent the safety accident, emergency rescue, and theft of building materials by unauthorized people and car, etc. To realize the tracking, it needs to adopt the Information Telecommunication technology to the construction field as an integrated support system. In this paper, we proposed the continuous positioning tracking algorithm for workers and moving cars using the selected wireless communication network. And we proposed the virtual gateway method to detect the entrance status of moving workers and cars. All of these proposed methods are evaluated in real construction field using the prototype of support system made by ourselves.

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Tackling range uncertainty in proton therapy: Development and evaluation of a new multi-slit prompt-gamma camera (MSPGC) system

  • Youngmo Ku;Sehoon Choi;Jaeho Cho;Sehyun Jang;Jong Hwi Jeong;Sung Hun Kim;Sungkoo Cho;Chan Hyeong Kim
    • Nuclear Engineering and Technology
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    • 제55권9호
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    • pp.3140-3149
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    • 2023
  • In theory, the sharp dose falloff at the distal end of a proton beam allows for high conformal dose to the target. However, conformity has not been fully achieved in practice, primarily due to beam range uncertainty, which is approximately 4% and varies slightly across institutions. To address this issue, we developed a new range verification system prototype: a multi-slit prompt-gamma camera (MSPGC). This system features high prompt-gamma detection sensitivity, an advanced range estimation algorithm, and a precise camera positioning system. We evaluated the range measurement precision of the prototype for single spot beams with varying energies, proton quantities, and positions, as well as for spot-scanning proton beams in a simulated SSPT treatment using a phantom. Our results demonstrated high accuracy (<0.4 mm) in range measurement for the tested beam energies and positions. Measurement precision increased significantly with the number of protons, achieving 1% precision with 5 × 108 protons. For spot-scanning proton beams, the prototype ensured more than 5 × 108 protons per spot with a 7 mm or larger spot aggregation, achieving 1% range measurement precision. Based on these findings, we anticipate that the clinical application of the new prototype will reduce range uncertainty (currently approximately 4%) to 1% or less.

On the Development of Spot and ARC Welding Dual-Purpose Robot System (스포트 및 아크 용접 겸용 로보트 시스템의 개발)

  • Ryuh, B.S.;Lee, Y.J.;Lee, Y.B.
    • Journal of the Korean Society for Precision Engineering
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    • 제12권6호
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    • pp.13-19
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    • 1995
  • A dual purpose robot automation system is developed for both arc welding and spot welding by one robot within a cell. The need for automation of both arc welding and spot welding processes is urgent while the production volume is not so big as to accommodate separate stations for the two processes. Also, space is too narrow for separate stations to be settled down in the factory. A spot welding robot is chosen and the functions for arc welding are implemented in-house at cost of advanced functions. For the spot welding, a single pole type gun is used and the robot has to push down the plate to be wolded, which causes the robot positioning error. Therefore, position error compensation algorithm is developed. The basic functions for the arc welding processes are implemented using the digital I/O board of robot controller, PLC, and A/D conversion PCB. The weaving pattern is taught in meticulously by manual teach. A fixture unit is also developed for dual purpose. The main aspects of the system is presented in this paper especially in the design and implementation procedure. The signal diagrams and sequence logic diagrams are also included. The outcome of the dual purpose welding cell is the increased productivity and good production stability which is indispensable for production volume prediction. Also, it leads to reduction of manufacturing lead time.

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A Kalman filter with sensor fusion for indoor position estimation (실내 측위 추정을 위한 센서 융합과 결합된 칼만 필터)

  • Janghoon Yang
    • Journal of Advanced Navigation Technology
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    • 제25권6호
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    • pp.441-449
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    • 2021
  • With advances in autonomous vehicles, there is a growing demand for more accurate position estimation. Especially, this is a case for a moving robot for the indoor operation which necessitates the higher accuracy in position estimation when the robot is required to execute the task at a predestined location. Thus, a method for improving the position estimation which is applicable to both the fixed and the moving object is proposed. The proposed method exploits the initial position estimation from Bluetooth beacon signals as observation signals. Then, it estimates the gravitational acceleration applied to each axis in an inertial frame coordinate through computing roll and pitch angles and combining them with magnetometer measurements to compute yaw angle. Finally, it refines the control inputs for an object with motion dynamics by computing acceleration on each axis, which is used for improving the performance of Kalman filter. The experimental assessment of the proposed algorithm shows that it improves the position estimation accuracy in comparison to a conventional Kalman filter in terms of average error distance at both the fixed and moving states.