• Title/Summary/Keyword: target localization

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On the Performance Enhancement of a Tactical Monopulse MIMO Radar (향상된 성능의 전술형 모노펄스 MIMO 레이더)

  • An, Chan-Ho;Jin, Hyun Bo;Yang, Janghoon;Pak, Ui Young;Ryu, Young-Jae;Kim, Dong Ku
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.1
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    • pp.19-25
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    • 2013
  • In this paper, we proposed an enhanced monopulse MIMO radar system for the tactical scenario where the ground receivers are connected wireless backhaul and closely spaced. By applying the ${\alpha}{\beta}$ filter to the conventional monopulse MIMO radar, we show that the localization performance can be improved significantly. We also propose an efficient localization algorithm for a system with lower rate feedback. Using numerical simulations, we demonstrate that the proposed scheme can improve the localization performance while reducing the feedback over conventional scheme.

Performance Analysis of Passive UHF RFID based Object Localization under Various Reader Antenna Locations (리더 안테나 위치에 따른 수동형 UHF RFID 기반 위치인식 성능 분석)

  • Choi, Jae Sung;Son, Byung Rak;Kim, Ju-Gon;Lee, Dong Ha
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.648-650
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    • 2015
  • In this research, we investigate an influence of a reader antenna location in Passive UHF RFID system based Object localization. When the localization system uses stationary RFID reader system, the performances of the system are significantly varied depending on the deployed antenna conditions due to its external environment such as reflection by the ground and obstacles. In this research we deeply study the RF conditions and differentiation with various antenna location. According to the empirical results, the localization system shows the best performance, where the reader antenna locates 1.5m from the target area of interest.

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Pallidotomy Guided by MRI and Microrecording for Parkinson's Disease (파킨슨환자의 자기공명영상과 미세전극기록을 이용한 담창구 파괴술)

  • Lee, Kyung Jin;Son, Hyung Sun;Park, Sung Chan;Cho, Kyung Keun;Park, Hae Kwan;Choi, Chang Rak
    • Journal of Korean Neurosurgical Society
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    • v.30 no.1
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    • pp.41-46
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    • 2001
  • Objective : The exact position of the lesion during the pallidotomy is critical to obtain the clinical improvement of parkinson's disease without damage to surrounding structure. Ventriculogrphy, CT(computed tomograpy) or MRI(magnetic resonance imaging) have been used to determine the initial coordinates of stereotactic target for pallidotomy. The goal of this study was to determine whether microelectrode recording significantly improves the neurophysiologic localization of the target obtained from MRI. Methods : Twenty patients were studied. They underwent a unilateral pallidotomy. Leksell frame was applied and T1 axial images parallel to the AC-PC(anterior commissure-posterior commissure) plane using a 1.5 Tesla MRI with 3mm slice thickness were obtained. Anteroposterior coordinate of target was chosen at 2mm in front of the midcommissural point and lateral coordinate between 19 and 22mm from the midline. The vertical coordinate was calculated on coronal slice using a fast spin echo inversion recovery sequence(FSEIR) related to the position of the choroidal fissure and ranged over 4-5mm below the AC-PC plane. Confirmation of the anatomical target was done on axial slices using the same FSEIR sequence . Microrecording was done at the pallidum contralateral to the symptomatic side using an electrode with a tip diameter of $1{{\mu}m}$ diameter tip and 1.1-1.4 mOhm impedance at 1000Hz. Electrophysiologic localization of the target was also confirmed intraoperatively by macrostimulation. Results : Microrecording techniques were reliable to define the transition from the base of the pallidum which was characterized by the disappearance of spike activity and by the change of the audible background activity. Signals from high amplitude neurons firing at 200-400Hz were recorded in the pallidal base. X, Y and Z coordinates of target obtained from the MRI were within 1mm from the X, Y, Z coordinates obtained with microrecording in 16 patients (80%), 15 patients(75%), 10 patients(50%) respectively. The difference of Y coordinate between on MRI and on microrecording was 4mm in only one patient. Conclusion : The MRI was accurate to localize the target within 1mm of the error from microrecording target in 70% of the patients. 4mm discrepancy was observed only once. We conclude that MRI alone can be used to determine the target for pallidotomy in most patients. However, microrecording technique can still be extremely valuable in patents with aberrant anatomy or unusual MRI coordinates. We also consider physiologic confirmation of the target using macrostimulation to be mandatory in all cases.

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Sonar-based yaw estimation of target object using shape prediction on viewing angle variation with neural network

  • Sung, Minsung;Yu, Son-Cheol
    • Ocean Systems Engineering
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    • v.10 no.4
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    • pp.435-449
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    • 2020
  • This paper proposes a method to estimate the underwater target object's yaw angle using a sonar image. A simulator modeling imaging mechanism of a sonar sensor and a generative adversarial network for style transfer generates realistic template images of the target object by predicting shapes according to the viewing angles. Then, the target object's yaw angle can be estimated by comparing the template images and a shape taken in real sonar images. We verified the proposed method by conducting water tank experiments. The proposed method was also applied to AUV in field experiments. The proposed method, which provides bearing information between underwater objects and the sonar sensor, can be applied to algorithms such as underwater localization or multi-view-based underwater object recognition.

Realization of Hybrid Localization System with Lighting LEDs and Ad-Hoc Wireless Network (LED 조명과 애드혹 무선 네트워크를 사용한 하이브리드 측위 시스템 구현)

  • Lee, Yong Up;Park, Joohyeon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.9
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    • pp.774-783
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    • 2012
  • A simple, accurate, secure, long-lasting, and portable hybrid positioning system is proposed and designed in this paper. It consists of a lighting LED that generates visible light data corresponding to position information of a target and a Zigbee wireless network communication module with low power, security, and service area expansion characteristics. Under an indoor environment where there is 23.62m distance between an observer and the target, the presented hybrid positioning system is tested and is verified with the functions of Zigbee three hop wireless networking and visible light communication (VLC) scheme. The test results are analyzed and discussed.

Non-classical role of Galectin-3 in cancer progression: translocation to nucleus by carbohydrate-recognition independent manner

  • Kim, Seok-Jun;Chun, Kyung-Hee
    • BMB Reports
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    • v.53 no.4
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    • pp.173-180
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    • 2020
  • Galectin-3 is a carbohydrate-binding protein and regulates diverse functions, including cell proliferation and differentiation, mRNA splicing, apoptosis induction, immune surveillance and inflammation, cell adhesion, angiogenesis, and cancer-cell metastasis. Galectin-3 is also recommended as a diagnostic or prognostic biomarker of various diseases, including heart disease, kidney disease, and cancer. Galectin-3 exists as a cytosol, is secreted in extracellular spaces on cells, and is also detected in nuclei. It has been found that galectin-3 has different functions in cellular localization: (i) Extracellular galectin-3 mediates cell attachment and detachment. (ii) cytosolic galectin-3 regulates cell survival by blocking the intrinsic apoptotic pathway, and (iii) nuclear galectin-3 supports the ability of the transcriptional factor for target gene expression. In this review, we focused on the role of galectin-3 on translocation from cytosol to nucleus, because it happens in a way independent of carbohydrate recognition and accelerates cancer progression. We also suggested here that intracellular galecin-3 could be a potent therapeutic target in cancer therapy.

Measure of Effectiveness Analysis for Tracking in SONAR System (소나시스템에서의 추적효과도 분석)

  • Cho, Jung-Hong;Kim, Hyoung Rok;Kim, Seongil;Kim, Jea Soo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.1
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    • pp.5-26
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    • 2013
  • Since the optimized use of sonar systems for target tracking is a practical problem for naval operations, the measure of mission achievability is needed for preparing efficient sonar-maneuver tactic. In order to quantify the mission achievability or Measure Of Effectiveness(MOE) for given sonar-maneuver tactics, we developed and tested a simulation algorithm. The proposed algorithm for tracking is based on Measure Of Performance(MOP) for localization and tracking system of sonar against target. Probability of Detection(PD) using steering beam patterns referenced to the aspect angle of sonar is presented to consider the tracking-performance of sonar. Also, the integrated software package, named as Optimal Acoustic Search Path Planning(OASPP) is used for generating sonar-maneuver patterns and vulnerability analysis for a given scenario. Through simulation of a simple case for which the intuitive solution is known, the proposed algorithm is verified.

Waveguide Spatial Interference Filtering in Adaptive Matched Field Processing (적응 정합장처리에서 도파관 공간간섭 필터링)

  • 김재수;김성일;신기철;김영규;박정수
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.4
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    • pp.288-295
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    • 2004
  • Detection and localization of a slow and quiet target in shallow water environments is a challenging problem for which it is well known that snapshot is deficient because of a fast and strong interferer. This paper presents waveguide interference filtering technique that mitigate strong interferer problems in adaptive matched field processing. MCM (multiple constraint method) based on NDC (null direction constraint) has been proposed for new spatial interferer filter. MCM-NDC using replica force a interferer component to be filtered through CSDM (cross-spectral density matrix). This filtering have an effect on sidelobe reduction and restoring of signal gain of a quiet target. This technique was applied to a simulation on Pekeris waveguide and vertical array data from MAPLE03 (matched acoustic properties and localization experiment) in the East Sea and was shown to improve SBNR (signal-to-background-and-noise ratio) over the standard MVDR (minimum-variance distortionless response) and NSP (null space projection) technique.

Outlier Reduction using C-SCGP for Target Localization based on RSS/AOA in Wireless Sensor Networks (무선 센서 네트워크에서 C-SCGP를 이용한 RSS/AOA 이상치 제거 기반 표적 위치추정 기법)

  • Kang, SeYoung;Lee, Jaehoon;Song, JongIn;Chung, Wonzoo
    • Journal of Convergence for Information Technology
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    • v.11 no.11
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    • pp.31-37
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    • 2021
  • In this paper, we propose an outlier detection algorithm called C-SCGP to prevent the degradation of localization performance based on RSS (Received Signal Strength) and AOA (Angle of Arrival) in the presence of outliers in wireless sensor networks. Since the accuracy of target estimation can significantly deteriorate due to various cause of outliers such as malfunction of sensor, jamming, and severe noise, it is important to detect and filter out all outliers. The single cluster graph partitioning (SCGP) algorithm has been widely used to remove such outliers. The proposed continuous-SCGP (C-SCGP) algorithm overcomes the weakness of the SCGP that requires the threshold and computing probability of outliers, which are impratical in many applications. The results of numerical simulations show that the performance of C-SCGP without setting threshold and probability computation is the same performance of SCGP.