• 제목/요약/키워드: Weak localization

검색결과 58건 처리시간 0.021초

가상 가시광 중첩을 이용한 RSSI 기반의 실내 측위법 (RSSI-Based Indoor Localization Method Using Virtually Overlapped Visible Light)

  • 김대영;이건영
    • 전기학회논문지
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    • 제63권12호
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    • pp.1697-1703
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    • 2014
  • In this paper, we propose an indoor RSSI (received signal strength indication)-based localization method that uses virtually overlapped visible light with an indoor LED lighting system. In our system, a photodiode (PD) measures the RSSI from LED lamps that blink in one row or column units. Subsequently, the RSSI is used to obtain the horizontal distances between the LED lamps and the receiver with the predetermined characteristics curve, R-D curve, that represents the relation between the RSSI and the horizontal distances. When the controlled LED lamps blink in one row or column units, the R-D curve at the border of the LED lamps is different because of the weak lighting, which results in the position sensing error of the receiver. The deviation of the optical power of each LED also causes the error. To solve these problems, we propose a method that overlaps the visible light through the numerical operation at the receiver side without any modification of the light source side. Our proposed method has been simulated in a room measuring $1.2{\times}1.2{\times}1.8m^3$ considering the effect of the error on the optical power of the LED. The simulation result shows that the proposed method eliminates the error condition with the R-D curve and achieves an average positioning error of 13.4 mm under the error rate 3% of the optical power.

Immunocytochemical Localization of Nitric Oxide Synthase-containing Neurons in Mouse and Rabbit Visual Cortex and Co-Localization with Calcium-binding Proteins

  • Lee, Jee-Eun;Jeon, Chang-Jin
    • Molecules and Cells
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    • 제19권3호
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    • pp.408-417
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    • 2005
  • Nitric oxide (NO) occurs in various types of cells in the central nervous system. We studied the distribution and morphology of neuronal nitric oxide synthase (NOS)-containing neurons in the visual cortex of mouse and rabbit with antibody immunocytochemistry. We also compared this labeling to that of calbindin D28K, calretinin, and parvalbumin. Staining for NOS was seen both in the specific layers and in selective cell types. The densest concentration of intense anti-NOS immunoreactive (IR) neurons was found in layer VI, while the weak anti-NOS-IR neurons were found in layer II/III in both animals. The NOS-IR neurons varied in morphology. The large majority of NOS-IR neurons were round or oval cells with many dendrites coursing in all directions. Two-color immunofluorescence revealed that only 16.7% of the NOS-IR cells were double-labeled with calbindin D28K in the mouse visual cortex, while more than half (51.7%) of the NOS-IR cells were double-labeled with calretinin and 25.0% of the NOS-IR cells were double-labeled with parvalbumin in mouse. By contrast, 92.4% of the NOS-IR neurons expressed calbindin D28K while only 2.5% of the NOS-IR neurons expressed calretinin in the rabbit visual cortex. In contrast with the mouse, none of the NOS-IR cells in the rabbit visual cortex were double-labeled with parvalbumin. The results indicate that neurons in the visual cortex of both animals express NOS in specific layers and cell types, which do not correlate with the expression of calbindin D28K, calretinin or parvalbumin between the two animals.

대칭모형 기반 SLAM : M-SLAM (Symmetrical model based SLAM : M-SLAM)

  • 오정석;심귀보
    • 한국지능시스템학회논문지
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    • 제20권4호
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    • pp.463-468
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    • 2010
  • 미지의 영역에서 작업을 수행하고자 하는 이동로봇은 주변의 지도가 없을 뿐만 아니라 자신의 위치도 알 수 없다. 이러한 환경의 극복을 위해 가장 많이 쓰이는 방법이 SLAM(Simultaneous Localization And Mapping)이다. SLAM 분야에서 가장 많이 쓰이는 방법은 EKF (Extended Kalman Filter) 기반의 SLAM이다. 최적의 센서 융합 기법이지만 odometeric error 등을 보상하기 위해서는 복잡한 과정이 점차 증가하게 된다. 사람은 SLAM 방식을 이용하여 낯선 장소에서 마음속의 지도를 쉽게 작성하지만 로봇의 경우 SLAM을 수행하는 것은 매우 어렵고 시간이 오래 걸린다는 단점이 생기는 것이 다. 이러한 단점의 보완을 위하여 본 논문에서는 대칭모형 SLAM(M-SLAM)을 제안한다. M-SLAM은 대칭에 사용할 모형을 미리 정하고 센서로 받아들인 데이터를 모형과 비교하여 대칭된 모형을 맵에 적용시켜서 작업의 양을 줄이는 방법이다. M-SLAM은 적은 특징점을 이용하여 선택된 대칭 도형과의 유사성 판별을 이용하는 방법이므로 특징점이 적은 거리센서에 사용하기 적합한 특성을 가지고 있다고 할 수 있다. 특징점이 적어도 된다는 장점은 SLAM의 시간을 크게 줄여 줄수 있다.

Automatic Identification of Fiducial Marks Based on Weak Constraints

  • Cho, Seong-Ik;Kim, Kyoung-Ok
    • 대한원격탐사학회지
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    • 제19권1호
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    • pp.61-70
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    • 2003
  • This paper proposes an autonomous approach to localize the center of fiducial marks included in aerial photographs without precise geometric information and human interactions. For this localization, we present a conceptual model based on two assumptions representing symmetric characteristics of fiducial area and fiducial mark. The model makes it possible to locate exact center of a fiducial mark by checking the symmetric characteristics of pixel value distribution around the mark. The proposed approach is composed of three steps: (a) determining the symmetric center of fiducial area, (b) finding the center of a fiducial mark with unit pixel accuracy, and finally (c) localizing the exact center up to sub-pixel accuracy. The symmetric center of the mark is calculated tv successively applying three geometric filters: simplified ${\nabla}^2$G (Laplacian of Gaussian) filter, symmetry enhancement filter, and high pass filter. By introducing a self-diagnosis function based on the self-similarity measurement, a way of rejecting unreliable cases of center calculation is proposed, as well. The experiments were done with respect to 284 samples of fiducial marks composed of RMK- and RC-style ones extracted from 51 scanned aerial photographs. It was evaluated in the visual inspection that the proposed approach had resulted the erroneous identification with respect to only one mark. Although the proposed approach is based on weak constraints, being free from the exact geometric model of the fiducial marks, experimental results showed that the proposed approach is sufficiently robust and reliable.

주관절의 정형 물리치료 (Elbow Orthopaedic Physical Therapy)

  • 박지환
    • 대한정형도수물리치료학회지
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    • 제1권1호
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    • pp.65-74
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    • 1995
  • There is no line of demarcation between the shoulder and elbow regions. Pain In the arm may originate at the shoulder with reference downwards or less often at the elbow with reference upwards. Most pains indicated by the patient at the elbow or forearm have a local origin, since at the more distal part of the upper limb the capacity for correct localization is good. Once it is clear that the elbow region is at fault, the joint and the muscles about it are tested by ten movements. 1. Four. Passive extension, flexion, pronation, supination-full range, LOM, painful, painless. 2. Four. Resisted extension, flexion, pronation, supination-strong, weak, painful, painless. 3. Two. Resisted flexion, extension at the wrist-painful, painless. The muscles that perform theses two movements arise from the humeral epicondyles and a lesion in either often causes pain felt at the elbow although the tissuse affected is not functionally a part of the elbow (i. e. Tennis elbow and Golfer's elbow).

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RADIATION SAFETY STUDIES AT TOHOKU UNIVERSITY CYRIC

  • Yamadera M. Baba A.;Miura T.;Aoki T.;Hagiwara M.;Kawata N.
    • Journal of Radiation Protection and Research
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    • 제26권3호
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    • pp.231-236
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    • 2001
  • A brief introduction is presented on the radiation safety studies at Tohoku University Cyclotron & Radioisotope Center. Studies on two subject are described; (1) measurement of the thick target neutron yield and radioisotope production / activation cross section for ten's of MeV neutrons and ions using K=110 Tohoku University cyclotron to provide basicdata for accelerator shielding, and (2) development of techniques for high sensitive radiation detection and profile measurement using an Imaging Plate which is a high sensitive two-dimensional radiation sensor. Application of the Imaging Plate techniques to localization of very weak radioactivity and to neutron profile measurement is described.

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WEAK SOLUTIONS AND ENERGY ESTIMATES FOR A DEGENERATE NONLOCAL PROBLEM INVOLVING SUB-LINEAR NONLINEARITIES

  • Chu, Jifeng;Heidarkhani, Shapour;Kou, Kit Ian;Salari, Amjad
    • 대한수학회지
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    • 제54권5호
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    • pp.1573-1594
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    • 2017
  • This paper deals with the existence and energy estimates of solutions for a class of degenerate nonlocal problems involving sub-linear nonlinearities, while the nonlinear part of the problem admits some hypotheses on the behavior at origin or perturbation property. In particular, for a precise localization of the parameter, the existence of a non-zero solution is established requiring the sublinearity of nonlinear part at origin and infinity. We also consider the existence of solutions for our problem under algebraic conditions with the classical Ambrosetti-Rabinowitz. In what follows, by combining two algebraic conditions on the nonlinear term which guarantees the existence of two solutions as well as applying the mountain pass theorem given by Pucci and Serrin, we establish the existence of the third solution for our problem. Moreover, concrete examples of applications are provided.

The Structural-Dependent Characteristics of Rashba Spin Transports in In0.5Ga0.5As/In0.5Al0.5As Heterojunctions

  • Choi, Hyon-Kwang;Hwang, Sook-Hyun;Jeon, Min-Hyon;Yamda, Syoji
    • Transactions on Electrical and Electronic Materials
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    • 제12권4호
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    • pp.140-143
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    • 2011
  • The growth and characterization of $In_{0.5}Ga_{0.5}As/In_{0.5}Al_{0.5}As$ narrow-gap inverted high electron mobility transistor structures, developed as a candidate material for spin-injection devices, are presented in this study. We have grown samples possessing surface $In_{0.5}Ga_{0.5}As$ channels of different thicknesses (30 nm and 60 nm) both with and without a thin 3 nm $In_{0.5}Ga_{0.5}As$ cap layer by using molecular beam epitaxy. We then investigated the in-plane transport properties as well as the Rashba spin-orbit coupling constant of the two-dimensional electron gas confined at the heterojunction interface.

Human and Robot Tracking Using Histogram of Oriented Gradient Feature

  • Lee, Jeong-eom;Yi, Chong-ho;Kim, Dong-won
    • Journal of Platform Technology
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    • 제6권4호
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    • pp.18-25
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    • 2018
  • This paper describes a real-time human and robot tracking method in Intelligent Space with multi-camera networks. The proposed method detects candidates for humans and robots by using the histogram of oriented gradients (HOG) feature in an image. To classify humans and robots from the candidates in real time, we apply cascaded structure to constructing a strong classifier which consists of many weak classifiers as follows: a linear support vector machine (SVM) and a radial-basis function (RBF) SVM. By using the multiple view geometry, the method estimates the 3D position of humans and robots from their 2D coordinates on image coordinate system, and tracks their positions by using stochastic approach. To test the performance of the method, humans and robots are asked to move according to given rectangular and circular paths. Experimental results show that the proposed method is able to reduce the localization error and be good for a practical application of human-centered services in the Intelligent Space.

WHEN EVERY FINITELY GENERATED REGULAR IDEAL IS FINITELY PRESENTED

  • Mohamed Chhiti;Salah Eddine Mahdou
    • 대한수학회논문집
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    • 제39권2호
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    • pp.363-372
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    • 2024
  • In this paper, we introduce a weak version of coherent that we call regular coherent property. A ring is called regular coherent, if every finitely generated regular ideal is finitely presented. We investigate the stability of this property under localization and homomorphic image, and its transfer to various contexts of constructions such as trivial ring extensions, pullbacks and amalgamated. Our results generate examples which enrich the current literature with new and original families of rings that satisfy this property.