• Title/Summary/Keyword: real-time localization

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Door Recognition using Visual Fuzzy System in Indoor Environments (시각 퍼지 시스템을 이용한 실내 문 인식)

  • Yi, Chu-Ho;Lee, Sang-Heon;Jeong, Seung-Do;Suh, Il-Hong;Choi, Byung-Uk
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.1
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    • pp.73-82
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    • 2010
  • Door is an important object to understand given environment and it could be used to distinguish with corridors and rooms. Doors are widely used natural landmark in mobile robotics for localization and navigation. However, almost algorithm for door recognition with camera is difficult real-time application because feature extraction and matching have heavy computation complexity. This paper proposes a method to recognize a door in corridor. First, we extract distinguished lines which have high possibility to comprise of door using Hough transformation. Then, we detect candidate of door region by applying previously extracted lines to first-stage visual fuzzy system. Finally, door regions are determined by verifying knob region in candidate of door region suing second-stage visual fuzzy system.

Performance Improvement of a Pedestrian Dead Reckoning System using a Low Cost IMU (저가형 관성센서를 이용한 보행자 관성항법 시스템의 성능 향상)

  • Kim, Yun-Ki;Park, Jae-Hyun;Kwak, Hwy-Kuen;Park, Sang-Hoon;Lee, ChoonWoo;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.6
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    • pp.569-575
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    • 2013
  • This paper proposes a method for PDR (Pedestrian Dead-Reckoning) using a low cost IMU. Generally, GPS has been widely used for localization of pedestrians. However, GPS is disabled in the indoor environment such as in buildings. To solve this problem, this research suggests the PDR scheme with an IMU attached to the pedestrian's waist. However, despite the fact many methods have been proposed to estimate the pedestrian's position, but their results are not sufficient. One of the most important factors to improve performance is, a new calibration method that has been proposed to obtain the reliable sensor data. In addition to this calibration, the PDR method is also proposed to detect steps, where estimation schemes of step length, attitude, and heading angles are developed. Peak and zero crossings are detected to count the steps from 3-axis acceleration values. For the estimation of step length, a nonlinear step model is adopted to take advantage of using one parameter. Complementary filter and zero angular velocity are utilized to estimate the attitude of the IMU module and to minimize the heading angle drift. To verify the effectiveness of this scheme, a real-time system is implemented and demonstrated. Experimental results show an accuracy of below 1% and below 3% in distance and position errors, respectively, which can be achievable using a high cost IMU.

Molecular Cloning, Tissue Distribution and Expression of Porcine y+L Amino Acid Transporter-1

  • Zhi, Ai-min;Zhou, Xiang-yan;Zuo, Jian-jun;Zou, Shi-geng;Huang, Zhi-yi;Wang, Xiao-lan;Tao, Lin;Feng, Ding-yuan
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.2
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    • pp.272-278
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    • 2010
  • In this study, we cloned, sequenced and characterized porcine y+L Amino Acid Transporter-1 (y+LAT1). By screening a translated EST database with the protein sequence of the human $y^{+}$LAT1 and by using rapid amplification of cDNA ends (RACE), the full-length cDNA encoding porcine $y^{+}$LAT1 was isolated from porcine intestine RNA. It was 2,111 bp long, encoding a 511 amino acid trans-membrane glycoprotein composed of 12 transmembrane domains. The predicted amino acid sequence was found to be 91%, 90%, 87% and 87% identical to those of cattle, human, mouse and rat $y^{+}$LAT1 respectively. Real-time RT-PCR results indicated that the small intestine had the highest $y^{+}$LAT1 mRNA abundance and the lung had the lowest $y^{+}$LAT1 mRNA abundance. Baby hamster kidney (BHK) cells transfected with green fluorescent protein (GFP) tagged porcine $y^{+}$LAT1 cDNA indicated that the cellular localization of the gene product in BHK was on the plasma membrane.

Accuracy of Freehand versus Navigated Thoracolumbar Pedicle Screw Placement in Patients with Metastatic Tumors of the Spine

  • De La Garza Ramos, Rafael;Echt, Murray;Benton, Joshua A.;Gelfand, Yaroslav;Longo, Michael;Yanamadala, Vijay;Yassari, Reza
    • Journal of Korean Neurosurgical Society
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    • v.63 no.6
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    • pp.777-783
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    • 2020
  • Objective : To compare the accuracy and breach rates of freehand (FH) versus navigated (NV) pedicle screws in the thoracic and lumbar spine in patients with metastatic spinal tumors. Methods : A retrospective review of adult patients who underwent pedicle screw fixation in the thoracic or lumbar spine for metastatic spinal tumors between 2012 and 2018 was conducted. Breaches were assessed based on the Gertzbein and Robbins classification and only screws placed >4 mm outside of the pedicle wall (lateral or medial) were considered breached. Results : A total of 62 patients received 547 pedicle screws (average 8 per patient) - 34 patients received 298 pedicle screws in the FH group and 28 patients received 249 screws in the NV group. There were 40/547 breaches, corresponding to a breach and accuracy rate of 7.3% and 92.7%, respectively. The breach rate was 9.7% in the FH group and 4.4% in the NV group (chi-squared test, p=0.017); this corresponded to an accuracy rate of 90.3% and 95.6%, respectively. Only one patient from the overall cohort (in the FH group) required revision surgery due to a medial breach abutting the spinal cord (1.6% of all patients; 2.9% of FH patients); no patient suffered organ, vessel, or neurological injury from screw breaches. Conclusion : Navigated pedicle screw placement in patients with metastatic spinal tumors has a significantly higher radiographic accuracy compared to the FH technique. However, the revision surgery was low and no patient suffered from clinically-relevant breach. Navigation also offers the advantage of real-time localization of spinal tumors and aids in targeting and resection of these lesions.

Realtime Facial Expression Recognition from Video Sequences Using Optical Flow and Expression HMM (광류와 표정 HMM에 의한 동영상으로부터의 실시간 얼굴표정 인식)

  • Chun, Jun-Chul;Shin, Gi-Han
    • Journal of Internet Computing and Services
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    • v.10 no.4
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    • pp.55-70
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    • 2009
  • Vision-based Human computer interaction is an emerging field of science and industry to provide natural way to communicate with human and computer. In that sense, inferring the emotional state of the person based on the facial expression recognition is an important issue. In this paper, we present a novel approach to recognize facial expression from a sequence of input images using emotional specific HMM (Hidden Markov Model) and facial motion tracking based on optical flow. Conventionally, in the HMM which consists of basic emotional states, it is considered natural that transitions between emotions are imposed to pass through neutral state. However, in this work we propose an enhanced transition framework model which consists of transitions between each emotional state without passing through neutral state in addition to a traditional transition model. For the localization of facial features from video sequence we exploit template matching and optical flow. The facial feature displacements traced by the optical flow are used for input parameters to HMM for facial expression recognition. From the experiment, we can prove that the proposed framework can effectively recognize the facial expression in real time.

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Assessment of the Optic-guided Patient Positioning for Spinal Stereotactic Radiosurgery Using Novalis ExacTrac System (노발리스 ExacTrac system을 이용한 척추 정위 방사선수술 방법 평가)

  • 이동준;손문준;최광영;이기택;최찬영;황금철;황충진
    • Progress in Medical Physics
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    • v.13 no.4
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    • pp.218-223
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    • 2002
  • Stereotactic radiosurgery for intracranial lesion is well established since the Lars Leksell first introduced radiosurgery concept in 1951 Its use in the treatment of spinal lesion has been limited by the availability of effective immobilization devices. The first clinical experience of the spinal stereotactic radiosurgery technique was reported by Hamilton AJ. in 1995. Recently, Optic-guided patient positioning technique for extracranial stereotactic radiosurgery was developed and reported. This study is for assess the target positioning accuracy of the optic guided patient positioning system Exactrac (BrainLab., Inc, Germany). We have designed phantom for assess the accuracy of spinal stereotactic radiosurgery The infrared reflective body markers attached to the relatively immobile part of the body and a series of 2 mm CT images was taken. The image sets were transferred to the planning computer. During the radiosurgery treatment, we measure the real-time display showing the positioning values from Exactrac computer. And we compare the isocenter deviation from irradiated center point of the film which was mounted on the lesion site of the phantom and pin hole site of that film. The accuracy of the ExacTrac system in positioning a target point shows enough for the clinical applications.

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Response of Saccharomyces cerevisiae to Ethanol Stress Involves Actions of Protein Asr1p

  • Ding, Junmei;Huang, Xiaowei;Zhao, Na;Gao, Feng;Lu, Qian;Zhang, Ke-Qin
    • Journal of Microbiology and Biotechnology
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    • v.20 no.12
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    • pp.1630-1636
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    • 2010
  • During the fermentation process of Saccharomyces cerevisiae, yeast cells must rapidly respond to a wide variety of external stresses in order to survive the constantly changing environment, including ethanol stress. The accumulation of ethanol can severely inhibit cell growth activity and productivity. Thus, the response to changing ethanol concentrations is one of the most important stress reactions in S. cerevisiae and worthy of thorough investigation. Therefore, this study examined the relationship between ethanol tolerance in S. cerevisiae and a unique protein called alcohol sensitive RING/PHD finger 1 protein (Asr1p). A real-time PCR showed that upon exposure to 8% ethanol, the expression of Asr1 was continuously enhanced, reaching a peak 2 h after stimulation. This result was confirmed by monitoring the fluorescence levels using a strain with a green fluorescent protein tagged to the C-terminal of Asr1p. The fluorescent microscopy also revealed a change in the subcellular localization before and after stimulation. Furthermore, the disruption of the Asr1 gene resulted in hypersensitivity on the medium containing ethanol, when compared with the wild-type strain. Thus, when taken together, the present results suggest that Asr1 is involved in the response to ethanol stress in the yeast S. cerevisiae.

Development of physical flip display and control technology (물리적 플립 디스플레이 및 제어기술 개발 연구)

  • Hong, Sung-Dae
    • Journal of Digital Contents Society
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    • v.18 no.3
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    • pp.577-584
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    • 2017
  • Despite growing participation of many researchers, the cases of applying the transformative emotional display technology using physical materials and media are still in its early stages and the concept and structure are not properly established in Korea. The emerging global trend of physical display shows a possibility of new digital signage using emotional flip display. In this context, this study attempts to develop related element technology necessary in physical flip display and electromagnetic rotation module along with the integration platform of aesthetic arbitrarily-shaped display. The found results will be applied in researching the contents for the main subject which will be exhibited at the EXPO 2017 in Astana. It is to build up the foundation pioneering the localization of associated industry by means of diverse technological breakthroughs including flip-display technology, electromagnetic module technology, real-time video inter-working technology, high-speed rotation module technology, and transformative 3D frame technology.

A Study on MPLS OAM Functions for Fast LSP Restoration on MPLS Network (MPLS 망에서의 신속한 LSP 복구를 위한 MPLS OAM 기능 연구)

  • 신해준;임은혁;장재준;김영탁
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.7C
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    • pp.677-684
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    • 2002
  • Today's Internet does not have efficient traffic engineering mechanism to support QoS for the explosive increasing internet traffic such as various multimedia traffic. This functional shortage degrades prominently the quality of service, and makes it difficult to provide multi-media service and real-time service. Various technologies are under developed to solve these problems. IETF (Internet Engineering Task Force) developed the MPLS (Multi-Protocol Label Switching) technology that provides a good capabilities of traffic engineering and is independent layer 2 protocol, so MPLS is expected to be used in the Internet backbone network$\^$[1][2]/. The faults occurring in high-speed network such as MPLS, may cause massive data loss and degrade quality of service. So fast network restoration function is essential requirement. Because MPLS is independent to layer 2 protocol, the fault detection and reporting mechanism for restoration should also be independent to layer 2 protocol. In this paper, we present the experimental results of the MPLS OAM function for the performance monitoring and fault detection 'll'&'ll' notification, localization in MPLS network, based on the OPNET network simulator

A Study on Development of a Smart Wellness Robot Platform (스마트 웰니스 로봇 플랫폼 개발에 관한 연구)

  • Lee, Byoungsu;Kim, Seungwoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.1
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    • pp.331-339
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    • 2016
  • This paper developed a home wellness robot platform to perform the roles in basic health care and life care in an aging society. A robotic platform and a sensory platform were implemented for an indoor wellness service. In the robotic platform, the precise mobility and the dexterous manipulation are not only developed in a symbiotic service-robot, but they also ensure the robot architecture of human friendliness. The mobile robot was made in the agile system, which consists of Omni-wheels. The manipulator was made in the anthropomorphic system to carry out dexterous handwork. In the sensing platform, RF tags and stereo camera were used for self and target localization. They were processed independently and cooperatively for accurate position and posture. The wellness robot platform was integrated in a real-time system. Finally, its good performance was confirmed through live indoor tests for health and life care.