• Title/Summary/Keyword: network localization

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Advanced neuroimaging techniques for evaluating pediatric epilepsy

  • Lee, Yun Jeong
    • Clinical and Experimental Pediatrics
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    • v.63 no.3
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    • pp.88-95
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    • 2020
  • Accurate localization of the seizure onset zone is important for better seizure outcomes and preventing deficits following epilepsy surgery. Recent advances in neuroimaging techniques have increased our understanding of the underlying etiology and improved our ability to noninvasively identify the seizure onset zone. Using epilepsy-specific magnetic resonance imaging (MRI) protocols, structural MRI allows better detection of the seizure onset zone, particularly when it is interpreted by experienced neuroradiologists. Ultra-high-field imaging and postprocessing analysis with automated machine learning algorithms can detect subtle structural abnormalities in MRI-negative patients. Tractography derived from diffusion tensor imaging can delineate white matter connections associated with epilepsy or eloquent function, thus, preventing deficits after epilepsy surgery. Arterial spin-labeling perfusion MRI, simultaneous electroencephalography (EEG)-functional MRI (fMRI), and magnetoencephalography (MEG) are noinvasive imaging modalities that can be used to localize the epileptogenic foci and assist in planning epilepsy surgery with positron emission tomography, ictal single-photon emission computed tomography, and intracranial EEG monitoring. MEG and fMRI can localize and lateralize the area of the cortex that is essential for language, motor, and memory function and identify its relationship with planned surgical resection sites to reduce the risk of neurological impairments. These advanced structural and functional imaging modalities can be combined with postprocessing methods to better understand the epileptic network and obtain valuable clinical information for predicting long-term outcomes in pediatric epilepsy.

Constant Amplitude Multiple Access Channel Coding for Impulse Radio UWB Networks (임펄스 UWB 네트워크에서의 일정진폭 다중접속 채널코팅)

  • Kim, Tong-Sok;Kim, Yong-Cheol
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.6
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    • pp.42-47
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    • 2008
  • In this article a novel constant amplitude precoding for impulse UWB system is proposed. According to IEEE 802.15.4a, impulse UWB can be used in indoor localization and sensor data transmission. Most USN(ubiquitous sensor networks) needs multiple access. However impulse UWB system has a limited capability to detect superpositioned signal induced by multiple access. To overcome this problem we have adopted the concept of CAMC(Constant Amplitude Multi-Code) deviced by Wada and Kim. The proposed system consists of systematic constant amplitude precoding and LDPC decoding. And this system shows a good BER performance in computer simulation.

Antioxidant enzymes as redox-based biomarkers: a brief review

  • Yang, Hee-Young;Lee, Tae-Hoon
    • BMB Reports
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    • v.48 no.4
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    • pp.200-208
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    • 2015
  • The field of redox proteomics focuses to a large extent on analyzing cysteine oxidation in proteins under different experimental conditions and states of diseases. The identification and localization of oxidized cysteines within the cellular milieu is critical for understanding the redox regulation of proteins under physiological and pathophysiological conditions, and it will in turn provide important information that are potentially useful for the development of novel strategies in the treatment and prevention of diseases associated with oxidative stress. Antioxidant enzymes that catalyze oxidation/reduction processes are able to serve as redox biomarkers in various human diseases, and they are key regulators controlling the redox state of functional proteins. Redox regulators with antioxidant properties related to active mediators, cellular organelles, and the surrounding environments are all connected within a network and are involved in diseases related to redox imbalance including cancer, ischemia/reperfusion injury, neurodegenerative diseases, as well as normal aging. In this review, we will briefly look at the selected aspects of oxidative thiol modification in antioxidant enzymes and thiol oxidation in proteins affected by redox control of antioxidant enzymes and their relation to disease. [BMB Reports 2015; 48(4): 200-208]

Target Separation using Wavelet for Multiple Target Localization in Wireless Sensor Network (다중 표적 위치 추정을 위한 무선 센서 네트워크에서 웨이블릿을 이용한 표적 분리)

  • Cha, Dae-Hyun;Lee, Tae-Young;Hong, Jin-Keun;Han, Kun-Hui;Hwang, Chan-Sik
    • Proceedings of the KAIS Fall Conference
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    • 2009.12a
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    • pp.295-298
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    • 2009
  • 다중 표적을 감시하는 무선 센서 네트워크에서 다중 표적이 서로 교차하게 될 때 각각의 표적을 분리하는 문제는 표적의 추적, 탐지, 식별 등의 분야에서 매우 중요하다. 기존의 무선 센서 네트워크에서는 에너지 기반의 기법을 사용하기 때문에 다중 표적의 위치를 추정할 수 없거나, 기지국에서의 원 신호 분석 방법을 통해 표적의 종류를 식별하여 각각의 표적을 분리한다. 후자의 방법은 무선 센서 노드의 통신량과 연산량을 증가시켜 센서 노드의 생존 시간이 짧아지는 단점이 있고, 표적 분리까지 걸리는 시간으로 인해 실시간 처리가 어렵다. 본 논문에서는 무선 센서 노드에서 웨이블릿 변환을 이용한 특징을 추출하고 이를 이용해 다중 표적이 센서 영역 내에서 교차하게 될 때 표적을 분리하는 방법을 제안한다. 제안된 방법은 웨이블릿 상수의 주파수 정보를 이용하여 적은 연산으로 표적을 분리한다.

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A Study on Particle Filter based on KLD-Resampling for Wireless Patient Tracking

  • Ly-Tu, Nga;Le-Tien, Thuong;Mai, Linh
    • Industrial Engineering and Management Systems
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    • v.16 no.1
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    • pp.92-102
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    • 2017
  • In this paper, we consider a typical health care system via the help of Wireless Sensor Network (WSN) for wireless patient tracking. The wireless patient tracking module of this system performs localization out of samples of Received Signal Strength (RSS) variations and tracking through a Particle Filter (PF) for WSN assisted by multiple transmit-power information. We propose a modified PF, Kullback-Leibler Distance (KLD)-resampling PF, to ameliorate the effect of RSS variations by generating a sample set near the high-likelihood region for improving the wireless patient tracking. The key idea of this method is to approximate a discrete distribution with an upper bound error on the KLD for reducing both location error and the number of particles used. To determine this bound error, an optimal algorithm is proposed based on the maximum gap error between the proposal and Sampling Important Resampling (SIR) algorithms. By setting up these values, a number of simulations using the health care system's data sets which contains the real RSSI measurements to evaluate the location error in term of various power levels and density nodes for all methods. Finally, we point out the effect of different power levels vs. different density nodes for the wireless patient tracking.

Construction of a Sensor Network-based Smart Environment for Service Robots (서비스 로봇을 위한 센서 네트워크 기반 스마트 환경 구축)

  • Baeg, Seung-Ho;Park, Jae-Han;Koh, Jae-Han;Baeg, Moon-Hong
    • The Journal of Korea Robotics Society
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    • v.2 no.4
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    • pp.334-340
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    • 2007
  • This paper introduces a prototype smart home environment that is built in the research building to demonstrate the feasibility of a robot-assisted future home environment. Localization, navigation, object recognition and handling are core functionalities that an intelligent service robot should provide. A huge amount of research effort has been made to make the service robot perform these functions with its own sensors, actuators and a knowledge base. With all complicated configuration of sensors, actuators and a database, the robot could only perform the given tasks in a predefined environment or show the limited capabilities in a natural environment. We started a smart home environment for service robots for simple service robots to provide reliable services by communicating with the environment through the wireless sensor networks. In this paper, we introduce various types of smart devices that are developed for assisting the robot in the environment by providing sensor and actuator capabilities. In addition, we present how the devices are integrated to constitute the smart home environment for service robots.

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Identification of the Arabidopsis thaliana cell growth defect factor suppressing yeast cell proliferation

  • Kim, Kyung-Min;Uchimiya, Hirofumi;Sohn, Jae-Keun
    • Current Research on Agriculture and Life Sciences
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    • v.30 no.1
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    • pp.1-11
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    • 2012
  • We identified cdf based on screening of the Arabidopsis cDNA library for functional suppressors of the AtBI-1 (a gene described to suppress the cell death induced by Bax gene expression in yeast). The cdf was located on Chr. V and was composed of 5 exons and 4 introns. It encodes a protein of 258 amino acid residues with a molecular weight of 28.8 kDa. The protein has 3 transmembrane domains in the C-terminal region. The cdf has one homologue, named cdf2, which was found in Arabidopsis. Like cdf, cdf2 also induced growth defect in yeast. The effect of the cell growth defect factor was somewhat lower than Bax. cdf could arrest the growth of yeast. Its localization to the nucleus was essential for the suppression of yeast cell proliferation. Morphological abnormality of intracellular network, which is a hallmark of AtBI-1, was attenuated by expression of cdf.

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LIGHT is Expressed in Foam Cells and Involved in Destabilization of Atherosclerotic Plaques through Induction of Matrix Metalloproteinase-9 and IL-8

  • Kim, Won-Jung;Lee, Won-Ha
    • IMMUNE NETWORK
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    • v.4 no.2
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    • pp.116-122
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    • 2004
  • Background: LIGHT (TNFSF14) is a member of tumor necrosis factor superfamily and is the ligand for TR2 (TNFRSF14/HVEM). LIGHT is known to have proinflammatory roles in atherosclerosis. Methods: To find out the expression pattern of LIGHT in atherosclerotic plaques, immunohistochemical analysis was performed on human carotid atherosclerotic plaque specimens. LIGHT induced atherogenic events using human monocytic cell line THP-1 were also investigated. Results: Immunohistochemical analysis revealed expression of LIGHT and TR2 in foam cell rich regions in the atherosclerotic plaques. Double immunohistochemical analysis further confirmed the expression of LIGHT in foam cells. Stimulation of THP-1 cells, which express TR2, with either recombinant LIGHT or immobilized anti-TR2 monoclonal antibody induced interleukin-8 and matrix metalloproteinase(MMP)-9. Electrophoretic mobility shift assay demonstrated that LIGHT induces nuclear localization of transcription factor, nuclear factor $(NF)-{\kappa}B$. LIGHT induced activation of MMP-9 is mediated by $NF-{\kappa}B$, since treatment of THP-1 cells with the $NF-{\kappa}B$ inhibitor PDTC (pyrrolidine dithiocarbamate) completely blocked the activation of MMP-9. Conclusion: These data indicate that LIGHT is expressed in foam cells in atherosclerotic plaques and is involved in atherogenesis through activation of pro-atherogenic cytokine IL-8 and destabilization of plaque by inducing matrix degrading enzyme.

Mobile Robot with Artificial Olfactory Function

  • Kim, Jeong-Do;Byun, Hyung-Gi;Hong, Chul-Ho
    • Transactions on Control, Automation and Systems Engineering
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    • v.3 no.4
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    • pp.223-228
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    • 2001
  • We have been developed an intelligent mobile robot with an artificial olfactory function to recognize odours and to track odour source location. This mobile robot also has ben installed an engine for speech recognition and synthesis and is controlled by wireless communication. An artificial olfactory system based on array of 7 gas sensors has been installed in the mobile robot for odour recognition, and 11 gas sensors also are located in the obttom of robot to track odour sources. 3 optical sensors are also in cluded in the intelligent mobile robot, which is driven by 2 D. C. motors, for clash avoidance in a way of direction toward an odour source. Throughout the experimental trails, it is confirmed that the intelligent mobile robot is capable of not only the odour recognition using artificial neural network algorithm, but also the tracking odour source using the step-by-step approach method. The preliminary results are promising that intelligent mobile robot, which has been developed, is applicable to service robot system for environmental monitoring, localization of odour source, odour tracking of hazardous areas etc.

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Structural damage detection by principle component analysis of long-gauge dynamic strains

  • Xia, Q.;Tian, Y.D.;Zhu, X.W.;Xu, D.W.;Zhang, J.
    • Structural Engineering and Mechanics
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    • v.54 no.2
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    • pp.379-392
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    • 2015
  • A number of acceleration-based damage detection methods have been developed but they have not been widely applied in engineering practices because the acceleration response is insensitive to minor damage of civil structures. In this article, a damage detection approach using the long-gauge strain sensing technology and the principle component analysis technology is proposed. The Long gauge FBG sensor has its special merit for damage detection by measuring the averaged strain over a long-gauge length, and it can be connected each other to make a distributed sensor network for monitoring the large-scale civil infrastructure. A new damage index is defined by performing the principle component analyses of the long-gauge strains measured from the intact and damaged structures respectively. Advantages of the long gauge sensing and the principle component analysis technologies guarantee the effectiveness for structural damage localization. Examples of a simple supported beam and a steel stringer bridge have been investigated to illustrate the successful applications of the proposed method for structural damage detection.