• Title/Summary/Keyword: circuit reconstruction

Search Result 28, Processing Time 0.024 seconds

Light-Microscopy-Based Sparse Neural Circuit Reconstruction: Array Tomography and Other Methods

  • Rah, Jong-Cheol
    • Applied Microscopy
    • /
    • v.46 no.4
    • /
    • pp.176-178
    • /
    • 2016
  • Efficient neural circuit reconstruction requires sufficient lateral and axial resolution to resolve individual synapses and map a large enough volume of brain tissue to reveal the molecular identity and origin of these synapses. Sparse circuit reconstruction using array tomography meets many of these requirements but also has some limitations. In this minireview, the advantages and disadvantages of applicable imaging techniques will be discussed.

Reconstruction of Neural Circuits Using Serial Block-Face Scanning Electron Microscopy

  • Kim, Gyu Hyun;Lee, Sang-Hoon;Lee, Kea Joo
    • Applied Microscopy
    • /
    • v.46 no.2
    • /
    • pp.100-104
    • /
    • 2016
  • Electron microscopy is currently the only available technique with a spatial resolution sufficient to identify fine neuronal processes and synaptic structures in densely packed neuropil. For large-scale volume reconstruction of neuronal connectivity, serial block-face scanning electron microscopy allows us to acquire thousands of serial images in an automated fashion and reconstruct neural circuits faster by reducing the alignment task. Here we introduce the whole reconstruction procedure of synaptic network in the rat hippocampal CA1 area and discuss technical issues to be resolved for improving image quality and segmentation. Compared to the serial section transmission electron microscopy, serial block-face scanning electron microscopy produced much reliable three-dimensional data sets and accelerated reconstruction by reducing the need of alignment and distortion adjustment. This approach will generate invaluable information on organizational features of our connectomes as well as diverse neurological disorders caused by synaptic impairments.

Nano-Resolution Connectomics Using Large-Volume Electron Microscopy

  • Kim, Gyu Hyun;Gim, Ja Won;Lee, Kea Joo
    • Applied Microscopy
    • /
    • v.46 no.4
    • /
    • pp.171-175
    • /
    • 2016
  • A distinctive neuronal network in the brain is believed to make us unique individuals. Electron microscopy is a valuable tool for examining ultrastructural characteristics of neurons, synapses, and subcellular organelles. A recent technological breakthrough in volume electron microscopy allows large-scale circuit reconstruction of the nervous system with unprecedented detail. Serial-section electron microscopy-previously the domain of specialists-became automated with the advent of innovative systems such as the focused ion beam and serial block-face scanning electron microscopes and the automated tape-collecting ultramicrotome. Further advances in microscopic design and instrumentation are also available, which allow the reconstruction of unprecedentedly large volumes of brain tissue at high speed. The recent introduction of correlative light and electron microscopy will help to identify specific neural circuits associated with behavioral characteristics and revolutionize our understanding of how the brain works.

3D Inspection of Printed Circuit Boards (PCB의 3차원 검사)

  • 조홍주;박현우;이준재
    • Proceedings of the IEEK Conference
    • /
    • 2003.07e
    • /
    • pp.2375-2378
    • /
    • 2003
  • In manufacture of printed circuit boards, one important issue is precisely to measure the three-dimensional shape of the solder paste silk-screened prior to direct surface mounting of chips. This paper presents the 3D shape reconstruction of solder paste using the optical triangulation method based on structured light or slit beam and the measurement algorithm for height, volume. area, and coplanarity on component pads from the 3D range image. Futhermore, statistical process control function is incorporated for process capability analysis.

  • PDF

A Modular System of the Propagation Neural Networks For Reconstruction of Lost Information (소실 정보의 복원을 위한 전송신경망 모듈라 시스템)

  • Kim, Jong-Man;Kim, Yeong-Min;Hwang, Jong-Sun;Kim, Hyun-Chul
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2002.05b
    • /
    • pp.119-123
    • /
    • 2002
  • A new modular Lateral Information Propagation Networks(LIPN) has been designed. The LIPN has shown to be useful for reconstruction of information[3]. The problem is the fact that only the small number of nodes can be implemented in a IC chip with the circuit VLSI technology. The proposed modular architecture is propagated the neural network through inter module connections. For such inter module connections, the host (computer or logic) mediates the exchange of information among modules. Also border nodes in each module have capacitors for temporarily retaining the information from outer modules. The LIPN with $4{\times}4$ modules has been designed and simulation of interpolation with the designed LIPN has been done.

  • PDF

Study on Reliability of New Digital Tachograph for Traffic Accident Investigation and Reconstruction (교통사고 조사 및 재현에서 신형 전자식운행기록계의 신뢰성에 관한 연구)

  • Park, Jongjin;Joh, Geonwoo;Park, Jongchan
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.23 no.6
    • /
    • pp.615-622
    • /
    • 2015
  • Recently Digital-TachoGraph(DTG) was mounted mandatorily in commercial vehicles(Taxi, Bus, etc.). DTG records accurate and detailed information of the running state of vehicles related to traffic accident, such as Time, Distance, Velocity, RPM, Brake ON/OFF, GPS, Azimuth, Acceleration. Thus those standardized data can play an important role in traffic accident investigation and reconstruction. To develope the accurate and objective method using the DTG data for the reconstruction of traffic accident, we had conducted several tests such as driving test, high speed circuit test, braking test, slalom test at Korea Automobile Testing & Research Institute(KATRI), and collision test at Korea Automobile insurance repair Research and Training center(KART) with the vehicle equipped with several DTG. Development of the program which enables the reading and analysis of the DTG data was followed. In the experiments, we have found velocity error, RPM error, brake signal error and azimuth error in several products, and also non-continuous event data. The cause of these errors was deduced to be related to the correction factor, the durability of electronic parts and the algorithm.

Finding Needles in a Haystack with Light: Resolving the Microcircuitry of the Brain with Fluorescence Microscopy

  • Rah, Jong-Cheol;Choi, Joon Ho
    • Molecules and Cells
    • /
    • v.45 no.2
    • /
    • pp.84-92
    • /
    • 2022
  • To understand the microcircuitry of the brain, the anatomical and functional connectivity among neurons must be resolved. One of the technical hurdles to achieving this goal is that the anatomical connections, or synapses, are often smaller than the diffraction limit of light and thus are difficult to resolve by conventional microscopy, while the microcircuitry of the brain is on the scale of 1 mm or larger. To date, the gold standard method for microcircuit reconstruction has been electron microscopy (EM). However, despite its rapid development, EM has clear shortcomings as a method for microcircuit reconstruction. The greatest weakness of this method is arguably its incompatibility with functional and molecular analysis. Fluorescence microscopy, on the other hand, is readily compatible with numerous physiological and molecular analyses. We believe that recent advances in various fluorescence microscopy techniques offer a new possibility for reliable synapse detection in large volumes of neural circuits. In this minireview, we summarize recent advances in fluorescence-based microcircuit reconstruction. In the same vein as these studies, we introduce our recent efforts to analyze the long-range connectivity among brain areas and the subcellular distribution of synapses of interest in relatively large volumes of cortical tissue with array tomography and superresolution microscopy.

Model-based Gradient Compensation in Spiral Imaging (나선주사영상에서 모델 기반 경사자계 보상)

  • Cho, S.H.;Kim, P.K.;Lim, J.W.;Ahn, C.B.
    • Investigative Magnetic Resonance Imaging
    • /
    • v.13 no.1
    • /
    • pp.15-21
    • /
    • 2009
  • Purpose : A method to estimate a real k-space trajectory based on a circuit model of the gradient system is proposed for spiral imaging. The estimated k-space trajectory instead of the ideal trajectory is used in the reconstruction to improve the image quality in the spiral imaging. Materials and Methods : Since the gradient system has self resistance, capacitance, and inductance, as well as the mutual inductance between the magnet and the gradient coils, the generated gradient fields have delays and transient responses compared to the input waveform to the gradient system. The real gradient fields and their trajectory in k-space play an important role in the reconstruction. In this paper, the gradient system is modeled with R-L-C circuits, and real gradient fields are estimated from the input to the model. An experimental method to determine the model parameters (R, L, C values) is also suggested from the quality of the reconstructed image. Results : The gradient fields are estimated from the circuit model of the gradient system at 1.5 Tesla MRI system. The spiral trajectory obtained by the integration of the estimated gradient fields is used for the reconstruction. From experiments, the reconstructed images using the estimated trajectory show improved uniformity, reduced overshoots near the edges, and enhanced resolutions compared to those using the ideal trajectory without model. Conclusion : The gradient system was successfully modeled by the R-L-C circuits. Much improved reconstruction was achieved in the spiral imaging using the trajectory estimated by the proposed model.

  • PDF

The Reconstruction of the Lip Defect due to Electrical Burn (Case Report) (전기적화상에 의한 구순결손의 재건-증례보고-)

  • Min, Byung-Il;Kim, Byeong-Rin;Kim, Kyoung-Won;Park, Jin-Kyu
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.12 no.3
    • /
    • pp.63-67
    • /
    • 1990
  • Electrical burns of the lips are most frequently seen in small children, who are apt to chew on electrical cord or plug, the ends of extension cords in their mouth, saliva creates a short circuit across the terminals within the plug, causing an electrical burn. Tissue destruction with electrical burns is sudden and extensive. Extensive, deep coagulation necrosis is instaneously produced by the extreme temparatures of electrical arc. If the child is well grounded, the circuit flow through his body may cause cardiac arrest. The purpose of this report is to document two cases of electrical lip burn and reconstruction of the lip defect with some local flap techniques. For case 1, Z plasty & V-Y plasty and lengthening of the commissure and in case 2, Abbe flap technique was used and scar was revised later. Z-plasty and V-Y plastry were used for scar release and Abbe flap was designed on lower lip to meet the need of upper lip. For short of right lip width, lengthening of the commissure was done. We are to report the improvement with forementioned operation on the patient of electrical burn upon the lip.

  • PDF

High-throughput and low-area implementation of orthogonal matching pursuit algorithm for compressive sensing reconstruction

  • Nguyen, Vu Quan;Son, Woo Hyun;Parfieniuk, Marek;Trung, Luong Tran Nhat;Park, Sang Yoon
    • ETRI Journal
    • /
    • v.42 no.3
    • /
    • pp.376-387
    • /
    • 2020
  • Massive computation of the reconstruction algorithm for compressive sensing (CS) has been a major concern for its real-time application. In this paper, we propose a novel high-speed architecture for the orthogonal matching pursuit (OMP) algorithm, which is the most frequently used to reconstruct compressively sensed signals. The proposed design offers a very high throughput and includes an innovative pipeline architecture and scheduling algorithm. Least-squares problem solving, which requires a huge amount of computations in the OMP, is implemented by using systolic arrays with four new processing elements. In addition, a distributed-arithmetic-based circuit for matrix multiplication is proposed to counterbalance the area overhead caused by the multi-stage pipelining. The results of logic synthesis show that the proposed design reconstructs signals nearly 19 times faster while occupying an only 1.06 times larger area than the existing designs for N = 256, M = 64, and m = 16, where N is the number of the original samples, M is the length of the measurement vector, and m is the sparsity level of the signal.