• Title/Summary/Keyword: Visual scanning

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Acoustic Effects on fMRI : A Study on Auditory, Motor and Visual cortices (소음이 뇌기능 영상에 미치는 영향 : 청각, 운동, 시각 피질에 관한 연구)

  • Chung, S.C.;Cho, Z.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.71-74
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    • 1997
  • MR acoustic sound or noise due to gradient pulsings has been one of the problems in MRI, both in patient scanning as well as in many areas of psychiatric and neuroscience research, such as brain fMRI. Especially in brain fMRI, sound noise is one of the serious noise sources which obscures the small signals obtainable from the subtle changes occurring in oxygenation status in the cortex and blood capillaries. Therefore, we have studied the effects of acoustic or sound noise arising in fMR imaging of the auditory, motor and visual cortices. The results show that the acoustical noise effects on motor and visual responses are opposite. That is, for the motor activity, it shows an increased total motor activation while for the visual stimulation, corresponding (visual) cortical activity has diminished substantially when the subject is exposed to a loud acoustic sound. Although the current observations are preliminary and require more experimental confirmation, it appears that the observed acoustic-noise effects on brain unctions, such as in the motor and visual cortices, are new observations and could have significant consequences in data observation and interpretation in future fMRI studies.

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A Histological Study on the Visual Cell Layer of the Endemic Korean Species Liobagrus mediadiposalis (Pisces: Amblycipitidae)

  • Kim, Jae Goo;Park, Jong Young
    • Applied Microscopy
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    • v.47 no.4
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    • pp.238-241
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    • 2017
  • A study on the visual cell and eyeball of the endemic Korean species Liobagrus mediadiposalis was investigated by light and electron microscopes. The retina of a small and 2 mm-diameter round eye was thin, $151.0{\pm}4.0{\mu}m$ and has two visual cells, a single cone and a rod cell. The single cone cells are short and thick, $18.0{\pm}0.9{\mu}m$ in length and $5.1{\pm}0.7{\mu}m$ (n=30) in diameter, while the rod cells are longer and thinner, $54.8{\pm}2.9{\mu}m$ in length and $3.3{\pm}0.6{\mu}m$ in diameter. The cone cells are seen an irregular and random mosaic pattern, and the rod cells are also randomly situated at between cone cells. As a rare phenomenon, such structure is one of characteristics reflecting the eye of a nocturnal and bottom-dwelling freshwater fish. The ultrastructure of visual cells was observed with scanning and transmission electron microscopy, both cone and rod cells are divided into an inner segment with numerous mitochondria and an outer segment with stacks of membrane discs.

The Structure of Visual Cells in the Retina of the Pond Loach, Misgurnus anguillicaudatus (Pisces; Cobitidae)

  • Kim, Chi-Hong;Kim, Jae-Goo;Park, Jong-Young
    • Applied Microscopy
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    • v.45 no.4
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    • pp.254-258
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    • 2015
  • A histological study on the retina of Misgurnus anguillicaudatus was carried out by light microscopy and scanning electron microscopy as part of getting information about relation between its habitat and visual cells. The visual cells of the retina in M. anguillicaudatus, a bottom-dwelling freshwater pond loach in stagnant or slow waters such as swamps, reservoirs and paddy fields, consists of double cones and large rods. The cones form a row mosaic pattern in which the partners of double cones are linearly oriented with a large rod. In a double cone, the two members are unequal such that one cone may be longer than the other.

Nano Visual Servoing Loop Using SEM Image (전자현미경 영상을 이용한 나노 비주얼 서보잉)

  • Choi, Jin-Ho;Ahn, Sang-Jung;Park, Byong-Chon;Lyou, Joon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.10
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    • pp.1876-1882
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    • 2008
  • Nano manipulator is used to manufacture Carbon NanoTube(CNT) tips. Using nano manipulator, operator attaches a CNT at the apex of Atomic Force Microscope(AFM) tip, which requires a mastery of mechanics and long manufacture time. Nano manipulator is installed inside a Scanning Electron Microscope(SEM) chamber to observe the operation. This paper presents a control scheme for horizontal axes of nano manipulator via processing SEM image. Edges of AFM tip and CNT are first detected, and the position information so obtained is fed to control horizontal axes of nano manipulator. That is, a visual servoing loop is realized to control the axes more precisely in nano scale.

Realization of Visual Servoing Loop for Position Control of a Nano Manipulator (나노조작기의 수평측 위치제어를 위한 Visual Servoing Loop 구성)

  • Choi, Jin-Ho;Park, Byong-Chon;Ahn, Sang-Jung;Kim, Dal-Hyun;Lyou, Joon
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.251-252
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    • 2007
  • Nano manipulator is used to manufacture Carbon NanoTube(CNT) tips. Using nano manipulator operator attaches a CNT at the end of Atomic Force Microscopy(AFM) tip, which requires a master mechanic and long manufacture time. Nano manipulator is installed inside Scanning Electron Microscopy (SEM) chamber to observe the operation. This paper presents a control of horizontal axis of nano manipulator via processing SEM image. Edges of AFM tip and CNT are first detected, the position information so obtained is fed to control horizontal axis of nano manipulator. To be specific, visual servoing loop was realized to control the axis more precisely.

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Structural Damage Localization for Visual Inspection Using Unmanned Aerial Vehicle with Building Information Modeling Information (UAV와 BIM 정보를 활용한 시설물 외관 손상의 위치 측정 방법)

  • Lee, Yong-Ju;Park, Man-Woo
    • Journal of KIBIM
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    • v.13 no.4
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    • pp.64-73
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    • 2023
  • This study introduces a method of estimating the 3D coordinates of structural damage from the detection results of visual inspection provided in 2D image coordinates using sensing data of UAV and 3D shape information of BIM. This estimation process takes place in a virtual space and utilizes the BIM model, so it is possible to immediately identify which member of the structure the estimated location corresponds to. Difference from conventional structural damage localization methods that require 3D scanning or additional sensor attachment, it is a method that can be applied locally and rapidly. Measurement accuracy was calculated through the distance difference between the measured position measured by TLS (Terrestrial Laser Scanner) and the estimated position calculated by the method proposed in this study, which can determine the applicability of this study and the direction of future research.

Comparison of Display Visual Effects in Control Task under Limited Reaction Time (반응시간제한시 제어작업의 디스플레이 시각효과 비교)

  • 오영진
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.47
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    • pp.57-68
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    • 1998
  • Work environments have been changed with the advent of new technologies, such as computer technology. However, human cognitive limits can't pace up with the change of work environment. Designing human-computer system requires knowledge and evaluation of the human cognitive processes which control information flow workload. Futhermore, under limited reaction time and/or urgent situation, human operator may the work stress, work error and resultant deleterious work environment. This paper evaluate the visual factors of major information processing factors(information density, amount of information, operational speed of speed)on operator performance of supervisory control under urgent(limited reaction time)environments which require deleterious work condition. To describe the work performance int the urgent work situations with time stress and dynamic event occurrence, a new concept of information density was introduced. For a series of experiments performed for this study, three independent variables(information amount, system proceeding speed, information density) were evaluated using five dependent variables. The result of statistical analyses indicate that the amount of information affected on all of five dependent measure. Number of failure and number of secondary task score were influenced by both amount of information and operational speed of system. However reaction time of secondary task were affected by both amount of information and information density. As a result, the deleterious factors for the performances seemed to be a scanning time to supervise each control panel. Consequently, a new display panel was suggest to reduce operator work load for scanning task showing better operator performance.

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Increase of Visual sensitivity by Zinc, Taurine, and Hypothermic-effect in Bullfrog's Eye (황소개구리 안구에서의 아연, 타우린, 저온효과에 의한 시각 감수성 증진)

  • Kim, Hyun Jung
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.1
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    • pp.23-33
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    • 2007
  • It has been reported high concentrations of zinc and taurine in ocular tissue, especially the retina-choroid, and the presence of physiological levels of zinc and taurine in these tissues seem essential for their normal function. In addition, several studies have reported temperature as another effector to the visual sensitivity. But, in spite of many studies, there are still remained many questions about their function and correlation in visual adaptation system. The purpose of present study was to clarify these points using electroretinogram(ERG) recording and absorption spectra scanning, before and after zinc and taurine treatments and hypothermic-effect in bullfrog(Rana catesbeiana) which is one of the poikilothermal animal. The optimal zinc concentration used in this study was determined $10^{-4}M$ while the optimal taurine concentration was 10-5 M, and temperature change for hypothermic-effect went through '$25^{\circ}C {\rightarrow}0^{\circ}C{\rightarrow}25^{\circ}C$'. In ERG recording, it is obtained that dark-adapted threshold became elevated and b-wave amplitudes was increased with zinc and taurine treatment and hypothermic-effect. In absorption spectra scanning, there is distinct absorbance increment over the whole spectral range(400~750 nm) after zinc and taurine treatment and hypothermic-effect. Furthermore there are some synergism effects between zinc and taurine as well as between zinc and hypothermic-effect as a result of co-treatment, respectively.

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A Framework for Automated Formwork Quality Inspection using Laser Scanning and Augmented Reality

  • Chi, Hung-lin;Kim, Min-Koo;Thedja, Julian
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.13-22
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    • 2020
  • Reinforcement steel fixing is a skilled and manually intensive construction trade. Current practice for the quality assessment of reinforcement steel fixing is normally performed by fabricators and has high potential in having errors due to the tedious nature of the work. In order to overcome the current inspection limitation, this study presents an approach that provides visual assistance and inspection enhancement for inspectors to assess the dimensional layout of reinforcement steel fixing. To this end, this study aims to establish an end-to-end framework for rebar layout quality inspection using laser scanning and Augmented Reality (AR). The proposed framework is composed of three parts: (1) the laser-scanned rebar data processing; (2) the rebar inspection procedure integrating with AR; and (3) the checking and fixing the rebar layout through AR visualization. In order to investigate the feasibility of the proposed framework, a case study assessing the rebar layout of a lab-scaled formwork containing two rebar layers is conducted. The results of the case studies demonstrate that the proposed approach using laser scanning and AR has the potential to produce an intuitive and accurate quality assessment for the rebar layout.

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A REVIEW OF STUDIES ON OPERATOR'S INFORMATION SEARCHING BEHAVIOR FOR HUMAN FACTORS STUDIES IN NPP MCRS

  • Ha, Jun-Su;Seong, Poong-Hyun
    • Nuclear Engineering and Technology
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    • v.41 no.3
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    • pp.247-270
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    • 2009
  • This paper reviews studies on information searching behavior in process control systems and discusses some implications learned from previous studies for use in human factors studies on nuclear power plants (NPPs) main control rooms (MCRs). Information searching behavior in NPPs depends on expectancy, value, salience, and effort. The first quantitative scanning model developed by Senders for instrument panel monitoring considered bandwidth (change rate) of instruments as a determining factor in scanning behavior. Senders' model was subsequently elaborated by other researchers to account for value in addition to bandwidth. There is also another type of model based on the operator's situation awareness (SA) which has been developed for NPP application. In these SA-based models, situation-event relations or rules on system dynamics are considered the most significant factor forming expectancy. From the review of previous studies it is recommended that, for NPP application, (1) a set of symptomatic information sources including both changed and unchanged symptoms should be considered along with bandwidth as determining factors governing information searching (or visual sampling) behavior; (2) both data-driven monitoring and knowledge-driven monitoring should be considered and balanced in a systematic way; (3) sound models describing mechanisms of cognitive activities during information searching tasks should be developed so as to bridge studies on information searching behavior and design improvement in HMI; (4) the attention-situation awareness (A-SA) modeling approach should be recognized as a promising approach to be examined further; and (5) information displays should be expected to have totally different characteristics in advanced control rooms. Hence much attention should be devoted to information searching behavior including human-machine interface (HMI) design and human cognitive processes.