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Functional Mapping of the Human Visual Cortex Using Electrical Cortical Stimulation and Flash Visual Evoked Potentials (전기극 뇌자극과 광시각 유발전위 검사를 통한 인간의 시각 피질에서의 기능적 분화 양상)

  • Lee, Hyang Woon;Hong, Seung Bong;Seo, Dae Won;Tae, Woo Suk;Hong, Seung Chyul
    • Annals of Clinical Neurophysiology
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    • v.1 no.1
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    • pp.10-18
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    • 1999
  • 연구배경 및 목적 : 시각 인지 과정은 영장류 실험을 통하여 다소 정보를 얻을 수 있었으나 인간에서는 아직 완전하게 이해되지 않고 있다. 이 연구의 목적은 뇌자극과 시가유발전위 검사를 토대로 인간의 시각피질의 기능적 분화와 시간 순으로 활성화되는 양상을 보고자 한 것이다. 연구방법 : 간질 수술을 위하여 후두엽과 인접 부위에 광범위하게 피질하전극을 넣은 22명의 환자를 대상으로 전기적 뇌자극과 시각유발전위 검사를 시행하였다. 뇌자극시 나타나는 반응은 형태, 색, 및 움직임의 세 가지로 크게 나누고 형태는 다시 단순, 중간 및 복잡한 형태로 세분하였다. 시각유발전위는 P1 혹은 IV파의 latency를 측정하였다. 결과 : 단순 혹은 중간 형태는 흔히 occipital pole과 striate cortex에서 발생하였다. 색반응은 후두엽의 기저부 즉, fusiform, lingual, inferior occipital gyri를 자극할 때 관찰되었다. 움직임 반응은 내측기저부 및 외측의 측후두엽 혹은 측두정후두부의 경계부에서 주로 나타났다. 결론 : 이러한 결과는 인간의 시각피질이 시각의 여러 가지 구성성분 즉, 형태, 색, 및 움직임에 대해서 각각 별도로 분화되어 있다는 것을 보여준다. 도한 시각자극이 전해지면 striate cortex와 occipital pole이 가장 먼저 활성화되고 이어서 내측 및 외측 후두엽 부위가 활성화된다는 것을 알 수 있다. 이러한 사실을 종합하여 보면 인간의 시각피질은 시각의 여러 구성성분별로 별도로 발달된 해부학적 경로를 통하여 각각의 기능에 대하여 특수하게 분화된 뇌세포에서 시각정보를 각각 분석하되 일정한 시간순서에 의한다는 것을 시사하는 것이다.

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An Analysis of Error Factors for Software Based Pseudolite Time Synchronization Performance Evaluation (소프트웨어 기반 의사위성 시각동기 기법 성능평가를 위한 오차 요소 분석)

  • Lee, Ju Hyun;Lee, Sun Yong;Hwang, Soyoung;Yu, Dong-Hui;Park, Chansik;Lee, Sang Jeong
    • Journal of Advanced Navigation Technology
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    • v.18 no.5
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    • pp.429-436
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    • 2014
  • This paper proposes three methods of the time synchronization for Pseudolite and GPS and analyzes pseudolite time synchronization error factors for software based performance evaluation on proposed time synchronization methods. Proposed three time synchronization methods are pseudolite time synchronization station construction method, method by using UTC(KRIS) clock source and GPS timing receiver based time synchronization method. Also, we analyze pseudolite time synchronization error factors such as errors of pseudolite clock and reference clock, time delay as clock transmission line, measurement error of time interval counter and error as clock synchronization algorithm to design simulation platform for performance evaluation of pseudolite time synchronization.

A Review on Expressive Materials and Approaches to Text Visualization (텍스트 데이터 시각화의 표현 재료와 접근 방식에 관한 고찰)

  • Kim, Hyoyoung;Park, Jin Wan
    • The Journal of the Korea Contents Association
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    • v.13 no.1
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    • pp.64-72
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    • 2013
  • In this study, we contemplated types, essence, characteristics of text data which is material for visual expression of text visualization part of data visualization research and also analysed the multidirectional means of expressive approach for it. Studies of text visualization are spread dramastically under the influence of computer development, open data, wide use of visualization tools, etc. For these reasons, text visualization works have been creating as art works or output of research through various inter-discipline convergent research with engineering, art, humanities, sociology, etc. Nevertheless the theoretical studies on text data itself and its visualization, and also systematic analysis of its approach are rarely made. Data is target of understanding and interpretation, and it has infinite information and possibility with process and approach for it. Considering the attainable status of data in future human society, text visualization which is convergent academic field of study starting with understanding and interpretation of data needs further methodological research and theoretical accumulate.

Two Perspectives in Developing a Visualization Environment (시각화 환경의 개발에 대한 두 관점)

  • 고상숙
    • Journal of Educational Research in Mathematics
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    • v.8 no.2
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    • pp.745-752
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    • 1998
  • 컴퓨터의 급속한 보급으로 시각화는 수학 교육자사이의 논의에 자주 등장하는 소재가 되었다. 우리는 다양한 소프트웨어를 사용하여 준비한 수업에 학생들로 임하게는 하지만 거의 그들의 사고 발달과정에는 관심을 갖지 못하고 있다. 이 논문은 구성주의(Constructivism)와 정보처리체계(Information-Processing System)에 입각하여 수학의 시각화를 생각해보고 어떻게 시각화 환경을 준비해야하는지 논해보고자 하였다. 구성주의의 시각화에서는 반영적 추상(reflective abstraction), 반복되는 경험(repeated experience), 그리고 지식 위계성이 학습의 기능 체계를 이루므로 발견적 학습을 통해 학생 스스로 의미를 구성할 수 있도록 Thomas (1992)의 세 가지 제안을 이용하여 수업을 준비할 수 있다. 정보처리체계에서는 지식은 서술적인 것과 과정적인 것으로 나뉘어지고, 시각적 표상을 수록하고 삭제하는 과정과 조작 가능한(manipulative) 환경과의 상호작용으로 기호적 시각으로 표상을 변화하는 과정을 통해 개념을 습득하게된다. 시각화는 스키마와 개념상을 통해서 일어난다. 그래프, 애니메이션, 그리고 다른 시각적 표상 등은 이 개념상에 직접적 효과를 주므로 매우 중요하다. 이런 논란을 바탕으로 교사는 반영적 추상화를 위해 시간을 충분히 제공해야하고, 비슷한 문제를 가지고 여러번 시도를 할 수 있게 하며, 학생을 잘 관찰하여 그들의 지식 위계성을 이해하고 방향을 제시하며, 논리적이고 잘 연결된 시각적 표상을 제공하고, 상징적 사관으로 확장할 수 있게 조작할 수 있는 환경에서 시각화에 대해 학생과 많은 대화를 하도록 수업을 준비해야한다. 그한 예로 타원을 가르치기 위해 몇 가지 테크놀로지를 활용한 시각화 환경을 구성해보았다.ates of bisected bovine embryos by micromanipulator and micropipett were 29.2% and 19.1%, respectively. The rates of non-bisection embryos(46.7%) were significantly higher than those of bisection embryos. 2. The in vitro developmental rates of bisected bovine embryos by micromanipulator, micropipett and pipetting method were 32.4%, 19.4% and 25.6%, respectively.3. The in vitro developmental rates of with and without-zona pellucida of bisected bovine embryos by raicromanipulator were 30.8% and 25.0%, respectively. The rates of nonbisection embryos(53.1%) were significantly higher than those of bisection embryos.랑크톤 군집내 종 천이와 일차생산력에 크게 영향을 미칠 수 있음을 시사한다.TEX>5.2개)였으며, 등급별 회수율은 각각 GI(8.5%), GII(13.4%), GIII(43.9%), GIV(34.2%)로 나타났다.ments of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the letter design. Asite- is also considered to

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Current Research Trends and Present Conditions on Visual Transformation of Digital Text (디지털텍스트의 시각적 변형에 관한 연구 동향 및 실태 분석)

  • Jin, Sung-Hee
    • The Journal of the Korea Contents Association
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    • v.10 no.1
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    • pp.486-497
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    • 2010
  • The purpose of this study is to investigate the research trends and the present conditions of real digital texts on "Visual Transformation." For the purpose of this study adopted two different methods: meta analysis and case study. The research trends on visual transformation of digital text were investigated through analyzing the total of 167 literature by means of synthetic meta analysis. Relevant literature was categorized into three types of research: functional, dynamic, and interactional transformation. The type of literature and research methods in each literature were analyzed. The present conditions of real digital texts on visual transformation were investigated by means of case study. The well designed 12 e-learning contents selected and analyzed in terms of the analysis framework which was drawn by the research trends. The results suggested problems as follows in designing e-learning contents. Firstly, there were some cases that did not follow the basic design principles related to typography. Secondly, the content was just provided in each learning steps without consideration of design to enhance text comprehension in many cases. Thirdly, web technology adequately was not applied to design e-learning contents.

Comparison of Time Offsets by Tropospheric Zenith Path delay models and Mapping Functions in GPS Time Transfer (GPS 시각 전송에서의 대류층 천정지연 모델과 매핑 함수에 따른 시각오프셋 비교)

  • Yu, Dong-Hui
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.6
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    • pp.1317-1322
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    • 2014
  • This paper shows effects of tropospheric delay models and mapping functions among delay features occurred when GPS code signal is transferred for GPS Time Transfer. GPS time transfer uses CGGTTS as the international standard format. For geodetic GPS receiver, ROB has provided r2cggtts software which generates CGGTTS data from RINEX data and all laboratories participated in TAI link use this software and send the CGGTTS results periodically. Though Saastamoinen zenith path model and Niell mapping function are commonly used in space geodesy, r2cggtts software applied NATO zenith path model and CHAO mapping function to the tropospheric delay model. Hence, this paper shows effects of two tropospheric delay models by implementing Saastamoinen model and Niell mapping function for the time offset.

A study on the development of job competency standards majoring in visual design -Focused on S University in Jiangsu Province, China - (시각디자인을 전공한 직업능력표준 개발에 관한 연구 -중국 장쑤성 S 대학을 중심으로-)

  • Zeng, Ying;Kim, Young-Sam
    • Journal of Digital Convergence
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    • v.20 no.4
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    • pp.321-331
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    • 2022
  • In order for visual design graduates to meet corporate requirements, it is necessary to develop a complete ncs system in the field of visual design like developed countries. The purpose of this study is to analyze students' self-evaluation, corporate job needs, and school education methods, and to develop vocational competency standards in China's visual design by referring to the national vocational competency standards in Korean visual design. The research method is to analyze the education system of the Department of Visual Design at a university in Jiangsu Province, China, survey graduates of the Department of Visual Design, and develop national vocational standards in China by referring to job requirements of Chinese visual design companies. Analyzing this, the research results suggested a development plan for the national vocational competency standard in the field of visual design in China.

Deep Learning based Time Offset Estimation in GPS Time Transfer Measurement Data (GPS 시각전송 측정데이터에 대한 딥러닝 모델 기반 시각오프셋 예측)

  • Yu, Dong-Hui;Kim, Min-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.3
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    • pp.456-462
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    • 2022
  • In this paper, we introduce a method of predicting time offset by applying LSTM, a deep learning model, to a precision time comparison technique based on measurement data extracted from code signals transmitted from GPS satellites to determine Universal Coordinated Time (UTC). First, we introduce a process of extracting time information from code signals received from a GPS satellite on a daily basis and constructing a daily time offset into one time series data. To apply the deep learning model to the constructed time offset time series data, LSTM, one of the recurrent neural networks, was applied to predict the time offset of a GPS satellite. Through this study, the possibility of time offset prediction by applying deep learning in the field of GNSS precise time transfer was confirmed.

Analysis of Visual Distortion and Suggestion of Design Criteria at Curve Sections (곡선부 시각왜곡현상 분석 및 설계기법 제시)

  • Ha, Tae-Jun;Jeong, Jun-Hwa;Lee, Jeong-Hwan;Lee, Suk-Ki
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.6D
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    • pp.663-673
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    • 2009
  • Driver's perceived curve radius is different from actual curve radius at curve sections. This is called visual distortion. It has effect on operation speed according to driver's perception and finally bad effect on safety at curve sections. At present, however, there is no research on quantitatively analysis of visual distortion and no criteria for curve section design considering the visual distortion. Therefore, this study focus on finding degree of visual distortion and suggesting design criteria by visual distortion analysis. The process of this study is as below; First, a calculaiton model of perceived curve radius was developed by survey using computer simulation. In this model, a dependent variable is perceived curve radius and an independent variable is geometric factors. Second, degree of visual distortion was calculated from ratio of perceived curve radius to actual curve radius. Finally, design criteria were suggested through influencing factor analysis of visual distortion at curve sections.

The Types, Roles and Socio-semiotic Features of Visual Materials in Elementary Science Textbooks (초등 과학 교과서에 실린 시각 자료의 종류, 역할 그리고 사회-기호학적 특징 분석)

  • Kim, Hyoungjin;Shin, Myeong-Kyeong;Lee, Gyuho;Kwon, Gyeong-Pil
    • Journal of Science Education
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    • v.38 no.3
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    • pp.641-656
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    • 2014
  • This study aimed at analyzing visual materials included in school science textbooks, specifically the textbooks for first semester courses of 3rd to 6th graders. The purpose was to provide directions for future textbooks by understanding the functions of the images in both pedagogical and social perspectives as well. The study was conducted by investigating the types, roles and socio-semiotic features of the images in science textbooks. The results were as follows. Firstly, the most used types of images in 2007 curriculum textbooks were photographs and drawn pictures. Uses of other visual aids than above were extremely rare. It was also found that as the educational level rises, the use of images for decorative functions drastically declined. The majority of the images were used in providing supplementary explanations or examples. This implies that the images effectively play the role of helping science education. In addition, more use of worksheets images was found, indicating that as educational level increases, students participate more actively in research sessions or data analysis. In socio-semiotic perspective, visual images showed high accessibility to students in 'Type of visual image', 'Function of visual image', 'Distance of shot', 'Horizontal angle of shot', 'Color moduation'. It was implied that there will a close correlation between the type, role and the socio-semiotic characteristics of visual images in textbooks. For example, photograph-type visuals were mostly used as supplementary references. And when applying the socio-semiotic analysis to photograph-type visuals, they showed 'real type', 'narrative-metaphor type', and 'shadow effect' among socio-semiotic features. Such correlations implied that knowing the type of the visual image may help determining the role of the image in the textbook to some extent, and also corresponding socio-semiotic characteristics. As a result, it was possible to infer how accessible certain visual images are to students. The above results have implications for the effective use of visual images in future textbooks.

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