• Title/Summary/Keyword: 측면거울

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괴델의 불완전성 정리:증명된 신화(神話)?

  • Hong, Seong-Gi
    • Korean Journal of Logic
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    • v.5 no.2
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    • pp.39-66
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    • 2002
  • 일반적으로 엄밀한 방법을 통하여 증명되었다고 말해지는 괴델의 불완전성 정리는 일련의 전제와 배경지식이 요구된다고 하겠다. 이들 중에서 무엇보다도 중요한 것은 정리의 증명에 사용되는 메타언어상의 수학적 참에 대한 개념이다. 일단 확인할 수 있는 것은 "증명도, 반증도 되지 않지만 참인 산수문장의 존재"라는 불완전성 정리의 내용에서 괴델이 가정하고 있는 수학적 참의 개념이 구문론적인 증명개념으로부터 완전히 독립되어야 한다는 점이다. 문제는 그가 가정하고 있는 수학적 참의 개념이 도대체 무엇이어야만 하겠는가라는 점이다. 이 논문은 이 질문과 관련하여 내용적으로 3부분으로 나누어 질 수 있다. I. 괴델의 정리의 증명에 필요한 전제들 및 표의 도움을 얻어 자세히 제시되는 증명과정의 개략도를 통해 문제의 지형도를 조감하였다. II, III. 비트겐슈타인의 괴델비판을 중심으로, "일련의 글자꼴이 산수문장이다"라는 주장의 의미에 대한 상식적 비판 및 해석에 바탕을 둔 모형이론에 대한 대안제시를 통하여 괴델의 정리를 증명하기 위해 필요한 산수적 참에 관한 전제가 결코 "확보된 것이 아니다"라는 점을 밝혔다. IV. 괴델의 정리에 대한 앞의 비판이 초수학적 전제에 대한 것이라면, 3번째 부분에서는 공리체계에서 생성 가능한 표현의 증명여부와 관련된 쌍조건문이 그 도입에 필수적인 괴델화가 갖는 임의성으로 인해 양쪽의 문장의 참, 거짓 여부가 서로 독립적으로 판단 가능하여야만 한다는 점에(외재적 관계!) 착안하여 궁극적으로 자기 자신의 증명여부를 판단하게 되는 한계상황에 도달할 경우(대각화와 관련된 표 참조) 그 독립성이 상실됨으로 인해 사실상 기능이 정지되어야만 한다는 점, 그럼에도 불구하고 이 한계상황을 간파할 경우(내재적 관계로 바뀜!)항상 순환논법을 피할 수 없다는 점을 밝혔다. 비유적으로 거울이 모든 것을 비출 수 있어도 자기 스스로를 비출 수 없다는 점과 같으며, 공리체계 내 표현의 증명여부를 그 체계내의 표현으로 판별하는 괴델의 거울 역시 스스로를 비출 수는 없다는 점을 밝혔다. 따라서 괴델문장이 산수문장에 속한다는 믿음은, 그 문장의 증명, 반증 여부도 아니고 또 그 문장의 사용에서 오는 것도 아니고, 플라톤적 수의 세계에 대한 그 어떤 직관에서 나오는 것도 아니다. 사실상 구문론적 측면을 제외하고는 그 어떤 것으로부터도 괴델문장이 산수문장이라는 근거는 없다. 그럼에도 불구하고 괴델문장을 산수문장으로 볼 경우(괴델의 정리의 증명과정이라는 마술을 통해!), 그것은 확보된 구성요소로부터 조합된 문장이 아니라 전체가 서로 분리불가능한 하나의 그림이라고 보아야한다. 이것은 비트겐슈타인이 공리를 그림이라고 본 것과 완전히 일치하는 맥락이다. 바론 그런 점에서 괴델문장은 새로운 공리로 도입된 것과 사실은 다름이 없다.

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Education-neurological Understanding of Digital Learning Materials and Implications for Education (디지털 학습자료에 대한 교육신경학적 이해와 교육적 시사점)

  • Cho, Joo-Yun;Kim, Mi-Hyun
    • Journal of The Korean Association of Information Education
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    • v.24 no.6
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    • pp.539-550
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    • 2020
  • This study establishes the scientific basis for the use of digital learning materials through the education-neurological research method and derives implications for education based on education-neurological understandings. The main findings of the education-neurological analysis of digital learning materials are as follows: First, various sensory stimuli go through multiple sensory neurons and deep sections of the upper sphere and make possible the cooperative processing of information. Second, indirect experience from digital learning materials helps students understand the learning contents vividly through the mirror neuron system. Third, positive emotions originating from digital learning materials promote functions of dopamine, the reticular activating system, frontal-striatal circuit, cerebrum cortex. Based on the findings, the study suggests the following educational implications. First of all, when selecting digital learning materials, teachers should consider expression forms, learning contents, the flow of classes, and the adverse effects of digital learning materials. Next, it is effective to utilize digital learning materials in the lecture for provoking curiosity and enjoyment, maintaining interest and effort, and reviewing what students learned.

Design of Interactive Teleprompter (인터렉티브 텔레프롬프터의 설계)

  • Park, Yuni;Park, Taejung
    • The Journal of the Korea Contents Association
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    • v.16 no.3
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    • pp.43-51
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    • 2016
  • This paper presents the concept of "interactive teleprompter", which provides the user with interaction with oneself or other users for live television broadcasts or smart mirrors. In such interactive applications, eye contacts between the user and the regenerated image or between the user and other persons are important in handling psychological processes or non-verbal communications. Unfortunately, it is not straightforward to address the eye contact issues with conventional combination of normal display and video camera. To address this problem, we propose an "interactive" teleprompter enhanced from conventional teleprompter devices. Our interactive teleprompter can recognize the user's gestures by applying infra-red (IR) depth sensor. This paper also presents test results for a beam splitter which plays a critical role for teleprompter and is designed to handle both visual light for RGB camera and IR for Depth sensor effectively.

Mobile Fashion Fitting Service System using I-phone (아이폰을 이용한 모바일 패션 피팅 서비스 시스템)

  • Tak, Myung-Ja;Kim, Cheeyong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.355-356
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    • 2012
  • Recently, Digital clothing techniques using computer graphics to reappear clothes are activated in fashion area and Researches incorporating fashion flows and 3D techniques are frequently progressed. In fashion industry, Using smartphone can make successful result by catching a change of trend and adding an emotional factor. Conventional 3D fitting services are only provided in store or internet sites installed avatar system, virtual mirror. This study suggests a fashion fitting service system saving time and oneself by using I-phone in consumers' position. In this system, Companies can market their product easily to consumers, consumers can choose various product and check their fitness.

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충북지역 초등수학 영재교육의 분석과 전망

  • Kim, Su-Hwan
    • Communications of Mathematical Education
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    • v.9
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    • pp.227-239
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    • 1999
  • 영재교육의 이론적 근거를 제시한 연구물이 국내에는 그다지 많지 않다. 뿐만 아니라 지금 한국과학재단에서 지원하고 있는 전국의 9개 대학 과학영재교육센터 역시 실천적인 차원의 활동을 벗어나지 못하고 있다. 외국의 대학부설 연구소들이 30년 이상 이와 같은 연구와 서비스를 지속적으로 실천해오고 있는 사례들을 우리는 쉽게 찾을 수 있다는 점을 거울 삼아 모처럼 마련된 국가적 차원의 지원을 토대로 그 바람직한 실천과 연구를 위한 방안을 다음과 같이 제시해본다. 첫째, 질적 연구의 집적에 힘써야 한다. 영재교육이라는 특수한 상황을 전제로 할 때는 더구나 그렇듯이 일반화를 전제로 한 양적 연구보다는, 사례연구와 같은 질적 연구물들의 집적에 노력을 아끼지 말아야할 것이다. 둘째, 교수-학습 활동은 활동이론과 구성주의 이론의 적절한 조화가 요망된다. 구성주의 이론에 입각한 교수-학습 활동의 모습을 단적으로 말하자면, 학습자 자신이 주어진 문제 상황에서의 탐구를 통하여, ‘구체적인 것에서 추상적인 것으로’ 나아가 스스로 지식을 구성하는 것이다. 그러나, 활동이론에 입각한 교수-학습 활동의 요지는 활동은 정말로 전형적인 활동에 국한하고 나머지는 교사의 설명에 의해 학습자들이 ‘추상적인 것에서 구체적인 것으로의 소급’이 가능하도록 하는 것이다. 완전히 정반대의 주장을 하는 것 같으면서도 일면 그 타당성들을 갖고 있는 것으로 볼 수 있다. 셋째, 학제적 ${\cdot}$ 통합적 연구가 절실하다. 연구의 측면에서 수학반 아동과 과학반 아동들의 활동상의 차이점이나 유사점 등에 대한 질적 연구를 시도해보는 것은 매우 의미있는 일이 될 것이다.

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Oscillation Mode and Grating Phase in DFB Laser Diode with an Anti-reflection Coated Mirror (무반사 코팅된 DFB 레이저 다이오드에서 발진 모드와 격자 위상)

  • Kwon, Keeyoung;Ki, Janggeun
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.5
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    • pp.483-488
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    • 2022
  • In this paper, when a gain grating and a refractive index grating exist simultaneously in a DFB laser diode having a wavelength of 1.55 ㎛, an anti-reflection coating is applied to the right mirror surface so that ρr=0. In case of δL<0, the characteristics of the oscillation frequency and oscillation gain have been analyzed. Whenever the phase of the grating on the left side of the mirror continuously decreases by π/2, the δL value of each oscillation mode decreases by about 0.6 to the left of the graph lines of each oscillation mode. The case of the oscillation mode having the lowest threshold gain is the case of κL=10, and in this case, the mode selectivity is relatively low compared to the case of other values of κL. From κL=0.1 to κL=6, the mode selectivity and the frequency stability are excellent. As the mode selectivity is excellent, the frequency stability is excellent. Compared to the case with two cleaved mirrors, the DFB laser diode with anti-reflection coating increases the threshold gain of the oscillation mode by about 2 times, but the mode selectivity becomes about 2 times better.

Study on the Influence of Wheel Arches, Wheels, and Side Mirrors on Aerodynamic Performance of a Fast Cruising Passenger Car (고속 주행 시 Wheel Arch, Wheel & Side Mirror가 자동차의 공력성능에 미치는 영향에 관한 연구)

  • Song, Ki-Sun;Kang, Seung-On;Park, Hoon-Il;Kee, Jung-Do;Kim, Kyu-Hong;Lee, Dong-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.5
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    • pp.26-35
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    • 2012
  • This paper investigates the influence on the aerodynamic performance of a passenger cruising very fast by some specific car body parts such as side mirrors, wheel arches and wheels designed hardly regarding aerodynamics. The magnitude of the contribution of each part is analyzed via on the CFD simulations. YF SONATA, a sedan of Hyundai Motors Company, plays a major role as the baseline car in this research, representing all passenger car. The CFD analysis condition consists of 6 different cases depending on whether each part exists or not. According to the CFD results, there were confirmed that additionally to the body parts' own drag, the car body went through somewhat the consequential increment of the drag by them. Among the 3 parts, wheel is the magnate that not only has the maximal drag but drives the drag of the passenger car to increase most steeply and the next is the side mirror.

A Study on the Hypercentric Lens Design and Optical Performance Analysis (하이퍼센트릭 렌즈 설계 방법 및 성능 분석에 대한 연구)

  • Koh, Jae Seok;Cho, Hyun Woo;Park, Tae Yang;Kim, Sang Hyun;An, Young Duk;Jung, Mee Suk
    • Korean Journal of Optics and Photonics
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    • v.29 no.1
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    • pp.7-12
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    • 2018
  • In the field of machine vision, a variety of lenses are used to inspect a product for defects. Only part of the appearance of an object can be photographed with a general lens. Optical components such as mirrors, multiple lenses and cameras are required to inspect the entire exterior. This increases the size of the optical system, and has the disadvantage of high cost. In this paper, we design a hypercentric lens, which can photograph the top and side of an object, and various sizes of objects while maintaining the image size. Also, the validity of the design is verified through the performance analysis of the product.

The vertical changes of the lip and perioral soft tissue resulting from incisor retraction (전치의 후방견인에 따른 입술과 주위 연조직의 수직적 변화)

  • Kang, Chang-Soo;Kim, Kyung-Ho;Choy, Kwang-Chul
    • The korean journal of orthodontics
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    • v.30 no.2 s.79
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    • pp.185-196
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    • 2000
  • Patients who want to reduce their lip protrusion usually estimate the severity of the lip protrusion on the frontal aspect. Most orthodontists have a perplexed experience of a reduced thin line of vermilion border on the frontal aspect as incisors we retracted, even though the lip protrusion is thought to be reduced favorably on the sagittal aspect. Some patients also look older after orthodontic treatment because of severe lip thinning. This unaesthetic reduction of vermilion border urges us to study the vertical lip change during orthodontic procedure. The purpose of this study was to evaluate the vertical lip and perioral soft tissue changes in respect to incisor retraction in an effort to analyze which factors might be responsible for their vertical changes, using the multiple regression analysis. The results were as follows. 1. Upper and lower lip philtrum length(SnLs, LiB') were increased after retraction of anterior teeth, where as upper and lower vermilion height(LsSuls, StmiLi), and vermilion length(LsLi) were decreased. 2. Upper and lower lip length(SnStms, StmiB'), and soft tissue lower anterior facial height(SnMe') did not show any significant difference after treatment. 3. The increase of the upper lip philtrum length was mainly influenced by the extrusion of upper anterior teeth(${\Delta}U1V$), and the increase of the lower lip philtrum length was mainly influenced by the initial overjet before treatment. 4. The decrease of the upper and lower lip vermilion height was mainly influenced by the decrease of upper lip thickness.

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Autopoiesis, Affordance, and Mimesis: Layout for Explication of Complexity of Cognitive Interaction between Environment and Human (오토포이에시스, 어포던스, 미메시스: 환경과 인간의 인지적 상호작용의 복잡성 해명을 위한 밑그림)

  • Shim, Kwang Hyun
    • Korean Journal of Cognitive Science
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    • v.25 no.4
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    • pp.343-384
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    • 2014
  • In order to unravel the problems of the mind, today's cognitive science has expanded its perspective from the narrow framework of the past computer model or neuronal network model to the wider frameworks of interaction with the brain in interaction with the body in interaction with their environments. The theories of 'the extended mind', 'embodied mind', or 'enactive mind' appeared through such processes are working on a way to move into the environments while the problem to unravel the complex process of interactions between the mind, the body and the environments are left alone. This problem can be traced back as far as to Gibson and Maturana & Varela who tried at first to unravel the problem of the mind in terms of interaction between the brain, the body and there environments in 1960~70s. It's because Gibson stressed the importance of the 'affordance' provided by the environment while Maturana & Varela emphasized the 'autonomy' of auto-poiesis of life. However, it will be proper to say that there are invariants in the affordances provided by the environment as well as the autonomy of life in the state of structural coupling of the environment's variants and life's openness toward the environment. In this case, the confrontational points between Gibson and Maturana & Varela will be resolved. In this article, I propose Benjamin's theory of mimesis as a mediator of both theories. Because Benjamin's concept of mimesis has the process of making a constellation of the embodiment of the affordance and the enaction of new affordance into the environment at the same time, Gibson's concept of the affordance and Maturana & Varela's concept of embodiment and enaction will be so smoothly interconnected to circulate through the medium of Benjamin's concept of mimesis.