• Title/Summary/Keyword: and symmetry

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A Study on Phosphor Synthetic and Low Temperature Photoluminescence Spectrum (저온 photoluminescence 스펙트럼 및 형광체 합성에 관한 연구)

  • Kim, Soo-Yong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.4
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    • pp.10-16
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    • 2010
  • In this paper, synthesis here Mn add to Ar injection the state and a vacuum an atomosphere $ZnGa_2O_4$ : Mn, ZnO and $Ga_2O_3$ power of 1 : 1 mole ratio mixture. Manufacture a close examination of oxygen a component variation luminescence a specific character reach an in fluence of $ZnGa_2O_4$ : Mn, luminescence spectrum observation also an explanation of Mn site symmetry and at luminescence spectrum reach an influence from low temperature photoluminescence spectrum.

A Model and an Index for the Balance of Researches in Science Education (과학교육 연구의 균현성을 위한 모형과 지수)

  • Song, Jin-Woong
    • Journal of The Korean Association For Science Education
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    • v.15 no.1
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    • pp.1-5
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    • 1995
  • One of the problem of science education in terms of its status as a unique discipline is the tendency of qualitative, rather than quantitative, arguments and judgements on research activities. In this study, a model called "Diamond Model" and an index formula for the balance of researches are suggested for achieving more pictoricaI and quantitative understandings on the distribution of researches in science education. Diamond Model is consisted of two dimensions corresponding to two main long-debated issues in science education, i.e. the dimension of cognitive-affective and the dimension of concept-process. In Diamond Model the geometrical symmetry represents the the balance of researches. An index formula for the balance was developed in order to ensure that the value of the index is between 0 to 1 and the numerical values of the index corresponds to the geometrical symmetry of the diamond. Then, in order to check their utility, the model and the index formula were applied to analyze the research papers appeared in JKARSE for the last 10 years.

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Detection of spatia-temporal gait parameter for hemiplegic patients based on an accelerometer and footswitches (Preliminary study) (체중심 가속도와 풋스위치를 이용한 편마비 환자의 시공간 보행인자 검출)

  • Lee, Hyo-Ki;Lee, Kyoung-Joung;Kim, Young-Ho;Park, Si-Woon
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.542-544
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    • 2005
  • This paper describes the detection of spatio-temporal parameter using an accelerometer and footswitches to evaluate a symmetry and balance of hemiplegic patients. We detected gait data using a 3-axis accelerometer that mounted between L3 and IA intervertebral area and footswitches made by FSR-Sensor attached insole. To minimize the error of the gait parameters to be detected incorrectly in case of using only accelerometer, we enhancement the performance of detection by measuring an accelerometer and foots witches data at the same time. So, it was possible to detect more accurate gait parameters. As a result, we can confirm the symmetry and balance of hemiplegic patients. In the future. these results could be used to evaluate the walking ability in hemiplegic patients in clinical pratice.

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Design of a face recognition system for person identificatin using a CCTV camera (폐쇄회로 카메라를 이용한 신분 확인용 실물 얼굴인식시스템의 설계)

  • 이전우;성효경;김성완;최흥문
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.35C no.5
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    • pp.50-58
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    • 1998
  • We propose an efficient face recognition system for controllinng the access to the restricted zone using both the face region detectors based on facial symmetry and the extended self-organizing maps (ESOM) which have sensory synapses and descriptive synapses. Based on the visual cues of the facial symmetry, we apply horizontal and vertical projections on elliptic regions detected by GHT(generalized hough transform) to identify all the face regions from the complex background.And we propose an ESOM which can exploit principal components and imitate an elastic similarity matching, to authenticate faces of the enlisted member. In order to cope with changes of facial experession or glasses wearing, etc, the facial descriptions of each member at the time of authentication are simultaneously updated on the discriptive synapses online using the incremental learning of the proposed ESOM. Experimental results prove the feasibility of our approach.

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Natural Vibration Analysis of Thick Rings (두꺼운 링의 고유진동 해석)

  • Kim Chang-Boo;Park Jung-Woo
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.459-466
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    • 2005
  • In this paper, we have systematically formulated the equations concerned to the in-plane and out-of-plane motions and deformations of a thick circular beam by using the kinetic and strain energies in order to analyse natural frequencies of a thick ring. The effects of variation of radius of curvature across the cross-section and also the effects of bending shear, extension and twist are considered. The equations of motion for natural vibration analysis of a ring are obtained utilizing the cyclic symmetry of vibration modes of the ring. The frequencies calculated using thick ring model and thin ring model are compared and discussed with the ones obtained from finite element analysis using the method of cyclic symmetry with 20-node hexahedral solid elements for rings with the different ratio of radial thickness to mean radius.

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EVOLUTIONARY MODELS OF ROTATING DENSE STELLAR SYSTEMS WITH EMBEDDED BLACK HOLES

  • FIESTAS, JOSE A.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.345-347
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    • 2015
  • We present evolutionary models of rotating self-gravitating systems (e.g. globular clusters, galaxy cores). These models are characterized by the presence of an initial axi-symmetry due to rotation. Central black hole seeds are included in our models, and black hole growth due to the consumption of stellar matter is simulated until the central potential dominates the kinematics of the core. Our goal is to study the long-term evolution (Gyr) of relaxed dense stellar systems which deviate from spherical symmetry, and their morphology and final kinematics. With this purpose in mind, we developed a 2D Fokker-Planck analytical code, and confirmed its results using detailed N-Body simulations, applying a high performance code developed for GPU machines. We conclude that the initial rotation significantly modifies the shape and lifetime of these systems, and cannot be neglected in the study of the evolution of globular clusters, and the galaxy itself. Our models give a constraint for the final intermediate black hole masses expected to be present in globular clusters.

Analysis of Coordination Ambiguity in Korean (한국어 병렬문의 중의성 분석)

  • 이호동;박종철
    • Language and Information
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    • v.7 no.2
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    • pp.59-79
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    • 2003
  • Coordination in natural language is often syntactically explained by the rule schema X \longrightarrow X′ and X", where X′ and X" refer to expressions of a like syntactic type. While this schema does explain a lot of instances of coordination, it is well known that this schema also gives rise to serious structural ambiguity, leading not only to numerous unintended interpretations but also to a high degree of unnecessary computational complexity. In order to identify intended interpretations, we need to take into account a number of clues at all the levels of morphology, syntax, semantics, and pragmatics/discourse. In this paper, we propose, with an accompanying data analysis, principles of symmetry and coherency for an effective and reasonable identification of intended interpretations from coordination-bearing sentences.

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Synthesis and Characterization of Dichloro and Dibromo(2-(dimethylaminomethyl)thiophene) Copper(II) Complexes

  • Kim, Young-Inn;Choi, Sung-Nak;Ro, Chul-Un
    • Bulletin of the Korean Chemical Society
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    • v.15 no.7
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    • pp.549-553
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    • 1994
  • The 2-(dimethylaminomethyl)thiophene (dmamt) complexes with copper(II) chloride and bromide were prepared and characterized by optical, EPR, XPS spectroscopies and magnetic susceptibility measurements. The low-energy absorption band above 850 nm and the relatively small EPR hyperfine coupling constant ($A_{//}{\simeq}$125 G) indicate the pseudotetrahedral site symmetry around copper(II) ion both in Cu(dmamt)$Cl_2$ and Cu(dmamt)$Br_2$ complexes. The higher satellite to main peak intensity of Cu $2P_{3/2}$ core electron binding energy in XPS spectra also supports the pseudotetrahedral geometry around the copper(II) ions having $CuNSX_2$ chromophores. The distortion from square-planar to pseudotetrahedral symmetry is likely to arise from the steric hindrance of the bulky dmamt ligand in the complex. Magnetic susceptibility study shows that these compounds follow Curie-Weiss law in the temperature range of 77-300 K with positive Weiss constant exhibiting the ferromagnetic interaction between copper(II) ions in solid state.

Real Time On-Road Vehicle Detection with Low-Level Visual Features and Boosted Cascade of Haar-Like Features (미약한 시각 특징과 Haar 유사 특징들의 강화 연결에 의한 도로 상의 실 시간 차량 검출)

  • Adhikari, Shyam Prasad;Yoo, Hyeon-Joong;Kim, Hyong-Suk
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.1
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    • pp.17-21
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    • 2011
  • This paper presents a real- time detection of on-road succeeding vehicles based on low level edge features and a boosted cascade of Haar-like features. At first, the candidate vehicle location in an image is found by low level horizontal edge and symmetry characteristic of vehicle. Then a boosted cascade of the Haar-like features is applied to the initial hypothesized vehicle location to extract the refined vehicle location. The initial hypothesis generation using simple edge features speeds up the whole detection process and the application of a trained cascade on the hypothesized location increases the accuracy of the detection process. Experimental results on real world road scenario with processing speed of up to 27 frames per second for $720{\times}480$ pixel images are presented.

Dynamics of a Micro Three-axis Ring Gyroscope Considering Electrode Effects (전극 효과를 고려한 마이크로 3축 링 자이로스코프의 동역학)

  • 김창부;강태민
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.1
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    • pp.64-72
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    • 2004
  • In this paper. we analyse and present electro-mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The motions of the ring are electro-statically derived. sensed and balanced by electrodes. The equations of motion are formulated. The measuring method of angular velocities by force-to-rebalance is presented. The dynamic characteristics of a ring gyroscope are calculated and compared.