• Journal of Korea Multimedia Society
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• v.14 no.12
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• pp.1517-1527
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• 2011

This paper presents a motion capture based rehabilitation training system for a lower-limb paretic patient. The system evaluates the rehabilitation status of the patient by using the bend posture of the knees and the weight balance of the body. The posture of both legs is captured with a single camera using the planar mirror. The weight distribution is obtained by the Wii Balance Board. Self-occlusion problem in the tracking of the legs is resolved by using k-nearest neighbor based clustering with body symmetry and local-linearity of the posture data. To do this, we present data normalization and its symmetric property in the normalized vector space.

• Journal of Magnetics
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• v.8 no.3
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• pp.103-107
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• 2003

Relaxation of magnon in a very thin ferromagnetic film through spontaneous emission of photon shows an enhancement of the decay rate due to the phase coherence between the magnon and the planar component of wave vector of photon. The coupling between magnon and photon under a strong external magnetic field is considered only at the lowest order one-magnon one-photon process, which we believe the most dominant channel for the radiation from the system. Theoretical understanding related to the geometric confinement is pursued; the phase coherence due to the crystal symmetry in the film plane gives rise to superradiative emission on one hand, but the symmetry breaking along the direction perpendicular to the film renders the possibility of emission itself, providing the increased degrees of freedom for the photon.

• 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.

• The Journal of Natural Sciences
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• v.16 no.1
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• pp.129-141
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• 2005

The equilibrium geometry, adiabatic electron affinity, harmonic vibrational frequencies, and infrared intensities of 1,4,6,9-Tetra chlorinated dibenzo-$\rho$-dioxin anion have been studied using B3LYP method. The local minimum conformation is found to be twisted form with $D_2$ symmetry. The predicted adiabatic electron affinity is 0.54 eV. The predicted inversion barrier between twisted and planar conformers was 0.9 kcal/mol, thus we expect that experimentally observed structure seems to be planar. the characteristic IR band of 1,4,6,9-TCDD anion appears at 1510 $cm^4$, which is a benzene ring skeleton vibration mode related with CaCb and C2C3 bond. this characteristic band could be sued for identication of 1,4,6,9-TCDD anion.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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• pp.121-132
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• 1999

We have compared Korean and American mathematics curriculums in 5 areas: whole number(concepts and its operations); geometry; pattern and relations; measurements; statistics and probability. We have found significant differences in geometry area. Korean curriculums contain simple planar figures (circles, triangles, rectangles, and squres) and some of the spatial figures until 3rd grades. But in America they learn various planar and spatial fugures(cone, pyramid, triangular prism, etc) since the 1st grade starts. They also start the 1st grade by dealing with topological concepts like open/closed, inside/outside, order, etc. As the grade goes on, students learn other geometrical concepts like congruence, symmetry, 3-dimensional views. We also found that American curriculum focuses on students' activities and courages communication through projects, groupwork, journal writing, etc. It's also superior in respects of motivation, and connections with real life and other subjects. Korean curriculum needs more improvements in these aspects. Furthermore for lower graders reviewing sections need to be enhanced for feedback.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1757-1763
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• 2004

A new series of nickel(II), cobalt(II)/(III) and copper(II) complexes of 14, 15 and 16-membered of macrocyclic ligands have been prepared and characterized by elemental analyses, IR, UV-VIS and $^1H-NMR$ spectra, magnetic susceptibilities, conductivities, DTA and ESR measurements. Molar conductances in DMF solution indicate that, the complexes are nonelectrolytes except (9-12) complexes. The electronic spectra show that, all complexes are square planar or distorted octahedral geometry. The ESR spectra of solid complexes (4), (8) and (11) show square planar of axial type symmetry $(d_{x2-y2})$ with considerable covalent bond character. However, complex (12) shows a spectrum of octahedral geometry with $d_{z2}$ ground state. Complex (12) shows exploitation in reducing the amount of electron adducts formed in DNA during irradiation with low radiation products.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.11
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• pp.1353-1362
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• 1999

그래프 드로잉이란 추상적인 그래프를 시각적으로 구성하여 2차원 평면상에 그려주는 작업으로 대칭성은 그래프 드로잉시 고려해야 하는 미적 기준들 중에서 그래프의 구조 및 특성을 표현해주는 가장 중요한 기준이다. 그러나 일반 그래프에서 대칭성을 찾아 그려 주는 문제는 NP-hard로 증명이 되어 있기 때문에 현재까지는 트리, 외부평면 그래프, 직병렬 유향 그래프나 평면 그래프 등으로 대상을 한정시켜 연구가 진행되어 왔다. 본 논문에서는 병렬 컴퓨터나 컴퓨터 네트워크 구조를 가시화 시키기 위하여 많이 사용되는 그래프인 상호연결망(interconnection network)의 대칭성을 분석하고 분석된 대칭성을 최대로 보여주는 대칭 드로잉 알고리즘을 제안하였다. 그리고 이를 기반으로 하여 상호연결망의 기존 드로잉 방법들과 본 논문에서 제안한 대칭 드로잉 등 다양한 드로잉을 지원하는 WWW 기반의 상호연결망 드로잉 시스템을 구현하였다.Abstract Graph drawing is constructing a visually-informative drawing of an abstract graph. Symmetry is one of the most important aesthetic criteria that clearly reveals the structures and the properties of graphs. However, the problem of finding geometric symmetry in general graphs is NP-hard. So the previous work has focused on the subclasses of general graphs such as trees, outerplanar graphs, series-parallel digraphs and planar graphs.In this paper, we analyze the geometric symmetry on the various interconnection networks which have many applications in the design of computer networks, parallel computer architectures and other fields of computer science. Based on these analysis, we develope algorithms for constructing the drawings of interconnection networks which show the maximal symmetries.We also design and implement Interconnection Network Drawing System (INDS) on WWW which supports the various drawings including the conventional drawings and our suggested symmetric drawings.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.6
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• pp.748-754
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• 2010

To reduce the computational cost required for assembling vessel fragments using surface geometry, this paper proposes a fast axis estimation method. Using circular constraint of pottery and local planar patch assumption, it finds the axis of the symmetry. First, the circular constraint on each cylinder is used. A circular symmetric pot can be thought of unions of many cylinders with different radii. It selects one arbitrary point on the pot fragment surface and searches a path where a circumference exists on that point. The variance of curvature will be calculated along the path and the path with the minimum variance will be selected. The symmetric axis will pass through the center of that circle. Second, the planar patch assumption and profile curve is used. The surface of fragment is divided into small patches and each patch is assumed as plane. The surface normal of each patch will intersects the axis in 3D space since each planar patch faces the center of the pot. A histogram method and minimization of the profile curve error are utilized to find the probability distribution of the axis location. Experimental results demonstrate the improvement in speed and robustness of the algorithms.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.257-262
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• 2017

In this paper, we proposed a rectangular planar monopole antenna with a double sleeve that applied to a half-cut and a discontinuous feed structure. A rectangular planar monopole antenna with a double sleeve was cut in half along the magnetic symmetry line, and impedance matching was achieved by a discontinuous structure was applied to a feeder and by adjusting the double sleeve gap. We used the HFSS simulator of ANSYS company to confirm the antenna parameter property, and the antenna size was $21{\times}40mm^2$. In the proposed antenna, the simulation frequency range with VSWR of 2 or less was 2.6GHz to 10.25GHz. The bandwidth was 7.65GHz. The frequency range of the fabricated antenna was 3.3GHz to 9.75GHz, and the bandwidth was 6.45GHz. The measured radiation pattern frequencies were 3.5GHz, 5.5GHz, 7.5GHz, and 9.5GHz. A radiation pattern similar to the dipole antenna pattern was obtained at all frequencies.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.834-839
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• 2004

In this paper, we investigate the optimal base position and joint configuration of a planar wheeled mobile manipulator in terms of manipulability measure. Taking into account the level of coordination between a manipulator and a platform, both local and global optimization problems are considered. First, based on the kinematic models of a mobile manipulator, the manipulability measures are expressed along with the analysis of the configurational dependency. Second, the geometric symmetry of a mobile manipulator in view of manipulability measure is analyzed, and for some base positions, the best and worst joint configurations are determined, Third, with reverence to the maximum, minimum, and average manipulability measures, the optimal base positions are determined, and the percent improvements due to the base relocation are discussed considering the relative scales among the platform size, the wheel radius, and the link length.