• 대한수학회지
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• 제53권6호
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• pp.1347-1370
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• 2016

On a closed eta-Einstein Sasakian spin manifold of dimension $2m+1{\geq}5$, $m{\equiv}0$ mod 2, we prove a new eigenvalue estimate for the Dirac operator. In dimension 5, the estimate is valid without the eta-Einstein condition. Moreover, we show that the limiting case of the estimate is attained if and only if there exists such a pair (${\varphi}_{{\frac{m}{2}}-1}$, ${\varphi}_{\frac{m}{2}}$) of spinor fields (called Sasakian duo, see Definition 2.1) that solves a special system of two differential equations.

• 대한수학회보
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• 제58권6호
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• pp.1539-1561
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• 2021

We prove Perelman type 𝒲-entropy formulae and differential Harnack estimates for positive solutions to weighed doubly nonlinear diffusion equation on weighted Riemannian manifolds with CD(-K, m) condition for some K ≥ 0 and m ≥ n, which are also new for the non-weighted case. As applications, we derive some Harnack inequalities.

• Journal of Preventive Medicine and Public Health
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• 제31권2호
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• pp.293-309
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• 1998

The purpose of this study is to compare the level of health-related quality of life and relating factor between institutional elderly and community living elderly. The subjects were 390 from Sanatorium or Nursing home and 467 from the community in Kwangju. The results are followed : 1) A comparison of ADL between two groups, institutional elderly and community living elderly, resulted in that community elderly were more significantly independent in the areas of bathing and transfer than institutional elderly. 2) A comparison of IADL between two groups resulted in that : Community elderly were more independent in the areas of using telephone and transportation, food preparation, house keeping, and doing laundry. Institutional elderly were more independent in the area of handling finances. 3) In the case of poor health-related quality of life, institutional elderly showed 2.4 times in the dimension of physical fitness, 1.8 times in daily activity, 2 times in social activity, 2 times in pain, 26.7 times in social support, and 0.4 times in subjective quality of life higher than community elderly There was no significant differences in the rest of dimensions. 4) In institutional elderly, the analysis of variables related to the health-related quality of life resulted in that; The relating factors were sex, education, and chronic illness in the dimension of physical function. Direct contact with family or significant others in the dimension of social activity. Chronic illness in the dimension of pain and perceived health status. Direct or indirect contact with family or significant others over the phone or through letters in the dimension of social support. 5) The analysis of variables related to the health-related quality of life showed that community elderly has more relating variables in each area than institutional elderly. The relating factors were age, sex, and chronic illness in the dimension of physical function. Education and chronic illness in the dimension of emotional status. Age and chronic illness in the dimension of daily activity and social activity Education and chronic illness in the dimension of pain and perceived health status. Sex, education, family size in the dimension of social support. Education and chronic illness in the dimension of subjective quality-of-life. Throughout general daily activity, community elderly showed more satisfactory results than institutional elderly, but in the subjective area of health-related quality of life, such as subjective quality of life, institutional elderly group showed more positive results. And community elderly had more relating factors than institutional elderly. For the health care of the elderly that focused on quality of life, new approaches considering the characteristics of both group, institutional and community living elderly, are needed.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.241-244
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• 2004

Dimension and tolerance are very important factors both in a design stage and in a manufacturing stage. As a part of process planning, the tolerance transfer aims at determining the method for converting design dimensions and tolerances into manufacturing dimensions and tolerances based on a given drawing. A procedure for the tolerance transfer is proposed in this paper. Tolerance chart is a valuable graphical tool for a process planner to determine the manufacturing dimensions and tolerances, and consisted of several steps. Among several steps necessary for making up the tolerance chart, the methods for the identification of dimension chain, the determination of tolerances, and the calculation of operational dimensions are presented by using concepts and new presentation methods. A solution method for each step is derived which will be used to establish the tolerance transfer techniques.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.690-695
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• 2004

A new dimension measuring method for the measurement of diameter of an object has been developed using laser triangulation. The 3-D data of an object was calculated from the 2dimensional image information obtained by the laser stripe using the laser triangulation. The system can measure the diameter of hole not only in a normal plane but also in an incline plane. We can experiment with magnification that is optimized according to size of object using zoom lens. In this paper, the theoretical formula and calibration of the system were described. The measuring precision of the system was investigated by experiment.

• 한국수학사학회지
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• 제26권4호
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• pp.245-257
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• 2013

Hermann Grassmann classified mathematics and extended the dimension of vector spaces by using dialectics of contrasts. In this paper, we investigate his mathematical idea and its background, and the process of the classification of mathematics. He made a synthetic concept of mathematics based on his idea of 'equal' and 'inequal', 'discrete' and 'indiscrete' mathematics. Also, he showed a creation of new mathematics and a process of generalization using a dialectic of contrast of 'special' and 'general', 'real' and 'formal'. In addition, we examine his unique development in using 'real' and 'formal' in a process of generalization of basis and dimension of a vector space. This research on Grassmann will give meaningful suggestion to an effective teaching and learning of linear algebra.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2003년도 추계 학술발표회 논문집
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• pp.69-72
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• 2003

The paper considers partial least squares (PLS) as a new dimension reduction technique for the feature vector to overcome the small sample size problem in face recognition. Principal component analysis (PCA), a conventional dimension reduction method, selects the components with maximum variability, irrespective of the class information. So PCA does not necessarily extract features that are important for the discrimination of classes. PLS, on the other hand, constructs the components so that the correlation between the class variable and themselves is maximized. Therefore PLS components are more predictive than PCA components in classification. The experimental results on Manchester and ORL databases show that PLS is to be preferred over PCA when classification is the goal and dimension reduction is needed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.211-214
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• 2002

Under a continuous manufacturing process, two dimension inspection system causes problems as blurring effect and low resolution and requires position calibration between frames. One dimension inspection system is, therefore, being researched as a substitution. In this paper, we implement mechanism of switching memory and processing data for reasonable one dimension inspection system. Redundant weft image and noise was suggested to be reduced by new method using modified morphological process and masked erosion process. From resulting image, line data and possible error information were obtained and constructed as a structure. Finally, error detecting algorithm was performed with this data structure. Processing time of error detecting was 0.625ms per line in applied system and experiment showed 94.7% of error detecting ability. This method is 20% faster in speed and 2.7% higher in error detecting ability comparing with the present method.

• 대한수학회지
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• 제57권4호
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• pp.1005-1018
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• 2020

A characterization of the C-projective vector fields on a Randers space is presented in terms of 𝚵-curvature. It is proved that the 𝚵-curvature is invariant for C-projective vector fields. The dimension of the algebra of the C-projective vector fields on an n-dimensional Randers space is at most n(n + 2). The generalized Funk metrics on the n-dimensional Euclidean unit ball 𝔹ⁿ(1) are shown to be explicit examples of the Randers metrics with a C-projective algebra of maximum dimension n(n+2). Then, it is also proved that an n-dimensional Randers space has a C-projective algebra of maximum dimension n(n + 2) if and only if it is locally Minkowskian or (up to re-scaling) locally isometric to the generalized Funk metric. A new projective invariant is also introduced.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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• pp.117-120
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• 2003

Fractal mathematics is being highlighted as a research method for classification of image. But the application of Fractal dimension(FD) has been required the complicated calculation method because of its complex repetition progressing. In this paper, it has been developed the new approach method to express the Fractal Dimension(FD) for aging level calculation and estimation system of outside insulator using special image processing algorithm. As a result after FD testing, the recognized aging estimation of FD has a very characteristics compared to the conventional visual inspection.