• Bulletin of the Korean Mathematical Society
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• v.53 no.3
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• pp.875-884
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• 2016

Let x : $^{Mn-1}{\rightarrow}{\mathbb{R}}^n$ ($n{\geq}4$) be an umbilical free hyper-surface with non-zero principal curvatures. Then x is associated with a Laguerre metric g, a Laguerre tensor L, a Laguerre form C, and a Laguerre second fundamental form B, which are invariants of x under Laguerre transformation group. We denote the Laguerre scalar curvature by R and the trace-free Laguerre tensor by ${\tilde{L}}:=L-{\frac{1}{n-1}}tr(L)g$. In this paper, we prove a local classification result under the assumption of parallel Laguerre form and an inequality of the type $${\parallel}{\tilde{L}}{\parallel}{\leq}cR$$ where $c={\frac{1}{(n-3){\sqrt{(n-2)(n-1)}}}$ is appropriate real constant, depending on the dimension.

• Journal of the Korean Mathematical Society
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• v.53 no.4
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• pp.737-767
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• 2016

This paper concerns closed hypersurfaces of dimension $n{\geq}2$ in the hyperbolic space ${\mathbb{H}}_{\kappa}^{n+1}$ of constant sectional curvature evolving in direction of its normal vector, where the speed equals a power ${\beta}{\geq}1$ of the mean curvature. The main result is that if the initial closed, weakly h-convex hypersurface satisfies that the ratio of the biggest and smallest principal curvature at everywhere is close enough to 1, depending only on n and ${\beta}$, then under the flow this is maintained, there exists a unique, smooth solution of the flow which converges to a single point in ${\mathbb{H}}_{\kappa}^{n+1}$ in a maximal finite time, and when rescaling appropriately, the evolving hypersurfaces exponential convergence to a unit geodesic sphere of ${\mathbb{H}}_{\kappa}^{n+1}$.

• Nutritional Sciences
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• v.8 no.2
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• pp.140-147
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• 2005

In order to promote foodservice for older adults, foodservice directors in Continuing Care Retirement Communities (CCRCs) must identify the dimensions used by residents to evaluate the service quality of dining service. A multidimensional measure of perceived service quality was developed based on residents' responses about their experiences with dining service. A survey was administered to residents in two CCRCs. Based on the results of principal component analysis, this study identified four dimensions: food quality, dining room employee's attitude and service skills, dining room employee's safety and cleanliness, and systemization of service delivery process. A new dimension that reflects residents' concern for the dining mom employees' safety and cleanliness also emerged. 1bis study points to areas of improvement for food quality and dining room employee's safety and cleanliness.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.4
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• pp.64-75
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• 1991

The design of structures of modern industry has developed to satisfy stringent service, realiability and safety. Up to now, geometric profile which means surface foughness and dimension accuracy is mainly treated in manufacturing process of work surface. But it is inevitable to evaluate changes of surface geometry as well as the nature of alterations in surface layers because surface of workpiece changes as a result of phase transformation, chemical changes, plastic deformation and stress changes. This paper is to present principal data for safety design by verifying the effect of grinding conditions and method in grinding layers and to explain the method of measuring surface integrity. In this paper, structural steel(SM20C) is used as a workpiece. Of integrity, surface roughness in view of surface texture is analyzed by frequency domain and residual stress, structures and defect of ground layers in view of surface metallurgy are investigated.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.405-405
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• 2000

We designed the artificial olfactory sensing system (Electronic Nose) using MOS type sensor array fur recognizing and analyzing odour. The response of individual sensors of sensor array, each processing a slightly different response towards the sample volatiles, can provide enough information to discriminate between sample odours. In this paper, we applied clustering algorithm for dimension reduction, such as linear projection mapping (PCA method), nonlinear mapping (Sammon mapping method) and the combination of PCA and Sammon mapping having a better discriminating ability. The odours used are VOC (Volatile chemical compound) and Toxic gases.

• Journal of Integrative Natural Science
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• v.5 no.2
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• pp.120-126
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• 2012

This paper describes the algorithm that lowers the dimension, maintains the gesture recognition and significantly reduces the eigenspace configuration time by combining the higher correlation feature information and Principle Component Analysis. Since the suggested method doesn't require a lot of computation than the method using existing geometric information or stereo image, the fact that it is very suitable for building the real-time system has been proved through the experiment. In addition, since the existing point to point method which is a simple distance calculation has many errors, in this paper to improve recognition rate the recognition error could be reduced by using several successive input images as a unit of recognition with K-Nearest Neighbor which is the improved Class to Class method.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.757-758
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• 2006

In this paper, the palmprint classification and recognition method based on PCA (Principal Components Analysis) using the dimension reduction of singular vector is proposed. And the 135dpi palmprint image which is obtained by the palmprint acquisition device is used for the effectual palmprint recognition system. The proposed system consists of the palmprint acquisition device, DB generation algorithm and the palmprint recognition algorithm. The palmprint recognition step is limited 2 times. As a results, GAR and FAR are 98.5% and 0.036%.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.3 s.39
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• pp.155-169
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• 1990

The main purpose of this study is to suggest fundamental materials and a guideline for design through grouping of the users' use route patterns and analyzing determinants to choose those route patterns in urban parks. Study sites were Jungang, Dlseong, and Beomeo park, where located Taegu city-Key results obtained through a series of investigation were as follows : When Users come in and out urban parks, most orientations of their use routes were counterclockwise, and not in such cases, greatly affected by facilities arrangement. There were a large number of users in the main route placed the principal facilities. Users' use route patterns were grouped by their characteristics, which were circulation, semi-circulation, irregular, and piston type. And all the types except piston type can be subdivided into spoon and loope type. Factors analysis to the types produced five meaningful patterns of variables. Five factors were named as dimension of characteristics : Park composition factor, facilities use factor, users' personal factor, park use behavioral factor, routes choice factor.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.7
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• pp.447-452
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• 2005

This paper presents a method that a mobile robot finds location of doors in complex environments and safely traverses the door PCA(Principal Component Analysis) algorithm using the vision information is used for a robot to find the location of door, PCA is a useful statistical technique that has found application in fields such as face recognition and image compression, and is a common technique for finding pattern in data of high dimension. Fuzzy controller using a sonar data is used for a robot to avoid obstacles and traverse the doors.

• Journal of Korean Society of Transportation
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• v.13 no.1
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• pp.35-62
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• 1995

Traffic has a very important function but has caused such social problems as traffic congestion parking and traffic accidents in metropolitan areas. It is difficult to examine the causes of traffic accidents related to human life, which occur by human, vehicle and environmental factors. But human factor is the only measure requlating these factors together an analyzing factors influencing establishment of counterplan of traffic accidents. Consequently , this study employs the principal component analysis and stepwise multiple regression analysis to estimate the characteristics and influential factors of traffic accidents and defines the typical patterns of happening lots of traffic accidents. Accordingly, this study establishes an acknowledgement model of the causes and preference model of the counterplan of traffic accidents using Multi-Dimension Preference(MDPREF) method.