• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.535-542
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• 2000

This paper presents a method for the dynamic analysis of constrained multibody systems undergoing abrupt collision. The proposed method uses a longer time interval to check collision than that of c onventional method. This reduces the computational effort significantly. To calculate collision points on two colliding rigid bodies, one may introduce constraints of contact. However, this causes reduction of degree of freedom and difficulty of numerical analysis. The proposed method can calculate collision points without above mentioned problems. Three numerical examples are given to demonstrate the computational efficiency and the usefulness of the proposed method.

• The Pure and Applied Mathematics
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• v.21 no.4
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• pp.271-279
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• 2014

Let $T_l$ be a transformation on the interval [-1, 1] defined by Chebyshev polynomial of degree $l(l{\geq}2)$, i.e., $T_l(cos{\theta})=cos(l{\theta})$. In this paper, we consider $T_l$ as a measure preserving transformation on [-1, 1] with an invariant measure $\frac{1}{\sqrt[\pi]{1-x^2}}dx$. We show that If f(x) is a nonconstant step function with finite k-discontinuity points with k < l-1, then it satisfies the Central Limit Theorem. We also give an explicit method how to check whether it satisfies the Central Limit Theorem or not in the cases of general step functions with finite discontinuity points.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.169-177
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• 2000

In machining screws which are important members in mono pumps or progressive cavity pumps CNC turning center with 3 axes is usually used. This sort of screw machining requires large amount of CL data points and rotational tools are used in machining. When working out the CL data points consideration of possible tool interference is important in order to avoid undercut. This paper describes the checking methods of tool interference in the screw machining on the CNC turning center. First of all a specific shape of a screw cross-section that could commonly be applied to all screws was chosen and then possible tool interference associated with that shape was identified. Checking method was mathematically developed and verified. This checking method will be utilized in the CAM system developed by the authors for screw machining on the 3-axis CNC turning center.

• Journal of the Korean Institute of Educational Facilities
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• v.16 no.6
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• pp.21-28
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• 2009

School Design in the future will be more important on exterior space plan. However, there is no specific definition or boundary regarding exterior space, and related regulations and guides define the essential factors only. The purpose of this study is to have a guideline for the concept of exterior space in elementary school buildings, and deducted strong and weak points by evaluating exterior space based on each business methods. A result of this study can be suggest what improvements should be made on exterior space design of elementary school buildings by comparative analysis of positive and weak points for each evaluation factors.

• Journal of Korea Multimedia Society
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• v.22 no.4
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• pp.417-423
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• 2019

This paper presents an evaluation system to determine the completeness of a space map obtained by a visual SLAM(Simultaneous Localization And Mapping) algorithm. The proposed system consists of three parts. First, the proposed system detects the occurrence of loop closing to confirm that users acquired the information from all directions. Thereafter, the acquired map is divided with regular intervals and is verified whether each area has enough map points to successfully estimate users' position. Finally, to check the effectiveness of each map point, the system checks whether the map points are identifiable even at the location where there is a large distance difference from the acquisition position. Experimental results show that space maps whose completeness is proven by the proposed system has higher stability and accuracy in terms of position estimation than other maps that are not proven.

• Journal of agricultural medicine and community health
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• v.41 no.3
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• pp.119-128
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• 2016

Objective: This study was to investigate the knowledge, health belief, and vaccination behavior on hepatitis A among university students. Methods: A self-administered questionnaire survey was conducted from $3^{rd}$ to $25^{th}$ March, 2014 and 197 subjects were enrolled in statistical analysis. Results: The result showed that the score for knowledge of the subjects on hepatitis A was $4.59{\pm}3.06$ out of 15 points, for health belief $2.39{\pm}0.28$ out of 4 points, and the vaccination rate of the subjects was 12.7%. There was significant difference in hepatitis A knowledge score according to experience of hepatitis A check-up and hepatitis A vaccination history of family members, and in health belief according to gender. For hepatitis A vaccination there was significant difference according to experience of hepatitis A check-up, family history of liver disease, hepatitis A vaccination history of family members, and education history of hepatitis A. As a result of logistic regression analysis experience of hepatitis check-up and hepatitis A vaccination history of family members were significant factors for hepatitis A vaccination. Conclusions: The level of knowledge, health belief for hepatitis A of the subjects was low and vaccination rate also low. The experience of hepatitis A check-up and hepatitis A vaccination history of family members were factors affecting hepatitis A vaccination. It would be necessary to develop programs for improving level of knowledge and health belief and raising the rate of hepatitis A vaccination for the university students in Korea.

• Journal of the Korean Mathematical Society
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• v.40 no.6
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• pp.951-962
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• 2003

In this paper we address focal points and treat manifolds (M, g) whose Lorentzian metric tensors g have a spacelike $C^{0}$-hypersurface $\Sigma$ [10]. We apply Jacobi fields for such manifolds, and check the local length maximizing properties of $C^1$-geodesics. The condition of maximality of timelike curves(geodesics) passing $C^{0}$-hypersurface is studied.ied.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.233-236
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• 2004

In this study, we analyzed the accuracy of the conversion from DLT parameters to physical camera parameters and optimized the use of DLT model for non-metric cameras in photogrammetric tasks. Using the simulated data, we computed two sets of physical camera parameters from DLT parameters and Bundle adjustment for various cases. Comparing two results based on the RMSE values of check points, we optimized the arrangement of GCPs for DLT.

• Journal of the Korean Statistical Society
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• v.27 no.4
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• pp.495-506
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• 1998

The proposed class of generalized logistic models, indexed by an extra parameter, can be used to model or to examine symmetric or asymmetric discrepancies from the logistic model. When there are a finite number of different design points, we are mainly concerned with maximum likelihood estimation of parameters and in deriving their large sample behavior A score test and a bootstrap hypothesis test are also considered to check if the standard logistic model is appropriate to fit the data or if a generalization is needed .

• Journal of the Korean Data and Information Science Society
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• v.19 no.1
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• pp.37-51
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• 2008

In this article, the aim is at evaluating the knowledge level of the foodbome disease by developing a reasonable survey questionnaire model. Each questions of the questionnaire is made up to check the knowledge covering the several fields of materials related to the foodbome disease. The pilot survey is implemented to evaluate the validity of questionnaire. Each question in questionnaire is scored to get the quantitative measure of the foodbome disease knowledge by converting the total score into 100 points.