• Communications of the Korean Mathematical Society
• /
• v.37 no.3
• /
• pp.915-938
• /
• 2022

We are interested in the problem of fitting a parabola to a set of data points in ℝ³. It can be usually solved by minimizing the geometric distances from the fitted parabola to the given data points. In this paper, a parabola fitting algorithm will be proposed in such a way that the sum of the squares of the geometric distances is minimized in ℝ³. Our algorithm is mainly based on the steepest descent technique which determines an adequate number λ such that h(λ) = Q(u - λ𝛁Q(u)) < Q(u). Some numerical examples are given to test our algorithm.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1544-1549
• /
• 2004

A new collision avoidance algorithm is presented for two mobile robots in narrow corridor environments. When two robots meet each other in a narrow corridor, one should yield the way to the other robot. To solve the problem arising in this situation, they exchange their path to get information about crossing-points to check avoidance conditions, which are necessary for choosing the robot to yield. The conditions are summarized as follows. 1) If one robot blocks the path to the closest crossing-point in front of the other robot. 2) If the closest crossing-point of each robot is the same point. 3) Which robot is closer to the closest crossing-point. In this paper, we propose a path planning algorithm for the robot which yield the way. Simulation results are presented to verify the feasibility of the proposed collision avoidance algorithm.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.172-174
• /
• 2004

This paper proposes an integerized approach to solve PCA(Principal Component Analysis) feature extract procedure mainly used for the face recognition. A simple conversion to integer values has the risk to reduce the precision compared to that of the floating points operations. We integerize the PC variables by normalizing with the maximum of them, and show the efficiency of the proposed scheme by comparing the results to those of the float/double precisions. The integerized scheme is expected to be an efficient way for the real-time implementation of PCA's recognition stage, because integer operator is more desirable than floating point ones. Further research is to find a way to implement face detection and to measure the distances from the stored PCs for the full real-time face recognition.

• Journal of Advanced Marine Engineering and Technology
• /
• v.29 no.1
• /
• pp.124-131
• /
• 2005

This paper suggests LOS(Line-Of-Sight) guidance system of a surface vessel in straight-line navigation under ocean currents An LOS vector from the vessel to a point on the path between two way-points is decided and a heading angle is calculated to converge to follow the desired path based on the LOS vector This guidance system is called LOS guidance system. The suggested LOS guidance law has parameters to be properly chosen according to navigational environment. Parameters of LOS guidance system are optimized to reduce propulsive energy and/or position error between desired Position and present position of a ship using genetic algorithm which is a strong optimization algorithm with adaptational random search The effectiveness of the suggested LOS guidance system is assured through computer simulations.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.05a
• /
• pp.431-436
• /
• 2001

Lateral confining effect due to the existence of the shear reinforcements in R.C. beam is investigate in a numerical way. For the purpose, a three dimensional constitutive model of concrete is developed based on the elasto-plasticity using non-associated plastic flow rule to control the excessive inelastic dilatancy. The plastic flow direction is determined based on the associated plastic flow direction in a way to adjust the directional angle between the two normal vector components along the hydrostatic and deviatoric axis in a meridian plane in which the loading function prescribed. The current formulation is combined with the four parameter elasto-plastic triaxial concrete model recently developed. The resulting elasto-plastic triaxial concrete model predicts the fundamental behaviors of concrete under different confining levels and the 4-points flexural test of a beam with shear reinforcements, compares with the experimental results.

• The Mathematical Education
• /
• v.38 no.2
• /
• pp.105-128
• /
• 1999

The aim of this study is to determine a way to make mathematics textbooks after Korea is reunited. For this, the analysis of curriculum in SouthㆍNorth Korea must be made before unification. Therefore this study compares and analyzes the contents, organization and mathematics terms used in the latest middle school textbooks(1995-1996). And it also compared and contrasted the two textbooks while determining the best points of each. In this way, this study will be a very useful guide for making new educational curriculum and new mathematics textbooks after South and North Korea be unified.

• Korean Institute of Interior Design Journal
• /
• no.31
• /
• pp.49-55
• /
• 2002

The purpose of this study is to suggest specific function of each areas and way to express reasonable interior elements within interior design of sports center in Korea. The method of this research is case study of sports center In various fields since 1980. During the study, it Is very clear that the most important points in designing of sports centers interior space to accomodate main body training areas and service area for the users. The other point is to explain within the space plan that there should be a clear understanding of general regulation for the installation element, function and behavioral facts. The social, cultural roles of sports center must have the function as a multi service facility. In summary this research is to present datas and suggestion to various areas in sports center and refine its new meaning of sports center space plan with much better designing.

• Journal of the Korean Society of Industry Convergence
• /
• v.16 no.1
• /
• pp.9-13
• /
• 2013

This paper measured some condition about differential height of two points for the comparison of measure by direct method and Geodimeter and trigonometric Leveling method. The research was compared relationship between the volue to get from three measure method and five measured man. The significance of between three measure method and five measured man has been investigated by analysis of two-way ANOVA. The result indicate that between five measured man show insignficance, and between the direct method and Geodeter method show signficance and between the direct method and trigonometric Leveling method show signficance but between the Geodeter method and trigonometric Leveling method, two method show insignficant. Therefore, when using Geodemeter leveling method and trigonometric Leveling method, you must keep particular attention when former two Leveling method about instrumental error, natural error, and personal error, two Leveling method using low precision leveling.

• English Language & Literature Teaching
• /
• no.5
• /
• pp.149-189
• /
• 1999

Assessment can be defined as any method used to understand the current knowledge that a student possesses. Assessment may influence decisions about grades, placement, instructional needs, and curriculum. Therefore, the purpose of assessment is to identify how the students think and know, to diagnose the difficulties they face, and to reflect the result of assessment on teaching. But the traditional multiple-choice test failed to evaluate and teach higher-level thinking and problem-solving skills. In this context, performance assessment is being required as an alternative assessment to get better understanding about what the students can do as well as what they know. This article points out some weaknesses of traditional assessments, and comments on the theoretical background and necessity of performance assessment. And it presents more specific information about performance assessment and some examples. It is certain that performance assessment is student-centered and future-oriented. But performance assessment can't be the surest and best way of evaluating the students' abilities. We are just on the way of another experimental stage for improving teaching methodology. More supplementary analyses and further improvements are needed.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.852-857
• /
• 2007

For electric traction using a large power converter, harmonic problem in the p-ower quality and regenerating energy in side of efficiency are important. Recently, by advance in power electronics technology, some countries are considering regenerative inverter from the points of view. when the electric tractions are stopped or driven through the falling slope way, it is very useful to supply surplus energy to the power source by regenerating system in the efficient side of energy and it is very economical. these regenerating energy are supported electrical equipment through DC line. In this research, the purposes are suppressing extra DC-line voltage and saving energy generated while electric traction is been driving on the falling slope way or reducing speed for railway using a 1500V DC-voltage. Besides, the accompanied defects of current distortion, low power factor and the voltage unbalance will be solved by developing the algorism of inverter having ability to compensate current harmonic.