• Journal of the Korean Mathematical Society
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• v.56 no.4
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• pp.1063-1081
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• 2019

In this paper, we formulate a new local move on virtual knot diagram, called arc shift move. Further, we extend it to another local move called region arc shift defined on a region of a virtual knot diagram. We establish that these arc shift and region arc shift moves are unknotting operations by showing that any virtual knot diagram can be turned into trivial knot using arc shift (region arc shift) moves. Based upon the arc shift move and region arc shift move, we define two virtual knot invariants, arc shift number and region arc shift number respectively.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.4
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• pp.143-151
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• 1996

The concept of cellular manufacturing is to decompose a manufacturing system into subsystems, which are easier to manage than the entire manufacturing system. The objective of cellular manufacturing is to group parts with similar processing requirements into part families and machines into cells which meet the processing needs of part families assigned to them. This paper presents a methodology for cell formation based on genetic algorithm which produces improved cell formation in terms of total moves, which is a weighted sum of both intercell moves and intracell moves. A sample problem is solved for two, three and four cells with an approach based on genetic algorithms.

• Journal of The Korean Association For Science Education
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• v.38 no.1
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• pp.69-85
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• 2018

The purpose of this study is to explore teachers' responsive moves that affect students' argumentation practices, and to propose responsive teaching strategies in argumentation-based science classroom. Two teachers, who have not implemented argumentation in their classes, and 57 students, participated in this study. We recorded and transcribed their classes and interviews for the analysis. According to grounded theory approach, we categorized the teachers' responsive moves as focused on either structural or dialogical aspects of argumentation, and qualitatively analyzed their responsive teaching practices in classes. We discovered that the teachers mostly responded to structural rather than dialogical aspects of argumentation, particularly during the students' small-group discussions. This was mainly due to their instructional goals, which focused on the structural aspect of argumentation, and the limited time available for supporting small-groups. Regarding the structural aspects, those responsive moves that explored the students' thinking or facilitated their reasoning helped them to share their thinking and justify their arguments further with recognition of learning goals in the argumentation activities. Regarding the dialogical aspects, which were seen mostly in whole-class discussions, the moves that underlined similarities and differences between arguments, facilitated the sharing of a small-group's arguments with the entire class, or asked a specific student to evaluate the arguments were notable. These moves supported clarification of various small-groups' arguments, which led to reconstruction of coherent argument through evaluation and rebuttal of these arguments, consequentially facilitating dialogical interactions. Based on these results, we proposed responsive teaching strategies in an argumentation-based science classroom.

• East Asian mathematical journal
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• v.36 no.5
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• pp.537-545
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• 2020

We investigate some polynomial invariants for virtual knots via virtualization moves. We define two types of polynomials W_G(t) and S²_G(t) from the definition of the index polynomial for virtual knots. And we show that they are invariants for virtual knots on the quotient ring Z[t^±1]/I where I is an ideal generated by t² - 1.

• Kyungpook Mathematical Journal
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• v.56 no.4
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• pp.1247-1257
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• 2016

In this paper, we discuss the crossing change operation along exchangeable double curves of a surface-knot diagram. We show that under certain condition, a finite sequence of Roseman moves preserves the property of those exchangeable double curves. As an application for this result, we also define a numerical invariant for a set of surface-knots called du-exchangeable set.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.674-679
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• 1998

In this paepr, we proposed a new way to make a pre-pruned searching tree for GO game moves from macroscopic strategy described in linguistic expression. The strategy was a consequence of macroscopic recognition of GO game situations. The definitions of fuzzy macroscopic strategy, fuzzy tactics and tactical sequences using fuzzy set are shown and its family, so called "multi level fuzzy set". Some examples are also shown.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.79-82
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• 1987

This paper describes the mobile robot system to recognize the guidance tape, and presents the locomotion algorithm. It is composed of image processing unit, A/ID converter and camera. This system converts video image to binary image by setting an optimal threshold and obtains the parameters to move the robot. The mobile robot moves according to the programmed route in memory. But after recognized the obstacle on the locomotion route, this system constructs the new route and the robot moves following the new route.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.147-158
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• 2008

The purpose of this study was to analyze the kinematical variables involved in two types of service motion in tennis pinpoint and platform stance, to find the fastest serving method. Seven skilled high school tennis players participated, and the kinematics were recorded by the Vicon motion analysis system. For the gathering and analysis of the data workstation, bodybuilder and polygon were used. During the back swing for the pinpoint stance, as the back leg moves forward the COM and the racquet moves more, thus taking 0.04 seconds longer than the platform stance. The body of the subject takes a bow-shape as the subject's foot moves back and their hip moves forward. This movement enables the subject to create more power during the backswing to impact. It also increases the spread of the COM racquet and the serve speed is increase. As there is no forward movement of the foot during the backswing of the platform stance, the COM and the racquet move less and thus the time required is shorter than that for the pinpoint stance by 0.04seconds. Similarly, the time spent creating the power for the serve is shortened, the COM racquet is narrower and the speed is lessened. However, the advantage of this serve is that it increases the stability.

• Journal of Environmental Science International
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• v.12 no.5
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• pp.521-527
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• 2003

To study the intruded phenomena of North Pacific Ocean around Boso peninsular, water property distribution in the adjacent seas to Japan is studied using the hydrographic data obtained by Japan Maritime Agency and Japan Fisheries Agency from 1973 to 1996, The scattering of water type in T-5 diagram is relatively small in the Kuroshio Region. Both the envelopes of saline side and of fresh side of the scattered data points shifts gradually from saline side to fresh side as the observation Line moves from southwest to northeast. In mixed water region, the scattering of water type increases rapidly as the observation line moves north; the envelope of fresh cold side moves towards fresh cold side much faster than that of saline side. This suggests that the water does not advect along the salinity minimum layer, but the salinity minimum layer can be understood as a boundary of two different waters aligned vertically, We defined the typical water masses as the Oyashio Water and the Kuroshio Water. The water mass below the salinity minimum layer may be created by isopycnal mixing of these two water masses with a fixed mixing rate. While the water mass above the salinity minimum cannot be created simply by isopycnal mixing. The salinity minimum layer may be eroded from upper side due to active minxing processes in the surface layer, while the water of the salinity minimum layer moves gradually southward. This appears to give an explanation why the thermosteric anomaly value at salinity minimun decereases towards south.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.31-40
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• 2009

The most common cleaning methods of cleaning robot can be divided into two categories: the random and the boustrophedon method. A cleaning robot using the random method moves straight until it bumps into an obstacle. If it collides with an obstacle, the cleaning robot turns a specific angle and continues moving straight. Therefore, the random method often tends to clean the already clean area repeatedly. In addition, it takes a long time to complete cleaning. A cleaning robot using the boustrophedon method moves straight until it collides with an obstacle. If it meets an obstacle, the cleaning robot moves to the next uncleaned space through turning and moving ahead. when resuming cleaning from the new region, a cleaning robot moves in the direction opposite to the direction of the previous cleaning. Because the boustrophedon method cleans a cleaning space more densely, its performance is excellent in an obstacle-free space or a small space. However, In a space with obstacles or a complex structure, it takes a long time to complete the cleaning work. Cleaning should be systematically approached with a good understanding of the work area. The virtual map-based cleaning robot proposed in this paper cleaned a work space efficiently. The efficiency of the proposed method was measured through simulation.