• 수산해양기술연구
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• 제35권3호
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• pp.209-214
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• 1999

The turning circle of a ship is the path followed by her center of gravity in making a turn of 360$^{\circ}$degrees or more with helm at constant angle. But generally it means her path traced at full angle of the rudder. For the ordinary ship the bow will be inside and the stern outside this circle.It has been usually understood that the turning circle is not essentinally affected by ship's speed at Froude numbers less than about 0.30. However, it is recently reported that the speed provide considerable effects upon the turning circle in piloting many ships actually at sea. In this paper, the author analyzed what effects the speed could provide on the turning circle theoretically from the viewpoint of ship motions and examined how the alteration of the speed at Froude no. under 0.30 affect the turning circle actually, through experiments of actual ships of a small and large size.The main results were as follows.1. Even though ship's speed at Froude no. under 0.30, the alteration of the speed affects the turning circle considerably.2. When the full ahead speeds at Froude no. under 0.30 of small and large ships were increased about 3 times slow ahead speeds, the mean rates of increase of the advances, tactical diameters and final diameters of thease ships were about 16%, 21% and 19% respectively.3. When the full ahead speeds at Froued no. under 0.30 of small and large ships were increased about 3 times slow ahead speed, the mean rate of increase of the turning circle elements of large ships was greater 10% than that of small ships. 4. When the full ahead speeds at Froued no. under 0.30 of small and large ships were increased about 3times slow ahead speeds, the mean rates of increase of the tactical diameter and final diameter of thease ships were greater than that of the advances of thease ships. 5. When only alteration of speed or sip's head turning is the effective action to avoid navigational fixed hagards, reducing the speed is always more advantageous than increasing the speed in order to shorten fore or transverse distance.

• 수산해양기술연구
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• 제35권3호
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• pp.210-210
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• 1999

The turning circle of a ship is the path followed by her center of gravity in making a turn of 360$^{\circ}$degrees or more with helm at constant angle. But generally it means her path traced at full angle of the rudder. For the ordinary ship the bow will be inside and the stern outside this circle.It has been usually understood that the turning circle is not essentinally affected by ship's speed at Froude numbers less than about 0.30. However, it is recently reported that the speed provide considerable effects upon the turning circle in piloting many ships actually at sea. In this paper, the author analyzed what effects the speed could provide on the turning circle theoretically from the viewpoint of ship motions and examined how the alteration of the speed at Froude no. under 0.30 affect the turning circle actually, through experiments of actual ships of a small and large size.The main results were as follows.1. Even though ship's speed at Froude no. under 0.30, the alteration of the speed affects the turning circle considerably.2. When the full ahead speeds at Froude no. under 0.30 of small and large ships were increased about 3 times slow ahead speeds, the mean rates of increase of the advances, tactical diameters and final diameters of thease ships were about 16%, 21% and 19% respectively.3. When the full ahead speeds at Froued no. under 0.30 of small and large ships were increased about 3 times slow ahead speed, the mean rate of increase of the turning circle elements of large ships was greater 10% than that of small ships. 4. When the full ahead speeds at Froued no. under 0.30 of small and large ships were increased about 3times slow ahead speeds, the mean rates of increase of the tactical diameter and final diameter of thease ships were greater than that of the advances of thease ships. 5. When only alteration of speed or sip's head turning is the effective action to avoid navigational fixed hagards, reducing the speed is always more advantageous than increasing the speed in order to shorten fore or transverse distance.

• 한국안광학회지
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• 제15권4호
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• pp.373-379
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• 2010

목적: 이 연구의 목적은 MYSTERY CIRCLE 시스템을 이용하여 폭주부족 사위와 간헐성 사시 환자의 시기능 훈련효과를 조사하였다. 방법: 시기능 훈련 대상자는 안질환과 조절이상 및 수직사위가 없는 폭주부족 사위(n=18)와 간헐성 사시(n=8) 이상자 26명을 대상으로 추적 관찰하였고, 훈련기간은 8주간 매주 한번은 안경원에 방문하여 시기능 훈련에 따른 변화를 측정하였다. 결과: MYSTERY CIRCLE 시스템으로 시기능 훈련을 실행한 결과 기능적 및 감각적 증상이 개선되었다. 그리고 Worth 4 Dot검사, 입체시 검사 및 적색렌즈 융합 속도 검사도 개선을 보여 주었다. 결론: MISTERY CIRCLE 시기능 훈련 시스템을 이용한 시기능 훈련은 좋은 양안시 이상 개선 효과를 보여주었다.

• Journal of Biosystems Engineering
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• 제42권4호
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• pp.265-275
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• 2017

Purpose: This study aims to identify the most stable boring shape among the circle, square, and inverted-triangle types in order to be applied to the development of a tractor-pulled underdrain boring device. Methods: The underdrain boring devices designed with the circle, inverted triangle, and square types were analyzed by numerical analysis, and they were evaluated by soil moisture and underground water level in the test field. Results: The results of the numerical analysis indicated that the increases in displacement, and strain when a uniform load is placed on the surface soil with soil weight were in the order of the inverted-triangle type, square type, and circle type. The soil moisture content and the underground water level after rainfall showed the largest difference in the order of the circle type, square type, and inverted-triangle type, indicating that the circle type had the largest drainage effects after rainfall. Conclusions: The overall findings of this study show that the circle type is the most stable among the circle, square, and inverted-triangle types.

• 한국비블리아학회지
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• 제10권1호
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• pp.223-241
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• 1999

공공도서관은 주민들의 문화수준을 향상시키기 위하여 주민들이 접근 할 수 있도록 도서관과 관외 봉사 거점을 많이 설립하고 이들을 거점으로 주민들이 독서활동을 할 수 있는 독서회를 조직하고 그 독서회를 중심으로 활동하는 것이 독서활동을 활성화하는 효율적인 방법으로 판단되어 공공도서관은 주민을 대상으로 계층별 및 주제별에 따라 또는 주민들이 자신의 취미나 특기에 따라 활동할 수 있는 독서회를 조직하도록 한다. 그리고 공공도서관은 관내 모든 독서회를 대상으로 하는 종합적인 총괄프로그램을 구성하여 운영한다. 또한 공공도서관은 독서회원들이 활동하는데 필요한 정보를 서로 주고받을 수 있도록 홈페이지를 개설해 운영하고,‘뉴스레터’의 발행으로 독서회 활동을 정리하면서 관리한다면 훌륭한 효과를 얻을 수 있을 것으로 판단하였다.

• 대한수학교육학회지:학교수학
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• 제8권3호
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• pp.291-300
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• 2006

본 논문에서는 학교수학에서 발견할 수 있는 순환논법의 예로서 고등학교 미분과 적분 교과서에서 정적분을 통해 원의 넓이를 구하는 과정에서 발견되는 순환논법을 수학적으로 분석하고, 학교수학의 수준에서 원의 넓이에 관련된 몇 가지 증명방법들의 의미를 비교 분석한다. 특히 원의 넓이에 대한 아르키메데스의 증명과정을 고찰하여 학교수학에서 국소적 조직화의 의미와 가치를 재조명한다.

• International Journal of Contents
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• 제2권3호
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• pp.22-26
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• 2006

In this paper we introduce a new circle detection algorithm for occluded on/off pupil and iris boundary extraction. The proposed algorithm employs 7-step processing to detect a center and radius of occluded on/off eye images using the property of the chords. The algorithm deals with two types of occluded pupil and iris boundary information; one is composed of circle-shaped, incomplete objects, which is called occluded on iris images and the other type consists of arc objects in which circular information has partially disappeared, called occluded off iris images. This method shows that the center and radius of iris boundary can be detected from as little as one-third of the occluded on/off iris information image. It is also shown that the proposed algorithm computed the center and radius of the incomplete iris boundary information which has partially occluded and disappeared. Experimental results on RGB images and IR images show that the proposed method has encouraging performance of boundary detection for pupil and iris segmentation. The experimental results show satisfactorily the detection of circle from incomplete circle shape information which is occluded as well as the detection of pupil/iris boundary circle of the occluded on/off image.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 1998년도 The 12th Asia Quality Management Symposium* Total Quality Management for Restoring Competitiveness
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• pp.463-478
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• 1998

This study aims to improve the activities of Quality Circle of Korea companies. For this purpose we studied the fctors to influence the performances of Quality Circle activities, and based upon this result we suggested the improvement method of Quality circle activities. This study will give one way of activating the Quality Circles of our companies.

• 호남수학학술지
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• 제34권1호
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• pp.103-111
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• 2012

Wetzel[5] proved if ${\Gamma}$ is a closed curve of length L in $E^n$, then ${\Gamma}$ lies in some ball of radius [L/4]. In this paper, we generalize Wetzel's result to the non-Euclidean plane with much stronger version. That is to develop a lower bound of length of a triangle inscribed in a circle in non-Euclidean plane in terms of a chord of the circle.

• 대한수학회보
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• 제46권6호
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• pp.1153-1158
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• 2009

Given two integral self-reciprocal polynomials having the same modulus at a point $z_0$ on the unit circle, we show that the minimal polynomial of $z_0$ is also self-reciprocal and it divides an explicit integral self-reciprocal polynomial. Moreover, for any two integral self-reciprocal polynomials, we give a sufficient condition for the existence of a point $z_0$ on the unit circle such that the two polynomials have the same modulus at $z_0$.