• 한국해양공학회지
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• 제31권6호
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• pp.397-404
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• 2017

In this study, an anchor dragging simulation was performed using the CEL method to design a rock-berm, which is a protection method for submarine cables. In order to simulate an anchor drag, preliminary simulations were first performed to determine the initial anchor penetration depth, anchor drag velocity, drag angle, and distance between the anchor and rock-berm. Based on the preceding simulation results, a safe rock-berm design for protecting the submarine cables was simulated to calculate the anchor penetration depth by the anchor dragging. As a result, the penetration depth of the anchor was found to be shallower in a hard seabed, and the penetration depth was deeper in a soft seabed, the height of the rock-berm was determined according to the physical properties of the seabed.

• 수산해양기술연구
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• 제59권2호
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• pp.135-144
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• 2023

In order to provide basic data to increase the efficiency and stability of seamanship at anchoring, the characteristics of the hull motion including dragging anchor due to external forces were observed at Mokpo and Jinhae anchorage for the avoidance of the typhoon. As a result, it is necessary to check the embedding motion and holding power of the anchor according to at initial position to decrease dragging anchor. Dragging anchor at anchorage seems to have been easily caused according to discrepancy between embedded anchor flukes and the towing direction due to the change in wind direction, rather than the wind speed. This discrepancy, thus, should be considered when anchoring. This test vessel with a small radius of curvature of the stem is relatively vulnerable to the influence of wind direction and wind speed, so it is easy to cause a decrease in the holding power due to an increase in the rate of turn. When the current speed is greater than or equal to 1 knot, the range of the rate of turn is reduced resulting in a relatively increased holding power. In addition, during the swing, the tension of the chain was high according to the angular velocity change of heading at three-quarters of the swing length rather than the left and right ends.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.551-552
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• 2006

• 대한인간공학회지
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• 제11권1호
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• pp.103-109
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• 1992

Direct manipulations are composed of pointing operations and dragging operations. In order to find the optimum design parameters (such as C/D ratio, moving direction) for the direct manipulation of a GUI(Graphical User Interface), an ergonomic experiment was devised (2*4*3*8 design) to measure the performance of a mouse (Microsoft) and a trackball (Logitech). The results showed that the mouse was more suitable for the direct manipulation (expecially for the dragging operation) than the trackball, and the suitable C/D ratio was 10 (for the mouse) and 16 (for the trackball). Also the movement direction was a determinant factor in trackball performance.

• 대한수학교육학회지:수학교육학연구
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• 제25권4호
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• pp.499-524
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• 2015

본 연구는 GSP 환경에서 합동변환 개념에 대한 발생적 분해를 제시하고, 중학교 2학년 영재학급 학생 4명을 대상으로 참여 학생들의 합동변환 개념에 대한 발생적 분해가 어떻게 드러나고 변화하는지, 또한 드래그 활동이 합동변환 개념의 이해에 어떤 역할을 하는지 알아보고자 하였다. 합동변환 개념을 이해할 때, 학생들은 중요한 두 스키마인 '한 점 이동 스키마'와 '변환 이동 스키마'를 동시에 고려하였으며, 한 학생이 어느 한 스키마를 선호하거나 치중하여 사용하기 보다는 두 스키마를 모두 고려하되 방향을 정하기 어려운 과제일수록 '한 점 이동 스키마'에 더 의존하는 경향을 보였다. Law(1991)의 '한 점 이동 스키마'의 집약화에 따른 '도형 이동 스키마'는 학생들에게 관찰되지 않았으며, 합동변환의 합성을 완벽하게 이해하기 위해서 조정뿐만 아니라 가역적 사고가 더 필요하였다. 또한, 합동변환 개념을 이해하는 과정에서 학생의 드래그 활동은 정의역과 치역을 평면 위의 점으로 확장하는데 도움이 되었고, 벡터, 회전의 중심, 대칭축의 역할을 인식하는데 도움이 되었다.

• 한국항해항만학회지
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• 제37권4호
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• pp.337-343
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• 2013

정박중인 선박의 안전을 위하여 항해사, 선장 및 해상교통관제사는 항상 선박이 주묘되고 있는가를 확인하여야 한다. 정박선의 주묘판별을 위하여 VTS 관제사가 선회권과 그 중심을 인지하는 것이 중요하다. VTS에서 정박선 주묘여부 감시는 레이더 및 AIS를 이용할 수 있다. 또한 이용가능하다면, CCTV 영상이나 육안에 의한 관측도 이루어 질 수 있다. 그러나 VTS 시스템은 AIS 및 ARPA Radar로부터 수집된 데이터만으로 정박선을 모니터링하고 있으므로 정박지내에서 정박선의 선회중심을 알기가 어렵다. 본 연구에서는 VTS에서 AIS에 의해 수집된 정박 선박의 선수방위각과 위치데이터를 활용하여 선회중심을 추정하는 알고리즘을 제시하고자 한다. 알고리즘의 유효성을 확인하기 위해, 실 환경에서 정박한 선박에 대한 실험연구를 수행하였다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2003년도 somma/kms meeting
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• pp.290-290
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• 2003

• Asian-Australasian Journal of Animal Sciences
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• 제8권6호
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• pp.647-650
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• 1995

The study on the sex ratios of natural population of Ixodid ticks in pasture was conducted in the Bangladesh Agricultural University Campus, Mymensingh, from 1988 to June 1990. The samples were collected from the five grazing fields consisting of five different vegetations. Dragging methods were used for the collection of samples. In 24 months of observations a total of 1113 ticks of two different species, Boophilus microplus (670), Haemaphysalis bispinosa (443) were collected and their sex ratio was determined. Females were recorded higher in both B. microplus and H. bispinosa.

• The Korean Journal of Ceramics
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• 제4권3호
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• pp.207-212
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• 1998

By comparison of the experimental results in two systems of ZnO varistors, it's appear that Sb2O3 is the indispensable element for twining in ZnO varistors and the Zn7Sb2O12 spinel acts as the nucleus to form twins. Al2O3 is not the origin of twining in ZnO varistor, but it was found that Al2O3 could strengthen the twining and form a deformation twining by ZnAl2O4 dragging and pinning effect. The inhibition ratios of grain and nonuniformity of two systems ZnO varistors increase with the increase of Al2O3 content. The twins affect the inhibition of grain growth, the mechanism could be explained follow as: twins increase the mobility viscosity of ZrO grain and grain boundary, and drag ZrO grain and liquid grain boundary during the sintering, then the grain growth is inhibited and the microstructure becomes more uniform.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.197-200
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• 1994

The study was conducted in the Bangladesh Agricultural University campus, Mymensingh, from July 1988 to June 1990. Five grazing fields consisting of five different vegetations were selected for this study. The specimen were collected from this study. The specimen were collected from the grazing fields by dragging method. The results revealed that two species of ticks namely Boophilus microplus and Haemaphysalis bispinosa were collected from five different vegetation. The highest incidence of both B. microplus and H. bispinosa were recorded during winter season and lowest in Monsoon for the year of 1988-89 and 1989-90. These two species were significantly occurred in Winter followed by Monsoon and Autumn.