• 전기학회논문지
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• 제68권1호
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• pp.199-206
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• 2019

Recently, an expansion of safety facilities has been widely applied to effectively manage the safety of train operation due to increase of the high-speed section of the general railway and the introduction of high-speed train. Accordingly, performance improvement, upgrading and high reliability of existing safety devices are required. the dragging detector, one of the safety devices, is an analogue system that consists of closed circuit with an electric current flows and operates when the closed circuit is opened by the impact of the dragging object. Such method has unreasonable problem that should be replaced after being detected. It is need to replace with an automatic return type dragging detector which is easy to maintain. In addition, it is necessary to develop a dragging detector that applicable to general railway and urban railway including high-speed railway, in accordance with the speeding up and densification of trains, although it is currently applied only to high-speed railway. In this paper, we propose an automatic return type dragging detector which has versatility and excellent maintainability with digital sensor and real time monitoring.

• 한국항해항만학회지
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• 제33권8호
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• pp.505-511
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• 2009

선박의 대형화에 따른 풍압면적의 증가 및 갑작스런 돌풍 등 자연환경의 급격한 변화 등으로 묘박 중인 선박이 주묘 되는 현상이 자주 발생되고 있다. 특히, 선박운항자의 관점에서는 풍속 및 파랑 등의 외력 변화에 따른 주묘 발생 시점 및 주묘 형태, 주묘시의 속력과 주변 선박 또는 장애물과의 충돌 가능성 등을 고려한 적절한 대응 방안이 모색되어야 한다. 본 논문은 실습선 한바다호가 단묘박으로 묘박 중 기상이 점점 악화되면서 실제로 주묘가 발생한 현상을 검토한 것으로, 묘박 당시의 풍압력, 유압력, 표류력, 선체운동 그리고 파주력 등을 분석하여 주묘의 발생 가능성 및 한계 외력을 고찰하였다. 또한, 당시의 외력 조건하에서 발생한 주묘패턴을 분석하여 선수방위 변화량, 스윙폭, 주묘 속도 등을 확인하였다.

• 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.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2005년도 춘계학술대회 논문집
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• pp.173-179
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• 2005

이전의 연구(묘박 중인 선박의 주묘 한계에 관한 연구- I )에 이어서, 본 연구에서는 묘박 중인 선박의 묘박 안정성을 검토하기 위해 선박조종 시뮬레이터를 이용한 주묘실험을 수행하였다. 이 실험의 주된 목적은 주묘중인 선박의 거동특성과 주묘 한계풍속을 파악하는데 있다. 실험의 대상이 된 선박은 2003년 9월 태풍 매미가 내습했을 당시 진해만에 묘박했던 소형 탱커선이며, 주묘실험의 결과는 이론분석 결과 및 현장보고와 매우 유사함을 확인하였다.

• 해양환경안전학회지
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• 제27권4호
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• pp.474-482
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• 2021

우리나라는 지리적 위치와 편서풍의 영향을 받아 필리핀이나 대만 근처에서 전향한 태풍이 매년 평균 2~3개 통과한다. 진해만은 우리나라의 대표적인 태풍 피항지로 알려져 있으며, 태풍 내습 시 피항 선박들로 가득차고 나중에는 주변 항로까지 묘박한 선박들로 포화상태에 이르게 된다. 이로 인하여 묘박중인 선박이 강풍으로 주묘가 발생될 경우에는 선박 간 이격거리가 짧아 충돌사고가 발생될 수 있으므로 진해만의 체계적인 묘박 안전관리가 필요한 실정이다. 따라서 본 연구에서는 진해만 묘박지 수심에 따른 선박 톤수별 주묘 한계 풍속을 제시하였다. 수심 20 m에서는 묘쇄를 7~9 Shackles 신출하였을 때 주묘 발생 한계 풍속은 48~63 knots, 수심 35 m에서는 46~61 knots, 수심 50 m에서는 39~54 knots로 평가되었다. 수심이 증가하면서 외력에 의해 파주부가 5 m 미만이 되는 상황이 발생하면서 주묘가 발생하는 한계 풍속은 4~8 knots로 큰 차이를 보였다. 또한 고파주력 앵커(AC-14형)가 설치된 선박이 재래형 앵커(ASS형)가 설치된 선박보다 주묘 한계 풍속이 더 크게 평가되었지만, 수심이 50 m로 깊은 곳에서는 고파주력 앵커를 사용하더라도 주묘가 쉽게 발생될 수 있는 것으로 확인되었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1454-1460
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• 2009

Ultra-speed tube train, which runs in vacuum atmosphere to overcome aero-dynamic dragging force, is considered as a high-speed ground transportation system to back up long-distance air travel. To realize the ultra-speed tube train, feasibility study of currently available Maglev technologies especially for propulsion and levitation system is needed. Propulsion by linear synchronous motor(LSM) and levitation by electro-dynamic suspension(EDS) which are utilized in the Japan's MLX system could be one of candidated technologies for ultra-speed tube train. In the LSM-EDS system, the key component is superconducting magnet, and its reliability and performance is very important to guarantee the safe-operation of Maglev. As the initiative of the feasibility study, this paper deals with the basic structure of superconducting magnet and core technologies to design and operate it. And by surveying the current R&D achievement in Korea, the nation's capability to develop advanced superconducting magnet for Maglev is presented.

• 해양환경안전학회지
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• 제20권2호
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• pp.172-178
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• 2014

본 연구에서는 울산항 E 집단정박지를 이용하는 대표적인 8척의 선박에 대한 단묘박 상태에서의 묘박안전성을 앵커와 앵커체인의 파주력과 바람, 파랑 및 조류에 따른 외력으로 상호 비교하여 평가하고, 주묘 발생이 가능한 최소 한계 외력을 분석하고자한다. 파주력은 해저저질과 실제 앵커 의장수를 반영했고, 선체에 작용하는 외력은 만재와 경하상태별로 풍압면적과 수면하부 침하면적을 조사하여 각 상태별로 선체에 작용하는 풍압력, 유압력 및 파랑 표류력을 산출하였다. 단묘박 상태에서의 주묘 한계 외력에 대한 분석 결과 선박의 종류, 규모 및 적재 상태별로 다소 차이는 있으나 조류 2 knots 조건 하에서 일반화물선은 풍속 15 m/s 이상, 유류운반선은 풍속 13 m/s 이상이면 주묘가 발생할 수 있음이 확인되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2967-2970
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• 2007

In a usual painting process, a liquid drop spreads on canvas by being dragged along a paintbrush. To obtain the fundamental understanding of the painting process from the mechanical point of view, we experimentally investigate various dynamic behavior of a liquid drop that spreads between moving solid plates. It is shown that three distinct types of drop spreading take place, i.e. shearing, spreading, and intact dragging, depending on the liquid viscosity and surface tension, the plate speed, and the wettability. We suggest a regime map based on the capillary number and the receding contact angle, which indicates the boundaries between different types of spreading behavior in a dimensionless space.

• 한국멀티미디어학회논문지
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• 제17권10호
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• pp.1213-1219
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• 2014

Keypad used in the portable terminal based on the touch screen such as current smart phones is complex on the input method because of placement for use a small screen on a character or number button and is inconvenient. In this paper, we propose a combination method for the Hangul through touch and drag. First, only keypad for consonants is displayed, if a single consonant is selected by touch, then the keypad for vowels will be displayed around the consonant. Dragging in the keypad is combined into a vowel by depending on the drag path. This method can input Hangul by rapid and intuitive process compared to conventional methods. Simulation results show that the proposed method is very efficient in terms of speed and convenience compared to the conventional methods.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.69.2-69.2
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• 2010

Recently, bulk hetero-junction cells have been extensively studied by many researchers. Most of these cells were fabricated by spin coater. However, the spin coating process is not favorable to the large-scaled industry because it is not compatible with roll-to-roll process. One of the alternative methods is Doctor blading. In this study, we fabricated large OPV cells having total area of $100cm^2$. The buffer layer was Poly-(3,4-ethylenedioxythiophene) : poly-(styrenesulfonate) aqueous dispersion (PEDOT:PSS) and the active material is poly (3-hexythiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) blend in the solvent of Chlorobenzene. All of the organic layers were coated by dragging the blade with a speed of 5~20 mm/s on the stage with a temperature of $50^{\circ}C$. As-bladed PEDOT:PSS layer was baked at $120^{\circ}C$ for 10 minutes to eliminate the water. The cell structure is patterned ITO substrate/PEDOT:PSS/P3HT:PCBM/LiF/Al. The topmost electrode, LiF/Al, was deposited by thermal evaporation. After depositing electrode, and the cell was annealed at $150^{\circ}C$ for 30 minutes. The measured ISC, VOC, fill factor, and PCE were 2.95 A, 5.86 V, 0.32, and 0.78%, respectively. PCE was quite low but the large active area could be obtained successfully.