• 제목/요약/키워드: ice-2

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북극 스발바드 콩스피오르덴 해역에서 L 밴드 PALSAR 데이터를 이용한 눈과 부빙에 의한 다중편파 산란특성 해석 (Polarimetric Scattering of Sea Ice and Snow Using L-band Quad-polarized PALSAR Data in Kongsfjorden, Svalbard)

  • 정정수;양찬수
    • Ocean and Polar Research
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    • 제33권1호
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    • pp.1-11
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    • 2011
  • This study describes measurements of fast ice recorded on May 23, 2009, in Kongsfjorden (translated as 'Kongs Fjord'), an inlet on the west coast of Spitsbergen in the Svalbard Archipelago. Seasonal fast ice is an important feature for Svalbard fjords, both in relation to their physical environment and also the local ecosystem, since it grows seaward from the coast and remains in place throughout the winter. Ice thickness, snow, ice properties, and wind speed were measured, while SAR (Synthetic Aperture Radar) data was observed simultaneously observed two times from ALOS-PALSAR (L-band). Measured ice thickness was about 25-35 cm while the thickness of ice floe broken from fast ice was measured as 10-15 cm. Average salinity was 1.9-2.0 ppt during the melting period. Polarimetric data was used to extract H/A/alpha-angle parameters of fast ice, ice floe, snow and glacier, which was classified into 18 classes based on these parameters. It was established that the area of fast ice represents surface scattering which indicates low and medium entropy surface scatters such as Bragg and random surfaces, while fast ice covered with snow belongs to a zone of low entropy surface scattering similar to snow-covered land surfaces. The results of this study will contribute to various interpretations of interrelationships between H/A/alpha parameters and the wave scattering Phenomenon of sea ice.

솟는 고드름의 형성 원리 (On the Occurrence Mechanism of the Ice Spike)

  • 변희룡;윤마병;심재면;김가빈;권상훈;권희내;김진아
    • 대기
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    • 제26권1호
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    • pp.73-84
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    • 2016
  • A method to make ice spike using home refrigerator with ice tray was found. Many experiments have carried out with this method and many natural phenomena occurring on the formation of ice spike are found. A new concept of the Latter Freezing Water (LFW) was imported to explain the ice spike formation. At LFW position on water surface, the Sprout of Super cooled Water (SSW) grows by the Volume Expansion Effect (VEE) caused by the phase change of water in water. And air bubbles that are expelled from ice during freezing process, gather, rise, and detonate at the upper most part of SSW that make SSW freeze and grow upward with the water pipe in it. Together with VEE the capillarity in the water pipe makes the column grow more, that makes the ice spike. Many other findings were succeeded; 1) Ice spike process is completed before the whole water freezes. 2) If water is corrupted or shocked, even though it is very slight, ice spike is not generated. 3) Rain water contains the most LFW among all kind of waters used in experiments. 4) LFW is changed into normal water after passing the ice spike. 5) A new concept of the ice bullet is introduced. 6) The reason of frequent occurrences of the ice spike at Mt. Mai is investigated also.

아이스슬러리형 빙축열 시스템을 이용한 냉각 시스템의 성능에 관한 실험적 연구 (Characteristic Analysis of the Cooling System Using Ice Slurry Type Heat Storage System)

  • 이동원;김정배
    • 에너지공학
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    • 제20권1호
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    • pp.30-35
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    • 2011
  • 2중관형과 판형 열교환기에 에틸렌 클리콜-물 수용액으로 만들어진 아이스슬러리를 적용하는 경우의 유동 및 열적 특성을 규명하기 위하여 실험을 수행하였다. 아이스슬러리의 질량유속과 얼음 분율은 각각 800에서 3500 kg/$m^2s$과 0에서 25%이었다. 실험을 통해, 압력강하와 열전달율은 질량유속과 얼음 분율에 따라 증가하였다. 그러나 얼음 분율의 효과는 높은 질량유속 영역에서는 크지 않은 것으로 나타났다. 낮은 질량유속에서는 압력강하와 열전달율의 급속한 증가가 질량 유속에 관계되는 것으로 나타났다.

8086 프로세서용 인 써키트 에뮬레이터의 제작에 관한 연구

  • 강중용
    • 전기의세계
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    • 제37권1호
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    • pp.55-62
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    • 1988
  • 본 연구에서는 현재 IBM PC등에 사용되는 8088프로세서의 16비트버젼인 8086프로세서의 ICE를 설계 제작하였다. 8088프로세서와 8086프로세서는 그 내부 기능이 동일하기 때문에 어셈블러나 링커등의 소프트웨어 개발장비들을 IBM PC에서 지원받을 수 있으므로 IBM PC에 연결된 ICE는 전체적으로 하나의 MDS시스템을 구성할 수 있다. 제작된 ICE는 1) 테스트하려는 시스템의 메모리에 대한 읽기 및 쓰기, 2) 테스트프로그램의 실제 조건에서의 수행, 3) 디버깅 기능, 4) ICE의 메모리 영역을 테스트하려는 시스템에서 활용하도록하는 기능 등을 수행할 수 있도록 하였다. 또 8086프로세서는 싱글프로세서모드와 멀티프로세서모드의 두가지 동작 모드가 있는데 싱글프로세서모드에서 동작될 수 있도록 설계되었으며 ICE의 기능 수행을 위한 논리 회로의 구성과 이해에 주안점을 두었다.

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수평 2열 원통관 주위의 동결형상에 관한 연구 (Experimental Study for Ice Formation around Two Horizontal Circular Tubes)

  • 윤정인;김재돌;도요후미 카토;오후규
    • 설비공학논문집
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    • 제7권1호
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    • pp.89-97
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    • 1995
  • Experimental study was performed for free convection and ice formation around two horizontal circular tubes which were placed vertically. Temperature and velocity distributions were visualized with real time holographic interferometry technique and tracer method. When water was cooled, super cooled region was formed around cooling pipe. It was found that flow induced by free convection always directed downwards when the coolant temperature was low, while it directed upwards when the coolant temperature was comparably high though it directed downwards initially. Flow phenomena with free convection were investigated in detail with varying cooling rate and length between cooling pipes. And growing process of dense ice was also investigated. Dendritic ice is suddenly formed within a supercooled region, and a dense ice layer begins to develop from the cooling wall.

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극지 해빙 위성관측을 위한 분석 기술 개발 (Research on Analytical Technique for Satellite Observstion of the Arctic Sea Ice)

  • 김현철;한향선;현창욱;지준화;손영선;이성재
    • 대한원격탐사학회지
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    • 제34권6_2호
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    • pp.1283-1298
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    • 2018
  • 온난화에 의한 이상기후의 징후가 직접적으로 감지되고 있는 북극권에 대한 연구 필요성이 사회적으로 강력히 요구되고 있다. 온난화의 추이를 가장 잘 보여주고 있는 해빙의 변화는 인공위성 원격탐사를 이용하여 추적 감시된다. 극지연구소에서 2017년부터 "북극해빙위성 관측을 위한 기술 개발" 연구를 진행하고 있다. 본 연구는 북극 해빙의 특성 정보를 위성자료로부터 추출하기 위한 다양한 접근법을 이용한 연구를 포함하고 있으며, 북극권 개발에 대비한 '북극 빙권 종합 위성 관측망' 구축에 필수적인 국제 공동 연구 협력도 포함하고 있다. 기후변화 연구와 더불어 북극항로 활용에 대한 기초정보를 제공하고 있는 극지연구소의 북극 원격탐사 연구 소개를 통해 국내 원격탐사 전문가들의 관심과 집중을 부탁하고자 한다. 북극연구에 대한 국제 동향과 국내 정책 배경을 소개하고, 극지연구소에서 연구 수행한 빙권 정보, 특히 한국항공우주연구원과 협동연구를 통해 아리랑위성을 활용한 북극 해빙 관측 연구를 소개한다.

Car-Parrinello Molecular Dynamics Study for the Isotope Effect on OH Vibration in Ice Ih

  • Yoon, Yeohoon
    • Bulletin of the Korean Chemical Society
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    • 제34권2호
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    • pp.553-557
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    • 2013
  • The stretching vibration of OH of ice Ih is studied by Car-Parrinello molecular dynamics in regarding the effect of mixed H/D contamination while the vibrational spectrum is considered by velocity-velocity autocorrelations of the sampled ensemble. When hydrogen atoms are immersed randomly into the deuterated ice, a typical vibrational frequency of OH stretching mode is observed to be similar to that from the pure $H_2O$ ice. When focusing on the correlation of isolated neighboring OH stretching, a narrower and blue shifted peak is observed at the high frequency range as a result of the screening from the complex many body correlations by $D_2O$ environment. It is also specifically related to the symmetric intermolecular correlations between neighboring OH stretching modes. More enhanced high frequency range can be explained by the expansion of such two body correlations to collective many body correlations among all possible OH stretching modes. This contribution becomes important when it involves in chemical interactions via excitation of such vibrational states.

Study on icebreaking performance of the Korea icebreaker ARAON in the arctic sea

  • Kim, Hyun-Soo;Lee, Chun-Ju;Choi, Kyung-Sik;Kim, Moon-Chan
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제3권3호
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    • pp.208-215
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    • 2011
  • A full-scale field trial in ice-covered sea is one of the most important tasks in the design of icebreaking ships. The first Korean icebreaking research vessel 'ARAON', after her delivery in late 2009, had a sea ice field trial in the Arctic Sea during July-August, 2010. This paper describes the test procedures and data analysis on the icebreaking performance of the IBRV ARAON. The data gathered from the icebreaking performance test in the Chukchi Sea and the Beaufort Sea during the Arctic voyage of ARAON includes the speed and engine power of the ship as well as sea ice thickness and strength data. The air temperature, wind speed and heading of the ship were also measured during each sea ice trial. The ARAON was designed to break 1 m thick level ice with a flexural strength of 630kPa at a continuous speed of 3knots. She is registered as a KR POLAR 10 class ship. The principal dimensions of ARAON are 110 m, 19 m and 6.8 m in length, breadth and draft respectively. She is equipped with four 3,500kW diesel-electric main engines and two Azipod type propulsion motors. Four sea ice trials were carried out to understand the relationship between the engine power and the ship speed, given the Arctic ice condition. The analysis shows that the ARAON was able to operate at 1.5knots in a 2.5m thick medium ice floe condition with the engine power of 5MW, and the speed reached 3.1 knots at the same ice floe condition when the power increased to 6.6MW. She showed a good performance of speed in medium ice floe compared to the speed performance in level ice. More detailed analysis is summarized in this paper.