• The Science & Technology
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• v.35 no.10 s.401
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• pp.86-87
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• 2002

• Korean Journal of Optics and Photonics
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• v.26 no.1
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• pp.9-16
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• 2015

We have developed ellipsometry lidar and measured aerosol and ice-cloud characteristics. To measure a full normalized backscattering phase matrix (NBSPM) composed of nine elements, we have designed an optical system with three kinds of transmission and three kinds of reception, composed of ${\lambda}/2$ waveplate, ${\lambda}/4$ waveplate and empty optic. To find systematic optical errors, we used clean day middle-altitude (4-6km) lidar signals for which the aerosol's concentration was small and its orientation chaotic. After calibrating our lidar system, we have calculated NBSPM elements scattered from an aerosol and from an ice cloud. In the case of an aerosol, we found that the off-diagonal values $m_{12},{\ldots},m_{34}$ of the NBSPM are smaller than those for a cirrus cloud. Also, the off-diagonal values of the NBSPM from a cirrus cloud depend on atmospheric conditions.

• Journal of the Korean association of regional geographers
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• v.7 no.1
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• pp.97-106
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• 2001

There are a few interesting areas which show freezing during summer season in Korea, three of them are especially important. They are located at Milyang(Gyungnam province), Uisung and Chungsong(Gyungbook province). They are named Eoleumgol(ice-valley) or Binghyul(ice-cave). The purpose of this study is to clarify geomorphological and geological characteristics about the distribution areas of freezing during summer season in Korea in relation to previous works, which have been studied in hydrological or micro-climatological viewpoints. The main results are summarized as follows. 1) The main geomorphological and geological characteristics in the distribution areas of freezing during summer season (1) Thick debris accumulated slope within deep valley (2) North facing slope (3) The component debris of volcanic rock such as andesite or rhyolite 2) The ice-cave as a system that give rise to freezing phenomenon in summer season is closely related to talus slope. The ice-cave has thick accumulated debris and lots of vacant spaces within the rock deposits, some of vacant spaces are very big and connected with underground water system. 3) A partly freezing within underground water system is required freezing phenomenon in summer season. Judging from this point of view, two ideas are suggested; one is the evaporation theory, another is that the frozen condition in winter remains untill late summer.

• Korean Journal of Remote Sensing
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• v.34 no.3
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• pp.545-552
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• 2018

Grounding line is used as evidence of the mass balance showing the vulnerability of Antarctic glaciers and ice shelves. In this research, we utilized a high resolution digital elevation model of glacier surface derived by recently launched satellites to estimate the position of grounding line of Campbell Glacier in East Antarctica. TanDEM-X and TerraSAR-X data in single-pass interferometry mode were acquired on June 21, 2013 and September 10, 2016 and CryoSat-2 radar altimeter data were acquired within 15 days from the acquisition date of TanDEM-X. The datasets were combined to generate a high resolution digital elevation model which was used to estimate the grounding line position. During the 3 years of observation, there weren't any significant changes in grounding line position. Since the average density of ice used in estimating grounding line is not accurately known, the variations of the grounding line was analyzed with respect to the density of ice. There was a spatial difference from the grounding line estimated by DDInSAR whereas the estimated grounding line using the characteristics of the surface of the optical satellite images agreed well when the ice column density was about $880kg/m^3$. Although the reliability of the results depends on the vertical accuracy of the bathymetry in this study, the hydrostatic ice thickness has greater influence on the grounding line estimation.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.87-97
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• 1992

Of various design factors affecting icebreaking capability of an icebreaker, the stem angle(i.e., angle between bow stem and ice sheet) is the most important one under continuous icebreaking operation. This study focuses on the relationship between the bow stem angle of an icebreaker and its icebreaking capability. Considering relatively high loading-rate conditions with typical advancing speed of 3 to 4 knots, the material properties and deformation characteristics of sea ice are regarded as entirely elastic and brittle. In this paper the interaction process of icebreaker with level ice is simplified as a beam of finite length supported by Winkler-type elastic foundation simulating water buoyancy. The wedge type ice beam is loaded by the vertical impact forces due to the inclined bow stem of icebreaking vessels. The numerical model provides locations of maximum bending moment where extreme tensile stress arises and also possible fracture occurs. The model can predict a characteristic length of broken ice sheet upon the given environmental and design parameters.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.322-322
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• 2011

본 연구는 동관의 관외착빙형 특성을 조사하기 위한 기초적인 연구로써, 실험의 파라메터와 범위는 브라인의 온도는 -10[$^{\circ}C$], -8[$^{\circ}C$], -6[$^{\circ}C$], 브라인의 유속은1.0[m/s], 1.4[m/s], 1.8[m/s] 그리고물의 초기온도는6[$^{\circ}C$], 9[$^{\circ}C$], 12[$^{\circ}C$] 등으로 설정하였다. 본 논문에서는 무차원 얼음 두께와 무차원 동결 시간의 관계에 대하여 실험적으로 정리 하였다. 브라인온도, 물의 온도, 브라인 유속, 물의 초기온도, 동관의 직경사이즈에 대한 무차원 상관 방정식은 다음과 같이 얻어진다. r+3 = $0.063{\bullet}(t+)+0.206$ [적용범위: R+T+=2.1~4.7].

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.558-564
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• 2021

The water purifier market has increased rapidly in recent years. The welding technology of the evaporator is a key component that determines the level of ice production and the cold water performance of an ice purifier. The finger type evaporator of an ice purifier can remove ice and is divided largely into an instant heat method and a hot gas method. In the hot gas type evaporator, particularly during the production process, the pinhole phenomenon inside the copper pipe and clogging problems occur intermittently when welding high-pressure pipes due to the high-temperature oxygen welding. Its use in a water purifier can cause a problem in that ice and cold water do not form, and repairs cannot be made on site. To solve this problem, in this study, a cap jig was applied to improve the welding defect of the hot gas evaporator. In addition, the oxygen welding flame size was adjusted so that the heat source could be well supplied to the cap jig, and the effectiveness was confirmed through a wave pressure test, a test, and a thermal shock test.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.61-67
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• 2021

Isotopic compositions of snow or ice have been used to reconstruct paleoclimate and to calculate contribution to streamwater using isotopic hydrograph separation as an end member. During freezing and melting of snow or ice, isotopic fractionation occurs between snow or ice and liquid water. Isotopic evolution during melting process has been studied by field, melting experiments and modeling works, but that during freezing has not been well studied. In this review, isotopic fractionation during equilibrium freezing is discussed using the linear relationship between two stable water isotopes (oxygen and hydrogen) and the Rayleigh fractionation. Snow, evaporated from nearby ocean and condensated, follows the Global Meteoric Water Line (slope of 8), but the melting and freezing of snow affect the linear relationship (slope of 19.5/3.1~6.3). The isotopic evolution of liquid water by freezing observed in the open system during Rayleigh fractionation is also seen in the closed system. The isotopic evolution of snow or ice in the open system where the snow or ice is continuously removed becomes more enriched than the residual liquid water by the fractionation factor. The isotopic evolution of snow or ice in the closed system eventually equals the original isotopic compositions of liquid water. It is expected the understanding of isotopic evolution of snow or ice by freezing to increase the accuracy of the paleoclimate studies and hydrograph separation.

• Food Science of Animal Resources
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• v.27 no.2
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• pp.157-162
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• 2007

Emulsification sausages were prepared in 3 different ways: T1: fat added after ice, T2: fat added before ice, T3: all ingredients added together. Each sample was ground for 4.5 min by a silent cutter at $15^{\circ}C$ and emulsified batters were stuffed into fibrous casing and then cooked for 40 min at $78^{\circ}C$ to determine the effect of the order of ingredient addition on the qualities of emulsion type sausage. The pH of T1 sausage was significantly higher, whereas the pH of T3 was significantly lower compared with the other samples(p<0.05). The shear force was significantly higher in T1 sausage, however the hardness and gumminess were significantly lower in T1 sausage compared with other two types(p<0.05). With regard to sensory evaluation, the relative amounts of flavor can be summarized as T2>T1>T3, and the color was significantly higher in T1 and T2 compared with T3(p<0.05). There was no significant difference among the test sausages with regard to aroma, juiciness, tenderness and overall acceptability(p>0.05). There were no significant differences in free moisture, water holding capacity(WHC), meat color and texture properties such as brittleness, cohesiveness, springiness and chewiness. As a result of this study, the sausage were much for sausage prepared by adding the fat after the ice(T1) than the other sausage samples in which fat was added after ice to make emulsion type sausages.

• Water for future
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• v.21 no.4
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• pp.399-406
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• 1988

Presented in this paper is a brief summary of the basic theory and observation from a laboratory investigation aimed at determining flow characteristics and ice jam topography in a sinuous channel, and in a single-bend channel. The sinuous channel comprised thirteen $90^{\circ}$ bends and was of comparatively small s\aspect ratio. The single-bend channel was a $180^{\circ}$ bend, which was an order of magnitude large in width as well as aspect ratios than the sinuous channel. The simulated ices were polyethylene and polypropylene beads and block. The streamwise velocities near the bottom were larger than that of surface in sinuous channel and forming ice jam in sinuous channel, this phenoumena were found strongly. Jams were generally thicker along the inner bank of bends. The path of maximum-streamwise velocity was displaced towards approachs side of the inner bank of bends. Radial variation of jam thickness was to be regular by increasing size of ice fragments. The rate of jam head progression around outer bank of the single bend was faster than that of inner bank and its velocity was roughly steady. With increasing Froude number, jm thickness became less uniformly distributed; being generally thicker along the inner bank and near the jam's toe. Two-layer model might be adaptable for the computing the streamwise velocity in shallow river bends. Two cells of secondary flow cound be expected in ice covered-river bends.