• 소성∙가공
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• 제6권6호
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• pp.517-526
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• 1997

The purpose of this study is to investigate changes in the wall thickness of tube sinking and working forces by the upper bound method and ABAQUS code. The independent variables are ; workpiece material, original wall thickness of tube, die angle, friction, and reduction of diameter. The results indicate that these five variables are factors of the increase in wall-thickness and working forces. Three variables, a inner tube wall angle and two angles of the velocity discontinuous surfaces, are optimized in this proposed velocity field by the upper bound method. In this method, we can estimate the working forces and final tube thicknesses similar to actual forming process. Optimum process variables which are obtained by upper bound method are used in ABAQUS pre-model.

• 대한기계학회논문집B
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• 제30권10호
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• pp.982-986
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• 2006

It is well known that the surface tension forces can make a particle denser than water float when the size of the particle is of the order of 1 mm. This is deeply related to the basic mechanism enabling small insects to wander around on the pond surface and also to a newly emerging technology of self-assembly using capillary forces. For the quantitative understanding of this effect, we experimentally study the maximum density of a cylinder that can float on water and how fast the cylinder sinks when the density exceeds the maximum value. We compare our experimental results with the theoretical prediction and find good agreement between them.

• 한국지구과학회지
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• 제28권5호
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• pp.598-602
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• 2007

A long-term in situ observation was carried out in the Ice-valley at Milyang in order to explain the factors and processes associated with the summertime ice formation. The variation of temperature inside Ice-valley in relation with ice formation in summer time was found to depend on precipitation rate in spring and cold air sinking in autumn and winter. The rate of temperature rising tends to correspond to sensible heat release depending on the precipitation amount at the freezing location. The reason of the cold air accumulation in a talus in the Ice-valley is the cold air sinking over the surface of talus due to the occurrence of outside clod air mass and the accumulated cold air from autumn to spring flow outside at the bottom of talus. The out-flowing cold air can result in the ice formation in the hot summer.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.781-784
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• 2006

This paper investigates the fundamental properties of light weight foamed concrete with the variances in unit weight of concrete and adding ratio of stability agent(SA). Test showed that concrete adding SA slightly decreased fluidity but secured stable flow appearances without segregation of concrete components. All specimens in a standard condition represented that a sinking depth was not observed, while, in the wet condition, a specimen adding SA decreased the sinking depth $2{\sim}4mm$ more than control concrete. Compressive strength values of control concrete showed $0.03{\sim}0.3MPa$ higher than the concrete adding SA. As for the tensile strength, the specimen adding SA also had lower value, while the ratios of comp. to tens. strength presented $0.43{\sim}0.62$, which is relatively higher than ordinary concrete.

• 수산해양기술연구
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• 제51권1호
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• pp.50-60
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• 2015

This paper conducted research on identifying the process of change in fishing gear and organizing the function of periodically-used fishing gear types through net plan and computer simulation by selecting the design of the four types of fishing gear used for the Korea tuna purse seiner in the Western and Central Pacific Ocean, which 1,000 G/T class and whose length over all 60 m class. In the late 1980s, the length of the tuna purse gear was 1,939 m and the design depth was 160 m, but currently, the length and the design depth are 2,515 m and 230 m, respectively. As a result of the simulation, the expansion of the fishing gear increased buoyance, sinking force, sinking depth, surrounded area, and purse wire continuously. Recently, the maximum tension of the currently used purse wire of tuna purse seiner is 23.5 tons and is close to 25.4 tons which is the maximum lift capacity of WS454 winch. The way to improve fishing gear should be proceeded to increase sinking speed rather than expand the size of fishing gear.

• 대한기계학회논문집A
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• 제38권11호
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• pp.1283-1290
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• 2014

최근에는 법공학 분야에 구조해석 및 구조-유동 연성해석을 이용한 다양한 시뮬레이션 기법을 활용하여 안전사고 및 재난사고에 대한 법적 책임문제를 해명하고 보다 정확한 원인분석을 통해 원인을 규명하고 있는 추세이다. 본 연구에서는 법공학적 관점에서 DCM(Deep Cement Mixing) 선박의 침몰 사고의 원인을 밝혀내고자 하였다. 사고 선박은 선박 건조 당시 SCP(Sand Compaction Pile) 전용 선박으로 건조되었으며, DCM 선박으로 구조 변경을 위해 안정성 검토 없이 리더부 높이 변경 및 증설을 하였다. 이러한 구조물의 증설 및 변경이 본 침몰 사고에 미치는 영향을 알아내고자 상용 구조 해석프로그램인 ADINA를 이용하여 구조안정성 평가를 수행하였으며, 본 연구를 통하여 구조물의 증설 및 변경에 따른 ADINA 해석 결과를 비교, 분석함으로써 DCM 선박 침몰 사고의 정확한 원인을 밝혀낼 수 있었다.

• Ocean and Polar Research
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• 제33권spc3호
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• pp.385-395
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• 2011

Time-series sediment traps were deployed at 1,000 m water depth of the northwestern subtropical Pacific from July 2009 to June 2010, with the aim of understanding temporal and spatial variations of sinking-particle fluxes. The opening and closing of the traps was synchronized at 18-day periods for 20 events. Total mass fluxes showed distinct seasonal variations with high values for the summer-fall seasons and relatively low values for winter-spring. This seasonal variation at two stations was characterized by a distinct difference in $CaCO_3$ fluxes between the two seasons. The enhanced $CaCO_3$ flux in the summer - fall seasons might be attributed to an increased planktonic foraminiferal flux. Total mass flux at FM10 station was nearly 50% higher than that at FM1 station. The difference in $CaCO_3$ fluxes between two stations contributed nearly 70% of the difference of total mass fluxes. The $CaCO_3$ flux was a major component controlling temporal and spatial variation of sinking - particle fluxes in the western subtropical Pacific Ocean.

• 한국한의학연구원논문집
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• 제14권3호
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• pp.121-126
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• 2008

Pulse diagnosis refers to the process of diagnosing a patient by feeling an artery on the wrist based on the shape that the pulse take s while the hold-down pressure increase. The styloid process artery on the wrist is usually felt, and the pulse is taken on Chon, Gwan and Cheok using three fingers. This study is to examine the structural difference in the location of pulse diagnosis by measuring and analyzing blood diameter, blood depth, and blood flow velocity of the location of pulse diagnosis by using ultrasonic wave (VOLUSION730 PRO, GE Medical, U.S.A). This study also attempted to grasp whether the characteristics of blood vessels differ depending on Body Mass Index (BMI) and analyzed their correlation with Oriental medical pulse diagnosis. The male subjects without cardiovascular diseases were divided into the normal BMI group, the underweight group and the overweight group and 10 people of each group were measured, Blood depth, blood diameter and blood flow velocity at the location of pulse diagnosis (Chon, Gwan, Cheok) of the wrists of left and right hands were measured and the pulse wave was measured by using pulse diagnosis instrument (3-D Mac, DaeyoMedi, Korea).The results of this study showed that the characteristics of blood vessels differ depending on the degrees of obesity, and the characteristics of floating pulse and sinking pulse of Oriental medical pulses were related to the degrees of obesity. This shows that the characteristics of the blood vessels of subjects and BMI information are the major indicators for diagnosis and are the matters that must always be considered when developing the algorithm of pulse diagnosis.

• 한국환경과학회지
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• 제5권2호
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• pp.153-170
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• 1996

멕시코 만에서 1987~1988년에 부유 및 칩강입자에 존재하는 광합성 색소 및 그 분해산물은 HPLC를 이용하여 측정하였다. 클로로필과 카로틴계열 및 그 분해산물의 단기 침하율이 Cold-Core Ring 과 Warm-Core Ring에서 비교 분석되었다. 클로로필 a는 CCR과 WCR에서 공통적으로 우세한 포르피린이었으며 카로틴계열 색소 중에는 19'-hwxanoyloxyfucoxanthin이 우세하였다. 초식자의 섭이과정에서 생성되는 것으로 알려진 phaeophobide a가 조사지역 침강입자에 우세하게 나타나는 분해색소 이었따. CCR에서의 전체색소 침하율은 WCR보다 한단게 높게 나타났다. WCR에서 색소현존량은 하루에 1% 이하가 유광밖으로 침하 되었는데 이 사실은 멕시코 만에서 부유고형입자의 재순환은 빠르게 일어나고 있지 않음을 의미한다.

• 동의생리병리학회지
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• 제19권2호
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• pp.358-362
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• 2005

Directional words like 'ascending(升, sheng)', 'descending(降, jiang)', 'floating(浮, fu)', 'sinking(沈, chen) are technical terminologies of Oriental Medicine to express the directions of material medica functioning-at the phase of Qi-superiorly, inferiorly, exteriorly, and interiorly in human body, and are constituting one of the major principles in prescribing medicines. Lacking the objective methodology to measure or, at least determine Qi, However, we can not expect to secure meaningful data to verify those directional terms. This problematic situation caused chaotic discrepancy between theory and practice of Oriental Medicine. Thus, adopting the method of dynamic meditation 'Hanalmomjit' of Lux Vitae meditation society, by which various state of Qi-sensational movements can be expressed, we compared its moves with the directional terms of traditional canons in Oriental Medicine. In this thesis, the experiment of expressing materia medica via 'Hanalmomjit' is resulted out and compared with the terms, confirmed to have a certain meaningfulness. The new method showed these results below: Herba Menthae, described to have the disposition of ascending and floating, showed 60% of ascending movements in 'Hanalmomjit' experiment. Radix Rehmanniae Praeparata, described to have the disposition of descending and sinking, showed 50% of descending movements. Radix Glycyrrhizae, described to have plain disposition, showed 60% of central movements. Rhizoma Atractylodis and Pericarpium Citri Reticulatae, described to have the disposition of ascending and floating, showed also ascending movements. Cortex Magnoliae Officinalis, described to have the disposition of descending and sinking, showed also descending movements. In conclusion, qi-sensational movement of 'Hanalmomjit' for materia medica showed sufficient relations described in classics, proving itself to be useful method for objective demonstration of material medica.