• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2004년도 춘계학술발표회
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• pp.13-18
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• 2004

최근 우리나라 연안해역은 선박교통 용량의 대형화로 해상교통이 폭주하고 있다. 이러한 교통혼잡은 연안해역에 대해 인명, 재산, 환경오염등의 심각한 해양사고를 야기한다. 본 연구에서는 우리나라 연안의 해양사고를 확률적으로 분석한다. 본 연구의 수행을 위해 해상교통 용량과 기상조건, 해양사고등의 다양한 연관성을 기반으로 원인을 분석하였다. 그리고 해양사고의 형태를 선박의 크기, 선령, 선종등 다양한 관점에서 분류하고 세부적으로 분석하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.111-113
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• 2011

This study investigated about how much the limestone's volume was changed as time passed while maintaining a certain level of moisture condition in the limestone material for concrete under high temperature. The result is summarized as follows: It was appeared that the limestone material under high temperature emitted some CO₂ resulting from the decarboxylation, so that as the heating temperature was increased, the limestone's length change rate was decreased. In the leave time change after heating the stone, the both conditions of 50% and 100% made the limestone create Ca(OH)₂ using some H₂O. So it was appeared that as time passed, the limestone's length change rate first increased because of its volume expansion, but the rate was reduced after the limestone material was crumbled.

• Preventive Nutrition and Food Science
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• 제16권1호
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• pp.62-66
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• 2011

Functional foods play an important role in daily diet, human health and the food industry. Hemp was reported to have many advantages for nutritional and medicinal usage. In this study, extruded hemp-rice (EHR) flour, containing 30% hemp, was mixed with the wheat flour to create bread loaves at the concentrations of 5, 10 and 15%. Bread made from 100% wheat flour (with no added EHR flour) was used as a control. The physical parameters, including expansion ratio, specific volume and crust/crumb color were evaluated separately. In addition, changes in hardness of the bread during storage at ambient temperature for 3 days were also studied. The results showed that 10%-EHR bread exhibited the highest hardness value, while 15%-EHR bread presented the lowest. The bread containing EHR flour had lower specific volume and bigger air cells compared to the control. Moreover, the crust and crumb color of EHR-containing bread was significantly darker than those of the control. In this study, the 15%-EHR bread showed higher specific volume, lower hardness and bigger air cell structures.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권4호
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• pp.373-378
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• 1998

In the midfacial fracture, the orbital region presents many additional complication unique to the orbit. Among them are ectropion, entropion, lid ptosis, injury to the lacrimal apparatus, diplopia or the late development of enophthalmos. The residual problem confronting the surgen is usually enophthalmos or diplopia. Enophthalmos becomes cosmetically obvious at 3mm and if more severe it can interfere with vision from obstruction by the orbital rim. In this clinical situation, many patients prefer the simpler intraorbital volume expansion to the more complex orbital osteotomy. In general, except in mild cases of enophthalmos, the procedure of choice is osteotomy and repositioning for zygoma fracture and volume augmentation for blow-out fracture. Late treatment is performed by volume augmentation based on the CT findings behind the axis of the globe. Inferiorly placed grafts elevate the globe, posterior superior grafts move the globe anterior and medially positioned grafts push the globe laterally. In this two cases, the patients who has stable orbitozygomatic rim, the use of calvarial bone grafts more than 3 areas around intraorbital content, we corrected late enophthalmos combined with diplopia. As result, the first patient had 2mm advance in exophthalmometric check with improvement of the diplopia gradually. The second patient had 1.5mm advance with correction of vertical ocular dystopia and cosmetically good results respectively.

• International Journal of Fluid Machinery and Systems
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• 제7권3호
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• pp.110-124
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• 2014

Surge phenomena in the zone of reduced speeds in a system of a nine-stage axial flow compressor coupled with ducts were studied analytically by use of a surge transient simulation code. Main results are as follows. (1) Expansion of apparently stable, non-surge working area of the pressure vs. flow field beyond the initial stage-stall line was predicted by the code in the lower speed region. The area proved analytically to be caused by significantly mismatched stage-working conditions, particularly with the front stages deep in the rotating stall branch of the characteristics, as was already known in situ and in steady-state calculations also. (2) Surge frequencies were found to increase for decreasing compressor speeds as far as the particular compressor system was concerned. (3) The tendency was found to be explained by a newly introduced volume-modified reduced surge frequency. It suggests that the surge frequency is related intimately with the process of emptying and filling of air into the delivery volume. (4) The upstream range of movement of the fluid mass having once passed through the compressor in surge was found to reduce toward the lower speeds, which could have caused additionally the increase in surge frequency. (5) The concept of the volume-modified reduced surge frequency was able to explain, though qualitatively at present, the behaviors of the area-pressure ratio parameter for the stall stagnation boundary proposed earlier by the author.

• Composites Research
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• 제28권6호
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• pp.366-371
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• 2015

In order to improve the mechanical properties of tungsten at room and elevated temperature, hafnium carbide (HfC) reinforced tungsten matrix composites were prepared using the spark plasma sintering technique. The effect of HfC content on the compressive strength and flexural strength of the tungsten composites was investigated. Mechanical properties of the composites were also measured at elevated temperatures and their trends, with varying reinforcement volume fraction, were studied. The effect of reinforcement fraction on the thermal properties of the composites was investigated. The thermal conductivity and diffusivity of the composites decreased with increasing temperature and reinforcement volume fraction. An inherently low thermal conductivity of the reinforcement as well as interfacial losses was responsible for lower values of thermal conductivity of the composites. Values of coefficient of thermal expansion of the composites were observed to increase with HfC volume fraction.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.157-164
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• 2008

The temperature-entropy diagram of water or vapor displays graphically the thermophysical properties, so it is very conveniently used in various thermal systems. On general T-s chart of water, there are temperature, pressure, quality, specific volume, specific enthalpy, specific entropy. However, various state and process values besides above properties can be plotted on T-s diagram. In this study, we developed the software drawing twenty six kinds of properties, that is temperature, pressure, quality, specific volume, specific internal energy, specific enthalpy, specific entropy, specific exergy, exergy ratio, density, isobaric specific heat, isochoric specific heat, ratio of specific heat, coefficient of viscosity, kinematic coefficient of viscosity, thermal conductivity, prandtl number, ion product, static dielectric constant, isentropic exponent, velocity of sound, joule-thomson coefficient, pressure coefficient, volumetric coefficient of expansion, isentropic compressibility, and isothermal compressibility. Also, this software can analyze and print the system values of mass flow rate, volume flow rate, internal energy flow rate, enthalpy flow rate, entropy flow rate, exergy flow rate, heat flow rate, power output, power efficiency, and reversible work. Additionally, this software support the functions such as MS-Power Point.

• Computers and Concrete
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• 제23권5호
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• pp.321-327
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• 2019

Experimental isotherm compressive tests show that concrete behaviour is dependent on temperature. The aim of such tests is to reproduce how concrete will behave under environmental changes within a moderate range of temperature. In this paper, a novel constitutive elastic damage behaviour law is proposed based on a free energy with an apparent damage depending on temperature. The proposed constitutive behaviour leads to classical theory of thermo-elasticity at small strains. Fixed elastic mechanical characteristics and fixed evolution law of damage independent of temperature and the material volume element size are considered. This approach is applied to compressive tests. The model predicts compressive strength and secant modulus of elasticity decrease as temperature increases. A power scaling law is assumed for specific entropy as function of the specimen size which leads to a volume size effect on the stress-strain compressive behaviour. The proposed model reproduces theoretical and experimental results from literature for tempertaures ranging between $20^{\circ}C$ and $70^{\circ}C$. The effect of the difference in the coefficient of thermal expansion between the mortar and coarse aggregates is also considered which gives a better agreement with FIB recommendations. It is shown that this effect is of a second order in the considered moderate range of temperature.

• 한국식품영양학회지
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• 제36권6호
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• pp.561-571
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• 2023

The aim of this study was to determine the quality characteristics of bread with 2%, 4%, 6%, and 8% cuttlefish ink added. The pH of the dough decreased as the addition percentage increased, and the addition of 8% was the lowest. The pH of the bread and the fermentation expansion power of the dough decreased as the addition percentage increased. Moisture and ash content were positively correlated with the addition percentage, and the crude protein and crude ash content were negatively correlated. As the addition percentage increased, the color of the bread became darker, and the bread volume decreased. The inside and outside color of the bread also decreased as the addition percentage increased. The volume and specific volume of bread decreased as the addition percentage increased. The amino acid analysis indicated glutamic acid was the largest, free amino acid analysis pointed out aspartic acid the highest. The springiness, cohesiveness, gumminess, brittleness, and hardness of the bread were positively correlated with the addition percentage. Overall, it seems possible to develop bakery items using cuttlefish ink as a functional ingredient.

• 대한전자공학회논문지SP
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• 제41권5호
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• pp.53-62
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• 2004

본 연구에서는 화상평면내 미지 호흡운동에 의한 MRI 아티팩트를 수정하기 위한 개선된 후처리 기법을 제안한다. 호흡운동은 2차원의 선형확대축소 운동으로 모델화 된다 신체조직을 비압축성 유체모양의 물질로 가정할 때 촬상 대상물체에 대한 단위체적당 푸로톤 밀도는 일정하다고 가정한다. 적용한 모델에 의하면 호흡운동은 위상오차와 불균일 표본화 및 진폭변조왜를 MRI 데이터에 부여한다. 운동파라메타가 알려져 있거나 추정가능하다고 할 때 양선형 중첩법에 기초한 재구성 알고리즘이 MRI 아티팩트를 수정하기 위해 사용된다. 운동 파라메타가 미지인 경우 스펙트럼 이동법을 적용해서 호흡변동함수와 x 방향 확대계수 및 x 방향 확대중심을 추정한다. 다음으로 에너지 최소법을 이용해서 y 방향 확대계수 및 y 방향 확대중심을 추정한다. 최종적으로 시뮬레이션된 체동화상을 통해서 제안한 본 방법의 유효성을 확인한다.