• 한국응용과학기술학회지
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• 제33권3호
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• pp.411-420
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• 2016

The objective of this study was to determine the effect of drinking water containing trimethyl glycine or ascorbic acid on growth performance and blood parameter profiles of duck exposed to scorching heat stress. A total of 480 ducks were randomly assigned to the following eight experiment groups for 42 days : control group C with general water, treatment group 1 (T1) with drinking water containing 100 ppm ascorbic acid, treatment group 2 (T2) with drinking water containing 200 ppm ascorbic acid, treatment group 3 (T3) with drinking water containing 300 ppm ascorbic acid, treatment group 4 (T4) with drinking water containing 400 ppm trimethyl glycine, treatment group 5 (T5) with drinking water containing 800 ppm trimethyl glycine, treatment group 6 (T6) with drinking water containing 1,200 ppm trimethyl glycine, treatment group 7 (T7) with electrolytes of KCl (0.5%) + $NaHCO_3$ (1.0%)+NaCl (0.5%). Our results revealed that the body weights and feed intakes of treatment groups, especially T3 and T6, were increased compared to the control group, where as the feed conversion ratios of treatment groups were decreased (p<0.05). Blood levels of total cholesterol, triglyceride, LDL-C, glucose, AST, ALT and pH in treatment groups were lower compared to those in the control group (p<0.05). Blood levels of red blood cell, platelets profiles, electrolyte and gas in treatment groups were higher compared to those of the control group (p<0.05).

• 대한조선학회논문집
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• 제46권5호
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• pp.510-519
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• 2009

Ship structure is composed of the welded mixture members which are plate and stiffeners. Ship structure is also influenced by variable loadings such as wave and inertia load. There have been several fatigue damage problems on the connection between longitudinal and transverse web due to wide usage of high tensile steel and adoption of wide web space to improve shipbuilding productivity. It is impossible to estimate the fatigue lives for all connection details through refined fatigue analysis. It is necessary to use the simplified approach for the fatigue life estimation of the connection details. PLUS analysis, which is suggested by the classification society, is one of the simplified approaches and is widely adopted to get fatigue lives for the connection details along whole cargo hold area. However, ship building yards still have difficulties to get fatigue lives due to large amount of calculation and time even if this approach reduce the time and amount of calculation. This paper treats the computing system developed to reduce efforts of estimating the fatigue lives. The influence factors of mean shear stress and local dynamic pressure are easily calculated and fatigue lives for all hot spots can be estimated automatically by the developed computing system. It is possible to reduce computing time and efforts to get the fatigue lives for the connection details between longitudinals and transverse webs along the ship. This system was applied to get fatigue lives on the connection details of a VLCC and verified the availability.

• 지질공학
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• 제15권3호
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• pp.309-323
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• 2005

지반의 동적 강성은 내진 설계나 내진 성능 평가외에도 구조물의 거동평가에 필요한 중요한 지반 정수이다. 지난 수십년동안 이 물성을 효율적이고 정밀하게 측정하기 위해, 여러 가지 검측공 탄성파 시험 기법들이 개발 및 적용되어왔다. 게다가, 최근 지하 공간의 개발 및 구조물의 대형화로 인해 암반 강성의 평가를 위한 신뢰성 있는 지반 조사기법의 개발이 더욱 절실히 요구되고 있다. 본 논문에서는 "인홀 탄성파 시험"으로 명명된 새로운 기법을 적용하여 구조물 기초 암반과 터널 막장 암반의 동적 강성을 측정하였다. 국내 여러지역의 암반에서 수행한 인홀 시험 결과를 다른 탄성파 시험 결과와 비교함으로써 인흘 시 험 기법의 신뢰도를 평가하고, 이 기법의 효율성과 정밀성을 입증하였다.

• 대한조선학회논문집
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• 제37권2호
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• pp.118-126
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• 2000

용접이음재에서는 용착금속, 열영항부 및 모재가 열사이클 및 조직의 변화에 의하여 각종 기계적 성질의 차이가 있으며, 특히 부식환경에서는 이들의 영향이 현저하게 나타나는 경우가 많다. 또 용접이음재의 피로강도는 이음형식, 용접금속 및 열영향부의 특성, 사용환경과 응력의 종류에 따라 변화한다. 따라서 본 연구에서는 현재 선박 및 해양구조물의 건조에 많이 채용되고 있는 TMCP 강재의 $CO_2$ 가스 용접이음재의 열영향부에 대한 대기중 및 부식환경중에서의 회전굽힘피로시험을 실시하여 피로균열의 발생 및 성장거동을 조사 검토하였다. 또한 대기중의 피로강도와 부식환경중의 피로강도를 비교함으로써 부식효과 및 응력집중효과 등을 고려한 용접이음재의 부식환경중에서의 피로강도 평가법 및 피로강도 설계곡선을 검토하였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 추계학술대회 논문집
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• pp.204-212
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• 2003

As the first step to investigate the nonlinear interactions between turbulence and marine structures inside a viscous NWT, a LES technique was applied to the turbulent channel flow for $Re_{T}=150$, in this paper. The employed models were 4 types, such as the Smagorinsky model, the Dynamic SGS model, the Structure Function model and the Generalized Normal Stress model. The simulated data in time-series for the LESs were averaged in both time and space and performed statistical analysis. And results of the LESs were compared with those of a DNS developed in the present study and two spectral methods by Yoon et al.(2003) & Kim et al.(1987). It seems to be quite difficult to evaluate their performances to the present problem, but is seen that the accuracy of LESs are still related to the number of grids(or fine grid size).

• 한국해양공학회지
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• 제25권2호
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• pp.120-126
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• 2011

The fatigue damages in structural details of offshore plants can be accumulated due to various environmental loadings such as swell, wave, wind and current. It is known that load histories acting on mooring and riser systems show stationary and ergodic bimodal wide-banded process. This paper provides refined approach to obtain time signals representing stress range histories from wide-banded bimodal spectrum which consists of ideally narrow-banded and fully separated two spectrums. Variations of the probabilistic characteristics for time signals according to frequency and sampling time increments are compared with the reference data to be the probabilistic characteristics such as zero-crossing period, peak period, and irregularity factor obtained from an assumed ideal spectrum. It is proved that the sampling time increment more affects on the probabilistic characteristics than frequency increment. The fatigue damages according to the frequency and sampling time increments are also compared with the ones with minimum increment condition which are thought to be exact fatigue damage. It is concluded that the maximum sampling time increment to obtain reliable time signals should be determined that ratio of applied maximum sampling time increment and minimum period is less than approximately 0.08.

• 한국의상디자인학회지
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• 제19권2호
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• pp.15-28
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• 2017

Today, modern people are exposed to various environmental pollutants such as harmful substances and stress, which can compromise health. Therefore, a healing culture that seeks to enjoy human life based on the healing of body and mind is attracting great attention. The purpose of this study is to develop environmentally friendly natural dyeing considering a healing concept with four elements: color, dye, material, and pattern. The research methods and scope are based on a theoretical review of healing and research on the literature of bedding related to natural dyes, national and international books, the Internet, etc., and naturally dyed bedding. This paper presents actual production research. The results of this study are as follows. First, the elements of color, dyeing, material and pattern were developed through the process of a bedding design development model that applies a healing concept and can be commercialized as a healing bedding product. Second, a healing color proposal was expressed in an intermediate color system of pink, ocher, lavender, and indigo colors for emotional stability, warmth, calmness, comfort and softness. Third, eco-friendly bedding using natural dyes with medicinal efficacy can obtain the healing effect of the natural treatment method, which can aid healthy sleep. Fourth, the pattern used in the bedclothes was a motif of Sarasa embroidery, flower embroidery, ribbon embroidery, and wave quilting motifs to provide psychological stability as a healing concept in the sleeping environment. The natural healing bedding with the healing concept proposed in this study has natural treatment that is beneficial to human health and the development of bedding with natural dyes will lead to an increase of demand for the sleeping environment.

• 대한토목학회논문집
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• 제34권1호
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• pp.9-16
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• 2014

최근 수중폭발로 인한 구조물의 충격응답에 대한 연구는 매우 높은 비용과 소요시간, 민감한 환경문제 등으로 인하여 실제 시험보다는 컴퓨터를 통한 수치해석적 연구가 활발히 진행되어 왔다. 또한 시뮬레이션의 기술 향상과 더욱 정교해진 기능들로 수치 시뮬레이션의 효율성이 증가되었을 뿐 아니라 그 신뢰성까지 증가하였다. 본 연구에서는 유체 표면의 Acoustic Pressure와 구조물 표면 변위의 적절한 관계를 다루는 구조-유체 상호작용(FSI : Fluid-Structure Interaction), 수중폭파 형태를 결정하는 유체의 깊이와 폭발물과 구조물 사이의 거리에 대한 파라미터를 상용 유한요소 프로그램인 ABAQUS에 적용한 시뮬레이션 값과 실험적 이론 값 비교에 중점을 두었다. 수중폭발로 인한 파이프의 충격테스트 응답 분석은 ABAQUS/Explicit을 사용하여 수행되었고, 시간이력에 따른 충격하중, Acoustic Pressure, 타격지점의 응력, 속도, 변형에너지 등 ABAQUS CAE에서 결과를 나타내었다.

• 한국가구학회지
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• 제26권1호
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• pp.77-91
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• 2015

The appeal of sauna is caused by the fact that through that, one can feel Korea's unique temperament and culture; however, because of its being a public facility and flooding of businesses due to excessive supplies of various additional features such as washing, playing, eating, sleeping and health care functions, issues of social resources and environment come to the fore, so it has reached a situation of red ocean that it is difficult to enter the market anymore. Taking these into account, this study focused on developing a thermal technology and design of the housing of an environment-friendly mobile home sauna, making the most use of the sauna's fundamental purpose and settling it as a tourist product, analyzing the marketing research on the existing sauna and considering the recent housing trends and lifestyles for a new concept sauna. Thus, regarding its characteristics and utilization, it was designed smaller than $10m^2$ (3 pyeong) so that it would be easy to install in any space and convenient to move. It can be installed in separate buildings and rest spaces such as country houses, resorts, pensions, camping grounds as well as outdoor houses, custom produced for a measure of pyeong that customers want so as to match up with the Enforcement Ordinance of the Agricultural Land Act in a concept of the farmer's hut and kitchen, bathroom and bathroom can be installed inside according to an option. In addition, regarding its efficacy, in order to give environment-friendly healing effects, materials such as Hinoki Cypress, red clay and hardwood charcoal were used, a fixed indoor temperature of $70{\sim}100^{\circ}C$ was maintained by heating methods such as electromagnetic wave free, energy saving and low-power boiler, and it was made to have excellent effects on fatigue recovery, relieving stress, skin care and diet through far-infrared emission.

• 대한교통학회지
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• 제34권6호
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• pp.560-569
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• 2016

운전자의 정신부하는 교통사고를 감소하는데 중요한 역할을 하는 것으로 선행연구에서 나타나고 있다. 본 연구에서는 도로 및 환경요소 뿐만 아니라 운전자의 알파파, 베타파, 감마파를 측정할 수 있는 운전시뮬레이터를 활용하여 분석자료를 확보하였다. 운전자의 운전부하와 감마파의 연관성을 분석하기 위한 방법으로 로지스틱모형을 적용하였다. 분석결과, 도로의 커브가 많을수록 운전자의 베타 영역은 증가하는 반면 알파와 감마 영역은 감소되는 것으로 나타났다. 그리고, 운전부하는 감마영역과 음의 상관관계를 지닌 것으로 나타났다. 결론적으로, 직선구간에서의 도로주행이 운전자의 스트레스를 줄이고 행복감을 높일 수 있을 것으로 판단된다.