• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.714-717
• /
• 2011

본 논문에서는 선체 블록의 운반 작업 중 발생하는 동적 하중 및 골리앗 크레인의 와이어로프와 선체블록 간의 동적 접촉력을 고려한 최적 러그 배치 시스템을 설계하고, 다물체계 동역학 커널과 외력 계산커널을 개발하였다. 다물체계 동역학 커널은 recursive formulation을 이용하여 운동 방정식을 구성하고, 외력 계산 커널은 비선형 유체정역학적 힘, 선형 유체동역학적 힘, 풍력, 계류력을 계산할 수 있다. 이를 이용해 블록에 작용하는 와이어로프와 블록 간의 간섭과 동적 접촉력을 계산하고, 그 결과를 이용하여 러그가 부착된 블록의 구조 해석을 수행하였다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2001.11a
• /
• pp.25-29
• /
• 2001

소비자 감성 분석에 근거한 블록 스트라이프 패턴(block stripe pattern)의 디자인 방법을 제안하고자 남녀 30명을 대상으로 명도, 폭, 간격이 조작된 서로 다른 27개의 블록 스트라이프 패턴의 자극물을 제시하여 감성평가를 실시하였다. Likert 척도에 의해 명도, 배열, 폭, 간격의 4가지 디자인 요소가 요인분석을 통해 도출된 12개의 감성차원에 미치는 영향을 측정하고, 물리량에 근거한 정량적 분석을 통해 감성과의 관계를 파악하였다. 이를 근거로 각각의 감성에 부합하는 명도, 배열, 폭과 간격의 디자인 요소별 물리량과 함께 디자인 요소의 물리적 변화에 따른 감성예측 회귀모형을 도출하였다. 디자인 요소 중 명도차, 간격, 폭의 순으로 디자인 요소의 물리량 변화가 유의적인 감성차를 유발하는 것으로 나타났다. 이 중 명도차는 "캐주얼한"을 제외한 모든 감성에서 감성차에 영향을 미치는 가장 설명력 높은 디자인 요소로 분석되었다. 이 결과를 토대로 각각의 감성에 부합하는 디자인 요소별 물리량과 함께 디자인 프로토타입을 제시하였다.

• Structural Engineering and Mechanics
• /
• v.23 no.3
• /
• pp.309-323
• /
• 2006

In this paper, seismic response of a free-standing ship located in a dry dock and supported by an arrangement of n keel blocks due to base excitation is addressed. Formulation of the problem including derivation of governing equations in various modes of motion as well as transition conditions from one mode to another is given in Moghaddasi and Bargi (2006) by same authors. On the base of numerical solution for presented formulation, several numbers of analyses are conducted to study sensitivity of system's responses to some major contributing parameters. These parameters include friction coefficients between contacting surfaces, block dimensions, peak ground acceleration, and the magnitude of vertical ground acceleration. Finally, performance of a system with usual parameters normally encountered in design is investigated.

• Communications for Statistical Applications and Methods
• /
• v.5 no.3
• /
• pp.607-621
• /
• 1998

When fitting a response surface model, the least squares estimates of the model's parameters and the prediction variance will generally depend on how the response surface design is blocked. That is, the choice of a blocking arrangement for a response surface design can have a considerable effect on estimating the mean response and on the size of the prediction variance even if the experimental runs are the same. Therefore, care should be exercised in the selection of blocks. In this paper, we prognose a graphical method for evaluating the effect of blocking in a response surface designs using cuboidal regions in the presence of a fixed block effect. This graphical method can be used to investigate how the blocking has influence on the prediction variance throughout the entire experimental region of interest when this region is cuboidal, and compare the block effect in the cases of the orthogonal and non-orthogonalblockdesigns, resfectively.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2008.09a
• /
• pp.10-15
• /
• 2008

The proper docking block arrangement, loading condition and structural reinforcement are required to ensure structural safety of ship, when she is in re-docking and launching for inspection or repair. The large reaction force due to narrow bottom tangent area, heavy weight and ballast loading are occurred at aft body and fore body of ship. Especially, in case of LNGC, the strength evaluation is necessary for cargo hold areas including mid-body because tank hydro test is performed in dry-dock. The analysis results and experiences to confirm structural safety for docking of conventional LNGC$(138K{\sim}151.7K)$ are introduced in this paper.

• Journal of Environmental Health Sciences
• /
• v.32 no.2 s.89
• /
• pp.118-125
• /
• 2006

The road traffic noise has been increasing broader effects on urban areas as well as rural areas because of rapidly increasing traffic volume and newly-constructed roads. 10 sites in building development areas were selected and the noise levels were measured by the apartment floors and by the various block plans of apartment complex. The results showed that the highest traffic noise level was obtained at the 5 and 7 floors on the apartment floors. On the basis of 7 floor with the highest level, the correction coefficient obtained from noise reduction by each floor and measurement point was -5.54 dB(A)(1st floors), -0.96 dB(A)(3rd floors), -0.38 dB(A)(5th floors), 0.00 dB(A)(7th floors), -1.98 dB(A)(l0th floors), -3.10 dB(A)(13th floors), -3.45 dB(A)(15th floors). The level of road traffic noise in the arrangement construction of right angle was about 3.0 dB(A) at N-4 point and 2.1 dB(A) at N-6 point lower than that of a plan figure, respectively. The results suggested that application of correction coefficient obtained by the apartment floor and by the arrangement construction can be improved in road traffic noise.

• Journal of Environmental Impact Assessment
• /
• v.14 no.5
• /
• pp.247-254
• /
• 2005

Road traffic noise has increasing broader effects on urban areas as well as rural areas because of rapidly increasing traffic volume and newly-constructed roads. 10 sites in building development areas were selected and the noise level were measured by the apartment floors and by the various block plans of apartment complex. Analysis result, about correction factor, in the case of right angle arrangement, apply - 2.5dB(A). In the case of apartment house correlation of each floor apply 1st floors 0dB(A), 2st floors 1.2dB(A), 3st floors 2.1dB(A), 4st floors 2.6dB(A), 5st floors 2.7dB(A), 6st floors 2.7dB(A), 7st floors 2.4dB(A), 8st floors 2.0dB(A), 9st floors 1.6dB(A), 10st floors 1.1dB(A), 13st floors 0.2dB(A), 15st floors 0.5dB(A). The level of road traffic noise in the arrangement construction of right angle was about 3.0dB(A) at N-4 point and 2.1dB(A) at N-6 point lower than that of a plan figure, respectively. The results suggested that application of correction coefficient obtained by the apartment floor and by the arrangement construction can be improved in road traffic noise. The results suggested that application of correction coefficient obtained by the apartment floor and by the arrangement construction can be improved in road traffic noise.

• Journal of the Korean Society of Safety
• /
• v.21 no.2 s.74
• /
• pp.80-88
• /
• 2006

In the present study damage behavior of resilient sleepers on concrete ballasts is analyzed. Cracks of resilient sleepers in a railway track system are concentrated on inside of blocks to which the tie bars are connected. Finite element analysis is performed by dividing a block into the straight section and the curved section according to the load condition of the resilient sleeper, and limited the interpretation within the range of resilience. In addition, the value of stress obtained from the interpretation was compared with the allowable stress of concrete to determine the safety. According to the result of numerical analysis, compared with the stress before unequal settlement, the tensile stress of the inside of the block increased significantly after the settlement considering the entire block, and the tensile stress of this part exceeded the allowable stress of concrete, so was undesirable in terms of safety. In reality, the arrangement of tensile stiffeners inside blocks connected to tie bars is improper in the design of resilient sleepers, and when unequal settlement occurs, tensile stress increases on this part and consequently causes cracking damage. It is necessary to arrange wire meshes or tensile reinforcing bars in a structurally safe way to reinforce the inside of blocks on which cracks are concentrated.

• Journal of the Korean Wood Science and Technology
• /
• v.49 no.4
• /
• pp.336-359
• /
• 2021

In this study, hybrid CLT research and development trends were analyzed to improve the low rolling shear strength of CLT, a large wooden panel used in high-rise wooden buildings. Through this, basic data that can be used in research and development directions for localization of CLT were prepared. As a way to improve the low rolling shear strength, the use of hardwood lamina, the change of the lamina arrangement angle, and the use of structural composite materials are mainly used. Rolling shear strength and shear modulus of hardwood lamina are more than twice as high as softwood lamina. It confirmed that hardwoods can be used and unused species can be used. Rolling shear strength 1.5 times, shear modulus 8.3 times, bending stiffness 4.1 times improved according to the change of the layer arrangement angle, and the CLT strength was confirmed by reducing the layer arrangement angle. Structural wood-based materials have been improved by up to 1.35 times MOR, 1.5 times MOE, and 1.59 times rolling shear strength when used as laminas. Block shear strength between the layer materials was also secured by 7.0 N/mm², which is the standard for block shear strength. Through the results of previous studies, it was confirmed that the strength performance was improved when a structural wood based materials having a flexural performance of MOE 7.0 GPa and MOR 40.0 MPa or more was used. This was determined based on the strength of layered materials in structural wood-based materials. The optimal method for improving rolling shear strength is judged to be the most advantageous application of structural wood based materials with strength values according to existing specifications. However, additional research is needed on the orientation of CLT lamina arrangement according to the fiber arrangement of structural wood-based materials, and the block shear strength between lamina materials.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.24 no.2
• /
• pp.146-153
• /
• 2014

This study investigates the effects of seat-design elements such as seating arrangement, shape, and height on speech privacy in high-speed trains. For the evaluation of speech privacy, acoustic simulation software was used to reproduce room acoustical conditions in passenger cars on the basis of in-situ measurement data. The influences of speech source directivity and source height on privacy distance ($r_P$) were investigated, and it was found that $r_P$ determined using an omni-directional source was relatively shorter than that determined using a directional source. It was also found that $r_P$ decreased when the source height was lower than the height of the seat-back because the seat-back blocked the propagation of speech from the sound source. The effect of seating arrangement was not significant when comparing the vis-a-vis seating and one-side seating arrangements. In addition, among the alternative seat-designs, the seats that block the space between the seats and cover the space near the ear were found to show significantly enhanced speech privacy in high-speed train passenger cars.