• Journal of Ocean Engineering and Technology
• /
• v.23 no.6
• /
• pp.44-52
• /
• 2009

In this study, the behavior of a breasting dolphin with various dolphin heights and formations in the coastal area of Incheon was investigated. The dynamic deflection, shear stress, and moment of the pile were analyzed using the coefficient of the horizontal subgrade reaction that resulted from loading tests of different DWT (Dead Weight Tonnage). In the case of a vertical pile type dolphin, the deflection, shear stress, and moment increased as the dolphin height increased. In the case of the battered pile type dolphin, small values of shear stress and moment were shown at a low dolphin height, and the characteristics of the dynamic behavior of the dolphin showed that the deflection, shear stress, and moment increased as the pile slope of the dolphin decreased or the DWT increased.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.224-228
• /
• 2005

Dynamic control tests for Backhole as a dynamic damper were performed. For the forced oscillation generated by pressure drop in the feed line and internal wave analysis of swirl injector, hydrodynamic pulsator and 1D visualization model injector was produced, respectively We focus on effect of Backhole as a dynamic damper instead of a acoustic one. So, the breakup length and film thickness of liquid sheet on the steady state and the forced oscillation state have been measured and compared.

• Wind and Structures
• /
• v.8 no.3
• /
• pp.147-161
• /
• 2005

Two identical tall building models with square cross-sections are experimentally studied in a wind tunnel with high-frequency-force-balance (HFFB) technique to investigate the interference effects on wind loads and dynamic responses of the interfered building. Another wind tunnel test, in which the interfered model is an aeroelastic one, is also carried out to further study the interference effects. The results from the two kinds of tests are compared with each other. Then the influences of turbulence in oncoming wind on dynamic interference factors are analyzed. At last the artificial neural networks method is used to deal with the experimental data and the along-wind and across-wind dynamic interference factor $IF_{dx}$ & $IF_{dy}$ contour maps are obtained, which could be used as references for wind load codes of buildings.

• International Journal of Concrete Structures and Materials
• /
• v.1 no.1
• /
• pp.19-28
• /
• 2007

A dynamic constitutive damage model for reinforced concrete (RC) structures and formulations of blast loading for contact or near-contact charges are considered and adapted from literatures. The model and the formulations are applied to the input parameters needed in commercial finite element method (FEM) codes which is validated by the laboratory blast tests of RC slabs from literature. The results indicate that the dynamic constitutive damage model based on the damage mechanics and the blast loading formulations work well. The framework on the dynamic constitutive damage model and the blast loading equations can therefore be used for the simulation of failure of bridge components in engineering applications.

• International Journal of Fluid Machinery and Systems
• /
• v.4 no.2
• /
• pp.289-306
• /
• 2011

In the development of very high head pumped storage projects, one of the critical problems is the strength of pumpturbine runners. Data obtained by stress measurements of high head pump-turbine runners indicated that dynamic stress due to the vibration of runner might be detrimental, possibly to cause fatigue failure, if the runner were designed without proper consideration on its dynamic behaviour. Numerous field stress measurements of runners and model tests conducted with hydrodynamic similarity revealed that the hydraulic excitation force developed by the interference of rotating runner blades with guide vane wakes sometimes would induce such heavy vibration of runner. Theoretical and experimental investigations on both the hydraulic excitation force and the natural frequencies of runner have been conducted to explore this forced vibration problem.

• International Journal of Human Ecology
• /
• v.14 no.2
• /
• pp.1-13
• /
• 2013

This study examined the factors that influenced school adaptation by adolescents from non-military families and military families; subsequently, our research targeted 387 middle school children located in Chungnam province. Questionnaires were used and data analysis was conducted by t-tests and multiple regression analysis. The results were as follows: First, adolescents from non-military families perceived higher levels of attachment to fathers and self-esteem than adolescents from military families. However, the stress level for adolescents from military families was higher than adolescents from non-military families and adolescents from non-military families adapted better to school than adolescents from military families. Secondly, family dynamic, attachment to fathers, and stress influenced school adaptation by adolescents of non-military families and family dynamic and the attachment to friends influenced the adaptation to school by adolescents from military families.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.04a
• /
• pp.326-331
• /
• 2009

An algorithm is proposed for computing dynamic displacements of a bridge using FBG sensors. An existing algorithm for estimating dynamic displacements of a simply supported beam through mode superposition is extended and applied to various types of bridges with bending and torsional modes. The proposed algorithm is examined through field tests on a suspension span steel deck plate box girder bridge. Guidelines are provided for determining the number of modes and the number of strain gages to be used.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2006.04a
• /
• pp.667-674
• /
• 2006

Dynamic analysis of the electrical transmission system including transmission towers and cables is carried out by a general purpose structural analysis computer program for examining the wind-resistance of the system The spectral representation method is introduced to generate dynamic wind loads by using the Kaimal's spectrum and the measured wind velocities from wind tunnel tests, respectively. The numerical simulation results show that the responses in the case of the measured wind velocities is slightly larger than those in the case of the code.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2001.09a
• /
• pp.320-328
• /
• 2001

Base Isolation system is an effective design strategy that provides a practical substitute for the seismic design of bridge. In this study, the dynamic tests were performed on two kinds of aseismic bridge bearings : Hydampot (hysteretic damping bearing) and Dynapot . Then, the dynamic analysis was carried out far a bridge using the experimental results to estimate the seismic performance of the bearings. Analysis was performed for four types oi earthquake loadings. The results of the dynamic test and theoretical analysis indicate that the performance of both bridge bearings is appropriate fur the earthquake loading.

• Journal of the Korean Society for Railway
• /
• v.9 no.4 s.35
• /
• pp.401-411
• /
• 2006

The major objective of this study is to investigate the dynamic behaviors of track due to the deterioration characteristics of ballast for servicing tracks by the field test. The durability of ballast plays an important role in the track behaviour. To estimate the deterioration characteristics of ballast, several tests have been carried out by several scholars. The deterioration characteristics of ballast is one of the most important factor in the dynamic behaviour of track and its life. In this paper abrasion/breakage characteristics of ballast is studied to predict the effect of physical ballast characteristics on ballast track. To reveal deterioration characteristics of ballast, the field test were carried out. The deterioration characteristics, studied in this paper, is applied to the dynamic behaviour of track in various conditions.