• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.11
• /
• pp.2266-2268
• /
• 2009

In this paper, a simple method of angle velocity estimation is presented for a passive dynamic biped robot. The estimation problem is not an easy task because its dynamic model is a hybrid system involved with an impact condition. Instead of designing a complex observer for hybrid systems we simply utilize the impact condition to reset the initial condition of the high-pass filter when the non-support leg hits the slope. The approach has been verified by simulation results.

• Nuclear Engineering and Technology
• /
• v.53 no.9
• /
• pp.3085-3099
• /
• 2021

Investigations of large commercial aircraft impact effect on nuclear power plant (NPP) buildings have been drawing extensive attentions, particularly after the 9/11 event, and this paper aims to numerically assess the damage and vibrations of NPP buildings subjected to aircrafts crash. In Part I of present paper, two shots of reduce-scaled model test of aircraft impact on NPP were conducted based on the large rocket sled loading test platform. In the present part, the numerical simulations of both scaled and prototype aircraft impact on NPP buildings are further performed by adopting the commercial program LS-DYNA. Firstly, the refined finite element (FE) models of both scaled aircraft and NPP models in Part I are established, and the model impact test is numerically simulated. The validities of the adopted numerical algorithm, constitutive model and the corresponding parameters are verified based on the experimental NPP model damages and accelerations. Then, the refined simulations of prototype A380 aircraft impact on a hypothetical NPP building are further carried out. It indicates that the NPP building can totally withstand the impact of A380 at a velocity of 150 m/s, while the accompanied intensive vibrations may still lead to different levels of damage on the nuclear related equipment. Referring to the guideline NEI07-13, a maximum acceleration contour is plotted and the shock damage propagation distances under aircraft impact are assessed, which indicates that the nuclear equipment located within 11.5 m from the impact point may endure malfunction. Finally, by respectively considering the rigid and deformable impacts mainly induced by aircraft engine and fuselage, an improved Riera function is proposed to predict the impact force of aircraft A380.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.4
• /
• pp.590-595
• /
• 2020

In this study, the small-scale collision experiments using a pendulum principle were carried out to evaluate the safety of the reinforced concrete building selected as a tsunami evacuation building due to the collision of the waterborne debris represented by ships. The experimental parameters were set as impact velocity, mass and length of the drifted ship. In this paper, the maximum impact force, impact duration, impact waveform and restitution coefficient affecting building response were investigated in detail. As a result, the impact force waveforms were distributed as a triangle in most of the experimental results, but became closer to a trapezoid as the length of the collision specimen increased. This is the very important result in calculating the momentum (impact waveform area) affecting building response, Furthermore, the restitution coefficients were constant regardless of the impact velocity, but they varied depending on the mass and length of the waterborne debris. However, the restitution coefficient for the mass per unit length of the waterborne debris can be evaluated.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.35 no.3
• /
• pp.206-214
• /
• 2015

In this study, low-velocity impact damage (LVID) in glass fiber reinforced plastic (GFRP) was investigated using pulse thermography (PT) and lock-in thermography (LIT) techniques. The main objective of this study was to evaluate the detection performance of each technique for LVID in GFRP. Unidirectional and cross-ply GFRPs were prepared with four energy levels using a drop weight impact machine and they were inspected from the impact side, which may be common in actual service conditions. When the impacted side was used for both inspection and thermal loading, results showed that the suggested techniques were able to identify the LVID which is barely visible to the naked eye. However, they also include limitations that depend on the GFRP thickness at the location of the delamination produced by the lowest impact energy of five joule.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.15 no.3
• /
• pp.350-357
• /
• 2012

The velocity response of stiffened rectangular plate under high velocity impact was studied. Numerical simulation was conducted on the stiffened plate with four stiffeners under various impact positions. Considered stiffener types were rib, I, hat and T stiffener. For the center impact position of I stiffened plate, the simulated residual velocity was 365.6 m/s with the initial projectile velocity 500 m/s. The reinforcing characteristic of I stiffened plate was excellent among four stiffeners.

• Journal of the Korea Furniture Society
• /
• v.24 no.4
• /
• pp.426-432
• /
• 2013

Fire resistance and impact sound insulation tests were performed for a floor assembly, of which stiffness was reinforced by shortening the span of floor joists by installing glulam beam additionally in the middle or one thirds of the original span, and which an additional ceiling component was installed apart from floor structure. By applying the isolated ceiling, timber framed floor showed 1 hour of fire resistance even in case that dead load was increased by considering cement mortar layer for radiant floor heating. Insulation performance against light and heavy impact sound was improved significantly by applying the sound absorbing layer of big mass and high elasticity in addition to the stiffness improvement and isolated ceiling.

• Journal of Environmental Impact Assessment
• /
• v.22 no.3
• /
• pp.255-264
• /
• 2013

This paper diagnosed the assessment problems and development types of the simple statement of the Sea Area Utilization Consultation System. and suggested the key assessment items for system improvement. The major types of Public Water occupation and use, and distribution characteristic of regional and coastal were analyzed by evaluate 529 review items during 2010-2012. The artificial structure installation including harbor and fishing port facilities in the South and West coast, and seawater supply and drainage for land-based aquaculture and power plant were dominated. The checklists considering each types of occupation and use in Public Water were suggested. In addition, policy proposals for system improvement were suggested.

• Journal of Navigation and Port Research
• /
• v.30 no.4
• /
• pp.303-308
• /
• 2006

This study is designed to analyze the production, employment, value added and income impacts tha, in the event of designation and development of Haeundae as 'Convention, Movie, Marine Leisure Special Zone', its marine sector would have on the local economy. The realization of marine leisure special zone of Haeundae in Busan is expected to lead to a direct and indirect investment of approx. \13.6 billion, resulting in \68.0 billion in production impact, 850 jobs in employment impact, \28.0 billion in value added impact and \14.5 billion in income impact. This is expected to give a boost to a stagnant local economy, offering opportunities for the revival of Busan's tourist industry.

• Journal of the Korean Institute of Educational Facilities
• /
• v.15 no.4
• /
• pp.14-25
• /
• 2008

The Purpose of this study is to find out the renewal methods of Dae-jun railway station areas, focusing on the domestic/foreign case studies of the railway station areas and the possibility of the Industry-University-Institute collaboration in this area. As a result, this study shows that the revitalization for the impact area around rail transit station in the aspect of urban spatial structure, mixed land use, type of facilities and exchanging transit system of mass traffic etc, as well as such non-physical aspects as Industry-University-Institute collaboration and administrative planning. It does so by strengthening ties between hardware and software studies of urban planning and University Facilities planning. Finally this study suggested the strategy for the renewal of impact area around the rail transit stations.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2004.05a
• /
• pp.5-10
• /
• 2004

Apartment Buildings have particularity to cluster together, especially, floor is close to resident, it is subject to dissatisfaction about impact noise between up and down floors. However, we require standard for counterplan to reduce the impact noise of floor. In point of fact, it difficult to objective evaluate for performance sound insulation that not physical sound volume but orignal form, means and effect of sound caused to complex noise in apartment house. Unique type of dwelling and structure pattern cause to noise of floor impact which is established by law for standard regulation. It is object to analysis and compare the result of performance sound insulation of upper floor impact and sample construct the subject resilient material of sound insulator