• Journal of the Korea Institute of Building Construction
• /
• v.14 no.6
• /
• pp.545-550
• /
• 2014

The re-locatable military facilities are significant in combat zones with limited infrastructures. Military tents are particularly one of the most essential components in the battlefields, During the offensive operation. This study assesses educational effectiveness of the 4D Building Information Modeling (BIM), which is used to deliver educational information with considering re-locatable military facility construction. Furthermore, the real time for constructing temporary concentration camp was measured, By using analysis of variance associated with the educational effects of the 4D BIM. Statistically, understandability of facility construction using 4D BIM was found to be higher than the conventional educational materials with field manual.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.21 no.4
• /
• pp.153-161
• /
• 2017

Liquid storage tank is one of the major infrastructures and generally used to store gases, drinking and utilizing water, dangerous fluids, fire water and so on. According to the recent reports and experiences, the tank structures are damaged in many earthquakes due to their low energy dissipating capacity. Therefore, many researchers have been tried to know the dynamic properties of the tanks including liquids. However, vary limited experimental studies are carried out using relatively small tank models. In this study, a series of shaking table tests are performed with maximum 2 m cubic rectangular liquid storage tanks made of steel to measure the natural frequency and estimate damping coefficient of impulsive and convective mode of the tanks. Especially, the damping values under different shapes and excitation methods are estimated by logarithmic decrement method and half power band-pass method and compared with current design code and standards such as ASCE 7, Eurocode 8 and NZS. Test results show that the impulsive mode damping is around 2% which is proposed by general standards and codes but the impulsive mode damping is 0.13% average that is slightly lower than the code recommendation.

• Nuclear Engineering and Technology
• /
• v.52 no.2
• /
• pp.417-428
• /
• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part III, the local damage of the rigid components of aircraft, e.g., engine and landing gear, impacting the steel concrete (SC) structures of NPP containment is mainly discussed. Two typical SC target panels with the thicknesses of 40 mm and 100 mm, as well as the steel cylindrical projectile with a mass of 2.15 kg and a diameter of 80 mm are fabricated. By using a large-caliber air gas gun, both the projectile penetration and perforation test are conducted, in which the striking velocities were ranged from 96 m/s to 157 m/s. The bulging velocity and the maximal deflection of rear steel plate, as well as penetration depth of projectile are derived, and the local deformation and failure modes of SC panels are assessed experimentally. Then, the commercial finite element program LS-DYNA is utilized to perform the numerical simulations, by comparisons with the experimental and simulated projectile impact process and SC panel damage, the numerical algorithm, constitutive models and the corresponding parameters are verified. The present work can provide helpful references for the evaluation of the local impact resistance of NPP buildings against the aircraft engine.

• Nuclear Engineering and Technology
• /
• v.52 no.2
• /
• pp.381-396
• /
• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part I, finite element (FE) models establishment and validations for both the aircrafts and NPP buildings are performed. (i) Airbus A320 and A380 aircrafts are selected as the representative medium and large commercial aircrafts, and the corresponding fine FE models including the skin, beam, fuel and etc. are established. By comparing the numerically derived impact force time-histories with the existing published literatures, the rationality of aircrafts models is verified. (ii) Fine FE model of the Chinese Zhejiang Sanao NPP buildings is established, including the detailed structures and reinforcing arrangement of both the containment and auxiliary buildings. (iii) By numerically reproducing the existing 1/7.5 scaled aircraft model impact tests on steel plate reinforced concrete (SC) panels and assessing the impact process and velocity time-history of aircraft model, as well as the damage and the maximum deflection of SC panels, the applicability of the existing three concrete constitutive models (i.e., K&C, Winfrith and CSC) are evaluated and the superiority of Winfrith model for SC panels under deformable missile impact is verified. The present work can provide beneficial reference for the integral aircraft crash analyses and structural damage assessment in the following two parts of this paper.

• Nuclear Engineering and Technology
• /
• v.52 no.2
• /
• pp.397-416
• /
• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part II, based on the verified finite element (FE) models of aircrafts Airbus A320 and A380, as well as the NPP containment and auxiliary buildings in Part I of this paper, the whole collision process is reproduced numerically by adopting the coupled missile-target interaction approach with the finite element code LS-DYNA. The impact induced damage of NPP plant under four impact locations of containment (cylinder, air intake, conical roof and PCS water tank) and two impact locations of auxiliary buildings (exterior wall and roof of spent fuel pool room) are evaluated. Furthermore, by considering the inner structures in the containment and raft foundation of NPP, the structural vibration analyses are conducted under two impact locations (middle height of cylinder, main control room in the auxiliary buildings). It indicates that, within the discussed scenarios, NPP structures can withstand the impact of both two aircrafts, while the functionality of internal equipment on higher floors will be affected to some extent under impact induced vibrations, and A380 aircraft will cause more serious structural damage and vibrations than A320 aircraft. The present work can provide helpful references to assess the safety of the structures and inner equipment of NPP plant under commercial aircraft impact.

• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.9
• /
• pp.563-573
• /
• 2006

Cyber-infrastructures for scientific and engineering applications require integrating heterogeneous legacy data in different formats and from various domains. Such data integration raises challenging issues: (1) Support for multiple independently-managed schemas, (2) Ease of schema evolution, and (3) Simple schema mappings. In order to address these issues, we propose a novel approach to semantic integration of scientific data which uses XML schemas and RDF-based schema mappings. In this approach, XML schema al-lows scientists to manage data models intuitively and to use commodity XML DBMS tools. A simple RDF-based ontological representation scheme is used for only structural relations among independently-managed XML schemas from different institutes or domains We present the design and implementation of a prototype system developed for the national cyber-environments for civil engi-neering research activities in Korea (similar to the NEES project in USA) which is called KOCEDgrid (http://www.koced.net).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.31 no.4
• /
• pp.293-300
• /
• 2013

Road signs are important infrastructures for safe and smooth traffic by providing useful information to drivers. It is necessary to establish road sign DB for managing road signs systematically. To provide such DB, manually detection and recognition from imagery can be done. However, it is time and cost consuming. In this study, we proposed algorithms for automatic recognition of direction information in road sign image. Also we developed algorithm code using OpenCV library, and applied it to road sign image. To automatically detect and recognize direction information, we developed program which is composed of various modules such as image enhancement, image binarization, arrow region extraction, interesting point extraction, and template image matching. As a result, we can confirm the possibility of automatic recognition of direction information in road sign image.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.9 no.2
• /
• pp.31-37
• /
• 2009

Most damages of civil infrastructures under natural disasters are frequently occurred at surrounding areas of the river or the road. Every year, Recovery for these disaster damages are performed by the government. Recently, the government decide to change current recovery plan system because current recovery plan which doesn't consider future disaster impacts at a site has been proved to be ineffective. Accordingly, new permanency recovery plan system is needed and its corresponding ideas are presented in this research considering more detailed disaster damage classifications and cause assessments. The proposed permanency recovery plan would also provide more systematic and diverse recovery response strategies including both two concepts, for example Preparedness considered by risk assessment and management, and Mitigation investigated by hazard impact analyses.

• Magazine of the Korea Concrete Institute
• /
• v.8 no.5
• /
• pp.123-133
• /
• 1996

Recently, the construction of infrastructures has been booming and accelerating to keep up with rapid economic growth. Construction activities and operation of transportation facilities cause unfavorable effects such as civil petitions associated with vibration-induced damages or nuisances. Accordingly, the objective of this study is to develop vibration-controlled concrete using various vibration-controlled mixtures, and also to recycle obsolete materials in part. As the first step to achieve this research, preliminary mix designs have been carried out to obtain an appropriate mix proportion above 200kg/$\textrm{cm}^2$ in uniaxial compressive strength. Test specimen based on the mix proportion selected have been actuated by the impact hammer to investigate their dynamic characteristics. Vibration-controlled mixtures are foam, latex, rubber powder and plastic resin, which have been determined to reduce a vibration by and large. KS F2437 and travel time method have been used to figure out 1st natural frequency and dynamic elastic moduli. Damping ratios have been computed by adopting the polynomial curvefitting method and the geometric analysis method on the frequency response spectrum curve. of which results have been compared and analyzed hereon.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.3
• /
• pp.1-8
• /
• 2017

An experimental study is needed a reinforcing method for seismic load to apply for RC structures because a lot of earthquakes have frequently happened in the world and those also collapsed infrastructures or damaged human lives. The reinforcing effect of PolyUrea (PU) appeared to be excellent under blast and impact about RC structures. In this study, Stiff Type PolyUrea (STPU) had developed by manipulating the ratio of the components of prepolymer and hardener of PU. And the durability performance evaluation of STPU for deterioration and chemical resistance has been performed. Acid environmental exposure test and ultraviolet (UV) exposure test have been performed as the durability performance evaluation for STPU. Concrete carbonation exposure test and freezing and thawing test for concrete coated with STPU have been performed. The experimental result showed that STPU has high resisting capacity and durability in all tests. Therefore, STPU would be used as seismic reinforcement materials.