• Structural Engineering and Mechanics
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• v.33 no.2
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• pp.113-136
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• 2009

The seismic induced interaction between multistory structures with unequal story heights (inter-story pounding) is studied taking into account the local response of the exterior beam-column joints. Although several parameters that influence the structural pounding have been studied sofar, the role of the joints local inelastic behaviour has not been yet investigated in the literature as key parameter for the pounding problem. Moreover, the influence of the infill panels as an additional parameter for the local damage effect of the joints on the inter-story pounding phenomenon is examined. Thirty six interaction cases between a multistory frame structure and an adjacent shorter and stiffer structure are studied for two different seismic excitations. The results are focused: (a) on the local response of the critical external column of the multistory structure that suffers the hit from the slab of the adjacent shorter structure, and (b) on the local response of the exterior beam-column joints of the multistory structure. Results of this investigation demonstrate that the possible local inelastic response of the exterior joints may be in some cases beneficial for the seismic behaviour of the critical column that suffers the impact. However, in all the examined cases the developing demands for deformation of the exterior joints are substantially increased and severe damages can be observed due to the pounding effect. The presence of the masonry infill panels has also been proved as an important parameter for the response of the exterior beam-column joints and thus for the safety of the building. Nevertheless, in all the examined inter-story pounding cases the presence of the infills was not enough for the total amelioration of the excessive demands for shear and ductility of the column that suffers the impact.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.33-42
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• 2016

Domestic harbor yard storage facilities are a place specifically located in a container terminal for import and export of packaged dangerous goods, and due to the recent relaxed criteria for the secured open area, concerns for the extended damage upon accidents are increasing. In this study, the impact of damages by radiant heat was analyzed through a simulation of a pool fire caused by the leakage of flammable liquids from a tank container. As a result, it was analyzed that the distance of radiant heat according to threshold damage levels was beyond the current criteria of the secured open area, and the structural damage of adjacent containers could happen within a very short time if they were exposed to the early pool fire continuously. It is considered that this study will be helpful in preparing the proper criteria for the secured open area between yard storage facilities in a container terminal.

• Advances in aircraft and spacecraft science
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• v.4 no.1
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• pp.37-52
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• 2017

Gas turbines operating in dusty or sandy environment polluted with micron-sized solid particles are highly prone to blade surface erosion damage in compressor stages and molten sand attack in the hot-sections of turbine stages. Commercial/Military fixed-wing aircraft engines and helicopter engines often have to operate over sandy terrains in the middle eastern countries or in volcanic zones; on the other hand gas turbines in marine applications are subjected to salt spray, while the coal-burning industrial power generation turbines are subjected to fly-ash. The presence of solid particles in the working fluid medium has an adverse effect on the durability of these engines as well as performance. Typical turbine blade damages include blade coating wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration including loss of aircraft. The focus of this research work is to simulate particle-surface kinetic interaction on typical turbomachinery material targets using non-linear dynamic impact analysis. The objective of this research is to understand the interfacial kinetic behaviors that can provide insights into the physics of particle interactions and to enable leap ahead technologies in material choices and to develop sand-phobic thermal barrier coatings for turbine blades. This paper outlines the research efforts at the U.S Army Research Laboratory to come up with novel turbine blade multifunctional protective coatings that are sand-phobic, sand impact wear resistant, as well as have very low thermal conductivity for improved performance of future gas turbine engines. The research scope includes development of protective coatings for both nickel-based super alloys and ceramic matrix composites.

• Journal of environmental and Sanitary engineering
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• v.8 no.2
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• pp.25-48
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• 1993

International concern over the environmental pollution is ever increasing, and diversified countermeasures must be devised in Korea also. Global trend, damages, problems and countermeasures with respect to issues mentioned in the Rio Declaration, such as prevention of ozone layer destruction, reduction of migratory atmospheric pollution between neighboring countries, and prevention of global greenhouse effect, were discussed in this report. Conclusion of the report is summarized as follows : A. Measurement, Planning and Monitoring (1) Development and implementation of a global network for measurement and monitoring from the global aspects such factors as related to acid rain(Pioneer substances, pH, sulfate, nitrate), effect of global temperature(Air temperature, $CO_2$, $CH_4$, CFC, $N_2O$) and destruction of ozone layer($CFC_S$). (2) Establishment of network system via satellite monitoring movement of regional air mass, damage on the ozone layer and ground temperature distribution. B. Elucidation of Present State (1) Improvement and development of devices for carbon circulation capable of accurately forecasting input and output of carbon. (2) Developmental research on chemical reactions of greenhouse gas in the air. (3) Improvement and development of global circulation model(GCM) C. Impact Assessment Impact assessment on ecosystem, human body, agriculture, floodgate, land use, coastal ecology, industries, etc. D. Preventive Measures and Technology Development (1) Development and consumption of new energy (2) Development of new technology for removal of pioneer substances (3) Development of substitute matter for $CFC_S$ (4) Improvement of agriculture and forestry means to prevent the destruction of ozone layer and the greenhouse effect of the globe (5) Improvement of housing to prevent the destruction of ozone layer and the greenhouse effect of the globe (6) Development of new technology for probing underground water (7) Preservation of forest (8) Biomass 5. Policy Development (1) Development of strategy model (2) Development of long term forecast model (3) Development of penalty charge effect and expense evaluation methods (4) Feasibility study on regulations By establishing the above mentioned measures for environmentally sound and sustainable development to establish the right to live for humankind and to preserve the one and only earth.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.265-274
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• 2015

The structural safety of nuclear power plant against impact from aircraft crash has been performed so far in two viewpoints such as local behavior and global behavior, and the local behavior has been evaluated using local damage evaluation formulas suggested based on the results of experimental data of RC (Reinforcement Concrete) wall. However, few data have been collected from recent research to evaluate the local behavior and damage of SC (Steel plate reinforced Concrete) wall, which is recently applied to the newly designed nuclear power plant. In this study, local damages of SC wall and RC wall against an idealized aircraft engine projectile impact are evaluated through FE simulation analyses with various wall thicknesses and steel ratio. Through analysis of local collision simulation results of SC and RC wall, the penetration depth of SC wall and RC wall are compared.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.11
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• pp.949-954
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• 2016

When a snowplow is operating in the up or down direction, the sensor stops the movement automatically and the wire could be broken from an endless drive in the reverse direction impact or conversely winding wire. In the present study, a new bobbin was designed to ensure the durability of snowplows; in this design, the bobbin plays the role of a clutch during power transfer or idling. This will protect the blade of the snowplow during an impact and maintain close contact of the blade with the road. Therefore, the new technology to eliminate the tension and fatigue of the wire is suggested by winding a chain instead of the wire in the newly designed bobbin. From these, it was developed to extend the life of the snowplow without causing damages to the vehicle.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.503-512
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• 2014

In this paper, various tire blow-out force experiment data were collected and analyzed to obtain approximate values of related coefficients such as rolling resistance, self-aligning torque, cornering stiffness, and radial stiffness for the analysis of the motion of vehicles with tire blow-outs. These coefficients related to tire blow-outs were input into a vehicle accident analysis program to simulate and examine the effects of tire blow-outs. Various configurations and velocities of vehicle collisions without tire blow-outs were also used as reference to establish collision events of vehicle collisions with tire blow-outs. For the events, the simulation analysis was performed and collision characteristics were obtained. Consideration of tire blow-outs or damages suggested in this study will greatly contribute to more reliable vehicle accident reconstructions.

• Journal of fish pathology
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• v.18 no.1
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• pp.81-89
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• 2005

The toxic effects of pentachlorophenol (PCP) on haematological parameters in olive flounder (Paralichthys olivaceus) after chronic exposure to dietary PCP (0.1, 0.5 and 1.0 mg/kg diet) for 2, 4 and 6 weeks were studied. A significant decrease in total RBC count, haemoglobin concentration and hematocrit value was noted in fish exposed to PCP compared to the non-exposed fish. The PCP treatment group showed significantly lower concentration of serum total protein and albumin, and significantly higher serum chloride, magnesium and total bilirubin levels compared with those in the control group. However, PCP had no major effects on serum glucose, total cholesterol, phosphate and calcium ions in flounder. These results demonstrated that PCP have induced adverse haematological impacts in the olive flounder, Paralichthys olivaceus. Because we found damages in blood-forming function and disruption in blood homeostasis due to chronic exposure to PCP, it is needed to develop further experimental studies for the risk assessment of this environmental pollutant.

• The KIPS Transactions:PartC
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• v.13C no.1 s.104
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• pp.63-68
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• 2006

Cyber Attacks have increased damages constantly in all over the world for several years. A survey said the cost caused by Cyber Attacks had increased 225 times from 1996 to 2003. It is very difficult to calculate the cost by the Attacks exactly but the calculating the cost of cyber attacks would be great helpful for a company to decide how much budget to spend to Information Security. In this research we could reach the conclusion : the cyber attacks has decreased the stock price of the companies, especially pure internet companies. But the stock market has not greatly impacted by the types of Cyber Attacks. Korean stock market also impacted by the Internet Destruction Accident happened Jan. 25. 2003. On the basis of this study we will recommend a policy or a regulation which force board of directors and officers of a company to have information security liability.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.1
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• pp.35-43
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• 2012

In general, load carrying capacity, one of the load & resistance capacities in bridges, has more margins than the load carrying capacity evaluated with theoretical methods, unless there are severe damages, defects or material deterioration phenomena that can have a great impact on the behavior of bridges. However, errors have been already included in the current processes of loading tests and structural analysis for measuring load carrying capacity, thus devaluing the reliability of response adjustment factor. Therefore, this study found out the problems of existing electric resistance strain and displacement sensors in sensor suite to solve the problems with sensors and the errors in the appropriateness of structural analysis model, thereby leading to the changes into an optical fiber smart sensor with excellent performance. Besides, the study attempted to ensure the accuracy of response adjustment factor by selecting the optimal models through the interpretation of various structural analysis models.