• Journal of Korean Society of Transportation
• /
• v.36 no.3
• /
• pp.216-228
• /
• 2018

In this study analyzed the ponding changing of plastic deformation section follwed time development to apply weather, geometry and traffic data in additon to time development to improve road management service and safety of roads during or after rain. After We selected an 8.3km section of old national highway the Seongnam-Janghowon section and created a three-demensional surface of terrain through the numerical transformantion of design drawing data, with reflection the linear data of the same coordinate system in order to describe more realistic roads, we design additional structures with shading above roads. The altitude and azimuth of the sun were calculated and set based on the longitude and latitude data of the survey line for the analysis of the sun rate, and the daylight impact zone was visualized by setting the shaded time to an interval of 1 hour and the shade rate of the corresponding section. In addition, the evaporation volume calculated from weather data such as temperature, humidity, radiant energy, and road temperature analyzes together, it will use the way of a safer and more efficient road management as grasping the ponding changing more efficent in time development.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.1
• /
• pp.69-75
• /
• 2009

The characteristics of disinfection and organic removal were investigated with pulse UV lamp in this study. The intensity and emission wavelength of pulse UV Lamp were compared with low pressure UV lamp. The emission spectrum range of pulse UV lamp was between 200 and 400 nm while the emission spectrum of low pressure UV lamp was only single wavelength of 254nm. 3 Log inactivation rate of B. subtilis spore by pulse UV and low pressure UV irradiation was determined as $44.71mJ/cm^2$ and $57.7mJ/cm^2$, respectively. This results implied that wide range of emission spectrum is more effective compared to single wavelength emission at 254nm. 500ng/L of initial 2-MIB concentration was investigated on the removal efficiency by UV only and $UV/H_2O_2$ process. The removal efficiency of UV only process achieved approximately 80% at $8,600mJ/cm^2$ dose. 2-MIB removal rate of $UV/H_2O_2$ (5 mg/L $H_2O_2$) process was 25 times increased compared to UV only process. DOC removal efficiency for the water treatment plant effluent was examined. The removal efficiency of DOC by UV and $UV/H_2O_2$ was no more than 20%. Removal efficiency of THMFP(Trihalomethane Formation Potential), one of the chlorination disinfection by-products, is determined on the UV irradiation and $UV/H_2O_2$ process. Maximum removal efficiency of THMFP was approximately 23%. This result indicates that more stable chemical structures of NOM(Natural Organic Matter) than low molecule compounds such as 2-MIB, hydrogen peroxide and other pollutants affect low removal efficiency for UV photolysis. Consequently, pulse UV lamp is more efficient compared to low pressure lamp in terms of disinfection due to it's broad wavelength emission of UV. Additional effect of pulse UV is to take place the reactions of both direct photolysis to remove micro organics and disinfection simultaneously. It is also expected that hydrogen peroxide enable to enhance the oxidation efficiency on the pulse UV irradiation due to formation of OH radical.

• Journal of the Korean Ceramic Society
• /
• v.39 no.2
• /
• pp.184-189
• /
• 2002

This study, compared with data of PbO-base glass system is a part of new glass composition design with Bi-base composition for PDP Rib. As $Bi_2O_3-B_2O_3-ZnO$ glass composition including Bi, which have similar density value and work facility to PbO, properties of softening point, thermal expansion coefficient, chemical durability, dielectric constant, and structural changing by XPS were investigated. $Bi_2O_3-B_2O_3-ZnO$ glass system, added 50∼80 wt% $Bi_2O_3$ widely, were presented 400∼480$^{\circ}C$ softening temperature, $68{\sim}72{\times}10^{-7}/^{\circ}C$ thermal expansion coefficient and 13∼25 dielectric constant. These results were showed similar physical properties with Pb-base glass system of same composition content, application possibility as starting composition of rib material was identified through micro-control of components and physical properties. The bonding energy of $O_{1s}$ as the $Bi_2O_3$ content decreasing was increased and full width at half-maximum (FWHM) was decreased, which is caused by non-bridging oxygen increasing.

• Journal of the Korea Concrete Institute
• /
• v.19 no.3
• /
• pp.359-366
• /
• 2007

Recently, analysis researches on durability are focused on chloride attack and carbonation due to increased social and engineering significance. Generally, chloride penetration and carbonation occur simultaneously except for in submerged condition and chloride behavior in carbonated concrete is evaluated to be different from that in normal concrete. Furthermore, if unavoidable crack occurs in concrete, it influences not only single attack but also coupled deterioration more severely. This is a study on analysis technique with system dynamics for chloride penetration in concrete structures exposed to coupled chloride attack and carbonation through chloride diffusion, permeation, and carbonation reaction. For the purpose, a modeling for chloride behavior considering diffusion and permeation is performed through previous models for early-aged concrete such as MCHHM (multi component hydration heat model) and MPSFM (micro pore structure formation). Then model for combined deterioration is developed considering changed characteristics such as pore distribution, saturation and dissociation of bound chloride content under carbonation. The developed model is verified through comparison with previous experimental data. Additionally, simulation for combined deterioration in cracked concrete is carried out through utilizing previously developed models for chloride penetration and carbonation in cracked concrete. From the simulated results, CCTZ (chloride-carbonation transition zone) for evaluating combined deterioration is proposed. It is numerically verified that concrete with slag has better resistance to combined deterioration than concrete with OPC in sound and cracked concrete.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.41 no.1
• /
• pp.63-67
• /
• 2017

In bioscience and biotechnology, the research of fundamental life mechanisms and their diseases caused by insufficiency is important. The study of a whole organism is difficult and sometimes impossible because of DNA, RNA, proteins, cellular organelles, various cells, and organs. Cell cultures can provide a simple method for researching cellular mechanisms and conditions, both in terms of physiological performance, and in response to chemical stimulation. According to conventional cell culture methodology, the flat surface is used with surface treatments for cell adhesion on the surface. Micro- and nanoscale patterns have been developed with chemical and biochemical modifications for cell immobilization. In this study, HeLa cell culture on nanostructures patterns was studied, including the 300 nm line and 150 nm pillar structures, using nanoimprint lithography and pyrrole as a biocompatible conducting polymer.

• Journal of Gifted/Talented Education
• /
• v.24 no.1
• /
• pp.113-147
• /
• 2014

This study is a case study of the process of emerging for creative products to lead world science and technology. The aim of the study is to understand the emerging process of scientific creative products, and is to provide the direction of gifted education that discovers and trains globally competitive science talents through this. To discuss the emerging process of creative products, this study has academically discussed the creativity of the complexity of dealing with theory of evolution, the real life settings, and self-organization of experience etc., and has methodologically adopted the qualitative research method through a case study to look at the structures and processes. Data collection has been formed through a discussion with 12 Korean scientists who have created selected creative products, greatly contributed for the world science and technology(12 areas). The analysis has been carried out by the latter part positivist methods. As a result, the emerging process of creative products in the field of science and technology were separated into four steps: (1)the foundation stage of knowledge, (2)the exploration stage of knowledge, (3)the construction stage of knowledge, and (4)the emerging stage of knowledge. Each stage has been revealed growing up through the macro-system and the self-organization of each micro-systems.

• Tunnel and Underground Space
• /
• v.16 no.2 s.61
• /
• pp.166-178
• /
• 2006

Recently, the frequency of occurring dynamic events such as earthquakes, explosives blasting and other types of vibration has been increasing. Besides, the chances of exposure for rock discontinuities to free faces get higher as the scale of rock mass structures become larger. For that reason, the frictional behavior of rock joints under dynamic conditions needs to be investigated. In this study, artificially fractured rock joint specimens were prepared in order to examine the dynamic frictional behavior of rough rock joint. Roughness of each specimen was characterized by measuring surface topography using a laser profilometer and a series of shaking table tests was carried out. For mated joints, the static friction angle back-calculated ken the yield acceleration was $2.7^{\circ}$ lower than the tilt angle on average. The averaged dynamic friction angle for unmated joints was $1.8^{\circ}$ lower than the tilt angle. Displacement patterns of sliding block were classified into 4 types and proved to be related to the first order asperity of rock joint. The tilt angle and the static friction angle for mated joints seem to be correlated to micro average inclination angle which represents the second order asperity. The tilt angle and the dynamic friction angle for unmated Joints, however, have no correlation with roughness parameters. Friction angles obtained by shaking table test were lower than those by direct shear test.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.1
• /
• pp.7-12
• /
• 2017

3YSZ + (x) $Al_2O_3$ composites (x = 20, 40, 60, 80 wt%) were fabricated and the influences of particle sizes of $Al_2O_3$ on their microstructures and mechanical properties were investigated with XRD, SEM, vickers hardness and fracture toughness. $Al_2O_3$-3YSZ composites containing $Al_2O_3$ powder of a $0.3{\mu}m$ and an $1.0{\mu}m$, which are here in after named as $Al_2O_3$($0.3{\mu}m$)-3YSZ and $Al_2O_3$($1.0{\mu}m$)-3YSZ, respectively, were made by mixing raw materials, uni-axial pressing and sintering at $1,400^{\circ}C$, $1,500^{\circ}C$, and $1,600^{\circ}C$. $Al_2O_3$($0.3{\mu}m$)-3YSZ composites show the higher density and the better mechanical properties than $Al_2O_3$($1.0{\mu}m$)-3YSZ composites. The Vickers hardness of the $Al_2O_3$($0.3{\mu}m$)-3YSZ composites show a peak value of 1,997 Hv at the content of 60 wt% $Al_2O_3$, which is a slightly higher value in comparison with 1,938 Hv of the $Al_2O_3$($1.0{\mu}m$)-3YSZ composite. However, the fracture toughness of $Al_2O_3$-3YSZ composites monotonically increases with decreasing the content of $Al_2O_3$ without any peak values. $Al_2O_3$($0.3{\mu}m$)-3YSZ and $Al_2O_3$($1.0{\mu}m$)-3YSZ composites sintered at $1,600^{\circ}C$ have a maximum value of a $6.9MPa{\cdot}m^{1/2}$ and a $6.2MPa{\cdot}m^{1/2}$, respectively at the composition of containing 20 wt% $Al_2O_3$. It should be noticed that the mechanical properties and the sintering density of the $Al_2O_3$-3YSZ composites can be enhanced by using more fine $Al_2O_3$ powder due to their denser microstructure and smaller grain size.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.33 no.6 s.113
• /
• pp.98-108
• /
• 2006

The climate of urban area is an unstable type with considerable seasonal variation in precipitation wind speed, and temperature and it grows worse. Besides, ozone is a serious air pollutant in most of large cities. So worldwide, some of large cities are investing in forestry options to offset their climate problems, but lack of information has hindered comparisons of urban un cost effectiveness to other options. This research intends to study the economic benefits of tree shading of 19 parking lots in UCD campus. The economic benefits of tree shading are air conditioning savings, air quality, stormwater run-off, and other benefits. Especially, this study focuses how much the economic benefit of parking lot shading has been increased from 1995 to 2003 year by aerophoto. Some data on dimensions of parking lots and the number, size, tree species, and location of trees around each parking lot was inventoried. Two aerophotos(1995,2003) were used in order to analyze the increasement of tree canopy in 19 parking lots for 8 years. However, increasing coverage of trees and managing them for healthy growth would not be sufficient for avoiding adverse impacts by future climate change. Additional measures should be followed such as an increase of energy use efficiency and development of substitute energy. For example, coverage of trees help to save cooling energy by blocking solar radiation reaching parking cars and building structures through shading, and creating cool micro-climates through evapotranspiration. They also reduce heating demand by decreasing air infiltration and heat conduction out of the interior of buildings. Proper arrangement of vegetation over the parking lots can reduce cooling and heating costs. So proper planting design around hard space paving including species selection and location can significantly save cooling and heating energy. And a reduction in car and building's heating and cooling costs results in the reduction in energy demand which causes to emissions of air pollutants. Total increased tree canopy from 1995 to 2003 is $8,470.45m^2$ and the economic benefits is US$ 5,282.10. The economic benefit of one tree has been US$ 7.21 for 8 years. And an annually increased benefit is US$ 0.9 per a tree. If this kind of study is applied to studying the economic benefits of tree canopy in parking lots of Korea, it could result in guidelines of tree planting of parking lots. Because the trees selected for planting in parking lots were not suitable for an environment, the guidelines should contain a recommended list of trees. The guidelines should propose the shading percentage of parking lot when we plan a parking lot and contain the maintenance of trees in order to maximize the economic benefits of tree canopy.

• Journal of Broadcast Engineering
• /
• v.25 no.4
• /
• pp.537-544
• /
• 2020

This paper proposes the creation of an android robot head based on the facial action coding system(FACS), and the generation of emotional expressions by FACS. The term android robot refers to robots with human-like appearance. These robots have artificial skin and muscles. To make the expression of emotions, the location and number of artificial muscles had to be determined. Therefore, it was necessary to anatomically analyze the motions of the human face by FACS. In FACS, expressions are composed of action units(AUs), which work as the basis of determining the location and number of artificial muscles in the robots. The android head developed in this study had servo motors and wires, which corresponded to 30 artificial muscles. Moreover, the android head was equipped with artificial skin in order to make the facial expressions. Spherical joints and springs were used to develop micro-eyeball structures, and the arrangement of the 30 servo motors was based on the efficient design of wire routing. The developed android head had 30-DOFs and could express 13 basic emotions. The recognition rate of these basic emotional expressions was evaluated at an exhibition by spectators.