• Journal of the Korean Vacuum Society
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• v.16 no.6
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• pp.424-432
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• 2007

Luminance properties of external electrode fluorescent lamps and optical components in backlight unit (BLU) and optical transmission rates of optical sheets, are investigated for LCD-TV of 32" in diagonal with WXGA level resolution (1366$\times$768). The luminance is measured in 12-lamps and 18-lamps of BLU. The luminance uniformity preserves about 85 % in the 12-lamps backlight, while the luminance of optical components and the efficiency of backlight in the 12-lamps are lower than those in the 18-lamps backlight. When the lamp luminance in BLU having 12-lamps and 18-lamps is normalized as 100 %, the relative luminance of a diffusion plate, a diffusion sheet, a prism sheet (BEF), a polarization sheet (DBEF), has a constant value without dependence on a lamp luminance. The relative luminance of optical components in 12-lamps BLU is lower than that in 18-lamps backlight. The light transmission rate, the relative luminance of liquid crystal display panel with the luminance 100 % of backlight, is 7.14 % in the use of DBEF and BEF, 6.12 % in the use of only DBEF, and 3.21 % in the use of only BEF. Those Data obtained in this experiment for the lamps and optical components, are the design parameters for the LCD backlight.

• Fire Science and Engineering
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• v.31 no.6
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• pp.33-39
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• 2017

Composite panel refers to the particular plywood produced in a way of stacking the different kinds of material in sandwich form and adhering them using adhesives and is widely used as building material for its constructability and cost efficiency. But as the surface is finished with steel plate, fire extinguishing agent cannot reach to the core material because of such steel plate on surface which causes the difficulties in suppressing the fire as well as in fire-fighting activities due to collapse. This study, to deal with such problem, is intended to set the fire pipe in core material to prevent the fire from spreading and in a bid to achieve this using minimized fire water, water supply test device was fabricated to estimate the required water flow of fire extinguisher and consequently, optimal water flow (0.5 L/min) was determined through a full-scale fire test.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.9
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• pp.909-916
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• 2015

In this study, to investigate the effect of spray behavior characteristics, we induce the mixing ratio of emulsified fuel using impinging spray. We formulate the emulsified fuel by mixing diesel and hydrogen peroxide($H_2O_2$). We set the temperature of the heating plate to $150^{\circ}C$, $200^{\circ}C$, and $250^{\circ}C$, and set the injection pressures to 400, 600, 800, and 1000bar. The surfactants for the emulsified fuel mixture, which were mixed span80 and tween80 was mixed as 9:1, were fixed to 3% of the total volume of the emulsified fuel. We set the mixing ratio of $H_2O_2$ in the emulsified fuel as emulsified fuel(EF)0, EF2, EF12, and EF22. Further, we visualize the evaporation impinging spray using the Schlieren method. Based on the results of this study, we found that a higher temperature and injection pressure of the heating plate impingement led to the active diffusion of the fuel vapor, which promoted emulsified fuel evaporation. When the emulsified fuel is utilized in an actual engine, because of the temperature-drop effect of the combustion chamber, which is due to the evaporation of $H_2O_2$ in fuel and faster mixture formation is expected to decrease the engine emissions.

• Journal of radiological science and technology
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• v.27 no.3
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• pp.25-29
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• 2004

Among the digital radiography systems, the computed radiography Image Plate Detector System is most frequently being used for the general radiography and also this system commonly diffracts the x-ray images since it is the system that is influenced by the light diffusion from the fluorescent substances. In this study, by using the X-ray Generator, a comparative analysis has been made between 2 different models of computer radiography image plate investigate each model's resolution and sharpness through the modulation transfer function(MTF) measurement. For the analysis, two image plates for general radiography one Fuji ST-VN model(more than 3years old) and one Fuji ST-VL model(less than 2years old) that are currently being used in "Hospital A" were sampled for the MTF measurement here. As the experimental method for this study, the resolution chart method has been carried out by using X-ray generator. Also all the experimental data were printed out by laser printer and measured by microdensitometer. As the results of the experiment carried out in this study, some differences have been found between the two different IP models and Fuji ST-VL has shown its excellence in both of the resolution and the sharpness fields.

• Fire Science and Engineering
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• v.30 no.3
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• pp.86-93
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• 2016

The effects of the shape of a drencher head on the flow characteristics and radiation attenuation of a water curtain, in order to prevent a fire spread, were experimentally studied. The distance (h) between the orifice exit and deflector and the diameter of deflector (D) were varied as the shape factors of the head, with the same orifice diameter (d). It was found that an increase in h leads to an increase in the water flow rate and spray angle. However, the change in the spray angle decreases with increasing D. Increasing D brings about a subtle increase in the water flow rate and a significant decrease in the spray angle. A larger value of D makes it possible to produce a flatter pattern of the water curtain, but reduces the uniformity of the droplets inside the spray angle. The mean droplet diameter decreases significantly as the operating pressure increases. However, the variation in the shape of the drencher head does not significantly affect the change in the mean diameter at the same operating pressure. Finally, it was found that the radiation attenuation afforded by the water curtain at the same operating pressure was affected by water flow rate and droplet uniformity, which were determined by h and D, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.775-784
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• 2000

Nitrate dry deposition fluxes were directly measured using knife-leading-edge surrogate surface (KSS) covered with greased strips and a water surface sampler (WSS). The average gaseous flux ($8.3mg/m^2/day$) was much higher than the average particulate one ($3.0mg/m^2/day$). The best fit gas phase mass transfer coefficient (MTC) of $HNO_3$ was obtained by linear regression analysis between measured gaseous flux containing nitrogen compounds and measured ambient $HNO_3$ concentration. The result showed that the MTCs of $HNO_3$ were approximately two times higher than those of $SO_2$. Especially, during the ozone action day, measured gaseous fluxes containing nitrogen compounds were much higher than those ones calculated as the product of measured ambient $HNO_3$ concentration and gas phase MTC of $HNO_3$, which is calculated from MTC of $SO_2$ using Graham's diffusion law. This result indicated that other nitrogen compounds except $HNO_3$ contributed to gaseous flux containing nitrogen compounds into the water surface sampler. The theoretical calculations suggest the contributions of nitrous acid ($HNO_2$) and PAN to the gaseous dry deposition flux of nitrogen containing compounds to the WSS.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.1 s.20
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• pp.29-38
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• 2006

There are increasing needs to provide sufficient information on road directions through road signs for expanding cities and traffic networks. Improving efficiency of direction guidance information from road signs not only requires criteria for but also systematic approach to selecting place names that appear on road signs. As such, this paper looks at road direction information from existing road signs that leads to Suwon and investigates whether the current system of road signs provides efficient, systematic and continuous direction information for road users to easily reach their destination. In this paper, Suwon's city hall is set up as the final destination, which is linked from five other cities, Anyang, Osan, Ansan, Yongin and Seongnam. The paper attempts to find out whether there is continuity and suitable number of road signs for direction information by analyzing the road signs between these 5 cities and Suwon with respect to direction, direction advance notice and direction guidance. It is found that drivers cannot easily find the needed information on their destination from the existing road signs and that continuity of selected place names that systematically appear on road signs is insufficiency. In addition, direction guidance on road signs is problematic, because the appearance frequency of road signs is not adequate and the continuity of road signs is not effective. Moreover, there is insufficient information on local direction guidance for immediate destinations on road signs with respect to turning left or right or going straight.

• CRM연구
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• v.2 no.2
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• pp.71-88
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• 2009

The purpose of this thesis is to examine the effects of e-CRM activities by the internet shopping mall companies on the purchase activities of purchase customers and the potential customers. The internet shopping companies utilize e-CRM to systematically identify customers' varying demands, and to utilize the results as marketing tools, thus producing a significant effect on the potential customers by generating customer feedback through e-Community. Contrary to their intention, however, cognitive dissonance can occur through e-Community, which may lead to customers' complaints. If these complaints are not properly managed and settled in a timely manner, they can be transferred to other potential customers, and the conformity phenomenon could be created by other complaining customers. Findings obtained through this thesis are as follows: If cognitive disharmony is created by customers who purchased products through the internet shopping malls, this can lead to private complaining behaviors, and subsequently, these behaviors are formed through e-Community. If the internet shopping mall companies do not take any timely and proper measures to intervene in the stage of private complaining behaviors in the first place, these behaviors will immediately escalate into the public complaining behaviors. Furthermore, the complaints will be transferred to other potential customers, ultimately resulting in their swift expansion. In other words, contrary to intention of the internet shopping mall companies, e-CRM does not facilitate the potential customers purchase decision, it rather affects them to postpone or withdraw their purchase decision. Accordingly, the internet shopping mall companies are required to manage e-Community with extreme care, and they should promptly respond to the complaining customers so that e-Community can function properly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.275-283
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• 2006

Recently, there are increasing needs to provide sufficient information on road signs for expanding cities and traffic networks. Improving efficiency of direction guidance information from road signs not only requires criteria for but also systematic approach to selecting place names that appear on road sings. As such, this paper looks at road direction information from existing road signs that leads to Suwon and investigates whether the current system of road sings provides efficient, systematic and continuous direction information for road users to easily reach their destination. In this paper, Suwon's city hall is set up as the final destination, which is linked from five other cities, Euiwang, Ansan, Hwaseong, Osan and Yongin. The paper attempts to find out whether there is continuity and suitable number of road signs for direction information by analyzing the road signs between these 5 cities and Suwon with respect to direction, direction advance notice and direction guidance. It is found that road users cannot easily find the needed information on their destination from the existing road signs and that continuity of selected place names that systematically appear on road signs is insufficiency. That is to say, the findings of the paper are that while it is easy for road users to find place names that are classified under land marks or the first-class selection of place names on road signs, it is difficult to obtain information from road signs on place names that are grouped under the second or third class. In addition, direction guidance on road signs is problematic, because the appearance frequency of road signs is not adequate and the continuity of road signs is not effective. Moreover, there is insufficient information on local direction guidance for immediate destinations on road signs with respect to turning left or right or going straight. Hence road signs in urban area need systematic improvement to find easily some destination.

• Korean Journal of Environment and Ecology
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• v.21 no.4
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• pp.311-317
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• 2007

This study was conducted to determine the geographical distribution and habitat for Rana catesbeiana and Trachemys scripta elegans in order to obtain the current basic data on biota needed for establishing a database on non-indigenous species(NIS) in Jeju-do and to develop management plans applicable to Jeju, starting from March 2005 until May 2006. As a result of an inspection, it was found that the habitat for R. catesbeiana in Jeju includes Hankyeong-myeon, Daejeong-eup, and Ahndeok-myeon. These areas are all located on the western side of Jeju-do, and considered to have favorable conditions for R. catesbeiana to inhabit. Thus, it is unlikely that the population of R. catesbeiana will possibly decrease; what's worse, there exists even a risk that it could not only expand to other regions but also do damage to the population of native insecta, fishes, amphibians and reptiles, so this terrible species ought to be exterminated. More than 92 individuals of T. scripta elegans species were found to inhabit in 15 ponds around Jeju Island. T. scripta elegans. as the topmost predator, could destruct the pond ecosystem, and also cause a problem of water pollution due to its excrement. Counter-measures against T. scripta elegans could include publicity activities encouraging self-control of the release of captive T. scripta elegans, extermination plans using its ecological habits, and sign-posting publicizing its hazard to healthy ecosystem at the areas with high population density of T. scripta elegans or at its habitats with high foot traffic, together with the continuous management of NIS(none-indigenous species).