• Journal of Korea Multimedia Society
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• v.19 no.12
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• pp.2000-2013
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• 2016

The purpose of this study is to validate the validity of the methodology for analyzing the space with complex characteristics and to evaluate the existing spatial structure analysis theory. Seven example models are designed and analyzed data of spatial syntax analysis and visibility graph analysis. And analyzed the agent-based model using two analytical methods: the adjacent space and the whole spatial connection. The results of this study are as follows. Based on the analysis of the agent - based model for perfectly freewalking, the validity of the method is verified in terms of predictive ability and effectiveness. Agent-based models can be simulated considering various variables, so realistic predictions will be possible and a new biography of complex systems can be met.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.131-140
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• 2012

Lane markings such as edgelines, centerlines, and lines that delineate lanes generally provide drivers with the various information for safe driving. Drivers can easily recognize the lane markings through the color differences between the markings and road surfaces during the daytime. However, it is a bit difficult for drivers to perceive them during the nighttime due to the lack of artificial lights. Although the glass beads with the 1.5-refractive index have been used to improve the visibility of the lane markings during the nighttime, it is still difficult for drivers to recognize the lane markings properly, especially during the rainy nighttime, which may often lead to traffic accidents. To improve the retroreflectivity and visibility of the lane markings during the rainy nighttime, the high refractive beads with the 2.4-refractive index are essentially required, but they do not work appropriately during the dry nighttime. Thus, the mixed materials with the 1.5, 1.9, and 2.4-refractive beads should be considered for the satisfactory implementation of the lane markings. This study reveals the best mixing rates of the beads by conducting benefit-cost analysis under various weather conditions in Korea. The analysis results show that the lane markings with the 100% of the 2.4-refractive beads provide the highest visibility of lane markings regardless of the roadway conditions, but the benefit-cost (B/C) ratio of the bead mixture is merely 0.46. The best mixing rate of the beads, from the highest B/C ratio viewpoint, was identified as the mixture with a 80% of 1.5-refractive beads and a 20% of 2.4-refractive beads. Some limitations and future research agenda have also been discussed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.4
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• pp.422-429
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• 2018

To make students recognize the danger of fire smoke that may occur in ships and to improve the response capability, spaces for safety educ ation were built inside the training ship, and scenarios were developed. This study is an analysis of the movement characteristics of the students acquire d under each scenario. Followings are the summary of the analysis results. In the non-smoke environments, there was no difference in the velocity of escape movement between the case of without block on the familiar route and the case of with unexpected block. However, when the indoor was filled with smoke, the visibility became very low because of the smoke density and the average velocity was 62.5 % slower than the case where it was not. Regardless of the scenarios, the average equivalent velocity on the complex path was faster than the simple straight path, and the standard deviation was smaller. Under the smoke-fullfilled environment, although the relative velocity probability distributions of the complex passage and the entire passag e are very similar, the inter-individual fluctuation of the relative velocity ratio of the complex passage to that of the entire passage was very large. On the other hand, equivalent velocity could be expressed by the logarithmic function of the visibility. Also, as the tension of the students increased, the equivalent velocities were accelerated on all scenarios.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.2
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• pp.127-135
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• 2022

Compared to the continuous increase of domestic nano-satellite development cases, the initial communication success rate is relatively low. In a situation where communication cases of LEO satellites using commercial satellite communication networks are increasing recently. In this situation, the SNIPE project developed by the KASI(Korea Astronomy and Space Science Institute), KARI(Korea Aerospace Research Institute), and Yonsei University apply an Iridium module for communication test to the SNIPE nano-satellites. Therefore, in this paper, the visibility analysis of the iridium module on the SNIPE satellite was analyzed under considering the orbital and communication environment of the iridium satellite constellation and the attitude control mode. In the case of LEO satellites, the communication possibility was limited due to the relatively small iridium communication coverage for high altitude and the high doppler shift considered in the iridium communication network. For this reason, in this paper, it could be simulated that there was a more performance difference according to the difference in relative RAAN(Right Ascension of Ascending Node) angle with the Iridium constellation. Finally, by checking the visibility of communication module under the tumbling situation that occurred during the initial deployment of the nano-satellite, the possibility of using the iridium communication technology was analyzed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.709-716
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• 2009

Thermal condition according to the operation attitude of a satellite in orbit would be essential to be known because the orbit attitude is a dominant factor to affect satellite thermal design. In this paper, the change in space thermal environment and the thermal effect in thermal design are studied for a low earth orbit satellite according to the yaw motion. The present satellite retains sun-pointing attitude during daylight due to the fixed type solar arrays. And it also moves along the orbit with constant yaw motion in a longitudinal axis so that a star tracker which is a star sensor for satellite's attitude control always looks into the deep space. This attitude is considered in its better visibility to the stars for a successful mission operation. Also, it is required to access the corresponding thermal effects due to the yaw motion. Therefore, we try to verify these by the thermal analysis for the satellite thermal model with the yaw motion.

• Korean Institute of Interior Design Journal
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• v.24 no.3
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• pp.59-68
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• 2015

As the economical and cultural levels become higher, the public have more various and new cultural desires, leading to an increase in the number and kinds of cultural facilities. Out of all the cultural facilities built in such a trend, art museums are the yardstick for a certain nation's cultural level, and the number of art museums is gradually increasing every year in Korea, as a cultural space where the public can make cultural exchanges with artists. On the contrary to the increasing number of art museums, however, the number of art museum visitors is decreasing every year, so various attempts are made to activate art museums in Korea. Thus, this study aims to seek a plan to activate the space of an art museum by improving the physical movement of art museum visitors, especially targeting small-sized ones out of all the art museums in Korea. For accurate analyses and verifications, this study used the visibility-ERAM program. As a result of analyses, this study found out and reconsidered several problems related to the space of art museums, and based on the results, the researcher could verify the related hypotheses, further comprehending possible errors of the proposed solution to those problems and supplement in a short period of time. Since such an analysis method and process has objective accuracy, it is expected that the results of this study will be used as basic data for future plans to activate the space of art museums.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.1 s.120
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• pp.48-58
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• 2007

The purpose of this study was not only to clearly examine the features of the scenery and visual elements of Oreum (parasitic cones) but also to investigate primary factors in landscape preferences for these cones. This study further attempted to gain basic information for examining the preservation of Oreum in regards to the influence of scenery on the general public. A Multiple Regression Analysis was used for this study for which the independent variable was the area ratio of the fore-, mid-, and background of the view under the feature element and the structure of the scenery at the Oreum. The dependent variables were the preference value, the number of summits, and the highest altitude of the Oreum. All but the highest inclination were positive variables. The area ratio of the Oreum was found to be the most important variable. The area of sky and the area of the distant scenery were shown to be positive explanation variables, while the area to the fore of the view and the area to the middle of the view were shown as negative explanation variable. In the preference for Oreum scenery, which has a high visibility and is clearly outlined against the skyline, it was found that as the hindrance element of visibility near to a visual point or the area ratio increased, the preference for the Oreum scenery decreased.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.6
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• pp.253-260
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• 2015

In this study, using the FDS as the fire simulation and evacuation simulations of the Pathfinder, set the main control room of the building to the fire point fire safety assessment studies were carried out. At first the quantitative result such as distribution of visibility as time passing, distribution of temperature, distribution of CO density produced results using fire-simulation and evacuation-simulation was carried out based on the result that produced the final safety evaluation result as being calculated of evacuation time. As the risk increased with the distribution of visibility at the result of fire-simulation, evacuation-simulation was carried out using the result. Finally the result was made 127.9 sec that everyone could evacuate. The numerical results are analyzed in case of the places in the building required safe egress time for safety a as the analysis to be no more than available safe egress time was analyzed to be secured. The results of this safety evaluation represent that more smooth evacuation safety performance can be secured by linking the event of fire firefighting equipment as a result of simulating the worst conditions.

• Journal of environmental and Sanitary engineering
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• v.9 no.2
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• pp.8-23
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• 1994

During the period from Mar., 1991 to Feb., 1992 66 tSP samples were collected by Hi volume air sampler at 1 sampling site in Seoul and the amount of concentration of 21 components(SO$_{4}$$^{2-}$, NO$_{3}$$^{-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Al, Ba, Ca, Cd, Cr, Cu, Fe, It Mg, Mn, Na, Ni, Pt Si, Ti, Zn, Zr ) were measured. And monthly and seasonal variation were surveyed and the principal component analysis( PCA ) were carried out with respect to these amount of pollutants, minimum of visibility and radiation on a horizontal surface. The total amount of soluble ion in water was high in order o(SO$_{4}$$^{2-}$> NO$_{3}$$^{-}$> N%'>Cl$^{-}$ and metal ion was high in order of Na> Ca>Si> Fe> Al> K> Mg> Zn> Pb> Cu>Ti> Mn > Ba> Cr> Zr> Ni> Cd. There was Seasonal variation in concentration for SO$_{4}$$^{2-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Na, Al, Ca, Bt Mg, Fe and Si. It was assumed that the components of the highest concentration on April were depend on yellow sand and the frequency of wind velocity and direction. As the results of PCA, the amount of pollution components was able to characterized with two principal components(Z$_{1}$, Z$_{2}$ ). The first principal components Z$_{1}$ was considered to be a factor indicating the pollutants originated from natural generation and The second principal components Z$_{2}$ was considered to be a factor indicating the pollutants originated from human work. The monthly concentration of pollutants in ISP, minimum of visibility and radiation on a horizontal surface was possible to evaluate by the use of these two principal components Z$_{1}$ and Z$_{2}$ .

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.1
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• pp.67-72
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• 2012

In this paper, we present an image enhancement method for atmospherically degraded images using atmospheric light and transmission based on color analysis. We first generate a normalized image using maximum value of each RGB color channel. Then, each atmospheric light is estimated from RGB color channel respectively by calculating reflectance of an image. We also, generate a transmission using gamma coefficients from the Y channel of the image. We can significantly enhance the visibility of an image by using the estimated atmospheric light and the transmission. The proposed algorithm can remove atmospheric degradation components better than existing techniques because the color prevents color distortion which is common problem of existing techniques. Experimental results demonstrate that the proposed algorithm can improve visibility be removing fog, smoke, and dust.