• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.358-365
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• 2023

As the Internet is used as a major channel for marketing and sales, the top ranking of search engine results is becoming a key competitor among websites. Various methods exist to maintain the top ranking of websites in search engines, typically investing heavily in organic coding or search engine optimization. The purpose of this paper, we present the ranking by recognizing factors that should be removed as negative factors when designing a web page in consideration of website visibility (SEO) because if website visibility is not met, the ranking may fall behind or be completely removed from the search engine index. The experiments that recognized and ranked the negative factors of website visibility proposed in this paper were provided through theory and experiments based on the existing website visibility analysis model. The models analyzed in this paper, we expressed or quantified as scores based on the methodology of each model, and 10 items were selected as negative factors through experiments and ranked as high scores. Therefore, when designing a website, it should be considered that the website is not removed from the search engine index as it is designed by excluding high-ranking items, which are negative factors.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.1-6
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• 1992

Using data measured in 1989, a study on variations of visibility and air pollution observed in Seoul, Chongju and Choopoongryong is carried out. Analysis includes on low visibility (< 10km) and smog occurring in the Metropolitan Seoul. It was observed that number of days of visibility less than 10km during 1989 was 56.7% (207 days) for Seoul, 45.7%(167 days) for Chongju and 5.8% (21 days) for Choopoongryong. Chongju is a medium size city (population : a half million) and Choopoongryong is a rural site. In the urban are as, however, the number of low visibility days was relatively large during the winter but with little seasonal variations. In each month these cities recorded more than 10 days of low visibility. The visibility reduction due to mist, fog and haze been occurred with air pollution. In particular, the reduction in a cold season related with an increase in high concentrations of $SO_x$ and aerosols. This type of low visibility occurring in Seoul is a similar type that is occurring in London, U.K. On the other hand, the visibility reduction during in a warm season is related with high concentrations of NOx and other photochemical precursors. The visibility reduction in Seoul during summer is the same type occurring in Los Angeles, U.S.A.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.2
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• pp.31-42
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• 1997

Visibility has been used for Visual Impact Assessment and Buildingheight Control. The purpose of this study is to elaborate visibility analysis technique in GIS, and to design a visual information system baed on this technique for diverse application. The results of this study are as follows : 1) By classifying visibility analysis techniques into two groups, Each one's merits and demerits were investigated. Practically GIS visibility analysis by DTM model using contour map and investigating it by means of site-observation can be the most effective method. 2) A visibility analysis techniquwe for V.I.A. and B.H.C. was presented by studying GIS visibility analysis by means of DTM model using contour map. There were 5 problems. 3) Adequate analysis techniques were presented according to the landscape factor-road, ship-route, port, mountain, etc. 4) Viewing distance from road and ship-route in visual corridor, landma가 visibility and distance, the angle of incidence and invisible region's depth are helpful for land scape management or land use planning.

• Korean Institute of Interior Design Journal
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• v.21 no.5
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• pp.106-113
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• 2012

A study on techniques to evaluate auditorium assignment visible efficiency using three-dimensional simulation. The most important thing to be considered is to ensure the visibility to the podium upon assigning auditorium of venues, classrooms or seminar rooms. However, since there are so many variables to be considered such as the form of the stage, the area and height of the stage, size of screen, and the distance and angle of the auditorium from the podium, the methods to assign auditorium are staying at the level of basic for a long time. Thus, in this study, we proposed simulation methodology to quantitatively evaluate the three-dimensional visible efficiency based on Visual Graph Analysis (VGA) theory. After analytical methodology manufactures application, it sets examples of visibility depending on location of screen, visibility depending on degree of height difference and visibility about three-dimensional Mass Zoning like a stage and verifies the efficacy. In addition, based on results, visibility expectation curve is drawn and the method to calculate the stepped height depending on necessary visibility is proposed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.6
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• pp.1-7
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• 2007

In this paper, It evaluated visibility about Metal Halide Lamp(MHL), High Pressure Sodium Lamp(HPS) and PLS(Plasma Lighting System) as Road lighting source in fog conditions. To evaluate visibility, it analyzed valuation of subjects about each light sources in special fog conditions. In result, it obtained that High Pressure Sodium Lamp has best visibility in photopic vision and PLS has best visibility in scotopic vision. This result is expected to help about select of Road lighting source.

• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.73-84
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• 2010

This paper is to analyze effectiveness and efficiency of topographic features in visibility analysis. For this research aim, this paper compares the analysis results of topographic features and relationships between topographic features and their visibility analysis on surfaces. This paper employs peak, pass, pit, ridge and valley features from the topographic features for which five areas including mountain and plain areas in Britain are selected and their DEM data are generated. The summaries of the analysis results are as follows: Firstly, it is clear that relationship between high elevation points and their visibility is not highly correlated. This means that highly elevated points are not necessarily better visible areas and they are not suitable for searching for large visible areas. Secondly, the positions that can see large visible areas are highly correlated with their elevation and are distributed within a certain range which has small deviation of their correlation between visibility and elevation. This means that to search for large visible areas, it is necessary to employ the positions located at relatively high elevation area. Thirdly, for all of the five areas, the visibility results of the topographic features are compared with maximal visibility resulted from a while surface areas, and it is identified that topographic features show similar visibility performances of that maximal visibility. From the results stated above, it can be inferred that topographic features and its topographic characteristics are enable to be a research motivation to the visibility analysis topics. Furthermore, the results of this paper can be contributed to explore suitable variables and factors for solving multiple viewshed problems.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.241-242
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• 2022

In this study, fire simualtion was performed to examine the necessity of smoke control system in the tunnel fire. The heat release rate was set to 5 MW and 20MW, and the visibility was measured at 1.8 m, which is the breathing limit, when there is no jet fan. Through this, it was confirmed that 5 MW did not affect the visibility even without the jet fan, and in the case of 20 MW, a jet fan was required to secure the visibility. The visibility was measured at the same location by installing the jet fan, and the simulation was performed by reducing the design volume flow rate of 8.5 m³/s by 80% and 50%, respectively. As a result, it was confirmed that sufficient visibility was secured when the design flow rate and 80% were reduced.

• Journal of Environmental Science International
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• v.3 no.3
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• pp.209-216
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• 1994

The Daechong dam is located nearby Chongju city, and the population alone in the Chongju-Chongwon area is over one half million. It is found that the number of days for fog occurrence after constructing the dam was much fewer than those before constructing it. It appears that the construction of a large dam did not cause to increase in the occurrence of fog in the Chongju area, and that was the increase due to topographical characteristics and wind direction. Low visibility in the Chongju-Chongwon area occurred frequently. In summer, Chongwon recorded more days of poor visibility than those observed at Chongju. It is thought that TSP, $\textrm{SO}_2$ and $\textrm{NO}_2$ 씨오투 were the main constituents of air pollutants causing the reduction in visibility. Those air Pollutants are produced by vehicles and industrial activities in the region.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1807-1810
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• 2003

Steganography based on Just Noticeable Difference(JND) has been used for natural images. However, it has been recognized to have defects for the non-natural images such as scanned text images, cartoons, etc. In this paper, an alternative method is proposed to improve this problem. A new scheme is designed specially for the non-natural images. Instead of JND, Noise Visibility Function(NVF) is used. NVF value and edge strength value of each pixel ate combined to decide the embedding data capacity and the visibility of data embedded images have been improved specially for the non-natural images.

• Journal of Environmental Science International
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• v.5 no.6
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• pp.719-725
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• 1996

To research the cause of the low and the poor visibility phenomena of Kimhae international airpot statistically, we analyzed the field routine data for the last five years from 1985 to 1989. The poor visibilities below 1km, 3km, and 5km usually occurred at about 6 o'clock in the morning under the condition of calm or light wind from south to southwest direction, and lasted for from 1 to 3 hours. they were caused by the radiative cooling and the inflow of moisture from the South Sea. The frequency of th low visibility(below 9km) recorded 48.1% a year. And the low visibility below 8km with relative humidity below 70% often occurred in the case of southeast, southwest, and northwest wind. And it reveals a peak at 11:00 a.m.. It is supposed to be caused by the pollutants flowing from the neighbouring industrila complex, Sasang, Jangnim and by the photochemical reaction. And, when the industrial direction from Kimhae international airport, the visibility and the air pollution may become worse and worse by the increased pollutants.