• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E2
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• pp.92-101
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• 2008

The objective of this study is to evaluate and improve the capability of the Weather Research and Forecasting (WRF) model in simulating fog and visibility in local airports over Korea. The WRF model system is statistically evaluated for the 48-fog cases over Korea from 2003 to 2006. Based on the 4-yr evaluations, attempts are made to improve the simulation skill of fog and visibility over Korea by revising the statistical coefficients in the visibility algorithms of the WRF model. A comparison of four existing visibility algorithms in the WRF model shows that uncertainties in the visibility algorithms include additional degree of freedom in accuracy of numerical fog forecasts over Korea. A revised statistical algorithm using a linear-regression between the observed visibility and simulated hydrometeors and humidity near the surface exhibits overall improvement in the visibility forecasts.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.5
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• pp.645-652
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• 2015

In underwater, such as fish farm and sea, turbidity is increased by water droplets and various suspended, therefore light attenuation occurs depending on the depth also caused by the scattering effect of light float. In this paper, in order to improve the visibility of underwater images obtained from these aquatic environment, we propose a visibility enhancement method using a haze removal method based on dark channel prior and a trained color transform model. In order to train a color transform model, we used underwater pattern images captured from Pohang and Yeosu, and to measure the performance of the proposed method, we carried out experiment of visibility enhancement using underwater images collected from Yeosu, Geomundo and Philippines. The results show that the proposed method can improve the visibility of underwater images of various locations.

• 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 the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.8
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• pp.14-23
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• 2014

According to the analysis of crosswalk pedestrian accidents, accidents that occur at night represent 70% of all deaths among crosswalk pedestrians when compared to accidents occurring in the daytime. This is due to the poor visibility that hinders drivers to recognize pedestrians at night. Illuminance on the horizontal plane of the road and the current state of crosswalk lighting are not sufficient enough to comply with standards. Thus, we analyzed factors derived from lighting environment studies on improving crosswalk visibility, domestic and foreign crosswalk lighting standards, and subsequently proposed solutions which are needed to raise domestic crosswalk lighting standards, and a means to uphold those standards through proper verification.

• Journal of Digital Contents Society
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• v.10 no.2
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• pp.299-307
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• 2009

It is well-known that the scenic visibility achieved in our naked eyes is related with the quality of aerosol condition which is composed of primary and secondary air pollutants. In recent, the IMPROVE organization in U.S.A. has developed two algorithms to estimate the visible length depending on the elements of air pollutant. Using these algorithms, we are to represent the condition of aerosol quality with the well-known scenic images of the observing area so that any one that have no sufficient chemical knowledge may feel and understand the level of air pollution in visuality.

• Journal of The Korea Institute of Healthcare Architecture
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• v.27 no.2
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• pp.49-56
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• 2021

Purpose: This study aims to provide a way to improve hospital satisfaction through improvement of hospital bulletins based on the analysis of the actual condition of hospital bulletins and satisfaction analysis for patients. Methods: First, a case study is conducted. After setting the analysis items based on previous studies and case study, a satisfaction survey is conducted on patients and statistical analysis is performed. Results: As a result of factor analysis, factors were classified into four categories: legibility, visibility, effectiveness, and frequency. As a result of the importance analysis through multiple regression analysis of four factors affecting hospital satisfaction, the importance of the "legibility" factor was the highest, followed by the "frequency", "effectiveness", and "visibility". As a result of the satisfaction analysis of the bulletins in the study site, the "visibility" factor was the highest, followed by "legibility", "effectiveness", and "frequency". Implications: In order to improve hospital satisfaction, the improvement of factors of high importance should be considered first. In other words, in hospital bulletins, legibility and frequency should be considered first. In addition, hospital satisfaction can be maximized by improving the level of factors and variables that are low in the satisfaction survey by factor.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.157-164
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• 2008

The optical characteristcs and visibility of emergence esit signs made with phosphorescent materials have been studied and compared with conventional signs. The phosphorescence of the materials meets standards as defineds by JIS, and achieved a level of brightness recognizable by the human eye. The visibility in the dard of the signs using the phosphorescent materials was shown to be higher than that of currently employed materials. It was confirmed that phosphorescent materials show excellent promise to improve the visibility of emergency exit signs.

• Journal of the military operations research society of Korea
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• v.31 no.2
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• pp.13-27
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• 2005

The most portion of the Korean Army's ammunition management system has achieved efficiency and automation based on the Ammunition Information System (AIS). However, a few limitations for the automation system constructed at each site, exist in verifying the real time situation. At the present state of technology, the asset visibility of the located ammunitions is basically achieved. On the other hand, the ammunitions in the middle of transportation are difficult to achieve asset visibility. The RFID(Radio Frequency Identification) technology could be an appropriate solution in these circumstances. Therefore, the objective of this paper is to apply the RFID to improve defense asset management, total asset visibility and ammunition distribution efficiency in the ammunition management system of the Korean Army.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.707-723
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• 2020

In this study, a decision tree type of quality control (QC) method was developed to improve the temporal-spatial representation and accuracy of the visibility data being operated by the Korea Meteorological Administration (KMA). The quality of the developed QC method was evaluated through the application to the 3 years (2016.03-2019.02) of 290 stations visibility data. For qualitative and quantitative verification of the developed QC method, visibility and naked-eye data provided by the KMA and QC method of the Norwegian Meteorological Institute (NMI) were used. Firstly, if the sum of missing and abnormal data exceeds 10% of the total data, the corresponding point was removed. In the 2nd step, a temporal continuity test was performed under the assumption that the visibility changes continuously in time. In this process, the threshold was dynamically set considering the different temporal variability depending on the visibility. In the 3rd step, the spatial continuity test was performed under the assumption of spatial continuity for visibility. Finally, the 10-minute visibility data was calculated using weighted average method, considering that the accuracy of the visibility meter was inversely proportional to the visibility. As results, about 10% of the data were removed in the first step due to the large temporal-spatial variability of visibility. In addition, because the spatial variability was significant, especially around the fog area, the 3rd step was not applied. Through the quantitative verification results, it suggested that the QC method developed in this study can be used as a QC tool for visibility data.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.77-85
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• 2007

The number of accidents occurring at railway crossings is less than the accidents on other sections of roads but they cause enormous socio-economic damages. The geometric aspects of the railway crossing have to allow the drivers to recognize the crossings and take precautions against collisions. Therefore, ensuring visibility for the vehicle approaching the railway crossing is necessary for safe operation of the crossing. However, as there is little research related to railway crossing visibility in Korea. validating visibility and maintaining visibility based on the validation is badly needed. This research develops a visibility validation model to support improving visibility and to reduce accidents at railway crossings to improve safety for the crossing users.