• Journal of the Society of Disaster Information
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• v.9 no.1
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• pp.22-29
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• 2013

Warm mix asphalt(WMA), which is produced at lower temperatures than hot mix asphalt, has advantages in reductions of fuel consumption and greenhouse-gas emission. In this study, field tests such as skid resistance, rutting(permanent deformation), and roughness were conducted for analysis of long-term field performance of modified warm mix asphalt pavement. Skid resistance after 20 months represents the result similar to initial performance results but rutting and roughness decreased somewhat depending on the period of performance. Measurement results of permanent deformation and roughness could be acceptable because measured pavement location is bus lane that a lot of buses pass and stop. There were no cracks after 11 months, but some minor cracks were observed after 20 months. These results were influenced by increased crack resistance due to fiber addition.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.1
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• pp.1-7
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• 2005

This paper describes the system for detecting vehicles in the rear and rear-side that access between sidewalk and bus stopped to city road at day by computer vision-based method. This system informs appearance of vehicles to bus driver and passenger for the safety of a bus passenger getting off. The camera mounted on the top portion of the bus exit door gets the rear and rear-side image of the bus whenever a bus stops at the stop. The system sets search area between bus and sidewalk from this image and detects a vehicle by using change of image and sobel filtering in this area. From a central point of the vehicle detected, we can find out the distance, speed and direction by its location, width and length. It alarms the driver and passengers when it's judged that dangerous situation for the passenger getting off happens. This experiment results in a detection rate more than 87% in driving by bus on the road.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.249-255
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• 2016

This study, Seoul City shelter, you are trying to seek medical cooperation and cure rate increase proposal Yu findings's current situation and tuberculosis of homeless tuberculosis. Inspector, and has a total 591 people is targeted to implement an interview after acquiring utilization agreement in studies conducted chest X-ray photography. Of the interview questions, three or more protons, it is determined that the TB symptomatic conducted sputum examination, chest X-ray examination confirms the physician radiology, when sputum examination primarily chromatic findings the double implemented and conducted by requesting the ship inspection also said inspection sputum acid-fast bacteria if it is true one, respectively. confirmed case result of checking whether there is a difference due to risk factors(Jb) at the chi square black, it was found that there is no statistically significant difference at 95% confidence level. (${\chi}^2=0.276$, p>0.05), suspected case (Ac, Ae) results of examining whether there is a difference due to risk factors in chi square black, that there is a statistically significant difference at 99% confidence level is I found (${\chi}^2=9.414$, p<0.01). The nature of the homeless tuberculosis screening and directed to the distance homeless specific location are likely to evaluate the actual incidence low and aggressive or management needs, the rationale is allowed insufficient reality is. Through this research, future, for tuberculosis high risk tuberculosis patient, such as homeless to expand the tuberculosis screening of infectious tuberculosis patients in private medical institutions, and one-stop service that chest X-ray examination and sputum examination is carried out at the same time introduced immediately to prevent the inspection and examination, cure, and should establish a foundation that can be up to post administration.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.145-150
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• 2021

In order to continuously perform quarantine in public places, it is not easy to secure manpower, but using self-driving-based robots can solve problems caused by manpower. Self-driving-based quarantine robots can continuously prevent the spread of harmful viruses and diseases in public institutions and hospitals without additional manpower. The location of the autonomous driving function was estimated by applying the Pinnacle filter algorithm, and the UV sterilization system and chlorine dioxide injection system were applied for quarantine. The driving time is more than 3 hours and the position error is 0.5m.Soon, the stop-avoidance function was operated at 95% and the obstacle detection distance was 1.5 m, and the automatic charge recovery was charged by moving to the charging cradle at the remaining 10% of the battery capacity. As a result of quarantine with an unmanned quarantine system, UV sterilization is 99% and chlorine dioxide is sterilized more than 95%, which can contribute to reducing enormous social costs.

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.803-813
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• 2021

Coastal erosion has been a threat to coastal communities and emerged as an urgent problem. Among the coastal communities that are under perceived threat, Cotonou located in Benin, West Africa, is considered as one of the most dangerous area due to its high vulnerability. To address this problem, in 2013, the Benin authorities established seven groynes at east of Cotonou port, and two additional intermediate groynes have recently been integrated in April 2018. However, there is no quantitative analysis of groynes so far, so it is hard to know how effective they have been. To analyze effectiveness, we used optical satellite images from different time periods, especially 2004 and 2020, and then compared changes in length, width and area of shoreline in Cotonou. The study area is divided into two sectors based on the location of Cotonou port. The difference of two areas is that Sector 2 has groynes installed while Sector 1 hasn't. As result of this study, shoreline in Sector 1 showed accretion by recovering 1.20 km² of area. In contrast, 3.67 km² of Sector 2 disappeared due to coastal erosion, although it has groynes. This may imply that groynes helped to lessen the rate of average erosion, however, still could not perfectly stop the coastal erosion in the area. Therefore, for the next step, we assume it is recommended to study how to maximize effectiveness of groynes.

• Journal of Energy Engineering
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• v.25 no.2
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• pp.86-93
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• 2016

The existence of high temperature equipment such as steam pipe, deaerator, steam storage tanks and main steam stop valves makes relatively higher workplace temperature in a power plant of the turbine building. In order to cool down the air temperature in the turbine building, the outside air flow with lower temperature passes through the window and the hotter air in the building is extracted to the outside by installing the ventilation fan on the roof. Nevertheless, higher temperature regions near the high temperature equipment still exist in the turbine building and additional fans for the temperature reduction in the higher temperature region should be examined for the optimal location and mass flow rate. The purpose of the present study is to suggest the optimized location and capacity of the additional ventilation fans for a comfortable working environment. From the present study, it has been elucidated that the additional ventilation fans might be located near the high temperature deaerator and it could reduce the mean temperature in the turbine building by $3.0^{\circ}C$ and the temperature near the deaerator could be reduced by $4.2^{\circ}C$.

• Journal of Korea Multimedia Society
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• v.16 no.3
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• pp.318-329
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• 2013

This paper proposes a DNA watermarking method for the privacy protection and the prevention of illegal copy. The proposed method allocates codons to random circular angles by using random mapping table and selects triplet codons for embedding target with the help of the Lipschitz regularity value of local modulus maxima of codon circular angles. Then the watermark is embedded into circular angles of triplet codons without changing the codes of amino acids in a DNA. The length and location of target triplet codons depend on the random mapping table for 64 codons that includes start and stop codons. This table is used as the watermark key and can be applied on any codon sequence regardless of the length of sequence. If this table is unknown, it is very difficult to detect the length and location of them for extracting the watermark. We evaluated our method and DNA-crypt watermarking of Heider method on the condition of similar capacity. From evaluation results, we verified that our method has lower base changing rate than DNA-crypt and has lower bit error rate on point mutation and insertions/deletions than DNA-crypt. Furthermore, we verified that the entropy of random mapping table and the locaton of triplet codons is high, meaning that the watermark security has high level.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.369-376
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• 2010

At present, many problems in traffic operation and safety occurs since there is no clear design criteria on designating the not-permitted entrance/exit section at curb areas within complex areas. Even, there is no specific and detailed researches on the not-permitted entrance/exit section by now. This research calculated the proper length of the entrance/exit section at curb areas by dividing the access not-permitted section into the two sections. First, the calculation of the entrance section was done by considering the location of crosswalks, stop line clearance, the queue length of vehicles approaching to second lanes, and marginal distance for safety have been considered. Second, the calculation of the exit section was done by comparing and analyzing the distance between cars of the entrance section according to the investigation point and the distance considering the location of crosswalks, the behavior of exit vehicles and the length of vehicles. In conclusion, by presenting the proper length in consideration of the traffic operation and safety on the access not-permitted section within complex areas, it can be used as a traffic safety improvement alternative and will be contributed in establishing and operating the proper installation criteria for the access not-permitted section within complex areas.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.148-162
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• 2023

The objective of this study is to derive the appropriate perception location for changes in driving behavior of autonomous vehicles in urban road environments based on traffic safety signs. For this purpose, 32 types of signs that induce changes in driving behavior were selected from currently used traffic safety signs and classified as three types according to changes in driving behavior. Based on this, three scenarios were designed: stop, speed change, and lane change scenarios. These were used to confirm the impact on traffic flow. As a result of the analysis, it was found that each scenario needs to receive information on traffic safety signs in advance to ensure changes in traffic flow and safety. Consequently, the appropriate perception location can be used as a basis for establishing standards for delivering message sets to autonomous vehicles or revising traffic safety signs for them. In addition, this study is expected to contribute to the establishment of safe and efficient driving strategies on urban roads as autonomous vehicles are introduced in the future.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.321-331
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• 2017

The objective of this study is to analyze the factors affecting the pedestrian accidents of roundabout near schools. To this end, this study has focus on the comparative analysis of pedestrian accidents across different school areas. The traffic accident data from 2007 to 2014 are collected from TAAS data set of Road Traffic Authority. To develop the pedestrian accident rate model, the linear regression model has been utilized in this study. 28 explanatory variables such as geometry and traffic volume factors are used. The main results are summarized as follows. First, the null hypotheses that the number of pedestrian accidents are the same are rejected. Second, 5 multiple linear regression accident models with higher statistical significance (adjusted $R^2$ of 0.651~0.788) have been developed. Third, while the common variables of 3 models (model I~III) related to school location are evaluated to be the pedestrian island, crosswalk, types of roundabout, elementary school and bus stop. Fourth, while the common variable of 3 models (model III~V) related to near school area or not is evaluated to be pedestrian island, type of roundabout, sidewalk, elementary school, speed hump, speed limit sign and number of entry lane. As a result, the installation of pedestrian islands and crosswalk might be expected to decrease the number of pedestrian accidents near schools.