• International Journal of Highway Engineering
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• v.11 no.4
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• pp.49-58
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• 2009

Current sunshine regulations of our country, focused on common houses and general construction, are failing to reflect adequately the characteristics of roads and elevated structures. Besides, researches are chiefly being conducted on a pitch between common houses and its diverse effects, neglecting clearance between a road or elevated structure and a residential area, environmental elements brought on by structures, such as sunshine difficulty, and their resultant factors Therefore, this study, focused on the sunshine environment of elevated structures adjacent to a residential district, as part of all roads and elevated structures, looked over currently used clearance adequacy level and analyzed the characteristics of structures in relation to an angle of direction. Then, clearance ratio by heights was calculated through a pitch by characteristics of a structure. With a view to minimize the sunshine difficulty that might occur in the future construction, it aims to propose the basic data needed for calculating the minimum clearance, while emphasizing the necessity for institutional alignment on structures.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.8
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• pp.630-640
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• 2003

As tunnel ventilation has recently been playing a major role in the tunnel construction and maintenance, longitudinal ventilation systems with jet fans have been utilized a great deal because they are economical and effective. However, due to the length of tunnels and heavy traffic, it is hard to take the field measurements. In this study, therefore, the computer simulation and the model experiment of producing a wind tunnel were carried out simultaneously and the results were compared. The ultimate objective of this research was to interpret the air flow pattern inside the tunnel with a jet-fan was set up, and to offer the useful data for jet-fan installation and operation. The experiment was carried out with varying the jet-fan diameters, location of installation, the discharge velocity. Result showed that as the initial static pressure came up with the negative pressure, the tunnel air flowed into the inside of tunnel from outside due to the entrainment-effect and the backflow-phenomenon by separation-effect was observed in the lower half part of the tunnel. As the jet-fan was getting closer to the tunnel wall, the entrainment-effect caused by the interaction with the wall was increased; however, the mixing distance and irregular flow section became longer, and also the air pressure loss generated by wall friction was large.

• Smart Media Journal
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• v.9 no.4
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• pp.9-16
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• 2020

Recently, various studies are being conducted to integrate Image Segmentation into smart factory industries and autonomous driving fields. In particular, Image Segmentation systems using deep learning algorithms have been researched and developed enough to learn from large volumes of data with higher accuracy. In order to use image segmentation in the autonomous driving sector, sufficient amount of learning is needed with large amounts of data and the streaming environment that processes drivers' data in real time is important for the accuracy of safe operation through highways and child protection zones. Therefore, we proposed a novel DFCN algorithm that enhanced existing FCN algorithms that could be applied to various road environments, demonstrated that the performance of the DFCN algorithm improved 1.3% in terms of "loss" value compared to the previous FCN algorithms. Moreover, the proposed DFCN algorithm was applied to the existing U-Net algorithm to maintain the information of frequencies in the image to produce better results, resulting in a better performance than the classical FCN algorithm in the autonomous environment.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.26-36
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• 2022

Recently, studies have been conducted to cluster vehicles and disseminate safety messages in a VANET environment for driver safety and smoothy traffic. This paper proposes cluster management scheme for safety message dissemination through V2V communication and V2I communication in a VANET environment with high vehicle density and mobility. The proposed scheme reduces packet loss by selecting CH considering reception quality, total data owned by vehicles, moving speed, and connected vehicles, and maintaining cluster head candidates, which are the main agents of message dissemination, considering frequent cluster departures and subscriptions. In addition, the proposed scheme reduces duplicate messages by utilizing clusters by collaborating with a Road side unit(RSU). To prove the excellence of the proposed scheme, various performance evaluations are performed in terms of message packet loss and the number of RSU processing requests. As a result of performance evaluation, the cluster management scheme proposed in this paper shows better performance than the existing scheme.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.3
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• pp.293-299
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• 2009

This paper discusses an autonomous navigation system for urban environments. For the localization of the robot, EKF (Extended Kalman Filter) algorithm is used with odometry, angle sensor, and DGPS (Differential Global Positioning System) measurement. Especially in an urban environment, DGPS is often blocked by buildings and trees and the resulting inaccurate positioning prevents the robot from safe and reliable navigation. In addition to the global information from DGPS, the local information of the curb on the roadway is used to track a route when the global DGPS information is inaccurate. For this purpose, curb detection algorithm is developed and implemented in the developed navigation algorithm. Four different types of navigation strategies are developed and they are switched to adapt to different localization conditions according to the availability of DGPS and the existence of the curbs on the roadway. The experimental results show that the designed switching strategy improves the navigation performance adapting to the environment conditions.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.273-278
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• 2002

Modern society is an interaction between many different environments. It is important to the mutual relationships between people and especially between people and the environment. One of the mutual relationships between people and the environment is the traffic system, especially the traffic signals which give priority to pedestrian and traffic flow. Traffic signals for the pedestrian on the crosswalk contribute to a safe road environment for the pedestrian, while the traffic signals for the pedestrian running for the flickering of the green signal causes psychological stress. Therefore, this study investigated whether the walking velocity was influenced by the flickering of the green signal or not. Also, this study investigated whether the walking distance had an effect on the walking velocity of the elderly pedestrian or not. It was proved that the flickering of the green signal and the walking distance influenced the walking velocity and subjective sensitiveness according to the result of this study.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.37-44
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• 2012

In this paper, the application of robust fuel gauge algorithm in the external environment to general fuel gauge system is proposed. The proposed fuel gauge system is composed of two modules which are Moving Average Filter (MAF) and Inclination Filter (IF). They are used to show correctly the amount of fuel in the external environment which are curve road, slope or acceleration/deceleration driving. In parallel, verification and validation processes using Software In the Loop Simulation (SILS) in personal computer and Hardware In the Loop Simulation (HILS) similar to actual vehicle environments are established. Through this research, it turned out to be possible to operation of gauge become correct of external environment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.547-552
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• 2002

The purpose of this study is to propose indoor noise level in residential buildings affected by transportation noise (road traffic, railway and air-craft noise) based on subjective evaluations, 30 subjects participated in the experiment to evaluate the noise. Experimental environment reproduced real living and office environment, and in asking subjects' annoyance to the noise. An experiment to investigate the subjective responses to various computer noises (CD-Rom, HDD, Fan) in office environment was also undertaken. The Result shows that the lower limit of transportation noise is $40{\sim}41dB(A)$ and upper limit is $55{\sim}60dB(A)$, whereas the lower limit of various computer noises is $36{\sim}40dB(A)$ and upper limit is $45{\sim}52dB(A)$.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.59-66
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• 2014

PURPOSES : This study is to suggest heavy snow risk analysis in Seoul. METHODS : Recently, the increase of extreme weather caused by global warming raises the occurrences of unpredictable natural disasters and the loss potential of human disasters by land use facilities accumulation. It is necessary to develop the risk analysis for the natural and human disasters. RESULTS : In this study, heavy snow risk analysis among natural disasters in Seoul was suggested. The spatial unit of risk analysis level was established for the lines and administrative districts. CONCLUSIONS : The risk analysis was performed using risk matrix of disaster occurrence score and disaster damage score. The components affecting the risk disaster analysis by types were analyzed and the application of heavy snow risk analysis was suggested.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.677-680
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• 2004

In the mobile environment, according to the movement of the object, the query finds the nearest special object or place from object position. However, because query object moves continuously in the mobile environment, query demand changes according to the direction attribute of query object. Also, in the case of moving of query object and simply the minimum distance value of query result, sometimes we find the result against the query object direction. Especially, in most road condition, as user has to return after reaching U-turn area, user rather spends time and cost. Therefore, in order to solve those problems, in this paper we propose the nearest neighbor method considering moving object position and direction for mobile recommendation system.