• Journal of Korean Society for Atmospheric Environment
• /
• v.4 no.1
• /
• pp.1-12
• /
• 1988

This study was carried out to measure the contents of soluble sulfur and heavy metals in the leaves of roadside tree at 34 sampling sites of Seoul area from the Sep. 1 to Sep. 30 during 1985 and 1986. The results were as follows; 1. Average contents of soluble sulfur at all sampling sites were; Plantanus orientalis 0.474%, Ginkgobioloba 0.562%, and Salix pseudolasiogyne 0.566%. 2. Correlation between sulfur dioxide concentration in the air and soluble sulfur in the leaves by area were; Green belt area R = 0.985, Residential area R = 0.856, Commercial area R = 0.668, Industrial area R = 0.886. Correlation by species were ; Platanus orientalis R = 0.817, Ginkgobiloba R = 0.771, Salix pseudo-lasiogyne R = 0.824. 3. Correlation between $SO_X$ concentration in the air and sulfur contents in the leaves showed positive significance. 4. Contents of soluble sulfur in the heavy traffic area were higher than that of light traffic area. 5. Heavy metal contents of 1986 were higher than that of 1985; Fe> Mn > Zn > Pb > Cu > Cd > Cr. 6. Lead contents in the leaves of 1986 were; Platanus orientalis 16, 701 ppm, Gingobiloba 21,729ppm, Salix Pseudo-lasiogyne 12.418 ppm.

• Journal of Korea Society of Industrial Information Systems
• /
• v.27 no.6
• /
• pp.77-93
• /
• 2022

In this study, we present an algorithm that analyzes the risk by reflecting regional characteristics for factors affected by direct and indirect damage from heavy-snow. Factors affected by heavy-snow damage by 29 regions are selected as influencing variables, and the concept of sensitivity is derived through the relationship with the amount of damage. A snow damage risk prediction model was developed using a machine learning (XGBoost) algorithm by setting weather conditions (snow cover, humidity, temperature) and sensitivity as independent variables, and setting the risk derived according to changes in the independent variables as dependent variables.

• Journal of Advanced Navigation Technology
• /
• v.3 no.1
• /
• pp.60-68
• /
• 1999

In this paper, we propose a new background generation method for image detector for traffic information collection. Conventional methods result in bad performance when there are frequent traffic jams due to heavy traffic. To improve on this, we use high level information from vehicle detection. Only part of the image that is not considered as vehicle is used in background generation. The proposed method finds background more robustly than that of the conventional methods even in the presence of heavy traffic.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.3D
• /
• pp.205-212
• /
• 2012

The national highway traffic counts system consists of short duration counts and continuous counts. Unlike continuous counts, short duration counts are performed by collection of a few days period and thus, the magnitude of deviation of collected data from AADT varies depending upon when data collection takes place. Therefore, this study was done to find out the best months and days of data collection of each highway classification in order to enhance the accuracy of AADT estimation. Continuous counts, another type of the national traffic counts system, are performed by collection of 365-day period using a permanent traffic counter. Therefore, it is necessary to keep the number of days for which the counter malfunctions to a minimum in order to enhance the accuracy of data. However, from time to time the permanent traffic counter malfunctions due to various causes and thus, cannot collect data. Therefore, this study was done to find out whether the age of counter, the ratio of heavy vehicle volume to total traffic volume, etc. could be the direct causes of counter's malfunction based on the number of maintenance for a certain time period.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.2D
• /
• pp.129-136
• /
• 2012

In the US, Japan and Germany the Aerial-Based Vehicle Detection System, which collects real-time traffic data using the Unmanned Aerial Vehicle (UAV), helicopters or fixed-wing aircraft has been developed for the last several years. Therefore, this study was done to find out whether the Aerial-Based Vehicle Detection System could be used for real-time traffic data collection. For this purpose the study was divided into two parts. In the first part the possibility of retrieving real-time traffic data such as travel speed from the aerial photographic image using the image processing technique was examined. In the second part the quality of the retrieved real-time traffic data was examined to find out whether the data are good enough to be used as traffic information source. Based on the results of examinations we could conclude that it would not be easy for the Aerial- Based Vehicle Detection System to replace the present Vehicle Detection System due to technological difficulties and high cost. However, the system could be effectively used to make the emergency traffic management plan in case of incidents such as abrupt heavy rain, heavy snow, multiple pile-up, etc.

• Korean Journal of Health Education and Promotion
• /
• v.14 no.2
• /
• pp.69-94
• /
• 1997

Recently, occurrence of alcohol-involved traffic accidents is increasing while all the accidents by violation of law except drunk driving. Traffic accidents by drunk driving has a great external cost. In detecting drunk driving, blood alcohol content Many studies reported close correlation between blood alcohol content and traffic accidents by drunk driving. The risk of traffic accidnet increases exponentially as blood alcohol content increases. To control traffic accidents by drunk driving, decide target population. Heavy drinkers are few and responsible for a small part of the loss while casual drinkers are many and responsible for a large part of the loss. Casual drinkers need to be included in the targer population for the control of traffic accident by drunk driving. Stragegies to reduce the quantity of alcohol consumed, change the pattern of drink, such as frequency of drinking, raise of perceived risk of accident need to be sought.

• Proceedings of the IEEK Conference
• /
• 2000.11a
• /
• pp.193-196
• /
• 2000

A new medium access control protocol is proposed to support stable wireless Internet services. Using the characteristics of the uplink Internet traffic and a Voice-Packet multi-session mode, the proposed protocol transmits the uplink Internet traffic via the voice traffic channel of silent duration in a multi-session mode. Out simulation results show that the proposed protocol guarantees stable wireless Internet services under heavy loads.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2001.10a
• /
• pp.77-82
• /
• 2001

An intelligent road transport management system focused on microscopic, real-time traffic signal control is proposed. Referring to the development of those systems in Japan, extensive use of image traffic detectors observing the movement of vehicles inside intersections, and direct data exchange between the signal controllers of neighboring intersections are newly assumed. On site investigation of five intersections in Japan or in Malaysia shows the possibility of effective information provision and simple algorithm for solving heavy congestion, as well as easy installation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.12B
• /
• pp.1996-2002
• /
• 2000

This paper investigates a priority scheme for IEEE 802.11 Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) protocol in order to provide short access times for priority frames (e.g. time-deadline traffic) even when the overall traffic on the wireless channel is heavy. Under the compatibility constraint for the IEEE 802.11 wireless LANs, two priority systems are simulated: no priority (current IEEE 802.11 standard) for time-deadline traffics and dynamic time-deadline priority. We evaluate algorithms to improve the time-deadline traffic performance using discrete event simulation (DES)

• Proceedings of the IEEK Conference
• /
• 2003.11a
• /
• pp.413-416
• /
• 2003

This paper proposes an adaptive background image generation method based on the frame difference for traffic monitoring. The performance of the conventional method is limited when there are more vehicles due to traffic Jam. To improve on this, we use frame differencing to separate vehicles from background in frame differencing, we adopt selective approach by using part of the image not considered as vehicle fer extraction of background. The proposed method generates background more efficiently than conventional methods even in the presence of heavy traffic.