• Journal of Korean Society of Transportation
• /
• v.25 no.4
• /
• pp.79-87
• /
• 2007

The interchanges of urban freeways have many problems with traffic operation due to high off-ramp flows and frequent congestion at adjacent intersections. The flow exiting from off-ramps is affected by the operational status and traffic volume conditions of the nearest signalized intersection. As a result, off-ramp flow cannot exit and the queue backs up the freeway mainline when queues from the signalized intersection form up to the junction of the off-ramp and street. The spacing between an off-ramp and an adjacent intersection is likely to determine the traffic conditions at the adjacent intersection. However, the current design guidelines do not consider such a factor. This study is to develop a model calculating the spacing between off-ramps and adjacent intersections considering the signal, traffic, and road conditions. The variables affecting the model in this study are effective green time (g/C), volume-capacity ratio (v/c), the number of lanes, and off-ramp volume. Various scenarios are designed to represent the effects of the variables and the road networks are constructed using VISSIM, which is a common traffic micro-simulation software package. The queue length is derived from VISSIM and this length is considered as the recommended spacing between the off-ramp and the adjacent intersection. Through the simulation analysis, regression models are developed to calculate the queue length reflecting the various conditions such as signals, traffic, and road configurations. The developed model can be used to create road design guidelines to determine the location of off-ramps in the planning stage.

• Journal of Korean Society of Transportation
• /
• v.34 no.2
• /
• pp.123-134
• /
• 2016

Traffic accident at intersections takes 44.3% of total number of accidents on entire road network of Korea in 2014. Although several studies addressed contributory factors of accidents at signalized intersection, very few is known about the factors at rural unsignalized intersections. The objective of this study is therefore to investigate specific characteristics of crashes at rural unsignalized intersection and to identify contributory factors in causing crashes by statistical approach using the Ordered Logistic Regression Model. The results show that main type of car crashes at unsignalized intersection during the daytime is T-bone crashes and the number of crashes at 4-legged intersections are 1.53 times more than that at 3-legged intersections. Most collisions are caused by negligence of drivers and violation of Right of Way. Based upon the analysis, accident severity is modeled as classified by two types such as 3-legged intersection and 4-legged intersection. It shows that contributory factors in causing crashes at rural unsignalized intersections are poor sight distance problem, average daily traffic, time of day(night, or day), angle of intersection, ratio of heavy vehicles, number of traffic violations at intersection, and number of lanes on minor street.

• Korean Security Journal
• /
• no.55
• /
• pp.117-141
• /
• 2018

Police crime statistics report that residential housing such as apartment, low rise, detached houses is the second most vulnerable to crime, which is closely followed by the number of street crimes. Also residential houses are often exposed to quality-of-life crime, e.g burglary. It threatens the basic human rights of house residents in terms of safety and comfort within the urban living environment. This study examines related precedent studies regarding the vulnerability of residential housing including studios, multi-family housing from the viewpoint of crime prevention through environment design(CPTED), extracted the elements and items suitable for the safety of residential facilities and the certification evaluation indicators and check items to be the basis for the checklist are derived. Based on these evaluation indicators and inspection items, we conducted on-site surveys of residential facilities in three areas of Seoul, Yongin and Asan, and the final draft of the checklist was revised based on the results of the field survey. There are 43 items on the 7 fields of evaluation in the final version of checklist, 11 items in the management and operation, 20 items in the surveillance, 7 items in the access control, 1 item in the territoriality, 2 items in the activity support, and 2 items in the security and safety facilities. In addition, various points of interest were added to allow the administrator of the residential facility to earn points for special measures taken for safety. This checklist can be appropriately modified and utilized in consideration of the characteristics of each facility. Korean national police agency has CPOs to check the residential facilities in their jurisdiction using checklists and to certify excellent facilities with high level of safety.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.32 no.2
• /
• pp.163-171
• /
• 2014

Based on the GPS/IMU integration, the car navigation has unstable conditions as well as drastically reduces accuracies in urban region. Nowadays, many cars mounted the camera to record driving states. If the ground coordinates of street furniture are known, the position and attitude of camera can be determined through SPR(Single Photo Resection). Therefore, an estimated position and attitude from SPR can be applied measurements in Kalman filter for updating errors of navigation solutions from GPS/IMU integration. In this study, the GPS/IMU/SPR integration algorithm was developed in loosely coupled modes through extended Kalman filters. Also, in order to analyze performances of GPS/IMU/SPR, simulation tests were conducted in GPS signal reception environments and the GCPs (Ground Control Points) distributions. In fact, the position and attitude gathered from GPS/IMU/SPR integration are more precise than the position and attitude from GPS/IMU integration. When IPs (image points), corresponded to GCPs, were concentrated in the center of image, the position error in the optical axis respectively increased. To understand effects from SPR, we plan to carry additional test on the magnitude of GCP, IP and initial exterior orientation errors.

• Journal of Korean Society of Transportation
• /
• v.21 no.3
• /
• pp.59-69
• /
• 2003

Signalized intersections are widely used in urban street network. However, it was reported that a roundabout is better than a signalized intersection in terms of delay when the approaching traffic volume for each bound is low. The objective of this study is to develop entry capacity models of roundabout and establish the warrant for signalized intersection based on the delay. The entry capacity of a roundabout is determined by the circulating traffic volume and the geometric design of the roundabout such as the diameter of central island, entry lane widths, and the circulating roadway width. The traffic and geometric characteristics of four roundabouts were collected and analyzed. The study reveals that; i)among the geometric features, the diameter of central island and the circulating roadway width influence the entry capacity, and ii)even though it is difficult to compare the models of each country due to different geometric features considered in the models, the models developed in this study show higher capacity than the models from Israel or Germany. These seem to be attributed to the facts that; i)the outside diameters of the roundabouts selected in this study are larger than in the other studies, and ii)the acceptable gap in Korea is smaller than that in the other countries. In order to compare the performances of round- about and signalized intersection, the performance of roundabouts was evaluated with the SIDRA. The simulation was conducted only for the roundabouts composed of single lane. According to the result of the analysis, it may be concluded that when the approaching traffic volume for each bound is lower than 600pcph, a roundabout is better than a signalized intersection in terms of its operational performance.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.30 no.3
• /
• pp.80-86
• /
• 2012

This study is about selecting Landscape Viewpoint on Bukchon Hanok Village, Jongno-Gu, Seoul. The process on selecting photo spots was focused on visualizing elements, and it was hard to find an objective standard for selecting landscape viewpoint. Therefore, by literature review and site study, this study selects more objective and empirical Landscape View Point on Bukchon. Landscape Viewpoint Standards are Traditional Hanok Landscape, Historical Heritage Landscape, Alley Street Landscape, City Architecture Landscape, and Natural Forest Landscape. By Landscape Preference and Character of Place survey, this study finds out another Landscape Viewpoint and correlation of those variables. A coefficient of correlation is 0.846, and its correlation is considerably high. Through this result, it could provide a concrete standard for selecting Landscape View Point and a preliminary information for finding Landscape View Point on Histo-Cultural area.

• Korean Journal of Remote Sensing
• /
• v.26 no.5
• /
• pp.593-603
• /
• 2010

Most spatial data acquisition systems employing a set of frame cameras may have suffered from their small fields of view and poor base-distance ratio. These limitations can be significantly reduced by employing an omni-directional camera that is capable of acquiring images in every direction. Bundle Block Adjustment (BBA) is one of the existing georeferencing methods to determine the exterior orientation parameters of two or more images. In this study, by extending the concept of the traditional BBA method, we attempt to develop a mathematical model of BBA for omni-directional images. The proposed mathematical model includes three main parts; observation equations based on the collinearity equations newly derived for omni-directional images, stochastic constraints imposed from GPS/INS data and GCPs. We also report the experimental results from the application of our proposed BBA to the real data obtained mainly in urban areas. With the different combinations of the constraints, we applied four different types of mathematical models. With the type where only GCPs are used as the constraints, the proposed BBA can provide the most accurate results, ${\pm}5cm$ of RMSE in the estimated ground point coordinates. In future, we plan to perform more sophisticated lens calibration for the omni-directional camera to improve the georeferencing accuracy of omni-directional images. These georeferenced omni-directional images can be effectively utilized for city modelling, particularly autonomous texture mapping for realistic street view.

• Safety and Health at Work
• /
• v.10 no.3
• /
• pp.377-383
• /
• 2019

Objectives: Exposure to fine particles in urban air has been associated with a number of negative health effects. High levels of fine particles have been detected at underground stations in big cities. We investigated the exposure conditions in four occupational groups in the Stockholm underground train system to identify high-exposed groups and study variations in exposure. Methods: $PM_1$ and $PM_{2.5}$ were measured during three full work shifts on 44 underground workers. Fluctuations in exposure were monitored by a real-time particle monitoring instrument, pDR, DataRAM. Qualitative analysis of particle content was performed using inductively coupled plasma mass spectrometry. Nitrogen dioxide was measured using passive monitors. Results: For all underground workers, the geometric mean (GM) of $PM_1$ was $18{\mu}g/m^3$ and of $PM_{2.5}$ was $37{\mu}g/m^3$. The particle exposure was highest for cleaners/platform workers, and the GM of $PM_1$ was $31.6{\mu}g/m^3$ [geometric standard deviation (GSD), 1.6] and of $PM_{2.5}$ was $76.5{\mu}g/m^3$ (GSD, 1.3); the particle exposure was lowest for ticket sellers, and the GM of $PM_1$ was $4.9{\mu}g/m^3$ (GSD, 2.1) and of $PM_{2.5}$ was $9.3{\mu}g/m^3$ (GSD, 1.5). The $PM_1$ and $PM_{2.5}$ levels were five times higher in the underground system than at the street level, and the particles in the underground had high iron content. The train driver's nitrogen dioxide exposure level was $64.1{\mu}g/m^3$ (GSD, 1.5). Conclusions: Cleaners and other platform workers were statistically significantly more exposed to particles than train drivers or ticket sellers. Particle concentrations ($PM_{2.5}$) in the Stockholm underground system were within the same range as in the New York underground system but were much lower than in several older underground systems around the world.

• The Journal of the Korea Contents Association
• /
• v.21 no.5
• /
• pp.561-580
• /
• 2021

This study analyses the historical and cultural streets at Pinggang Road in the city of Suzhou, by understanding the development and conservation of the area, and uses the following ways to investigate its development, re-organization, and current state. This paper comprehensively compares, collates and investigates 4 different historical and cultural areas in Insadong and Samcheong-dong in South Korea, and South Luogu Lane in China. From initial research and analysis, this paper gathers the cultural, economic, and societal perspectives as non-physical measures, and spatial structure, road structure, and building maintenance as physical factor framework. It is significant in that it can provide an evaluation model for the preservation and regeneration of historical and cultural streets by presenting the viewpoint of complex development of non-physical and physical elements in Pyeonggang-ro. In addition, it is necessary to conduct optimization and specific research on insufficient areas, such as maintenance and development of programs and signature systems for visitors, and continuous development of historical and cultural network platforms by combining on-site surveys. Basic data should be provided for reference on the street.

• Korea Science and Art Forum
• /
• v.24
• /
• pp.143-157
• /
• 2016

Focusing on the Gwangheemun that have a history of spatial specificity. Gwangheemun increase the value of space in the surrounding area, focused to derive a plan that can be activated. Research method was to analyze the characteristics and advantages and disadvantages of the surrounding space and the associated cultural content through SWOT analysis around the base of Gwangheemun. After considering the potential of the current location of physical characteristics and spatial resources, the possibility Gwangheemun development were mainly fashion and art content for the Space Vitalization in the surrounding area. Fashion and art space of Gwangheemun activated based on the possibility of Gwangheemun cultural meaning and value in the history of the past and the present time presented the main directions and strategic approach. The results of this research suggested Fashion art Hotel in applying urban regeneration methodologies, Cheongguro-16 plan for content development, arts and culture fashion street planning. Through this research, we want to establish the strategic control strategy between the policy decision making structures for the successful development of the fashion arts content.