• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2218-2224
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• 2016

Opportunistic routing is designed for an environment where there is no stable end-to-end routing path between source node and destination node, and messages are forwarded via intermittent contacts between nodes and routed using a store-carry-forward mechanism. In this paper, we consider PRoPHET(Probabilistic Routing Protocol using History of Encounters and Transitivity) protocol as a base opportunistic routing protocol and propose an efficient context-aware opportunistic routing protocol by using the context information of delivery predictability and node type, e.g., pedestrian, car, and tram. In the proposed protocol, the node types of sending node and receiving node are checked. Then, if either sending node or receiving node is tram, messages are forwarded by comparing the delivery predictability of receiving node with predefined delivery predictability thresholds depending on the combination of sending node and receiving node types. Otherwise, messages are forwarded if the delivery predictability of receiving node is higher than that of sending node, as defined in PRoPHET protocol. Finally, we analyze the performance of the proposed protocol from the aspect of delivery ratio, overhead ratio, and delivery latency. Simulation results show that the proposed protocol has better delivery ratio, overhead ratio, and delivery latency than PRoPHET protocol in most of the considered simulation environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.586-589
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• 2018

As the convergence of traffic system and Big-data technology, new convenient services which is helpful for drivers and pedestrian are appeared. Recently, the various researches about the traffic system, such as prediction of traffic jam and finding the shortest path, are studied. In this paper, we collect the data of taxi trips in Daegu City, and visualize them on the map of Daegu City. And then, we select specific sections of roads in the city, and by using the data of location and speed about taxis and the information of the road sections, calculate the traffic of that section and the average speed of cars on that section. As a result of this, we give help solving the problem of the specific road sections.

• Hwankyungkyoyuk
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• v.25 no.1
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• pp.15-24
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• 2012

The goal of this study, as an effort to reduce national greenhouse gas (GHG) emissions, is to calculate the carbon footprint of students based on the commute pattern of high school students in big (Seoul), middle (Suwon) and small (Icheon) size city. By conducting a survey, the commute pattern and method of students as well as students' carbon footprint were evaluated. As a result, the carbon footprint of the high school student in Icheon ($1.698kgCO_2$) had 2~3 times higher than student's carbon footprint in Seoul ($0.623kgCO_2$) and Suwon ($0.699kgCO_2$). One of the reasons for the different carbon footprint result between big and small city was whether the public pedestrian facilities and a bicycle path or not. Based on our research results, we pointed out the problems and suggested some ways to reduce carbon footprint of students.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.6
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• pp.57-65
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• 2010

Physical activity of the people has decreased due to a sedentary lifestyle according to developing the economy throughout the world. It is thought to increase the risk of chronic diseases, including obesity, diabetes, etc. People are interested in walking, which is an easy activity to engage in as an antidote to chronic diseases. The aim of this study is to increase the diminishing physical activity of modem society by inducing walking as part of everyday life through building a walking-based activity-friendly city where people can live merrily, safely and pleasantly. For this purpose, this study conducted a satisfaction survey to dwellers of Jinhae on the physical pedestrian environments which affect determining walking participation and intentions of people, and also provided a valid model to evaluate the effects of the physical environmental factors on walking satisfaction using factor analysis and multiple linear regression analysis. The results are summarized as follows. The 18 variables of the physical pedestrian environments were selected based on pre-literature reviews. The results of the satisfaction surveys showed that the satisfaction of crossing aids in segments was highest, while the building feature was the lowest. Factor analysis was run through a two-step process. The first analysis was conducted to examine the adequacy of this factor analysis on the selected 18 variables. As a result, two variables were removed and the remaining 16 variables were extracted to the four factors by second analysis. Each factor was named function of path, effect of traffic, amenity and safety based on the each factor's commonality. Each factor score of the extracted four factors was set as the independent variable, while the overall walking satisfaction was set as the dependent variable. Then, the multiple linear regression analysis was conducted and showed that all four factors had a positive influence on the overall satisfaction of walking, especially the 'function of path' and 'amenity' factors, followed by 'effect of traffic' and 'safety'. The results of this research will be used as foundational data for creating a walking-based activity-friendly city.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.1-14
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• 2024

The most optimal route-search algorithm thus far has introduced a method of applying node labels and link labels. Node labels consider two nodes simultaneously in the optimal route-search process, while link labels consider two links simultaneously. This study proposes a turn-label-based optimal route-search technique that considers two turns simultaneously in the process. Turn-label-based optimal route search guarantees the optimal solution of dynamic programming based on Bellman's principle as it considers a two-turn search process. Turn-label-based optimal route search can accommodate the advantages of applying link labels because the concept of approaching the limit of link labels is applied equally. Therefore, it is possible to reflect rational cyclic traffic where nodes allow multiple visits without expanding the network, while links do not allow visits. In particular, it reflects the additional cost structure that appears in two consecutive turns, making it possible to express the structure of the travel-cost function more flexibly. A case study was conducted on the metropolitan urban railway network consisting of transportation card terminal readers, aiming to examine the scalability of the research by introducing parameters that reflect psychological resistance in travel with continuous pedestrian transfers into turn label optimal path search. Simulation results showed that it is possible to avoid conservative transfers even if the travel time and distance increase as the psychological resistance value for continuous turns increases, confirming the need to reflect the cost structure of turn labels. Nevertheless, further research is needed to secure diversity in the travel-cost functions of road and public-transportation networks.

• The Journal of Sustainable Design and Educational Environment Research
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• v.19 no.2
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• pp.1-10
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• 2020

Despite the legal and institutional measures that have been enacted for the safety management of school facilities, the number of school accidents has continued to rise, particularly in regards to the number of accidents related to schools. However, school facilities have had a difficult time creating safe school environments for the school administration and local governments. This is due to the fact that the Office of Education and the Ministry of Education, not the school or educational offices, have insufficient institutional devices such as standards and systems for the promotion of safe school environments. This study attempted to confirm the direction of the improvement of the safety of school facilities. To this end, four safety assessment topics (separation of pedestrians, pedestrian path management, pedestrian visibility, and surrounding risk factors) were derived based on the surveyed data for the safety of the external environment of domestic and international school facilities. 179 school facilities nationwide (kindergartens, elementary schools, middle schools, high schools, and special schools) were analyzed for current cases of accidents that occurred mainly on school roads. Roughly 50% of the analyzed evaluation scores showed that it is necessary to improve the external environment of school facilities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.581-590
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• 2022

It is important to create a decent pedestrian space in order to realize a public space that can ultimately improve the quality of life based on guaranteeing people's right to move while also enhancing urban activity. The goal of this study is to develop a pedestrian path evaluation system in order to lay the foundation for data construction leading to the creation of such elegant walking space. First, a basic system was established in keeping with factors and the space, and this system was used as the basic framework of the study. The trends identified in the literature can be divided into eight categories, denoted here as: Walking safety policy, Walking focused plan, Recognition transition, Transportaion system, Activity-linked walking, Facility utilization walking, Nature and history linked walking and Content convergence walking. The macro- and micro-indices and factors mentioned in related studies were synthesized and classified, and the basis for universality and differentiation was established by integrating them. Next, according to the basic composition of the walking system, Walking potential and slope safety in the Safety category, Basic walking connectivity and Traffic linkage in the Efficiency category, Walking arrangement and Rest convenience in the Health category, and Resource connectivity and Activity abundance in the Comfortability category macro evaluation system of the eight categories were established and a corresponding measurement method was developed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.15-27
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• 2022

An omnidirectional VR treadmill is a highly-immersive walking simulator that allows identical body movements, such as walking, running, and sitting. However, the operation difficulty of an omnidirectional VR treadmill may cause data reliability problems. Therefore, this study aims to verify the effectiveness of a VR treadmill by comparing the ability to orient in the real and virtual worlds spatially. For this purpose, a rotating and searching path experiment was conducted with participants. This experiment showed that there was no statistically significant difference in the ability of the participants to orient in the real and virtual worlds spatially. In addition, the omnidirectional VR treadmill requires an adaptation time for the users due to the difficulty in the treadmill operation. However, there was no significant difference in the difficulty felt by the participants according to the adaptation time. Hence, these findings supported the possibility of collecting realistic walking data without safety concerns through an omnidirectional VR treadmill. Furthermore, this treadmill could be used in future research to solve problems directly related to pedestrian safety, such as the interaction between vehicles and pedestrians.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.104-113
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• 2005

This landscape design proposal was presented for a competition for mixed-use development project by project financing in Asan Baebang which was held by the Korea National Housing Corporation in July of 2005. The site is a center of Asan Baebang New Town Development District and has a commercial area of $57,929m^{2}$. Design guidelines and judging criteria of this competition were to build a symbolic center and cultural core for district, to elevate positive image and identity of Asan New Town by attractive place making, to link with separated block in the site and regional context, and to make environmentally sustainable design by creating an attractive waterfront of Jang Jae stream passing through the site. This is the most important condition for the design. Therefore, the authors developed design concept and strategy within the guidelines and this conditions. The schema of the design was introduced by the water in the site. To evolve design concept, we reinterpreted water and context in the site combining with landscape design strategy. So the proposal set the main design concept as 'all that is solid melt into water' as if Marshall Berman said. By doing that, design concept of the proposal evolved as follows: 'extension' of water and greer, 'a joint' of space,'newness' of experience, 'breath' of consensus with each other. The spatial concept of this project was developed by expressing five theme spaces; eco zone, entertainment zone, art zone, culture zone, leisure zone. These theme spaces were consecutively placed along the pedestrian path and to consists of vertical layer in each level and diverse design technique and spatial effects are used.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.323-331
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• 2018

This study was conducted to examine the effects of constructing streetside urban forests on particulate matter (PM) content in pedestrian paths and open spaces created between the main streets and buildings in a high-rise, high-density urban area. The study site is a 70m-wide open space between Busan City Hall and Jungang-street in Busan, Korea. The results showed that the density of PM differences between the open space and the adjacent main street were small in regions without linear trees and shrub rows during both the weekdays and weekend. On the other hand, the areas with linear trees and shrub rows were found to have significantly higher concentrations of PM compared to the roadway. In particular, sections with linear trees and shrub rows had higher PM levels both on roads and in adjacent open space, indicating that the composition of linear trees and shrub rows increased the concentration of PM in the off-street open space in areas with wide space between the roadway and building. The impact was more significant in the open space than the roadway. This phenomenon can be explained by the fact that PM generated by vehicles flows through the roadside shrubs by rapid wind flow but does not disperse widely in the pedestrian paths where the wind flow was reduced. In this study, we found that the roadside tree and shrub walls slowed the flow of wind, causing vehicle-emitted PM to accumulate if a wide open space was created between the road and building, resulting in higher concentration of PM in the open space. We confirmed that the distance between the road and building was a critical factor for constructing linear trees and shrub rows to reduce PM generated by vehicle traffic.