• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.161-169
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• 2000

In this study, the temporal changes in the chemical characteristics of soil in a reclaimed coastal area, the Shihwa Industrial Complex in the West Coast in Kyung-Gi Province, and the correlations between chemical components were investigated to provide useful information needed for introducing vegetation in the area. The sites were filled with mountain forest soils from 1987 to 1996, and developed into various landuses such as neighbourhood parks, children's parks, buffer greens, pedestrian roads and others. The correlation analyses shoed that pH, organic matter(OM) and available P205 had not been closely related to other chemical parameters such as various cations electro-conductivity(EC) and cation exchange capacity(CEC): especially, pH showed a very low correlation with other factors. The EC turned out to have positive relationships with cations, especially with Na+ ions. There seemed to be fairly good correlations between cations except Ca++ ion. The relation between cations and OM was inconclusive possible because the OM contents in the soils were too low for the analysis. The OM seemed to increase slowly with time and the EC decreased slowly. The salinity and CEC in the original soils decreased rapidly possibly because of leaching. It is believed that there were some external disturbances such as rainfall which had affected the soil properties. The soils sampled in dry season showed a very high salinity. From this it is possible to assume that the rainfall would affect the sol properties significantly. So it is necessary to continue further studies to investigate the impacts of external disturbances such as rainfall on vertical soil profile and temporal variations as well as to delineate correlations between parameters with external disturbances controlled.

• Journal of Trauma and Injury
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• v.21 no.2
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• pp.100-107
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• 2008

Purpose: A traumatic lung cyst (TLC) is a rare complication and is usually detected with a pulmonary contusion. This study attempted to identify the prognostic factors and the clinical characteristics for pulmonary contusion with TLCs. Methods: We retrospectively reviewed the medical records and chest CT findings of 71 TLC patients who visited our hospital from January 2006 to December 2007. Patients were assessed for any clinical characteristics. We evaluated significant differences between the survival and the death groups for patients with a traumatic lung cyst. Results: The male-to-female ratio of patients with TLCs was 54:17, and the mean age of the patients was $37.70{\pm}19.78years$ with 36.6% of the patients being under 30 years fo age. The cause of blunt thoracic trauma was mainly pedestrian traffic accidents (26.8%) and falls (25.4%). Associated conditions included pulmonary contusion in 68 patients (95.7%), hemopneumothorax in 63 patients (88.7%), and rib fracture in 52 patitents (73.2%). There was no consistent relationship between the number of TLCs and the pulmonary contusion score. The overall mortality rate of TLC patients was 26.8%. Death correlated with a need for ventilatory assistance, mean arterial pressure, worst mean arterial pressure in 24 hours, initial pH and base excess, worst pH and base excess in 24 hours, refractory shock, initial GCS score, and pulmonary contusion score. Conclusion: The presence of the aforementioned predictors indicate serious injury, which is the main determinant of the outcome for thoracic injuries with TLCs.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.137-151
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• 2021

Revitalized alley-type urban commercial streets have recently received a lot of attention as a preferred place for people. The purpose of this study is to present implications in the planning and design methods for the making of alley-type urban commercial street. For that, theoretical review and case analysis were conducted on the street spatial characteristics of 'Jeonridan-gil' and 'Mangmidan-gil' in Busan, about site overview, street spatial composition, building use, streetscape and street furniture. The implications through the study are as follows. (1) Street environment should be created to improve the pedestrian space and environment. (2) The existing main use and the newly introduced use need to be coexisted. (3) The identity of the street must be maintained through adaptive reuse, etc. (4) The voluntary formation of the private sector and the planned making of the public need to be cooperated.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.40-53
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• 2021

Recently, shared dockless e-scooter usage has rapidly increased, rather than the station-based shared mobility service, because of convenience. This transition leads to new social problems in urban areas such as increased traffic accidents and hindrance of pedestrian environments. In this study, we analyze the usage characteristics of shared e-scooters in Seoul, and identify factors influencing demand for shared e-scooters by developing a negative binomial regression model. As a result, the usage characteristics show that the average trip distance, the average trip duration, and the average trip speed were 1.5km, 9.4min, and 10.3km/h, respectively. Demographic factor, transport facility factors, land use factors, and weather factors have statistically significant impacts on demand for shared e-scooters. The results of this study will be used as basic data for suggesting effective operation strategies for areas with higher shared e-scooter demand and for establishing transport policies for facilitating shared e-scooter usage.

• Journal of the Korean housing association
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• v.24 no.2
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• pp.89-96
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• 2013

Urban design is a specific and detailed action plan which regulates from the development plan to the architectural characteristics of every building and now many new towns by Urban design has been developed after 2000. But recently doubts about the effectiveness of Urban design have been raised in locals. The purpose of this study is to verify the effectiveness of urban design in terms of residents, through case study and the survey of resident's satisfaction on Urban design guidelines. The result of survey of resident's satisfaction on Urban design were above-average satisfaction. And main factors influencing to the resident's satisfaction are the public infrastructure factors, transportation factors, development density factors, and pedestrian environment factors, urban landscape factors. And the total satisfaction was most influenced by the public infrastructure factors among the five factors. To improve the effectiveness of urban design, it is necessary to build specific planning and guidelines to the general.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.2
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• pp.135-144
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• 2003

Traffic performance in a microcellular system is much more affected by cell dwell time and channel holding time in each cell. Cell dwell time of a call is characterized by its mobility pattern, i.e., stochastic changes of moving speed and direction. Cell dwell time provides important information for other analyses on traffic performance such as channel holding time, handover rate, and the average number of handovers per call. In the next generation mobile communication system, the cell size is expected to be much smaller than that of current one to accommodate the increase of user demand and to achieve high bandwidth utilization. As the cell size gets small, traffic performance is much more affected by variable mobility of users, especially by that of pedestrians. In previous work, analytical models are based on simple probability models. They provide sufficient accuracy in a simple second-generation cellular system. However, the role of them is becoming invalid in a picocellular environment where there are rapid change of network traffic conditions and highly random mobility of pedestrians. Unlike in previous work, we propose an improved probability model evolved from so-called Random walk model in order to mathematically formulate variable mobility of pedestrians and analyze the traffic performance. With our model, we can figure out variable characteristics of pedestrian mobility with stochastic correlation. The above-mentioned traffic performance measures are analyzed using our model.

• International Journal of Concrete Structures and Materials
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• v.7 no.1
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• pp.79-93
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• 2013

One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. The causes of early age cracking are primarily attributed to plastic shrinkage, temperature effects, autogenous shrinkage, and drying shrinkage. The cracks can be influenced by material characteristics, casting sequence, formwork, climate conditions, geometry, and time dependent factors. The cracking of bridge decks not only creates unsightly aesthetic condition but also greatly reduces durability. It leads to a loss of functionality, loss of stiffness, and ultimately loss of structural safety. This investigation consists of field, laboratory, and analytical phases. The experimental and field testing investigate the early age transverse cracking of bridge decks and evaluate the use of sealant materials. The research identifies suitable materials, for crack sealing, with an ability to span cracks of various widths and to achieve performance criteria such as penetration depth, bond strength, and elongation. This paper also analytically examines the effect of a wide range of parameters on the development of cracking such as the number of spans, the span length, girder spacing, deck thickness, concrete compressive strength, dead load, hydration, temperature, shrinkage, and creep. The importance of each parameter is identified and then evaluated. Also, the AASHTO Standard Specification limits liveload deflections to L/800 for ordinary bridges and L/1000 for bridges in urban areas that are subject to pedestrian use. The deflection is found to be an important parameter to affect cracking. A set of recommendations to limit the transverse deck cracks in bridge decks is also presented.

• International Journal of Highway Engineering
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• v.15 no.3
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• pp.151-157
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• 2013

PURPOSES : This study aims to suggest the optimal spacing between speed humps which is placed at traffic calming areas including pedestrian priority zones, school zones, and residential areas. METHODS: The study measured the operating speed of vehicles passing through two successive humps by using laser gun in 0.2 seconds interval, and analysed the basic statistical characteristics of speeds data to have an insight on the relationship between spacing and speed. Assumption was made to derive the maximum spacing within which two successive humps influence each other. RESULTS: The statistically significant model explaining the relationship between spacing and 85th percentile speed of vehicles was derived as well as the maximum spacing maintained in order to take the benefits of successive installation of humps. CONCLUSIONS: Spacing of 20 meters was suggested to achieve the widely accepted target speed of 30 km/h in traffic calming zone, and spacing of 70 meters was suggested as a maximum spacing. The comparison across the studies were made and empirical reasoning the difference of results between studies was discussed as well as the future studies.

• Korean Institute of Interior Design Journal
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• v.22 no.3
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• pp.205-216
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• 2013

Korean cities need sustainable urban regeneration based on the effective application of space and resource. Especially a sustainable urban regeneration needs the activation of community in the urban underground space as urban development center. The purpose of this study is to propose elements and factors of spatial planning of community in urban underground space for sustainable urban regeneration and to propose the characteristics of spatial planning of community in urban underground space according to strategies of sustainable urban regeneration. The research methods of this study used to conduct research include precedent study reviews and survey. The conclusions of this study are as following; The application of various factors related to spatial planning aspect of communication, supportive cultural facilities, accessibility and nature is needed for creating a sustainable urban regeneration. Especially, in urban underground space, the application of spatial planning for community activation considered strategies of sustainable urban regeneration should be necessary. And introduction of cultural facilities, multi-dimensional pedestrian network for accessibility and natural elements for activating community in urban underground space are needed for making sustainable urban regeneration.

• KIEAE Journal
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• v.15 no.2
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• pp.5-17
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• 2015

Purpose: The goal of this research is to identify the planning techniques of Smart Green City with Ubiquitous method and carbon-neutral city planning techniques and to induce the main planning techniques through the analysis of relative importance and practical adaptation. Method: First of all, eighteen planning techniques were derived and categorized into three organization systems and six sectors through literature review and FGI analysis considering the applicability of Ubiquitous service for carbon-neutral city planning techniques. Secondly, based on expert surveys and AHP analysis, the importance of Smart Green City planning techniques was evaluated. Thirdly, using case study, six cases related to Smart Green City were analyzed for the current status of application of planning techniques. Lastly, considering the importance of planning techniques and practical aspects, the characteristics of Smart Green City and its implication were estimated. Result: Energy, Resource and Waste and Transportation sector were identified as important sectors for Smart Green City. In addition, 'Construction of Smart Grid', 'System for Utilization of New & Renewable Energy', 'Smart Resource Circulation Management System', 'Establishment of Public Transportation Information System basis', 'Construction of Pedestrian / Bicycle oriented Road Environment' are essential planning techniques to create Smart Green City.