• Journal of Urban Science
• /
• v.10 no.1
• /
• pp.11-20
• /
• 2021

In this study, the vibration characteristics were theoretically analyzed by modeling a free isotropic rotating disk with an outer periphery with a fixed inner periphery, paying attention to disks used as storage devices for information devices, especially magnetic disks, magneto-optical disks, and compact disks in which the head and disk are non-contact. Iluminate with Composite materials represented by fiber-reinforced plastics (FRP) have high specific strength (strength/density) and specific stiffness (narrowness/density). It is used in the elements, and its use is rapidly expanding. Under this circumstance, the disk currently manufactured using an isotropic material made of various plastic materials such as aluminum or polycarbonate as a base material is an extremely anisotropic material made of a composite material, and the circumferential stiffness of the disk is made of reinforcing fibers in the circumferential direction. It is modeled as an anisotropic rotating disk with increased, and its influence on the vibration characteristics is revealed.

• Journal of Urban Science
• /
• v.9 no.2
• /
• pp.63-68
• /
• 2020

In recent years, the planning of livable communities has emerged as a new paradigm. The concept of livable communities is related to both the spatial balance of working, playing, and living and the promotion of green modes of transportation, such as walking and biking. This study uses a disaggregate travel survey conducted by the Seoul Metropolitan Area in 2006. I applied a multi-level random intercept logit model to estimate the effects of land-use characteristics on the choice of green modes, holding a traveler's socio-demographic characteristics constant. The empirical results show that higher density and more mixed land-use development encourages people to walk and bike even when individuals have the same socio-economic characteristics. This paper demonstrates that land-use planning by itself can play a role in the creation of livable cities and the decline of greenhouse gas production.

• Journal of Urban Science
• /
• v.9 no.2
• /
• pp.57-62
• /
• 2020

The United Kingdom and the United States are designating and implementing enterprise zones for the purpose of promoting the revitalization of the local economy. However, there are still mixed views on the effectiveness of the Enterprise Zone's policies. At this point, the purpose of this study is to look at policies in the form of enterprise zones in the country and see how these policies affect the revitalization of the local economy. As a result of the analysis, the areas designated as enterprise zones were becoming more economically vitalize than those that were not. In addition, it was analyzed that redundant designation of enterprise zones has a greater effect on regional economic revitalization than single designation.

• Journal of Urban Science
• /
• v.9 no.2
• /
• pp.69-82
• /
• 2020

The purpose of this study were to examine the deterioration of the old downtown in the southern area of Pyeongtaek City and derive suggestions for an urban regeneration project in South Pyeongtaek City. To do so, the researchers investigated the researchers investigated the deterioration and current status of the downtown from a multifaceted perspective based on previous in depth. It was found that in Pyeongtaek City, problems unique to the southern, Pyeongtaek, and Paengeong areas interplayed in a complicated manner. Accordingly, for the urban regeneration project to be effective, continuous participation of experts and community residents with intimate knowledge of the regional features is essential. This study focused on identifying the reasons why the old downtown has deteriorated and suggesting ways to revitalize it. The study is of significance in that it derived urban regeneration strategies based on regional features.

• Journal of Urban Science
• /
• v.9 no.2
• /
• pp.51-56
• /
• 2020

The installation of soft ground instruments and the performance of measurement and management of the measurement shall be carried out in order to ensure the safety of the construction work and to improve the quality of the construction work. The purpose of the pressure density deposition calculation is to determine the stability of the foundation ground and the formulation by measuring and calculating the density conditions generated on the soil through the period of neglect after completion of the soil at each stage. In practice, it is judged that the analysis by the hyperbolic method can be applied to the safety side.

• New & Renewable Energy
• /
• v.19 no.3
• /
• pp.13-21
• /
• 2023

Smart windows are capable of varying their visible light transmittance (VLT) in response to changing environmental conditions. The VLT variability of architectural windows is highly valuable because it enables indoor lighting and energy environments to align with external changes. However, challenges such as high installation costs and assurance of glass visibility have prompted the exploration of alternative solutions, including models incorporating partially applied smart windows., Prior research focused on useful daylight illuminance (UDI) analysis for south-facing office buildings, pointing out suitable areas for smart-window implementation to enhance lighting control. In this study, we broadened this scope by determining optimal smart-window application zones under changing building orientation. Furthermore, we studied the correlation between building orientation and smart-window deployment areas.

• Journal of Urban Science
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2022

As the magnitude and frequency of earthquakes increase in Korea, interest in earthquake damage reduction technology has increased. Therefore, research on vibration damping devices that directly respond to seismic loads is being actively researched. After an earthquake, damage or destruction of the device occurs due to the yield of materials, and thus it takes considerable cost and time for restoration and replacement. To supplement the problems of the existing earthquake damage reduction technology, a study was conducted on the recentering smart damper that can be used continuously after an earthquake. In this study, the recentering smart damper that can be restored to its original shape after load removal was developed using superelastic shape memory alloy, pre-compressed polyurethane. General steel was commonly applied to verify the seismic performance of the superelastic shape memory alloy, and the performance of the smart damper was verified according to the amount of polyurethane pre-compressed

• Journal of Urban Science
• /
• v.11 no.1
• /
• pp.9-13
• /
• 2022

Currently, RC slab bridges in use in Korea account for most of the total bridges, and bridges with a service life of 20 years or more account for about 75%. However, most of these RC slab bridges have a span of less than 20m and are not included in the first and second types of facilities, so maintenance is very neglected. Therefore, in this study, field load test is performed on an aged RC slab bridge, and the performance evaluation is performed based on the structural response results (deflection, impact coefficient, natural frequency, etc.) of the bridge obtained through field load test. In addition, the performance evaluation results obtained through the load test are intended to be used as basic data for the damage evaluation process of the bridge currently under development.

• Journal of Urban Science
• /
• v.11 no.1
• /
• pp.21-28
• /
• 2022

Raman spectroscopy is effective to investigate functional groups via molecular vibration. The technique offers the structural information of compounds including subtle changes in the chemical composition of local atomic coordination without critical damage. Thus, the effect of carbonation on the hydration characteristics of Portland cement under pre-curing conditions for carbonation was investigated via Raman spectroscopy in the present study. Gaseous CO₂ was injected within 60 seconds, and the reaction time was varied from 0 minute to 90 minutes. The test results indicated that the Ca/Si ratio of C-S-H reduced immediately after mixing and then the C-S-H with a relatively high Ca/Si ratio coexisted as the reaction time increased. The calcium carbonates formed in the present study included calcite and amorphous calcium carbonates. The test results via Raman spectroscopy provide valuable information about the carbonation characteristics of OPC under pre-curing conditions for carbonation.

• Journal of Urban Science
• /
• v.11 no.1
• /
• pp.59-68
• /
• 2022

This study, the meaning of historical and cultural content utilization in urban regeneration was examined and in the process, the causal relationship between each variable was verified through path analysis among physical, cultural, social, and economic factors. The purpose of this study is to find the main variables of historical and cultural content urban regeneration projects in which the moderating effect of economic factors and demographic characteristics, which are mediating effects, have a significant effect on resident participation and life satisfaction of local residents. Furthermore, by presenting a more integrated and effective urban regeneration policy plan, it is intended to ultimately contribute to the vitalization and direction of urban regeneration.