• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.2
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• pp.65-72
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• 2011

Since walking and physical activity are critical for older adults to maintain their health, it is important to provide neighborhood environments which encourage their walking in daily life. The purposes of the present study were to investigate walking activity patterns of older people in an urban setting and to identify environmental correlates with walking of older adults. This study examined spatial and temporal patterns of physical activities, environmental barriers and motivations, satisfaction levels and demands on the physical environment. In-depth interviews with older adults over age sixty residing in Seoul metropolitan areas revealed that most respondents have a positive perception on walking in daily life, and many of them walk regularly for their health. A primary purpose of walking for older adults was exercise for health rather than transportation. The study result demonstrated that parks and trails were the most preferred places for walking by older adults, and there is an association between frequency of walking participation and access or convenience to parks, traffic safety, and street lights. Most respondents were concerned about traffic safety when they walk in their neighborhoods due to traffic speeds and unsafe streets. Lack of separate sidewalks or benches, stairs and slopes were barriers to older adults' walking habits. This data suggests that the promotion of walking behavior among older adults, some level of public health action, and community support are needed to ensure safe physical environments within communities.

• Elastomers and Composites
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• v.34 no.2
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• pp.156-176
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• 1999

Rubber chemicals such as accelerators, antidegradants, vulcanizing agents, processing agents and retarders are very important to the production and protection of tires and rubber goods. The use of accelerators and antidegradants are evaluated in various tire components. This paper will focus on how to vulcanize tires economically and maintain the physical properties of each tire component without severe degradation due to oxygen, heat and ozone. Also, new non-nitrosoamine accelerators and non-staining antiozonants will be discussed. Lastly, the future requirements of antidegradants and accelerators in the tire industry will be reviewed. Tires have been vulcanized with Sulfenamides as primary accelerators and either Guamdine's or Thiurams as secondary accelerators to achieve proper properties at service conditions. However, interior components such as the carcass can be vulcanized with Thiazoles as a primary accelerator to cure faster than the external components. Using the combination of Sulfenamide with secondary accelerators in a tire tread compound and the combination of a Thiazole and Guanidine in a carcass compound will be presented with performance data. Uniroyal Chemical and another Rubber Chemical Manufacturer have developed, "Tetrabenzyl Thiuram Disulfide," (TBzTD) as a non-Nitrosoamine accelerator, which could replace Nitrosoamine generating Thiurams. This new accelerator has been evaluated in a tread compound as a secondary accelerator. Also, Flexsys has developed N-t-butyl-2-benzothiazole Sulfenamide (TBSI) as a non-Nitrosoamine accelerator which could replace 2-(Morpholinothio) -benzothiazole (MBS), a scorch delayed Sulfendamide accelerator. TBSI has been evaluated in a Natural Rubber (NR) belt skim compound vs. MBS. An optimum low rolling resistant cure system has been developed in a NR tread with Dithiomorpholine (DTDM). Also, future requirements for developing accelerators will be discussed such as the replacement of DTDM and other stable crosslink systems. Antidegradants are divided into two different types for use in tire compounds. Internal tire compounds such as apex, carcass, liner, wire breaker, cushion, base tread and bead compounds are protected by antioxidants against degradation from oxygen and heat due to mechanical shear. The external components such as sidewall, chafer and cap tread com-pounds are protected from ozone by antiozonants and waxes. Various kinds of staining and non-staining antioxidants have been evaluated in a tire carcass compound. Also, various para-phenylene diamine antiozonants have been evaluated in a tire sidewall compound to achieve the improved lifetime of the tire. New non-staining antiozonants such as 2, 4, 6-tris-(N-1, 4-dimethylpentyl-p-phenylene diamine) 1, 3, 5 Trizine (D-37) and un-saturated Acetal (AFS) will be discussed in the tire sidewall to achieve better appearance. The future requirements of antidegradants will be presented to improve tire performance such as durability, better appearance and longer lasting tires.

• Fire Science and Engineering
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• v.23 no.6
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• pp.116-125
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• 2009

This study is progressed function ratio, it's trued taste by an experiment to present data for human work light weight aggregate development that use clink ash progressed liquid limit, small success limit, wear loss in quantity, sand equivalent, sieve cutting examination. 80 : 20's match of function rain examination is 1.4, and that use rubble Goljae as ckink ash lightweight aggregate's capacity ratio increases by 1.0 increase of function rain many. Also, examination multiplied delicate flavor gradually according to increase of the mixing rate, and absorption coefficient increased. This is judged by phenomenon that appear by special quality upper clink ash of polystyrene bid and porosity's increase between lightweight aggregate. It is case that use aggregate of wear loss in quantity is 13.5 in sand equivalent and a wear loss in quantity experiment and although case that mix 20% increases by 14.4, this phenomenon by weak tissue of lightweight aggergate be judge. When it's as a these experiment, the statue prevention floor of a street improvement specifications is prescribing so that satisfy by sand equivalent 20, CBR 10. This is showed result that this satisfies in quality standard all in match experiment ago that see.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.35-44
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• 2021

In recent times, several studies have been conducted focusing on crashes occurring on the main segment of the highway. However, there is a dearth of research dealing with traffic safety relating to other highway facilities, especially ramp areas. According to the Korea Expressway Corporation's Expressway Information Service, 6,717 crashes have occurred on ramps in the five years from 2015~2019, which accounts for about 15% of all highway accidents. In this study, the simple and full safety performance functions (SPFs) were evaluated and explored using different statistical distributions (i.e., Poisson Gamma (PG) and Poisson Inverse Gaussian (PIG)) and techniques (i.e., fixed effects (FE) and random effects (RE)) to provide more accurate crash prediction models for highway ramp sections. Data on the geometric characteristics of traffic and roadways were collected from various systems and with extensive efforts using a street-view application. The results showed that the PIG models present more accurate crash predictions in general. The results also indicated that the RE models performed better than FE models for simple and full SPFs. The findings from this study offer transportation practitioners using the Korea Expressway Corporation's Expressway a dependable reference to enhance and understand traffic safety in ramp areas based on accurate crash prediction models and empirical evidence.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.1
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• pp.74-82
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• 2019

The revolution of industry 4.0 is enabling us to build an intelligent connection society called smart cities. The use of renewable energy in particular solar energy is extremely important for modern society due to the growing power demand in smart cities, but its difficult to monitor and manage in each buildings since need to be deploy low energy sensors and information need to be transfer via wireless sensor network (WSN). The Internet of Things (IoT) / low-power wide-area (LPWA) is an emerging WSN technology, to collect and monitor data about environmental and physical electrical / electronics devices conditions in real time. However, providing power to IoT sensor end devices and other public electrical loads such as street lights, etc is an important challenging role because the sensor are usually battery powered and have a limited life time. In this paper, we proposes an efficient solar energy-based power management scheme for smart city based on IoT technology using LoRa wide-area network (LoRaWAN). This approach facilitates to maintain and prevent errors of solar panel based energy systems. The proposed solution maximizing output the power generated from solar panels system to distribute the power to the load and the grid. In this paper, we proved the efficiency of the proposed system with Simulink based system modeling and real-time emulation.

• Journal of Korea Water Resources Association
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• v.52 no.4
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• pp.301-312
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• 2019

The importance of the dual drainage system model has increased as the urban flood damage has increased due to the increase of local storm due to climate change. The dual drainage model is a model for more accurately expressing the phenomena of surface flow and conduit flow. Surface runoff and pipe runoff are analyzed through the respective equations and parameters. And the results are expressed visually in various ways. Therefore, inundation analysis results of dual drainage model are used as important data for urban flood prevention plan. In this study, the applicability of the COBRA model, which can be interpreted by combining the dual drainage system with the natural watershed and the urban watershed, was investigated. And the results were compared with other dual drainage models (XP-SWMM, UFAM) to determine suitability of the results. For the same watershed, the XP-SWMM simulates the flooding characteristics of 3 types of dual drainage system model and the internal flooding characteristics due to the lack of capacity of the conduit. UFAM showed the lowest inundation analysis results compared with the other models according to characteristics of consideration of street inlet. COBRA showed the general result that the flooded area and the maximum flooding depth are proportional to the increase in rainfall. It is considered that the COBRA model is good in terms of the stability of the model considering the characteristics of the model to simulate the effective rainfall according to the soil conditions and the realistic appearance of the flooding due to the surface reservoir.

• Journal of Korea Water Resources Association
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• v.52 no.3
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• pp.219-226
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• 2019

Recently, research about Low-Impact Development (LID) techniques has been expanded due to problems with the effects of climate change and urbanization that have been increasing. LID technology is used to control flood damage environmentally to reduce runoff and is reduce runoff on city also restore into previous water circulation system from present developed city. However, studies about quantitative data of LID techniques are insufficient. Therefore in this study, the Curve Number (CN) was calculated with the Planter Box, which is storage type LID technology to conduct the water circulation (infiltration, runoff, overflow) analysis. Rainfall intensity scenario (60.4 mm/hr, 83.1 mm/hr, 97.4 mm/hr, 108.2 mm/hr) about water circulation analysis of Planter Box is selected on the basis of probable rainfall intensity table. According to the experimental results, the storage rate of rainwater in Building Planter Box and Street Planter Box was 43.5% to 52.9% and 33.4% to 39%, respectively. In addition, CN value is estimated to 83 at the Planter box and the runoff reduction effect by applying Horton's infiltration capacity curve showed on 51% to 98%.

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

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.10
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• pp.3-12
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• 2018

This research aims at analyzing the changes in residential environment after a residential environment improvement project focusing on the analysis into the physical environment of a residential environment improvement project, and examining in what direction the changes by residents' own efforts occurred after public support, such as infrastructure. The present residence development method has become different from the previous pulling down method and is focused on regeneration. By examining in what direction the target residence is being changed because of the development by residents' own efforts after the government's public investment at this time, this study also aims at investigating the direction to develop a guideline for residential improvement for later improvement of deteriorated residence. As for the contents of the analysis, changes in public support, such as infrastructure, and other areas after the residential environment improvement project were compared and analyzed from the land use, street system, and condition of buildings before the residential environment improvement project through field survey, geographic information system(GIS), registered land and building data and so on. The biggest change since the support from the government was that at the beginning of the project, the application of special provision of building laws and different financial supports led to lots of newly built buildings. Since then, their number has decreased rapidly, and in most cases, there have been some changes in part, such as changes in the use of land or repair of disposal tanks. Most newly built buildings were multi-household houses, and it has caused road capacity and parking lot capacity, etc., to be exceeded, which has worsened the pleasantness of the living environment. In addition, other problems have also appeared, for example, the lack of residence supporting facilities yet with a higher level of residential density. Regarding the changes in the residential environment after the residential environment improvement project, maintenance of houses were conducted in some degree as diverse alleviation policies to improve poor residence, yet the absence of the guideline for the direction of developing the whole district has made the residence environment more dense and deteriorated. To solve these problems, in advance to a residential improvement project, specific management methods based on short-, mid- and long-term plans for the direction of development by residents' own efforts and a sustainable guideline seem to be necessary.

• Journal of Wetlands Research
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• v.24 no.4
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• pp.213-223
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• 2022

This study was conducted to establish a Habitat Suitability index (HSI) based on literature research and field surveys on ecology and habitat of 'Hynobius leechii'. And this study will be used as basic data for qualitative evaluation of habitat environment. The survey sites were divided into natural habitats close to the prototype habitat and artificial restoration areas where Hynobius leechii was monitored. So the types of habitats were diversified. Hynobius leechii is a vulnerable species to climate change because it is affected by the microhabitat and has low mobility. HSI variables of Hynobius leechii were extracted through domestic and overseas literature, and standards were extracted from literature research and field survey. The standards were presented as a value of the physical allowable category in consideration of realization. To verify the study, an in-depth consultation was conducted by amphibians experts. HSI variables of Hynobius leechii were included 9 variables such as Overstory canopy cover(%), Understory cover(%), Water-pH, Soil-pH, Soil relative humidity(%), Leaf litter depth(cm), Rock substrates (%), Type of Coarse woody, Distance from Street or Pollutant(m).