• Resources Recycling
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• v.25 no.1
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• pp.31-39
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• 2016

Small household appliances such as electric rice cooker, a vacuum cleaner, an electric fan, etc. are diverse and complex due to the materials and components and waste streams from the manufacturing processes. In the present study, physical characterization of small e-wastes was analyzed on major items including electric rice cooker after manual dismantling. Small household appliances is an important potential source of waste plastic, however, recycling plastics from small e-waste is still unusual. The present communication gives results of separation processes on black plastics and the limitations of these sorting processes in used small household appliances.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.746-753
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• 2022

Purpose: The purpose of this study is to review the safety of small tunnels for food storage excavation in the 1960s~1970s and to improve the stability of small tunnels. Method: A visual inspection and a hammer test were used to conduct safety tests, and the visual inspection is one of the tests conducted for non-destructive testing, and the hammer test is one of the types of hitting methods of rebound hardness. Result: According to the integrated analysis of the survey area data, there are generally good appearance, but there are many small cracks and complex geological conditions, requiring continuous observation and attention. Seven of the 23 tunnels require safety diagnosis, one collapse, one safe, and 14 require continuous observation and attention. Conclusion: All parts of small tunnels should be checked and recorded from time to time, and stability is expected to be improved when reinforcing small tunnels proposed in this study.

• KIEAE Journal
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• v.13 no.2
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• pp.53-60
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• 2013

This study examined the building envelope structure used in small housings near urban area which have not good energy source in relation to the application of passive design for energy saving of small-sized architectural design firms in local cities and aimed to provide the basic materials of future design direction of designers and housing owners by analyzing economy of a project in order to know the amount of energy saving and additional expenses depending on the building envelope pattern. As a result of comparing and examining the energy saving cost from the period of use compared to investment by the thickness of insulating materials based on building envelope pattern for energy saving, it was found that the thicker the insulating materials are, the more energy saving amount is. While the current bead-type insulating materials have short payback period due to low initial investment, extruded insulating materials show the difference of five years compared to bead-type insulation because of its high initial investment.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.316-320
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• 2008

A light rail transit, using a linear induction motor, is generally composed with reaction plates along railroad track and the three phase primary on the vehicle. This linear induction motor is driven to keep clearance between the primary and the secondary of the ground for preventing any contact. Therefore efficiency and power factor is very low. In addition, the reaction plate installed on the ground throughout entire railway is impossible to keep uniform gap and it may cause system deterioration. In this paper, A rotary-type small-scale model of a linear induction motor for various characteristic analysis is designed. Thrust force, normal force and input current of the model by air-gap variation have been analyzed by using a Finite Element Method (FEM). The effects of air-gap variation on system performance have been considered by analysis results.

• Korean Journal of Environment and Ecology
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• v.23 no.2
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• pp.194-207
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• 2009

The study is to suggest a management method for improvement of natural and cultural landscape of Hwayang valley which is degraded in Songnisan National Park. It was carried out to study original shape of landscape of it and analyse nine major properties of Hoayang Gugok, based on old literatures. The landscape of Gugok was composed of rocks and small ponds, Pinus densiflora community and most of them were degraded by the situation of covered rocks by growth of vegetation, destructed small ponds by sedimented sands and degradation of natural landscape by artificial forest. Vegetation landscape of artificial forest composed of Populus tomentiglandulosa, Robinia pseudo-acacia, Pinus koraiensis in periphery of the valley was not matched with natural landscape. The goal of landscape management was established to conserve natural and cultural landscape in Joseon Dynasty. For this, It was needed to protect landscape values of gugok through the management of vegetation and visitors. In addition, it was required to provide opportunity to easily access to the landscape of Gugok. As a management method of vegetation, it was suggested to maintain P. densiflora community and to restore artificial forest to natural forest through the density management.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.81-91
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• 2019

Although the number of users of urban railways is greatly influenced by the land use plan around the railway station, Korea has been studying this problem in a small scale, so that the entrance width is uniformly calculated irrespective of the land use plan, And there is little deviation. Therefore, this study aims to establish a demand estimation model for the entrance and exit of urban railway stations. For this purpose, the demand, land use area, and socioeconomic indicators for each of the 20 urban railway stations were surveyed at 200m and 500m Regression model. The model is based on the assumption that the dependent variable (response variable) of the model is set to 1 day, peak 1 hour, peak time 5 minutes, Education, and park) and socioeconomic indicators (population, employer, employee, and student) as independent variables (explanatory variables). As a result, it was analyzed that the fit of the model is more statistically significant when the use area of the land use by 500 meters of the center radius of the city rail is used as an independent variable and the demand for the daily use of the railway station is used as a dependent variable. The purpose of this study is to estimate the optimal size of urban railway entrance in order to improve the mobility of the user and the transportation weak in urban railway station.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.189-196
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• 2004

Characteristics of urban wanning phenomenon were studied using degree days for three big cities(Seoul, Busan, Daegu) adjacent to airport. Time variation of the cooling and heating degree days was analyzed using the daily mean air temperature data measured at the six meteorological observatory for long-term periods(25～43years). The results for the big cities are as followings: 1) It was found that the heating degree days trended to decrease from year to year. 2) The cooling degree days were nearly unchanged during the same analysis periods. 3) The number of days calling for air-heating also tended to decrease as time passes. 4) Those of air-cooling were nearly unchanged during the same time. It suggests that the change of air-heating condition owing to urbanization came in evidence in the winter season, but that of air-cooling condition was slight in the summer season. On the other hand, the long-term trends of degree days were very small in airport areas except for Kimhae airport. Hence, the gaps of degree days between big cities and rural airport areas are increasing.

• KIEAE Journal
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• v.13 no.2
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• pp.151-156
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• 2013

This study examines the properties of spaces where historical and cultural resources have been preserved in the street system of Daegu Yakryeong market district, by using Space Syntax methodology. The results were obtained through ASA(Angular Segment Analysis) on each node (spatial unit) in the street network. An overall characteristic of spatial configuration in street system of the surveyed district is that nodes in the street network tend to form socially integrated spatial structure to allow easy access to each space in the system. There are a small number of socially isolated spaces in the street system, which are located at nodes in narrow streets adjacent to the roadway outside the district, or in narrow alleys between early modern Korean buildings. More than half of the surveyed spaces have high levels of social integration, which contain buildings playing a central role of the community, a traditional street market, symbolic landmarks. In conclusion, it is expected that the achievements of this study will contribute in leading to rational land use planning for sound and sustainable development of historical and cultural resources in an urban district.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.5
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• pp.146-153
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• 2010

Urban development typically results in many species being confined to small, isolated and degraded habitat fragments. Fragment size and isolation underpin many studies of modified landscape to prevent biodiversity loss. However, habitat characteristics such as vegetation structure and edge effects are less frequently incorporated in planning. The relative influence of biogeographic (e.g. size, isolation) and vegetation parameters on assemblages is poorly understood, but critical for conservation management. In this study, the relative importance of biogeographic and vegetation parameters in explaining the diversity of forest-interior dwelling birds in forest fragments in Chungcheong Province Area. Fragment size and vegetation characteristics were consistently important predictors of bird diversity. Forestinterior bird richness was influenced by fragment size (0.437), wood age (0.332), wood diameter (0.068), and patch shape (-0.079). To preserve bird diversity of Chungcheong Province Area, it is important to consider differing responses of bird diversity to landscape change, move beyond a focus primarily on spatial attributes (size, isolation) to recognize that landscape change also has profound effects on habitat composition and quality. The result is very useful for long-term aspect of biodiversity conservation plan in regional scale.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.62-67
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• 2013

Recently, users have been receiving LBS(Local Based Service) which provides various services. The LBS uses positioning information from satellites with using GPS(Global Positioning System). However, due to satellite signal's characteristics which are reflection and refraction in urban areas, users get unexpected positioning information error, expecially if there are so many tall buildings in a small area. To solve this problem, this paper offers a post-processing algorithm. It is consisted of users' direction vectors and positioning information. The positioning information with error is designed to be put on the direction vector. Through a car driving test in urban areas, we've got 11.1m(43%) improved result and demonstrated the superiority of its algorithm.