• Land and Housing Review
• /
• v.15 no.1
• /
• pp.147-156
• /
• 2024

This study aims to reduce CO₂ generated during the manufacturing process by using limestone (CaCO₃), a carbonate mineral used in the production of cement clinker, as a decarbonated raw material that does not contain CO₂. Among various industrial by-products, we attempted to use cement paste attached to waste concrete. In general, limestone for cement must have a CaCO₃ content of at least 80% (CaO, 44% or more) to ensure the quality of cement clinker. However, the CaO content of waste concrete fine powder is about 20% on average, so in order to use it as a cement clinker raw material, the CaO content must be increased to more than 35%. Therefore, by using the difference in hardness of the mineral composition of waste concrete fine powder to selectively crush CaO type minerals with relatively low hardness, classify and sieve, the CaO content can be increased by more than 35%. Accordingly, in this study, we experimentally and statistically reviewed and analyzed the optimal conditions for efficiently separating CaO and SiO₂ and other components by selectively pulverizing minerals containing relatively low CaO through a grinding process. As a result of the optimal grinding conditions experiment, it was found that the optimal conditions were a grinding time of less than 5 minutes, a type of material to be crushed of 30 mm, and an amount of material to be crushed of 1.0 or more. However, it is judged that it is necessary to review pulverized materials of mixed particle sizes rather than pulverized products of single particle size.

• Land and Housing Review
• /
• v.15 no.2
• /
• pp.73-87
• /
• 2024

To evaluate the efficiency of commuting patterns, various commuting indicators such as excess commute and commuting potential utilized have been developed and used. It is crucial to calculate these indicators reasonably to reveal the differences in commuting patterns among metropolitan areas and to consider these in the process of formulating commuting policies. However, commuting indicators are generally calculated at the administrative district level, and thus, they are not free from the problem of the modifiable areal unit problem (MAUP). This issue can undermine the rationality of comparing commuting efficiency between metropolitan areas, making it necessary to handle the calculation of commuting indicators carefully. Therefore, this study utilises Monte Carlo Simulation to calculate optimal, actual, and maximum commuting distances, and thereby presents the excess commute and the commuting potential utilized. To apply Monte Carlo Simulation to the context of South Korea, a constrained Monte Carlo Simulation is conducted, where residential and workplace locations used in the simulation are selected based on the actual locations of buildings. The analysis is conducted on 13 metropolitan areas with established metropolitan plans using the 2016 Household Travel Survey data. The commuting indicators calculated through the simulation showed minimal differences compared to the results obtained through conventional methods. The comparison of commuting efficiency among metropolitan areas revealed that even if the degree of spafial balance between residential and workplace locations is similar, the actual commuting patterns can differ significantly. It is suggested that further research considering characteristics such as the area of each metropolitan region will be necessary in the future.

• Fire Science and Engineering
• /
• v.32 no.2
• /
• pp.30-37
• /
• 2018

This study is an analysis of combustion characteristics of synthetic insulation materials such as houses and warehouses. Using combustion cone calorimeter and SEM, the researching has experimented combustion characteristics of four kinds of materials such as flame retardant styrofoam, general styrofoam, urethane and gypsum board. And analyzed. As a result of the test, the ignition time (TTI) for the thermal insulation material was found at 27 s~43 s, and the flame retardant styrofoam was ignited at the lowest TTI at 27 s and disappears at 28 s. In addition, the maximum heat release rate (peak HRR) and average heat release rate (mean HRR) of each material were expressed in the following order: urethane> flame retardant styrofoam> styrofoam> gypsum board. Also, the total smoke release ($m^2/m^2$) was the largest at $30.798m^2/m^2$ in flame-retardant styrofoam. The general CO concentration of styrofoam was 0.275 kg/kg and the emission concentration was 12.807 kg/kg. The residues showed the highest 0.029 g in the gypsum board among the above materials.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.5 s.347
• /
• pp.77-83
• /
• 2006

In this paper, we designed, constructed and evaluated the system for the FTTH suited to a residence and apartment using CWDM-PON techniques. These systems have capacity to service at 100Mbps rate to 384 users in the same breath. Also, the services include the internet, CATV, IPTV and wireless LAN. In the case of ire network, the data could be transmitted by UTP cable and optical fiber and case of wireless one, the data transmitted using WLAN. The distance between the cental office and the user is 20km and the data rate is 100Mbps maximum. Of course, the optical network used just one fiber optical core. For the basic material, we obtained the characteristics of optical transceiver module, Mux/Demux and transmission qualities depends on the environment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.2
• /
• pp.90-99
• /
• 2004

High speed info-communications equipment are required with development of highly information-oriented society, the intelligent industrial facilities and social systems such as administrative, financial and traffic systems, are gradually becoming to automation, which are composed of the integrated circuits and micro-semiconductors, remote control and operation. Thus modern micro-electronic circuits can frequently be damaged by lightning surge. The protection of electronic circuits from lightning overvoltages is concentrated very interesting. In this paper, for the purpose of providing the effective protection method of electronic devices such micro-computers from lightning surges in a residential building, the protection effect of surge protective devices according to types of system groundings were experimentally analyzed. Also the effective installation method of surge protective devices was examined and proposed. The installation of SPDs in retrofits was a high remnant voltage across the protected device owing to the inductance in the long wires to the SPDs. Finally the method of installing the SPD by twisted pain wires is remarkably effective for fast rising transient overvoltages.

• Journal of the Korea Institute of Building Construction
• /
• v.12 no.2
• /
• pp.142-151
• /
• 2012

Despite the changes to demands and perceptions according to building deterioration, most of the previous studies on remodeling have focused on apartment buildings, which are residential buildings. Few studies have been conducted on buildings for general commercial use, or office buildings. Accordingly, this study set out to prepare a set of performance criteria to assess the remodeling feasibility of office buildings. For that purpose, 23 assessment items were devised, their importance was tested, 13 were extracted, and a set of scoring criteria for each item was prepared. Case analysis was conducted to check the reliability of the assessment items and scoring criteria. Through this analysis, it was found that the criteria were reliable.

• Journal of Labour Economics
• /
• v.24 no.1
• /
• pp.1-33
• /
• 2001

Public investment in education has been justified by assumed positive externalities of education. Using the 1995 10% Population and Housing Census and 1998 Korean Labor and Income Panel Study, this study first examines the distribution of human capital across Korean cities and industries, and second, investigates the sizes of external economies of education by exploring how the average schooling of workers in cities and industries affect an individual worker's hourly wage. Generally, the average schooling of workers in the capital region cities is much higher than in other cities and the average schooling of workers in high tech industries is much higher than in other industries. As the average years of schooling in a city increases by one year, workers with the same personal and job characteristics such as sex, education, experience, occupation, and firm size, earn about 3% more. Also as the average years of schooling of workers in an industry increases by one year, the workers with the same personal and job characteristics earns about 5~7% more.

• Journal of the Korean Regional Science Association
• /
• v.32 no.2
• /
• pp.15-29
• /
• 2016

Suburbs rural areas in the Capital region have been diversified by the influence of the Seoul and large cities for the last 10 years. This study aims to classify suburban rural areas and to analyze the differentiated characteristics of different types in order to propose more area-specific policy approach to suburban rural areas in the Capital region. Using the cluster analysis method, the suburban rural areas in the Capital region have been classified into four types; garden villages in rural areas, urbanization areas, agricultural-industrial mixed use areas, general rural areas. The result of this study shows that the four types of suburban rural areas are much differentiated one another in terms of internal characteristics and local dynamics and problems. In order to suburban rural sustainable development in the Capital region, the policy efforts should be address the area-specific problems and policy demand for each type of suburban rural areas.

• Journal of the Korean association of regional geographers
• /
• v.19 no.3
• /
• pp.514-540
• /
• 2013

Today human rights are the most complex and prominent issue in the system of international law, and the right to housing(housing right) is also recognized as a basic human right in the international human right instruments including the Universal Declaration of Human Rights. This study targets to comprehensive review of the housing rights provisions with 85 international human rights laws and instruments. And the contents and characteristics of housing rights are analyzed with categorization based on housing rights in general, housing rights of workers, socially vulnerable groups, international regional organizations. Housing right takes also the features of universality, indivisibility, interdependence, and right to adequate housing should be interpreted with holistic view including legal security of tenure, accessibility, affordability, location beyond ensuring just a physical housing space. Approaches to the housing right comprehensively reflect the view of the right to development, the perspective of gender equality, the principle of non-discrimination, the participation rights, and orient the housing right should be seen as the right to live somewhere in security(safety), peace and dignity.

• Journal of Korean Society of Transportation
• /
• v.27 no.5
• /
• pp.63-74
• /
• 2009

One of the effective countermeasures for preventing traffic accidents is to provide traffic safety warning information to drivers. Provision of warning information would lead to safer driving to avoid accident occurrence. This study investigated the effects of in-vehicle warning information on driver's behavior. A variety of warning information contents using text, sound, and pictograms were prepared for the field experiments. Individual vehicle speed and acceleration data, which represent quantitative drivers' behavior in response to in-vehicle warning information, were collected using differential global positioning systems (DGPS). Statistical analyses including ANOVA and Tukey's pairwise comparison were conducted. It is expected that the results could be invaluable for designing more effective warning information.