• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1027-1034
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• 2005

IEEE802.15.4a, which is started to realize the PHY layer including high precision ranging/positioning and low data rate communication functions, requires a simple and low power consumable transceiver architecture. To satisfy this requirements, the simple noncoherent on-off keying (OOK) UWB transceiver with the parallel energy window banks (PEWB) giving high precision signal processing interface is proposed. The flexibility of the proposed system in multipath fading channel environments is acquired with the pulse and bit repetition method. To analyze the bit error rate (BER) performance of this proposed system, a noise model in receiver is derived with commonly used random variable distribution, chi-square. BER of $10^{-5}$ under the line-of-sight (LOS) residential channel is achieved with the integration time of 32 ns and signal to noise ratio (SNR) of 15.3 dB. For the non-line-of-sight (NLOS) outdoor channel, the integration time of 72 ns and SNR of 16.2 dB are needed. The integrated energy to total received energy (IRR) for the best BER performance is about $86\%$.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.483-494
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• 2022

Owing to the saturation of ground spaces in downtown areas, underground spaces are being developed increasingly. Underground spaces are utilized for transportation, water supply and sewerage, communication zones, electric power zones, and various cultural complexes. In Korea, for excavating underground spaces, blasting methods using gunpowder such as the New Austrian Tunneling Method (NATM) are mainly used. However, the blasting method causes vibration and noise during tunnel excavation, generating many complaints from residents in the vicinity of the excavation site. To address this problem, various methods have been developed, and recently, vibration and noise have been reduced using deep excavation. This study predicts blast vibration changes according to the depth, under the same blasting and tunnel conditions, using numerical analysis based on the blast vibration measurement data of the GTX-A route, the tunnel cross-section drawings, and ground investigation reports. Furthermore, the necessary separation distance from densely populated areas such as residential areas is suggested by analyzing the trend of decreasing blast vibration according to the distance from ground surface directly above the blasting location.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.10
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• pp.1006-1012
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• 2008

The effect of small and medium scale shipyard operations on environmental pollutions related with civil appeal of nearby residential areas was estimated. PM-10(particles with an aerodynamic diameter less than or equal to 10 $\mu$m) concentrations were higher, as the sampling sites were nearer from shipyards. PM-10 concentrations of sampling sites closer to shipbuilding companies were higher during the normal operation periods than on vacation at which only small works were done. The larger amount of dry deposition was observed as the sampling sites were closer to shipyards. The odor intensity was highly influenced by ambient temperature. Almost all odor intensities measured by air dilution sensory test went over the emission standard in summer. Odor properties measured by instrumental analysis were observed to exceed the emission standard enforced to the shipyards. Odor compounds such as ammonia, sulfur compounds and trimethylamine went over the standard. Concentrations of styrene and aldehydes were lower than the olfactory threshold. All equivalent sound levels measured at daytime except the value of SP-3 pont were in excess of the environmental standard. Almost all sound levels at nighttime in all measuring sites were higher than the environmental standard. The results of this study shows counterplans need to be established for reducing the civil appeal related pollutions in the research areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.314-321
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• 2016

After the 1980s, as the economy was growing rapidly and the real estate market was active, a large increase in population was supplied to the city. Accordingly, the national apartment housing market is located in the form of Urban Housing Culture. On the other hand, with time, the supply apartment houses became superannuated and the residential environment became poor. Therefore, the environment of old apartment houses has been changed to improve by reconstruction. Despite this, reconstruction incurred not only a lot of construction waste, but also problems of environmental degradation, noise, traffic congestion, increasing number of households, and so on. Recently, the housing law has changed, and vertical extension remodeling focused on Small/Medium Town House is underway. This has been changed in response to the demand. This is one of essential parts in the remodeling field for the future, even though it has some problems in how uses existing buildings. Therefore, this study analyzed occurrence risk factor for each type through research materials and case analysis regarding the vertical extension remodeling of apartment housing. In addition, the relative importance was determined through questionnaires and interviews from constructors, designers, and experts in the field.

• Journal of Korean Home Economics Education Association
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• v.34 no.2
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• pp.1-19
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• 2022

The purpose of this study is to analyze the keywords of the middle school textbooks based on the 2015 revision of the technology and home economics curriculum to understand the core concepts and contents composition of the 'housing' unit. Using TEXTOM and UCINET programs, the frequencies and centralities of the keywords were analyzed, and CONCOR analysis was performed. The results are as follows. First, the content system of the 'housing' unit is divided into 'life culture' and 'safety' in the 'family life and safety' area. Second, in the 'safety' section, the frequencies of occurrence of the words were high in the order of indoor, occurrence, use, noise, and safety accidents, in the order of frequency of occurrence. It was confirmed that words related to daily life, safety accidents, and prevention were closely connected to each other. In the 'life culture' section, the frequencies of occurrence were high in the order of space, housing, family, and residential space, and the correlations between these keywords were also high. Third, the most influential core keywords were, indoor and occurrence in the 'safety' section, and space, family, and housing, in the 'life culture' section. Fourth, the 'safety' section were divided into two subunits, 'safe living environment' and 'comfortable living environment', and the 'life culture' section were divided into four subunits, 'living space composition', 'space utilization', 'housing value and lifestyle', and 'housing culture'.

• The Journal of the Acoustical Society of Korea
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• v.42 no.2
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• pp.152-160
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• 2023

Sound barrier walls are the most basic way to cope with noise problems in urban residential environments. The most important acoustic function of sound insulation board is represented by sound transmission loss and sound absorption coefficient. However, Korea has not yet established a standard for measuring the sound absorption rate of sound insulation boards. In addition, even in the European standard, where the overall acoustic standard of soundproofing boards has already been established, the sound absorption rate is applied only to the standard for measuring the sound absorption rate of general building finishing materials, and a separate measurement method considering the characteristics of soundproof walls and soundproofing boards is not presented. The sound absorption coefficient should be evaluated by summing up the energy absorbed into the material as well as the energy transmitted through the material, but the current European standard has a problem in that the transmitted sound energy is not taken into account. In this paper, we reviewed the sound absorption coefficient measurement standards of sound insulation boards currently being presented, and verified the difference between the results and the new measurement method considering transmission sound for sound insulation boards actually used in Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6D
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• pp.711-717
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• 2009

This study develops model for analysis of relationship between major node (Interchange in expressway) and land price formation of apartments along with Seoul Belt Expressway by using CHAID analysis. The results show that first, regions(outer side: Gyeongido, inner side: Seoul) on the line of Seoul Belt Expressway are different and a graph generally show llinear relationships between land price and traffic node but it does not; second, CHAID analysis shows two different spatial distribution at the point of 2.6km in the outer side, but three different spatial distribution at the point of 1.4km and 3.8km in the inner side. In other words, traffic access does not necessarily guarantee high housing price since the graphs shows land price related to composite spatial distribution. This implies that residential environments (highway noise and regional discontinuity) and traffic accessibility cause mutual interaction to generate this phenomenon. Therefore, the highway IC landprice model will be beneficial for calculation of land price in New Town which constantly is being built along the highway.

• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.489-507
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• 1996

The purpose of this study is to examine the increasing number of unregistered manufacturing plants and related problems, and to recommend alternative solutions to the problems. Data are obtained from a field survey of randomly selected small scale manufacturing plants in Seoul and its suburban cities. A total number or respondents are 533, and 416 of them are unregistered plants. The Capital Regional Planning has had a goal during last three decades to lead a balanced regional economic development by restriction manufacturing plants in the Capital Region and by encouraging them in other regions in the nation. It was 1984 when a comprehensive planning was established to achieve this goal. Sets of various regulations, by-laws and codes have been implemented to regulate manu-facturing activities in the Capital Region to achieve the goal. The region is divided into three sub-regions, and a different degree of regulations is applied to each sub-region. Only a certain types of industries are allowed in a particular sub-region. For instance, a plant manufacturing high-technology products could be allowed in the most urbanized sub-region. All manu-facturing plant in the Capital Region which has ares size of larger than 200"\;"$m^2$ is compulsory to register to the local government office. In practice, however, it is not common or sometimes almost impossible to get approval for many applicant manufacturers because of strict regulations. There have been increasing number of plants in the Capital Region during last several decades, despite the strict regulations. Many of those newly established plants are without formal registration at the local administration office. howerver. These are so called 'unregisterd' plants. Surveyed data and many government official data show that many of unregistered plants have been established in recent years. which indicate that current regulations are no longer effective. The number of unregistered plants are increasing tin the Capital Region because of many locational advantages in the region for plants, particularly those in small scale. Unregistered plants are the source of many problems, such as local water pollution or noise pollution in residential areas. There are also many administration problems, bed\cause they are not registered. The central government has attempted to cure the problems of unregistered plants. For example, the government allowed a unregistered plant to remain at present site for three ydars, if it met certain conditions in three years. However, this program was unsuccessful because many of those plants were not able to meet the concitions. Three times the government renewed the term for those which did not meet conditions since 1989, but it was afraid to be without success. There are many evidences that current policies to control manufacturing plants are not effective. The Capital Region must face mounting problems if ploicies are not reformed soon. This study suggests that the policy of the Capital Regional Planning has to be reoriented to provide more favorable policies for manufacturing plants in the Capital Region than current regulations which is aimed to restrict manufacturing activities. It is time to improve many existing problems in the region through reforms and of current regulations to foster unregistered plants. This study also proposes many smaller-area sub-divisions instead of current three large area sub-regions which is too broad to apply single kind of regulation, or codes. Flexible regulations and codes can be applied to such a small-area sub-divivisions based on location and industrial characteristics of the individual sub-divisions. It is necessary to provide decent industrial environment in the Capital Region, which is best equipped to provide many favorable industrial locational factors in the nation, thus this nation can be further prepared to compete in an inter-national market at an era of globalization in manufacturing.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.62-75
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• 2017

This study analyzes the multiple effects of the following three aspects of waterscape facilities within apartment complexes: planning/designing, maintenance/management, and use of the facilities and suggests primary documents that will be fundamental for the methods to accelerate the implementation of waterscape facilities. A survey and analysis was conducted among a few of the most representative private apartment complexes in Seoul in accordance with the management and operation of waterscape facilities. The analysis used frequency analysis, descriptive statistics, reliability test, t-test, and PLS regression analysis. The research findings are as follows: first, the degree of use of waterscape facilities was found to be low regardless of the levels of operation, but residents' preference for the facilities was shown to be high, thus indicating there are still high expectations on the part of residents. Second, regardless of whether the facilities are being operated efficiently, the two items of location and display method under the section of planning and designing and the two items of aptitude and convenience under the section of use were found to positively affect the operation and use of waterscape facilities. Particularly, the item of freshness, cleanliness was shown to be directly and indirectly correlated with obsolescence, administration costs, and noise, which negatively affect the operation. Third, it was found that the administration costs itself that had been shown as the most negative factor of operating landscaping facilities in previous research did not cause problems in the residential area where the facilities are not operated efficiently. The finding suggests that the administration costs do not matter but that in the case of experience- and entertainment-typed facilities that residents want, they are linked to problems that do not introduce the desired facilities. Fourth, it was found that various aspects of planning, designing, maintaining, and using facilities interconnect and affect one another in the process of operating and using waterscape facilities resulting in the need to have a comprehensive approach to these three factors of planning, design, maintenance, management, and utilization. This study proposes that the needs and values of residents should be reflected to activate the introduction of landscaping facilities in the apartment complexes.