• ETRI Journal
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• v.28 no.2
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• pp.247-249
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• 2006

In the development of a new wireless communications system, a versatile and accurate radio channel for indoor communications is needed. In particular, the investigation of radio transmission into buildings is very important. In this letter, we present an improved three-dimensional electromagnetic wave propagation prediction model for indoor wireless communications that takes into consideration building penetration loss. A ray tracing technique based on an image method is also employed in this study. Three-dimensional models can predict any complex indoor environment composed of arbitrarily shaped walls. A speed-up algorithm, which is a modified deterministic ray tube method, is also introduced for efficient prediction and computation.

• Journal of the Korea Institute of Building Construction
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• v.9 no.1
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• pp.95-101
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• 2009

Although the concept of RTLS is very unfamiliar to construction industry, recently it is popular in other industry, such as logistics, ship building, mobile telecommunication based on state-of-the-art information technology. Effective resource management using cutting-edge information technology makes it possible to succeed a project with saving the time and cost. And effective information management in construction project can be achieved by the new technologies such as RFID, WEB-based internet, DB technology, real-time monitoring technology, etc. This paper suggest the characteristics and applicability of the international standard electric waves to be used for the real-time locating system (RTLS) on the viewpoint of transmission loss in construction field to monitor and manage resources of construction project effectively The two types of electric waves based on the international standard is to be suggested after surveying the as-is technology in the related industries and then is analyzed to find out the characteristics of those by the concept of the electric wave transition loss in the several construction situations. Two main electric waves, the 2.4GHz and the 433MHz technologies as the international standard is researched on the applicability to the indoor environment of construction site.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.174-175
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• 2019

In this study, the spalling and ultrasonic pulse transmission time of concrete were investigated according to compressive strength during heating. As a result, the higher the compressive strength of the concrete, the more the explosion occurs, which affects the cross-sectional loss and the spalling fragment size. Also, ultrasonic pulse transmission time was found to be strongly influenced by the section loss of concrete.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.701-705
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• 2007

The equipment noise of machine room that generates at the building where human-being is living, is becoming to an object of strong civil appeal, and because it influences to the residential space through the floor or wall, its damage is very serious level. Accordingly, while an efficient forming of the sound insulating measures is earnest, as most of the transmission loss data was the material measured in laboratory, in case when it was applied to the job site, due to the precision difference of constructing work and the influence of detoured transmitting sound, the case of disaccord is the most. Therefore, this thesis has intended to present a fundamental data for an efficient establishment of sound insulation measure, by means of comparison analysis with the existing transmission loss data, after measurement of the transmission loss on the object of various walls, at the construction equipment machinery room.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.476-478
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• 1993

Instead of installing new communication wiring to each house in the apartment house building. the power distribution network. which is already installed in the building. can be use as communication medium. In a safty management, by adoption of power line communication system, at remote we can monitor safty related sensors such as fire, gas leakage, burglar intrusion and emergency call which are located at each house. From this viewpoint, we developed security monitoring system for apartment house building using power lines. Security monitoring system consists of Power Line Communication-Sub Controller (PLC-SC). Power Line Communication-Main Controller (PLC-MC) and Management System (MS). Between a PLC-MC and a PLC-SC, the transmission rate is 1200 bps in power lines and modulation technique is frequency shirt keying (FSK). In between a PLC-MC and a MS, the transmission rate is 1200 bps in communication line (RS-485). As a result of this research. transmission loss is 0.1dB per meter of intrabuilding distribution network. Transmission can be reach in 250 meters. So it is enough to communicate for security monitoring system in apartment house building.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1477-1482
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• 2012

This paper deals with a new variable microwave power distributor and a connector between a deck plate and a input power waveguide for indoor microwave wireless power transmission. We design a new type connector built in the 3-stage coaxial line structure, and calculate the return loss of the connector at 2.45GHz. Newly designed connector shows the excellent return loss performance less than -30dB at the operating frequency of 2.45GHz. And we show a power distributor in which the dividing ratio of the power is controlled mechanically by three rotary fins. The distributor can control the dividing power from 4.5% to 58% with the variance of 5% output power. The experimentally tested results of the distributor are good agreement with the simulation within the return loss of 1%.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.699-704
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• 2004

As being inconvenient to apply reinforced concrete structure to high-rise buildings, it is applied steel structured system. Therefore light-weight wall systems are applied as partition wall to reduce the self-load of the building. But, the required performances of a light-weight wall are not evaluated systematically. As a field survey result, partition walls of house-to-house were not showed their respected performances, so the dwellers are feel so worse the quality of the whole building. In steel-structured high-rise buildings especially, occupant's dissatisfaction concerned indoor noise was high because curtain wall systems having a high air-tight performance isolate the outdoor noise making masking effect. Therefore wall systems which have high performances of sound insulation and air-tightness are required in high-rise buildings. As a result, a new drywall system was presented and the performance was verified with field test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1723-1728
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• 2000

This paper deals experimentally with the effect of the sound-damping sheet on building wall system; brick wall, light wall panel, and gypsum board. Experimental results show that when the sound-damping sheet is attached on wall systems, the mass and/or damping effects result in increasing of STL of wall system depending on the characteristics of the original partition. It is pointed out that the performances of sound damping sheets must be presented with specific wall structures that applied, not by the sound transmission loss of the sheet itself.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.855-860
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• 2001

As being inconvenient to apply reinforced concrete structure to high-rise buildings. it is applied steel structured system. Therefore light-weight wall systems are applied as partition wall to reduce the self-load of the building. But. the required performances of a light-weight wall are not evaluated systematically. As a field survey result. partition walls of house-to-house and room-to-room were not showed their respected performances. so the dwellers are feel so worse the quality of the whole building. In steel-structured high-rise buildings especially. occupant's dissatisfaction concerned indoor noise was high because curtain wall systems having a high air-tight performance isolate the outdoor noise making masking effect. Also to suppress indoor air movement. stact effect must be concerned. Therefore wall systems which have high performances of sound insulation and air-tightness are required in high-rise buildings.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.235-239
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• 2004

Sound transmission either as airborne or structure borne is a potential problem that occurs in buildings either from sources within or from outside. With the expansion of real estate activities in countries like India, the need to attend sound insulation requirements also assumes greater dimensions. The focus of this research is on studying the sound transmission characteristics of building structures made of hollow blocks, neocrete block, aerocon block and prefabricated panels such as Ferrocement panel. The tests were carried out the blocks with and without plastering and their sound reduction index was measured at one-third octave frequencies. In the case of ferrocement panels, different types of systems were tested in the TL suite. Panels with cavity, with cavity ties, with insulation, with stiffeners and with plasterboard were investigated. Sound reduction index of these panels was measured with additional quantities like longitudinal wavespeed, and loss factors (internal and total loss factor). Tests were also conducted on Cypcrete wall panel and Sandwiched wooden panel in a similar way. Theoretical investigations were carried out using Statistical Energy Analysis (SEA) for the above systems. Sound reduction index was then compared between the predicted and the measured values.