• The Journal of the Acoustical Society of Korea
• /
• v.32 no.1
• /
• pp.43-55
• /
• 2013

The window ventilation system based on the heat recovery device was developed which make air ventilation possible without opening the windows. However, mechanical and aerodynamic noises were come to pass which annoyed people in rooms. In the present study, noise of new window ventilation system was measured in both general room and anechoic chamber. Also, the noise path was detected to find cause of noise generation and vulnerable area of the device. Sound absorptive and insulation materials were applied to mitigate the noise. Finally, an alternative noise control method was suggested which can satisfy with the indoor noise standards. As a result, it was shown that the cause of noise was the low transmission loss in the ventilation system. As a result, it was shown that the main noise source of the ventilation system was the blower and the major cause of noise was the low transmission loss of the ventilation system. It is also concluded that the noise levels complies with the noise standards of 40 dBA when 2 mm rubber sheet is applied inside the ventilation system.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.2
• /
• pp.141-147
• /
• 2018

In this study, a cyclic loading test was carried out for a reinforced concrete frame installed a TS(tension-spring) damper for the purpose of verifying the seismic strengthening effect of the TS seismic reinforcing method. The test specimens are four specimens of non - reinforced frame and three reinforced frame specimens. Experimental parameters are Shape of damper and construction method of damper. As a result, the construction method of inserting type inside window was twice as much in terms of strength and stiffness, and the method of externally attached type showed a performance improvement of about 2 times in terms of energy dissipation. From these results, it can be confirmed that the TS seismic reinforcing method is a superior method for field application and seismic strengthening.

• 한국가시화정보학회:학술대회논문집
• /
• 2003.11a
• /
• pp.71-74
• /
• 2003

In this paper, we report the numerical and experimental results in a half-cylinder. In the numerical computation, we used the zonal embedded grid system. Flow visualization for the spin-up flows was used by PIV. The results show that at left hand side an cyclonic cell moves along a wall and separates into both cells at right hand side.

• Journal of the Korean Society of Visualization
• /
• v.2 no.2
• /
• pp.32-37
• /
• 2004

In this paper the numerical method with a zonal embedded grid system for an incompressible flow within a semi-circular container is presented. The algorithm is validated by its application to some typical flow models including the spin-up flow inside a semi-circular geometry. Flow visualization for the spin-up flows was used by PIV. The results show that at high Reynolds numbers the cyclonic cell at the left-hand side region moves along the circular wall and merges with the cell at the right-hand side region.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.1885-1890
• /
• 2004

In this paper the numerical method with a zonal embedded grid system was applied to the spin-up flow within a semi-circular container. Flow visualization was also performed on a rotating table. The results show that at a low level of damping (i.e. low viscosity and high liquid depth) a cyclonic cell produced initially near the left-hand-side corner of the container moves along a wall and merged with the cell on the right-hand-side.

• Journal of Sensor Science and Technology
• /
• v.7 no.4
• /
• pp.285-292
• /
• 1998

Shape Memory Alloy(SMA) has been used in many engineering fields because of its good characteristics of actuator. For example, SMA wire can be embedded easily in the polymer composite laminate and then be used as actuator for structural control. Since the strain have a significant influence on the electrical resistance of SMA wire, It is a possible to use the SMA wire as a sensor of such physical quantities. In this study, the possibility for the application of Ni-Ti SMA wire as a sensor embedded within a composite laminate is investigated.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.12B
• /
• pp.1712-1723
• /
• 2001

This paper presents a design procedure and manufacturing techniques realizing of a 5.8 GHz duplexer based on cylindrical coaxial dielectric resonator. Upto Q$\times$f$\_$o/=30,000 cylindric coaxial dielectric resonator was developed control by addition of dielectric materials. This resonator shows attenuation characteristics -40 dB for transmitter and -50 dB for receiver by consisting of two sets of 4-stage cavity resonator within f$\_$o/$\pm$10 MHz bandwidth which was requirement of DSRC. Employing the measurement results, design procedure to characterize the transmission and reflection properties are presented.

• Tuberculosis and Respiratory Diseases
• /
• v.53 no.2
• /
• pp.113-126
• /
• 2002

Background : DNA repair plays a crucial role in protection from cancer-causing agents. Therefore, a reduced DNA repair capacity can increase the susceptibility to lung cancer. The XPC gene contains 15 exons and encodes a 940 amino acid protein that plays a central role in DNA damage recognition of the nucleotide excision repair pathway, which is a major DNA repair mechanisim removing the bulky-helix distorting DNA lesions caused by smoking. Recently several polymorphisms in the XPC gene were identified. In addition, it is possible that these polymorphisms may affect the DNA repair capacity, which modulate cancer susceptibility. The relationship between codon 499 and 939 polymorphisms, and a poly(AT) insertion/deletion polymorphism in the XPC gene, and the lung cancer risk were investigated. Materials and Methods : The genotypes were determined using either PCR or PCR-RFLP analysis in 219 male lung cancer patients and 150 healthy males controls. Results : The frequencies of the genotypes (Val499Ala, PAT and Lys939Gln) among the cases were not significantly different from those of the controls. There was no significant associantion between these polymorphi는 and the lung cancer risk when the analyses were stratified according to age, smoking status and the pack-years of smoking. Moreover, the genotypes had no apparent relationship with any of the histological types of lung cancer. There was a linkage disequilibrium among the Val499Ala, PAT and Lys939Gln polymorphisms. The PAT polymorphism had a strong linkage disequilibrium with the Lys939Gln polymorphism (kappa value=0.87). The XPC haplotypes showed no significant association with the lung cancer risk. Conclusion : These results suggest that XPC Val499Ala, PAT and Lys939Gln polymorphisms are not major contributors to the individual lung cancer susceptibility in Koreans.