• 한국소음진동공학회논문집
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• 제15권4호
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• pp.465-473
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• 2005

The impact sounds, generated by the walking of people, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. The characteristics and level of this impact noise depends on the object striking the floor, on the basic structure of the floor, and on the finish materials of floor. The focus of this paper is to investigate the amount of improvement impact sound pressure level according to the change of the composition method of ceiling and wall. For this purpose, we tested impact sound pressure level of several cases which is the inserting of mineral wool, the increase of the thickness of air layer, the using of anti-vibration rubber in ceiling and attach the mineral wool on wall in the Floor Impact Sound Test Building of KICT. The results show that the composition method of ceiling and wall is more effective in the reduction of light weight impact sound specially in 125Hz and 250Hz.

• 미생물학회지
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• 제22권4호
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• pp.215-222
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• 1984

Rhodotorula gl$\varkappa$tinis 세포벽에 작용하는 용해 효소 생산곰팡이를 토양으로부터 분리하였고, Aspergillus f'||'&'||'micro;mig$\alpha$tus에 속하는 species로 동정되었다. 이 세포벽 용해효소는 세표외 유도효소였으며 lytic polysaccharidase 와 protease로 구성되어 생세포 용해에 공동으로 착용하였다. 이 lytic polysaccharidase는 Ascomycetous 효모에서의 주 구성 결합인 ${\beta}-1,3-$와 ${\beta}-1$, 6-glucan에는 작용치 않았다. 이 효소는 생세포에는 역가가 낮았지만 R. glutinis의 분획된 세포액에는 protease의 도움없이 작용할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.261-264
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• 2004

Impact sounds, such as those created by footsteps, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. The character and level of impact noise generated depends on the object striking the floor, on the basic structure of the floor, and on the floor covering. This study base on the evaluate of isolation performance of impact sound according to the installation of ceiling and wall. In this test, we measured the reduction of impact sound in the case of inserting absorption materials, increasing of the thickness of air layer and using anti-vibration rubber in ceiling, install of absorption materials in wall. The results of this study show that treatment of ceiling and wall have some reduction of the light weight impact sound and heavy weight impact sound.

• 미생물학회지
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• 제28권1호
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• pp.83-89
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• 1990

토양으로부터 세포의 adcnosinedeaminase를 생산하는 두종의 방선균 J-845S주와 J-326TK 주름 분리하여 각각 Streptomycs sp. J-845S와 Nocardioides sp. J326TK로 동정하였다. Streptomyces sp. J-845S는 그람염색 양성, 비항산성균으로 기균사의 흰색계열의 간상형의 비운동성의 포자를 형성하였으며, 포자의 표면은 평할하였고 나선상의 포자연쇄를 형성하였다. 균사체의 분자는 양호하였다. 세포벽 구성성분을 분석한 결과 LL-diaminopimelic acid를 함유하는 cell wall type I 이었으며, phospholipid type II였다. Nocardioides sp. J-326TK는 그람염색반응 양성, 항산성염색반응 음성이었으며, 균사체는 불규칙한 간상 또는 구사으이 절편으로 분절되었다. 기균사의 분자는 그다지 인정되지 않았으며, 포자형태의 긴 elements의 표면은 평할하였다. 세포벽 구성성분을 검토한 결과 cell wall type I과 phospholipid type I으로나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.738-745
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• 2004

There are a number of ways to reduce the ground vibrations, one of which is by installing underground walls. Model tests for ground vibration have been conducted in recent years, but limited attention has been paid to underground wall which can reduce high vibrations. Up to date, only barriers have been actually installed in dry sand because of many unknown factors subsisting on the behavior of the ground. The characteristics of vibration sources, ground conditions and wall barriers have not been well understood yet, therefore centrifugal modeling was adopted to examine all these characteristics. This paper describes a ball dropping system, which can generate a pulse wave propagation through soil mass, and the test results show the effectiveness of underground wall barrier in reducing mechanical vibration.

• Journal of Plant Biology
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• 제28권3호
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• pp.233-241
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• 1985

The isolation and culture of protoplasts from hypocotyl-derived calluses of Glycine max (L.) Merr. cv. Jangyeop were obtained by digestion for 6 hrs in an enzyme solution containing 3.5% cellulase, 1.5% macerozyme, 10% sorbitol and 0.1% CaCl2.2H2O at pH 5.8. Newly formed cell wall of protoplasts cultured in MS agar medium containing 10 $\mu$M $\alpha$-naphthaleneacetic acid (NAA) and 32 $\mu$M N6-benzylaminopurine (BAP) could be observed after 24 hrs culture. The first cell division of the protoplasts was observed after 3 days of culture; cell clusters after 2 weeks of culture. When transferred to solid media, the protoplasts formed cell clusters gave rise to proliferating calluses.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.499-504
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• 2004

The purpose of this study is to investigate a investigating of a floor-impact isolation system using damping materials in apartment buildings. The stiffness elastic modulus(k) by puls impact forces were calculated loss factor by Hilbert transforms. It is absolved that natural frequency was moved floor shock-absorbing materials and the impact force was reduced by floor panel. The slab was constructed by damping materials. As towards a result, the system showed inverse A 45dB by heavy weight-impact noise and inverse A 52dB by light-impact noise. High frequencies impact-noise can be reduced by upgrading naturial frequency of vibration and noise in the system.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권2호
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• pp.85-91
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• 2002

A novel multi-section power divider configuration is Proposed to obtain wide-band frequency performance up to microwave frequency region. Design procedures for the proposed microwave broadband power divider are composed of a Planar multi-section three-Ports hybrid and a waveguide transformer design procedures. The multi∼section power divider is based on design theory of the optimum quarter- wave transformer Furthermore, in order to obtain the broadband isolation performance between the two adjacent output ports, the odd mode equivalent circuit should be matched by using the lossy element such as resistor. The derived design formula for calculating these odd mode∼matching elements is based on the singly terminated filter design theory. The waveguide transformer section is designed to suppress the propagation of the higher order modes such as waveguide modes due to employing the metallic electric wall. Simulation and experiment show excellent performance of multi section power divider.

• 도시과학
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• 제9권2호
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• pp.13-20
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• 2020

The Recently, several countries have been affected by respiratory diseases, resulting in renewed research interest in their prevention and control. One such example was the 2015 outbreak of Middle East Respiratory Syndrome (MERS) in South Korea and COVID-19. In this study, we performed experiments and simulations based on concentration decay using CO2 as the tracer gas to elucidate the pollutant-removal efficiency for different inlet and exhaust locations and outdoor air-supply ratios. The wall inlet exhibited a higher pollutant-removal efficiency, owing to the upward movement of the air from the lower zone to the upper one. In conclusion, it is recommended that a total air-conditioning plan for isolation rooms be established as well as efficient system operation for pollutant removal and air-flow control to prevent the transmission of infections from the patients to others.

• Journal of Microbiology and Biotechnology
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• 제6권4호
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• pp.270-277
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• 1996

A bacteriocin-producing strain, DU-0608, was isolated from Kimchi and identified as Leuconostoc mesenteroides subsp. mesenteroides. The bacteriocin from isolate was inhibitory against Listeria monocytogenes, Micrococcus luteus and several strains of lactic acid bacteria. The bacteriocin was inactivated by pepsin, trypsin, $\alpha$-chymotrypsin, protease, $\alpha$-amylase and lipase, but not by catalase or by heating at $100^{\circ}C$ for 60 min. The molecular weight of the bacteriocin was estimated approximately 6 kDa. The inhibitory effect was bactericidal and rapid. Following treatment with isolate bacteriocin, cells of indicator strain (Lactobacillus sake JCM 1157) were damaged at the end regions of the cell wall, whereas the cells treated with nisin were damaged at many places around the cell wall.