• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.116-124
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• 2019

The rapid development of the poultry industry has led to the production of large amounts of manure, which produce substances like hydrogen sulfide ($H_2S$) that contribute to odor pollution. $H_2S$ is a highly undesirable gas component and its removal from the environment is therefore necessary. Sulfur-oxidizing bacteria (SOB) are widely known to remove contaminating $H_2S$ due to their ability to oxidize reduced sulfur compounds. In this study, three potential SOB (designated AH18, AH25, and AH28) that were previously isolated from a hot spring in Malaysia were identified by 16S rRNA gene analysis. Laboratory-scale biological deodorization experiments were conducted to test the performance of the three isolates-in the form of pure or mixed cultures, with the cells immobilized onto alginate as a carrier-in reducing the $H_2S$ from chicken manure. On the basis of 16S rRNA phylogenetic analysis, isolate AH18 was identified as Pseudomonas sp., whereas isolates AH25 and AH28 were identified as Achromobacter sp. The most active deodorizing isolate was AH18, with an $H_2S$ reduction rate of 74.7% (p < 0.05). Meanwhile, the reduction rates for isolates AH25 and AH28 were 54.2% and 60.8% (p > 0.05), respectively. However, the $H_2S$ removal performance was enhanced in the mixed culture, with a reduction rate of 81.9% (p < 0.05). In conclusion, the three potential SOB isolates were capable of reducing the $H_2S$ from chicken manure in the form of a pure culture immobilized on alginate, and the reduction performance was enhanced in the mixed culture.

• Archives of Pharmacal Research
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• v.26 no.7
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• pp.554-558
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• 2003

Platelet activating factor acetylhydrolase (PAF-AH) activity has been identified in cerebrospinal fluid (CSF) samples taken from children with meningitis. We reported that PAF-AH activity is significantly increased, by about 3 fold, in patients with meningitis compared to control subjects. Because of limited knowledge about this enzyme in CSF, we examined the biochemical properties of CSF PAF-AH. PAF-AH of CSF was calcium independent, showed a broad pH spectrum and was relatively heat stable. In addition, this enzyme activity was strongly inhibited by phenylmethanesulfonyl fluoride (PMSF), partially inhibited by p-bromophenacylbromide (p-BPB), uninhibited by iodoacetamide, and moderately stimulated by dithiothreitol (DTT). PAF-AH of CSF did not degrade phospholipid with a long chain fatty acyl group at sn-2 position. This enzyme hydrolyzed PAF and oxidatively modified phosphatidylcholine. Furthermore, we identified a monomeric polypeptide with a molecular weight of approximately 45 kDa by Western blot using human plasma PAF-AH antibody. These results suggested that plasma type PAF-AH activity exist in CSF taken from children with meningitis.

• Journal of the Korea Safety Management & Science
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• v.15 no.3
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• pp.133-141
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• 2013

As a work analysis technique, Work Domain Analysis (WDA) aims to identify the design knowledge structure of a work domain that human operators interact with through human-system interfaces. Abstraction hierarchy (AH) is a multi-level, hierarchical knowledge representation framework for modeling the functional structure of any kinds of systems. Thus, WDA based on AH aims to identify the functional knowledge structure of a work domain. AH has been used in a range of work domains and problems to model their functional knowledge structure and has proven its generality and usefulness. However, many of researchers and system designers have reported that it is never easy to understand the concepts underlying AH and use it effectively for WDA. This would be because WDA is a form of work analysis that is different from other types of work analysis techniques such as task analysis and AH has several unique characteristics that are differentiated from other types of function analysis techniques used in systems engineering. With this issue in mind, this paper introduces the concepts of WDA based on AH and offers a comprehensive list of references. Next, this paper proposes a set of principles for effectively applying AH for work domain analysis, which are developed based on the author's experiences, consultation with experts, and literature reviews.

• The Korea Journal of Herbology
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• v.25 no.4
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• pp.31-37
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• 2010

Objects : This study was performed in order to evaluate the effects of Agrimoniae herba (AH) ethanol extract on intrastriatal hemorrhage (ISH). Method : ISH was induced by the stereotaxic intrastriatal injection of bacterial collagenase type IV in Sprague-Dawley rats. AH was orally given once a day for 3 days after ISH. Hematoma volume and percentage edema were examined. Immunohistochemistry was processed for iNOS, c-Fos, MMP-9, and MMP-12 expressions in the brain sections and each immuno-labeling were calculated with image analysis. Results : results are as follows; 1. AH reduced the hematoma volume and percentage edema of the ISH-induced rat brain. 2. AH swollen apoptotic bodies and neurons in the peri-hematoma regions of the ISH-induced rat brain. 3. AH significantly reduced c-Fos, MMP-9 and MMP-12 positive cells in the peri-hematoma regions of the ISH-induced rat brain. 4. AH swollen iNOS expressions in the peri-hematoma regions of the ISH-induced rat brain. Conclusion : These results suggest that AH plays an anti-apoptotic neuroprotective effect through control of ISH, suppression of c-Fos, and down-regulation of MMP-9 and MMP-12 expressions in the brain tissues.

• Microbiology and Biotechnology Letters
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• v.46 no.3
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• pp.288-299
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• 2018

Food bio preservation is of major interest in the food industry. Many types of antimicrobial compounds can be produced by lactic acid bacteria (LAB), including bacteriocins. Bacteriocins increase the shelf-life of food by decreasing some food-borne diseases. In this study, a multi-coding sequence of bacteriocin genes was used for primer design to produce bacteriocin genes in Enterococcus faecium AH2 strain and Pediococcus pentosaceus AH1. Multi-coding sequences were aligned to detect conserved sequences in the bacteriocin gene. Eight genes encoding proteins involved in bacteriocin production were isolated and sequenced, including six from E. faecium AH2 (entA, entI, entF, entR, orfA2, orfA3) and two from P. pentoceseus AH1 (papA, pedB), and all gene sequences were deposited in the Gen Bank database under accession numbers LC064146-LC064151, LC101300, and LC101789, respectively. P. pentosaceus AH1 and E. faecium AH2 strains displayed bacteriocin activities of $2610AU\;mL^{-1}$ and $690AU\;mL^{-1}$ and inhibition zones of 26 mm and 19 mm, respectively. Overexpression of entA in E. faecium AH2 increased the bacteriocin and antimicrobial activities.

• Phonetics and Speech Sciences
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• v.7 no.4
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• pp.59-65
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• 2015

This study was conducted to identify the differences in voice characteristic variables before and after taking a certain amount of high-caffeine. Linear PCM-M10 Recorder (SONY) was used for the recorder and basic frequency of the voice (Fo), frequency fluctuation rate (jitter), amplitude fluctuation rate (shimmer) and Signal-to-Noise Ratio (SNR) were measured using TF-32(University of Wisconsin-Madison, USA). First, prolonged phonation analysis results of /ah/ by male subjects showed the shimmer values after taking high-caffeine increased statistically significantly(p<.05) compared with before the intake and SNR values significantly decreased. (p<.05). On the other hand, female subjects didn't show any statistically significant differences in all variables. Second, male subjects showed statistically significant increased shimmer values after the intake compared with before the intake at /ah/ of syllable 'na' and /ah/ in 'ra' in 'autumn' paragraph (p<.05), and jitter values significantly increased at /ah/ in 'ah' (p<.05). However, female subjects didn't show any statistically significant differences in all variables. Results of this study showed that high-caffeine intake more affects male subjects than female subjects. In male subjects, shimmer and SNR changed at vowel prolonged phonation, /ah/, and study results showed that shimmer and SNR in 'Autumn' paragraph /na/, /ra/ and jitter in /ah/ could be identified as the variables to show the voice change.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.146-148
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• 2017

기술의 발전에 따라 촬영기기 및 영상장비들의 성능이 비약적으로 향상되고, 본격적인 UHD(Ultra High Definition) 시대가 맞이하여 자연스럽게 소비자들은 더 나은 화질을 요구하고 많은 콘텐츠업체들은 초고화질기술을 적용시킨 작품을 제작하고 있다. 또한, 고품질 콘텐츠에 대한 요구 뿐 만 아니라 데이터 관리(Data Management) 및 색보정(Calibration) 등 이와 관련된 기술의 중요도 증가되고 있다. 따라서 본 논문은 DIT(Digital Imaging Technician) 작업을 차량 내에서 할 수 있도록 특수제작 된 차량을 제작함으로써 현장에서 실시간으로 컬러 그레이딩(Color Grading), 데이터 관리(Data Management) 업무를 수행하여 업무 효율성을 높이고 제작편의성을 증대하고자 한다. 컬러 그레이딩과 데이터 관리라는 요소들이 현재 방송분야보다는 영화와 관련한 분야에서 많이 사용되지만 UHD 시대가 열리는 미래의 방송환경에서는 방송에서도 중요한 요소가 되고 있다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.248-251
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• 2021

방송장비가 네트워크 기술을 만나 진화하고 있다. 네트워크 케이블로 초고해상도 영상과 다채널 음향 데이터를 송·수신하고, 다수의 방송장비 제어를 가능케 하는 NDI(Network Device Interface)의 등장으로 방송장비와 네트워크 기술이 융합되고 있다. 최근 국내외 여러 기업이 네트워크 기반의 방송 솔루션을 출시하고 있어, 관련 산업계는 향후 방송장비 시장이 네트워크 기반으로 개편될 것으로 전망하고 있다. NDI는 뉴텍(NewTek)에서 개발한 IP 전송 프로토콜의 일종으로 무(無)손실, 압축, 제로(Zero) 딜레이, 멀티캐스트 등의 특징을 갖고 있다. 기존 비디오 전송 프로토콜이었던 SDI(Serial Device Interface)와는 다르게 네트워크에서 방송장비를 운용할 수 있도록 만들어진 프로토콜이다. 본 논문에서는 NDI를 기반으로 앞으로 다가올 포스트 코로나 시대에 대응할 효율적인 방송 환경을 제안하고자 한다.

• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.207-211
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• 2002

항균 활성도는 Root canal sealer가 갖추어야 할 필수요소 중 하나이다. 본 연구는 최근 임상술식에 사용되고 있는 8종의 root canal sealer의 근관내 혐기성 세균에 대한 항균효과를 알아보기 위해 시행되었다. 또한 본 연구에서는 혼합직후의 경화되지 않은 sealer와 경화 7일 후 sealer의 항균효과도 비교하였다. 항균효과 측정을 위해 사용된 균주는 최근 실패한 근관치료 증례에서 배양되어 보고된 바 있는 Enterococcus faecalis와 근관내 주요 감염균인 그램음성 혐기성세균인 Staphylococcus aureus를 대상으로 하였고, Agar diffusion test 방법을 사용하였다. 실험방법으로는 2개의 paper disk에 신선하게 혼합한 각각의 sealer를 도포하여 한개의 disk는 즉시 실험에 사용하고 다른 한개의 disk는 일주일간 혐기성 배양기에서 경화시킨 다음 사용한다 각각의 균주를 Brucellar blood agar plate에 접종한 다음, sealer가 도포된 paper disk를 plate상에 올려놓는다. 대조군으로는 식염수에 침윤시킨 disc를 같은 방법으로 각 실험단계에 사용한다. 각 plate를 혐기성 배양기에서 48시간동안 배양한 뒤 실험에 사용한 sealer의 항균효과를 6mm paper-disk를 둘러싼 inhibition zone을 측정하여 평가한다. Fisher's PLSD분석방법 결과 E. faecalis에 대하여 경화 전과 후의 AH26모두 경화 전과 후의 Roth 801, Dentalis, Apexit, AH Plus, RSA그리고 경화 후의 MCS보다 유의성 있게 강한 항균효과를 나타내는 것으로 보고되었으며. 경화 후의 AH26은 경화 전의 AH 26, 경화 전의 Ketac Endo, 경화 전의 MCS보다 통계학적으로 유의성이 있는 항균작용을 하는 것이 관찰되었다 (p＜0.05). 경화 후 Roth 801, 경화전과 후의 Dentalis, AH plus, Apexit, RSA는 E. faecalis에 대한 항균효과를 나타내지 못하였다. S. aureus에 대하여 경화후의 AH26이 경화 전과 후의 Roth 801, Apexit, AH Plus, RSA보다 유의성있는 항균효과를 보이는 것을 발견 할 수 있었고, 경화 전의 AH 26이 경화 후의 AH plus보다 나은 항균효과를 나타냄을 알 수 있었다. 또, 경화 전과 후의 Apexit, 경화 후의 AH Plus, 경화 전과 후의 RSA에서는 S. aureus에 대한 항균작용이 발견되지 않았다. 본 실험의 결과 AH26이 가장 강한 항균 작용을 갖는 것을 알 수 있었으며, 각 sealer의 경화 전과 후의 항균효과는 AH26이 경화 전보다 경화 후에서 더 강한 항균효과를 나타내는 것 이외에는 효과의 차이가 없었다.

• Information and Communications Magazine
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• v.30 no.6
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• pp.20-25
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• 2013

본고에서는 1GHz 이하 주파수에서 동작하는 Wireless LAN(WLAN) 표준으로, IEEE 802.11ah PHY/MAC 표준 규격에 대해서 알아 본다. IEEE 802.11ah 표준은, Smart Grid, M2M, IoT 와 같이 실내, 실외에서 많은 수의 단말들을 최소한의 전력소모로 데이터 통신을 하기 위한 목적으로 개발되었다. WLAN의 서비스 범위가 1Km 이상으로 늘어나게 되면, 그 동안 WLAN 에서 심각하게 다루지 않았던 Hidden Node 문제가 단말의 전력 소모, throughput performance 을 결정하는 중요한 요소로 등장하게 된다. 특별히 IEEE 802.11ah 에서는, 많은 수의 단말들간에 Hidden Node 을 고려한 Restricted Access Window 라는 새로운 channel access 기법이 제안되었고, 이에 본 고에서는 IEEE 802.11ah 에 새롭게 지원되는 MAC 기능들에 대해 중점적으로 살펴 보도록 한다.