PM2.5 concentration prediction using deep learning in internet of things air monitoring system

Wei Bai,Fengying Li 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.1

Aiming at the problems of low accuracy and less prediction time step in traditional statistical model for PM2.5 concentration prediction, a PM2.5 concentration prediction method based on deep learning in Internet of Things air monitoring system is proposed. Firstly, the spatiotemporal correlation of each station data in the Internet of Things monitoring system is analyzed, and the cubic spline interpolation method is used to fill in the missing data. Then, the temporal attention of the input data is obtained by attention mechanism, and the feature encoder is used to encode the data to obtain the intermediate features. Finally, the intermediate feature is fused with the historical information of PM2.5 concentration, and the predicted value is obtained through the feature decoder. Using the proposed model to predict the PM2.5 concentration in Beijing, the experimental results show that the long-term PM2.5 predicted value is very close to the real value, and the RMSE and MAE are 17.93 μg/m3 and 11.52 μg/m3, respectively, which are better than other comparison models. So, this model is suitable for multivariable long time series forecasting scenarios.

Evaluation of potassium clavulanate as supplement to selective medium and the effect of incubation conditions for detecting Campylobacter

Bai Wei,Se Yeoun Cha,Ke Shang,Jeong Woo Kang,Hae Chul Park,Kwang Jick Lee,Hyung Kwan Jang 대한수의학회 2016 대한수의학회 학술대회발표집 Vol.2016 No.-

Molecular Basis of Macrolide Resistance in <i> Campylobacter</i> Strains Isolated from Poultry in South Korea

Wei, Bai,Kang, Min Hindawi 2018 BioMed research international Vol.2018 No.-

<P>We investigated the molecular mechanisms underlying macrolide resistance in 38 strains of<I> Campylobacter</I> isolated from poultry. Twenty-seven strains were resistant to azithromycin and erythromycin, five showed intermediate azithromycin resistance and erythromycin susceptibility, and six showed azithromycin resistance and erythromycin susceptibility. Four<I> Campylobacter jejuni</I> and six<I> Campylobacter coli</I> strains had azithromycin MICs which were 8–16 and 2–8-fold greater than those of erythromycin, respectively. The A2075G mutation in the 23S rRNA gene was detected in 11 resistant strains with MICs ranging from 64 to ≥ 512 <I>μ</I>g/mL. Mutations including V137A, V137S, and a six-amino acid insertion (114-VAKKAP-115) in ribosomal protein L22 were detected in the<I> C. jejuni </I>strains. Erythromycin ribosome methylase B-<I>erm</I>(B) was not detected in any strain. All strains except three showed increased susceptibility to erythromycin with twofold to 256-fold MIC change in the presence of phenylalanine arginine ß-naphthylamide (PAßN); the effects of PAßN on azithromycin MICs were limited in comparison to those on erythromycin MICs, and 13 strains showed no azithromycin MIC change in the presence of PAßN. Differences between azithromycin and erythromycin resistance and macrolide resistance phenotypes and genotypes were observed even in highly resistant strains. Further studies are required to better understand macrolide resistance in<I> Campylobacter</I>.</P>

Investigation of surface-piercing fixed structures with different shapes for Bragg reflection of water waves

Wei-Wei Ding,Zao-jian Zou,Jing-Ping Wu,Bai-Gang Huang 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.2

Bragg reflection of water waves by three kinds of surface-piercing fixed structures with rectangular, cosinoidal and triangular shapes is studied. Boundary element method is used to analyze the wave scattering by these structures based on the linear wave theory. Results of reflection and transmission coefficients are validated by comparing with those available in literature. These structures with proper configurations are proved to be effective in attenuating waves by using Bragg reflection, and the triangular structures are found to be the best choices among the structures with same width and same area. Systematic calculations are then carried out for the triangular structures by varying the number, the draft, the width, the gap and the combination of width and gap of the structures to analyze their influences on the characteristics of Bragg reflection. The results are of reference values for design of the structures to attenuate waves based on the Bragg reflection.

Antimicrobial susceptibility of Campylobacter isolates from breeder and broiler flocks in Korea

Bai Wei,Se Yeoun Cha,Min Kang,Jun Feng Zhang,Yong Tack Hong,Jeong Woo Kang,Hae Chul Park,Kwang Jick Lee,Hyung Kwan Jang 대한수의학회 2016 대한수의학회 학술대회발표집 Vol.2016 No.-

Prevalence and pathogenic potential of Campylobacter isolates from wild birds in Korea

Bai Wei,Ran Hee Yoon,Jae Hee Roh,Hye Suk Seo,Jae Young Oh,Min Kang,Se Yeoun Cha,Hyung Kwan Jang 대한수의학회 2015 대한수의학회 학술대회발표집 Vol.2015 No.-

Serum Resistance in Riemerella anatipestifer is Associated with Systemic Disease in Ducks

Bai Wei,Hye-Suk Seo,Ke Shang,Jong-Yeol Park,Yea-Jin Lee,Yu-ri Choi,Sang-Won Kim,Se-Yeoun Cha,Hyung-Kwan Jang,Min Kang 한국가금학회 2021 韓國家禽學會誌 Vol.48 No.4

리메렐라 아나티페스티퍼 감염증은 오리와 거위에서 섬유소성 심막염, 간주위염증, 기낭염, 건락성난관염, 뇌막염을 특징으로 하는 급성 또는 만성 패혈증이다. 이 균은 혈청형 또는 분리주별로 병원성에 큰 차이가 나타나는 것으로 알려져 있다. 그럼에도 불구하고 지금까지 이러한 다양한 병원성과 그 이유에 대한 연구는 거의 이루어지지 않았다. 본 연구에서는 리메렐라 아나티페스티퍼의 병원성과 serum resistance 상관성을 구명하였다. 우리는 다양한 분리원으로부터 확보한 130주의 균주를 대상으로 serum resistance 특성을 분석하였다. 건강한 오리 인후두에서 분리된 균주들은 혈청에 대한 감수성이 높은 반면에 전신감염을 일으킨 균주들은 강한 serum resistance를 보였다. 또한 우리는 이러한 혈청의 살균효과가 혈청내 보체 성분에 의해 유도됨을 확인하였다. 강한 serum resistance를 유발하는 세균의 표면 유전자와의 관련성을 조사한 결과, 외막 단백질의 AS87_09335, AS87_00480, AS87_05195 유전자가 serum resistance와 관련 있음을 알 수 있었다. 본 연구 결과로 serum resistance 특성이 리메렐라 아나티페스티퍼의 병원성 결정 요소 중 하나라는 것을 확인하였다. Riemerella anatipestifer (RA) can cause septicemia, polyserositis, and ataxia in ducks. It can also colonize the upper respiratory tract of healthy ducks. These differences in pathogenicity are probably the result of diverse mechanisms of virulence in different strains. Since serum resistance is a feature frequently found in systemic pathogens, 130 RA strains having different clinical origins were tested. A variety of serum susceptibility levels were detected. Pharynx strains from healthy ducks were mainly susceptible to the bactericidal effect of the serum, while systemic strains were serum resistant. Heat-treatment of the sera abolished the bactericidal activity, indicating that complement is a key factor in this effect. In an attempt to associate serum-resistance to surface determinant genes of the bacteria, we screened for six genes involved in lipopolysaccharide synthesis and membrane proteins in RA. Of these, three genes (AS87_09335, AS87_00480, and AS87_05195) encoding outer membrane proteins might be implicated in serum resistance statistically. The results indicate that serum resistance is a virulence mechanism in RA.

Antiviral activity of Chongkukjang extracts against influenza A virus in vitro and in vivo

Bai Wei,Se-Yeoun Cha,Min Kang,Young Jin Kim,Chang-Won Cho,Young Kyoung Rhee,Hee-Do Hong,Hyung-Kwan Jang 한국식품연구원 2015 Journal of Ethnic Foods Vol.2 No.2

Background: Chongkukjang is a traditional Korean fermented product prepared from soybeans and reported to have multiple biological functions, including antidiabetic, antiinflammatory, and neuroprotective effects. Influenza is a respiratory disease caused by influenza viruses and continues to be a worldwide threat with a high potential to cause pandemics. Besides vaccination, only two classes of drugs are available for antiviral treatment against these pathogens. Methods: We tested the inhibitory activity of an ethyl acetate extract from Chongkukjang toward influenza A virus neuraminidase. Results: All 10 compounds extracted from Chongkukjang showed neuraminidase inhibitory activity. Extracts A3 and A8, with high neuraminidase content, had the best inhibitory activities. The in vivo antiinfluenza virus activities of the ethyl acetate, A3, and A8 extracts as well as commercially available genistein were evaluated using H1N1 (A/NWS/33) to test mice survivability after virus challenge. The Chongkukjang extracts did not reduce mortality, but the A3 and A8 extracts delayed the median time to death after influenza A virus infection of mice. Conclusion: Our results suggest that the Chongkukjang extracts may have potential as a therapeutic agent to treat influenza virus infection.

Antimicrobial Susceptibility Profiles and Molecular Typing of <i>Campylobacter jejuni</i> and <i>Campylobacter coli</i> Isolates from Ducks in South Korea

Wei, Bai,Cha, Se-Yeoun,Kang, Min,Roh, Jae-Hee,Seo, Hye-Suk,Yoon, Ran-Hee,Jang, Hyung-Kwan American Society for Microbiology 2014 Applied and environmental microbiology Vol.80 No.24

<P><I>Campylobacter</I> is a food-borne zoonotic pathogen that causes human gastroenteritis worldwide. <I>Campylobacter</I> bacteria are commensal in the intestines of many food production animals, including ducks and chickens. The objective of the study was to determine the prevalence of <I>Campylobacter</I> species in domestic ducks, and the agar dilution method was used to determine resistance of the isolates to eight antibiotics. In addition, multilocus sequence typing (MLST) was performed to determine the sequence types (STs) of selected <I>Campylobacter</I> isolates. Between May and September 2012, 58 duck farms were analyzed, and 56 (96.6%) were positive for <I>Campylobacter</I>. Among the isolates, 82.1% were <I>Campylobacter jejuni</I>, 16.1% were <I>C. coli</I>, and one was unidentified by PCR. Of the 46 <I>C. jejuni</I> isolates, 87.0%, 10.9%, and 21.7% were resistant to ciprofloxacin, erythromycin, and azithromycin, respectively. Among the <I>C. coli</I> isolates, all 9 strains were resistant to ampicillin, and 77.8% and 33.3% were resistant to ciprofloxacin and azithromycin, respectively. The majority of the <I>Campylobacter</I> isolates were classified as multidrug resistant. Twenty-eight STs were identified, including 20 STs for <I>C. jejuni</I> and 8 STs for <I>C. coli</I>. The most common clonal complexes in <I>C. jejuni</I> were the ST-21 complex and the ST-45 complex, while the ST-828 complex predominated in <I>C. coli</I>. The majority of isolates were of STs noted in ducks and humans from earlier studies, along with seven STs previously associated only with human disease. These STs overlapped between duck and human isolates, indicating that <I>Campylobacter</I> isolates from ducks should be considered potential sources of human infection.</P>

PIAS: Practical Information-Agnostic Flow Scheduling for Commodity Data Centers

Bai, Wei,Chen, Li,Chen, Kai,Han, Dongsu,Tian, Chen,Wang, Hao IEEE 2017 IEEE/ACM transactions on networking Vol.25 No.4

<P>Many existing data center network (DCN) flow scheduling schemes, that minimize flow completion times (FCT) assume prior knowledge of flows and custom switch functions, making them superior in performance but hard to implement in practice. By contrast, we seek to minimize FCT with no prior knowledge and existing commodity switch hardware. To this end, we present PIAS, a DCN flow scheduling mechanism that aims to minimize FCT by mimicking shortest job first (SJF) on the premise that flow size is not known a priori. At its heart, PIAS leverages multiple priority queues available in existing commodity switches to implement a multiple level feedback queue, in which a PIAS flow is gradually demoted from higher-priority queues to lower-priority queues based on the number of bytes it has sent. As a result, short flows are likely to be finished in the first few high-priority queues and thus be prioritized over long flows in general, which enables PIAS to emulate SJF without knowing flow sizes beforehand. We have implemented a PIAS prototype and evaluated PIAS through both testbed experiments and ns-2 simulations. We show that PIAS is readily deployable with commodity switches and backward compatible with legacy TCP/IP stacks. Our evaluation results show that PIAS significantly outperforms existing information-agnostic schemes, for example, it reduces FCT by up to 50% compared to DCTCP [11] and L2DCT [32]; and it only has a 1.1% performance gap to an ideal information-aware scheme, pFabric [13], for short flows under a production DCN workload.</P>