• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.35-42
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• 2003

A 1,3 kb cellulase gene encoding novel bifunctional cellulase-chitosanase activity was cloned from biopolymer-producing alkali-tolerant B. lichenformis NBL420 in E. coli. A recombinant cellulase-chitosanase, named CelA, was expressed and purified to homogeneity. The activity staining and the enzymatic characterization of the purified CeIA revealed bifunctional activities on carboxymethyl cellulose (CMC) and glycol-chitosan. The similar characteristics of the enzymatic activities at the optimum pH, optimum temperature, and thermostability Indicated that CelA used a common catalytic domain with relaxed substrate specificity. A comparison of the deduced amino acids in the N-terminal region revealed that the mature CelA had a high homology with the previously identified bifunctional cellulase-chitosanase of Myxobacter sp. AL- 1.

• Journal of information and communication convergence engineering
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• 제2권4호
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• pp.228-232
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• 2004

This paper proposes an efficient detection algorithm, which is composed of an interference nulling-and cancelling-based detection algorithm and a maximum likelihood (ML) detection algorithm having reduced numbers of signal points to be tested, for the quasi-orthogonal space-time code with four transmit antennas. When high-level modulation schemes are employed, the algorithm enables the quasi-orthogonal code to achieve near ML performance with a significant reduction in the computational load.

• Journal of information and communication convergence engineering
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• 제3권2호
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• pp.76-79
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• 2005

In this paper, a low-complexity maximum-likelihood (ML) decoder based on QR decomposition, called real-valued LCMLDec decoder or RVLCMLDec for short, is proposed for the Vertical Bell Labs Layered Space-Time (V-BLAST) architecture, a promising candidate for providing high data rates in future fixed wireless communication systems [1]. Computer simulations, in comparison with other detection techniques, show that the proposed decoder is capable of providing the V­BLAST schemes with ML performance at low detection complexity

• Journal of information and communication convergence engineering
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• 제3권2호
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• pp.72-75
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• 2005

In this work, we first present our study on the decoding schemes for space-time block code as well as our comments on their complexity. Then, we propose a new modified complex sphere decoding scheme, which has lower computational load than that of conventional complex sphere decoders. In the proposed scheme, the boundary for searching is aided with the intersection of approximate polygon of searching circle and disk of constellation. Therefore, the proposed scheme can reduce the searching boundary while can avoid missing searching points. The performance of the proposed scheme is verified by computer simulation that consolidates our scheme.

• International Journal of Computer Science & Network Security
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• 제21권6호
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• pp.71-76
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• 2021

Education is one of the pillars of sustainable development. For this reason, the discovery of useful information in its process of adaptation to new challenges is treated with care. This paper aims to present the initiation of a process of exploring the data collected from the results obtained by Romanian students at the BBaccalaureate (the Romanian high school graduation) exam, through data mining methods, in order to try an in-depth analysis to find and remedy some of the causes that lead to unsatisfactory results. Specifically, a set of public data was collected from the website of the Ministry of Education, on which several classification methods were tested in order to find the most efficient modeling algorithm. It is the first time that this type of data is subjected to such interests.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.43-50
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• 2022

The students' feedback is important to measure and improve teaching performance. Many teacher performance evaluation systems are based on responses to closed question, but the free text answers can contain useful information which had to be explored. In this paper we present a lexicon-based sentiment analysis to explore students' text feedback. The data was collected from a system for the evaluation of teachers by students developed and used in our university. The students comments are in Romanian language so we built a Romanian sentiment word lexicon. We used this to categorize the feeback text as positive, negative or neutral. In addition, we added a new polarity - indifferent - in order to categorize blank and "I don't answer" responses.

• International Journal of Computer Science & Network Security
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• 제22권11호
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• pp.381-389
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• 2022

With the collection of huge volumes of text, image, audio, video or combinations of these, in a word multimedia data, the need to explore them in order to discover possible new, unexpected and possibly valuable information for decision making was born. Starting from the already existing data mining, but not as its extension, multimedia mining appeared as a distinct field with increased complexity and many characteristic aspects. Later, the concept of big data was extended to multimedia, resulting in multimedia big data, which in turn attracted the multimedia big data mining process. This paper aims to survey multimedia data mining, starting from the general concept and following the transition from multimedia data mining to multimedia big data mining, through an up-to-date synthesis of works in the field, which is a novelty, from our best of knowledge.

• 한국미생물·생명공학회지
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• 제33권4호
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• pp.267-273
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• 2005

효과적이고 강력한 효모 생균제를 개발하기 위해, Saccharomyces cerevisiae 균주들 에서 섬유소 분해효소를 유전공학적 방법으로 생산하였다. Thermomonospora fusca 유래의 exoglucanase유전자(E3)를 구성적 ADHl promoter 하류에 subcloning하여 구성적 발현계인 plasmid pVT-TE태(8.8 kb)를 제작하였고, 이를 S. cerevisiae 숙주세포 SEY2102에 형질전환 시켜, YPD에서 배양한 결과, 총 생산된 exoglucanase의 avicelase 활성은 190 unit/l에 도달하였고, 분비효율은 $50\%$, plasmid 안정성은 $91\%$로 나타났다. 재조합 exoglucanase의 양은 Clostridium endoglucanase(CelA)와 Trichoderma endoglucanase(C4) 보다 더 높은 avicel 결합능을 나타냈다. 각 혼합비에 대한 avicel분해에 대한 상승효과와 당 생성은, E3와 CelA의 흔합비가 4:1일 때 가장 좋은 포도당 생성이 관찰되었으며 , endoglucanase(CelA)와 exoglucanase(E3)의 혼합물은, 단독으로 처리했을 때보다, 포도당의 생산은 2.5배 향상되었고, avicelase활성은 결과적으로 3.2배 증가하였다.

• 한국미생물·생명공학회지
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• 제37권1호
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• pp.1-9
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• 2009

식물성장촉진물질인 auxin을 비롯한 식물병원성진균을 방제하는 siderophore 그리고 식물병원성 진균의 세포벽을 분해하는 cellulase를 동시에 생산하는 생물방제균주 B. subtilis AH18의 토양내 monitoring을 위하여 각 생산물질에 관여하는 유전자를 기초로 primer(sid, aec, cel)를 제작하였다. Single PCR 및 multiplex PCR을 수행하여 800-bp(sid), 1000-bp(air), 1600-bp(cel)의 DNA fragment를 확인하였으며, 각각의 fragment는 siderophore의 생합성 key enzyme인 2,3-dihydro-2,3-dihydroxy benzoate dehydrogenase[EC : 1. 3. 1, 28]gene (sid-794bp)이며, auxin efflux carrier gene (aec - 1052 bp), 그리고 cellulase gene(cel - 1582 bp)임을 확인하고, NCBI Genbank에 등록하였다(Genbank accession sid: No. EF408238, aec: No. EF408239, cel: No. EF070194). 또한 B. subtilis AH18을 처리한 일반 경작지 토양에서 multiplex PCR을 통하여 3종의 유전자에서 증폭된 triple band를 확인하였으며, 고추를 실제 토양을 이용해 Pot에 이식 후 고추의 rhizosphere와 non-rhizosphere에서 B. subtilis AH18의 존재를 확인할 수 있다. 뿐만아니라 본 균주를 고추가 이식된 Pot의 토양에 처리 후 monitoring시 민감도는 $1.8\times10^5$ cfu/g이었고, monitoring 가능한 기간은 3주이상 확인 할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제28권7호
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• pp.1078-1085
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• 2018

A salt-tolerant cellulase secreted by a marine Bacillus sp. SR22 strain with wide resistance to temperature and pH was purified and characterized. Its approximate mass was 37 kDa. The endoglucanase, named as Bc22Cel, was purified by ammonium sulfate precipitation, gel filtration chromatography, and extraction from the gel after non-reducing sodium dodecyl sufate-polyacrylamide gel electrophoresis. The optimal pH value and temperature of Bc22Cel were 6.5 and $60^{\circ}C$, respectively. The purified Bc22Cel showed a considerable halophilic property, being able to maintain more than 70% of residual activity even when pre-incubated with 1.5 M NaCl for 1 h. Kinetic analysis of the purified enzyme showed the $K_m$ and $V_{max}$ to be 0.704 mg/ml and $29.85{\mu}mol{\cdot}ml^{-1}{\cdot}min^{-1}$, respectively. Taken together, the present data indicate Bc22Cel as a potential and useful candidate for industrial applications, such as the bioconversion of sugarcane bagasse to its derivatives.