• Journal of Microbiology and Biotechnology
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• v.13 no.1
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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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• v.2 no.4
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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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• v.3 no.2
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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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• v.3 no.2
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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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• v.21 no.6
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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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• v.22 no.10
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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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• v.22 no.11
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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.

• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.267-273
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• 2005

To develop effective and powerful probiotic, Saccharomyces cerevisiae strains producing cellulolytic enzymes were genetically brooded. For the production of exoglucanase, the plasmid pVT-TExo (8.8 kb) was constructed, in which Thermomonosporafusca exoglucanase gene (E3) was under the control of ADHl promoter, and introduced into S. cerevisiae SEY2102. When the transformant, S. cerevisiae SEY2102/pVT-TExo, was cultivated on YPD medium, the total expression level of avicelase reached about 190 unit/l. The secretion efficiency and plasmid stability were about $50\%\;and\;91\%$, respectively. Recombination exoglucanase enzyme bound to avicel better than Clostridium endoglucanase (CelA) and Trichoderma endoglucanase (C4) enzymes. The mixing ratio of E3 and CelA displaying the best synergistic hydrolysis for avicel was observed at 4:1. The mixture of endoglucanase (CelA) and exoglucanase (E3) resulted in 3.2-fold increase of avicelase activity and 2.5-fold enhanced production of sugar production from avicel, compared to the single enzyme treatment.

• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.1-9
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• 2009

The genetic monitoring method was developed for the rapid detection of the PGPR and biocontrol agent, B. subtilis AH18 in red-pepper field soil by multiplex PCR using sid, aec and cel gene primers. The monitoring of B. subtilis AH18 in the soil was carried by amplified a 2,3-dihydro-2,3-dihydroxy benzoate dehydrogenase [EC: 1. 3. 1. 28]gene (sid - 794 bp : EF408238) which is a key enzyme of siderophore synthesis, an auxin efflux carrier gene (aec - 1,052 bp : EF408239) and a cellulase gene (cel - 1,582 bp : EF070194). The natural un sterilized soil was inoculated with B. subtilis AH18 to determine the sensitivity ($1.8\times10^5$ cfu/g) of multiplex PCR for the rapid dectection and then the strain was monitored successfully in rhizosphere or non-rhizosphere soil of red-pepper cultural soil. At 3 weeks after the treatment, density of the strain was monitored more abundantly in rhizosphere soil.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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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.