• Quantitative Bio-Science
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• v.36 no.1
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• pp.23-31
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• 2017

Datasets from DNA microarray experiments, which are in the form of large matrices of expression levels of genes, often have missing values. However, the existing statistical methods including the principle components analysis (PCA) and Hotelling's t-test are not directly applicable for the datasets having missing values due to the fact that they assume the observed dataset is complete in general. Many methods have been proposed in previous literature to impute the missing in the observed data. Troyanskaya et al. [1] study the k-nearest neighbor (kNN) imputation, Kim et al. [2] propose the local least squares (LLS) method and Rubin [3] propose the multiple imputation (MI) for missing values. To identify differentially expressed genes, we propose a new testing procedure when the missing exists in the observed data. The proposed procedure uses the Stouffer's z-scores and combines the test results of individual imputed samples, which are dependent to each other. We numerically show that the proposed test procedure based on MI performs better than the existing test procedures based on single imputation (SI) by comparing their ROC curves. We apply the proposed method to analyzing a public microarray data.

• Journal of Korean language education
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• v.29 no.3
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• pp.293-324
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• 2018

The purpose of this study was to identify differences in the report assessment patterns of international undergraduate students and instructors. Based on two sample reports, the following differences were confirmed between international students and instructors' assessments of reports. First, instructors and students showed no differences in their assessments of the well-formatted report. However, the two groups exhibited differences in their assessments of the report that was not well formatted in that students evaluated the report more highly than instructors did. Second, instructors and students exhibited notable differences in their assessments of items such as citation, logic, and expression. This may have been because students lacked knowledge on citation methods and the use of grounds for arguments based on citation methods and topics. Third, students and instructors showed differences in their areas of focus when evaluating reports. Instructors mostly focused on the main topics of each report, whereas students focused on supporting details for the main topics. Based on these findings, instructors need to emphasize the following areas in educating international undergraduate students on report writing. First, they should stress proper source citation. They should provide frequent guidance on how to accurately cite sources. Second, they should help students to first think about the overall form and content of their reports. Instructors should emphasize that having a logical overall report structure and content that is relevant to the subject is more important in general than grammar or accuracy of vocabulary.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1184-1192
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• 2019

The influenza A virus is a highly infectious respiratory pathogen that sickens many people with respiratory disease annually. To prevent outbreaks of this viral infection, an understanding of the characteristics of virus-host interaction and development of an anti-viral agent is urgently needed. The influenza A virus can infect mammalian species including humans, pigs, horses and seals. Furthermore, this virus can switch hosts and form a novel lineage. This so-called zoonotic infection provides an opportunity for virus adaptation to the new host and leads to pandemics. Most influenza A viruses express proteins that antagonize the antiviral defense of the host cell. The non-structural protein 1 (NS1) of the influenza A virus is the most important viral regulatory factor controlling cellular processes to modulate host cell gene expression and double-stranded RNA (dsRNA)-mediated antiviral response. This review focuses on the influenza A virus NS1 protein and outlines current issues including the life cycle of the influenza A virus, structural characterization of the influenza A virus NS1, interaction between NS1 and host immune response factor, and design of inhibitors resistant to the influenza A virus.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.59-65
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• 2019

Fusaricidin analogs, produced by Paenibacillus polymyxa, were tested for selective control of a major bloom-forming cyanobacterium, Microcystis sp. Fusaricidin (A and B mixtures) and four analogs were isolated from P. polymyxa E681 and investigated for their inhibition of cyanobacterial cell growth. Among the four fusaricidin analogs, fraction 915 Da (designated as Fus901) showed growth inhibition activity for Microcystis aeruginosa but not for Anabaena variabilis and Scenedesmus acutus. Microcystin concentration decreased up to 70% and its content per cell also decreased over 50% after 3 days. Fusaricidin exhibited growth inhibition against Gram-positive bacteria but Fus901 did not. Molecular weights of fusaricidin A and B were 883 Da and 897 Da, whereas that of Fus901 was 915 Da. Structure analysis by a ring-opening method revealed a linear form for Fus901. Expression of the pod gene related to oxidative stress was increased 2.1-fold by Fus901 and that of mcyD decreased up to 40%. These results indicate that Fus901 exerts oxidative stress against M. aeruginosa. Thus, Fus901 can be used as a selective cyanobactericide without disturbing the ecological system and could help in decreasing the microcystin concentration.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4446-4462
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• 2019

In this paper, we focus on interference cancellation for three-hop cognitive radio networks (CRNs) over Rayleigh fading channels. In CRNs, secondary users (SUs) are allowed to opportunistically utilize the licensed spectrum during the idle time of primary users (PUs) to achieve spectrum sharing. However, the SUs maybe power constrained to avoid interference and cover a very short transmission range. We here propose an interference cancellation scheme (ICS) for three-hop CRNs to prolong the transmission range of SUs and improve their transmission efficiency. In the proposed scheme, a flexible transmission protocol is adopted to cancel the interference at both secondary relays and destinations at the same time. And a closed-form expression for the secondary outage probability over Rayleigh fading channels is derived to measure the system performance. Simulation results show that the proposed scheme can significantly reduce the secondary outage probability and increase the secondary diversity in comparison with the traditional cases.

• The Korean Journal of Food & Health Convergence
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• v.6 no.6
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• pp.17-23
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• 2020

The main task of agro-industrial production is to provide the population with food products for the production of which energy is expended in the form of electricity, technical means, fuels and lubricants, mineral fertilizers, etc. Accordingly, we have developed a concept and general methodological principles for the analysis of ecological and biotechnical systems in animal husbandry, it makes it possible to simulate the influence of various factors on the energy and ecological efficiency of systems, to compare and search for energy-saving modes and technologies. General methodological principles have been developed for the analysis of energy efficiency and environmental safety of agricultural ecological and biotechnical systems, which are based on the definition of the bioenergy efficiency coefficient, the quantitative expression of which is the ratio of energy accumulated in products to the total energy consumption for its production. This makes it possible to model with sufficient accuracy the influence of various factors on the energy and environmental efficiency of the system, to compare and search for energy-saving modes and technologies in order to find and select the most energy efficient ones to increase the energy efficiency of the complex.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.513-522
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• 2021

The current research aims to explore which type of identity-based message can be more persuasive for Chinese consumers to form positive restaurant brand attitude based on their cultural orientation, and to examine the roles of brand objective relevance and psychological power state in the persuasive process. The study employs a 2(identity expression focus: warmth vs. competence) × 2(message description manner: identity-defining vs. identity-referencing) × 2(experienced power state: high vs. low) between-subjects design, and conducts an online survey where 240 Chinese participants in total has responded to the questionnaires. SPSS and AMOS programs have been used to examine the hypotheses. The findings suggest that, first, the warmth-focused messages (identity-defining messages) more positively affected Chinese consumers' object relevance than the competence-focused messages (identity-referencing messages); Second, high power-experienced Chinese consumers rather than low power consumers tend to perceive more object relevance at the warmth self-defining messages; Third, brand object relevance revealed a mediation effect in the process of the warmth-focused messages (identity-defining messages) affecting brand attitude. This research offers new insight into the relationships between consumers' cultural orientation, understandings of power, and identity-based consumer behavior, suggesting marketers should take those social influences and consumer diversities into account when developing the message to persuade consumers.

• International journal of advanced smart convergence
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• v.9 no.4
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• pp.34-41
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• 2020

Nowadays, the advanced smart convergences of the artificial intelligence (AI) and the internet of things (IoT) have been more and more important, in the fifth generation (5G) and beyond 5G (B5G) mobile communication. In 5G and B5G mobile networks, non-orthogonal multiple access (NOMA) has been extensively investigated as one of the most promising multiple access (MA) technologies. In this paper, we investigate the achievable data rate for the asymmetric binary pulse amplitude modulation (2PAM), in non-orthogonal multiple access (NOMA). First, we derive the closed-form expression for the achievable data rate of the asymmetric 2PAM NOMA. Then it is shown that the achievable data rate of the asymmetric 2PAM NOMA reduces for the stronger channel user over the entire range of power allocation, whereas the achievable data rate of the asymmetric 2PAM NOMA increases for the weaker channel user improves over the power allocation range less than 50%. We also show that the sum rate of the asymmetric 2PAM NOMA is larger than that of the conventional standard 2PAM NOMA, over the power allocation range larger than 25%. In result, the asymmetric 2PAM could be a promising modulation scheme for NOMA of 5G systems, with the proper power allocation.

• Food Science and Industry
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• v.50 no.1
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• pp.26-35
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• 2017

Obesity is a worldwide problem that is associated with metabolic disorders. Obesity is caused by the accumulation of an abnormal amount of body fat in adipose tissue. Adipose tissue is a major metabolic organ, and it has been classified as either white adipose tissue (WAT) or brown adipose tissue (BAT). WAT and BAT are characterized by different anatomical locations, morphological structures, functions, and gene expression patterns. WAT is mainly involved in the storage and mobilization of energy in the form of triglycerides. On the other hand, BAT specializes in dissipating energy as heat through uncoupling protein-1 (UCP-1)-mediated non-shivering thermogenesis. Novel type of brown-like adipocyte within WAT called beige/brite cells was recently discovered, and this transdifferentiation process is referred to as the "browning" or "britening" of WAT. Recently, Brown fat and/or browning of WAT have been highlights as a new therapeutic target for treatment of obesity and its related metabolic disorders. Here, we describe recent advances in the study of BAT and browning of WAT, focusing on proteomic approaches.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.1
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• pp.79-85
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• 2021

α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors are differentially regulated in the nucleus accumbens (NAcc) of the brain after cocaine exposure. However, these results are supported only by biochemical and electrophysiological methods, but have not been validated with immunohistochemistry. To overcome the restriction of antigen loss on the postsynaptic target molecules that occurs during perfusion-fixation, we adopted an immersion-fixation method that enabled us to immunohistochemically quantify the expression levels of the AMPA receptor GluA1 subunit in the NAcc. Interestingly, compared to saline exposure, cocaine significantly increased the immunofluorescence intensity of GluA1 in two sub-regions, the core and the shell, of the NAcc on withdrawal day 21 following cocaine exposure, which led to locomotor sensitization. Increases in GluA1 intensity were observed in both the extra-post synaptic density (PSD) and PSD areas in the two sub-regions of the NAcc. These results clearly indicate that AMPA receptor plasticity, as exemplified by GluA1, in the NAcc can be visually detected by immunohistochemistry and confocal imaging. These results expand our understanding of the molecular changes occurring in neuronal synapses by adding a new form of analysis to conventional biochemical and electrophysiological methods.