A laser scabbling experiment was performed using a high-power fiber laser to investigate the removal rate of the concrete block and the scabbled depth. Concrete specimens with a 28-day compressive strength of 30 MPa were used in this study. Initially, we conducted the scabbling experiment under a stationary laser beam condition to determine the optimum scan speed. The laser interaction time with the concrete surface varied between 3 s and 40 s. The degree of spalling and vitrification on the surface was primarily dependent on the laser interaction time and beam power. Furthermore, thermal images were captured to investigate the spatial and temporal distribution of temperature during the scabbling process. Based on the experimental results, the scan speed at which the optical head moved over the concrete was set to be 300 mm∙min−1 or 600 mm∙min−1 for the 4.8-kW or 6.8-kW laser beam, respectively. The spalling rates and average depth on the concrete blocks were measured to be 87 cm3∙min−1 or 227 cm3∙min−1 and 6.9 mm or 9.8 mm with the 4.8-kW or 6.8-kW laser beams, respectively.

Non-face-to-face lectures have become a necessity rather than an option since COVID-19, and in order to improve the quality of university education, it is necessary to explore the properties of non-face-to-face lectures and make active efforts to improve them. This study, focusing on this, aims to provide basic data necessary for decision-making for non-face-to-face lecture design by analyzing the relative importance and execution satisfaction of non-face-to-face lecture attributes for professors and students. Based on previous research, a questionnaire was constructed by deriving 4 factors from 1st layer and 17 from 2nd layer attributes of non-face-to-face lectures. A total of 180 valid samples were used for analysis, including 60 professors and 120 students. The importance of the non-face-to-face lecture properties was calculated by obtaining the weights for each stratified element through AHP(Analytic Hierachy Process) analysis, and performance satisfaction was calculated through statistical analysis based on the Likert 5-point scale. As a result of the AHP analysis, both the professor group and the student group had the same priority for the first tier factors, but there was a difference in the priorities between the second tier factors, so it seems necessary to discuss this. As a result of the IPA(Importance Performance Analysis) analysis, the professor group selected the level of interaction as an area to focus on, and it was confirmed that research and investment in teaching methods for smooth interaction are necessary. The student group was able to confirm that it is urgent to improve and invest in the current situation so that the system can be operated stably by selecting the system stability. This study uses AHP analysis for professors and students groups to derive relative importance and priority, and calculates the IPA matrix using IPA analysis to establish the basis for decision-making on future face-to-face and non-face-to-face lecture design and revision. It is meaningful that it was presented.

In this study, using the concept of perezhivanie as an analytical tool, we were trying out new ways to investigate L2 identity taking the peripheral educational context into account. We examined how two graduates from non-academic high schools perceived their peripheral school situation through their perezhivanie, and described how this situation affected the individual trajectories of L2 identity development as well. When two students immersed themselves in marginalized classroom contexts, they have experienced academic stigma in the context of classroom community. Moreover, they all experienced emotional conflicts related to English learning. Besides, they struggled over deficit remedial L2 identity, entailing identity tensions. As they attempted to reconcile the contradictions between themselves and their circumstances, their perezhivanie made their social situation of development differently. Depending on how the contradiction was being emotionally experienced through the prism of each student’s perezhivanie, the same contradiction had different meanings, led to different reactions, and had differing impacts on their L2 identity.

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the colon and rectum with intervals of acute exacerbation. Its etiology remains unknown, although recent studies suggest that pro-inflammatory cytokines initiate the inflammatory responses. In this study, we investigated the ameliorative effects of YB-21 (new product containining Lactobacillus plantarum, Barley Bran and Nymphaeaceae) in a dextran sulfate sodium (DSS)-induced colitis in mice. The experimental groups were divided into 6 groups (n = 10) of ICR mice: normal control(NC), DSS-treated(PC, positive control), DSS+latic-L-treated (3×107CFU/ml), DSS+latic-M-treated (3×109CFU/ml), DSS+latic-H-treated (3×1011CFU/ml), and DSS+YB-21-treated. Histological examinations indicated that YB-21 suppressed edema, mucosal damage, and the loss of crypts induced by DSS. Moreover, YB-21 reduced serum level expressions of, tumor necrosis factor-α (TNF-α). These results suggest that YB-21 has an anti-colitic effect by the suppression of intestinal inflammatory responses in DSS-induced colitis in mice.

Unarmored dinoflagellates, in the family Kareniaceae, include harmful or toxic bloom-forming species, which are associated with massive fish kills and mortalities of marine organisms worldwide. The occurrence and distribution of the toxigenic species in the family Kareniaceae were investigated in the brackish and coastal waters of Korea between July 2018 and October 2020. During the survey, we collected seven newly recorded species; Karenia papilionacea, Karlodinium digitatum, Karl. veneficum, Karl. zhouanum, Takayama acrotrocha, T. helix, and T. tasmanica. A total of fifteen strains of the seven taxa were successfully established as clonal cultures and examined using LM, SEM, and molecular phylogeny inferred from LSU rDNA sequences. Herein, we present the taxonomic information, morphological features, and molecular phylogenetic positions of the unrecorded dinoflagellate species collected from Korean coastal waters.

In this paper, following the recent development of optical transmission device equipped with Post-Quantum Cryptography, it proposes to improve the level of defense security system by applying USB security token with Q-PUF USB technology. Although trends of quantum computer development are currently in progress, quantum computer, which have been developed so far, have exceeded the computational capabilities of existing supercomputers. This allows us to easily decode the public certificates and encryption keys. Although the frequency of using public certificates is decreasing due to the abolition of public certificates in May 2020, Republic of Korea Army still uses public certificates for various defense authentication systems. This reality calls for a stronger security systems. Meanwhile, korean technology companies have developed a portable USB security token that can increase security against the use of the quantum computer, and the author suggests the application of it at the defense environment. This report suggests the application of the defense and its expected effectiveness.