• Journal of Digital Convergence
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• v.19 no.6
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• pp.239-250
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• 2021

When considering the introduction of a new technology, it is important to accurately grasp and selectively apply the technical characteristics related to the technology in order to fully utilize the advantages of the technology. In this study, the technical characteristics of high relative importance were analyzed in order to increase the efficiency of new application of blockchain technology by companies. The technical characteristics of the blockchain identified through previous research were reclassified from the perspective of the system hierarchy, and sub-factors of the technical characteristics were derived. In addition, a questionnaire survey on the relative importance of technical characteristics was conducted for internal experts and SI experts using the Analytical Hierarchy Process (AHP) technique. As a result of the analysis, respondents evaluated data protection as the most important factor in the threat of hacking related to security. In addition, it was different that the comparison results of the importance of the technical characteristics between the experts in the company and the SI experts and the priority of the technical characteristics between the expert groups by industry. It is expected that the results of this study will be usefully utilized when using blockchain technology in enterprises in line with the upcoming changes of the 4th industrial revolution. An empirical analysis of the internal and external factors required for adoption of blockchain technology by industry and the effect of technology introduction will be a meaningful study.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.3
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• pp.77-84
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• 2021

In this study, flexural tests of prestressed high strength spun concrete (PHC) piles reinforced with infilled concrete and longitudinal rebars were conducted, where the longitudinal rebar ratio and the presence of sludge formed on the inner surface of PHC pile were set as key test variables. A total of six PHC pile specimens were manufactured, and their flexural behaviors including failure mode, crack pattern, longitudinal strain distribution in a section and end slip between external PHC pile and infilled concrete were measured and discussed in detail. The test results revealed that the flexural stiffness and strength increased as the longitudinal rebar ratio became larger, and that the sludge formed on the inner surface of PHC pile did not show any detrimental effect on the flexural performance. In addition to the experimental approach, this study presents a nonlinear flexural analysis model considering compatibility conditions and strain and stress distributions of the PHC piles and infilled concrete. The rationality of the nonlinear flexural analysis model was verified by comparing it with test results, and it appeared that the proposed model well evaluated the flexural behavior of PHC piles reinforced with infilled concrete and longitudinal rebars with a good accuracy.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.4
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• pp.550-556
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• 2021

The scissor-type rope cutter is the most widely used amongst all kinds of commercially available rope cutters in Korea. In this study, we performed finite element analysis on the scissor-type rope cutter. We determined the structure of the cutter that would ensure its stable operation in various situations involving rope entanglement, and verified its effectiveness by testing it in the lab and in an actual ship. These investigations revealed that when the propeller shaft was not rotated by rope entanglement, the constant torque generated by the engine resulted in the torsion of the rope cutter and maximum deformation in the lower blade, which was not restricted by finite element analysis. With increasing blade thickness, the maximum values of deformation and equivalent stress decreased, resulting in a rise in the safety factor. At the constant blade thickness, the effect of the torque variations on the maximum equivalent stress and the maximum deformation is independent of the position of the external force of the rope cutter and decreases in direct proportion. The results of this study confirmed that the rope-cutter structure determined by analysis could lead to a hassle-free removal of ropes and fishing nets under all conditions and environments.

• Korean Journal of Applied Biomechanics
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• v.31 no.1
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• pp.72-78
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• 2021

Objective: The purpose of this study was to investigate relations and effectiveness about mountain climbling exercise with different level of support surfaces by analyzing heart rate and EMG data. A total of 10 male college students with no musculoskeltal disorder were recruited for this study. Method: The biomechanical analysis was performed using heart rate monitor (Polar V800, Polar Electro Oy, Finland), step-box, exercise mat, and EMG device (QEMG8, Laxtha Inc. Korea, sampling frequency = 1,024 Hz, gain = 1,000, input impedance > 1012 Ω, CMRR > 100 dB). In this research, step-box were used to create different surface levels on the upper body (flat surface, 10% of subject's height, 20% of subject's height, and 30% of subject's hight). Based on these different conditions, data was collected by performing mountain climbing exercise during 30 seconds. Subjects were given 5 minutes of break to prevent muscular fatigue after each exercise. For each dependent variable, a one-way analysis of variance with repeated measures was conducted to find significant differences and Bonferroni post-hoc test was performed. Results: The results of this study showed that exercise intensity was reduced statistically as increased surface level on the upper body. Muscle activity of the upper rectus abdominis and biceps femoris for 30% of surface level was significantly higher than the corresponding values for flat surface. However, the opposite was found in the rectus femoris. In general, muscle activity of the lower rectus abdominis, erector spinae, external oblique abdominis, and gluteus maximus increased when surface level increased, but the differences were not significant. Conclusion: As a result, the increase in surface level of the body would change muscle activity of the upper body, indicating that different surface level of the upper body may cause significant effect on particular muscles to be more active during mountain climbing exercise. Based on results of this study, it is suggested to set up an appropriate surface level to target particular muscle to expect an effective training. It is also important to set adequate surface levels to create an effective training condition for preventing exercise injuries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.446-452
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• 2021

As a higher standard for food consumption is required, the consumption of chicken meat that can satisfy the subdivided food preferences is increasing. In March 2003, the quality criteria for chicken carcasses notified by the Livestock Quality Assessment Service suggested quality grades according to fecal contamination and the size and weight of blood and bruises. On the other hand, it is too difficult for human inspection to qualify mass products, which is key to maintaining consistency for grading thousands of chicken carcasses. This paper proposed the computer vision algorithm as a non-destructive inspection, which can identify chicken carcass parts according to the detailed standards. To inspect the chicken carcasses conveyed at high speed, the image calibration was involved in providing robustness to the side effect of external lighting interference. The separation between chicken and background was achieved by a series of image processing, such as binarization based on Expectation Maximization, Erosion, and Labeling. In terms of shape analysis of chicken carcasses, the features are presented to reveal geometric information. After applying the algorithm to 78 chicken carcass samples, the algorithm was effective in segmenting chicken carcass against a background and analyzing its geometric features.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.32 no.1
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• pp.391-413
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• 2021

Policy study information is the essential source of information in every step of decision making process to plan, execute and assess the national operation policy. The policy study subject of a national policy research center from study design the performance assessment on its practical effect is managed via thorough process to secure its effectiveness and efficiency. However, the directly exposed information to the practical user or the public who are in need of actual policy study information is the resource published in a form of policy study report, the final result. NKIS operated by the National Research Council for Economics, Humanities and Social Sciences under the Office for Government Policy Coordination, Prime Minister's Secretariat is a public information offering service that conduct integrated management on study reports from cooperative study among institutes along with policy outcome from 27 national policy research centers. This study aims to introduce the current status of operation and information management of NKIS, apprehend the management characteristics of policy study information resources of national policy research center, and deduce remarks that need to be considered for API with external service for the derivation of standardized sharing data element.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.171-180
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• 2021

The present study investigated the effects of dynamic tubing gait (DTG II) program on the balancing ability for the promotion of life care of patients with chronic stroke. In the study, 25 sessions of DTG II program (30 minutes per session, 5 sessions per week, for a total of 5 weeks) were applied to 10 patients with chronic stroke. To determine the effects of DTG II program for improving balance, surface electromyography(external oblique, erector spinae, iliopsoas, gluteus maximus), symmetry index test on three pelvic axes, and dynamic gait index test were performed before and after the intervention. The results showed statistically significant differences between preand post-intervention measurements of the gluteus maximus muscle at early and mid-stance phases(p<.05). The pelvic symmetry index differed significantly between pre- and post-intervention measurements of diagonal and rotational movement(p<.05). Comparison of dynamic gait index also showed statistically significant differences between pre- and post-intervention measurements(p<.05). Based on these findings, it was determined that the DTG II program was able to improve the balancing ability of patients with chronic stroke by activating their trunk muscles and improving the symmetry of diagonal pelvic movement and rotation. Therefore, DTG II program is recommended as an interventional method to improve life-care through improving the balancing ability of patients with chronic stroke.

• Journal of Life Science
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• v.32 no.8
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• pp.647-658
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• 2022

Particulate matter (PM) is known to be involved in the onset and progression of various diseases by promoting oxidative and inflammatory reactions as air pollutants containing various small particles that are harmful. In this study, the protective efficacy of herbal medicines was evaluated in human corneal epithelial cells (hCECs) to select natural products that can protect the eye, the primary organ directly exposed to external pollutants from PM. As a result, five candid ate herbal medicines [Cheonmundong, Asparagus Rhizome; Seokchangpo, Aciru Gramineri Rhizoma; Hwangryeon, Coptidis Rhizoma; Gamgug, Chrysanthemi Indici Flos; and Geumjanhwa (Marigold flower petals)] which showed inhibitory efficacy on PM_2.5-induced cytotoxicity, were selected from among 12 candidate herbal medicines. To evaluate the antioxidant activity of these candidate substances, the reactive oxygen species (ROS) scavenging ability was investigated, and it was found that the extracts of Seokchangpo, Cheonmundong and Hwangryeon showed a significant inhibitory effect on PM_2.5-induced ROS production, which was correlated with the preservation of mitochondrial activity. In addition, it was confirmed that they could block DNA damage caused by PM_2.5 through analysis of 8-hydroxy-2'-deoxyguanosine generation and phosphorylated-H2A histone family member X (γ- H2AX) expression. Furthermore, the increase in inflammasome activity and inflammatory response in PM_2.5-treated hCECs was also canceled in the presence of these extracts. Although additional studies are needed, the results of this study will be used as primary data to find novel natural compounds that protect hCECs from PM.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.95-108
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• 2022

The increase in the use time of tunnel users due to the lengthening of the road tunnel may increase the evacuation time in case of fire, resulting in a large number of casualties. In order to reduce the casualties caused by fire, the "Road Tunnel Design Manual, Part 6 Tunnel" and "Road Tunnel Disaster Prevention Facility Installation and Management Guidelines" stipulate that ventilation facilities should be installed along with the extension of the tunnel. The ventilation system design factor considers the wind speed of the external natural wind to be at least 2.5 m/s, and it is applied upward according to the characteristics of the tunnel. As a result of analyzing the five-minute average wind speed data in the Daegwallyeong region for the past 6 years, it was analyzed that 15.8% of the windy days were winds of 10 m/s or more, and the maximum was 20 m/s. Therefore, in this study, when a fire occurs in a tunnel, the pattern of natural wind flowing into the tunnel and the backlayering distance of the tunnel fire smoke according to the maximum wind speed were analyzed. As a result, it was analyzed that a backflow of up to 490 m occurs when a gust of 20 m/s blows.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.156-168
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• 2022

This study was conducted to investigate the staging principle, the staging work and the trial performance of Shingeuk troupe Geukyesulyeonguhoe during the period of coterie system, focusing on Gogol work·Ham Daehoon translation·Hong Haeseong directing's (5Act). As a result, the first trial performance was based on a faithful full-scale description rather than an interpretive directing of play. It was a performance that focused on copying and implanting the external form of the performance stage of Shingeki troupe Tsukiji Little Theater. The general review of the time was summarized to the point that it was a relatively successful performance that exceeded expectations as a trial demonstration of amateur actors. However, in terms of the content of play and the form of performance, reservations and lack of contemporary(modern) interpretation caused the problem that the general audience was alienated. Therefore, it was difficult to achieve the effect of reflecting the reality of Chosun through , as Geukyesulyeonguhoe intended.