• Journal of the Korean Society of Radiology
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• v.16 no.6
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• pp.719-725
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• 2022

This study aimed to measure, quantitatively evaluate, and set the criteria for the minimum lead(Pb) shield thickness per level of clinically applied electron beam energy. The lead shield thickness per electron beam energy was measured using the primary field 95% reduction based on the open field at the depth of maximum dose (d_max) and depth from the surface as the reference depth of tissue dose(10 mm). The measured values were 1.906 mmPb and 1.992 mmPb at the d_max and 10 mm, respectively, regarding the lead shield thickness for 6 MeV electron beam; 2.746 mmPb and 3.743 mmPb for 9 MeV electron beam, 3.718 mmPb and 6.093 mmPb for 12 MeV electron beam, 7.300 mmPb and 15.270 mmPb for 16 MeV electron beam, and 16.825 mmPb and 25.090 mmPb for 20 MeV electron beam. Consequently, a thicker lead shield was required if the measurement was at 10 mm. The required lead shield thickness was also higher than that of the theoretical formula for electron beams of ≥ 16 MeV.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.81-93
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• 2022

There are many natural hot springs and mineral springs as well as the cultural heritage of the three kingdoms period in the Geum River basin including Chungcheong region. No specific regeneration and publicity plans for deteriorated facilities in this area has been presented. This study aims to suggest promising hot spots and complex water culture belt in the Chungcheong region and Geum River basin through the spatial interpretation of resources. The northern part of the Geum River basin is expected to become a therapeutic spring belt with many hot springs and CO₂-rich springs. In the central and southern parts of the Geum River basin, it is considered that it will be possible to promote convergence publicity by using groundwater resources and cultural assets.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.599-608
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• 2022

There has been criticism that the government-led makerspace did not reflect the actual demand of makers, so there was a limit to performance creation. In this regard, the study aims to diagnose the current status and problems of makerspace and to suggest the implication to respond to policy demand. To this end, we analyzed the current status of makerspace by utilizing the government documents. Then, we conducted a survey of SMEs related to ICT devices that experienced makerspace, and analyzed their opinions on D·N·A technology demand, management difficulties, and governments' support policies. As results, the study proposed several improvement measures to upgrade makerspace as a digital conversion platform as follows. First, due to the nature of the existing industry for introducing D·N·A technology, there is a limit for companies to enter the market on their own, so comprehensive support from the government is needed. Second, it is necessary to establish and expand an empirical test bed for the development of new products and services so that various types of metaverse contents can be discovered and digital transformation convergence models of existing businesses can be derived. Third, by modifying the support method to operate the makerspace as a platform that implements the government-led start-up support policy, boldly transfer what the private sector can do well to the private sector. The participants of Industry·University·Institute Collaboration should freely share ideas and help the common problem be solved. Based on the problems and the findings for improvement, it is expected that the current makerspace would be upgraded to a digital conversion platform suitable for the demand of the field.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.643-659
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• 2022

Geologic sequestration technologies such as CCS (carbon capture and storage), EGS (enhanced geothermal systems), and EOR (enhanced oil recovery) have been widely implemented in recent years, prompting evaluation of the mechanical stability of storage sites. As fluid injection can stimulate mechanical instability in storage layers by perturbing the stress state and pore pressure, poroelastic models considering various injection scenarios are required. In this study, we calculate the pore pressure, stress distribution, and vertical displacement along a surface using commercial finite element software (COMSOL); fault slips are subsequently simulated using PyLith, an open-source finite element software. The displacement fields, are obtained from PyLith is transferred back to COMSOL to determine changes in coseismic stresses and surface displacements. Our sequential use of COMSOL-PyLith-COMSOL for poroelastic modeling of fluid-injection and induced-earthquakes reveals large variations of pore pressure, vertical displacement, and Coulomb failure stress change during injection periods. On the other hand, the residual stress diffuses into the remote field after injection stops. This flow pattern suggests the necessity of numerical modeling and long-term monitoring, even after injection has stopped. We found that the time at which the Coulomb failure stress reaches the critical point greatly varies with the hydraulic and poroelastic properties (e.g., permeability and Biot-Willis coefficient) of the fault and injection layer. We suggest that an understanding of the detailed physical properties of the surrounding layer is important in selecting the injection site. Our numerical results showing the surface displacement and deviatoric stress distribution with different amounts of fault slip highlight the need to test more variable fault slip scenarios.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.134-146
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• 2022

BACKGROUND/OBJECTIVES: Accumulating evidence has shown the beneficial effects of isoflavone on health. There is limited information on the usual isoflavone intake for Koreans. This study examined the usual intake of total isoflavone and its major food sources in Koreans according to age and gender. SUBJECTS/METHODS: The dietary intake data of 21,271 participants aged 1 yrs and older from the Korea National Health and Nutrition Examination Survey (KNHANES) VII 2016-2018 were analyzed. The average isoflavone intake was estimated based on the 24-h dietary recall data in KNHANES and the isoflavone database from the Korea Rural Development Administration (RDA) and literatures. The usual isoflavone intake was estimated by applying the ratio of within- and between-participant variance estimated from the 2009 KNHANES data to the 7th KNHANES (2016-2018) data. The variance of the isoflavone intake was calculated using MIXTRAN macro with intake data for two days in the 2009 KNHANES. Complex sample analysis with stratified variables and integrated weights was conducted. RESULTS: The mean total isoflavone intake in the Korean population aged 1 yrs and older (n = 21,271) was 139.27 mg/d, which was higher than the usual intake of 47.44mg/d. Legumes were a major contributing food group (91%), with arrowroot being a major individual contributor to the isoflavone intake (67.2%), followed by 21.3% of soybean, 5.4% of bean sprouts, and 2.1% of tofu. The usual isoflavone intake was highest in the participants aged 50 to 64 yrs old and increased with age until 50 to 64 yrs and then decreased with further increases in age. The usual isoflavone intake of participants aged 65 yrs and older was higher for men than for women, showing gender differences. CONCLUSIONS: The usual dietary intake of isoflavone varied according to age and gender in the Korean population. This study showed that the usual isoflavone intake was lower than the average isoflavone intake. The difference between percentiles of the usual isoflavone intake was similarly smaller than the average intake. An estimation of average intake can be hindered by the occasional consumption of foods high in isoflavones, suggesting that the usual intake estimation method can be more appropriate. Further research will be needed to establish isoflavone dietary guidelines regarding the effects of isoflavone intake on health outcomes.

• Science of Emotion and Sensibility
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• v.25 no.2
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• pp.79-86
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• 2022

With external air pollution forcing many people indoors, new methods of facilitating healthier indoor life are necessary. This study, therefore, investigates the effects of indoor oxygen concentration and respiration methods on biosignals and cognitive ability. The study included twenty healthy subjects who inhaled air through a mask from a gas delivery system. All subjects were asked to perform three types of breathing (nasal, oral, and oral breathing with high oxygenation) and respond to cognitive stimuli (rest close eye, rest open eye, 1-back and 2-back working memory tasks). The changes in cognitive load according to respiration were analyzed by measuring response time, accuracy, and biosignals to stimuli. The result showed that, in all three respirations, heart rate significantly increased with the increase in cognitive load. Also, in oral respiration, the airway respiration rate significantly increased according to the increase in cognitive load. The change appeared to compensate for insufficient oxygen supply in oral respiration during cognitive activity. Conversely, there was no significant change in airway respiration rate during oral respiration with a high concentration oxygen supply as in nasal respiration. This result suggests that a high concentration oxygen supply might play a role in compensating for insufficient oxygen concentration or inefficient oxygen inhalation, such as oral respiration. Based on the results of this study, a follow-up study is necessary to determine the impact of changes in the autonomic nervous system, such as stress and emotions, to find out more precise and comprehensive effects of oxygen concentration and breathing type.

• Journal of the Korea Society for Simulation
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• v.19 no.4
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• pp.291-299
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• 2010

As recent advances in science, technology and performance requirements of the weapons system are getting highly diversified and complex, the performance requirements also get stringent and strict. Moreover, the weapons system should be intimately connected with other systems such as watchdog system, command and control system, C4I system, etc. However, a tremendous amount of time, cost and risk being spent to acquire new weapons system, and not being diminished compared to the rapid pace of its development speed. Defense Modeling and Simulation(M&S) comes into the spotlight as an alternative to overcoming these difficulties as well as constraints. In this paper, we propose the development process of virtual test framework based on the synthetic environment as a tool to analyze the effectiveness of the weapons system of underwater engagement model. To prove the proposed concept, we develop the test-bed of virtual test using Delta3D simulation engine, which is open source S/W. We also design the High Level Architecture and Real-time Infrastructure(HLA/RTI) based Federation for the interoperation with heterogeneous simulators. The significance of the study entails (1)the rapid and easy development of simulation tools that are customized for the Korean Theater of War; (2)the federation of environmental entities and the moving equations of the combat entities to manifest a realistic simulation.

• Journal of Korean Philosophical Society
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• no.126
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• pp.85-115
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• 2019

With the dramatic development of science and technology since the twentieth century, attempts to overcome human's natural and physical limitations through technology have actually reached a peak. Transhumanism is a movement that strongly affirms these human technological attempts. However, this optimistic belief of transhumanism in technology meets the strong resistance of opponents contending that transhumanism might destroy human nature and severely undermine human values and rights. The focus of the transhumanism debate lies in what technology means to humans. However, in order to exactly grasp the essence of transhumanism, we should first consider our 'life-world', where technology and humans are closely intertwined. The word 'life-world(Lebenswelt)' which originally comes from Husserl, is an open and universal world as a horizon that is the basis of all human practical activities and at the same time encompasses its products in itself. According to Husserl, the process of incorporating human products into the life-world is a kind of 'familiarization' process through which specific theories and techniques are harmonized with our lives in the life-world. Such harmonization and familiarization of technology could be also considered a humanization of technology. It is a process in which technology is assimilated and corresponds to the finiteness of human and the life-world. In this sense, we could say that the transhumanistic attempts are just a natural expression of human desire to be perfect in the life-world and that they should not be overly concerned or overestimated.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.35-46
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• 2005

This research was conducted to improve and establish Bokto direct seeding technology use of silicate in rice. Bokto direct seeding technology has recently released to alternative new method for transplanting method of the rice plant. In recent rice production has serious problem due to higher cost and labor shortage in Korea. In particular rice has been faced on open market to internationally due to WTO, FTA agreement etc. Thus rice growers in Korea have been more concentrated on cost reduction using by direct seeding technology such as dry seeding and water seeding while those methods have severe constraints like poor seedling, more weed occurrence, lodging and poor grain quality. In recent a new technology for improvement of these problem has released to farmer's field and proven to alternative rice growing technology of transplanting. In this technology there was additional application of silicate which has known as soil improvement and this research was obtained in the following results. At the application of silicate, sand, and soil there was high in seedling establishment by 90~100% in pot experiment but there was 55.0% seedling stand of the untreated control. Under dry condition seedling stand was 0% at the untreated control while 65~100% high in application of silicate, sand, and soil. Meanwhile, under rainy condition untreated control there was 85% of seedling stand but soil application was 20% of seedling establishment due to blocking of oxygen and physical soil blockage.

• Journal of Service Research and Studies
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• v.12 no.4
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• pp.30-49
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• 2022

Recently, as the transition to the untact era due to COVID-19 accelerates, non-face-to-face and non-contact practices have become commonplace, and the OTT (Over-The-Top) service market that provides media content such as movies and broadcast programs through the open Internet is largely expanded and it is receiving great attention from the MZ generation, who are familiar with digital devices and environments. In this study, the effects of OTT service characteristics on MZ generation users' flow, satisfaction and brand loyalty were examined, focusing on Netflix users, one of the representative OTT service brands. In order to carry out this study, a total of 216 people who have used the Netflix OTT service platform were empirically verified by using the survey data of those who have used it for analysis. As a result of the analysis, it was found that among the characteristics of OTT service, contents diversity, convenience, and reliability had a positive (+) effect on flow. Also, flow has a positive (+) effect on satisfaction, and satisfaction has a positive (+) effect on brand loyalty. However, among the characteristics of the OTT service, the recommended service did not have a positive (+) effect on the flow, and the flow did not have a direct positive (+) effect on the brand loyalty. Flow had a positive (+) effect on the brand loyalty through satisfaction. Through this study, it is expected that the market revitalization of the OTT service-related industry and the increasing number of OTT service brands will be able to contribute to the establishment of marketing strategies for the MZ generation consumers, and to provide practical implications.