• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.2
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• pp.122-131
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• 2010

This paper introduces the concept of a virtual ecosystem and reports the following three mathematical approaches that could be widely used to construct such an ecosystem, along with examples: (1) a molecular dynamics simulation approach for animal flocking behavior, (2) a stochastic lattice model approach for termite colony behavior, and (3) a rule-based cellular automata approach for biofilm growth. The ecosystem considered in this study consists of artificial organisms and their environment. Each organism in the ecosystem is an agent that interacts autonomously with the dynamic environment, including the other organisms within it. The three types of model were successful to account for each corresponding ecosystem. In order to accurately mimic a natural ecosystem, a virtual ecosystem needs to take many ecological variables into account. However, doing so is likely to introduce excess complexity and nonlinearity in the analysis of the virtual ecosystem's dynamics. Nonetheless, the development of a virtual ecosystem is important, because it can provide possible explanations for various phenomena such as environmental disturbances and disasters, and can also give insights into ecological functions from an individual to a community level from a synthetic viewpoint. As an example of how lower and higher levels in an ecosystem can be connected, this paper also briefly discusses the application of the second model to the simulation of a termite ecosystem and the influence of climate change on the termite ecosystem.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.437-447
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• 2020

The purpose of this study is to research the countermeasures and expected effects through the use of drones in the field of disaster prevention as a drone-based smart quarantine performance method. The environmental, market, and technological approaches to the review of the current quarantine performance task and its countermeasures are as follows. First, in terms of the environment, the effectiveness of the quarantine performance business using drone-based control is to broaden the utilization of forest, bird flu, livestock, facility areas, mosquito larvae, pests, and to simplify and provide various effective prevention systems such as AI and cholera. Second, in terms of market, the standardization of livestock and livestock quarantine laws and regulations according to the use of disinfection and quarantine missions using domestic standardized drones through the introduction of new technologies in the quarantine method, shared growth of related industries and discovery of new markets, and animal disease prevention It brings about the effect of annual budget savings. Third, the technical aspects are (1) on-site application of disinfection and prevention using multi-drone, a new form of animal disease prevention, (2) innovation in the drone industry software field, and (3) diversification of the industry with an integrated drone control / control system applicable to various markets. (4) Big data drone moving path 3D spatial information analysis precise drone traffic information ensures high flight safety, (5) Multiple drones can simultaneously auto-operate and fly, enabling low-cost, high-efficiency system deployment, (6) High precision that this was considered due to the increase in drone users by sector due to the necessity of airplane technology. This study was prepared based on literature surveys and expert opinions, and the future research field needs to prove its effectiveness based on empirical data on drone-based services. The expected effect of this study is to contribute to the active use of drones for disaster prevention work and to establish policies related to them.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.133-141
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• 2013

The objective of this study is to empirically examine the effect that social welfare officials' awareness of welfare, who play the core role in delivering public welfare service, has on their sense of duty value and duty efficiency. The implications this study suggests are as follows; First, this study has a meaning in that it empirically proved the social welfare officials' awareness level of welfare. Second, this study provided the specific theoretical basis for the approaches and alternatives for the need to improve social welfare officials' awareness of welfare and operate the desirable welfare policy and system, by examining the effect that social welfare officials' awareness of welfare has on their sense of duty value and duty efficiency. Third, we can find the political implication from this study that welfare policy should be established and operated toward the direction of enhancing equalization effect of welfare system, and minimizing free ride or hampering the will to work, if we intend to improve social welfare officials' awareness of welfare. Fourth, this study presented the need to improve the work system of social welfare officials, through the fact that the shorter their work period is, the lower sense of welfare, duty value and duty efficiency they have. Based on the study results above, we suggest the activation of studies on social welfare officials' awareness of welfare, the need to regularly educate social welfare officials about welfare policy, system and value, the need to improve social welfare officials' positive awareness of welfare and their duty performance through deciding welfare policy toward the direction of enhancing social equality and equalization, and the need to improve social welfare officials' work system.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.5
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• pp.107-116
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• 2011

In this paper, a traffic adaptive sleep based medium access control (TAS-MAC) protocol for wireless sensor networks (WSNs) is proposed. The protocol aims for WSNs which consist of clustered sensor nodes and is based on TDMA-like schema. It is a typical schedule based mechanism which is adopted in previous protocols such as LEACH and Bit-Map Assisted MAC. The proposed MAC, however, considers unexpected long silent period in which sensor nodes have no data input and events do not happen in monitoring environment. With the simple traffic measurement, the TAS-MAC eliminates scheduling phases consuming energy in previous centralized approaches. A frame structure of the protocol includes three periods, investigation (I), transmission (T), and sleep-period (S). Through the I-period, TAS-MAC aggregates current traffic information from each end node and dynamically decide the length of sleep period to avoid energy waste in long silent period. In spite of the energy efficiency of this approach, the delay of data might increase. Thus, we propose an advanced version of TAS-MAC as well, each node in cluster sends one or more data packets to cluster head during the T-period of a frame. Through simulation, the performance in terms of energy consumption and transmission delay is evaluated. By comparing to BMA-MAC, the results indicate the proposed protocol is more energy efficient with tolerable expense in latency, especially in variable traffic situation.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.63-68
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• 2020

The need for literal education, matching the rapid changes in the media has been increasing in recent years. However, it is true that not enough research has been done on the efficiency of literacy compared to the increasing need. For example, empirical approaches such as studies on the effects of integrated media literacy on youth learning. Thus, this paper took multimedia education, which is different from existing image education, as a subject of research and studied the results of education that fused text and video and sound to teenagers in terms of learning effectiveness. It is an academic quest to see if multimedia education really has positive ㄷ effect for teenagers' learning. As a result of both quantitative and qualitative research as a method of research, multimedia education was concluded to be meaningful in improving learning ability, and based on this, it presented a practical-oriented learner participation education while expanding appearance such as language education through multimedia education. The suggestions for these various education policies will spread to the confidence that multimedia education can be the center of all learning activities as the core of education that achieves an all-round personality, not just an aid to existing education.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.221-226
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• 2016

Production of eco-friendly and biologically harmless materials is strongly required in all industries. In particular, reducing volatile organic compounds in coating processes is extremely important to secure worker's safety. During recent two decades, extensive research works on water-borne polyurethane dispersion (PUD) have been continuously developed as an alternative to solvent-borne polyurethane. However, PUD was shown inferior mechanical properties to the organic solvent-borne polyurethane due to a limit to the molecular weight increase, which resulted in the limit of applications. To overcome this drawback, several approaches have been examined such as polymer blends and thermal/radiation induced crosslinking. Among these methods, the radiation curing system was suitable for industrialization because of the high crosslinking density and fast curing speed. In this study, we overcame the drawback for PUD via introducing benzophenone radiation curable units to PUD. We synthesized PUD films which possessed good dispersion in water for 30 days, increased Tg and Td more than $5^{\circ}C$ after UV curing film as well as improved young's modulus more than double.

• Geophysics and Geophysical Exploration
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• v.1 no.1
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• pp.49-56
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• 1998

Seismic tomography has been widely used as high resolution subsurface imaging techniques in engineering applications. Although most of the techniques have been using travel time inversion, waveform method is being driven forward owing to the progress of computational environments. Although full-waveform inversion method has been known as the best method in terms of model resolving power without high-frequency restriction and weak scattering approximation, it has practical disadvantage that it is apt to get stuck in local minimum if the initial guess is far from the actual model and it consumes so much time to calculate. In this study, 2-D full-waveform inversion algorithm in acoustic medium is developed, which uses result of traveltime tomography as initial model. From the application on synthetic data, it is proved that this approach can efficiently reduce the problem of conventional approaches: our algorithm shows much faster convergence rate and improvement of model resolution. Result of application on physical modeling data also shows much improvement. It is expected that this algorithm can be applicable to real data.

• Genes and Genomics
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• v.40 no.11
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• pp.1169-1180
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• 2018

Cave shrimps from the genera Typhlatya, Stygiocaris and Typhlopatsa (TST complex) comprises twenty cave-adapted taxa, which mainly occur in the anchialine environment. Anchialine habitats may undergo drastic environmental fluctuations, including spatial and temporal changes in salinity, temperature, and dissolved oxygen content. Previous studies of crustaceans from anchialine caves suggest that they have possessed morphological, behavioral, and physiological adaptations to cope with the extreme conditions, similar to other cave-dwelling crustaceans. However, the genetic basis has not been thoroughly explored in crustaceans from anchialine habitats, which can experience hypoxic regimes. To test whether the TST shrimp-complex hypoxia adaptations matched adaptive evolution of mitochondrial OXPHOS genes. The 13 OXPHOS genes from mitochondrial genomes of 98 shrimps and 1 outgroup were examined. For each of these genes was investigated and compared to orthologous sequences using both gene (i.e. branch-site and Datamonkey) and protein (i.e. TreeSAAP) level approaches. Positive selection was detected in 11 of the 13 candidate genes, and the radical amino acid changes sites scattered throughout the entire TST complex phylogeny. Additionally, a series of parallel/convergent amino acid substitutions were identified in mitochondrial OXPHOS genes of TST complex shrimps, which reflect functional convergence or similar genetic mechanisms of cave adaptation. The extensive occurrence of positive selection is suggestive of their essential role in adaptation to hypoxic anchialine environment, and further implying that TST complex shrimps might have acquired a finely capacity for energy metabolism. These results provided some new insights into the genetic basis of anchialine hypoxia adaptation.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.453-463
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• 2019

The purpose of this study was to investigate one-person household its health-related quality of life(HRQOL) using data from the seventh Korea national health and nutrition examination survey(KNHANES Ⅶ-2) 2017. The subjects were 301. The data were analyzed by frequency, descriptive analysis and linear regression analysis using SPSS complex samples Win 25 program. The HRQOL score was 0.92, and 2.5% of the subjects in the pain and discomfort area had severe problems. HRQOL related to the subject was 0.034, 0.039, and 0.031, respectively, when the household income level was lower, the education level was lower than elementary school graduates, and if they did not drink at present. HRQOL was 0.072, 0.065, 0.103, and 0.040 in perceived health status good or moderate, the absence of activity limitation and arthritis, was explained 43.1%. There is a need to develop interdisciplinary approaches with great interest in improving the one-person households HRQOL.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.397-404
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• 2021

This study examined how different types of remote video lectures, which universities are using in earnest now due to the COVID-19 pandemic, impact the academic achievement of learners. Zoom-based remote video lectures were divided into two types-general lecture-centered and group task-oriented-and experimental and control groups were set up accordingly. An achievement test and a questionnaire were conducted to determine how academic achievement differed between these two approaches. The achievement test revealed no significant differences in achievement scores between the two groups. Meanwhile, the questionnaire regarding satisfaction with Zoom-based video lectures indicated that both groups were highly satisfied. Participants in the general lecture-centered type group cited the effect of learning, their instructors' class preparation and attitudes towards the class, and the promotion of participation in learning activities as the causes of their satisfaction, while participants in the task-oriented type group highlighted communication and sharing, the efficiency of group discussions, and the moderate difficulty level of group tasks as the reasons for their satisfaction with the video lectures. Remote video lectures in the untact era are becoming increasingly common, and educators will need to develop various Zoom-based teaching strategies to maximize their efficiency.