• Journal of Digital Convergence
• /
• v.20 no.2
• /
• pp.203-215
• /
• 2022

The study is to investigate research trends and knowledge structures in the Smart Farm field. To achieve the research purpose, keywords and the relationship among keywords were analyzed targeting 104 Korean academic journals related to the Smart Farm in KCI(Korea Citation Index), and topics were analyzed using the LDA Topic Modeling technique. As a result of the analysis, the main keywords in the Korean Smart Farm-related research field were 'environment', 'system', 'use', 'technology', 'cultivation', etc. The results of Degree, Betweenness, and Eigenvector Centrality were presented. There were 7 topics, such as 'Introduction analysis of Smart Farm', 'Eco-friendly Smart Farm and economic efficiency of Smart Farm', 'Smart Farm platform design', 'Smart Farm production optimization', 'Smart Farm ecosystem', 'Smart Farm system implementation', and 'Government policy for Smart Farm' in the results of Topic Modeling. This study will be expected to serve as basic data for policy development necessary to advance Korean Smart Farm research in the future by examining research trends related to Korean Smart Farm.

• Journal of Broadcast Engineering
• /
• v.27 no.6
• /
• pp.848-859
• /
• 2022

This paper presents a novel 360-degree video streaming system for large-scale immersive displays and its ongoing implementation. Recent VR systems aim to provide a service for a single viewer on HMD. However, the proposed 360-degree video streaming system enables multiple viewers to explore immersive contents on a large-scale immersive display. The proposed 360-degree video streaming system is being developed in 3 research phases, with the final goal of providing 6DoF. Currently, the phase 1: implementation of the 3DoF 360-degree video streaming system prototype is finished. The implemented prototype employs subpicture-based viewport-dependent streaming technique, and it achieved bit-rate saving of about 80% and decoding speed up of 543% compared to the conventional viewport-independent streaming technique. Additionally, this paper demonstrated the implemented prototype on UCSB AlloSphere, the large-scale instrument for immersive media art exhibition.

• Journal of the Korean Wood Science and Technology
• /
• v.32 no.1
• /
• pp.17-27
• /
• 2004

Cholesterol inhibitory activity was investigated to develop the functional food from edible forest resources such as Allium victorialis var. platyphyllum and other 12 species. Among tested samples by enzyme-linked immunosorbant assay (ELISA), leaf extracts of A. victorialis var. platyphyllum inhibited 73.9% of the activities of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) which is the highly regulated and major rate-limiting of the cholesterol biosynthesis pathway. Moreover, those extracts inhibited 76.7% of squalene synthase which catalyzes the head-to-head condensation of two farnesyl pyrophosphate molecules to form squalene in the biosynthesis of cholesterol. In order to find out the compounds which would play a key role in inhibitory activity of cholesterol, kaempferol and quercetin were isolated from the dichloromethane soluble fraction of extracts of A. victorialis var. platyphyllum. Kampferol, quercetin and each soluble fraction was also subjected to the test of the mRNA expression of HMG-CoA reductase and squalene synthase by reverse transcriptase-polymerase chain reaction (RT-PCR) assay, respectively. By treating both enzymes with 10 ㎍/㎖ of kaempferol and quercetin for 24 hours, respectively, the mRNA expression was not observed, suggesting that both compounds inhibited the biosynthesis of cholesterol at mRNA level. In this regard, it could be inferred that cholesterol inhibitory activity of A. victorialis var. platyphyllum was derived from kaempferol and quercetin. Both compounds have already been found in many plant extracts including hardwood and softwood, but it might be first known that they have cholesterol inhibitory activity.

• Composites Research
• /
• v.35 no.2
• /
• pp.115-119
• /
• 2022

The performance of carbon fiber is important for the production of these high-quality polymer composite materials such as CFRP (Carbon Fiber Reinforced Plastic). For this purpose, it is essential to use an optimized spinning process for improving the mechanical, physical, and structural properties of the precursor fiber, which greatly affects the properties of the carbon fiber, and the use of a suitable precursor polymer. In this study, the content of MAA (Methacrylic Acid), MAA injection time, and concentration of AIBN (2,2'-Azobis(2-methylpropionitrile)) were set as parameters for the polymer synthesis process, and Poly(AN-co-MAA) (poly(acrylonitrile-co-methacrylic acid)) was polymerized by solution polymerization. Poly(AN-co-MAA) with a molecular weight of 305,138 g/mol and an MAA ratio of 4.2% was dissolved in DMF (N,N-dimethylformamide) at a concentration of 16.0 wt%, and then a precursor fiber was prepared through dry-jet-wet spinning. The precursor fiber had a tensile strength of ~1.06 GPa and a tensile modulus of ~22.01 GPa, and no voids and structural defects were observed on the fiber.

• Composites Research
• /
• v.34 no.6
• /
• pp.357-372
• /
• 2021

The energy harvesting device is known to be promising as an alternative to solve the resource shortage caused by the depletion of petroleum resources. In order to overcome the limitations (environmental pollution and low mechanical properties) of piezoelectric elements capable of converting mechanical motion into electrical energy, many studies have been conducted on a polymer matrix-based composite piezoelectric energy harvesting device. In this paper, the output performance and related applications of the reported piezoelectric composites are reviewed based on the applied materials and processes. As for the piezoelectric fillers, zinc oxide, which is advantageous in terms of eco-friendliness, biocompatibility, and flexibility, as well as ceramic fillers based on lead zirconate titanate and barium titanate, were reviewed. The polymer matrix was classified into piezoelectric polymers composed of polyvinylidene fluoride and copolymers, and flexible polymers based on epoxy and polydimethylsiloxane, to discuss piezoelectric synergy of composite materials and improvement of piezoelectric output by high external force application, respectively. In addition, the effect of improving the conductivity or the mechanical properties of composite material by the application of a metal or carbon-based secondary filler on the output performance of the piezoelectric harvesting device was explained in terms of the structure of the composite material. Composite material-based piezoelectric harvesting devices, which can be applied to small electronic devices, smart sensors, and medicine with improved performance, can provide potential insights as a power source for wireless electronic devices expected to be encountered in future daily life.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.7
• /
• pp.1-15
• /
• 2021

With the prolonged COVID-19 pandemic situation, the attention on Metaverse has been soared throughout media and publications. Recently the entertainment industry is also changing to actively utilize the virtual world with artists working through Metaverse platforms. With the recent high interests on Metaverse, this study attempts to illuminate how the public perceives and accepts Metaverse experiences. While research on Metaverse has been mainly focused on specific technologies or technical objects, this study focuses on exploring how fans recognize and understand the concept of Metaverse through newly debuted idol group 'aespa', composing of 4 human members and 4 AI avatar members that integrate real and virtual world. For this, this study seeks to analyze the reaction and recognition of fans by exploring online community 'DC Inside'. As a result of analyzing the reactions of fans in the early days of aespa's debut, the perspectives of understanding AI members of aespa are categorized into three groups: first, the type of equating and accepting the real and the virtual world; second, the type of recognizing the real world and the virtual world separately and recognizing the virtual member as an avatar or concept, not a genuine member; and finally, a type of recognizing virtual worlds separately from reality. Based on these results, the implications that Metaverse contents may have in the entertainment industry are suggested.

• Journal of Korea Entertainment Industry Association
• /
• v.14 no.7
• /
• pp.421-427
• /
• 2020

The aim of this study was to examine the impacts of pre-briefing using structured video simulations in the pre-hospital trauma care simulation-based education on simulation immersion, simulation confidence, and simulation satisfaction. For both the experimental group and the control group, orientations were conducted on the simulation environment. Subsequently, the experimental group watched a video of about 8 minutes, similar to the scenario situation, in which the goal and result of the training were presented. The control group, on the other hand, conducted a classical way of orientation related to the scenario during the same time period. In addition, the experimental group and the control group underwent simulation practice in the same situation for 12 minutes, and debriefing was performed for 40 minutes by the same research assistant. Afterwards, we measured the simulation immersion, confidence, and satisfaction of the participants. Data were analyzed using χ² and independent t-test using the SPSS 22.0 program. It was found that the experimental group that conducted the pre-briefing using video had higher immersion and confidence than the control group. On the other hand, satisfaction was not significantly different between the two groups. The results indicate that pre-briefing using structured video was an effective educational method to increase simulation immersion and simulation confidence.

• Journal of the Korea Society for Simulation
• /
• v.18 no.2
• /
• pp.39-48
• /
• 2009

This study reviews the limit of image search by considering on the image search methods related to content-based image retrieval and suggests a user interface for more efficient content-based image retrieval and the ways to utilize image properties. For now, most studies on image search are being performed focusing on content-based image retrieval; they try to search based on the image's colors, texture, shapes, and the overall form of the image. However, the results are not satisfactory because there are various technological limits. Accordingly, this study suggests a new retrieval system which adapts content-based image retrieval and the conventional keyword search method. This is about a way to attribute properties to images using texts and a fast way to search images by expressing the attribute of images as keywords and utilizing them to search images. Also, the study focuses on a simulation for a user interface to make query language on the Internet and a search for clothes in an online shopping mall as an application of the retrieval system based on image attribute. This study will contribute to adding a new purchase pattern in online shopping malls and to the development of the area of similar image search.

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.6
• /
• pp.329-339
• /
• 2019

This study intends to identify the effect of the simulation-based adult nursing education on resilience, clinical competence, and role transition of nursing students. Similar experimental study of a single group pretest-posttest design was used to investigate the effects of the program. The study was conducted from March to June, 2017 on senior nursing students at the university in M city who take an 'Integrated nursing practice I' class for the semester. Data were collected through self-report questionnaires and data of 52 participants were analyzed. The data were analyzed by frequencies, paired t-test and pearson's correlation coefficient using SPSS 21.0 program. As a result, the effectiveness of the simulation-based adult nursing education on resilience, clinical competence, and role transition were found. The result of this study showed that the improvement after simulation education was significant in resilience(t=-2.51, p=.016), clinical competence(t=-4.18, p<.001), and role transition(t=-2.89, p=.006). Resilience was found to be positively correlated with clinical competence(r=.464, p<.001) and role transition(r=.473, p<.001). These findings imply the value of simulation education to enhance the resilience, clinical competence, and role transition of nursing students. In the future, more studies should be conducted in the same group with control group to validate the effectiveness of variables.

• Korean Journal of Social Welfare Studies
• /
• v.42 no.1
• /
• pp.117-149
• /
• 2011

This study examined the relationship between discrimination experienced by children of multicultural families and their psychological distress. As new minorities growing up with bicultural identities in Korean society, children from multicultural families are often exposed to racial discrimination and such experience often acts as a stressor in their everyday life. In order to examine the effect of discrimination on their psychological distress as well as the role of social support, a survey was conducted in 25 elementary schools in Daejeon city and Chungnam and Chungbuk province. Results indicated that children's experiences of discrimination significantly affected their psychological distress level that the more they were exposed to discrimination, the higher levels of depression and anxiety they experienced. Among social support domains, only peer support was found to be significantly related to both the experience of discrimination and their depression and anxiety levels. Supporting the social support deterioration model, the findings showed that more experiences of discrimination led to reduced peer support which in turn, increased the likelihood of being depressed and anxious. Peer support was also significant in partially mediating the discrimination-psychological distress relationship. Implications for social work practice with children from multicultural families are provided.