• Journal of Cadastre & Land InformatiX
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• v.51 no.1
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• pp.111-124
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• 2021

Recently, Interest in the restoration and 3D reconstruction of cultural properties due to the fire of Notre Dame Cathedral on April 15, 2019 has been focused once again after the 2008 Sungnyemun fire incident in South Korea. In particular, research to restore and reconstruct the actual measurement of cultural properties using LiDAR(Light Detection and ranging) and conventional surveying, which were previously used, using various 3D reconstruction technologies, is being actively conducted. This study acquires data using unmanned aerial imagery of UAV(Unmanned Aerial Vehicle), which has recently established itself as a core technology in the era of the 4th industrial revolution, and the existing CRP(Closed Range Photogrammetry) and terrestrial LiDAR scanning for the Recumbent Buddha of Unju Temple. Then, the 3D reconstruction was performed with three fusion models based on SfM(Structure-from-Motion), and the reproducibility and accuracy of the models were compared and analyzed. In addition, using the best fusion model among the three models, the relationship with the Polar Star(Polaris) was confirmed based on the real world coordinates of the Recumbent Buddha, which contains the astronomical history of Buddhism in the early 11th century Goryeo Dynasty. Through this study, not only the simple external 3D reconstruction of cultural properties, but also the method of reconstructing the historical evidence according to the type and shape of the cultural properties was sought by confirming the historical evidence of the cultural properties in terms of spatial information.

• The Journal of Industrial Distribution & Business
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• v.12 no.1
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• pp.47-62
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• 2021

Purpose: Our purpose in this study was to examine the strategies for the development of watermelon industry using unstructured big data analysis. That is, this study was to look the change of issues and consumer's perception about watermelon using big data and social network analysis and to investigate ways to strengthen the competitiveness of watermelon industry based on that. Methodology: For this purpose, the data was collected from Naver (blog, news) and Daum (blog, news) by TEXTOM 4.5 and the analysis period was set from 2015 to 2016 and from 2017-2018 and from 2019-2020 in order to understand change of issues and consumer's perception about watermelon or watermelon industry. For the data analysis, TEXTOM 4.5 was used to conduct key word frequency analysis, word cloud analysis and extraction of metrics data. UCINET 6.0 and NetDraw function of UCINET 6.0 were utilized to find the connection structure of words and to visualize the network relations, and to make a cluster of words. Results: The keywords related to the watermelon extracted such as 'the stalk end of a watermelon', 'E-mart', 'Haman', 'Gochang', and 'Lotte Mart' (news: 015-2016), 'apple watermelon', 'Haman', 'E-mart', 'Gochang', and' Mudeungsan watermelon' (news: 2017-2018), 'E-mart', 'apple watermelon', 'household', 'chobok', and 'donation' (news: 2019-2020), 'watermelon salad', 'taste', 'the heat', 'baby', and 'effect' (blog: 2015-2016), 'taste', 'watermelon juice', 'method', 'watermelon salad', and 'baby' (blog: 2017-2018), 'taste', 'effect', 'watermelon juice', 'method', and 'apple watermelon' (blog: 2019-2020) and the results from frequency and TF-IDF analysis presented. And in CONCOR analysis, appeared as four types, respectively. Conclusions: Based on the results, the authors discussed the strategies and policies for boosting the watermelon industry and limitations of this study and future research directions. The results of this study will help prioritize strategies and policies for boosting the consumption of the watermelon and contribute to improving the competitiveness of watermelon industry in Korea. Also, it is expected that this study will be used as a very important basis for agricultural big data studies to be conducted in the future and this study will offer watermelon producers and policy-makers practical points helpful in crafting tailor-made marketing strategies.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.91-103
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• 2021

In order to estimate the vertical and horizontal structural in the Yangsan fault core line (Naengsuri area, Pohang), we carried out gravity field measurements and interpretation procedures such as Euler deconvolution method and curvature analysis in addition to the forward modelling technique (i.e. IGMAS+). We found a prominent gravity difference of more than 1.5 mGal across the fault core. This indicates a distinct density difference between the western and eastern crustal area across the Yangsan fault line. Comparing this gravity field interpretation with other existent geologic and geophysical survey data (e.g. LiDAR, trenching, electric resistivity measurements), It is concluded that (1) the prominent gravity difference is caused by the density difference of about 0.1 g/㎤ between the Bulguksa Granite in the west and the Cretaceous Sandstone in the east side, (2) the fault core is elongated vertically into a depth of about 2,000 meters and extended horizontally 3,000 meters to the NNE direction from Naengsuri area. Our results present that the gravity field method is a very effective tool to estimate a three -dimensional image of the active fault core.

• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.361-370
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• 2021

Carbon fiber reinforced polymer (CFRP) is one of the composite materials, which has a unique property that is lightweight but strong. The CFRPs are widely used in various industries where their unique characteristics are required. In particular, electric and unmanned aerial vehicles critically need lightweight parts and bodies with sufficient mechanical strengths. Vehicles using the battery as a power source should simultaneously meet two requirements that the battery has to be safely protected. The vehicle should be light of increasing the mileage. The CFRP has considered as the one that satisfies the requirements and is widely used as battery housing and other vehicle parts. On the other hand, in the battery area, carbon fibers are intensively tested as battery components such as electrodes and/or current collectors. Furthermore, using carbon fibers as both structure reinforcements and battery components to build a structural battery is intensively investigated in Sweden and the USA. This mini-review encompasses recent research trends that cover the classification of structural batteries in terms of functionality of carbon fibers and issues and efforts in the battery and discusses the prospect of structural batteries.

• The Journal of Society for e-Business Studies
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• v.26 no.2
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• pp.123-141
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• 2021

As the dependence of technology on the economic structure increases, the importance of National Core Technology is increasing. However, due to the nature of the technology itself, it is difficult to determine the scope of the technology to be protected because the scope of the relation is abstract and information disclosure is limited due to the nature of the National Core Technology. To solve this problem, we propose the most appropriate literature type and method of analysis to distinguish important technologies related to National Core Technology. We conducted a pilot test to apply TF-IDF, and LDA topic modeling, two techniques of text mining analysis for big data analysis, to four types of literature (news, papers, reports, patents) collected with National Core Technology keywords in the field of Display industry. As a result, applying LDA theme modeling to patent data are highly relevant to National Core Technology. Important technologies related to the front and rear industries of displays, including OLEDs and microLEDs, were identified, and the results were visualized as networks to clarify the scope of important technologies associated with National Core Technology. Throughout this study, we have clarified the ambiguity of the scope of association of technologies and overcome the limited information disclosure characteristics of national core technologies.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.679-684
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• 2011

Branched polypropylenes (LCB-PP) with a long chain branch were prepared by the solid-state and molt-state reaction. Divinylbenzene (DVB), 1,4-benzenediol (RES), and furfuryl sulphide (FS) were used as branching agents of fabricate LCB-PP/silicate composites. Chemical structures, thermal properties, and rheological properties of the LCB-PP were determined by FT-IR, DSC, TGA, and dynamic rheometer (ARES). The chemical structure of the LCB-PP was confirmed by the existence of =C-H stretching peak of the branching agent at $3100cm^{-1}$. From DSC and TGA results, the melting reaction was more effective than the solid state reaction in the manufacture of LCB-PP, which was additionally certified by rheological properties. Based on rheological properties, FS was the best for branching efficiency of PP. Compared to PP, LCB-PPs indicated an increase of complex viscosity in the low frequency and shear thinning tendency, and G'-G" plot represented an increase in elasticity and the heterogeneousness in a melt state. Rheological properties of LCB-PP/silicate composites were observed with the silicate content. When 5 wt% silicate was added in LCB-PP, distinct changes in the shear thinning and the slope of G'-G" plots were observed.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.277-285
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• 2011

Polysulfone (PSf) membranes were prepared via the phase inversion process. Polyvinylpyrrolidone (PVP) was added as a nonsolvent additive in the casting solution containing a mixture of PSf and n-methylpyrrolidone. The added PVP played a role of enhancing liquid-liquid phase separation of the casting solution, and significantly reduced the solution fluidity. When prepared via the diffusion-induced process using water as a precipitation nonsolvent, the solidified membranes revealed a typical asymmetric structure irrespective of the addition of PVP. With 5 wt% PVP content, the finger-like cavities were more developed in the membrane sublayer compared to that of the membranes prepared without PVP. In contrast, with more than 10 wt% of PVP, the formation of finger-like cavities was suppressed, and the thickness of polymer nodule layer was increased. The surface porosity was also increased with the PSf content in the casting solution. The water permeability curve as a function of PVP addition revealed the inflection point. The maximum water permeability for 12 wt% PSf membrane was obtained with 5 wt% PVP content, and that for 18 wt% PSf membrane with 15 wt% PVP.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.353-357
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• 2011

For the purpose of introducing hydrophilic function to pristine PVDF, pristine PVDF was modified under atmosphere and aqueous vapor by irradiating electron beam (EB). EB dose was varied from 0 to 125 K Gray, respectively. Their changes of chemical composition /structure were observed and evaluated by FT-IR, EDS and DSC. Also, their surface behaviors were evaluated by contact angle. In FT-IR study, it was confirmed that hydroxyl functions were introduced to pristine PVDF. In EDS analysis, mole ratio of F (fluoride) was almost constant (about 33%) in spite of increasing EB dose, meaning that hydroxyl function was introduced via dehydrozenation, not via deflurodination. In DSC study, $T_g$ increased with increasing EB dose, which was reconfirmed that hydroxyl function was introduced via dehydrozenation. $T_m$ increased with increasing EB dose, inferring that the increase in EB dose led to more outbreak of hydroxyl function which led to more enhanced hydrogen bond. In the result of contact angle, pristine PVDF film was $62^{\circ}$ and 125 K Gray-irradiated PVDF film was even $13^{\circ}$. All results showed that pristine PVDF was successfully changed to hydrophilic PVDF.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.467-472
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• 2011

This study investigated illite/polypropylene (PP) composite filament formation via melt-spinning and evaluated their physical properties to prepare functional fibers using natural materials. When composite filaments were formed, the composite filaments exhibited smaller fiber diameters compared to that of neat PP filament because of the lubricant effect of illite induced by its layered structure. Moreover, fluorination effect increased interfacial affinity and dispersion in the polymer, resulting in smaller diameter of fluorinated illite/PP composite filament, which was 2/3 of the neat PP filament diameter. Addition of raw and fluorinated illite improved thermal stability of illite/PP composite filament. Raw illite/PP composite filament cannot be used for a practical application, because it broke during drawing process, whereas the fluorinated illite/PP composite filament can be used for a practical application, because it exhibited similar tensile strength of the neat PP filament and 50% increased modulus. Even with improved illite/PP interfacial affinity and illite dispersion in the polymer, illite/PP composite filament formed microcomposite, because non-expandable illite had strongly bound layers, resulting in only a little illite exfoliation and PP intercalation into illite.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.610-616
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• 2011

A series of polyurethane acrylate/ZnO (PUA/ZnO) nanocomposite films with different ZnO contents were successfully prepared via a UV-curing system. The synthesis and physical properties including morphological structure, thermal properties, barrier properties and optical properties, and antimicrobial properties were investigated as a function of ZnO concentration. FTIR and SEM results showed that these PUA/ZnO nanocomposite films did not have a strong interaction between PUA and ZnO, which may lead to no increase in thermal stability. By incorporating ZnO nanoparticles, the UV blocking and antibacterial properties increased as the content of ZnO increased. Specially, the oxygen permeability in composite films changed from $2005cc/m^2/day$ to $150cc/m^2/day$ by adding the ZnO nanoparticle, which indicates that the PUA/ZnO nanocomposite films can be applied as good barrier packaging materials. Physical properties of the UV-cured PUA/ZnO nanocomposite film are strongly dependent upon the dispersion state of ZnO nanoparticles and their morphology in the films.