• The Korean Journal of Mycology
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• v.40 no.4
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• pp.229-234
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• 2012

A key molecule in the pathogenesis of Alzheimer's disease (AD) is the ${\beta}$-amyloid peptide ($A{\beta}$) generated by ${\beta}$-secretase activity, an aspartic protease. This study was designed to evaluate inhibitory effect of the high-molecular weight water-soluble polysaccharides (Et-P) isolated and purified from Phellinus linteus fruiting body on ${\beta}$-secretase activity. The Et-P was purified from the hot water extract of Phellinus linteus fruiting body mainly by 75% ethanol precipitation and DEAE-Cellulose column chromatography. From the DEAE-Cellulose chromato-gram and molecular weight analysis, the Et-P was shown to be a mixture of three polysaccharides with molecular mass of 1,629, 1,294, and 21 kDa, respectively. The monosaccharide composition of Et-P was determined to be glu-cose, galactose, and mannose as major sugars, glucose being the most prominent one (48% in mole percentage). The elemental analysis and FT-IR analysis suggested that Et-P is typical polysaccharides having at least partially ${\beta}$-linkages and possible existing as complex with phenolic compounds. The laminarinase digestion and HPAEC-PAD analysis suggested that Et-P is a variant of beta-(1,3)-glucans. The Et-P showed DPPH radical scavenging activity and, especially, a significant inhibitory activity on ${\beta}$-secreatase activity (48% inhibitin at 100 ${\mu}g/mL$), suggesting that they may inhibit the formation of $A{\beta}$ which is the major causative of Alzheimer's disease. The results of this study suggest that the water soluble polysaccharides of Phellinus linteus fruiting body can be a potent material for the development of preventive or therapeutic agents for AD.

• Current Research on Agriculture and Life Sciences
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• v.26
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• pp.23-30
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• 2008

In this paper, when the silk fabric was modified by ethylene cyanohydrine, the reaction mechanism between both was studied at various treatment conditions such as curing temperatures and times, ethylene cyanohydrin concentrations and $ZnCl_2$ concentrations. Through the FT-IR and DSC analyses of the treated silk fabrics, we found the results as follows : It was observed in FT-IR analysis of the treated silk fabrics that the -OH characteristic peak($3,450cm^{-1}$)position and shape were all changed when drying and curing treatment conditions were at $80^{\circ}C$ for 3 minute and $110^{\circ}C$ for 2.5 minute, and the concentration of the $ZnCl_2$ was 0.1%. It indicated that the -OH group of the silk participated in the reaction between the silk fabric and ethylene cyanohydrin. From the DSC analysis, it was found that the pyrolysis temperatures of the treated silk fabrics by ethylene cyanohydrin which was processed in the same condition, were all increased from $311^{\circ}C$ to ab. $320^{\circ}C$. From the FT-IR analyses of the silk fabrics treated by ethylene cyanohydrin at the various concentrations of $ZnCl_2$, it was found that the -OH characteristic peaks($3,450cm^{-1}$) were similar to the nontreated one except that of the fabric treated at the $ZnCl_2$ conconcentration of 0.8% when drying and curing treatment conditions were at $80^{\circ}C$ for 3minute and $110^{\circ}C$ for 2.5 minute, and the concentration of the ethylene cyanohydrin was 5%. In the case of the $ZnCl_2$ concentration of 0.8% solution, a lot of change were observed in peak. From the DSC analysis of the treated silk fabrics which was processed in the same condition, it was showed that the pyrolysis temperatures of treated silk fabric were all increased from $311^{\circ}C$ to ab. $320^{\circ}C$, which was no relation with the concentration of $ZnCl_2$.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.1-7
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• 2021

In this paper, by embedding a bare-die chip-type drive amplifier into the PCB composed of ABF and FR-4, it implements an embedded active device that can be applied in 28 GHz band modules. The ABF has a dielectric constant of 3.2 and a dielectric loss of 0.016. The FR-4 where the drive amplifier is embedded has a dielectric constant of 3.5 and a dielectric loss of 0.02. The proposed embedded module is processed into two structures, and S-parameter properties are confirmed with measurements. The two process structures are an embedding structure of face-up and an embedding structure of face-down. The fabricated module is measured on a designed test board using Taconic's TLY-5A(dielectric constant : 2.17, dielectric loss : 0.0002). The PCB which embedded into the face-down expected better gain performance due to shorter interconnection-line from the RF pad of the Bear-die chip to the pattern of formed layer. But it is verified that the ground at the bottom of the bear-die chip is grounded Through via, resulting in an oscillation. On the other hand, the face-up structure has a stable gain characteristic of more than 10 dB from 25 GHz to 30 GHz, with a gain of 12.32 dB at the center frequency of 28 GHz. The output characteristics of module embedded into the face-up structure are measured using signal generator and spectrum analyzer. When the input power (P_in) of the signal generator was applied from -10 dBm to 20 dBm, the gain compression point (P_1dB) of the embedded module was 20.38 dB. Ultimately, the bare-die chip used in this paper was verified through measurement that the oscillation is improved according to the grounding methods when embedding in a PCB. Thus, the module embedded into the face-up structure will be able to be properly used for communication modules in millimeter wave bands.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.18-26
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• 2021

Purpose: Generally, patients are noticed to store denture in water when removed from the mouth. However, few studies have reported the advantage of volumetric change in underwater storage over dry storage. To be a reference in defining the proper denture storage method, this study aims to evaluate the volumetric change and dimensional deformation in case of underwater and dry storage. Materials and methods: Definitive casts were scanned by a model scanner, and denture bases were designed with computer-aided design (CAD) software. Twelve denture bases (upper 6, lower 6) were printed with 3D printer. Printed denture bases were invested and flasked with heat-curing method. 6 upper and 6 lower dentures were divided into group A and B, and each group contains 3 upper and 3 lower dentures. Group A was stored dry at room temperature, group B was stored underwater. Group B was scanned at every 24 hours for 28 days and scanned data was saved as stereolithography (SLA) file. These SLA files were analyzed to measure the difference in volumetric change of a month and Kruskal-Wallis test were used for statistical analysis. Best-fit algorithm was used to overlap and 3-dimensional color-coded map was used to observe the changing pattern of impression surface. Results: No significant difference was found in volumetric changes regardless of the storage methods. In dry-stored denture base, significant changes were found in the palate of upper jaw and posterior lingual border of lower jaw in direction away from the underlying tissue, maxillary tuberosity of upper jaw and retromolar pad area of lower jaw in direction towards the underlying tissue. Conclusion: Storing the denture underwater shows less volumetric change of impression surface than storing in the dry air.

• Korean Journal of Heritage: History & Science
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• v.56 no.1
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• pp.80-97
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• 2023

By taking wallpaper specimens from Gyeongbokgung Palace, Changdeokgung Palace, and Chilgung Palace preserved from the late Joseon Dynasty to the present, we planned in this study to determine the types and characteristics of the paper used as wallpaper in the Joseon royal family. First, we confirmed the features of paper hanging in the palaces with old literature on the wallpaper used by the royal family based on archival research. Second, we conducted a field survey targeting the royal palaces whose construction period was relatively clear, and analyzed the first layer of wallpaper directly attached to the wall structure after sampling the specimens. Therefore, we confirmed that the main raw material was hanji, which was used as a wallpaper by the royal family, and grasped the types of substances(dyes and pigments) used to produce a blue color in spaces that must have formality by analyzing the blue-colored paper. Based on the results confirmed through the analysis, we checked documents and the existing wallpaper by comparing the old literature related to wallpaper records of the Joseon Dynasty palaces. We also built a database for the restoration of cultural properties when conserving the wallpaper in the royal palaces. We examined the changes in wallpaper types by century and the content according to the place of use by extracting wallpaper-related contents recorded in 36 cases of Uigwe from the 17th to 20th centuries. As a result, it was found that the names used for document paper and wallpaper were not different, thus document paper and wallpaper were used without distinction during the Joseon Dynasty. And though there are differences in the types of wallpaper depending on the period, it was confirmed that the foundation of wallpaper continued until the late Joseon Dynasty, with Baekji(white hanji), Hubaekji(thick white paper), jeojuji(common hanji used to write documents), chojuji(hanji used as a draft for writing documents) and Gakjang(a wide and thick hanji used as a pad). As a result of fiber identification by the morphological characteristics of fibers and the normal color reaction(KS M ISO 9184-4: Graph "C" staining test) for the first layer of paper directly attached to the palace wall, the main materials of hanji used by the royal family were confirmed and the raw materials used to make hanii in buildings of palaces based on the construction period were determined. Also, as a result of analyzing the coloring materials of the blue decorative paper with an optical microscope, ultraviolet-visible spectroscopic analysis(UV-Vis), and X-ray diffraction analysis(XRD), we determined that the type of blue decorative paper dyes and pigments used in the palaces must have formality and identified that the raw materials used to produce the blue color were natural indigo, lazurite and cobalt blue.

• Journal of Intelligence and Information Systems
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• v.19 no.2
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• pp.177-189
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• 2013

In Smart Education, the roles of digital textbook is very important as face-to-face media to learners. The standardization of digital textbook will promote the industrialization of digital textbook for contents providers and distributers as well as learner and instructors. In this study, the following three objectives-oriented digital textbooks are looking for ways to standardize. (1) digital textbooks should undertake the role of the media for blended learning which supports on-off classes, should be operating on common EPUB viewer without special dedicated viewer, should utilize the existing framework of the e-learning learning contents and learning management. The reason to consider the EPUB as the standard for digital textbooks is that digital textbooks don't need to specify antoher standard for the form of books, and can take advantage od industrial base with EPUB standards-rich content and distribution structure (2) digital textbooks should provide a low-cost open market service that are currently available as the standard open software (3) To provide appropriate learning feedback information to students, digital textbooks should provide a foundation which accumulates and manages all the learning activity information according to standard infrastructure for educational Big Data processing. In this study, the digital textbook in a smart education environment was referred to open digital textbook. The components of open digital textbooks service framework are (1) digital textbook terminals such as smart pad, smart TVs, smart phones, PC, etc., (2) digital textbooks platform to show and perform digital contents on digital textbook terminals, (3) learning contents repository, which exist on the cloud, maintains accredited learning, (4) App Store providing and distributing secondary learning contents and learning tools by learning contents developing companies, and (5) LMS as a learning support/management tool which on-site class teacher use for creating classroom instruction materials. In addition, locating all of the hardware and software implement a smart education service within the cloud must have take advantage of the cloud computing for efficient management and reducing expense. The open digital textbooks of smart education is consdered as providing e-book style interface of LMS to learners. In open digital textbooks, the representation of text, image, audio, video, equations, etc. is basic function. But painting, writing, problem solving, etc are beyond the capabilities of a simple e-book. The Communication of teacher-to-student, learner-to-learnert, tems-to-team is required by using the open digital textbook. To represent student demographics, portfolio information, and class information, the standard used in e-learning is desirable. To process learner tracking information about the activities of the learner for LMS(Learning Management System), open digital textbook must have the recording function and the commnincating function with LMS. DRM is a function for protecting various copyright. Currently DRMs of e-boook are controlled by the corresponding book viewer. If open digital textbook admitt DRM that is used in a variety of different DRM standards of various e-book viewer, the implementation of redundant features can be avoided. Security/privacy functions are required to protect information about the study or instruction from a third party UDL (Universal Design for Learning) is learning support function for those with disabilities have difficulty in learning courses. The open digital textbook, which is based on E-book standard EPUB 3.0, must (1) record the learning activity log information, and (2) communicate with the server to support the learning activity. While the recording function and the communication function, which is not determined on current standards, is implemented as a JavaScript and is utilized in the current EPUB 3.0 viewer, ths strategy of proposing such recording and communication functions as the next generation of e-book standard, or special standard (EPUB 3.0 for education) is needed. Future research in this study will implement open source program with the proposed open digital textbook standard and present a new educational services including Big Data analysis.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.1
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• pp.54-59
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• 2017

Purpose The present study aimed at assessing the effectiveness of the respiratory gating method used in the flow mode and additional localized respiratory-gated imaging, which differs from the step and go method. Materials and Methods Respiratory gated imaging was performed in the flow mode to twenty patients with lung cancer (10 patients with stable signals and 10 patients with unstable signals), who underwent PET/CT scanning of the torso using Biograph mCT Flow PET/CT at Bundang Seoul University Hospital from June 2016 to September 2016. Additional images of the lungs were obtained by using the respiratory gating method. SUVmax, SUVmean, and Tumor Volume ($cm^3$) of non-gating images, gating images, and additional lung gating images were found with Syngo,bia (Siemens, Germany). A paired t-test was performed with GraphPad Prism6, and changes in the width of the amplitude range were compared between the two types of gating images. Results The following results were obtained from all patients when the respiratory gating method was applied: $SUV_{max}=9.43{\pm}3.93$, $SUV_{mean}=1.77{\pm}0.89$, and $Tumor\;Volume=4.17{\pm}2.41$ for the non-gating images, $SUV_{max}=10.08{\pm}4.07$, $SUV_{mean}=1.75{\pm}0.81$, and $Tumor\;Volume=3.56{\pm}2.11$ for the gating images, and $SUV_{max}=10.86{\pm}4.36$, $SUV_{mean}=1.77{\pm}0.85$, $Tumor\;Volume=3.36{\pm}1.98$ for the additional lung gating images. No statistically significant difference in the values of $SUV_{mean}$ was found between the non-gating and gating images, and between the gating and lung gating images (P>0.05). A significant difference in the values of $SUV_{max}$ and Tumor Volume were found between the aforementioned groups (P<0.05). The width of the amplitude range was smaller for lung gating images than gating images for 12 from 20 patients (3 patients with stable signals, 9 patients with unstable signals). Conclusion In PET/CT scanning using the respiratory gating method in the flow mode, any lesion movements caused by respiration were adjusted; therefore, more accurate measurements of $SUV_{max}$, and Tumor Volume could be obtained from the gating images than the non-gating images in this study. In addition, the width of the amplitude range decreased according to the stability of respiration to a more significant degree in the additional lung gating images than the gating images. We found that gating images provide information that is more useful for diagnosis than the one provided by non-gating images. For patients with irregular signals, it may be helpful to perform localized scanning additionally if time allows.

• Korean Journal of Heritage: History & Science
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• v.54 no.1
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• pp.220-237
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• 2021

This study carried out the conservation treatment for the mattress put on the bed, which is one of 4 items in National Folklore Cultural Heritage, the Red-lacquered Furniture with the inlaid mother-of-pearl design used by Empress Sunjeonghyo (presumed), after identifying the characteristics of the manufacturing techniques and the used materials. And the study intends to compare it with the mattress placed in the Daejojeong in the Changdeokgung Palace in order to identify the characteristics of mattresses domestically used during the 1920s and 1930s. From the analysis of the mattress presumably used by Empress Sunjeonghyo, it was identified that the mattress frame was made of pinaceous hemlock spruce while the webbing and twine in the structural parts were made of jute. The findings are as follows: the burlap had a filling material that was made of jute; the straw mat was made from Oryza; and, the rest of the filling material was cotton. Rayon was used for the top cover while cotton was used for the bottom. As a result of research on the materials and the inner structure, it was found that mattress was manufactured in the form of the upholstery style mainly found in chairs and day-beds in Western furniture. Based on analysis results, materials identical to the original were adopted during the conservation treatment. Next, the process of dismantling, cleaning, repair, reinforcement and assembling was conducted. During the dismantling process, the top cover was newly discovered and some letters (Yokohama, Kobe, and Joseon) were found in the burlap filling, but there was no trace which can clarify its maker or production place. dry cleaning was carried out on the structural parts, filling materials, and the cover, and then the repair and reinforcement were done, preserving the existing materials in the upholstery structure and using the same materials for conservation. The webbing in the structural parts was reinforced using materials identical to the original, and the twine was used for arranging and fixing the springs into wooden frames. For the damaged cotton cloth and burlap, reinforcement materials identical to the original were put over it and sown. For the damaged area of the top cover, reinforcement cloth was cut and then added inside and the damaged area was sown. Assembling was carried out in the reverse order of the dismantling. After the burlap identical to the original material was inserted into the areas in contact with the springs and then fastened, a filling pad, reinforcement cloth, a straw mat, cotton cloth, cotton felt, wide cotton cloth for protecting the cover, and the cover were layered and fastened with tacks. The two mattresses used by Empress Sunjeonghyo differed only by the period of production and followed the same Western upholstery style consisting of the frames, filling materials, and covers. During the conservation treatment process, a velvet cover was newly discovered and the traces of repair in the past were found. Furthermore, identifying straw mats, straw bags, and straws for filling material, this study confirmed changes in the materials used according to the production environment. In the future, it is expected to see changes in the conservation materials during the conservation treatment and manufacturing techniques used for chairs and sofas in the upholstery style belonging to the modern cultural artifacts.