• Vacuum Magazine
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• v.3 no.4
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• pp.4-7
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• 2016

An X-ray Free Electron laser facility (PAL-XFEL) has been built in Pohang Accelerator Laboratory to provide X-ray FEL radiations for photon users. The machine consists of a 10 GeV normalconducting S-band linear accelerator and two undulator beamlines. The hard and soft X-ray beamlines will provide FEL radiations with wavelengths of 0.6 to 0.1 nm and 4.5 to 1 nm, respectively. Beam commissioning of PAL-XFEL is ongoing and user service will start in 2017. In this report, the PAL-XFEL layout and the working principle are discussed.

• Korean Journal of Environment and Ecology
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• v.22 no.4
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• pp.435-441
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• 2008

This study conducted a survey on the moulting sequence subsequent to age of Haliaeetus pelagicus raised in captivity at the Ornithology Laboratory attached to Kyungsung University for about six years from November, 2000 until July, 2006. The survey indicated that the moult of rectrices usually began in July and continued until April of the next year and most of the rectrices were replaced by one-time moult. Usually, about two thirds of the tail feathers were replaced while the rest were replaced no later than April of the next year, and the moult also continued during the wintertime. The total number of rectrices was 14, and the moult progressed alternately on a systematic basis. The progress of the moult for female & male was made on four stages and three stages respectively and the characteristic shown on every stage of the moult was that the left & right tail feathers progressed symmetrically and not until one stage of progress almost completed did the next stage began. The color of the juvenile steller's sea-eagle was dotted with black spots on its original white color and there existed regular black belt on its feather's fringes; however, it was difficult to identify its age by tail feathers only because there was almost no difference in color between feathers ranging from the first to the third generation(1st-3rd summer feathers). In addition, this research took the different amounts of black-speckled pattern appearing by individual into consideration. There existed slight black speckles in white color feathers of the fourth generation(the 4th summer feathers) while showing a big difference compared to the 3rd generation feathers. The 5th generation feathers[the 5th summer feathers]were found to be equipped with perfect tail feathers having virgin white of a steller's sea-eagle after completing its 4th molt. When observing a steller's sea-eagle in the open air, it is necessary for an observer to have a deliberate examination in judging its age belonging to the 1st-3rd generation feathers, and it is considered that the changes of other parts of feathers should be also observed besides tail feathers.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.3
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• pp.279-287
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• 2018

This study investigated applicability of the fast running model for damage assessment of underground structures by ground shock. For this reason, the fast running model that consists of two main models such as the ground shock generation and propagation model and the underground structural damage assessment model was developed. The ground shock generation and propagation model was programed using theoretical formula and empirical formula introduced in TM5-855-1(US army manual). The single degree of freedom model of structural components was utilized to predict structural dynamic displacements which are used as index to assess damage level of components. In order to confirm the feasibility of the developed fast running model, underground structural dynamic displacements estimated from the fast running model were compared to displacements obtained from the finite element analysis.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.31-42
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• 2019

As smartphone H/W performance and mobile communication service have been enhanced, large-capacity 3D modeling files are available in smartphones. Common formats of 3D modeling files include STL (STereoLithography), OBJ (Wavefront file format specification), FBX (Filmbox), and glTF (open GL Transmission Format). Each format has different characteristics depending on the configuration and functions, and formats that are supported are varied depending on the applications. Large-size files are commonly used. The 4th generation mobile communication network secures loading of 3D modeling files and transmission of large-size geometric files in order to provide augmented reality services via smartphones. This paper explains the concepts and characteristics of major 3D file formats such as OBJ, FBX, and glTF. In addition, it compares their performance in a wired web with that in the 4th generation mobile communication network. The loading time and packet transmission in each 3D format are also measured by means of different mobile web browsers (Google Chrome and MS Edge). The experiment result shows that glTF demonstrated the most efficient performance while the loading time of OBJ was relatively excessive. Findings of this study can be utilized in selecting specific 3D file formats for rendering time reduction depending on the mobile web environments.

• The Korean Journal of Food And Nutrition
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• v.36 no.4
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• pp.334-339
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• 2023

To suppress mold generation of yujacheong, Penicillium chrysogenum LB31 was cultured, and spores were harvested and put into yujacheong. Antioxidant activity, useful ingredients, mold size and incidence were investigated while storing yujacheong for 30 days, after sterilization with different methods (nontreatment, ozone gas emission, heating after ozone gas emission and heating). The results showed that the content of narirutin, naringin, hesperidin, or neohesperidin, which are functional components of yuzu, increased as the storage period increased in all the treatment units. In addition, mold generation was not observed until the 15th day in the heat treatment group after ozone gas emission. As the treatment group emitted ozone gas. molds of 34.8 and 112 mm2 in size were observed on the 30th day. These results suggested that ozone sterilization can prevent microbial contamination, further extending the shelf life of yuzacheong and maintaining a fresh state.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.11
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• pp.329-331
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• 2020

Edutech is a compound word of education and technology, and is an educational paradigm in the era of the 4th industrial revolution. This refers to next-generation education using information and communication technology (ICT) such as big data, artificial intelligence (AI), robots, and virtual reality (VR) of the 4th industrial revolution. e-Learning is being used as an online lecture for education in ICT, but edutech is attracting attention along with e-learning as the feeding of non-face-to-face education has rapidly increased due to COVID-19. Therefore, this paper summarizes the reviewed papers on the blockchain-based badge service platform, simulation-based collaborative e-Learning system, video English dictionary, and blockchain-based access control audit system.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.219-235
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• 2012

Objective: The aim of this study is to analyze the change characteristics of boys among the ages of 13 and 18 years. This study is based on the $4^{th}$ to the $6^{th}$ national anthropometric survey(Size Korea) data. Background: Many changes can affect the body characteristics compared withthe past. The significant changes were shown in Pepsi generation according to the report of national anthropometric survey of Korea 1997. Method: The subjects of the survey were 1,899 boys of the $4^{th}$ Size Korea, 1,587 boys of the $5^{th}$Size Korea and 2,317 boys of the $6^{th}$ Size Korea, who were from 13 to 18 years old. The change characteristics were analyzed withanthropometric measurements, height index value and proportion. Results: Stature was increased in 17~18 years old age group of the $5^{th}$ and the $6^{th}$ Size Korea and height items of the lower body showed the tendency to increase as the $6^{th}$ Size Korea over the time. In the case of circumference items, the tendency to increase in the $5^{th}$ and the $6^{th}$ Size Korea was observed. If the $5^{th}$ and the $6^{th}$ Size Korea were compared, there were no changes of other circumference items but chest circumference of the $6^{th}$ Size Korea was decreased in comparison with the $5^{th}$ Size Korea. Waist breadth(natural indentation) was increased in the $6^{th}$ Size Korea in spite of chest breadth was decreased in the $5^{th}$ and the $6^{th}$ Size Korea. And shoulder length, biacromion length and bishoulder length were decreased. The proportion of chest circumference, abdominal extension circumference and hip circumference to waist circumference and the proportion of chest breadth to waist breadth(natural indentation) showed the tendency to decrease as the $6^{th}$ Size Korea over the time. Conclusion: There was no change of stature excluding 17~18 years old. Circumference items showed tendency to increase as the $6^{th}$ Size Korea over the time. Shoulder and chest breadth became narrow. The somatotype changed to board chest with narrow waist in comparison with the previous. Application: In this way, the body size of 13~18 years' old boys changes. If these change characteristics reflects to the school uniform design, research for the pattern development, and etc., these will be able to improve fit and satisfaction of clothes.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.4
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• pp.462-468
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• 2016

In this paper, we present the results of the numerical analysis employing CONWEP, LS-DYNA FSI(Fluid Structure Interaction), AUTODYN FSI, LS-DYNA ALE(Arbitrary Lagrange Eulerian) and combination of CONWEP and LS-DYNA ALE for blast door fracture and wave propagation through the tunnel by the external explosion. We compared the numerical analysis results with the subscale test data and selected combination of CONWEP and LS-DYNA ALE method as adequate data generation method for the FRM(Fast Running Model) software development. It is expected to save much time and costs by using the numerical simulation data for the various test conditions.

• Journal of Digital Contents Society
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• v.19 no.3
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• pp.561-567
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• 2018

In this paper, we apply this method to the entire process of smart disaster safety management based on the $4^{th}$ industrial revolution to minimize human, social, economic and environment damage from accidents and disasters, prevention evaluation and disaster information collection analysis and real-time detection of field situation. Prevention of $5^{th}$ generation communication system by analysis, contrast by education and training using virtual reality and augmented reality disaster safety management decision support system intelligent robot for recovery, disaster, discovery, reconnaissance relief, and scale analysis of damages were proposed.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.2
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• pp.115-132
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• 2012

The purpose of this study is to examine the current status of user-contributed reviews for the Next Generation Library Catalogs, and the potential impact of user reviews available from the external sources, including Amazon.com and GoodReads.com. During the period of February 16th through April 4th, 2012, the number of holding libraries and user-contributed reviews, tags and reading lists of ten selected books were examined from the WorldCat. Also the user-contributed reviews for the same books available from Amazon.com and GoodReads.com were examined, and a case of reviews for one book was analyzed. The result shows that only a few users participated in the WorldCat, and user-contributed reviews were rarely used, when compared with tags or reading lists. Several hundred to thousand user-contributed reviews for the same books were available from Amazon.com and GoodReads.com directly linked with bibliographic records. A case of one book from Amazon.com reveals the possibility of distorting the function of user-contribution. With the introduction of the function of user-contribution, it is expected that its growth rate should be carefully observed and its potential impact on users should be thoroughly and systematically analyzed in the near future.