• Advances in concrete construction
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• v.14 no.5
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• pp.355-368
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• 2022

This paper investigates the impact of length and volume fractions (VFs) of banana fibres (BFs) on the mechanical and physical properties of concrete. The mechanical properties were compressive strength, splitting tensile, flexural strength, and bond stress, while the physical properties were unit weight and absorption. The slump test was used to determine workability. The concrete's behaviour with BFs was studied using scanning electron microscopy. Experimental work of concrete mixtures with BFs of various lengths (12 mm, 25 mm, and 35 mm) and VFs (0%, 0.5%, 1.0%, and 1.5%) were carried out. The samples did not indicate any agglomeration of fibres or heterogeneity during mixing. The addition of BFs to concrete with VFs of up to 1.50% for all fibre lengths have a significant impact on mechanical properties, also the longer fibres performed better than shorter ones at all volume fractions of BFs. The mix10, which contain BFs with VFs 1.5% and length 35 mm, demonstrated the highest mechanical properties. The compressive strength, splitting tensile, flexural strength, and bond stress of the mix10 were 37.71 MPa, 4.27 Mpa, 6.12 MPa, and 6.75 MPa, an increase of 7.37%, 20.96%, 24.13%, and 11.2% over the reference concrete, which was 35.12 MPa, 3.53 MPa, 4.93 MPa, and 6.07 MP, respectively. The absorption is increased for all lengths by increasing the VFs up to 1.5%. Longer fibres have lower absorption, while shorter fibres have higher absorption. The mix8 had the highest absorption of 4.52%, compared to 3.12% for the control mix. Furthermore, the microstructure of concrete was improved through improved bonding between the fibres and the matrix, which resulted in improved mechanical properties of the composite.

• Journal of muscle and joint health
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• v.16 no.1
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• pp.55-65
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• 2009

Purpose: The purpose of this study was to determine the effects of water exercise program on physical fitness, pain and quality of life(QoL) in patients with osteoarthritis. Methods: Thirty-four old women were divided into the exercise(EG, n=18) and control groups(CG, n=16) after 6-week self-help education program. The EG carried out 6-week supervised water exercise program(60min/day, 2days/wk). Physical fitness, pain, and QoL were assessed by Senior Fitness Test Manual(Rikli & Jones, 2005), Pain rating scale(0-10) and World Health Organization QoL BREF(Min et al., 2000), respectively. Results: Both EG and CG increased upper and lower-body strength(all, p<.05), which were measured by arm curl and chair stand, respectively. For flexibility test, the EG increased upper and lower body(all, p<.05). Balance of the EG increased(p<.05), but not in the CG. Pain significantly decreased in the EG post training(p=.000). However, both EG and CG did not significantly improve for QoL. Conclusion: Six weeks of water exercise program did induce significant improvement in physical fitness and pain control in patients with osteoarthritis.

• Journal of the Korean Society for information Management
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• v.40 no.4
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• pp.259-277
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• 2023

This study aims to identify the academic landscape of the field of Library and Information Science by analyzing the research areas of the four major domestic journals using structural topic modeling and network analysis. The results show that each journal focuses on different research areas. The Journal of the Korean Society for Library and Information Science covers the most comprehensive range of research areas in the field, while the Journal of the Korean Biblia Society for Library and Information Science shows a similar research trend but with a higher preference for research areas related to library management and library programs. The Journal of Korean Library and Information Science Society deals more with topics related to school libraries and reading education and the Journal of the Korean Society for Information Management focuses more on information technology and information science. This study is able to provide valuable foundational data for researchers in submitting their papers and for the topical specialization and diversification of the journals in the field of Library and Information Science.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.4
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• pp.107-112
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• 2024

One More Pumpkin won the grand prize at the 2023 Dubai International AI Film Festival, and new possibilities were also opened through the International AI and Metaverse Film Festival (GAMFF), which was held for the first time in Korea. Generative works began to stand out in earnest, with 527 diverse works from 42 countries at home and abroad using AI and metaverse technology submitted to this contest. AI is being used in a variety of fields, including the creation and implementation of digital characters through combination with VFX, improving the efficiency of video production, and managing the overall video production process. This contributes to saving human and material resources required for production and significantly improving the quality of produced videos. However, generative AI also has ambiguity in copyright attribution, ethical issues inherent in the learned dataset, and technical limitations that fall short of the level of human emotion and creativity. Accordingly, this study suggests implications at the level of production, screening, and use, as generative AI may have an impact in more areas in the future.

• Journal of the Korean earth science society
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• v.41 no.5
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• pp.504-519
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• 2020

Oceanic fronts, which are areas where sea water with different properties meet in the ocean, play an important role in controlling weather and climate change through air-sea interactions and marine dynamics such as heat and momentum exchange and processes by which properties of sea water are mixed. Such oceanic fronts have long been described in secondary school textbooks with the term 'Jokyung water zone (JWC hereafter) or oceanic front', meaning areas where the different currents met, and were related to fishing grounds in the East Sea. However, higher education materials and marine scientists have not used this term for the past few decades; therefore, the appropriateness of the term needs to be analyzed to remove any misconceptions presented. This study analyzed 11 secondary school textbooks (5 middle school textbooks and 6 high school textbooks) based on the revised 2015 curriculum. A survey of 30 secondary school science teachers was also conducted to analyze their awareness of the problems. An analysis of the textbook contents related to the JWC and fishing grounds found several errors and misconceptions that did not correspond with scientific facts. Although the textbooks mainly uses the concept of the JWC to represent the meeting of cold and warm currents, it would be reasonable to replace it with the more comprehensive term 'oceanic front', which would indicate an area where different properties of sea water-such as its temperature, salinity, density, and velocity-interact. In the textbooks, seasonal changes in the fishing grounds are linked to seasonal changes in the North Korean Cold Current (NKCC), which moves southwards in winter and northwards in summer; this is the complete opposite of previous scientific knowledge, which describes it strengthening in summer. Fishing grounds are not limited to narrow coastal zones; they are widespread throughout the East Sea. The results of the survey of teachers demonstrated that this misconception has persisted for decades. This study emphasized the importance of using scientific knowledge to correct misconceptions related to the JWC, fishing grounds, and the NKCC and addressed the importance of transferring procedures to the curriculum. It is expected that the conclusions of this study will have an important role on textbook revision and teacher education in the future.

• Journal of Nutrition and Health
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• v.54 no.5
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• pp.547-559
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• 2021

Purpose: This study compares the snacking pattern, diet, lifestyle, and food preference of children by evaluating the most frequently eaten snacks. Methods: The survey enrolled 435 students from three elementary schools in Gyeonggi. Based on the most frequently eaten snacks, the subjects were divided into 3 groups: fruits and milk/dairy products for natural snacks (NS, n = 114); noodles, snack foods and fast foods for meal-like snacks (MS, n = 74); cookies, beverages and bread as sweet snacks (SS, n = 247). Results: Compared to the MS group, preferences of the NS group were significantly higher for jabgokbap (cooked rice with multi-grains, p < 0.05) and saengchae (seasoned raw vegetables, p < 0.01), and significantly lower for gogitwigim (deep-fried meat, p < 0.05). Taste preference of the NS group was considered to be more desirable; the taste preference of more subjects was 'sweet taste' in the SS group, 'spicy taste' in the MS group, 'salty taste' in the MS and SS groups, and 'sour taste' and 'bland taste' in the NS group than the other groups. Compared to the MS and SS groups, the NS group was determined to exercise more frequently; exercising for more than 30 minutes/day was determined to be 76.3% in the NS group and 58.1% and 57.9% in the other groups (p < 0.01). Moreover, a higher proportion of subjects in the MS group tended to answer 'not hungry' as the reason for leaving school meals, as compared to other groups (p = 0.055), thereby suggesting that inappropriate snacking habits interfere with regular meals. Conclusion: This study provides evidence that healthy snacking habits, which include natural snacks such as milk/dairy products and fruits, are important for children during the elementary school years, since these habits are associated with healthier diet, lifestyle, and food and taste preferences. These results provide basic information for developing nutritional education materials for elementary school children.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.6
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• pp.787-794
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• 2006

The purpose of this study was to investigate the interests in food and nutrition information of internet users, and find the major problems associated with the use of internet information. Of 660 internet users, including 152 professionals, 127 white-collars, 130 college students, and 29 others, 66.4% had accessed the internet to obtain information. Of the subjects, 71% had used the internet to obtain nutrition information, 91.3% of which answered that they would keep using the internet for this purpose. The area of greatest interest and need of the professional users, in relation to nutrition information from the internet, was 'recipe and menu' (p<0.001). Whereas, the white-collars were most interested in nutrition information for 'diet for weight control' and 'diet'(p<0.001). Students were most interested in nutrition information related to 'diet' and 'diet for weight control'(p<0.001). Due to the variety of interests and applications of different users, there is a need to develop specialized nutrition information sites for internet users to easily obtain reliable and valuable information.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.1
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• pp.76-84
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• 2009

This paper proposes a SOC platform which is eligible for education and application SOC design. The platform, fully synthesizable and reconfigurable, includes the OpenRISC embedded processor, some basic peripherals such as GPIO, UART, debug interlace, VGA controller and WISHBONE interconnect. The platform uses a set of development environment such as compiler, assembler, debugger and RTOS that is built for HW/SW system debugging and software development. Designed SOC, IPs and Testbenches are described in the Verilog HDL and verified using commercial logic simulator, GNU SW development tool kits and the FPGA. Finally, a multimedia SOC derived from the SOC platform is implemented to ASIC using the Magnachip cell library based on 0.18um 1-poly 6-metal technology.

• Structural Engineering and Mechanics
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• v.66 no.5
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• pp.569-582
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• 2018

Effects of crack separation, bridge area, on the tensile behaviour of concrete are studied experimentally and numerically through the Brazilian tensile test. The physical data obtained from the Brazilian tests are used to calibrate the two-dimensional particle flow code based on discrete element method (DEM). Then some specially designed Brazilian disc specimens containing two parallel cracks are used to perform the physical tests in the laboratory and numerically simulated to make the suitable numerical models to be tested. The experimental and numerical results of the Brazilian disc specimens are compared to conclude the validity and applicability of these models used in this research. Validation of the simulated models can be easily checked with the results of Brazilian tests performed on non-persistent cracked physical models. The Brazilian discs used in this work have a diameter of 54 mm and contain two parallel centred cracks ($90^{\circ}$ to the horizontal) loaded indirectly under the compressive line loading. The lengths of cracks are considered as; 10 mm, 20 mm, 30 mm and 40 mm, respectively. The visually observed failure process gained through numerical Brazilian tests are found to be very similar to those obtained through the experimental tests. The fracture patterns demonstrated by DEM simulations are mostly affected by the crack separation but the tensile strength of bridge area is related to the fracture pattern and failure mechanism of the testing samples. It has also been shown that when the crack lengths are less than 30 mm, the tensile cracks may initiate from the cracks tips and propagate parallel to loading direction till coalesce with the other cracks tips while when the cracks lengths are more than 30 mm, these tensile cracks may propagate through the intact concrete itself rather than that of the bridge area.

• Geomechanics and Engineering
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• v.13 no.4
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• pp.535-570
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• 2017

There are only few cases where cause and location of failure of a rock structure are limited to a single discontinuity. Usually several discontinuities of limited size interact and eventually form a combined shear plane where failure takes place. So, besides the discontinuities, the regions between adjacent discontinuities, which consist of strong rock and are called material or rock bridges, are of utmost importance for the shear strength of the compound failure plane. Shear behaviour of persistent and non-persistent joint are different from each other. Shear strength of rock mass containing non-persistent joints is highly affected by mechanical behavior and geometrical configuration of non-persistent joints located in a rock mass. Therefore investigation is essential to study the fundamental failures occurring in a rock bridge, for assessing anticipated and actual performances of the structures built on or in rock masses. The purpose of this review paper is to present techniques, progresses and the likely future development directions in experimental testing of non-persistent joint failure behaviour. Experimental results showed that the presence of rock bridges in not fully persistent natural discontinuity sets is a significant factor affecting the stability of rock structures. Compared with intact rocks, jointed rock masses are usually weaker, more deformable and highly anisotropic, depending upon the mechanical properties of each joint and the explicit joint positions. The joint spacing, joint persistency, number of rock joint, angle of rock joint, length of rock bridge, angle of rock bridge, normal load, scale effect and material mixture have important effect on the failure mechanism of a rock bridge.