• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.4
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• pp.403-414
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• 1997

The distribution of the space debris caused by any source affects the DBS & FSS wave propagation for satellite communication. In this paper, the normalized expansion coefficients are evaluated with varying the volume distribution density of space debris and the operating frequency, and then the attenuation and phase shift are calculated by using the normalized expansion coefficients. Conclusively, the attenuation and phase shift are mostly affected with the real and imaginary part of the amplitude function, respectively, which represented by electric field component of the Bessel function. The results of this paper adapted for the design of the link budget for satellite communication system and the reconsideration of space environment as the space debris increses by geometric progression.

• Journal of Radiation Protection and Research
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• v.43 no.1
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• pp.20-28
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• 2018

Background: Heat energy produced in nuclear reactors and nuclear fuel cycle facilities interactions modifies the physical properties of the shielding materials containing water content. Therefore, in the present paper, effect of the heat on shielding effectiveness of the concretes is investigated for gamma and neutron. The mass attenuation coefficients, effective atomic numbers, fast neutron removal cross-section and exposure buildup factors. Materials and Methods: The mass attenuation coefficients, effective atomic numbers, fast neutron removal cross-section and exposure buildup factors of ordinary and heavy concretes were investigated using NIST data of XCOM program and Geometric Progression method. Results and Discussion: The improvement in shielding effectiveness for photon and reduction in fast neutron for ordinary concrete was observed. The change in the neutron shielding effectiveness was insignificant. Conclusion: The present investigation on interaction of gamma and neutron radiation would be very useful for assessment of shielding efficiency of the concrete used in high temperature applications such as reactors.

• Journal of the Korean Society for Library and Information Science
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• v.37 no.2
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• pp.135-152
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• 2003

With the rapid growth of the Internet, digital contents have increased in a geometric progression and the types also became much varied. In order to make it easier to identify and search digital contents on the Internet, which is basically a distributed network environment, it is essential to organize and manage metadata. In this study, we have comparatively analyzed the data elements of the meta data formats currently approached from different aspects in diverse fields, so as to provide basic materials for securing interoperability of the meta data formats. We selected Dublin Core, Semantic Header, MARC, IAFA Templates, and TEI Header as the general metadata formats of digital contents used widely in all areas, and we carried out comparisons and analyses based on the literature.

• Smart Media Journal
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• v.8 no.2
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• pp.80-85
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• 2019

Generally, interlayer noise is measured in decibels (A) in terms of free field. In this paper, we propose a measurement method of interlayer vibration acceleration in the diffusion field perspective. The proposed method can represent a vibration-embodied formula similar to the sensitivity of earthquake intensity when the natural vibration of apartment house is measured by acceleration with its average value of $20mm/s^2$ represented by an the geometric progression of radix. Based on this theory, this paper proposes a method to show the optimal user experience (UX) by applying the interlayer vibration acceleration of the epicenter to the system of human - computer interaction (HCI).

• Structural Engineering and Mechanics
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• v.70 no.4
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• pp.431-443
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• 2019

The present paper illustrates a numerical investigation on the failure behaviour of ring-stiffened cylinder subjected to external hydrostatic pressure. The published test data of steel welded ring-stiffened cylinder are surveyed and collected. Eight test models are chosen for the verification of the modelling and FE analyses procedures. The imperfection as the consequences of the fabrication processes, such as initial geometric deformation and residual stresses due to welding and cold forming, which reduced the ultimate strength, are simulated. The results show that the collapse pressure and failure mode predicted by the nonlinear FE analyses agree acceptably with the experimental results. In addition, the failure mode parameter obtained from the characteristic pressure such as interframe buckling pressure known as local buckling pressure, overall buckling pressure, and yield pressure are also examined through the collected data and shows a good correlation. A parametric study is then conducted to confirm the failure progression as the basic parameters such as the shell radius, thickness, overall length of the compartment, and stiffener spacing are varied.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4426-4430
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• 2023

In this article, Exposure Buildup Factor(EBF) and the Energy Absorption Buildup Factor(EABF) have been determined for blood, brain, and muscle using the Monte Carlo method which is represented by MCNP5 codes and compared with geometric progression(G-P) fitting method which is represented by Phy-X/PSD online platform. The novelty of the present work is used an energy source of less than 0.1 MeV to determine buildup factors using MCNP5 and using Phy-X/PSD for some human tissues. thus, the energy range used in this case study was 0.06-3 MeV for penetration depths covered 0.5-3 MFP. Results of MCNP5 and Phy-X/PSD are validated against reference values of water that were reported at ANS-6.4.3. present results of EABFs and EBFs for the previously mentioned human tissues appeared good agreement between MCNP5 in comparison with Phy-X/PSD, whereas, the maximum average relative deviation did not exceed 2.37%. results of our article can be used in different medical applications, such as brachytherapy, radiotherapy, and diagnostics.

• Journal of Nutrition and Health
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• v.36 no.3
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• pp.280-286
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• 2003

Conjugated linoleic acid (CLA) consists of several geometric isomers of linoleic acid. CLA is found in foods derived from ruminants and exhibits strong anticarcinogenic effects in a variety of animal models. Matrix metalloproteinases (MMPs) play a key role in cancer progression. Specifically, MMP-2 and -9, which hydrolyze the basal membrane type IV collagen, are involved in the initial breakdown of collagen and basement membrane components during tumor growth and invasion. However, the effects of CLA on cancer cell motility and MMP expression and activity are not currently well known. Therefore, the present study examined whether CLA reduces the activity of MMP and cell motility in SW480 and SW620 cells, the human colon cancer cell lines. Gelatin zymography and Western blot analysis revealed that phorbol 12-myristate 13-acetate (PMA) induced the activity and protein expression of Mr 92,000 MMP-9 in both cell lines. To examine whether CLA inhibits the MMP activity, cells were incubated with 100 ngfmL PMA in the presence of various concentrations of CLA. PMA-induced MMP-9 activity was decreased by 20 $\mu$ M CLA in SW480 cells, and by 10 $\mu$ M and 20 $\mu$ M CLA in SW620 cells. Results from the Hoyden chamber assay showed that cell motility was increased by PMA and that PMA-induced cell motility was significantly decreased by 20 $\mu$ M CLA in SW480 cells. These results indicate that CLA may reduce the motility and MMP activity in human colon cancer cells.

• Journal of The Korean Association of Information Education
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• v.8 no.4
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• pp.501-510
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• 2004

The activation of the latest ICT(Information and Communication Technology)education has been putting more importance on the education of the application SW(software). By the way, the geometric progression of knowledge and the fast development of computer technology have continuously created new SW. Accordingly, the previous traditional SW learning paradigm runs into various problems. This study starts from the recognition of such problems. In this study, the SW adaptability is defined as the ability that learners can efficiently find and apply the suitable functions of SW to those problems in the problematic circumstances as well as promote retention and metastasis. With these premises, this paper makes an inquiry into the teaching-learning method. Besides, This paper explores the SW usability and the principles of UI(User Interface) design and deduces the SW learning strategy. Furthermore, it probes problems of the SW teaching-learning of the demonstration practice method and proposes the inquiring master for SW adaptability teaching-learning model.

• Journal of Korean society of Dental Hygiene
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• v.7 no.3
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• pp.259-271
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• 2007

AIDS is increasing by geometric progression in the world with more seriousness and HIV/AIDS is still spreading. Thus, the study enforced a self-administered survey with 526 dental hygiennics students to carry out an upright recognition and education on AIDS by grasping knowledge and attitude of dental hygienics students who will work at dental hospitals or clinics after graduating in AIDS. As the result, the study got the following conclusion. 1. 51.1% of the students got knowledge on AIDS and the majority out of them got its knowledge through school(35.2%) or mass media(10.8%). 2. The average score of dental hygienics students' knowledge in AIDS was 87.67: The first-grade students(86.00), the second-grade students(88.88) and the third-grade students(88.37) (p=0.000). 3. They had an accurate recognition about AIDS' causes, its infection ways and interceptive methods of its infection way in knowledge of AIDS(p=0.000). 4. In their attitudes for AIDS, the average score was $57.43{\pm}$: The first-grade students(56.19), the second-grade students(57.70) and the third-grade students(58.70)(p=0.001). 5. In their attitudes for AIDS, the students($4.09{\pm}0.82$ scores) responded that they would prepare for AIDS' infection of their families(p=0.004) while, on the other hand, the students($4.06{\pm}0.82$ scores) responded that they wanted to avoid PWA's dental treatment(p=0.001). Therefore, it is judged that vocational education as a specialized worker as well as AIDS education should be realized since it was appeared that they had not enough thought as a mature professional worker. 6. Dental hygienics students who would work at dental hospitals or clinics after graduating were in the environment infected in all diseases and so most of the students($4.23{\pm}0.74$) responded that AIDS education should be included in curriculum.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1456-1461
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• 2003

Recently, the quantity of using information go on increasing geometric-progression. At the same time, the management of information is effected on the most organization's effective operation so that many user call for the powerful equipment which expound. access more information. As information searching technology is concentrated about the object of information based on a letter mainly, an effective searching technology for the object of multimedia such as a still image, a video and a sound must be studied. As a monitor of computer is 2-D, it difficult for one to grasp the whole aspect at a look glance like a library. Accordingly, some condition is necessary. First, it acquired the virtual video, turning a camera around by 30 degrees with a camera of 15mm lens, giving a warping and distortion. Second, it improved the books for user to search easily, adding to the video in existing books information system. The original text suggests some way which can embody the video searching technology under the base of personal computer.