• The Korean Journal of Community Living Science
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• v.16 no.2
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• pp.61-73
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• 2005

This study aims to examine the socio-demographic heterogeneity of community participation in rural Korea. Data was collected through interviews with 1,870 rural householders and housewives who have lived in Up or Myen as an administrative unit of rural communities, and analyzed by the SPSS/PC Win V.10 program. The statistical techniques used for this study were frequency and percentile. The major findings of this study were as follows. Firstly, the extent to which rural people have participated in community organizations were: cooperative groups, $80.8\%$; religious groups, $20.6\%$; learning groups, $12.7\%$; political groups, $9.8\%;$ civil groups $6.7\%$; and voluntary groups, $5.3\%$. Whereas the numbers were high for community participation in groups related to agricultural production, participation in civil and voluntary groups were lower. Secondly, it showed that people who lived in urbanized and high population density areas were more likely to participate in community groups. The diversity of community organizations was different according to the level of rurality. Thirdly, farm householders were more likely to participate in religious, civil and voluntary groups than non-farm householders. Fourthly, people with higher education, females, those in the 40 to 50 age groups were more likely to participate in community organizations. Fifthly, even though men are more likely to participate in political parties, women were more likely then men to agree that women should participate in political parties. This empirical study could support the results of Sundeen (1988) and Wilson and Musick (1997) in that education was related positively to community participation. In addition, we concluded that community participation in a rural development process has two main considerations: philosophical and pragmatic. This implies that there is room for government to enable and facilitate 'true' community participation. That can be done through policy reform which creates a permissive environment for community decision-making and input, in addition to simply supporting community development through financial assistance.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.82.1-82.1
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• 2012

GRB100205A is a Gamma Ray Burst (GRB) which is suspected to be at redshift z=11-13 due to its very red H-K color($(H-K)_{vega}=2.1{\pm}0.5$). We observed a field centered at GRB100205A with Wide Field Camera (WFCAM) at United Kingdom Infrared Telescope (UKIRT) in Hawaii, in order to search a quasar that could be located around the GRB. The images were obtained in J, H, and K filters covering a square area of $0.78deg^2$. Our J-, H-, and K-band data reach the depths of 22.5, 22.1, and 21.0 mag (Vega) at $5{\sigma}$, respectively. Also using z-band image observed by CFHT, we find 8 candidates that have colors consistent with a quasar at z=11-13(non-detection in z-, J-band and $(H-K)_{vega}$ > 1.6). However, the shallow depths of J-, H-band are not enough to verify their true nature. Instead, we identify many red objects to be old or dusty galaxies at $z{\geq}3$. The number density of such objects appears about twice or more than that of the field of Cosmological Evolution Survey (COSMOS) and Ultra Deep Survey (UDS) of UKIRT Infrared deep sky survey (UKIDSS). On scales between 0.18' and 15' the correlation function is well described by a power law with an exponent of ${\approx}-0.9$ and this implies that those objects are like galaxies. It is interesting that many red galaxies exist in the region where the GRB was detected.

• Journal of KIISE:Software and Applications
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• v.27 no.4
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• pp.432-440
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• 2000

In this study, a new algorithm for canceling MRI artifact due to translational motion in image plane is described. Unlike the conventional iterative phase retrieval algorithm, in which there is no guarantee for the convergence, a direct method for estimating the motion is presented. In previous approaches, the motions in the x(read out) direction and the y(phase encoding) direction are estimated simultaneously. However, the features of x and y directional motions are different from each other. By analyzing their features, each x and y directional motion is canceled by different algorithms in two steps. First, it is noticed that the x directional motion corresponds to a shift of the x directional spectrum of the MRI signal, and the non-zero area of the spectrum just corresponds to the projected area of the density function on the x-axis. So the motion is estimated by tracing the edges between non-zero area and zero area of the spectrum, and the x directional motion is canceled by shifting the spectrum in inverse direction. Next, the y directional motion is canceled by using a new constraint condition, with which the motion component and the true image component can be separated. This algorithm is shown to be effective by using a phantom image with simulated motion.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.526-532
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• 2019

In this study, an in-house $^{152}Eu$ calibration source was produced from a custom epoxy matrix with a density of ${\rho}=1.14g\;cm^{-3}$, which is chemically stable and durable form after its solidification. The homogeneity of $^{152}Eu$ in matrix was obtained better than 98%. For a Marinelli beaker geometry, an efficiency calibration procedure was applied to a n-type, coaxial, 78.5% relative efficient HPGe detector in the energy range of 121.7-1408.0 keV by using in-house $^{152}Eu$ calibration source. Then the measured efficiencies for Marinelli geometry were compared with the results calculated by MEFFTRAN and ANGLE softwares for the validation. Although MEFFTRAN and ANGLE have two different efficiency transfer algorithms to calculate the efficiencies, they usually need to use a reliable and accurate reference efficiency values as input data. Hence, reference efficiency values were obtained experimentally from a multinuclide standard source for the same detector-Marinelli geometry. In the present source characterization, the corrections required for self-absorption and true coincidence summing effects for $^{152}Eu$ gamma-rays were also obtained for a such close counting geometry condition. The experimental results confirmed the validity of efficiency calculations obtained by MEFFTRAN and ANGLE softwares that are calculation tools.

• Steel and Composite Structures
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• v.46 no.4
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• pp.471-483
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• 2023

This paper presents an analytical hyperbolic theory based on the refined shear deformation theory for mechanical stability analysis of the simply supported advanced composites plates (exponentially, sigmoidal and power-law graded) under triangular, trapezoidal and uniform uniaxial and biaxial loading. The developed model ensures the boundary condition of the zero transverse stresses at the top and bottom surfaces without using the correction factor as first order shear deformation theory. The mathematical formulation of displacement contains only four unknowns in which the transverse deflection is divided to shear and bending components. The current study includes the effect of the geometric imperfection of the material. The modeling of the micro-void presence in the structure is based on the both true and apparent density formulas in which the porosity will be dense in the mid-plane and zero in the upper and lower surfaces (free surface) according to a logarithmic function. The analytical solutions of the uniaxial and biaxial critical buckling load are determined by solving the differential equilibrium equations of the system with the help of the Navier's method. The correctness and the effectiveness of the proposed HyRPT is confirmed by comparing the results with those found in the open literature which shows the high performance of this model to predict the stability characteristics of the FG structures employed in various fields. Several parametric analyses are performed to extract the most influenced parameters on the mechanical stability of this type of advanced composites plates.

• Journal of Convergence for Information Technology
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• v.12 no.2
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• pp.192-197
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• 2022

Although various studies have focused on the relationship between essential oils (EOs) and skin flora, there are only few comparative studies on the antibacterial properties of EOs and their efficacy against common microorganisms. In this study, we tested the antibacterial activity of 10 different EOs against Staphylococcus epidermidis(S. epidermidis) with oxacillin as control. Optical density was used to measure the activity of solutions containing the EOs and S. epidermidis at two different concentrations. Three EOs (palmarosa, lemongrass, and Mellissa True) had higher antibacterial activity than oxacillin, but their concentrations had negligible effect on antibacterial activity.

• Journal of Internet Computing and Services
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• v.20 no.5
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• pp.113-119
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• 2019

The key features of 5G mobile communications recently commercialized can be represented by High Data Rate, Connection Density and Low Latency, of which the features most distinct from the existing 4G will be low Latency, which will be the foundation for various new service offerings. AR and self-driving technologies are being considered as services that utilize these features, and 5G Network Latency is also being discussed in related standards. However, it is true that the discussion of E2E Latency from a service perspective is much lacking. The final goal to achieve low Latency at 5G is to achieve 1ms of air interface based on RTD, which can be done through Ultra-reliable Low Latency Communications (URLLC) through Rel-16 in early 20 years, and further network parity through Mobile Edge Computing (MEC) is also being studied. In addition to 5G network-related factors, the overall 5G E2E Latency also includes link/equipment Latency on the path between the 5G network and the IDC server for service delivery, and the Processing Latency for service processing within the mobile app and server. Meanwhile, it is also necessary to study detailed service requirements by separating Latency for initial setup of service and Latency for continuous service. In this paper, the following three factors were reviewed for initial setup of service. First, the experiment and analysis presented the impact on Latency on the Latency in the case of 1 Data Lake Setup, 2 CRDX On/Off for efficient power, and finally 3H/O on Latency. Through this, we expect Low Latency to contribute to the service requirements and planning associated with Latency in the initial setup of the required services.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3874-3897
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• 2023

A high-fidelity computational fluid dynamics (CFD) analysis was performed using the Large Eddy Simulation (LES) model for the lower plenum of the High-Temperature Test Facility (HTTF), a ¼ scale test facility of the modular high temperature gas-cooled reactor (MHTGR) managed by Oregon State University. In most next-generation nuclear reactors, thermal stress due to thermal striping is one of the risks to be curiously considered. This is also true for HTGRs, especially since the exhaust helium gas temperature is high. In order to evaluate these risks and performance, organizations in the United States led by the OECD NEA are conducting a thermal hydraulic code benchmark for HTGR, and the test facility used for this benchmark is HTTF. HTTF can perform experiments in both normal and accident situations and provide high-quality experimental data. However, it is difficult to provide sufficient data for benchmarking through experiments, and there is a problem with the reliability of CFD analysis results based on Reynolds-averaged Navier-Stokes to analyze thermal hydraulic behavior without verification. To solve this problem, high-fidelity 3-D CFD analysis was performed using the LES model for HTTF. It was also verified that the LES model can properly simulate this jet mixing phenomenon via a unit cell test that provides experimental information. As a result of CFD analysis, the lower the dependency of the sub-grid scale model, the closer to the actual analysis result. In the case of unit cell test CFD analysis and HTTF CFD analysis, the volume-averaged sub-grid scale model dependency was calculated to be 13.0% and 9.16%, respectively. As a result of HTTF analysis, quantitative data of the fluid inside the HTTF lower plenum was provided in this paper. As a result of qualitative analysis, the temperature was highest at the center of the lower plenum, while the temperature fluctuation was highest near the edge of the lower plenum wall. The power spectral density of temperature was analyzed via fast Fourier transform (FFT) for specific points on the center and side of the lower plenum. FFT results did not reveal specific frequency-dominant temperature fluctuations in the center part. It was confirmed that the temperature power spectral density (PSD) at the top increased from the center to the wake. The vortex was visualized using the well-known scalar Q-criterion, and as a result, the closer to the outlet duct, the greater the influence of the mainstream, so that the inflow jet vortex was dissipated and mixed at the top of the lower plenum. Additionally, FFT analysis was performed on the support structure near the corner of the lower plenum with large temperature fluctuations, and as a result, it was confirmed that the temperature fluctuation of the flow did not have a significant effect near the corner wall. In addition, the vortices generated from the lower plenum to the outlet duct were identified in this paper. It is considered that the quantitative and qualitative results presented in this paper will serve as reference data for the benchmark.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.1 no.1
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• pp.11-23
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• 2003

A study on the electrolytic dissolution of SUS-304 and Inconel-600 specimen was carried out in neutral salt electrolyte to evaluate the applicability of electrochemical decontamination process for recycle or self disposal with authorization of large amount of metallic wastes contaminated with uranium compounds generated by dismantling a retired uranium conversion plant in Korea. Although the best electrolytic dissolution performance for the specimens was observed in a Na2s04 electrolyte, a NaNO$_3$ neutral salt electrolyte, in which about 30% for SUS-304 and the same for Inconel-600 in the weight loss was shown in comparison with that in a Na$_2$SO$_4$ solution, was selected as an electrolyte for the electrochemical decontamination of metallic wastes with the consideration on the surface of system components contacted with nitric acid and the compatibility with lagoon wastes generated during the facility operation. The effects of current density, electrolytic dissolution time, and concentration of NaNO$_3$ on the electrolytic dissolution of the specimens were investigated. On the basis of the results obtained through the basic inactive experiments, electrochemical decontamination tests using the specimens contaminated with uranium compounds such as UO$_2$, AUC (ammonium uranyl carbonate) and ADU (ammonium diuranate) taken from an uranium conversion facility were performed in 1M NaNO$_3$ solution with the current density or In mA/$\textrm{cm}^2$. it was verified that the electrochemical decontamination of the metallic wastes contaminated uranium compounds was quite successful in a NaNO$_3$ neutral salt electrolyte by reducing $\alpha$ and $\beta$ radioactivities below the level of self disposal within 10 minutes regardless of the type of contaminants and the degree of contamination.

• Investigative Magnetic Resonance Imaging
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• v.18 no.3
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• pp.219-224
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• 2014

Purpose : To determine the incidence of truncated triangle appearance of anterior horn (AH) to body of medial meniscus (MM) and determine its clinical significance. Materials and Methods: IRB approval was obtained, and informed consent waived for this study. The criteria of "pseudoradial tear" was truncated triangle appearance of the tip of AH to body of MM on one or more coronal images with adjacent fluid signal intensity at the blunted tip. Two musculoskeletal radiologists retrospectively evaluated 485 knee MR images independently for the presence and number of sections with "pseudoradial tear" of AH to body of MM using proton density-weighted coronal MR images. Inter-and intraobserver agreement was calculated using kappa coefficients. Medical records were reviewed for arthroscopic correlation. Results: A pseudoradial tear in the AH to body of MM was present in 381 (78.6%) patients. Locations were 112 in AH (29.4%), 143 in AH to body (37.5%), and 126 in body (33.1%). Number of consecutive sections of pseudoradial tear were 1 in 100 (26.2%), 2 in 164 (43.0%), 3 in 94 (24.7%), 4 in 21 (5.5%), and 5 in 2 (0.5%). Interobserver agreement was 0.99 for presence and 0.43 for number of sections of pseudoradial tear. Arthroscopies were performed in 96 patients and none of the pseudoradial tears were proven as true radial tears on arthroscopy. Conclusion: Pseudoradial tears are frequently seen in AH to body of MM on coronal MR images and may be another pitfall that a radiologist needs to be aware of and be able to differentiate from true radial tear.