• Journal of radiological science and technology
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• v.38 no.1
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• pp.39-49
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• 2015

One of properties which X-ray and Neutron can be applied nondestructive test is penetration into the object with interaction leads to decrease in intensity. X-ray interaction with the matter caused by electrons, Neutron caused by atoms. They share applications in nondestructive test area because of their similarities of interaction mechanism. Grating interferometer is the one of applications produces phase contrast image and dark field image. It is defined by Talbot interferometer and Talbot-Lau interferometer according to Talbot effect and Talbot-Lau effect respectively. Talbot interferometer works with coherence beam like X-ray, and Talbot-Lau has an effect with incoherence beam like Neutron. It is important to expect the interference in grating interferometer compared normal nondestructive system. In this paper, simulation works are conducted according to Talbot and Talbot-Lau interferometer in case of X-ray and Neutron. Variation of interference intensity with X-ray and Neutron based on wave theory is constructed and calculate elements consist the system. Additionally, Talbot and Talbot-Lau interferometer is simulated in different kinds of conditions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.1
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• pp.65-74
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• 1985

This study is an experimental analysis for local scour of the riverbed at pier. The basic equation with dimensionless elements(Pier Reynolds Number, Dimensionless Turbulence Intensity) is derived through dimensional analysis. After testing the goodness of fit of data, the coefficients are determined by multiple regression analysis. In the region where the value of the attack angle is near 20 degrees, there exists a transition region where the slope of equation with Pier Reynolds Number changes from positive to negative and that of equation with Dimensionless Turbulence Intensity changes from negative to positive adversely. As a result of testing the equation suggested on this study by using the data of the Institute of National Construction, it is found that the scour depth and width at pier can be predicted approximately.

• Analytical Science and Technology
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• v.13 no.6
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• pp.766-774
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• 2000

The major and trace constituents of Mongolian chromite were analyzed by ICP-AES. The dissolution procedures, mixed acid ($HClO_4+H_3PO_4$) digestion and fusion with $Na_2O_2$ flux, have been studied to dissolve the chromite. The optimum dissolution method was found to be a fusion with $Na_2O_2$ flux. The effect of large amount of Na on major and trace constituents was examined when these elements were determined by ICP-AES. There was no effect on major elements at a concentration of Na 250 mg/L solution. The emission intensity of trace constituents containing Na 1,250 mg/L decreased to 1.0-5.2% according to elements and wavelengths. The result of this method was compared with that of neutron activation analysis (NAA) to confirm the accuracy of this procedure. The results between two methods were in a good agreement within less than 5% for $Al_2O_3$, $Cr_2O_3$, MgO and -20 to 8% for Co, Mn, V, Zn, respectively.

• Fire Science and Engineering
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• v.34 no.2
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• pp.97-102
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• 2020

The purpose of this study was to investigate the effectiveness of a Tabata exercise program as an alternative for firefighters whose working environment makes it difficult to manage physical fitness. The Tabata exercise program, in which 16 people participated, led to increased muscle mass and reduced weight and body fat, which not only improved the health of the firefighters but also improved their cardiopulmonary endurance, muscle endurance, and muscle strength, which are essential elements during firefighting emergency relief activities. On the basis of these results, it is believed that developing and providing guidelines for scientific and systematic exercise programs to firefighters will lead to better work capability during fire and disaster situations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6440-6445
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• 2014

In steel structures, including ships and offshore structures, defects induced during construction or in use causes cracks and damages. Calculation of the stress intensity factor (SIF) K is one method for crack analysis by fracture mechanics approach. In this paper, an evaluation of K was carried out using the J integral. In particular, in this study, a CT specimen was used to calculate the J integral. In the evaluation, 859 nodes and 1618 elements were used for the J integral calculation of the CT specimen by the in-house FEM program. A comparison of the result with the ASTM formula showed that the results from the current research of the J integral was in the 99% coincidence interval. Overall, cracks in this study can be studied satisfactorily by the J integral from the above mesh size.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.235-243
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• 2014

In this paper, we propose an efficient control system for intelligent LED indoor lighting. The proposed an efficient control system for intelligent LED indoor lighting were included to elements such as daylight intensity measured through the PIR sensor and illuminance sensor at lighting style by the schedule defined and the occupancy detection. And it was controlled lighting through to the wireless sensor network, and was designed for the energy savings. Also, the lighting control of indoor lighting based on occupancy detection detect fine movements using a PIR sensor. And an unnecessary lighting intensity control of the window-side and the inside were controlled according to daylight level measurement result using the light sensor. In daylight inflow many case, the window-side lighting was to automatically darker, and in daylight inflow less case, was designed to be automatically bright. The efficiency validate results of an efficient control system for intelligent LED indoor lighting, the brightness of the indoor light were to maximize the energy saving by controlling in real time when entering as indoor a little that external lighting or daylight.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.713-724
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• 2004

A fatigue crack found at the coped stringer of the old dismantled Dangsan Subway Bridge was numerically simulated. A model of a single span of the plate girder bridge with its beam elements was created and analyzed in order to obtain the nominal stress history caused by trains. A detailed FEM analysis of the coped stringer was conducted using a shell element model. A fracture mechanical model was used to estimate crack propagation. The stress intensity factors were calculated using the J-Integral method. The simulation with some reasonable assumptions showed that the calculated crack lengths were comparable to those found on the site.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.5 s.311
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• pp.37-44
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• 2006

In this paper, a new version of the ICM method(MICM, modified ICM) in which the contextual information is modelled by Markov random fields (MRF) is introduced. To extract the feature, a new local MRF model with a fitting block neighbourhood is proposed. This model selects contextual information not only from the relative intensity levels but also from the geometrically directional position of neighbouring cliques. Feature extraction depends on each block's contribution to the local variance. They discriminates it into several regions, for example context and background. Boundaries between these regions are also distinctive. The proposed algerian performs segmentation using directional block fitting procedure which confines merging to spatially adjacent elements and generates a partition such that pixels in unified cluster have a homogeneous intensity level. From experiment with ink rubbed copy images(Takbon, 拓本), this method is determined to be quite effective for feature identification. In particular, the new algorithm preserves the details of the images well without over- and under-smoothing problem occurring in general iterated conditional modes (ICM). And also, it may be noted that this method is applicable to the handwriting recognition.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.380-387
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• 2011

This study was to investigate the effects of music-combined respiration and oral motor training on the voice of healthy elderly. 27 women attending a senior center in Seoul participated and were randomly assigned to the experimental (n = 16) and the control group (n = 11). Subjects attended music program(25 minutes per session) once a week for 4 weeks. For both groups, Fundamental Frequency (F0), Maximum Phonation Time (MPT) and Sequential Motion Rates (SMR) were measured using the Praat speech analysis program before and after the training. The results showed statistical significance in scores of intensity, F0, MPT, and SMR in the experimental group while only intensity was statistically significant in the control group. Considering that, the increasing life expectancy and growing number of older adults, their quality of life has been important. So this study suggests that the respiration and oral motor training would be effectively incorporated into training and services for this population.

• Nuclear Engineering and Technology
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• v.32 no.1
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• pp.1-9
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• 2000

Delayed hydride cracking (DHC) velocity and threshold stress intensity factor for DHC ($K_{IH}$) tests in the radial direction on M11 pressure tube material in Wolsong unit 1 were carried out following the Atomic Energy Canada Limited (AECL) standard test procedure in order to identify the effect of undercooling on DHCV and to acquire the $K_{IH}$ data. The results showed that $K_{IH}$ 's were 8.8$\pm$0.8 MPa√m in the back offcut and 11.4$\pm$0.7 MPa√m in the front offcut. The fact that $K_{IH}$ in the front offcut is about 20% higher than that in the back offcut is attributed to the microstructural difference between the materials of the front and back ends. $K_{IH}$ 's in M11 pressure tube appeared to be higher than the values from the tubes made of double melted ingot reported earlier. This can be interpreted by the fact that very small amounts of Chlorine (Cl) and Phosphorus (P) are contained in the ingot and that the content of the harmful elements in the M11 pressure tube is equivalent to that made of a quadruple melting process. DHC velocities at 25$0^{\circ}C$ in the front offcut in the radial direction are measured to be 5~8$\times$10$^{-8}$ m/s. The results show that the prior thermal history change the DHC velocity significantly. This effect was confirmed by the experiment of undercooling prior to the DHC tests.DHC tests.