• Nuclear Engineering and Technology
• /
• v.55 no.8
• /
• pp.3030-3038
• /
• 2023

Nowadays, mobile robots have been used to search for uncontrolled radioactive source in indoor environments to avoid radiation exposure for technicians. However, in the indoor environments, especially in the presence of obstacles, how to make the robots with limited sensing capabilities automatically search for the radioactive source remains a major challenge. Also, the source search efficiency of robots needs to be further improved to meet practical scenarios such as limited exploration time. This paper proposes an automatic source search strategy, abbreviated as ACA: the location of source is estimated by a convolutional neural network (CNN), and the path is planned by the A-star algorithm. First, the search area is represented as an occupancy grid map. Then, the radiation dose distribution of the radioactive source in the occupancy grid map is obtained by Monte Carlo (MC) method simulation, and multiple sets of radiation data are collected through the eight neighborhood self-avoiding random walk (ENSAW) algorithm as the radiation data set. Further, the radiation data set is fed into the designed CNN architecture to train the network model in advance. When the searcher enters the search area where the radioactive source exists, the location of source is estimated by the network model and the search path is planned by the A-star algorithm, and this process is iterated continuously until the searcher reaches the location of radioactive source. The experimental results show that the average number of radiometric measurements and the average number of moving steps of the ACA algorithm are only 2.1% and 33.2% of those of the gradient search (GS) algorithm in the indoor environment without obstacles. In the indoor environment shielded by concrete walls, the GS algorithm fails to search for the source, while the ACA algorithm successfully searches for the source with fewer moving steps and sparse radiometric data.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.47 no.3
• /
• pp.151-156
• /
• 2002

The heritability of sink-source characters was estimated by regression coefficient between F$_2$ and F$_{5}$ in two crosses of IR 66738-118-1-2/Gayabyeo and the Ilpumbyeo/YR 15965 Acp 33. In order to get the some basic information for breeding of high yielding rice, genetic resources of new plant type with low tiller and heavy panicle were used. Most of the sink and source characters in Ilpumbyeo/YR 15965 Acp 33 cross showed high heritability over than 0.224. But the specific leaf area and sink-source ratio displayed low heritability being 0.009 and 0.013, respectively. Heritability of all sink and source characters in IR 66738-118-1-2/Gayabyeo cross ranged from 0.115 to 0.247. Correlation coefficient between yield and yield components in both combination were in the ranged between 0.001 and 0.247. But correlations among the yield components were not significant. Correlations between the yield and sink-source characters in both combinations were also highly significant. Particularly, correlation between the grain tiling ratio and most of the sink-source characters in IR 66738-118-1-2/Gayabyeo cross were not significant. In Ilpumbyeo/YR 15965 Acp 33 cross, correlations between grain filling ratio and source characters were positively significant. but sink characters (sink capacity and sink-source ratio, etc) were negatively significant.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.10a
• /
• pp.1069-1070
• /
• 2005

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.6
• /
• pp.701-717
• /
• 2003

The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

• The Research Journal of the Costume Culture
• /
• v.4 no.2
• /
• pp.157-171
• /
• 1996

The purpose of this study was to find out the effect of fashion information source in the stage of purchase decision-making and difference by stage of purchase decision-making and difference by stage of the effect extend, and to analyze the difference by fashion information source. For this study, the data were collected through the questionnaire distributed to 337 female students from five universities. The results are as follows: 1) There was significant difference among the effect to fashion information source according to the purchase decision-making stage. At the adoption stage, fashion information source have the most effect on clothing purchase. 2) The effect of Impersonal Source in the purchase decision-making stage was gradually decreased fro the initial (awareness, interest) sage to the late stage. 3) The effect of Personal Source in the purchase decision-making stage was gradually increased from the initial (awareness, interest) stage to the late stage. 4) Addition stage was highly influenced by friend and family that was Personal Independent Source than other fashion information source. However the final selection on clothing purchase was not influenced by friend and family. 5. There was significant difference among the effect of fashion information source according to the grade. Low garde students were highly influenced by Personal Source on clothing purchase, but high grade students were highly influenced by Impersonal Sources on clothing purchase. 6) There was significant difference among the effect of fashion information source according to the major. The students a majored clothing & textile-design were highly influenced by Impersional Source. These results suggest that fashion information source was significantly different according to purchase decision-making stage and was influenced by grade and major of subjects.

• The Korean Journal of Mycology
• /
• v.1 no.2
• /
• pp.25-30
• /
• 1973

The Aspergilli can be isolated from many of damaged domestic fowl's lung which were collected at fowl slaughter house from July to August 1973, during two months at Dapsimri, Dongdaemoon-ku, Seoul city. The survey of incubation condition for carbon source and nitrogen source were summerized as follows: 1. One of the Aspergillius fumigatus group were isolated from damaged domestic fowl's lung. 2. In the preparation of isolation media, adding the 4 gs of silkworm pupa and Meju to Czapek's agar medium is more preferable than Austick's media (2% malt extract agar) 3. In survey of incubation condition, the growth rate and sporulation shown that higher differences according to varieties and amounts of C-source. And in the case of 20% C-source concentration shown that low growth rate than lower concentration of C-source. 4. In N-source, the growth rate indicated that some difference according to varieties of N-source, difference of growth rate demonstrated almost not shown at various amounts differences of mycelium and sporulation was only detected reversely.

• Nuclear Engineering and Technology
• /
• v.52 no.6
• /
• pp.1266-1270
• /
• 2020

A code is developed to correct for the coincidence summing effect in detecting a voluminous gamma source, and this code is applied to a¹⁵²Eu standard source as a test case. The source is 1000 mL of liquid in a cylindrical shape. To calculate the coincidence summing effect, the cylindrical source is considered as 10(radial) × 8(height) sectional sources. For each sectional source, the peak efficiency and total efficiency are obtained by Monte Carlo simulation at each energy for 10 energies between 50 keV and 2000 keV. The efficiencies of each sector are then expressed as polynomials of gamma energy. To calculate the correction coefficients for the coincidence summing effect, the KORSUM code is used after modification. The magnitudes of correction are 4%-17% for the standard ¹⁵²Eu source measured in this study. The relative deviation of 4.7% before the coincidence correction is reduced to 0.8% after the correction is applied to the efficiency based on the measured gamma line. Hence, this study has shown that a new method has been developed that is applicable for correcting the coincidence effect in a voluminous source, and the method is applied to the measured data of a standard ¹⁵²Eu cylinder source.

• The Journal of Korean Association of Computer Education
• /
• v.18 no.4
• /
• pp.63-70
• /
• 2015

Program source code is a set of complex syntactic information which are expressed in text forms, and contains complex logical structures. Structural and logical complexity inside source code become barriers in applying visualization techniques shown in traditional big-data approaches when the volume of source code become over ten-thousand lines of code. This paper suggests a procedure for making visualization of structural characteristics in source code. For this purpose, this paper defines internal data structures as well as inter-procedural relationships among functions. The paper also suggests a means of outlining the structural characteristics of source code by visualizing the source codes with network forms The result of the research work can be used as a means of controling and understanding the massive volume of source code.

• The Journal of the Acoustical Society of Korea
• /
• v.35 no.1
• /
• pp.35-41
• /
• 2016

Based on correlation and least square method, a closed-form algorithm for estimating the location of mixed far-field and near-field source is presented using the Uniform Circular Array (UCA). Recently, for a homogeneous circular arrangement case, a correlation based closed-form algorithm is proposed to estimate 2-D angle (azimuth, elevation) and the extended algorithm is proposed to 3-D location (azimuth, elevation, range). These algorithms assume the far-field source or near-field source only. Therefore, for mixed source localization, the proposed algorithm estimates source location with the assumption of far-field source, and then estimates the range to distinguish the far-field from the near-field source. For both cases, numerical experiments have been performed, which confirmed the validity of the proposed algorithm.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.1 no.1
• /
• pp.67-76
• /
• 2012

Due to the increasing amount of applications of power electronic ac-dc converters, it is necessary to design a single-stage converter that can reliably perform both buck and boost operations. Traditionally, this can be achieved by double-stage conversion (ac/dc-dc/dc) which ultimately leads to less efficiency and a more complex control system. This paper discusses two types of modern ac-dc converters. First, the novel impedance-source ac-dc converter, abbreviated as custom Z-source rectifier, is analyzed; and then, switched inductor (SL) Z-source ac-dc converter is proposed. This paper describes the Z-source rectifiers' operating principles, the concepts behind them, and their superiorities. Analysis and simulation results show that the proposed custom Z-source rectifier can step up and step down voltage; and the main advantage of the SL Z-source ac-dc converter is its high step-up capability. Low ripple of the output dc voltage is the other advantage of the proposed converters. Finally, the SL Z-source ac-dc converter is compared with the custom Z-source ac-dc converter.