• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.949-959
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• 2021

The current study aims to explore the shielding properties of multi-component borate-based glass series. Seven glass-samples with composition of (80-y)H₃BO₃-10ZnO-10Na₂O-yBaO where (y = 0, 5, 10, 15, 20, 25 and 30 mol.%) were synthesized by melt-quench method. Various shielding features for photons, neutrons, and protons were determined for all prepared samples. XCOM, Phy-X program, and SRIM code were performed to determine and explain several shielding properties such as equivalent atomic number, exposure build-up factor, specific gamma-ray constants, effective removal cross-section (Σ_R), neutron scattering and absorption, Mass Stopping Power (MSP) and projected range. The energy ranges for photons and protons were 0.015-15 MeV and 0.01-10 MeV, respectively. The mass attenuation coefficient (μ/ρ) was also determined experimentally by utilizing two radioactive sources (¹⁶⁶Ho and ¹³⁷Cs). Consistent results were obtained between experimental and XCOM values in determining μ/ρ of the new glasses. The addition of BaO to the glass matrix led to enhance the μ/ρ and specific gamma-ray constants of glasses. Whereas the remarkable reductions in Σ_R, MSP, and projected range values were reported with increasing BaO concentrations. The acquired results nominate the use of these glasses in different radiation shielding purposes.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.5
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• pp.287-296
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• 2020

The present study aims to improve the accuracy of the maneuvering simulations based on captive model test results. To derive the hydrodynamic coefficients in a self-propelled condition, a mathematical maneuvering model using a whole vehicle model was established. Captive model tests were carried out using the Vertical Planar Motion Mechanism (VPMM) equipment. A motor controller was used to control the constant propeller revolution rate during pure motion tests. The resistance tests, self-propulsion tests, static drift tests, and VPMM tests were performed in the towing tank of Seoul National University. When the vertical drift angle changes, the gravity load on the sensors were changed. The hydrodynamic forces were deduced by subtracting the gravity load from the measured forces. The hydrodynamic coefficients were calculated using the least-square method. The simulation of the turning circle test was compared with the free-running model test result, and the error of the turning radius was 8.3 % compared to the free-running model test.

• Nutrition Research and Practice
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• v.15 no.1
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• pp.95-105
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• 2021

BACKGROUND/OBJECTIVES: The measurement of body composition, including muscle and fat mass, remains challenging in large epidemiological studies due to time constraint and cost when using accurate modalities. Therefore, this study aimed to develop and validate prediction equations according to sex to measure lean body mass (LBM), appendicular skeletal muscle mass (ASM), and body fat mass (BFM) using anthropometric measurement, serum creatinine level, and lifestyle factors as independent variables and dual-energy X-ray absorptiometry as the reference method. SUBJECTS/METHODS: A sample of the Korean general adult population (men: 7,599; women: 10,009) from the Korean National Health and Nutrition Examination Survey 2008-2011 was included in this study. The participants were divided into the derivation and validation groups via a random number generator (with a ratio of 70:30). The prediction equations were developed using a series of multivariable linear regressions and validated using the Bland-Altman plot and intraclass correlation coefficient (ICC). RESULTS: The initial and practical equations that included age, height, weight, and waist circumference had a different predictive ability for LBM (men: R2 = 0.85, standard error of estimate [SEE] = 2.7 kg; women: R2 = 0.78, SEE = 2.2 kg), ASM (men: R2 = 0.81, SEE = 1.6 kg; women: R2 = 0.71, SEE = 1.2 kg), and BFM (men: R2 = 0.74, SEE = 2.7 kg; women: R2 = 0.83, SEE = 2.2 kg) according to sex. Compared with the first prediction equation, the addition of other factors, including serum creatinine level, physical activity, smoking status, and alcohol use, resulted in an R2 that is higher by 0.01 and SEE that is lower by 0.1. CONCLUSIONS: All equations had low bias, moderate agreement based on the Bland-Altman plot, and high ICC, and this result showed that these equations can be further applied to other epidemiologic studies.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.5
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• pp.137-145
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• 2003

Nowadays, people can communicate with each other on any time at my place by development of wireless communications. But, the openness of mobile communications Poses serious security threats and the security is necessary on mobile communications to support the secure communication channel. The most commonly method is stream cipher for mobile communications. Generally, this stream cipher is implemented by LFSR(Linear Feedback Shift Register). On this paper proposes the modified mechanism of the S box is usually used in block cipher to advance security og the stream cipher and this mechanism is the modified three one in consideration og the randomness. Generally, S box that is function with nonlinear property makes data more strong by attack. The randomness test of the proposed algorithm is used Ent Pseudorandom Number Sequence Test Program and by the test result it proves that it has better randomness and serial correlation value than the based stream cipher on respective test.

• The Journal of Economics, Marketing and Management
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• v.8 no.2
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• pp.13-17
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• 2020

Purpose: In modern corporate management, the establishment of a crisis management system that minimizes damage through measures used to respond to corporate crises is no longer an option. The importance of corporate reputation and brand asset management in modern enterprise management cannot be overemphasized and negative events that might arise from a number of different causes can cause brand crises. Research design, data and methodology: More than half of the questionnaire respondents were female (252 or 53%). More than a fourth of the respondents were aged 20 (122 or 26%) and the number of married participants was 196 (41%). Of the participants, 32% (153) had graduated from college. Only 18% (87) were employees and the monthly household income was 121. In this study, we conducted factor analysis in order to extract the variables that may enhance the explanation capability of each variable. For the method of factor extraction, an Eigen value of at least 1 was used as was factor loading. An analysis was performed using the Cronbach's alpha coefficient to verify the reliability of the measurement scale. Results: First, the analysis of the impact of the social responsibility activities on brand image revealed that the social, economic, philanthropic, ethical, and environmental responsibility activities significantly affected brand image, but legal responsibility activities were not statistically significant. Second, the analysis of the impact of brand image on loyalty showed that brand image had a significant impact on loyalty. Third, the analysis of the impact of social responsibility activities on loyalty showed that they had a significant impact on loyalty. Conclusions: The pro-social enterprise image is not only a brand asset that can be shared, but also a heavy proposition followed by a corresponding social responsibility, it will have to practice transparent corporate management based on clear principles through the establishment of various systems and the implementation of a strict code of conduct within the enterprise.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1211-1220
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• 2020

This research detects the features of the bright band (BB) through analysis of the vertical profile of range height indicator (RHI) and the slant range beam profile of plane position indicator (PPI) of the polarimetric radar measurements-horizontal reflectivity (ZH), differential reflectivity (ZDR), and cross-correlation coefficient (ρHV). As a result of the analysis, it is possible to clearly detect the bright band using the polarimetric radar measurements, and it is confirmed that the result is consistent by double searching for the BB using the RHI and PPI scan data at the same time. Based on these results, the accuracy of QPE (quantification of precipitation estimation) can be improved by applying the BB search method by the PPI slant range in this research to large rainfall radars that only scan PPI volumes in the field without RHI observations.

• Korean Journal of Artificial Intelligence
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• v.8 no.2
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• pp.17-22
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• 2020

Purpose: After entering the 21st century, a new industrial revolution, i.e. industrial revolution 4.0, which is characterized by intelligence, automation and networking, has opened the curtain of the "industry 4.0" era. In recent years, "low-carbon economy" has been a development goal that has been paid close attention to and adhered to at home and abroad. As a major economic province, Shandong Province has not only brought about rapid economic growth, but also caused rapid environmental deterioration due to its high energy consumption, high dependence and high environmental pollution. In this environment, low-carbon economy has become an inevitable trend in the development of foreign trade in Shandong Province. Based on the current situation of foreign trade in Shandong Province and various existing problems, this paper explores the relationship between low-carbon economy and foreign trade in Shandong Province under this strategic background. Research design, data and methodology: By selecting the data from 2008 to 2017, using the carbon emission coefficient method to measure the CO2 emissions in the past decade, analyzing the impact of ecological factors on trade, selecting the most representative GDP and total imports for regression analysis, it is proved that they have a real impact on CO2 emissions. The total GDP is positively correlated with carbon emissions, while the total import is negatively correlated with carbon emissions. Results:This paper discusses the impact of low-carbon economy on foreign trade of Shandong Province from the perspective of foreign trade. Especially in today's "low-carbon economy" background. Conclusions:it is helpful for relevant departments to formulate relevant policies and promote the sustainable development of foreign trade in Shandong Province.

• Research in Community and Public Health Nursing
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• v.32 no.4
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• pp.555-565
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• 2021

Purpose: This study was conducted to develop the contents of disaster nursing education in community health nursing at universities. Methods: To validate contents, the Delphi method was used. We categorized two domains(indirect disaster management and direct disaster management) and developed 48 draft items. This study applied two round surveys and 23 experts participated in this study. The content validity was calculated using content validity ratio and coefficient of variation. Results: Indirect disaster management domain was composed of three categories including 12 items: 1) Understanding of the disaster, 2) disaster management system, and 3) response by disaster stage and recovery. Direct disaster management domain was composed of nine categories including 30 items: 1) Ethical considerations, 2) communication in disasters, 3) nursing activity by disaster stage, 4) emergency nursing in disasters, 5) patient severity classification in disasters, 6) disaster nursing for vulnerable groups, 7) disaster nursing for victims, 8) psychosocial nursing and health in disasters, and 9) cases of disaster nursing in communities. Conclusion: This Delphi study identified the contents of disaster nursing education curriculum, and confirmed the validity for disaster education program in community health nursing. Based on the results, it will be helpful for training the disaster nursing and improving the competency on disaster nursing of the nursing students.

• Journal of Veterinary Clinics
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• v.39 no.3
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• pp.114-120
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• 2022

The purpose of this study is to examine the status of quality control using multipurpose phantom of ultrasound equipment used in hospital of veterinary college in South Korea by using ATS-539 multipurpose phantom so as to examine quantitative and objective new image evaluation method. Specialists discussed and analyzed multipurpose phantom images acquired by using convex transducer of 10 ultrasound imaging devices, currently used in 9 veterinary colleges, at 4.0-6.0 MHz. Total 8 items that can be measured with ATS-539 multipurpose phantom including dead zone, vertical and horizontal measurement, axial/lateral resolution, sensitivity, focal zone, functional resolution and gray scale/dynamic range were evaluated. For qualitative evaluation, valid decisions were made based on dead zone, axial/lateral resolution, and gray scale/dynamic range which are resolution index, and coefficient of variation (COV) and blind referenceless image spatial quality evaluator (BRISQUE) were found to increase objectivity. As a result of experiment, all the targeted ultrasonic devices were found appropriate from qualitative evaluation items of dead zone, axial/lateral resolution, and gray scale/dynamic range. In other evaluation items, they were found to be appropriate from focal zone and vertical measurement of quantitative evaluation while inappropriate from horizontal measurement, sensitivity, and functional resolution. COV value was 0.12 ± 0.04, and BRISQUE value was 47.77 ± 2.77, both analysis results show that the noise level of all ultrasonic devices was located within tolerance range. Upon image examination using ATS-539 multipurpose phantom, they were 100% appropriate with inspection standards of dead zone, axial/lateral resolution, and gray scale/dynamic range, and besides, focal zone and functional resolution can be used as evaluation items. In the field of veterinary medicine, 8 standard items using ATS-539 multipurpose phantom and image evaluation items using COV and BRISQUE can be used as standards for quality control of ultrasonography machine.

• Atmosphere
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• v.31 no.5
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• pp.637-656
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• 2021

The United States has been known as the world's major producer of crops such as wheat, corn, and soybeans. Therefore, using meteorological long-term forecast data to project reliable crop yields in the United States is important for planning domestic food policies. The current study is part of an effort to improve the seasonal predictability of regional-scale precipitation across the United States for estimating crop production in the country. For the purpose, a dynamic downscaling method using Weather Research and Forecasting (WRF) model is utilized. The WRF simulation covers the crop-growing period (March to October) during 2000-2020. The initial and lateral boundary conditions of WRF are derived from the Pusan National University Coupled General Circulation Model (PNU CGCM), a participant model of Asia-Pacific Economic Cooperation Climate Center (APCC) Long-Term Multi-Model Ensemble Prediction System. For bias correction of downscaled daily precipitation, empirical quantile mapping (EQM) is applied. The downscaled data set without and with correction are called WRF_UC and WRF_C, respectively. In terms of mean precipitation, the EQM effectively reduces the wet biases over most of the United States and improves the spatial correlation coefficient with observation. The daily precipitation of WRF_C shows the better performance in terms of frequency and extreme precipitation intensity compared to WRF_UC. In addition, WRF_C shows a more reasonable performance in predicting drought frequency according to intensity than WRF_UC.