• International Journal of Computer Science & Network Security
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• v.23 no.10
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• pp.115-128
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• 2023

Deep learning has been incorporating various optimization techniques motivated by new pragmatic optimizing algorithm advancements and their usage has a central role in Machine learning. In recent past, new avatars of various optimizers are being put into practice and their suitability and applicability has been reported on various domains. The resurgence of novelty starts from Stochastic Gradient Descent to convex and non-convex and derivative-free approaches. In the contemporary of these horizons of optimizers, choosing a best-fit or appropriate optimizer is an important consideration in deep learning theme as these working-horse engines determines the final performance predicted by the model. Moreover with increasing number of deep layers tantamount higher complexity with hyper-parameter tuning and consequently need to delve for a befitting optimizer. We empirically examine most popular and widely used optimizers on various data sets and networks-like MNIST and GAN plus others. The pragmatic comparison focuses on their similarities, differences and possibilities of their suitability for a given application. Additionally, the recent optimizer variants are highlighted with their subtlety. The article emphasizes on their critical role and pinpoints buttress options while choosing among them.

• Journal of Navigation and Port Research
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• v.36 no.4
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• pp.279-284
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• 2012

This study aims to identify the degree of safety when mariners take their actions in several different situations. We have carried out many experiments to observe mariners' behavior and then measured the safety level based on their actions to avoid dangerous situations of ships collision. One of the most important actions that mariners have to take, either as their daily routine or when they are in a collision situation and then want to avoid that situation is the lookout. In this paper, behaviors on the lookout have been defined as a standard sequence of three steps which are "time of first detection", "time of recognition as risky vessel" and "time of starting avoiding action", and the suitability and applicability of the definition have been shown. And also we propose the risk assessment on ships collision and the recommendation for reducing ships collision at sea. Some analyzing results and the application of the results are reported. By combining these knowledge and some systematic studies, we propose the risk assessment on ships collision and the recommendation for reducing ships collision at sea.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.707-710
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• 2011

System safety is defined as the state where the hazard risks due to internal system, interface, operation and maintenance are controlled as acceptable levels. It is represented and evaluated either with the risk level of each risk factor with the consideration of operation environments or with Safety Integrity Level (SIL) which is the system functional safety without considering application environments. The assessment results are issued in forms of certificates and they are reused in many cases. However, the conditions and restrictions for different application environments vary in each case, therefore, additional evaluation on the preconditions of assessment in comparison with the actual application environment must be carried out. For the area of train control, TR 50506-1 has been established based on the IEC 62425 (international standard for safety of train control system by RSSB) and EN 50129 (Europe standard) for the further assessment. In this paper, the analysis on TR 5056-1 has been conducted in depth. The purpose of the study is to determine the requirements for inter-acceptability including scope, procedures, principles, examination and suitability. The results can be utilized for the system safety maintenance when new devices or components are introduced in conventional systems.

• Journal of Environmental Science International
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• v.24 no.7
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• pp.865-874
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• 2015

This study was conducted to investigate the correlation between the distribution chart and input data of the predicted 3-second gust and damage cost, by using the forecast field and analysis field of Regional Data Assimilation Prediction System (RDAPS) as initial input data of Korea risk assessment model (RAM) developed in the preceding study. In this study the cases of typhoon Rusa which caused occurred great damage to the Korean peninsula was analyzed to assess the suitability of initial input data. As a result, this study has found out that the distribution chart from the forecast field and analysis field predicted from the point where the effect due to the typhoon began had similarity in both 3-second gust and damage cost with the course of time. As a result of examining the correlation, the 3-second gust had over 0.8, and it means that the forecast field and analysis field show similar results. This study has shown that utilizing the forecast field as initial input data of Korea RAM could suit the purpose of pre-disaster prevention.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.3
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• pp.145-153
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• 2018

The purpose of this study is to seek ways how you can apply social responsibility requirements in accordance with the organizational characteristics of 'Dong' community service centers which are administrative service platform organizations, by applying the ISO 26000 to these centers. The ISO 26000, which is an international standard for social responsibility, defines the requirements for social responsibility which all organizations, regardless of their sizes or characteristics, can apply. This does not mean that all organizations must apply all the requirements regardless of their sizes or characteristics, but means that each organization can redefine the requirements applicable to its size and characteristics and apply them. Hence, this study defined 'Dong' community service centers' organizational characteristics and stakeholders and assessed the suitability of 251 categories in the ISO 26000 requirements by using the Delphi technique. Through this assessment process, 135 categories were selected. Then, after conducting an importance test by experts, 83 social responsibility assessment indicators applicable to 'Dong' community service centers were developed.

• Progress in Superconductivity and Cryogenics
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• v.25 no.3
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• pp.34-37
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• 2023

The practical application of REBCO coated conductor (CC) tapes, vital for energy transmission (e.g., cable application) and high-field magnets (e.g., coil application), necessitates efficient and simple quality assessment procedures. This study introduces a systematic approach to assess the electromechanical properties of REBCO CC tapes under 77 K and self-field conditions. The approach involves customized tensile and bending tests that clarify the critical current (I_c) response of the CC tapes under mechanical loads induced by tension and bending. This study measures the retained Ic values of commercially available GdBCO CC tapes under 250 MPa tensile stress and 40 mm bending diameter. Through experimentation, the study demonstrates the resilience of these tapes and their suitability for applications. By presenting a simplified stress-based analysis and a bending test of the tapes, the study contributes to effective quality assessment methods for the development of practical superconducting products.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.386-394
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• 2016

This study investigates the validity of a Korean version of the Client Assessment Summary (CAS), which is a tool used to assess the recovery of alcoholics. We investigated the Korean CAS's suitability for use in assessing the scale of recovery scale of general alcoholics in Korea. In this study, we analyzed the data of 205 abstaining alcoholics in order to determine the validity of the Korean CAS. We undertook relationship analyses of CAS contents, reliability, and composition validity through factor analysis. In addition, we assessed ARS, abstinence period, abstinence self-efficacy, illness insight, and motivation change variables. The factor analysis results, performed after verification of content suitability by assessing 12 questions and 4 factors, confirmed the tool's composition validity, with the results showing relatively high values (R2 = 76.26%, communality ${\geq}0.6$, and KMO = 0.92). Moreover, internal consistency was acceptable (Cronbach's alpha = 0.92), and the correlations among ARS, abstinence self-efficacy, illness insight, and motivation change variables confirmed the validity of the Korean CAS. The proposed Korean CAS is expected to be useful when academically and clinically assessing the recovery of alcoholics; thereby, eventually contributing to successful recoveries from alcoholism.

• Journal of Environmental Impact Assessment
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• v.24 no.2
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• pp.175-189
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• 2015

The objective of this study was to analyze characteristics of distribution of amphibian species and the affecting ecological factors. For the study, habitat environment factors were determined and applied to a habitat suitability model for the data collected from the Seom River in Hoengseong County and Wonju City, Gangwon Province, Korea between March 2013 to October 2013. The analyzed amphibian species were Rana nigromaculata, Hyla japonica, Rana dybowski, and Rana rugosa Temminck and Schlegel, and a logistic regression model was used with the pseudo-absence data. The result of the model analysis suggests that the major factors for Rana nigromaculata are distance to vegetation and rock and that for Hyla japonica is waterway. Rana dybowski and Rana rugosa Temminck and Schlegel have similar habitat characteristics, but the latter is shown to be dominant due to its wider habitat preference. According to the species richness model, the analyzed amphibian species are shown to have tendency to move between valleys or streams. This study quantitatively analyzed habitat environment characteristics using species distribution model, however, there is a limitation in terms of analysis on food factor and connectivity with other species. Combined with additional density or habitat analysis on birds or fish, this study can lead to more comprehensive analysis on biological environment factors.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.5
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• pp.31-48
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• 2012

The purpose of this study is to select indicators by a methodical approach and to establish a functional assessment system as a basic study for planning and constructing green space of forest. The types of green space were divided into 6 classes based on theoretical reviews of literature and the functions of green space were restricted to 'nature-ecological function', 'environment-control function' and 'usage function'. As a result of the selection of indicators, 35 indicators were initially selected by theoretical review and these indicators were reduced to 29 through brainstorming. Also, these indicators were classified into three functions such as 12 indicators (nature-ecological function), 8 indicators (environment-control function), 6 indicators (usage function) by analysis of suitability. According to the result of selection of the optimum indicators using MCB (Multiple Comparisons with the Best treatment) analysis, the optimum indicators of 7, 5, and 4 respectively by each function were selected for forest green space. The results of AHP (Analytic Hierarchy Process) for the establishment of the assessment system in forest, the weight of nature-ecological function was evaluated highest at 0.558, while the weight of environment-control and usage function were calculated at each 0.277, 0.165. 'Naturality (0.189)', 'Carbon sink (0.235)', and 'Accessibility (0.354)' among indicators showed highest by each function. The weight of indicator and assessment system may be used as a valuable guideline in case of assessing synthetically green space within urban planning.

• Journal of Digital Convergence
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• v.18 no.7
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• pp.1-8
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• 2020

This study aimed to develop a self-reporting assessment tool for digital literacy competence to use it as a tool for self-diagnosis or effectiveness verification in educational programs, considering that digital literacy competence is one of the core competencies for the present and future society. Based on the previous research on digital literacy competence, the tool was developed with 45 question items of 2 areas and 8 factors. The results of an exploratory factor analysis and confirmatory factor analysis conducted to determine suitability were generally satisfactory based on the assessment data from about 3,000 middle school students. The assessment tools developed in this study are primarily applicable to primary and secondary school and adult education. In future research, if the system is developed to be accessible to anyone online based on this tool, and the accumulated data provide educational information for each individual's self-development, it will greatly contribute to improving the digital literacy competence of the people.