• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.557-565
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• 2021

Path-following control is considered as one of the most fundamental skills to realize autonomous navigation of marine vessels in the ocean. This study addresses with the path-following control for a ship in which there are environmental disturbances in the directions of the surge, sway, and yaw motions. The guiding principle and back-stepping method was utilized to solve the ship's tracking problem on the reference path generated by a virtual ship. For path-following control, error dynamics is one of the most important skills, and it extends to the research fields of automatic collision avoidance and automatic berthing control. The algorithms for the guiding principles and error variables have been verified by numerical simulation. As a result, most error variables converged to zero values with the controller except for the yaw angle error. One of the most interesting results is that the tracking errors of path-following control between two ships are smaller than the existing safe passing distances considering interaction forces from near passing ships. Moreover, a trade-off between tracking performance and the ship's safety should be considered for determining the proper control parameters to prevent the destructive failure of actuators such as propellers, fins, and rudders during the path-following of marine vessels.

• Journal of Convergence for Information Technology
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• v.11 no.12
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• pp.49-58
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• 2021

This study examined the effects of antecedent variables on life satisfaction of elderly people who live alone and who live with others by comparing the levels of depression, self-esteem, and life satisfaction. Using the 15th data of the Korean Welfare Panel held in 2020, independent sample t-test and hierarchical regression analysis were conducted. Elderly people who live alone had a high sense of depression, low self-esteem, and low life satisfaction. For both of them, the older the age and the higher the income level, the higher the life satisfaction. The regression model, which added depression and self-esteem, had a significant effect on both of them, but the effect of self-esteem was higher (𝛽=.40, .41) than that of depression (𝛽=-.28, -.29). The effects of depression and self-esteem on life satisfaction were higher in elderly people who live alone (R²=.409) than in elderly people who live with others (R²=.398). Based on the research results, this study suggested appropriate policies and practice directions to enhance self-esteem and improve life satisfaction of elderly people who live alone.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.258-269
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• 2021

The purpose of this study was to explore relations between college students' dating violence perception and professional help-seeking attitudes and other factors that affect professional help-seeking attitude and their effect size. 508 students from a college in Chungcheong region responed to self-report questionnaires. Data were analyzed by Partial correlation coefficients and regression analysis using the SPSS 22.0 program. As a resullt, self-disclosure and anticipated utility on self-disclosure had positively effect on professional help-seeking attitudes. In contrast, violence perception, perceived social support, risk on self-disclosure and barriers to seeking help had negative effect on professional help-seeking attitudes. The total effect size was 46.1%, and the effect size of anticipated utility on self-disclosure was the largest, followed by risk on self-disclosure and barriers to seeking help. This study contributed to the broading of dating violence research topics and provided the directions to the endavour to increase the use of professional services among college students

• Journal of Convergence for Information Technology
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• v.11 no.9
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• pp.145-156
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• 2021

This study is aimed to improve the youth theft prevention program with rationality and practicality, based on the needs of practitioners who conduct these programs in fields. The survey questionnaire was prepared based on previous researches, and the survey was conducted on 72 probation officers and education instructors nationwide running a youth theft prevention program. As a result, practitioners reported the lack of self-control and high impulsivity as the main characteristics of the theft delinquent adolescents. And they recognized peer alignment and family problems as the causes of theft. As for the contents of the program, they reported that recidivism prevention skills such as understanding psychological problems, peer relationships, raising a sense of law compliance, anger, impulse control, dealing with negative emotions, and finding alternative behaviors, as well as moral development, are necessary. These results indicate that multi-dimensional interventions such as individuals, families, and peers are needed to prevent recidivism of juvenile theft. Implications of these results, future research directions, and limitations and significance of the study were discussed.

• Journal of Family Resource Management and Policy Review
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• v.25 no.4
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• pp.1-14
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• 2021

This study was conducted to examine the realistic problems of flexible work arrangements, which was a representative policy for work-family balance, based on a review of its effect and influence on double-income couples who were actual users of the system. In this study, an in-depth interview with three double-income couples, totaling 6 parents, with preschool children was conducted on the experience of their flexible work arrangements, and the purposes of the study were to figure out their experienced positive effectiveness and the problems with the difficulty of using the system and to look for their solutions. For the data analysis of the study, it was organized into three high categories and nine low ones by reviewing the entire data on the basis of the frame structured in the derived data through the interview and categorizing the subjects by area. The derived analysis results were changes in households, social and cultural perspectives, and demand for policy and social economic changes. This study is significant in the sense that the perspectives and voice of the actual users of flexible work arrangements have been reflected in the study, and in the future, we expect that it will provide justification and persuasive power for the improvement of flexible work arrangements and serve as basic data for establishing policy directions and support.

• Smart Media Journal
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• v.10 no.2
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• pp.61-69
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• 2021

Wayfinding is a 'Process solving problem to find destination', and it is important to select spatial data for optimal way. Recently, due to the complexity of space and the expansion of the medium of the wayfinding service, it is necessary to the approach on the information design for them. Therefore, the purpose of this study is to propose a meta guideline on the information design for the design of orientation sign, which is an important cognitive clue in the wayfinding. It was conducted in 3 stages, First, a design process was proposed and design elements were derived for each step by literature research related to information and sign design, and analysis of manual for signage design. Second, a meta guideline for information organization and visualization in the three-stage design process was proposed by FGI and analysis. Third, the meta guideline was applied to the sign design on an area for user evaluation to inspect the applicability of the meta guideline. Through the user questionnaire, the possibility of applying the guideline for visualization of directions and spaces, information hierarchy according to spatial characteristics and information priority was identified. It is meaningful in that necessary element for signage design are systematized centering on the process and that it presents a macroscopic methodology according to spatial characteristics.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.254-265
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• 2021

Purpose: Inspection and diagnosis on the performance and safety through domestic port facilities have been conducted for over 20 years. However, the long-term development strategies and directions for facility renewal and performance improvement using the diagnosis history and results are not working in realistically. In particular, in the case of port structures with a long service life, there are many problems in terms of safety and functionality due to increasing of the large-sized ships, of port use frequency, and the effects of natural disasters due to climate change. Method: In this study, the maintenance history data of the gravity type quay in element level were collected, defined as big data, and a predictive approximation model was derived to estimate the pattern of deterioration and aging of the facility of project level based on the data. In particular, we compared and proposed models suitable for the use of big data by examining the validity of the state-based deterioration pattern and deterioration approximation model generated through machine learning algorithms of GP and SGP techniques. Result: As a result of reviewing the suitability of the proposed technique, it was considered that the RMSE and R² in GP technique were 0.9854 and 0.0721, and the SGP technique was 0.7246 and 0.2518. Conclusion: This research through machine learning techniques is expected to play an important role in decision-making on investment in port facilities in the future if port facility data collection is continuously performed in the future.

• Journal of Korea Trade
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• v.23 no.3
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• pp.68-83
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• 2019

Purpose - The UNCITRAL Model Law on Electronic Transferable Records (Model Law) is based on the principles of non-discrimination against the use of electronic means, functional equivalence, and technology neutrality underpinning all UNCITRAL texts on electronic commerce. Investigating the disagreements between the Model Law and the Koran Commercial Act (KC Act), including the B/L Regulation, and suggesting the revision of the KC Act including the B/L Regulation, could be a valuable study. The purpose of this paper is to contribute to the harmonization of Korean legislation regarding electronic bill of lading in compliance with the Model Law. Design/methodology - The Model Law is flexible to accommodate the use of all technologies and models, such as registries, tokens, and distributed ledgers: that is, blockchain. In 2007, the KC Act was revised to regulate electronic bills of lading to promote the widespread legal use of electronic bills of lading. In addition, The Regulation on Implementation of the Provisions of the Commercial Act Regarding Electronic Bills of Lading (the B/L Regulation) was enacted to regulate the detailed procedures in using electronic bills of lading in 2008. This paper employs a legal analysis by which this paper does find differences between two rules in light of technology neutrality and global standard of electronic bills of lading model. Findings - The main findings are as follows: i) the Korean registry agency has characteristics of a closed system. ii) The KC Act has no provision regarding control. iii) The KC Act discriminates other electronic bills of lading on the ground that it was issued or used abroad. Moreover, this study does comprehensive analysis of Korean Acts in comparison with the Model Law and, in particular, this study analyzes the differences between the KC Act and the Model Law by comparing article by article in view of the harmonization of the two rules. Originality/value - The subject of previous several studies was draft provisions on Electronic Transferable Records before completion of the Model Law; thus, these studies did not take into consideration the character of the Model Law as the Model Law was chosen at the final stage of legislation. This study is aimed at the final version of the Model Law. So, this study is meaningful by finding the suggestion and directions for the Korean government to revise the KC Act and the B/L Regulation in line with the Model Law.

• Journal of Technology Innovation
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• v.29 no.4
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• pp.1-30
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• 2021

Due to the recent development of system semiconductors, technical innovation for the electric devices of the automobile industry is rapidly progressing. In particular, the electric device of automobiles is accelerating technology development competition among automobile parts makers, and the development cycle is also changing rapidly. Due to these changes, the importance of strategic planning for R&D is further strengthened. Due to the paradigm shift in the automobile industry, the Product-Technical Roadmap (P/TRM), one of the R&D strategies, analyzes technology forecasting, technology level evaluation, and technology acquisition method (Make/Collaborate/Buy) at the planning stage. The product-technical roadmap is a tool that identifies customer needs of products and technologies, selects technologies and sets development directions. However, most companies are developing the product-technical roadmap through a qualitative method that mainly relies on the technical papers, patent analysis, and expert Delphi method. In this study, empirical research was conducted through simulations that can supplement and strengthen the product-technical roadmap centered on the automobile industry by fusing Gartner's hype cycle, cumulative moving average-based data preprocessing, and deep learning (LSTM) time series analysis techniques. The empirical study presented in this paper can be used not only in the automobile industry but also in other manufacturing fields in general. In addition, from the corporate point of view, it is considered that it will become a foundation for moving forward as a leading company by providing products to the market in a timely manner through a more accurate product-technical roadmap, breaking away from the roadmap preparation method that has relied on qualitative methods.

• Ocean and Polar Research
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• v.43 no.4
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• pp.307-320
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• 2021

Udo Rhodolith Beach is a small-scale, mixed sand-and-gravel beach embayed on the N-S trending rocky coast of Udo, Jeju Island, South Korea. This study analyzes the short-term topographic changes of the beach during the extreme storm conditions of four typhoons from 2016 to 2020: Chaba (2016), Soulik (2018), Lingling (2019), and Maysak (2020). The analysis uses the topographic data of terrestrial LiDAR scanning and drone photogrammetry, aided by weather and oceanographic datasets of wind, wave, current and tide. The analysis suggests two contrasting features of alongshore topographic change depending on the typhoon pathway, although the intensity and duration of the storm conditions differed in each case. During the Soulik and Lingling events, which moved northward following the western sea of the Jeju Island, the northern part of the beach accreted while the southern part eroded. In contrast, the Chaba and Maysak events passed over the eastern sea of Jeju Island. The central part of the beach was then significantly eroded while sediments accumulated mainly at the northern and southern ends of the beach. Based on the wave and current measurements in the nearshore zone and computer simulations of the wave field, it was inferred that the observed topographic change of the beach after the storm events is related to the directions of the wind-driven current and wave propagation in the nearshore zone. The dominant direction of water movement was southeastward and northeastward when the typhoon pathway lay to the east or west of Jeju Island, respectively. As these enhanced waves and currents approached obliquely to the N-S trending coastline, the beach sediments were reworked and transported southward or northward mainly by longshore currents, which likely acts as a major control mechanism regarding alongshore topographic change with respect to Udo Rhodolith Beach. In contrast to the topographic change, the subaerial volume of the beach overall increased after all storms except for Maysak. The volume increase was attributed to the enhanced transport of onshore sediment under the combined effect of storm-induced long periodic waves and a strong residual component of the near-bottom current. In the Maysak event, the raised sea level during the spring tide probably enhanced the backshore erosion by storm waves, eventually causing sediment loss to the inland area.