• Current Optics and Photonics
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• v.7 no.6
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• pp.608-637
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• 2023

The initial motivation in colloid science and engineering was driven by the fact that colloids can serve as excellent models to study atomic and molecular behavior at the mesoscale or microscale. The thermal behaviors of actual atoms and molecules are similar to those of colloids at the mesoscale or microscale, with the primary distinction being the slower dynamics of the latter. While atoms and molecules are challenging to observe directly in situ, colloidal motions can be easily monitored in situ using simple and versatile optical microscopic imaging. This foundational approach in colloid research persisted until the 1980s, and began to be extensively implemented in optics and photonics research in the 1990s. This shift in research direction was brought by an interplay of several factors. In 1987, Yablonovitch and John modernized the concept of photonic crystals (initially conceptualized by Lord Rayleigh in 1887). Around this time, mesoscale dielectric colloids, which were predominantly in a suspended state, began to be self-assembled into three-dimensional (3D) crystals. For photonic crystals operating at optical frequencies (visible to near-infrared), mesoscale crystal units are needed. At that time, no manufacturing process could achieve this, except through colloidal self-assembly. This convergence of the thirst for advances in optics and photonics and the interest in the expanding field of colloids led to a significant shift in the research paradigm of colloids. Initially limited to polymers and ceramics, colloidal elements subsequently expanded to include semiconductors, metals, and DNA after the year 2000. As a result, the application of colloids extended beyond dielectric-based photonic crystals to encompass plasmonics, metamaterials, and metasurfaces, shaping the present field of colloidal optics and photonics. In this review we aim to introduce the research trajectory of colloidal optics and photonics over the past three decades; To elucidate the utility of colloids in photonic crystals, plasmonics, and metamaterials; And to present the challenges that must be overcome and potential research prospects for the future.

• Industry Promotion Research
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• v.8 no.4
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• pp.201-207
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• 2023

This study presents literature research on solitude and mental health in psychology as one of the problems in modern society. Solitude has been understood as a psychologically diverse concept. In psychology, solitude has been understood in a variety of ways: as a pathological phenomenon, a source of conflict in childhood, an expression of maladjustment, and a factor influencing current experiences. Solitude is an objective state of being alone without social interaction, while loneliness and privacy are subjective concepts, with loneliness indicating a need for the presence of others. On the contrary, the religious solitary is a solitary being before God. Isolation and sensory restriction, which humans voluntarily choose, is a cure for loneliness. Also, solitude is associated with positive well-being and healthy adaptability. Humans need to have inner freedom by turning loneliness into solitude. This suggests that loneliness can be overcome through solitude, and that positive thinking can overcome negativity, loneliness, and depression.

• Journal of Information Technology Services
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• v.22 no.5
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• pp.109-124
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• 2023

This study aims to apply the concept of regulatory stringency to the regulatory sandbox with a fresh perspective. The regulatory sandbox is a system that gives opportunities under certain conditions to new technologies or businesses that have not been launched due to inadequacy or insufficiency in legal systems. Previous research on regulatory sandboxes has mainly focused on discussions about their impact on specific technologies or business domains. This study attention to the results according to the evaluations. Among them, whether special cases for demonstration can evolve into official permission has garnered significant attention. For this study, among the cases that passed the regulatory sandbox evaluation from February, 2019, to December, 2022, 162 cases in the field of ICT convergence were selected. The evaluation results were classified into three groups 'positive interpretation (Fast Track)', 'temporary permission', and 'special case for demonstration.' Each case was assigned to one of the three groups. Through the comparative analysis, the common characteristics and differences were summarized. Then, this study explored improvement measures to pass a less restrictive regulatory sandbox. The analysis of the cases revealed that the differences in each evaluation result were attributed to variations in the technological characteristics and user protection features. Considering these differences, as well as the higher weight and importance of the preparation stage for sandbox application, this study suggested a three-step approach to prepare for temporary permission and positive interpretation rather than special case for demonstration. In addition, this thesis discussed the policy limitations of the regulatory sandbox mechanism in South Korea and the limitations of the current study. Hopefully, the results of this study would be beneficial to individuals and companies, particularly venture companies and startups seeking to develop new technologies or businesses and utilize regulatory sandboxes.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.34-42
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• 2023

Considering the contribution of industrial facilities to the national economy, securing operability against earthquakes is very important. However, the basic concept of current seismic design mainly allows ductile behavior of facilities against large-scale earthquakes and only considers structural safety for the purpose of preventing collapse. In order to secure the operability of industrial facilities, the level of seismic performance to maintain operability may vary depending on the structural behavior characteristics of the industrial facility, and a seismic design method is needed to satisfy this. In this study, a ground storage tanks Nonlinear seismic behavior characteristics(R-μ-T) were analyzed through nonlinear response history analysis, and based on this, a new reliability-based, performance-based seismic design method was proposed.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.3
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• pp.39-51
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• 2024

To effectively implement the integrated water management policy outlined in the National Water Management Act, it is essential to analyze agricultural water supply and demand at both basin and water district levels. Currently, agricultural water is primarily distributed through open canal systems and controlled by floodgates, yet the utilization-to-supply ratio remains at a mere 48%. In the case of agricultural water, when analyzing water balance through existing national basin water resource models (K-WEAP, K-MODISM), distortion of supply and regression occurs due to calculation of regression rate based on the concept of net water consumption. In addition, by simplifying the complex and diverse agricultural water supply system within the basin into a single virtual reservoir, it is difficult to analyze the surplus or shortage of agricultural water for each field within the basin. There are limitations in reflecting the characteristics and actual sites of rural water areas, such as inconsistencies with river and reservoir supply priority sites. This study focuses on the development of a model aimed at improving the deficiencies of current water balance analysis methods. The developed model aims to provide standardized water balance analysis nationwide, with initial application to the Anseo standard watershed. Utilizing data from 32 facilities within the standard watershed, the study conducted water balance analysis through watershed linkage, highlighting differences and improvements compared to existing methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.1
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• pp.170-191
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• 2024

The transmission of confidential data using cover media is called steganography. The three requirements of any effective steganography system are high embedding capacity, security, and imperceptibility. The text file's structure, which makes syntax and grammar more visually obvious than in other media, contributes to its poor imperceptibility. Text steganography is regarded as the most challenging carrier to hide secret data because of its insufficient redundant data compared to other digital objects. Unicode characters, especially non-printing or invisible, are employed for hiding data by mapping a specific amount of secret data bits in each character and inserting the character into cover text spaces. These characters are known with limited spaces to embed secret data. Current studies that used Unicode characters in text steganography focused on increasing the data hiding capacity with insufficient redundant data in a text file. A sequential embedding pattern is often selected and included in all available positions in the cover text. This embedding pattern negatively affects the text steganography system's imperceptibility and security. Thus, this study attempts to solve these limitations using the Part-of-speech (POS) tagging technique combined with the randomization concept in data hiding. Combining these two techniques allows inserting the Unicode characters in randomized patterns with specific positions in the cover text to increase data hiding capacity with minimum effects on imperceptibility and security. Format-preserving encryption (FPE) is also used to encrypt a secret message without changing its size before the embedding processes. By comparing the proposed technique to already existing ones, the results demonstrate that it fulfils the cover file's capacity, imperceptibility, and security requirements.

• Journal of the Korean Society of Safety
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• v.39 no.1
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• pp.82-95
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• 2024

Analyzing the aftermath of events at domestic nuclear power plants brings in the question: "Why do workers not comply with the prescribed procedures?" The current investigation of nuclear power plant events identifies their reasons considering the factors affecting the workers' behaviors. However, there are some complications to it: in addition to confirming the action such as an error or a violation, there is a limit to identifying the intention of the actor. To overcome this limitation, the study analyzed and examined the reasons for non-compliance identified in nuclear power plant events by Reason's rule-related behavior classification. For behavior analysis, I selected unit behaviors for events that are related to human and organizational factors and occurred at domestic nuclear power plants since 2017, and then I applied the rule-related behavior classification introduced by Reason (2008). This allowed me to identify the intentions by classifying unit behaviors according to quality and compliance with the rules. I also identified the factors that influenced unit behaviors. The analysis showed that most often, non-compliance only pursued personal goals and was based on inadequate risk appraisal. On the other hand, the analysis identified cases where it was caused by such factors as poorly written procedures or human system interfaces. Therefore, the probability of non-compliance can be reduced if these factors are properly addressed. Unlike event investigation techniques that struggle to identify the reasons for employee behavior, this study provides a new interpretation of non-compliance in nuclear power plant events by examining workers' intentions based on the concept of rule-related behavior classification.

• Journal of the Korean Society for information Management
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• v.41 no.2
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• pp.71-96
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• 2024

This study focused on the fact that limitations of implementing school-centric models and standards of information literacy construction. This study was conducted with the purpose of developing and validating an instructional model to effectively design and practice online information literacy instruction for upper elementary school students based on a public library. Through a review of prior literature and analysis of current status and cases, a primary model was developed including the definition and area of information literacy, learning stages and activities, conceptual and procedural model, and teaching and learning plan. In addition, the first and second expert surveys were conducted to evaluate the internal validity of the model. The final model was derived by synthesizing and converging the collected opinions. As a result of the study, the final model consisted of 7 areas: 'Information literacy concept', 'Instruction component area', 'Conceptual model', 'Procedure model', 'Design principles and detailed guidelines', and 'Learning Steps and Activities' and 'Teaching and Learning Plan'.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.447-452
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• 2024

As the remarkable achievements of generative artificial intelligence technology become increasingly visible, the issue of 'controllability' in artificial intelligence is emerging as a prominent global keyword. This comes at a time when existential threats, such as the possibility of machines dominating humans, are being raised. Accordingly, this study aims to establish the groundwork for shaping a social public sphere by closely examining the concept of control, the current status, and the global landscape of artificial intelligence. It seeks to address the innovative changes anticipated in future society, with artificial intelligence technology at its core. The study aims to derive implications for preparing countermeasures against social problems and unpredictable variables that may arise from the evolution of artificial intelligence technology. It also aims to present guidelines and strategic insights for the establishment of government regulations. Furthermore, the study seeks to uncover implications for the formation of social public discourse.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.155-164
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• 2024

This study examines whether startup firms start with the resources they already have and expand the resources they can mobilize in the process of business management (Effectuation Model) using public data provided by the government. The results of the study show that the Effectuation Model can partially explain the behavior of early-stage startup firms. Therefore, in terms of policy implications based on these findings, government policies for entrepreneurship should not be based on the selection of companies based on sophisticated business models and hypothetical profit models, but rather on a system that actively supports entrepreneurship in areas that are challenging, even if they seem somewhat reckless at the moment, or that best match the entrepreneur's knowledge. Next, in order to actively spread entrepreneurship, it is necessary to spread business history or entrepreneurial experience. To this end, it is necessary to drastically change the current financial system for startups, where the founder bears all the financial risk, and to more actively consider ways to reduce the risk of startups by allowing society and the financial system to share some of the risk of startups.