• Journal of Korean Society of Water and Wastewater
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• v.36 no.4
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• pp.229-237
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• 2022

The sewer capacity design have been based on the Huff model or the rational equation in South Korea and often failed to determine optimal capacity, resulting in frequent urban flooding or over-sizing. A time distribution of rainfall (i.e., Huff or ABM method) could be used instead of a rainfall hyetograph obtained from statistical analysis of previous rainfalls. In this study, the Huff method and the ABM method, which predict the time distribution of rain intensity, which are widely used to calculate sewage pipe drainage capacity using the SWMM, were compared with the standard rainfall intensity hyetograph of Seoul. If the rainfall duration was 30 minutes to 180 minutes, the rainfall intensity value calculated by the Huff model tended to be less than the rainfall intensity value of the standard rainfall intensity in the initial 5-10 minutes. As a result, more than 10% to 30% of under-design would be made. In addition, the rainfall intensity value calculated by the Huff model from the section excluding the initial 5-10 minutes of rainfall to the rainfall duration was calculated larger than the value using the standard rainfall intensity equation, which would result in an over-design of 10% to 30%. In the case of a relatively long rainfall duration of 360 minutes (6 hours) to 1,440 minutes (24 hours), it showed an lower rainfall intensity of 60 to 90% in the early stages of rainfall, but the problem of under-design had been solved as the rainfall duration time had elapsed. On the other hand, in the alternating block method (ABM) method, it was found that the rainfall intensity at the entire period at each assumed rainfall duration accurately matched the standard rainfall intensity hyetograph of Seoul.

• Journal of architectural history
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• v.32 no.1
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• pp.73-88
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• 2023

Recently, local studies looking at the 'local(region) as a whole' are gradually increasing. The study of local architectural history is important in that it provides specific information that encompasses the local and the entire and clues to three-dimensionalize the time and space in the local. To infer the 'presentness' of each era, reliable data in various fields are needed. Recently, as many databases (DB) and archives, from the 'National Archives of Korea' to other local archives, have been established and publicized, research resources in the local are growing rapidly in quantity and quality. Nevertheless, it is difficult to comprehensively check the data necessary to study the local architectural history(local architectural history research resources). Against this background, this study confirmed the trend of changes in the archive construction environment and the status and problems of local architectural history research resources in places that currently disclose local history research resources among generalized web-archives. Next, the relationship between the actual research on local architectural history was confirmed through the analysis of existing studies and the data used for Jeju. As a result, local studies, local archives, and local architectural history research agree with recent changes in local research trends, and the degree of archival construction has reached the same level as the available research resources except core data in local architectural history research. However, there is a problem that the density of information that can be used is low because the local architectural history research resources that can be obtained are fragmented because there are no archives and construction entities specialized in local architecture. As each archive has entered the stabilization and upgrading stage, the construction of new archives needs to be reconsidered, but it is time to find a detailed way to link related information quickly and accurately, such as private records, to reduce the gap in information needed in terms of research on local architecture and architecture history.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.109-117
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• 2022

Most of real-world decision-making processes are used to optimize problems with many objectives of conflicting. Since the betterment of some objectives requires the sacrifice of other objectives, different objectives may not be optimized simultaneously. Consequently, Pareto solution can be considered as candidates of a solution with respect to a multi-objective optimization (MOP). Such problem involves two main procedures: finding Pareto solutions and choosing one solution among them. So-called multi-objective genetic algorithms have been proved to be effective for finding many Pareto solutions. In this study, we suggest a fitness evaluation method based on the achievement level up to the target value to improve the solution search performance by the multi-objective genetic algorithm. Using numerical examples and benchmark problems, we compare the proposed method, which considers the achievement level, with conventional Pareto ranking methods. Based on the comparison, it is verified that the proposed method can generate a highly convergent and diverse solution set. Most of the existing multi-objective genetic algorithms mainly focus on finding solutions, however the ultimate aim of MOP is not to find the entire set of Pareto solutions, but to choose one solution among many obtained solutions. We further propose an interactive decision-making process based on a visualized trade-off analysis that incorporates the satisfaction of the decision maker. The findings of the study will serve as a reference to build a multi-objective decision-making support system.

• Korean Journal of Community Nutrition
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• v.27 no.6
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• pp.480-491
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• 2022

Objectives: This study examined the problems encountered when analyzing the market size, purchase, and consumption of HMR (home meal replacements) in the Republic of Korea. Methods: The macro data relevant to the market size and purchase status of HMR were critically summarized. The micro data retrieved from the 2019 & 2020 Korea National Health and Nutrition Examination Survey (KNHANES) were analyzed to understand the consumption of HMR. Results: The Korea Agro-Fisheries & Food Trade Corporation and the Ministry of Food and Drug Administration reported the market size of HMR, whereas the Korean Rural Economic Institute and the Rural Development Administration reported the purchase expense and frequencies of HMR. Since the values on the market size and purchase status were calculated or surveyed using different scopes of HMR, there have been reliability issues for the data presented. Additionally, lack of consensus on the use of Korean terms corresponding to HMR was found to be a problem. To examine the consumption of HMR, analysis of the food intake data from KNHANES presented results with very low validity due to the inappropriate survey and coding scheme not reflecting the inclusion of new food types. Conclusions: Several problematic discrepancies were encountered in the statistics on HMR. The fundamental cause of these problems was the absence of agreement on the scope of HMR and the Korean terms corresponding to it. Considering the increasing importance of HMR in Korean diets, urgent cooperative efforts are required between the government and academia to derive an agreed Korean term and establish the scope of HMR.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.104-111
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• 2023

Rolling stock maintenance, which focuses on preventive maintenance, is typically implemented considering the potential harm that may be inflicted to passengers in the event of failure. The cost of preventive maintenance throughout the life cycle of a rolling stock is 60%-75% of the initial purchase cost. Therefore, ensuring stability and reducing maintenance costs are essential in terms of economy. In particular, private railroad operators must reduce government support budget by effectively utilizing railroad resources and reducing maintenance costs. Accordingly, this study analyzes the reliability characteristics of components using field data. Moreover, it resolves the problem of determining an economical replacement interval considering the timing of scrapping railroad vehicles. The procedure for determining the optimal replacement interval involves five steps. According to the decision model, the optimal replacement interval for the onboard signal device components of the "A" line train is calculated using field data, such as failure data, preventive maintenance cost, and failure maintenance cost. The field data analysis indicates that the mileage meter is 9 years, which is less than the designed durability of 15 years. Furthermore, a life cycle in which the phase signal has few failures is found to be the same as the actual durability of 15 years.

• Journal of Platform Technology
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• v.11 no.3
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• pp.45-55
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• 2023

This paper presents a model that supports decision-makers in the Korean film industry to maximize the success of online movies. To achieve this, we collected historical box office movies and clustered them into types to propose a model predicting each type's online box office performance. We considered various features to identify factors contributing to movie success and reduced feature dimensionality for computational efficiency. We systematically classified the movies into types and predicted each type's online box office performance while analyzing the contributing factors. We used automated machine learning (AutoML) techniques to automatically propose and select machine learning algorithms optimized for the problem, allowing for easy experimentation and selection of multiple algorithms. This approach is expected to provide a foundation for informed decision-making and contribute to better performance in the film industry.

• Journal of Korean Biological Nursing Science
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• v.25 no.3
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• pp.143-159
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• 2023

Purpose: The purpose of this study was to provide evidence for future research by analyzing the contents, delivery methods, and educational effects of educational programs for hemodialysis patients. Methods: A literature review was conducted in the following order: problem identification, literature search and data collection, data evaluation, data analysis, and data presentation. In total, 936 documents were retrieved from the search, and 24 documents were finally included in this study. Results: The contents of the educational programs were comprehensive hemodialysis-related knowledge education in seven studies, exercise-related education in 10 studies, diet-related education in four studies, drug-related education in one study, and complex education in two studies. The delivery methods were pamphlets in six studies, audio-visual materials in four studies, direct guidance by researchers in six studies, and multiple methods in seven studies. The effects of the educational program were divided into physical indicators, emotional indicators, and knowledge and performance related to hemodialysis. Sixteen out of 20 articles using physical indicators showed significant outcomes, and 10 out of 12 articles using emotional indicators derived positive results. Hemodialysis-related knowledge and performance were measured in eight and 10 studies, respectively, and meaningful results were found in six studies for knowledge and seven studies for performance. Conclusion: Future research will require the development of a systematic and standardized educational program with comprehensive content that can be provided to all hemodialysis patients, as well as a highly accessible education delivery method to enhance the effectiveness of education.

• Journal of Platform Technology
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• v.10 no.4
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• pp.91-96
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• 2022

Recently, the importance of Research and Development(R&D) security as well as R&D investment is emphasized in the flow of technology hegemony competition, where technology is directly related to national competitiveness.However, despite the enormous impact of the R&D security failure results, research output leakage accidents continue to occur.To solve this problem, this study analyzed leakage accidents and cases of R&D output and concluded that it is priory to develop regulations to raise security awareness at the field researcher level rather than the macroscopic security management system. In addition, in order to design the direction of the researcher security measures, observational study was conducted at the university research site, and four directions were presented, including case analysis and integration. The direction for designing researcher security measures will be used as a basis for developing security regulations specialized in future research sites and security management systems for research institutes.

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.3
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• pp.89-100
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• 2023

Recently, on-device artificial intelligence (AI) solutions using mobile devices and embedded edge devices have emerged in various fields, such as computer vision, to address network traffic burdens, low-energy operations, and security problems. Although vision transformer deep learning models have outperformed conventional convolutional neural network (CNN) models in computer vision, they require more computations and parameters than CNN models. Thus, they are not directly applicable to embedded edge devices with limited hardware resources. Many researchers have proposed various model compression methods or lightweight architectures for vision transformers; however, there are only a few studies evaluating the effects of model compression techniques of vision transformers on performance. Regarding this problem, this paper presents a performance evaluation of vision transformers on embedded platforms. We investigated the behaviors of three vision transformers: DeiT, LeViT, and MobileViT. Each model performance was evaluated by accuracy and inference time on edge devices using the ImageNet dataset. We assessed the effects of the quantization method applied to the models on latency enhancement and accuracy degradation by profiling the proportion of response time occupied by major operations. In addition, we evaluated the performance of each model on GPU and EdgeTPU-based edge devices. In our experimental results, LeViT showed the best performance in CPU-based edge devices, and DeiT-small showed the highest performance improvement in GPU-based edge devices. In addition, only MobileViT models showed performance improvement on EdgeTPU. Summarizing the analysis results through profiling, the degree of performance improvement of each vision transformer model was highly dependent on the proportion of parts that could be optimized in the target edge device. In summary, to apply vision transformers to on-device AI solutions, either proper operation composition and optimizations specific to target edge devices must be considered.

• Annual Conference of KIPS
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• 2010.04a
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• pp.581-584
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• 2010

Based on superspeed nation-wide communication infrastructure, high speed and high quality ALL IP communication network is created. It is a point in time where such infrastructure allows residential and commercial phones to be ported from PSTN to IP network. The problem experienced on IP phones in ALL IP environment and IMS server products are not easily approachable and dealt with. Therefore, this paper discusses approaches used in analyzing and resolving problems before they actually occur. This paper first discusses briefly the IP phones used in IMS network and their related problems. Then next topic deals with characteristics of these problems and current status. Last but not least, the causes of the problems are analyzed and solutions to these problems are introduced. Also discussed are solutions to possible future issues followed by conclusion.