• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.742-746
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• 2008

With the trend of factory automation, nowadays, much industrial machinery tends to be put into 24-hours operation a day. However, these trends in industrial equipments also increase the possibility of various mechanical problems and bring about innumerable maintenance cost. There is a strong need of the condition monitoring and diagnosis for industrial equipment, especially rotating machinery, since they are connected not only to the reduction in the maintenance costs but also connected to the enhancement of production efficiency. Generally, to evaluate the operating conditions in the machinery in the industrial field, various physical properties are monitored. Among them, vibration and Noise signals are the mist important indicator and it is effectively used in many diagnosis systems for machinery. Much previous research is based in the FFT (Fast Fourier Transform) method. The spectral analysis is assumed that the signal is stationary. However, almost random signals are non-stationary. The wavelet transform has been recognized an efficient Method. Most interesting sounds have time-varying features. Signal processing techniques for the analysis of transient sound have been not clearly given yet.

• Journal of Space Technology and Applications
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• v.2 no.2
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• pp.67-80
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• 2022

The missile early-warning satellite systems have been developed and upgraded by some space-developed nations, under the inevitable trend that the space is more strongly considered as another battle field than before. As the key function of such a satellite-based early warning system, the prediction algorithm of the missile flight trajectory is studied in the paper. In particular, the evolution computation, receiving broad attention in the artificial intelligence area, is applied to the proposed prediction method so that the global optimum-like solution is found avoiding disadvantage of the previous non-linear optimization search tools. Moreover, using the prediction simulator of the launch vehicle flight trajectory which is newly developed in C# and Python, the paper verifies the performance and the feature of the proposed algorithm.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.1989-2001
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• 2024

Artificial intelligence (AI) techniques are now being considered in the nuclear field, but application faces with the lack of actual plant data. For this reason, most previous studies on AI applications in nuclear power plants (NPPs) have relied on simulators or thermal-hydraulic codes to mimic the plants. However, it remains uncertain whether an AI model trained using a simulator can properly work in an actual NPP. To address this issue, this study suggests the use of metadata, which can give information about parameter trends. Referred to here as robust AI, this concept started with the idea that although the absolute value of a plant parameter differs between a simulator and actual NPP, the parameter trend is identical under the same scenario. Based on the proposed robust AI, this study designs an event diagnosis algorithm to classify abnormal and emergency scenarios in NPPs using prototypical learning. The algorithm was trained using a simulator referencing a Westinghouse 990 MWe reactor and then tested in different environments in Advanced Power Reactor 1400 MWe simulators. The algorithm demonstrated robustness with 100 % diagnostic accuracy (117 out of 117 scenarios). This indicates the potential of the robust AI-based algorithm to be used in actual plants.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.5
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• pp.581-588
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• 2019

A long-term trend analysis of cold water masses along eastern coast of South Korea was performed during summer, based on wind speed, wind direction, and sea surface temperature (SST) data. Wind data collected over a 22-year period (1997-2011) were compared with another set of data collected over the successive 7-year (2012-2018), highlighting a general decrease in the frequency and speed of south winds. However, both the frequency and speed of these winds have been higher in June between 2012-2018, rather than between 1997-2011. The cold water season between July and August was faster during the 7-year period; moreover, the SSTs registered around Gangneung (EN) rose by $0.5^{\circ}C- 1.8^{\circ}C$, while those around Yeongdeok (EC) and Gijang (ES) increased by only $0.1^{\circ}C-0.3^{\circ}C$. The number of cold water days during the 7-year period, compared to those recorded during previous years (1990-2011, satellite SST data by NOAA/AVHRR), decreased in the proximity of Yeongdeok and Gijang, but increased in the proximity of Kangneung. Additionally, the number of cold water days around Kangneung, Yeongdeok, and Gijang increased in June highlighting a geographical and temporal change in the occurrence of cold waters. These observation can be explained by variations in the pressure distribution that should have weakened the East Asian monsoon, affecting the direction and speed of winds that regulate the flow of cold waters.

• Culinary science and hospitality research
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• v.15 no.1
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• pp.209-224
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• 2009

The objective of this study is to find out how well-being influences consumer behavior of dining-out. Based on this objective, this study covers plans for improving marketing strategies, which contributes to menu development and purchase behavior of consumers. This study consists of two parts : a research based on the review of the literature and empirical study methods. The finding of the study would also be valuable for the development of management of advertising strategies to be implemented in the foodservice industry. Based on the survey statistics, Program SPSS 12.0 and Amos 5.0 were used in order to look into a casual relationship among group units. The findings of the demonstration analysis are as follows. Most of previous research regarding well-being in local study is psychological well-being dealt with individual health and psychological satisfaction. On the other hand, social well-being is likely to focus on public relation rather than private concerns. The fact that the term 'well-being' have not been definitely defined yet was a problem in research. Also, well-being should not be recognized as a temporary trend but as a general trend. Therefore, it is necessary to understand consumer behavior which is changeable as the circumstance of the foodservice industry changes.

• Korean Journal of Child Studies
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• v.33 no.6
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• pp.187-205
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• 2012

In this study, 150 previous studies of young children's challenging behavior, conducted over the past 10 years, from 2003 to 2012, were selected. These studies were in relation to young children both with and without disabilities, and they were thus used for the purposes of comparative analysis. The major findings are as follows. First, research on challenging behavior not only of young children with disabilities but also of those without disabilities has been an increasing trend from 2008. While most studies of those without disabilities were based on observations by parents or teachers using a variety of tools, studies regarding those with disabilities mainly used single-subject research methods using an operational definition. Second, the bulk of the studies of young children without disabilities were focused on interaction between various children's internal variables and a variety of parent-related variables related to the occurrence of challenging behavior. In comparison, studies of young children with disabilities were focused excessively on direct intervention after the occurrence of problems. Regarding those without disabilities, the interaction between children's temperament, internal variables, and their mothers' parenting behavior, external variables were the main areas of interest for these researchers. There is clearly a growing need for more active research aimed at the prevention of challenging behavior. Challenging behavior in early childhood has an influence not only on each child's present and future academic achievement levels and their quality of life but also on the quality of instruction in classroom available to all children.

• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.499-523
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• 2017

Objective: This study is to provide a foundation for developing comprehensive ergonomic design guidelines for in-vehicle information systems (IVIS) by giving an overview of existing researches as well as setting further research directions. Background: The drivers get much more information recently while interacting with new safety functions of the cars. To avoid cognitive overload of the drivers, IVIS should be deigned appropriately by considering various human factors and task conditions. Method: We gathered, analyzed, and summarized ergonomic researches concerned with IVIS design conducted inside and outside Korea according to a categorization system proposed in the study. Frequency analysis was conducted for figuring out what kind of issues took major part of the researches, and their trends across time and regions. Results: Compared to domestic researches, those done in overseas tend to deal with more variety of independent, dependent and extraneous variables. The overseas researches also showed a tendency to get ahead in making ergonomic guidelines for IVIS design by adapting and integrating the results from previous researches. Conclusion and Application: There have been many researches regarding with ergonomic IVIS design, but some of their results became old-fashioned as the technology evolved. Not many researches have considered diverse human factors regarding the drivers' characteristics except age and gender. It is expected that researchers and designers take advantage of this study to find and review relevant results and set out issues of their own for more progressive researches of the field.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1546-1550
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• 2007

This study aimed to provide basic information as the foundation for further studies on the assessment of velvet antler quality by investigating the changes in fatty acid, vitamin A and E, minerals and GAGs contents by development stage of antler in spotted deer (Cervus nippon). Twelve stags (aged 4 to 5 years) were divided into two groups and velvet antler harvested 40 days (FDG) and 60 days (SDG) after casting of the buttons from the previous set. Total saturated fatty acid was lower in FDG than SDG (p<0.05). Total monounsaturated fatty acid, conjugated linoleic acid (p<0.05), polyunsaturated fatty acid and ${\omega}$3 fatty acid were higher in FDG than SDG. The vitamin A content of FDG was higher than that of SDG, but the vitamin E content of FDG was lower than that of SDG (p<0.05). SDG had significantly higher calcium and phosphate content than FDG (p<0.05). The magnesium content showed a similar trend to the contents of calcium and phosphate, but there was no significant difference between SDG and FDG. Uronic acid content was higher in FDG than SDG but there was no significant difference. The contents of GAGs and sialic acid were significantly higher (p<0.05) in FDG than SDG. These results indicated that the longer stage of antler development had lower content of activating components and this lead to a decrease of antler quality.

• Food Science of Animal Resources
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• v.41 no.4
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• pp.563-588
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• 2021

Increasing meat demand in terms of both quality and quantity in conjunction with feeding a growing population has resulted in regulatory agencies imposing stringent guidelines on meat quality and safety. Objective and accurate rapid non-destructive detection methods and evaluation techniques based on artificial intelligence have become the research hotspot in recent years and have been widely applied in the meat industry. Therefore, this review surveyed the key technologies of non-destructive detection for meat quality, mainly including ultrasonic technology, machine (computer) vision technology, near-infrared spectroscopy technology, hyperspectral technology, Raman spectra technology, and electronic nose/tongue. The technical characteristics and evaluation methods were compared and analyzed; the practical applications of non-destructive detection technologies in meat quality assessment were explored; and the current challenges and future research directions were discussed. The literature presented in this review clearly demonstrate that previous research on non-destructive technologies are of great significance to ensure consumers' urgent demand for high-quality meat by promoting automatic, real-time inspection and quality control in meat production. In the near future, with ever-growing application requirements and research developments, it is a trend to integrate such systems to provide effective solutions for various grain quality evaluation applications.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.4
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• pp.99-117
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• 2012

This paper proposes a method of using national R&D patents' CoIPC networks to identify interdisciplinary trends of technology areas related to Korean national R&D. While previous research analyzed interdisciplinarity of national R&D with simple bibliometric descriptions, this research uses the network-based indexes to analyze its interdisciplinarity from the viewpoints of interdisciplinary "diversity of coupling" and "strength of coupling". In this research, this proposed method was used to form a R&D CoIPC network from the Korean national R&D patents registered from 2007 to 2010. It is expected that the proposed method can be incorporated into a system for a national R&D trend analysis, and used to identify the issues of technology convergence in national R&D and formulate its related research policies.