• Proceedings of the IEEK Conference
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• 2001.06d
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• pp.33-36
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• 2001

We introduce, in this paper, the face recognition method that improves recognition rate and training time in eigen system. To increase recognition rate we use Gabor filter. To reduce the increasing training time owing to use Gabor filtering, we extract new feature vectors that are made with average and standard deviation. In experimental results, we get higher recognition rate and shorter training time in improved system than it in original eigen system.

• Journal of the Korean Society of School Health
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• v.21 no.2
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• pp.23-33
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• 2008

Purpose: Internet is one of the essential tools in South Korean adolescent life. Recently, researchers suggest that Internet use is positively associated with teens' mental health problems such as depression and suicide. Thus, this study explored a relationship between Internet use and suicide ideation among South Korean adolescents. Methods:　Secondary data, the three-wave Korean Youth Panel Survey, were analyzed. First, in terms of the levels of Internet use and suicidal ideation, t-test was used for examining a gender difference, and Analysis of Variance were used for examining differences across three points in time(waves 2 - 4). Second, logistic analysis was performed to examine the significant association between Internet use and suicide ideation after controlling for the other factors' effects. In this analysis, Fixed Effect Regression Method(FERM) was incorporated as well. FERM was useful in adjusting for the effects of time-invariant factors even without measuring them. As a result, it was possible to obtain more accurate findings. Results: Adolescent depression was an important factor influencing the association between Internet use and suicide ideation. After controlling for the effect of depression, the relationship between Internet use and suicide ideation was no longer statistically significant. Conclusion:　As a proxy to identify teens who are obsessed with suicide ideation, levels of Internet use do not seem useful. Instead, it is necessary to examine teens' access to websites related to suicide.

• Journal of Information Technology Applications and Management
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• v.12 no.3
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• pp.57-80
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• 2005

This study defined the notion of general idea on m-learning as based upon e-Learning and mobile internet related literature review and identified the m-Learning distinctive features. Also, this study has searched for factors that are expected to influence the use intended for m-Learning from self-regulated learning, which is acknowledged to be a useful method for learning accomplishment in education field, in order to measure the relationship between learners' motivation and use intention. Then it has empirically validated the conceptual model based on Davis' TAM (Technology Acceptance Model) As a result, self-efficacy, self-determination, interest, contents quality, time management, help seeking, and Peer study are factors affecting Perceived usefulness. Also self-efficacy, self-determination, interest, contents qualify, time management, and peer study are factors affecting perceived ease of use. Finally both perceived usefulness and perceived ease of use are significant factors affecting use intention.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.484-497
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• 2021

This paper proposes an extended time uncertainty analysis approach in Level 2 human reliability analysis (HRA) considering severe accident management (SAM) strategies. The method is a time-based model that classifies two time distribution functions-time required and time available-to calculate human failure probabilities from delayed action when implementing SAM strategies. The time required function can be obtained by the combination of four time factors: 1) time for diagnosis and decision by the technical support center (TSC) for a given strategy, 2) time for strategy implementation mainly by the local emergency response organization (ERO), 3) time to verify the effectiveness of the strategy and 4) time for portable equipment transport and installation. This function can vary depending on the given scenario and includes a summation of lognormal distributions and a choice regarding shifting the distribution. The time available function can be obtained via thermal-hydraulic code simulation (MAAP 5.03). The proposed approach was applied to assess SAM strategies that use portable equipment and safety depressurization system valves in a total loss of component cooling water event that could cause reactor vessel failure. The results from the proposed method are more realistic (i.e., not conservative) than other existing methods in evaluating SAM strategies involving the use of portable equipment.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1256-1263
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• 2022

With the advent of the Fourth Industrial Revolution, the amount of energy used in buildings has been increasing due to changes in the energy use structure caused by the massive spread of information-oriented equipment, climate change and greenhouse gas emissions. For the efficient use of energy, it is necessary to have a plan that can predict and reduce the amount of energy use according to the type of energy source and the use of buildings. To address such issues, this study presents a model embedded in a digital twin that predicts energy use in buildings. The digital twin is a system that can support a solution of urban problems through the process of simulations and analyses based on the data collected via sensors in real-time. To develop the energy use prediction model, energy-related data such as actual room use, power use and gas use were collected. Factors that significantly affect energy use were identified through a correlation analysis and multiple regression analysis based on the collected data. The proof-of-concept prototype was developed with an exhibition facility for performance evaluation and validation. The test results confirm that the error rate of the energy consumption prediction model decreases, and the prediction performance improves as the data is accumulated by comparing the error rates of the model. The energy use prediction model thus predicts future energy use and supports formulating a systematic energy management plan in consideration of characteristics of building spaces such as the purpose and the occupancy time of each room. It is suggested to collect and analyze data from other facilities in the future to develop a general-purpose energy use prediction model.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.371-374
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• 1996

Experiments were conducted to determine the effect of time intervals between collecting and use of cattle faeces as a source of micro-organisms in in vitro digestibility assays of forages. The results suggested that temperature conservation capacity by faeces depended on the size of the sample. There was no significant difference(p>0.05) between the first (T1 or 08:30 h) and second using time (T2 or 10:30 h). In vitro organic matter digestibility was significantly lower when faeces was used 5 h (T3 or 13:30 h) after collection. However, the organic matter digestibility determined at the second using time (T2) and third using time (T3) were highly correlated ($R^2=0.99$) with the first using time. It was concluded that faeces can be used as a source of microorganisms for in vitro digestibility assays of forages even 5 h after being voided.

• Journal of the Korean Data and Information Science Society
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• v.16 no.4
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• pp.849-860
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• 2005

This Paper analyzed activities of the average time use survey in 1999 and 2004 by Korea National Statistical Office. The survey of National Statistical Office considered general analysis for activities like that personal care(eating), employment and study, leisure, travel by purpose. Change of time of living causes a lot of effects on society whole economy, culture etc., and is used basic data in policy proposal of the country and enterprise's marketing operation establishment. Analysis for average time could look at change in a role of gender, holiday of saturday's enforcement and increasing of temporary post. Using this analysis we can do more developed and analytical sociological study.

• Journal of the Korean Home Economics Association
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• v.42 no.10 s.200
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• pp.63-77
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• 2004

The overuse of Internet has caused the problem of 'Internet addiction' in the life of college students. The purpose of this study was to develop a program of time management education for preventing Internet addiction among college students. The program consists of sessions. The first session is an introduction to the program which includes a pre-test about Internet addiction. The second session is designed to allow them to check their pattern of Internet use and time use by themselves. The third session is designed to set their tie goals and make long-range plans. The fourth session is designed to make short-range plans and look for alternative activities. The final session is the completion of the program. This study has some significance in developing a time management program for Internet addiction. and will be utilized in practical education.

• Nuclear Engineering and Technology
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• v.43 no.3
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• pp.243-256
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• 2011

This paper considers the concept of analog computing based on a cellular neural network (CNN) paradigm to simulate nuclear reactor dynamics using a time-dependent second order form of the neutron transport equation. Instead of solving nuclear reactor dynamic equations numerically, which is time-consuming and suffers from such weaknesses as vulnerability to transient phenomena, accumulation of round-off errors and floating-point overflows, use is made of a new method based on a cellular neural network. The state-of-the-art shows the CNN as being an alternative solution to the conventional numerical computation method. Indeed CNN is an analog computing paradigm that performs ultra-fast calculations and provides accurate results. In this study use is made of the CNN model to simulate the space-time response of scalar flux distribution in steady state and transient conditions. The CNN model also is used to simulate step perturbation in the core. The accuracy and capability of the CNN model are examined in 2D Cartesian geometry for two fixed source problems, a mini-BWR assembly, and a TWIGL Seed/Blanket problem. We also use the CNN model concurrently for a typical small PWR assembly to simulate the effect of temperature feedback, poisons, and control rods on the scalar flux distribution.

• Journal of Family Relations
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• v.22 no.4
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• pp.135-156
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• 2018

Objectives: This study aim to determine adolescent meal time, which provides the important context of parent-child sharing time. We divided mealtime into family meal and alone meal, and analyzed the time/space context of each meal time as well as the social determinations. Method: We employed adolescents age 10-18 who live with married patents and attends school at the present (n=5,128) from the original data of Korean Time Use Survey. Results: More adolescent were engaged in family meal rather than eating alone in daily bases. However, the trend show difference by day of week and academic grade; family meal are more prevalent in weekends rather than weekdays. As adolescent reaches high school age, the proportion of eating alone beats the proportion of family meal time. Most of the meal occur at home. Having meal outside was relatively scares, especially on weekdays. Tobit and logistic analysis reveal that, on weekday meal, less school hours, more time spent at the private academy, having family leisure event, and long mother's housework hours were positively associated with family meal time. In weekend model, father's education gradient was associated with family meal time, showing higher the father's education level, there were higher chance of having weekend family meal. As for the eating alone, relevant factors were similar with family meal but the directions were the opposite; having family leisure were negatively associated with alone meal, both weekdays and weekend. Long academy hours, meal preparing and leisure alone were positively associated eating alone. Overall, weekday meal time was strongly linked with adolescent daily schedules and time use, while for weekends meal, in both family meal and alone meal, the influence of parent factors were discovered. Conclusion: The results indicates that alone meal and the family meal are not exclusively related but seem to be complementary. Families tend to enjoy family meal yet, there are some necessary situation that adolescent need to be on their own. Increase in ready-made food industries, growing independence of children by age seem partly allow adolescent children to eat alone. Careful attentions may require for monitoring weekends meal situation and the family factor of adolescent in future studies.