• Journal of KIISE:Computer Systems and Theory
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• v.34 no.10
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• pp.493-501
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• 2007

The imprecise real-time system provides flexibility in scheduling time-critical tasks. Most scheduling problems of satisfying both 0/1 constraint and timing constraints, while the total error is minimized, are NP-complete when the optional tasks have arbitrary processing times. Liu suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on uniprocessors for minimizing the total error. Song et at suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on multiprocessors for minimizing the total error. But, these algorithms are all off-line algorithms. In the online scheduling, the NORA algorithm can find a schedule with the minimum total error for the imprecise online task system. In NORA algorithm, EDF strategy is adopted in the optional scheduling. On the other hand, for the task system with 0/1 constraint, EDF_Scheduling may not be optimal in the sense that the total error is minimized. Furthermore, when the optional tasks are scheduled in the ascending order of their required processing times, NORA algorithm which EDF strategy is adopted may not produce minimum total error. Therefore, in this paper, an online algorithm is proposed to minimize total error for the imprecise task system with 0/1 constraint. Then, to compare the performance between the proposed algorithm and NORA algorithm, a series of experiments are performed. As a conseqence of the performance comparison between two algorithms, it has been concluded that the proposed algorithm can produce similar total error to NORA algorithm when the optional tasks are scheduled in the random order of their required processing times but, the proposed algorithm can produce less total error than NORA algorithm especially when the optional tasks are scheduled in the ascending order of their required processing times.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.1
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• pp.75-82
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• 2007

This paper addresses a method for shape optimization of a continuous elastic body considering stability, i.e., buckling behavior. The sensitivity formula for critical load is analytically derived and expressed in terms of shape variation, based on the continuum formulation of the stability problem. Unlike the conventional finite difference method (FDM), this method is efficient in that only a couple of analyses are required regardless of the number of design parameters. Commercial software such as ANSYS can be employed since the method requires only the result of the analysis in computation of the sensitivity. Though the buckling problem is more efficiently solved by structural elements such as a beam and shell, elastic solids have been chosen for the buckling analysis because solid elements can generally be used for any kind of structure whether it is thick or thin. Sensitivity is then computed by using the mathematical package MATLAB with the initial stress and buckling analysis of ANSYS. Several problems we chosen in order to illustrate the efficiency of the presented method. They are applied to the shape optimization problems to minimize weight under allowed critical loads and to maximize critical loads under same volume.

• Journal of The Korean Association For Science Education
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• v.39 no.5
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• pp.669-679
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• 2019

In this study, we investigated how 'Scientific Inquiry Experiment,' a newly introduced subject under the 2015 revised curriculum, was implemented to identify the difficulties that science teachers face in the process of teaching the subject and to explore how to support them through online survey and interview methods. A questionnaire of the survey, which consisted of environmental factors of class, preparation and execution of class, teacher self-evaluation of class, and direction for the subject, was developed, and the online survey was requested with a response from one teacher per school from 1674 high schools nationwide. We analyzed the results from 814 teachers who answered all required questions, and we also conducted interviews and online advisory discussions to ensure the validity of our analysis. In the results of the study, teachers complained of lack of time for preparation and execution of the subject, and they demanded laboratory assistants and quality teaching materials. In addition, in order to achieve the goal of the subject, they agreed the necessity of using the 'block scheduling' though they also agreed the difficulties of its implementation. Meanwhile, the alteration of guidelines for evaluation, which was changed from 9-grade system to 3-grade system, was positively recognized by teachers. As a result of this change, the percentage of performance assessment increased in 2019 compared to 2018, but there were no significant changes in the number of 'hands-on activity.' Finally, we proposed ways to support 'scientific inquiry experiment'.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.117-124
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• 2017

A Smart Grid is a system that can efficiently use energy by exchanging real-time information in both directions between a consumer and a power supplier using ICT technology on an existing power network. DR(Demand response) is an arrangement in which electricity users can sell the electricity they save to the electricity market when the price of electricity is high or the power system is crisis. In this study, we developed a power meter data transmission device and power IT system that measure the demand information in real-time using a smart meter and transmit it to a cloud server. The power meter data transmission device developed in this study uses alight sensor connected to a Raspberry Pi 3 to measure the number of blinking lamps on the KEPCO meter per unit of power, in order to provide reliable data without any measurement errors with respect to the KEPCO power data. The power measurement data transmission device uses the standard communication protocol, OpenADR 2.0b. The measured data is transmitted to the power IT system, which consists of the VEN, VTN, and calculation program, via the LTE WiFi communication network and stored in its MySQL DB. The developed power measurement data transmission device issues a power supply instruction and performs a peak reduction DR when a power system crisis occurs. The developed power meter data transmission device has the advantage of allowing the user to adjust it every 1 minute, where as the existing smart metering time is fixed at once every 15 minutes.

• Journal of dental hygiene science
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• v.16 no.2
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• pp.165-175
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• 2016

Health behavior is one component of life style and is defined as behaviors performed by a person to protect, promote, or maintain the their health. General health behavior habits include not smoking, weight management, moderate drinking, regular exercise. The aim of this study was to analyze the relationship between toothbrushing and general health behaviors in 1,013 adults using data from the 2008 Daejeon Health Promotion Survey. Results showed no significant difference by region in general health behavior and toothbrushing. Smoking, alcohol consumption and toothbrushing frequency were related to sex, age, monthly income, occupation, and the degree of obesity. The predictoers of toothbrushing more than a day by losistic regression were female sex (vs. male, OR 1.88, 95% CI 1.20~2.95), age ${\geq}65$ years (vs. twenties, OR 0.51, 95% CI 0.26~0.99), monthly income 2 miillions Korean Won (KRW) to 3 millions KRW (vs. <2 million won, OR 1.58, 95% CI 1.04~2.42), white collar (vs. self-employment, OR 2.74, 95% CI 1.62~4.64), and regular exercise (vs. never, OR 1.60, 95% CI 1.21~2.11). We recommend the independent administration of oral health promotion programs focusing on aged and vulnerable social group because general health behaviors except regular exercise were not related to toothbrushing frequency.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.729-734
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• 2006

This paper aimed to suggest decision-making method for forest management planning using integer programming. Thus, the study examined 85 stands consisting of Korean pine, Japanese larch and oak stands-all of which were at the most suitable time for tending, selection thinning, commercial thinning and final cutting-in the experimental forest of Kangwon National University. The forest management model comprised one objective function, maximizing harvest volume in each stand according to tree species and the kinds of practices, and seven constraints: frequency and stands of practices, minimum and maximum yields, even yields, maximum production, and decision-making varialbes. Besides, the entire period intended by the study was 10 years, divided into 5 management periods. In conclusion, the forest management planning model using integer programming proved that among 85 stands, forest practices were conducted over 68 stands (202.8 ha), producing the total harveted volume of $20,000m^3$, while the rest was reserved. This case study could help make decisions on whether and when the forest practices and harvests could be done in a specific condition.

• Journal of the HCI Society of Korea
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• v.7 no.2
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• pp.49-56
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• 2012

The camera-based mobile applications such as color, pattern and object reading can improve the living quality of blind people. However currently available camera-based applications are uncomfortable for the blind, since these applications do not reflect accessibility requirements of the blind especially on touch screen. We investigated accessibility requirements about rapidly growing camera-based mobile applications on touch screen devices for the blind. In order to identify accessibility requirements, we conducted a usability testing for color reading applications with three different types of interfaces on Android OS. The results of the usability testing were as follows: (1) users preferred short depth of menu hierarchy, (2) the initial audio help was more useful than just-in-time help, (3) users needed both manual and automatic camera shooting modes although they preferred manual to automatic mode, (4) users wanted the OS supported screen reader function to be turned off during the color reading application was running, and (5) users required tactile feedback to identify touch screen boundary. We designed a new user interface for blind people by applying the identified accessibility requirements. From a usability testing of the new user interface with 10 blind people, we showed that the identified accessibility requirements were very useful accessibility guidelines for camera-based mobile applications.

• Journal of Nutrition and Health
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• v.52 no.3
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• pp.268-276
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• 2019

Purpose: Metabolic syndrome causes diabetes and increases the risk of cardiovascular disease. This study examined the correlation between metabolic syndrome, nutrition intake, and triglyceride (TG)/high-density lipoprotein (HDL) cholesterol ratio. Methods: Using the data from the $7^{th}$ KNHANES (2016), this study was conducted on healthy adults aged 19 and older. The components and existence of metabolic syndrome and nutrition intake were independent variables and the TG/HDLcholesterol ratio was a dependent variable. A complex sample logistic progress test was used with age, sex, smoking, and drinking frequency corrected. Results: The TG/HDLcholesterol ratio of people with metabolic syndrome was as high as 1.314 on average, compared to people without metabolic syndrome (p < 0.0001). Among each component of metabolic syndrome, the TG/HDL cholesterol ratio had a significant association with fasting blood glucose, TG, HDL cholesterol, and waist circumference (p < 0.05). Only energy and carbohydrate intake were significantly related to the TG/HDLcholesterol ratio (p < 0.05). Conclusion: The TG/HDLcholesterol ratio is associated with each component of metabolic syndrome, but in particular, it is positively correlated with the presence of metabolic syndrome. Lower energy intakehad a positive correlation with the TG/HDLcholesterol ratio. These results show that metabolic syndrome can be predicted using the TG/HDLcholesterol ratio, and a diet strategy through nutrition and health education is necessary to prevent metabolic syndrome.

• 한국노년학
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• v.28 no.4
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• pp.1179-1200
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• 2008

Knowledge about somatization (somatic manifestation of psychological distress symptoms) among immigrant populations is limited. While several studies have recognized somatization as a culturally distinctive expression of depression amongst older Korean immigrant population, somatization has not been incorporated into the comprehensive empirical model for depression of this population. In order to improve our general understanding of the phenomenon, the objective of this study is to empirically investigate principal contributing factors of somatization as well as inter-relationships among them. Data were collected from a cross-sectional community survey of 234 older Korean immigrants ($$age{\geq_-}55$$) in the New York metropolitan area. The statistical methodology employed a robust hierarchical regression procedure that iteratively downweights outliers. The results indicated that living arrangement, greater numbers of physical illnesses, and depression were significant explanatory factors of somatization. Furthermore, physical illness had a significant joint effect with perception of health on somatization, which confirms that positive perception of health exerts a moderating effect on the relationship between physical illness and somatization. The knowledge obtained from this study will contribute toward extending our knowledge on somatization and implementing more culturally sensitive mental health services for this population.

• Journal of Platform Technology
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• v.11 no.2
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• pp.39-53
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• 2023

Non-installation program (hereinafter referred to as "portable program") is a program that can be used without an installation process, unlike general software. Since there is no separate installation process, portable programs have high mobility and are used in various ways. For example, when initial setup of multiple PCs is required, a portable program can be stored on one USB drive to perform initial setup. Alternatively, when a problem occurs with the PC and it is difficult to boot normally, Windows PE can be configured on the USB drive and portable programs can be stored for PC recovery. And the portable program does not directly affect PC settings, such as changing registry values, and does not leave a trace. This means that the portable program has high security. If a portable program is deleted after using it, it is difficult to analyze behavior in a general way. If a user used a portable program for malicious behavior, analysis in a general way has limitations in collecting evidence. Therefore, portable programs must have a new way of behavioral analysis that is different from ordinary installation software. In this paper, after installing the Windows 10 operating system on a virtual machine, we proceed with the scenario with a portable program of Opera and Notepad++. And we analyze this in various ways such as file analysis of the operating system and memory forensics, collect information such as program execution time and frequency, and conduct specific behavioral analysis of user.