• Korean Journal of Human Ecology
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• v.20 no.2
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• pp.311-325
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• 2011

The purpose of this study was to analyze patterns of time usage of the retired elderly so as to improve their quality of life. The subjects of this study were 225 elderly people in Jeonnam Province. The statistics used for data analysis were frequency, percentage, mean, standard deviation, t-test, and multiple regression. The major findings were as follows : (1) The retired elderly spend more time in physiological activities and leisure, and there was no day difference in time use. (2) On weekdays, the variables affecting labor time were age, former job, health state, and education. On the weekends, education, health state, and former job had significant effects on the amount of time spent on labor. (3) The variables affecting participation and volunteer time were: monthly living expenses, age, spouse, former job, and house, on weekdays, and on the weekends, significant factors were spouse, age, and former job. (4) The variables affecting leisure time were education, age, monthly living expenses, religion, and economic state, on the weekdays, and on weekends, the significant factors were education, economic state, house, religion, and former job.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.2
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• pp.121-129
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• 2016

As the lifespan of concrete structures increases, their load carrying capacity decreases owing to cyclic loads and long-term effects such as creep and shrinkage. For these reasons, there is a necessity for stress state monitoring of concrete members. Particularly, it is necessary to evaluate the concrete structures for behavioral changes by using a technique that can overcome the measuring limitations of usual ultrasonic nondestructive evaluation methods. This paper proposes the use of a nonlinear ultrasonic method, namely, nonlinear resonant ultrasonic spectroscopy (NRUS) for the measurement of nonlinearity parameters for stress monitoring. An experiment compared the use of NRUS method and a linear ultrasonic method, namely, ultrasonic pulse velocity (UPV) to study the effects of continuously increasing loads and cyclic loads on the nonlinearity parameter. Both NRUS and UPV methods found a similar direct relationship between load level and that parameter. The NRUS method showed a higher sensitivity to micro-structural changes of concrete than UPV method. Thus, the experiment confirms the possibility of using the nonlinear ultrasonic method for stress state monitoring of concrete members.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.4
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• pp.214-217
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• 2017

An IGBT (insulated gate bipolar transistor) device has an excellent current-conducting capability. It has been widely employed as a switching device to use in power supplies, converters, solar inverters, and household appliances or the like, designed to handle high power. The aim with IGBT is to meet the requirements for use in ideal power semiconductor devices with a high breakdown voltage, an on-state voltage drop, a high switching speed, and high reliability for power-device applications. In general, the concentration of the drift region decreases when the breakdown voltage increases, but the on-resistance and other characteristics should be reduced to improve the breakdown voltage and on-state voltage drop characteristics by optimizing the design and structure changes. In this paper, using the T-CAD, we designed the NPT-IGBT (non punch-through IGBT) and FS-IGBT (field stop IGBT) and analyzed the electrical characteristics of those devices. Our analysis of the electrical characteristics showed that the FS-IGBT was superior to the NPT-IGBT in terms of the on-state voltage drop.

• International Journal of Knowledge Content Development & Technology
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• v.11 no.2
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• pp.37-54
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• 2021

The study determined the access, skills and constraints towards the usage of ICT among barangay officials. A complete enumeration technique was used due to the small size of the population. A total of 121 barangay secretaries and barangay treasurers comprised the study respondents. The findings revealed that most of barangay officials have access to personal computer at home and in the office using their own mobile data and office internet connectivity. With the support from the Local Government Unit (LGU), it was found that most of the respondents are advance and proficient in computer usage. As constraints to ICT usage, the study respondents still experienced slow internet bandwidth that makes connection and communication weak along with the low income status. Consequently, it was found that there were no significant differences in terms of skills and constraints among barangay secretaries and barangay treasurers towards using ICT. It can be concluded that study respondents prefer to use office computer to access the information they need due to the convenience and availability of resources. The study respondents were competent enough to handle their job well but listed slow internet and low financial resources may hamper their ICT usage. Research implications were also offered.

• International Journal of Computer Science & Network Security
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• v.22 no.6
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• pp.51-56
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• 2022

It is relevant and timely for the existence and prosperity of today's tourism to build up a stock of new abilities and a set of innovations. At present, the tourism industry is experiencing a new stage in its digital transformation. The newest technologies, which are now spreading en masse and one of which is rightfully considered to be blockchain technology, enable tourists to receive tourist services directly from the producers, which not only gives the consumer the opportunity to enjoy higher quality and inexpensive products but also increases the responsibility of the producer. The article analyzes research literature on the possibility of using blockchain technology in the tourism industry. Based on an expert survey, the main problems, prospects, and advantages of the implementation of blockchain technology in the tourism industry are identified. The paper proposes and analyzes an option for the use of blockchain technology on the basis of a blockchain project with a mobile app for users and a dedicated website and public API for travel service providers.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.4
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• pp.81-87
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• 2013

A grounding scheme is one of important parts in protection for safety of electrical installations. Terminologies are successively creating and gradually increasing due to diversity and external environments. The declaration and definition of terminologies concerning grounding are in disorder in several KS standards, electrotechnical provisions for electrical installations and electrotechnical guides related to electrical installations. There seem to be serious confusions in use among technicians and experts. In this paper, we proposed a new scheme and system to consistently use the technical terms concerning grounding described in KS standards and technical provisions. Different use examples and the present state of terminologies on grounding described in Korean documents such as KS IEC standards, technical provisions for electrical installations, consumer's electrical installation guide, and etc are investigated. Although the scope of this work is limited to examine the terminologies on grounding, it is expected that the proposed method could be contributed to the consistent use of terminologies in all areas in KS C IEC standards and technical provisions for electrical installations.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.58-66
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• 2012

This paper describes a design and a verification of linear state observers for a motorized seat belt system to estimate state information such as angular velocity and load torque. The motorized seat belt system provides functions to protect passengers and improve passenger's convenience. To realize these functions, sensors which can measure an angular velocity and load torque are needed. By use of the linear state observer, state information can be estimated without sensors. The motorized seat belt system is analysed and represented as a state space model which contains load torque as an augmented state. By the developed state space model, a full and reduced order observer are designed and verified by experiments. The full and reduced order observer are also compared from points of view of execution time and noise robustness.

• Journal of Sasang Constitutional Medicine
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• v.20 no.2
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• pp.11-20
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• 2008

1. Objectives The objective of this paper is to understand on treatment of in critical state patients based on the text book of Sasang Constitutional Medicine. We expect this study can be helpful in treating the critical state patients. 2. Methods The study is mainly based on the bibliographical research on the "Dongyisoosebowon" and on the "Principle of dosing for patient in critical state". 3. Results and conclusions Lee je-ma suggested a health scale which people can measure his health grade from a standard healthy state to severe diseases. We investigated the treatment of 'critical state' patients according to his scale. Lee je-ma also confirmed the standard dose of herbs and how to take herbs in compliance with the state which each patient in. We tried to find a rules of treating the critical state patients based on the text "Dongyisoosebowon" and we suggested brief principles in treating patients.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.707-717
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• 2022

As the variability of recent rainfall is increasing, it is becoming important to recognize the possibility of changes in the current reservoir state in advance and to inspect the stability based on accurate evaluation standards. However, the evaluation standards for the state change factors of reservoirs are still not suitable for agricultural reservoirs and thus much improvement is needed. Therefore, in this study, the evaluation criteria for state change factors specialized for small reservoirs were categorized and standards were prepared by considering factors that may cause state changes on the dam crest, upstream slope, and downstream slope of the embankment. The categorized results were configured based on the number of mentions of the precision safety inspection report on major defects in 102 reservoirs and the defect factors found in field investigations. The findings of the study indicated that the current state change standards require many revisions for excessive or unnecessary state change factors in the reservoir. Specifically, the deletion of measurement gauges not applicable to the reservoir, the addition of defects found in the reservoir, and the scope of use of the term were proposed. The results of this study can contribute to efficient system operation and management by improving the deficiencies in the system and introducing a new state change factor.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.3
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• pp.408-415
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• 2013

The objective of this experiment was to assess the use of different vitamin D metabolites in the feed of broiler chickens and the effects of the metabolites on performance, bone parameters and meat quality. A total of 952 one-day-old male broiler chicks were distributed in a completely randomised design, with four treatments, seven replicates and 34 birds per experimental unit. The treatments consisted of four different sources of vitamin D included in the diet, $D_3$, $25(OH)D_3$, $1,25(OH)_2D_3$, and $1{\alpha}(OH)D_3$, providing 2000 and 1600 IU of vitamin D in the starter (1 to 21 d) and growth phases (22 to 42 d), respectively. Mean weight, feed:gain and weight gain throughout the rearing period were less in animals fed $1{\alpha}(OH)D_3$ when compared with the other treatments (p<0.05). No significant differences were noted among the treatments (p>0.05) for various bone parameters. Meat colour differed among the treatments (p>0.05). All of the metabolites used in the diets, with the exception of $1{\alpha}(OH)D_3$, can be used for broiler chickens without problems for performance and bone quality, however, some aspects of meat quality were affected.