• Progress in Superconductivity and Cryogenics
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• v.9 no.4
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• pp.41-45
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• 2007

Superconductor is developed for applications in high-power devices such as power-transmission cables, transformers, motor and generators. In such applications, HTS tapes are subjected to various kinds of stress or strain. AC loss is also important consideration for many large-scale superconducting devices. In the fabrication of the devices, the critical current $(I_c)$ of the high temperature superconductor degrades due to many reasons including the tension applied by bending and thermal contraction. These bending or tension reduces the $I_c$ of superconducting wire and the $I_c$ degradation affects the AC loss of the wire. The $I_c$ degradation and AC loss (self field loss) of Bi-2223 HTS and Coated conductor were measured under tension and bending conditions at 77K and self-field.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.785-792
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• 2012

In this paper, a current-voltage characteristics of n-channel junctionless and inversion mode(IM) MuGFET, and p-channel junctionless and accumulation mode(AM) MuGFET has been measured and analyzed for the application in high speed and low power switching devices. From the variation of the threshold voltage and the saturation drain current with the substrate bias voltages, their variations in IM devices are larger than junctionless devices for n-channel devices, but their variations in junctioness devices are larger than AM devices for p-channel devices. The variations of transconductance with substrate biases are more significant in p-channel devices than n-channel devices. From the characteristics of subthreshold swing, it was observed that the S value is almost independent on the substrate biases in n-channel devices and p-channel junctionless devices but it is increased with the increase of the substrate biases in p-channel AM devices. For the application in high speed and low power switching devices using the substrate biases, IM device is better than junctionless devices for n-channel devices and junctionless device is better than AM devices for p-channel devices.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.2
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• pp.55-62
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• 2012

Convergence of information technology (IT) and medical devices enables people to measure health-related information ubiquitously, such as measuring blood glucose at home and checking cardiac signals during exercise and it allows us to access to medical care anywhere and anytime. Nowadays, the market for U-healthcare medical devices is growing rapidly, but guidelines for the evaluation of safety and effectiveness of such devices remain to be formulated. We performed a study on the development of safety and performance evaluation method for portable, hand-held, U-healthcare medical devices. We reviewed current guidelines and standards for home-health devices from the Korea Food and Drug Administration (KFDA) and related international committees such as the ISO/IEEE and CE. We summarized the test methods and items for the evaluation of safety and performance related to U-healthcare medical devices from the above guidelines and standards. We defined requirements for a U-healthcare medical device to demonstrate good performance. In conclusion, we propose an evaluation method for U-healthcare medical devices, which will help improve the safety and reliability of these devices.

• Proceedings of the Korean Vacuum Society Conference
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• 2008.08a
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• pp.73-73
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• 2008

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.49-60
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• 2015

Smart Grid devices are the major components of the Smart Grid. They collect and process a variety informations relating power services and support intelligent power services by exchanging informations with other SG devices or systems. However, If a SG device is attacked, the device can provide attack route to attacker and attacker can attack other SG devices or systems using the route. It may cause problem in power services. So, when cyber incident is happened, we need to acquire and examine digital evidence of SG device quickly to secure availability of SG. In this paper, we designed remote evidence acquisition system to acquire digital evidences from SG devices to response quickly to incidents of SG devices. To achieve this, we analyzed operating environment of SG devices and thought remote digital evidence acquisition system of SG devices will be more effective than remote digital evidence acquisition system targeted general IT devices. So, we introduce design method for SG devices remote evidence acquisition system considered operating environment of SG devices.

• Korean Journal of Veterinary Research
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• v.57 no.2
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• pp.71-78
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• 2017

Well-established standards and specifications for medical devices not only provide clarity and consistency in licensing processes but also secure device safety and effectiveness. This study reviewed regulatory standards and specifications for veterinary medical devices in Korea based on data obtained through analyses of those medical devices. General standards for electromechanical, electromagnetic, and biological safety and individual standards for 76 electric and 70 general medical device products have been established by the Korean Ministry of Food and Drug Safety. However, the first standards and specifications for veterinary medical devices were established in March 2000 for two products (disposable needle and syringe). Similar to the large number of standards for medical devices, there have been general standards for safety and individual standards for 72 veterinary medical devices (27 electric medical devices, 12 non-electric medical devices, 10 medical supplies, and 23 other types) established since 2014. These new standards considered, among other aspects, the devices' applications, usage characteristics, and industrial environment. To date, the establishment of standards and specifications for veterinary medical devices remains limited. This study suggests that improvements should be made to the regulation of general and individual standards associated with various veterinary medical instruments, supplies, and in vitro diagnostic medical reagents.

• Journal of Information Technology Services
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• v.7 no.2
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• pp.113-125
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• 2008

To test if the developed ubiquitous health care devices working well and vital information could be collected and monitored systematically through internet and to test if the devices and services could be used further. Kyungwon University, KT Co., Gil Medical Center, LIG Nex1 Co., and Sujeong Health Center conducted an ubiquitous health care demonstration project in Sujeong-Gu, Sungnam, Korea from Mar. 5 to May 16. We developed and applied several medical devices to monitor health of the elderly in their houses through internet. The devices were sphygmomanometer, glucometer, body fat scale, Health Pad, and activity sensor. We distributed the devices to 20 recipients of home care and 7 diabetes patients. After received the devices and were explained how to use them, they used the devices in their houses. The vital signs of the residents were monitored through internet. A nurse monitored and consulted their vital signs in the monitoring center in Kyungwon University during the demonstration period. The consultant called them and consulted on their blood pressure, blood sugar level, and body fat after a few seconds they used the devices as well as provision of recommended contents such as diets and activities through Health Pad. To investigate cognition and satisfaction of the participants for the devices, we surveyed the participants at the end of the demonstration period. For the change in blood pressure, blood sugar level, and activities, we conducted statistical test. After the demonstration period. cognition and satisfaction for the devices and change in blood pressure, blood sugar level, and activities were evaluated. Most of the participants were acknowledged how to use the device and satisfied with the use of the devices. The internet monitoring and services are considered to be promising because most of the participants were satisfied especially because somebody was monitoring their health status. However some weaknesses such as short battery life of the activity sensor, lack of connection of consultations with hospitals, and low understanding on usage of some of the devices need to be complemented.

• Human Ecology Research
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• v.56 no.6
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• pp.541-553
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• 2018

This study examined the influences of infants' age for the first use of smart devices and the amount of time to use them on the externalizing problem behavior as well as investigated whether maternal managing behavior (setting rules on accessing smart devices and monitoring their child's use of smart devices) had moderating effects. The study participants consisted of 521 three to six year old infants (235 boys and 286 girls). The data were analyzed by means of descriptive statistics and a hierarchical regression. The results of this study indicated that the age at first use of smart devices and maternal managing behavior had significant effects on the externalizing problem behavior of infants. The earlier the infants first used smart devices, the higher the level of externalizing problem behavior. Externalizing problem behavior was also found to be higher when the mothers showed no managing behavior. Second, maternal managing behavior moderated the relation between the age at first use of smart devices and the externalizing problem behavior of infants. The effects of the age at first use of smart devices on the externalizing problem behavior of infants were greater when the mothers did not set rules regarding the use of smart devices and did not supervise children when using smart devices.

• Journal of Korean society of Dental Hygiene
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• v.10 no.6
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• pp.1107-1119
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• 2010

Objectivs : The purpose of this study is to provide basic data for the use of oral hygiene devices and to improve oral health care continuously by encouraging the use of oral hygiene devices. Methods : The survey was carried out by questionnaire research targeting 395 respondents in metropolitan area in June-August 2009. The collected data is analyzed by statistics program SPSS version 12.0. 1. General characteristics of subjects are analyzed by percentage and descriptive statistics. 2. Recognition about how to use oral hygiene devices, usage of oral hygiene devices, recognition of dental brush usage, Effect after using oral hygiene devices are analyzed by mean difference test(t, F verification). 3. Effect after using oral hygiene devices, relation of oral hygiene devices usage with subjective oral health status, oral hygiene devices usage and participation in education are analyzed by Correlation, Regression analysis. Results : 1. Investigation shows that most oral health devices are rarely used except toothbrush(4.57) in case of the use of oral hygiene devices. 2. In the case of awareness of oral hygiene devices usage, almost everyone knows how to use dental brushes(MEAN 4.16) the most. And the next ones are like these-tooth picks(MEAN 3.38), dental floss(MEAN 3.28), mouth rinse(MEAN 3.24). And they don't know how to use the other oral hygiene devices usage. 3. respondents who use dental floss(${\beta}$=.238, p<.001), interdental brush(${\beta}$=.242, p<.001) and water pik(${\beta}$ =.180, p<.05) recognize that the result and effect after using them are more positive than the others in different case. 4. Respondents who use toothbrush(${\beta}$=.119), dental floss(${\beta}$=.120) and interdental brush(${\beta}$=.136). frequently evaluate their subjective oral health status positively in case of frequency of using oral hygiene devices and subjective oral health status(p<.05). 5. Respondents who use toothbrush and interdental brush properly and frequently, who are older than the others show more concern about participating in education of "How to use oral hygiene devices" than the others(p<.05). Conclusions : In conclusion, to prevent oral disease, the opportunity of participating in education about correct knowledge and proper way should be expanded. And we should contribute to oral health improvement through developing, executing and informing systematic, popular oral health education with active one.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.9 no.1
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• pp.101-112
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• 2002

Purpose: This study evaluated the accuracy of electronic devices compared with mercury sphygmomanometer. Of 132 outpatients with electronic devices. 77 who possessed oscillometric cuff devices participated in this study. Method: When the blood pressure was measured, all electronic devices were connected by means of a Y-connector to a mercury sphygmomanometer. Using the simultaneous same arm approach, each comparison was carried out three times at 2-minute intervals. Results: Compared with the mercury sphygmomanometer, the electronic devices underestimated systolic and diastolic blood pressure, respectively by $4.0{\pm}5.8mmHg$ and $2.5{\pm}67mmHg$, which satisfies the standard error range of the American Association for the Advancement of Medical Instrumentation. According to the British Hypertension Society criteria, these differences achieved C grade for both systolic and diastolic pressure. For the graphical analysis, the differences had a tendency to fulfill the permitted error limits in both diastolic and systolic blood pressure. Moreover, the purchase duration was not correlated with the accuracy of electronic devices. Conclusion: These results indicate that difference in blood pressure between electronic devices and mercury sphygmomanometer is within the standard error. Therefore, electronic blood pressure measuring devices may be useful for therapeutic self-management of hypertension.