• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.9
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• pp.57-63
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• 2007

The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154[kV] dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in 154[kV] power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method(FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.

• Journal of Information Processing Systems
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• v.5 no.2
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• pp.69-76
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• 2009

Self healing systems are considered as cognation-enabled sub form of fault tolerance system. But our experiments that we report in this paper show that self healing systems can be used for performance optimization, configuration management, access control management and bunch of other functions. The exponential complexity that results from interaction between autonomic systems and users (software and human users) has hindered the deployment and user of intelligent systems for a while now. We show that if that exceptional complexity is converted into self-growing knowledge (policies in our case), can make up for initial development cost of building an intelligent system. In this paper, we report the application of AHSEN (Autonomic Healing-based Self management Engine) to in OKKAM Project infrastructure backbone cluster that mimics the web service based architecture of u-Zone gateway infrastructure. The 'blind' load division on per-request bases is not optimal for distributed and performance hungry infrastructure such as OKKAM. The approach adopted assesses the active threads on the virtual machine and does resource estimates for active processes. The availability of a certain server is represented through worker modules at load server. Our simulation results on the OKKAM infrastructure show that the self healing significantly improves the performance and clearly demarcates the logical ambiguities in contemporary designs of self healing infrastructures proposed for large scale computing infrastructures.

• Research in Community and Public Health Nursing
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• v.27 no.1
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• pp.21-30
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• 2016

Purpose: This research was conducted to identify long-term care service needs in the baby boom generation. Methods: Data were collected from September 3 to October 9, 2012 targeting 196 baby boomers residing in Seoul and Gyeonggi-do with the measurement of long-term care service needs having five domains. Collected data were analyzed using the SPSS 20.0 program. Results: Demand for long term care service in those who preferred nursing homes was highest as $4.40{\pm}0.69$ in the safe environment domain. In case of those preferring home care services, demand was highest as $4.37{\pm}0.56$ in the social interaction domain. People who preferred nursing homes had higher needs in personal health care and improvement of the service quality domains. Those who preferred home care services showed diverse needs according to their characteristics. Conclusion: The baby boom generation had high needs in all the domains of long-term care services and such needs were diverse according to their characteristics. However, long-term care services had limitations that they provided standardized and uniformed services only. Therefore, health care services and improved quality services should be provided in a way of meeting the users' needs, and tailored services should be provided in consideration of the users' characteristics.

• The Journal of Korean Physical Therapy
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• v.22 no.4
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• pp.91-96
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• 2010

Purpose: Among computer users, the awkward posture and workstation setups of workers contribute to work-related upper limb musculoskeletal disorders. The purpose of this study was to evaluate the efficacy of a traditional physical therapy and ergonomic intervention by physical therapists in 4 computer users. Methods: After checking Visual Analogue Scores (VAS), four subjects who were treated by physical therapy for neck and shoulder problems related to VDT syndrome were enrolled in the study. All subjects spent at least 40 hours per week at a computer workstation. All subjects had pain and ergonomic states evaluated using methods such as VAS, Neck Disability Index (NDI), Workstyle short form, Rapid Upper Limb Assessment (RULA), and OSHA VDT checklist (Occupational Safety and Health Administration video display terminal) before a physical therapy + ergonomic intervention. Participants were re-evaluated 1 month later. Results: Participants showed more improvement of their neck pain after being treated with a physical therapy plus ergonomic intervention than when treatment consisted only of physical therapy. Improvements in RULA, Workstyle short form, and OSHA VDT checklist also were achieved. Conclusion: This case study suggests the importance of examining the work habits and work-related postures of subjects who complain of neck and shoulder pain that is exacerbated by computer use. Personalized ergonomic interventions and physical therapy can lead to improvement of patients with VDT syndrome.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.374-395
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• 2017

Users quite often experience volatile channel conditions which negatively influence multimedia transmission. HTTP adaptive streaming has emerged as a new promising technology where the video quality can be adjusted to variable network conditions. Nevertheless, the new technology does not remain without drawbacks. As it has been observed, multiple video players sharing the same network link have often problems with achieving good efficiency and stability of play-out due to a mutual interference and competition among video players. Our investigation indicates that there may be another cause for under-performance of the streamed video. In an emulated environment, we implemented three algorithms of adaptive video play-out based on bandwidth or buffer assessment. As we show, traffic generated by players employing the same or similar play-out strategies is positively correlated and synchronised (clustered), whereas traffic originated from different play-out strategies shows negative or no correlations. However, when some of the parameters of the play-out strategies are randomised, the correlation and synchronisation diminish what has a positive impact on the smoothness of the traffic and on the video quality perceived by end users. Our research shows that non-correlated traffic flows generated by play-out strategies improve efficiency and stability of streamed adaptive video.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.1
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• pp.155-167
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• 1998

In the climate of increasing calls for academic assessment, the author undertook a study to ascertain availability of original texts and their translations in the academic library. The object of this study is to compare the use frequency of original texts by academic major of users in the university libraries. To achieve this object, the author collected the data stored in 3 Korean university library online systems from September 10th to 30th, 1995 and tested the hypotheses by using the Minitab statistical package. Libraries with multilingual collection and automated systems will find the methodology Presented here Particularly valuable.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.10
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• pp.4886-4907
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• 2019

The use of mobile devices is increasing in multimedia applications. The multimedia contents are delivered to mobile users over heterogeneous networks. Due to fluctuation in bandwidth and user mobility, the service providers are facing difficulties in providing Quality of Service (QoS) guaranteed delivery for multimedia applications. Multimedia applications depend on QoS parameters such as delay, bandwidth, and jitter to offer better user experience. The existing schemes use the single source and multisource delivery but are unable to balance between stream quality and network congestion for mobile users. We proposed a Quality Oriented Multimedia Content Delivery Scheme (QOMCDS) for the mobile cloud to deliver better quality multimedia contents for the mobile user. The multimedia contents are delivered to the mobile device based on the device's parameters and network environment. The objective video quality assessment models like Peak Signal-to-Noise Ratio (PSNR), Structural Similarity (SSIM), and Video Quality Measurement (VQM) are used to measure the quality of the video. The client side Quality of Experience metric such as Startup delay, Rebuffering events, and Bitrate switch count was used for evaluation. The proposed scheme is evaluated using dash.js and is compared to existing schemes. The results show significant improvement over existing multimedia content delivery schemes.

• The Journal of Korean Physical Therapy
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• v.28 no.3
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• pp.183-188
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• 2016

Purpose: The aim of the study was to investigate neck posture, range of motion, muscle endurance and self-report of pain and disability in smartphone users. Methods: Seventy-eight university student volunteers, aged between 18 and 30 years (mean age 23.2), were assessed for: a head-neck posture by measuring cranial vertical angle, neck range of motions using cervical range of motion device, and a deep neck flexor endurance using a stabilizer. Finally, subjects were asked about their neck pain and completed disability questionnaires, ie, Short Form McGill Pain Questionnaire, Neck Disability Index, and World Health Organization Disability Assessment Schedule 2.0. Results: Thirty-eight subjects experienced recurrent neck pain with/without upper limb pain (neck pain group) and 40 reported no current neck pain with/without upper limb pain (no neck pain group). Differences were found between groups on pain and disability questionnaires. Subjects with neck pain had significantly higher disability scores than those of no neck pain group. However, there were no differences observed between groups in a head-neck posture, neck range of motions, and deep neck muscle endurance time. The smartphone usage time was negatively correlated with neck pain intensity and disability score whereas it had positive relationship with flexibility and posture. Conclusion: Group differences were observed as lower capacity not only for neck specific daily activities but for general functioning in daily routine when the neck pain and no neck pain groups were compared. Therefore, functioning in daily activities should be investigated as prevention for further developing neck pain in smartphone users.

• The Korean Journal of Health Service Management
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• v.7 no.1
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• pp.133-144
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• 2013

The present study is aimed at assessing medical service quality as perceived by in-patients of geriatric hospitals and at analyzing the excitement factors by using revised IPA Applying the Kano's model for users' satisfaction. The data was collected from Nov. 5 to Dec. 7, 2012. Among a total of 503 cases of questionaries, only 419 cases were used. To data were analyzed by PASW statistics 18.0 and revised IPA applying Kano's model. The paired t-test results reveal that satisfaction was higher than the expectation level at a statistically significant level across all the medical service quality factors. The revised IPA results categorized facility convenience, hospitalization and care, and kindness as basic factors and medical reliability and access as excitement factors. In conclusion, medical reliability and access, which were identified as excitement factors of medical service quality, are essential opportunity factors for users and should accordingly be used as strategic factors to increase satisfaction with a geriatric hospital and induce customer surprise.

• Electronics and Telecommunications Trends
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• v.36 no.5
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• pp.32-41
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• 2021

As the COVID-19 crisis continues, working environments and lifestyles have been changed unexpectedly, therefore the importance of mental health in the working environments has been highlighted. When the workers' mental health deteriorates, there will be personal losses but also human resources losses caused productivity decrements of the company or the organization. Many researchers have been tried to solve these issues with the help of ICT technologies such as wearable devices. Most wearable healthcare devices have been designed to detect the physiological status of users and collect the physical activities of users, and their applications are gradually expanding. Those devices may be good candidates to prevent loss of human resources from working environments especially under the COVID-19 situation by continuously monitoring mental health status in connection with mobile devices and managing the mental health on their own by combining mental well-being with support solutions. In this paper, the development trend of mental health measurement and mental well-being support technologies is analyzed, and development prospects are examined.