• Journal of the Ergonomics Society of Korea
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• v.27 no.3
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• pp.33-41
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• 2008

The goal of this study was to compare wrist posture, muscular loads and perceived comfort among wearable wrist rest (WR), general wrist rest(GR), no wrist rest(NR) during keyboard and mouse use. Thirteen subjects performed text editing task in three test conditions: wearable wrist rest(WR), general wrist rest(GR), no wrist rest(NR). During text editing task, the right wrist posture was recorded by an electrogoniometer and the muscle activity in upper trapezius, anterior deltoid, extensor digitorum, extensor carpi ulnaris were recorded by electromyography. After all of the tests, the subjects rated perceived comfort. Working with wearable wrist rest(WR), compared to no wrist rest(NR) and general wrist rest(GR), decreased wrist radial/ulnar deviation and also decreased muscle activity in upper trapezius and anterior deltoid. At the same time, in work with wearable wrist rest(WR), the subjects rated more comfort at 5 of 8 body locations(shoulder, upper arm, wrist, hand, body).

• Journal of Korea Multimedia Society
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• v.20 no.5
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• pp.808-826
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• 2017

Most of conventional DSS's(Digital Signage Systems) have been built based on LAMP framework. Recent researches have shown that MEAN or MERN stack framework is simpler, more flexible, faster and more suitable for web-based application than LAMP stack framework. In this paper, we propose a design and implementation of MEARN (ME(A+R)N) stack-based real-time digital signage system, MR-DSS, which supports handing real-time tasks like urgent/instant messaging, system status monitoring and so on, efficiently in addition to conventional digital signage CMS service tasks. MR-DSCMS, CMS of MR-DSS, is designed to provide most of its normal services by REST APIs and real-time services like urgent/instant messaging by Socket.IO base under MEARN stack environment. In addition to architecture description of components composing MR-DSS, design and implementation issues are clarified in more detail. Through experimental testing, it is shown that 1) MR-DSS works functionally well, 2) the networking load performance of MR-DSCMS's REST APIs is better compared to a well-known open source Xibo CMS, and 3) real-time messaging via Socket.IO works much faster than REST APIs.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.2
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• pp.235-251
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• 2005

German working hour law of 1994(Arbeitszeitgesetz) provides maximum working hour as 8 hours a day and 48 hours per week. The law provides that minimum 11 hours rest-time is required between the end of a day's work and the beginning of the next day's work. Namely, the hour that the workers are put under commanding of the user is restricted within 13 hours per day. In the meantime, article 5, 7, 14, and 15 of the law have some letting the exceptional provisions regarding the working hour and rest-time of flight crew, and 2nd administrative order for the aviation transportation business owner, which is established based on such exceptional provisions(2.DV LuftBO), provides the working hour and rest-time of flight crew quite in detail. The administrative order is detailed quite regarding block time, flight working hour, and rest-time. So, it does not need to interpret additionally. Airlines in Korea should observe the both Labor Standard Act applying to general workers and Aviation Act focused on flight crew, so it is difficult that airlines manages working hour and rest-time of the flight crew efficiently. Therefore, it is desirable that our country refers to and considers adopting this legislation method of Germany which regulates working hour and rest-time of flight crew in detail in the 2.DV LuftBO.

• Journal of Korean Clinical Nursing Research
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• v.27 no.2
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• pp.179-186
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• 2021

Purpose: The purpose of our study was to identify the bleeding risk factors and to validate the safety of shortening the bed rest time after bone marrow examination in pediatric hemato-oncologic patients. Methods: From July 2019 to September 2020, 145 patients were enrolled from a single center. Medical records were reviewed retrospectively. Descriptive statistics were presented, and the data were analyzed using 𝑥²-test, Fisher's exact test, and a logistic regression. Results: After two hours of bed rest, most of the patients (91.7%) did not have bleeding complications, and only 8.3% of the patients had a minor bleeding. The rate of major bleeding complications, including hematoma, retroperitoneal hemorrhage rate was zero. The bleeding complications was frequently found on bilateral procedures than unilateral procedures and the difference were statistically significant (p<.05). Conclusion: Two hours of bed rest time after bone marrow examination could be safe and adequate in pediatric hemato-oncologic patients.

• Korean Journal of Childcare and Education
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• v.9 no.5
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• pp.335-355
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• 2013

The purpose of this study was to investigate children's recognition and needs about rest and naps at child care education centers, in the view of respecting children's rights. The participants were 40 children(20 4 year olds and 20 5 year olds), attending B Public Child Care Education Center in Seoul. The research methods were accomplished by participant observation in project activities and interviews with semi-structured questions. The collections of this process which were recorded document materials and video materials were analyzed by transcribed method. The results of this study were as follows: First, the meaning of the children's recognized rest showed time for family together, time for fun play, time required when they were very stressful and angry, and time for eating delicious meals. Second, children recognized that nap time in the child care center was time for a forced nap, time for listening to quiet music, and time for feeling good after a nap. Third, as for the needs to take a rest and a nap for children, they wanted to rest when they came together at full day class after their friends had returned home, they wanted a special area except the classroom, and they wanted to be cared for by familiar adults. Based on these results of the study, future research directions were proposed in terms of respecting children's rights of enjoying a rest and a nap.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.119-124
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• 2008

Many automobile assembly workers often do several cycles of tasks continuously, i.e., without breaks, to get a longer break. This is not recommended since the dose of fatigue increases exponetially with time and it takes much longer time to recover. In this study, a laboratory experiment was conducted to investigate the effect of work/rest schedules on workload of a repetitive upper-limb task. Eleven male subjects participated in the experiment, in which simulated screw driving tasks were carried out repetitively with 3 different work/rest schedules: standard breaks(1 cycle of work at a time, 60 20-s breaks), medium breaks(5 cycles of work at a time, 12 100-s breaks), and long breaks(10 cycles of work at a time, 6 200-s breaks). The result showed that medium- and long-breaks schedules significantly increased the level of perceived discomfort and %HRR as compared to the standard-break schedule. The subjects' preference was not statistically different among work/rest schedules, which might be caused from the absolutely low level of workload of the experimental tasks. From the results, it is recommended to have frequent and shorter breaks rather than infrequent and longer breaks to decrease the level of physical workload. A more expanded studies, however, should be carried out to provide more practical safety guidelines on the work practice of continuous working without breaks among automobile assembly workers.

• Tribology and Lubricants
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• v.22 no.2
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• pp.59-65
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• 2006

In hard disk drives as the head to disk spacing continues to decrease to facilitate recording densities, slider disk interactions have become much more severe due to direct contact of head and disk surfaces in both start/stop and flying cases. The slider disk interaction in CSS (contact-start-stop) mode is an important source of particle generation and tribocharge build-up. The tribocharge build-up in the slider disk interface can cause ESD (electrostatic discharge) damage. In turn, ESD can cause severe melting damage to MR or GMR heads. The spindle speed of typical hard disk drives has increased in recent years from 5400 rpm to 15000 rpm and even higher speeds are anticipated in the near future. And the increasing disk velocity leads to increasing disk acceleration and this might affect the tribocharging phenomena of the slider/disk interface. We investigated the tribocurrent/voltage build-up generated in HDD, operating at increasing disk accelerations. In addition, we examined the effects with relative humidity conditions and rest time. We found that the tribocurrent/voltage was generated during pico-slider/disk interaction and its level was about $3\sim16pA$ and $0.1\sim0.3V$, respectively. Tribocurrent/voltage build-up was reduced with increasing disk acceleration. Higher humidity conditions $(75\sim80%)$ produced lower levels tribovoltage/current. Therefore, a higher tribocharge is expected at a lower disk acceleration and lower relative humidity condition. Rest time affected the charge build-up at the slider-disk interface. The degree of tribocharge build-up increased with increasing rest time.

• The Korean Nurse
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• v.36 no.2
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• pp.73-83
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• 1997

Bed rest is recommended to prevent postlumbar puncture headaches(PLPHA), but the period of bed rest varies in the literature from 6 hours to 24 hours. In clinical practice the period of bed rest varies but nursing methods for adults and children have little difference. In Seoul National University Hospital, children have been given at least 6 hours bed rest after a lumbar puncture. Pediatric oncology patients require a lumbar puncture for an initial diagnosis, follow up treatment or administration of chemotherapeutic agent. But it is difficult for young children to lie supine or to refrain from their usual activities in any way, and unpleasant problems related to a shortage of beds often occurs during discharge or in an outpatient setting. The purpose of this study is to substantiate the preventive effect of PLPHA by the period of bed rest, to identify the other factors that influence PLPHA, and to use the nursing methods proper to children. The subjects were 65 children, ages 1-17, undergoing treatment in the children's cancer center at SNUCH during the period June 1, 1995, to Aug. 31, 1995. The team nurses asked questions about PLPHA of the parents and children in order to fill out a questionnaire. The data were evaluated by percent, t-test, Chi-square test and Mann-Whitney U test. Result; 1. There was no significant difference relating the bed rest time spent to the occurrence of postspinal headaches (t-test). 2. There was a significant risk of PLPHA in the children who were irritable before procedure and/or had experienced previous PLPHA(p<0.05, ${x^2}-test$). 3. The following factors were not found to be associated with increased risk of PLPHA: previous puncture experience, giving analgesics, the choice of puncturist, inpatient/outpatient status, gauge of needle, purpose, the amount of CSF removed, gender, diagnosis, the number of peripheral WBCs, previous lumbago experience after LP, position after bed rest, age, the number of aural puncture at the time. A longer period of bed rest is unlikely to be more effective to prevent PLPHA and seems impractical. A shorter period will save time and effort. Perhaps it will also allay some of the fears which surround LP. So 1 hour bed rest after LP is suggested and nursing methods for emotional support should be investigated to reduce PLPH.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1295-1304
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• 2015

In this paper, an approach to extend the life of lead-acid batteries through the elimination of sulfation with "rest time" using the pulse current of a conventional DPV (Differential Pulse Voltammetry) method is discussed. A new rest time without "0" current in "saw-tooth" pattern pulses is proposed to overcome the "0" current (blackout period), which is a shortcoming of DPV. This will enable the proposed method to be used in the loaded state. In the proposed approach, ESSs (Energy Storage Systems) were discharged for 5 h twice per day for 6 months on weekdays. To observe the changes in the lifespan of the systems, for the same period, the changes in the impedances of lead-acid batteries which were being charged e without charging and discharging were measure and compared. This study is focused on determining the effectiveness of lead-acid batteries as ESSs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.709-716
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• 2018

In 2017, there was an accident in which a cadet onboard training was killed. This cadet worked 12 hours a day. No regulation has yet been laid down to define hours and breaks for interns. Therefore, the purpose of this study is to investigate the working status of commissioned training, the satisfaction survey of commissioned training, and to improve the treatment of commissioned trainees. The survey was conducted on students commissioned from merchant vessels, and 461 respondents answered the questionnaire. The results of the survey are as follows. First, 43.0 % of cadets said that they worked 10 hours a day on average, regardless of the vessel type, and 35.2 % said that the average rest time was 8 hours. 15.6 % of respondents said they had worked more than 12 hours. Unreasonable order cases deviating from the purpose of education were "making ramen, working at rest time, instruction of dangerous work, making night snack and private errands." Second, the satisfaction level of cadets who practiced on LNG carriers was high, while the satisfaction level of cadets on bulk carriers and container carriers was low. It was confirmed that the ship's size, ship's age, working hours, rest time and training support costs had little minor effect on educational satisfaction. Lastly, 56.8 % of the cadets answered 'commissioned training is like work.' Based on the results of the questionnaires, we proposed the following improvement methods; providing legislation for working hours and rest time for commissioned training cadets, protection system against violence and sexual harassment and victim protection. This study focuses on the working and rest time of merchant ship's cadet and it is meaningful to investigated the onboard training satisfaction by ship's type, size and age.