• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.121-130
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• 2021

Recently, the need for new approaches and recognition of safety and maintenance has been raised for small vulnerable facilities in Korea due to the acceleration of aging facilities, various safety accidents, and increased frequency of use. In particular, small vulnerable facilities(SVF), including most social welfare facilities, are facilities used by many of the vulnerable groups, and safety management is very important. Therefore, this study investigated various statuses based on safety inspection results (31,114 cases) conducted over the past 13 years (2008-2020) for small vulnerable facilities in Korea, and evaluated the characteristics of each field and safety and maintenance performance level. This aims to present policy directions for strengthening safety management of facilities for the vulnerable by using basic data such as improvement of safety standards and maintenance strategies for small vulnerable facilities in Korea in the future.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.389-394
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• 2019

In case of damaged timber sleepers, maintenance is carried out according to the track inspection standard. However, it is difficult to detect the extent of damage on the bridge, and maintenance is depended on inspector's judgment. In this study, we propose to improve the evaluation criterion of timber sleepers for the ballast-less tracks on serviced urban railway bridge. The timber sleepers on railway bridge was classified according to degree of damage, and damage scores were calculated for each damage grade. Also we have improved the maintenance system of the timber sleepers through the history management system of the individual timber sleepers on railway bridge. As a results, it was judged that systematic management of timber sleepers could be possible during maintenance.

• Korean Journal of Social Welfare
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• v.58 no.1
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• pp.209-235
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• 2006

This study was performed to analysis the social worker's duty in korea and suggest for typology duties of 1st grade social worker, 2nd or 3th grade social worker's qualification. 911 social workers responded to questioner. This objectives was accomplished by the measuring to frequency of duties, and the qualifying cognition of each grade social worker's duties. As a result, social worker spent more time carried out maintenance of facility, direct services, intake, management of file and official document duties than personal management, planning and financial program, evaluation and termination duties. Type of social worker's duties fined out composed of 4 type. Type I(The 1st grade social worker's duties) was belonged to 53 task elements, type IV(The 2nd or 3rd grade social worker's duties) was subjected to 11 task elements. 21 task elements performed to either 1st grade social worker or 2nd, 3rd grade social worker by type or uniqueness of social work practices. To allocation of duties by each grade social worker, fitting out of qualification system, the task elements for each grade of social worker must be prescribed by the rules. This allocation of duties by each grade social worker would be utilized to support qualified social work services, and to strengthening of their professional.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.184-190
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• 2009

Recently, the concern for the reliability of railway is increasing, also the study about reliability is being processed at a good pace. However, in case of an existing railway operating it is true that the railway system is being operated without a clear RAM standard. There is not a clear RAM standard about product menual of a city railroad, and there are only basic provisions concerning traction motor which can be called a main equipment. In this paper, we calculated the availability and reliability of subway having MKBSF, MKBF, MTBF, MTTR analyzing accumulated maintenance data about a main equipment of a VVVF direct subway being operated in line #4. By watching the reliability grade of a VVVF subway being operated and manufactured within the country and being applied with the development of a city railway reflected by RAM menual when the new subway is manufactured, and with the basic data of RCM, we'd like to grope the methods which can be improved by operation stability of a city railway.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.2
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• pp.155-160
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• 1999

Recently, the study on mix design of lightweight concrete using the polystyrene foam balls is put into practice from the viewpoint to grade up the quality of concrete and recyclable usage of industrial by products. Polystyrene aggregate concrete, PAC, can be used as structural concrete in low strength application. For instance, PAC could be used in the middle part of sandwich panel where stresses are generally low and in the case of grid-type reinforcement where it does not need high bond strength but little compressive strength to resist the pressure of transverse reinforcement. From this point of view, the authors discussed the influence of fluidity and compressive strength of concrete by the difference of the volume percentage of polystyrene foam balls and water cement ratio.

• Journal of Korean Clinical Nursing Research
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• v.22 no.2
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• pp.238-247
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• 2016

Purpose: This study was done to develop an evidence-based practice guideline for catheter dysfunction in hemodialysis patients. Methods: Development of the guideline process was done according to the De Novo development version 1.0 by NECA which consists of 12 steps. Results: The developed guideline consisted of 5 domains and 14 recommendations. The number of recommendations for each domain were: 3 on catheter dysfunction assessment, 1 on conservative management of catheter dysfunction, 7 on drug management of catheter dysfunction, 1 on catheter function test and 2 on maintenance management. Of the recommendations, 7.15% were marked as A grade, 52.85% of B grade, and 50% of C grade. Conclusion: Findings in this study indicate that this guideline can be added to the evidence-based practice guidelines for fundamentals of practice and that this guideline can be disseminated to nurses nationwide in order to improve the care of hemodialysis patients with catheter dysfunction.

• Tribology and Lubricants
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• v.38 no.1
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• pp.22-26
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• 2022

A 1.7-ton grade small excavator is a construction equipment that can perform various functions in limited spaces where heavy equipment cannot enter easily. Owing to the recent acceleration of urbanization, it has been used increasingly in drainage and gas pipes, as well as for road repair works in urban areas. The power train of a traveling reducer for a 1.7-ton grade small excavator utilizes a complex planetary gear system. Complex planetary gears are vital to the power train of a traveling reducer as it mitigates the fatigue strength problem. In the present study, the specifications of a complex planetary gear train are calculated; furthermore, the gear bending and compressive stresses of the complex planetary gears are analyzed to achieve an optimal design of the latter in terms of cost and reliability. In this study, the actual gear bending and compressive stresses of a planetary gear system are analyzed using a self-developed gear design program based on the Lewes and Hertz equation. Subsequently, the calculated specifications of the complex planetary gears are verified by evaluating the results with the data of allowable bending and compressive stress based on curves of stress vs. number of cycles of the gears.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.2945-2965
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• 2023

The laser inertial measurement unit is a precision device widely used in rocket navigation system and other equipment, and its quality is directly related to navigation accuracy. In the quality evaluation of laser inertial measurement unit, there is inevitably uncertainty in the index input information. First, the input numerical information is in interval form. Second, the index input grade and the quality evaluation result grade are given according to different national standards. So, it is a key step to transform the interval information input by the index into the data form consistent with the evaluation result grade. In the case of uncertain input, this paper puts forward a method based on probability distribution to solve the problem of asymmetry between the reference grade given by the index and the evaluation result grade when evaluating the quality of laser inertial measurement unit. By mapping the numerical relationship between the designated reference level and the evaluation reference level of the index information under different distributions, the index evidence symmetrical with the evaluation reference level is given. After the uncertain input information is transformed into evidence of interval degree distribution by this method, the information fusion of interval degree distribution evidence is carried out by interval evidential reasoning algorithm, and the evaluation result is obtained by projection covariance matrix adaptive evolution strategy optimization. Taking a five-meter redundant laser inertial measurement unit as an example, the applicability and effectiveness of this method are verified.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.145-154
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• 1994

In this paper, monitoring processor in a circuit switched network is considered. Monitoring processor monitors communication links, and offers a grade of service in each link to controller. Such an information is useful for an effective maintenance of system. Two links with nonsymmetric system Parameters are considered. each link is assumed independent M/M/1/1 type. The Markov process is introduced to compute busy and idle portions of monitoring processor and monitored rate of each link. Inter-idle times and inter-monitoring times of monitoring processor between two links are respectively computed. A recursive formula is introduced to make computational procedure rigorous.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.130-136
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• 1999

The management method of the irrigation facilities are different with management agency , type, user, purpose of use, and the accuracy of data applied for the grasp of present situation and maintenance is of a low grade. Therefore the information management system is needed to classify and systematize the data. The purpose of this study is to prepare the digital map of Chonbuk FLIA district, to construct the database of the irrigation facilities , to develop the information system for the management using World Wide Web, to supply and be able to use easily to whomever needs it.