• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.43-46
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• 1997

Reliability engineering is regarded as the major and important roll for all industry. And advanced manufacturing systems with high sped and intelligent have been developing for betterment of machining ability. In this study, we have systemized evaluation of reliability for machinery system. We proposed the reliability assessment and designed and manufactured reliability test-bed to evaluate reliability. In addition we acquired reliability data using test-bed system and made database to handle reliability data. And also we not only use reliability data by analyzing reliability, but also apply design review method using analyzing critical units of machinery system. Form this study, we will expect to guide and increase the reliability engineering in developing and processing phase of high quality product.

• Transactions of Materials Processing
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• v.3 no.2
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• pp.147-155
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• 1994

The service life of tools in metal forming technology is to a large extent limited by wear and fatigue fracture of the active elements. This presents a basic request for tool cost minimization and reduction of extensive machine down time, caused by premature tool failure. Currents developments are dominated by steps to reduce the causes of tool failure. A main problem of forming technology remains the insufficient reliability of tools due to a large and incalculable life time fluctuation. Only a systematic investigation of the failure mechanisms and operational loading of tools can lead to future improvements in tool layout, that is optimization of tool usage.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.3
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• pp.50-53
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• 2007

Improving the reliability or long-term dependability of a system requires a different approach from the previous emphasis on short-term concerns. The purpose of this paper is to present a reliability evaluation method for an oil cooler intended for high-precision machining centers. The oil cooler system in question is a cooling device that minimizes the deformation caused from the heat generated by driving devices. This system is used for machine tools and semiconductor equipment. We predicted the reliability of the system based on the failure rate database and conducted the reliability test using a test-bed to evaluate the life of the oil cooler. The results provided an indication of the reliability of the system in terms of the failure rate and the MTBF of the oil cooler system and its components, as well as a distribution of the failure mode. These results will help increase the reliability of oil cooler systems. The evaluation method can also be used to determine the reliability of other machinery products.

• Journal of Korean Physical Therapy Science
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• v.3 no.2
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• pp.1037-1045
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• 1996

The purposes of this survey are to investigate which inventory are used to assess the disables children, to give information and basic data for developing new inventory for disabled children. 1. 8 institutes (40 %) have no test or evaluate tools. 2. Number of tools of rehabilitation institutes have more than hospital. 3. 86.8% of tools are made in United States. 4. 52.2 % of tools do not test validity and reliability 5. 43.5% of tools are tested for gross and fine motor functions. 6. The interval of reassesstment are very irregulary(43.5 %). So, We suggest that Korean physical therapist should be made tools which is tested motor, perception and cognition with validity and relability for CNS dysfuntion patients.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.133-134
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• 2013

• Journal of the Korean Society of Systems Engineering
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• v.12 no.2
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• pp.9-18
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• 2016

Machine switch type control panel is widely used for machine tools in Korea. They, however, have some difficulties in identifying the current operating status of machine tools especially when exposed to cutting oil. And also they have quality problems of operating failures. A new capacitor touch type machine control panel is developed and its reliability is predicted. MIL-HDBK-217F and Teclordia SR-332 are used for its reliability prediction and the prediction results are compared.

• The Journal of Korean Physical Therapy
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• v.25 no.5
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• pp.303-310
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• 2013

Purpose: The purposes of this study were to evaluate the correlation of clinical tools for assessment of balance and ability of gait, in order to discriminate the phases of sit-to-walk movement of patients with stroke using the motion analysis system, and to investigate the reliability of the phase of sit-to-walk movement according to functional ability of patients with stroke. Methods: Twenty -one patients participated (men 17, women 4) in this study. Sit-to-walk movement of all patients was recorded by the motion analysis system. Berg Balance Scale, Timed Up and Go test, Functional Reach Test, 10 meter Walk Timed Test, and Performance-Oriented Mobility Assessment were used as functional assessment tools. Results: The results of this study showed significant correlation between the phase I, II, IV and total phase duration of sit-to-walk movement and functional assessment tools. In addition, the intraclass correlation coefficient (ICC) showed high reliability in accordance with the functional ability of patients with stroke (Pearson's r 0.93 to 1.00). Conclusion: In conclusion, there is high reliability between measures of the phase of sit-to-walk movement of chronic stroke patients and the clinical assessment tool. Results of this study suggest that measurement of the phase of sit-to-walk movement can be used significantly as an intervention and a clinical tool for patients with stroke.

• Journal of Korean Academy of Nursing Administration
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• v.10 no.1
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• pp.25-36
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• 2004

Purpose: Nursing puts much weight en the organization of hospital. Therefore it is necessity to improve nursing care. One of the most important things is to secure confident nurses and to develop nurse' potentiality. It directs nurse evaluation system. The concept of "performance appraisal tools" is extremely important in evaluation system. Therefore, the purpose of this study aims to define performance appraisal process. Method: In order to do this, two main study has been observed interviewing appraisers and employees in-depth and analyzing performance appraisal tools of seven hospitals and analysed validity, reliability, acceptability and practicability. Result: The result of this study can be summarized as follows; Firstly, the result of analysis of performance appraisal tools. Regard to validity, Hospitals had a typical goal, but had not put to practice use. Regard to reliability, 1) Appraisal rule had been focused on appraiser's error, how to avoid. 2) 5 hospitals accessed nurses with relative rating and 2 hospitals with absolute rating both in practice. 3) 3 hospitals informed nurses the result of performance appraisal but 4 hospitals did not. 4) All hospitals in this study had conducted superiors rating. Regard to acceptability, 1)Rating scale method had been implemented by 6 hospitals and among those conducted beth ranking method and descriptive method. 2) Most hospitals had focused on personal traits in performance appraisal factors. Regard to practicality, The term of appraisal took $10{\sim}14$ days; performance appraisal happened 1 or 2 times per year; appraisal factors were based on 10 different items. Secondly, the result of in-depth interview with head nurses and staff nurses Regard to validity, head nurses and nurses wared that the goal of performance appraisal is to develop nurse's ability. Regard to reliability, head nurses pointed out that they were doubt of the justice of performance appraisal and they should have got training. Nurses insisted that raters should have been trained due to lack of qualification of appraiser; Head nurses and nurse proposed to convert form relative rating to absolute rating; to inform the result of appraisal; to implement peers rating. Regard to acceptability, One of the critical problems of performance appraisal tools was abstract of appraisal factors ; Lack of job analysis. Regard to practicality, Head nurses used to take overtime for appraisal. There was only a little respond despite of their efforts. Nurses questioned that appraisal tools exist for only appraisal; there was less cost-effectiveness. Conclusion: Based en these findings, it could be suggested to improve the performance appraisal tools for nurses evaluation. Firstly, it is necessary to describe goal of performance appraisal clearly set up, so that nurses could improve their positive word performance and develop their potentiality. Secondly, it is necessary to obtain various training on raters, implement absolute rating and inform the result of appraisal to nurses and use peers rating. Thirdly, it is necessary to convert from rating scale method to management by objectives or behaviorally anchored rating scale and take measurable appraisal factors based en job analysis. Finally, it is necessary to reduce the appraisal cost but increase effectiveness of performance appraisal.

• Journal of the Korea Society of Computer and Information
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• v.22 no.9
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• pp.187-192
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• 2017

In this paper, we have studied scale tools for measure programming task value and learning persistence at elementary school students. In order to develop complete test tools, we have improved the completeness by revising tests through stepwise verification. The first scales were constructed based on the previous studies. As a result of the content validity test, 5 out of 14 items of the task value test tool and 1 out of 10 items of the learning persistence test were not suitable. The second test tools were constructed by revising and supplementing the first scale, and consisted of 13 items of task value and 8 items of learning persistence. As a result of the contents validity test, all the items included in the test tool proved to be valid. The reliability of the secondary testing tools were also found to be reliable at ${\alpha}=.970$ and ${\alpha}=.975$, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.778-783
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• 1994

In operating automated manufacturing system, the long term stability and reliability of NC machine tools become most critical issues. Especially the machining accuracy is dominated by the thermal deformation of machine tools which remains still unsolved and causes troubles in manufacturing operations. Although researches have been carried out on the thermal behavior of a machine tools to minimize or control the thermal deformation of machine tools, the computer models for an analysis of the thermal behacior in machine tools has yet to appear in the open literature. The object of the paper is to present a method of modeling the thermal behavior of a machine tool. The method will make use of finite elements ad be capable of modeling whole machine structures as well as of heat generation processes in the kinematic system components. And temperature distributions and thermal deformations of a CNC lathe are analyzed using the finite element method and are compared with those measured in practice.