• Journal of the Korean Data and Information Science Society
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• v.21 no.3
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• pp.547-554
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• 2010

In this paper, we extend the work by Lee et al. (2010) to multidimensional di usion processes. A test statistic analogous to the one-dimensional case is proposed to inves-tigate the joint stability of covariance matrix parameters and, under certain regularity conditions, is shown to have a limiting distribution of the sup of a multidimensional Brownian bridge. A simulation result is provided for illustration.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.653-658
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• 2000

For testing machine tools, we used test the work by measure of 3-D object that it was made by the machine tool. By reason of these, we have spent to the cost of measure and have delayed supply to user. In this study, we made a macro-program and a application program in order to test automatic the machine tool. So, if you constitute a ring core and a touch prove in machine tool, you should test the property of machine tool.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2329-2331
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• 1999

Metal oxide surge arrester were developed in the late 1970s, and were immediately adopted as significant breakthrough in over voltage protection of power system. Work was continued throughout the world on the design, development and application of metal oxide surge arrester. This paper describes the evaluating test and results of practical use for analyzing the performance of gapless metal oxide surge arresters under various type test.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.431-437
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• 2000

The aim of the work described in this paper is to develope a pavement method for farm road. To this ends, a series of material test are conducted on in-situ soil which was mixed additives-coarse aggregate, polypropylene fiber, excellent soil compound etc. With the laboratory test results, in-situ pavement test was conducted during two years. The serious problem of the pavement is not appeared up to this time. And the measurement of field data is continued presently. The majority merits of this pavement method is low cost and using environmental materials.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.3-6
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• 2003

In this work the AC loss measurement setup based on an iron core background magnet, not used in a conventional one, has been successfully developed, To prove its validity, a round-robin test for the same Bi-2223 tape sample among three institutes has been done. The results show that test data from the developed setup well agree with losses measured at different institutes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.2
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• pp.146-152
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• 2022

Objectives: The purpose of this study is to confirm whether there is a factor to affect the evaluation of fit test of a 2nd class half masks using a OPC test method. Methods: Total 34 adults including Males and Females were tested using OPC-based fit testing equipment while wearing a 2nd class half filtered mask. Results: 1. The result of measuring face dimensions using different tools such as a 3D scanner and digital calipers revealed that the variation of lip width was not statistically significant because there was only a difference of about 4 mm. However, it showed that a difference in face length was statistically significant enough with 10 mm(p<0.000). 2. The fit factor for each exercise stage according to gender was the highest at 124.54(p<0.001) in Step 3, and the fit factor was the lowest at 73.75 in Step 1. 3. In the evaluation of the degree of fit factor according to gender, female passed 67.44%, which was higher than the value in male(p<0.038). 4. The acceptance rate of the group having a face length of shorter than 110 mm was 91.67%. On the other hand, the acceptance rate of the group with a face length of longer than 110 mm was 47.27%(p<0.000). 5. The fit test was possible because the fit factor with 2nd class half masks corresponding to FFP1(Filtering Face Piece 1) was passed 55% or more. Conclusions: The test results showed that using a 2nd class half filtered mask, it is important to wear a properly designed mask so that face size does not affect the fit factor.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.4
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• pp.19-28
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• 1999

In order to control thermal deformation of the machine origin of machine tools a empirical model and a compensation system have been developed, Prior to empirical modeling the volumetric error considering shape errors and joint errors of slides is formulated through the homogeneous transformation matrix (HTM) and kinematic chain. Simulation results of the HTM method show that the thermal error of the machine origin is more critical than position-dependent errors. In order to make a stable and effective software error compensation system the GMDH (Group Method of Data Handling) models are constructed to estimate the thermal deformation of the machine origin by measuring deformation data and temperature data. A test bar and gap sensors are used to measure the deformation data. In order to compensate the estimated error the work origin shift method is developed by implementing a digital I/O interface board between a CNC controller and an IBM PC. The method shifts the work origin as much as the amounts which are calculated by the pre-established thermal error model. The experiment results for a vertical machining center show that the thermal deformation of the machine origin is reduced within $\pm$5$mu extrm{m}$.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2125-2128
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• 2011

The continuous welded rail(CWR) track without the rail expansion joint has many advantages over the conventional track in a variety of fields including the speed-up and the ride comport. However, due to the excessive axial force in the CWR and the track-bridge interactive behavior, inevitably, the rail expansion joint must be installed at the vulnerable zone such as the bridge end zone, etc. In this rail expansion joint zone, the frequency of the maintenance work to repair the track irregularity is on the rise. This is because that the creep of the sleeper is occurred in the moveable zone of the rail expansion joint. In this study, among the several options for reducing the track irregularity on the rail expansion joint zone, the application and efficiency of the tied sleeper is investigated. Field test construction has been conducted, then the progress of the track irregularity and the frequency of the maintenance work are analyzed before and after the filed test construction.

• Physical Therapy Korea
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• v.16 no.4
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• pp.37-43
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• 2009

This study compared the electromyographic activities and input performance of computer operators using a computer mouse and a trackball. Muscle activities were assessed at the upper trapezius (UT), middle deltoid (MD), extensor digitorum (ED), and first dorsal interosseous muscle (FDI). Twenty-six healthy subjects were recruited, and the test order was selected randomly for each subject. The task set was to click moving targets on a Windows program. The EMG amplitude was normalized using the percentage of reference voluntary contraction for UT and MD and the percentage of maximal voluntary contraction for ED and FDI. To analyze the differences in EMG activity, a paired t-test was used. UT muscle activities were significantly greater when the computer mouse was used (p<.05). FDI muscle activities were significantly greater when the trackball was used (p<.05). Using a trackball can reduce the load on the UT during computer work and help to prevent and manage work-related musculoskeletal disorders.

• Journal of Korean Academy of Nursing Administration
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• v.18 no.4
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• pp.374-382
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• 2012

Purpose: This study was done to investigate the effects of university hospital nurses' organizational conflict between organizational commitment and labor union commitment, so as to provide data on prevention of conflict with the hospital and to improve work achievement with commitment of two different groups: hospital and labor union commitment. Methods: Data collection was conducted from May 15 to 31, 2011 for nurses registered in the labor union of a university hospital. The collected data were analyzed using t-test, ANOVA, Scheffe test and multiple regression. Results: Organizational commitment of the nurses showed significant differences according to age, position and work experience, and degree of labor union commitment according to academic achievement. The factors affecting labor union commitment were organizational conflict and recognition of need for labor union, which accounted for 19% of the variance. Factors affecting organizational commitment were organizational conflict, recognition of need for labor union, participation in organizational events, and renewal of membership in the union, which accounted for 33% of the variance. Conclusion: The results of this study indicate that there is a need to improve work achievement by minimizing conflict and preventing labor disputes for better organizational commitment and labor union commitment of nurses.