• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.97-98
• /
• 2006

This study deals with the Transmission Error of gear tooth profile by modifying a Profile and lead of a surface of Tooth. First, we experimentally confirmed that the Transmission Error is a synthesis of the sliding Velocity between both gears. Since various types of Transmission errors appear in the experiments, we introduced definition of Transmission Error and The Optimism Design by modifying a surface parameters The test stand's performance is then evaluated through a series of multiple torque transmission error tests. Comparisons are made between data recorded before and after the test stand's redesign, and subsequently repeatability studies are performed to verify the veracity of the measured data. Finally, the experimental results are compared to the analytical predictions of two different gear analysis programs.

• The Korean Journal of Health Service Management
• /
• v.7 no.4
• /
• pp.105-117
• /
• 2013

The purpose of this study was to identify the relationships among critical thinking disposition, professional self-concept and clinical competence in nursing students. The participants were 291 nursing students in Gwangju Province. A questionnaire survey was conducted from March 02 to 16, 2013. Data were analyzed using descriptive statistics, t-test, ANOVA, Scheffe test, pearson's correlation coefficients, and stepwise multiple regression analysis with SPSS/WIN 20.0 version. There was a significant positive correlations among critical thinking disposition, professional self-concept, and clinical competence. The variable predicting clinical competency were professional self-concept and critical thinking disposition. These factors accounted for 44.1% of the variance. The findings of this study suggest that the most influential factor for clinical competence was professional self-concept. Therefore it is necessary to improve professional self-concept through effective education program.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.4 no.4
• /
• pp.171-178
• /
• 1996

DCB(pure mode I) and CLS(mixed mode) tests were performed to investigate the effect of fracture mode on the interlaminar fracture of composite laminate. Mode I critical strain energy release rate was found to be $133J/m^2$ from the DCB test and total strain energy release rate decreased from $1, 270J/m^2$ as thickness ratio(tl/t) varied from 0.333 to 0.667 from the crease from the CLS test. Crack length had no effect on the total strain energy release rate and load was almost constant during the crack growth of the specimen which had the specific thickness ratio. Crack initiated when the stress of the strap ply reached constant stress $42kgf/mm^2$ which was found to be independent of the thickness ratio.

• The Korean Journal of Rheology
• /
• v.3 no.1
• /
• pp.22-29
• /
• 1991

In an effort to predict the long term durability of carbon fiber/epoxy composites in a space environ-ment interlaminar shear strength (ILSS) of the composites was measured as a function of 0.5 MeV electron radiation dosage. For the ILSS measurements a notch method (ASTM D3846) was used with and without side-supports. the supports were used to prevent peeling or bending during the test. The ILSS of both T300/ 5209 longitudinal composite system increases monotonically with radiation when the test is corried out without the support the ILSS of the composites increases initially but then decreases with further radiation. It is also observed that the ILSS of the unsupported case is much lower than that of the supported case. Measurement of epoxy modulus shows that the elastic modulus increases monotonically with radiation. But the breaking strength of the epoxy decreases with radiation. Electron Spectroscopy for Chemcal Analysis shows that the oxygen contents at both the pure epoxy surface and the composite fracture surface increase with radiation dose resulting in the increase of polarity at the interfacial region. This may be a supporting evidence for the increase in the ILSS of the composites.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.1
• /
• pp.99-108
• /
• 2016

Objectives: The purpose of this study is to analyze factors associated with depression among wage earners by subjective health and stress perception. Methods: The study subjects include 1,787 wage earners(aged 19 and older) who are currently working, using data from the 2014 National Health and Nutrition Survey. Data were analyzed using frequency test, t-test, ANOVA and multiple regression. Results: Multiple regression analysis showed that perceived stress level, subjective health status, age, monthly household income, sex, marital status, average daily sleeping time, and whether type of employment was regular or non-regular were significantly related to depression. Conclusions: It is necessary to develop an appropriate mental health promotion program and to manage prevention of depression at the national level.

• Journal of the military operations research society of Korea
• /
• v.30 no.2
• /
• pp.108-121
• /
• 2004

This paper deals with a procedure of changing the current inspection & replacement periods for ROKAF aircraft parts. ROKAF is mostly operating aircraft of foreign makes, and takes maintenance actions according to Technical Orders(TO.) published by foreign aircraft manufacturers. Therefore ROKAF inspects and replaces specific parts at the time noticed from T.O.. These inspection and replacement periods are determined by manufacturers according to the standard operating environment and parts' durability. But the standard operating environment Is different from operator's environment. Because of this difference, the inspection and replacement periods have to be changed according to operators' operation environment. It is resonable that the manufacturer, having design materials and life test data of parts, changes those periods together with materials of operators' operation environment. But we have many difficulties in obtaining the design materials and life test data. Then this paper proposes a procedure of changing the periods of aircraft's parts with life data obtained during operating aircraft. For the reliability analysis, a software of RELEST (Reliability Estimation Version 1.0) is used.

• Korean journal of food and cookery science
• /
• v.17 no.4
• /
• pp.380-390
• /
• 2001

Utilization practice of garlic and seasonings in industry foodservice was surveyed by questionnaire. Statistical data analysis was performed with SAS package program in order to have frequencies, means, t-test, ANOVA and Duncan's multiple range test. The results of this study can be summarized as follows; The mean value of Food Processing Index(FPI) score for purchased vegetable and seasonings is 3.5 which indicates the prepreparation is between partially preprepared and completely preprepared. The garlic was mainly purchased from brokers(51.0%), on a daily basis(58.8%) and peeled-form(74.5%). The average purchased amount is 6.66㎏ at a time. The unit price of the garlic makes significant differences(p＜0.05) by the scale and location of foodservice establishments. As for the storage method and Period, in room temperature, no storage(2.1%) and for one day(2.1%) and in refrigeration, for one day(39.6%) and fer three days(18.7%).

• Journal of Surface Science and Engineering
• /
• v.33 no.1
• /
• pp.38-47
• /
• 2000

A Ti(CN) layer was formed on aluminum alloy by using diethylamino titanium, hydrogen and nitrogen with the pulsed DC PACVD process. Effect of process parameters such as precursor evaporation temperature, duty ratio, frequency, voltage, $H_2$/$N_2$gas ratio on the properties of Ti(CN) layer were investigated. The layer thus obtained had high hardness and low friction coefficient. Detailed results on the hardness, surface morphology, XRD, WDS analysis, wear test and scratch test of this layer are presented.

• Child Health Nursing Research
• /
• v.23 no.2
• /
• pp.179-189
• /
• 2017

Purpose: The purpose of this study was to investigate NICU nurses' nursing interventions for pain and factors affecting nursing interventions for pain. Methods: Participants were 120 NICU nurses from 5 university hospitals located in Daejeon Metropolitan City and Chungcheong Province. The collected data were analyzed using descriptive statistics, independent t-test, one-way ANOVA and Duncan test, Pearson correlation coefficients and multiple regression analysis with SPSS Windows 23.0 IBM program. Results: The factors affecting nursing interventions for pain included knowledge about non-pharmacological nursing interventions for pain and self-efficacy about nursing interventions for pain. These variables explained 28.3% of nursing interventions for pain. Conclusion: The results of this study suggest that it is necessary to develop education programs in which effective nursing interventions for neonatal pain are considered. The programs should be made available to NICU nurses.

• The Journal of Pediatrics of Korean Medicine
• /
• v.15 no.1
• /
• pp.47-57
• /
• 2001

Heights of children ranged from 91.10 to 144.70 and the mean height rate after the administration of Boyangsungjangtang was significantly greater than that, 0.036, of prepuberty children who are in 50 percentile(One sampled T test, p<0.001). A highly significant difference was observed among three groups, divided according to the duration of taking Boyangsungjangtang(ANOVA, p=0.015). Further analysis(Tukey's Multiple Range test) indicated that the mean height rate of the group taking Boyangsungjangtang for under 3 months was significantly higher than that of both group for 3 to 6 months and group for over 6 months. The mean height rate of the latter two groups were not significantly different.