• Journal of Digital Convergence
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• v.16 no.5
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• pp.463-468
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• 2018

The purpose of the study was to investigate the gender differences of anaerobic capabilities between anaerobic capacity(AC) from Wingate test and anaerobic work capacity(AWC) from critical power test in untrained male and female adults. Both tests were carried out to 12 male and 13 female subjects on a Monark cycle ergometer. The results of this study demonstrated that men were higher than women in AC for the Wingate test, but no gender difference(J/kg) in AWC for the Critical Power test. There was a significant relationship between AC(J/kg) and AWC(J/kg) in women(r=0.61, p<0.05), but no significant relationship in men(r=-0.32, p>0.05). ANCOVA analyses using $VO_{2max}$ and body weight as covariates had significant influence on the AWC gender difference. The study provides preliminary data on gender differences of anaerobic capabilities.

• Journal of Navigation and Port Research
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• v.36 no.5
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• pp.395-400
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• 2012

The stress-strain relationship of soil is dependent on a number of factors such as soil type, density, stress level and stress path. Th accurate stress-stain relationship can be predict using a constitutive model incorporated all influencing factors. In this study, an isotropic compression-expansion test and a series of drained conventional triaxial tests with several stress paths were performed on Baekma river sand to investigate parameters characteristics of Lade's single work hardening model depending on the stress path.. Based on test results, the parameters of yield function (h, ${\alpha}$) are not much influenced by stress level and stress path, the these parameters do affect a little bit of stress-strain behavior. The parameters h and ${\alpha}$ are closely related to failure criterion ${\eta}_1$, they can be replaced by failure criterion parament. We also observed that predicted values from the Lade's single hardening constitutive model are well matched with the observed data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4147-4157
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• 2015

The weapon system has developed by adding various functions because of the warfare change. And, an weapon system test set (WSTS) that is used to test and judge the condition of weapon system also deal with a lot of complex information. However, almost WSTS is developed on the basis of developer-centric. Because of it, it is hard to make a result by apprehending information on WSTS's display. Thus, I proposed a new display of WSTS by adapting the Ecological Interface Design(EID) Methodology to reduce operator's cognitive workload and assure safe testing. WSTS's Display is developed through Information Requirement and Work Domain Model as a result of Work Domain Analysis. The most powerful thing in the new display is that operator can identify his testing and status of WSTS directly. I expect that it reduces operator's cognitive workload and helps safe testing.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.314-319
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• 2004

Many of researches regarding mechanical properties of composite materials are associated with humid environment and temperature. Especially the temperature is a very important factor influencing the design of thermoplastic composites. However, the effect of temperature on impact behavior of reinforced composites have not yet been fully explored. An approach which predicts critical fracture toughness GIC was performed by the impact test in this work The main goal of this work is to study effects of temperature in the impact test with glass fiber/polypropylene(GF/pp) composites. The critical fracture energy and failure mechanisms of GF/PP composites are investigated in the temperature range of $60^{\circ}C\;to\;-50^{\circ}C$ by impact test. The critical fracture energy shows a maximum at ambient temperature and it tends to decrease as temperature goes up or goes down. Major failure mechanisms can be classified such as fiber matrix debonding, fiber pull-out and/or delamination and matrix deformation.

• Corrosion Science and Technology
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• v.12 no.2
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• pp.85-92
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• 2013

This work is concerned with an evaluation of dynamic boric acid corrosion (BAC) of low alloy steel for reactor pressure vessel of a pressurized water reactor (PWR). Mockup test method was newly established to investigate dynamic BAC of the low alloy steel under various conditions simulating a primary water leakage incident. The average corrosion rate was measured from the weight loss of the low alloy steel specimen, and the maximum corrosion rate was obtained by the surface profilometry after the mockup test. The corrosion rates increased with the rise of the leakage rate of the primary water containing boric acid, and the presence of oxygen dissolved in the primary water also accelerated the corrosion. From the specimen surface analysis, it was found that typical flow-accelerated corrosion and jet-impingement occurred under two-phase fluid of water droplet and steam environment. The maximum corrosion rate was determined as 5.97 mm/year at the leakage rate of 20 cc/min of the primary water with a saturated content of oxygen within the range of experimental condition of this work.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.167-173
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• 2003

Many of researches regarding mechanical properties of composite materials are associated with humid environment and temperature. Especially the temperature is a very important factor influencing the design of thermoplastic composites. However, the effect of temperature on impact behavior of reinforced composites have not yet been fully explored. An approach which predicts critical fracture toughness G$_{IC}$ was performed by the impact test in this work. The main goal of this work is to study the effect of temperature and span of specimen supports on the results of Charpy impact test for GF/PE composite. The critical fracture energy and failure mechanism of GF/PE composites were investigated in the temperature range of $60^{\circ}C;to;-50^{\circ}C$ by the Charpy impact test. The critical fracture energy showed the maximum at the ambient temperature, and it tended to decrease as the temperature increased or decreased from the ambient temperature. The major failure mechanisms are the fiber matrix debonding, the fiber pull-out and/or delamination and the matrix deformation.n.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.713-718
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• 2016

Predicting precise specifications of differential mixed-signal circuits is a difficult problem, because analytically derived correlation between process variations and conventional specifications exhibits the limited prediction accuracy due to the phase unbalance, for most self-tests. This paper proposes an efficient prediction technique to provide accurate specifications of differential mixed-signal circuits in a system-on-chip (SoC) based on a nonlinear statistical nonlinear regression technique. A spectrally pure sinusoidal signal is applied to a differential DUT, and its output is fed into another differential DUT through a weighting circuitry in the loopback configuration. The weighting circuitry, which is employed from the previous work [3], efficiently produces different weights on the harmonics of the loopback responses, i.e., the signatures. The correlation models, which map the signatures to the conventional specifications, are built based on the statistical nonlinear regression technique, in order to predict accurate nonlinearities of individual DUTs. In production testing, once the efficient signatures are measured, and plugged into the obtained correlation models, the harmonic coefficients of DUTs are readily identified. This work provides a practical test solution to overcome the serious test issue of differential mixed-signal circuits; the low accuracy of analytically derived model is much lower by the errors from the unbalance. Hardware measurement results showed less than 1.0 dB of the prediction error, validating that this approach can be used as production test.

• Journal of muscle and joint health
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• v.26 no.3
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• pp.281-289
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• 2019

Purpose: This study aims to develop the Korean version of Presenteeism Scale for Students and verify its reliability and validity. Methods: This study conducted a survey with 320 undergraduate students who are attending nursing departments at three universities. The survey was conducted twice, from June 1 to August 31, 2017. Results: The Cronbach's α of K-PSS was .70 indicating high reliability. As a result of testing the content validity of K-PSS was verified by calculating the Item level-Content Validity Index (I-CVI) of .87. The correlation between Medical Outcome Study 36-item Short Form Health Survey (SF-36) score and Work Impairment Score (WIS), Work Output Score (WOS), Hours of absenteeism (HA) was analyzed to verify the concurrent validity of K-PSS. SF-36 score was correlated with WIS, WOS, HA. To test the differentiated validity of K-PSS, a total of 38 subjects were assessed by the paired t-test. As a result, only WIS score showed a significant difference between pre-test and post-test. Conclusion: Since the reliability and validity of the K-PSS developed through this study have been verified, it is expected to be used in various studies related to the presenteeism of students.

• Journal of Sensor Science and Technology
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• v.25 no.2
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• pp.155-159
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• 2016

In this work, we have developed a test system to examine whether the charge indicator of the plug-in hybrid electric vehicle (PHEV) works properly or not. In PHEV, the driver should charge the necessary electricity by plugging in manually and be able to know the charging status through the charge indicator conveniently located for the charging individual. Our system used the CAN bus to transmit the same commands from ECU to the indicator to test the proper operation of the indicator lights. It measured the electric current values during operation and analyzed to determine the quality of the indicators. The inspection items included the proper packaging, the electrical shorts, the LED lighting during charging, the LED lighting for charging failure, and the LED lighting when errors occur. We developed the system for the operators in the factory allowing them to approve the test results at the site. We developed the hardware, the control software, and the software to store the test results and the history of the products in the database. Serial numbers were given to the good quality products and the bar code labels were printed to trace the products afterwards. Through this work, we developed a system to inspect the electric parts in real time upon fabrication. We are planning to further improve our system to inspect the brightness of the indicator by adding the vision inspection in future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.462-470
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• 2018

This descriptive survey was conducted to explore the effects of work engagement and its associated factors among general hospital nurses. Nurses working in general hospitals were recruited in D city and K region. Data were analyzed by descriptive statistics, t-test, one-way ANOVA, Pearson's correlations, and stepwise multiple regression using IBM SPSS 25. The mean score of work engagement of the subjects was 3.08. The mean scores of emotional modulation effects in profession, patient focused emotional suppression, and emotional pretense by norms which are subgroups of emotional labor by norms were 3.82, 3.28, and 3.22, respectively, while that of the nursing work environment was 2.59. Work engagement was significantly positively correlated with emotional modulation effects in profession (r=0.30, p=0.001), patient-focused emotional suppression (r=0.20, p=0.030), and nursing work environment (r=0.21, p=0.024). The results showed that the factors that affect the work engagement were age, current position, and emotional modulation effects in profession, which explained 20% of the variance in work engagement (F=10.37, p<0.001). Therefore, to establish strategies for improving the level of work engagement, it is necessary to consider age and current positions of nurses and to develop a nursing intervention program to strengthen emotional modulation effects among general hospital nurses.