• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.10
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• pp.1077-1083
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• 2009

To reject the Doppler frequency spectrum dispersion of clutter caused by high-speed antenna rotation of MTI radar system due to terrain characteristics, signal processing parameters(MTI filter constant, M/N detector ration, K-factor and offset of CFAR) are adjusted for the optimal elimination of the ground clutter. For this investigation, logging equipment is designed and utilized for the collection of classified ground clutter data. Test case is devised through Matlab simulation for the classified analysis and optimization of clutter rejection. Then indoor radar test and outside test in accordance with terrain characteristics are repeatedly performed for the verification of the test. This whole process is through the evolutional development model and repeated for the optimization. Final result is that ground-clutter rejection capability is 5.6 times(7.5 dB) better than that of existing radar system.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.613-621
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• 2013

This paper presents the direction finding proximity fuze sensor using the clutter rejection method and the adaptive target detection algorithm for anti-air missiles. To remove effects by clutter and detect a target accurately, the clutter rejection method of Legendre sequence with BPSK(Bi phase Shift Keying) modulation has been proposed and the Doppler signal which has cross correlation characteristics is obtained from reflected target signals. Considering the change of the Doppler signal, the adaptive target detection algorithm has been developed and the direction finding algorithm has been fulfilled by comparing received powers from adjacent three receiving antennas. The encounter simulation test apparatus was made to collect and analyze reflected signal and test results showed that the -10 dBsm target was detected over 10 meters and the target with mesh clutter was detected and direction was distinguished definitely.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.371-379
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• 2021

This study aimed to verify the mediating effect of rejection sensitivity on the relationship between self-esteem and happiness among nursing students. From May 30 to June 10, 2018, 214 nursing students from a university were selected for convenience, and the results were analyzed using SPSS 22.0. The degree to which the rejection sensitivity of nursing students is mediated by self-esteem and happiness was determined following the guidelines of Baron and Kenny, and the Sobel test was used to verify the statistical significance of the mediated effects. There was a positive correlation between self-esteem and happiness among nursing students(r=.62, p<.001) and a negative correlation between rejection sensitivity and happiness(r=-.33, p<.001). A partially mediated effect (Z=3.769, p<.001) of rejection sensitivity was found on the relationship between self-esteem and happiness of nursing students. Therefore, education and activity programs are needed to increase the happiness of nursing students and help them maintain a satisfactory college life.

• Journal of Power System Engineering
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• v.18 no.1
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• pp.135-139
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• 2014

We propose some properties for fuzzy hypothesis test by fuzzy significance probability. First, we define fuzzy number data and fuzzy significance probability for repeatedly observed data with alternated error term. By the agreement index, we compare fuzzy significance probability with significance level and drawing conclusions the degree of acceptance and rejection by agreement index.

• Journal of Ocean Engineering and Technology
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• v.21 no.3 s.76
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• pp.1-7
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• 2007

In this study, the heat balance test of an engine was conducted, and the heat released to coolant is measured and corrected using a power adjustment factor for high fuel temperature to simulate heat rejection of the engine. An engine-converter matching simulation program which can compute the engine speed, transmission output speed, transmission input and output power is developed from the vehicle, transmission and engine performance curve. With this information and the engine heat rejection characteristics, the engine and transmission heat rejection rates can be determined at given condition. In analyzing the air mass flow, a sub program computing the air mass flow rate from the equation of the pressure balance between cooling fan static pressure rise and pressure losses of cooling components is developed.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.91-94
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• 1996

A simulation procedure was developed for identifying Yungnam unit 2 excitation model parameters to improve the accuracy of stability simulation of KEPCO. First, generator model parameters are derived by using modified load rejection technique from measured load rejection test. For identifying excitation model parameters, switch was changed from MVR mode to AVR mode in Yungnam unit 2 excitation system instead of applying to a small step to the voltage reference($V_{ref}$) because of saving time and efforts, assuming the test result would show coincided result with applying to a small step to the $V_{ref}$. However, it was found that the response of switching from MVR to AVR is greatly different from it of applying small signal to the $V_{ref}$. A simulation procedure was needed to take into accounts of real AVR component status before and after switching from MVR to AVR. This paper reports the procedure which duplicated the measured response and addresses the merits of this test on conventional AVR step test.

• Journal of Industrial Convergence
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• v.22 no.5
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• pp.127-136
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• 2024

This study was conducted to examine the self-efficacy and rejection sensitivity of nursing college students and their college life adjustment, as well as to identify the impact of self-efficacy and rejection sensitivity on college life adjustment. An online survey via URL was conducted on 154 enrolled students from nursing colleges nationwide. The collected data were analyzed using SPSS/WIN 23.0 statistical software for descriptive statistics, independent t-test, ANOVA, Pearson's correlation coefficients, and hierarchical regression analysis. The results of the study showed that the self-efficacy of the subjects was 3.80±0.63 points, rejection sensitivity was 2.67±0.83 points, and college life adjustment was 3.58±0.54 points. The factor influencing the college life adjustment among nursing college students was self-efficacy (β=.42, p<.001), while rejection sensitivity showed a significant negative correlation with adaptation to university life (r=-0.24, p=.003), but it was not a significant influencing factor. Therefore, it is necessary to develop and utilize various teaching methods and programs for psychological and social support to enhance self-efficacy in order to improve the adjustment of nursing college students to college life.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.1
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• pp.1-5
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• 2011

We furnished some properties of fuzzy testing of independence for correlation in a bivariate normal distribution by agreement index. First we present some restriction of the fuzzy data, define fuzzy sample correlation coefficient and agreement index for testing hypothesis with acceptance or rejection degree. Also, we show that UMP unbiased fuzzy test and drawing conclusions the fuzzy test.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1384-1386
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• 2005

This paper focuses on development of load test simulator of a steam turbine-generator in a nuclear power plant. When load is taken off from electrical power network, it is very difficult to effectively control the steam flow to turbine of the nuclear turbine-generator, because of disturbances, such as electrical load and network unbalance on electrical network. Up to the present time, the conventional control system has been used for the load control on nuclear steam generator, owing to the easy control algorithms and the advantage which have been proven on the nuclear power plant. However, since there are problems with stability control during low power and start-up, only a highly experienced operator can operate during those procedures. Also, a great deal of time and an expensive simulator is needed for the training of an operator. The KEPRI is developed simulator for 600MW nuclear power plant to take a test of generator load rejection, throttle valve, and turbine load control. Total load test is implemented before start up.

• Membrane Journal
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• v.14 no.3
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• pp.207-217
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• 2004

In this study, we prepared nanofiltration membrane by applying the interfacial polymerization method as a way of manufacturing composite membranes. We have examined the effects of various preparation factors such as monomer concentration and composition, thermal curing condition, post treatment condition. In addition to preparation conditions, we also monitored the effects of operation conditions such as feed solution concentration and operation pressure on the permeation properties of the resulting nanofiltration membrane. We intended to increase the permeation rate of nanofiltration membrane by the enlargement of effective surface area using additives during interfacial polymerization step. With increasing the monomer concentration, membrane permeation rate are decreased with maintaining almost constant rejection. With respect to curing condition, with increasing the curing temperature both permeation rate and rejection are decreased. With increasing the ratio of MPD in amino monomer composition, permeation rate decreased drastically with high rejection. With increasing the feed solution concentration, both permeation rate and rejection decreased. Both permeation rates and rejection increased with increasing the operating pressure. Nanofiltration membrane have higher surface roughness with increasing additive concentration in the case of using MPD contained amine composition than using piperazine alone. Permeation rates are much lower than the nanofiltration membrane prepared by piperazine.