• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.122-122
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• 2017

Recently, environmental problems have become an area of growing interests. In-situ monitoring of water quality is fundamental to most environmental applications. The accurate measurement of nitrate concentrations is fundamental to understanding biogeochemistry in aquatic ecosystems. Several studies have reported that one of the most feasible methods to measure nitrate concentration is the use of Ion Selective-electrodes (ISEs). The ISE application to water monitoring has several advantages, such as direct measurement methodology, high sensitivity, wide measurement range, low cost, and portability. However, the ISE methods may yield inconsistent results where there was a difference in temperature between the calibration and measurement solutions, which is associated with the temperature dependence of ionic activity coefficients in solution. In this study, to investigate the potential of using the combination of a temperature sensor and nitrate ISEs for minimizing the effect of temperature on real-time nitrate sensing in natural water, a prototype of on-site water monitoring system was built, mainly consisting of a sensor chamber, an array of 3 ISEs, an waterproof temperature sensor, an automatic sampling system, and an arduino MCU board. The analog signals of ISEs were obtained using the second-order Sallen-key filter for performing voltage following, differential amplification, and low pass filtering. The performance test of the developed water nitrate sensing system was conducted in a monitoring station of drinking water located in Jeongseon, Kangwon. A temperature compensation method based on two-point normalization was proposed, which incorporated the determination of temperature coefficient values using regression equations relating solution temperature and electrode signal determined in our previous studies.

• Journal of Sensor Science and Technology
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• v.13 no.5
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• pp.329-334
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• 2004

Functional residual capacity (FRC) is an important diagnostic parameter measured using $N_{2}$ analyzer. Since $N_{2}$ analyzer is expensive as well as cumbersome for use of noisy vacuum pump, the FRC measurement becomes possible only in large well-equipped hospitals. The present study introduced a new $TN_{2}$ wash-out technique to measure FRC by $O_{2}/CO_{2}$ analysis, which is relatively cheaper and much simpler to apply. Slower $O_{2}$ response was compensated for high frequency to be coincided with $CO_{2}$ response, thereby enabled indirect, but accurate $N_{2}$ concentration measurement. FRC was estimated by continuous integration of expired $N_{2}$ volume obtained with air flow signal. Experiment with 3 L syringe, a standard calibration device recommended by the American Thoracic Society, demonstrated less than 1% error at 0, 1, and 2 L. Correlation coefficient was almost ideal, guaranteeing linear estimation of FRC. The present technique is inexpensive and simple to apply, thus should he of great convenience.

• Journal of the Korean Ceramic Society
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• v.48 no.4
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• pp.323-327
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• 2011

The effects of $Dy_2O_3$ and $Er_2O_3$ co-doping on electrical properties and temperature stability of barium titanate ($BaTiO_3$) ceramics were investigated in terms of microstructure and structural analysis. The dielectric constant and the insulation resistance (IR) of 0.7 mol% $Dy_2O_3$ and 0.3 mol% $Er_2O_3$ co-doped dielectrics had about 60% and 20% higher than the values of undoped one, respectively, and the temperature coefficient of capacitance (TCC) met the X7R specification. The addition of $Dy_2O_3$ contributed to electrical properties caused by increase of tetragonality; however, preferential diffusion of $Dy^{3+}$ ions toward A site in $BaTiO_3$ grain exhibited an adverse effect on temperature stability by grain growth. On the other hand, The $Er_2O_3$ addition in $BaTiO_3$ could affect the TCC behavior and the IR with suppression of grain growth caused by reinforcement of grain boundary and electrical compensation. Therefore, the enhanced electrical properties and temperature stability through the co-doping could be deduced from the increase of tetragonality and the suppression of grain growth.

• Korean Journal of Occupational Health Nursing
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• v.27 no.1
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• pp.36-47
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• 2018

Purpose: This study aimed to examine the effects of interpersonal relationship ability, job stress, and stress coping type on the turnover intention of nurses in the early stage of their careers. Methods: Data were collected from 136 early stage nurses from two general hospitals and one tertiary hospital in Chungbuk province. An early stage nurse was defined as the nurse with a work experience of 3 to 36 months. The collected data were analyzed using independent t-test, one-way ANOVA, Mann-Whitney U test, Person's correlation coefficient, and stepwise multiple regression. Results: It was seen that turnover intention had a negative correlation with interpersonal competency (r=-.20, p=.020) and a positive correlation with job stress (r=.56, p<.001). Job stress due to work over load, inadequate compensation and working environment, interpersonal relationship ability, and length of clinical career were significant factors influencing turnover intention (p<.05). These variables explained for 50.4% of the variance in turnover intention. Conclusion: It is necessary to develop an interpersonal relationship ability improvement program to decrease turnover intention among early stage nurses by helping them to successfully adapt to their job. Moreover, it is important to bring about continuous improvements in terms of provision of adequate workload and appropriate rewards, and creation of a suitable work environment to reduce the job stress of early stage nurses.

• Journal of Korean Academy of Nursing Administration
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• v.17 no.4
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• pp.391-401
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• 2011

Purpose: The purpose of this study was to explore the effect of empowerment on nursing performance, job satisfaction, organizational commitment and turnover intention in hospital nurses. Method: The subjects were 345 nurses at a general hospital in D city. Data were collected by structured questionnaire from January 10 to February 15, 2009. Data were analyzed by using descriptive statistics, ANOVA, Scheffe's test, and Pearson correlation coefficient, multiple regression by SPSS win 17.0 program. Results: The mean scores were 3.60(${\pm}.43$) of empowerment, 3.80(${\pm}.38$) of nursing performance, 3.49(${\pm}.55$) of job satisfaction, 4.70(${\pm}.74$) of organizational commitment, and 2.34(${\pm}.84$) of turnover intention. Empowerment was correlated with nursing performance, job satisfaction, and organizational commitment positively, but correlated with turnover intention negatively. As a result of multiple regression, empowerment has 34.3% of the explanatory power on nursing performance, 24.0% on job satisfaction, 30.7% on organizational commitment, and 15.6% on turnover intention. Conclusion: Empowerment was a critical variable affecting nursing job performance, job satisfaction, organizational commitment, and turnover. Also, if various variable - active and adequate child-care support system, provided conditions continue to study, and adequate and appropriate compensation for nursing performance - affecting empowerment are managed, nurses' empowerment level will rise at the same time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.85-90
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• 2018

This paper compares the equalization algorithm of CR-MMA (Constellation Reduction-Multi Modulus Algorithm) and FC-MMA (Fast Convergence-Multi Modulus Algorithm) for the compensation of channel's distortion in transmitting the 2 dimensional 16-QAM signals. The CR-MMA adaptive equalizer use the error signal by reduce the nonconstant modulus signal to constant modulus signal in order to updates the tap coefficient, and the FC-MMA adptive equalizer use the error signal applying the modified dispersion constant considering the number of symbol level instead of signal point reduction. These two algorithm are known to its superior to the convergence characteristic among the MMA series equalizer. In this paper, the other equalization performance including the convergence characteristic was compared by computer simulation. As a result of computer simulation, FC-MMA has more good performance in the residual isi, maximum distortion and SER performance than CR-MMA, but not in convergence speed.

• Korean Journal of Occupational Health Nursing
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• v.17 no.2
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• pp.146-154
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• 2008

Purpose: The purpose of this study is to investigate the degree of job stress and job satisfaction and the relationship between job stress and job satisfaction of Medical Aid Client Managers. Method: Data were collected from 185 Medical Aid Client Managers in 234 areas between April 2-15, 2007. Collected data was analyzed for the frequency, t-test, ANOVA, Pearson's Correlation Coefficient etc. Results: The average score of job stress was 2.6. Job instability was highest as 2.9 and job autonomy was lowest as 2.2. in eight items. When the job stress of Medical Aid Client Managers was converted to 100 point, the average was 51.7 and ranked in upper 50% of Korean woman workers' job stress. Among the eight items, because the relationship satisfaction and the instability of duty regime ranked in upper 25% of Korean woman workers' job stress, those items were identified to have high stress. The average score of job satisfaction was 2.3 out 4.0 which could be interpreted as unsatisfactory. The correlation between the job stress and the job satisfaction demonstrated significant difference. Decrease of the job satisfaction was associated with increase of the job stress. In regard to the eight items, the inverse correlation was demonstrated to be significant in organization, inappropriate compensation, and workplace culture. Conclusion: Medical Aid Client Managers have high stress in carrying out their duties. They have experienced very severe instability in their duty regime. Also, they have felt alienated from their organization and experienced unfair rewards. They had low duty satisfaction but got a heavy workload and experienced overtime work. To relieve job overburden of Medical Aid Client Managers. it was necessary to improve business system and also was necessary to relieve a regional disparity of business charge.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.15-22
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• 2012

This paper deals with the performance comparison and evaluation of blind adaptive equalizer, the PMCMA-MDD and DW-MCMA, that is used for compensation of the amplitude and phase distortion which occurs in the time dispersive channel. Basically, these algorithms are modification of MCMA cost function in order to obtain the fast convergence speed and reduced residual isi by taking the parallel and serial double structured and the combination of the concept of RCA for the updating the tap coefficient. We implements the algorithm of it and compare the recovered constellation, residual isi, MSE characteristics curve and SER in the signal to noise ratio given the time dispersive channel. As a result of simulation, the PMCMA-MDD has a good in recovered constellation than DW-MCMA. But in the SER, the DW-MCMA has a good than PMCMA-MDD.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.91-97
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• 2016

This paper evaluates the equalization algorithm of FC-MMA (Fast Convergence-Multi Modulus Algorithm) and RMMA (Region based Multi Modulus Algorithm) for the compensation of intersymbol interference which is due to the distortion of communication channel. In order to obtain the error signal for adaptive equalization, the FC-MMA use the modified dispersion constant considering the number of signal symbol, the RMMA separates the 4 region which every symbol points are located, then reduce the symbol point based on this region into constant modulus symbol point. By applying the different principle in order to get the error signal for the updating the tap coefficient of adaptive equalizer, it has the different equalization performance by these error signal. The computer simulation was performed in order to compare the different equalization performance in this paper. The performance index includes the output signal constellation, the residual isi and maximum distortion that is for the convergence characteristics, the SER. As a result of computer simulation, RMMA has more good performance in the residual isi, maximum distortion after in steady state and SER performance than FC-MMA, but not in convergence speed to reach the steady state.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.1
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• pp.83-88
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• 2017

This paper related with the performance evaluation of H-MMA (Hybrid-MMA) which is applying the adaptive modulus and adaptive step size concept to MMA adaptive equalization algorithm in order to reduce the intersymbol interference that is occurred in communication channel for digital code transmission. In the conventional MMA adaptive equalizer, the coefficient is updated by using the equalizer output and possible to compensation of amplitude and phase in 2nd dimensional QAM signal, the equalization performance were degraded due to fixed modulus and step size. For the overcomming the abovemensioned problem, it is possible to improving the equalization performance in the 2nd dimensional QAM signal by applying the adaptive modulus and adaptive step size propotional to equalizer output signal to the conventional MMA algorithm. The computer simulation was performed in the same channel for the compare the performance of MMA and proposed H-MMA which is proposed in this paper. As a result of simulation, the proposed H-MMA has slower convergence time in order to arriving the steady state than MMA. But after the steady state, H-MMA has more superior to the MMA in every performance index and the equalization noise was reduced.