• Journal of Distribution Science
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• v.14 no.5
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• pp.91-96
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• 2016

Purpose - Although various studies have been conducted on the stress of service employees, there are still lack of studies regarding job stress and job satisfaction of call center workers. Especially there are quite few studies on the job stress according to employment type. This study focused on job stress and job satisfaction for call center employees and the correlation between the two factors and aimed to provide basic materials for seeking for the plans to reduce job stress and improve job satisfaction. Research design, data, and methodology - Frequency, percentage, and mean value were calculated through descriptive statistics in order to find out demographic characteristics, level of job stress, and job satisfaction. Differences in job stress according to employment type were calculated by using one-way ANOVA. Correlation between job stress and job satisfaction were identified through empirical analysis with Pearson's correlation coefficient. 150 materials were used for final analysis. The collected materials were analyzed to get statistics by using SPSS 20. Results - First, as for the job stress of call center workers, overall mean value was 2.54 in 4-point scales. Among the six sub-factors, job demands had the highest score, which was 2.67. Second, as for the job stress according to employment type, others showed higher score than mean value followed by contract job and full-time job in that order, in terms of job insecurity and organizational system. In terms of inappropriate remuneration, contract job showed higher score than mean value followed by others and full-time job. Third, as for the satisfaction with job, the mean value was 2.37 in 4-point scale and "very much satisfied" was only 3.3%. Lastly, in terms of job stress and job satisfaction, all sub-factors except for job demands showed significant correlation. The more job stress increased, the more job satisfaction decreased. Conclusions - First, as a result of analyzing job stress according to the employment type of call center workers, job stress increased more when the employment type was not full-time. Therefore, it was assumed that self-rescue efforts should be followed for effective employment management of call center business where contract employment takes most part as well as efforts to transfer them to full-time job. Second, decrease in job satisfaction of call center workers may affect the performance of an organization as well as service quality of the company providing the service. Therefore, various supports are required to decrease job stress and increase job satisfaction for call center workers through the expansion of rest area or break time. Third, I could recognize that there were lack of academic research on call center business in the whole service industry. Therefore, further research should be conducted more actively in the future. In particular, this study has special significance in the aspect that there were few studies on the job stress of call center workers according to employment type.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.5
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• pp.95-103
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• 2009

An efficient symbol time synchronization scheme for IEEE 802.11n MIMO-OFDM based WLAN systems using cyclic shift diversity (CSD) preamble is proposed. CSD is used to prevent unintentional beamforming when the same preamble signal is transmitted through transmit antennas. However, it is difficult to find a proper starting-point of the OFDM symbol with the conventional algorithms because of time offset by multi-peaks which are result from cross-correlation of received CSD preamble with a known short training symbol. In addition, the performance of symbol time sync. is affected by AGC and packet detection position. In this paper, an optimal symbol time synch. algorithm which is composed of the boundary detection scheme between LTS and OFDM symbols, the verification scheme for enhancement of boundary detection accuracy, and the SNR-varying threshold estimation scheme is proposed. Simulation result show that the proposed algorithm has performance gains of 4.3dB in SNR compared to the conventional algorithms at the rate of 1% sync. failure probability for $2{\times}2$ MIMO-OFDM system and 18dB at 0.1% when maximum frequency offset exists. It also can be applied to $4{\times}4$ MIMO-OFDM system without any modification. Hence, it is very suitable for MIMO-OFDM WLAN systems using CSD preamble.

• Journal of the Korean Society of Food Culture
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• v.22 no.2
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• pp.176-184
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• 2007

The purpose of this dissertation is to analyze the factors which university students feel as stress in their daily life and the correlation between these and their eating habits. The subject are students enrolled at 'H' university in Asan. There are 801 students who response for this research. We surveyed and analyzed the correlation between the life stress and eating habit of university students. It is analyzed that the objects suffered stress most by 'schooling' and 'job complication.' Surveying the general eating habit of university students, it is found that they do not eat meal regularly, i.e., 'average meals (40.9%)' and 'irregular meal(35.2%).' No significant difference was observed in the regularity of meals between sexes. When it comes to overeating or voracity, male students answered 'sometimes(77.6%)' or 'often(22.5%)', but female students answered 'sometimes(66.2%)' or 'often(28.2%)', which means that female students are more frequent in overeating or voracity. The frequency of eating snack is more than once a day 60.1% in female students and 47.3% in male students, which shows that the rate of female students is much higher than that of male students. Surveying the correlation between stress that male and female university students suffer and the regular meal, we found that both of them tend to eat meal irregularly if they are stressed. Comparing the stress for its factor, male students eat meal irregularly if they are stressed by 'schooling' and female students eat meal irregularly if they are stressed by 'figure.' Checking the correlation between stress and time spent for meal, it is found that while male students eat meal in a hurry when they are stressed by 'job affair', female students do so when they are stressed by 'home economy. Analyzing the correlation between frequency of snack and stress, both male and female tend to eat snack more frequently when they are stressed more. In general, males like the oily food more than male, but when students get stresses, females want to eat oily food than male. Analyzing the correlation between stress and preferential menu, males like green vegetables, sea food in the life get less stresses than others Females like a menu of meat get higher stress than others.

• Tribology and Lubricants
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• v.33 no.4
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• pp.141-147
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• 2017

The vibration data of bearings are very useful for monitoring and determining the condition of the bearings. The defect frequencies of ball bearings have been used for monitoring there condition. However, it is not easy to verify the defect frequencies as the wear progress. Therefore there is a need for an easy method to monitor the damages of bearings in real-time and to observe the variations in vibration characteristics as the wear progress. In this study, a bearing test equipment is constructed to diagnose the damage of bearings. The friction coefficient and vibration data are measured by using a torque sensor and an acceleration sensor, and the correlation between the measured data is analyzed to diagnose the condition of the bearing. We reached the following conclusions from the results. When the ball surface, inner and outer rings of a ball bearing are damaged, the friction coefficient increases to over 0.02 with an adhesion on the surface. Moreover this damage occurs more quickly with an increase in the number of revolutions. In the vibration characteristics, the amplitude of vibration wave appears high with an increase in the friction coefficient. In the high frequency range between 1000 and 2000 Hz, a wide range of frequency components with high amplitude occurs continuously irrespective of the number of revolutions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.9
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• pp.1029-1039
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• 1992

This paper presents the filtering method which is processed on the frequency domain among Hangul character recognition methods. It is processed the Hangul character parrern with spatial positioning modulation and mapped the Hangul character element which have spatial position variant feature onto frequency domain, at this time, normalized spatial position and so normalized the character size in frequency domain. And it is grouped the Hangul character element according to the generating position and set the standard pattern, and used each standard character element pattern with character element filter and filtering the character pattern of Hangul character, it is derived the normalized cross correlation function and the coherence function led to the filtering results, and calculated classification threshold.

• Structural Monitoring and Maintenance
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• v.9 no.4
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• pp.305-321
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• 2022

Bridge structural health monitoring with the aim of continuously assessing structural safety and reliability represents a topic of major importance for worldwide infrastructure managers. In the last two decades, due to their potential economic and operational advantages, drive-by approaches experienced growing consideration from researcher and engineers. This work addresses two technical topics regarding indirect frequency estimation methods: bridge and vehicle dynamics overlapping, and bridge expansion joints impact. The experimental campaign was conducted on a mixed multi-span bridge located in Lombardy using a Ford Galaxy instrumented with a mesh of wireless accelerometers. The onboard time series were acquired for a number of 10 passages over the bridge,performed at a travelling speed of 30 km/h, with no limitations imposed to traffic. Exploiting an ad-hoc sensors positioning, pitch vehicle motion was compensated, allowing to estimate the first two bridge bending frequencies from PSD functions; moreover, the herein adopted approach proved to be insensitive to joints disturbance. Conclusively, a sensitivity study has been conducted to trace the relationship between estimation accuracy and number of trips considered in the analysis. Promising results were found, pointing out a clear positive correlation especially for the first bending frequency.

• Journal of Biomedical Engineering Research
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• v.44 no.3
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• pp.218-224
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• 2023

This study aimed to analyze the coordination of muscle and muscle fatigue between biceps, lateral deltoid, and anterior deltoid during dumbbell side lateral raise using bio-signal. One male subject performed dumbbell side lateral raise with 3% of 1RM dumbbell at the rate of 30bpm until failure (8 minutes). While performing, ECG were recorded to observe the participant's performance. EMG were recorded from biceps, lateral deltoid, and anterior deltoid for observing coordination and fatigue. ECG were analyzed in time and frequency domain to observe Heart rate, normLF, normHF. Changes in heart rate, normLF, and normHF indicate that the sympathetic nervous system is activated, while changes in median frequency (MDF) indicate the occurrence of muscle fatigue. Moreover, the coordination relationship of muscle changed. The correlation of MDF between each muscles indicated that lateral deltoid is associated with biceps and anterior deltoid. These results showed that our study can contribute to improving understanding of muscle fatigue and muscle coordination relationships.

• Journal of Korean society of Dental Hygiene
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• v.10 no.6
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• pp.1083-1093
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• 2010

Objective : The purpose of this study was to examine the relationship of the oral health behavior of oral prophylaxis clients and some residents in a community to their simplified oral environment index. Methods : The subjects in this study were 520 people who had their teeth cleaned in the oral prophylaxis practice lab in the department of dental hygiene at J health college. A survey was conducted from March 23 to June 3, 2010, by way of the self-reported questionnaire. The data materials are analyzed by general characteristics frequency and ratio, the relationship of oral health behavior and sex, age, scaling experience, simplified oral hygiene index $x^{2}$ test analysis. Results : 1. Concerning links between gender and oral health behavior including daily toothbrushing frequency, the largest group of the respondents brushed their teeth three times a day(p<0.05). As to educational experiences on toothbrushing method and the use of oral hygiene supplies, the women had more educational experiences than the men(p<0.05). 2. Regarding connections between age and oral health behavior involving daily toothbrushing frequency, the largest number of the respondents brushed their teeth three times a day in every age group (p <0.001). As for educational experiences on toothbrushing method, those who were in their 50s and up(64.7%) learned about that, and they had more educational experiences with age(p<0.05). As for scaling experiences, the older respondents had their teeth scaled more often (p<0.001). 3. As to relationship between scaling experiences and oral health behavior, there were differences in toothbrushing frequency according to scaling experiences(p <0.05). Regarding educational experiences on toothbrushing method, those who had their teeth cleaned received more toothbrushing education(p<0.001). Concerning smoking, the nonsmokers had more experiences to get their teeth cleaned (p<0.001). 4. As for links between simplified oral environment index and oral health behavior including a time for toothbrushing, the respondents who did toothbrushing after every meal(80.4%) had good simplified oral environment indexes(p<0.05). 5. In regard to relationship between simplified oral environment index and oral health behavior, oral environment index had a positive correlation to the use of oral hygiene supplies( r=0.129**), toothbrushing time(r=0.116**) and educational experiences on toothbrushing method (r=0.099**). Smoking(r=-0.092**) had a negative correlation to that. Conclusion : The above-mentioned findings illustrate that oral health behavior is one of crucial factors to affect oral health status and oral environment care. Therefore oral prophylaxis practice lab visitors should receive education on the right toothbrushing method and the use of oral hygiene supplies to promote their oral health, and an incremental oral health care system that involves regular scaling should be introduced.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3C
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• pp.302-313
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• 2010

In this paper, we propose an enhanced AGC (Automatic Gain Control) structure and P-SCH detection method for initial cell search in 3GPP (3rdGenerationPartnershipProject) LTE (Long Term Evolution) FDD(Frequency Division Duplex) / TDD (Time Division Duplex) dual mode system. Since TDD frame structure consists of uplink subframe and downlink subframe, conventional AGC structure causes P-SCH detection performance degradation by increase of AGC variation due to signal power difference between uplink and downlink subframe. Also, P-SCH detection performance is degraded by distortion of P-SCH correlation characteristic in frequency offset and multipath fading channel environments. Therefore, we propose an AGC structure which can minimize P-SCH detection performance degradation with stable operation in 3GPP LTE TDD mode as well as FDD mode. Also we propose a P-SCH detection method which can reduce distortion of correlation chareteristics in frequency offset and multipath fading environments and obtain good P-SCH detection performance. Simulation results show that the proposed AGC structure and P-SCH detection method have stable AGC operation and excellent P-SCH detection performance for 3GPP LTE TDD / FDD dual mode downlink receiver in various channel environments.

• 재활복지
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• v.22 no.4
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• pp.59-81
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• 2018

The purpose of this study is to investigate the effect of participation of sports activities on job duties by analyzing job satisfaction of workers in rehabilitation hospital. From April to May 2015, 400 nurses, nursing assistants, physiotherapists, occupational therapists, and administrative staffs were selected from eight rehabilitation hospitals in Busan Metropolitan City. Analysis was performed by t-test, frequency analysis, exploratory factor analysis, Cronbach's alpha analysis, one-way ANOVA and Duncan tests. correlation analysis and regression analysis were conducted to obtain the following conclusions. As a result of the difference of job satisfaction according to participation form of sports activity, there was a significant difference in all factors such as exercise time, exercise frequency, sports item, and exercise period. As the exercise time and exercise frequency were higher and the athletic career was higher, Among the items, participation of aquarobic and aerobic was found to increase job satisfaction. Regression analysis showed that self - evaluation, job orientation, job commitment, and job satisfaction had positive effects among the five factors of job satisfaction. There is a significant difference.