• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1A
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• pp.58-65
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• 2002

This paper deals with a delay problem in the endpoint detection of double-talk detection algorithm using correlation coefficient in the acoustic echo canceller. In case that past power is much bigger than current power like at the end of double-talking period, the power, estimated using forgetting factor, decreases slowly to cause a delay problem in the endpoint detection. In this paper, two methods are proposed to solve this problem. One is that the current power is periodically replaced by a new average power and the other is that the past power in recursive equation is periodically removed or replaced by other values. The simulation results show that proposed methods outperform conventional method in the endpoint of double-talking periods without increasing the computational burden much more.

• Journal of Korea Multimedia Society
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• v.3 no.3
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• pp.263-271
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• 2000

In this paper, an acoustic echo canceller(AEC) is implemented by ADSP-2181. This AEC uses a noise robust adaptive algorithm and a postprocessing method which attenuates residual echo using cross-correlation between estimated error signal and microphone input signal. We propose new postprocessing method that uses two thresholds to prevent signal distortion after postprocessing and to improve the performance of AEC without extra computational burden. Through experiments using a 16 bit fixed-point DSP board (ADSP-2181 EZ-KIT Lite board), it is shown that the noise robust adaptive algorithm performs well in the double-talk situations and the convergence speed is comparable to NLMS. Using the postprocessor, ERLE is improved about 20 dB. As a result, the AEC with a postprocessor shows better performance than conventional ones.

• The Korean Journal of Emergency Medical Services
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• v.8 no.1
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• pp.71-86
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• 2004

This study selected emergency medical technicians at 24 fire police boxes in Jeonnam in order to examine the relationship between job stress, fatigue and job satisfaction of 119 emergency medical technicians. Data were collected from Apr. 10 to May 9, 2004, questionnaires were mailed and returned by mail. Total 109 questionnaires were distributed and 89 questionnaires were collected and 80 except 9 omitting answers and showing inappropriate answers were used for final analysis. The results of this study are as follows. A. The total mean of areas composing job stress in the degree of job stress of 119 emergency medical technicians was over the average as 2.54 (SD .44) of 4 full marks. According to the degree of job stress by each area, the highest area of job stress was crisis situation (2.98), followed by role conflict as professional job (2.58), social factors (2.57), involvement in organization (2.55). To the contrary, the areas of the lowest job stress were professional knowledge and technique (2.35), psychological burden of medical limitation (2.38), conflicts in personal relationship and services (2.45) and improper treatment (2.53). B. The degree of fatigue of 119 emergency medical technicians by areas was over mean as 2.09(SD .49) of 4 full scores and physical fatigue was highest (2.18), followed by mental fatigue (2.11) and neurosensory fatigue (1.99). C. The degree of job satisfaction of 119 emergency medical technicians was 2.71 of 5 full scores and working condition area (3.70) showed the highest job satisfaction, followed by requirement of organization (2.85) and the lowest job satisfaction area was job itself (2.18), followed by desire for job (2.49). D. According to differences in demographical characteristics of 119 emergency medical technicians, there was no variable of statistical difference at job stress and job satisfaction in significance level .05, but fatigue showed statistical difference at final education (F=2.393, p=.046). E. According to differences related to job characteristics of 119 emergency medical technicians, job stress showed statistical differences at motif of current services (F=4.935, p=.003), fatigue showed those at health conditions (F=2.732, p=.008), job satisfaction at overtime (F=3.038, p.034) and the greatest reason of having job (F=3.217, p=.017), F. As a result of analyzing correlations between job stress. fatigue and job satisfaction of the subject, job stress showed positive correlations (r=.411, p=.000) with fatigue and negative correlation (r=-.267, p=.008) with job satisfaction. Fatigue showed negative correlation (r=-.287, p=.005) with job satisfaction. Therefore, the hypothesis of this study. "There will be relationship between degree of stress, fatigue and job satisfaction of subjects." was supported.

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.653-663
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• 2018

This study is a descriptive survey to examine the dementia related attitudes and dementia preventive behaviors in middle aged and to determine the relationships between the both sides. In this study, between October 1st and 9th, 2017, data were collected from the middle aged people in their 40s~60s in Korea through online questionnaires. Finally, 220 questionnaires were analyzed by t-test One way ANOVA, Pearson's correlation coefficient, and etc. The results of the study are as follows. First, 52.7% of the subjects were interested in prevention of dementia, but only 5.9% of them had experience of receiving education related to dementia. Second, fear of dementia was higher than cancer, cerebrovascular disease, and cardiovascular disease, but confidence in coping with the disease, expectation of the possibility of maintaining the daily life, expectation of the help of the family and the surrounding people, expectation of the national medical and economic support were significantly lower. Third, as the dementia preventive behaviors were implemented, the confidence in overcoming the disease, the expectation of the possibility of maintaining the daily life, the expectation of the help of the family and the surrounding people, the expectation of the medical and economic support of the country increased and the burden of the treatment cost was lowered. As a result, it is thought that this personal and social effort will improve the quality of life of the people by reducing physical, psychological, social and economic problems caused by dementia.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.634-643
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• 2020

Because of the continuous increase in the demand for and importance of marine space, marine exploration and survey activities are being actively conducted in Korea actively. Because the marine survey vessels used for these activities have special operational patterns depending on the purpose and probe vessels, research on maritime traffic risk is required. In this study, an attempt was made to determine the correlation of each factor with the effect of marine exploration and survey vessel operation on maritime traffic. The status of ocean exploration and survey vessels in operation in Korea was identified, as well as the special operational conditions of some of the ocean physical probes. Generally, the number of exploration and survey vessels involved per hour, total vessel length(including exploration equipment), operation, interval distance of exploration as per plan, and marine traffic conditions(traffic volume and speed) can be classified as operating factors. To compare the results of the environmental stress, a maritime traffic flow simulation based on the "ES" Model was performed with each of the identified operating factors as independent variables. The results of the analysis confirmed that the environmental stress significantly changed in the order of traffic volume, ship length and speed. In addition, it was confirmed that the environmental stress is reduced when the operation course is set at an angle with the nearby maritime traffic flow. Accordingly, it can help reduce the operator's burden if the survey vessel operator understands nearby maritime traffic conditions and reflects them in the operation method when setting the operation plan.

• Korean Journal of Environmental Agriculture
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• v.26 no.2
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• pp.116-123
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• 2007

This experiment was conducted to investigate the distribution and burden characteristics of heavy metals in the rainwater sampled at Suwon area, in the middle part of Korea, from April 2002 to October 2003. The relationship between concentration of heavy metal and other chemical properties in the rainwater was also evaluated. Chemical properties in the rainwater were various differences with raining periods and years. It appeared that a weighted average pH of rainwater was ranged from 4.7 to 5.5. Heavy metal concentrations in the rainwater were ranked as Zn>Pb>Cu>Ni>Cr>As>Cd. As compared with heavy metal concentrations of rainwater in 2002, Cd, Cu and As were higher than other element in 2003. There were positive correlation between major ionic components, such as Ca, Mg, and K, and heavy metal concentrations of rainwater, and As, CU, Cu, Zn and Ni were relatively higher relationship than Pb and Cr in respective to correlation coefficient. For heavy metal distribution of rainwater, the order of average enrichment factors was Cd>Pb>AS>Cu>Zn>Ni>Cr, and these were relatively higher than the natural component such as Fe, Mg and Ca. The monthly enrichment factors were relatively high in the spring (from April to May) at Suwon. The monthly amount of heavy metal precipitation was high in the rainy season from June to August because of great influence of rainfall.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.2
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• pp.105-112
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• 2023

Leucine-rich repeat kinase 2 (LRRK2) is known to play a crucial role in the pathophysiology of neurodegenerative disorders such as Parkinson's disease. LRRK2 is predominantly expressed in the lung as well as the brain. However, it is unclear whether LRRK2 expression correlates with the pathogenesis of lung squamous cell carcinoma (LUSC). This study analyzes the prognostic significance of LRRK2 in LUSC using the Kaplan-Meier plotter tool. High expression of LRRK2 is known to be associated with a bad prognosis in patients with LUSC. Patients with high LRRK2 expression, tumor mutational burden, high neoantigen load, and even gender correlation reportedly have the worse survival rates. In the gene expression profiling interactive analysis (GEPIA) database, the severity of pathogenesis in LUSC with high LRRK2 expression positively corresponds to a high expression of anti-inflammatory cytokines but not inflammatory cytokines. Similarly, the increased expression of interleukin (IL)10-related genes was shown to be significantly linked in LRRK2-high LUSC patients having a poor prognosis. Moreover, the tumor immune estimation resource (TIMER) database suggests that macrophages are one of the cellular sources of IL10 in LRRK2-high LUSC patients. Collectively, our results demonstrate that the postulated LRRK2-IL10 axis is a potential therapeutic target and prognostic biomarker for LUSC.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.233-243
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• 2020

This study determined the relationship between organizational conflicts and job satisfaction of administrative staff members employed in university hospitals. The sample consisted of 232 hospital administrators working at four different college hospitals located in D city. The survey was conducted using a self-administered questionnaire during the period from January 10th 2019 to February 15th 2019. As a result of the study, the job satisfaction levels were significantly different according to age, education, BMI, subjective sleep evaluation, subjective health status, job position, monthly income, physical burden of work, sense of satisfaction at work, fit to the job and consideration to quit the job. The job satisfaction levels according to the organizational conflicts were significantly lower with higher organizational conflicts. Further, the job satisfaction level showed a significant negative correlation with organizational conflicts. The risk ratio of lower job satisfaction significantly increased for the group with higher organizational conflict scores than that of the group with lower organizational conflict scores. The results suggest that job satisfaction of administrative staff at university hospitals is significantly related with organizational conflicts. It is necessary to present specific measures to resolve conflicts within an organization in order to enhance job satisfaction for administrative staff at university hospitals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.433-442
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• 2020

This study established the relationship between job stress and burn-out syndrome of firefighters. The research targets were 582 firefighters who worked at five fire stations in the D metropolitan city. The survey was conducted using a self-administered questionnaire during the period from July 1st 2019 to September 30, 2019. On the correlation analysis, burn-out showed a significant positive correlation with job stress. On the results of the logistic regression anaylsis, the risk ratio of high levels of burn-out was significantly higher in the very high stress groups than that in the groups with low job stress. According to the multiple regression analysis, the factors having an influence on burn-out were gender, age, the specific level of job career, shift work, the physical burden of work, the sense of satisfaction with the work, consideration for quitting the job and job stress. These findings suggest that the job stress of firefighters is closely related to burn-out. This demands the development and implementation of programs that can properly control and curb the factors of job-stress.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.599-607
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• 2017

Since 2015, small and medium domestic enterprises that treat more than a certain quantity of chemical substances in accordance with the Chemical Substance Control Act are obliged to submit an off-site impact assessment and risk management plan. In order to reduce the administrative and economic burden of the risk assessment, its impact was determined. Toxic leaks of nitric acid, methanol, and acetic acid were estimated and the correlations (between them?) were calculated. In addition, the correlations of this study were used to compare the KORA results according to the accident scenarios of the actual workplace and the extent of the damage as a function of distance in the case of toxic leaks. In this study, the correlation formula of the materials can be used to quickly determine the damage distance in the event of the accidental leakage of materials in the road or workplace, and to prepare emergency plans and respond to emergencies more quickly.