• Geomechanics and Engineering
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• 제9권6호
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• pp.729-742
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• 2015

The aim of the present work was the study of instability in a loose sand from Les Dunes beach in Ain Beninan, Algeria, where the Boumerdes earthquake occurred in 2003. This earthquake caused significant structural damages and claimed the lives of many people. Damages caused to infrastructures were strongly related to phenomena of liquefaction. The study was based on the results of two drained and six undrained triaxial tests over a local sand collected in a region where liquefaction occurred. All the tests hereby analyzed followed compression stress-paths in monotonic conditions and the specimens were isotropically consolidated, since the objective was to study the instability due to static loading as part of a more general project, which also included cyclic studies. The instability was modeled with the second-order work increment criterion. The definition of the instability line for Les Dunes sand and its relation with yield surfaces allowed the identification of the region of potential instability and helped in the evaluation of the susceptibility of soils to liquefy under undrained conditions and its modeling. The dilatancy rate was studied in the points where instability began. Some mixed tests were also simulated, starting with drained conditions and then changing to undrained conditions at different time steps.

• Nuclear Engineering and Technology
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• 제50권7호
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• pp.1006-1016
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• 2018

Since the early forties, researchers from around the world have been studying the phenomenon of deadtime in radiation detectors. Many have attempted to develop models to represent this phenomenon. Two highly idealized models; paralyzable and non-paralyzable are commonly used by most individuals involved in radiation measurements. Most put little thought about the operating conditions and applicability of these ideal models for their experimental conditions. So far, there is no general agreement on the applicability of any given model for a specific detector under specific operating conditions, let alone a universal model for all detectors and all operating conditions. Further the related problem of pile-up is often confused with the deadtime phenomenon. Much work, is needed to devise a generalized and practical solution to these related problems. Many methods have been developed to measure and compensate for the detector deadtime count loss, and many researchers have addressed deadtime and pulse pile-up. The goal of this article is to summarize the state of science of deadtime; measurement and compensation techniques as proposed by some of the most significant work on these topics and to review the deadtime correction models applicable to present day radiation detection systems.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 하계 학술대회 논문집
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• pp.22-28
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• 2000

• 보건의료산업학회지
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• 제9권1호
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• pp.41-55
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• 2015

Working the night-shift and long working hours may be linked to insomnia. The purpose of this study is to determine the association between night-shift work and long working-hours with regard to subjective insomnia in Korean workers. This study was based on the Third Korean Working Condition Survey (KWCS) conducted on workers in 2011. The total number of individuals included in the analysis was 34,708 workers. Adjusted odd ratios showed statistically effective associations to insomnia. For night-shift work, the results were 2.71 (1.53 - 4.82) for night shift work by experts and managers, 2.95 (2.11 - 4.11) for night-shift work by officers, and 3.90 (2.05 - 7.42) for night-shift work by engineers compared with day duty. For long working hours, the scores were 2.43 (1.68-3.51) for >52 working hours by officers, 1.72 (1.15 - 2.58) for those in sales and service compared to ${\leq}40$ working hours. We suggest the need for Korean workers to target specific groups when creating policies related to reasonable environmental conditions.

• 한국산업보건학회지
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• 제23권2호
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• pp.114-122
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• 2013

Objectives: This study was performed in order to investigate by questionnaire the factors affecting the occupational satisfaction of work-environment measurement workers, as well as to suggest fundamental materials for systematic, administrative and economic improvements which are necessary to create a vision for the future. Material and Methods: A structured questionnaire was used at a total of 152 institutions and 1,254 work-environment measurement workers throughout the country from February to September 2012. Responses came from 97 institutions (64%) and 941 work-environment measurement workers (75.1%). The factors affecting the job satisfaction of work-environment measurement workers were statistically evaluated through $x^2$-test and ordinal logistic regression analysis. Results: Major factors affecting the job satisfaction of workers in relation to work-environment measurement were working, financial, and psychological conditions (p<0.05). Conclusions: Considering the results of this study, the improvement of labor conditions should be undertaken because workers engaged in work-environment measurement are fundamental to occupational health.

• 국제물리치료학회지
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• 제7권1호
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• pp.938-948
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• 2016

In the present study, the general characteristics, job stress, working conditions, and aspects of pain of some industrial workers working in Changwon-si, Gyeongsangnam-do, were surveyed. In analyzing the relationship between job stress and the existence of pain, the variables "working speed" and "opportunities to develop abilities" were shown to have statistically significant relationships with the existence of pain ($p{\leq}.05$). Regarding the relationship between working conditions and the existence of pain, the variables" amount of work per hour," "amount of work per day," "number of parts handled during work," "work production per person," and" inconvenient postures or motions during work" were shown to have statistically significant relationships with the existence of pain($p{\leq}.05$). Regarding aspects of pain", within 1~3 years" was the most common answer to time of occurrence of symptoms, with a percentage of 27.6%; "appear almost always" was the most common answer to frequency of symptoms, with a percentage of 37.1%; "slight pain" was the most common answer to degree of pain, with a percentage of 50.5%; and "moderate" was the most common answer to encumbrance caused by pain to living and work, with a percentage of 41.2%. The aim of the present study was to determine the factors that affect pain due to musculoskeletal diseases in industrial workers and to define the aspects of pain in order to provide basic data for the preparation of measures to prevent musculoskeletal diseases. To control pain due to musculoskeletal diseases, factors that affect pain, as well as the aspects of pain, should be recognized early, and efforts should be made to supplement and improve systems for preventing recurrence.

• 한국농공학회논문집
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• 제62권1호
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• pp.105-115
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• 2020

With the decrease of the agricultural population in Korea, the workers who is vulnerable to labor are increasing in agricultural industry because of aging, feminization of population. They are exposed in poor working environment with higher temperature and concentrations of dust, gas. Higher concentration of harmful gas and dust can cause chronic and acute disease to workers depending on exposure intensity and frequency. In order to improve the working environment in the livestock facilities, It is important to secure monitoring data of the thermal environment and the concentration of harmful gases and fine dust. Multi-point measurement was performed to analyze the regional environmental conditions in the pig rooms. When analyzing the working environment, video monitoring was conducted to analyze the concentration changes of ammonia, hydrogen sulfide and fine dust according to worker movement and work type. Ammonia and hydrogen sulfide monitoring result showed 1.5~2 times higher concentrations than other work when working in the pigs living zone, and 2~4 times higher than other work when working to increase the activity of pigs. In the case of fine dust, the result was 1.3 times higher than the worker's exposure standard in a specific work. The concentrations of gases and dusts from pig farms are not of concern for acute poisoning in normal work, but there is a risk of chronic respiratory disease if they are continuously exposed. Accordingly, there is a need for development of work environment monitoring device tailored to workers and preparation of alternatives.

• 한국치위생학회지
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• 제19권6호
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• pp.907-918
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• 2019

Objectives: This qualitative research was conducted to clearly find and clinically understand dental hygienists' work experience in order to lay the legal foundation for their work range and safe execution. Methods: From March 1 to April 30, 2019, seven study participants were selected and participated in-depth interviews. Phenomenological research methodology was applied for intensive analysis. Results: They performed jobs that required no professionalism, such as dental assistance, except for scaling. Dental hygienists, nurses' aids, and dental technicians performed the same jobs regardless of difficulty level and legal work range. Dental hygienists failed to accurately recognize their legal work range. Since there was the wide gap between their legal work range and actual work range, it was necessary to expand the work range in line with actual conditions. Conclusions: Given the results, it is necessary to conduct in-depth discussions within the dental circle to make dental hygienists' work execution in line with reality by improving and discussing a legal system for job assignment and expansion of workers. Therefore, it is required to form a plan for the many jobs dental hygienists executed in a clinical setting.

• 한국직업건강간호학회지
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• 제26권2호
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• pp.114-123
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• 2017

Purpose: This study aimed to explore personal as well as occupational factors and health status associated with work-life balance in Korean registered nurses. Methods: This study was a secondary data analysis using cross-sectional nationally representative data from the Korean Working Conditions Survey (KWCS) in 2014. Study participants included 450 registered nurses in South Korea. Descriptive analysis, Independent t-test, $x^2$ test, and Logistic regression analyses were performed using the SPSS 21.0 statistical program. Results: Work-life balance was reported in 70.6% individuals with 85.7% being male and 70.0% being female nurses. Logistic regression analysis revealed that being male good health state, having less than 40-hour working week, lower number of night duty, policy on flexible work arrangement were significant predictors of work-life balance. Conclusion: This study provided evidence that identify predictors of work-life balance in registered nurses in South Korea. Therefore, we need the actively support health care service promotion and prevention for work-life balance predictors.

• 산업경영시스템학회지
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• 제17권32호
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• pp.243-253
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• 1994

Work environments have been changed with the advent of new technologies, such as computer technology. The newer technologies, the more changes in our work conditions. However, human cognitive limits can't keep up with the change of work environments. Mental workload has been an important factors in designing modem work environments such as human-computer interaction. Designing man-machine systems requires knowledge and evaluation of the human cognitive processes which control information flow workload. Futhermore, under an urgent situation, human operator may suffer the work stress, work error, and resultant deleterious work performance. To describe the work performance in the urgent work situations, with time stress and dynamic event occurence, a new concept of information density was introduced. For a series of experiments performed for this study, three independent variables(information amount system processing time, information density) were evaluated using such dependent variables as reaction time, number of error, and number of failure. The results of statistical anlysiss indicate that the amount of information effected on all of five dependent measure. Number of failure and number of secondary task score were effected by both amount of information and operational speed of system, but reaction time of secondary task were effected by both amount of information and information density.