• Safety and Health at Work
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• v.10 no.1
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• pp.61-66
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• 2019

Background: Emergency workers such as firefighters are cataloged within the most demanding and injurious professions globally. Considering the health and safety implications in firefighting, a lot of research needs to be conducted to examine how firefighters' task characteristics and their work demand influence the development of work-related musculoskeletal disorders (WMSDs). This study therefore examines how the task characteristics of firefighters moderates the relationship between their work demand and the development of WMSDs. Methods: Convenient sampling was employed to select 320 firefighters in the Greater Accra region of Ghana. Data were analyzed using descriptive statistics, correlation, and regression. Results: The findings revealed that work demand and task characteristics have significant positive effects on WMSDs. Again, the task characteristics of firefighters moderates the relationship between their work demand and WMSDs. Conclusion: Since the study shows that task characteristics influences the relationship between work demand and WMSDs, it is vital for managers to constantly modify the nature of tasks performed by and work demand of emergency workers to minimize the development of WMSDs and other industrial health complications.

• International Journal of Safety
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• v.3 no.1
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• pp.27-31
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• 2004

Some of the petroleum products contain benzene which is well known as a confirmed human carcinogen. For example, gasoline products contain benzene ranging up to several percents by weight. High exposures to the benzene and other organic solvents would be likely to occur during intermittent tasks and or processes rather than continuous jobs such as sampling, repair, inspection, and loading/unloading jobs. The work time for these jobs is various. However, most of work time is very short and the representative time interval is 15 minutes. Thus, it is preferable to do exposure assessment for 15 minute time weighted average which is known as a short time exposure level(STEL) by ACGIH rather than for 8-hours TWA. It is particularly significant to the exposure monitoring for benzene since it has been known that the exposure rate plays an important role to provoke the leukemia. Due to the large variations, a number of processes/tasks, the traditional sampling technique for organic solvents with the use of the charcoal and sampling pumps is not appropriate. Limited number of samples can be obtained due to the shortage of sampling pumps. Passive samplers can eliminate these limitations. However, low sampling rates resulted in collection of small amount of the target analysts in the passive samplers. This is originated the nature of passive samplers. Field applications were made with use of passive samplers to compare with the charcoal tube methods for 15 minutes. Gasoline loading processes to the tank lorry trucks at the loading stations in the petroleum products storage area. Good agreements between the results of passive samplers and those of the charcoal tubes were achieved. However, it was found that special cautions were necessary during the analysis at very low concentration levels.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.49-56
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• 2010

A competitive construction project must address factors such as cost, performance, aesthetics, schedule and quality. The importance of these factors will vary from project to project and from market to market. Productivity is becoming an ever-more important factor in the acquisition of a project. As the technology or aesthetics of a product matures or stabilizes, and the competitive playing field levels, competition is increasingly based on time. Recently, the construction industry has been depressed due to difficult market circumstances. At this time in particular, construction companies are striving to rationalize their management, both in their planning offices and in the field. In this study, we present a method of calculating a reasonable duration for reinforced form work. We did this by first developing a question for field workers, then sampling form workers based the question. Second, we employed a work analysis method to analyze worker"s work-methods and Time. Then, using the result of this analysis, we measured the Productivity of form work. This measure can be used as basic data to determine the appropriate duration of form work.

• Communications for Statistical Applications and Methods
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• v.20 no.4
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• pp.247-257
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• 2013

A variety of practical problems can be addressed in the framework of rotation (successive) sampling. The present work presents a sample rotation pattern where sampling units are drawn on two successive occasions. The problem of estimation of population variance on current (second) occasion in two - occasion successive (rotation) sampling has been considered. A class of estimators has been proposed for population variance that includes many estimators as a particular case. Asymptotic properties of the proposed class of estimators are discussed. The proposed class of estimators is compared with the sample variance estimator when there is no matching from the previous occasion. Optimum replacement policy is discussed. Results are supported with the empirical means of comparison.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.2
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• pp.22-26
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• 1981

Truncated expansions based upon the sampling theorem but containing only a few terms can be very useful for practical interpolations of band-limited or narrow-band random signals. The major goal of this work is to find and coiupare efficient and "statistically accurate" algorithms for the dynamic analysis of the ocean systems. The stalistical accuracy of truncated sampling interpolations is investicated, and one simple ocean systems, which yields a Runge-Kutta simulation algorithm of improved accuracy with very little increase in computation, is indicated.indicated.

• International Journal of Contents
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• v.2 no.2
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• pp.17-24
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• 2006

The work presented in this paper is divided into two parts. The first part presents finite urn problems which generate truncated negative binomial random variables. Some combinatorial identities that arose from the negative binomial sampling and truncated negative binomial sampling are established. These identities are constructed and serve important roles when we deal with these distributions and their characteristics. Other important results including cumulants and moments of the distributions are given in somewhat simple forms. Second, the distributions of the maximum of two chi-square variables and the distributions of the maximum correlated F-variables are then derived within the negative binomial sampling scheme. Although multinomial theory applied to order statistics and standard transformation techniques can be used to derive these distributions, the negative binomial sampling approach provides more information and deeper insight regarding the nature of the relationship between the sampling vehicle and the probability distributions of these functions of chi-square variables. We also provide an algorithm to compute the percentage points of these distributions. We supplement our findings with exact simple computational methods where no interpolations are involved.

• International Journal of Contents
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• v.3 no.1
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• pp.1-8
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• 2007

The distributions of the minimum correlated F-variable arises in many applied statistical problems including simultaneous analysis of variance (SANOVA), equality of variance, selection and ranking populations, and reliability analysis. In this paper, negative binomial sampling technique is employed to derive the distributions of the minimum of chi-square variables and hence the distributions of the minimum correlated F-variables. The work presented in this paper is divided in two parts. The first part is devoted to develop some combinatorial identities arised from the negative binomial sampling. These identities are constructed and justified to serve important purpose, when we deal with these distributions or their characteristics. Other important results including cumulants and moments of these distributions are also given in somewhat simple forms. Second, the distributions of minimum, chisquare variable and hence the distribution of the minimum correlated F-variables are then derived within the negative binomial sampling framework. Although, multinomial theory applied to order statistics and standard transformation techniques can be used to derive these distributions, the negative binomial sampling approach provides more information regarding the nature of the relationship between the sampling vehicle and the probability distributions of these functions of chi-square variables. We also provide an algorithm to compute the percentage points of the distributions. The computation methods we adopted are exact and no interpolations are involved.

• Journal of the Korea Institute of Building Construction
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• v.5 no.4 s.18
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• pp.131-137
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• 2005

Lately Construction industry has been depressing by hard construction market circumstance. Construction company, especial at this time, makes more rationalize the management of inside Company and Construction field. In this study we are to present the method of calculation reasonable duration at Reinforced Concrete Work. For the study first make up a question at field workers, then sampling the Form workers based the question. Second, We are using Work Analysis Method analysing the worker's work-method and Time. And then using the result of analysis, measure the Productivity of Form work. The productivity of Form work is used the basic data of duration at Reinforced Concrete Work

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.4
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• pp.348-355
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• 2013

Objectives: In working environment measurement, sampling is an important stage for obtaining reliable result as analysis. A personal air sampling pump is one of the most fundamental and important element in the work environment measurement, but it remains at the level of calibrating the flow rate of the pump before and after sampling. There is no checking whether the flow rate set at the initial stage would be hold during sampling. The purpose of this study was to develop a method to evaluate the flow rate performance of particulate sampling pump with three-pieces cassette holder containing filters commonly used to sample particulate. Materials and methods: We tested back pressure of particulate sampling pumps commonly used in Korea with three-pieces cassette holder containing various filters, and tried to find out the combination conditions of filters in accordance with back pressure required by ISO standard 13137. Results: We found out the matrix of sampling media such as three-pieces cassette holder containing filters applicable to the pressure drop required by the ISO standard for evaluating the flow rate stability under increasing pressure drop and long term(8 hour) performance. Conclusions: This evaluation method using sampling media matrix for checking flow rate stability proposed by this study could be very useful tool to find out good performance pumps before sampling.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.149-155
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• 2005

Lately Construction industry depressed by hard construction market condition. So Construction company, especial at this time, make more rationalize the management of inside Company and Construction field. So in this study we are to present the method of calculation reasonable duration at Reinforced Concrete Work. For the study first make up a question at field workers, then sampling the Form workers based the question. Second, We are using Work Analysis Method analysing the worker's work-method and Time. And then using the result of analysis, measure the Productivity of Form work. The productivity of Form work is used the basic data of duration at Reinforced Concrete Work