• Journal of Korean Society for Quality Management
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• v.16 no.1
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• pp.23-31
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• 1988

This paper studies the handling of significant digits and rounding off methods in domestic industries. ANOVA tables made by six well-known big companies are selected and analyzed. There exist various mistakes in handling of significant digits and rounding off methods such as: * too many significant digits in the Sum of Squares values in comparison to the original data * too many significant digits in the variance ratio in comparison to the F table values. * no consistancy in the number of significant digits * no consideration for the number of significant digits in computations * ignoring the KS A 0021 in rounding off methods etc. Such mistakes are caused from the characteristics of the personal computers rather than the misunderstandings about the significant digits conception. A subroutine is developed for PC in BASIC language to help the handling of significant digits and rounding off.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.420-422
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• 1998

All Fault Detection and Diagnosis(FDD) methods utilize classification techniques. The objective of this study was to demonstrate the application of classification techniques to the problem of diagnosing faults in data generated by a variable-air-volume(VAV) air-handling unit(AHU) simulation model and to describe the characteristics of the techniques considered. Artificial neural network classifier and fuzzy clustering classifier were considered for fault diagnostics.

• The International Journal of Costume Culture
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• v.9 no.2
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• pp.133-148
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• 2006

This research endeavors to provide correct handling methods of jeans through a study on care labels for wearing and handling behaviors of female university students in their twenties. The conclusion of the research is as follows: The study indicates that coeds own more than seven jeans and wear them three or four times a week on the average. The research showed that washing jeans once weekly is the highest. It showed that the jeans are mainly laundered with water and also with water and dry cleaning together. The students responded that they dry cleaned the pants several times and then water wash them after buying the pants in order to prevent change in colors and shapes of the pants. Content of labels should be improved because most female students indicated the importance of the care labels. The reliability and understanding of the labels were surveyed to be lacking. The survey indicated that the percentage of checking the sizes was the highest when the students bought the jeans. Furthermore, the label "handle with care" turned out to be examined more frequently than the indication, "textile materials breakdown" when they took care of the clothes including laundering or ironing. Moreover, the students experienced extensive color change after water washing and other accidents when taking care of their clothes. Their attitudes were surveyed to be very passive on handling the problems after washing or handling jeans. Therefore, the study concluded that the labeling methods should be improved especially in regard to the validity verification of the label contents and also the manufacturers should make concerted efforts to improve and enhance the consumer's rights and interests for effectiveness and accuracy of the descriptive labels.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.84-94
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• 2013

Objectives: The objective of this study is to identify the composition of dominant microorganisms in waste handling industries. Methods: We collected airborne bacteria and fungi by agar plate impaction method in recyclable waste sorting industry, food recycling industry, landfill and incineration. Isolated dominant microorganisms were identified by VITEK system or morphological analysis. Results: We isolated totally 330 microorganisms in the process and outdoor. Bacillus was the most dominant genus in the all industries, and Sphingomonas, Acinetobacter, Staphylococcus, and Proteus was dominant bacterial genus. The dominant genus of fungi was Penicillium, Aspergillus, and Cladosporium in each industries. Enterobacter, Pseudomonas, Klebsiella, and Proteus was identified as the dominant gram negative bacteria. The ratio of bacteria being biosafety levels(class 1 or 2) was 58.3~77.8%. Conclusions: This study has investigated the dominant microorganisms in the waste handling industries. The genus of dominant microorganisms was similar among the industries but the composition was different. We used biosafety levels as qualitative method, but further studies are needed about specific process of qualitative evaluation methods.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.50-54
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• 1999

In the process of designing a wheel balancer an ergonomic evaluation model has shown that manual tire handling onthe machine was often the major problem, The root of the problem lay in the design of machine's shaft which is influenced by the opeative handling task. Several methods were reviewed for determining the correct shaft' sizes but the Revised NIOSH Equation and the Lifting Stress Calculator were found to be the only suitable models for this study. An application of these mathematical models has shoed that the shaft length and the shaft height were the most critical measurement By analyzing these conclusion s the correct shaft size parameters became clearly defined.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.3
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• pp.203-209
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• 2003

Control algorithms of an air handling unit by using the mixing box plenum pressures were developed and verified by experiments. Control algorithms developed for this study were the setpoint algorithms for the outdoor damper position, the outdoor/fixed plenum pressure, and the return/exhaust plenum pressure. The outdoor/fixed plenum pressure setpoint was used to control the bypass damper position, and the return/exhaust plenum pressure setpoint was used to control the return fan speed. Experimental results showed the good control of the required outdoor air demand. Therefore, setpoint algorithms developed for this study may effectively be applied for the control of the VAV air handling unit.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.4
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• pp.410-418
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• 1999

This paper describes the use of residual and parameter identification methods for fault detection in an air handling unit. Faults can be detected by comparing expected condition with the measured faulty data using residuals. Faults can also be detected by examining unmeasurable parameter changes in a model of a controlled system using a system identification technique. In this study, AutoRegressive Moving Average with seXtrnal input(ARMAX) and AutoRegressive with eXternal input(ARX) models with both single-input/single-input and multi-input/single-input structures are examined. Model parameters are determined using the Kalman filter recursive identification method. Regression equations are calculated from normal experimental data and are used to compute expected operating variables. These approaches are tested using experimental data from a laboratory's variable-air-volume air-handling-unit.

• IE interfaces
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• v.17 no.2
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• pp.233-241
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• 2004

The main subject to become a hub port is automation. The automated container terminal has already operated in advanced ports and it has been planned for the basic planning and operation design in domestic case. The key of automated container terminal is effective operation of both ATC(automated transfer crane) and AGV(automated guided vehicle) which is automated handling equipments. This is essential to productivity of automated container terminal. This study suggests the most optimal method of equipment operation in order to minimize loading time using each three types of effective ATC operation methods and AGV dispatching rules in automated container terminals. As the automated equipment operation causes unexpected deadlocks or interferences, it should be proceeded on event-based real time. Therefore we propose the most effective ATC operation methods and AGV dispatching rules in this paper. The various states occurred in real automated container terminals are simulated to evaluate these methods. This experiment will show the most robust automated equipment operation method on various parameters(the degree of yard re-marshaling, the number of containers and AGV)

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.1
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• pp.23-37
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• 2017

Objectives : This study was conducted to evaluate the level of exposure to volatile organic compounds (VOCs) among workers handling rust preventive oils. Methods : A total of 30 bulk samples and 54 personal air samples were collected using diffusive samplers at 22 workplaces handling rust preventive oils in Daegu and Gyongsangbuk-do Province from March to October 2013. We also investigated detailed information on the related work conditions, such as kinds of products, handling methods, local exhaustive ventilation systems, and the status of the wearing personal protective equipment. All bulk samples and air samples were analyzed using gas chromatography mass spectrometry (GC-MS) to identify components to which workers potentially were exposed. Quantitative airborne concentrations of VOCs were confirmed using gas chromatography with flame ionized detectors. Results : In terms of qualitative analyses for the 30 bulk samples, we found carcinogenic, mutagenic and reproductive toxic(CMR) substances such as butane(carcinogenic Group 1A, mutagenic Group 1B), butoxy ethanol(carcinogenic Group 2), cumene (carcinogenic Group 2), ethyl benzene(carcinogenic Group 2), methyl isobutyl ketone(carcinogenic Group 2) and toluene (reproductive toxic, Group 2). As a result of full-shift based personal air samples, eight substances such as n-hexane, n-heptane, octane, nonane, decane, toluene, ethyl benzene and xylene were detected. Among them, n-hexane and n-heptane were detected in all of 54 air samples with $13.13mg/m^3$ and $8.61mg/m^3$ of maximum concentration, respectively. The level of airborne concentration from all of samples were bellow the occupational exposure limit in Korea. Conclusions : Based on the results of this study, workers handling rust preventive oils could be exposed to CMR substances contained in rust preventive oils and n-hexane and n-heptane were found as the most frequent sources of VOC exposure.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2471-2474
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• 2003

This paper focuses on the stability and operability of a man-machine system considering a human operator. Some papers' main interest has been the stability only, but the operability such as fatigue is also the other main interest. In a man-machine system, feelings such as motional, visual, and kinesthetic are important since those enable operators to work easily or fatigue operators. A model of a man-machine system has been developed. Motional, visual, and kinesthetic feelings may be considered as feedbacked sensor signals. We also have quantified the degree of fatigue with respect to reference operation. This is a performance index to be optimized. Several methods are presented to optimize the degree of fatigue and the stability of the integrated system. Examples are presented to show that the usefulness of the proposed modeling method and fatigue mitigating algorithm.