• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.391-402
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• 2021

Earthworms play an important role in soil fertilization, interacting continually with microorganisms. This study aims to demonstrate the existence of beneficial microorganisms living in the earthworm's immune system, the coelomic fluid. To achieve this goal, a molecular identification technique was performed, using cytochrome c oxidase I (COI) barcoding to identify abundant endogenic earthworms inhabiting the temperate zone of Rabat, Morocco. Then, 16S rDNA and ITS sequencing techniques were adopted for bacteria and fungi, respectively. Biochemical analysis, showed the ability of bacteria to produce characteristic enzymes and utilize substrates. Qualitative screening of plant growth-promoting traits, including nitrogen fixation, phosphate and potassium solubilization, and indole acetic acid (IAA) production, was also performed. The result of mitochondrial COI barcoding allowed the identification of the earthworm species Aporrectodea molleri. Phenotypic and genotypic studies of the sixteen isolated bacteria and the two isolated fungi showed that they belong to the Pseudomonas, Aeromonas, Bacillus, Buttiauxella, Enterobacter, Pantoea, and Raoultella, and the Penicillium genera, respectively. Most of the isolated bacteria in the coelomic fluid showed the ability to produce β-glucosidase, β-glucosaminidase, Glutamyl-β-naphthylamidase, and aminopeptidase enzymes, utilizing substrates like aliphatic thiol, sorbitol, and fatty acid ester. Furthermore, three bacteria were able to fix nitrogen, solubilize phosphate and potassium, and produce IAA. This initial study demonstrated that despite the immune property of earthworms' coelomic fluid, it harbors beneficial microorganisms. Thus, the presence of resistant microorganisms in the earthworm's immune system highlights a possible selection process at the coelomic fluid level.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.80-83
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• 2005

The competitiveness of the manufacturing company is evaluated in terms of line productivity, quality cost, inventory level, logistics efficiency, and so on. The productivity is defined by the number of products divided by the number of workers within the given operation time. Increasing the productivity is not easy to man-operated situation in the line, since it heavily depends on the standard time of the workers. This paper deals with the productivity of the Back Light Unit assembler for TFT-LCD, and proposes the methodology of investigating the optimal process by simulation of Arena.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.943-949
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• 2010

When PCB soldering is performed with microscope due to the electronic components' microminiaturization, workers' awkward upper body postures and difficulties being in focus among lens, object and eyes are one of reasons for productivity decline. The object of this study is to investigate the level of difficulties of work and the extent of productivity improvement by changing work interfaces from the work using microscope to the work using LCD monitor. Independent variables was usage of microscope and image system and dependent variables were upper body segments including neck, shoulder, back, and waist, task convenience and eye fatigue. The Visual Analogue Scale (10cm) was used for questionnaire and one way ANOVA (two levels) and two sample t-test were conducted. In addition, RULA rating was conducted for working postures. The result showed that interface changes of LCD monitor, suggested by productivity comparison per one Man Hour, highly contributed to work convenience and productivity improvement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.191-192
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• 2011

The construction projects contain a lot of variables and risk affecting productivity. The duration of the project must be recognized important as for quality, unit cost and safety. There is need for improving work efficiency by investigating relationship of works to prevent delay. This study focuses on analysing the delay factors of steel staircase system to suggest regression model that enables construction productivity estimation. The position of the observers and construction delay factors were expressed by the independent variable of the regression model and productivity was expressed by a dependent variable. This paper suggests quantitative productivity and it is expected that will be helpful estimating application in construction new technologies.

• The Korean Journal of Health Service Management
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• v.10 no.2
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• pp.15-23
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• 2016

Objectives : The purpose of this study was to evaluate the productivity changes of 18 public health centers in Gangwon-do from 2006 to 2013 using the Malmquist Productivity Index(MPI). Methods : Data were collected from Statistics Korea from 2006 to 2013. The input variables were the numbers of medical, nursing and administrative personnels. The output variables were the performances of health promotion programs. Along with the traditional input-oriented DEA analysis, the MPI was calculated. Results : First, among the 18 public health centers, the productivity index of 14 public health centers was increased. Second, the annual productivity showed a 6% increase. Third, the productivity improvements were mainly caused by Scale Efficiency Change. Conclusions : Improving the productivity of public health centers requires the support and external policies of the national and local government. Internally, public health centers need to maintain scale optimization of the center. Additionally, efforts should be made to effectively use limited resources.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.409-416
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• 2020

This paper proposes a study measuring productivity improvement by using a type of technology called "Machine Guidance" through work sampling in earthwork. Earthwork is the activity typically on the critical path, indicating that productivity for the activity is critical for managing schedule on time. Thanks to the development of sensing and information system technologies, productivity for earthwork has been improved. While there have been many studies investigating the application of a certain type of technology to earthwork, few studies have measured the productivity improvement and presented how the technology leads to productivity improvement. Based on the thorough literature review, it is hypothesized that Machine Guidance contributes to improving productivity of earthwork by reducing indirect workhours spent for information waiting and inspection. In addition to the literature review, this paper presents a research model to test the hypothesis by using the work sampling technique. By proving and quantifying the productivity improvement from the technology use, this study can help practitioners justify the investment for technology use, which will contribute to the deployment of technology and more effective execution of earthwork.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.4
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• pp.123-130
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• 2012

The automobile industry has been rapidly developing and the manufacturers in Korea as well as auto makers in other advanced countries are putting every ounce of their energies in securing their competitive edges in technology and in marketing. To that purpose, each company focuses on (i) reducing costs and (ii) improving productivity. We believe that the improved productivity can be capitalized by a set of various factors including improved organization-internal environment and employees' job satisfaction. The present research aims to identify how the internal elements contribute and lead to improved productivity. The present paper is a report of an empirical survey performed to 161 employees working in small and medium-sized firms in the automobile industry. After testing reliability and validity of the collected data, we have performed structural equation analysis using Amos of SPSS and tested a set of research hypotheses and models. The reported results will clarify the factors that influence productivity and job satisfaction and also shed light on the directions for strategic polices to keep up with the ever changing climate of the industry.

• Proceedings of the Korea Port Economic Association Conference
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• 2007.07a
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• pp.65-86
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• 2007

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.13-16
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• 2018

• Journal of Navigation and Port Research
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• v.28 no.4
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• pp.285-291
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• 2004

The productivity of container terminal is determined by its various operation methods. This paper aims at finding out the factors to enhance the productivity of container handling of quay crane, using simulation technique. Three levels of decision making in terminal operation, strategy, and tactics and operation are selected for defining parameters of simulation The result of the simulation and test shows that the significant factors to improve the productivity are the stack height of container, block dispersion and the distance in yard planning for shipment. Decision making in the operation level, however, is of significance in the mixed condition of strategic and tactical level. The result shows meaningful guidelines in decision making under strategic, tactical and operation level.