• Korean small business review
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• v.41 no.4
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• pp.1-36
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• 2019

The purpose of this study is to identify the relationships among purposes and contents of smart factory building and continuous utilization of smart factory. Specifically, this study identifies two types of purposes of smart factory building as follows: (1) improving productivity, (2) increasing flexibility. In this study, three aspects of smart factory building contents were suggested like this: (1) automation area (facility automation vs. work automation), (2) big data system focus (radical transformation vs. incremental improvement), and (3) value chain integration area (internal value chain integration vs. external value chain integration). In addition, we looked at how firm size moderates the purposes - contents - continuous utilization of smart factory relationship. A questionnaire survey was conducted on 151 manufacturing companies. More specifically, out of 151 companies, 100 are small-and-medium-sized enterprises and 51 large-sized enterprises. All questionnaires were targeted at companies with Smart Factory level above level 2. The analysis results of this study using Smart PLS statistical programs are as follows. First, the purposes of smart factory building including increasing productivity and flexibility had positive impacts on all of the contents of smart factory building. Second, all of smart factory building contents had positive impacts on the continuous use of smart factory except big data system for incremental improvement of manufacturing process. Third, the impacts of smart factory building purposes implementation on smart factory building contents varied depending on whether the purpose is productivity improvement or flexibility. Fourth, it was founded that firm size moderated the relationships of purposes - contents - continuous utilization of smart factory in such a way that large-sized firms tend to empathize the link between flexibility and smart factory building contents for continuous use of smart factory, while small-and-medium-sized-firms emphasizing the link between productivity and smart factory building contents. Most of the previous studies have focused on presenting current smart factory deployment cases. However, it is believed that this research has made a theoretical contribution in this field in that it established and verified a research model for the smart factory building strategy. Based on the findings from a working-level perspective, corporate practitioners also need to have a different approach to smart factory building, which should be emphasized depending on whether their purpose of building smart factory is to increase productivity or flexibility. In particular, since the results of this study identify the moderating effect of firm size, it is deemed necessary for firms to implement a smart factory building strategy suitable for their firm size.

• Asian Journal of Atmospheric Environment
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• v.11 no.2
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• pp.122-130
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• 2017

The main purpose of the study was to clarify the properties of individual particles collected at each behavior space of a factory worker. The samplings of size-segregated ($PM_{2.1-1.1}$ and $PM_{4.7-3.3}$) indoor particles were conducted at three different behavior spaces of a factory worker who is engaged in an auto parts manufacturing plant (i.e., his home, his work place in factory, and his favorite restaurant). Elemental specification (i.e., relative elemental content and distribution in and/or on individual particles) was performed by a micro-PIXE system. Every element detected from the coarse particulate matters of home was classified into three groups, i.e., a group of high net-counts (Na, Al, and Si), a group of intermediate net-counts (Mg, S, Cl, K, and Ca), and a group of minor trace elements (P, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb). The results of EF for $PM_{4.7-3.3}$ in home indicated that several heavy metals were generated from the sources within the house itself. An exceptional feature shown in the individual particles in workplace is that Cr, Mn, and Co were clearly detected in both fine and coarse particles. Cluster analysis suggested that the individual coarse particles ($PM_{4.7-3.3}$) collected at the indoor of factory were chemically heterogeneous and they modified with sea-salt, mineral, and artificially derived elements. The principal components in individual coarse particles collected at restaurant were sea-salt and mineral without mixing with harmful trace elements like chromium and manganese. Compared to the indoor fine particles of home and restaurant, many elements, especially, Cl, Na, Cr, Mn, Pb, and Zn showed overwhelmingly high net-counts in those of factory.

• Korean Journal of Computational Design and Engineering
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• v.19 no.2
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• pp.138-147
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• 2014

In manufacturing companies, different types of production have been developed based on diverse production strategies and differentiated technologies. The production systems have become smart, factories are filled with unmanned manufacturing lines, and sustainable manufacturing technologies are under development. Nowadays, the digital manufacturing technology is being adopted and used in manufacturing industries. When this technology is applied, a lot of efforts, time and cost are required and training professionals in-house is limited. In this paper, we introduce e-FEED system (electronic based Front End Engineering and Design) that is the integrated design and analysis system for optimized manufacturing line development on virtual environment. This system provides the functions that can be designed easily using library and template based on standardized modules and analyzed automatically the logistic and capacity simulation by one-click and verified the result using visual reports. Also, we can review the factory layout using automatically created 3D virtual factory and increase the knowledge reuse by e-FEED system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.1
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• pp.1-12
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• 2016

The current economic crisis is making new demands on manufacturing industry, in particular, in terms of the flexibility and efficiency of production processes. This requires production and administrative processes to be meshed with each other by means of IT systems to optimise the use and capacity utilisation of machines and lines but also to be able to respond rapidly to wrong developments in production and thus to minimise adverse impacts on the business. The future scenario of the "smart factory" represents the zenith of this development. The factory can be modified and expanded at will, combines all components from different manufacturers and enables them to take on context-related tasks autonomously. Integrated user interfaces will still be required at most for basic functionalities. The complex control operations will run wirelessly and ad hoc via mobile terminals such as PDAs or smartphones. The comnination of IoT, and Big Data optimisation is bringing about huge opportunities. these processes are not just limited to manufacturing, anywhere a supply chain environment exists can benefit from information provided by linked devices and access to big data to inform their decision support. Building a smart factory with smart assets at its core means reaching those desired new levels of productivity and efficiency. It means smart products that leverage advanced traceability, connectivity and intelligence. For businesses, it means being able to address the talent crunch through more autonomous. In a Smart Factory, machinery and equipment will have the ability to improve processes through self-optimization and autonomous decision-making.

• The Southeast Asian review
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• v.23 no.3
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• pp.1-48
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• 2013

Taking the cases of Korean garment factories in Binh Duong area, this study aims to explain the phases and causes of the wildcat strikes that have rapidly expanded recently in Vietnam. For the purpose, this study raises several questions as follows. Why the strikes sometimes increase and decrease other times? Why the factory workers prefer a wildcat strike even though it is politically risky, unproductive, and complicated? By the same token, why the foreign management cannot or will not preemptively preclude the wildcat strikes that are usually predictable and the workers are mostly able to accomplish their demands? While answering these questions, this study explores the economic, political, and socio-cultural conditions of the wildcat strikes respectively. Based on the fieldwork in around 30 Korean owned garment factories and the interview with around 100 Vietnamese factory workers in Binh Duong, this study confirms several findings on the phases and causes of the strikes in the area in specific and in Vietnam in general. First, the annual trends of the wildcat strikes reflect the macroeconomic conditions in which the consumer prices and the labor market in Vietnamese economy and business conditions in the world economy are pivotal. Second, however, the influence of macroeconomic conditions on both the management and the workers in the garment factories are differential, depending on the financial situations of the multinational corporations and the workers' capability of reproducing their household economies. Thirdly, the possibility of the wildcat strike in each factory is relatively independent on the financial conditions of a factory and rather associated with the stable political structure and active political processes within the factory that enable the management and the workers to efficiently communicate each other. Lastly, the necessity of establishing political stability in a factory arises from the distinctive social and cultural characteristics of the multinational corporation in which foreign managers and native workers inevitably live in separate and different socio-cultural worlds.

• The Korean Journal of Mycology
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• v.21 no.2
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• pp.127-132
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• 1993

269 yeast strains were isolated from water samples collected from different sites in Minia governorate. These included 126 strains from fresh water, 108 strains from sewage and 35 strains from wastewater from sugar-cane factory. On the basis of 23 different physiological and morphological merkmals, the isolated strains were assigned to 16 species belonging to 11 genera. Total yeast cell counts as well as spectra of yeast species were highly variable in tested water. Total yeast cell counts ranged between $3.0{\times}10^3/l\;and\;1.8{\times}10^6/l$ for fresh water, $3.0{\times}10^4/l\;and\;3.0{\times}10^7/l$ for sewage and $1.5{\times}10^6/l\;and\;2.6{\times}10^7/l$ for wastewater from sugarcane factory. Debaryomyces hansenii, Rhodotorula mucilaginosa and Torulaspora delbrueckii were the dominant species in fresh water, whereas Debaryomyces hansenii, Thrichosporon beigelii, Rhodoforula mucilaginosa and Kluyveromyces marxianus were the dominant species in sewage and Saccharomyces cerevisiae, Kluyveromyces marxianus and Trichosporon beigelii were the dominant species in wastewater from sugar-cane factory. Yeast human pathogens, Trichosporon beigelii, Rhodotorula mucilaginosa and Candida albicans were encountered in water samples indicating that water in El-Minia governorate is also polluted by some pathogenic yeasts.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.630-637
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• 2018

The high rate algal ponds (HRAP) powered and mixed by a paddlewheel have been widely used for over 50 years to culture microalgae for the production of various products. Since light incidence is limited to the surface, water depth can affect microalgal growth in HRAP. To investigate the effect of water depth on microalgal growth, a mixed microalgal culture constituting three major strains of microalgae including Chlorella sp., Scenedesmus sp., and Stigeoclonium sp. (CSS), was grown at different water depths (20, 30, and 40 cm) in the HRAP, respectively. The HRAP with 20cm of water depth had about 38% higher biomass productivity per unit area ($6.16{\pm}0.33g{\cdot}m^{-2}{\cdot}d^{-1}$) and required lower nutrients and energy consumption than the other water depths. Specifically, the algal biomass of HRAP under 20cm of water depth had higher settleability through larger floc size (83.6% settleability within 5 min). These results indicate that water depth can affect the harvesting process as well as cultivation of microalgae. Therefore, we conclude that water depth is an important parameter in HRAP design for mass cultivation of microalgae.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.395-403
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• 2013

Plant factory has drawn attention in many countries in the world due to capability of environmental control not only for better yield and quality, but also for increase in functional and medicinal components of the products. In this paper, an experimental plant factory was constructed for various tests under different environmental conditions, and the operations were evaluated. A production room was constructed with adiabatic materials with dimensions of $6,900{\times}3,000{\times}2,500$ mm ($L{\times}W{\times}H$). Four sets of $2,890{\times}600{\times}2,320$ mm ($L{\times}W{\times}H$) production frame unit, each with 9 light-installed beds and an aeroponic fertigation system, resulting in 36 beds, were prepared. Accuracy and response were evaluated for each environmental control component with and without crops. Air temperature, humidity, $CO_2$ concentration, light intensity, frequency, and duty ratio, fertigation rate and scheduling were controllable from a main control computer through wireless communication devices. When the plant factory was operated without crop condition, the response times were 8 minutes for change in temperature from 20 to $15^{\circ}C$ and 20 minutes from 15 to $20^{\circ}C$; 7 minutes for change in humidity from 40 to 65%; and 4 minutes for change in $CO_2$ concentration from 450 to 1000 ppm. When operated for 24 hours with crop cultivation; average, maximum, and minimum values of temperatures were 20.06, 20.8, and $18.8^{\circ}C$; humidity were 66.72, 69.37, and 63.73%; $CO_2$ concentrations were 1017, 1168, and 911 ppm, respectively. Photosynthetic Photon Flux Density was increased as the distance from the light source decreased, but variability was greater at shorter distances. Results of the study would provide useful information for efficient application of the plant factory and to investigate the optimum environment for crop growth through various experiments.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1785-1791
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• 2020

In a previous study, the sequential optimization and regulation of environmental parameters using the PhotoBiobox were demonstrated with high-throughput screening tests. In this study, we estimated changes in the biovolume-based composition of a polyculture built in vitro and composed of three algal strains: Chlorella sp., Scenedesmus sp., and Parachlorella sp. We performed this work using the PhotoBiobox under different temperatures (10-36℃) and light intensities (50-700 μmol m^-2 s^-1) in air and in 5% CO₂. In 5% CO₂, Chlorella sp. exhibited better adaptation to high temperatures than in air conditions. Pearson's correlation analysis showed that the composition of Parachlorella sp. was highly related to temperature whereas Chlorella sp. and Scenedesmus sp. showed negative correlations in both air and 5% CO₂. Furthermore, light intensity slightly affected the composition of Scenedesmus sp., whereas no significant effect was observed in other species. Based on these results, it is speculated that temperature is an important factor in influencing changes in algal polyculture community structure (PCS). These results further confirm that the PhotoBiobox is a convenient and available tool for performance of lab-scale experiments on PCS changes. The application of the PhotoBiobox in PCS studies will provide new insight into polyculture-based ecology.

• Korean Journal of Chemical Engineering
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• v.39
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• pp.1004-1010
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• 2022

Ceramides are a major lipid class known to play an essential role in maintaining skin function. Thus, efforts have been made to produce ceramides and ceramide precursors in large quantities for industrial applications. The yeast Wickerhamomyces ciferrii, a natural producer of the ceramide precursor tetraacetyl phytosphingosine (TAPS), has been isolated and engineered through various mutagenesis approaches aiming to enhance TAPS production. Herein, a high-throughput screening platform for isolating W. ciferrii mutants with improved TAPS production is described. A fluorescence-mediated reporter system that allows initial quantification of TAPS content in yeast cells based on BODIPY staining was developed. The optimal concentration of BODIPY for monitoring intracellular TAPS levels in W. ciferrii was 400 ㎍/L, as shown by a linear correlation between the actual TAPS levels and mean fluorescence intensities. Fluorescence-activated cell sorting was used for isolating high TAPS-producing strains from an ethyl methanesulfonate-induced mutant library. After several rounds of sorting, mutants exhibiting a high-TAPS phenotype were isolated, and the M40 strain with the highest TAPS titer was chosen for large-scale cultivation. The influence of different carbon sources for optimizing TAPS production was also evaluated using the M40 strain. A maximum production yield of 5.114 g/L of ceramide precursors, including TAPS and triacetyl phytosphingosine, was achieved with the supplementation of molasses. This novel platform enables rapid screening of high TAPS-producing strains using the common dye BODIPY and can be easily extended for the development of mutants with high productivity of ceramide precursors in yeast and other microorganisms.