• KSBB Journal
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• v.22 no.5
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• pp.297-304
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• 2007

For large and rapid screening of high-yielding mutants of lovastatin produced by filamentous fungal cells of Aspergillus terreus, one of the most important stage is to test as large amounts of mutated strains as possible. For this purpose, we intended to develop a miniaturized cultivation method using $7m{\ell}$ culture tube instead of traditional $250m{\ell}$ flask (working volume $50m{\ell}$). For obtaining large amounts of conidiospores to be used as inoculums for miniaturized cultures, 4 components i.e., glucose, sucrose, yeast extract and $KH_2PO_4$ were intensively investigated, which had been observed to show positive effect on enhancement of spore production through Plackett-Burman design experimet. When optimum concentrations of these components that were determined through application of response surface method (RSM) based on central composite design (CCD) were used, maximum spore numbers amounting to $1.9\times10^{10}$ spores/plate were obtained, resulting in approximately 190 fold increase as compared to the commonly used PDA sporulation medium. Using the miniaturized cultures, intensive strain development programs were carried out for screening of lovastatin high-yielding as well as highly reproducible mutants. It was observed that, for maximum production of lovastatin, the producers should be activated through 'PaB' adaptation process during the early solid culture stage. In addition, they should be proliferated in condensed filamentous forms in miniaturized growth cultures, so that optimum amounts of highly active cells could be transferred to the production culture-tube as reproducible inoculums. Under these highly controlled fermentation conditions, compact-pelleted morphology of optimum size (less than 1 mm in diameter) was successfully induced in the miniaturized production cultures, which proved essential for maximal utilization of the producers' physiology leading to significantly enhanced production of lovastatin. As a result of continuous screening in the miniaturized cultures, lovastatin production levels of the 81% of the daughter cells derived from the high-yielding producers turned out to be in the range of 80%$\sim$120% of the lovastatin production level of the parallel flask cultures. These results demonstrate that the miniaturized cultivation method developed in this study is efficient high throughput system for large and rapid screening of highly stable and productive strains.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.63-64
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• 2005

This paper proposed a miniaturization passive element employing the multiple microstrip line. As a result of this method, we realized the transmission line miniaturized. The applying structure designed and evaluated a power divider on GaAS MMIC circuit. It draws a plan in a center Frequency as the observation could do good characteristic.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.401-405
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• 2005

This paper proposed a miniaturization passive element employing the multiple microstrip line. As a result of this method, we realized the transmission line miniaturized. The applying structure designed and evaluated a power divider on GaAS MMIC circuit. It draws a plan in a center Frequency as the observation could do good characteristic.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.5
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• pp.680-687
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• 1999

An extensive study on miniaturized bandpass filter(BPF) appropriate for mobile communication systems is presented in this paper. The miniaturization has been accomplished by incorporating low-loss high-index materials inside a resonating cavity fabricated in silicon substrate using micromachining etching techniques. By use of materials with dielectric constant $\varepsilon_r$=500, filters with volume less than 0.11 $mm^3$ have been designed at the center frequency of 5.8 GHz with 3.3% bandwidth. The electrical performances and design tolerances of these filters for a variety of materials and shapes are discussed and design guidelines are presented herein.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.147-150
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• 2000

Bioprocess chromatography is probably the most widely used unit operation in biopharmaceutics manufacturing. To obtain a good quality product reproducibly, the chromatography process validation should be performed carefully. We developed a miniaturized automatic chromatography system, MiniValChrom, for column performance validation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.12
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• pp.1995-2001
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• 2001

In this study, a small punch creep(SP-Creep) test using miniaturized specimen(10${\times}$10${\times}$0.5mm) is described to develop the new creep test method for high temperature structural materials. The SP-Creep test is applied to 2.25Cr-lMo(STBA24) steel which is widely used as boiler tube material. The test temperatures applied for the creep deformation of miniaturized specimens are between 550∼600$^{\circ}C$. The SP-Creep curves depend definitely on applied load and creep temperature, and show the three stages of creep behavior like in conventional uniaxial tensile creep curves. The load exponent of miniaturized specimen decreases with increasing test temperature, and its behavior is similar to stress exponent behavior of uniaxial creep test. The creep activation energy obtained from the relationship between SP-Creep rate and test temperature decreases as the applied load increases. A predicting equation or SP-Creep rate for 2.25Cr-lMo steel is suggested. and a good agreement between experimental and calculated data has been found.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.101-111
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• 2017

The task of improving a fungal strain is highly time-consuming due to the requirement of a large number of flasks in order to obtain a library with enough diversity. In addition, fermentations (particularly those for fungal cells) are typically performed in high-volume (100-250 ml) shake-flasks. In this study, for large and rapid screening of itaconic acid (IA) high-yielding mutants of Aspergillus terreus, a miniaturized culture method was developed using 12-well and 24-well microtiter plates (MTPs, working volume = 1-2 ml). These miniaturized MTP fermentations were successful, only when highly filamentous forms were induced in the growth cultures. Under these conditions, loose-pelleted morphologies of optimum sizes (less than 0.5 mm in diameter) were casually induced in the MTP production cultures, which turned out to be the prerequisite for the active IA biosynthesis by the mutated strains in the miniaturized fermentations. Another crucial factor for successful MTP fermentation was to supply an optimal amount of dissolved oxygen into the fermentation broth through increasing the agitation speed (240 rpm) and reducing the working volume (1 ml) of each 24-well microtiter plate. Notably, almost identical fermentation physiologies resulted in the 250 ml shake-flasks, as well as in the 12-well and 24-well MTP cultures conducted under the respective optimum conditions, as expressed in terms of the distribution of IA productivity of each mutant. These results reveal that MTP cultures could be considered as viable alternatives for the labor-intensive shake-flask fermentations even for filamentous fungal cells, leading to the rapid development of IA high-yield mutant strains.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.157-165
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• 2012

In this study, a short-wavelength transmission line employing periodically arrayed capacitive devices (PACD) was studied for application to miniaturized on-chip passive component on monolithic microwave integrated circuit (MMIC). The transmission line employing PACD showed shorter wavelength and lower characteristic impedance than conventional microstrip transmission line. The wavelength transmission line employing PACD structure was 8% of the conventional microstrip transmission line on GaAs substrate. Using the theoretical analysis, basic characteristic of the transmission line employing PACD (e.g., loss, effective dielectric constant, effective propagation constant, bandwidth ) were also investigated in order to evaluate its suitability for application to a development of miniaturized passive on-chip components on MMIC. Above results indicate that the transmission line employing PACD is a promising candidate for a development of miniaturized passive components on MMIC.

• Journal of Sensor Science and Technology
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• v.12 no.6
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• pp.249-257
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• 2003

The bio-telemetry technologies, that use the wireless miniaturized telemetry module implanted in the human body and transmits several biomedical signal from inside to outside of the body, have been expected to solve the problem such as the patient's inconvenience and the limit for diagnosis. In the case of transceiver system using the wireless RF transmission method, the method of three-dimensional localization for implantable miniaturized telemetry module is necessary to detect the exact position of disease. A new method for three-dimensional localization using small loop antenna in the implantable miniaturized telemetry module was proposed in this paper. We proposed a method that can accurately determine the position of telemetry module by analyzing the differences in the strength of signal, which is received at each of the small size RF receiver array installed on the body surface.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1107-1114
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• 2017

In this paper, a miniaturized distribution line was experimentally made. The smart grid distribution system was modeled by analyzing the distribution system, and a miniaturized micro three phase distribution system recloser was designed. The micro recloser was designed as a sensor part, a main part and a relay part, and the main part was designed to cut off the fault current by determining the fault from the input current based on the DSP. Finally, based on the results of the modeling, the micro three phase power distribution line and the micro three phase recloser were experimentally fabricated, and the basic making technology of the miniaturized micro smart grid was obtained through the making process.