• Korean Journal of Animal Reproduction
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• v.19 no.3
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• pp.191-195
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• 1995

Bovine follicular oocytes were matured in vitro for 3D hr and exposed to Dulbecco's phosphate buffered saline containing 7% ethanol for 7 minutes for their activation, and incubated in TCM199 containing 10% fetal calf serum (FCS) and cytochalasin D (CD). When the oocytes were exposed to cytochalasin D for 0, 5, 10 and 15 hr, 5 hr showed highest developmental rate to blastocyst (16%), expanded blastocyst (13%) and hatched blastocyst (7%). Also when the oocytes were cultured for 7 hours in medium contai ning 0, 2.5, 5 and 7.5 ${\mu}\textrm{g}$/ml cytochalasin D, 2.5 ${\mu}\textrm{g}$/ml showed highest developmental rate to blastocyst (13%), expanded blastocyst (7%) and hatched blastocyst (4%). In conclusion, cytochalasin D played very important role for parthenogenetic development of follicular oocytes and 5 hr of exposure time to CD and 2.5 ${\mu}\textrm{g}$/ml CD in the medium was optimal for development of the follicular oocyte.

• KIEAE Journal
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• v.14 no.5
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• pp.21-28
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• 2014

To improve environmental problem as globally climate changes, domestic and foreign government have been trying to reduce green gas emitted by all industries. With making the green building certification system that assess the substantiality and energy performance of building, a governments have been using by a way for reducing green gas emitted in building industry. G-SEED(Green Standard for Energy & Environmental Design) developed in Korea have been reinforcing, and a number of projects certifying the G-SEED have been increasing continuously. As a demand of G-SEED certification is rising, a question on the additional cost data as certifying G-SEED is rising. It is because additional cost as getting the certification is important fact for G-SEED level decision and whether getting the certification or not. Therefore, this study analyzed additional construction cost as certifying G-SEED through performance improvement and design change of general office building not to get G-SEED. In conclusion, an additional construction cost ratio of G-SEED projects to the reference building is drawn as certified level; +0.26%, silver level; +2.29%, gold level; +3.89%, and platinum level; +5.48%.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.5 no.1
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• pp.43-59
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• 2006

A compact and broadband $4\times1$ array antenna was developed for 3G smart antenna system testbed. The $4\times1$ uniform linear away antenna was designed to operate at 1.885 to 2.2GHz with a total bandwidth of 315MHz. The array elements were based on the novel broadband L-probe fed inverted hybrid E-H (LIEH) shaped microstrip patch, which offers 22% size reduction to the conventional rectangular microstrip patch antenna. For steering the antenna beam, a commercial variable attenuator (KAT1D04SA002), a variable phase shifter (KPH350SC00) with four units each, and the corporate 4-ways Wilkinson power divider which was fabricated in-house were integrated to form the beamforming feed network. The developed antenna has an impedance bandwidth of 17.32% $(VSWR\leq1.5)$, 21.78% $(VSWR\leq2)$ with respect to center frequency 2.02GHz and with an achievable gain of 11.9dBi. The design antenna offer a broadband, compact and mobile solution for a 3G smart antenna testbed to fully characterized the IMT-2000 radio specifications and system performances.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.136-144
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• 2023

This study aimed to determine the optimal fertilization level for the production of Hovenia dulcis Thunb. seedlings. The height, root collar diameter, biomass, seedling quality index, and chlorophyll content of Hovenia dulcis container seedlings (1-0) according to six fertilization treatments (control, 0.5, 1.0, 1.5, 2.0, 2.5 g·L^-1) were investigated. The height, root collar diameter, and biomass of Hovenia dulcis container seedlings increased with increasing fertilization, but there were no significant differences among the ≥1.5 g·L^-1 treatments, and the 2.5 g·L^-1 fertilization treatment was associated with significantly lower height growth. The seedling-quality index showed a high but non-significant difference in the ≥1.5 g·L^-1 treatment range, and the chlorophyll content was highest in the 1.5 g·L^-1 treatment group. Considering the environmental and cost aspects of fertilization, the appropriate level of fertilization required for superior container seedling production of Hovenia dulcis was 1.5 g·L^-1, and a minimum fertilization treatment of ≥0.5 g·L^-1 should be applied to meet the minimum seedling specifications. These results are expected to be used as basic data for establishing an efficient seedling-production system and stable supply of Hovenia dulcis, which is used as a medicinal and honey plant.

• Journal of Life Science
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• v.16 no.6
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• pp.919-924
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• 2006

Toxicity evaluation systems for various chemicals and their metabolites have been developed during last decades. In this study, the acute toxicity of endocrine disrupting chemicals, such as endosulfan, bisphenol A, vinclozolin, and 3,5-dichloroaniline, was evaluated using HepG2 cell line, Lumbricus rubellus and Saccharomyces cerevisiae, respectively. The extents of toxicity of the chemicals in different bioassay systems varied substantially, such as endosulfan>3,5-dichloroaniline> bisphenol A in HepG2 cell line system, endosulfan>bisphenol A>3,5-dichloro aniline in L. rubellus system, and 3,5-dichloroaniline>endosulfan>bisphenol A in S. cerevisiae system. Meanwhile, no cytotoxicity was observed by treatment of vinclozolin in the evaluation systems. Our results suggest that earthworm and yeast are useful to evaluate acute toxicity of endocrine disrupting chemicals, and direct comparison of toxicity data from different bioassay systems is unattainable. Based on our results, we propose that the bioassay system with earthworm or yeast, a rapid, simple and economic system, could be applied as pre-test for the toxicity evaluation using human cell line or animals.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1234-1242
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• 2013

To verify the effectiveness of the proposed system, the charges in power demand are analyzed for an AC and DC distribution system for the existing V2G concept and electric vehicle charging stations connected to a Battery Energy Storage System. In addition, since many power-converter-based chargers are operated simultaneously in an EV charging station, the change in the system harmonics when several EV chargers are connected at a single point is analyzed through simulations.

• Korean Journal of Optics and Photonics
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• v.11 no.3
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• pp.179-186
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• 2000

Optical coupling coefficients and misalignment tolerance of 155 Mbps optical transmitter module of passive alignment technology, to be usable in ATM system, B-NT (Broadband Network Termination) system, and 10 G transmission system for information super-highway networks, were calculated, compaired with it's engineer samples, and discussed. These engineer samples of -4.5 dBm maximum output power were packaged in the method of butt coupling of flat-fiber and tested reliability evaluation. Hence the cheap packaging method of optical transmitter module was researched. rched.

• Journal of Information Technology Applications and Management
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• v.31 no.4
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• pp.47-61
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• 2024

A manned and unmanned complex combat system refers to a combat system that performs various missions by operating manned and unmanned aircraft together. The combat system is rapidly becoming more advanced due to recent remarkable developments in information and communication technologies(ICT), including AI and 5G, and major countries are actively using it in actual battlefields. Furthermore, the importance of this combat system is increasing and it is emerging as the core of future warfare. Accordingly, this study analyzed the concept of the manned and unmanned complex combat system and the current status of its integration with ICT, presented an operational concept utilizing it, and then analyzed the actual current status of related combat systems at home and abroad. Lastly, five suggestions were presented for the development of domestic manned and unmanned complex combat systems.

• Journal of Plant Biotechnology
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• v.4 no.3
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• pp.129-134
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• 2002

We report the development of a new selection system for the transformation of pepper plants by mannose. In order to achieve this, we first tested several factors related to regeneration conditions. Among the 30 inbred lines examined, line P9l5 was able to generate shoots at the highest rate from both cotyledons and hyporotyls in MS media. A dosage curve for optimizing the selection conditions was established by mixing mannose (range 0-50 g/L) and sucrose (range 0-30 g/L). The least selection pressure on shoot formation was created by a mixture of sucrose and mannose at 20 g/L and 15 g/L, respectively, and the threshold for ultimate tissue death was 50 g/L of mannose irrespective of the sucrose concentration. However, we found that mannose itself was not the sole inhibitor of pepper shoot development. High concentrations of sucrose (30 g/L) contributed additively to the inhibition of shoot formation at higher mannose concentrations. Genotype preference is a major factor that enhances regeneration ability in mannose media, as was observed in MS media. P9l5 and P410 line had high regeneration rates under mannose selection conditions in the presence of Agrobacterium infection. Different virulence levels of Agrobacterium strains did change the regeneration rates, probably due to interaction with the specificities of the inbred lines. Taken together, P9l5 offers the best pepper inbred line for transformation and we recommend a selection condition of 20 g/L of sucrose and 15 g/L or more of mannose up to 50 g/L in media.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.622-628
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• 2010

In this study, Solid-phase microextraction (SPME) with GC/FID was studied as a possible alternative to liquid-liquid extraction for the analysis of BTEX and MTBE. Experimental parameters affecting the SPME process (such as kind of fibers, adsorption time, desorption time, volume ratio of sample to headspace, salt addition, and magnetic stirring) were optimized. Experimental parameters such as CAR/PDMS, adsorption time of 20 min, desorption time of 5 min at $250^{\circ}C$, headspace volume of 50 mL, sodium chloride (NaCl) concentration of 25% combined with magnetic stirring were selected in optimal experimental conditions for analysis of BTEX and MTBE. The general affinity of analytes to CAR/PDMS fiber was high in the order p-Xylene>Toluene>Ethylbenzene>MTBE>Benzene. The linearity of $R^2$ for BTEX and MTBE was from 0.970 to 0.999 when analyte concentration ranges from $30{\mu}g/L$ to $500{\mu}g/L$, respectively. The relative standard deviation (% RSD) were from 2.5% to 3.2% for concentration of $100{\mu}g/L$ (n=5), respectively. Finally, the limited of detection (LOD) observed in our study for BTEX and MTBE were from $7.5{\mu}g/L$ to $15{\mu}g/L$, respectively.