• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.143-146
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• 2000

This study was conducted to compare the cellular fatty acid composition and genotypic analysis of Bifidobacterium longum MK-G7 originated from Koreans with other commercial type strains of bifidobacteria. The cellular fatty acid of Bif. longum MK-G7 was shown to be composed of $C_{160FAME},C_{181\;c18DMA},C_{18.1\;CIS9\; FAME},C_{14.0FAME},C_{19\;0cye9,10 DMA},Feature7(C_{17.2 FAME), and Feature 10(C_{181\; Cll/t9/t6 FAME}$. Bif. longum MK-G7 showed 99.9% homology and the highest relatedness with Bif. longum ATCC 15707 type strain. Both Bif. longum MK-G7 and Bif. longum ATCC 15707 showed 153 bp products on RAPD (randomly amplified polymorphic DNA) analysis, however, they showed quite different band patterns on PFGE (pulsed-field gel electrophoresis) analysis. Consequently, our present study showed that Bif. longum MK-G7 was different from any commercial type strains of Bif. longum tested.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.12
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• pp.2210-2216
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• 2007

In this paper, triple-band plastic chip antennas for mobile terminal are investigated. Plastic chip antenna is composed of Foamex material with circle of PVC(Polyvilyl chloride). For its electric characteristics, the dielectric constant is 1.9, the insulation intensity is 112KV/cm. Plastic chip antennas are don't tend to break easily against to external shock, have more gain and efficiency than ceramic chip antennas. Triple-band plastic chip antennas of four type are implemented and experimented. From the experiments results, the antenna resonate at the triple-band, the gain of the antennas has about above -2dB, the pattern is ommidirectional the same as the conventional antennas. So, the antennas realized with Foamex material will be application for mobile phone antenna operated at the triple band which is cellular band and Korea-PCS band and ISM band or the antenna for other wireless communication system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.73-78
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• 2007

In this paper, the CPW-fed triple-band internal planar monopole antenna which simultaneously meets the three bands such as Cellular, PCS and Wibro is designed. The size of the radiation elements can be reduced to about $\lambda/4$ by designing the CPW-fed monopole antenna and then we can miniaturize the antenna size by meandering the radiation elements. In addition, we design the planar antenna for the slim-type mobile phone. We can obtain the desired antenna properties by controlling the length of each radiation elements. The measured return loss of the antenna is less than -7 dB at the desired bandwidth. And the measured radiation patterns are similar to that of the monopole antenna. The designed antenna has the gains -5.2 dBi. -2 dBi, -0.4 dBi at each resonant frequencies respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.3
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• pp.262-268
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• 2010

In this paper, a high power active tunable bandpass filter made of dielectric resonators and varactor diodes is designed using the active capacitance circuit generating negative resistance for tuning cellular TX, RX band. An active capacitance circuit's series feedback circuit using GaAs HFET whose $P_{1dB}$ is 32 dBm is used for compensating the losses from the varactor diodes of the tunable bandpass filter. The tuning elements, the varactor diodes are used as the back-to-back configuration to achieve the high power performance, The designed active capacitance circuit improves the insertion loss characteristics. The designed 2-stage active tunable dielectric bandpass filter at cellular band can cover from 800 MHz to 900 MHz. The insertion losses at 836 MHz and 881.5 MHz with 25 MHz bandwidth are 0.48 dB and 0.39 dB, respectively. The $P_{1dB}$ of the designed bandpass filter at TX and RX band are measured as 19.5 dBm and 23 dBm, respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.41-47
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• 2013

This letter describes a dual-band compact monopole antenna with two branches for Wi-Fi applications. The proposed antenna is based on a planar monopole design, and composed of two branches of radiating patches for dual-band operation. The ground size of the antenna matches the ground size of a typical hand-held cellular phone for improved compatibility with mobile phone printed circuit boards. The antenna is designed using a simulator and fabricated with optimized parameters. The fabricated antenna is measured at the lower and higher operating frequencies, and the return loss coefficient, gain, and radiation patterns are determined.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.2
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• pp.171-178
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• 2015

3GPP long-term evolution(LTE) band 2.3~2.4 GHz is adjacent to 2.4~2.5 GHz band for WLAN, and therefore compatibility study of the two systems is desirable. We propose a dynamic system simulation methodology to investigate the effect of WLAN interference on LTE systems. As capturing space/time/frequency changes in system parameters, the dynamic system simulation can exactly predict real system performance. Using the proposed methodology, we obtain LTE downlink throughput loss for the frequency separation between the two systems. Throughput loss under 1 % is obtained from guard band over 11 MHz(single channel allocation) or 10 MHz(three channel allocation).

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.4
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• pp.31-37
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• 2010

In this paper, highly efficient dual-band class-F power amplifiers(PAs) for cellular and WLAN bands are suggested and implemented. For the first step, single-band class-F amplifiers at 840MHz, 2.4GHz are designed using commercial E-pHEMT FETs. The performance of two single band PAs are as much as 81.2% of efficiency with the output power of 24.4dBm with 840MHz PA and 93.5% of efficiency with 22.4dBm from the 2.4GHz. For the dual-band class-F PA, the harmonic controlling circuit with ideal SPDT switch was suggested. The length of transmission line is variable by a SPDT switch. As a results, the operation in 840MHz showed the peak efficiency of 60.5% with 23.5dBm, while in 2.4GHz mode the efficiency was 50.9% with the output power of 19.62dBm. Besides, it is shown that the harmonic controller of class-F above 2Ghz could be implemented on the low cost FR-4 substrate.

• Biomedical Science Letters
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• v.3 no.2
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• pp.169-175
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• 1997

The hypoglycemic and metabolic effects of Commelina communis L. extract were investigated in alloxan-induced diabetic rats. The increased blood glucose level in the diabetic rats was sinificantly lowered with the treatments of the plant protein extract. Administration of the plant extract ellicited the significant increase of glucose-6-phosphate dehydrogenase (G6PD) activity in liver of alloxan-induced rats. Three isozyme patterns(band I, II & III : in order decreasing mobility) of G6PD were found when normal rat liver extract were subjected to electrophoresis on native polyacrylamide gel. On the other hand, G6PD band patterns of alloxan-induced rat liver extract were found band II isozyme missing. By treatment of plant extract in alloxan-induced rats has been showed pattern the recovery of missing band patterns. This indicates that changes of the G6PD isozyme might be related to the cellular process of diabetes.

• Tuberculosis and Respiratory Diseases
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• v.50 no.5
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• pp.549-556
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• 2001

Background : IGF-I is an important mitogen in many types of malignancies. Tumors also express many IGF binding proteins, which modulate IGF action. The propose of this study was to evaluate the effect of IGF-I and IGFBP on cell proliferation in mouse lung cancer cells (3LL). Methods : The cellular proliferation of 3LL with the treatment of growth factors was evaluated using MTT assay. Western ligand blot was performed in order to determine whether 3LL cells secrete IGFBPs and we evaluated the effect of IGFBP on cellular proliferation. Results : The treatment of 3LL cells with IGF-I increased cellular proliferation in a serum free media. Western ligand blot of conditioned medium of 3LL with $^{125}I$-IGF-I demonstrated one single major band with an estimated molecular mass of 24 kDa. This band was identified as IGFBP-4 with immunoblot analysis using antisera. The addition of anti-IGFBP-4 antibody to abrogate the effect of IGFBP-4 resulted in increased cellular proliferation suggesting that IGFBP-4 inhibits cell growth. Conclusion : IGF-I increases cellular proliferation, however the secreted IGFBP-4 has an inhibitory function on cell growth in 3LL. These findings suggest that IGF-I and IGFBP are involved in the cell proliferation.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.2
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• pp.83-90
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• 2005

In this paper, we proposed the newly design method for extracting of the saw resonator characteristic. For the parameters of the proposed equivalent model, we adjusted and optimized the variables of several functions. As verification of proposed method, we firstly designed and fabricated cellular saw resonator by using the proposed model resonator. As the simulated and measured results of the proposed design method are almost equaled, we confirmed the usefulness of this method. we knew the usefulness of this method. Finally we designed the 800MHz cellular Tx/Rx band pass filter by using this designed resonator.