• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.9
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• pp.1083-1089
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• 2007

In this paper, we applied the CMRC to a resonator to improve the harmonic characteristic of VCO. The CMRC filters have some advantage. It is a small size as well as easy to manufacture than PBG, DGS and other filters. This paper was proposed by using CMRC for a VCO. The second harmonic of -42.83 dBc and the phase noise at 100 kHz offset of -95.83 dBc/Hz was achieved, respectively. The VCO has better second harmonic character by 15.73 dB and phase noise by 31.13 dB in case of CMRC applied behind a resonator than CMRC used as a resonator.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.105
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• pp.124-128
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• 2006

In this paper, Compact Microstrip Resonant Cell(CMRC)s have been employed to suppress IMD(Intermodulation Distortion) of the 3-Way Doherty amplifier. This method can not only improve the linearity and the efficiency but also be simpler, smaller and more inexpensive than existing linearity methods; (for example harmonic feedback, back off, feed-forward, predistortion and so on) Also, using only one divider reduces the size of the proposed 3-Way Doherty amplifier. As a result, the IMD3 and the PAE have been improved by 4.5 dB and by $9.2\%$, respectively, using the proposed Doherty amplifier with CMRC.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.149-153
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• 2005

A new method of power amplifier's linearity improvement using a Compact Microstrip Resonant Cell(CMRC) is proposed. It is found out that a CMRC at the input side gives better performance than that at the output. Tuning lines are used in the input and the output matching network to get the optimum performance. As a result, the 14.77 dB improvement fur the third-order IMD is obtained. And the size of the CMRC is only $17.1\times5.22mm$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.7 s.361
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• pp.12-16
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• 2007

In this paper, The 3rd-IMD of class-F power amplifier is improved using CMRC structure in order to remove the parasitic End harmonic at the output load of class-F power amplifier. The total size is very small more than class-F power amplifier using PBG. (Photonicband Gap) structure during improved 3rd-IMD characteristic performance.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.77-78
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• 2005

In this paper, Compact Microstrip Resonants Cell(CMRC) have been employed to suppress IMD(Intermodulation Distortion) of the 3-Way Doherty amplifier. This method can not only improve the linearly and the efficiency but also is simpler, smaller and more inexpensive than existing linearly methods; (for example Harmonic feedback, Back off, Feed-forward, Predistortion and so on.) Also, the proposed 3-way Doherty amplifier using only one divider has been reduced size of existing 3-Way Doherty amplifier. As a result, the proposed Doherty amplifier using CMRC and only one divider has been improved for the IMD$_3$ by 4.474dBc, and the PAE by 9.199%, respectively.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.303-303
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• 2004

• The Korean Journal of Applied Statistics
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• v.24 no.5
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• pp.847-859
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• 2011

cDNA microarray-based comparative genomic hybridization(CGH) data includes low-intensity spots and thus a statistical strategy is needed to detect subtle differences between different cancer classes. In this study, genes displaying a high frequency of alteration in one of the different classes were selected among the pre-selected genes that show relatively large variations between genes compared to total variations. Utilizing copy-number changes of the selected genes, this study suggests a statistical approach to predict patients' classes with increased performance by pre-classifying patients with similar genetic alteration scores. Two-stage logistic regression model(TLRM) was suggested to pre-classify homogeneous patients and predict patients' classes for cancer prediction; a decision tree(DT) was combined with logistic regression on the set of informative genes. TLRM was constructed in cDNA microarray-based CGH data from the Cancer Metastasis Research Center(CMRC) at Yonsei University; it predicted the patients' clinical diagnoses with perfect matches (except for one patient among the high-risk and low-risk classified patients where the performance of predictions is critical due to the high sensitivity and specificity requirements for clinical treatments. Accuracy validated by leave-one-out cross-validation(LOOCV) was 83.3% while other classification methods of CART and DT performed as comparisons showed worse performances than TLRM.

• YAKHAK HOEJI
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• v.55 no.3
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• pp.267-272
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• 2011

Human NK cells, identified 30 years ago based on their ability to spontaneously kill tumor cells, constitute a subset of lymphocytes, which play an important role in the first line of immune defense and the effective function of these cells are enhanced by cytokines. Lung carcinoma has been one of the most commonly diagonosed cancer as well as the leading cause of cancer death in male. Here we provide the evidence that human natural killer cells has inhibitory effects on tumor growth of human lung cancer cell NCI-H460 (non-small cell lung cancer). Enriched NK cell population was obtained by 2 weeks cultivation in interleukin-2(IL-2)-containing medium. The resulting population comprised 26% CD3$^+$ cells, 9% CD3$^+$CD4$^+$ cells, 16% CD3$^+$CD8$^+$ cells, 76% CD56$^+$ cells, 6% CD3$^+$CD56$^+$ cells and 70% CD3$^-$CD56$^+$ cells. Activated NK cells at doese of 2.5, 5, and 10 million cells per mouse inhibited 2%, 12% and 45% of NCI-H460-induced tumor growth in nude mouse xenograft assays, repectively. This result suggests that NK cell-based immunotherapy may be used as an adoptive immunotherapy for lung cancer patients.

• YAKHAK HOEJI
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• v.54 no.3
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• pp.192-199
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• 2010

Colorectal cancer is one of the most common alimentary malignancies. In this study, the antitumor activity of activated human natural killer (NK) cells against human colorectal cancer was evaluated in vivo. Human NK cells are the key contributors of innate immune response and the effective functions of these cells are enhanced by cytokines. Human peripheral blood mononuclear cells (PBMC) were cultured with interleukin-2 (IL-2)-containing medium for 14 days and resulted in enriched NK cell population. The resulting populations of the cells comprised 7% $CD3^+CD4^+$ cells, 25% $CD3^+CD8^+$ cells, 13% $CD3^-CD8^+$ cells, 4% $CD3^+$CD16/$CD56^+$ cells, 39% $CD3^+$CD16/$CD56^-$ cells, and 52% $CD3^-$CD16/$CD56^+$ cells. Tumor necrosis factor alpha (TNF-$\alpha$), interferon gamma (IFN-$\gamma$), IL-2, IL-4, and IL-5 transcripts of the activated NK cells were confirmed by RT-PCR. In addition, activated NK cells at doses of 2.5, 5 and 10 million cells per mouse inhibited 10%, 34% and 47% of SW620-induced tumor growth in nude mouse xenograft assays, respectively. This study suggests that NK cell-based immunotherapy may be used as an adoptive immunotherapy for colorectal cancer patients.