• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.2 s.105
• /
• pp.134-138
• /
• 2006

The isolation performance of the S-band single-pole single-throw(SPST) monolithic microwave integrated circuit (MMIC) switch with two different RF-interconnection approaches, microstrip and grounded coplanar waveguide(GCPW) lines, are investigated. On-to-off isolation is improved by 5.8 dB with the GCPW design compared with the microstrip design and additional improvement of 6.9 dB is obtained with the coplanar wire-bond interconnection(CWBI) at a 3.4 GHz. The measured insertion loss and third-order inter-modulation distortion(IMD3) are less than 1.94 dB over $3.2{\sim}3.6\;GHz$ and greater than 64 dBc.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.5
• /
• pp.1347-1355
• /
• 2004

In this study, the immunological effect of a traditional Korea herbal acupuncture, that has been widely used for the treatment of various immunological disorders including inflammation in Korea, was examined in vitro and in vivo. In our previous study demonstrated that BV increased the expression of IFN-γ mRNA, that plays pivotal role in T cell response. This study was designated to evaluate the effect of BV on helper T cell development by monitoring Th1/Th2 specific cytokine secretion patterns in artificially induced Th1/Th2 polarized condition and in vivo. The results demonstrated that BV didn't have mitogenic effects on the unstimulated CD4+ T cell, but increased the CD4+ T cell proliferation upon activation with anti-CD3/CD28 antibody. The Th1 cells were over-populated dramatically in Th1 driven condition with BV treatment, while the Th2 cells were increased slightly in Th2 skewed condition. Furthermore, under Th1-skewed conditions, the level of IFN-γ was considerably increased with BV treatment. Besides, the expression of T-bet, a transcription factor that plays pivotal role in Th1 lineage programming, was increased with BV treatment. The expressions of IFN-γ and T-bet were also significantly increased in vivo. The results that Th1 specific cytokine secretion were considerably increased and Th2 specific cytokine secretion were not significantly changed in vitro and in vivo indicated that BV enhances Th1 lineage development, Therefore, these results suggest that BV might be desirable agent for correction of Th1 dominant pathological disorders.

• Biomolecules & Therapeutics
• /
• v.17 no.3
• /
• pp.282-287
• /
• 2009

Ochnaflavone is a natural biflavonoid and mainly found in the caulis of Lonicera japonica (Caprifoliaceae). Biological activities such as anti-inflammatory and anti-atherogenic effects have been previously reported. The anticancer activity of ochnaflavone, however, has been poorly elucidated yet. In the present study, we investigated the effect of ochnaflavone on the growth inhibitory activity in cultured human colon cancer cell line HCT-15. Ochnaflavone inhibited the proliferation of the cancer cells with an $IC_{50}$ value of $4.1{\mu}M$. Flow cytometric analysis showed that ochnaflavone arrested cell cycle progression in the G2/M phase, and induced the increase of sub-G1 peak in a concentration-dependent manner. Induction of cell cycle arrest was correlated with the modulation of the expression of cell cycle regulating proteins including cdc2 (Tyr15), cyclin A, cyclin B1 and cyclin E. The increase of sub-G1 peak by the higher concentrations of ochnaflavone (over $20{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, activation of caspase-3, -8 and -9, and cleavage of poly-(ADP-ribose) polymerase. These findings suggest that the cell cycle arrest and induction of apoptosis might be one possible mechanism of actions for the anti-proliferative activity of ochnaflavone in human colon cancer cells.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.5B
• /
• pp.573-581
• /
• 2011

The underwater channel is known to offer poor communications channel. The channel medium is highly absorptive and the transmission bandwidth is limited. In addition, the channel is highly frequency selective; the degree of selectiveness depends on a detailed geometry of the channel. Furthermore, the response changes over time as the channel conditions affecting the response such as water temperature, sea surface wind and salinity are time-varying. The transceiver design to deal with the frequency and time selective channel, therefore, becomes very challenging. It has been known that deep fading at certain specific sub-carriers are detrimental to OFDM systems. To mitigate this negative effect, the proposed coded OFDM system employs an LDPC code based modulation. In this paper, we aim 1) to provide a detailed underwater channel model; 2) to design a robust LDPC coded OFDM system; 3) to test the proposed system under a variety of channel conditions enabled by the channel model.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.2B
• /
• pp.159-167
• /
• 2011

LTE-Advanced system requires uplink multi-antenna transmission in order to achieve the peak spectral efficiency of 15bps/Hz. In this paper, the uplink MIMO system model for the LTE-Advanced is proposed and an efficient link adaptation shceme using precoding is considered providing error rate reduction and system capacity enhancement. In particular, the proposed scheme determines a transmission rank by selecting the optimal wideband precoding matrix, which is based on the derived signal-to-interference and noise ratio (SINR) for the minimum mean squared error (MMSE) receivers of $2{\times}4$ multiple input multiple output (MIMO). The proposed scheme is verified by simulation with a practical MIMO channel model. The simulation results of average block-error-rate(BLER) reflect that the gain due to the proposed rank adapted transmission over full-rank transmission is evident particularly in the case of lower modulation and coding scheme (MCS) and high mobility, which means the severe channel fading environment.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.23 no.6
• /
• pp.609-617
• /
• 2020

Non-destructive inspection using X-rays is used as a method to check the inside of products. In order to accurately inspect, a X-ray image requires a higher spatial resolution. However, the reduction in pixel size of the X-ray detector, which determines the spatial resolution, is time-consuming and expensive. In this regard, a DMM has been proposed to obtain an improved spatial resolution using the same X-ray detector. However, this has a limitation that the motion blur phenomenon, which is a decrease in spatial resolution. In this paper, motion blur was removed by applying Non-Blind Deconvolution to the DMM image, and the increase in spatial resolution was confirmed. DMM and Non-Blind Deconvolution were sequentially applied to X-ray images, confirming 62 % MTF value by an additional 29 % over 33 % of DMM only. In addition, SSIM and PSNR were compared to confirm the similarity to the 1/2 pixel detector image through 0.68 and 33.21 dB, respectively.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.4
• /
• pp.1540-1551
• /
• 2015

The detection of position and speed in BLDC motors without using position sensors has meant many efforts for the last decades. The aim of this paper is to develop a sensorless technique for detecting the position and speed of BLDC motors, and to overcome the drawbacks of position sensor-based methods by improving the performance of traditional approaches oriented to motor phase voltage sensing. The position and speed information is obtained by computing the derivative of the terminal phase voltages regarding to a virtual neutral point. For starting-up the motor and implementing the algorithms of the detection technique, a FPGA board with a real-time processor is used. Also, a versatile hardware has been developed for driving BLDC motors through pulse width modulation (PWM) signals. Delta and wye winding motors have been considered for evaluating the performance of the designed hardware and software, and tests with and without load are performed. Experimental results for validating the detection technique were attained in the range 5-1500 rpm and 5-150 rpm under no-load and full-load conditions, respectively. Specifically, speed and position square errors lower than 3 rpm and between 10º-30º were obtained without load. In addition, the speed and position errors after full-load tests were around 1 rpm and between 10º-15º, respectively. These results provide the evidence that the developed technique allows to detect the position and speed of BLDC motors with low accuracy errors at starting-up and over a wide speed range, and reduce the influence of noise in position sensing, which suggest that it can be satisfactorily used as a reliable alternative to position sensors in precision applications.

• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.3
• /
• pp.268-273
• /
• 2015

Recently many countries are researching actively underwater sensor networks for securing ocean resources and changes of ocean environment in all over the world. Current the commercial modem are not suitable because it has characteristics of long distance, higher price, larger power consumption with the special object mainly. In this paper, a low power and compact underwater communication modem which is suitable for underwater sensor networks is implemented. It is comprised by using a simple analog circuit for non-coherent BFSK modulation method, ultra low power MCU and orthogonal codes with a less operation and a simple implementation. It was experimented an underwater communication using our modem in a water tank and open sea farms. It communicates fewer than $10^{-4}$ bit error rate.

• The Journal of Internal Korean Medicine
• /
• v.22 no.4
• /
• pp.613-619
• /
• 2001

Objectives: The purpose of this study was to examine the efficacy of Gamichunggan-san(Jiaweiqinggan-san) on 25 patients who have suffered from alcoholic liver disease. Methods: Gamichunggan-san(Jiaweiqinggan-san) was administered to patients for over 1 months continuously. We checked improvement of clinical symptoms, changes of chemistry hematological test and especially lymphocyte count. Results: The results obtained are summarized as follows. Gamichunggan-san(Jiaweiqinggan-san) has significant effect on the improvement of clinical symptoms. And the improvement ratio of AST, ALT, ${\gamma}$-GTP was 77.8%, 61.5%, 76.2%. In patients with alcohoiic hepatitis, WBC was increased effectively within normal range and those with liver cirrhosis, All of the patients with the inverted ratio of lymphocyte was improved. Conclusions: From the above results, it is suggested that Gamichunggan-san(Jiaweiqinggan-san) have significant effects on recovery of liver malfunction and immune modulation, and also could be recommended as a prescription for alcoholic liver disease.

• The Journal of Korean Medicine
• /
• v.29 no.2
• /
• pp.71-80
• /
• 2008

Objective: There is increasing evidence that chronic non-bacterial prostatitis is recognized to be a local inflammatory disease, and there is substantiating evidence to support the role of the inflammatory responses in its pathogenesis, and clinical value in the evaluation of therapeutic efficacy. Prunella vulgaris has been traditionally used in treatment of inflammatory diseases, including of scrofula, goiter, and allergy diseases. In this study, we investigated the effects of Prunella vulgaris on inflammatory cytokines and cytopathological alternation in the rat model of non-bacterial prostatitis induced by castration and $17{\beta}-estradiol$ treatment. Methods: Two-month-old rats were treated with $17{\beta}-estradiol$ after castration for induction of experimental non-bacterial prostatitis, which is similar to human chronic prostatitis in histopathological profiles. Prunella vulgaris as an experimental specimen, and testosterone as a positive control, were administered orally. The prostates were evaluated by histopathological parameters including the epithelial score and epithelial-stromal ratio for glandular damage, and the expression of inflammatory cytokine genes including the interleukin $(IL)-1{\beta}$, IL-5, IL-12, and tumor necrosis factor $(TNF)-{\alpha}$. Results: While prostates of control rats revealed severe acinar gland atrophy and stromal proliferation, the rats treated with Prunella vulgaris showed a diminished range of tissue damage. Epithelial score was improved in Prunella vulgaris over that of the control (P<0.05). The epithelial-stromal ratio was lower with Prunella vulgaris when compared to that of the control (P<0.05). In the reverse transcription-polymerase chain reaction (RT-PCR) of inflammatory cytokine genes, Prunella vulgaris inhibited the expression of $IL-1{\beta}$ and $TNF-{\alpha}$ genes, while it modulated the expression of IL-5, which is an anti-inflammatory cytokine. Conclusions: These findings suggest that Prunella vulgaris may protect the glandular epithelial cells and also inhibit stromal proliferation in association with the immune modulation including the suppression of inflammatory cytokines and promotion of anti-inflammatory cytokine. From theses results, we suggest that Prunella vulgaris could be a useful remedy agent for treating chronic non-bacterial prostatitis.