• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.41-46
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• 2011

Purpose: The result of exam using an imaging device is very closely related with the image quality. Moreover, this image quality can be changed according to the condition of image acquisition and evaluation method. In this study, we evaluated the image quality according to the difference of pre-set method in PET/CT image. Materials & Methods: PET/CT Discovery STe16 (GE Healthcare, Milwaukee, USA), Chest PET phantom (Experiment 1) and 94 NEMA phantom (Experiment 2) were used. Phantom were filled with $^{18}F$-FDG maintaining hot sphere and background ratio to 4:1. In the case of experiment 1, we set the radio activity concentration on 3.5, 6.0, 8.6 kBq/mL. In the case of experiment 2, we set the radio activity concentration on 3.3, 5.5, 7.7, 9.9, 12.1, 16.5 kBq/mL. All experiments were performed with the time-set method for 2 minutes 30 seconds per frame and the count-set method with one hundred million counts in 3D mode after CT transmission scan. For the evaluation of the image quality, we compared each results by using the NECR and SNR. Results: In the experiment 1, both the NECR and SNR were increased as radioactivity concentration getting increased. The NECR was shown as 53.7, 66.9, 91.4. and SNR was shown as 7.9, 10.0, 11.7. Both the NECR and SNR were increased in time-set method. But the count-set method's pattern was not similar with the time-set method. The NECR was shown as 53.8, 69.1, 97.8, and SNR was shown as 14.1, 14.7 14.4. The SNR was not increased in count-set method. In experiment 2, results of both the NECR and SNR were shown as 45.1, 70.6, 95.3, 115.6, 134.6, 162.2 and 7.1, 8.8, 10.6, 11.5, 12.7, 14.0. These results were shown similar patten with the experiment 1. Moreover, when the count-set method was applied, the NECR was shown as 42.1, 67.3, 92.1, 112.2, 130.7, 158.7, and SNR was shown as 15.2, 15.9, 15.6, 15.4, 15.5, 14.9. The NECR was increased but SNR was not shown same pattern. Conclusion: Increment of administered radioactivity improves the quality of image unconcerned with the pre-set method. However, NECR was not influenced by increment of total acquisition counts through simple increasing scan duration without increment of administered activity. In case of count-set method, the SNR was shown similar value despite of increment of radioactivity. So, the administered activity is more important than the scan duration. And we have to consider that evaluation of image quality using only SNR may not be appropriate.

• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.357-364
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• 1995

The protozoan parasite, Entcmoeba histoIWticc, is one of major causative agents of intestinal disease all over the world. In acute experimental infection, the early host response to 5. histoIHtica is characterized by an infiltration of neutrophils. However, the chemotactic signal for this response is not well known. Based on the (jading that human epithelial cells produce the potent neutrophil chemoattractant and activator, interleukin-8 (IL-8), IL-8 gene expression was examined thoroughly in human colon epithelial cells exposed to 5. histolvtica trophozoites. Cellular RNAs were extracted from HT-29 or Caco-2 human colon epithelial cells exposed to 5. histoLvtica trophozoites for 30 minutes, 1 and 3 hours. IL-8 mRNA transcripts were measured by reverse transcriptional polprnerase chain reaction (RT-PCR) using synthetic standard RNA. The number of IL-8 mRNA molecules increased from 30 minutes to 3 hours of exposure period, reaching 3.1 H 107 molecules/ug of total RNA. Expression pattern of IL-8 mRNA transcripts was parallel to the amounts of IL-8 protein measured by enzyme-linked immunosorbent assay (ELISA) . Lysates of 5. histoIVtica also induced expression of mRNA for IL-8 in colon epithelial cells. These results sugf:esc that acute inflammatory reaction by 5. histoIVticc may be initially triggered by proinflammatory cytokines such as IL-8 secreted from epithelial cells of the colon.

• Journal of the Korean Chemical Society
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• v.41 no.5
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• pp.223-233
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• 1997

Ultra-thin $TiO_2$ films are grown on the Mo(100) surface using evaporated Ti metal under ambient $O_2$ pressure. The thickness of the $TiO_2$ film is controlled by the dosing rate of Ti metal over Mo(100) which is determined from the Auger signal changes with dosing time. 30 ML, 5 ML, and 1.6 ML thick films are prepared and used to determine the growth mechanism, the chemical composition, and the surface structure of the films. The growth mechanism of the $TiO_2$ film on Mo(100) is observed to follow the layer-by-layer growth mechanism. The chemical composition of the film is found to be that of bulk $TiO_2$. The surface plane of the film is (001), which facets irreversibly at 1200 K. The LEED pattern obtained from the film can be explained with the faceted surface with {011} planes reconstructed to $(2\sqrt2{\times}\sqrt2)R45^{\circ}$ with respect to the $TiO_2$ (001) surface. The film is somewhat thermally unstable when annealed to 1300 K. The film sputtered with $Ar^+$ ion is also studied by XPS.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.59-64
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• 2008

D. W. KANG, J. S. CHOI, and G. R. TACK, A Study on Real-Time Sports Activity Classification & Monitoring Using a Tri-axial Accelerometer. Korean Jouranl of Sport Biomechanics, Vol. 18, No. 2, pp. 59-64, 2008. This study was conducted to study the real-time sports activity classification and monitoring using single waist mounted tri-axial accelerometer. This monitoring system detects events of sports activities such as walking, running, cycling, transitions between movements, resting and emergency event of falls. Accelerometer module was developed small and easily attachable on waist using wireless communication system which does not constrain sports activities. The sensor signal was transferred to PC and each movement pattern was classified using the developed algorithm in real-time environment. To evaluate proposed algorithm, experiment was performed with several sports activities such as walking, running, cycling movement for 100sec each and falls, transition movements(sit to stand, lie to stand, stand to sit, lie to sit, stand to lie and sit to lie) for 20 times each with 5 healthy subjects. The results showed that successful detection rate of the system for all activities was 95.4%. In this study, through sports activity monitoring. it was possible to classify accurate sports activities and to notify emergency event such as falls. For further study, the accurate energy consumption algorithm for each sports activity is under development.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.4
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• pp.477-483
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• 2008

The paper introduces mobile handset multi-band chip antenna to be used on meander line PIFA structure and parasite patch. The proposed antenna uses an FR-4 substrate. The top layer is consist of meander lines PIFA structure to implement GSM900 and is connected with each rad and meander line on the via-hole for maximize space efficiency. The middle layer is designed with the signal line and gap to implement a DCS and PCS bands, the bottom layer which is added to a parasite patch on the ground can be show an adjust of frequency and impedance character by the connection of the radiators of middle layer and coupling. The fabricated antenna with the dimension of $28{\times}6{\times}4\;mm^3$. The ground plane a dimension of $45{\times}90\;mm$, designed by a commercial software CST simulator. The experimental results show that the bandwidth for(VSWR<3) is 90($875{\sim}965$) MHz in GSM900 band operation and 380($1,670{\sim}2,050$) MHz in DCS, PCS band operation. The maximum gains of antenna are 0.25 dBi, 3.65 dBi and 3.3 dBi at resonance frequencies and it has omni-directional pattern practically.

• Journal of Sensor Science and Technology
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• v.9 no.2
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• pp.96-105
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• 2000

Fiber optic TR-EFPI(total reflected extrtinsic Fabry-Perot interferometric) sensor was developed to measure the strain of structures, such as building, bridge, aircraft, etc. It has been difficult to distinguish the increase and decrease of the strain from the conventional fiber optic EFPI sensor because their signals only have a sinusoidal wave pattern related to the change of strain. Also, the absolute strain could not be measured by the simple fiber optic EFPI sensor. In this study, in order to measure the magnitude of strain with the direction of strain, the fiber optic sensor was simply constructed with the total reflected EFPI sensor probe. This probe was manufactured with a single mode fiber and a mirror coated fiber in a silica glass capillary tube. The output signal of this fiber optic TR-EFPT sensor can give the information about the magnitude and the direction of strain. The loading-unloading test was performed by the universal testing machine with alluminum beam specimen to compare the strain from fiber optic TR-EFPI sensor with the value from electrical strain gauge. In the result of this experiment. the strain from fiber optic TR-EFPI sensor had a good agreement with the values from the electrical strain gauge.

• Biomedical Science Letters
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• v.18 no.2
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• pp.104-111
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• 2012

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases which degrade extracellular matrix (ECM) during embryogenesis, wound healing, and tissue remodeling. Dysregulation of MMP activity is also associated with various pathological inflammatory conditions. In this study, we examined the expression pattern of MMPs during PMA-induced differentiation of THP-1 monocytic cells into macrophages. We found that MMP1, MMP8, MMP3, MMP10, MMP12, MMP19, MMP9, and MMP7 were upregulated during differentiation whereas MMP2 remained unchanged. Expression of MMPs increased in a time-dependent manner; MMP1, MMP8, MMP3, MMP10, and MMP12 increased beginning at 60 hr post PMA treatment whereas MMP19, MMP9, and MMP7 increased beginning at 24 hr post PMA treatment. To identify signal transduction pathways involved in PMA-induced upregulation of MMPs, we treated PMA-differentiated THP-1 cells with specific inhibitors for PKC, MEK1, NF-${\kappa}B$, PI3K, p38 MAPK and PLC. We found that inhibition of the MEK1 pathway blocked PMA-induced upregulation of all MMPs to varying degrees except for MMP-2. In addition, expression of select MMPs was inhibited by PI3K, p38 MAPK and PLC inhibitors. In conclusion, we show that of the MMPs examined, most MMPs were up-regulated during differentiation of monocyte into macrophage via the MEK1 pathway. These results provide basic information for studying MMPs expression during macrophage differentiation.

• The Journal of Internal Korean Medicine
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• v.21 no.2
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• pp.259-266
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• 2000

Objectives : The effects of aqueous extracts of Cortex ulmi pumilae (a traditional medicine for cancer treatment in oriental medicine) on the induction of apoptotic cell death were investigated in human liver origm hepatoma cell lines, HepG2. Methods : The death of HepG2 cells was markedly induced by the addition of extracts of Cortex ulmi pumilae in a dose-dependent manner. The apoptotic characteristic ladder pattern of DNA strand break was not observed in cell death of HepG2. In addition, it was not shown nucleus chromatin condensation and fragmentation under hoechst staining. However, by the using annexin V staining assay, externalizations of phosphatidylserine in HepG2 cell which were treated with Cortex ulmi pumilae extracts were detected in the early time (at 9 hr after extract treatment). Furthermore, LDH release was not detected in this early stage. Therefore, Cortex ulmi pumilae extracts-induced cell death of HepG2 cells is mediated by apoptotic death signal processes. Result : The activity of caspase 3-like proteases remained in a basal level in HepG2 cells which treated with the extract of Cordyceps sinensis. However, it was markedly increased in HepG2 cells which treated with two extracts of Cortex ulmi pumilae (C.U.P.-C, C.U.P.-K) which were differently extracted (respectively, 2.3 and 3.3 fold). On a while, the phosphotransferase activities of JNK1 was markedly induced in HepG2 cells which were treated with two extracts of Cortex ulmi pumilae. On the contrary, the activation of transcriptional activator, activating protein1(AP-1) and NF-kB were severely decreased by these two extracts of Cortex ulmi pumilae (C.U.P.-C, C.U.P.-K). In addition, antioxidants (GSH and NAC) and intracellular $Ca2^+$ level regulator (Bapta/AM and Thapsigargin) did not affect Cortex ulmi pumilae extracts-induced apoptotic death of HepG2 cells. Conclusions : In conclusion, our results suggest that two extracts of Cortex ulmi pumilae (C.U.P.-C, C.U.P.-K) induces the apoptotic death of human liver origin hepatoma HepG2 cells via activation of caspase 3-like proteases as well as JNK1, and inhibition of transcriptional activators, AP-1 and $NK-{\kappa}B$.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.158-162
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• 2009

Sound effects coming with appropriate tactile stimuli can strengthen its reality. For example, gunfire in games and movies, if it is accompanied by vibrating effects, can enhance the impressiveness. On a similar principle, adding the vibration information to existing sound data file and playing sound while generating vibration effects through haptic interfaces can augment the sound experience. In this paper, we propose a method to generate vibration information by analyzing the sound. The vibration information consists of vibration patterns and the timing within a sound file. Adding the vibration information is labor-intensive if it is done manually. We propose a sound detection algorithm to search the moments when specific sounds occur in a sound file and a method to create vibration effects at those moments. The sound detection algorithm compares the frequency characteristic of specific sounds and finds the moments which have similar frequency characteristic within a sound file. The detection ratio of the algorithm was 98% for five different kinds of gunfire. We also develop a GUI based vibrating pattern editor to easily perform the sound search and vibration generation.

• Journal of Astronomy and Space Sciences
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• v.24 no.4
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• pp.349-366
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• 2007

We designed and developed a multi-purpose CCD camera system for three kinds of CCDs; KAF-0401E($768{\times}512$), KAF-1602E($1536{\times}1024$), KAF-3200E($2184{\times}1472$) made by KODAK Co.. The system supports fast USB port as well as parallel port for data I/O and control signal. The packing is based on two stage circuit boards for size reduction and contains built-in filter wheel. Basic hardware components include clock pattern circuit, A/D conversion circuit, CCD data flow control circuit, and CCD temperature control unit. The CCD temperature can be controlled with accuracy of approximately $0.4^{\circ}C$ in the max. range of temperature, ${\Delta}33^{\circ}C$. This CCD camera system has with readout noise $6\;e^-$, and system gain $5\;e^-/ADU$. A total of 10 CCD camera systems were produced and our tests show that all of them show passable performance.