• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.05a
• /
• pp.1.1-1.1
• /
• 2011

Printed electronics based on the direct writing of solution processable functional materials have been of paramount interest and importance. In this talk, the synthesis of printable inorganic functional materials (conductors and semiconductors) for thin-film transistors (TFTs) and photovoltaic devices, device fabrication based on a printing technique, and specific characteristics of devices are presented. For printable conductor materials, Ag ink is designed to achieve the long-term dispersion stability and good adhesion property on a glass substrate, and Cu ink is sophisticatedly formulated to endow the oxidation stability in air and even aqueous solvent system. The both inks were successfully printed onto either polymer or glass substrate, exhibiting the superior conductivity comparable to that of bulk one. In addition, the organic thin-film transistor based on the printed metal source/drain electrode exhibits the electrical performance comparable to that of a transistor based on a vacuum deposited Au electrode. For printable amorphous oxide semiconductors (AOSs), I introduce the noble ways to resolve the critical problems, a high processing temperature above $400^{\circ}C$ and low mobility of AOSs annealed at a low temperature below $400^{\circ}C$. The dependency of TFT performances on the chemical structure of AOSs is compared and contrasted to clarify which factor should be considered to realize the low temperature annealed, high performance AOSs. For photovoltaic application, CI(G)S nanoparticle ink for solution processable high performance solar cells is presented. By overcoming the critical drawbacks of conventional solution processed CI(G)S absorber layers, the device quality dense CI(G)S layer is obtained, affording 7.3% efficiency CI(G)S photovoltaic device.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.36C no.6
• /
• pp.18-26
• /
• 1999

This paper presents the architecture and design of a DSSS MODEM ASIC chip for wireless local area networks (WLAN). The implemented MODEM chip supports the DSSS physical layer specifications of the IEEE 802.11. The chip consits of a transmitter and a receiver which contain a CRC encoder/decoder, a differential encoder/decoder, a frequency offset compensator and a timing recovery circuit. The chip supports various data rates, i.e., 4,2 and 1Mbps and provides both DBPSK and DQPSK for data modulation. We have performed logic synthesis using the $SAMSUNG^{TM}$ $0.6{\mu}m$ gate array library and the implemented chip consists of 53,355 gates. The MODEM chip operates at 44MHz, the package type is 100-pin QFP and the power consumption is 1.2watt at 44MHz. The implemented MODEM architecture shows lower BER compared with the Harris HSP3824.

• BMB Reports
• /
• v.39 no.5
• /
• pp.469-478
• /
• 2006

Vascular endothelial growth factor (VEGF)-A, a major regulator for angiogenesis, binds and activates two tyrosine kinase receptors, VEGFR1 (Flt-1) and VEGFR2 (KDR/Flk-1). These receptors regulate physiological as well as pathological angiogenesis. VEGFR2 has strong tyrosine kinase activity, and transduces the major signals for angiogenesis. However, unlike other representative tyrosine kinase receptors which use the Ras pathway, VEGFR2 mostly uses the Phospholipase-$C{\gamma}$-Protein kinase-C pathway to activate MAP-kinase and DNA synthesis. VEGFR2 is a direct signal transducer for pathological angiogenesis including cancer and diabetic retinopathy, thus, VEGFR2 itself and the signaling appear to be critical targets for the suppression of these diseases. VEGFR1 plays dual role, a negative role in angiogenesis in the embryo most likely by trapping VEGF-A, and a positive role in adulthood in a tyrosine kinase-dependent manner. VEGFR1 is expressed not only in endothelial cells but also in macrophage-lineage cells, and promotes tumor growth, metastasis, and inflammation. Furthermore, a soluble form of VEGFR1 was found to be present at abnormally high levels in the serum of preeclampsia patients, and induces proteinurea and renal dysfunction. Therefore, VEGFR1 is also an important target in the treatment of human diseases. Recently, the VEGFR2-specific ligand VEGF-E (Orf-VEGF) was extensively characterized. Interestingly, the activation of VEGFR2 via VEGF-E in vivo results in a strong angiogenic response in mice with minor side effects such as inflammation compared with VEGF-A, suggesting VEGF-E to be a novel material for pro-angiogenic therapy.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.10 no.1
• /
• pp.99-108
• /
• 1990

A Synthetic Unit Hydrograph Method was investigated for representation of the effective rainfall-direct runoff hydrograph by using a Geomorphologic Instantaneous Unit Hydrograpb(GIUH) proposed by Gupta et al(1980). The response function of the basin was assumed to be the two-parameter gamma probability density function. The physical parameters of the response function(Nash Model) was determined by using the regression eqs. were parameterized in terms of Horton order ratios and the relations between the basin lag time and time-scale parameter. The capability of the Synthetic Unit Hydrograph to the real basin was tested for the Pyungchang river basin and Wi Stream basin, and its capability to reproduce the hydrologic response was investigate and compared with the Moment Method and the Least Square Method used incomplete gamma function. The representation of the peak flow, the time to peak and the hydrographs the derived Synthetic Unit Hydrograph were tested on some obseved flood data and showed promising, and it was approved to be used for prediction of the ungaged basins.

• Journal of architectural history
• /
• v.15 no.2
• /
• pp.39-54
• /
• 2006

Focusing on the emergence of the basic course in American schools of architecture, in particular Gyorgy Kepes' courses at MIT, this paper studies the transformation of architectural pedagogy during the years after World War II. Kepes centered his architectural pedagogy on the picture plane, which was to function as the primary media for applying the principles of Gestalt psychology, that is the identification of the whole and its parts and the reciprocity between the internal human organism and the outside world. Kepes hence introduced a set of unconventional visual practices that were not readily assimilated to architectural conventions. Paralleling the establishment of the basic course, MIT also formulated a functionalist and spatial pedagogy with its two initial design studios, courses 4.721 and 4.722. These studios shared the notion that architectural design evolved from the inside toward the outside, an idea that took hold not just in the pragmatic environment of MIT's studios but also in conservative academic programs as well as in popular magazines, picture books, and exhibitions for the consumer public. The architectural surface became inseparable from the objects of art, furniture, and design, all of which were to be the generators of space. Hence, during the 1950s, the architectural surface provided a specific locus of intersection between the visual fundamentals of the basic course and the working principles of architectural design. Kepes, however, had by this time become disillusioned with architecture's potential as the medium of unity. Though he maintained the Gestalt logic of identity, he expanded it toward the goal of grander synthesis of society and consciousness freeing himself from the constraints of disciplinary instruction. In the case of Kepes, the mediating role of the picture plane was foregone in a regressive turn toward a primal, innocent, and direct experience.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.12
• /
• pp.3553-3558
• /
• 2014

The reduced graphene oxide(rGO)/aluminum phosphate($AlPO_4$)-coated $LiMn_{1.5}Ni_{0.5}O_4$ (LMNO) cathode material has been developed by hydroxide precursor method for LMNO and by a facile solution based process for the coating with GO/$AlPO_4$ on the surface of LMNO, followed by annealing process. The amount of $AlPO_4$ has been varied from 0.5 wt % to 1.0 wt %, while the amount of rGO is maintained at 1.0 wt %. The samples have been characterized by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. The rGO/$AlPO_4$-coated LMNO electrodes exhibit better cyclic performance compared to that of pristine LMNO electrode. Specifically, rGO(1%)/$AlPO_4$(0.5%)- and rGO(1%)/$AlPO_4$(1%)-coated electrodes deliver a discharge capacity of, respectively, $123mAhg^{-1}$ and $122mAhg^{-1}$ at C/6 rate, with a capacity retention of, respectively, 96% and 98% at 100 cycles. Furthermore, the surface-modified LMNO electrodes demonstrate higher-rate capability. The rGO(1%)/$AlPO_4$(0.5%)-coated LMNO electrode shows the highest rate performance demonstrating a capacity retention of 91% at 10 C rate. The enhanced electrochemical performance can be attributed to (1) the suppression of the direct contact of electrode surface with the electrolyte, resulting in side reactions with the electrolyte due to the high cut-off voltage, and (2) smaller surface resistance and charge transfer resistance, which is confirmed by total polarization resistance and electrochemical impedance spectroscopy.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.163-163
• /
• 2017

A deletion analysis of the Oryza sativa dihydroflavonol reductase (DFR) promoter defined a 25 bp region (-386 to -362) sufficient to confer pericarp-specific expression of ${\beta}$ -glucuronidase(GUS) reporter gene in transgenic rice. Site-specific mutagenesis of these conserved sequences and subsequent expression analysis in calli which transiently expressed the mutated promoter::GUS gene showed that both bHLH (-386 to -381) and Myb (-368 to -362) binding sites in the DEL3 (-440 to 70) promoter were necessary for complete expression of the GUS gene including the tissue-specific expression of DFR::GUS gene. The GUS gene was expressed well in the mutated Myb (-368 to -362) binding site, but not as strong as in normal condition, implying that the Myb is also necessary to express GUS gene fully. Also, we found the non-epistatic relation between Rc and DFR. There were no changes of expression patterns GUS under the Rc and rc genotypes. Thus, DFR expression might be independent of the presence of functional Rc gene and suggested that Rc and Rd (DFR) share the same pathway controlling the regulation of flavonoid synthesis but not a direct positive transcriptional regulator of DFR gene.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.8
• /
• pp.3507-3511
• /
• 2014

Background: The prostaglandin-endoperoxide synthase 2 [PTGS2, commonly known as cyclooxygenase-2 (COX-2)] is an enzyme induced by proinflammatory stimuli that is often overexpressed in malignant tissue and involved in the synthesis of prostaglandins and thromboxanes, regulators of processes such as inflammation, cell proliferation, and angiogenesis, all relevant for cancer development. We investigated whether a functional genetic polymorphism, rs5277, in COX-2 may have a risk-modifying effect on sporadic colorectal cancer in an Iranian population. Materials and Methods: We conducted a case-control study on 167 patients with colorectal cancer and 197 cancer-free controls in Taleghani Hospital in Tehran, Iran, between 2007 and 2011. Peripheral blood samples of both groups were processed for DNA extraction and genotyping of the COX-2 gene polymorphism (rs5277) using PCR-RFLP. RFLP results were confirmed by direct sequencing. Logistic regression analysis was performed to calculate the adjusted odds ratio (OR) and 95% confidence interval (95% CI). Results: There was no significant difference in the distribution of COX-2 gene rs5277 polymorphism genotype and the allelic form, among CRC patients compared with the healthy control group (p: 0.867). Conclusions: Our results suggest that rs5277 polymorphism in COX2 could not be a good prognostic indicator for patients with CRC.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.14 no.4
• /
• pp.93-103
• /
• 2006

Biogas is a byproduct after anaerobic digestion of organic materials and has been used as an energy source for heating and generating electricity. Demands of methanol for fuel mixed with gasoline and reactant in biodiesel production are steadily being increased. In this review, we summarized recent advancements in direct partial oxidation of methane to methanol with the brief history of methanol synthesis. The steam reforming and the catalytic oxidation of methane to methanol were compared, the former of which are mainly used in industrial scale and the latter in a stage of research and development. On the basis of this review, the possibility of methanol conversion from biogas was proposed in the aspects of the technological feasibility and the economical practicability.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.12
• /
• pp.1309-1316
• /
• 2011

This paper presents a high-speed RNA microextractor for the direct isolation of RNA from blood lysate using magnetic oligo(dT) beads. The extraction is performed through lateral magnetophoresis, which is induced by a ferromagnetic wire array inlaid. With this RNA microextractor, more than 80% of the magnetic beads could be separated at a flow rate up to 20 ml/h, and the overall extraction procedure was completed within 1 min. The absorbance ratio of RNA to protein(A260/A280) was greater than 1.7, indicating that the extraction technique yields pure RNA. The feasibility of using this technique in reverse transcription polymerase chain reaction procedures was investigated by cDNA synthesis and PCR processes. The results confirmed that the RNA microextractor is a practical device for easy, fast, and high-precision RT-PCR using minimal amounts of reagent.