• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.469-472
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• 1999

CeO$_2$ thin films have used in wide applications such as SOI, buffer layer, antirflection coating, and gate dielectric layer. CeO$_2$takes one of the cubic system of fluorite structure and shows similar lattice constant (a=0.541nm) to silicon (a=0.543nm). We investigated CeO$_2$films as buffer layer material for nonvolatile memory device application of a single transistor. Aiming at the single transistor FRAM device with a gate region configuration of PZT/CeO$_2$ /P-Si , this paper focused on CeO$_2$-Si interface properties. CeO$_2$ films were grown on P-type Si(100) substrates by 13.56MHz RF magnetron sputtering system using a 2 inch Ce metal target. To characterize the CeO$_2$ films, we employed an XRD, AFM, C-V, and I-V for structural, surface morphological, and electrical property investigations, respectively. This paper demonstrates the best lattice mismatch as low as 0.2 % and average surface roughness down to 6.8 $\AA$. MIS structure of CeO$_2$ shows that breakdown electric field of 1.2 MV/cm, dielectric constant around 13.6 at growth temperature of 200 $^{\circ}C$, and interface state densities as low as 1.84$\times$10$^{11}$ cm $^{-1}$ eV$^{-1}$ . We probes the material properties of CeO$_2$ films for a buffer layer of FRAM applications.

• Journal of the Korean Ceramic Society
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• v.37 no.7
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• pp.705-712
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• 2000

In this study, the dispersion stability of CeO2 based complex oxide was studied, and density, porosity, and microstructure of green body were investigated using colloid surface chemistry to manufacture the Gd2O3 doped CeO2 solid electrolyte in an aqueous system. To prepare the stable slurry for slip casting, the dispersion stability was examined as a function of pH using ESA(electrokinetic sonic anplitude) analysis. The dynamic mobility of particles was enhanced with anionic and cationic dispersant were added the amount of 0.5wt% respectively, but pH value in slurries didn't move to below 6.0 because of the influence of dopants. This phenomenon also appeared in the CeO2-Y2O3 and CeO2-Sm2O3 systems, so it could be inferred that rare earth dopants such as Gd2O3, Sm2O3 and Y2O3 not only have the similar motion with changing pH in an aqueous system but also can be dissolved in the range of pH 6.0∼6.5. In CeO2-Gd2O3 system, when the anionic dispersant was added the amount of 0.5wt% and pH value in slurries was fixed at 9.5, the green body density was 4.07g/㎤, and the relative density of sintered body was 95.2%. It could be inferred from XRD analysis that Gd3+ substituted into Ce4+ site because there was no free Gd2O3 peak.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.193-198
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• 2015

Ceria supported on various commercial $TiO_2$ catalysts were prepared by wet-impregnation method. We confirmed that the correlation between physicochemical properties of $TiO_2$ supports and SCR activities. Physicochemical properties of the various $TiO_2$ were evaluated using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), and pH analysis. Ce/Ti catalyst exhibited different SCR activities with respect to physicochemical properties of $TiO_2$. An excellent activity was obtained as the surface area of $TiO_2$ increased. In the case of CeOx surface density, the excellent activity in a range of $2.5{\sim}14.5CeOx/nm^2$ was achieved and the activity tended to decrease above $14.5CeOx/nm^2$. The O/Ti mole ratio of $TiO_2$ in the range of 1.32 to 1.79 showed an excellent SCR activity. It was also confirmed that the pH of the $TiO_2$ has no effects on the SCR activity. In order to achieve excellent SCR activities, ceria oxide should be supported on $TiO_2$ possessing a high specific surface area and certain O/Ti mole ratio. In addition, the catalyst with the low CeOx surface density resulted from the high dispersed ceria oxide should be prepared.

• Korean Journal of Medicinal Crop Science
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• v.28 no.4
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• pp.276-286
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• 2020

Background: Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with multiple metabolic disorders. The medicinal plant Curcuma longa L. is widely distributed in Asia and has been used to treat a spectrum diseases in clinical practice. To date, there are inadequate reports of the effects of C. longa 50% EtOH extract (CE) on NAFLD. Therefore, in this study, we evaluate the CE on an NAFLD animal and elucidate the mechanism of action. Methods and Results: C57BL/6J mice fed a methionine-choline deficient diet (MCD) were treated with CE or milk thistle, and changes in inflammation and stetosis were assessed. Experimental animals were divided into six group (n = 10); Normal, MCD, MCD + CE 50 mg/kg/day (CE 50), MCD + CE 100 mg/kg/day (CE 100), MCD + CE 150 mg/kg/day (CE 150), and the Control, MCD + Milk thistle 150 mg/kg/day (MT 150). Body weight, liver weight, liver function, and histological changes were assessed in experimental animals. Quantitative real-time polymerase chain reaction and western blot analyses were performed on samples collected after 4 weeks of treatment. We observed that CE administration improved MCD-diet-induced lipid accumulation, and triglyceride (TG) and total cholesterol (TC) levels in serum. Treatment with CE also decreased hepatic lipogenesis through modulation of the sterol regulatory element binding protein-1 (SREBP-1), CCAAT-enhancer binding protein α (C/EBPα), fatty acid synthase (FAS), and peroxisome proliferator-activated receptor γ (PPARγ) expresion. In addition, the use of CE increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and inhibited the up-regulation of toll-like receptor (TLR)-2 and TLR-4 signaling and the production of inflammatory mediators. Conclusions: In this report, we observed that CE regulated lipid accumulation in an MCD dietinduced NAFLD model by decreasing lipogenesis. These data suggeste that CE could effectively protect mice against MCD-induced NAFLD, by inhibiting the TLR-2 and TLR-4 signaling cascades.

• The Journal of Information Technology
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• v.8 no.4
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• pp.91-102
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• 2005

In this paper, development of embedded system based on Windows CE 5.0 which released recently is studied. Embedded softwares for the target board using S3C2410A SOC based on ARM920T core are composed of (1) BSP(Board Support Package) contains an OAL(OEM Adaptation Layer) which includes a boot loader for initializing and customizing target hardware, device drivers, and a corresponding set of configuration files (2) Windows CE 5.0 kernel (3) SDK and MP3 test application. Particularly, PB(Platform Builder) provides the efficient functions to build, test and debug the BSP and CE kernel. It is looked forward to being widely spread that Windows CE 5.0 will be utilized at smart devices such as PMP, CNS and DMB phone which inevitably require a display device.

• Journal of Applied Reliability
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• v.11 no.4
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• pp.419-432
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• 2011

In order to distribute machinery to European Union, it is mandatory to get CE marking to ensure the machinery is safe and reliable. The EHSR(Essential Health and Safety Requirements) of the EC Machinery Directive requires the machinery to be designed and manufactured to prevent from any dangerous situation. This study presents a case of CE Certification in Back Cover Nut Insert Machine and introduces an improvement method of product safety and reliability. This study also presents how to eliminate the deficiencies in design and manufacturing, and the process of applying EHSR for CE Marking.

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.107-109
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• 1998

The $SnO_2$, Sn-doped $In_2O+3\; and \;Ce-doped\; TiO_2$ films have been prepared by RF sputtering method, and their opto-electrochemical properties were investigated in view of the applicability as counter electrodes in the electrochromic window system. These oxide films could reversibly intercalate $Li^+$ ions owing to the nanocrystalline texture, but remained colorless and transparent. The high transmittance of the lithiated films could be attributed to the prevalence of the $Sn^{4+}/Sn^{2+}\; and\; Ce^{4+}/Ce^{3+}$ redox couples having 5s and 6s character conduction bands, respectively. For the Ce-doped $TiO_2$ film, $(TiO_2)_{1-x}(CeO_2)_x$, an optimized electrochemical reversibility was found in the film with the composition of x = 0.1.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.85.2-85.2
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• 2014

The origin of the Korean Screen Planisphere with both Traditional and New Star-Charts, made by Korean Astronomers in the Royal Astronomical Bureau of the Joseon Dynasty by adopting the knowledge of the European astronomy, is investigated by analyzing its inscriptions and star charts. The considerations on both the changes in notations or representations of names of asterisms and the naming taboos used in the Old-style planisphere imply that the star-chart is originated from either the Sukjong-Stele-Replica of Cheonsang-Yeolcha-Punyajido(天象列次分野之圖). The New style planisphere is just the reproduction of Huangdao-congxingtu (黃道總星圖), with the exception of the non-Chinese-traditional stars. The Huangdao-congxingtu was made in 1723 CE by Ignatius K$\ddot{o}$gler who was a Jesuit missionary and worked for the Bureau of Astronomy (欽天監) in the Qing Dyansty. I find that the star chart was imported in 1742 CE from the Qing by An Gukrin (安國麟) who was an astronomer in the Royal Astronomical Bureau of Joseon. The chart became model for the screen star-chart made in 1743 CE and now housed in Bopju temple. I found that the inscriptions are extracted from the sentences in both Xinzhi Lingtai Yixiangzhi (新製靈臺儀象志) and Qinding Yixiangkaocheng (欽定儀象考成). Korean historical records in either Daily Records of the Royal Secretariat of the Joseon Dynasty (承政院日記) or Annals of the Joseonn Dynasty (朝鮮王朝實錄) show that Xinzhi Lingtai-Yixiangzhi was imported from the Qing Dynasty in 1708 CE, and the Qinding Yixiangkaocheng was imported in 1766 CE. Thus, the Korean Screen Planisphere with both Old and New Star-charts was certainly made after 1766 CE.

• ETRI Journal
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• v.43 no.6
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• pp.966-977
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• 2021

Filterbank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) is an attractive alternative to the orthogonal frequency division multiplexing (OFDM) modulation technique. In comparison with OFDM, the FBMC-OQAM signal has better spectral confinement and higher spectral efficiency and tolerance to synchronization errors, primarily due to per-subcarrier filtering using a frequency-time localized prototype filter. However, the filtering process introduces intrinsic interference among the symbols and complicates channel estimation (CE). An efficient way to improve the CE in FBMC-OQAM is using a technique known as windowed frequency domain averaging (FDA); however, it requires a priori knowledge of the window length parameter which is set based on the channel's frequency selectivity (FS). As the channel's FS is not fixed and not a priori known, we propose a k-nearest neighbor-based machine learning algorithm to classify the FS and decide on the FDA's window length. A comparative theoretical analysis of the mean-squared error (MSE) is performed to prove the proposed CE scheme's effectiveness, validated through extensive simulations. The adaptive CE scheme is shown to yield a reduction in CE-MSE and improved bit error rates compared with the popular preamble-based CE schemes for FBMC-OQAM, without a priori knowledge of channel's frequency selectivity.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.689-692
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• 1996

The environment surrounded by industries is represented by the 3Cs : Customers, Competition, and Changes. The 3Cs drive industries to pursue external business targets such as customer's needs and marketplaces with BPR (Business Process Reengineering). BPR addresses core business process. One of these core business processes is product development. This product development process has been reengineered by the concept of CE (Concurrent Engineering). The aim of the paper is to build frameworks of CE to clarify the CE concept. This paper begins with investigating the product development process from the perspectives of three drivers: cost, quality and speed. CE frameworks are then followed. The first frmework is concerned with the CE definition and thus three keyphrases are extracted : from the outset, concurrent design and systematic approach. Concerned with the CE implementation, the second framework is composed of five components: generalist & specialist, cross-function team, enabling tools & techniques, success metrics, and total visibility. This paper concludes that the CE practice is hard to achieve because of the 'dont't-tell-them-early' attitude of upstream people, and the 'wait-and-see' attitude of downstream people. As resolution, a change management program is recommended that changes an employees mind-set. This paper also supposes computer systems which facilitate and keep automatic track of the CE process as engineered. Finally it gives a warning that computer systems alone do not guarantee success without being preceded by process re-engineering.