• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.9
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• pp.108-116
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• 2009

In this paper, we develop an ELM(Extreme Learning Machine) based short-tenn water demand prediction algorithm which solves overfitting problem of MLP(Multi Layer Perceptron) and has quick training time. To show effectiveness of proposed method, we analyzed time series data collected in A water treatment plant at Chung-Nam province during $2007{\sim}2008$ years and used the selected data for the verification of developed algorithm. According to the experimental results, MLP model showed 5.82[%], but the proposed ELM based model showed 5.61[%] with respect to MAPE, respectively. Also, MLP model needed 7.57s training time, but ELM based model was 0.09s. Therefore, the proposed ELM based short-term water demand prediction model can be used to operate the water treatment plant effectively.

• Korean Journal of Materials Research
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• v.19 no.9
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• pp.462-467
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• 2009

The Charge Trap Flash (CTF) memory device is a replacement candidate for the NAND Flash device. In this study, Pt/$Al_2O_3/La_2O_3/SiO_2$/Si multilayer structures with lanthanum oxide charge trap layers were fabricated for nonvolatile memory device applications. Aluminum oxide films were used as blocking oxides for low power consumption in program/erase operations and reduced charge transports through blocking oxide layers. The thicknesses of $SiO_2$ were from 30 $\AA$ to 50 $\AA$. From the C-V measurement, the largest memory window of 1.3V was obtained in the 40 $\AA$ tunnel oxide specimen, and the 50 $\AA$ tunnel oxide specimen showed the smallest memory window. In the cycling test for reliability, the 30 $\AA$ tunnel oxide sample showed an abrupt memory window reduction due to a high electric field of 9$\sim$10MV/cm through the tunnel oxide while the other samples showed less than a 10% loss of memory window for $10^4$ cycles of program/erase operation. The I-V measurement data of the capacitor structures indicated leakage current values in the order of $10^{-4}A/cm^2$ at 1V. These values are small enough to be used in nonvolatile memory devices, and the sample with tunnel oxide formed at $850^{\circ}C$ showed superior memory characteristics compared to the sample with $750^{\circ}C$ tunnel oxide due to higher concentration of trap sites at the interface region originating from the rough interface.

• Journal of the Korean Ceramic Society
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• v.43 no.2 s.285
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• pp.85-91
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• 2006

Electron Beam Physical Vapor Deposition (EB-PVD) was applied to fabricate a thin film YSZ electrolyte with large area on the porous NiO-YSZ anode substrate. Microstructural and thermal stability of the as-deposited electrolyte film was investigated via SEM and XRD analysis. In order to obtain an optimized YSZ film with high stability, both temperature and surface roughness of substrate were varied. A structurally homogeneous YSZ film with large area of $12\times12\;cm^2$ and high thermal stability up to $900^{\circ}C$ was fabricated at the substrate temperature of $T_s/T_m$ higher than 0.4. The smoother surface was proved to give the better film quality. Precise control of heating and cooling rate of the anode substrate was necessary to obtain a very dense YSZ electrolyte with high thermal stability, which affords to survive after post heat treatment for fabrication a cathode layer on it as well as after long time operation of solid oxide fuel cell at high temperature.

• Journal of Periodontal and Implant Science
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• v.26 no.3
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• pp.655-668
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• 1996

The change in vascular adhesion molecule expression and number of infiltrating leukocytes were investigated irnmunohistochemically in clinically healthy and inflammed gingiva. Monoclonal antibodies to ICAM-1, VCAM-1 and E-cadherin were used to identify positive vessels and leukocyte within gingival biopsies. 10 healthy gingiva and 30 inflammed gingiva was resected by clinical crown lengthening and modified Widman flap operation, respectively. Leukocyte entry into tissues at sites of inflammation is controlled by the interaction between adhesion molecule and endothelium. Because of rapid and severe destructive periodontal disease that is remarkable leukocyte adhesion deficiency, it is very important to unerdstand the mechanism of host defence against periodontal disease. The purpose of this investigation was the characterization of the presence and distribution of the adhesion molecule(ICAM-1, VCAM-1 and Evcadherin) in inflammatory gingival tissues compared to clinically healthy gingiva. The results were as followed; 1. ICAM-1 was distributed on basal layer, endothelium and mononuclear cells 10 healthy gingiva but inflammed gingiva was observed stronger stain than healthy gingiva. 2. Rare expression was observed in both group but few positive VCAM-1 cells were investigated in inflammatory gingival tissues 3. E-cadherin was expressed in only epithelium and reduced expression was observed in inflammatory gingival tissues. ICAM-1, VCAM-1 showed more expression in inflammatory tissues compared to healthy gingiva. Conversely, E-cadherin revealed a opposite result. These finding demonstrate a characteristic distribution and degree of adhesion molecule in healthy and inflammatory gingival tissues. But it is suggested that more detail study be progressive associated with leukocyte adhesion molecule to determine characterization of periodontal disease.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.56-62
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• 2001

The investigation was carried out to analyze the generation and the composition of landfill gas generated from inserted pipe wells into the underground by boring operation and also study the undecomposed waste characteristics by open-cut test at S. waste landfill site in Pusan city. Pilot test was conducted for stabilization. The experimental results from this study were summerized as follows. ; Since COD matter was easuer decomposed than COD matter for continuously biological stabilization in underground, it seemed that BOD and CO $D_{Mn}$ were in the range of 854~4,813mg/$\ell$ and 1,156~6,977mg/$\ell$ and their ratio were generally as high as 0.55~0.74. As C $H_4$ compositions of generated gas were measured in the range of 37.36~60.1%, we could know that C $H_4$ gas was actively generated. Organic matters by open-cut test averaged 13.4~16.6% at each landfill layer, and considering rate of combustible compositions(36.2~66.5%) for landfilling wastes, they have been actively decomposed. The measured and theoretical values of generated gas in waste landfill site were almost similar to C $H_4$ 50.0% and 53.4%, $CO_2$ 39.63% and 45.24%, and after 0.5$^{\circ}C$ with heavy depth and long landfill period. From the results of pilot test for stabilization, after 180 days organic matters were actively decomposed beyond 2.2 times in facultative aerobic lystimeter(B) to exsiting anaerobic lysimeter(A). Therefore, it seemed that landfill site was of benefical to the conversion of facultative aerobic for stabilization.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.737-746
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• 2017

In 2017, amid changes in the security market such as integrated security (IS) and convergence security (CS), a variety of security paradigms in terms of operation and management have been suggested. Rather than changing existing network infrastructure and bringing about fluid, multi-dimensional changes, these solutions and technologies focus entire security capacity on a primary protection, leading to network infrastructure suffering from unexpected inherent violations and problems in a continued manner. Therefore, it is time to propose and develop a flexible network section that can protect from attacks of similar pattern and concentrated traffic attacks by applying a new concept of WB (Water-Bubble) to network infrastructure and analyzing on the basis of experiment and installation. Methodology of the WB-based highly secure flexible network section proposed in this study is expected to provide materials for studies on how to achieve network section security taking into account three major limitations and security standards: fluidity, unpredictability, and non-area scalability by contact point ratio, by changing a network area predicted to be the final target of attack into resonant network section (area) with flexible area changes.

• Journal of Sensor Science and Technology
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• v.27 no.3
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• pp.204-208
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• 2018

Monolayer graphene grown via chemical vapor deposition (CVD) is recognized as a promising material for sensor applications owing to its extremely large surface-to-volume ratio and outstanding electrical properties, as well as the fact that it can be easily transferred onto arbitrary substrates on a large-scale. However, the Dirac voltage of CVD-graphene devices fabricated with transferred graphene layers typically exhibit positive shifts arising from transfer and photolithography residues on the graphene surface. Furthermore, the Dirac voltage is dependent on the channel lengths because of the effect of metal-graphene contacts. Thus, large and nonuniform Dirac voltage of the transferred graphene is a critical issue in the fabrication of graphene-based sensor devices. In this work, we propose a fabrication process for graphene field-effect transistors with Dirac voltages close to zero. A vacuum annealing process at $300^{\circ}C$ was performed to eliminate the positive shift and channel-length-dependence of the Dirac voltage. In addition, the annealing process improved the carrier mobility of electrons and holes significantly by removing the residues on the graphene layer and reducing the effect of metal-graphene contacts. Uniform and close to zero Dirac voltage is crucial for the uniformity and low-power/voltage operation for sensor applications. Thus, the current study is expected to contribute significantly to the development of graphene-based practical sensor devices.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.11
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• pp.921-930
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• 2013

Satrec Initiative successfully developed and verified a high-resolution electro-optical camera system, EOS-D Ver.1.0. We designed this system to give improved spatial and radiometric resolution compared with EOS-C series systems. The thermal control subsystem (TCS) of the EOS-D Ver.1.0 uses heaters to meet the opto-mechanical requirements during in-orbit operation and uses different thermal coatings and multi-layer insulation (MLI) blankets to minimize the heater power consumption. Also, we designed and verified a refocusing mechanism to compensate the misalignment caused by moisture desorption from the metering structure. We verified the design margin and workmanship by conducting the qualification level thermal vacuum test. We also performed the verification of thermal math model (TMM) by comparing with thermal balance test results. As a result, we concluded that it faithfully represents the thermal characteristics of the EOS-D Ver.1.0.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.526-530
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• 2010

Purpose: With the recent recognition of the importance of soft-tissue fillers, fat grafting has been assumed an increasingly important role as both an adjunctive and a primary procedure in aesthetic and reconstructive surgery. The main problem in achieving long-term soft-tissue augmentation is partial absorption of the injected fat and hence the need for overcorrection and re-injection. The purpose of this study is to improve the viability of the injected fat by the use of Lipo-PGE1. Methods: Human adipose tissue, obtained by suctionassisted lipectomy, was re -injected into the subcutaneous layer in the scalp of ICR mice. Lipo-PGE1 ($0.5{\mu}g$/kg) was injected intravenously in experimental group for 7 days from the operation day and saline was injected in control group. There were 5 animals in each group. The animals were euthanized 4 weeks after the procedure. Graft weight and volume were measured and histologic evaluation was performed. Result: Histologic analysis demonstrated significantly less cyst formation and less inflammatory reaction in the group treated with Lipo-PGE1. No significant difference was found between the groups regarding graft volume or the other histologic parameters investigated. Significant differences were demonstrated in microvascular density count. Conclusion: Less cyst formation, less inflammation, more angiogenesis indicating improved quality of the injected fat can be obtained by the addition of Lipo-PGE1. Further studies of various dosages of Lipo-PGE1 and their long-term effect are required before these encouraging results could be applied clinically.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3910-3922
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• 2000

Current power systems are distributed geographically and operated in the form of Energy Management System(EMS)/ Supervision Control and Data Acquisition(SCADA) with the aid of computers and communications. Recently a variety of utilities have had interests in using inforrration technology to bring the efficiency and low operational costs. There is also a trend to integrdte the production, transmission, distribution and management/control of power into one and unified distributed system. To this end, Electric Power Hesearch Institute(EPRI) announced a new standard communication protocol called Inter-Control Center Protocol(ICCP).ICCP specifies the use of Manufacturing Message Specification(MMS) for services required by rccr in application layer and supports the communications between heterogeneous control centers. This paper presents the characteristics of MMS,ICCP and their relationship. Futherrnore, we implement the basic functional blocks of ICCP using MMS services under TCI/IP environments. Finally, we model a simple power system and apply the rccp protocol to this system in a window-based scheme, and finally show the operation and validation of this protocol.