• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.199-199
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• 2011

Recently, Thin film transistors (TFTs) with amorphous oxide semiconductors (AOSs) can offer an important aspect for next generation displays with high mobility. Several oxide semiconductor such as ZnO, $SnO_2$ and InGaZnO have been extensively researched. Especially, as a well-known binary metal oxide, tin oxide ($SnO_2$), usually acts as n-type semiconductor with a wide band gap of 3.6eV. Over the past several decades intensive research activities have been conducted on $SnO_2$ in the bulk, thin film and nanostructure forms due to its interesting electrical properties making it a promising material for applications in solar cells, flat panel displays, and light emitting devices. But, its application to the active channel of TFTs have been limited due to the difficulties in controlling the electron density and n-type of operation with depletion mode. In this study, we fabricated staggered bottom-gate structure $SnO_2$-TFTs and patterned channel layer used a shadow mask. Then we compare to the performance intrinsic $SnO_2$-TFTs and doping hafnium $SnO_2$-TFTs. As a result, we suggest that can be control the defect formation of $SnO_2$-TFTs by doping hafnium. The hafnium element into the $SnO_2$ thin-films maybe acts to control the carrier concentration by suppressing carrier generation via oxygen vacancy formation. Furthermore, it can be also control the mobility. And bias stability of $SnO_2$-TFTs is improvement using doping hafnium. Enhancement of device stability was attributed to the reduced defect in channel layer or interface. In order to verify this effect, we employed to measure activation energy that can be explained by the thermal activation process of the subthreshold drain current.

• Korean Journal of Materials Research
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• v.13 no.2
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• pp.126-132
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• 2003

In order to evaluate the corrosion resistance at the anode side separator for molten carbonate fuel cell, STS316 and SACC-STS316 (chromium and aluminum were simultaneously deposited by diffusion into STS316 authentic stainless steel substrate by pack-cementation process) were applied as the separator material. In case of STS316, corrosion proceeded via three steps ; a formation step of corrosion product until stable corrosion product, a protection step against corrosion until breakaway occurs, a advance step of corrosion after breakaway. Especially, STS316 would be impossible to use the separator without suitable surface modification because of rapid corrosion rate after formation of corrosion product, occurs the severe problem on stability of cell during long-time operation. Whereas, SACC-STS316 was showed more effective corrosion resistance than the present separator, STS316 due to the intermetallic compound layer such as NiAl, Ni3Al formed on the surface of STS316 specimen. And it is anticipated that, in order to use SACC-STS316 alternative separator at the anode side, coating process, which can lead to dense coating layer, has to be developed, and by suitable pre-treatment before using it, very effective corrosion resistance will be achieved.

• Korean Journal of Acupuncture
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• v.28 no.4
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• pp.17-28
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• 2011

Objectives : Burn is the important adverse effect of the moxibustion treatment. This research does with the purpose to utilize as basic data which the results of histological observation of the burn tissue which generates when operating various commercial indirect moxa (CIM) on the skin, evaluate the burn because of the surgical operation. Methods : It operated 6 kinds of CIM on the depilated abdomen of the rat. By using the H-E staining and TUNEL assay, the image was observed and analyzed. Results : It could be the moxibustion medical treatment using the CIM generated in the first degree burn until the third degree. And in some case, burn has not generated. By using the H-E stain, the second-degree burn and third degree was observed, and it was observed the first degree burn by using TUNEL assay. In the first degree burn, TUNEL reaction in the epidermal layer was confirmed. The damage to the dermal layer was observed in more than 2 degree burn. In the third degree, the tissue degeneration to the subcutaneous fat was observed but the thickness of the skin tissue was not observed. Conclusions : Basic data classifying the burn generated by the CIM treatment through the histological observation of the burn tissue caused by the CIM treatment were built according to this research result.

• Journal of Digital Contents Society
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• v.11 no.1
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• pp.91-97
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• 2010

Flash memory has been used by many digital devices for data storage, exploiting the advantages of non-volatility, low power, stability, and so on, with the help of high integrity, large capacity, and low price. As the fast growing popularity of flash memory, the density of it increases so significantly that its entire address mapping table becomes too big to be stored in SRAM. This paper proposes the associated page address cache with an efficient table management scheme for hybrid flash translation layer mapping. For this purpose, all tables are integrated into a map block containing entire physical page tables. Simulation results show that the proposed scheme can save the extra memory areas and decrease the searching time with less 2.5% of miss ratio on PC workload and can decrease the write overhead by performing write operation 33% out of total writes requested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.96-103
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• 2009

This paper presents a L3 mobile terminal platform of the mobile terminal system which is a subsystem of HMm(Hig-speed Mobile Multimedia) system, which layer 3 control protocols such as RC(Radio Control), SC(Session Control), MC(Mobility Control) and application services such as VOD, FTP, VoIP for a multimedia mobile terminal are implemented on. The hardware platform is based on PXA255 and supports various interfaces and multimedia devices, and under the platform, an embedded Linux generated by the self-maden cross-toolchain, L3 control protocols and application programs were installed. The operation of HMm system under the HMm testbed has shown that this platform successfully supported SIP services, web browsing services, streaming services and etc as well as call processing. It could be the reference of the upcoming Fourth-Generation mobile terminal which the multimedia functionality will be enforced.

• Journal of Wetlands Research
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• v.16 no.3
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• pp.347-353
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• 2014

This work was performed to find the effect of operation parameters on the permeate flux through the activated sludge dynamic layer, and to indicate the relationship between the water quality of supernatant and flux based on the results. Since the effluent can be obtained through steady and stable formation of cake layer in the bio-filter media system, it is an important subject to keep and control microbes with activated state in the bio-reactor. Filtration resistance was drastically increased at more than 18000mg/L of MLSS. With filtration time continued, the flux was gradually decreased and the water qualities of supernatant monitored by turbidity and TOC were also deteriorated. This phenomenon indicated that the organic materials generated by microbes and accumulated in the reactor might affect the flux in the system. In addition, the decrease of flux was simultaneously observed in the sludge volume index. When SVI was controlled from 150 to 250, the flux was also decreased. The proper aeration time was recommended to 30 to 60 seconds in this system. In order to operate this system steadily, therefore, the control of water quality of supernatant and SVI should be proceeded.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03a
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• pp.8-10
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• 2010

We report the enhancement of hole injection using thermally evaporated $CuO_x$ layer between Ag anode and 4,4'-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl ($\alpha$-NPD) in top-emitting organic light-emitting diode (TEOLED). The operation voltage at the current density of $1mA/cm^2$ of TEOLEDs decreased from 6.2 V to 5.0 V as the $CuO_x$ layer inserted between Ag and $\alpha$-NPD. $\alpha$-NPD was deposited in situ on Ag/$CuO_x$ and Ag anodes, and their interface dipole energies were quantitatively determined using synchrotron radiation photoemission spectroscopy. The dipole energy of Ag/$CuO_x$ was lower by 0.05 eV even though Ag/$CuO_x$ had a higher work function. The work function of Ag/$CuO_x$ is higher by 0.53 eV than that of Ag, resulting in a decrease of the turn-on voltage via reduction of hole injection barrier.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.343-343
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• 2002

This study examines the influence of long-range transport of dust particles and air pollutants on both local/regional DMS oxidation chemistry and the distribution of sulfur compounds at Jeju Island (33.17$^{\circ}$ N. 126.10$^{\circ}$ E) during the Asian dust-storm(ADS) period in April 2001. The atmospheric concentrations of these sulfur species were measured at a ground station on Jeju Island. Korea as Part of the ACE-Asia intensive operation. Three ADS events were observed during the periods of 10-12, 13-14. and 25-26 April. respectively. The concentrations of DMS and CS$_2$ were higher during the ADS period than during the non-Asian-dust-storm (NADS) period. Conversely. a difference in SO$_2$ levels during the ADS period was not distinguishable from those during the NADS period. The diurnal variation pattern of DMS observed was largely different from that in the remote marine boundary layer. DMS loss by NO$_3$ in the atmospheric boundary layer was dominant due to significantly high NOx levels influenced by the long-range transport of pollutants from East Asia to Jeju Island The DMS maximum during the ADS period was observed in the late afternoon. The oceanic fluxes of DMS during the ADS and NADS periods were estimated to be 5.7$\pm$2.3 and 2.9 (+2.8/-1.5) mole m$^{-2}$ day$^{-1}$ . respectively. The contribution of oxidized DMS to SO$_2$ levels at Jeju Island during the study period was found to be insignificant.

• Journal of Electrochemical Science and Technology
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• v.8 no.1
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• pp.7-14
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• 2017

This study aims to examine the influences of substrates/diffusion layers (DL) and oxygen reduction reaction catalysts ($M_{ORR}$) on the performance of $M_{ORR}/IrO_2$/DL-type bifunctional oxygen electrodes for use in polymer electrolyte membrane (PEM)-type unitized regenerative fuel cells (URFC). The $M_{ORR}/IrO_2$/DL electrodes were prepared via two sequential steps: anodic electrodeposition of $IrO_2$ on various DLs and fabrication of $M_{ORR}$ layers (Pt, Pd, and Pt-Ru) by spraying on $IrO_2/DL$. Experiments using different DLs, with Pt as the $M_{ORR}$, revealed that the roughness factor of the DL mainly determined the electrode performance for both water electrolyzer (WE) and fuel cell (FC) operations, while the contributions of porosity and substrate material were insignificant. When Pt-Ru was utilized as the $M_{ORR}$ instead of Pt, WE performance was enhanced and the electrode performance was assessed by analyzing round-trip efficiencies (${\varepsilon}_{RT}$) at current densities of 0.2 and $0.4A/cm^2$. As a result, using Pt-Ru instead of Pt alone provided better ${\varepsilon}_{RT}$ at both current densities, while Pd resulted in very low ${\varepsilon}_{RT}$. Improved efficiency was related to the additional catalytic action by Ru toward ORR during WE operation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1096-1101
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• 2004

By a tremendous expansion of Internet users, there's a number effects that cause the phenomenon of bottlenecked switching packets from routers. In order to tear down this problem, distributed system is applicable to almost every highly performed router systems. The main processor of distributed system, which manages routing table, commands IPC to delivering the forwarding table line processor that eases functionalities of the router. This makes the system having wired-speed forwarding function based on the hardware so that the performance of the network can be enhanced. Therefore, IPC, which assign a part of router, is necessary to exchange data smoothly and the constitution of IPC using Ethernet is widely adapted as a method for saving investment. In this paper, R-IPC mechanism improve the packet-processing rate over 10% through changed from defect of conventional Ethernet IPC, that is, 2 layer processing to TCP/IP or UDP/ IP into 1 layer processing for efficient packet forwarding.