• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.149-153
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• 2009

Physics-based distributed rainfall-runoff models are now commonly used in a variety of hydrologic applications such as to estimate flooding, water pollutant transport, sedimentation yield and so on. Moreover, it is not surprising that GIS has become an integral part of hydrologic research since this technology offers abundant information about spatial heterogeneity for both model parameters and input data that control hydrological processes. This study presents the development of a distributed rainfall-runoff prediction system for the Guem river basin ($9,835km^2$) using an Object-oriented Hydrological Modeling System (OHyMoS). We developed three types of element modules: Slope Runoff Module (SRM), Channel Routing Module (CRM), and Dam Reservoir Module (DRM) and then incorporated them systemically into a catchment modeling system under the OHyMoS. The study basin delineated by the 250m DEM (resampled from SRTM90) was divided into 14 midsize catchments and 80 sub-catchments where correspond to the WAMIS digital map. Each sub-catchment was represented by rectangular slope and channel components; water flows among these components were simulated by both SRM and CRM. In addition, outflows of two multi-purpose dams: Yongdam and Daechung dams were calculated by DRM reflecting decision makers' opinions. Therefore, the Guem river basin rainfall-runoff modeling system can provide not only each sub-catchment outflow but also dam inand outflow at one hour (or less) time step such that users can obtain comprehensive hydrological information readily for the effective and efficient flood control during a flood season.

• Ocean and Polar Research
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• v.32 no.2
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• pp.123-135
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• 2010

Around Tongyeong coasts which located in southern coast of Korea composed to the complex coastal line and scattered by small islands. It also has been distributed to a complicated bathymetric structure by several types of channels. This study carried to analyze the spatial characteristics of macrobenthic community and benthic environmental variance on sub-tidal area based on multivariate statistics tools. Sediment composition varied from muddy sand to mud, and along the channels, it composed to a heterogeneous bottoms mixed by shell fragment, cobbles and mud. Organic contents on the surface sediment varied 1.1-3.9%. Total of 272 species, $33,349\;ind./m^2$ of macrobenthos identified in all of sample area. Polychaetes also prevailed among the specimen. L. longifolia, P. pinnata dominated based on density. Considering on the biomass, echinoderm S. lacunosa, A. tricoides listed. Closer to the coastal area, the density and diversity were higher. Community structure based on cluster analysis was discriminated into three groups. Each group was also characterized by geographical state such as depth, sediment composition. In addition, when applied to the bathymetric data, the channel, which composed to the mixed sediment, made a role of limited factor which characterized to benthic community. Because the specimen around the channel have been affected on the diverse sediment mixture. Most of benthic studies in the southern coast of Korea focused to the condition of benthic organic pollution spatially, because along the coast, it also developed a aquaculture ground and industrial complex. But, as results, most of the area, it turn out the less polluted areas nevertheless similar environment situation. It supposed that benthic community affect to the bottom sediment composition by physical characteristics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.403-406
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• 1999

The influence of temperature variation (25～125$^{\circ}C$) on poly-Si thin-film transistors (TFT's) was investigated by examining the electrical properties change of poly-Si films formed by solid phase crystallization (SPC). The n-channel poly-Si TFT's fabricated by SPC with channel length of 1.5 and loon ,respectively, exhibit good characteristics with a high ${\mu}$$\sub$FE/ ($\geq$82 and $\geq$60$\textrm{cm}^2$/V-s in 1.5 and 10$\mu\textrm{m}$, respectively), low V$\sub$t/, ($\leq$1.52 and $\leq$ 2.75V in 1.5 and 10$\mu\textrm{m}$, respectively), low S$\sub$t/, and good ON-OFF characteristics in spite of temperature variation. Thus, poly-Si films formed by SPC can be applied for the application to poly-Si TFT liquid crystal display with peripheral integrated circuits.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2A
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• pp.86-96
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• 2006

In recent year, EPON(Ethernet PON) system is expected to be more attractive solutions for high speed, broadband access networks in next generation access networks due to the conversionce of low-cost ethernet equipment and low-cost fiber infrastructure. Upstream channel control algorithm is essential to hare upstream bandwidth in EPON. In this paper, we suggest HUHG(High Utilization and Hybrid Granting) algorithm for supporting high bandwidth utilization and QoS for different service class. This algorithm improves bandwidth utilization as removing or diminishing idle time of upstream channel using characteristics of fixed EF(Expedited Forwarding) sub-cycle. The proposed algorithm also minimizes the packet delay and delay variation of EF class. We conduct detailed simulation experiments using OPNET to study the performance and validate the effectiveness of the proposed algorithm.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.6
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• pp.655-661
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• 2013

In this paper, the 1/f noise characteristics of n-channel MOSFET (NMOSFET) and p-channel MOSFET (PMOSFET) are analyzed in depth as a function of body bias. The normalized drain current noise, $S_{ID}/I_D{^2}$ showed strong dependence on the body bias in the sub-threshold region for both NMOSFET and PMOSFET, and NMOSFET showed stronger dependence than PMOSFET on the body bias. On the contrary, both of NMOSFET and PMOSFET do not exhibit the dependence of $S_{ID}/I_D{^2}$ on body bias in strong inversion region, although the noise mechanisms of two MOSFETs are different from each other.

• Journal of Soil and Groundwater Environment
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• v.20 no.1
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• pp.41-55
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• 2015

Monitoring of $CO_2$ release through the ground surface is essential to confirm the safety of carbon storage projects. We conducted a feasibility study of the multi-channel surface-soil $CO_2$-concentration monitoring (SCM) system as a soil $CO_2$ monitoring tool with a small scale injection test. The background concentrations showed the distinct diurnal variation. The negative relation of $CO_2$ with temperature and the low $CO_2$ concentrations during the day imply that surface-soil $CO_2$ depends on photosynthesis and respiration. After 4.2 kg of $CO_2$ injection (1 m depth for 29 minutes), surface-soil $CO_2$ concentrations increased in the all five chambers, which were located less than 2.8 m of distance from each other. The $CO_2$ concentrations seem to be recovered to the background around 4 hours after the injection ended. To determine the leakage, the data from Chamber 2 and 5 with low increase rates were used for statistical analyses. Coefficient of variation for 30 minutes ($CV_{30min}$.) is efficient to determine a leakage signal, with reflecting the fast change in $CO_2$ concentrations. Consequently, SCM and $CV_{30min}$ could be applied for an efficient monitoring tool to detect $CO_2$ release through the ground surface. Also, this study provides ideas for establishing action steps after leakage detection.

• Animal Bioscience
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• v.35 no.10
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• pp.1616-1627
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• 2022

Objective: This work was conducted to investigate the effects of oxidative stress on meat quality, mitochondrial function, calcium metabolism and ferroptosis of broilers. Methods: In this study, a total of 144 one-day-old male Ross 308 chicks were divided into 3 groups (control group, saline group, and hydrogen peroxide [H₂O₂] group) with 6 replicates of 8 broilers each. The study lasted for 42 d. The broilers in the saline and H₂O₂ groups were intraperitoneally injected with 0.75% saline and 10.0% H₂O₂ on the 16th and 37th day of the experimental period respectively, the injection volumes were 1.0 mL/kg of broiler body weight. On the 42nd day of the experimental period, two chicks were randomly selected from each cage, a total of thirty-six chicks were stunned by electric shock and slaughtered to collect breast muscle samples. Results: The H₂O₂ exposure reduced pH value, increased drip loss and shear force of breast meat (p<0.05), impaired the ultrastructure and function of mitochondria. The H₂O₂ exposure damaged the antioxidant system in mitochondria, excessive reactive oxygen species carbonylation modified calcium channels on mitochondria, which impaired the activities of key enzymes on calcium channel, resulted in the increased calcium concentration in cytoplasm and mitochondria (p<0.05). In addition, the H₂O₂ exposure increased the iron content and lipid peroxidation (p<0.05), which induced ferroptosis. Conclusion: Oxidative stress could impair meat quality by causing mitochondrial dysfunction, resulting in calcium metabolism disorder and ferroptosis.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.6
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• pp.255-260
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• 2023

As demanding the detection of explosive molecules, it is required to develop rapidly and precisely responsive sensors with ultra-high sensitivity. Since two-dimensional semiconductors have an atomically thin body nature where mobile carriers accumulate, the abrupt modulation carrier in the thin body channel can be expected. To investigate the effectiveness of WSe₂ semiconductor materials as a detection material for TNT (Trinitrotoluene) explosives, WSe₂ was synthesized using thermal chemical vapor deposition, and afterward, WSe₂ FETs (Field Effect Transistors) were fabricated using standard photo-lithograph processes. Raman Spectrum and FT-IR (Fourier-transform infrared) spectroscopy reveal that the adsorption of TNT molecules induces the structural transition of WSe₂ crystalline. The electrical properties before and after adsorption of TNT molecules on the WSe₂ surface were compared; as -50 V was applied as the back gate bias, 0.02 μA was recorded in the bare state, and the drain current increased to 0.41 μA with a dropping 0.6% (w/v) TNT while maintaining the p-type behavior. Afterward, the electrical characteristics were additionally evaluated by comparing the carrier mobility, hysteresis, and on/off ratio. Consequently, the present report provides the milestone for developing ultra-sensitive sensors with rapid response and high precision.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.6
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• pp.1045-1061
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• 2016

This study clarifies differences in attitudes toward the Omni-Channel service (Pintech service, Beacon service, and Click and Collect service) and fashion consumption behavior among four clusters grouped by level of technology readiness. An online survey was conducted; 572 individuals between 20 and 30 years of age were collected, but only 539 were used. Factor analysis, cluster analysis, descriptive statistics, ANOVA, and frequency analysis were adopted to analyze data using SPSS 20.0. The results are as follows. Technology readiness was divided into four factors: optimism, innovativeness, discomfort, and insecurity. Participants were divided into four groups according to four sub-factors of technology readiness: brave adopters, optimistic laggards, indifferent adopters, and critical adopters. These groups showed significant differences in attitudes toward the Omni-Channel service and fashion consumption behavior. Critical adopters and brave adopters recognized the value of the Omni-Channel service and had more positive attitudes toward it than other groups. Critical adopters also better perceived the risk of service with new technology that showed higher fashion innovativeness and monthly consumption of fashion products than other groups. We inferred that the indifferent adopters did not use the Omni-Channel service or services offered by fashion retailers as much as other groups because indifferent adopters were less interested in both the Omni-Channel service and fashion consumption behavior than other groups. Optimistic laggards viewed the Omni-Channel service optimistically, despite perceptions of high risks to accompanying it and a low intent to use it. The results of this study assisted in the formation of a theoretical framework of consumer behavior associated with the Omni-Channel, which is an emerging issue in research related to distribution. The results can help fashion industries that operate consumer-oriented marketing based on Omni-Channel strategies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.7
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• pp.472-476
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• 2014

We report the characteristics of thin-film transistor (TFT) to make the bi-channel structure with stacked $Mg_{0.1}Zn_{0.9}O$ (Mg= 10 at.%) and ZnO. The ZnO and $Mg_{0.1}ZnO_{0.9}O$ thin films were deposited by radio frequency (RF) co-sputter system onto the thermally oxidized silicon substrate. A total thickness of active layer was 50 nm. Firstly, the ZnO thin films were deposited to control the thickness from 5 nm to 30 nm. Sequentially, the $Mg_{0.1}ZnO_{0.9}O$ thin films were deposited to change from 45 nm to 20 nm. The bi-layer TFT shows more improved properties than the single layer TFT. The field effect mobility and subthreshold slope for $Mg_{0.1}ZnO_{0.9}O$/ZnO-TFT are $7.40cm^2V^{-1}s^{-1}$ and 0.24 V/decade at the ZnO thickness of 10 nm, respectively.