• Korean Journal of Remote Sensing
• /
• v.19 no.5
• /
• pp.403-409
• /
• 2003

Since SPOT4 satellite contained VEGETATION 1 sensor launched, the noise in VEGETATION data was occasionally arisen a difficulty for the data traitement. Blind line noise types were studied in VEGETATION-l short wave infrared channel(SWIR). In order to provide a precis product, the procedure for removing this noise is strongly recommended. In the case that the blind values are clearly distinguished from contamination-free values a simple threshold method was applied, while a changeable threshold method was used for the blind value mixed with contamination-free values. New algorithm presented in this study is consists of two method for each type of SWIR blind. After removing blind line, there were again some residual pixels of blind, because the threshold is not determinated sufficiently low. Lower threshold could remove the blind line as well as the contamination-free pixels. Nevertheless, the results showed a good qualitative improvement as compared with other algorithm.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.03a
• /
• pp.97-104
• /
• 2008

Most of engine control systems for helicopter turboshaft engines are equipped with dual sensors. For the system with dual redundancy, analytic methods are used to detect faults based on the system dynamical model. Helicopter engine dynamics are affected by aerodynamic torque induced from the dynamics of the main rotor. In this paper an engine model including the rotor dynamics is constructed for the T700-GE-700 turboshaft engine powering UH-60 helicopter. The singular value decomposition(SVD) method is applied to the developed model in order to detect sensor faults. The SVD method which do not need an additional computation to generate residual uses the characteristics that the system outputs in direction of the left singular vector if an input is applied in direction of the right singular vector. Simulations show that the SVD method works well in detecting and isolating the sensor faults.

• Journal of Ship and Ocean Technology
• /
• v.8 no.3
• /
• pp.8-17
• /
• 2004

A numerical method is developed for computing the free surface flows around a transom stern of a ship at a high Froude number. At high speed, the flow may be detached from the flat transom stern. In the limit of the high Froude number, the problem becomes a planning problem. In the present study, we make the finite-element computations for a transom stern flows around a wedge-shaped floating ship. The numerical method is based on the Hamilton's principle. The problem is formulated as an initial value problem with nonlinear free surface conditions. In the numerical procedures, the domain was discretized into a set of finite elements and the numerical quadrature was used for the functional equation. The time integrations of the nonlinear free surface condition are made iteratively at each time step. A set of large algebraic equations is solved by GMRES(Generalized Minimal RESidual, Saad and Schultz 1986) method which is proven very efficient. The computed results are compared with previous numerical results obtained by others.

• Textile Coloration and Finishing
• /
• v.31 no.1
• /
• pp.25-32
• /
• 2019

The influence of the contact amount of carbon dioxide per unit mass of dyestuff(${\alpha}$) on dyeing uniformity in supercritical fluid dyeing is analyzed in this study. The experiments using a 5L class Pilot Scale dyeing machine is carried out for this study purpose. For a fixed temperature and pressure, the amount of sample and the dyeing leveling time were considered as process variables. The results show that the increase in the amount of the sample causes a higher color difference than the reference sample, and it also increases the amount of residual dye. On the other hand, the color difference tended to decrease with the increase in dyeing time. Based on these results, the correlation between ${\alpha}$ value and dyeing uniformity in supercritical fluid dyeing is obtained.

• International Journal of Advanced Culture Technology
• /
• v.10 no.3
• /
• pp.281-286
• /
• 2022

In this study, design of an intuitive internal resistance diagnostic device is to diagnose the residual capacity and aging of the battery regardless of the model and the internal protocol of the waste battery through the method of measuring the internal resistance of a waste battery. In this paper, charging and discharging were continuously performed with 2A charging and 5A discharging in order to secure data on impedance changes that may occur in the charging and discharging process of various methods. As a result of the final experiment, it was confirmed that the impedance change occurred during charging and discharging, and the amount of change increased as the charging/discharging C-rate increased. In addition, it was confirmed that the waste battery aged or abnormal cell had a large change in the impedance value.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.4
• /
• pp.1234-1257
• /
• 2023

In this paper, we propose a framework for multi-focus image fusion called PATN. In our approach, by aggregating deep features extracted based on the U-type Transformer mechanism and shallow features extracted using the PSA module, we make PATN feed both long-range image texture information and focus on local detail information of the image. Meanwhile, the edge-preserving information value of the fused image is enhanced using a dense residual block containing the Sobel gradient operator, and three loss functions are introduced to retain more source image texture information. PATN is compared with 17 more advanced MFIF methods on three datasets to verify the effectiveness and robustness of PATN.

• Restorative Dentistry and Endodontics
• /
• v.46 no.4
• /
• pp.58.1-58.8
• /
• 2021

Objectives: This study addresses the effect of using nanoparticles (np) on the antimicrobial properties of bioactive glass (BAG) when used in intracanal medicaments against Enterococcus faecalis (E. faecalis) biofilms. Materials and Methods: E. faecalis biofilms, grown inside 90 root canals for 21 days, were randomly divided into 4 groups according to the antimicrobial regimen followed (n = 20; BAG-np, BAG, calcium hydroxide [CaOH], and saline). After 1 week, residual live bacteria were quantified in terms of colony-forming units (CFU), while dead bacteria were assessed with a confocal laser scanning microscope. Results: Although there was a statistically significant decrease in the mean CFU value among all groups, the nano-group performed the best. The highest percentage of dead bacteria was detected in the BAG-np group, with a significant difference from the BAG group. Conclusions: The reduction of particle size and use of a nano-form of BAG improved the antimicrobial properties of the intracanal treatment of E. faecalis biofilms

• Economic and Environmental Geology
• /
• v.30 no.6
• /
• pp.587-601
• /
• 1997

This study had three purposes: (1) to investigate the enrichment levels and dispersion patterns of potentially toxic elements in the rock-soil-plant system; (2) to evaluate the uptake ratios of heavy metals from soils into plants and (3) to assess the chemical speciation of heavy metals in soils. Rock, surface soil and plant samples were collected in the Boeun area underlain by black shales of the Okchon Zone. These samples were analyzed for multi-elements using INAA, ICP-AES and AAS. The maximum abundance of U in black shales is 16 mg/kg and radioactivity counts up to 300 cpm. In particular, Mo, V, Ba, Cd, Pb and U are enriched in black shales. Most of soils derived from black shales show high concentrations of U, As, Mo, Ba, Cu, Cd, Pb, Zn and mean concentrations of As and Mo in soils (20 mg/kg of As and 6.6 mg/kg of Mo) are higher than the permissible level suggested by Kloke (1979). Enrichment index values of soils are calculated and higher than 1.0 in the black shale area with the highest value of 6.4. Mean concentration of Cd in plants is higher than those of Cu, Pb and Zn. The concentration of Cd in plant species decreases in the order of Chinese cabbage > red pepper > soybean=sesame > rice stalk > com > rice grain. The biological absorption coefficients (BAC) in plants are in the order of Cd > Zn=Cu > Pb, which suggests that Cd is more bioavailable to plants than Cu, Pb and Zn. From the results of sequential extraction analysis of soils, relatively high proportion of Cu, Pb and Zn are present as residual fractions whereas that of Cd as non-residual fractions. Cadmuim occurs predominantly as exchangeable/water-acid soluble phase in soils, and Cd is more mobile and bioavailable than Cu, Pb and Zn.

• Journal of the Korean Ceramic Society
• /
• v.39 no.1
• /
• pp.33-37
• /
• 2002

The phosphorescence powder, $SrA1_2O_4:Eu^{2+}$, synthesized by a Polymerized Complex Method(PCM), has been compared with that by a Solid-State Reaction(SSR), and their luminescence characteristics have been studied. The PCM powders were synthesized at $900^{\circ}C$ and the SSR powders at $1200^{\circ}C$. The size of PCM powders was about $0.1{\mu}m$ and one tenth of that of the SSR powders, which was due to the lower synthesized temperature. On the other hand, residual carbon in the PCM powders decreased with an increase in the crystallinity of host lattice, which was responsible for the non-white color of the powders. Both powders showed the maximum luminescence peaks around 520nm in the wave length at room temperature. However, the peak position for the PCM powders was shifted to a slightly lower wavelength and the value of half-width of the peak was broad comparing to that of the SSR powders, and the peak intensity decreased significantly. Such a change in the luminescence characteristics was due to the large difference in size for two types of powders and partly the residual carbon in the PCM powders.

• Textile Coloration and Finishing
• /
• v.1 no.1
• /
• pp.54-62
• /
• 1989

The woven fabric composed of nylon 6 filaments was treated with aqueous solutions (20, 30, 40, 50, 60%) of formic acid at 3$0^{\circ}C$ for 10 minutes under unrestrained condition, and the shrinkage behavior and some kinds of properties were examined. The shrinkages of the constituent yarns and fabric were increased with formic acid concentration, but they were lower than that of the original filaments because of fabric-structural factors. And the shrinkage of the warp was lower than that of the weft because of the residual stress from weaving process. By the restraint forces such as fabric-structural factors and residual stress, the constituent filaments were damaged partially at 60% of formic acid concentration and the degree of damage on the warp was greater than on the weft. And though the fabric count were increased overall, the spacing between the warps was decreased prior to the weft and eliminated nearly at 60% of formic acid concentration. The thickness, tensile strength, elongation, and handle value of fabric were increased overall with formic acid concentration excepting that the tensile strength for both the warp and weft directions and the elongation for the warp direction were decreased instead by the damage of yarns. But the crease recovery was decreased except the case of the weft direction at 60% of formic acid concentration.