• Smart Structures and Systems
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• v.29 no.5
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• pp.747-755
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• 2022

Hierarchical structure parameters, proposed in She-Leveque model, are investigated for velocity components obtained from different flow types over a large range of Reynolds numbers 255 < Re_𝜆 < 720. The values of intermittency parameter 𝛽, with respect to a fixed velocity component, are observed nearly same for all four types of turbulence. The parameter 𝛾, for streamwise velocity components is nearly the same but significantly different for vertical components in different flows. It is also observed that for both parameters, an obvious relation between the longitudinal and transverse components 𝛽_T < 𝛽_L (and 𝛾_T < 𝛾_L) always holds. However, the difference between 𝛽_L and 𝛽_T is found very small in all types of turbulent flows, we studied here. It is evidenced that at low Reynolds numbers, the deviations from K41 scaling are mainly due to the most intense structures and slightly because of more heterogeneous hierarchy of fluctuation structures. However, at higher Reynolds numbers the deviations seem as a consequence of the most intense structures only. Over all, the study suggests that the hierarchy parameter 𝛽 may be consider as a universal constant.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.407-414
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• 2010

Until now, the pore size distribution, PSD, of soil profile has been calculated from soil moisture characteristic data by water release method or mercury porosimetry using the capillary rise equation. But the current methods are often difficult to use and time consuming. Thus, in this work, theoretical framework for an easy and fast technique was suggested to estimate the PSD from unsaturated hydraulic conductivity data in an undisturbed field soil profile. In this study, unsaturated hydraulic conductivity data were collected and simulated by the variation of soil parameters in the given boundary conditions (Brooks and Corey soil parameters, ${\alpha}_{BC}=1-5L^{-1}$, b = 1 - 10; van Genuchten soil parameters, ${\alpha}_{VG}=0.001-1.0L^{-1}$, m = 0.1 - 0.9). Then, $K_s$ (1.0 cm $h^{-1})$ was used as the fixed input parameter for the simulation of each models. The PSDs were estimated from the collected K(h) data by model simulation. In the simulation of Brooks-Corey parameter, the saturated hydraulic conductivity, $K_s$, played a role of scaling factor for unsaturated hydraulic conductivity, K(h) Changes of parameter b explained the shape of PSD curve of soil intimately, and a ${\alpha}_{BC}$ affected on the sensitivity of PSD curve. In the case of van Genuchten model, $K_s$ and ${\alpha}_{VG}$ played the role of scaling factor for a vertical axis and a horizontal axis, respectively. Parameter m described the shape of PSD curve and K(h) systematically. This study suggests that the new theoretical technique can be applied to the in situ prediction of PSD in undisturbed field soil.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.93-101
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• 2001

In this paper, we propose an image downscaler used in multimedia video applications, such as DTV, TV-PIP, PC-video, camcorder, videophone and so on. The proposed image downscaler provides a scaled image of high-quality and high-performance. This paper will explain the scaling theory using two-dimensional digital filters. It is the method that removes an aliasing noise and decreases the hardware complexity, compared with Pixel-drop and Upsamling. Also, this paper will prove it improves scaling precisians and decreases the loss of data, compared with the Scaler32, the Bt829 of Brooktree, and the SAA7114H of Philips. The proposed downscaler consists of the following four blocks: line memory, vertical scaler, horizontal scaler, and FIFO memory. In order to reduce the hardware complexity, the using digital filters are implemented by the multiplexer-adder type scheme and their all the coefficients can be simply implemented by using shifters and adders. It also decreases the loss of high frequency data because it provides the wider BW of 6MHz as adding the compensation filter. The proposed downscaler is modeled by using the Verilog-HDL and the model is verified by using the Cadence simulator. After the verification is done, the model is synthesized into gates by using the Synopsys. The synthesized downscaler is Placed and routed by the Mentor with the IDEC-C632 0.65${\mu}{\textrm}{m}$ library for further IC implementation. The IC master is fixed in size by 4,500${\mu}{\textrm}{m}$$\times$4,500${\mu}{\textrm}{m}$. The active layout size of the proposed downscaler is 2,528${\mu}{\textrm}{m}$$\times$3,237${\mu}{\textrm}{m}$.

• The Journal of Engineering Geology
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• v.27 no.3
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• pp.293-304
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• 2017

This study was performed in order to hydrogeological analysis of aquifer, which is a necessary part for evaluating the efficiency of the combined well and open-closed loops geothermal (CWG) systems. CWG systems have been proposed for the effective utilization of geothermal energy by combining open loop geothermal systems and closed loop geothermal systems. Small aperture CWG systems and large aperture CWG systems were installed at a green house land with water curtain facilities in Chungju City. Aquifer tests include pumping tests and step-drawdown tests were conducted to analyse hydrogeological characteristics of aquifer in the study area. The transmissivity was estimated in the range of $13.49{\sim}58.99cm^2/sec$, and the storativity was estimated in the range of $1.13{\times}10^{-5}{\sim}5.20{\times}10^{-3}$. The geochemical analysis showed $Ca^{2+}$ ion and ${HCO_3}^-$ ion were dominant in groundwater. The Langelier Saturation Index and the Ryznar Stability Index showed low scaling potential of groundwater. In the analysis of vertical water temperature change, the geothermal gradient was estimated as $2.1^{\circ}C/100m$, which indicated the aquifer was enough for geothermal systems. In conclusion, groundwater is rich, can stably use geothermal heat, and it is less likely to cause deterioration of thermal energy efficiency by precipitation of carbonate minerals in study area. Therefore, the study area is suitable for installation of the combined geothermal system.

• Ocean and Polar Research
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• v.38 no.2
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• pp.115-128
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• 2016

This study examined the relationship between macrobenthic distribution patterns and environmental factors in salt marsh vegetation in Donggeomdo, Ganghwa on the west coast of Korea. Nine stations were fixed on a transect across the salt marsh vegetation, and field sampling was carried out monthly from July 1997 to June 1998. A total of 38 species of macrobenthos were recorded: each of faunal groups, 13 (34.2%) Arthropoda, 12 (31.6%) Polychaeta, 8 (21.1%) Mollusca, and 5 (13.2%) others. The mean density was $2,659individuals/m^2$, with a mean biomass of $178.6gWWt/m^2$. Mollusca dominated in terms of abundance and biomass, with a mean density of $2,172individuals/m^2$ (81.7%) and a mean biomass of $131.9gWWt/m^2$ (73.9%). The number of species decreased in winter (January-February), while mean density increased in the spring (May-June). The biomass was relatively in Summer and Fall (July-November), than any other season. The number of species was high in pure stands of Suaeda japonica in the lower salt marsh vegetation, and the mean density and biomass were high in mixed halophyte communities in the middle salt marsh vegetation. Two Mollusca, the bivalve Glauconome chinensis and gastropod Assiminea lutea, were dominant. The densities of these two species were high in mixed halophyte communities in the middle salt marsh vegetation. Non-metric multi-dimensional scaling (nMDS) showed that the study area could be divided into four groups corresponding to the vertical distribution of tidal levels and halophytes. Spearman's rank correlation revealed that the distribution patterns and community structure of macrobenthos were related to environment variables such as salinity of the substrates, exposure time, and grain size compositions of the sediment in the salt marsh vegetation. Particularly, the distribution and density of some dominant species showed differences along the vertical distributions of halophytes.

• The Journal of the Korean dental association
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• v.50 no.8
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• pp.474-481
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• 2012

The periodontal flap surgery is the most widely utilized surgical procedure to reduce the pocket depth and to access the subgingival root surfaces for scaling and root planing. The diagnosis of the periodontal lesion and the objective of the surgery will dictate the type of flap procedure which will be utilized to obtain the best result. The incisions, type of flap and the selection of suturing design must be planned and executed to fit the problem. Periodontal flaps are designed to preserve gingival integrity and to gain access to root surfaces for residual calculus removal and to thoroughly remove granulation tissue so bone defects can be visualized and treated. Gentle and efficient procedures result in optimum healing and minimal postoperative pain. When flaps need to be repositioned apically or less often, coronally, then the flaps must sit passively at the appropriate level before suturing. To ensure this, buccal and lingual flaps need to be elevated beyond the mucogingival junction so the elasticity of the mucosa allows for flap mobility. Sometimes it may be necessary to extend the flap elevation apically with a split incision approach to minimize the effect of the less elastic periosteum. Vertical incisions can aid in flap positioning by allow ing the clinician to suture the flap at a different level to the adjacent untreated gingiva. In osseous periodontal surgery, flaps are apically positioned to minimize postoperative pocket depth. In regenerative periodontal surgery including implant surgery, soft tissue cove rage of bony defects, graft materials, membranes, and bio logic agents is important so sulcular incisions and light suturing techniques are crucial.

• The Journal of the Korean dental association
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• v.47 no.8
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• pp.479-486
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• 2009

Purpose: The aim of this study was to show the clinical results of combination of Nd-YAP (1340nm) laser therapy with conventional endodontic and periodontal treatment. Materials and Methods: Four patients with chronic advanced periodontitis and endodontic infection were treated with conventional treatment and Nd-YAP laser therapy. Occlusal adjustment and splinting were done for stabilization of the teeth with severe horizontal and vertical mobility. The protocol for periodontal treatment was followed as scaling and root planing, pocket irrigation with 3% $H_2O_2$ and exposure of Nd-YAP laser using 320${\mu}m$ optical fiber with 160mJ/pluse, 30Hz. The other protocol for endodontic treatment was followed as access opening, canal preparation by hand and rotary instrument, canal filling, and exposure of Nd-YAP laser using 200${\mu}m$ optical fiber with 200mJ/pluse, 10Hz and 180mJ/pluse, 5Hz which were used respectively for disinfection and canal filling. The assessments of probing depth, mobility, and radiography were made prior to and after treatment. Result: All of these four clinical cases showed good healing of periodontium, which presented decrease of mobility and pocket depth, and increase of bone regeneration and bone density on the radiography. Conclusion: The bactericidal effect of Nd-YAP laser would provide benefits for improving clinical results that are obtained from conventional therapy.

• Tunnel and Underground Space
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• v.12 no.1
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• pp.31-36
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• 2002

This paper concerns smoke propagation in tunnel fires with various size of fire source. Experiments carried out in model tunnel and those results were compared with numerical results. The Froude scaling law was used to scale model tests for comparison with larger scale tests. In order to validate for numerical analysis, temperature distribution of predicted data was compared with measured data. Examining the temperature distribution, we found that smoke layer does not come down under 50% of tunnel heights for a short tunnel heights for a short tunnel firs without ventilation. Front velocity of smoke layer is proportional to the cube root of heat release rate. And it is in good agreement with existing empirical expression and numerical prediction. In a short tunnel fire, horizontal propagation of smoke layer is more important than vertical smoke movement for evacuation plan.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.2
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• pp.37-59
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• 2017

The Korean peninsula belongs to the temperate forest biome dominated by many deciduous oaks. We quantitatively and qualitatively studied vertical and horizontal distributions and habitat characteristics on the major oak species such as Quercus mongolica, Q. serrata, Q. variabilis, Q. dentata, Q. aliena and Q. acutissima. A total of 5,278 samples were analyzed with a species coverage and 6 principal environmental variables extracted from public database of nationwide natural environment survey. Correlation analysis was accomplished by the CANOCO using Canonical Correspondence Analysis and the Pearson correlation coefficient using PASW Statistics. The hierarchical distribution tendency of six oaks was finalized using the Goodman-Kruskal lambda coefficient of non-metric multidimensional scaling by SYN-TAX 2000. The utmost factor on the distributional segregation of oak species was the elevation, i.e. temperature. Q. serrata and Q. mongolica show clearly a diametrical distribution patterns with zonal distribution. Q. variabilis was determined as a thermophilic and xerophilous species that is a component of not only natural pseudo-climax forest but also secondary forest. The highest frequency of the dominant forest was found Q. mongolica. Whereas, Q. serrata showed the highest frequency of individual tree but the relatively lower frequency of dominant forest, which is resulted from the original habitat loss. By the benefit of the traditional Soopjeong-E, Q. acutissima dominant forests were remained rather largely. Individuals of Q. dentata occurred horizontally nationwide, but its dominant forest was the poorest. Dominant forest of Q. aliena, which is a natural vegetation, was the most rare due to a limited potential habitat.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2253-2260
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• 2012

In this paper, an efficient hardware architecture is proposed for inverse transform and inverse quantization of H.264/AVC decoder. The previous inverse transform and quantization architecture has a different AC and DC coefficients decoding order. In the proposed architecture, IQ is achieved after IT regardless of the DC or AC coefficients. A common operation unit is also proposed to reduce the computational complexity of inverse quantization. Since division operation is included in the previous architecture, it will generate errors if the processing order is changed. In order to solve the problem, the division operation is achieved after IT to prevent errors in the proposed architecture. The architecture is implemented with 3-stage pipeline and a parallel vertical and horizontal IDCT is also implemented to reduce the operation cycle. As a result of analyzing the proposed ITIQ architecture operation cycle for one macroblock, the proposed one has improved by 45% than the previous one.