• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.10
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• pp.4060-4079
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• 2020

Blur is an important type of image distortion. How to evaluate the quality of blurred image accurately and efficiently is a research hotspot in the field of image processing in recent years. Inspired by the multi-scale perceptual characteristics of the human visual system (HVS), this paper presents a no-reference image blur/sharpness assessment method based on multi-scale local features in the spatial domain. First, considering various content has different sensitivity to blur distortion, the image is divided into smooth, edge, and texture regions in blocks. Then, the Gaussian scale space of the image is constructed, and the categorized contrast features between the original image and the Gaussian scale space images are calculated to express the blur degree of different image contents. To simulate the impact of viewing distance on blur distortion, the distribution characteristics of local maximum gradient of multi-resolution images were also calculated in the spatial domain. Finally, the image blur assessment model is obtained by fusing all features and learning the mapping from features to quality scores by support vector regression (SVR). Performance of the proposed method is evaluated on four synthetically blurred databases and one real blurred database. The experimental results demonstrate that our method can produce quality scores more consistent with subjective evaluations than other methods, especially for real burred images.

• KOMUNHWA
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• no.57
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• pp.3-24
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• 2001

In terms of Typology, Korean Grooved Adzes are mainly grouped into two major types with some variations. Type 1 is characterized by such basic attributes as slant edge; trapezoidal groove; and rectangular or trapezoidal cross-section of a body. Whereas, T

• Journal of the Korean Ceramic Society
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• v.41 no.1
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• pp.1-8
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• 2004

The microstructural features and mechanical behavior of directionally solidified $(Y_2O_3)ZrO_2/Al_2O_3$ eutectic fibers after extended beat treatment in oxidizing environment were investigated. The fiber was grown continuously by an Edge-defined Film-fed Growth (EFG) technique. The microstructure was characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscopy(SEM). The microstructure of the fiber in the as-fabricated state consists of highly oriented colonv and fine lamellar microstructure along the fiber axis. Tensile strength of the $(Y_2O_3)ZrO_2/Al_2O_3$ eutectic fiber remained unchanged with heat treatment at temperatures between $1200^{\circ}C$ and $1500^{\circ}C$ up to 300h. The weibulls modulus remained fairly constant after extended thermal exposure. The fracture toughness and crack propagation behavior were investigated. The fracture toughness ($K_{1C}$) of the $(Y_2O_3)ZrO_2/Al_2O_3$ eutectic fiber in the as-fabricated state were measured to be 3.6 ${\pm}$ 0.5 MPa${\cdot}m^{1/2}$ by an indentation technique and 2.2 ${\pm}$ 0.2 MPa${\cdot}m^{1/2}$ by assuming elliptical flaw of a semi-infinite solid, respectively. The $(Y_2O_3)ZrO_2/Al_2O_3$ eutectic fiber showed a radial (Palmqvist) crack type and exhibited an orthotropic crack growth behavior under 100 g load.

• Structural Engineering and Mechanics
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• v.9 no.6
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• pp.615-636
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• 2000

Some elevated water tanks have failed due to torsional vibrations in past earthquakes. The overall axisymmetric structural geometry and mass distribution of such structures may leave only a small accidental eccentricity between centre of stiffness and centre of mass. Such a small accidental eccentricity is not expected to cause a torsional failure. This paper studies the possibility of amplified torsional behaviour of elevated water tanks due to such small accidental eccentricity in the elastic as well as inelastic range; using two simple idealized systems with two coupled lateral-torsional degrees of freedom. The systems are capable of retaining the characteristics of two extreme categories of water tanks namely, a) tanks on staging with less number of columns and panels and b) tanks on staging with large number of columns and panels. The study shows that the presence of a small eccentricity may lead to large displacement of the staging edge in the elastic range, if the torsional-to-lateral time period ratio $({\tau})$ of the elevated tanks lies within a critical range of 0.7< ${\tau}$ <1.25. Inelastic behaviour study reveals that such excessive displacement in some of the reinforced concrete staging elements may cause unsymmetric yielding. This may lead to progressive strength deterioration through successive yielding in same elements under cyclic loading during earthquakes. Such localized strength drop progressively develop large strength eccentricity resulting in large localized inelastic displacement and ductility demand, leading to failure. So, elevated water tanks should have ${\tau}$ outside the said critical range to avoid amplified torsional response. The tanks supported on staging with less number of columns and panels are found to have greater torsional vulnerability. Tanks located near faults seem to have torsional vulnerability for large ${\tau}$.

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.133-150
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• 1991

To study the mechanical behavior depended on the restoration method and alveolar bone height at endodontically treated teeth. a finite element model was made which was applied by four types of restoration methods and alveolar bone height on upper central incisor and then 1 Kg force was applied on each model as follows; 1) $45^{\circ}$ diagonal load on incisal edge. 2) $26^{\circ}$ diagonal load on lingual surface. and 3) horizontal load on labial surface. The author analyzed the displacement and stress of teeth and their supporting tissue by finite element method according to three type of loading conditions. The results were as follows : 1. The displacement by restoration method and the stress in dentin was found greater in restoration without a post than in that with a post. 2. The displacement and stress was found about the same when compared : A) in Resin model and PFM model applied by restoration method without a post and B) in PRC model and CPC model applied by restoration method with a post. 3. The lower alveolar bone height was. the greater was the displacement and stress. 4. The lower alveolar bone height was. the greater slightly was the stress of restoration without a post than in that with a post. 5. The stress in loading condition was the greatest in P1 in dentin and post. and was greatest in P3 in alveolar hone. 6. In the restoration method without a post. stress concentration in labial dentin was distributed to a figure of long belt in adjacent part to periodontal ligament. while in restoration method with a post. it was distributed in adjacent part to post side. And in all types of restoration method stress concentration in alveolar bone was distributed along the compact bone of labial and lingual surface.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.4
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• pp.15-26
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• 1990

This paper describes a potential-baoed panel method formulated for the analysis cf a supercavitating two-dimensional symmetri strut. The method employs normal dipoles and sources distributed on the foil and cavity surfaces to represent the potential flow around the cavitating hydrofoil. The kinematic boundary condition on the wetted portion of the foil surface is satisfied by requiring that the total potential vanish in the fictitious inner flow region of the foil, and the dynamic boundary condition on the cavity surface is satisfied by requiring that the potential vary linearly, i.e., the tangential velocity be constant. Green's theorem then results in a potential-based integral equation rather than the usual velocity-based formulation of Hess & Smith type, With the singularities distributed on the exact hydrofoil surface, the pressure distributions are predicted with improved accuracy compared to those of the linearized lifting surface theory, especially near the leading edge. The theory then predicts the cavity shape and cavitation number for an assumed cavity length. To improve the accuracy, the sources and dipoles on the cavity surface are moved to the newly computed cavity surface, where the boundary conditions are satisfied again. This iteration process is repeated until the results are converged.

• Journal of the Korea Computer Graphics Society
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• v.26 no.3
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• pp.21-29
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• 2020

This study defines the pipeline for digital fashion contents production using CLO 3D, a 3D fashion design software that supports virtual clothing visualization as a cutting-edge simulation technology for fashion, and vuforia, a mobile platform augmented reality (AR) development kit for creating AR applications. The proposed production pipeline is organized in a method to produce a virtual clothing model through CLO 3D software through works of patterns, sewing lines, textures, etc., and AR contents based on computer vision techniques using the functions and properties of vuforia development kits in the Unity engine development environment. In addition, we present application method that can be practically utilized from the perspective of practical users, such as fashion designers and directors, by creating a new type of AR digital fashion contents directly as a flow of the defined production pipeline.

• Journal of Electrochemical Science and Technology
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• v.2 no.1
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• pp.1-7
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• 2011

Nanocomposites of reduced graphene oxide and manganese (II,III) oxide can be synthesized by the freeze-drying process of the mixed colloidal suspension of graphene oxide and manganese oxide, and the subsequent heat-treatment. The calcined reduced graphene oxide-manganese (II,III) oxide nanocomposites are X-ray amorphous, suggesting the formation of homogeneous and disordered mixture without any phase separation. The reduction of graphene oxide to reduced graphene oxide upon the heat-treatment is evidenced by Fourier-transformed infrared spectroscopy. Field emission-scanning electronic microscopy and energy dispersive spectrometry clearly demonstrate the formation of porous structure by the house-of-cards type stacking of reduced graphene oxide nanosheets and the homogeneous distribution of manganese ions in the nanocomposites. According to Mn K-edge X-ray absorption spectroscopy, manganese ions in the calcined nanocomposites are stabilized in octahedral symmetry with mixed Mn oxidation state of Mn(II)/Mn(III). The present reduced graphene oxide-manganese oxide nanocomposites show characteristic pseudocapacitance behavior superior to the pristine manganese oxide, suggesting their applicability as electrode material for supercapacitors.

• KIEAE Journal
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• v.3 no.3
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• pp.43-50
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• 2003

Nowdays the apartment is a main type of modernized residential buildings. According to the improvement of construction techniques and functions of windows and doors, recent apartments are enhanced air tightness of windows, doors and building envelopes. As Infiltration is decreased and natural ventilation is reduced, energy could be saved in winter. However, indoor air quality is bad. The air Infiltration of a building could be enlarged by physical actions, such as building designs, constructions and reduction of air tightness which is caused by aging. This research analyzes and measures with KNS-4000P (Sapporo air tightness measurement) the air tightness of the high rise apartments which is recently constructed and not occupied yet. With depressurization method, the KNS-4000 installed on the window and the indoor air-leakage was measured. At that time, Air come out from the edge of the windows and doors because of the pressure differences between indoor and outdoor. We measure the amount of the air as effective air leakage areas. This method of depressurization takes less time to measure than other methods and is less affected from other conditions. We measured infiltration of total 56 household, 29 households S apartment (total floor area : $64.42m^2$) in Balan and 29 households D apartment(total floor area : $78.21m^2$) in Chonan. As a result of the field measurements at October 2003, normalized leakage area of D apartment in Cheonan was $2.05cm^2/m^2{\sim}3.49cm^2/m^2$ (average: $2.77cm^2/m^2$) and normalized leakage area of S apartment in Balan is $1.23cm^2/m^2{\sim}1.68cm^2/m^2$ (average: $1.5cm^2/m^2$).

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.934-940
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• 2010

The reduction of [$Os_3(CO)_{11}P(OMe)_3$] and subsequent ionic coupling of the reduced species with $[Ru({\eta}^5-C_5H_5)(CH_3CN)_3]^+$ resulted in the formation of [$Os_3(CO)_{11}P(OMe)_3(Ru({\eta}^5-C_5H_5))_2$] which can be converted to spiked tetrahedral cluster, [$HOs_3(CO)_{11}P(OMe)_3Ru_2({\eta}^5-C_5H_5)(C_5H_4)$] via the intramolecular hydrogen transfer. Due to the unavailability of a suitable single crystal, the PW91/SDD and LDA/SDD density functional methods were used to predict possible structures and the available spectroscopic information (IR, NMR) of [$Os_3(CO)_{11}P(OMe)_3(Ru({\eta}^5-C_5H_5))_2$]. The most probable geometry found by constrained search is the isomer (a2) in which the phosphite, $P(OMe)_3$, occupies an axial position on one of the two osmium atoms that is edge bridged by the $Ru(CO)_2({\eta}^5-C_5H_5)$ unit. By using the most probably geometry, the predicted infrared frequencies and $^1H$, $^{13}C$ and $^{31}P$ NMR chemical shifts of the compound are in the same range as the experimental values. For this type of complex, the LDA/SDD method is appropriate for IR predictions whereas the OPBE/IGLO-II method is appropriate for NMR predictions. The activation energy and reaction energy of the intramolecular hydrogen transfer coupled with the structural change of the transition metal framework were estimated at the PW91/SDD level to be 110.32 and -0.14 kcal/mol respectively.