• Title/Summary/Keyword: Symmetrical

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A Study on Design Characteristics of Korean War Memorials in the United States (한국전쟁 메모리얼의 설계요소에 나타난 기념성)

  • Lee, Sang-Suk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.1
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    • pp.12-24
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    • 2010
  • The purpose of this study was to analyze design characteristics of Korean War Memorials(KWM) in the United States(KWMUS). Through site survey and internet searching, the researcher selected 25 KWMUS and analyzed four analysis categories: design concept, spatial form, landscape details, and sculptures. The results are as follows: 1. The analysis revealed that main concepts of KWMUS were to cherish victims of the Korean War, show membership/locality/patriotism, express feelings and the meaning of war, and explain the Korean War realistically and symbolically. 2. Most KWMUS in memorial parks and plazas were designed to pursue the completion of each memorial assuming the form of typical and symmetrical circles and squares. Also, spatial order including spatial sequence was seen in some of KWMUS. 3. Stone walls, stone monument, flags, emblems and paving were used as main landscape details. The map of the Korean peninsula and Taegeuk were often introduced to symbolize Korea and the Korean War, and the symbolic phrase, 'Forgotten War' or 'Freedom is Not Free' were written on the stone to keep the Korean War in the minds of Americans. 4. Sculptures were used as important media to represent the Korean War in a variety of ways. Most of them were formed realistically, except for a few sculptures that aimed to represent the Korean War symbolically and narratively. In particular, the sculptures in Washington D.C. KWVM and Minnesota KWM were remarkable as symbolic media of war memorials in contemporary society. Further study will be required to analyze comparatively KWM in Korea and the U.S. and to understand characteristics of KWM in the point of design style.

Efficient Integer pel and Fractional pel Motion Estimation on H.264/AVC (H.264/AVC에서 효율적인 정화소.부화소 움직임 추정)

  • Yoon, Hyo-Sun;Kim, Hye-Suk;Jung, Mi-Gyoung;Kim, Mi-Young;Cho, Young-Joo;Kim, Gi-Hong;Lee, Guee-Sang
    • The KIPS Transactions:PartB
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    • v.16B no.2
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    • pp.123-130
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    • 2009
  • Motion estimation (ME) plays an important role in digital video compression. But it limits the performance of image quality and encoding speed and is computational demanding part of the encoder. To reduce computational time and maintain the image quality, integer pel and fractional pel ME methods are proposed in this paper. The proposed method for integer pel ME uses a hierarchical search strategy. This strategy method consists of symmetrical cross-X pattern, multi square grid pattern, diamond patterns. These search patterns places search points symmetrically and evenly that can cover the overall search area not to fall into the local minimum and to reduce the computational time. The proposed method for fractional pel uses full search pattern, center biased fractional pel search pattern and the proposed search pattern. According to block sizes, the proposed method for fractional pel decides the search pattern adaptively. Experiment results show that the speedup improvement of the proposed method over Unsymmetrical cross Multi Hexagon grid Search (UMHexagonS) and Full Search (FS) can be up to around $1.2{\sim}5.2$ times faster. Compared to image quality of FS, the proposed method shows an average PSNR drop of 0.01 dB while showing an average PSNR gain of 0.02 dB in comparison to that of UMHexagonS.

Structure of Fluorometholone (Fluorometholone 의 구조)

  • Young Ja Park;Mee Youn Lee;Sung Il Cho
    • Journal of the Korean Chemical Society
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    • v.36 no.6
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    • pp.812-817
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    • 1992
  • Fluorometholone $(C_{22}H_{29}FO_4)$, M.W. = 376.5, monoclinic, $P2_1$, a = 6.410(4), b = 13.431(3), c = 10.996(3)$\AA$, $\beta$ = 92.81$(3)^{\circ}$, Z = 2, F(000) = 404, T = 292K, $\lambda$(Mo-$K_\alpha$) = 0.7107$\AA$, $\mu$ = 0.57$cm^{-1}$, $D_c$ = 1.32 $g/cm^3$, $D_m$ = 1.31 $g/cm^3$ and final R = 0.032 for 1769 observed reflections. All bond lengths and angles are within normal limits. Ring A is almost planar, B ring has a highly symmetrical chair conformation and C ring is in a distorted chair conformation. Ring D is in a intermediate conformation between 13$\alpha$-14$\beta$-half-chair and 13$\alpha$-envelope. Torsion angle C(16)-C(17)-C(20)-O(20) of $-7.9^{\circ}$ is a lower value than those of $-31.9^{\circ}$ and $-16.5^{\circ}$ for 9-fluoro-6-methylprednisolone I and II respectively.

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Two-Dimensional Magnetotelluric Interpretation by Finite-Element Method (유한요소법에 의한 MT 법의 2차원 해석)

  • Kim, Hee-Joon;Choi, Ji-Hyang;Han, Nu-Ree;Lee, Seong-Kon;Song, Yoon-Ho
    • Geophysics and Geophysical Exploration
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    • v.11 no.2
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    • pp.85-92
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    • 2008
  • Magnetotelluric (MT) methods are widely applied as an effective exploration technique to geothermal surveys. Two-dimensional (2-D) analysis is frequently used to investigate a complicated subsurface structure in a geothermal region. A 2-D finite-element method (FEM) is usually applied to the MT analysis, but we must pay attention to the accuracy of so-called auxiliary fields. Rodi (1976) proposed an algorithm of improving the accuracy of auxiliary fields, and named it as the MOM method. Because it introduces zeros into the diagonal elements of coefficient matrix of the FEM total equation, a pivoting procedure applied to the symmetrical band matrix makes the numerical solution far less efficient. The MOM method was devised mainly for the inversion analysis, in which partial derivatives of both electric and magnetic fields with respect to model parameters are required. In the case of forward modeling, however, we do not have to resort to the MOM method; there is no need of modifying the coefficient matrix, and the auxiliary fields can be elicited from the regular FEM solution. The computational efficiency of the MOM method, however, can be greatly improved through a sophisticated rearrangement of the total equation.

Positional change in mandibular condyle in facial asymmetric patients after orthognathic surgery: cone-beam computed tomography study

  • Choi, Byung-Joon;Kim, Byung-Soo;Lim, Ji-Min;Jung, Junho;Lee, Jung-Woo;Ohe, Joo-Young
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.40
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    • pp.13.1-13.8
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    • 2018
  • Background: We evaluated change in the mandibular condyle after orthognathic surgery using cone-beam computed tomography (CBCT) in patients with facial asymmetry. Methods: Thirty patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry were classified into two groups according to the amount of menton deviation (MD) from the facial midline on anteroposterior (AP) cephalogram: group A (asymmetry, MD ≥ 4 mm; n = 15) and group B (symmetry, MD < 4 mm; n = 15). Position and angle of condylar heads on the axial, sagittal, and coronal views were measured within 1 month preoperatively (T0) and postoperatively (T1) and 6 months (T2) postoperatively. Results: On axial view, both groups showed inward rotation of condylar heads at T1, but at T2, the change was gradually removed and the condylar head returned to its original position. At T1, both groups showed no AP condylar head changes on sagittal view, although downward movement of the condylar heads occurred. Then, at T2, the condylar heads tended to return to their original position. The change in distance between the two condylar heads showed that they had moved outward in both groups, causing an increase in the width between the two heads postoperatively. Analysis of all three-dimensional changes of the condylar head positions demonstrated statistically significant changes in the three different CBCT views in group B and no statistically significant changes in group A. Conclusions: There was no significant difference between the two groups in condylar head position. Because sagittal split ramus osteotomy can be performed without significant change in symmetrical and asymmetrical cases, it can be regarded as an effective method to stabilize the condylar head position in patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry.

Interstitial Lung Disease Associated with Polymyositis: Response to Cyclophosphamide and Prednisolone Combination Treatment (Cyclophosphamide와 Prednisolone 병합요법에 치료반응을 보인 다발성근염에 동반된 간질성폐질환 1예)

  • Moon, Jong-Ho;Park, Jun-Young;Lee, Sang-Moo;Kim, Hyeon-Tae;Uh, Soo-Taek;Chung, Yeon-Tae;Kim, Yong-Hoon;Park, Choon-Sik;Lee, Kyung-Soo;Kang, Dae-Young
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.2
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    • pp.197-202
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    • 1993
  • Polymyositis (PM) is a inflammatory connective tissue disease involving predominantly skeletal muscles, characterized by symmetrical, proximal muscle weakness, inflammation, and frequently, degeneration. Interstitial lung disease in association with PM occurs in 5~10% of cases and carries an especially grave prognosis. Although the cause of lung involvement in PM is not known, the underlying pathologic process in the lung is an immune mediated inflammation of alveolar structures, alveolitis. It is of interest, therefore, that cyclophosphamide, an immune modulating agent, has been reported to be effective in the treatment of PM. We report a case of corticosteroid resistant PM associated with interstitial lung disease, successfully treated with cyclophosphamide. A 37-year-old female was presented with 8 months duration of cough, exertional dyspnea, and muscle weakness. She had typical symptoms, physical findings, and elevated muscle enzyme levels in serum with characteristic findings of muscle biopsy. She also had typical interstitial lung disease pattern on chest X-ray and high resolution CT with restrictive pattern on pulmonary function test. The findings of transbronchial lung biopsy was compatible with interstitial lung disease. She failed to respond to corticosteroid initially. Subsequently steroids and cyclophosphamide were given with excellent clinical improvement.

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A STUDY ON MORPHOLOGY AND SIZE OF CLINICAL CROWN OF PERMANENT MANDIBULAR MOLAR IN KOREAN ADULT (한국 성인의 하악대구치 임상치관의 형태와 크기에 관한 연구)

  • Oh, Sang-Chun
    • The Journal of Korean Academy of Prosthodontics
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    • v.37 no.2
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    • pp.242-255
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    • 1999
  • The purpose of this study was to estimate the morphology and the size of permanent mandibular molar in Korean Adult. The 100 dental college students with a normal dentition and without any dental prosthesis and severe caries were selected for this study The subjects were taken impression to make study model. On the study model, the 5 dentists measured those sizes and estimated morphological structures with a calipers, a Boley gauge and a protractor. The results were as follows; 1. The clinical crown height, width, thickness and the other anatomical structures had symmetrical relationship between the left and right mandibular molar. 2. In the clinical crown height aspect, the buccal crown heights always were higher than the lingual crown height. The heights of the each surface, the buccal or lingual surface, were gradually decreased from the 1st molar to the 2nd molar and the difference on the buccal surface was higher than that on the lingual surface. 3. In the clinical crown width aspect, the mesiodistal measurement of the mandibular 1st molar was higher than that of the mandibular 2st molar. 4. In the clinical crown thickness aspect, the mesial buccolingual measurement was highest on the mandibular 1st molar and the distal buccolingual distance was lowest on the mandibular 2nd molar. This distal thickness of the mandibular molar always was higher than that of the mesial half. 5. The well-developed mesiobuccal groove of the 1st molar was observed more often than that of the 2nd molar. The buccal pit was also observed more frequently at the 1st molar, but the frequency(35%) was not high. 6. The occlusal type according to the number of cusp was almost 5-cusp(98%) in the 1st molar and was also 5-cusp(63%) in the 2nd molar. The frequency of the 6th cusp was 31% in the 1st molar and was 22% in the 2nd molar. The frequency of the 7th cusp was below 2of in the both teeth. 7. In the buccolingual intercuspal distance aspect of the mesial and distal half, the intercuspal distance of distal half was higher than that of the mesial half on the 1st and 2nd molar, but the difference on the 1st molar was higher than that on the 2nd molar. 8. The difference between the widths of the buccal and lingual half was 1.5mm in the 1st molar and 0.8mm in the 2nd molar. Therefore the lingual convergency of the occlusal surface was more higher in the 1st molar. 9. On the mandibular 1st and 2nd molar, the distobuccal external angle was more acute than the mesiobuccal external angle. But the mesiobuccal internal angle was more acute than the distobuccal internal angle. 10. When the mandibular molar was a 5-cusp type, the development of the distal cusp on the 1st molar was better than that on the 2nd molar. The difference between the cusps was around 0.4mm.

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Photoelastic Stress Analysis of Fixed Partial Dentures (가공의치(架工義齒)에 작용(作用)하는 Stress에 관(關)한 광탄성학적(光彈性學的) 분석(分析))

  • Cho, Won-Haeng
    • The Journal of Korean Academy of Prosthodontics
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    • v.18 no.1
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    • pp.15-35
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    • 1980
  • The purpose of this study was to investigate stresses in the various components of fixed partial dentures restoring the posterior teeth of the lower jaw, and to measure quantitatively the effects of certain modifications in structural design on the stresses in the restorations using two-dimensional photoelasticity. Two-dimensional photoelastic methods were used in this study. Several models of fixed partial dentures were constructed. Shoulder less margins and anatomic occlusal reduction were incorporated in Model 1. Rounded shoulders and flat occlusal reduction were incorporated in Model 2, while Model 3 was a cantilever fixed partial denture. Other similar fixed partial dentures were constructed with V and U notches deliverately included in the region of the fixed joints for comparative reasons. The birefringent materials used in this study were PSM-1 and PSM-5 in standard sheets. PSM-1 was used for constructing the substructure, and PSM-5 was used in making the components of the fixed partial dentures. The two materials were used in the construction of composite photoelastic models. Improved artificial stone was used to represent dental cement in luting the composite photoelastic models. Static loading procedures were used at preplanned sites to represent occlusal loads in the mouth. 35 mm color and B/W film were used to record isochromatics in accordance with photoelastic procedures. Data reduction was performed using the grid method, which helped in, the mathematical integration procedure (Shear difference method) to separate the principal stresses. The results were as follows. 1. Fixed partial dentures do not function in bending as a symmetrical beam. Alternate areas of tension and compression were demonstrated when multiple contact loading was used. 2. The weakest part in posterior fixed partial dentures is the fixed joint. 3. (1) Models I and modified Model I were loaded on the pontic using a 50 pound vertical static load. The shear stress near the posterior fixed joint in Model 1 (U notches) was+129.4 p.s.i., and at the same fixed joint in modified Model 1 (V notches) was+239.4 p.s.i. The concentration of stress in fixed joint was reduced by 50% when U notches replaced the V notches. (2) Modified Model 2 was loaded using a multiple contact loader at a total load of 125 pounds. The difference between the principal stresses (${\sigma}_1-{\sigma}_2$), shear stress, at the V notches was+600 p.s.i., and at the U notches was+3l7 p.s.i. The shear stress was reduced by 50% when U notches replaced the V notches. V-grooves at the fixed joints should be avoided, and should be replaced by regular shaped U-grooves. 4. Cantilever fixed partial dentures had much higher stresses at the fixed joint than fixed partial dentures that were attached at both ends.

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Metal-Dinitrosyl Complexes(III) : Synthesis and Structural Study of Homo-, Hetero-dinuclear Molybdenum and Tungsten Complexes, $[Cl(phen)(NO)_2M({\mu}-pyz)M'(NO)_2(phen)Cl][ClO_4]_2 $(phen = 1,10-phenanthroline, pyz = pyrazine) (금속-디니트로실 착물 (제 3 보) : 몰리브덴과 텅스텐의 호모 및 헤테로 이핵 착물, $[Cl(phen)(NO)_2M({\mu}-pyz)M'(NO)_2(phen)Cl][ClO_4]_2 (phen=1,10-phenanthroline,\;pyz=pyrazine)$의 합성 및 구조에 대한 연구)

  • Sang-Oh Oh;Seong-Jong Mo
    • Journal of the Korean Chemical Society
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    • v.37 no.7
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    • pp.655-661
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    • 1993
  • The neutral monomeric compounds $[Mo(NO)_2Cl_2(phen)]$ and $[W(NO)_2Cl_2(phen)]$ (phen= 1,10-phenanthroline) have been prepared by reactions of polymeric compounds $[{Mo(NO)_2Cl_2}n],\;[{W(NO)_2Cl_2}n]$ with chelate ligands. Additions of one equivalent of silver(I) perchlorate to these cis-dinitrosyl compounds in acetone solution produce $[Mo(NO)_2(phen)(S)Cl][ClO_4]\;and\;[W(NO)_2(phen)(S)Cl][ClO_4]$ (S = acetone). The homo- and hetero-dinuclear complexes, $[Cl(phen)(NO)_2M(pyz)M'(NO)_2(phen)Cl][ClO_4]_2$ (M = Mo, W) and $[Cl(phen)(NO)_2M(pyz)M'(NO)_2(phen)Cl][C1O_4]_2$ (M = Mo, M' = W) have been prepared by these monocationic complexes with pyrazine ligand respectively. These complexes characterized by elemental analysis, $1^H-\;and\;^{13}C-NMR$, infrared, and UV-visible spectroscopy are reported. The spectral data indicate that homo- and hetero-dinuclear complexes were symmetrical structures of $C_{2v}$.

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Development of FURA Code and Application for Load Follow Operation (FURA 코드 개발과 부하 추종 운전에 대한 적용)

  • Park, Young-Seob;Lee, Byong-Whi
    • Nuclear Engineering and Technology
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    • v.20 no.2
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    • pp.88-104
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    • 1988
  • The FUel Rod Analysis(FURA) code is developed using two-dimensional finite element methods for axisymmetric and plane stress analysis of fuel rod. It predicts the thermal and mechanical behavior of fuel rod during normal and load follow operations. To evaluate the exact temperature distribution and the inner gas pressure, the radial deformation of pellet and clad, the fission gas release are considered over the full-length of fuel rod. The thermal element equation is derived using Galerkin's techniques. The displacement element equation is derived using the principle of virtual works. The mechanical analysis can accommodate various components of strain: elastic, plastic, creep and thermal strain as well as strain due to swelling, relocation and densification. The 4-node quadratic isoparametric elements are adopted, and the geometric model is confined to a half-pellet-height region with the assumption that pellet-pellet interaction is symmetrical. The pellet cracking and crack healing, pellet-cladding interaction are modelled. The Newton-Raphson iteration with an implicit algorithm is applied to perform the analysis of non-linear material behavior accurately and stably. The pellet and cladding model has been compared with both analytical solutions and experimental results. The observed and predicted results are in good agreement. The general behavior of fuel rod is calculated by axisymmetric system and the cladding behavior against radial crack is used by plane stress system. The sensitivity of strain aging of PWR fuel cladding tube due to load following is evaluated in terms of linear power, load cycle frequency and amplitude.

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