• Title/Summary/Keyword: Half-symmetry

Search Result 65, Processing Time 0.031 seconds

Simulation of Static Characteristics of Railway Vehicle's Airspring (철도차량용 공기 스프링의 정적 특성 시뮬레이션)

  • Heo, Sin;Gu, Jeong-Seo;U, Chang-Su;Kim, Yu-Il
    • 연구논문집
    • /
    • s.26
    • /
    • pp.15-24
    • /
    • 1996
  • In this study, we performed the static analysis of a cord-reinforced rubber airspring and generated the three-dimensional half-symmetry model which use the finite-strain shell elements to model the airbag. the three-dimensional hydrostatic fluid elements to model the air-filled cavity, and the rebar elements to model the multi-ply nylon reinforcement of airbag. In addition, a three-dimensional rigid surface is used to define the contact between the airspring and metal bead. The air inside the airspring cavity has been modeled as a compressible fluid satisfying the ideal gas law. The conclusions of this study are as follows. 1) In the pressurization step of analysis, we could predict the change of vertical reaction force, cavity volume and pressure within the airspring. 2) In the second step of analyzing vertical static stiffness, the increase of the vertical load increases the vertical stiffness. 3) In case of changing the angle of nylon cord, the increase the angle of nylon cord increases the vertical stiffness.

  • PDF

Ship Frame Ring Analysis by a Matrix Method (매트릭스법(法)에 의한 선체근골환(船體筋骨環) 해석(解析))

  • S.J.,Yim
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.10 no.1
    • /
    • pp.21-26
    • /
    • 1973
  • A simple matrix method to analyze the ship's transverse frame ring is proposed. In this approach, the frame ring is treated as a plane frame of uniform slender members. The loadings on the frame consist of buoyancy loads, deck loads and cargo loads. The hatch coaming are considered to deflect under the loads. Because of symmetry, only the half of the frame is analyzed. The method is to obtain the forces and moments on each member. The deformation of the frame can be determined from the nodal displacements. For a sample calculation, a frame ring of a 10,000 ton class cargo liner is analyzed on the IBM 1130 computer. The numerical results obtained are proved to be resonable.

  • PDF

Crystal and Molecular Structure of Hexaimidazolidone Chromium(III) Nitrate, $[Cr(OC_3H_6N_2)_6](NO_3)_3\cdot4H_2O$ (Hexaimidazolidone Chromium(III) Nitrate, $[Cr(OC_3H_6N_2)_6](NO_3)_3.4H_2O$의 결정 및 분자 구조)

  • Suh, Jung-Sun;Lee, Kyu-Wang;Suh, Il-Hwan
    • Korean Journal of Crystallography
    • /
    • v.11 no.2
    • /
    • pp.71-74
    • /
    • 2000
  • The title compound, [Cr(OC3H6N2)6](NO3)3·4H2O, was crystallized in the centrosymmetric space group P with two half molecules in an asymmetric unit, and the two complete molecules are generated by inversion symmetry located at Cr atoms. Therefore, the Cr atoms are coordinated to six imidazolidone ligands through the oxygen atoms, and both CrO6 units have a slightly distorted octahedral geometry.

  • PDF

Development of textured Ni and Ni alloy(Ni-W and Ni-Cu) substrates for YBCO coated conductor (YBCO 박막선재용 Ni 및 Ni 합금 기판의 집합도 분석)

  • 지봉기;김민우;김찬중
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
    • /
    • 2003.10a
    • /
    • pp.24-26
    • /
    • 2003
  • We fabricated Ni and Ni alloy substrates for YBCO coated conductors. The Ni and Ni alloy substrate was fabricated by powder metallurgy technique and cold rolling. The texture of substrates had a strong 4-fold symmetry and [111]∥ND texture after annealing temperature of 100$0^{\circ}C$. The measured full-width half-maximum (FWHM) of in-plane and out-of-plane was in the range of 6$^{\circ}$-10$^{\circ}$. The powder metallurgy technique is fabrication of the substrates for considered to be suitable for the application of YBCO coated conductors.

  • PDF

A Miniaturized Aperture-Coupled Multilayer Hairpin Bandpass Filter

  • Moon, Han-Ul;Choi, Seung-Un;Yun, Sang-Won
    • Journal of electromagnetic engineering and science
    • /
    • v.8 no.1
    • /
    • pp.12-16
    • /
    • 2008
  • In this paper, we introduce a coupling, which is achieved through the aperture instead of the conventional edge coupling, so that the bandpass filter is reduced less than half in size compared to conventional planar type. The resulting filter configuration has a near two-fold symmetry, where the aperture coupling is used in the middle of the coupling stages. We designed a bandpass filter using two tapped hairpin resonators, of which the order becomes four. The designed bandpass filter has the size of $8.9{\times}18.3\;mm$. It has the return loss better than 17dB and the insertion loss of less than 5 dB in overall passband. The measured results show good agreements with simulated ones.

Characteristics Analysis Eddy Current Sensor Using by Numerical Analysis (수치해석을 이용한 와전류센서의 특성해석)

  • Choi, Duck-Su;Lee, Hyang-Beom;Na, Eun-Jin
    • Proceedings of the KIEE Conference
    • /
    • 2003.07b
    • /
    • pp.1000-1002
    • /
    • 2003
  • The characteristics of eddy current sensor has been analyzed by using numerical analysis which is performed by modeling eddy current sensor and analytic object into three-dimension axis-symmetry in this paper. The eddy current sensor is modeled as cylindrical shape with variation of inside and outside diameter and frequency range between 1[kHz] and 1[MHa] for numerical analysis. The value of impendence on eddy current sensor depending on frequency variation was calculated through numerical analysis. The characteristics of eddy current sensor can be studied by normalized impendence which is gained from the calculated impendence. Therefore, sensitivity of eddy current sensor depending on frequency, inside and outside diameter can be known by investigating diameter of half circle impendence and its locus.

  • PDF

Architectural Characteristics of Catholic Churches built in 1950s in Gangwon Province (1950년대 건립된 강원지역 성당건축의 건축적 특성)

  • Seo, Seong Nam;Choi, Jang Soon
    • Journal of the Korean Institute of Rural Architecture
    • /
    • v.20 no.4
    • /
    • pp.65-75
    • /
    • 2018
  • This thesis attempts to investigate and analyse the architectural characteristics of catholic churches in Gangwon province built in the 1950s. Catholic churches built at that time in Korea had many similarities basically since they were supported by UN forces after the Korean War and were established by priests connected to the Missionary Society of St. Columban. The results of study are as follows. In location, Except one catholic church, the catholic churches preferred low and gentle hill. In layout axis, catholic churches at Youngseo area preferred the north-south layout axis, whereas those at Youngdong favor the east-west layout axis. In approach, most of catholic churches around the Youngseo and Youngdong areas preferred entering the front entrance with a bell tower, whereas three of them at Youngdong did entering the front entrance with a bell tower around the rear corner. In floor plan, catholic churches at Youngseo preferred symmetry, whereas those at Youngdong preferred asymmetry. And every floor plan of catholic churches is rectangular type with transepts except one semicircular type. In apse shape, catholic churches in the Youngseo area preferred non-extruded types like a straight wall, whereas those in Youngdong have extruded types. Every catholic churches have no crypt under ground except one at Gangreung. Except one at Sokcho, every catholic church in this study has choir space in half story.

The Particle Size Distribution of $\alpha-Fe_2O_3$from Mossbauer Spectra (${\Alpha}-Fe_2O_3$ 미세입자의 크기분포에 관한 Mossbauer 분광학적 연구)

  • 이민용;김시정;고영복;서정철;이충섭
    • Journal of the Korean Magnetics Society
    • /
    • v.9 no.1
    • /
    • pp.23-28
    • /
    • 1999
  • ${\Alpha}-Fe_2O_3$ was accomplished by chemical method as low temperature as possible and the crystallographic and magnetic properties have been studied by Mossbauer spectroscopy and X-ray diffraction. The sample heated at 15$0^{\circ}C$ is found to have a Corundums symmetry with the hexagonal lattice constant a=8.26$\pm$0.05$\AA$, c=8.75$\pm$0.05$\AA$. The M$\"{o}$ssbauer spectra between the 4.2K and the room temperature show that the ${\Alpha}-Fe_2O_3$ crystallized with a single phase and fine sizes. The particle size distribution has the Gaussian distribution center at 98$\AA$ and the half width of 32$\AA$.TEX>.

  • PDF

PERCEPTION ASSESSMENT OF ESTHETICS OF UPPER ANTERIOR TEETH (상악전치부 심미에 대한 인식도 평가)

  • Jung Jae-Hoon;Oh Sang-Chun
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.41 no.5
    • /
    • pp.640-655
    • /
    • 2003
  • Statement of problem : The beauty has a little different meaning according to a time, culture, and nation. Purpose : This study was undertaken to determine the Korean perception of the altered upper anterior dental esthetics including the lack of symmetry, the midline deviation, the gingival exposure, the inclination of incisal plane, the type of incisal plane, and the type of gingival line. Material and Method : 670 subjects were participated in this survey. A questionnaire accompanied by 12 sets of computer-manipulated images using 3D MAX 4.2 software was used to record the ranking of the geometric preference related to the anterior esthetic discrepancies in three or four degrees of alteration. The statistical significance of the differences between the groups was determined by a one-way ANOVA and a t-test. Results : The results obtained were as follows: 1) The Korean perception of the anterior dental esthetics according to the subjects' occupation, sex, and age was most affected by occupation. 2) The masked image emphasizing the dentition and lips appeared stranger than the non-masked image at the same alteration. 3) The lack of symmetry, which was expressed as a unilateral discoloration of the tooth, showed incongruity in any teeth of the anterior dentition. The incongruity was more severe as the degree occurred closer to the midline. 4) The deviation of midline was showed more severe strangeness as the degree of deviation increased. However, more than half of the subjects did not perceive a deviation of 5mm. 5) During smiling, the exposure of the upper gingiva showed more severe incongruity as the degree of gingival exposure increased. 77% of the subjects perceived strangeness at the gingival exposure of 4.5mm. 6) The inclination of the incisal plane appeared stranger as the degree of inclination increased. 62% of subjects perceived strangeness at the $7.5^{\circ}$ inclination of the incisal plane. 7) The type of incisal plane showed increasing strangeness in the order of convex/downward, straight/horizontal, and concave/upward. 80% of subjects perceived strangeness at concave/upward. 8) The type of gingival line was showed increasing incongruity in the order of the same, a little above, and a little under the zenith of the lateral incisor to the line joining the zenith of the central incisor and the canine. However, less than half the subjects did not perceive strangeness at any alteration of the gingival line. Conclusion : The Korean perception of the upper anterior dental esthetics was different to the westerner's perception in the some respects.

Half-metallicity and Magnetism of Co2ZrSi/ZnTe(001) Interface: A First-principles Study (Co2ZrSi/ZnTe(001)계면의 자성과 반쪽금속성에 대한 제일원리 연구)

  • Jin, Y.J.;Lee, J.I.
    • Journal of the Korean Magnetics Society
    • /
    • v.17 no.4
    • /
    • pp.147-151
    • /
    • 2007
  • We have investigated the half-metallicity and magnetism for the Heusler ferromagnet $Co_2$ZrSi interfaced with semiconductor ZnTe along the (001) plane by using the full-potential linearized augmented plane wave (FLAPW) method. We considered low types of possible interfaces: ZrSi/Zn, ZrSi/Te, Co/Zn, and Co/Te, respectively. From the calculated density of states, it was found that the half-metallicity was lost at all the interfaces, however for the Co/Te system the value of minority spin density of states was close to zero at the Fermi level. These facts are due to the interface states, appeared in the minority spin gap in bulk $Co_2$ZrSi, caused by the changes of the coordination and symmetry and the hybridizations between the interface atoms. At the Co/Te interface, the magnetic moments of Co atoms are 0.68 and $0.78{\mu}_B$ for the "bridge" and "antibridge" sites, respectively, which are much reduced with respect to that ($1.15{\mu}_B$) of the bulk $Co_2$ZrSi. In the case of Co/Zn, Co atoms at the "bridge" and "antibridge" sites have magnetic moments of 1.16 and $0.93{\mu}_B$, respectively, which are almost same or slightly decreased compared to that of the bulk $Co_2$ZrSi. On the other hand, for the ZrSi/Zn and ZrSi/Te systems, the magnetic moments of Co atoms at the sub-interface layers are in the range of $1.13{\sim}1.30\;{\mu}_B$, which are almost same or slightly increased than that of the bulk $Co_2$ZrSi.