• Title, Summary, Keyword: Multiple Material

Search Result 1,027, Processing Time 0.036 seconds

Specular Reflectance Measurements of Dielectric Plates in Millimeter Frequency Range

  • Kang, Jin-Seob;Kim, Jeong-Hwan;Kang, Kwang Yong;Yoon, Dae Hwan;Park, Sung Won
    • Journal of electromagnetic engineering and science
    • /
    • v.18 no.2
    • /
    • pp.78-87
    • /
    • 2018
  • This paper describes specular reflectance measurements of dielectric plates in three waveguide frequency bands: D-band (110-170 GHz), G-band (140-220 GHz), and J-band (220-325 GHz). The transmit (Tx) part of the proposed specular reflectance measurement system is stationary, while the receive (Rx) part and the material under test (MUT) holder are concentric-rotating with a 2:1 speed ratio for specular reflectance measurements. In specular reflectance measurements, the first step measures the specular reflection coefficients of an MUT and a metal plate on the MUT holder located at the center of the Tx and Rx parts, and the second step calculates the specular reflectance defined by the specular reflection power (i.e., intensity) of the MUT normalized to that of the metal plate. Multiple reflection effects between the Tx and Rx antennas and the MUT on the measured specular reflectance are minimized by averaging out the multiple specular reflectances measured with changing the separation distance between the two antennas by ${\lambda}/8$ intervals. Measurement results of the perpendicular-polarized specular reflectance of commonly used dielectric plates are verified by comparing those with the analytic results and show that the results measured over the overlapped frequency range of the D-/G-bands and at the boundary frequency of the G-/J-bands agree well with the results for the other band, respectively.

Nonlinear Analysis of Reinforced Concrete Members using Plasticity with Multiple Failure Criteria (다중 파괴기준의 소성모델을 이용한 철근콘크리트부재의 비선형 해석)

  • 박홍근
    • Magazine of the Korea Concrete Institute
    • /
    • v.7 no.5
    • /
    • pp.145-154
    • /
    • 1995
  • Concrete has two different failure mechanisms : compressive crushing and tensile cracking. Concrete models should use the two different failure criteria to analyze the inelastic behavior of concrete including multiaxial crushing and tensile cracking. Concrete models used in this study are based on plasticity with multiple failure criteria of compressive crushing and tensile cracking. For tensile cracking behavior, two different plasticity models are investigated. The* ,e are rotating-crack and fixed-crack plasticity models, classified according to idealization of crack 0rientat:ions. The material models simplify inelastic behavior of concrete for plane stress problenls. The material models are used for the finite element anlaysis. Analytical results are compared with several experiments of reinforced concrete member. The advantages and disadva.ntages of rotating-crack and fixed -crack plasticity models are discussed.

Development of Multiple Wireless Communication Controller for Smart Factory Construction (스마트팩토리 구축을 위한 다중 무선통신 컨트롤러 개발)

  • Oh, Jae-Jun;Choi, Seong-Ju;Kim, Jin-Sa
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.30 no.9
    • /
    • pp.602-608
    • /
    • 2017
  • Due to recent industry 4.0, manufacturing has changed a lot. In particular, it is necessary to control the controller and controller of the control system, to communicate various production information and measurement information, and to produce a database in accordance with the flexible production for a small quantity of various items, and to manage the trend of major parts of production facilities. In this paper, we developed a multiple wireless communication controller for small scale control system for smart factory by applying XBee and microcomputer. This controller is cheap and easy to build multi-radio communication environment of 1: N and can control and monitor control system. In addition, we tested multiple wireless communication controllers by using signal processing device and C++, and constructed network, control, and database for mechanism module, and confirmed effectiveness for industrial application.

Green Consumption Behavior According to the Lifestyles of College Students (대학생 소비자의 라이프스타일에 따른 녹색소비행동에 관한 연구)

  • Kim, Hyo-Chung
    • Korean Journal of Human Ecology
    • /
    • v.20 no.6
    • /
    • pp.1135-1151
    • /
    • 2011
  • This study examined green consumption behavior according to the lifestyles of college students. The data were collected from 314 college students in Yeungnam region by a self-administered questionnaire. Frequencies, Cronbach's alpha, factor analysis, cluster analysis, chi-square tests, one-way analysis of variance, Duncan's multiple range tests, Pearson's correlation analysis, and multiple regression analyses were conducted by SPSS Windows V.18.0. According to the result of factor analysis, lifestyles were categorized into six factors: thrift-saving type, enthusiastic activity type, brand ostentation type, freedom-seeking type, material oriented type, and practice-seeking type. Cluster analysis showed respondents belonged to one of four groups: thrift practice group, indifference group, freedom-seeking group, and material ostentation group. The levels of green purchase behavior, green usage behavior and green disposal behavior of the respondents was not high. The thrift practice group showed higher levels of green purchase behavior, green usage behavior, and green disposal behavior. Finally, according to multiple regression analyses, environmental consciousness, knowledge about green consumption, lifestyle groups were the significant factors affecting green consumption behaviors. These results imply that green consumption education for college students should be activated to induce green life.

Embodiment of Spatially Arterial Pulse Diagnostic Apparatus using Array Multiple Hall Devices

  • Lee, Sang-Suk;Kim, Gi-Wang;Ahn, Myung-Cheon;Park, Young-Seok;Choi, Jong-Gu;Choi, Sang-Dae;Park, Dal-Ho;Hwang, Do-Guwn;Yoon, Hyung-Rho
    • Journal of Biomedical Engineering Research
    • /
    • v.28 no.6
    • /
    • pp.721-726
    • /
    • 2007
  • The study relates to achievement and analysis of 3-dimensional spatial pulse wave archived by a spatially arterial pulse diagnostic apparatus (SAPDA), wherein a pulse sensing part array consists of multiple hall devices and is located over a skin contacting part which consists of a magnetic material. When a radially arterial pulse is transferred to the magnetic material, which is contacted skin that results in changes in a magnetic field of the lower part of the pulse sensing part array, the changes in a magnetic field can be detected by the commercial Hall semiconductor device of the pulse sensing part array. Finally, according to development of SAPDA, the 3-dimensionally arterial pulse waveform can be measured noninvasively by detecting the changes of the magnetic field.

Analysis of the Uses of External Representations in Material Units of 7th Grade Science Textbooks Developed Under the 7th National Curriculum (제7차 중학교 1학년 과학 교과서의 물질 단원에서 외적 표상들의 활용 실태 분석)

  • Kang, Hun-Sik;Kim, You-Jung;Noh, Tae-Hee
    • Journal of The Korean Association For Science Education
    • /
    • v.27 no.3
    • /
    • pp.190-200
    • /
    • 2007
  • In this study, we analyzed the uses of external representations in material units of 7th grade science textbooks developed under the 7th National Curriculum on the basis of theories and research results on learning with multiple representations. The results revealed that the frequencies of microscopic external representations were higher than those of macroscopic and symbolic external representations. The external representations with drawing and/or writing were presented more frequently than those without drawing and/or writing. Furthermore, the external representations were rarely presented on the basis of the principles (e.g., personalization principle) and/or theories (e.g., dual coding theory, cognitive load theory, and social constructivism theory) for effective uses of the external representations in learning with multiple representations. Educational implications are discussed.

Fabrication of Photonic Quasicrystals using Multiple-exposure Holographic Method (다중-노출 홀로그라피 방법을 이용한 광자준결정 제작)

  • Yun, Sang-Don;Yeo, Jong-Bin;Lee, Hyun-Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.21 no.9
    • /
    • pp.829-834
    • /
    • 2008
  • Two-dimensional photonic quasicrystal (PQCs) template patterns have been fabricated on a 1.1 ${\mu}m$-thick DMI-150 photoresist using a multiple-exposure holographic method. A 442-nm HeCd laser was utilized as a light source and the holographic exposure was carried out at a fixed angle of ${\theta}$ = 6$^{\circ}$. After the first holographic exposure, the sample was rotated to a proper angle and the second exposure was performed to the same manner. This exposure process was repeated n/2 times to obtain n-fold symmetric PQC patterns and then the sample was developed. The diffraction patterns of the fabricated PQC template were observed using a 632.8-nm HeNe laser. The fabricated PQCs exhibited 8, 10 and 12-fold rotational symmetry, which was in a good agreement with the interference simulation results. In addition, the diffraction patterns with n-rotation symmetry were observed for the corresponding n-fold PQCs. We believe that the multiple-exposure holography is a good method to fabricate the mesoscale PQCs with a high rotational symmetry.

Material feature representation and identification with composite surfacelets

  • Huang, Wei;Wang, Yan;Rosen, David W.
    • Journal of Computational Design and Engineering
    • /
    • v.3 no.4
    • /
    • pp.370-384
    • /
    • 2016
  • Computer-aided materials design requires new modeling approaches to characterize and represent fine-grained geometric structures and material compositions at multiple scales. Recently, a dual-Rep approach was developed to model materials microstructures based on a new basis function, called surfacelet. As a combination of implicit surface and wavelets, surfacelets can efficiently identify and represent planar, cylindrical, and ellipsoidal geometries in material microstructures and describe the distribution of compositions and properties. In this paper, these primitive surfacelets are extended and composite surfacelets are proposed to model more complex geometries. Composite surfacelets are constructed by Boolean operations on the primitives. The surfacelet transform is applied to match geometric features in three-dimensional images. The composition of the material near the identified features can then be modeled. A cubic surfacelet and a v-joint surfacelet are developed to demonstrate the reverse engineering process of retrieving material compositions from material images.

Piezoelectric Beam Rotating Actuator for Multiple Beam Disk Drives (압전소자률 이용한 다중빔 광디스크용 빔 회전 구동기)

  • 김병준;김수현;곽윤근
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.5
    • /
    • pp.154-159
    • /
    • 2000
  • A multi-beam optical disk drive is presented as a method for improving the effective data transfer rate by increasing the beam spot number formed on an optical disk. The beam rotating actuator is necessary for putting multi-beam on more than one track. The beam rotating actuator is made up of piezoelectric material, high stiffness wire hinge and dove prism. The actuator has good frequency response above 1KHz and suitable operational range. The dynamic equation for the actuator is derived.

  • PDF

Algorithm Development of Electric Door Lock for Security Improvement (전자 도어록의 보안성 향상을 위한 알고리즘 개발)

  • 장긍덕;고영준;남효덕;장호경
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.515-518
    • /
    • 2001
  • In this study, the electric door lock using the password input system for security improvement was fabricated. The security has been improved by using the multiple micro process. The controller with solenoid valve has been designed indirect driving system for releasing the door lock system. Also, the self checkup system for improving the trustworthy was developed with two kinds of micro process. The results will be applied IC card system and fingerprint identification system for security improvement.

  • PDF