• Title/Summary/Keyword: Field correction

Search Result 737, Processing Time 0.042 seconds

A New Expression of Near-Field Gain Correction Using Photonic Sensor and Planar Near-Field Measurements

  • Hirose, Masanobu;Kurokawa, Satoru
    • Journal of electromagnetic engineering and science
    • /
    • v.12 no.1
    • /
    • pp.85-93
    • /
    • 2012
  • We propose a new expression of the near-field gain correction to calculate the on-axis far-field gain from the onaxis near-field gain for a directive antenna. The new expression is represented by transversal vectorial transmitting characteristics of two antennas that are measured by planar near-field equipment. Due to the advantages of the photonic sensor, the utilization of the new expression realizes the measurements of the on-axis far-field gains for two kinds of double ridged waveguide horn antennas within 0.1 dB deviation from 1 GHz to 6 GHz without calibrating the photonic sensor system.

Optimum Field Balancing of Ratating Machinery Using Genetic Algorithm (유전 알고리즘을 이용한 회전기계의 최적 현장평형잡이)

  • Choi, Won-Ho;Yang, Bo-Suk;Joo, Ho-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.20 no.6
    • /
    • pp.1819-1826
    • /
    • 1996
  • This paper present the claculating method of optimum correction mass within permissible vibration linits for ratating machinery in two-plane field balancing. Basic technique of this method is based on influence coefficient method, and grphic vector composition that the resultant of two influence vectors obtained by trial mass have to be equilibrium with initial vibration vector in the each correction plane. Genetic algorithm which is a search algorithm based on the mechanism of natural selection and natural genetics is sued for vector composition, and SUMT method is used to objective function which seeks optimum correction mass for balancing a rotor.

Diffraction of Electromagnetic Waves by a Dielectric Wedge, Part II: Correction by Multipole Line Source (쇄기형 유전체에 의한 전자파의 회절, II부 : 다극선전원에 의한 수정)

  • 김세윤;라정웅;신상영
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.25 no.8
    • /
    • pp.884-892
    • /
    • 1988
  • An asymptotic solution of electromagnetic waves scattered by an arbitrary-angled dielectric wedge in the E-polarized plane wave incidence is obtained by adding a correction to the physical optical fields given in the previous paper of these companion papers, Part I. The source for the asymptotic correction field valid in the far-field region can be equivalent to the multipole line sources at the tip of the wedge, of which coefficients are evaluated numerically by solving a dual series equation. The corrected field patterns are plotted for the typical case treated in Part I.

  • PDF

The Study on Correction Factor of a Small Scale Reverberation Chamber to Estimate Transmission Loss (소형 잔향실의 확산 음장 보정 계수 측정 연구)

  • Kim, Tae Min;Kim, Da Rae;Kim, Jeung Tae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2014.10a
    • /
    • pp.960-965
    • /
    • 2014
  • Transmission loss of specimen is calculated by measuring energy of incident and transmission and using reverberant room of large size. But normal measurement of transmission loss has trouble because it is actually demanded that large area and specimen of certain size is satisfied with condition of diffused sound field. Especially, in case of mechanical component, interested frequency band is mid-frequency band between 500 ~ 2k Hz, and it is used to be available to minimize a reverberation chamber under conditions satisfying acoustic one because production of specimen for transmission loss measurement has limit. But, as in semi-reverberation room, it is difficult to satisfy condition of diffuse sound field and modification factor is applied to complement that. Correction factor when measuring transmission loss using semi-reverberation chamber is required accuracy because it works as main factor determining reliability of reuslts on transmission loss. In this study, it is analyzed that an effect on correction factor based on varying materials and sizes of specimens in order to deduction of it. Also It is confirmed that applied by elicited correction factor with actual railway vehicle's floor has reliability.

  • PDF

Atmospheric and BRDF Correction Method for Geostationary Ocean Color Imagery (GOCI) (정지궤도 해색탑재체(GOCI) 자료를 위한 대기 및 BRDF 보정 연구)

  • Min, Jee-Eun;Ryu, Joo-Hyung;Ahn, Yu-Hwan;Palanisamy, Shanmugam;Deschamps, Pierre-Yves;Lee, Zhong-Ping
    • Korean Journal of Remote Sensing
    • /
    • v.26 no.2
    • /
    • pp.175-188
    • /
    • 2010
  • A new correction method is required for the Geostationary Ocean Color Imager (GOCI), which is the world's first ocean color observing sensor in geostationary orbit. In this paper we introduce a new method of atmospheric and the Bidirectional Reflectance Distribution Function(BRDF) correction for GOCI. The Spectral Shape Matching Method(SSMM) and the Sun Glint Correction Algorithm(SGCA) were developed for atmospheric correction, and BRDF correction was improved using Inherent Optical Property(IOP) data. Each method was applied to the Sea-Viewing Wide Field-of-view Sensor(SeaWiFS) images obtained in the Korean sea area. More accurate estimates of chlorophyll concentrations could be possible in the turbid coastal waters as well as areas severely affected by aerosols.

An Overview of Clinical Studies on Pelvic Correction in Korea (골반교정에 대한 국내 임상 연구 동향)

  • Beag, Ji You;Bae, Jae Ryong;Ahn, Hun Mo;Lee, Jae Heung
    • Journal of Korean Medical Ki-Gong Academy
    • /
    • v.20 no.1
    • /
    • pp.118-147
    • /
    • 2020
  • Objective : The purpose of this study is to understand trends of pelvic correction therapy in Korea and to assist research activities on pelvic correction therapy. Also, this study selected and presented indicators for measuring pelvic slope to help ensure consistent studies with uniform indicators in future studies related to pelvic correction. Methods : The following keywords "골반", "골반 교정", "골반 변위" "Pelvic correction" were searched on three specialized search sites (RISS, NAI, DBpia). Trends in pelvic correction therapy were analyzed through the selected researches suitable among these searched researches in an overview format. Results : 1. A total of 7,806 studies were searched and a total of 268 studies were finally selected. 2. Studies began in 1977 and have been actively studied until recently, with 35 studies in 2017 being the most recent trend since 2000. 3. In the results according to the Main Field of Research, the 'Arts and Kinesiology'(113, 42.16%) and 'Medicine and Pharmacy'(103, 38.43%) were the most in order. To the Middle Field, the 'Kinesiology was the largest with 96(35.82%) studies. 4. In the results according to the study design, 'Pre-Post Test(PPT)' was the largest with 107 studies. 5. In the results according to the Intervention, 'Exercise' was the largest with 165 studies, of which 'Pilates' and 'Yoga' in 'Training' was the largest. 6. Among the evaluation method, the 'Pelvic Index' was used 146 times, followed by 'Spinal Alignment (99)', 'Other Joints (93)', and 'Kinetic Specialized Measurement Test (56)'. 7. Among the evaluation methods, the pelvic slope measurement indicators were PT (58), PH (48), Pelvic Torsion (40), Iliac Crest (38), ASIS-PSIS distance/angle (27), and Pelvic Width (I.W., I.L., S.W) (25) in order. 8. The journals that published the most researches were KJSS(Korean Alliance For Health, Physical Education, Recreation, And Dance;9), and JKPT(Korean Physical Therapy;9). Among the University, the Graduate School of Silla University published the most papers (12). 9. The author who published the most studies were Seungjin Park(3), the co-authors were Hoseong Lee, Gideok Park, Seongsu Bae(3), and the Thesis-Director Gyeongok Lee(7). Conclusions : 1. Studies on pelvic correction treatment continue to increase every year. 2. The main academic field of pelvic correction is 'Sports', 'Physical Therapy', and 'Medical Science'. 3. The most chosen research design method in the study on pelvic correction treatment was 'Pre-Post Test(PPT)', primarily as an intermediary, Pilates and yoga during exercise therapy, and then Chiropractic during handcraft were used as multiple frequencies. 4. Among the various measurement method indicators of pelvic correction previously used, multiple frequency was taken up in the order of PT, PH, Pelvic Torsion, iliac crest, ASIS-PSIS distance/angle, and pelvic width (I.W.,I.L.,S.W). Typically, measurements through "ASIS-PSIS angle" are recommended and are considered as the most rational in clinical trials.

Development of Mathematics Assessment and Correction Materials according to Mathematics Learning Hierarchy: Focused on the Function for 7th Grade (수학 학습 위계에 따른 수학 평가·보정 자료 개발 연구: 중학교 1학년 함수 영역을 중심으로)

  • Huh, Nan;Kim, Soocheol
    • East Asian mathematical journal
    • /
    • v.36 no.4
    • /
    • pp.437-454
    • /
    • 2020
  • The purpose of this study is to develop a mathematical assessment and correction materials according to the mathematics learning hierarchy. The scope of the study is set to 'function' in 7th grade of middle school. The researchers developed a draft of the mathematical assessment and correction materials based on the mathematics learning hierarchy through the pilot test and the expert review. Using the results of the expert review, the researchers modified and supplemented the math assessment and correction materials to produce the final version. The mathematics assessment and correction material developed in this study is expected to build an effective guidance system for students with mathematics deficits. In addition, by presenting a mathematical assessment and correction materials to the teachers in the field, it is possible to reduce the effort for the management of underachievers and to provide guidance for the education of students with a lack of math learning.

Clinical Use of Shielding Block Correction factors (차폐블록보정인자의 임상적 응용)

  • 이정옥;정동혁
    • Progress in Medical Physics
    • /
    • v.14 no.2
    • /
    • pp.69-73
    • /
    • 2003
  • In this study, we measured shielding block correction factors for irregular fields and compared them with published data for the square blocked field. We devised a methods to measure the factors at an arbitrary depth in phantom. The measurements were performed for 12 shielding blocks used in radiation therapy. The measured correction factors for irregular blocked fields were consistent within $\pm$0.5% with those of the square blocked fields. Our results show that the shielding block correction factors for the typical square blocked fields can be used in clinical dose calculations for irregular blocked fields. However, for small fields, we suggest that verification be done by measurement.

  • PDF