• Title/Summary/Keyword: Range Alignment

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통신방송위성 안테나 얼라인먼트 측정

  • Yoon, Yong-Sik;Park, Hong-Chul;Son, Young-Seon;Lee, Byoung-Gi
    • Aerospace Engineering and Technology
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    • v.3 no.1
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    • pp.117-125
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    • 2004
  • The three-dimensional precision measurement technology for industrial product of middle and/or large scale has been developed. Theodolite measurement system which is one of the technology is widely used in aerospace industry. This paper describes a range alignment method of parabolic antenna to RF probe in the near field range by using the theodolite system. The range alignment of the Ku-band and Ka-band antennas has been accomplished within the requirements, ±1 mm and ±$0.05^{circ}$.

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Evaluation of Optimal Horizontal Alignment Considering Ride Comfort in Renewal of Curved Tracks (곡선부 선형개량 시 승차감을 고려한 최적평면선형 평가)

  • Um, Ju-Hwan;Choi, Il-Yoon;Lee, Jun S.
    • Journal of the Korean Society for Railway
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    • v.18 no.5
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    • pp.457-465
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    • 2015
  • A method of evaluating the optimal alignment range while considering ride comfort when performing line renewal of curved tracks for speed-up is proposed in this study. The proposed method was applied to analyze the optimal renewal range for horizontal alignments with the smallest curve radii in the Kyung-Bu high-speed line; a parametric study on the effects of various initial design conditions on the permissible renewal range and optimal alignment range was also performed. From the analysis results, it was found that the permissible range is enhanced in proportion to the increase in the curve radius and the cant. It was also verified that a slight adjustment of the horizontal alignment enables speed-up even in the case of R7000/R8000, placed in the ballasted track section of the Kyung-Bu high-speed line.

Range Alignment Measurement for Satellite Antenna by Using Theodolite System (데오드라이트 시스템을 이용한 위성 안테나 레인지 얼라인먼트 측정)

  • Park, Hong-Cheol;Son, Yeong-Seon;Yun, Yong-Sik
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.6
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    • pp.134-141
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    • 2004
  • The three-dimensional precision measurement technology for industrial product of middle and/or large scale has been developed. Theodolite measurement system which is one of the technology is widely used in aerospace industry. This paper describes a range alignment method of parabolic antenna to RF probe in the near field range by using the theodolite system, The range alignments of the Ku-band and Ka-band antennas have been accomplished within the requirements, ${\pm}1mm\;and\;{\pm}0.05^{\circ}$.

Vertical Alignment of Nematic Liquid Crystal on the SiC Thin Film Layer with Ion-beam Irradiation

  • Oh, Yong-Cheul;Lee, Dong-Gyu
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.6
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    • pp.301-304
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    • 2006
  • We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of the SiC (Silicon Carbide) thin film. The SiC thin film exhibits good chemical and thermal stability. The good thermal and chemical stability make SiC an attractive candidate for electronic applications. A vertical alignment of nematic liquid crystal by atomic beam exposure on the SiC thin film surface was achieved. The about $87^{\circ}$ of stable pretilt angle was achieved at the range from $30^{\circ}\;to\;45^{\circ}$ of incident angle. Consequently, the vertical alignment effect of liquid crystal electro-optical characteristic by the atomic beam alignment method on the SiC thin film layer can be achieved.

Chemical Structural Effects of Polyimides on the Alignment and Electro-optical Properties of Liquid Crystal Cells

  • Paek, Sang-Hyon;Wonseok Dong
    • Macromolecular Research
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    • v.12 no.3
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    • pp.251-257
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    • 2004
  • The nature of the nematic liquid crystal (LC) alignment induced by the rubbed polyimide (PI) alignment layers (ALs) and the electro-optical (EO) properties of the LC cells are expected to depend on the chemical and physical features of the PI. By employing five pyromellitic dianhydride (PMDA)-type PIs having different functionalities, we have studied the effects of the PI's structure and chemistry on the alignment characteristics and the cell's EO properties. Increasing the flexibility of the PI increases the pretilt angle and tends to improve the alignment stability. On the other hand, the rigid, fluorinated PI displays poor stability for LCs and induces a less stable/uniform LC alignment and, subsequently, a small pre tilt angle. It also transpired that fluorination of the PI deteriorated the voltage-transmittance characteristics and the voltage holding ratio; increasing the flexibility of the PI structure improves these EO properties. The finding that the qualitative trends for the PI's functionalities are similar for both the alignment and EO properties suggests that the EO properties are closely related to the alignment characteristics, which are determined by short-range interactions between LC and PI molecules.

A Study of Comparison of Pelvic Alignment, Hip Joint Range of Motion About 20's Female University Students' With Dysmenorrhea (여대생의 월경곤란증 정도에 따른 골반정렬과 고관절 가동범위의 비교연구)

  • Choi, Im-soon;Jang, Hyun-jeong
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.21 no.2
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    • pp.47-52
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    • 2015
  • Background: The objective of this study was to compare dysmenorrhea with pelvic alignment, hip joint range of motion about 20's female university students. Sixty two female students participated in this study. To investigate the measure of dysmenorrhea, we used modified menstrual distress questionnaire (MMDQ) and numerric rating scale (NRS). The pelvic alignment was assessed by using the palpation meter. The active range of motion (ROM) were assessed by measuring the flexion, extension, abduction, adduction, internal rotation and external rotation. Each measurement was assessed by goniometer. The data were analyzed by calculating independent T-test. Consequently, As the increase of dysmenorrhea, we observed significantly the increase of pelvic anterior tilt in right and left pelvic (p<.05). Otherwise, as the increase of dysmenorrhea, range of motion of hip joint was significantly limited in right and left external rotation (p<.05). Thus, this study provides young female with valuable information about dysmenorrhea.

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The Effect of Neck and Shoulder Self-Stretching Exercise Using Audiovisual Media on Neck Pain, Postural Alignment, and Joint Position Error in Women with Chronic Neck Pain (시청각 매체를 활용한 목, 어깨 자가신장운동이 만성 목통증 여성의 통증, 자세정렬과 관절위치감각에 미치는 영향)

  • Jeong, Yeon-woo
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.28 no.1
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    • pp.39-51
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    • 2022
  • Background: The purpose of this study is to investigate the effect of neck and shoulder self-stretching exercise using audiovisual media on neck pain, postural alignment, and joint position error in women with chronic neck pain. Methods: The subjects included 20 women that gave consent to participate in the study voluntarily. They performed the self-stretching exercises using audiovisual media was carried out 20 minutes 5 times a week during 3 weeks. Neck disability index (NDI) and visual analogue scale (VAS) were used to measure the functional disability and pain, A pressure pain threshold was measured using an algometer, and a cervical range of motion (CROM) measurement tool was used to measure the range of motion and error of proprioceptive position sense of the cervical spine. To assess posture alignment, forward head angle (FHA), forward shoulder angle (FSA) were measured using image J software. Results: The neck pain intensity was statistically significantly within group (p<.05). Neck and shoulder functional disability were a statistically significant difference within group (p<.05). Splenius capitis and upper trapezius pressure pain threshold were statistically significant difference in within group (p<.05). The postural alignment was statistically significantly within group (p<.05). The cervical range of motion in neck extension, right and left lateral flexion were statistically significantly within group (p<.05). The joint position error in neck flexion, extension, right and left lateral flexion decreased statistically significantly within group (p<.05). Conclusion: Self-stretching exercise using audiovisual media increased the mobility of the neck, decreased neck pain and joint position error, and improved posture alignment. As a result, there was a positive effect by applying the self-stretching exercise using audiovisual media to people with neck pain. Based on this, it is thought that it can be used as the basis for research related to home training programs for healthy self-management.

The Effect of Corrective Exercise in a patient with knee joint valgus deformity: A single-subject A-B-A experimental design (외반슬 환자의 교정운동의 효과: 단일 피험자 A-B-A 실험 설계)

  • Lee, Ho-Seong;Kim, Ah-Ram
    • Journal of the Korean Society of Physical Medicine
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    • v.11 no.1
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    • pp.93-105
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    • 2016
  • PURPOSE: The purpose of this study was to determine the effect of corrective exercise on hip joint range of motion, lower limb alignment, radiographs of hip and knee joints, and quadriceps muscle activity in a patient with knee joint valgus deformity. METHODS: A single-subject A-B-A experimental design was used to determine the effects of therapeutic exercise. The single-subject was a 27-year-old male, who presented with knee joint valgus deformity. Corrective exercise program was performed for 40 min/day twice a week for 12-week. Range of motion (hip flexion, extension, abduction, adduction, internal rotation, and external rotation), lower limb alignment test (Q-angle, rear foot alignment, and leg length), standing anterior-posterior radiographs (neck shaft angle and knee joint space), and quadriceps muscle activity of both lower limbs were measured before (A 1), after 6 weeks (B 1) and after 12-weeks (B 2) of corrective exercise and after 6 weeks of exercise completion (A 2). RESULTS: Hip range of motion increased in all directions of both sides at B 2 and A 2 compared to at A 1. Q-angle of both side and leg length discrepancy decreased at B 2 and A 2 compared to at A 1. Neck shaft angle and knee joint space of both sides improve at B 2 and A 2 compared to at A 1. Quadriceps of both side muscle activities improved at B 2 and A 2 compared to at A 1. CONCLUSION: We demonstrated that corrective exercise increases range of motion, and improves lower limb alignment and muscle activity in a patient with knee joint valgus deformity.

Analysis of Performance for Entropy-Based ISAR Autofocus Technique (엔트로피 기반의 ISAR 자동 초점 기법에 대한 성능 분석)

  • Bae, Jun-Woo;Kim, Kyung-Tae;Lee, Jin-Ho;Im, Jeong-Heom
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.12 s.115
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    • pp.1249-1258
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    • 2006
  • Two-dimensional(2-D) radar images, namely, ISAR images from a maneuvering target include unwanted phase errors due to the target's motion. These phase errors make ISAR images to be blurred. The ISAR autofocus technique is required in order to remove these unwanted phase errors. Unless those unwanted phase errors produced by the target's motion are removed prior to target identification, we cannot expect a reliable target identification performance. In this paper, we use the entropy-based ISAR autofocus technique which consists of two steps: range alignment and phase adjustment. We analyze a relationship between the number of sampling point and a image quality in a range alignment algorithm and also analyze a technique for reducing computation time of the SSA(Stage-by-Stage Approachng) algorithm in a phase adjustment.