• Title/Summary/Keyword: Axial rotation

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Dual-Polarized Tx/Rx Antenna for UHF RFID Reader (UHF RFID 리더기용 송수신겸용 이중편파 안테나)

  • Kang, Chae-Woon;Yun, Gi-Ho
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2005.11a
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    • pp.231-234
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    • 2005
  • In this paper, Dual-polarized Tx/Rx antenna for RFID reader is designed and fabricated to apply to RFID reader. Each feeding network of Tx/Rx is designed to improve the port-isolation and cross-polarization, and sequential rotation feeding scheme has been applied to increase of axial ratio bandwidth. Measured results show that 2.35dBi of antenna gain in 900MHz$\sim$928MHz, 150MHz of 3dB axial ratio bandwidth, -38dB$\sim$-40dB of port-isolation, and -30dB$\sim$-40dB of cross-polarization.

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Circular Polarization of Sierpinski Fractal Triangular Antenna by Sequential Rotation Techniques (Sierpinski 프랙탈 삼각형의 Sequential 회전 기법에 의한 원형 편파 특성)

  • 심재륜
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.3
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    • pp.440-444
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    • 2002
  • A microstrip patch antenna with circular polarization based on the Sierpinski fractal geometry is proposed. The Sierpinski fractal is composed of 3 equilaterial triangular patch and is easy to produce a circular polarization by sequentially rotation techniques. The characteristics of a 1x3 antenna array from Sierpinski geometry are investigated, i.e. port isolation and AR(axial Ratio).

The Effect of Various Interventions on an Adult with Scoliosis (척추측만증 치료를 위한 다양한 중재의 적용-사례연구)

  • Choi, Woon-Ho
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.17 no.2
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    • pp.57-63
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    • 2011
  • Background: To investigate the effect of various intervention application on idiopathic scoliosis patient. Methods: One 20-years-old female subject underwent various intervention 3 times per week for 7 weeks. Modality physical therapy, muscle energy technique, combined pelvic tilt exercise and self exercise was performed for 50minutes. Degree of pain, axial trunk rotation, Cobb's angle, kyphotic angle, lumbar lordotic angle, and sacral angle were measured. Results: The subject decreased in degree of pan, axial trunk rotation, Cobb's angle, thoracic kyphotic angle, lumbar lordotic angle and sacral angle. Conclusions: The various interventions for scoliosis patients are effective in the pain and the improvement of angle on radiograph. However, any method is difficult to determine effective interventions.

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Walking Measures with a Tri-axial Accelerometer in Stroke Patients (가속도계를 이용한 뇌졸중 환자의 보행 측정)

  • Oh, Yong-Seop;Woo, Young-Keun
    • PNF and Movement
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    • v.11 no.2
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    • pp.31-40
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    • 2013
  • Purpose : The purpose of this study was to measure the center of mass in body with stroke patients using a tri-axial accelerometer during walking. Methods : Twenty-eight patients were recruited and divided into two groups for this study. To measure their walking ability, Timed Up & Go (TUG) test and Fucntioanl Gait Assessment (FGA) were conducted and acceleration at rotation of center of mass (COM) in body were measure for each group. Results : In the comparisons between the two groups, the TUG and FGA were not significant differences and acceleration at rotation of COM was not significant differences also. Conclusion : Our research results suggesting that the accelerometer may be used as a testing tool and ongoing assessment tool for stroke patients during effects of intervention in walking.

Biomechanical Analysis on Kinematic Chains Type of Trunk (체간의 운동연쇄 형태에 따른 운동역학적 분석)

  • Han, Je-Hee;Woo, Byung-Hoon
    • Korean Journal of Applied Biomechanics
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    • v.20 no.3
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    • pp.277-284
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    • 2010
  • The purpose of this study was to investigate the trunk rotation type by wheel and axle. In order to analysis, 3D-motion analysis and electromyography were conducted on kinematic variables, impulse, average-EMG and integrated-EMG. Twelve healthy (age: $21.8{\pm}2.2$ yrs, height: $175.4{\pm}5.0cm$, weight: $66.7{\pm}6.4kg$) participated in the experiment. The results were as follows; in hand's velocity and acceleration, wheel and axial rotating movement using kinematic chain(type 3) were much faster. In impulse, type 3 was much stronger. In average-EMG, right and left, latissimus dorsi muscles was much stronger. In integrated-EMG, left erector spinae, right/left latissimus dorsi, and left external oblique muscles was much stronger. These results considered that, in the trunk rotation utilizing the kinematic chains action, latissimus dorsi muscles highly contribute to the muscle utilization that makes the rotating movement maximally effective.

An analysis of torsional flange-upsetting process based on slab method (슬래브법을 이용한 회전 다이 플랜지 업세팅 공정 해석)

  • Jae-Hoon Park
    • Design & Manufacturing
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    • v.18 no.2
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    • pp.29-34
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    • 2024
  • This study intends to reduce forming load by adding die rotation to flange-upsetting process. Materials arc formed by the compression and rotational torque which are accrued from rotation of the lower die accompanied by axial compression of the punch. For the theoretic analysis of flange-upsetting process using rotation die, slab method was used. Furthermore, for the verification of the theoretic analysis results, FEM simulation using DEFORM 3D a commercial software was done, and through the model material experiment using Prasticine, the results were compared and reviewed. Flange-upsetting process using rotation die shows reduced forming load compared with process without die rotation and demonstrates uniform distribution of strain. And as for the effect of the reduction of forming load, the less the aspect ratio(h0/d0) and the greater friction coefficient, the greater effect is. With increase in die rotation velocity, the effect of forming load reduction also increases little by little, but its effect on forming load reduction is very negligible compared with other forming parameters. Theoretic analysis results and simulation results coincided pretty well. The flange-upsetting process using die rotation are evaluated as useful process that can produce reduction of forming load and uniform strain.

Correlations between Axial Rotation of Toric Soft Contact Lenses and Corneal Eccentricity according to the Wearing Time and Gaze Directions (착용시간 및 응시방향에 따른 토릭소프트콘택트렌즈의 축 회전과 각막이심률과의 상관관계)

  • Seo, Woo Hyun;Kim, So Ra;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.21 no.1
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    • pp.35-45
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    • 2016
  • Purpose: The present study was aimed to investigate the effect of corneal eccentricity on the axial rotation when wearing toric soft contact lenses were worn for certain time and changing the gaze directions. Methods: Toric soft contact lenses with double thin zone design applied on 85 of with-the-rule astigmatic eyes. Then, rotational direction and amount of contact lenses were measured after 15 minutes and 6 hours of lens wear. The difference was further compared and analyzed according to corneal eccentricity. Results: The rotation of toric lens showed a tendency to rotate to temporal direction in all gaze directions except temporal-upper direction in all groups of corneal eccentricity. The amount of lens rotation in the frontal gaze direction exhibited a negative correlation since the amount was decreased with increasing corneal eccentricity after both 15 minutes and 6 hours of lens wearing. In many cases, the cornea with small eccentricity also showed the lens rotation larger than $10^{\circ}$. The difference in rotational amount after 15 minutes of toric lens wear was small according to the corneal eccentricity however, the change of rotational amount of contact lens according to corneal eccentricity was shown after 6 hours of lens wear. Conclusions: The present study revealed that the amount of axial rotation was largely varied according to the wearer's corneal eccentricity when wearing toric lens and the rotational amount after certain time of lens was also affected by corneal eccentricity. Thus, it is suggested that the selection of toric soft contact lenses based on corneal eccentricity is necessary.

Change in Axial Rotation of Toric Soft Contact Lens according to Tear Volume (눈물양에 따른 토릭 소프트콘택트렌즈의 축 회전양 변화)

  • Seo, Woo Hyun;Kim, So Ra;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.4
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    • pp.445-454
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    • 2015
  • Purpose: The present study was aimed to investigate the effect of tear volume on a change of axial rotation according to wearing time of toric soft contact lens and gaze directions. Method: Toric soft contact lenses with double thin zone design applied on 62 eyes. Then, changes in non invasive tear film break-up time and the rotational direction/amount of lens when changing gaze direction were respectively measured after 15 minutes and 6 hours of lens wear. Results: Lens rotation to temporal direction was more found when changing gaze direction after lens wear. However, its rotation was varied according to wearing time and the subjects' tear volume. Furthermore, the frequency of lens rotation to temporal direction was higher in dry eyes compared with normal eyes at nearly all gaze directions after 15 minutes and 6 hour of lens wear. The rotational amount of lens was generally greater in dry eyes after 15 minutes of lens wear. However, its difference between normal eyes and dry eyes was not great after 6 hours of lens wear. Conclusion: The present study revealed that axial rotation of toric soft contact lens was varied according to the wearer's tear volume and lens rotational patterns at the initial, and extending periods of lens wear were different. The change in rotational pattern of toric soft contact lens from these results means the possibility of visual change after extending lens wear, and the identification of its correlation with tear volume suggests the necessity of considering factors for choosing appropriate toric soft contact lens.

On the Rotational Barrier of Organic Molecules (I). Role of Axial Carbon in Ethane (유기분자의 내부 회전장벽에 관한 이론적 연구 (제1보). 에탄에서의 중심 탄소의 역할)

  • Young Sik Kim;Hojing Kim
    • Journal of the Korean Chemical Society
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    • v.26 no.3
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    • pp.117-127
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    • 1982
  • In order to analyze the role of axial carbon atoms in rotational barrier of ethane, we take the carbonless ethane, as a model, which is made of six hydrogens in coordinates of ethane. The energy of the system is calculated by McWeeny's open-shell restricted Hartree-Foch selfconsistent-field (RHF-SCF) method, and the transition density on the staggered-to-eclipsed rotation is examined. As being expected, the eclipsed form of the model is more stable than the staggered one. Through the transition density comparison of this model and real ethane, it is found that the existence of the axial carbon atoms induces the electronic density to be diluted in the vicinity of protonic sites and to be attracted to the region of carbon atoms or further to C-C bond region as the barrier is traversed. This migration of electronic charge tell us that the barrier to the internal rotation of ethane originates from the fact that the magnitude of electronic energy depression is not large enough to offset the increased nuclear-nuclear repulsion on the staggered-to-eclipsed rotation.

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A Biomechanical Comparison among Three Surgical Methods in Bilateral Subaxial Cervical Facet Dislocation

  • Byun, Jae-Sung;Kim, Sung-Min;Choi, Sun-Kil;Lim, T. Jesse;Kim, Daniel H.
    • Journal of Korean Neurosurgical Society
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    • v.37 no.2
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    • pp.89-95
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    • 2005
  • Objective: The biomechanical stabilities between the anterior plate fixation after anterior discectomy and fusion (ACDFP) and the posterior transpedicular fixation after ACDF(ACDFTP) have not been compared using human cadaver in bilateral cervical facet dislocation. The purpose of this study is to compare the stability of ACDFP, a posterior wiring procedure after ACDFP(ACDFPW), and ACDFTP for treatment of bilateral cervical facet dislocation. Methods: Ten human spines (C3-T1) were tested in the following sequence: the intact state, after ACDFP(Group 1), ACDFPW(Group 2), and ACDFTP(Group 3). Intervertebral motions were measured by a video-based motion capture system. The range of motion(ROM) and neutral zone(NZ) were compared for each loading mode to a maximum of 2.0Nm. Results: ROMs for Group 1 were below that of the intact spine in all loading modes, with statistical significance in flexion and extension, but NZs were decreased in flexion and extension and slightly increased in bending and axial rotation without significances. Group 2 produced additional stability in axial rotation of ROM and in flexion of NZ than Group 1 with significance. Group 3 provided better stability than Group 1 in bending and axial rotation, and better stability than Group 2 in bending of both ROM and NZ. There was no significant difference in extension modes for the three Groups. Conclusion: ACDFTP(Group 3) demonstrates the most effective stabilization followed by ACDFPW(Group 2), and ACDFP(Group 1). ACDFP provides sufficient strength in most loading modes, ACDFP can provide an effective stabilization for bilateral cervical facet dislocation with a brace.