• Title/Summary/Keyword: Range Alignment

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Liquid crystal alignment on rubbed self-assembled monolayers according to alkyl chain length (알킬 사슬 길이에 따른 러빙 처리된 자기 조립 단분자막의 액정 배향 연구)

  • Park, Hong-Gyu;Park, Mu-Hun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.5
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    • pp.362-368
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    • 2021
  • A homeotropic liquid crystal (LC) alignment state on rubbed fluorinated self-assembled monolayers (FSAMs) is described according to alkyl chain length. A simple procedure, gas-phase method, for the preparation of FSAM was used. The average optical transmittance in the visible light range of FSAMs were 76.63% to 78.21%, which were superior to the conventional polyimide layer having a transmittance of 75.89%. In addition, the excellent homeotropic LC alignment characteristics of FSAMs were observed through pretilt angle measurement and polarized optical microscope images. By measuring the contact angles and the surface energies of FSAMs, it was confirmed that pretilt angles of LC molecules increased according to the alkyl chain length. High optical transparency and uniform homeotropic LC alignment characteristics of FSAMs showed the possibility of FSAMs as an LC alignment layers.

Efficient Translational Motion Compensation for Micro-Doppler Extraction of Ballistic Missiles

  • Jung, Joo-Ho;Kim, Si-Ho;Choi, In-O;Kim, Kyung-Tae;Park, Sang-Hong
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.1
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    • pp.129-137
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    • 2017
  • When the micro-Doppler (MD) image of a ballistic missile is derived, the translational motion compensation (TMC) method is usually applied to the inverse synthetic aperture radar (ISAR) image, but yields poor results because of the micro-motion of the ballistic missile. This paper proposes an efficient TMC method to obtain a focused MD image of a ballistic missile engaged in complicated micro-motion. During range alignment, range profiles (RPs) are coarsely aligned by using the 1D entropy cost function of RPs as a mark, then the coarsely-aligned RPs are fine-aligned by using the minimum 2D entropy of the MD image. During phase adjustment, the gradient of the phase error is appropriately weighted and added to the previous phase error to further fine-tune the aligned RPs. In simulations using the point scatterer model and the measured data from the real missile model, the proposed method provided better image focus than the existing method.

The Effects of Muscle Energy Technique on the Shoulder Complex Range of Motion and Posture Alignment of Female College Students in their Twenties with a Round Shoulder (근에너지기법이 둥근어깨를 가진 20대 여대생의 어깨복합체 가동성과 자세정렬에 미치는 영향)

  • Im, Gyeong-eun;Jeong, Yeon-woo;Seo, Tae-hwa
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.27 no.2
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    • pp.17-25
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    • 2021
  • Background: The purpose of this study is to investigate basic data about the effects of muscle energy technique on the shoulder complex range of motion and posture alignment in the round shoulder posture. Methods: The subjects included 15 women that gave consent to participate in the study voluntarily. They performed the muscle energy technique for 30 minutes twice. The round shoulder posture was measured with a straight edge ruler. The shoulder complex range of motion was measured with the apley scratch test. The forward head posture was measured with ImageJ. The pectoralis minor muscle length was measured with a tape measure. Results: There were statistically significant differences in the round shoulder posture both right and left (p<.05). The experiment group showed statistically significant differences in the pectoralis minor muscle length (p<.05). There were significant differences in the shoulder complex range of motion including flexion, left lateral flexion, right lateral flexion, left side bending, and right side bending (p<.05), but no significant differences were found in extension (p>.05). The forward head posture showed significant differences in CVA changes (p<.05) and no significant differences in CRA changes (p>.05). Conclusion: These findings demonstrate that the muscle energy technique relaxed muscles around the shoulders and increased the shoulder complex range of motion. The technique is also expected to prevent pain in the neck and shoulders and lower injury risk. In conclusion, the muscle energy technique can be applied as an effective intervention for round shoulder posture.

Effect of the Underwater Ai-Chi Exercise Program on Hip Joint Mobility, Body Balance and Posture Change Based on Amount of the Physical Activity of College Students (수중 Ai-Chi 운동프로그램이 신체 활동량에 따른 대상자의 엉덩관절 가동성과 자세 및 균형에 미치는 영향 )

  • Ki-Won Nam;Se-Hun Kim
    • Journal of the Korean Society of Physical Medicine
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    • v.18 no.4
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    • pp.89-96
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    • 2023
  • PURPOSE: To investigate the effects of the underwater Ai-Chi exercise on the joint range of motion, balance and posture. METHODS: Thirty-six college students (30 men, 6 women) were divided into a 'low physical activity' groups (Group I). and an 'appropriate physical activity' groups (Group II). The Ai-Chi underwater exercise was conducted three times a week for two weeks for both groups. A goniometer was used to measure the range of motion of the hip joint, and Y-Balance and the posture screen mobile were used to measure the stability of the lower extremities. RESULTS: An evaluation of the range of motion of the hip joint before and after the Ai-Chi exercise showed significant results in the low physical activity group. However, the flexural range showed a significant increase after exercise, but not significant result. In the comparison of the mean increase between groups, only the right hip joint showed a significant difference in both groups. Also, in the comparison of the Y balance test and posture screen test before and after exercise, both groups showed significant. CONCLUSION: The Ai-Chi underwater exercise helped improve the range of motion of the hip joint and the ability to balance. Also It helped improve posture alignment. In addition, although the increase in all physical activity groups lower than the appropriate physical activity groups was greater in all figures, the increase in the number of samples, the extension of the experimental period, and various variables could be obtained.

Dual-mode Transmission Strategy for Blind Interference Alignment Scheme in MISO Broadcast Channels (MISO 브로드캐스트 채널에서의 블라인드 간섭 정렬 기법 기반 이중 전송 기법 설계)

  • Yang, Minho;Jang, Jinyoung;Kim, Dong Ku
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.12
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    • pp.1102-1109
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    • 2013
  • Blind interference alignment (BIA) scheme has demonstrated a way of interference alignment (IA) without channel state information at transmitter (CSIT). While it shows superior performance in high signal-to-noise ratio (SNR) regime stemming from the maximal degrees of freedom (DoF) gain, BIA scheme achieves inferior sum-rate performance in low SNR regime. This paper proposes a dual-mode transmission strategy which switches between single user (SU) SISO with receive mode selection and the BIA scheme depending upon the range of SNR. First, we derive a closed-form achievable rate for each transmission-mode. Secondly, we propose a low-complex transmission-mode selection algorithm.

Effects of Kinesio Taping on Craniovertebral Angle and Balance Ability in Subject with Forward Head Posture

  • Jeon, Yong-Jin;Kim, Gyoung-Mo
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.8
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    • pp.145-150
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    • 2020
  • Forward head posture is one of the most recognized types of poor head and neck alignment. Poor head and neck alignment posture is a major contributor to compromised balance and neck pain, due to abnormal joint position sense and proprioception. Kinesio taping is an intervention method used clinically for the management of pain. Kinesio taping may produce its effects through pain reduction, stimulation of blood circulation, induction of muscle relaxation which provides correction of joint position, and providing stability to the muscles and joints without limiting the range of motion. Many studies have proved that kinesio taping has positive effects on the reduction of pain and improves alignment, on the other hand, some studies have not found. Kinesio taping may provide immediate pain relief and improved alignment following the application, but there is insufficient evidence to support sustained relief beyond that time and they recommended future studies to examine the benefits of kinesio taping as this would have a greater value in clinical practice. Therefore, this study is to investigate the effects of kinesio taping on the alignment of head posture and dynamic balance ability in people with forward head posture.

Effects of trunk Muscles Endurance, Hip Joint Muscular Strength, and Pelvic Alignment on Mild Low Back Pain

  • Kim, Wondeuk;Seo, Miryea;Park, Dongchun;Shin, Doochul
    • Physical Therapy Rehabilitation Science
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    • v.10 no.2
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    • pp.156-160
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    • 2021
  • Objective: Low back pain easily becomes chronic and has a high recurrence rate. Therefore, it is most important to prevent chronicity and reduce the risk of recurrence in the early stages of back pain or at the stage with mild pain. Therefore, this study was conducted to compare hip joint muscle strength, trunk muscle endurance, and pelvic alignment between subjects with mild low back pain and subjects without back pain. Design: Crossed-sectional study Methods: The study was conducted by recruiting 30 students in their twenties who are enrolled in K University in Gyeongsangnam-do, and classifying them into 15 patients with mild back pain and 15 patients with normal. The subjects who participated in the experiment were measured for hip flexor and extensor muscle strength, trunk flexion and extension muscle endurance, and pelvic alignment. To measure hip joint muscle strength, biodex was used, and muscle endurance of the trunk was recorded at the end range of the trunk flexion and extension. And pelvic alignment was measured using Formetric 4D. Results: There were no significant differences in hip joint muscle strength, pelvic alignment, and trunk extension muscle endurance. The retention time was found to be significantly shorter in the mild low back pain group than in the normal group for trunk flexion muscle endurance. Conclusions: In the early stages of back pain or in the mild pain stage, training to increase muscle endurance of the flexor muscles may be helpful.

ISAR Motion Compensation based on Accumulation and Limitation of Consecutive Radar Returns

  • Seo, Dong-Shin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.10B
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    • pp.1803-1812
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    • 2000
  • A new motion compensation method for ISAR is presented in this paper. It employs amplitude limiting and integration of consecutive range profiles to improve the range and phase alignment accuracy and to alter the propagation properties of compensation errors. These allow the image quality to be significantly improved. It is shown from the imaging results that the new motion compensation algorithm can get images of targets in field situations with much better quality than the traditional cross-correlation algorithm.

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Effects of Vertical Alignment of Leg on the Knee Trajectory and Pedal Force during Pedaling

  • Kim, Daehyeok;Seo, Jeongwoo;Yang, Seungtae;Kang, DongWon;Choi, Jinseung;Kim, Jinhyun;Tack, Gyerae
    • Korean Journal of Applied Biomechanics
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    • v.26 no.3
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    • pp.303-308
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    • 2016
  • Objective: This study evaluated the vertical and horizontal forces in the frontal plane acting on a pedal due to the vertical alignment of the lower limbs. Method: Seven male subjects (age: $25.3{\pm} 0.8years$, height: $175.4{\pm}4.7cm$, weight: $74.7{\pm}14.2kg$, foot size: $262.9{\pm}7.6mm$) participated in two 2-minute cycle pedaling tests, with the same load and cadence (60 revolutions per minute) across all subjects. The subject's saddle height was determined by the height when the knee was at $25^{\circ}$ flexion when the pedal crank was at the 6 o'clock position (knee angle method). The horizontal force acting on the pedal, vertical force acting on the pedal in the frontal plane, ratio of the two forces, and knee range of motion in the frontal plane were calculated for four pedaling phases (phase 1: $330{\sim}30^{\circ}$, phase 2: $30{\sim}150^{\circ}$, phase 3: $150{\sim}210^{\circ}$, phase 4: $210{\sim}330^{\circ}$) and the complete pedaling cycle. Results: The range of motion of the knee in the frontal plane was decreased, and the ratio of vertical force to horizontal force and overall pedal force in the complete cycle were increased after vertical alignment. Conclusion: The ratio of vertical force to horizontal force in the frontal plane may be used as an injury prevention index of the lower limb.

High Out-of-Plane Alignment of Liquid Crystalline Methacrylate Copolymer Bearing Photoreactive 4-Styrylpyridine Moiety

  • Kwak, Gi-Seop;Kong, Jong-Yun;Kim, Min-Woo;Hyun, Seok-Hee;Kim, Woo-Sik
    • Macromolecular Research
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    • v.17 no.4
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    • pp.271-275
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    • 2009
  • This paper describes the out-of-plane order of a liquid crystalline(LC) methacrylate copolymer(3) comprised of a methacrylate(1) with a 4-styrylpyridine moiety as the photo-cyclodimerizable group and a benzoate moiety as the mesogenic group in the side chain, and another methacrylate(2) with a 4-(4-methoxyphenyl)benzoate moiety as the mesogenic group. The composition of 1 and 2 units in 3 was estimated to have a molar ratio of 54.2:45.8 by $^{1}H$ NMR spectroscopy. The X-ray diffraction study revealed that the copolymer forms a partial bilayer smectic structure. The copolymer gave rise to a high out-of-plane order parameter of about 0.74 in a wide LC temperature range of $110{\sim}160^{\circ}C$ after linearly polarized, UV light irradiation and subsequent annealing. Moreover, the external reflection IR analysis indicated that excess UV-light irradiation makes the out-of-plane LC structure of the copolymer appear in a higher and wider temperature range.